Thermal protection relay PCS-987R

Sub-synchronous oscillations (SSO) can occur when the turbinegenerators are connected to the power grid with some electrical cases include: transmission line series capacitors, HVDC converters, large-scale wind power generation, etc. Under the action of SSO, the shaft system of turbine-generator will be in a state of torsional vibration, resulting in fatigue loss. In some severe cases, it may lead to the shaft cracks, bolt cut or coupling twist. PCS-987R is a digital protective relay of torsional stress relay (TSR) which provides monitoring and protection of the torsional vibration for large-scale thermal power, nuclear power and other power generation units. • Current transformer supervision function (CTS) • Voltage transformer supervision function (VTS) • Rotational speed signal supervision function (four rotational speed signal sensors, installed at turbine end and exciter end) • Optical fiber communication supervision