Three-phase real load warning and severe unbalance alarm system on the low-voltage side of the distribution transformer station area

Abstract

The invention discloses a three-phase real load warning and severe unbalance alarm system on the low-voltage side of a distribution transformer station area. The system includes a three-phase load severe unbalance alarm circuit, including: three sampling coils arranged on the three-phase phase lines And a three-phase open triangle residual voltage acquisition device, a bridge shaping circuit, a filter circuit, a voltage stabilizing circuit and an alarm circuit connected in sequence; it also includes a three-phase real load warning circuit, the three-phase real load warning circuit and three sampling Hollow coil connection, including sequentially connected A / D conversion circuit, micro control unit MCU for internal logic control and data processing of warning circuit, D / f conversion circuit, frequency division counter and LCD three-phase load current real-time display device. The system of the present invention can be directly connected to the three-phase phase line, not only can send out the alarm of three-phase load imbalance in time, but also can display the specific line current value of the three-phase load in real time, adjust the load in time, and avoid the occurrence or expansion of accidents.

Description

technical field [0001] The invention relates to transformer operation protection and low-voltage distribution line operation protection, in particular to a three-phase real load warning system and serious imbalance alarm system on the low-voltage side of a distribution transformer station area. Background technique [0002] There are a large number of three-phase four-wire connection methods in urban and rural areas in my country, and the distribution transformer is Yyn0 connection method, and there are many single-phase user loads. Therefore, unbalanced operation of three-phase loads is actually inevitable. When the three-phase load is unbalanced, it is very likely to cause transformer burnout and serious accidents in distribution lines. [0003] At present, there are two kinds of methods to solve the problem of unbalanced three-phase load: [0004] One is the manual adjustment method. When one of the three-phase loads is sensed or measured with a larger current, it transf...

AI Technical Summary

Problems solved by technology

When the three-phase load is unbalanced, it is very likely to cause transformer burnout and serious accidents in distribution lines

The problem with this method is: first, the unbalanced state of the three-phase load cannot be found immediately, so the dangerous state cannot be relieved immediately; second, even if the three-phase unbalance is found, the three-phase cannot be adjusted to the basic balance, because by monitoring the zero line The current method can only know that the three-phase load is unbalanced, but it cannot know which phase load is too large or too small, so the adjustment is blind

The problem of this method is: the cost is huge, it is easy to affect the normal operation of the line, it is easy to interfere with the normal operation of the power consumption information collection system, it is easy to cause power outages for users, and the installation and maintenance costs are high. The only advantage of this system is that it can automatically load adjust

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