Auxiliary power supply control circuit of photovoltaic inverter

Abstract

The invention relates to the technical field of photovoltaic inverters, and discloses an auxiliary power supply control circuit of a photovoltaic inverter. The control circuit comprises a control chip U1, a triode Q2, a resistor R2, a resistor R4 and a resistor R5. The emitting electrode of the triode Q2 is connected with the VCC pin of the control chip U1, the collector electrode of the triode Q2 is connected with the output positive pole PV+ of a solar cell panel through the resistor R5, the base electrode of the triode Q2 is grounded after passing through the resistor R2, one end of the resistor R4 is connected with the output positive pole PV+ of the solar cell panel, and the other end of the resistor R4 is connected with the base electrode of the triode Q2. In the using process of the control circuit, when voltage input of the solar cell panel is low, the resistor R2 and the resistor R4 do not produce enough voltage to the base electrode of the triode Q2, the triode Q2 is not conductive, the VCC pin of the control chip U1 provides no voltage, and an auxiliary power supply does not work; when the voltage is high enough, the triode Q2 is conductive, the solar cell panel provides enough starting current for the VCC pin of the control chip U1 through the current-limiting resistor 5. By means of the control circuit, the auxiliary power supply can be prevented from being frequently started.

Description

technical field [0001] The present invention relates to the technical field of photovoltaic inverters, and more specifically relates to a photovoltaic inverter auxiliary power supply control circuit. Background technique [0002] Photovoltaic power generation is a technology that directly converts light energy into electrical energy by using the photovoltaic effect at the semiconductor interface. It is mainly composed of three parts: solar panels (components), controllers and inverters. [0003] During the use of the photovoltaic inverter, since the input of the inverter is a solar panel. The voltage and current generated by solar panels depend on the intensity of sunlight. In the morning, evening and rainy days, the power of the solar panel is limited, which is not enough to support the power required for the inverter to start. However, the auxiliary power supply of the inverter needs relatively large power at the moment of startup. As soon as it is started, the voltage ...

AI Technical Summary

Problems solved by technology

In the morning, evening and rainy days, the power of solar panels is limited, which is not enough to support the power required to start the inverter

However, the auxiliary power supply of the inverter needs relatively large power at the moment of startup. As soon as it is started, the voltage of the battery board will be pulled down to the voltage condition that the auxiliary power supply can start, causing the switching power supply to restart.

For this reason, the auxiliary power supply frequently restarts when the power is insufficient.

Moreover, since the current quality assurance of photovoltaic inverters is at least 5 years, the service life of related circuits is greatly affected due to frequent restarts of the auxiliary power supply every day.

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