Synchronous Machines - 1. Introduction

This virtual test bench was designed to stimulate the user interaction with the electrical machines and to provide a wide range of available exercises to improve the understanding and mastering the fundamentals on synchronous machines.

The basic teaching approach for electric machines consists in using both lectures and practical exercises to teach the fundamentals, the operating modes and characteristics, the modeling on steady state and transient period, and finally the industrial applications.

Laboratory exercises are an essential complement to theory.
They allow students to experience test implementation of real devices that consider the limits imposed by the protection systems.
Furthermore, the characterization tests of electrical machine models at reduced power is an essential goal for lab tests performed as a part of training.

The user can take advantage of this virtual simulator to understand the typical sizing methods for electrical networks and industrial applications using electric machine models with several levels of complexity.
These models are integrated into powerful simulation tools that operate in real-time or offline.
The main problem, often overlooked in training programs, is identifying model parameters for real devices.
When designing or sizing a specific installation, the simulation can only be efficient if the model of the implemented system represents real behavior.

The five basic synchronous machine tests included in this manual were developed with these problems in mind and allow users to learn:

• Startup, synchronization and various generator and motor operating modes for the synchronous machine (and the DC machine coupled to it).
• Identifying synchronous machine steady state and dynamic model parameters through standard low power tests.
• Validation of the model parameters identified by direct comparison of the measured characteristics under load in (i) an AC grid or (ii) a passive load with theoretical characteristics calculated by models.
• The understanding of the synchronous machine’s dynamic behavior, their stability limits and the regulation process for exchange active P and reactive power Q with the grid.

The five basic exercises that can be run on the virtual test bench developed by OPAL-RT:

• Exercise 1: Parameter identification of the steady state synchronous machine model.
• Exercise 2: Synchronous generator not connected to the grid feeding a passive load.
• Exercise 3: Synchronous generator connected to the grid.
• Exercise 4: Synchronous motor.
• Exercise 5: Standardized three-phase bolted fault and recovery of the synchronous machine voltage.

Detailed protocols are available in sections 4 to 8 of this document.