Author(s): Husam Samkari & Rafael Castillo Sierra
Type:On-demand webinars
Date: 2022-02-17

Slideshow of the projects from our grand prize winners857

Abstract
During this webinar, our two winners of the EMTP® Research Contribution Prize Program 2021 will present their work. The aim of the award is to recognize student contributions to the technology associ... see moreated with power system transients. The two competition categories are:
- Best accepted IEEE, IET, PSCC, EPSR or IPST journal or conference paper on EMT simulations;
- Best EMTP® model developed.

Discover our winner and the topics of their presentation:

o Husam Samkari, Ph.D. and P.E. in Electrical Engineering
Impact of Distributed Inverter-Based Resources on Incremental Quantities-Based Protection

Abstract:
This paper studies the impact of distributed inverter-based resources (IBR) on time-domain incremental quantities-based relays. One implementation of the incremental quantities for protection is a high-speed sub-cycle directional element. The incremental, also known as superimposed, quantities are fault-generated instantaneous components of voltages and currents. The directional element indicates fault direction based on the transient voltages and currents’ relative polarities. It is essential to ensure that the element does not fail to indicate the correct direction if IBRs fault current responses impact the quantities. IBRs’ fast control response impacts the current quantities by changing both magnitude and angle.

This paper characterizes the incremental quantities-based relay response to IBRs’ nonlinear fault currents. A modified IEEE 34-bus distribution with an IBR system is modeled and simulated using the electromagnetic transients program (EMTP-RV) for demonstration.

o Rafael Castillo Sierra, Electrical Engineer, Ph.D. Student
Model category for his model on Power System with a Transmission Line operating at low frequency

Abstract:
The transmission of electric power with alternating current (AC) faces constraints that are inherent both to the stable operation of the power system and to the physical properties of the transmission lines or cables. Many factors stand to motivate the alleviation of these constraints without a need to construct new transmission lines or cables. One demonstrated method to accomplish this is to lower the electrical frequency of a transmission branch or section of the network, an approach known as low frequency AC (LFAC) transmission. The resulting lower reactance of the lines improves the transmission under the stability concerns which arise with long, inductive overhead lines, as well as under thermal concerns that can be substantial due to charging currents in underground cables. In this order of ideas, the Modular Multilevel Matrix Converter (MMMC) offers the necessary frequency conversion for low-frequency transmission, while allowing controllability of power through the transmission line.

For this reason, this presentation focuses on the EMTP modeling and simulation of this converter starting from a design that meets the typical voltage and power requirements for a transmission line. The averaged model of the converter has been implemented to evaluate its performance as a frequency converter and how it interacts with the power system. Simulations have been carried out under nominal operating conditions in a study case power system.

Tag(s): EMTP, Prize winners, IBR, Protection, Power system, Transmission Line, Low frequency,

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