GRID TIED INVERTER

Project Title

GRID TIED INVERTER

Project Area of Specialization Electrical/Electronic EngineeringProject Summary

Project theme:

Due to shortage of power generation in pakistan our aim is to design mulltilevel level inverter  for increasing the capacity of national grid by producing our own power and then supplying to our national grid .

Background:

Due to the shortage of fossil fuels and environmental problems caused by conventional power generation, renewable energy, particularly solar energy, has become very popular. Solar-electric-energy demand has grown consistently by 20%– 25% per annum over the past 20 years, and the growth is mostly in grid-connected applications. With the extraordinary market growth in grid connected photovoltaic (PV) systems, there are increasing interests in grid-connected PV configurations.

Project Objectives

Objective :

• To obtain 220-240 V at inverter output and tie grid to the designed system.
•  To solve the frequency and phase mismatch problem using PLL circuit.

Project Implementation Method

                                                                                     

                                                                                                                                          project implementation diagram 

• First we need a DC source that may be (PV panel ,battery etc).
• We will then design  the inverter .
• Inverter is fed by DC source.
• We wiil use step up  transformer (24:220V) .
• For controlling and monitoring we will use PID controller and PLL circuitory .
• After proper synchronization The grid-tie inverters connect the local electrical generators such as hydroelectric, wind turbine, and solar panel with the grid. They are responsible for converting the direct current into  the alternating current. A good-quality grid-tie inverter maintains the output voltage higher than the voltage of the grid. Some of the grid tie inverterhave a fixed power factor which basically means that their current  and the voltage are perfectly lined up.
• The homeowners can use the alternative power generation source such as wind or solar power without the need of batteries and exhaustive wiring. In the case of alternative power not being sufficient, the power from the grid compensates the shortage of it.we will  tie the inverter with the grid.

Benefits of the Project

• The grid-tie inverters connect the local electrical generators such as hydroelectric, wind turbine, and solar panel with the grid.
• They are capable  for converting the direct current into the alternating current.
• A good-quality grid-tie inverter maintains the output voltage higher than the voltage of the grid. 

Cascaded inverters consist of several converters connected in series; thus, the high power and high voltage from the combination of the multiple modules would favor this topology in medium and large grid-connected PV systems. Similarly, cascaded inverter would maintain the benefits of “one converter per panel,” such as better utilization per PV module, capability of mixing different sources, and redundancy of the system. Major challenges in grid tie inverter are low total hormonic distortion (THD) and mismatch of phase and frequency. As per IEEE Standard the total hormonic distortion (THD) of the inverter should be less than 5% in order to feed power to grid similarly mismatch of frequency and phase may turn grid-tie-inverter into a load to grid. The cascaded multilevel inverter topology consists of H-bridge converters connecter in series . Each DC link is fed by a short string of PV panels. By different combinations of the fourswitchesin each H-bridge, three output voltage levels can be generated, –vdc, 0, or +vdc. A cascaded multilevel inverter with n input sources will provide 2n+1 level to synthesize the AC output waveform. This (2n+1)-level voltage waveform enables the reduction of harmonics in the synthesized current, reducing the output filters. Multilevel inverters also have other advantages such as reduced voltage stresses on the semiconductor switches, as well as having higher efficiency when compared to other converter topologies. As shown in Fig. 6, the cascaded multilevel inverter is connected to the grid through an L filter, which is used to reduce the switching harmonics in the current. There is also a local load connected in parallel. PV power is delivered to the load/grid according to the system operation conditions.

Technical Details of Final Deliverable

Cascaded inverters consist of several converters connected in series; thus, the high power and high voltage from the combination of the multiple modules would favor this topology in medium and large grid-connected PV systems. Similarly, cascaded inverter would maintain the benefits of “one converter per panel,” such as better utilization per PV module, capability of mixing different sources, and redundancy of the system. Major challenges in grid tie inverter are low total hormonic distortion (THD) and mismatch of phase and frequency. As per IEEE Standard the total hormonic distortion (THD) of the inverter should be less than 5% in order to feed power to grid similarly mismatch of frequency and phase may turn grid-tie-inverter into a load to grid. 

                                                                            

                                                                                                                   schematic circuit of  grid tie inverter

Final Deliverable of the Project HW/SW integrated systemCore Industry Energy Other Industries Education Core Technology Clean TechOther TechnologiesSustainable Development Goals Affordable and Clean EnergyRequired Resources

Item Name	Type	No. of Units	Per Unit Cost (in Rs)	Total (in Rs)
			Total in (Rs)	20731
transistor	Equipment	8	150	1200
battery	Equipment	2	4500	9000
transformer	Equipment	1	350	350
PCB	Equipment	1	1200	1200
inductor	Equipment	1	150	150
capacitor	Equipment	1	150	150
controller	Equipment	1	2000	2000
prototype board	Equipment	1	1500	1500
fuel	Miscellaneous	9	109	981
lcd display	Equipment	1	700	700
connecting wires	Equipment	1	1000	1000
other hardware cost	Equipment	1	1000	1000
thesis binding and printing	Miscellaneous	1	1500	1500