Comparative study of the dynamic programming-based and rule-based operation strategies for grid-connected PV-battery systems of office buildings

Abstract

The proper operation strategy is of great importance for photovoltaic-battery (PVB) systems to achieve desirable performance. Therefore, it's necessary to identify and evaluate the characteristics of different operation strategies for engineering application. In this study, three operation strategies including the dynamic programming (DP)-based strategy and two widely used rule-based strategies, namely the maximizing self-consumption (MSC) strategy and time-of-use (TOU) strategy, are compared comprehensively for the grid-connected PVB system of an office building. Several important performance aspects, including battery charge/discharge process, techno-economic performance, energy distribution, battery aging and impacts on utility grid, are analyzed and compared. The results show that the DP strategy has greater flexibility than the rule-based strategies to adapt to different PV-load distributions and electricity pricing mechanisms, and has the advantage of achieving better economic performance and reducing burden on the grid. Although the economic performance of the MSC strategy is relatively poor, it has the highest self-consumption rate (SCR) and self-sufficiency rate (SSR), thereby having the advantage of using PV generation in timely manner to suit load demand. In addition, the MSC strategy results in the least battery aging, while having the greatest negative impact on the utility grid. The TOU strategy only outperforms the MSC strategy in economic performance under the condition of relatively low battery cost (<1600 CNY/kWh) and causes the most battery aging as well. The findings in this work can provide guidance for decisionmakers to determine the proper management strategy for practical grid-connected PVB systems.