Investigation And Analysis On Configuration Of Low Voltage Protection Device For Client’s Electricity Load

Power system voltage fluctuations or fluctuations within the grid will not only on the safety and economic operation of the network has a significant adverse impact, it may lead to user equipment can not work properly, serious and even endanger the equipment and personal safety. In order to reduce the voltage in the grid, the timely removal of part of the load, to restore the normal power grid to create favorable conditions, but also reduce the voltage fluctuations caused by damage to electrical equipment, low-voltage release has become increasingly widely used. However, in the actual use of some of the unreasonable power user configuration, resulting in low voltage circuit breakers often occur because of the voltage flicker trip, resulting in unnecessary load loss, also contributed to the expansion of the fault range.Based on the data of 1.76 million high-voltage power customers surveyed in China, according to the electricity characteristics of various industries, the configuration of low-voltage protection device of power customer load is combed comprehensively. Combining with the data of Nanjing, The load loss is researched and the model of regional load low-voltage tripping characteristic of Nanjing Power Grid is established. According to the characteristics of users’ demand for low-voltage release, the load shedding model is developed to solve the problem of load shedding. Buckle ratio and the amplitude of voltage sag, we can accurately estimate the active power loss under the condition of known voltage sag amplitude. The example shows that the load low- voltage trip model can basically reflect the load tripping situation of each site affected by voltage sag. At the same time, this article on the market mainstream GXQ-M-type low-voltage release, for example, the use of test methods to explore its action under the action of voltage sag characteristics, combined with the test results, proposed low-voltage release of voltage dips to deal with the configuration strategy, And 455 high-voltage users in Lhasa, Tibet pilot operation, the effect is good, abnormal fluctuations in the power grid significantly reduced the impact on users.