{
  "$type": "site.standard.document",
  "description": "A method for detecting islanding conditions of a distributed grid, wherein transfer of power through a power electrical unit is controlled on the basis of a control reference and the method comprises a first stage and a second stage. The first stage comprises injecting a reactive component to the…",
  "path": "/patents/990925",
  "publishedAt": "2013-05-08T00:00:00.000Z",
  "site": "at://did:plc:oql6ds5vnff4ugar6rruliwd/site.standard.publication/3mn3ohu7oxx5w",
  "tags": [
    "H02J3/38",
    "ABB RESEARCH LTD [CH]"
  ],
  "textContent": "A method for detecting islanding conditions of a distributed grid, wherein transfer of power through a power electrical unit is controlled on the basis of a control reference and the method comprises a first stage and a second stage. The first stage comprises injecting a reactive component to the control reference, and, for at least one electrical quantity of the grid, determining a change in the quantity induced by the injected component, and determining, on the basis of the change in the electrical quantity, whether or not to move to the second stage of the method. The second stage comprises, for at least one electrical quantity of the grid, determining a value of the electrical quantity, forming a positive feedback term using at the determined value adding a positive feedback term to the control reference, determining a change in an electrical quantity induced by the feedback term, and determining islanding condition on the basis of the change in the quantity induced by the feedback term.",
  "title": "Method and apparatus for detecting islanding conditions of a distributed grid"
}