Electricity + Control July 2018

FEATURES: · Control valves + electric actuators · Energy management + environmental engineering · IIoT + Industry 4.0 · Drives, motors + switchgear · Flow measurement + instrumentation

COMMENT

ON THE COVER

Industrial revolution, learning evolution

I t is hard not to become despondent now and then when we look at the economy we’re engaged in, and are trying to build. So many indicators seem upbeat ... and then we drag ourselves down again. Obviously, no one expects reviving in- dustry to be an easy task. But one does anticipate that law-makers will make the time and effort to craft a policy environ- ment that brings stability and confidence to all involved. It is their job, is it not? I also find myself wondering about the way we perceive the future – whether it is a perception of slow progress, slow decline, or a revolution about a revolution (which is certainly one of the options on the table). Experiences of my own have brought a few things into sharp focus of late. The first I have become conscious of relates to our inherent tendency to see extremes, rather than the middle ground. For example, we hear about violent crime all over the world. The most recent report I heard was of an incident in Sweden. Yet, when I was in Sweden, I wondered if any- thing happened there at all – ever. You get the point. The exception is newsworthy, it is scary, and it gets our at- tention. It also confuses our world view, and leads us very easily to believe the end is nigh. The fact is that violent crime, per capita , has – on average – been decreasing for decades. But that seems invisible. (Of course it has not been decreasing every- where, which remains a major concern.) Similarly, there are many examples of progress in our own country that we tend to hide with examples of dramatic excep- tions, such as extreme natural disaster, poverty, road accidents, heists, and the like. Yet, most of this is getting better. This does not mean we should be accepting of horrible situations. Of course not. But we should be mindful that things may not be quite as bad as we tend to think. Allied to this is the realisation that In-

dustry 4.0 is a nice way of packaging ‘stuff’ that, in our industry, has been happening for a long time. It seems that society, more broadly, is now cottoning on to it too and, these days, what we have done for dec- ades has a name and is now pervasive. Industry 4.0 is not a subtle creep. It is a massive tidal wave, probably best thought of as one tidal wave after another – in rap- id succession driven by an ever-changing world. This is not the time to be mulling over getting ready for it. It is inevitable, and it is a revolution. Call it the Fourth Industrial Revolution if you like – and we all know that folk get hurt in times of revolution. And they get scared. However, counter-revolution is futile, and way too late. The future is upon us. Our options are limited, but one aspect of the future that emerges clearly is the need for agility. Dare we think of agility as being more important that an ability to plan over a period of time? Does it ne- gate the need for that much-sought-after stable policy environment? Not really. It is the one thing that can be stable, while technology and human behaviour demand agility in other spheres. The other, and more important aspect of a stable policy environment is that it creates the opportunity for industry to grow, flourish and become competitive. The world is one huge village, and unless we firmly entrench ourselves as part of it, we will just become a rather little suburb ... and possibly not too well off.

FEATURES: · Control valves+ electric actuators · Energymanagement+ environmental engineering · IIoT+ Industry4.0 · Drives,motors+ switchgear · Flowmeasurement+ instrumentation

EC JULY2018.indd 1 6/25/2018 8:36:27AM www.electricityandcontrolmagazine.co.za

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CONTENTS

4

Features

CONTROL VALVES+ELECTRIC ACTUATORS 4 Breathing new life into electric control valve actuation: Barb Boynton, Curtiss-Wright/Exlar Actuation Solutions

8 Electric actuators aid design of medical devices: Leslie Langnau, Fluid Power World

10 Round Up

ENERGY MANAGEMENT+ENVIRONMENTAL ENGINEERING 12 Is smart metering smart enough for Africa?: Kobus van den Berg, Aurecon 16 How artificial intelligence will revolutionise the energy industry: Franklin Wolfe, Harvard University

19 Solutions for Cape Town water crisis: Hennie Pretorius, Endress+Hauser

21 Round Up

IIOT+INDUSTRY 4.0 24 Data and the smart machine revolution: Omron Industrial Automation

26 How remote monitoring improves machine maintenance: Brandon Topham, RET Automation

28 Round Up

16

DRIVE, MOTORS+SWITCHGEAR 32 The ins and outs of variable frequency drives

36 Round Up

FLOW MEASUREMENT+INSTRUMENTATION 40 Demystifying transducers in fluid power: Paul J Heney, Design World/ WTWH Media

44 Round Up

24

40

Regulars

1 Comment 35 Cover Article 46 Light+Current 40 Events 48 Advertisers 48 Write @ the back

2 Electricity + Control

JULY 2018

Bringing new life into electric control valve actuation

Barb Boynton, Curtiss-Wright/Exlar ® Actuation Solutions

Electric actuators based on servo-motor and roller-screw technologies can enable a responsive and accurate electric actuator solution that is well suited to valve control.

