Discussion on Method of Improving the Voltage Pass Rate of High Voltage Bus in Power Plants
The deviation between the actual voltage and the reference voltage of the power grid is too large,which not only causes damage to various household and industrial electrical equipment,but also potentially endangers the normal operation of the entire grid and grid-connected generating units,and may even cause local oscillation or overall disconnection of the grid,and the grid-connected generator tripping.Maintaining the voltage of the power system within a reasonable deviation range has always been one of the issues that are highly valued by power grids and power generation companies.By ana-lyzing the AVC system architecture and operating mechanism of the power plants under unified dis-patching of East China Grid,analyzing the factors affecting the qualification rate of high voltage bus in power plants,and analyzing the reasons for the low qualification rate of 500 kV bus voltage in a certain power plant,a targeted solution is proposed.The main methods to improve the qualification rate of bus voltage are:checking the sampling accuracy and voltage drop of generator-transformer unit protection;checking and adjusting AVC constant value;checking and adjusting AVC control logic;checking the correctness of remote control device and data network;replacing the traditional voltage transmitter of generating unit with digital voltage transmitter.After treatment,the AVC qualification rate of this power plant has significantly increased.
Unified Power PlantHigh VoltageBus VoltagePass RatePower Grid