Adetokun Bukola Babatunde, Ojo Joseph Olorunfemi, Muriithi Christopher Maina
Department of Electrical and Electronics Engineering, Faculty of Engineering, Nile University of Nigeria, Abuja, Nigeria.
Department of Electrical and Computer Engineering, Tennessee Technological University, Cookeville, TN, USA.
Sci Rep. 2021 Dec 31;11(1):24526. doi: 10.1038/s41598-021-04300-w.
This paper investigates the application of large-scale solar photovoltaic (SPV) system for voltage stability improvement of weak national grids. Large-scale SPV integration has been investigated on the Nigerian power system to enhance voltage stability and as a viable alternative to the aged shunt reactors currently being used in the Nigerian national grid to mitigate overvoltage issues in Northern Nigeria. Two scenarios of increasing SPV penetration level (PL) are investigated in this work, namely, centralized large-scale SPV at the critical bus and dispersed large-scale SPV across the weak buses. The voltage stability of the system is evaluated using the active power margin (APM) also called megawatt margin (MWM) derived from Active Power-Voltage (P-V) analysis, the reactive power margin (RPM) and the associated critical voltage-reactive power ratio (CVQR) index obtained from Reactive Power-Voltage (Q-V) analysis. All simulations are carried out in DIgSILENT PowerFactory software and result analyses done with MATLAB. The results show that with centralized SPV generation for the case study system, the highest bus voltage is able to fall within acceptable limits at 26.29% (1000 MW), while the dispersed SPV achieves this at 21.44% (800 MW). Also, the dispersed SPV scenario provides better voltage stability improvement for the system as indicated by the MWM, RPM and the CVQR index of the system. Therefore, this work provides a baseline insight on the potential application of large-scale SPV in weak grids such as the Nigerian case to address the voltage stability problems in the power system while utilizing the abundant solar resource to meet the increasing energy demand.
本文研究了大规模太阳能光伏（SPV）系统在改善国家弱电网电压稳定性方面的应用。已对尼日利亚电力系统中的大规模SPV集成进行了研究，以增强电压稳定性，并作为尼日利亚国家电网目前用于缓解尼日利亚北部过电压问题的老化并联电抗器的可行替代方案。本文研究了两种提高SPV渗透率水平（PL）的情景，即在关键母线处集中式大规模SPV和在弱母线处分散式大规模SPV。使用从有功功率-电压（P-V）分析得出的有功功率裕度（APM）（也称为兆瓦裕度（MWM））、无功功率裕度（RPM）以及从无功功率-电压（Q-V）分析获得的相关临界电压-无功功率比（CVQR）指标来评估系统的电压稳定性。所有仿真均在DIgSILENT PowerFactory软件中进行，并使用MATLAB进行结果分析。结果表明，对于案例研究系统，采用集中式SPV发电时，最高母线电压在26.29%（1000兆瓦）时能够降至可接受范围内，而分散式SPV在21.44%（800兆瓦）时达到这一水平。此外，如系统的MWM、RPM和CVQR指标所示，分散式SPV情景为系统提供了更好的电压稳定性改善。因此，这项工作为大规模SPV在尼日利亚这样的弱电网中的潜在应用提供了基线见解，以解决电力系统中的电压稳定性问题，同时利用丰富的太阳能资源来满足不断增长的能源需求。
