As microgrids and renewable energy sources increasingly dominate the power system, the availability of detailed study tools and comprehensive testing facilities is more relevant than ever. The behaviour of protection, control, and power devices in a microgrid environment can be nuanced and unpredictable. Microgrids must supply resilient and reliable power while operating securely for a wide range of power system conditions. Hardware-in-the-loop testing allows the engineer to verify the secure operation of microgrids, optimize environmental and economic performance, and de-risk the deployment of novel control and protection systems in the safety of a laboratory.
A wide variety of distributed energy resource (DER) models are available in the RSCAD model library
Wind Turbines: RSCAD includes a vertical axis wind turbine model, which can be used in conjunction with other available components to model a full wind energy system. RSCAD also includes machine models, grid connection components, and reactive power compensation components, as well as control components for the modelling of pitch angle, reactive power, startup/shutdown, and other control schemes.
Machines: RSCAD includes wound rotor / doubly fed induction machine models, squirrel cage induction machines, and permanent magnet synchronous machine models.
Photovoltaics: RSCAD includes a solar PV panel model for which the user can define the module and array size. The control components library can be used to implement decoupled DQ-current control and other schemes, and includes a maximum power point tracking control model.
Fuel Cells: RSCAD includes a PEM type fuel cell model.
Storage: RSCAD includes a lithium ion battery model.
Pre-built and custom models for representing power electronic converters
RSCAD contains an entire component library dedicated to small timestep modeling—components which run at a smaller simulation timestep in order to represent high frequency switching and circuit dynamics. A key feature of these small timestep subnetworks is that the circuit and valve topology is user configurable.
RSCAD’s small timestep VSC models can represent switching frequencies as high as ~40 kHz.
The RSCAD library also contains average models, which represent the steady state and transient behavior of converters without requiring a small timestep model. Average models are less computationally intensive and useful for cases in which a large number of converters must be simulated.
Simulate large distribution systems with Distribution Mode
RSCAD’s Distribution Mode is capable of simulating distribution networks of over 1000 nodes in one tightly coupled area.
Distribution Mode was developed to accommodate the implementation of large feeder models made of up short lines and/or cables that are not long enough to allow the circuit to be separated into multiple subsystems. The component library available in Distribution Mode is a limited subset of the RSCAD modelling library, including sources, transformers, induction machines, pi-section transmission lines, renewable energy models, synchronous machines, and average models for power electronic converters. Distribution Mode has a full suite of input/output capabilities, allowing users to interface distribution-level protection and control devices in a closed loop with the simulation.
Closed-loop testing of microgrid control systems
The RTDS Simulator offers the most advanced and effective means available for the closed-loop testing of protection and control system equipment. Primary, secondary, and/or tertiary-level microgrid controllers can be interfaced with the real time simulation for hardware-in-the-loop testing.
Control systems developed in MATLAB/SIMULINK can also be imported into the real time simulation environment and interfaced with the simulation.
High level communication protocols: In addition to the conventional analogue and digital interface, the RTDS Simulator can be interfaced with external equipment via ethernet-based communication protocols. Available protocols include:
- DNP3 and IEC 60870-5-104 for SCADA applications
- High-speed TCP/UDP
- IEC 61850 Sampled Values and GOOSE Messaging
- IEEE C37.118 for synchrophasor data
Power-hardware-in-the-loop testing for renewable energy hardware, batteries, and more
Power-hardware-in-the-loop (PHIL) simulation involves the real-time simulation environment exchanging power with real, physical power hardware, such as inverters, electric vehicles, batteries, motors, and loads.
When combined with a four-quadrant amplifier, the RTDS Simulator can be used in the PHIL context to test photovoltaic inverters, wind turbine generators, and batteries.