Emi Filter Design And Optimization For Three Phase Motor Drive Systems

Author : Yu Zhang
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (134 download)

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Download or read book Light-Weight Filter Design for Sic Power Inverters in Emi Frequency written by Yu Zhang and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wide bandgap (WBG) semiconductors such as silicon carbide (SiC) and gallium nitride (GaN) devices have received increasing attention over the past two decades due to their better electric and thermal performance. Compared with Si devices, WBG devices have low on-resistance, fast switching speed and high junction temperature capability. These characteristics are beneficial for the efficiency, power density and reliability of power electronics converters. SiC devices mainly target high voltage high power applications (600 V, kilowatts or above). The lower switching loss and higher temperature operation characteristics enable the SiC converter to operate at much higher switching frequency with lower cooling demands. Therefore, the size and weight of the components can be significantly reduced, especially for the power inductors and capacitors. However, the higher switching frequency also makes the electromagnetic interference (EMI) issue more challenging. The electromagnetic noise tends to concentrate in the high frequency range, which overlaps with the EMI frequency (150 kHz to 30 MHz). Thus, higher attenuation is required for the EMI filter design, resulting in larger EMI filter size. Another issue is the high dv/dt associated with WBG devices. In motor drive applications, the high dv/dt will aggravate reflected wave phenomenon, which results in the load voltage being twice of the input voltage, increasing the chance of winding damage. Thus, dv/dt filters are required to reduce the overvoltage at the load terminal. These two issues will offset the benefit of the SiC devices. To reduce the EMI filter size, many methods have been proposed. Compared to the traditional Si inverter, the EMI filter design for SiC inverters has some specific considerations, especially for PV inverters without power inductor. Two approaches are proposed here to reduce the EMI filter size. For DM filter, a notch branch is adopted to reduce the filter size, while the unbalanced Wheatstone bridge is applied to optimize the CM filter design. An active reflected wave canceller (ARWC) is proposed to reduce the overvoltage caused by the reflected wave phenomenon in motor drive application. Compared to other dv/dt filters, this ARWC doesn't change the dv/dt. A small pulse voltage is inserted into the circuit at each rising / falling edge which breaks the rising / falling edge into two steps. The reflected load voltage caused by each step compensates with each other. Thus, no overvoltage appears at the load terminal. Since the pulse width generated by the canceller is very narrow, which is related to the cable length, the power loss is much smaller compared to passive dv/dt filter. With this principle, an ARWC is designed for two-level inverters in low voltage application. A single phase inverter is built to verify its effectiveness. With the same principle, the ARWC is extended to three-level inverter in Medium Voltage (MV) application. Three different topologies are proposed for the ARWC design. The experiment of the proposed ARWC with a single phase three level inverter is conducted to verify its effectiveness. Finally, conclusions are given and the scope of future work is discussed.