高功率要求的弦波轉換過程裡 MOSFET遭遇高壓高流極限 因此發展出 Cascaded H-bridge CHB
概念是 將單ㄧ電壓源換成多組串級疊加 每組MOSFET額定電壓voltage rating得以下降
(a) Cascaded H-bridge inverter (n = 1, 2, 3): voltage and current half-waves (p.u.) for staircase modulation in case of (b) five levels and (c) seven levels.
Next stage
Intriduce SPWM Sine pluse width modulation
PS-PWM phase-shifed pluse width modulation