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Early inverter use of simulation, the open-loop control circuit is simple and low cost, but the output waveform harmonic distortion, THD value, system dynamic response slow, when the mutation of the load, the output voltage will be big fluctuations and takes a long time to stabilize, and when the input voltage fluctuations, the output voltage is not stable. Open-loop control only applies to less demanding situations of power quality, must be closed-loop control strategy to overcome the limitations of the open-loop control for demanding occasions. Today, power inverter increasingly wide range of applications, and with the advent of high-performance digital signal processor (DSP), the full digital inverter power control to become a reality. Digital control hardware circuit structure is simple, high reliability, and advanced control algorithms and to facilitate real-time control. This paper studies a a TMS320LF2407A type DSP control core single-phase inverter digital control system. The digital system will be introduced into the control system output inductor current, together form a double-loop control and the output capacitor voltage, and the outer loop is a fixed value control system in a dual loop control system, the inner ring loop servo control system, and the outer regulator can be adjusted accordingly in accordance with the load change a given value of the regulator of the inner ring, so that the regulating system still has a better quality, so the the bicyclic control system having a strong ability to adapt to changes in load, allows the inverter power output performance than a big improvement. This paper described the power inverter digital control of superiority and existing digital control strategy, a detailed analysis of SPWM single-phase full-bridge inverter power control technology and its implementation, the establishment of a single-phase SPWM inverter mathematical model and the use of MATLAB simulation. DSP microprocessor digital control system of the inverter, the article detailed analysis of the theoretical and experimental needs, on this basis, the detailed design of the entire hardware platform, including the power of the overall structure, main circuit, filtering circuit, drive circuit, signal conditioning circuits. The control system software focuses on inverter digital control system design aspects, given the overall structure of the software. Selected output voltage control, output voltage outer ring and the inductor current inner ring bicyclic control inverter as the object of study by the in discrete domain controller design, analysis compared two control strategies, the stability of the inverter and dynamic response, the results show that the double-loop control inverter voltage stability and dynamic response to be superior to single-loop control inverter. Finally, the article discusses the implementation of the control system to solve the main problems facing the digital inverter control system, and software flow chart given the parameters of the principle prototype design and thought control, the principle prototype experimental verification, The experimental results verify the correctness and effectiveness of the control system.
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