Isolated power grid operation mode identification and control method

• Main Authors: HUANG XIAOPENG, LU JUNFENG, ZHAO SHUAIDA, WEI LAI, DING YONGYUN, YE ZHENQI, QI YUNFENG, ZHAO YIZHOU
• Format: Patent
• Language: Chinese; English
• Published: 31.07.2020
• Subjects: CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTINGELECTRIC POWER; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; GENERATION; SYSTEMS FOR STORING ELECTRIC ENERGY

An isolated power grid operation mode identification and frequency control method is used for identifying whether a regional power grid where a generator set is located is in an isolated power grid operation mode after being split from a large power grid, and converting a DEH of a steam turbine generator set into a rotating speed control mode. The method comprises the following steps that (1) it is judged that the rotating speed of the steam turbine generator unit exceeds 3090 rpm twice within T1 time; (2) judging that the reduction amplitude of the power of the generator reaches Q1 within T2;(3) the residual load of the generator is greater than the maximum power consumption Q2 of the plant; and (4) converting the DEH system of the generator set into a rotating speed control mode from apower control mode. According to the method, the steam turbine generator unit can operate without disconnecting the main transformer high-voltage side circuit breaker with the regional isolated powergrid, and the frequency of