A Simple Model Predictive Power Control Strategy for Single-phase PWM Converters with Modulation Function Optimization

Abstract

This paper proposes a simple model predictive direct power control (MP-DPC) of single-phase pulsewidth-modulated rectifiers with constant switching frequency using modulation function optimization. The instantaneous active and reactive power theory for single-phase converters is discussed, on the basis of a second-order generalized integrator. The modulation function is resolved from the cost function of the MP-DPC scheme. The relationship between the instantaneous powers and ac-side inductance mismatch is discussed. The inductance mismatch has an effect on the reactive power, but not effect on active power. The quantitative expression of reactive power caused by inductance mismatch is shown and verified in the experimental test. An inductance parameter online estimation scheme is proposed to eliminate its effect on reactive power. Compared with the conventional proportional-integral-based instantaneous current control scheme and finite-control-set MP-DPC scheme, the proposed MP-DPC can provide these advantageous features: lower current harmonics and total harmonic distortion components, faster dynamic response, fewer adjusted parameters, and zero steady-state error. In addition, the proposed MP-DPC is free of the weighting factor selection in cost function. The effectiveness of the proposed MP-DPC scheme is verified by experimental results.