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.
Why is the electricity grid becoming more complex?
For decades, high voltage switchboards and control panels have been engineered to handle a relatively simple mission: Electricity flowed in one direction-from great centralized power stations via transmission and distribution networks down to the end user. Protection schemes were predictable, fault levels were stable, and switching operations were largely planned and seldom occurred.
That operating environment has fundamentally changed.
The Australian electricity grid is today among the most complex in the world: the rapid growth in rooftop solar, large-scale wind and solar farms, battery energy storage systems, electric vehicles, and microgrid is pressuring current models of generation and consumption. Power no longer flows from the grid to customers but increasingly vice versa, back into the network from distributed energy resources.
Renewables bring additional variability, and an electrical grid was never designed to deal with it. Solar power can disappear instantly when clouds show up, and wind power is inevitably linked to weather. But also, inverter-based resources behave very differently from traditional synchronous generators, especially when faults happen.
The load profiles also have shifted. High-power EV charging, electrified heating, data centre operation, and automation have resulted in unpredictable load fluctuations. All this causes fresh stress for HV assets and pushes traditional ideas of protection strategy away.
All of this has increased the need for visibility, flexibility, and real-time management at high voltage levels.
Why are traditional HV switchboards no longer sufficient?
Traditionally, high voltage switchboards were designed around robust mechanical devices intended to perform their duties for long periods of time, often in excess of decades. Circuit breakers, isolators, busbars, and earthing comprised the essential elements of high voltage switchboards. The elements also included relays and controllers.
Though these systems are reliable, they are also failing to handle the new grid conditions well.
Lack of real-time information is one of the major drawbacks of switches, as they provide little information with regard to operating systems such as load trend information, temperature rise curves, or power quality information, which results in undetected faults until an unexpected failure happens in systems utilizing them.
– Inflexibility is another issue. Typically, protective setting parameters used for earlier equipment installations tend to remain fixed and conservatively set. Consider, for example, a network that has varying conditions for fault level and power flow, depending on generation and load situations.
Manual operations also have an associated problem. In many traditional HV panels, there is the need to have persons on site to perform such operations as switching, fault analysis, and reset procedures. This is not only costly in terms of operations, as outages are prolonged, but also poses a threat to human safety.
Finally, a legacy switchboard is, by definition, not expected to integrate perfectly into a modern network control system. Indeed, a lack of communication capability makes it difficult to accommodate the high degrees of automation currently desired by network operators.
What does “smart” actually mean for HV switchboards and control panels?
It’s not simply a conventional switchboard with the addition of a communication interface; it’s a complete concept in which all the hardware components work in cooperation with communications systems and information technology to serve electrical engineering’s needs in “intelligent” fashion.
At its heart, however, it appears that the most critical pieces of equipment in terms of switches are as relevant as ever. There are still requirements in terms of circuit breaker, busbar, and enclosure specifications. What makes it smart, presumably, are additional intelligences that are overlaid on top of these.
Advanced forms of protection relays have the capacity to relate and measure voltage, current, frequency, as well as power qualities, and they have the option to evolve as they display real-time information.
These control panels may feature PLCs, remote terminal units, and intelligent electronic devices in order to allow switching sequences, interlocks, and operation in remote control. This facilitates safe control of HV assets from central control rooms.
Smart switchboards will also include a variety of sensors. Temperature sensors on busbars and cable terminations, as well as sensors for partial discharge within compartments of switchgear will monitor condition.
The communication infrastructure brings all the pieces together. Data from the smart high-voltage panels may be sent safely to the SCADA systems or asset management systems in real-time.
How do smart HV switchboards support renewable energy integration?
One of the strongest growth factors for a ‘smarter’ HV infrastructure is renewable energy integration.
Utility-scale solar farms, wind farms, and even battery energy storage systems interface with the power system at high voltage levels. They need to achieve strict performance conditions for voltage regulation, frequency response, and fault ride through.
Smart HV switchboards include the monitoring programs required for connection management. In addition, protection schemes can be adapted to settings corresponding to real-time fault levels; fault levels can vary widely depending on installed levels of inverter-based generation.
