Simulation of Hawaiian Electric Companies Feeder Operations with Advanced Inverters and Analysis of Annual Photovoltaic Energy Curtailment

Abstract

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Advanced Inverter Voltage Controls: Simulation and Field Pilot Findings

“…This report is a continuation of the work presented in (Giraldez, et al, 2017) of the collaboration among the U.S. Department of Energy (DOE), National Renewable Energy Laboratory (NREL) and Hawaiian Electric Companies to research the implementation of advanced inverter gridsupport functions. It includes some updated results of the simulation of a high-penetration photovoltaic (PV) scenario of a Hawaiian Electric distribution feeder with advanced inverters and different penetrations of non-exporting versus exporting new PV customers as well as the findings of the field validation of inverter-based voltage regulation functions at approximately 15 customer locations.…”

“…The key concern expressed by the members of the SITWG was that the activation of voltage regulation grid-support functions-especially volt/VAR with reactive power priority and volt/Watt-would cause significant curtailment to the PV customer. The VROS work was published in September 2017 (and is referred to as "VROS 2017" in the remaining of this report), and it provided a series of recommendations, such as activating reactive power-based grid-support functions in reactive power priority mode (versus active power priority mode), the benefits of volt/VAR compared to constant power factor mode, the activation of volt/VAR in combination with volt/Watt to provide a backstop against voltages above American National Standards Institute (ANSI) Standard C84.1 levels 6 , and the overall low annual energy curtailment impacts (less than 5%) on PV customers due to the activation of volt/VAR in combination with volt/Watt (Giraldez, et al, 2017).…”

“…To address the voltage management problem previously described, the project leveraged the distribution feeder models prepared in (Giraldez, et al, 2017), which included the necessary level of detail to more accurately capture the voltage drop/rise that occurs in the secondary lowvoltage circuits. The simulation in this project was run using PyDSS, which is an NRELdeveloped Python programming language wrapper around the OpenDSS tool that has PV and storage inverter controllers that can be flexibly programmed outside OpenDSS (Latif et.…”

“…Feeder M34 was selected because of the diversity of the different types of PV installations already existing on a circuit-residential, commercial, and large feed-in-tariff (FIT) projects that are approximately 500 kW each. For more information on the feeder model preparation for QSTS simulation see (Giraldez, et al, 2017).…”

“…In parallel to the Voltage Regulation Operational Strategies (VROS) study in 2017, NREL published a report conducted under the DOE Grid Modernization Laboratory Consortium by a regional partnership for Hawaii that recommended the blanket activation of the frequency/watt function to minimize negative impacts on frequency stability. That report also found that the impact of frequency/watt control on PV system owners' energy production is predicted to be negligible (Hoke, et al, 2017).…”