E lectrical systems are vital to many produc- tion operations, and affect worker safety and costs. It is important therefore to minimise arc-flash hazards, choose motor-control technology, protect motors, and understand safety interlocking standard (EN) ISO 14119. This article explores how forge press builders cut energy consumption using VFDs and visualisation solutions; how EtherNet/ IP-connected SCR power control modules can help cut costs; and how to synchronise controls config- uration data. Electric actuators have long been used for gener- al valve automation. However, when applied to con- trol valves, limitations inherent with legacy electric technology can restrict its effective use for modu- lation control, especially when fast response is re- quired. Servo motor control and roller screw tech- nology, both used for years in the motion control industry, do not have these limitations and can offer a responsive, accurate electric solution, well suited to demanding valve-control applications. Motor technology Legacy electric valve actuators use single- or three- phase induction motors to provide the necessary driving force. While they are suitable for on/off ap- plications, induction motors suffer from heat-rise limitations and a high mechanical time constant that limits their ability to modulate on a continuous basis. All motors produce torque through the interaction of two slightly offset magnetic fields, one on the sta- tor (stationary, or housing portion of the motor), and one on the rotor (rotating, or shaft portion of the mo- tor). In an induction motor, electrical current flowing through wound copper wire in the stator generates a magnetic field. The stator magnetic field then in- duces a similar, but offset, magnetic field in the rotor, similar to how a generator generates electricity. Unfortunately, building a magnetic field through induction requires a significant amount of electrical

4 Electricity + Control JULY 2018

CONTROL VALVES + ELECTRIC ACTUATORS

current, a by-product of which is heat generation caused by inefficiencies inherent in the design. Because the induced magnetic field must be built each time the motor starts or reverses direction, the more an induction motor must start and stop, the more current is consumed, and therefore heat is generated. This heat must be dissipated to pre- vent damage to the motor windings. During steady-state operation, current con- sumption is at a minimum, and the small amount of heat generated is easily dissipated. With each start and stop, additional current is consumed and heat generated. Under extreme circumstances, such as continuously modulating a control valve, the induc- tion motor will not be able to dissipate enough heat and must be powered down for a period of time to allow for cooling. High ambient temperatures can prolong the needed cooling time. Induction motors also have inherently high rotor inertia. This is a benefit when trying to maintain a constant speed. However, high rotor inertia requires more torque, and therefore more current to accel- erate and decelerate, leading to more heat gener- ation as described previously. The high rotor inertia of an induction motor therefore severely limits the motor’s ability to accelerate quickly and frequently, making it a poor choice for modulating applications. In contrast, permanent magnet servo motors use permanent magnets to supply the rotor’s mag- netic field. As the name implies, a permanent mag- net continuously supplies a magnetic field without the need for additional current during field build-up. Also, permanent magnet servo motors have signif- icantly lower rotor inertia than induction motors, and therefore consume less current while offering significantly higher acceleration and deceleration capability. Additional benefits of permanent mag- net servo motors include a smaller overall package size and significantly higher efficiency, making them an ideal choice for modulation. Mechanical powertrain To minimise the inherently larger induction motor package size while still providing the desired output force, legacy electric actuators incorporate substan- tial gear reduction in the form of worm or spur gears.

While accomplishing the goal of minimising package size, the high reduction severely limits the available output speed of the actuator. Additional drawbacks of this type of mechanical transmission include a relatively short useful life and low energy efficiency. Because of their limitations, application of tradi- tional electric actuators has been limited to slow, low duty cycle applications, because they are un- suitable for controlling rapidly and continuously changing process parameters such as pressure. For linear applications, an additional lead screw or ball/roller screw assembly is needed to convert the motor’s rotary torque to linear force.While they are economical, lead screws use a nut that rides directly on the screw, which can result in high slid- ing friction and low efficiency, limiting useful life and maximum speed. Using lead screws in contin- uous duty applications also can result in premature screw failure and a short life. The limitations of legacy electric actuators sig- nificantly affect system life. The most common failure mode in a legacy system is exceeding the rated duty cycle, leading to premature motor fail- ure. Wear in the mechanical transmission resulting in significant reduction in system stiffness, and therefore unacceptable system response, is an- other common failure mode. The net result of lim- itations with legacy electric actuator technology is that even high-end solutions have a design life of about only 50 000 operations. Major electric actuator wear areas include: • Drive sleeve and worm shaft bearings. • Sliding surfaces – drive sleeve splines, worm shaft splines, worm and worm gear teeth. • Motor pinion and drive gear.

Take Note!

Failure areas include:

Circuit boards damaged by heat or steam. Vibration-induced damage. Sticking of interlock relays.

1

2

3

Permanent magnet servo motors have

significantly lower rotor inertia than induction motors,

and therefore consume less current.

Failure areas include: • Circuit boards damaged by heat and steam.

• Vibration-induced damage. • Sticking of interlock relays.

Ball and roller screws A better choice for converting rotary to linear mo- tion is ball screws, which have been successfully employed in the industrial motion-control industry

Electricity + Control

JULY 2018

5

CONTROL VALVES + ELECTRIC ACTUATORS

times the life expectancy compared to an equiva- lently sized ball screw. Servo-motor technology coupled with planetary roller screws has been employed in the industrial motion control industry in a variety of arduous ap- plications, including military environments and high cycle/high speed loads. The technology offers no duty-cycle limitations, response and stroke times of milliseconds, and virtually no dead time.This makes the actuators a good choice when electric actuation is needed for control-valve applications. In fact, the combination of servo motor and plan- etary roller screw offers the only true electric alter- native to a hydraulic cylinder in terms of force den- sity, life and overall durability. Removing limitations legacy electric actuator technology has drawbacks that limit its effectiveness for use on control valves. Electric actuators based on servo-motor and roll- er-screw technologies remove legacy limitations, al- lowing for a highly responsive and accurate electric actuator solution that is well suited to valve control.

