Multilevel inverter (MLI) is one of the most efficient power converters which are especially suited for high power applications with reduced harmonics. MLI not only achieves high output power and is also used in renew...Multilevel inverter (MLI) is one of the most efficient power converters which are especially suited for high power applications with reduced harmonics. MLI not only achieves high output power and is also used in renewable energy sources such as photovoltaic, wind and fuel cells. Among various topologies of MLI, this paper mainly focuses on cascaded MLI with three unequal DC sources called asymmetric cascaded MLI which reduces the number of power switches. Various modulation techniques are also reviewed in literature [1]. In this paper we focus on sinusoidal (or) multicarrier pulse width modulation (SPWM) which improves the output voltage at lower modulation index for obtaining lower Total Harmonic Distortion (THD) level. The gating signal for the 13-level hybrid inverter using SPWM technique is generated using Field Programmable Gate Array (FPGA) processor. The proposed modulation technique results in reduced percentage of THD, but lower order harmonics are not eliminated. So a new technique called Selective Harmonic Elimination (SHE) is also implemented in order to reduce the lower order harmonics. The optimum switching angles are determined for obtaining minimum THD. The performance evaluation of the proposed PWM inverter is verified using an experimental model of 13-level cascaded hybrid MLI and compared with MATLAB/SIMULINK model.展开更多
为了缩短对大功率电子装置(如逆变电源)的研制周期和减少研制费用,借助计算机仿真技术,利用Matlab软件中Simulink和Power System B lochset建立了以IGBT(绝缘栅双极性晶体管)为开关器件具有数字PI调压功能的SPWM电压型逆变电源仿真模型...为了缩短对大功率电子装置(如逆变电源)的研制周期和减少研制费用,借助计算机仿真技术,利用Matlab软件中Simulink和Power System B lochset建立了以IGBT(绝缘栅双极性晶体管)为开关器件具有数字PI调压功能的SPWM电压型逆变电源仿真模型,对其输出特性进行仿真,并利用傅里叶快速变换(FFT)分析工具对其仿真输出电压进行谐波分析。仿真模型分别考虑了主电路和控制器模型,较为精确地反映了实际情况,验证了此模型和仿真方法的正确性,同样适用于其他电力电子线路。展开更多
文摘Multilevel inverter (MLI) is one of the most efficient power converters which are especially suited for high power applications with reduced harmonics. MLI not only achieves high output power and is also used in renewable energy sources such as photovoltaic, wind and fuel cells. Among various topologies of MLI, this paper mainly focuses on cascaded MLI with three unequal DC sources called asymmetric cascaded MLI which reduces the number of power switches. Various modulation techniques are also reviewed in literature [1]. In this paper we focus on sinusoidal (or) multicarrier pulse width modulation (SPWM) which improves the output voltage at lower modulation index for obtaining lower Total Harmonic Distortion (THD) level. The gating signal for the 13-level hybrid inverter using SPWM technique is generated using Field Programmable Gate Array (FPGA) processor. The proposed modulation technique results in reduced percentage of THD, but lower order harmonics are not eliminated. So a new technique called Selective Harmonic Elimination (SHE) is also implemented in order to reduce the lower order harmonics. The optimum switching angles are determined for obtaining minimum THD. The performance evaluation of the proposed PWM inverter is verified using an experimental model of 13-level cascaded hybrid MLI and compared with MATLAB/SIMULINK model.
文摘为了缩短对大功率电子装置(如逆变电源)的研制周期和减少研制费用,借助计算机仿真技术,利用Matlab软件中Simulink和Power System B lochset建立了以IGBT(绝缘栅双极性晶体管)为开关器件具有数字PI调压功能的SPWM电压型逆变电源仿真模型,对其输出特性进行仿真,并利用傅里叶快速变换(FFT)分析工具对其仿真输出电压进行谐波分析。仿真模型分别考虑了主电路和控制器模型,较为精确地反映了实际情况,验证了此模型和仿真方法的正确性,同样适用于其他电力电子线路。
