Control Design of Four-Bridge Three-Phase Inverter

GW MB10F 0.8A 1000V rectifier bridge

The outer diameter of the probe domestic PA50-F small four-jaw gold-plated needle is 0.68. The total length of the needle is 16

Overview:
A novel three-phase four-wire inverter is proposed, which has four bridge arms, and the fourth bridge arm is used to form the midpoint, thereby eliminating the midpoint forming transformer in the three-phase three-leg inverter. , reducing the size and weight of the inverter. For this kind of inverter, this paper proposes a current regulator that selects the switching mode of the inverter according to the phase in which the three-phase filter inductor current and the given current have the largest error value. In order to eliminate the static error of the output phase voltage, this paper discusses an improved voltage regulation scheme based on PI regulator. The simulation results show that the idea of ​​this paper is feasible. This paper provides a reliable theoretical basis for constructing a high-power, high-efficiency three-phase four-wire inverter.

1 Introduction Three-phase inverters generally use a topology consisting of three bridge arms. In order to supply power to the asymmetric load, a Neutral Formed Transformer (NFT) must be added to the output, as shown in Figure 1. The midpoint forming transformer is an autotransformer with a ratio of 1. The operating frequency is the frequency of the output alternating current, the volume and weight are large, and the volume and weight vary with the degree of load asymmetry. The greater the asymmetry, the NFT The volumetric weight is also greater.

Figure 1 Three-phase inverter with NFT (please read the PDF for details)