Sinusoidal Pulse Width Modulation for a PhotoVoltaic Based Single Stage Inverter

The work proposed in this paper focuses on providing an effective solution to shortage of power in rural 17 areas with an effective technique implemented in an economically feasible way. The traditional Inverters 18 used for either residential or commercial purposes consume electrical energy from the grid to fulfill the 19 charging and discharging of the battery, which may lead to overloading. The shortcomings of the 20 traditional inverters such as Non-Renewable nature of power sources, increased cost of manufacturing, 21 and multi-stage conversion complexity, are considered by the researchers for improvement. As a result, 22 an attempt has been made to provide a cost effective renewable energy system with single stage topology 23 for AC power applications. Single stage power conversion with allowed shoot through state is used here 24 to avoid additional components and reduce the switching losses. Unlike the traditional inverters, the Quasi 25 Impedance Source Inverter that is brought forward can be utilized as a Standalone system or a capable 26 backup at the time of power outages. Sinusoidal pulse width modulation (SPWM) is applied to attain 27 reduced harmonics which are measured by observing the harmonic pattern in Total Harmonic Distortion 28 (THD) curve. The lab results obtained through MATLAB simulation confirm the noteworthy diminution 29 of THD level in

an attempt has been made to provide a cost effective renewable energy system with single stage topology 23 for AC power applications. Single stage power conversion with allowed shoot through state is used here 24 to avoid additional components and reduce the switching losses. Unlike the traditional inverters, the Quasi 25 Impedance Source Inverter that is brought forward can be utilized as a Standalone system or a capable  2010)). Later part of the same year, a method to inculcate constant peak 64 voltage that is present at the dc link was brought to the limelight. In 2015, for various load conditions, an 65 analysis of the impedance source inverter was done (Kavya Santhoshi and Sudharsan (2015)). In case of 66 bidirectional DC-DC converter, batteries are employed for energy storage and management of them yields 67 to a system which is costly, less efficient and complex (Liu et al. (2013)). Thus, the QZSI with more 68 advantages can be used instead of the previous topologies. In the proposed work, sinusoidal pulse width 69 modulation is applied for controlling the switches of the inverter switches to mitigate harmonics to a 70 greater extent. power sources that is both the Photovoltaic panels as well as the battery act as power sources. The load 76 acts as he power consumer. While controlling power flows from two sources of power, the third 77 involuntarily matches due to the equation (1). 78 Where, P in is the power at the input side due to PV, Pout is the power at the output due to inverter and P bat 80 is the power due to battery. P in is a one-way power flow and P bat is a two-way power flow. It has two 81 modes: shoot-through mode which is undesirable in conventional inverters and the non-shoot-through 82 mode. When the mode is shoot-through, reverse biased diode gets turned off. While operating in non-83 shoot through mode, the quasi-impedance source inverter presumes one state out of the available active 84 states (six in number) and zero states (two in numbers).

III. PROPOSED WORK AND ITS MERITS 86
The proposed work uses a QZSI compared to the traditional inverter. There are certain benefits of 87 using this topology. The inductor and capacitor elements present in the quasi z source network behave as 88 storage elements. When solar power is available, these elements get charged by solar voltage and later 89 when the solar source is unavailable, these elements discharge the voltage. Hence high voltage at the 90 output of this network can be obtained since voltage from battery and the quasi z source network elements 91 get summed to produce higher voltage. The current in the circuit remains constant. Boost feature is one of 92 the important features of a quasi impedance source network. 93  The reference signal is a sinusoidal wave and the carrier signal is triangular. The gate signal is 109 generated by comparing these two signals. The pulse width is varied in accordance with the magnitude of 110 the reference signal calculated at the center of the pulse. The modulation index can determine the output 111 voltage. Hence the harmonics are reduced in the output voltage. A cost effective and energy efficient 112 system with reduced components due to absence of two stage conversion can be achieved. The 113 modulation index is given by equation (2). 114 Where, V m is the voltage of the modulating signal and V c is the voltage of the carrier signal. 116

Simulink
Then the similar PV system performance was reducing the total harmonic distortion by using the 122 Q-ZSI based sinusoidal pulse width modulation techniques, which result and discussion can be briefly 123 described in the following section. The presented system has been simulated with input PV voltage of 52V. The simulation has been 130 carried out using R and L loads and further research on the same using other loads is being done. The 131 outcome of the simulation has proven to reduce THD to 1.9% compared to the reported system that yields 132 a THD of 12.73% under R load condition. FOR RL load condition, the results show that the THD of line 133 current reduces from a level of 14.01% to 3.81%. The simulink model for the reported work and proposed 134 work using R load and RL load are shown in Fig. 4, 5, 6 and 7 respectively. The parameters used for 135 simulating the proposed model are tabulated in table 1. 136

VI. PERFORMANCE ANALYSIS OF THE PROPOSED CONTROLLER 141
The performance evaluation of the proposed system and its simulation results are analyzed for 142 irradiance input conditions. The performance analysis of the proposed controller is tested with Q-ZSI with 143 PV panel based sinusoidal pulse width modulation techniques in two different conditions. 144  Condition 1: Analysis of R load 145  Condition 2: Analysis of RL load 146 The PV panel was controlled by using proposed Q-ZSI based sinusoidal pulse width modulation 147 technique for mitigating the total harmonic distortion. While converter circuit uses predicted voltage and 148 current control in order to have the optimal sinusoidal pulse with modulation. This system was simulated 149 to learn the operation of the PV panel connected system. Initially, the input irradiance, the current, 150 inverter voltage, load current, load voltage and dc link voltage are analyzed in the normal conditions and 151 illustrated in the Fig. 8, 9 (a, b), 10 (a-c) respectively.

Analysis of case 2: RL load 188
Here, the harmonic problem is created to analyze the performance of proposed method. By using 189 the proposed QZSI with sinusoidal pulse width modulation based PV panel, current, inverter voltage, load 190 current, load voltage and dc link voltage are determined. To compensate the total harmonic distortion 191 problem, the dc link voltage performance is analyzed. Figure 11, shows that the execution of irradiance 192 has been illustrated and Fig. 12 illustrates, performance of the current and inverter voltage has been 193 analyzed. After that, reduced the total harmonic distortion analyzing of the load current, load voltage and 194 dc link voltage has been illustrated in the Fig. 13. From the investigation of dc link voltage of the system 195 is improved after injecting the compensating current and voltage. Along these lines, the total harmonics at 196 the inverter is reduced. The general investigation of proposed strategy gives better repaying the harmonic 197 detection successfully. voltage of the proposed methodologies. In Fig. 13 (a), (b) and (c) illustrates, the performance analysis of 217 the load current, load voltage and dc link voltage has been performed. During the current take the limits at 218 -0.3 A to 0.3 A then the output analysis at three phae current has been performed in the Fig. 13 (a). In Fig.  219 13 (b) illustrates, performance of the load voltage at takes the 150 V has been reached and output is the 220 three phase volage. Then the Fig. 13 (c), the analysis of the dc link voltage output has been presented. 221 Here, takes the voltage at 0 to 130V it is reached the settling time at 0.23 seconds. comparison of the RL load is better than the R load because the settling time and total harmonic detection 237 at inverter output are better performance. This assessment shows that the proposed methodologies is 238 the finest method to incredulous the nonlinearity in this system with great reliability, more robust 239 and good performance than the other approaches.         Analysis of (a) modulation current and (b) inverter voltage for proposed method  Analysis of irradiance for proposed method in RL load