Device for switching capacitor bank based on synchronous precharging switch

Abstract

The invention provides a device for switching a capacitor bank based on a synchronous precharging switch, wherein a single-pole synchronous switch (K1), a two-pole synchronous switch (K2) and the capacitor bank are connected in series to three-phase power network voltage , precharging circuits (1), (2) and (3) are connected in parallel with two ends of main contacts of the single-pole synchronous switch (K1) and the two-pole synchronous switch (K2), the capacitor bank is precharged through the precharging circuits (1), (2) and (3) under the line voltage of a power network, and when the voltage on the main contacts of the single-pole synchronous switch and the two-pole synchronous switch and the voltage change ratio are at the zero point at the same time, the main contacts of the single-pole synchronous switch (K1) and the two-pole synchronous switch (K2) are opened or closed for switching the capacitor bank through a phase control device according to the predetermined phase angle of power network voltage. The invention further provides a scheme that two single-pole synchronous switches are used for replacing the two-pole synchronous switch. The device avoids the rush current during the process of switching the parallel capacitor bank, and is shut off during the current zero-crossing process, and the switching action is set in second level. The device is environmental-friendly and energy-saving.

Description

technical field [0001] The invention relates to the fields of reactive power compensation, harmonic filtering and grid power quality control of electric power systems, in particular to a device for switching capacitor banks based on synchronous pre-charging switches. Background technique [0002] The power grid needs reactive power compensation to achieve the purpose of stabilizing the grid voltage, improving the power factor, and reducing line loss. Switching capacitor bank is the main method to realize reactive power compensation. However, the technical status of switching capacitor bank is not optimistic. [0003] In the field of reactive power compensation, about 80% use mechanical contact switches to switch capacitors. The mechanical contact switches are three-pole switches. The three main contacts of the three-pole switch are closed and opened at the same time. The voltage phase angle switches the capacitor, and the current when it is switched in exceeds 4 times to 10...

AI Technical Summary

Problems solved by technology

Due to the difficulty of TSC technology, high energy consumption and high cost, it is only used in the low-voltage field, and there are not many applications in the medium-voltage field.

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