Single-phase inverter power regulator circuit diagram simulated by Simulink library

Single chip microcomputer STM32L151CCU6

1206RGB (single)

MOS power IC full range

Adjustable capacitor Murata genuine original

Photocoupler

Overview:
Based on Simulink library, the modeling and simulation of single-phase inverter double-closed-loop PID regulator with SPWM wave control are studied. The system simulates the generation of SPWM waveforms in the Simulink library, and establishes the rectification and inverter circuits under ideal conditions. It is proposed to adjust the output voltage through voltage average loop and voltage instantaneous loop double loop control. This modeling idea is transplanted to the 10K modular single-phase UPS power supply, and the control accuracy and accuracy can achieve the expected results.

With the rapid development of the power industry, the application of inverters is more and more extensive, and the quality of inverters will directly affect the inverter performance and load capacity of the entire system. The control goal of the inverter is to improve the steady-state and dynamic performance of the inverter output voltage. The steady-state performance mainly refers to the steady-state accuracy of the output voltage and the ability to improve the unbalanced load; the dynamic performance mainly refers to the THD of the output voltage. (Total Hannonic Distortion) and the level of dynamic response when the load is abrupt. In these indicators, the THD requirement for the output voltage is relatively high. For a three-phase inverter, the THD is generally less than 2% when the resistive load is fully loaded, and the THD of the nonlinear full load (rectifying load) is less than 5%. The control strategy of the transformer is closely related. This paper mainly introduces how to establish a mathematical model of voltage double-loop SPWM inverter, and uses voltage RMS outer loop and voltage instantaneous value inner loop to control. Modeling and simulation of UPS single-module 10 kVA single-phase voltage SPWM inverter. Through simulation, the correctness of the control idea and the robustness of the inverter under the control strategy are strong, the dynamic response is fast, and the THD is low. With simulation as the guide, the idea is transplanted into the specific development to achieve the expected results.

1 Three-level inverter single-phase control model construction The main circuit structure of a single-phase inverter with LC filter is shown in Figure 1. In Figure 1, L is the output filter inductor, C is the filter capacitor, T1, T2, T3, T4 are the three-level SPWM waves used to drive the IGBT, and U0 is the voltage across the output load. When establishing the simulation model of the control system, it is necessary to compare the voltage across the load with the actual required electric music value, and then obtain the value to be adjusted through the regulator. In this simulation model, the driving waveform is a three-level SPWM waveform, and the specific generation principle will not be described in detail here. The SPWM wave is generated in Matlah's Simlink library as shown in Figure 2, where the modulation ratio is set to 0.8.

Figure 1 Three-level inverter single-phase main circuit

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