Spot network type power receiving and transforming protective apparatus

Claim 1

An apparatus for protecting a spot network type power receiving and transforming system, comprising: (i) spot network protector means including: a common bus connected to loads, a plurality of branch buses connected to one end of said common bus and connected also to a plurality of power supply buses respectively, series circuits of network transformers, current transformers and protector circuit breakers connected to said branch buses respectively, and network relays connected in parallel with said series circuits of said current transformers and said protector circuit breakers respectively, said current transformers detecting reverse current flowing toward said power supply buses through said common bus, and said network relays operating in response to the detection of said current to trip said protector circuit breakers; (ii) an electric generator connected to the other end of said common bus through a generator circuit breaker and operating in parallel with said spot network protector means; and (iii) a link circuit breaker connected to said common bus between said spot network protector means and said electric generator, any one of said protector circuit breakers, said link circuit breaker and said generator circuit breaker being tripped under the condition that all of said circuit breakers and said network relays are in operation, thereby cutting off the path of current from said electric generator.

Claim 2

An apparatus for protecting a spot network type power receiving and transforming system, comprising: (i) spot network protector means including: a common bus connected to loads, a plurality of branch buses connected to one end of said common bus and connected also to a plurality of power supply buses respectively, series circuits of network transformers, current transformers and protector circuit breakers connected to said branch buses respectively, and network relays connected in parallel with said series circuits of said current transformers and said protector circuit breakers respectively, said current transformers detecting reverse current flowing toward said power supply buses through said common bus, and said network relays operating in response to the detection of said current to trip said protector circuit breakers; (ii) an electric generator connected to the other end of said common bus through a generator circuit breaker and operating in parallel with said spot network protector means; and (iii) a link circuit breaker connected to said common bus between said spot network protector means and said electric generator, any one of said protector circuit breakers, said link circuit breaker and said generator circuit breaker being tripped under the condition that all of said circuit breakers and said network relays are in operation, thereby cutting off the path of current from said electric generator.

Claim 12

An apparatus for protecting a spot network type power receiving and transforming system, comprising: (i) spot network protector means, including: a common bus connected to loads, a plurality of circuits connected between said common bus and a plurality of power supply buses, each said circuit including a network transformer in series with a current transformer and a protective circuit breaker with said current transformer and said protector circuit breaker located on the common bus side of said network transformer, and a plurality of network relays each connected in parallel with a series connection of said current transformer and said protector circuit breaker, said current transformers detecting reverse current flowing toward said power supply buses through said common bus, and said network relays operating in response to said current to trip said protector circuit breakers; (ii) an electric power generator connected to an end of said common bus through a generator circuit breaker and operating coincident with said spot network protector means; (iii) a link circuit breaker connected to said common bus between said spot network protector means and said electric power generator; and (iv) condition means for selectively causing one of said protector circuit breakers, said link circuit breaker or said generator circuit breaker to be tripped under the condition that all of said circuit breakers and said network relays are in operation, thereby cutting off the path of current from said electric generator.

Claim 13

An apparatus for protecting a spot network type power receiving and transforming system, comprising: (i) spot network protector means, including: a common bus connected to loads, a plurality of circuits connected between said common bus and a plurality of power supply buses, each said circuit including a network transformer in series with a current transformer and a protective circuit breaker with said current transformer and said protector circuit breaker located on the common bus side of said network transformer, and a plurality of network relays each connected in parallel with a series connection of said current transformer and said protector circuit breaker, said current transformers detecting reverse current flowing toward said power supply buses through said common bus, and said network relays operating in response to said current to trip said protector circuit breakers; (ii) an electric power generator connected to an end of said common bus through a generator circuit breaker and operating coincident with said spot network protector means; (iii) a link circuit breaker connected to said common bus between said spot network protector means and said electric power generator; and (iv) condition means for selectively causing one of said protector circuit breakers, said link circuit breaker or said generator circuit breaker to be tripped under the condition that all of said circuit breakers and said network relays are in operation, thereby cutting off the path of current from said electric generator.