{
  "$type": "site.standard.document",
  "description": "A pumped storage system has: a reversible pump turbine (3); a synchronous motor generator (2) directly coupled to a runner shaft of the reversible pump turbine; and a frequency converter (1). The frequency converter has: a first power conversion unit (11) performing bidirectional AC/DC conversion…",
  "path": "/patents/965497",
  "publishedAt": "2014-12-31T00:00:00.000Z",
  "site": "at://did:plc:oql6ds5vnff4ugar6rruliwd/site.standard.publication/3mn3ohu7oxx5w",
  "tags": [
    "F03B13/06",
    "HITACHI MITSUBISHI HYDRO CORPORATION [JP]"
  ],
  "textContent": "A pumped storage system has: a reversible pump turbine (3); a synchronous motor generator (2) directly coupled to a runner shaft of the reversible pump turbine; and a frequency converter (1). The frequency converter has: a first power conversion unit (11) performing bidirectional AC/DC conversion and connected to a grid; a second power conversion unit (12) performing bidirectional AC/DC conversion and connected to the synchronous motor generator; and a storage battery (13) connected between the first and second power conversion units. The pumped storage system further has: a governor (5) for adjusting a guide vane opening of the reversible pump turbine; and a control device (4) for controlling the first and second power conversion units and the governor. The control device has a first frequency converter control unit (41) that controls the first power conversion unit (11) based on a reactive power command and an active power command input externally.",
  "title": "Pumped storage system"
}