{
  "$type": "site.standard.document",
  "description": "The present application provides an interconnected co-phase traction power supply system based on a four-port modular multilevel converter (4P-MMC), which is constituted by connecting traction busbars of multiple interconnected co-phase traction substations to overhead lines in communication with…",
  "path": "/patents/1402640",
  "publishedAt": "2025-06-04T00:00:00.000Z",
  "site": "at://did:plc:oql6ds5vnff4ugar6rruliwd/site.standard.publication/3mn3ohu7oxx5w",
  "tags": [
    "B60M1/13",
    "CHINA RAILWAY ELECTRICAL IND CO LTD [CN]"
  ],
  "textContent": "The present application provides an interconnected co-phase traction power supply system based on a four-port modular multilevel converter (4P-MMC), which is constituted by connecting traction busbars of multiple interconnected co-phase traction substations to overhead lines in communication with each other. Each of the interconnected co-phase traction substations comprises traction transformers T1 and T2, and a stationary power converter (SPC) having three input ports and one output port. Three-phase primary ports of T1 and T2 are connected to three phases of a synchronous public alternating current electrical grid by means of circuit breakers. Three-phase secondary ports of T1 and T2 are all connected to the three input ports of the SPC, respectively. The output port of the SPC is connected to the traction busbar. The SPC is constituted by connecting k 4P-MMCs in parallel. Each of the 4P-MMCs comprises four phases. Each phase is constituted by connecting upper and lower legs in series. Neutral points of three phases of each 4P-MMC are respectively connected to corresponding input ports of the SPC by means of a three-phase circuit breaker. A neutral point of a fourth phase of each 4P-MMC is connected to the output port of the SPC by means of a circuit breaker. The present application has advantages of removal of electric phase separation for the entire overhead line, simple connections of traction transformers of substations, and high capacity utilization rate, flexible configuration, high reliability, and low costs of a system device.",
  "title": "INTERCONNECTED CO-PHASE TRACTION POWER SUPPLY SYSTEM BASED ON FOUR-PORT MODULAR MULTILEVEL CONVERTER"
}