This project describes the design of a hybrid filter in the single-phase inverter with CPPM. Under the CPPM strategy, the output CMV of the inverter will be only two levels in all cases. So the active CM filter in the hybrid filter is designed to be a simple half-bridge structure, which can be used to counteract almost all the CMV. a hybrid filter is presented to reduce the CM voltage (CMV) and the differential-mode (DM) harmonics in a single-phase inverter with carrier peak position modulation (CPPM). Because the use of CPPM strategy in the inverter can ensure that the output CMV will be only two levels in any condition, the simple active CM filter (composed of a half-bridge circuit) in the hybrid filter can effectively suppress the output CMV and CM current. In Pulse Width Modulation (PWM) Inverters, the peaks of output Common Mode Voltage (CMV) are very high due to the instantaneous imbalance of Phase Voltages. The CMV will produce a huge pulsating Common Mode Current (CMC) through the distributed capacitance of the system and will cause the high shaft voltage leads to damage of the motor bearing. The CMC could interfere with the adjacent devices along the ground wire and even will result in the wrong operation of the devices. The Differential Mode (DM) is conducted on the signal line and ground line in the opposite direction to each other, which causes harmonics there by noise in the line and will, distorts the system. In this paper, a Hybrid filter is used to reduce the CMV and DM harmonics in a three-phase inverter with Carrier Peak Position Modulation (CPPM).In the proposed scheme, hybrid filter is implemented for Photovoltaic (PV) based inverter fed  single Phase Induction motor is proposed.    

Components Used:

• Step-down transformer.
• Charging circuit.
• Rechargeable battery.
• Carrier peak position modulation.
• Inverter
• Single phase Induction motor.

 

Block diagram:

video: