Australia’s electricity networks were

designed for electricity to flow one

way and with the assumption it will

dry up as it goes down the line.

Solar photovoltaic (PV) integration to the

network is causing extreme and erratic

voltage discrepancies the system is

not equipped to deal with. The solar PV

panels feed power back into the network

during sunlight hours when electricity

is not being consumed, leading to an

oversupply on the lines.

As a result, United Energy (UE) is trialling

an innovative and cost-effective technology

that will allow the existing network to accept

higher levels of solar generated power and

regulate supply.

ZNX Network Services Victoria, a Zinfra

Group company and service provider

to UE’s northern network in Victoria, is

installing low voltage regulators (LVRs) on

UE’s metropolitan, interconnected three

phase network as part of a six month trial.

The self-automated LVR units solve the

common utility problems of flicker and

excessive voltage drop.

The power electronics contained in the

LVR dynamically regulate voltage flow

up or down to within 1 per cent of a

programmable set point, in UE’s case,

stabilising the voltage to a set point voltage

of 230. This precise regulation of voltage

ensures grid stability and compliance with

appropriate service standards.

The units are produced and sourced from

Microplanet, based in Seattle, US. Engineer

Greg Wiegand, from Microplanet, visited

Australia to provide guidance and technical

advice for their use on UE’s networks.

The installation of the units on the pole,

currently involves the placement of

three units on a pole, one for each three

phase wire.

Mr Wiegand explained these units were

initially designed for single wire earth return

(SWER) networks in Queensland and

Microplanet is currently designing a custom

three phase integrated unit that will conform

to height restriction and other regulations on

the UE network.

The new, customised units, known as

U3Ps, will consist of one box containing the

contents of three of the current LVR units.

These units have recently undergone an

extensive testing regime at the Queensland

University of Technology under the Guided

Innovation Alliance (GIA) program.

The GIA is an industry applied research

collaboration established in October

2011 to address barriers and shorten the

pathway to market for new innovations in

the electricity sector.

The GIA program is looking to identify

technologies to counter the problems

associated with the increasing trend of

domestic solar PV installation. It was

through this program UE identified the

LVR units as a solution to their network

difficulties.

ZNX construction supervisor Grant

Attewell said the units provide a very

economical solution to the problem of

voltage regulation.

“The LVR units allow the network

to be updated without updating the

infrastructure,” he said.

“The traditional solution to this problem

would be the installation of a new pole

substation and the high voltage lines

needed to feed it, which would cost at least

three times as much as these LVRs.”

Each LVR can also transmit the activity and

performance of the unit. Incoming voltage,

output voltage, current and temperature of

the unit can be retrieved by downloading it

to a laptop via Bluetooth. This can be done

from the ground, thereby removing the

requirement for a worker to access the unit

up on the pole.

Mr Wiegand said Microplanet is currently

working on improving the data functionality

on future units by installing an SD card that

will record data on a minute-by-minute basis

and be stored for one year. A wi-fi solution

to improve reliability when data gathering is

also being added to future models.

The trials are being conducted in known

trouble spots on the UE network. Three

separate poles will have the units installed

on them by mid-May as part of the trial. In

some cases, UE will use smart meters on

individual premises with known issues to

monitor and gauge their effectiveness.

The first trial devices have been installed

on the low voltage network of Steven-

Woodcrest substation which is a pole-

mounted 300kVA transformer located in

Vermont, Victoria.

Mr Attewell said he is excited about the

potential for the LVRs.

“There are many short-term and long-term

benefits associated with this technology.

The problem of voltage regulation is

addressed with minimal impact on the

end customer and they get a more reliable

service,” he said.

The pole units are small and it all comes at

a fraction of the cost of traditional ways of

dealing with these problems.”

When you take into account the short

installation time, which is as little as 30

minutes, the immediate increased grid

reliability and improved service for utility

customers, the potential for this new

technology to tackle the issues associated

with long runs and the growing use of

domestic solar panels looks very promising.

ZNX is proud to be partnering with UE on

this innovative initiative, bringing their skill,

experience and expertise to the team.

ZNX INSTALL innovative TECHNOLOGY FOR United Energy: LOW VOLTAGE REGULATORSWith the lure of a green power source and the incentive of government rebates and feed-in tariffs, Australian customers are installing solar photovoltaic panels at an ever increasing rate. While this is positive action for residential customers, it is creating challenges for our electricity networks.

ZNX line workers install LVR units

By Helen Roberts-Ferguson, Zinfra Group

How tHe LVR woRks

Microplanet’s LVR combines traditional

power electronics with patented

technology. The LVR will dynamically

raise or lower and balance the incoming

voltage to maintain a constant output

level. The system consists of:

• AnAC-to-ACconverterthatproduces

voltage with a varying magnitude. The

converter drives the primary of a high-

efficiency toroidal transformer.

• Acontrolboardwithamicroprocessor

for measuring the output voltage and

controllingtheAC-to-ACconverterto

precisely maintain a fixed level set by

the customer.

The control board senses line-to-

neutral output voltage and compares

it to the desired reference. Depending

on whether the voltage is too low or

too high, the unit decides if it should be

raising or lowering the voltage, and how

much.ThenitcontrolstheAC-to-AC

converter to adjust the output voltage to

exactly match the reference voltage. The

regulator maintains its output (load side)

voltage even when the power reverses

and is flowing from the customer PV

backwards to the utility.

In the event of electronics failure,

regulation stops but power is not

interrupted. Fault alarms can be sent

to a connected network.

2014 JUL|AUG6