The major application of the real-time simulator is to test the real hardware controller. The controller and the simulator form the closed-loop through I/O signals or communication. This kind of testing approach is often called Controller Hardware-In-the-Loop (HIL) testing.

The HIL approach tests both the control algorithm and the controller I/O interfaces in a way that closes to the real system test. In addition, it is easy to test various working conditions, especially the fault conditions. It is also much easier to automate the test sequences with different system parameters or conditions. So the HIL testing can shorten the development cycle and improve the test efficiency.

The controller under test can be an embedded controller or a RCP type controller.

Power Hardware-In-the-Loop Testing

The real power electronic device contains both the signal level controller and circuit components such as power electronic switches, inductors and capacitors. Due to the advantages of the real-time simulator, engineers also would like to test the power electronic devices with it. However, the challenge is that the real-time simulator usually only has the signal level interface, which means it can't be connected to the power devices directly. With the development of power amplifier technology, the power amplifier has better response speed and higher power level, it can be used to bridge the real-time simulator and the power electronic device. The system diagram is shown below:

The test system above consists of the real-time simulator, the power amplifier and the power electronic device. The power electronic device is generally modeled as controlled current sources in the real-time simulator; the power amplifier amplifies the voltage from the simulator to drive the power electronic device; the sensor collects and feeds back the voltage and the current information of the power electronic device to the real-time simulator. PHIL system has the advantages of the real-time simulator as well as the power interface to connect with the power electronic device, therefore it is widely used in the research and test of power electronics industry.