中高压大功率电机系统三电平变流器综合损耗建模与损耗抑制调制策略

The technological requirements of converter, including operation performance, operation efficiency, are continually rising for high/medium voltage and high power motor drive system. Traditional converter loss analysis method is limited in accuracy, and only single object optimization could be realized by traditional modulation strategy, which are difficult to meet the requirements of high efficient and high performance. This project will focus on the integrated converter loss modeling and full speed range loss suppression modulation strategy. Firstly, the correlation mechanism between vector synthesis process and harmonic loss will be analyzed, and the impact of neutral point voltage fluctuation on harmonic loss will be revealed. Then the accurate harmonic loss model will be obtained and the comprehensive loss model of device and harmonic loss will be established. Secondly, considering the low switching frequency modulation characteristics and constraint mechanism of high power converter, the asynchronous modulation strategy of low speed range will be optimized. The relationship between space vector synthesis process and the amplitude and angle of the vector will be analyzed, and the modulation segments will be further divided, the synchronous modulation strategy of medium speed region will be optimized. Thus, the loss reduction modulation strategy for the full speed range will be established. Based on the above research contents and results, new ways can be provided for the further improvement of operation and control methods with high efficient and high performance of the high/medium voltage and high power motor drive system.

中高压大功率电机驱动领域对变流器的运行性能和运行效率等方面要求不断提升。传统变流器损耗分析方法精确度受限，而且传统调制策略仅以单一性能提升为目标进行优化设计，难以满足高效能运行要求。本项目拟从变流器综合损耗建模与全速域范围损耗抑制调制策略两方面展开研究。首先，探明矢量合成方式与变流器谐波损耗之间的关联机制，揭示中点箝位型三电平变流器中点电压波动对变流器谐波损耗的作用规律，进而得到精确化谐波损耗模型，建立同时考虑谐波损耗与器件损耗的变流器综合损耗模型。其次，考虑中高压大功率变流器低开关频率调制特性与约束机制，以综合损耗模型为评价标准，优化低速区异步调制策略；揭示矢量合成方式与矢量幅值及角度的映射关系，进一步细化调制度分段区间，优化中速区分段同步调制策略，形成全速域范围损耗抑制调制策略。基于上述研究内容与成果，为中高压大功率电机驱动系统高效能运行与控制方法的进一步完善提供新的思路。

中高压大功率电机驱动领域对变流器的运行性能和运行效率等方面要求不断提升。传统变流器损耗分析方法精确度受限，而且传统调制策略仅以单一性能提升为目标进行优化设计，难以满足高效能运行要求。本项目从变流器损耗建模与全速域范围损耗抑制调制策略两方面展开研究。首先，探明矢量合成方式与变流器谐波损耗之间的关联机制，揭示中点箝位型三电平变流器中点电压波动对变流器谐波损耗的作用规律，进而得到谐波损耗精确量化评价模型。与传统评价模型相比，本项目所提以变流器输出平均误差电流矢量幅值为指标的评价模型仅包含有限次初等函数运算，在提升损耗计算精度的同时降低了计算复杂度。其次，考虑中高压大功率变流器低开关频率调制特性与约束机制，以损耗模型为评价标准，优化低速区异步调制策略；揭示矢量合成方式与矢量幅值及角度的映射关系，进一步细化调制度分段区间，优化中速区分段同步调制策略，形成全速域范围损耗抑制调制策略。上述研究成果可有效提升中高压大功率电机驱动系统运行效率与运行性能，在轨道交通牵引系统、舰船推进系统等应用场合具有广泛的应用前景。