POWER QUALITY & RISK in the 21st Century®

Presented by: Rod McPherson

Prepared for: SAEEC

Date: 14/15 November 2019

Venue: Pretoria

The Global Network Challenges

• Old Architecture challenged by New “Renewable” Technology

• Unidirectional supply change to Multi-directional supply

• Wind/solar/battery/micro-generation, demand and frequency response

• Increased switching and transients

• Higher Voltage levels (Voltage stacking from Grid supply competition)

• Increased Voltage volatility (from intermittent renewable supply)

• Reduced inertia due to switch from Carbon Generation to Renewables

NERSA Regulations

Regulatory Supply

The deviations as specified in the NRS 048-2 which is listed in the table below:

Item NRS 048-2Over Voltage 440V (+10%)Under voltage 360V (-10%)Over frequency 48.75Hz (-2.5%)Under frequency 51.25Hz (+2.5%)THD 8%

Impact on LV of poor PQ

• Excess energy costs in kWh, kVA & Kvar Charges

• Equipment increased maintenance

• Equipment failures

• Interruptions in manufacturing from failures in sensitive electronics

Components of Power Quality

• Detailed Site Analysis understanding of load

• Power Factor Correction

• Active Harmonic Filtration

• Voltage Optimisation

Detailed Site Analysis

• Analysis of metering data and/or billing

• Installation of PQA to measure power

• Audit of site equipment

• Report produced on findings with recommendations

Power Factor Correction

• Power factor refers to the ratio of power supplied to the measurement points (measured in kilowatts or kW) to the demand pulled from the supply (measured in kilovolt-amperes or kVA). Ideal systems have a power factor of 1 (or unity) which means that the demand exactly equals the power, but in the real world you can see power factors running from as low as 0.6 to 0.999.

• Power factor correction is a simple system that ties into your electricity distribution system and regulates the power factor by bringing suitably sized capacitors in and out of the system depending on load. The system is designed specifically for your site’s operating profile and installation is quick and easy.

Active Harmonic Filtration

• Reduce the harmonic currents produced by the load. Add filters to either siphon the harmonic currents off the system, block the currents from entering the system, or supply the harmonic currents locally. Modify the frequency response of the system by filters, inductors, or capacitors

Effects of Harmonic Distortion

Harmonic distortion at sites occurs when voltage is applied to a non-linear load e.g,

variable speed drives, programmable logic controller, or any ac/dc converter. These

harmonics circulate in the distribution system and cause the following deleterious effects:

• Overheating of transformers and rotating equipment

• Increased hysteresis losses

• Decreased kVA capacity

• Neutral overloading

• Distorted voltage and current waveforms

• Failing capacitor banks

• Breakers and fuses tripping

• Interference on phone and communication systems

• Unreliable operation of electronic equipment

• Wasted energy, kW-kWh

• Wasted capacity

• Increased maintenance of equipment and machinery

Voltage Optimisation

• Voltage Optimisation. Voltage optimisation aims to reduce the voltage received by electrical equipment to improve operating efficiency as well as reduce energy costs and power demand. It can improve power quality by filtering harmonic and transient voltages as well as balancing phase voltages

Voltage Optimisation

Overvoltage, voltage imbalance and harmonic distortion are factors that can significantly shorten the lifespan of electrical equipment. Most 3 phase electrical equipment have a kW rating that relates to the energy consumption of the equipment and an operating voltage range which is typically 380V - 440V.

Ohm’s law states that the current in a circuit is directly proportional to the supply voltage and inversely proportional to the resistance. Research shows that if the voltage supplied is optimized and filtered, the energy consumption will be reduced due of the direct relationship between voltage and current.

Inductive v Resistive Load Effects

Meeting Agenda

1. Voltage creep upwards

o Site generation, CHP & PV, need to feed back into a site at a higher voltage

2. Harmonics increasing due to sites having far more electronic controls

3. Voltage imbalance

o greater interest and understanding from large consuming clients

o unequal incoming voltages between the three supply lines means the motor will run hotter and is subject to a shorter life span. A small voltage imbalance causes a larger current imbalance, which in turn causes the motor windings to run hotter. 2% Voltage Imbalance = 8% Temperature Rise

4. Voltage Optimisation and Power Factor Correction often combined

o similar installation connection point therefore cost saving

o single site power interruption

What trends are we seeing?

powerPerfectorFixed reduction settings

powerPerfector Plus+Auto settings + 3% boost

• Is the original VO product offering

• Can be set to optimise the incoming voltage from the mains to the desired level

• Incorporates powerPerfector’sdifferentiated core technology

• Dynamic VO with voltage boost

• Provides autonomous and real-timecontrol of the level of optimisation delivered by the VPO

• Created to protect from volatile voltage

powerPerfector iQ 250ms response time + 11% boost

Specification comparison

The iQ Features

✓ Responsive Power Optimisation – Output ±0.5V

✓ Active 3 Phase balancing – Balances 3 phases within ±0.5V

✓ Super Fast Response – 0.25 seconds

✓ Intelligent Voltage Control – 0.1V Incremental Control

✓ Voltage Recovery – Boost voltage by 11%

✓ Wi-Fi/LAN remote monitoring & control

✓ Simple Installation

pPiQ and iQ retro-fit

Demonstrating an energy saving

• >9% saving• £28,000 of annual financial savings• 172,000 kg of carbon dioxide emissions• 315,000 kWh of energy• Full savings report available

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The iQ Technology has demonstrated that it can increase an existing customers energy saving whilst also offering an improved payback for new customers, but what else could it do?

