Primary side single-phase bridge-subsidiary side three-phase bridge high frequency chain inverter and digital control system thereof and method thereof

Abstract

The invention discloses a primary side single-phase bridge-subsidiary side three-phase bridge high frequency chain inverter, a digital control system of the primary side single-phase bridge-subsidiary side three-phase bridge high frequency chain inverter and a method for the primary side single-phase bridge-subsidiary side three-phase bridge high frequency chain inverter and belongs to the field of a power electronic converter and control of the power electronic converter. The primary side single-phase bridge-subsidiary side three-phase bridge high frequency chain inverter comprises input voltage Uin, a single-phase bridge type circuit, a high frequency isolation transformer, a three-phase bridge type circuit, an LC filter, a voltage sensor, a current sensor and a DSP digital controller. The single-phase bridge type circuit is composed of four electricity MOSFETs. A primary side of the high frequency isolation transformer is a single winding and a subsidiary side of the high frequency isolation transformer is a winding with a center tap. The three-phase bridge type circuit is composed of six electricity MOSFETs. The LC filter is composed of an inductor L and a capacitor C. TMS320F28335 is adopted by the DSP digital controller and the functions of the DSP digital controller comprises outputting a voltage control loop, an inductive current control loop, a signal conditioner and a drive signal selective switch. Two-stage power conversion is adopted, so that electrical insulation of an input side and an output side is achieved, size is small, weight is light, efficiency is high, energy flows in two directions, soft switching is achieved, heat emission of devices is dispersed, and the requirement for heat dissipation is low.

Description

technical field [0001] The invention relates to a primary-side single-phase bridge-secondary-side three-phase bridge high-frequency chain inverter and its digital control system and method, belonging to the field of power electronic converters and their control. Background technique [0002] The worldwide fossil energy crisis has accelerated the development of new energy in various countries. An important aspect of new energy application is new energy power generation and its control technology. Electric energy output by devices such as photovoltaic cells, wind turbines, and fuel cells can not only supply local loads, but also be delivered to the grid through grid-connected inverters. At present, grid-connected inverters have multiple circuit structures: 1. Single-stage non-isolated grid-connected inverter; 2. Single-stage non-isolated inverter + power frequency transformer; 3. Non-isolated DC converter (DC / DC) + non-isolated single-stage inverter + power frequency transfor...

AI Technical Summary

Problems solved by technology

[0008] The existing two-stage high-frequency link inverter can be divided into a circuit structure based on a flyback converter and a circuit structure based on a forward converter, and a flyback-based high-frequency link inverter The transformer is used as an energy storage element, so it limits the amount of power it can handle, while the high-frequency link inverter based on the forward converter can handle larger power, which meets the power demand of the converter for new energy generation

However, in the current two-stage high-frequency link inverter, the cycloconverter on the secondary side of the transformer generally adopts bidirectional switches, and all of them are high-frequency switches, and the voltage peak of the switching tube in the cycloconverter is relatively large, which limits the two-stage inverter. Application of High Frequency Link Inverter

Although there have been circuit improvements for cycloconverters, the circuit structure is very complex, and the entire two-stage high-frequency link inverter requires 16 switching tubes, which also limits its application to a certain extent.

Images