Research On Reactive And Harmonic Compensation Of Single-phase Solar Grid-Connected Inverter Based On Adaptive Notch Filter

With the environment problem and the shortage of the energy becoming serious, more and more people start to pay close attention to new energy and exploring its development. Solar energy, as one of the new energy, is attracting many explorers for its cleaning, abundant and contaminative-less advantages. Meanwhile, with the development of power electronics, more and more power equipment comes into use in people’s daily life and work accompanying with the vast harmonics, which affect the grid quality. So grid pollution is also an inconvenient problem. Under this background, this paper did some research about the single-phase PV inverter. Based on the research, aiming at the problem of grid pollution, a new approach to extracting the load’s reactive and harmonic current is proposed, which is adapted to single-phase load current. And this method could acquire these necessary messages of frequency, amplitude and phase angle accurately。This paper consists of two parts. First part analyses and tests a lKW PV grid-connected inverter through in each aspect of theory and experiment. Firstly, the paper introduces some key technologies about the inverter, such as MPPT, isolate island detection and Phase locking loop (PLL). Secondly, the paper lays down the circuit’s topology, that is:two-level structure of BOOST firstly and H inverter secondly. MPPT could be realized by controlling the duty of BOOST and the current source inverter is employed in this project. Besides, only one inductance is used for filtering. Thirdly, dual-loop control method is presented in this paper. It’s necessary to add that voltage loop is the outer one and current loop is the inside one. At last, this paper analyses the experiment results.The second part of this paper introduced the theory of adaptive notch filter (ANF) firstly. On the basis of the first part, rectifier load and inverter is in parallel in this design and the load’s reactive and harmonic current are extracted and compensated based on the improved ANF theory. What’s more, the system could reach a quicker response when the load is changed. In a consequence, this PV grid-connected inverter is provided with transferring active power, compensating the reactive and harmonic current and improving the power quality. The ultimate goal is making the grid current sinusoidal. At last, the result of Matlab/Simulink simulation demonstrated the above-mentioned theory is effective...