Interpolation and Extrapolation Algorithm for Switching Events Compensation in Semi-Physical Simulation of Cascaded STATCOM

To improve the accuracy of semi-physical simulation, this paper mainly discussed interpolation and extrapolation algorithms for switching events compensation of cascaded static synchronous compensators (STATCOM). The moment of the switching events was captured by Field-programmable gate array (FPGA). Two linear interpolations and one extrapolation were adopted to compensate the error caused by multiple switching events during one simulation step. In addition, a linear interpolation was also applied for time delay compensation in hardware in loop test. Both rapid control prototyping and hardware in loop tests were performed to verify the effectiveness of the interpolation algorithms. Experimental results indicated that the time delay was almost eliminated and the output waveform was improved after compensation.