This paper presents the design of new real time digital simulator (RTDS) based novel relay test systems. The background of the developments in protection relays and their associated technologies, such as optical transducers and IEC 61850, are introduced. The new developments in RTDS systems are described. It is shown that the recent developments in transducers and communication technology will have great impacts to the developments of protection relays and their associated RTDS based relay test systems. The paper further describes the existing, new developments and future trend in the development of protection relays and their associated RTDS systems.
Index Terms--Integrated Protection, Real-time DigitalSimulator, Relay Testing. such as conventional CTs and VTs, optical combined sensors and electronic combined sensors. The analogue and digital signals measured are converted into optical format and sent to the central protection relay through the redundant optical network. The unit also receives and executes control signals from the relay through the control circuit. Secondly an optical communication network interfaces not only to measurement and control unit, and the relay, but also to a number of other equipment, such as communication gateway, human machine interface and GPS clock, etc. The use of standard communication protocol for the network will enable IEDs from different manufacturers to be easily interfaced to the