Hydro power plant governor testing using hardware-in-the-loop simulation

Today Hardware-in-the-loop is standard testing procedure in controller design procedure. Once the design of the controller is completed using off-line desktop simulations and the algorithm is transferred in C code, it is necessary to test the code as well as the final controller for his capabilities of running in real-time. In the process of designing the hydro turbine speed governor this is more than necessary since the controller and the real hydraulic actuator are integrated part. With the purpose of real-time testing of the controllers for hydropower plant speed governors a general model of a Hydro power plant with Francis turbine is created using Matlab/Simulink. The model is then translated to C code using Matlab Real-Time Workshop and run in real-time on a powerful industrial PLC. Through I/O interface the virtual hydro power plant and real speed governor (actuator together with controller) are combined as a closed loop control system. Easy parameter changing and monitoring of the whole process is accomplished through PC program which is in communication with the real-time simulation system through Object Linking and Embedding (OPC) connection. With this testing bench the controller can be tested in two ways: together with the real hydraulic actuator or a scaled physical model of it, if the real hydraulic actuator is available or with the real-time model of the hydraulic actuator if the real hydraulic actuator is not available. In this way we can examine and adjust the performance of governor before installing it to the power plant. By using this test system, the efficiency and security of the speed governor can be improved.