Details:

Project: RTDS Model Development for Italy-Montenegro HVDC

Service: RTDS

Client: Toshiba

Country: Italy

Year: 2014-2015

Overview:

Monita is an HVDC link between Italy and Montenegro under construction by Toshiba. As part of this project, the HVDC control and protection need to be tested using a Real Time Digital Simulator (RTDS). TGS was hired by Toshiba to develop the RTDS AC network models required for testing.

TGS RTDS services:

  • Investigation of Network Model for RTDS (both Italy and Montenegro sides) 
    • Power Factory models were converted to PSS/E files using a TGS in-house conversion program
    • PSS/E cases were converted to RSCAD files using PSS/E to RSCAD conversion program
    • New custom models were developed in RSCAD in order to represent non-standard exciters and power system stabilizers
  • Node Count Reduction
    • The size of the AC electrical network was reduced in order to minimize the number of RTDS racks required to model the AC networks
    • Transmission lines with a small reactance were removed and the number of nodes were optimized to a minimum value
    • Electrical machines were combined with their corresponding step-up transformers, again to minimize the number of nodes in RSCAD
  • Model Verification — power flow, short circuit, dynamic response
  • Determination of the Number of RTDS Racks — minimum number to minimize cost

Challenges:

Many modifications for PSS/E to RSCAD conversion program were needed to be done in order to properly perform the conversion. This was done through a lot of cooperation and discussion with RTDS engineers. Verification of RTDS results against Power Factory was a challenging task due to different modeling of external grids, equivalent impedances, phase-shifting transformers, etc. in the two software packages.