The concept of utilising the technology on different parts of the network is actually quite simple and when one considers a powerPerfector Installation it is already applied to the network by nature of where it sits in the system! The difference being who pays for it, who gets the benefit and who owns it?

Progressive thought leadership by Imperial College London & later UK Power Networks resulted in the pPiQ Technology being included in an Ofgem sponsored Loss Reduction project in 2018.

UK Power Networks and their testing Partners, the University of Strathclyde designed and implemented a robust test plan to demonstrate that the pPiQ applied to different parts of the network could reduce Cable Losses by up to 20% -

https://www.ukpowernetworks.co.uk/losses/static/pdfs/lv-feeder-losses-reduction-using-the-powerperfector-iq-test-report.23267b4.pdf

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Installation of the pPiQ within the Distribution Network could:

• Reduce System Losses (up to 20%).

• Reduce overall system demand – End User consumption would also be reduced contributing at a greater rate to reduction of electricity at a time when electricity requirements are increasing.

• Provide further capacity to the infrastructure without the need for costly cable upgrades allowing the reduction to be used for Electric Car Charge Points.

• Amass a large portion of power that could be controlled for Demand Response services

powerPerfector iQ can be easily adapted to allow it to be utilised in many different engineered applications.

powerPerfector iQ Applications – Distribution System Operator – Loss Reduction

Meeting Agenda

powerPerfector standard units:

- Pre and post half-hourly data analysis (3 months)

- IPMVP

powerPerfector iQ:

- iQ installed in series allowing us full control

- Short-duration ‘in and out’ testing

- PQA (Fluke 435) on grid side of unit to replicate DNO/billing meter

- Results are still regularly above what the theory around ‘voltage dependent’ and ‘voltage independent’ load classifications suggests

o In-situ site circuit testing (Woolwich – Premier Inn Video)

o Lab testing of individual loads

Predicting and Proving an energy saving

Meeting Agenda

Osram LED - What are the effects of over-voltages?

- Slight over-voltages do not necessarily cause the immediate failure of unprotected LED modules or LED drivers, however if over-voltages occur frequently they can cause the premature ageing of the LEDs and thus shorten their service life. This would then limit the economic advantage of LED technology.

- powerPerfector to protect their significant investment in LED by managing the incoming voltages to prolong the life of the LED and drivers.

- Extended warranties from LED suppliers?

VO and LEDs – complimentary solutions?

Testing in partnership with……

Type of Load Test

1. Lighting – focus on LEDs

Deemed ‘voltage independent’

Measure the change in all parameters of power as we

control the voltage via pPiQ from 207 to 253V.

Lux meter and thermal cameras to be used to

measure lamp output and losses.

2. Air Conditioning Systems –

focus on industry leading

systems:

• Mitsubishi – VRF, IPM (City

Multi), Inverter driven

technology.

• Daikin - VRV

• Fujitsu - VRF & Multi split

systems

Prove 3 phase voltage imbalance improvement

benefits (in line with Daikin reference that we use on

our savings reports).

3. Process loads / CNC machines Little is known about these loads - machines originate

from a wide range of countries. 3-phase motors and

therefore voltage balance could be key.

Manufacturing sites so normally good load factors and

medium to high kWh totals.

4. Whole system losses 3 phase voltage imbalance improvements could have

a significant impact here.

UKPN Report

iESCo Clients

Who is purchasing powerPerfector units? (2018 – 2019)

Retailers Leisure Groups Hospitality Manufacturing

Financials FM / Managing Agent

Other

Meeting Agenda

1. Should we be looking more closely at incoming power to sites ?

2. Are power quality solutions being overlooked ?

3. Are we driving our sites and buildings in the “right gear” for optimal performance ?

Thoughts & Questions ?

Contact: Rod McPherson

Email: rod@energy-saver.co.za

For further information :

Website: www.powerperfector.co.uk

Mobile: +27 (083) 397 2011

Demand Response / Savings Test 1 – Site 1

Charts shows change in current the site drew as the iQ being activated from Mains to 220V.

Average change c6% or 25A per phase

Charts show the kW change as the iQ being activated from Mains to 220V.

Average 11kW response c4%

The quantity of change is double what was modelled during the Demand Response Project

National Grid Services(ESO Balancing Services)

Demand Response / Savings Test 2 – Site 1

Charts shows change in current the site drew as the iQ being forced to bypass mains from 220V.

Average change c6% or 25A per phase

Charts show the kW change as the iQ being bypassed to mains from 220V.

Average 8kW response c3%

National Grid Services

Demand Response Test 3 – Site 1

National Grid Services

Meeting AgendaLoad testing - LEDs

CT – VM guide 2011

In-situ individual load / circuit testing of hotel corridor GU10 LEDs