Keywords

1 Introduction

At the turn of the last twenty years, significant progress has been made in the field of computer sciences and information technology. New solutions and applications of modern technologies have been intensively searched for in both the science and entertainment sectors in order to facilitate and optimize everyday life. This translated directly into the development of technology which is virtual reality, which with each successive year manifests its application in subsequent areas of life.

Virtual reality (VR) is used in those industries where making a mistake may result in damage to health or exposure to costs related to the destruction of equipment. Due to the affordability and wide range of possibilities of this technology, it is gaining more and more popularity all over the world. Among others, Schneider Electrics used virtual reality as a training medium in the field of electrical power devices offered by the company [1]. Another example of the use of virtual reality in practice is a project implemented by Enea Operator, consisting in mapping a training means for learning work under voltage. This project involves the development of training scenarios for selected Main Power Supply Points and MV stations [2].

Computer-generated artificial reality is not limited to a computer that generates virtual space. Necessary to use VR technology are devices that are the medium between humans and the virtual world. The combination of such devices enabling real-time interaction of the real world and the computer-created space, creating an extension of the real world, is called AR (Augmented Reality) [3, 4]. This interaction applies to both adding virtual objects in the real world and placing real objects in the virtual space, creating a mixture of both these environments.

The main purpose of this work was to create and evaluate a laboratory stand for testing MV switchgear with the use of VR technology. As part of the work, an exemplary program of operation of a VR application developed by PRADMA and Institute of Power Engineering in Warsaw University of Technology (WUT) was developed in order to create a comfortable and effective environment for teaching purposes in the field of power engineering, with the specification of issues related to medium voltage switchgear. Then, on the basis of the developed scheme, application tests were performed and an evaluation questionnaire was conducted to develop the results of the tests.

During the work, the profitability of the VR application, the impact of its use on the learning outcomes and other aspects of the use of virtual reality, such as its impact on the well-being of users or the level of complexity of operating devices in virtual space, were analyzed.

2 The MV Switchgear

The main aspect of the VR application that was used for the work is the virtual model of the MV switchgear. A switchgear is a set of electrical power equipment operating at the same rated voltage, used to distribute electricity. It consists of a structure equipped with busbars and insulating elements, as well as electric power equipment serving as distribution, protection or measurement [5]. The medium voltage switchgear implemented in the application is based on the real model of the switchgear produced by Elektrometal Energetyka SA presented in Fig. 1.

MV switchgears with power equipment are characterized by characteristic electrical quantities, the values of which depend on the method of execution, electrical solutions and materials used. These values are crucial when selecting the equipment, and the designers make every effort to achieve the highest possible values of current, voltage or temperature to which the switchgear will be adapted, while keeping its dimensions and production costs as small as possible. The standardization of the e2ALPHA switchgear in terms of limit values and design applications is described in standards, i.e. [6]. Due to the nature of the work, the focus was mainly on the design properties of the discussed switchgear.

MV switchgear as an electrical power device should be as reliable and safe as possible for its users. For the benefit of its users, switchgears are equipped with a number of interlocks related to the user’s inaccessibility to conductive elements during its operation under voltage. One of the most important interlocks in the e2ALPHA switchgear are interlocks for the withdrawable unit compartment door while the withdrawable unit is in the operating state, the interlock of closing the earthing switch during the operating state of the movable unit or the interlocking of opening the cable compartment while the earthing switch is in the open position.

Fig. 1.
figure 1

MV switchear from Elektrometal Energetyka SA (picture taken in WUT).

Full size image

3 Development of a VR Application Operation Program

The aim of the program development was to adapt the user of the application to the virtual reality environment, to familiarize with the rules of moving inside the virtual space and to perform two pre-prepared didactic exercises in the field of testing the MV switchgear and its components.

3.1 Description of Equipment and Installations

For the proper functioning of the VR application, a set of necessary devices was used, which included:

  • VR glasses, two touch controllers included in the Oculus Quest 2 set [7],

  • A computer equipped with a modern processor and graphics card, with sufficient computing power,

  • Monitor displaying a view from the perspective of using VR glasses, used to analyze the respondent’s movements in real time,

  • USB type cable - USB Type C, connecting the glasses with a computer unit in order to transmit the image to the monitor and increase the computing power of the glasses.

The created laboratory stand is shown in Fig. 2. In the further description of the application, for easier identification, the user is the person who is currently using VR glasses, and the avatar is the character that the user moves in the virtual world.

Fig. 2.
figure 2

Laboratory setup in the Laboratory of Power Apparatus and Switching Process (picture taken in WUT).

Full size image

3.2 Description of the Application Interface Using the Tutorial Example

After launching the VR application, the user will see a menu on the glasses screen containing the selection of a specific part of the exercise. The virtual application menu is presented on the Fig. 3. The selection is made using the main button, targeting the selected option with the indicator generated by the controller. During the first contact with the program, the target option will be to select the tutorial first.

After selecting the tutorial, we will be greeted with a visual message along with the tutor reading its content, in which we will be informed about the purpose of the tutorial. After accepting the message with the main button, you will find yourself in a virtual room. The teacher will then inform the user about the rules of navigating in the virtual world. The avatar is rotated by physically turning the user’s head or by using the knob on the top panel of the controller. Moving around the virtual room takes place through physical movement of the user or teleportation with an avatar. After pointing the controller pointer at any place on the virtual room floor, the user will see a circle appearing in the selected place. After pressing the circle, the avatar will be teleported to the indicated place. Such an application is intended to facilitate the user’s movement and to limit the user’s movement within the security zone.

