Impact of solar photovoltaics on the low-voltage distribution network in New Zealand

• Published in: IET generation, transmission & distribution transmission & distribution, 2016-01, Vol.10 (1), p.1-9
• Main Authors: Watson, Jeremy D, Watson, Neville R, Santos-Martin, David, Wood, Alan R, Lemon, Scott, Miller, Allan J.V
• Format: Article
• Language: English
• Subjects: building integrated photovoltaics; Computer simulation; distribution feeder; invertors; load flow; low‐voltage distribution network; LV distribution network; Networks; New Zealand; Overvoltage; overvoltage problem alleviation; overvoltage protection; Panels; Penetration; Photovoltaic cells; power distribution protection; power flow; power transformer; power transformers; PV inverter; residential rooftop‐mounted solar photovoltaic panel; Solar cells; solar PV penetration; Urban areas; voltage 11 kV; voltage 415 V; voltage control; voltage regulation
• ISSN: 1751-8687; 1751-8695; 1751-8695
• DOI: 10.1049/iet-gtd.2014.1076

Residential rooftop-mounted solar photovoltaic (PV) panels are being installed at an increasing rate, both in New Zealand and globally. There have been concerns over possible issues such as overvoltage and overcurrent. These PV systems are mostly connected at low voltage (LV). This study presents a case study of simulating the entire LV network from a single utility, comprising 10,558 11 kV–415 V transformers and their associated distribution feeders. These results are also presented by network type. Various solar PV penetration levels are added to the model and the power-flow results are presented. From these results, possible maximum limits of solar PV penetration are investigated and measures to alleviate overvoltage problems are simulated. The effect of using PV inverters with voltage regulation is simulated. Results show that some minor overvoltage problems can be expected in the future, particularly in urban areas. However, in most cases the overvoltage would not be much higher than the statutory limit of 1.06 p.u.