Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection integrated protection

HELECTRICITY H02Electric power H02HEMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS

H02H3/00Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection integrated protection

H02H3/003responsive to reversal of power transmission direction H02H3/006Calibration or setting of parameters H02H3/02Details H02H3/021concerning the disconnection itself H02H3/023by short-circuiting H02H3/025Disconnection after limiting H02H3/027with automatic disconnection after a predetermined time H02H3/033with several disconnections in a preferential order H02H3/04with warning or supervision in addition to disconnection H02H3/042combined with means for locating the fault H02H3/044Checking correct functioning of protective arrangements H02H3/046Signalling the blowing of a fuse H02H3/048Checking overvoltage diverters H02H3/05with means for increasing reliability H02H3/06with automatic reconnection H02H3/063Details concerning the co-operation of many similar arrangements H02H3/066Reconnection being a consequence of eliminating the fault which caused disconnection H02H3/07and with permanent disconnection after a predetermined number of reconnection cycles H02H3/08responsive to excess current H02H3/081and depending on the direction H02H3/083for three-phase systems H02H3/085making use of a thermal sensor H02H3/087for dc applications H02H3/093with timing means H02H3/0935the timing being determined by numerical means H02H3/10additionally responsive to some other abnormal electrical conditions H02H3/105responsive to excess current and fault current to earth H02H3/12responsive to underload or no-load H02H3/13for multiphase applications H02H3/14responsive to occurrence of voltage on parts normally at earth potential H02H3/16responsive to fault current to earth, frame or mass H02H3/162for ac systems H02H3/165for three-phase systems H02H3/167combined with other earth-fault protective arrangements H02H3/17by means of an auxiliary voltage injected into the installation to be protected H02H3/18responsive to reversal of direct current H02H3/20responsive to excess voltage H02H3/202for dc systems H02H3/205using a spark-gap as detector H02H3/207also responsive to under-voltage H02H3/22of short duration H02H3/24responsive to undervoltage or no-voltage H02H3/243for DC systems H02H3/247having timing means H02H3/253for multiphase applications H02H3/26responsive to difference between voltages or between currents responsive to phase angle between voltages or between currents H02H3/265responsive to phase angle between voltages or between currents H02H3/28involving comparison of the voltage or current values at two spaced portions of a single system H02H3/283and taking into account saturation of current transformers H02H3/286involving comparison of similar homopolar quantities H02H3/30using pilot wires or other signalling channel H02H3/302involving phase comparison H02H3/305involving current comparison H02H3/307involving comparison of quantities derived from a plurality of phases H02H3/32involving comparison of the voltage or current values at corresponding points in different conductors of a single system H02H3/325involving voltage comparison H02H3/33using summation current transformers H02H3/331responsive to earthing of the neutral conductor H02H3/332with means responsive to dc component in the fault current H02H3/334with means to produce an artificial unbalance for other protection or monitoring reasons or remote control H02H3/335the main function being self testing of the device H02H3/337avoiding disconnection due to reactive fault currents H02H3/338also responsive to wiring error H02H3/34of a three-phase system H02H3/343using phase sequence analysers H02H3/347using summation current transformers H02H3/353involving comparison of phase voltages H02H3/36involving comparison of the voltage or current values at corresponding points of different systems H02H3/365one of the systems simulating the other system H02H3/38responsive to both voltage and current responsive to phase angle between voltage and current H02H3/382involving phase comparison between current and voltage or between values derived from current and voltage H02H3/385using at least one homopolar quantity H02H3/387using phase-sequence analysing arrangements H02H3/40responsive to ratio of voltage and current H02H3/402using homopolar quantities H02H3/405using phase sequence analysing arrangements H02H3/407using induction relays H02H3/42responsive to product of voltage and current H02H3/422using homopolar quantities H02H3/425using phase sequence analysing arrangements H02H3/427using induction relays H02H3/44responsive to the rate of change of electrical quantities H02H3/445of DC quantities H02H3/46responsive to frequency deviations H02H3/48responsive to loss of synchronism H02H3/50responsive to the appearance of abnormal wave forms H02H3/52responsive to the appearance of harmonics