Conducted electromagnetic interference (EMI) from a 7.5kVA DC/DC high power converter is investigated to agree with EN class A. Here in some passive methods of suppressing conducted EM Noise, such as mixed-mode (MM) E...Conducted electromagnetic interference (EMI) from a 7.5kVA DC/DC high power converter is investigated to agree with EN class A. Here in some passive methods of suppressing conducted EM Noise, such as mixed-mode (MM) EMI filters, snubbing circuits and other means, are used. Based on measurement, the sources of noise are detected with the characteristics analyzed in detail. The MM EMI filters is valuable means with which low-frequency part and some of the high frequency part of conducted EM Noise can be efficiently reduced. How to lay out the MM filters on both sides of the converter is outlined in detail. In addition, multiple grounding and RDC snubbing circuits are employed to improve the performance in high frequency. The experimental results confirm the methods adopted.展开更多
This paper addresses the principle and control topology of active pow er filter( APF). The control strategy of direct pow er control based on DC side is introduced,and the control output is implemented by using the pr...This paper addresses the principle and control topology of active pow er filter( APF). The control strategy of direct pow er control based on DC side is introduced,and the control output is implemented by using the principle of hysteresis control.The active pow er filter can effectively control the pow er system harmonics,improve the quality of electricity and purify pow er grid. The experimental results are provided to illustrate that the direct pow er control based on DC side has the advantages of simple structure,stable DC output voltage and fast dynamic response.展开更多
In industries DC motor drives are very essential due to their high performance applications such as its reliability, ease of control, low cost and simplicity. And speed control of these motors is very easy due to powe...In industries DC motor drives are very essential due to their high performance applications such as its reliability, ease of control, low cost and simplicity. And speed control of these motors is very easy due to power electronic AC-DC converters. These power electronic converters are with prominent low power factor and higher Total Harmonic Distortion (THD). These converters operate only for short time resulting non-sinusoidal waveform. This problem of harmonic distortion can be mitigated by reshaping the non-sinusoidal waveform to pure sine wave. Different wave shaping techniques have been developed by using different filters among which one is tuned passive filter. This paper proposed power factor improvement and harmonic mitigation of AC-DC converters based on separately excited DC motor using tuned passive filter. In this context experimental model is designed and results are analyzed by power quality analyzer.展开更多
针对已有串联结构有源滤波器(active DC filter,ADF)的不足,分析了HVDC系统中直流ADF基本原理后,提出了一种低成本的结合有、无源滤波方案,保证滤波器有源模块不承受直流电压,不流过直流电流,有效降低ADF装置容量的串联混合型结构;从传...针对已有串联结构有源滤波器(active DC filter,ADF)的不足,分析了HVDC系统中直流ADF基本原理后,提出了一种低成本的结合有、无源滤波方案,保证滤波器有源模块不承受直流电压,不流过直流电流,有效降低ADF装置容量的串联混合型结构;从传递函数角度建立ADF系统数学模型,将消谐控制方法用于ADF,分析其补偿原理;初步分析ADF设备与无源滤波PF设备的配合使用情况,以进一步减小有源滤波装置容量。仿真和实验结果验证该方案的有效性。展开更多
文摘Conducted electromagnetic interference (EMI) from a 7.5kVA DC/DC high power converter is investigated to agree with EN class A. Here in some passive methods of suppressing conducted EM Noise, such as mixed-mode (MM) EMI filters, snubbing circuits and other means, are used. Based on measurement, the sources of noise are detected with the characteristics analyzed in detail. The MM EMI filters is valuable means with which low-frequency part and some of the high frequency part of conducted EM Noise can be efficiently reduced. How to lay out the MM filters on both sides of the converter is outlined in detail. In addition, multiple grounding and RDC snubbing circuits are employed to improve the performance in high frequency. The experimental results confirm the methods adopted.
文摘This paper addresses the principle and control topology of active pow er filter( APF). The control strategy of direct pow er control based on DC side is introduced,and the control output is implemented by using the principle of hysteresis control.The active pow er filter can effectively control the pow er system harmonics,improve the quality of electricity and purify pow er grid. The experimental results are provided to illustrate that the direct pow er control based on DC side has the advantages of simple structure,stable DC output voltage and fast dynamic response.
文摘In industries DC motor drives are very essential due to their high performance applications such as its reliability, ease of control, low cost and simplicity. And speed control of these motors is very easy due to power electronic AC-DC converters. These power electronic converters are with prominent low power factor and higher Total Harmonic Distortion (THD). These converters operate only for short time resulting non-sinusoidal waveform. This problem of harmonic distortion can be mitigated by reshaping the non-sinusoidal waveform to pure sine wave. Different wave shaping techniques have been developed by using different filters among which one is tuned passive filter. This paper proposed power factor improvement and harmonic mitigation of AC-DC converters based on separately excited DC motor using tuned passive filter. In this context experimental model is designed and results are analyzed by power quality analyzer.
文摘针对已有串联结构有源滤波器(active DC filter,ADF)的不足,分析了HVDC系统中直流ADF基本原理后,提出了一种低成本的结合有、无源滤波方案,保证滤波器有源模块不承受直流电压,不流过直流电流,有效降低ADF装置容量的串联混合型结构;从传递函数角度建立ADF系统数学模型,将消谐控制方法用于ADF,分析其补偿原理;初步分析ADF设备与无源滤波PF设备的配合使用情况,以进一步减小有源滤波装置容量。仿真和实验结果验证该方案的有效性。
