Time-varying damping characteristic control method for voltage-sensitive industrial loads in isolated power grid

• Main Authors: SUN YUANZHANG, DONG JIANXUN, XU JIAN, QU YINPENG, LI XIAOMIN, LIAO SIYANG, GU JUNHE, BAO YI, ZHOU MI
• Format: Patent
• Language: English
• Published: 01.04.2015
• Subjects: CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTINGELECTRIC POWER; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; GENERATION; SYSTEMS FOR STORING ELECTRIC ENERGY

The invention discloses a time-varying damping characteristic control method for voltage-sensitive industrial loads in an isolated power grid. When system power disturbance is larger than the primary frequency modulation capacity of a power generator set, the control method is started. The method includes the steps that first, steady-state frequency offset and a steady-state load damping coefficient are acquired; second, a transient-state load damping coefficient and the time moment corresponding to maximum frequency offset under the transient-state load damping coefficient are acquired; third, a voltage sensitivity coefficient between load nodes and power generator nodes is acquired; fourth, according to the steady-state load damping efficient, the transient-state load damping coefficient and the voltage sensitivity coefficient, gain parameters corresponding to the steady-state load damping efficient and the transient-state load damping coefficient are calculated; fifth, a parameter K, fed back by pull-in frequency deviation, in a closed loop control excitation system is set as the gain parameters. According to the control method, the frequency response characteristics of the system are changed by changing the damping coefficients of electrolytic aluminum loads, and therefore frequency stability under isolated power grid power disturbance can be improved.