Design and Simulation of a Transformer Coupled Push-Pull Inverter and Matrix Converter Types Smart Solar Grid System

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Design and Simulation of a Transformer Coupled Push-Pull Inverter and Matrix Converter Types Smart Solar Grid System

S. Preethi Sai

Dept of EEE-PITS

  1. Shanmuga Priya Assistant Professor Dept of EEE-PITS

    1. Azhagunila

Dept of EEE-PITS

Abstract:- This research paper deals with the design and simulation of facile and robust AC voltage originator using a solar power. PV technology is used for generating DC voltage as solar power is very reliable source. Push-pull inverter is used to convert the DC to AC as well as enhanced the magnitude of single phase signal. Matrix converter is also used to convert the single phase AC to three-phase AC signal. LCL filters are used to suppress transient and harmonic distortion of AC signals and made it pure sinusoidal output. MOSFET are used as switching circuitry for push-pull inverter. Pulse generators are affixed for triggering the MOSFET switches. Consecutive tests are performed.

INTRODUCTION

Energy crisis is an alarming issue all over the world. The demand of the energy resources minute electricity is facing a rapid increase. Such hasty increase in electricity demand, using conventional electricity generation techniques, such as burning the fossil fuel, is no longer a solution to this crux. Moreover, burning the fossil fuel will result environmental problems. The emission of carbon dioxide, methane and other greenhouse gasses will result in global warming. Most of the researchers have focused their concentration on renewable energy and researchers are actively looking for cost effective solution of energy crisis. Solar energy is one of the potential sources which are preferred over other renewable sources due to availability, ingenuousness, lower maintenance and reliability. Photovoltaic (PV) arrays drastically reduce energy expenditure and dependability on other non-renewable energy sources. It can provide a worthy, cost effective solution for consumers requiring large amount of power. Due to these reasons, solar energy can be an effective solution for the power crisis in the world.

METHODOLOGY

The main view of this project is to analyze and simulate AC power supply and to synchronize with the grid output. Synchronizing the frequency, magnitude and phase with the grid might be proved tricky. An appropriate PV array is designed to meet the requirements of the conventional AC signal characteristics of Bangladesh. Transformer coupled push-pull inverter converts DC to AC voltage as well as increases the magnitude. LCL filters are used for a smooth single-phase output. Using a matrix converter, the single

phase output can be converted into a three phase output. The three phase output from the matrix converter will be passed through LCL filter to remove harmonic distortion. . The output will then be supplied on various loads for example: resistive load, capacitive load and inductive load. After that the output voltage and current graphs is analyzed as it varies in different load.

VARYING IRRADIANCE /

TEMPERATURE

Here, it is shown the variation of irradiance of sun with respect to time as well as temperature of the panel. The irradiance was varied between 25°C to 55°C.

SELECTION OF PV PANEL

A photovoltaic array is the complete Power generating unit, consisting of any number of PV panels. 1Soltech 1STH- 215-

WH panels were used in the research. Each panel parameters are: Short circuit current,

I sh =9.4 A

Open circuit voltage, V oc =51.5 V Voltage at maximum power, V mp =110 V Current at maximum power, I mp =8.13 A Shunt Resistance R sh =47.9694

Series Resistance R s =0.2282 Number of parallel strings used: 1

Number of Series-connected modules per string: 3 Inverter Switching Pulse Generator

Parameters

Two pulse generators are being used for constructing a push-pull inverter. Two pulses were triggered the switches continuously and made square AC output [3, 11]. The parameters for the switching pulse 1 are:

Amplitude=1 V Time Period=0.02 s

Pulse width=50 (% of period) Phase delay=0 s

The parameters for the switching pulse 2 are: Amplitude=1 V

Time Period=0.02 s

Pulse width=50(% of period) Phase delay=0.01 s

By using a time period 0.02 secs, the frequency of the wave is 50 Hz which is equal to the grid frequency.

LCL FILTER

Following parameters have considered and determined for suppressing harmonic distortion and attained splendid AC output [3, 11].

f=Where,

f is frequency (Hz) L is inductance (H) C is capacitance (F)

F= 50 Hz and L= Assume, C= 50 µF

Thus value of L=202 mH

Here, L2= the coefficient can vary from

0.5 to 1.0

From this, we can calculate L1=600 mH and L2=300 mH approximately.

