Low Voltage Governance in Distribution Networks Based on Wide Range On-load Regulating Transformer

The problem of over-radius of power supply is common in rural distribution network, which causes the problem of low voltage in terminal area. The existing distribution transformers in the station area have short regulation steps and a narrow range, which are not suitable for the current demand of low voltage management in the rural distribution network station area. To address this, this paper constructs a model of 10kV medium voltage distribution system and analyzes the distribution line length when low voltage occurs under typical operating conditions, so as to clarify the applicable range of wide range on-load regulating transformers. Through the research of a provincial distribution network regulating range needs, designed -5 ~ +15% regulating range, 5% wide step of the wide range of on-load regulators, its internal controller to take into account the unbalanced conditions of the regulating control strategy, in order to apply the three-phase unbalance caused by low voltage problems in the station area. A simulation study was conducted with the exit voltage data of a three-phase balanced low-voltage station area and a three-phase unbalanced low-voltage station area in Hunan province to verify the effectiveness and feasibility of using a wide range of on-load regulating transformers described in this paper to manage the low-voltage problem in the distribution network station area.