Abstract: A gas insulated switchgear has: circuit breakers, circuit breaker vessels, first disconnector and maintenance earthning switches connected to first bus bars connected to circuit breaker vessels and also to main bus bars, second disconnector and maintenance earthning switches connected to second bus bars connected to the circuit breaker vessels, circuit breaker operating mechanisms, first and second disconnector and maintenance earthning switch operating mechanisms, and first and second disconnector and maintenance earthning switch operation links for linking the disconnector and maintenance earthning switches and the operating mechanisms for three phases. The second disconnector and maintenance earthning switch operation links are arranged so as to pass through inter-phases of the first bus bars and the operating panels of the circuit breaker operating mechanism and the first and second disconnector and maintenance earthning switch operating mechanisms of each phase are arranged on a common flat plane.

Abstract: A gas insulated switchgear has: circuit breakers, circuit breaker vessels, first disconnector and maintenance earthning switches connected to first bus bars connected to circuit breaker vessels and also to main bus bars, second disconnector and maintenance earthning switches connected to second bus bars connected to the circuit breaker vessels, circuit breaker operating mechanisms, first and second disconnector and maintenance earthning switch operating mechanisms, and first and second disconnector and maintenance earthning switch operation links for linking the disconnector and maintenance earthning switches and the operating mechanisms for three phases. The second disconnector and maintenance earthning switch operation links are arranged so as to pass through inter-phases of the first bus bars and the operating panels of the circuit breaker operating mechanism and the first and second disconnector and maintenance earthning switch operating mechanisms of each phase are arranged on a common flat plane.

Abstract: A digital protection and control device is so configured that at least parts of a digital data merging unit coupled to sensor units by a transmission medium, a protection and control unit, a communication unit for component control devices coupled to component control devices by a transmission medium, and a process bus communication unit are coupled by a parallel transmission medium, and at least a part of data exchange is based on a multimaster mode. Transmission based on the multimaster mode enables each unit to transmit/receive data independently and enables the reduction in unbalanced communication load. As a result, such a risk can be reduced that time responsiveness of operation is lowered as the entire digital protection and control device due to unbalanced concentration of data bus processing in a particular unit.

Abstract: The present invention relates to a system for protecting and controlling main-circuit components of an electricity transmission substation. The system includes devices for digital data output, protection-and-controlling, component controlling-and-monitoring, and communication. The digital data output devices input analogue AC electric values and output digital data. The protection-and-controlling devices input the data from the digital data output devices, and further control, monitor, and protect the substation main-circuit components. The component controlling-and-monitoring devices receive commands from the protection-and-controlling devices or from the substation controlling-and-monitoring equipment, and further control and monitor the substation main-circuit components. The devices for digital data output, the protection-and-controlling, and component controlling-and-monitoring are disposed near or within their corresponding substation main-circuit components.

Abstract: A digital protection and control device is so configured that at least parts of a digital data merging unit coupled to sensor units by a transmission medium, a protection and control unit, a communication unit for component control devices coupled to component control devices by a transmission medium, and a process bus communication unit are coupled by a parallel transmission medium, and at least a part of data exchange is based on a multimaster mode. Transmission based on the multimaster mode enables each unit to transmit/receive data independently and enables the reduction in unbalanced communication load. As a result, such a risk can be reduced that time responsiveness of operation is lowered as the entire digital protection and control device due to unbalanced concentration of data bus processing in a particular unit.

Abstract: A system for protecting and controlling substation main-circuit components. The system comprises: digital data output means for inputting analogue AC electric values and outputting digital data; protection-and-controlling means for inputting the data from the digital data output means, and for controlling, monitoring and protecting the substation main-circuit components; component controlling-and-monitoring means for receiving commands from the protection-and-controlling means or the substation controlling-and-monitoring equipment, and for controlling and monitoring the substation main-circuit components; and communication means. The digital data output means, the protection-and-controlling means and the component controlling-and-monitoring means are built in their corresponding substation main-circuit components.