Rapid switching device for 110kV power system of petrochemical enterprises

Abstract

Provided is a rapid switching device for a 110kV power supply system of petrochemical enterprises. The rapid switching device comprises a microcomputer chip, and the microcomputer chip determines whether a reverse power starting condition, a zero-current starting condition, a voltage-loss starting condition, a tripping error starting condition and a protection starting condition are satisfied; if the tripping error condition is satisfied, a switching operation is started, and whether the other conditions are satisfied are further determined successively; if any condition except the tripping error condition is satisfied, an incoming switch tripping command is emitted, the switching operation is started, and whether a rapid switching condition, a same-period capture switching condition, a residual voltage switching condition and a long delay switching condition are satisfied is determined successively; if one of the condition is satisfied, determination is stopped, and a corresponding switching command, namely a rapid switching command or a same-period capture switching command or a residual voltage switching command or a long time delay switching command, is transmitted. Thus, the 110kV power supply system of petrochemical enterprises can be stably switched between a working power supply and a standby power supply.

Description

technical field [0001] The invention relates to a fast switching device used in a 110kV power system of a petrochemical enterprise. Background technique [0002] The traditional standby automatic switching method is to switch on the backup power supply by detecting the residual voltage on the line after the external line trips due to a fault such as lightning strike. [0003] Such as figure 1 It is a schematic diagram of the 6KV bus residual voltage characteristics of a 300MW unit, V D is the residual voltage of the busbar, the arc ABCD indicates the phasor change trajectory of the residual voltage of the busbar, and △U is the differential pressure between the backup power supply voltage and the residual voltage of the busbar. [0004] For the convenience of analysis, we take a power system and a single motor as an example, fully simplify the equivalent circuit of the backup power system and the motor according to the transient analysis model, ignore the winding resistance...

AI Technical Summary

Problems solved by technology

However, since the power system of petrochemical enterprises contains large-scale electrical equipment such as generators and synchronous motors, it is quite different from the type of factory electrical equipment. For example, the motors used in factories are asynchronous motors. The fast switching device of the factory power backup power supply cannot guarantee the safety of the above-mentioned generators, synchronous motors and other large electrical equipment when switching

[0021] In addition, there are many large-capacity fans, compressors and other equipment inside the petrochemical system. These devices are loads with large moment of inertia. There is a large difference in speed, and there are also differences in the settings of the fast switching device and the factory power.

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