A Hardware-In-the-Loop Simulation Platform for Prototyping and Testing of Wind Generator Controllers

To meet the growing demand for integration of renewable energy sources onto today’s power grids, many engineers from different specialized fields must be involved since various types of studies need to be conducted. The integration of distributed generation (DG) sources significantly changes the characteristics of an entire network. Such interconnection projects will require analysis of power quality, transient response to fault occurrences, protection coordination studies and controller interaction studies. The first considerable challenge is related to power electronic converters, which are increasing in number and found on most DG sources. Accurately simulating fast switching devices requires the use of very small time steps to solve the system’s equations. Off-line simulation is widely used in the field, but it is time consuming if no precision compromise has been made on models (i.e. the use of average models). Moreover, off-line simulation tools do not offer the wide range of possibilities available with state-of-the-art distributed real-time simulators. Such tools combine, for instance, the efforts of control engineers and specialists from wind turbine manufacturers, who need to test their controllers using hardware-in-the-loop (HIL), together with those of network planning engineers from public utilities, who will conduct interconnection, interaction and protection studies. The eMEGAsim simulation platform is fully integrated with Simulink/SimPowerSystems (SPS) from The MathWorks and EMTP-RV. This makes eMEGAsim a valuable solution for engineers who already have models built with these off-line simulation applications, as well as for less experienced users. This paper focuses on the prototyping and testing of DG controllers using hardware-in-the-loop simulation. The model described in this paper is a 10-turbine wind farm connected to a single feeder, simulated using an eMEGAsim real-time simulator equipped with 8-processor cores. One of the wind turbines is controlled using an externally emulated controller. The emulated controller model consists of a replica of all other wind turbine controllers, which are locally simulated in the plant model. It is modeled and simulated using a dual-processor core real-time simulator, which interacts with the plant model via analog and fast digital inputs and outputs. This paper validates the proposed real-time simulator for the study of wind-farm electromagnetic disturbance studies with HIL-connected DFIG controllers, specifically that the simulator can be interfaced with high-frequency PWM controllers without distortions caused by the sampling time of the simulator.