for years. Ball screws use ball bearings to provide rolling contact between the nut and screw, pro- viding longer life and higher efficiency when com- pared to a lead screw. Unfortunately, ball screws still do not offer ad- equate life for high duty cycle modulating applica- tions, and their moderate force capacity results in a larger-than-necessary system package size. They are also difficult to maintain, particularly with lu- brication. The ultimate choice for converting rotary to linear motion in high-duty cycle, high-response applications is the roller screw. Instead of ball bearings to provide rolling con- tact, roller screws use threaded rollers that gear the nut to the screw, similar to the relationship of planet gears to the sun and ring gears in a plane- tary gearbox. Unlike ball screws, which transmit loads through the ball bearings via point contact, roller screws transmit loads via line contact, thus distributing the loads over a greater surface area. This results in higher force capacity and five to 15

Barb Boynton is a business development manager for Curtiss-Wright/Exlar Ac- tuator Solutions. She has more than 30 years’ experience in the process control industry.

6 Electricity + Control

JULY 2018

Electric actuators aid design of medical devices

Leslie Langnau, Fluid Power World

Many of today’s medical devices rely on electric actuators for motion control in criti- cal, lifesaving applications. They offer a number of advantages that suit this industry, including their performance and increased efficiency. Clean operation – operating without the need for fluids or ancillary equipment – is one of the major advantages of electric actuators.

Electric actuators deliver de- pendable motion control in applications requiring: Precise positioning. Smooth motion. Tightly controlled velocity. Take Note! 3 2 1

E lectric actuators use roller screw technolo- gy, which enables high load capacity (more than 50 tons). Load capacity and rigidity of planetary roller screws suit applications requiring continuous force. Yet, these devices operate qui- etly. The planetary design of roller screws allows operations at higher rotational speeds than other screw technologies, which is useful in high-speed applications. Another benefit of electric actuators is the ability to integrate power, control, and actuation mechanisms into one device. Electric actuators combine force, velocity, and positioning in a sin- gle, compact motion control device. Actuator size constraints can be problematic, as medical devices are built to precise specifica- tions. Innovations in motor technology offer small- er package sizes, but with the same power output as previous motor designs. Integrating the motor

and linear actuators into one package reduces the overall size of the actuator, enabling it to install easily into equipment or other applications using minimal space. In a compact design, electric actuators also of- fer the option of integrating the electric controls and power circuitry. Such a configuration elimi-

8 Electricity + Control

JULY 2018

Copyright : Yuriy Klochan

Featuring high force density, certain electric ac- tuators are easily concealed within these types of devices, minimising space requirements and ena- bling a piece of equipment, such as a patient table, to feature a logical design without excessive size to contain oversized actuators. In addition to performance and size, electric actuators also minimise the noise associated with operation. Studies show that when patients can hear noise from medical equipment during a procedure, there is a noticeable increase in their anxiety. Due to the proximity of the actuator to the patient, any audible noises produced during operation are easy to hear, creating unnecessary nervousness during medical procedures. There- fore, implementing electric actuators with roller screw technology, which offers significantly less noise than alternative actuators, assures quiet op- eration, increases patient relaxation and reduces apprehension during this necessary and intricate treatment.

nates external components and expensive cables. These actuators operate without a stationary elec- trical cabinet, thus allowing the actuator, drive, and control to operate as a stand-alone piece of equipment. By combining all crucial motion control com- ponents into the actuator, it is possible to design mobile medical devices that offer the same capa- bilities as in stationary applications. Medical devices are only as reliable as their components. Electric actuators deliver depend- able motion control in diverse situations ranging from simple solutions to critical, lifesaving appli- cations that demand precise positioning, smooth motion, and tightly controlled velocity. For example, directed radiation therapy, used commonly as part of cancer treatment pro- grammes, applies radiation to patients in progres- sive increments, slice-by-slice, delivered to differ- ent sections of a tumour. During this treatment, the position of the patient must be beneath a pre- cise, fixed source of radiation. To accommodate this, electric actuators manipulate the position of the patient’s bed, a critical aspect of the applica- tion. Not only does the actuator provide the position- ing necessary in these applications, it also delivers the smooth motion and velocity control necessary for proper radiation application.

By combining all crucial

motion control components it is possible to design mobile medical devices that offer the same capabilities as in stationary applications.

Leslie Langnau is the Managing Editor of Design World, EE Network & Fluid Power World.