Gate Pulse Logic of Matrix Converter

It is essential to generate six pulse generating signals for three bidirectional switching cells corresponding to three phase output of the single phase to three phase converter. Two gate signals for each bidirectional switching cell. The gate signal waveforms for six switches of single phase to three phase converter operating in 120 degree conduction modes can be suitable for generating through logic circuits for reduced pulse duration [12].

The parameters for the pulse generators are all the same except the phase delay.

Amplitude=1 V Time Period=0.02 s

Pulse width=50(% of period) Phase delays for three couple of switches are as bellow:

The first two pulse generators named pulse generator 1 and pulse generator

2 Phase delays 0 s and 0.01 s, respectively. The next two pulse generators named pulse generator 3 and pulse generator 4

Phase delays 0.0067 s and -0.0033 s, respectively.

The last two pulse generators named pulse generator 5 and pulse generator 6

Phase delays -0.0067 s and 0.0033 s, respectively.

SIMULATION CIRCUIT

The total simulation of this research paper has done by MATLAB Simulink version

16. The simulation of PV array, Single phase push-pull inverter, Single phase LCL filter, Matrix converter.

PUSH-PULL INVERTER

The specific Simulink model of single phase push-pull inverter is given below in Figure 3.

This was used for converting Solar power generated DC to Single-phase rectangular AC.

LCL FILTER

The simulation model of LCL filter consisting of capacitor and inductor is illustrated in Figure 4. This type of filter is used for converting rectangular AC output of push-pull inverter to pure sinusoidal AC.

MATRIX CONVERTER

The simulation model of LCL filter consisting of capacitor and inductor is illustrated in Figure 4. This type of filter is used for converting rectangular AC output of push-pull inverter to pure sinusoidal AC.

THREE PHASE LCL FILTER

Three phase LCL filter Simulink design is shown in Figure

  1. It can feed to the Matrix converter output to suppress the harmonic distortion of three phase AC signal.

    The simulation output of Photovoltaic array is depicted in below figures. The I-V and P-V characteristics of Solar cell have exhibited the current (A) and power (W) ofthis proposed project in Figure 7. The pure DC voltage is slightly higher than 100 V and DC current is nearly 7.8 A shown inFigure 8.

    INVERTER GATE PULSE

    Two switching gate pulses of push-pullinverter are demonstrated below in Figure 9.

    Here phase delay between two gate pulses is 0.01s which is used for generating singlephase AC output.

    PUSH-PULL INVERTER OUTPUT

    Push-Pull inverter generates square AC output. Peak voltage is almost 312 Vol and peak current is almost 3.8

    1. Time period is 0.02s and Frequency is 50 Hz. Simulation outputs have shown in Figure10.

LCL FILTER OUTPUT

LCL Filters were used to make square wave to sinusoidal AC signal. The output LCL filter is pure sinusoidal as same as Inverter output.

Simulation outputs have shown in Figure 11.

MATRIX CONVERTER GATE PULSE SEQUENCE

The simulation model of Matrix converter gate pulse sequences are exhibited in Figure 12. It is

designed to generate 120 conduction mode of three phase signal.

Fig. 12: Gate Pulses for 120 degree Conduction Mode of Operation.

Matrix Converter Output

Matrix converter were made for single phase AC to three phase AC Signal with harmonic distortion,

phase difference is 120 degree from one signal to another and time period is 0.02 s and Frequency of

each phase is 50 Hz shown in Figure 13.

Three Phase LCL Filter Output

Three phase LCL filter suppresses the harmonic distortion of three phase signal and the output is

sinusoidal, though peak voltage is almost 300 V (Figure

14) and current is 2 A (Figure 15) but time

period has enhanced and frequency has reduced the simulation were performed for various three phase

loads (e.g. Resistive, Inductive and Capacitive) three phase loads and output voltage and currents are

pretty same.

INPUT OUTPUT COMPARISION

Numeric data have been picked (Figure 7 and Figure 8) of Input (DC) specification, output Single

Phase (AC) (Figure 11), Three Phase (AC) (Figure 14 and Figure 15) and entrust all data in Table.

