Program of the UGM & Workshop

Wednesday 8th August 2018: Welcoming cocktail reception

The EMTP-RV team will have the pleasure to open this 2-day User Group Meeting and Workshop with a beer degustation from 8:00 to 10:00 pm. The hotel address will be communicated soon.

Thursday 9th August 2018: User Group Meeting

08:00 Breakfast and Registration
09:00 Opening Remarks 
09:15

Recent developments and Road MapJean Mahseredjian

Upcoming EMTP developments and versions. 

10:00

Geomagnetic Disturbance Simulation Studies: Recent Developments and ChallengesAfshin Rezae & Jean Mahseredjian

During a Geomagnetic Disturbance (GMD) event, geomagnetically-induced currents (GIC) may cause transformer saturation, hot-spot heating or damage, elevated harmonic distortion levels, increased reactive power demand, and loss of reactive power sources, the combination of which may result in voltage collapse and blackout. To ensure safe operation, NERC standard TPL-007 requires vulnerability assessments to establish requirements for transmission system planned performance during GMD events. Existing phasor domain packages face challenges particularly with regard to the simulation of harmonics and network nonlinearities which limits their use for GMD simulation studies. By contrast, EMTP enables such studies by accurately modeling nonlinearities and representing the system at a very high precision level in a wideband range of frequencies. This presentation studies how to perform a GMD study in EMTP in compliance with the NERC requirements. Required modeling details and data have been identified using a GMD simulation case study in EMTP.

10:30

Reproducing the 1989 GMD event in EMTP, Luc Gérin-Lajoie, Hydro-Quebec

Development of Hydro-Quebec network in EMTP for GMD studies. Methodology for GMD sensitivity analysis. Analysis of simulation results.

11:00

Coffee break

11:15

The new frequency dependent line and cable model: Wideband Model, Ilhan Kocar, Polytechnique Montreal

The new WB model encapsulates many improvements including state-of-the-art research results. It eliminates the modeling problems encountered with the existing universal line model (ULM) approach. 
In the new model, there is no limitation on the number of conductors. For symmetric coaxial cable systems with several cables, numerical problems are avoided by using the new cable correction function. The newly added DC correction scheme together with frequency band partitioning ensures high precision both at low frequencies and high frequencies. Frequency partitioning also improves the numerical conditioning of the system of equations. Unrealistic delays are avoided thanks to the new routines for the identification and adjustment of time delays. The delay adjustment is a search routine with boundaries for optimized fitting.
The state space formulation in time domain is reformulated using a precise discrete integration method. It minimizes the numerical integration and interpolation errors. This allows achieving stable simulations with larger time steps. The object oriented programming approach with vectorized variables and new memory allocation routines significantly improves the simulation speed and use of memory. The new initialization routines allow seamless transition from steady state solution into time domain simulations.

11:45

Impact of Wind & Solar Generation on Negative Sequence and Power Swing Protection, Evangelos Farantatos, EPRI

Inverter-based resources have much more complex fault current characteristics compared to conventional synchronous generators. Hence, legacy protective relays set under the assumption of a conventional power system with predominantly synchronous generation, may misoperate under high level of renewables. 
This presentation first investigates the impact of wind generation on the performance of negative-sequence-based protection. In many applications, wind generators are designed to suppress negative sequence current partially or entirely. Negative sequence current suppression control may result in the misoperation of protection schemes whose operation relies on the assumption of negative sequence quantities being present in substantial levels during unbalanced faulted conditions. The impact of wind generation on negative-sequence overcurrent and negative-sequence-based directional elements is investigated in this work. 
In addition, the impact of renewable resources on the performance of power swing protection is investigated. Case studies with examples of Power Swing Blocking (PSB) and Out-of-Step Tripping (OST) elements misoperation under wind generation will be presented.”

