Design of a Control System for a Modular Multi-Level Converter of a Single-Phase Solar Power System Based on a Proportional-Resonant Controller

Abstract

Modern solar power stations traditionally use lumped elements to convert electrical energy. This approach is simple and affordable for small power plants; however, the cost of such controllers increases significantly for power of several kilowatts. It is also necessary to place other lumped conversion elements such as MPPT (maximum power point tracking) controller, inverter and the sine filter. Presented control system allows to combine all these devices into one distributed system per moving to a modular multilevel conversion topology. In order to ensure the flexibility and the ability to operate in any network configurations, the proposed article also considers the use of a proportional-resonant regulator to abandon the use of phase-locked loop frequency and, as a consequence, simplify the control system. The presented article will consider a model of a 10 kW power station for a standard mains voltage of 220 V.