Single-phase sine wave inverter power supply based on single-chip microcomputer

Abstract

The invention discloses a single-phase sine wave inverter power supply based on a single-chip microcomputer. The single-phase sine wave inverter power supply is composed of a full-bridge inverter circuit and an LC filter circuit. An inputted direct-current voltage is transformed into an alternating current by the full-bridge inverter circuit; and the LC filter circuit carries out filtering to forma sine wave alternating current. The output terminal of the LC filter circuit is sequentially connected to the full-bridge inverter circuit through a voltage sampling circuit, a PID regulator, an SPWM signal generator and a photoelectric coupler. The voltage sampling circuit collects the output voltage from the LC filter circuit; the PID regulator carries out calculation on the output voltage anda reference voltage and then a control quantity is outputted; and the SPWM signal generator carries out calculation to form a new SPWM wave and the new SPWM wave is inputted into the full-bridge inverter circuit to adjust the output voltage value. According to the invention, the power and efficiency of the inverter power supply are improved; the fast conduction speed and low switching losses arerealized. Feedback adjustment is carried out on the output voltage by the PID regulator and the SPWM signal generator carries out calculation to form the new SPWM wave, so that the output voltage keeps to be stable and the system can work stably for long time.

Description

technical field [0001] The invention relates to the technical field of switching power supplies, in particular to a single-phase sine wave inverter power supply based on a single-chip microcomputer. Background technique [0002] The inverter power supply can convert the mains power into the AC power of the frequency required by the user, and at the same time convert the single-phase AC power into multi-phase AC power. Therefore, the inverter power supply has been widely used in many fields such as aviation, electric power, railway transportation and communication. The power of the existing inverter power supply is low, and the conduction speed of the switch tube is low. In addition, because the input voltage will decrease with the change of the load, and the system filter inductance has a resistance component, this will cause the system to open-loop under load. The adjustment rate increases, which makes the output voltage unstable and affects the use of the load. Contents ...

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Problems solved by technology

The power of the existing inverter power supply is low, and the conduction speed of the switch tube is low. In addition, because the input voltage will decrease with the change of the load, and the system filter inductance has a resistance component, this will cause the system to open-loop under load. The adjustment rate increases, which makes the output voltage unstable and affects the use of the load

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