Abstract: The present disclosure relates to a protective relay. According to the present disclosure, the handle is fixed or separated by a lever structure rather than a gear structure, so that the user may easily fix or separate the handle to or from the outer casing. Therefore, convenience and operability of the user are improved.

Abstract: The present disclosure relates to a protective relay. According to the present disclosure, the handle is fixed or separated by a lever structure rather than a gear structure, so that the user may easily fix or separate the handle to or from the outer casing. Therefore, convenience and operability of the user are improved.

Abstract: Embodiments of an electric power measuring system capable of computing accurate electric power information using a low voltage measuring instrument in a small-scale electric power system are provided. The electric power measuring system may include a first measuring instrument for measuring and detecting a current and a zero-cross point from a distribution line and for generating and outputting current information of the distribution line from the current and the zero-cross point, and a second measuring instrument for computing electric power information of the distribution line according to a voltage thereof and the current information output from the first measuring instrument.

Abstract: Embodiments of an electric power measuring system capable of computing accurate electric power information using a low voltage measuring instrument in a small-scale electric power system are provided. The electric power measuring system may include a first measuring instrument for measuring and detecting a current and a zero-cross point from a distribution line and for generating and outputting current information of the distribution line from the current and the zero-cross point, and a second measuring instrument for computing electric power information of the distribution line according to a voltage thereof and the current information output from the first measuring instrument.

Abstract: Disclosed are a control unit for a circuit breaker capable of controlling and monitoring various types of switches such as a circuit breaker and a switchgear included in power system equipment, by being attached to the switches or by being implemented in the form of an independent module, and a controlling method thereof. The control unit for a circuit breaker, which interworks with a relay and a circuit breaker, includes: an Ethernet drive configured to receive a GOOSE message type control signal from the relay connected thereto through Ethernet communication; a control module configured to operate the circuit breaker based on the GOOSE message type control signal; and a main control unit (MCU) module configured to transmit the GOOSE message type control signal to the control module, if the received GOOSE message type control signal is related to the control unit.

Abstract: Disclosed is a memory sharing circuit for sharing a memory, the circuit including a plurality of unit processors connected to the memory, wherein the unit processor includes a buffer configured to be connected through the memory, a buffering address and a data bus, and a processor configured to be connected to the buffer for access to the memory through the buffer, and wherein the plurality of unit processors is configured to allow the processors to share the memory by preventing address/data bus collision for access to the memory by the processors.

Abstract: A digital protective relay includes at least one daughter PCB having an electronic circuit which generates electromagnetic interference noise or high frequency noise; and a backplane printed circuit board having, on an upper surface thereof, a plurality of first connectors for connection with the daughter PCB, connected to the daughter PCB through the first connectors, and providing a noise discharge path along which the electromagnetic interference noise or the high frequency noise from the daughter PCB flows to an external ground.

Abstract: Disclosed are a control unit for a circuit breaker capable of controlling and monitoring various types of switches such as a circuit breaker and a switchgear included in power system equipment, by being attached to the switches or by being implemented in the form of an independent module, and a controlling method thereof. The control unit for a circuit breaker, which interworks with a relay and a circuit breaker, includes: an Ethernet drive configured to receive a GOOSE message type control signal from the relay connected thereto through Ethernet communication; a control module configured to operate the circuit breaker based on the GOOSE message type control signal; and a main control unit (MCU) module configured to transmit the GOOSE message type control signal to the control module, if the received GOOSE message type control signal is related to the control unit.

Abstract: A self-power circuit for a protecting relay includes: a rectifying circuit section rectifying an AC current from an electric power system; a power source circuit section includes: a comparator comparing whether an output voltage from the rectifying circuit section exceeds a reference voltage and a semiconductor switch configured to be switched by an output from the comparator, and supply the output voltage from the rectifying circuit section, as a constant voltage to a microcomputer unit of the protecting relay; an inductor configured to, when a DC current supplied from the rectifying circuit section is rapidly increased, gradually increase the DC current to flow to thus have an increased voltage thereacross; and a bi-directional diode connected between the power source circuit section and a ground and turned on to form a bypass path of a current when a DC voltage supplied from the power source circuit section is rapidly increased.

Abstract: Disclosed is a memory sharing circuit for sharing a memory, the circuit including a plurality of unit processors connected to the memory, wherein the unit processor includes a buffer configured to be connected through the memory, a buffering address and a data bus, and a processor configured to be connected to the buffer for access to the memory through the buffer, and wherein the plurality of unit processors is configured to allow the processors to share the memory by preventing address/data bus collision for access to the memory by the processors.

Abstract: A digital protective relay includes at least one daughter PCB having an electronic circuit which generates electromagnetic interference noise or high frequency noise; and a backplane printed circuit board having, on an upper surface thereof, a plurality of first connectors for connection with the daughter PCB, connected to the daughter PCB through the first connectors, and providing a noise discharge path along which the electromagnetic interference noise or the high frequency noise from the daughter PCB flows to an external ground.