|
Abstract: |
An analytical evaluation method for output waveform quality of space vector pulse width modulation (PWM) strategies applied in neutral-point-clamped three-level converter (3L-NPC) is proposed in this paper. Low frequency error caused by neutral point voltage ripple and high frequency error introduced by space vector synthesis were both taken into account, and the unified error model of output current ripple was established. By taking continuous and discontinuous modulation strategies as examples, the unified error model was validated through Fourier analysis of the experimental results. The proposed evaluation method will be helpful for the switching sequence optimization and the modulation strategy selection. |
Key words: neutral-point-clamped (NPC), three-level (3L) converter, space vector modulation (SVM), neutral point voltage ripple, output waveform quality |
DOI:10.11916/j.issn.1005-9113.20026 |
Clc Number:TM301.2 |
Fund: |
|
Descriptions in Chinese: |
中点箝位型三电平变流器输出波形质量评价方法 张国政1 , 夏长亮1, 2 (1. 高效能电机系统智能设计与制造国家地方联合工程研究中心, 天津工业大学 天津 300387; 2. 电气工程学院 浙江大学, 杭州 310058) 中文说明:本文以中点箝位型三电平变流器为对象,针对空间矢量调制策略,提出一种变流器输出波形质量精确评价方法。该方法充分考虑直流侧中点电压波动这一中点箝位型变流器固有特性,通过建立同时考虑中点电压波动低频误差与空间矢量合成高频误差的统一误差模型,实现对变流器输出波形质量的精确量化评估。以通过傅里叶分析得到的输出电流总需求谐波畸变率为参照,并以连续调制与不连续调制方法为例,验证了本文所提评价方法的正确性与有效性。本文所提评价方法对中点箝位型变流器不同调制度工况下调制方法的选择及开关序列的优化设计具有指导意义。 关键词:中点箝位,三电平变流器,空间矢量调制,中点电压波动,输出波形质量 |