US 11,990,758 B2
Control method, auxiliary power supply of photovoltaic inverter and photovoltaic power generation system
Yuxi Wang, Shanghai (CN); Xuancai Zhu, Shanghai (CN); and Bingwen Weng, Shanghai (CN)
Assigned to Delta Electronics (Shanghai) Co., Ltd., Shanghai (CN)
Filed by Delta Electronics (Shanghai) Co., Ltd., Shanghai (CN)
Filed on Dec. 1, 2021, as Appl. No. 17/457,253.
Claims priority of application No. 202011400442.7 (CN), filed on Dec. 3, 2020.
Prior Publication US 2022/0181884 A1, Jun. 9, 2022
Int. Cl. H02M 1/36 (2007.01); H02J 3/00 (2006.01); H02J 3/38 (2006.01); H02S 40/32 (2014.01); H02M 1/00 (2006.01)
CPC H02J 3/381 (2013.01) [H02J 3/007 (2020.01); H02M 1/36 (2013.01); H02S 40/32 (2014.12); H02J 2300/26 (2020.01); H02M 1/0006 (2021.05)] 17 Claims
OG exemplary drawing
 
1. An auxiliary power supply of a photovoltaic inverter, comprising: a rectifier circuit and a conversion circuit with at least one output terminal, wherein the conversion circuit comprises a voltage determining unit and a power determining unit;
an input terminal of the rectifier circuit is coupled to a power grid, and the rectifier circuit is configured to convert alternating current power of the power grid into direct current power;
the conversion circuit is coupled to an output terminal of the rectifier circuit, and is configured to convert the direct current power into at least one auxiliary voltage;
the power determining unit is coupled to an input terminal of the photovoltaic inverter or an input terminal of an inverter circuit of the photovoltaic inverter, and is configured to obtain output power of a solar panel; the voltage determining unit is coupled to the input terminal of the photovoltaic inverter or the input terminal of the inverter circuit of the photovoltaic inverter, and is configured to obtain an output voltage of the solar panel; wherein, when the output voltage is greater than a start-up voltage and the output power is greater than start-up power, the auxiliary power supply is started to generate a corresponding auxiliary voltage at the at least one output terminal;
wherein the voltage determining unit comprises: a start-up resistor, a start-up capacitor and a control chip;
a first terminal of the start-up resistor is coupled to a positive terminal of the input terminal of the inverter circuit or a positive terminal of the input terminal of the photovoltaic inverter, and a second terminal of the start-up resistor is coupled to a start-up terminal of the control chip, a first output terminal of the at least one output terminal and a first terminal of the start-up capacitor, respectively, and a second terminal of the start-up capacitor is grounded;
the solar panel provides an input current to the control chip via the start-up resistor, so that the voltage determining unit obtains the output voltage;
wherein when the output voltage is greater than the start-up voltage and the output power is greater than the start-up power, the control chip is started to control the auxiliary power supply to start, and a first auxiliary voltage is generated at the first output terminal to provide an operating voltage for the control chip.