[Technology Program] What are the dangers of three-phase unbalance

In 0.4kV low-voltage three-phase four-wire urban and rural power supply systems, the majority of electrical loads are single-phase loads. Differences in electricity usage patterns and load sizes lead to severe imbalance in actual operation of the distribution network, with most distribution substations experiencing significant three-phase imbalance exceeding the standard limits.

The hazards of three-phase load imbalance in substations are as follows:

Therefore, the power grid company has clear operational regulations: for Dy-connected transformer substations, the imbalance limit is 25%, and for Yy-connected transformer substations, the imbalance limit is 15%. Substations exceeding the limit should undergo rectification. The traditional method for rectifying three-phase imbalance in power grid companies is manual phase adjustment. However, practice has shown that manual phase adjustment is time-consuming, labor-intensive, lacks timeliness, and has poor targeting, thus ineffective in solving the problem.

ETCR5500 Phase Change Switch-type Three-phase Imbalance Management Device is a real-time, intelligent automatic load control system that schedules loaded phase changes for single-phase loads, effectively solving the problem of three-phase imbalance in low-voltage distribution networks. The ETCR5500 Phase Change Switch-type Three-phase Imbalance Management Device consists of a main controller and phase change switches. The main controller collects real-time load data for the substation, analyzes the load voltage and current for each phase change switch, and sends instructions to the phase change switches. The phase change switch ETCR5500-PEX receives instructions from the main controller and executes them.

To rectify a substation, one main controller and several phase change switches are configured based on the capacity of the substation transformer and the severity of the imbalance. The phase change switch receives instructions from the main controller to switch single-phase loads between the three phases without interrupting power supply, thus effectively solving the problem of three-phase load imbalance in distribution networks.

Guangdong ETCR Electronic Technology CO.,Ltd. focuses on the research and development, and production of intelligent electrical testing and control instruments. We adhere to technological innovation and quality excellence, meticulously crafting each product. Our main products include: ground resistance testers, high-voltage insulation resistance testers, DC resistance testers, proximity alarmers, wireless high-voltage phase detectors, ground fault patrol testers, zinc oxide arrester testers, clamp leakage current meters, high and low voltage clamp ammeters, phase volt-ampere meters, power quality analyzers, leakage current transformers, and three-phase imbalance management devices. For more information, please contact Guangdong ETCR Electronic Technology CO.,Ltd. hotline: +(86-757)66860936, or visit the Guangdong ETCR Electronic Technology CO.,Ltd. official website: www.etcr-instruments.com