12:15 Buffet Lunch
14:00

Safe Operation of DFIG based Wind Parks in Series Compensated SystemsUlas Karaagac, Hong Kong Polytechnic University

Subsynchronous control interaction (SSCI) is the interaction between the power electronics control and the series compensated transmission system that occurs at frequencies below the system nominal frequency. SSCI may occur between the doubly-fed induction generator (DFIG) control system and the series compensated transmission line, to which the wind park (WP) is connected. Not only the DFIG control system parameters, but also the WP operating conditions have significant impact on SSCI.

This presentation will demonstrate the impact of WP operating conditions and DFIG control system parameters on SSCI. Guidelines will be also presented for modifying the DFIG control system parameters to ensure safe operation and acceptable transient responses due to faults. In addition, the accuracies of various analytical tools used for SSCI problem identification will be discussed.

14:30

Investigation of Undesirable Impacts of Voltage Control Actions from Smart InvertersJens Schoene, Enernex  

We present the results of an investigation of undesirable impacts of voltage control actions from autonomously acting residential Smart Photovoltaic generators (PVs) in response to abnormal voltage conditions. The smart PV capability we investigated is Volt-var Control (VVC), which provides dynamic reactive power (var) output (absorption or injection) through autonomous responses to local voltage measurements. The investigation was performed on a real-world secondary distribution system using an innovative simulation process involving time-series simulations. The simulation process was verified by comparing the time-series simulation results with results from time-domain simulations performed in EMTP-RV. For the EMTP-RV simulations, we developed an rms (root-mean-square) PV model that captures the dynamic behavior of the smart PV system. The var output can be controlled by either a Volt-var curve, a Volt-Watt curve or by specifying the power factor (i.e., fixed var output) operating in Watt or var priority mode. In addition, we developed an EMTP-RV model of the split phase 240 transformer that was used on the real-world secondary system. Our simulations have shown that some Volt-var curve settings without var ramp rate limit can result in unacceptable sustained oscillation, which can be particularly severe for curves without a deadband.

15:00 Coffee Break
15:15

Advanced Topological Transformer Model, Afshin Rezae

15:45

Coming soon

16:15

Coming soon

16:30

Coming soon

16:45 Closing Remarks
17:00 End of the EMTP User Group Meeting

* Conference information and program are subject to change without notice.

Friday 10th August 2018: Workshop

The objective of this workshop is to give to beginner participants a good first hands-on experience on EMTP-RV and an overview of the EMTP-RV capabilities. The workshop is based on the usage of EMTP-RV for demonstrating concepts and teaching through practical problem cases.

09:00

Part 1: EMTP get started, EMTP team, Powersys

The objective of this first part of the workshop is to get familiar with the usage of EMT-type software and the study of power-system transients. How to model power-systems, what scenarios to run and how to interpret and verify results are as many questions that will be addressed. The software EMTP is used for demonstrating concepts and teaching through practical cases. Prior experience with EMTP is not required. Simulating Power System transients with EMTP is easy! Study how to build networks from small to large scale, from load-flow to time-domain.

10:30 Coffee break 
10:45

Part 2: TRV analysis, Henry Gras, Powersys

The objective of this second part of the workshop is to get familiar with TRV analysis concepts. Two study cases will be presented: TRV on transfmission lines and TRV on transformer-limited fault scenarios. 

12:15

Buffet Lunch

13:00

Part 3: Wind turbine modelling and Sub-Synchronous-Control-Interaction (SSCI) Studies, Ulas Karaagac

The objective to learn how to simulated networks with wind turbine models. Both average value and detailed models will be discussed. The presentation will include Wind Park integration studies and analysis methods for sub-synchronous iteraction problems.

15:00

Coffee break

15:15

Part 4: GMD analysis in EMTP: compliance with the NERC requirementsJean Mahseredjian

Presentation of network cases for GMD studies. Modeling details and topological impact on GMD.

16:45 End of the workshop session

Computer and temporary EMTP-RV license:

Each participant will have to bring a personal computer
EMTP-RV temporary licenses will be provided for the duration of the course.