The WMH-800 is a microcomputer-based complete busbar protection device specifically designed for power plants and substations of all voltage levels with generator capacities up to 1000 MW. It is applicable to various main connection schemes including single busbar, sectionalized single busbar, double busbar, and double busbar with bypass. The device integrates comprehensive busbar protection functions, ensuring fast and reliable clearing of busbar zone faults.

The device provides phase-segregated conventional percentage restrained differential protection and phase-segregated sudden-change percentage restrained differential protection, featuring large differential backup protection and composite voltage blocking for differential protection. For special bus coupler and breaker conditions, it includes bus coupler dead-zone protection, bus coupler breaker failure protection, breaker failure protection with composite voltage blocking, bus coupler charging overcurrent protection, and bus coupler non-full-phase protection. Additionally, it supports line breaker failure de-blocking of voltage blocking, CT break alarm and blocking, PT break alarm, and features automatic busbar configuration identification to adapt to changes in operating conditions.

Application Scenario

Power plants up to 1000 MW

Substations of 110 kV and above

Single busbar and sectionalized single busbar connections

Double busbar and sectionalized double busbar connections

Double busbar with bypass connection

The WMH-800 management unit (control module) serves as the central processor, implementing the complete set of protection functions.

As an acquisition and execution unit, the WMMH-800S sub-unit is configured by bay. Each sub-unit can acquire three sets of busbar voltages, or acquire current and binary input signals of one circuit and transmit them to the master unit.