Topic20Main contentsConverter based Power Factor Correction
Main contents • Converter based Power Factor Correction Topic 20
18-6-3 Interface for a Bidirectional power flow1 Thyristor Converters for 4-Quadrant OperationLd260-Hz?acinputCdUdFigure 18-7 Back-to-back connected converters forbidirectional powerflow.>The input current is has a distorted and the powerfactorislow
18-6-3 Interface for a Bidirectional power flow 1 Thyristor Converters for 4-Quadrant Operation ➢The input current is has a distorted and the power factor is low
2 Switch-Mode Converter Interface ☆（开关模式变流器、PWM变流器）DUdDonFigure18-8Switch-modeconverterfor the utility interface>
2 Switch-Mode Converter Interface ☆ (开关模式变流器、PWM变流器) Vd Vs ˆ
T1 1T3JD3eLD1A+VLVsV=CdVconvBOC2T4T2北FD.DoSingle-phasevoltage sourcePWM converter(1)各元件的作用☆单相电压型PWM变流器①支撑电容Cd：用于滤波，使直流侧电压恒定。②交流侧电感Ls：承担vs与Vcony之间的电压差，实现对输入电流相位的调节从而实现对功率因数的调节，同时也限制交流侧谐波电流diV. =V.+VLVIconvSdt
D1 D3 D2 D4 Single-phase voltage source PWM converter 单相电压型PWM变流器 T1 T3 T2 T4 is Ls vs A B L2 C2 Cd + - Vd + vL - vconv ① 支撑电容Cd：用于滤波，使直流侧电压恒定。 ② 交流侧电感Ls：承担vs与vconv之间的电压差，实现对 输入电流相位的调节从而实现对功率因数的调节，同时 也限制交流侧谐波电流。 (1) 各元件的作用☆ dt dis s conv L L s v = v + v v = L
+3TD3LDA+VLVd=CdconvOPS0Single-phasevoltagesourcePWMconverter单相电压型PWM变流器③二次滤波回路L2、C2：用于提供2次谐波电流通路，限制直流侧二次谐波电流，从而减小v中的二次谐波电压。其谐振频率为基波频率的2倍
③二次滤波回路L2、C2：用于提供2次谐波电流通路，限制直 流侧二次谐波电流，从而减小vd中的二次谐波电压。其谐振 频率为基波频率的2倍。 D1 D3 D2 D4 Single-phase voltage source PWM converter 单相电压型PWM变流器 T1 T3 T2 T4 is Ls vs A B L2 C2 Cd + - Vd + vL - vconv