MY Training at TexasInstruments Made by: anurag Kinger 4 th year ( eCe) 101086002
Inverter Design Topologies HF Inverter LF Inverter ( Analog and with MCU) 100 VA InverterOthers Projects and Key Learnings Works Feedbacks and Suggestions….
High Frequency Low FrequencyBased Upon Output Waveforms Square Wave Inverter Modified Sine Wave Inverter Pure Sine Wave Inverter
It has following Main Parts DC-DC Converter Inverter Bridge and Buck Switches Current and Voltage sense Circuit Driver Section Sense and Protection Circuit Auxiliary Power Supply DSP Section
Microcontroller for PWM Current and generating PWMs, for Voltage Sense Level Sense and other Boost Circuits Control Circuits PWM for 50 HZ AC generation PWM duringFilter and Noise Relay & Switch O/P chargingrejection circuit Over circuitFull Bridge Current Fed Half Bridge forCircuits for HF transformer Push Pull Charging State50 Hz Ac Circuit IGBTs Generation +15 V Auxiliary Power +5V Supplies Battery (+12V) -5V
•AC Input Range : 180V to 265V• Relay : ON• Inverter : OFF• AC Output : Same as Input• Battery Mode : Charging• Charger IGBTs : SWITCHING• Inverter IGBTs : OFF• Mode : Buck
Switchover Load CircuitACMAINS AC Mains Sense Microcontroller Battery Inverter IGBTs Charging Internal diode Buck Circuit IGBTs Acting as Rectifier
AC Input : OFF Relay : OFF Inverter : ON AC Output : 200V-240V,50Hz,Sine wave Battery Mode : Discharging Charger IGBTs : OFF (acts as Rectifier) Inverter IGBTs : SWITCHING Mode : Boost
NO MAINS AC MainsLoad Sense MicrocontrollerSwitch OverCircuitFilter and Current Fed Inverter DoublerNoise Push Pull Battery Bridge Rectifiercanceller Boost Mode
Proper care should be taken to up DC-DC Convertor Debugging is very difficult at very high voltage. Controller waveforms should be in proper phasing. Otherwise short circuit can happen. Auxiliary supplies should be stable and proper, otherwise controller and Driver circuit will not work properly.
Higher efficiency Less weight use high frequency transformers, much smaller and a lot cheaper as compared to the ones used in LF.More complex as compared to LF .
Working Operation Challenges faced During Design Advantages and Disadvantage
Load H-Bridge SwitchLDO Controller Full Bridge Over Driver Circuit Mains Sensing & Switching
AC Input: 180V to 265V to charge battery AC Output: Same as AC Input (Inverter will be off) Battery Mode: Charging Charger output: 1. CV: 13.7V 2. Max Current: 15Amp (150Ah can be charged @ c/10 rate)
Switch Over Load CircuitAC Mains AC Mains ControllerPresent Sense Transformer H-Bridge
AC Input: Off AC Output: 200V -240V, 50Hz, Sine wave Sine Distortion: < 5% (typical) Frequency: 50Hz +/- 0.01Hz Battery Mode: Discharging Battery Voltage: 12V +/-10% Max output power: 800 VA Efficiency: 70% (typically)
Waveforms should be in proper phasing with each other. Enough dead time should be there AC Input to AMC should be less than +/- 250mV and Auxiliary supply should be given to primary side of AMC otherwise it wont work in absence of AC. Regulation loop should be fast. Design of current sense circuit with SM72295 should be done with proper care.
LF design is less complex as compared to HF design. Simple design is there, so need less costly controller Good galvanic Isolation between AC and DC• LF inverter are bulkier due to use of very heavy and big transformer• Efficiency is very less
It consists of the following Parts Sine Wave and PWM generation (Using Analog Circuit) Driver Circuit (SM 72295) H-Bridge Circuit Protection Circuit Current Sense and Amplifier circuit Switchover Circuit
Current ProtectionSine Wave PWM generation Sense circuitGenerator 4 PWM drives (inverter) MUX 2 DrivesDC value as (charging) Driver CircuitProportional SM72295To input AC Goes for protection circuit Clamper Battery and regulation H-Bridge Circuit Regulation AMC Circuitry Mains AC mains Transformer Sense FilterOutput Voltage Sense for inverter Switchover Load
Create a DC levelAC input AMC Compare with 1100 reference Provides isolation Invert and provide delay lay inv re er t Mains Or Charging Inverter mode Waveform Or inverter waveform
4th order Square wave Butterworth Sine wavegenerated at 50Hz filter generated DC Value from Charging INV MUX AC Sense Circuit DC value Comparator Generator 180 phase shift And PWM And dead time Generator generator Ramp Generator AH AL BH Generation of PWM waves BL
Input PWM SM 72295 CurrentDrives Driver IC Sense input Switch Driver Over voltage off Output Protection Gate Circuit Drives Current sense Output to Regulation Loop Transformer H-Bridge CircuitAC BatteryMains Relay and Switchover Ckt Load
Boost Circuit Drive and Full Bridge Circuit Switchover Circuit Charging Circuit Controller Section Sense and Protection Circuit
Load, Mains, Current and Voltage Sense Sense and Protection MicrocontrollerAC Mains Circuit Section Switchover signal PWM for Switchover PWM for charging Circuit Boost LOAD Charging Section Drive and Full Bridge Boost Circuit Battery +12 V Circuit