Electricity + Control

JULY 2018

9

round up

CONTROL VALVES + ELECTRIC ACTUATORS

In-field valve positioner checks using a handheld ProcessMeter

of the valve. In setting the point at which the valve starts to open, one would want to be sure there is no counter pressure by the actuator against the force holding the valve closed when there is 4.0 mA on the controller’s input. In a spring-to-close valve, there should be no pressure on the diaph- ram. With a double acting piston actuator, there should be no pressure on one side of the piston. The user may want to set the start of opening between 4.1 and 4.2 mA to get that insurance at the closed setting. To check the opening of the valve, press the coarse button up from 4.0 mA. The ProcessMeter will increase 0.1 mA for each press of the coarse button. The user should adjust the zero adjustment on the positioner to set the valve for the clos- ing you desire. The next check is with the valve at the next extreme: fully open. This is referred to as a span position check. Using the range buttons on the ProcessMeter, adjust the source current for a 20 mA reading and allow time for the valve to stabilise. While watching or feeling for valve movement, press the Coarse Up range button once to 20.1 mA. This movement should be as small as possible and can be adjusted us- ing the span adjustment on the positioner. Using the coarse control of the 789, adjust current up and down between 20.1 mA and 19.9 mA. There should be no movement of the valve stem from 20.1 to 20 mA and slight movement from 20 mA and 19.9 mA. In most valves, there is an interaction between the zero and span settings of a valve controller. Therefore, it is best to en- sure proper valve position adjustment by repeating the test of the fully closed and fully open positions until no further adjust- ment is necessary. For valves with linear action, linearity can be checked by setting the tester to 4 mA and then, using the % step button, step the current to 12 mA (50 %) and con- firm the valve position indicator is at 50 % travel. If the valve is of a non linear type, refer to the valve manual for proper oper- ation. For checking for smooth valve operation use the slow ramp function. Set the rotary switch to output mA and select slow ramp using the blue button. Allow the tester to ramp through several cycles while watch-

Valves, the actuators that move them, and the electronic circuits that control them, are all subject to the effects of aging soon after they are installed. The valve seat wears not only from the repeated seating of the valve, but also from the liquid or gas that passes through it. Depending on the application, a valve can be stroked from hundreds to tens of thousands of times over a one-year period. This amount of mechanical motion inev- itably causes screws to reposition, springs to weaken and mechanical linkage to loos- en. In addition, electronic components change value over time. The results are valves that don’t fully open or close, close prematurely, or operate erratically and cause improper regulation of the gas or liq- uid under its control. This is more common- ly referred to as 'calibration drift.' To keep a system operating properly, a good preventative maintenance pro- gramme that mandates periodic checks of valve positoners is required. These checks need to be conducted quickly to minimise down time. When the checks reveal cali- bration drift, recalibration of the electronic valve positioner must be performed quick- ly.With the varied locations in which a valve can be installed and the difficulty in remov- ing it, the equipment used to perform the checks must be brought to the valve posi-

tioner itself. Therefore, this 'in-field' tester must be portable, easy to use and rugged. The tester, with signal sourcing, must simulate a controller connected to a valve positioner’s input. Through the controls on the ProcessMeter, the operator can set the positioner’s input current to a specified level and visually inspect the reaction of the valve’s position using the mechanical position indicator, the valve stem position or flow indicators. In addition, the process meter must continuously adjust the source current in a ramping or stepping fashion, allowing the user to check the valve’s line- arity and response time. An example will help explain how to make these checks. This example only demonstrates the basic principles in mak- ing position checks on a valve positioner. Manufacturer’s specific instructions should always be consulted for proper and appro- priate valve positioner testing and calibra- tion. General steps in checking valve posi- tioning. The first order of business is to set up the ProcessMeter in the sourcing mode using the appropriate range of current for the po- sitioner. The tester uses a separate pair of jacks to source current. First connect the test leads into the 24 V loop power mA

output jacks. Next, select the 4-20 mA range by moving the function switch from Off to the first mA output posi- tion. Now user is the ready to connect the tester to the input terminals of the valve positioner. With the test equipment properly set up and connect- ed to the positioner, it can be determined if the posi- tioner fully closes the valve at the 4 mA input current level. Using the push but- tons on the ProcessMeter, adjust the source current to 4.0 mA. Now, while watching the valve for any movement, press the coarse down but- ton once to decrease the current to 3.9 mA. There should be no movement

10 Electricity + Control

JULY 2018

round up

CONTROL VALVES + ELECTRIC ACTUATORS

site for checking and recalibrating elec- tronic valve positioners. In addition, the tester not only simulates a current loop transmitter, but it’s a measurement tool as well. Along with the normal DMM meas- urements (dc/ac volts, dc/ac current, and resistance), the tester can also measure frequency. Additional features include MIN\MAX, relative measurements, diode test and autohold. A feature-rich product designed specifically for the loop process techni- cian, the ProcessMeter also complies with IEC 1010-1 standard for CAT III 1000 V en- vironments. Enquiries:Tel. +27 (0) 10 595 1821 or email sales@comtest.co.za

ing or feeling for any abnormal operation of the valve. The valve should NOT oscillate or hunt at any of the step positions of the slow ramp. At the same time however, the valve should not be sluggish.

