MMC-BASED TRANSFORMERLESS FOUR-QUADRANT HIGH-VOLTAGE VARIABLE-FREQUENCY POWER SUPPLY TOPOLOGY

摘要

An modular multilevel converter (MMC)-based transformerless four-quadrant high-voltage variable-frequency power supply topology. In the power supply topology, the rectification module and conversion module both have modular multilevel topologies formed by serially connecting a plurality of sub-units. The input side of the rectification module is directly connected to the high-voltage of the grid side by means of a charging circuit. The rectification module converts a high-voltage alternating current into a direct current and inputs same into the conversion module. The conversion module converts the direct current into an alternating current to achieve simulations of various states of a power grid. The power supply topology is a four-quadrant topology that achieves energy feedback. The advantages of the power supply topology are: elimination of a high-voltage transformer on the power supply input end, reduction in cost, reduction in the bulk and weight of the high-voltage variable-frequency power supply, reduction in the wear and tear of components and parts, an increase in operating efficiency, a simple sub-unit structure, convenient wiring, and easy installation and dismantling.