• Byamba Wicki

• Celina Spiess

• Sven Achermann

• Philippe Viarouge

• David Cajander

• Angelo Chrabieh

• Wolf Peter Jean Philippe

• Figure 1: Complete electrical diagram

• Figure 2: Methodology for transitioning from a three-phase circuit topology to that of a single-phase circuit

• Figure 3: Topology of the transformer

• Figure 4: State of the switches and configurations of single phase loads

• Figure 5: State of the switches and configurations of three phase loads

• Figure 6: Network and Transformer tab & Passive Loads tab

• Figure 7: Example 1 of the user interface of the “Network and Transformer” tab

• Figure 8: Example 2 of the user interface of the “Network and Transformer” tab

• Figure 9: User interface of the “Oscilloscope” tab

• Table 1: Control switches and LED status indicators for the fuses in “Network and Transformer”

• Table 2: Control switches in the “Passive Loads” tab

• Table 3: Control switches in the “Network and Transformer” tab

• Table 4: Control switches in the “Oscilloscope” tab

The purpose of this virtual laboratory is to assimilate and apply theoretical knowledge. In particular, it involves understanding how processes work, implementing devices and equipment, using instrumentation, and processing measurements.

The laboratory aims to facilitate the acquisition of knowledge and the conduct of experiments by providing a guiding framework that allows students to focus on the experiment’s subject without initially having to worry about all the components needed for the experiments.

This virtual laboratory is designed to provide exercises to improve the understanding and mastery of the fundamental principles of electrical engineering . Laboratory exercises are an essential complement to the theory. They allow students to experiment with various circuits and applications. Therefore, users can take advantage of this virtual simulator to understand their behavior with varying levels of complexity.

This courseware will cover the following subjects:

1. Single-Phase Systems

2. Three-Phase Systems

3. Single-Phase Transformer (Coming soon)

4. Three-Phase Transformer (Coming soon)

5. Harmonics (Coming soon)

The overall electrical diagram of the laboratory can be configured interactively using contactors, as shown in Figure 1 below. It provides the ability to adjust the voltage source in either single-phase or three-phase mode, whether it is balanced or not, with adjustable or non-adjustable harmonic components. Additionally, it is possible to control the tension engagement angle. Transformers supplied by these networks undergo standardized identification tests, such as short-circuit tests and no-load tests.

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Figure 1: Complete electrical diagram

The main elements of the laboratory are as follows:

• A three-phase network with three adjustable sources for both the fundamental and harmonics.

• A circuit breaker with adjustable parameters.

• A transformer that can be deactivated by short-circuiting it or by creating an open circuit.

• Two blocks of series and parallel resistors.

• Six measurement points for voltage, current, and power for each phase. There is also the Fortescue transformation of the network.

• Contactors to create different circuits, with lamps to indicate open and closed switches.

This interactive display of the electrical diagram with lamps indicating open and closed contactors allows the user to quickly grasp the structure of the entire laboratory circuit. This diagram enables the creation of both single-phase and three-phase circuits.

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Figure 2: Methodology for transitioning from a three-phase circuit topology to that of a single-phase circuit

In general, there are three components that can be modified to achieve the desired circuit and scenario.

The network is designed so that you can adjust the frequency, amplitude, and phase shift of each phase. The voltage source operates in either single-phase or three-phase mode. Furthermore, the network’s measurement values are displayed directly.

The network is equipped with a circuit breaker, which is part of the standard protection equipment. It allows for circuit interruption in case of overload or short circuit. Generally, it consists of a thermal trip and a magnetic trip. In this laboratory, a functionality has been added to trip the circuit breaker if the voltage drops below a certain threshold.

Experiments can be conducted with a transformer by configuring it in various ways to achieve the desired setup. When it is not in use, it is short-circuited, and passive loads are supplied power without the transformer. In this case, the windings are isolated to avoid interfering with the rest of the circuit. By also short-circuiting the loads, short-circuit tests can be performed.

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Figure 3: Topology of the transformer

There are six branches of passive loads available, each consisting of a series RLC load and a parallel RLC load, as well as three passive loads in the neutral wires. These loads can be modified and arranged based on the state of the contactors and Figure 2 to create different couplings. As mentioned, when the single-phase option is chosen, the additional sources are automatically grounded and nullified for single-phase couplings. The different possible single-phase couplings are illustrated below:

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Figure 4: State of the switches and configurations of single phase loads

There are six branches of passive loads available, each consisting of a series RLC load and a parallel RLC load, as well as three passive loads in the neutral wires. These loads can be modified and arranged based on the state of the contactors and Figure 2 to create different couplings. The different possible three-phase couplings are illustrated below:

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Figure 5: State of the switches and configurations of three phase loads

The tabs constitute the interactive interface of the virtual laboratory, which includes access to settings, measurement displays, and the electrical diagram. This interface allows users to manually control the virtual laboratory by modifying network and protection settings, assembling the electrical diagram, and observing measurements.