整流器功率平衡的多级串联高压变频器

现有实用的中高压变频器方案包括功率开关直接串联的两电平逆变器、单相逆变器的多级串联变频器、三相直接输出的三电平逆变器。该文提出一种整流器功率平衡的多级串联高压变频器,即一个整流器负担三个对称的单相交流电压输出,相位相同的单相逆变器通过变压器次级串联,构成一相高压交流输出。整个电路由网侧工频降压变压器、整流器与逆变器阵列、载侧高频升压变压器构成。串联级数为N的多级串联高压变频器包括N个整流器和3N个单相逆变器。该文分析这种变频器的拓扑构成和载波移相调制原理,并利用MATLAB/SIMULINK给予仿真分析,所得结果表明,所提出的多级串联高压变频器具有可行性和低成本。

Multistage Serial High Voltage Frequency Converter with Balanced Output Powers of Rectifiers

The existing practical schemes of middle and high voltage frequency converter include two-level inverter with power switch cascaded directly,multi-stage in-series frequency converter with single-phase inverter and three-level inverter with three-phase direct output. This paper gives a multistage serial high voltage frequency converter with balanced output powers of rectifiers,in which a rectifier burdens three symmetric single-phase ac output and the same phase outputs of single-phase inverters are cascaded at the secondary side of the transformers,making up a high-voltage ac output. The circuit is consisted of a step-down industry frequency transformer in the network side,rectifier and inverter array and a step-up high frequency transformer in load side. The N-stage in series high voltage frequency converter includes N rectifiers and 3N single-phase inverters. This paper analyses the topology structure of this frequency converter and the principle of carrier phase shifting modulation. The simulation result based on MATLAB/SIMULINK shows that the proposed multi-stage in-series high voltage frequency converter is feasible and low-cost.