1.

Table 1: Input and Output Comparison. Specification Input(DC) Output (AC) Single

Phase Three Phase

Voltage (V) 110 312 300

Current (A) 7.8 2.7 2 Power (Peak

Watt)

869 842 600

Time period (s) 0.02 0.08

Frequency (Hz) Nil 50 13

From the above numeric analysis in Table 1, single-phase output is splendid and every specification is similar to our conventional AC system. On the other hand, though the three phase outputs of voltage and current are more identical but due to inductance and capacitance effect of LCL filter, frequency has drastically reduced and its different from our system.

CONCLUSION

This paper discusses the design and implementation of the cost effective efficient DC to AC conversion process. The main objective of this research was to find an efficient power conversion system to use photovoltaic energy to meet the increasing power demands. It is optimal solution for converting solar power to AC. Specially it is fabricated for remote areas. It may be used for different AC load. Another switching based Active filter should be imposed in three phase system instead of LCL filter for better development of frequency. Cyclo-Converter may be added for enhancing the system frequency. It has met every goal set at the commencement of this venture, though more experimental data is needed to be gathered and a closed loop MPPT system is required to be installed before applying it at any operation.

REFERENCES

  1. Ullah MH, Ahmad T, Haque MNM, Rahimi MJ, Dhar RK. An Efficient Solar Pumping System for Rural Areas of Bangladesh. Haque NM, Ahammad I, Miah S, Miki AA, Ahmed H. Design and Implementation of Cost Effective Inverter. International Journal of Scientific & Technology Research. 2017; 6 (10): 269272p.

  2. Rashid MH. Power Electronics Circuits, Devices and Applications, Third Edition. London, United Kingdom: Pearson; 2004.

  3. Haider R, Alam R, Yousuf NB, Salim KM. Design and Construction of Single Phase Pure Sine Wave Inverter for Photovoltaic Application. International Conference on Informatics, Electronics & Vision (ICIEV); 2012 May 18- 19; Dhaka, Bangladesh. IEEE; 2012:190-194p.

  4. Dehbonei H, Borle LJ. Design and implementation of a low cost sine Wave inverter. IEEE International Symposium on Industrial Electronics; 2003 June 9-11; Rio de Janeiro, Brazil. IEEE; 2004. 280 285p.

  5. Qazalbash AA, Amin A, Manan A, Khalid M. Design and implementation of microcontroller based PWM technique for sine wave inverter. IEEE POWERENG. Lisbon. Portugal, March 2009; 163167p.

  6. Haque NM, Naem-Ur-Rahman M, Sarker SC, Miah MS, Ahammad I, Islam MA. Design and Simulation of a Forcible BuckBoost Controlling Solar Powered DC Motor.

  7. Proceedings of IEEE International Conference on Power, Control, Signals and Instrumentation Engineering (ICPCSI); 2017 Sept. 21-22; Chennai, India: IEEE; 2018 June 21: 131-136p.

  8. ehirli E, Altinay M. Simulation of Three -Phase Voltage Source Pulse Width Modulated (PWM) LCL Filtered Rectifier Based on Input-Output Linearization Nonlinear Control. 12th International

  9. Conference on Optimization of Electrical and Electronic Equipment; 2010; Basov, Romania: IEEE; 2010: 564-569p.

  10. Kahlane AEWH, Hassaine L, Kherchi M. LCL filter design for photovoltaic grid connected systems. Revue des Energies Renouvelables SIENR14 Ghardaï. 2014; 227232p.

  11. The World Bank. Solar Program Brings Electricity to Off-the- Grid Rural Areas in Bangladesh. [Online]. Available from http://www.worldbank.org/en/news/featur e/2016/10/10/solar- program- bringselectricity-off-grid-rural-areas [Accessed on October, 2018].

  12. Boylestad RL, Nashelsky L. Electronic Devices and Circuit Theory. Eleventh Edition. New Jersey, United States of America: Pearson Education Inc; 2013.

  13. International Journal of Scientific & Engineering Research. 2013; 4 (8): 1765-1770p. Theraja AK, Theraja BL. A Textbook of Electrical Technology. 22nd Edition. S. Chand and Co. Ltd. Ram Nagar, New Delhi; 1999.

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