This paper presents a digitally controlled way of generating the sinusoidal signal with less memory consumption. Moreover, this paper also presents a new switching frequency modulation technique. This technique utilizes the concept of spread spectrum frequency modulation that is used to suppress the electromagnetic interference (EMI) caused by high switching frequencies. Measurement results at the output sine pulse-width generation show that when the spread spectrum technique was applied to the conventional triangular wave and the fundamental, second, and third harmonics of switching frequency were reduced, respectively, by 12.8, 11.2, and 16.4 dB trading off with the slight increase in total harmonic distortion (THD) of 0.092% from a THD of 2.34%. While in the inverter output, there was a 14-dB reduction in EMI peak in exchange to 0.12% increase in THD from a THD of 2.57%.

A Digitally Controlled Low-EMI SPWM Generation Method for Inverter Applications

Due to rapid growth of photovoltaic (PV) power generation, highly efficient and cost effective pure sine wave inverters are greatly demanded in the local market. Based on the simulation result in PSIM software, a low ripple and almost 97% efficient single-phase pure sine-wave inverter for PV application has been designed and implemented which has a total harmonic distortion (THD) of less than 0.6%. Sinusoidal pulse width modulation (SPWM) generated by PIC16F876 Microcontroller is used to control the switching of the inverter power circuit. Error in the output signal is minimized for both inductive and capacitive load by employing a closed loop control scheme that ensures suitable harmonic elimination technique to achieve better performance of the inverter output waveform. To reduce cost we have used low frequency transformer that is available in the local market, which aids to make our design cheaper compared to the design that is based on high frequency transformer. To validate simulation results a prototype has been constructed and tested. Simulation and practical results were compared and both the results conform to each other.

Design and implementation of a highly efficient pure sine-wave inverter for photovoltaic applications

Power converter with maximum power point tracking MPPT for small wind-electric pumping systems

The most basic requirement of all human life is energy. Nowadays the demand of energy consumption in India is becoming more. The need for power and energy develops in tandem with the population. In recent days/times the most used energy resource is renewable energy resources which can be utilised for various purposes. The most extensively used renewable energy source is solar energy. Solar energy is the most widely used renewable energy source since it is abundant, unlimited, pollution-free, and environmentally benign. This document displays a solar-powered irrigation pumping system. The solar irrigation pump system is one in which the functioning of a three-phase induction motor coupled pump system is powered by solar energy. The key variables influencing the amount of energy collected from a PV module is solar irradiation and ambient temperature. As a result, output energy will be generated in the PV array. One of the MPPT techniques used to track maximum power and enhance PV system efficiency is the incremental conductance method. MPPT generates the needed pulse based on the PV module’s output voltage. The DC-DC Converter, which is a boost converter, receives this pulse. The boost converter is used to regulate the voltage of the PV system. The boost converter utilised to provide the boosted DC output is the Dickson voltage multiplier. Three-phase VSI is used to convert DC electricity into high-frequency AC power. 

https://aip.scitation.org/doi/pdf/10.1063/5.0092263

Modeling and simulation of solar irrigation system with IM drive using PWM controller

1 Post-Graduate Student (M.E. Power System), 2 Assistant Professor, 3 Associate Professor Department of Electrical Engineering, Government Engineering College, Bhuj, India jatinpatel_ee@yahoo.in,amkubavat@rediffmail.com,jhl_mahipal@yahoo.co.in ______________________________________________________________________________________ Abstract— There are different method of speed control of three phase induction motor and to control the speed of three phase induction motor generally using V/F control strategy. Out of the a number of methods of speed control of an induction such as pole changing, frequency variation, variable rotor resistance, variable stator voltage, constant V/f control, slip recovery method etc., the constant V/f speed control method is the majority generally used. In this method, the V/f ratio is kept constant which in turn maintains the magnetizing flux constant so that the maximum torque remains unchanged. Thus, the motor is totally utilized in this method. This paper include with simulation of V/F speed control of three-phase induction motor using PWM inverter strategy. The simulation work proves the idea of V/F control using PWM inverter and the software used for simulation is PSIM (Powersim).The performance of the volt per hertz strategy were evaluated through simulation shown in results. In constant V/F control, by use PWM inverter, we can vary the supply voltage as well as the supply frequency such that the V/F ratio remains constant so that the flux remains constant too. So, we can get different operating zone for various speeds and torques and also we can get different synchronous speed with almost same maximum torque. Thus the motor is fully utilized and also we have a good variety of speed control. It is effortless, cost-effective to easier to design in open loop. But the drawbacks of open loop is it doesn’t correct the change in output also it doesn’t reach the steady state quickly.

https://www.ijedr.org/papers/IJEDR1401089.pdf

Speed control of a three phase induction motor using pwm inverter

A microcontroller based advanced technique of generating sine wave with minimized harmonics is implemented in this paper. The proposed technique “impulse-sine product” aims to design and implement a voltage regulated inverter with ripple free and glitch free output sine wave that can operate electronic devices efficiently. The output voltage of the inverter is regulated by a feedback loop using analog to digital protocol of PIC16f877 microcontroller. The design is essentially focused upon low power electronic appliances such as personal computers, chargers, television sets. The inverter output is regulated from 16-volt rms to 220-volt rms for a variation of load between 1-Ω to 180-Ω loads. The designed inverter provides a range of operation from 25 Watts to 250 Watts. The design is mathematically modeled which is simulated in Matlab, Proteus and finally the results are practically verified.

Mahveen Khalid

Papers

Design and implementation of microcontroller based PWM technique for sine wave inverter