Set the gain of the valve controller to a point that gives the best response be- tween these two conditions. As the ex- ample above shows, the ProcessMeter brings all the necessary tools to the job

New filling valve platform with innovative PD design

cycles. This means that what has become known as the lift effect, in which the remains of the product are trans- ported through the inserted spindle into areas in the actu- ator which are not to be cleaned, is excluded. In addition to the improved ease of cleaning of the media-wetted area, the valve stands out thanks to its extremely com- pact design and the ability to quickly and easily replace worn parts. Besides the conventional pneumatic vari- ants, a motorised version with an innovative generation of drives is also available. Both the GEMÜ F40 and GEMÜ F60 valves have a num- ber of areas of application in virtually all filling processes in the hygienic and aseptic sector. Due to the one-piece PTFE seal that is used, the two valve types are also suitable for media containing oil or fat. Both of the first valve types of the new filling valve platform will be presented to the pub- lic later in the year, at the ACHEMA trade fair in June. Enquiries:Tel. +27 (0) 11 462 7795 or email info@gemue.co.za

Valve specialist GEMÜ based in Ingelfingen, Germany is laying the cornerstone for the latest generation of filling valves with the F40 and F60 valve types. Thanks to close contact and communication with plant engineers and operators working in the area of filling processes, GEMÜ has been able to build up

considerable expertise in this field over time. This has meant that we have been able to develop solutions to the widest variety of challenges relating to this area in years gone by. GEMÜ is continuing this tradition with the introduction of a new filling valve platform. The use of the GEMÜ PD design has made it possible to securely isolate the moving parts of the actuator hermetically from the product area while simultaneous- ly achieving a high number of switching

Electricity + Control

JULY 2018

11

ENERGY MANAGEMENT + ENVIRONMENTAL ENGINEERING

Is Smart Metering smart enough for Africa?

Kobus van den Berg, Aurecon

Smart metering (SM) systems can support various aspects of electricity distribution management and are generally recommended internationally as the way to enhance the services and financial viability of electricity utilities.

K obus van den Berg, an electrical engineer at Aurecon, takes a different approach, saying it is important to understand the additional functionality of an SM system and see if it meets the specific requirements of Africa. “The extensive functionality of a smart meter- ing system is not always fully appreciated,” says van den Berg. “However, collecting vast amounts of system data is, in itself, pointless: the value is in the management of the data. The solution lies in the integration with a highly effective Meter Data Management System (MDMS) and being able to demonstrate benefits for the consumer.” The metering system A typical SM system will comprise a smart me- ter at the customer’s premises with a load switch and in-house display. These devices communicate via various communications media and the data is transferred to a MDMS for storage and process- ing. In metering mode, the system provides meas- urement and recording functions to enable effec-

tive measurement of consumption data for billing purposes. It records data at 30-minute intervals, which enables the utility to determine when and where energy has been used. The meters can be switched between cred- it mode and pre-payment mode remotely. Credit tokens purchased at vending outlets or online via the internet or cell phone can be transferred to the meter directly or manually through the keypad on the Customer Interface Unit (CIU, display and key- board installed at a customer’s premises). The me- ter also allows the implementation of complex tar- iffs. The use of TOU (Time of Use) tariffs allows the utility to offer new energy products to customers, as well as use pricing signals to manipulate the consumption pattern of consumers to enhance energy efficiency. The ‘smartness’ of the metering system de- rives from being flexible and multifunctional, able to enhance the management of distribution sys- tems and improve energy efficiency. Advantages of a smart metering system Revenue management The SM system can provide accurate meter read- ings, timeous billing, pre-processed readings with VEE (validation, estimation and editing) and re- mote connect/disconnect. One of the most important challenges munici- palities face in South Africa is to read meters and produce accurate bills to enable customers to pay their dues. It is not always possible for meter readers to get access to a customer’s premises, resulting in ‘no reads’ or ‘estimated’ readings on a customer bill. In the case of SM, the consump-

The Smart Metering system provides: Accurate meter readings. Timeous billing. Pre-processed readings. Take Note! 1 2 3

12 Electricity + Control

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ENERGY MANAGEMENT + ENVIRONMENTAL ENGINEERING

tion data will be validated and any inconsistencies corrected in the MDMS before it reaches the bill- ing system, ensuring much higher quality billing. The VEE functions allow the utility to effectively man- age consumption levels, missed readings due to meter failure and energy theft due to bypassing of meters. The SM system supports func- tionalities such as remote connec- tion/disconnection. If the customer does not pay his or her bill, a warn- ing can be sent to the CIU. If there is no reaction from the customer, the supply can be switched off re- motely. As soon as payment takes place, the supply can be restored immediately. An especially impor- tant benefit is that accurate meter reading and billing will restore cus- tomer confidence in the utility and result in improved payment perfor- mance. Revenue protection (RP) Most utilities employ RP officials or contract meter auditors to visit and inspect meter installations for safety and especially tampering issues. SM systems can be this ‘guard dog’ to monitor meters 24/7 and provide reading VEE to de- tect anomalies, tamper detection, alarm generation, energy balancing and loss detection, and non-pay- ment/tamper disconnection.

clude distribution system loading and power flow, fault log system, power quality (PQ) information, system loss measurement, parameter trending facilities, maintenance alert, job scheduling, and meter error detection. Meter failures can be detected immediately and the necessary maintenance and repair teams acti- vated. Customer service will improve as a result of prompt reaction to failures in the distribution net- work. Capital and maintenance budgets can now be based on operational information from the SM systems rather than ad hoc measurements in the network.

