REU615 is available in two standard configurations, denoted A and B. The A configuration is designed for voltage and frequency based protection applications in utility and industrial power systems. The B configuration is designed for automatic voltage regulator functions for power transformers equipped with an on-load tap-changer. The A and B configurations also allow CB control and provide measuring and supervising functions.
A configuration
The A configuration provides busbar overvoltage and undervoltage supervision, network residual voltage and frequency supervision. REU615 also offers the functionality needed to provide load shedding and generation rejection in order to enhance network stability in situations of excessive load. In generator and motor applications REU615 provides additional protection by supervising frequency and voltage. An integrated synchro-check function ensures a safe connection of a rotating machine to the network. In distribution networks with distributed power generation REU615 can be used for loss-of-mains (LOM) protection for single power generation units.
B configuration
The B configuration featuring voltage regulation capability is targeted for automatic and manual voltage regulation of power transformers equipped with a motor driven on-load tap-changer. In small substations with a single power transformer REU615 can be used for load-side voltage regulation. For substations with two or more power transformers operating in parallel three alternative voltage regulation methods are selectable, i.e. the master/follower principle, the negative reactance principle or the minimizing circulating current principle.
REU615 features genuine support for the IEC 61850 standard for communication in substations covering both vertical and horizontal communication, including GOOSE messaging both binary and analog signals and parameter setting according to IEC 61850-8-1. It also supports the DNP3, the IEC 60870-5-103 and the Modbus® protocols. REU615 offers an optional Ethernet port for self-healing communication in ring networks. The solution eliminates single point of failure concerns and improves the reliability of the communication. The solution can be applied for the Ethernet based IEC 61850, Modbus® and DNP3 protocols.
REU615 is a member of ABB’s Relion® product family and its 615 series.