A three-phase load balancing method for distribution transformers

Abstract

The invention discloses a three-phase load balance adjusting method for a distribution transformer. The three-phase load balance adjusting method for the distribution transformer comprises the steps of switching A phase to B phase; switching A phase to C phase, and switching B phase to C phase; switching B phase to A phase. According to the three-phase load balance adjusting method for the distribution transformer, on-load switching is achieved, the switching time is shorten than 2 ms, and the three-phase load balance adjusting method for the distribution transformer is more scientific and more practical.

Description

technical field [0001] The invention relates to a balancing method, in particular to a three-phase load balancing method for distribution transformers. Background technique [0002] At present, the total capacity of transformers in operation in my country is about 3.5×10 9 kVA, due to the large number of units and large capacity, the power loss is very large. According to statistics, the power loss of distribution transformers (referred to as distribution transformers) alone is about 30-50 TWh per year, accounting for about 2-3% of the total power generation. At present, the capacity of low-efficiency distribution transformers operating on the power grid for more than 20 years is about 2.4×10 8 At the same time, these distribution transformers have aging parameters, high loss, many defects, and poor operation reliability, which threatens the safe operation of the power grid. Therefore, the distribution transformation task and the potential for energy saving are huge, amon...

AI Technical Summary

Problems solved by technology

[0004] 1. Impact on distribution transformers: unbalanced three-phase loads will increase the loss of transformers: unbalanced three-phase loads may cause serious consequences of burning the transformer; unbalanced operation of three-phase loads will cause excessive zero-sequence current of the transformer, local metal The temperature rise of the components increases, resulting in safety hazards

[0005] 2. The impact on high-voltage lines: increase the loss of high-voltage lines; increase the number of high-voltage line trips and reduce the service life of switchgear

[0006] 3. Impact on power distribution panels and low-voltage lines: Unbalanced three-phase loads will increase line losses; unbalanced three-phase loads may cause serious consequences of burning out lines and burning switchgear

[0007] 4. Impact on power supply companies: power supply companies directly manage households, low-voltage power grids have large losses, transformers burn out, lines burn out, and switchgear burns out. On the one hand, it increases the power supply costs of power supply companies; Replacement causes long-term power outages and less power supply, which not only reduces the economic benefits of power supply companies

[0008] 5. Impact on users: unbalanced three-phase load, abnormal weight of one or two phases will increase the voltage drop in the line, reduce power quality, and affect the use of electrical appliances by users

[0009] The defects of the existing balancing method are as follows: the commutation time is long, and the switching time is more than 100 milliseconds. The switching process will cause a short-term power outage and affect the normal operation; Can only be switched under no-load conditions; remote control switching cannot be realized

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