Then, the user will be informed about the possibility of interacting with objects using the main controller button and about the possibility of catching virtual items. Using the middle finger button, the user can grab the switchgear element and rotate it freely by moving the controller. After executing the instructions, the user will be asked to check the acquired skills by pressing the green button on the wall and dragging the switch in the trolley into the vicinity of the green zone. After completing the tutorial, the user will be informed about the possibility of leaving it.

Fig. 3.
figure 3

Basic menu of the VR application.

Full size image

3.3 VR Exercise 1

After completing the tutorial, the user from the application menu should enter the main part of the first exercise, entitled “Switchgear construction”. In this part of the exercise, the user was presented with the construction of MV switchgear on the example of the e2ALPHA switchgear described in chapter two. The user of the application will get to know the basic structural elements of the switchgear, view its devices, read the information prepared about them and view construction diagrams displayed on the virtual board.

After entering the exercise part concerning the construction of the switchgear, the user will be transported again to the virtual room and will be informed about the purpose of the exercise. Then the user will be instructed to approach the switchgear located in the room and to click it with the main button. After these steps are completed, a short animation will be shown showing the elements separating from the switchgear and moving towards the center of the room.

The element to which the controller will be approached will be highlighted in yellow, which mean that one can interact. After pressing the button, the avatar will be transported to the room where the user can freely move the isolated element, read the information on the board and view a photo or diagram of the actual device. Example of isolated element of MV switchgear (circuit breaker) is shown in Fig. 4.

After examining a given element, the return button on the wall can be pressed, which results in returning to the training field and marking the examined element on the list of elements on the wall, presented in Fig. 5.

Fig. 4.
figure 4

Separated elements of the virtual switchgear (left) and the virtual model of the e2BRAVO circuit breaker (right).

Full size image
Fig. 5.
figure 5

The list of possible to view elements in MV switchgear.

Full size image

Additionally, on one of the walls of the virtual room there is a table with diagrams of devices and elements used in the exercise. After pressing an arrow associated with a given element, its detailed diagram will be displayed.

3.4 VR Exercise 2

In the second exercise, entitled “Switchgear diagnostics”, the user was supposed to use a trolley to pull out the MV circuit breaker located in the withdrawable compartment of the switchgear. Then he was subjected to the task of finding five damages to the MV switchgear and its elements caused by the action of an electric arc. In order to open the withdrawable compartment of the switchgear, it was first necessary to release the lock preventing the opening of the compartment door in the absence of safe conditions. This is done by then opening the switch contacts by pressing the red button responsible for controlling the switch and closing the earthing switch via the green control button of the earthing switch. If any wrong steps are taken, the user will be notified that they cannot be performed. On Fig. 6 the MV circuit breaker used in the exercise is shown. The maneuvering of devices and electrical apparatus in the model is carried out in accordance with the principles of operating works at MV switchgears.

Fig. 6.
figure 6

The MV circuit breaker in VR application

Full size image

4 Testing of VR Application

For the purpose of testing VR applications, a group of forty-three students of electrical and related faculties was assembled. Before performing the VR application test, each student was acquainted with the construction of a real MV switchgear located at the test site, shown in Fig. 1. In order to verify the correctness of the switchgear implementation into the virtual environment.

Then, each student started the application program discussed earlier, and then conveyed his feelings from the virtual exercise by performing a prepared evaluation questionnaire. The basis of the survey questions were questions developed by the author of this work and, inter alia, in close cooperation with Dr. M. Marzec, Dr. M. Kotyśko and Dr. E. Waszkiewicz, employees of the Faculty of Social Sciences of the Department of Clinical Development and Education at the University of Warmia and Mazury. The questions were arranged for the purposes of the study in order to develop conclusions from the use of VR applications. The survey was made with the use of the Microsoft Forms survey editor and consisted of 45 questions concerning the feelings associated with the use of VR, the accessibility of this technology, the developed exercises and the level of mapping virtual elements. The results of the survey were then used to develop the results of the tests and the quality of the prepared application scheme.

5 Summary and Conclusions

The proposed VR application operation program is a proven example for substantive classes in the field of power engineering, detailing issues related to the MV switchgear. It allowed for quick and effective adaptation of the user to the virtual world, while leaving him as much knowledge gained during the prepared exercises as possible. The test participants showed a high level of focus and interest during the execution of the developed VR application program.

The laboratory stand created for the purpose of testing the application allowed for the effective conduct of the research participants through the developed diagram of the VR application. The process of creating a laboratory stand allowed to learn about the affordability and ease of installation and operation of equipment adapted to virtual reality operations.

The prepared evaluation questionnaire allowed to collect the users’ feelings about the prepared exercises and the overall use of VR. The test participants’ answers confirmed the belief that VR technology is attractive in the academic environment. According to the respondents, the exercises prepared in VR made it possible to effectively remember the presented content about the switchgear and its elements, which confirmed the sense of using VR as a way to supplement standard teaching techniques. The models implemented in the VR application were recreated realistically enough to ensure a positive reception of the application among the respondents. The entire VR exercise was received positively by the test participants and they firmly supported the attractiveness of the presented exercises and the opportunities created by virtual reality.

Current attempts to use VR technology indicate the trend of the increasingly common use of VR technology in subsequent sectors of life. In the future, the discussed VR application will be developed in a project from Polish Ministry of Education and Science “Development and implementation of a cognitive training platform using VR and AR technologies”.

“Publication co-financed from the state budget under the program of the Minister of Education and Science under the name” Science for Society “project number NdS/532684/2021/2022 amount of funding 13 500 zł total value of the project 1 355 390 zł”.