Analysis of Power Quality Problems in Large-Scale Application of Air-Source Heat Pump

Abstract

With the implementation of electric energy alternatives, the large-scale application of electric energy substitution represented by air-source heat pumps has replaced traditional coal-fired heating, which is beneficial for the environment and alleviates air pollution. However, the large-scale application of airsource heat pumps has brought power quality problems such as voltage sags, harmonic pollution, and three-phase imbalance to the distribution network. This paper studies the fixed-frequency and variablefrequency air-source heat pump, introduces its working principle, analyzes the mechanism of its power quality problem. Moreover, the paper establishes a simulation model for the fixed-frequency heat pump and variable-frequency heat pump to connect to the distribution network. This research mainly studies the impact of large-scale fixed-frequency heat pumps on the depth of voltage sags in the distribution network and the impact of large-scale variable-frequency heat pumps on the harmonic content of the distribution network under different penetration rates and uses measured data to verify the reliability of the simulation results. This paper uses experimental data for the first time to verify the real power quality problems of large-scale heat pumps, which can provide a reference for determining the power quality standards for heat pumps connected to the power grid. At the same time, it can also provide a reference for the power quality management of the distribution network that is actually connected to electric heating.