Inverter's Nonlinear Efficiency and Demand-Side Management Challenges

Renewable energy resources have become an increasingly significant part of power generation for reducing fossil fuel consumption and pollutant emission. Wind and solar energy resources are the most promising options among available renewable energy resources, as they are ever-present, freely available, and environmentally friendly. However, in the presence of renewable resources such as wind and solar energy, the future power grid faces uncertainties that can cause serious issues such as blackouts. In this regard, battery energy storage systems (BESSs) are promising solutions to overcome potential challenges in transmission and distribution levels [1]. Renewables are accompanied by converters and need a smart management strategy to optimize their performances while connected to the power system. Therefore, dc to ac and dc to dc converters and their efficiency play significant roles in renewables? performance in power systems, particularly at the distribution level that a higher number of renewables with lower capacities are involved. Authors in [2] show that the main factor in solar panels sizing is the inverter?s efficiency curve. It is shown that the utilized technologies in solar panel modules have less influence on photovoltaic (PV) sizing than the inverter's efficiency. This concept is more highlighted in BESSs as the battery's lifetime and its efficiency highly depend on its operating condition [3]-[5]. In this subject, the state of California in 2005 started publishing a list of eligible PV products and their detailed characteristics, such as inverters. In this report, customers can find detailed information on the inverter efficiency available in the United States market [6], [7].