Three phase inverter used for solar photovoltaic grid-connected system

Abstract

The invention relates to a three phase inverter used for a solar photovoltaic grid-connected system. The three phase inverter used for the solar photovoltaic grid-connected system comprises an inverting circuit, a control circular, a filter circuit and a detection circuit. The control circuit comprises a digital signal processor (DSP), a protective module and a digital lock-phase module used for locking voltage phase of an electrical grid. The digital lock-phase module comprises a digital phase discriminator, a digital filter and a digital-controlled oscillator which are sequentially connected. The digital phase discriminator detects phase difference of input signal and output signal by comparing the input signal and the output signal. The digital filter conducts filtering on the input signal. The digital oscillator is used for regulating phase difference of digital signals. Compared with the prior art, the three phase inverter used for the solar photovoltaic grid-connected system can conduct digital phase locking on voltage of the electric grid, can effectively prevent phenomenon of jittering or losing lock of the voltage phase from occurring, and ensures normal operation of the solar photovoltaic grid-connected system.

Description

technical field [0001] The invention relates to a solar photovoltaic grid-connected system, in particular to a three-phase inverter used in a solar photovoltaic grid-connected system. Background technique [0002] With the increase of population and the development of economy, human beings' demand for energy is also increasing, and the traditional energy reserves are becoming increasingly depleted, which brings about the problem of energy shortage. Moreover, the extensive use of fossil fuels is increasingly harmful to the human living environment, and even leads to ecological deterioration, which has become a major problem facing all countries in the world today. Therefore, the development and utilization of renewable energy and various green energy is a measure that human beings must take, and considering many factors of energy supply, solar energy is undoubtedly the ideal green energy that is most in line with the sustainable development strategy. Global energy experts be...

AI Technical Summary

Problems solved by technology

Since the power system will generate large electromagnetic interference when it is working, its simple phase-locking method is easily disturbed and lost lock, which will cause the system to fail to operate normally.

Images