Abstract:The relationship between space vector pulse width modulation (SVPWM) and carrier-based PWM methods is comprehensively analyzed. The explicit modulation function expression, in which various continuous and discontinuous SVPWM strategies are intuitively embodied, is established, and a unified carrier-based SVPWM method is presented. Furthermore, a unified SVPWM fast algorithm for three-phase inverters is proposed. The proposed algorithm calculates the actual gating times for each inverter leg directly by use of three-phase reference voltages and needn't complex coordinate transformations, trigonometric function calculations, sector number identification, and the recombination of actual gating times, so it can be more easily implemented with a microprocessor compared with SVPWM conventional algorithm. At last, the output voltage harmonic characteristics of the three-phase inverter under the SPWM and various SVPWM control are investigated. The simulation and experimental results show that the unified SVPWM implementation method for three-phase inverters is feasible and valid.
[1] Vlatkovic V, Borojevic D. Digital-signal-processor- base control of three-phase space vector modulated converters[J]. IEEE Transaction on Industrial Electronics, 1994, 41(3): 326-332. [2] 吴茂刚, 赵荣祥, 汤新舟. 正弦和空间矢量PWM逆变器死区效应分析与补偿[J]. 中国电机工程学报, 2006, 26(12):102-105. [3] Bowes S R, Lai Y S. The relationship between space-vector modulation and regular-sampled PWM[J]. IEEE Transaction on Industrial Electronics, 1997, 44(5): 670-679. [4] Zhou K L, Wang D W. Relationship between space-vector modulation and three-phase carrier-based PWM: a comprehensive analysis[J]. IEEE Transaction on Industrial Electronics, 2002, 49(1): 186-195. [5] Blasko V. Analysis of hybrid PWM based on modified space-vector and triangle-comparison methods[J]. IEEE Transaction on Industry Applications, 1997, 33(3): 756-764. [6] Hava A M, Kerkmen R J, Lipo T A. Simple analytical and graphical methods for carrier-based PWM-VSI drives[J]. IEEE Transaction on Power Electronics, 1999, 14(1): 49-61. [7] 杨贵杰, 孙力, 崔乃政, 等. 空间矢量脉宽调制方法的研究[J]. 中国电机工程学报, 2001, 21(5):79-83. [8] 孙文焕, 程善美, 秦忆. 基于FPGA的空间矢量PWM的实现[J]. 电气传动, 2000, 35(6):21-24. [9] 何罡, 杨耕, 窦曰轩. 基于非标准正交基的空间电压矢量快速算法[J]. 电力电子技术, 2003, 37(6):1-3. [10] 郑琼林, 郝荣泰. 关联指令分区控制脉宽调制技 术[J]. 中国电机工程学报, 2000, 20(6):43-46. [11] 王永, 沈颂华, 吕宏丽, 等. 基于简单电压空间矢量三相逆变器的研究[J]. 电工技术学报, 2005, 20(10):25-29. [12] 周卫平, 吴正国, 唐劲松, 等. SVPWM的等效算法及SVPWM与SPWM的本质联系[J]. 中国电机工程学报, 2006, 26(2):133-137. [13] Chung D W, Kim J S, Sul S K. Unified voltage modulation technique for real-time three-phase power conversion[J]. IEEE Transaction on Industry Applications, 1998, 34(2): 374-380. [14] Trzynadlowski A M, Kirlin R L, Legowski S F. Space vector PWM technique with minimum switching losses and a variable pulse rate[J]. IEEE Transaction on Industrial Electronics, 1997, 44(2): 173-181.