Simple and fast synchronous reference frame current control for single-phase grid-connnected votage souce converters

Zero steady state error in the line current of a single-phase grid-connected voltage source converter is usually obtained in the synchronous reference frame with different orthogonal signal generation schemes, which may lead to slow dynamic response and stability problems. This paper analyzes a simple rotating reference frame current control of the single-phase converters using the desired steady state fictitious current as the orthogonal signal. Double line frequency components are present in the current error signals, which will be completely eliminated at the steady state condition. The control loops were tuned at the bandwidth greater than such oscillating frequency, which gave the dynamic performance even better than the ideal balance two-phase system. The generated orthogonal current was mathematically proved that no potential stability problem was found. Only two multiplications and one addition were required without stored memory for the calculation of the quadrature current. Simulation and experimental results of a 1.5-kVA PWM rectifier validated the proposed control scheme.