A New Constant Switching Frequency Model Predictive Control Method for Grid Connected 5-level ANPC Inverter with Capacitors Sensor-less Voltage Balancing

摘要

In this paper, a constant switching frequency model predictive control (MPC) method with capacitors voltages self-balancing is proposed for the 5-level active-neutral-point-clamped (5L-ANPC) grid connected inverter. The proposed MPC provides optimum reference voltage for the 5L-ANPC inverter based on minimizing the derivative of defined cost function with respect to the output voltage of the 5L-ANPC inverter. The generated reference voltage by the proposed MPC is applied to a phase shifted pulse width modulation (PS-PWM) method to provide constant switching frequency and sensor-less voltage balancing of the dc-link and flying capacitors of the 5L-ANPC inverter. Hence, the proposed MPC only needs to measure grid current; thus, the complexity of control system and number of required sensors are notably decreased. The proposed MPC is described and simulation and experimental results are provided for the grid connected 5L-ANPC inverter. The provided simulation and experimental results verify the dynamic and steady state performance as well as viability of the proposed constant switching frequency MPC for the grid connected 5L-ANPC inverter.