Analysis of Influence of Air Source Heat Pump Load on Distribution Network Power Quality

Air source heat pump (ASHP) is common electric heating equipment in the "coal to electricity" project in China. ASHPs connected into the power grid can cause reactive power shortage, voltage sag, harmonic current violation and other power quality problems. Based on the typical topological structure of ASHPs and the mechanism of power quality problems, the simulation model of ASHP is built, and the power quality emission characteristics of ASHP connected to distribution network are studied. The power quality problems caused by ASHP connected to distribution network are measured and analyzed. The results of simulation and measurement analysis show that fixed frequency ASHPs will generate large reactive power when start, and will cause voltage sag. And the harmonic violation problem will occur when variable frequency ASHP runs.