While the visibility of meter officials motivates customers not to tamper with meters, the main challenge is the time and cost to maintain this vis- ibility. Soon after a meter audit, customers tend to revert back to their old tampering habits or pay ‘contractors’ to ‘adjust’ their metering systems. The SM system can provide a focused, enhanced and more cost-effective RP service for the utility. Maintenance and planning Data collected from the SM system can be used to identify maintenance actions as well as network extension and upgrade planning. Applications in-

Electricity + Control

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ENERGY MANAGEMENT + ENVIRONMENTAL ENGINEERING

Keeping customers informed Customers can either accept and use the SM fa- cilities or view them as a method to ‘spy’ on them and force them to pay for services. Whatever the case may be, the customer should be persuaded and shown that the SM provides essential and useful information, such as consumption feed- back, cost and tariff information, outage warnings, bill payment information, remote disconnection/ reconnection, and pre-payment options. For successful implementation of SM, it must be to the advantage of the customer in terms of energy management, as well as the improvement of services. The SM system opens a new commu- nication channel to customers to inform them of the actions and intentions of the utility without re- verting to call centres and the media.

Demand control Many African countries are in the predicament where demand for electricity at times is very close to or exceeds supply capability. The SM system provides methods of managing the demand for electricity on the consumer side of the supply net- work by direct control of devices such as geysers, air conditioners and pool pumps, load limiting dur- ing high demand/supply shortage crisis situations, and indirect load and energy efficiency control via TOU (Time of Use) tariff structures. The first method enables the utility to switch off the supply to non-critical appliances such as air conditioners, pool pumps and hot water gey- sers, as well as other residential loads or, moti- vate customers to disconnect loads themselves. The second method is to use TOU tariff structures

One of the most significant challenges facing South African municipalities is to read meters

and produce accurate bills.

14 Electricity + Control

JULY 2018

INTERNATIONAL CONFERENCE TOWARD SUSTAINABLE ENERGY SOLUTIONS FOR THE DEVELOPING WORLD INDUSTRIAL

ENERGY MANAGEMENT + ENVIRONMENTAL ENGINEERING

& COMMERCIAL USE OF ENERGY

to reflect the actual cost of energy at a particular moment and send a strong price signal to the cus- tomer. This information enables the customer to reschedule certain loads and save electricity cost, as well as improve energy efficiency. Conclusion SM has a place in African utilities to meet the needs and particular characteristics of Africa’s electricity consumers. SM is only really smart if it is carefully integrated into the distribution system with a specialised MDMS, and the system used to improve business processes, utility operations and particularly, customer services.

Kobus van den Berg (PrEng), BEng (Elec). MMedSc, MBA is an Electrical Engineer at Aurecon.

13 - 15 August 2018

Conference Venue: Sports Science Conference Centre Boundary Road, Newlands Cape Town South Africa

ConferenceTopics: • Energy Management • Energy use in Mines and Industry

• Heating Ventilation and Air-Conditioning • Climate change, Environmental Issues • Energy Audits and M&V • Power Generation, Transmission and Distribution • Renewable Energy • Tariffs, Metering and Cost of Electricity

Conference Workshop: Experience of industrial-level renewable energy systems

Social functions: Monday 13 August 10h00 Industrial visit; 17h30 Cocktails and snacks Tuesday 14 August 18h30 Conference Dinner

Registration and Information: Tel: +27(0) 21 959 4330 Email: icue@cput.ac.za Web: http://energyuse.org.za/icue

ENERGY MANAGEMENT + ENVIRONMENTAL ENGINEERING

How artificial intelligence will revolutionise the energy industry

Franklin Wolfe, Harvard University

Earlier this year, Bill Gates, founder of Microsoft and one of the richest men on Earth, wrote an essay online at ‘The blog of Bill Gates,’ to college students graduating world- wide in 2017.

Take Note!

The energy grid comprises A vast network of power plants. 1

Transmission lines. Distribution centres.

2 3

H e stated, “If I were starting out today… I would consider three fields. One is artificial intelligence (AI). We have only begun to tap into all the ways it will make people’s lives more productive and creative. The second is energy, be- causemaking it clean, affordable, and reliable will be essential for fighting poverty and climate change.” The third field he mentioned was biosciences. What is inspiring for individuals who are dedi- cated to improving living conditions today and for future generations to come is that AI and energy are not mutually exclusive career paths. In fact, they are becoming increasingly interconnected as computing power, data collection, and storage ca- pabilities scale exponentially on an annual basis. According to DanWalker, who leads the emerging technology team in British Petroleum’s (BP) Tech- nology Group, “AI is enabling the fourth industrial revolution, and it has the potential to help deliver the next level of performance.”

Why does the energy grid need to be modernised? In 1882, Thomas Edison opened America’s first power plant at Pearl Street Station in lower Manhat- tan to deliver power to 59 customers. The custom- er base has since swelled to hundreds of millions of users, but the overall structure has yet to receive a modern overhaul. It consists of a vast network of power plants, transmission lines, and distribution centres (comprising roughly 5 800 power plants and over 2.7 million miles of power lines). High costs for infrastructure and distribution lines, as well as stringent governmental regula- tions, naturally create opportunities for monopo- lies to develop in the market. As a result, three separate U.S. grids produce and transmit power under the mandate to provide low-cost, reliable energy as a public good. In the U.S., the average age of power plants is over 30 years and of power transformers is over 40

Although AI is in the early stages of implementation, it is poised to revolu- tionise the way we produce, transmit, and consume energy. At the same time, AI is also limiting the industry’s environmental impact at a time when demand is steadily growing, our ener- gy production portfolio is diversifying, and we are witnessing the ramifica- tions of fossil fuel consumption on biodiversity, air quality, and quality of life.

