Method for online testing performance of lead-acid storage cells of transformer substation

Abstract

The invention discloses a method for online testing performance of lead-acid storage cells of a transformer substation. The method includes the steps that capacity of each single storage cell body is acquired through an instantaneous discharge method, the inner resistance of each single storage cell body is detected through an alternating current phase method, the instantaneous discharge method is corrected by the alternating current phase method, interference of the instantaneous discharge method in neighbors of open-circuit cells is eliminated, and then real-time online nondestructive testing of the performance of a storage cell set is achieved. According to the method for online testing the performance of the lead-acid storage cells of the transformer substation, the instantaneous discharge method and the alternating current phase method are combined, the inner resistance, the capacity and other performance parameters of each single storage cell body can be measured in real time, and then the cells with degraded performance can be found in time at the early stage of degradation of the storage cells, and severe direct current system accidents caused by degradation accumulation and intensification of the storage cells are avoided.

Description

technical field [0001] The invention relates to an on-line performance testing method of a substation lead-acid storage battery, which relates to the field of substation direct current power supply monitoring. Background technique [0002] The DC power supply part of the substation in the power system is composed of battery packs, charging modules, DC screens and other equipment. As a DC backup power supply, the battery is usually in a floating charge state. Once the AC power fails, the battery can supply power to the DC system. At present, most of the batteries used in substations are "maintenance-free batteries", namely: valve-regulated sealed lead-acid batteries (VRLA). The so-called "maintenance-free" means that there is no need to add water, add acid, change fluid and other maintenance. The detection of the performance state of the battery is only to measure the floating charge voltage and current of the battery pack; the real capacity of the battery cannot be accurat...

AI Technical Summary

Problems solved by technology

The disadvantage is: there is no linear correspondence between impedance or conductance and battery capacity, and the data needs to be analyzed after the measurement results are obtained

Disadvantages are: for the battery pack connected in series, the open-circuit battery has a great influence on the test of the internal resistance of adjacent batteries. In addition, there is no completely linear correspondence between the internal resistance and the capacity. After the internal resistance test, manual analysis is still required to judge the condition of the battery.

The open circuit voltage has a good correspondence with the battery capacity. The disadvantage is that the measurement of the open circuit voltage must be carried out in the offline state of the battery, and it must be stable for more than two hours, so it cannot be put into the current substation battery.

The instantaneous discharge method can detect the true internal resistance of a single battery, but since the battery packs are connected in series, if there is an open circuit battery, it will affect the test results of the batteries near the series

The AC phase method is an effective online real-time detection method for batteries, but in the actual application process, the reliability of the detection results is greatly reduced due to the influence of various interferences such as component tolerances and charger ripples.

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