Balance control system and method of three-phase active unbalanced loads of isolated grid generator

Abstract

The invention discloses a balance control system and method of the three-phase active unbalanced loads of an isolated grid generator. A phasor measurement unit is used for rapidly monitoring the unbalanced situation of three-phase active loads at the machine end of the generator and loads with large capacity and likely to run in an unbalanced way in real time. When the unbalanced degree exceeds a threshold, a single-phase controllable and adjustable balancing resistor is used to compensate one phase or two phases of a small load and at the same time, a user load unbalanced alarming system in a dispatching center is started to notice a user to increase the load at the compensated phase for the unbalanced load; in the process that the unbalanced load regains balance, the balancing resistor for compensating can be withdrawn gradually, so as to deal with next load unbalanced phenomenon.

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 generator three-phase asymmetric active loads. Background technique [0002] In isolated-operated corporate power grids, there are often serious imbalances in the three-phase active power output of certain types of loads, such as submerged arc furnaces in ferronickel production companies, due to the different depths of the electrodes inserted into the ore, and the ore material or smelting The difference in degree often results in a large difference in the active power of the three electrodes. Moreover, because the power of this type of load accounts for a large proportion of the load of the isolated grid, after the other three-phase balanced power loads are superimposed on it, the active power and current shown at the generator end still have a large degree of imbalance. The generator running under unbalanced load power will cause...

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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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