Off Grid Solar Three Phase Multilevel Inverter

Project Title

Off Grid Solar Three Phase Multilevel Inverter

Project Area of Specialization Shared EconomyProject Summary

Implemented an efficient and cost  effective Cascaded Switch Ladder Multilevel Inverter for Smart Grid application. Optimized use of hardware and DC links to generate the maximum levels in the output. Generated the output having very less total harmonic distortion and made it effective for grid connectivity.

Project Objectives

• To design the highly efficient inverter in order to make it versatile enough for grid connectivity.
• To make it suitable for interfacing with different renewable resources.
• To minimize the switching losses and voltage stress on electronic switches.
• To make the inverter cost-effective with the removal of expensive active filters for producing low harmonic distortion in the output.

Project Implementation Method

1. Switching Sequence is generatedto implement 17-level inverter. For this purpose, Sampling based PWM technique is implemented using MATLAB.
2. Gate Driver Circuit is required to drive the electronic switches along with providing the isolation to the micro-controller from the remaining circuit.
3. Cascaded Switch Ladder Multilevel Inverter Structure consists of 10 electronic switches per phase. The switching circuit is driven by the gate driver circuit through the switching sequence provided by Arduino.
4. Four interfacing DC Links are required per phase which can be minimized to three by using the capacitive voltage divider for two low voltage sources.

Benefits of the Project

• Less THD as compared to conventional inverters that is 4.1%(less than IEEE standand which is 5%).
• No use of Step up transformer.
• The inverter can be used for high voltage system interconnections.
• Can be used in electric vehicle drives and motor drives.
• Suitable for interfacing with different renewable energy resources.
• Applicable for domestic renewable energy systems.
• Medium voltage and high power industrial loads.

Technical Details of Final Deliverable

• Development of Gate signal via Arduino
• Isolation and Amplification of Gate signal via gate driver circuit using TLP 250
• Amplified Signal is given to the bridge circuit (consist of 10 igbts, with two bi-directional and eight unidirectional switches).
• 12 vols signal is given to the converters which step up the voltages upto required level.
• The stepup voltages are given to bridge circuit
• Bridge circuit then converts these voltages into a 17 level Quasi Sine wane with THD 4.1%.

Final Deliverable of the Project HW/SW integrated systemType of Industry Energy Technologies OthersSustainable Development Goals Affordable and Clean EnergyRequired Resources

Item Name	Type	No. of Units	Per Unit Cost (in Rs)	Total (in Rs)
			Total in (Rs)	68100
TLP 250	Equipment	30	90	2700
Connectors	Equipment	60	5	300
Capacitor	Equipment	40	3	120
2w10	Equipment	30	5	150
FGA25N120	Equipment	35	180	6300
7815	Equipment	30	15	450
Transformer(for Gate signals)	Equipment	15	90	1350
Ic base	Equipment	30	5	150
Connectors(15 pin)	Equipment	7	30	210
led	Equipment	35	2	70
Solar Panels	Equipment	3	6500	19500
Converters	Equipment	12	1500	18000
Arduino UNO	Equipment	3	550	1650
PCB	Equipment	6	1300	7800
Heat Sink	Equipment	30	10	300
wire	Equipment	1	50	50
DSO-138	Miscellaneous	1	3000	3000
PCB(Prototype)	Miscellaneous	6	1000	6000