Author(s): Neeraj Patel
Type:Technical Presentation
Date: 2021-09-07

Reactive Power Energy Management, Analysis of Reactive Power Consumption in Solar Power Plant847

Abstract
For any Power Plant, it is aimed to have maximum Energy Generation and yielding for the Power Output. Solar power plant comprises PV cells, framing array by connecting with each solar panel and then c... see moreonnected with step-up transformer (Inductive element) by cable network (capacitance formed). The energy generated by PV cells are being converted by Solar inverters (Power electronics) and operated at almost Unity Power Factor.
It has been observed that with export of Active energy and increasing output, there is also import of Reactive energy varying with solar generation. The Tariff charges are involved and applicable for Reactive Power Consumption in said solar power plant. Active energy also imported during evening and night hours in absence of solar generation to run critical equipments and trend between active and reactive energy has been observed vice versa.
As per the State Tariff regulations, beneficiary must pay/gets paid for reactive power drawl/supply which is decided and bounded by the system voltage limit (e.g. 97% to 103% of Rated system voltage).

Considering varying MVAR absorption phenomena associated with active power generation and effect of supply voltage, it has been decided to study and model solar generation in EMTP. Different cases have been simulated in EMTP software. Major sources consume Reactive Power identified from modelling and matched observation with actual recorded data. Mitigation technique for reactive power compensation has been studied and modelled. Rating for reactive power compensation source has been validated. Switching phenomena associated with reactive power compensation technique along with voltage profile at different points has also been studied and appropriate rating for switching devices/switchgear has been suggested.
Detail study and simulation results will be shared during presentation.

Tag(s): reactive power, compensation, pv park, inverter

Author(s): Pr. Yong Cheol KANG
Type:Technical Presentation
Date: 2021-09-06

Closed-loop Synthetic Inertia Control of a Variable-speed Wind Turbine Generator834

Abstract
This presentation introduces a closed-loop SIC scheme of a doubly-fed induction generator (DFIG), which relies on the measured frequency. The SIC scheme employs an additional control loop that operate... see mores in conjunction with the MPPT control loop. Simulation results using an EMTP-RV simulator will be presented under various wind and system conditions for the IEEE 14-bus system.

Tag(s): synthetic inertia, wind park, inverter, stability, frequency control

Author(s): Bikrant Poudel
Type:Technical Presentation
Date: 2021-09-02

Optimization of Control Parameters of Grid-Connected PV System in EMTP845

Abstract
It is observed that the controller gain parameters of the PV model have a significant impact on the PV plant’s response during the fault recovery and the PV plant’s interaction with the rest of th... see moree system in general. Manual tuning of the PV park parameter considering multiple fault and contingency scenarios is a time-consuming task and might even be impossible. Optimization techniques such as particle swarm optimization (PSO) can be used to optimize the gain parameters considering fault/ contingency scenarios. The presentation will talk about the implementation of PSO in EMTP-RV using javascript to optimize PV park controller gain parameters.

Tag(s): pv plant, ibr, pso, optimization, scripting, pll, inverter control, inverter based resources, DER

Author(s): Chandra Pallem
Type:Technical Presentation
Date: 2021-09-02

Dynamic Overvoltage Conditions Experienced at a PV Solar Power Plant838

Abstract
We present the results from an investigation of the cause of dynamic overvoltage conditions experienced at a solar power plant, that resulted from energizing the PV solar plant 34.5 kV collection syst... see moreem feeders using a back-up diesel generator. The diesel generator unit was installed at the solar plant for emergency back-up power to the project, in case of power outage from the connecting transmission utility system.
The back-up power source was provided to allow the operation of the solar power tracking system during emergency conditions. A subsequent study was performed using EMTP software program, to investigate the cause of these dynamic overvoltage conditions at the solar power plant. A detailed transient model of the solar plant and the diesel generator were developed using EMTP.


The EMTP simulations were useful in replicating the overvoltage event measurement recordings from the site, and the simulation results from the study, concluded that the diesel generator did not have sufficient capability to pick up capacitive loads and therefore, the unit was unable to control the overvoltage conditions which led to the overvoltage event that caused equipment damage to the PV inverters and their auxiliary systems. The study evaluated various solution alternatives and mitigation strategies to reduce these dynamic overvoltages to acceptable conditions.

Tag(s): pv park, tov, diesel generator, temporary overvoltage

Author(s): Aboutaleb Haddadi
Type:Technical Presentation
Date: 2021-09-02

Ground Fault Overvoltage with Inverter-Based Distributed Energy Resources841

Abstract
A Ground Fault Overvoltage (GFO) can occur in situations where an ungrounded transmission line and associated ungrounded transmission equipment is energized from distribution connected Distributed En... see moreergy Resource (DER) during a transmission single-phase-to-ground (SLG) fault. The condition could result in 1.73 pu overvoltage on phase to ground connected equipment which will be sustained until the DER ceases to energize the substation distribution transformer. Transmission equipment on the isolated circuit will be subjected to the above phase to ground overvoltage, also if there is frequency shift, the isolating transmission circuit breakers could potentially see up to 2.73 pu phase to ground overvoltage. Such an overvoltage can cause damage to customer or utility equipment and must be avoided. GFO concerns are already becoming a barrier to large-scale DER deployment either by posing low hosting capacity or by necessitating installation of costly mitigation equipment. Utilities need to study GFO risks and identify low-cost mitigation options to enable large-scale DER deployment. Given the fundamental differences in mechanisms and phenomena driving a GFO under DERs, classical GFO analysis methods do not apply to inverters, and advanced simulation methods and tools are required.


This presentation highlights EPRI’s work on GFO analysis, concerns, and evaluation of mitigation options using EMTP. The objective is to determine if or when high DER penetration presents a GFO problem and how to prioritize the mitigation and equipment evaluation. This includes evaluating the impact lightning arresters can have in reducing or clamping the overvoltage, the application and performance of high voltage substation overvoltage protection, and DER on-board voltage/frequency protection. The presentation further provides modeling recommendations for such a study using EMTP. As DER deployment increases, utilities will need to perform similar analysis to identify potential overvoltage risks and develop low-cost mitigation methods. This work provides a basis for such a study.

Tag(s): gfov, tov, ibr, DER, inverter, islanding, load rejection, inverter based resources