Sécheron is currently releasing a new configuration of its unidirectional circuit breakers type UR60 & UR80 for DC traction substations.
Whereas unidirectional DC circuit breakers must remain closed in the event of a short circuit current flowing in one direction, in the opposite direction they are required to trip in case of a short circuit. The new configuration enables to equip the breaker with a unidirectional tripping device offering a much broader range for the setting 4 to 10 kA. This new feature meets requirements raised by customers on several key markets.
The unidirectional breaker can be used in different ways and for different functions as illustrated on the typical application examples below. It is sometimes used as a rectifier breaker (case A) to trip only on reverse currents in case of rectifier short-circuits. It can also be used as a line breaker to trip only in the forward direction on line short-circuits (cases A and B). Another typical application is as interconnection breaker for interconnection substations (case C), where the breaker trips only in the forward direction to limit the power supply interruption to the only line section where the short-circuit has been detected, keeping the other line sections powered.
Typical applications
Tripping devices equipped with this new feature can be installed on UR60 & UR80 compliant to EN 50123-2 / IEC 61992-2 standards and to ANSI C37.16 & C37.14 standards.
The UR60 & UR80 DC high speed circuit breakers have been protecting thousands of kilometres of heavy metro line sections since their release to the market in 2010. They can be delivered together with our disconnector range type SW for DC traction substations and other energy intensive industries including power generation, metal industries and others.
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