As the complexity of grid and integration requirements rises, High Voltage (HV) switchboards, control panels, and switchgear need to be expertly made to meet safety and performance criteria for demanding applications. “Switchboard and switchgear requirements differ from State to State, so it’s important that any supplier understands the technical requirements for the region they are working in,” says Steve Bell, Managing Director, Clean Tech Controls. Clean Tech Controls is highly familiar with the unique requirements of each region, having supplied high and low voltage switchboards to thousands of projects across Australia. High Voltage connected sites, which includes anything above 1000V according to Australian Standards, often have different requirements set out by each Distributed Network Service Provider (DNSP), and each of the state’s Service Installation Rules. “In well designed high voltage installations, you have to have more electronics, control, measurement, and communication devices in the switchboard, all working together in a reliable way.”

High Voltage switchgear considerations

Bell says that switchgear for any application should be tailored to suit each project, but there are a number of features that may need to be included in the HV switchboard or control panels:

• • • Protection relays, which measure the power and disconnect the fault before it can cause injury or damage.

 

• • • Supervisory Control and Data Acquisition (SCADA) panels, SCADA gateways, timeclocks, power supply inverters, Programmable Logic Controllers (PLCs), and Remote Terminal Units (RTUs) – this allows the asset owner to communicate with the asset and monitor its status.

 

• • • Integrated Uninterruptable Power Supply (UPS) panels to provide power to the switchboard and control panels if the grid power is lost.

 

• • • Rapid Earth Fault Current Limiter (REFCL) compatibility, which is a special requirement in some States and regions.

 

• • • Factory testing, to ensure quality and reliability.

    “At our Tempe facility in Sydney, we perform factory testing on switchgear, including primary injection testing of Voltage Transformers (VTs), Current Transformers (CTs), bus resistance, and secondary injection testing of the protection relay,” says Bell.

Renewable energy assets

Renewable generation assets such as solar and wind farms often have complex grid integration and control requirements for High Voltage switchgear. Solar and wind farms tend to be more complicated than standard Ring Main Units (RMUs) due to the grid integration and control requirements, so having an experienced switchgear provider is even more crucial, both for renewables, and for other purposes,” he adds. Often the DNSP has specific control over the assets involved. “This is normally to monitor or remotely disconnect the site, but could also involve dynamic export limits or other more specific types of control,” explains Bell, whose company has deep technical experience in projects up to 33kV, including standardised and custom designs as well as local stock to ensure reduced lead times on a variety of projects. Renewable energy projects such as wind, solar or battery installations often trade on the Frequency Control Ancillary Services (FCAS) market which has its own specific requirements. FCAS is a process used by the energy market operator to maintain the frequency of the system, by injecting or reducing energy to better manage supply and demand. These renewable generation assets are being used to supply green power to sites including manufacturing, mining, infrastructure, construction, and a broad range of industrial applications, as Australia takes steps to reduce carbon emissions and accelerate the transition to Net Zero.

Safety features

“For high voltage applications, we can build indoor or outdoor rated enclosures to house the switchgear and control panels on one skid,” says Bell. For further safety, Clean Tech Controls can construct the switchboard with either upward or downward arc venting. Bell explains that when there is a fault, a lot of energy needs to be dissipated through the switchgear – often as a fireball – and you don’t want that to come out anywhere close to where someone might be standing, so a release either above or below is required. “For upward arc venting, we put a pressure release plenum on top of the enclosure, or for downward arc venting there needs to be adequate space in the pit below the switchboard to meet the requirements for dissipating the pressure,” he explains. Clean Tech Controls supplies switchboards with Arc Front Lateral Rear (AFLR) ratings, meaning a person can safely be standing in front, at the side, or behind the switchgear if there is a fault.