In order to output sine wave with small degree of distortion and improve stability,a type of inverter power supply is designed based on harmonic elimination pulse-width modulation(PWM)control.The rectifier and filter ...In order to output sine wave with small degree of distortion and improve stability,a type of inverter power supply is designed based on harmonic elimination pulse-width modulation(PWM)control.The rectifier and filter are added to input circuit of the inverter.Single-phrase full-bridge inverter performs the function of converting direct current into alternating current(DC/AC).In the control circuit,single chip micyoco(SCM)AT89C2051 is used for main control chip to accomplish the hardware design of the control system.A given value of output frequency of the inverter is input in the way of coding.According to the output frequency code which is read,SCM AT89C2051 defined harmonic elimination PWM control data which will be selected.Through internal timing control,the switches are switched under this provision of PWM control data.Then the driving signals of the switches in the inverter are output from I/O of SCM AT89C2051 to realize harmonic elimination PWM control.The results show that adding Newton homotopic algorithm of harmonic elimination PWM control to corresponding software of the control system can make the quality of output voltage of the inverter higher and it will have broad application prospects.展开更多
This paper presents a unique voltage-raising topology for a single-phase seven-level inverter with triple output voltage gain using single input source and two switched capacitors.The output voltage has been boosted u...This paper presents a unique voltage-raising topology for a single-phase seven-level inverter with triple output voltage gain using single input source and two switched capacitors.The output voltage has been boosted up to three times the value of input voltage by configuring the switched capacitors in series and parallel combinations which eliminates the use of additional step-up converters and transformers.The selective harmonic elimination(SHE)approach is used to remove the lower-order harmonics.The optimal switching angles for SHE is determined using the genetic algorithm.These switching angles are com-bined with a level-shifted pulse width modulation(PWM)technique for pulse generation,resulting in reduced total harmonic distortion(THD).A detailed com-parison has been made against other relevant seven-level inverter topologies in terms of the number of switches,drivers,diodes,capacitors,and boosting facil-ities to emphasize the benefits of the proposed model.The proposed topology is simulated using MATLAB/SIMULINK and an experimental prototype has been developed to validate the results.The Digital Signal Processing(DSP)TMS320F2812 board is used to generate the switching pulses for the proposed technique and the experimental results concur with the simulated model outputs.展开更多
针对基于传统特定谐波消除调制(SHEPWM)的三电平NPC逆变器的中点电压波动问题,分析了相电压中基波与三次谐波对中点电压波动的影响。建立了中点电压与三次谐波含量之间的关系,提出了基于三次谐波定量控制的改进SHEPWM方法,通过引入三次...针对基于传统特定谐波消除调制(SHEPWM)的三电平NPC逆变器的中点电压波动问题,分析了相电压中基波与三次谐波对中点电压波动的影响。建立了中点电压与三次谐波含量之间的关系,提出了基于三次谐波定量控制的改进SHEPWM方法,通过引入三次谐波控制方程重构SHEPWM开关角求解方程,并在此基础上以最大化程度抑制中点电压波动为目的,推导出了最优的三次谐波含量,在Matlab/Simulink平台上搭建了2 MW/3 k V逆变器并网模型,对改进SHEPWM方法的中点电压波动抑制效果进行了测试。研究结果表明:利用基于三次谐波最优含量控制的改进SHEPWM方法,能有效抑制中点电压的低频波动,提高NPC逆变器输出性能,降低直流环节电容。展开更多
文摘In order to output sine wave with small degree of distortion and improve stability,a type of inverter power supply is designed based on harmonic elimination pulse-width modulation(PWM)control.The rectifier and filter are added to input circuit of the inverter.Single-phrase full-bridge inverter performs the function of converting direct current into alternating current(DC/AC).In the control circuit,single chip micyoco(SCM)AT89C2051 is used for main control chip to accomplish the hardware design of the control system.A given value of output frequency of the inverter is input in the way of coding.According to the output frequency code which is read,SCM AT89C2051 defined harmonic elimination PWM control data which will be selected.Through internal timing control,the switches are switched under this provision of PWM control data.Then the driving signals of the switches in the inverter are output from I/O of SCM AT89C2051 to realize harmonic elimination PWM control.The results show that adding Newton homotopic algorithm of harmonic elimination PWM control to corresponding software of the control system can make the quality of output voltage of the inverter higher and it will have broad application prospects.
文摘This paper presents a unique voltage-raising topology for a single-phase seven-level inverter with triple output voltage gain using single input source and two switched capacitors.The output voltage has been boosted up to three times the value of input voltage by configuring the switched capacitors in series and parallel combinations which eliminates the use of additional step-up converters and transformers.The selective harmonic elimination(SHE)approach is used to remove the lower-order harmonics.The optimal switching angles for SHE is determined using the genetic algorithm.These switching angles are com-bined with a level-shifted pulse width modulation(PWM)technique for pulse generation,resulting in reduced total harmonic distortion(THD).A detailed com-parison has been made against other relevant seven-level inverter topologies in terms of the number of switches,drivers,diodes,capacitors,and boosting facil-ities to emphasize the benefits of the proposed model.The proposed topology is simulated using MATLAB/SIMULINK and an experimental prototype has been developed to validate the results.The Digital Signal Processing(DSP)TMS320F2812 board is used to generate the switching pulses for the proposed technique and the experimental results concur with the simulated model outputs.
文摘针对基于传统特定谐波消除调制(SHEPWM)的三电平NPC逆变器的中点电压波动问题,分析了相电压中基波与三次谐波对中点电压波动的影响。建立了中点电压与三次谐波含量之间的关系,提出了基于三次谐波定量控制的改进SHEPWM方法,通过引入三次谐波控制方程重构SHEPWM开关角求解方程,并在此基础上以最大化程度抑制中点电压波动为目的,推导出了最优的三次谐波含量,在Matlab/Simulink平台上搭建了2 MW/3 k V逆变器并网模型,对改进SHEPWM方法的中点电压波动抑制效果进行了测试。研究结果表明:利用基于三次谐波最优含量控制的改进SHEPWM方法,能有效抑制中点电压的低频波动,提高NPC逆变器输出性能,降低直流环节电容。
