Three-phase imbalance adjusting device and method based on phase-change switch

Abstract

The invention provides a three-phase imbalance adjusting device and method based on phase-change switches. The three-phase imbalance adjusting device comprises a main controller and a plurality of phase-change switches, wherein the main controller is installed at the wire outlet end of a transformer, the phase-change switches are installed at the wire inlet ends of corresponding single-phase loads, and the main controller is in communication connection with the phase-change switches. According to the scheme, the problem of actual load distribution is fundamentally solved, the line loss rate of the transformer area is reduced while the problem of three-phase load imbalance is treated, and the concept of treating both symptoms and root causes is met.

Description

technical field [0001] The invention belongs to the technical field of DC resistance test of offshore transformer windings, and in particular relates to a three-phase unbalance adjustment device and an adjustment method based on a commutation switch. Background technique [0002] Three-phase current imbalance is an important index to measure the quality of power grid, and the quality of power grid directly determines the quality of power consumption of users, and its importance is self-evident. [0003] The power load of the low-voltage distribution network is relatively complex, and most of them are single loads. Although the load has been evenly distributed to the three phases A, B, and C during the construction of the station area, due to the randomness of users' electricity consumption habits and loads, the actual The upper load cannot achieve balanced distribution, which is the root cause of the unbalanced three-phase load problem. [0004] The harm caused by the unbal...

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Problems solved by technology

[0005] 1 Causes the loss of distribution transformers and lines to increase, reducing the reliability of power supply;

[0006] 2 The distribution transformer will generate a large zero-sequence current when the three-phase load is seriously unbalanced, and the zero-sequence flux generated by the zero-sequence current will cause the transformer to generate additional iron loss and generate heat. In severe cases, the distribution transformer will be burned

Generate zero-sequence current through the neutral wire, causing additional loss, and in severe cases, the neutral wire will be burned;

[0007] 3 The quality of the heavy-duty phase power supply voltage is greatly reduced;

[0008] 4. It causes the neutral point of the system to shift, and the voltage at the end of the heavy-duty phase is low, resulting in partial load failure, resulting in a reduction in the output of the distribution transformer and a decrease in power conversion efficiency;

However, there are still some defects in the above-mentioned scheme. For example, the above-mentioned scheme cannot fundamentally solve the problem of actual load balance distribution. It is not suitable to install the adjustment device of the above-mentioned scheme in the distribution station area where the conventional low-voltage reactive power compensation device has been configured, resulting in the above-mentioned adjustment device. The scope of application is limited

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