Research Of Wind Power Grid-Connected Inverter Control System

Wind energy is a clean renewable energy resources is extremely rich. The large number of the current with the energy consumption and increase the environmental awareness of people, both at home and abroad more and more importance on green energy.Experts estimate that the total wind energy resources around the world two trillion kilowatts per year, only l% of the surface wind will be able to meet the worldwide demand for energy. Comprehensive resources, technical, economic, environmental and other factors, to develop wind power industries, is to solve the shortage of energy and power to choose the most realistic strategy.In recent years, the installed capacity of wind power around the world to grow rapidly.For small-scale wind power generation system of "distributed generation" model in China is still in the preliminary study stage, has broad application prospects and commercial value.Wind power technology is new energy in the most mature, the largest commercial development of the conditions and prospects for development of one of the ways of power generation.Wind power into the grid using wind energy will become the major trends, so how to change the wind into electricity is the use of renewable energy one of the key technologies, but also the current use of renewable energy research in the field of hot spots.In this paper, main research of wind power grid-connected inverter control system related research to inverter technology.Study of wind power into the grid requirements and standards to compare the form of inverter circuit design used to AC-DC-AC the structure of inverter. Main circuit for the full-bridge inverter circuit, inverter circuit of the work done a detailed analysis of the state.Power switching devices and high-performance applications of IGBT technology unipolar SPWM modulation switch control.AC and DC side of the filter has done a detailed analysis and design.T-AC filters used for addition to formula for calculating capacitance and inductance simulation analysis.The results show that the filter can effectively suppress the effect of significantly harmonics, can be incorporated into the power grid to improve power factor.System was designed and the overall control structure, the functional modules.This as the key link, in order to provide guidance for future research ideas. Inverter into the power grid control system uses a voltage source input current-mode output control mode, after filtering through into the power grid inverter current control can reduce the impact of fluctuations in power grids, so that the inverter output in line with the power grid to improve system stability.Detailed analysis of the single-phase modulation SPWM inverter into the power grid of the working principle of a power grid into the digital current command SPWM current dynamic tracking control strategy.Incorporated into the power grid current control is based on the DSP of the digital closed-loop regulator to generate SPWM current directives and to establish the mathematical model of the system to digital PI control for the control of the core, combined with disturbance compensation control voltage to eliminate voltage fluctuations of the current impact of to improve the control effect. Inverter output current and voltage simultaneously, is wind power and a system of technical problems. In this paper, a detailed analysis of phase-locked loop principle, to simulate the basic principles of lock-based, design based on DSP chip digital phase-locked control technology. According to the mechanism of DSP to generate SPWM waves, modulated sine wave stored in tabular form, the use of Hall-exchange components of voltage and current sampling grid respectively after filtering inverter voltage and the current signal into the power grid will be sampled two to capture the signal sent to the DSP unit , according to the difference between the two control signals generated through the sine table pointer and the triangular wave frequency adjustment, change the SPWM wave output so that current and voltage to maintain the same frequency and phase. The use of MATLAB / Simulink simulation of the power system toolbox modules, set up a simulation model, simulation was made on the control strategy analysis, results show that the system of active high and close to unity power factor into the power grid.The design of system-core processors is TMS320LF2407A, the processor chip eripheral resources rich and powerful, especially applicable to digital control systems. Given the use of the chip to generate SPWM wave method, using symmetry rules of sampling, the use of EVA module 1 the distribution of general-purpose timers and compare the two units, each unit has the corresponding comparison compare register, when set to PWM mode may have the opposite polarity of the PWM output. Universal Counter Timer 1 is set to increase / decrease count patterns and comparison of register values, when the match occurs, the comparison of the two units will control the output of the digital register for hopping. Register control bit to determine when comparing each of the output matching for high-or low-efficient and effective. The cycle timer register value must T1PR when compared by changing the value of register CMPRx can change the width of rectangular pulse output. This will have a duty cycle can be calculated in real-time updates of SPWM wave output.Theory in the analysis of the system based on the detailed design of the hardware and software structure. AC and DC designed sampling circuit, fault protection option, AC voltage and current use of Huo Yuan-production sample of the Hall element as a sensor. Performance power switching device determines that the work of the state of the inverter main circuit, the text of static and dynamic characteristics of IGBT, model-driven selection and made a detailed analysis of the requirements. The use of models for the design of a power switch and protection of IGBT driver circuit. Drive circuit uses two types of circuit forms: First, drive through the pulse transformer isolation, and the other is driven via a dedicated chip, the latter comparison IGBT drive to work on a more safe and reliable. The design of the system is the main program, SPWM wave generated by the DSP and the grid current and voltage of the digital phase-locked to keep the software process methods. According to design, build a system experiment platform DSP oscilloscope measured output SPWM waveform, is divided into high-frequency and low frequency arm arm IGBT drive waveform. By T-type filter after filtering the sine wave-shaped, in view of the experiment phenomenon, analysis of its causes and ways to improve debugging. Through the static and dynamic experimental verification of the control strategy and the exchange of filtering accuracy and reliability.