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): Carlo Alberto Nucci & Fabio Tossani
Type:Technical Presentation
Date: 2021-09-07

Response of Overhead Lines to Direct Lightning Strikes: Assessment of the LEMP Effects852

Abstract
In the usual practice, the evaluation of the overvoltages due to direct lightning strikes to overhead power line conductors is focused on the representation of the effects of the lightning current inj... see moreection, whilst the effects of the coupling between the conductors and the lightning electromagnetic pulse (LEMP) is disregarded. Motivated by recent results obtained for the case of a medium voltage line configuration with a shield wire, this extends the analysis to assess the contribution of the LEMP on the lightning performance of an overhead distribution with and without periodically grounded wires and surge arresters. Moreover, the presentation deals with the LEMP effect on the occurrence probability of flashovers on different phases, which is an important information on the service continuity of networks with isolated or compensated neutral earthing. A validation of the results is obtained by comparing the overvoltages calculated by using EMTP, together with the LIOV library for the LEMP calculation, and those obtained by a three-dimensional finite difference time-domain approach.

Tag(s): lightning, pulse, LIOV, surge, arrester

Author(s): Rohit Kunte
Type:Technical Presentation
Date: 2021-09-06

Induced Voltage Study843

Abstract
MidAmerican Energy has conducted studies at some locations on our system to identify voltages that are induced due to lines on the same structures. For example, MidAmerican added a new 161 kV line fro... see morem substation D to substation E (not shown) through substation C. The line is mostly single circuit except between substations B and C where a second 161 kV line was added on the structures. There is also an existing 13.2 kV underbuilt distribution circuit on the structures between substations A to C.

The induced voltage study was performed to get an understanding on the level of voltages that may be expected when the 161 kV line from substation A to substation C is out of service, but the 161 kV line from substation D to substation C is in service and vice versa. The analysis provided very useful information on the level of induced voltages that may be expected on the 13 kV distribution feeder and helped MidAmerican to develop mitigation measures.

Tag(s): line, induced voltage, EMI

Author(s): Frédéric Colas
Type:Technical Presentation
Date: 2021-09-05

From FEMM to EMTP Cable Data – How to Use FEMM to Compute the Power Cable Parameters839

Abstract
In the context of the simulation of an electrical network, different models of lines / cables are available. Among these, we can cite the PI models, the frequency dependent models (FD-Line) or the mod... see moreels called Wideband. This last type of modeling is considered in the power system community as a sufficiently precise model to simulate the behavior of the cable under non-symmetrical faults and more particularly in the case of underground or submarine cables. However, the parameters of this type of model are generally still calculated from a standard geometry.

In this presentation, a methodology to obtain, from the software FEMM, the cable data parameters needed for EMTP will be presented. This methodology allows to easily obtain the correct parameters from specific cable geometry.

Tag(s): fem, cable, parameters

Author(s): Mr. Suyash Kulkarni - Mr. Suved - M. Pakade
Type:Technical Presentation
Date: 2021-09-03

Ground Fault Detection and Feeder Protection of 2x25kV Railway Traction System840

Abstract
In a new 2X25 kV System, Scott transformer is used as a traction transformer and to supply the power to the railway traction system. It is protected using the percentage differential relay.

... see more
However, region from the low voltage side of the Scott transformer to the first autotransformer is unprotected at the field and to protect the system during fault on this region is very important. Thus, development of protection scheme is required. Herein, we modeled 2X25kV traction system in EMTP, simulate faults and developed a specific relationship to provide the protection for this scheme. We have taken the current input from feeder current transformers and observed its current during the faults.


This performance of this scheme is verified using EMTP. Further, impedance to distance ratio is non-linear due to the autotransformer between catenary, rail and feeders in 2x25kV railway traction system. To observe this behavior as per field details and provide the accurate relay setting, we simulate the faults over the length of protected line in EMTP and field test are carried out. In the event of a fault on unprotected region and on the protected line, trip occurs and relay recorded fault details at the field.

Tag(s): Fault Detection, protection, railway, traction