【摘要】 提出一种能自适应补偿绕组是分级绝缘的新型发电机———高压发电机(Powerformer)的定子电容电流方法,以提高其差动保护的灵敏度。根据高压发电机正常运行时产生的电容电流,自适应地确定一个“虚拟”的等效系数,用该等效系数将绕组总电容以集中电容的形式分割成2个电容,等效“虚拟”地分布在机端和中性点以计算电容电流。在此基础上,依据线路差动保护的补偿方式进行电容电流补偿,则无论高压发电机处于何种运行状态,差动电流中的电容电流都可以被完全补偿,从而提高了保护的灵敏度。经过仿真验证,该自适应补偿方法简单可行,效果显著。更多还原

【Abstract】 This paper presents a self-adaptive compensated differential protection of AC synchronous generators, a particular type of high-voltage graded insulated cable-wound generator, Powerformer. The phase voltages at the terminals are utilized to estimate the capacitive currents when the generator is synchronized and no fault is detected. With the calculated capacitive current the “suppositional” capacitance distribution coefficient along with the winding of the generator can be determined. This capacitance will be equivalently arranged “suppositionally” on the terminal and neutral of the generator respectively. Then, the capacitive current in the case of normal operation, external fault and internal fault can be calculated using the terminal voltage and the determined capacitance. It can be compensated to improve the reliability of the differential protection. The feasibility and effectiveness of the proposed scheme is demonstrated with the simulation test results.更多还原