The Development Of Three-phase PV Grid-connected Inverter And Realization Of The SVPWM Algorithm

With the continued growth of the global economy, it was found that the problem of energy shortage and environmental protection has seriously constrained global economy. Researchers are urgent to find renewable resource-rich and non-polluting new energy. With years of research it is found that solar energy is the best candidate for the future new energy. Solar energy has many advantages to meet the requirements of human. The development and use of solar energy has become the main direction to solve the current energy problems in the world, and photovoltaic power generation system is the main utilization method of solar energy.With theoretical analysis of the photovoltaic power generation system, exposition of the hardware circuit, the design of the inverter circuit structure, as well as the overall design, we decide to use process of the PV inverter, the DC-DC boost circuit, high frequency inverse variable structure, the matrix phase transformation, the tertiary structure of the solar panel of the DC input inverter to become a three-phase alternating current could be grid. Tertiary-structure with the PWM pulse width modulation, pulse width modulation SPWM sinusoidal pulse width modulation of SVPWM space vector modulation of matrix converter structure, the dead time to protect the inverter circuit, and by SVPWM modulation alternating current of the output three-phase alternating current compensation dead-time, its photovoltaic power generation system with the national grid to maintain the consistency of the current, voltage, frequency, phase, harmonics. The main contents of this paper are as follows:1. A simple introduction to the analysis of each of the photovoltaic power generation system applications is given, the photovoltaic use this grid of the power generation system is analyzed to determine the photovoltaic research network discovery system.2. We introduced a three-phase photovoltaic grid inverters types of photovoltaic grid-connected inverter main circuit of the circuit topology to determine the three-phase photovoltaic grid inverters overall system design. Tertiary structure design analysis:DC-DC boost circuit, high-frequency link inverter circuit matrix conversion circuit. Through the analysis of its principle as well as the work process, the overall design.3. The three modulation technique used in the current domestic and foreign inverter process are analyzed in-depth:PWM modulation technology. SPWM modulation technique SVPWM modulation techniques. According to the different characteristics of the three modulation techniques used in this paper, the design of photovoltaic grid inverter tertiary structure.4. Safe commutation matrix converter, proposed adding the dead time to protect the main circuit of the inverter, SVPWM space vector modulation strategy to compensate for the dead time effect, namely to protect photovoltaic grid-connected inverter main circuit system, and can ensure the quality of the three-phase AC system output.5. The analysis of the photovoltaic power generation system in the detection process of grid MPPT maximum power point tracking and islanding effect. In order to ensure the efficiency of the inverter system, you must use MPPT technology; island effect becomes a major problem for grid process, this paper presents a simple and secure testing program island effect. Finally, simulation results, comparison by this paper design of photovoltaic grid-connected inverter output of three-phase alternating current with the national grid three-phase AC, and certainly the design output three-phase alternating current waveform national grid three-phase AC waveform current, voltage, frequency, phase, harmonic consistent.