Also, fast and selective fault detection is critical in such grids, which are rich in renewable energy. For instance, smart intelligent devices can quickly switch to off positions to isolate faulty points, thereby reducing their impacts on connected generations.
As battery systems begin to play a larger role, smart control panels provide complex operation modes as well. The power supplies can switch between charging, discharging, and other grid-support tasks, which must be operated safely on the high voltage level as well;
How do smart switchboards improve grid reliability and resilience?
Reliability trends continue heavily upward even while network complexity increases. Consumers have increasing outages and expect quicker restoration times, with ever-tighter scrutiny from regulators.
The smart switchboards are central to satisfying these expectations.
Continuous monitoring helps in the early detection of abnormal conditions, where gradual increases in temperature, abnormal patterns of loading, and weakening of insulation can be detected before they result in failure.
For instance, in the event of fault occurrences, response time is greatly reduced by automation. Remote controls can be carried out, which enables other stations in the system to be operated once more.
Also, the level of resilience is raised with the element of redundancy. Smart control panels are designed with an alternative power source, such as a battery backup, to provide power in case of an outage.
How do smart HV systems improve safety for personnel?
In general, high voltage environments represent inherent risks. Safety is naturally one of its primary considerations.
Smart switchboards minimize manual intervention requirements. Moreover, since smart switchboards can be controlled from remote locations, people work on these sites less, hence reducing arc flash hazard.
The digital interlocking system ensures correct sequences, thus eliminating any kind of unsafe action that may take place due to human error. This is an advantage in a complex substation with various sources and interconnections.
Another way in which condition monitoring can enhance safety is in preventing catastrophic failure. Being able to identify early signs of malfunctioning equipment can prevent emergency responses from having to occur in the first place.
How does smart technology enable data-driven asset management?
Traditional maintenance practices like maintenance by regular inspections or breakage-repair may become inefficient in the modern grid environment to the extent that the above approaches traditionally used are no longer applicable.
Smart HV Switchboards offer the possibility of condition-based maintenance, offering constant information on equipment performance, rather than relying on presumptions to inform asset management decisions.
Trend analysis can, over time, validate predictive maintenance approaches, where maintenance is carried out on components when needed, i.e., prior to failures.
For a utility, it represents a fundamental change in the way in which higher voltage assets are managed, switch boards going from being purely pieces of infrastructure to sources of data.
How do smart HV switchboards integrate with modern grid control systems?
Modern electric networks employ complex control systems to manage voltages, frequencies, and power transfers in wide geographical areas.
The smart high voltage switchboards have been specifically developed to integrate smoothly and functionally into this environment. The information is conveyed to SCADA and other advanced distribution management systems on a live basis, enabling a broad overview to be maintained.
The control commands can also be sent backwards towards HV assets, with the option for remote switching, restoration, and adaptive protection. This communication is important for controlling large sections of the grid with significant degrees of DG.
What cybersecurity challenges come with smarter HV infrastructure?
As switchboards progress to a more networked setup, there is a growing concern about cybersecurity as well.
Smart systems in electrical grids need to have design criteria for safe communication, access control, and authentication schemes. Electrical grids’ protection from cyber attacks has emerged as one of the essential design criteria in smart systems.
The utilities should ensure that smart swtch boards are introduced as an integral component of a larger cybersecurity policy.
What challenges still exist in adopting smart HV switchboards?
Even though smart HV switchboards have various benefits, they face a number of challenges as well
Additionally, while upfront costs will be higher due to advanced hardware, software, and integration requirements, these costs can be partially mitigated by long-term cost savings from reliability enhancements.
There is also a skills gap. It is not straightforward to design, commission, and operate smart HV systems since it requires understanding power and technology aspects. There is also a training and workforce skills necessity.
The integration of legacy system infrastructure can also be challenging, more so when dealing with different eras and brands.
We design and manufacture high-quality switchboards. Contact us today to discuss your requirements and get started!