CPLD-based photovoltaic inverter phase locking protection circuit

Abstract

The invention discloses a CPLD-based photovoltaic inverter phase locking protection circuit. The CPLD-based photovoltaic inverter phase locking protection circuit comprises an analog comparator, a digital filter, a DSP, a PWM wave processing module, a pulse width anomaly detection device and a common-mode conduction detection device, wherein the analog comparator is electrically connected with thedigital filter, and the analog comparator is used for transmitting overvoltage signals, overcurrent signals and temperature anomaly signals to the digital filter; the digital filter is electrically connected with the PWM wave processing module; the DSP is electrically connected with the PWM wave processing module, the DSP is used for transmitting DSP control signals to the PWM wave processing module and inputting three paths of PWM wave signals to the PWM wave processing module, and the PWM wave processing module is used for feeding back abnormal interruption signals and a state code to the DSP; the DSP is electrically connected with the PWM wave processing module through pulse width anomaly detection device; and the DSP is electrically connected with the PWM wave processing module through common-mode conduction detection device. The CPLD-based photovoltaic inverter phase locking protection circuit has the beneficial effects that the protection effect is good, a common-mode conductioncondition is unlikely to appear, and the working effect of the photovoltaic inverter is improved.

Description

technical field [0001] The invention belongs to the technical field of photovoltaic inverters, and in particular relates to a phase-locked protection circuit for photovoltaic inverters based on CPLD. Background technique [0002] Photovoltaic inverter is a power adjustment device composed of semiconductor devices, which is mainly used to convert DC power into AC power. It is generally composed of a boost circuit and an inverter bridge circuit. The boost circuit boosts the DC voltage of the solar battery to the DC voltage required for inverter output control; the inverter bridge circuit converts the boosted DC voltage into an AC voltage of common frequency equivalently. During the use of photovoltaic inverters, protection circuits are required. [0003] The current phase-locked protection circuit of the photovoltaic inverter has poor protection effect and is prone to common conduction, which affects the working effect of the photovoltaic inverter. [0004] Therefore, it is...

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Problems solved by technology

[0005] The purpose of the present invention is to provide a CPLD-based photovoltaic inverter phase-locked protection circuit to solve the problem of the current photovoltaic inverter phase-locked protection circuit proposed in the above-mentioned background technology, which has poor protection effect and is prone to common state conduction The situation, the problem that affects the working effect of the photovoltaic inverter

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