No abstract

No abstract

No abstract

Reliable and accurate distribution system modeling, including the secondary network, is essential in examining distribution system performance with high penetration of distributed energy resources (DERs). This paper presents a highly automated, novel method to enhance the accuracy of utility distribution feeder models to capture their performance by matching simulation results with corresponding field measurements. The method is demonstrated using an actual feeder from an electrical utility with high penetration of DERs. The method proposed uses advanced metering infrastructure (AMI) voltage and derived active power measurements at the customer level, and data acquisition systems (DAS) measurements at the feeder-head, in conjunction with an AC optimal power flow (ACOPF) to estimate customer active and reactive power consumption over a time horizon, while accounting for unmetered loads. The ACOPF uses the measured voltage magnitudes, derived active power measurements, and the feeder head measurements to obtain a complete active power and reactive power capture of the feeder loads. Additionally, the method proposed estimates both voltage magnitude and angle for each phase at the unbalanced distribution substation. The accuracy of the method developed is verified in two stages: by comparing the time-series power flow results obtained from the enhancement algorithm with OpenDSS results and with the field measurements available. The proposed approach seamlessly manages the data available from the optimization procedure

There has been a significant growth in the distributed energy resources (DERs) connected to the distribution networks in recent years, increasing the need for modeling the distribution networks in detail in conjunction with the sub-transmission/transmission networks. This paper models a real distribution/ sub-transmission network using a three-phase/three-sequence co-simulation. One of the modeled distribution feeders has a high penetration of DERs with significant reverse power flow and is modeled including the secondary network. Custom user-defined models are used to represent the solar photovoltaic (PV) units on the feeder including advanced controls and abnormal voltage responses from IEEE 1547-2018 standard. The co-simulation framework developed supports power flow/steady state as well as dynamic analysis. Using this developed framework, this paper studies the impact of balanced and unbalanced faults applied to the distribution and sub-transmission networks. The impacts of the faults on the feeder with the high penetration of DERs are studied in terms of the solar PV units tripping due to under/overvoltages and the resulting change in the feeder-head flow. It is seen that the detailed modeling of the distribution network is needed for accurately capturing the response from the distribution-connected DERs during fault events both on the distribution as well as sub-transmission networks.