| As the development of the world’s economy, the resource constraints and environmental pollution have been more and more serious. The task of new energy’s development and utilization has been taken seriously. Especially the solar energy has been taken seriously by the world because of its clean energy. Solar inverter is the core of the using of solar energy, so the study on it will have great significance.Usually, the solar photovoltaic inverter divided into two kinds including isolated form and non-isolated form. The non-isolated form abandons the heavy transformer and has advantages like simple and portable, low cost and high transfer efficiency. But in the system of the non-isolated form solar photovoltaic inverter grid-connected, it exists the parasitic capacitance between the PV and ground shell. And this parasitic capacitance will compose the common mode resonant circuit with output Filter components and grid impedance. The changing common mode voltage on the parasitic capacitance will stimulate the the common mode resonant circuit and produce the common mode current. To restrain this common mode current, this paper use the H6 inventor topological structure and analyze the principle of the restraining of this topological structure to common mode current. Then we introduce the working condition in detail.The model of peak current injection feedback control is a new type of controlling strategy. Its using scope is mainly focusing the arc welding inverter. In this paper, we use this controlling strategy in the solar inventor system and take the experimental verification. Pulse Width Modulation of peak current injection feedback control is a controlling unit of double input single output. Duty cycle of pulse width modulation depend on the two input signal of reference signal and instantaneous signal. This controlling system has the ability of inside current limit and self calibration. In this paper, we will analyze its basic theory, feature and stability.In this paper, we use MATLAB to build the H6 topology photovoltaic grid-connected inverter experimental model basing on the peak current injection feedback control. This model consists three parts, including the realization of the phase locked loop technology, the peak current injection feedback control algorithmic and the constructing of the H6 topology photovoltaic grid-connected inverter platform. Through the observation and analyzation of the simulation result, we proved the feasibility of the controlling strategy in the H6 topology photovoltaic grid connected inverter.According to the analyzation above, this paper designs the H6 topology photovoltaic grid connected inverter platform basing on the peak current injection feedback control. This controlling strategy is realized using the dual-core controlling mode of FPGA and DSP. DSP is mainly used for phase lock the grid signal and produce the reference signal of peak current injection feedback control and then sending to FPGA. FPGA is the core of the peak current injection feedback control. It receives the reference signal coming from DSP and the real-time signal coming from AD’s sampling. And then it provides the pulse drive signals of the power switch tube. FPGA has the performance advantage of high speed of calculation and concurrent progcessing. So it can satisfy the demand of stability and instantaneity of the peak current injection feedback controlling. Then, this paper introduces the design principle of the main hardware part of the experimental platform.Lastly, we prove and analyze the system of peak current injection feedback control on the H6 topology photovoltaic grid-connected inverter on the designed experimental platform. And then we summarize the performance of the task and give an outlook of the work in future. |
PDF Full Text Request