Three-phase active power asymmetrical load balance control system and control method for isolated power grid generators

Abstract

A three-phase active power asymmetrical load balance control system and control method for isolated power grid generators. Use the phasor measurement unit to monitor the asymmetry of the three-phase active load at the generator end and the load with large capacity and easy to run asymmetrically in real time. When the degree of asymmetry exceeds the threshold, use the single-phase controllable and adjustable balance resistance to compensate the 1-phase or 2-phase with a relatively small load, and at the same time start the user load asymmetry alarm system in the dispatch center to notify the user of the asymmetric load. The compensated phase increases the load, and gradually withdraws from the compensated balance resistance in the process of restoring the symmetry of the asymmetric user load to prepare for the next occurrence of asymmetric load.

Description

technical field [0001] The application belongs to the field of safe operation of generators, and in particular relates to a balance control method for three-phase asymmetric active loads of generators. Background technique [0002] In the isolated operation of the enterprise power grid, some types of loads often have serious imbalances in the three-phase active output, such as submerged arc furnaces in ferronickel production enterprises, due to the different depths of electrodes inserted into the ore, and the ore material or smelting The difference in degree often leads to a large difference in the active power of the three electrodes. Moreover, since the power of this type of load accounts for a large proportion of the isolated grid load, after the loads of other three-phase balanced power are superimposed on it, the active power and current displayed at the generator end still have a large degree of imbalance. The operation of the generator under the condition of unbalanc...

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Problems solved by technology

Moreover, since the power of this type of load accounts for a large proportion of the isolated grid load, after the load of other three-phase balanced power is superimposed on it, the active power and current displayed at the generator end still have a large degree of imbalance

The operation of the generator under the condition of unbalanced load power will cause serious vibration and heat, and damage the shaft. Therefore, in the case of serious unbalanced three-phase load current, the unbalance protection will operate, causing a shutdown event, resulting in failure to supply power normally

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