Precompensator for Disturbance Signal Elimination in Single-Phase Inverters With Virtual Vector Control

In virtual vector control schemes for single-phase current-regulated voltage source inverters, many methods are proposed to generate a virtual orthogonal feedback current from the real feedback current. However, the generation stage causes mismatch between feedback and command currents, which may deteriorate dynamic current-tracking capability and power quality. A precise scalar model is developed to analyze the phenomenon. Based on this model, the mismatch is presented as a current disturbance signal introduced into the control loop. The mathematical analysis establishes that the current disturbance cannot be eliminated by any orthogonal signal generation (OSG) method. To solve the problem, a current precompensator is mooted. In this paper, the effect of the current precompensator is studied in detail. Furthermore, a voltage precompensator is proposed, which better suits OSG methods than the current precompensator. Experimental results of both the current and voltage precompensator are compared with the conventional solution to substantiate enhanced dynamic performance.