On June 7, 2021, the generator terminal subsynchronous damping control (GTSDC) system of Datang Xilinhaote (Xilinhot) power plant completed the oscillation suppression test and put into operation successfully. NR worked as the total solution provider for this project.
The successful operation of the system enhances the damping performance of the complex resonance between the generator and the grid, and can effectively solve the torsional vibration problem of the turbine generator shaft system under complex grid conditions such as UHV AC series compensation and UHV DC. It adds an effective, flexible control scheme for the shaft system safety of the unit, which has great engineering application value.
Complex grid conditions
GTSDC system is based on the chain power electronic converter installed in the stator side of the turbine generator unit.
Controlled by the speed deviation of the generator set, the power electronic converter injects the subsynchronous / supersynchronous current complementary with each mode frequency of the shafting torsional vibration to the generator set, to generate the electromagnetic torque increment of damping shaft torsional vibration, so as to suppress the subsynchronous vibration of the turbine generator set.
Reliable speed signal measurement
The GTSDC system developed by NR can adaptively identify various modal parameters of the generator set
The GTSDC system developed by NR can adaptively identify various modal parameters of the generator set, and apply such pioneering technologies as real-time correction of speed measurement deviation value, electric sudden variable startup, and variable gain combined with feed forward control, etc.
It has the advantages of high mode frequency resolution, accurate and reliable speed signal measurement, strong multi-mode damping ability, and fast response speed.
The successful operation of generator terminal subsynchronous damping control in Xilinhot power plant indicates that NR has mastered a complete set of solutions for torsional vibration of generator shaft system with risk assessment and system research, torsional stress relay (TSR), supplementary excitation damping controller (SEDC) and generator terminal subsynchronous damping control (GTSDC) as the core.
