MPC Using Modulated Optimal Voltage Vector for Voltage Source Inverter with LC Output Filter

Voltage source inverters with LC output filters are widely used for high-quality output of ac power supplies. They are also a potential solution for embedded electrical networks in more-electrical aircraft of the future. In this paper, a recently developed model predictive control technique that selects modulated optimal voltage vector is applied for high dynamic output voltage control of these systems especially when the required output frequency is well above the standard 50/60 Hz as required by aerospace applications. The studied predictive control optimizes the switch duty cycles when in linear regulation range by solving analytical equations. The over-modulation region is covered by optimized linear combination of the adjacent hexagon vertices unlike how it happens in classical space vector modulation. A load current observer is also designed in this paper which is made independent of output frequency for improving the disturbance rejection capability of the voltage control loop when the load current sensors are not present. Simulation and experimental results that validate the control and observer performance are presented under different steady state and dynamic operating conditions.