Abstract—This research will bridge the gap between theoretical concepts of transformer banking and its actual operation without risking the safety of the students as well as the initiating personnel for the laboratory exercises. In electrical engineering, the concept of transformers is very essential to the success of engineering students in terms of electrical engineering applications. Thus, learning the basic of transformers should be taught properly in universities. However, the danger of dealing with high voltages in a range of 220 Vac and above should be taken seriously. To address this problem, a Programmable Logic Controller (PLC) will be integrated into the system. Programmable Logic Controller (PLC) is an industrial solid-state computer that monitors inputs and outputs and makes logic-based decisions for automated processes or machines. The integration of PLC into the system configuration of any transformer banking served as the protection system. Students will be able to learn on how to configure the four (4) different types of transformer banking, namely, (a) delta-wye; (b) wye-delta; (c) delta-delta; and (d) wye-wye. The interconnection of the system is made possible with the aid of relays. The problem with transformer banking is whenever students misconfigured the connection there is a big chance of damaging the equipment and hurting the user. With this trainer, the equipment is being protected along with the user. The trainer developed in this research will be a good equipment to fully grasp the concept of transformers and best way for the students to expand their knowledge towards electrical engineering. Index Terms—Logic controller, plc, three-phase transformer, trainer kit, transformer banking. I. INTRODUCTION A transformer is an important component in the electrical engineering power system. A typical transformer consists of coils of wire conductor insulated with paper insulation, which are assembled to the core [1]. In electrical engineering education, understanding the basic concept of transformer banking is very necessary to appreciate and utilize the field of power system to its core. However, transformer banking deals with high voltages, thus, it needs to be handled properly to avoid any accidents. Transmission and distribution of electrical power are more economical in three phase system than single phase system. There are two ways in having three phase connection. This Manuscript received June 9, 2019; revised October 13, 2019. The authors are with the Caraga State University, Cabadbaran City, Philippines (e-mail: anthony.minoza@gmail.com, sanchezbt@yahoo.com, jaysonloreto12@gmail.com). can be done by using a single three phase transformer or by using a bank of three phase transformers. Three single-phase transformers can be connected to form a three-phase transformer bank. For transformers, as a particular case, there are three advantages of using a three-phase transformer instead a of three-phase transformer bank: a) cost reduction, b) mass reduction, and c) reduced space [2]. To address the need in understanding the concept of transformer banking this paper proposed a trainer intended for electrical engineering students in learning the basic concepts of three phase systems using a bank of three single phase transformers. For this trainer, Programmable Logic Controller (PLC) is being integrated for the safety of the students. A typical PLC is a device, which consists of a CPU, input and output interfaces, memory, programming device, and user program [3]. CPU act as the brain of the system which allows the user to put command to achieve the desired functionality. In addition, three phase transformers are effectively three interconnected single phase transformers on a single core in cost, size, and weight [4]. The design of the trainer aims to protect the students from dangerous voltage ratings in connecting the configuration for the various types of transformer banking. II. MATERIALS AND METHODS A. Transformer Configuration A three-phase transformer has three sets of primary and secondary windings. The type of interconnection of these windings determines whether the transformers are in star or delta configuration [5]. Fig. 1. Star connection. Fig. 1 shows how the transformers are being connected in star configuration. In this configuration, the phase voltage is equal to line voltage divided by square root of three. Also, the phase current is equal to the line current. On the other hand, Programmable Logic Controller (PLC) Protected Transformer Banking Trainer Kit for Electrical Engineering Education Anthony M. Minoza, Blondie T. Sanchez, and Jayson C. Loreto International Journal of Information and Education Technology, Vol. 9, No. 12, December 2019 933 doi: 10.18178/ijiet.2019.9.12.1329