公开(公告)号：US11239746B2

公开(公告)日：2022-02-01

申请号：US16783310

申请日：2020-02-06

Applicant: SUNGROW POWER SUPPLY CO., LTD.

Inventor： Tao Zhao ,  Fushuai Zhuang ,  Xinyu Wang ,  Jiacai Zhuang ,  Mingda Wang ,  Yuan Zhuang

IPC: H02M1/36 ,  H02M1/08 ,  H02M3/335 ,  H02M7/5387 ,  H02J3/38 ,  H02M1/00

Abstract: A two-stage converter, a method for starting the two-stage converter, an LLC converter, and an application system are provided. A controller of the LLC converter of the two-stage converter first controls a main circuit of the LLC converter to perform hiccup charging on a direct current bus of a later-stage converter at a preset interval, so that the direct current bus voltage of the later-stage converter gradually increases, until an auxiliary power supply of the later-stage converter starts to operate, to supply power to the controller of the later-stage converter. After the controller of the later-stage converter reports the detected direct current bus voltage, the controller of the LLC converter determines whether the output voltage of the LLC converter increases to a hiccup starting voltage. If so, the controller of the LLC converter controls the main circuit to operate in a hiccup voltage stabilization phase.

公开(公告)号：US10680550B2

公开(公告)日：2020-06-09

申请号：US15474022

申请日：2017-03-30

Applicant: SUNGROW POWER SUPPLY CO., LTD.

Inventor： Jun Xu ,  Tao Zhao ,  Yilei Gu

IPC: H02S40/32 ,  H01L31/05 ,  H02J3/16 ,  H02J3/38 ,  H02S40/36 ,  H02M7/49 ,  H02M1/42 ,  H02M1/00

Abstract: Provided are a cascaded photovoltaic grid-connected inverter, a control method and a control device for the same. The method includes: determining whether at least one of inverter units of the cascaded photovoltaic grid-connected inverter is over-modulated; injecting a reactive current to a power grid to make a grid-connected current effective value greater than or equal to √{square root over (2)}*idcmin, in a case that at least one of the inverter units is over-modulated; determining a voltage U0 required for grid connection for the cascaded photovoltaic grid-connected inverter corresponding to a current grid-connected current effective value; and adjusting an output active voltage of each of the inverter units according to Ujd=Pj/P0*U0d, and adjusting an output reactive voltage of each of the inverter units in a case that none of the inverter units is over-modulated.

公开(公告)号：US10978964B2

公开(公告)日：2021-04-13

申请号：US16239160

申请日：2019-01-03

Applicant: SUNGROW POWER SUPPLY CO., LTD.

Inventor： Xinyu Wang ,  Tao Zhao ,  Jiacai Zhuang ,  Jun Xu ,  Yilei Gu

IPC: H02M7/49 ,  H02J3/38 ,  H02M3/335 ,  H02M1/00 ,  H02J3/18

Abstract: A medium and high voltage energy conversion system is provided. An input terminal of each of high-voltage isolated DC/DC converters in a phase circuit of the system is connected to a common DC bus. Each of the high-voltage isolated DC/DC converters converts, based on an open-loop control strategy or a closed-loop control strategy, a DC input voltage of a cascade module connected to the high-voltage isolated DC/DC converter into an instruction value related to a voltage of the common DC bus. A system controller of the system calculates, based on at least a voltage-current double loop control strategy, a three-phase modulation instruction to be sent to the cascade modules in three phases according to a parameter related to the voltage of the common DC bus, to implement grid-connected control on three phase circuits.