This paper describes the measurement-based load current model of electric apparatus after a voltage sag occurrence. The terminal voltage and load current of a personal computer (PC), an inverter fluorescent light and an incandescent light were measured to find out the dependences of load characteristics on the voltage sag. The magnitude of the load current after voltage sag depends on both the magnitude of residual voltage and the time period of voltage sag. In order to make it possible to take account of these transient load characteristics in the power quality estimation, a load current model is proposed. The load current waveform is obtained using the database of harmonic component of load current and time variation in the parameters of load voltage characteristic. The proposed model enables us to estimate the load current within an error of about 5% when the voltage sag occur.
- Load modeling
- Load voltage characteristics
- Voltage sag
ASJC Scopus subject areas
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering