Preliminary Study on Reducing Three-phase Imbalance Degree Using Thermostatically Controlled Loads in Low Voltage Distribution Networks

Abstract

The three-phase imbalance is a common problem in distribution network. It will cause a series of problems, such as reducing the distribution transformer output, poor power quality, increasing loss in distribution network, etc. The common solutions for reducing the three-phase imbalance degree are installing reactive power compensation devices, manually adjusting the load phase, or installing commutation switches. The thermostatically controlled load in distribution network has high operating power, and the load characteristics are random and intermittent. Considering the power adjustability of the thermostatically controlled load, the paper explores the feasibility of applying it to reduce the three-phase imbalance degree in the distribution network. This study describes how to adjust the temperature setting value of the thermostatically controlled load to achieve the purpose of adjusting power so as to adjust the phase current. Then, it introduces how to adjust the temperature setting value to reduce the three-phase imbalance. The final results of case study show the effectiveness of the method proposed in this paper.