De-risk controls for renewable energy resources at the power plant level

Validate power plant controllers (PPCs) with
hardware-in-the-loop testing

Increasing penetration levels of solar PV, wind, and other distributed energy resources has resulted in the introduction of new and improved grid codes which require these technologies to provide grid support. As a result, a coordinated approach for controls at the power plant level is needed. High-level PPCs coordinate the lower-level controls (i.e. individual inverter controls) to provide the necessary functionality at the plant level.

PPCs typically control the plant’s active/reactive power output, power factor, voltage, and frequency. They may coordinate many inverters and sites, along with other static compensation equipment. PPCs are critical infrastructure on the modern grid, and validating their operation via hardware-in-the-loop (HIL) testing ensures that they will operate securely – and in line with the expectations of manufacturers and grid operators – when installed.

An example of what PPC testing might look like with the RTDS Simulator

Benefits of hardware-in-the-loop testing for PPCs

Validate offline PPC models

Vendors are often required to supply a detailed EMT model of their PPC to utilities. The RTDS Simulator has been used to validate these models against the performance of the actual hardware controller via HIL testing, providing increased confidence to the manufacturer and end user.

De-risk via interoperability testing

HIL testing allows for multiple devices to be tested simultaneously, providing unique insights on device interactions at the systems level that are often not revealed by conventional testing. The ability of PPCs to securely operate alongside existing protection and control can be verified using real hardware.

Support factory/site acceptance testing

Including HIL testing in the factory and site acceptance testing process can improve project schedules. Troubleshooting in the lab allows for accurate replication of commissioning events and representation of a much wider range of contingencies than can safely be imposed on the real grid.

Test the impact of communication protocols

The impact of communication protocols – namely, any associated communication delays – are incorporated into the HIL test so the engineer can understand their impacts on system operation. This is an advantage of HIL over offline PPC simulation.

PPC testing is supported by our simulation software

RSCAD FX includes sample cases which walk users through modelling and testing PPCs. The sample case includes scaled-down PV systems including inverters, a high-voltage circuit including transformer and source representing the grid, and a simulated PPC using controls components. A second case includes a sample input/output interface to an external PPC via MODBUS protocol.
  • Solar PV array
  • Wind turbine
  • PEM fuel cell
  • Lithium Ion energy storage
  • Reactive power compensation
  • Dynamic loads
  • Wound rotor / doubly fed induction machine
  • Squirrel cage induction machine
  • Permanent magnet synchronous machine
  • And more
  • The Universal Converter Model represents 2- level, 3-level T-type, 3-level NPC, boost, buck, flying capacitor, and DAB topologies.
  • The UCM’s Improved Firing input can be used for switching at up to ~10 kHz in the Mainstep environment and up to ~150 kHz in the Substep environment.
  • Average Value Models, using the UCM’s Modulation Waveform input, are also available.
  • Custom topology converters can also be represented.

Freely configurable controls components allow the modeling of:

  • P&Q droop control
  • DQ-current control
  • Maximum power point tracking
  • Pitch angle control
  • Breaker control / sync check
  • Startup/shutdown
  • Governor/exciter models.

Control systems developed in MATLAB/SIMULINK can be directly imported.

The GTNETx2 network interface card is used to interface external devices to the RTDS Simulator via standard-compliant communication protocols, including:

  • High-speed TCP/UDP
  • DNP3 and IEC 60870-5-104
  • IEC 61850-9-2LE and IEC 61869-9 Sampled Values
  • IEC 61850 GOOSE Messaging
  • Synchrophasor data