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Our Services

HIL Testing System Setup

Simulo Technologies has the expertises to help set up your HIL (Hardware-In-the-Loop) simulation test system for closed loop testing of protective relays or phsyical controllers for studies or factory acceptance tests.

Building FDNE

Simulo Technologies Inc. can help customers to build FDNEs to be used in their RTDS simulation studies based on PSS/E, BPA or other data files.

Component Model Development

Dr. Yu has extensive experiences in simulation model development.

If you need a component model that is not currently in the RTDS or PSCAD/EMTDC component library, Simulo Technologies Inc. could develop such a model for you.

Simulation Case Development

Simulo Technologies Inc. can help customers to build large simulation cases for RTDS or PSCAD/EMTDC based on PSS/E, BPA or other data files.


Dr. Yu has gained extensive experiences and insights through over 20 years working in the cutting edge technology of EMT simulation, espeically real time digital simulation.

Simulo Technologies can provide training courses to your organization at a very cost effective and competitive rate.


Please contact us if you have any other simulation related needs.

We are constantly expanding our area of simulation services.

Building FDNE

FDNE (Frequency Dependent Network Equivalent) is a powerful feature implemented on the RTDS simulator which can convert a large portion of a power system into an equivalent model.

An FDNE model consists of two part. The first part is a group of s demain branch models obtained using frequency scan and curve-fitting. This part can accurately represent the fast responses of the electro-magnetic transients in the system. The second part is a 50/60 Hz phasor domain models containing generators. This part can accurately represent the electro-mechnical responses of the many generators inside the FDNE.

An FDNE uses a fraction of the computational power required to simulate the orignal power system from which it is derived, thus greatly increases the simulation capabilities of an existing RTDS simulator without costly hard expansion.

For more detailed description of the FDNE, please refer to publication [1] and [2] as well RTDS user manual.

Before his retirement from RTDS, Dr. Yu implemented the FDNE algorithm on the RTDS simulators. Before and after retirement he also helped several RTDS customers ( including AMSC ) in their application of the FDNE models.

Training Courses

Simulo Technologies can provide the following training courses:

Basic Training for the RTDS Simulator

An introductory course on how to use RSCAD and RTDS hardware:

- The concept of real time simulation

- Basic structure of a RTDS hardware

- RSCAD - Fileman, Draft, RunTime, Multiplot

- RSCAD power system and controls library models

- RTDS case building and RunTime setup

- RTDS I/O cards

- Hardware-in-the-loop test

Introduction to Numerical Simulation of Electro-Magnetic Transients in Power Systems

An introductory course on the numerical simulation of EMT (Electro-Magnetic transients) in power systems:

- Fundamentals of electric circuit analysis

- Fundamentals of numerical solutions of differential equations

- Fundamentals of EMTP type of algorithms

- Simple inductor and capacitor models

- Transformer models

- Transmission line models

- Electric machine models

- Control system models

RTDS Component Model Development using CBuilder

 The traing course will focus on:

   - Overviw of a RTDS component model

   - how to create the graphics of a component

   - how to create the parameter menu of a component

   - how to create the COMPUTATION section of a component

   - how to create the ERROR section of a component

   - how to create variables for

        - power system nodes,

        - current injections,

        - variable conductances,

        - pointers for swithed matrices,

        - input and output signals,

        - plot signals,

        - sliders, dials, switches

    - examples of simple models

        - RL, RC models

        - a linear transformer model

        - control model of a real pole

Frequency Dependent Network Equivalent

Network equivalents are normally used in EMT type simulations to represent parts of power systems that are far from the area of interests for the current studies to expand the simulation capabilities of an existing simulator without extra costs.

The training course will focus on:

   - Fundamentals of FDNE

       - Frequency dependent network equivalent branches

       - Transient Stability Analysis (TSA) models interfaced to EMT simulation

   - Curve fitting methods for FDNE branches, passivity and numerical stability

   - how to build an FDNE with a RSCAD/Draft file

   - how to build an FDNE with data extracted directly from PSS/E data file

   - how to create a sib file automatically

   - how to validate an FDNE


Reference for FDNE:

[1] Xi Lin, A. M. Gole, Ming Yu,

“A Wide-Band Multi-Port System Equivalent for Real-Time Digital Power System Simulators”,  IEEE TRANSACTIONS ON POWER SYSTEMS, VOL. 24, NO. 1, pp. 237-249, FEBRUARY 2009


[2] Z. Xiaofeng, Y. Shihao, Z. Desheng and S. Jie, "Research on application of FDNE based on RTDS and comparison analysis of fault transient of Shanghai Sijing power grid," in The Journal of Engineering, vol. 2019, no. 16, pp. 1393-1397, 3 2019, doi: 10.1049/joe.2018.8777.