Beyond the curves: Modeling the electrical efficiency of photovoltaic inverters

Abstract

It has been noted that the models typically used to represent inverters in simulation and design tools at the present are inadequate because they do not capture the variations in electrical efficiency over the full range of operating conditions. Data to develop more detailed models have been scarce in the past, but are now increasingly available from multiple sources, therefore it is time to rectify the situation. This paper examines efficiency measurements for a wide range of different inverter products at multiple power levels and input voltages. A model is developed that expresses efficiency as a function of both power and voltage, and it is demonstrated that this model can approximate the efficiency with an appropriate level of accuracy using a small number of parameters. This combination of accuracy and simplicity should facilitate implementation in software and dissemination of model parameters.

A finite state machine model to represent inverters in photovoltaic system simulations

“…The inverter electrical efficiency is calculated as a function of both power and voltage, which is described in [7]. The MPPT efficiency is currently specified as a fixed percentage.…”

“…These latest data document how inverter efficiency varies with DC input voltage as well, therefore out loss model includes both power and voltage dependencies. Further detail on this aspect is provided in [7].…”

Battery Energy Management in a Microgrid Using Batch Reinforcement Learning

“…To make use of this information, it is necessary to integrate the inverter model into the system and consider its influence on the control policy and, therefore, the system performance. The inverter model considered in this work is extracted from the work of Driesse et al [33]. …”

Mathematical efficiency modeling of static power converters

“…Driesse et al [7] presents a continuous and simple model, where the efficiency of power converters is approximated by the second order function…”

“…Finally, Driesse et al [7] proposes an improved model, as named by authors, in which the quadratic term, that do not have a physical meaning, is substituted by the inverse of input voltage to represent the existence of multiple dependencies with this variable. The model proposed by authors is defined by…”