Performance and Harmonic Evaluation of a Modified Sinewave 1kVA Solar Powered Inverter

Abstract

An inverter is a device that takes a direct current input and produces a sinusoidal alternating current output. It maintains a continuous supply of electric power to connected equipment or load by supplying power from a separate source, like battery, when utility power is not available. It is inserted between the source of power and the load is protecting. This paper evaluates and analyses the harmonic characteristics of a 1kVA solar powered inverter under different load conditions. The performance of inverter is affected by the presence of harmonics which is generated from non-linear loads as used in PV systems (i.e inverter) which in turn consequently affects the inverter output voltage and waveform. The methods used comprises of 12V, 250W solar panel connected to a 30A pulse width modulation (PWM) charge controller and a 12V, 100Ah deep cycle battery was connected to the controller to enable charging of the battery while a 1kVA, 220V inverter was connected to the battery to produce the AC output needed. The performance of the inverter was evaluated and analyzed from the load test results and harmonic characteristics occurring in the inverter output voltages and waveforms were obtained using DENT Power meter. The parameters were taken at an interval of minutes and it was observed that the nonlinear loads have more harmonics injection effects on the output waveforms of the inverter. The paper recommends on best practices and further research to identify harmonic constraints in PV inverters, and on the application of mitigation techniques that lead to more PV penetration without sacrificing the safety and reliability of the distribution networks.