The research of the “Solar panels – commutator – inverter – load” system with the pulse-amplitude control

Autors:
1. Kyrmyzy Taissariyeva
2. Issembergenov N.T.

Summary:
The “Solar panels – commutator – inverter – load” system with the pulse-amplitude control had been researched.
Modular construction type of solar panel enables to create facilities of almost any power. Each module of solar panel generates DC electrical energy, which needs to be converted to AC single or three-phase voltage. Efficient conversion of DC to AC with stable frequency and voltage and the optimal use of solar panels are the issues of the day.
This paper shows that output voltage of an inverter with pulse-amplitude control can be multilevel and close to a sine. This requires a specific connection of solar panels and creation multilevel voltage. Each voltage level should be connected through an electronic switch to the inverter. This “Solar panels – commutator – inverter – load” system with pulse-amplitude control allows to reduce the amount of solar panels without reducing power.
Each element of solar panel is represented as an element of mathematical matrix. Using matrix theory the expression was obtained in the form of a matrix with which the economy of the solar panels can be calculated. In addition, voltage, current and power calculation method and solar cells connection method were developed.
Using pulse-amplitude commutator control the output voltage of the inverter becomes multilevel and close to a sine and the use of solar cells is efficient. Solar cells saving depends on the amount of levels. For example, using eight-level inverter solar cells saving is 28,2 %, thirteen-level inverter – 30,5 %, 26-level inverter – 30,5 %. Increasing the number of voltage levels the quality of output voltage also improves. Total Harmonic Distortions in eight-level inverters is 4,64 %, thirteen-level inverter – 2,65 %, 26-level inverter – 1,22 %. However, the increase in the number of voltage level complicates the control system and requires a large amount of energy sources. Based on the modeling and research results it is found that the optimum is thirteen-level inverter. Simulation and experimental results are included in this paper.