A new high speed bus transfer relay design, implementation and testing

Bus transfer restores designated critical loads to an alternate source when utility derived service becomes inadequate or goes out of service due to any contingency. The proliferation of technology has made global conduction of business increasingly dependent upon the availability of reliable power. As a result, alternate power systems are being installed and expanded to protect the broadening scope of critical electrical loads. This paper describes the design, implementation and testing of a new bus transfer relay which decides the type of transfer to alternate source based on the motor bus open circuit voltage. The algorithm detects the fast bus transfer, in-phase transfer and the residual voltage transfer. A new high-speed automatic bus transfer scheme is proposed which includes the development of a new algorithm for determining the type of bus transfer required and the realization of the scheme by using modern suitable hardware