Abstract：Aiming at the problem that most of the existing methods need to obtain internal electrical quantities of grid-connected inverter (GCI) to realize the measurement of control parameters, which imposes high demands on the testing conditions. A virtual measurement method for GCI parameters based on frequency response is proposed, which just applies disturbance and measures output currents at the common coupling point of the grid-connected inverter. Firstly, the operational principles and mathematical models of GCIs are analyzed, establishing corresponding transfer functions and obtained their frequency response characteristics. On this basis, an optimization model for virtual measurement of GCIs is constructed, and the particle swarm optimization is utilized to calculate the parameters that approximates the actual frequency response characteristics of the GCI. Simulation results indicate that, this algorithm realizes the virtual measurement of the control parameters of the inner loop, outer loop and phase-locked loop only by using the measurement information of the terminal voltage and current of the GCI, and the maximum error does not exceed 2.6%.
2025, Vol. 46 
