{
  "$type": "site.standard.document",
  "description": "This application discloses an energy storage system, an on/off-grid switching method, and a power conversion system. The energy storage system includes at least two power conversion systems PCSs, output terminals of the at least two PCSs are connected in parallel to connect to an alternating…",
  "path": "/patents/1402653",
  "publishedAt": "2025-01-29T00:00:00.000Z",
  "site": "at://did:plc:oql6ds5vnff4ugar6rruliwd/site.standard.publication/3mn3ohu7oxx5w",
  "tags": [
    "H02J15/00",
    "HUAWEI DIGITAL POWER TECH CO LTD [CN]"
  ],
  "textContent": "This application discloses an energy storage system, an on/off-grid switching method, and a power conversion system. The energy storage system includes at least two power conversion systems PCSs, output terminals of the at least two PCSs are connected in parallel to connect to an alternating current power grid, and input terminals of the at least two PCSs are connected to an energy storage power supply. A first PCS of the at least two PCSs includes a voltage detection circuit, a power conversion circuit, and a controller. The first PCS is any one of the at least two PCSs. The voltage detection circuit detects a power grid voltage at a parallel connection point of the output terminals of the at least two PCSs. When determining, based on the power grid voltage at the parallel connection point, that islanding occurs in the alternating current power grid, the controller adjusts an angle of an output voltage of the first PCS to a reference angle, so that angles of output voltages of the at least two PCSs are the same. The reference angle is obtained by the first PCS based on an angular frequency of the power grid voltage when the at least two PCSs are on-grid. During on/off-grid switching, angles of the output voltages of the PCSs are the same, thereby suppressing a cross current.",
  "title": "ENERGY STORAGE SYSTEM AND ON/OFF-GRID SWITCHING METHOD"
}