Power Electronics Lab Experiments

To study Series Inverter using MOSFET in Power Electronics Lab

Nov 27 2023

Aim

To study Series Inverter using MOSFET.

Apparatus Required:

S.No.	Apparatus/Software Used	Specification	Range/Rating	Quantity
1
2
3
4
5

Theory & Formulae Used:

The Gate frequency generation circuit is given in Fig-'1'. To operate gate wave circuit +5 DC is developed through diode D10, D11, D12, D13, C7,C8 and IC7. IC1 is stable vibrator VR1 to control its frequency. It will give the output from pin No.3 and fed to IC2 that is JK flip flop and its output will come through pin no.14 & pin No. 15. The frequency at 14 and 15 will half the astable multivibrator frequency. The out¬put from pin no. 15 will feed to pulse generator using IC3. Here IC3 is monostable mul¬tivibrator and gives the pulse to diode side of opto coupler IC4. The opto coupler is given for electrically isolation between gate frequency to Mosfet 1& 2. The output of IC2 (JK flip-flop) pin no. 14 is also fed to another monostable mul-tivibrator using IC5. The output of IC5 from pin no. 3 is fed to optocoupler IC6. For electric isolation every gate pulses generation is required separate isolated +12 V supply, so it's also given in diagram.

Explanation of series Inverter Diagram using MOSFET:Consider the fig. '2', the first gate wave will appear at Mosfet-1. So this MOSFET will fire and current will flow from 110V DC to MOSFET 1, inductor, load & capacitor C2. At the time of appearing the gate wave at MOSFET-2 will remain zero. The current will flow upto the charging of C2 only. Now after disappearing/zeroing the gate wave at Mosfet-1, the gate wave at Mos- fet-2 in opposite direction with respect to previous case. Along with discharging the C2 & C1 charging current will also flow. This path will be 110 V DC, C1, load, inductor and Mosfet-2. The process will repeat.