Renewables Consumption Geothermal Hydropower

10

Liquid Biofuels Others biomass Solar Wind power Wood Biomass

9

2,787

8

2,321

7

2,562

3,103

1,295

6

1,221

2,669

0,777 0,527

1,097

5

2,446

0,426 0,518

1,150

0,496

4

0,902 0,452 0,721

0,462

Quadrillion Btu

0,549 0,413 0,341

2,298

1,600

3

1,776

1,167

2

2,170

2,089

2,071

2,010

1

1,957

1,931

0

2007

2009

2011

2013

2015

2017

Figure 1: This figure demonstrates the rising trend of U.S. renewable energy supply over the past decade.

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years. This deteriorating transmission system led to the 2003 Northeast blackout, the largest failure in U.S. history according to the federal task force charged with its investigation. It left 50 million peo- ple without power for several days when an over- loaded transmission line sagged and struck a tree. Instances like these can have cascading effects on an entire regional grid and pose a difficult task for utility companies to manage ( see Figure 1 ). Hydropower includes conventional hydroelec- tric power only, and excludes pumped storage generation. Liquid biofuels include ethanol and biodiesel. Other renewables includes biofuels production losses and co-products (data retrieved from the U.S. Energy Information Administration). An additional challenge is the rise of distributed generation, where private users generate and use their own electricity from renewable sources, such as wind and solar. This complicates supply and de- mand and forces utility companies to buy excess energy from private users, who generate more electricity than they use and send the excess ener- gy back to the grid. Since 2010, solar use has more than tripled, and this trend is poised to continue into the future as photovoltaic cells, the devices that generate electricity from sunlight, decrease in cost and increase in efficiency. The current system was not built to accom- modate this diversification in energy sources, especially not the rise in renewable resources. Rather, when demand outpaces supply, utilities turn on backup fossil fuel-powered plants, known as ‘peaker plants’, at a minute’s notice to avoid a cascading catastrophe. This procedure is the most expensive and wasteful part of business for these companies, manifesting itself in higher electricity

bills for consumers and enhanced greenhouse gas emissions into the atmosphere. These problems will be exacerbated as the U.S. energy demand is projected to steadily increase into the future. How can the energy grid be modernised? To combat these problems, the U.S. Department of Energy (DOE) has made supporting the ‘smart grid’ a national policy goal, which entails a “fully automated power delivery network that monitors and controls every consumer and node, ensur- ing a two-way flow of electricity and information”. Since 2010, the DOE has invested $4.5 billion in smart grid infrastructure and installed over 15 mil- lion smart metres that monitor energy usage per device and alert utilities of local blackouts. It is estimated that while total U.S. energy demand is expected to increase 25 percent by 2050, this pro- gramme will limit the rise in peak electricity load on the grid to only one percent. Artificial Intelligence (AI) will be the brain of this future smart grid. The technology will continuously

We have only begun to tap into all the ways AI will improve productivity and creativity.

136,00

140 130 120 110 100

132,00

128,00

125,00

124,00

118,00

90 80 70 60 50 40 30 20 10 0 Quadrillion Btu

Figure 2: Past and projected U.S. energy consumption in quadrillion Btu. By 2040, world energy consumption is expected to increase by 15.3% (Data retrieved from the U.S. Energy Information Administration).

2012 2020 2025 2030 2035 2040

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ENERGY MANAGEMENT + ENVIRONMENTAL ENGINEERING

Smart Meter & Customer Facing Apps

Distribution Intelligence Apps

Renewable Apps

Tarrif Systems, Billing, POS, Customer Service, and Scheduling Systems

Cross- Functional 'Tribal- Knowledge' Apps

Industrial IoT Apps

Asset Management Apps

Are there concerns with the future smart grid? One of the major concerns with the smart grid is the increased use of Information and Commu- nication Technology, which relies on the Internet as well as computing and processing power to run. This industry has become a large contributor of greenhouse gas emissions in recent years as companies shifted to machine-run operations, and the use of the Internet has increased by 30-40 per- cent per year. To process the amount of data nec- essary to run the smart grid, additional machines and computing power will be needed, and the im- pact of energy consumption on the environment from further greenhouse gas emissions is sure to increase. Therefore, players in the AI energy grid industry need to address this problem. Fortunately, industry leaders are aware of the challenge and are already taking steps in the right di- rection. The three leading greenhouse gas emitters in this industry – computer makers, data centres, and telecoms – are looking to reduce emissions in many ways. For example, computer makers are in- vesting in new hard drives and screens; Fuel cell data centres are monitoring temperatures, pooling resources and researching cloud computing; Tele- coms are looking into network optimisation pack- ages, solar-powered base stations, and fibre optics. If the smart grid is able to use fossil fuels in the most efficient way possible through increased incorporation of renewable resources as those technologies advance in sophistication and capa- bility, the entire system may be able to reduce its carbon footprint. Despite this uncertainty associ- ated with future technological innovation, we can be optimistic in expecting the smart grid system to lower electricity bills and prevent catastrophic blackouts by optimising supply and demand at lo- cal and national levels. For those looking to make a difference in shaping the future of society, the interface between AI and energy is a great place to start.Technological innova- tion is drastically changing the way we think about these two industries and their integration is in its early stages. Their synergy may change the world in ways we could never have imagined, and they are primed for innovative thinkers to make their mark. Acknowledgement Courtesy Harvard's Science in the News: sitnbos- ton.com

Energy Management Value Chain

collect and synthesise overwhelming amounts of data from millions of smart sensors nationwide to make timely decisions on how best to allocate ener- gy resources. Additionally, the advances made from ‘deep learning’ algorithms, a system where ma- chines learn on their own by spotting patterns and anomalies in large data sets, will revolutionise both the demand and supply side of the energy economy. As a result, large regional grids will be replaced by specialised micro-grids that manage local ener- gy needs with finer resolution.These can be paired with new battery technologies that allow power to continually flow to and between local communi- ties, even when severe weather or other outages afflict the broader power system. On the demand side, smart metres for consum- ers, including homes and businesses, and sensors along transmission lines will be able to constant- ly monitor demand and supply. Further, brief- case-sized devices known as ‘synchrophasers’ will measure the flow of electricity through the grid in real time, allowing operators to actively manage and avoid disruptions. These sensors will com- municate with the grid and modify electricity use during off-peak times, thereby relaxing the work- load of the grid and lowering prices for consum- ers. Google recently applied this AI technology to reduce its total data centre power consumption, which translated to millions of dollars in savings. On the supply side, AI will allow the U.S. to transition to an energy portfolio with increased renewable resource production and minimal dis- ruptions from the natural intermittency that comes with these sources owing to variable sunlight and wind intensity. For example, when renewables are operating above a certain threshold, either be- cause of increases in wind strength or sunny days, the grid will reduce its production from fossil fuels, thus limiting harmful greenhouse gas emissions. The opposite would be true during times of be- low-peak renewable power generation, thus allow- ing all sources of energy to be used as efficiently as possible and only relying on fossil fuels when necessary. Additionally, producers will be able to manage the output of energy generated from mul- tiple sources to match social, spatial, and temporal variations in demand in real-time.

Franklin Wolfe is a graduate student in the Earth and Planetary Science program at Harvard University.

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ENERGY MANAGEMENT + ENVIRONMENTAL ENGINEERING

Solutions for Cape Town water crisis

Hennie Pretorius, Endress+Hauser

South Africa, a water scarce country, should consider its water supply as its most valuable resource. All South Africans with access to piped water should always be responsible water users, and not only when a crisis looms, as is currently the case in the Western and Eastern Cape regions.

Take Note!

Cape Town has three main options to augment its water supply in times of drought: Large aquifers in the City 1

and the Cape Flats. The desalination of abundant sea water. Direct potable reuse.

2

W e focus on Cape Town and the Western Cape in order to indicate what possible solutions there are for drought strick- en areas. The Cape Town region experiences a Mediterranean climate with warm dry summers and winter rainfall. It is dependent on water that comes from mostly six large dams of which Thee- waterskloof is by far the largest. Since 2013 the stored volume of water has slowly been decreas- ing but three consecutive years of extremely low rainfall has accelerated the crisis. The period 2015 – 2017 is regarded as the driest three-year period in more than 80 years, and 2017 was the region’s driest year since 1933. Modelling by consultants indicates that this is a ‘one in 400-year’ event. Cape Town has three main options to augment its water supply in times of drought, with the first being the large aquifers in the City and Cape Flats regions: The Cape Flats aquifer, theTable Mountain aquifer and the Atlantis aquifer. They can deliver, as per early estimates, 80, 40 and 30 Megalitres per day respectively. This water is, for the most part, treated in conventional water treatment plants. The second option is desalination of abundant sea water. This process uses membrane technolo- gy to remove the salt from the water and to deliver potable water. It is, however a costly method be- cause of the high energy demand. Desalination process overview • Sea water is drawn from the sea through pipe- lines and enters the plant through screens to filter out larger material. • Pre-treatment filters, which may include ultra- filtration, remove smaller particles. • The filtered sea water is pumped to the Re-

verse Osmosis building where it is pushed through RO membranes at pressures of more than 60 bar. • These membranes remove the salts and only the water molecules are let through. • The ultra-pure water is then demineralised and disinfected to comply with local drinking water standards. • This potable water is stored in tanks from where it is pumped into the water distribution network. • The salt concentrate, known as brine, is re- turned to the ocean. Source: Sydneydesal.com.au The third option is direct potable reuse. This is de- fined as the injection of recycled water into the potable water network once it has been through a traditional water treatment plant, or into the raw water supply before passing through the tradi- tional water treatment plant. Many people would like direct water reuse to be limited to agricultural or industrial use. Unfortunately, with the current and future water emergencies, using it as potable water would be essential. The purified municipal waste water is taken through various membrane filters and finally through RO membranes to get to the required quality. This is a viable solution, and unavoidable in future, for inland drought strick- en areas such as Gauteng. Beaufort West’s water supply during the current drought has relied on its direct potable reuse plant. The City of Cape Town will have to get the cor- rect blend of water supply mix that will be cost-ef- fective during times of plenty but can step up to

3

Desalination technology is

widely used within the South African mining industry.

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