[Editor's Note] As motor control technology is emerging as a key technology in advanced industries such as electric vehicles, smart factories, and robotics, the use of Matlab, Simulink, and various MCU tools is being upgraded. The e4ds Motor Control Technology Conference will be held at COEX in Samseong-dong, Seoul on the 14th. Industry and academic experts will be invited to one place to share the latest technology insights and enhance technical capabilities for engineers and developers.

Before this, we met with Professor Lee Taek-gi of Hankyung University, who will be presenting on 'Industrial Motor Control Concepts and Advanced Control Technology Training', and had a brief discussion about motor control and technological prospects. Professor Lee Taek-gi is a professor in the Department of Electrical Engineering at Hankyung University and served as the president of the Korean Institute of Power Electronics in 2022. He is currently working as the head of the Semiconductor Bootcamp Business Unit, focusing on various educational activities.

■ About recent active activities in education

He served as the president of the Power Electronics Society in 2022 and is currently the business unit manager of the semiconductor boot camp project run by the Ministry of Education. As he is nearing retirement age, he is currently focusing on education and working on various projects.

As Anseong City has been designated as a specialized small business complex, a boom in education for semiconductor-related companies is currently taking place in Anseong. In conjunction with Anseong City becoming a specialized small business complex, approximately 40 billion won in national funds will be provided to support equipment.

In addition, there is a training program for in-service personnel that supports the training of personnel worth about 1.5 billion won over a five-year period. Hankyung National University, Doowon College of Technology, and Polytechnic University were selected for the program and are also conducting training programs for in-service personnel.

The mayor of Anseong City is passionate about education, so he is running a contract department business for employees in Anseong City. Anseong City is also currently running a business that supports 50% of the tuition for students enrolled in contract departments. The 3rd and 4th year transfer classes started last year with new students this year. The 2nd transfer class and the master's course started this year, so we started 3 contract departments. We are in charge of these businesses.

In Pyeongtaek, there is also a semiconductor-related education program called 'Future Technology School' for the unemployed. We were selected last year to run an educational program for the unemployed for one year, and we are seeing results in the students who received the education getting jobs. This year, we are also preparing to start a future technology school in Pyeongtaek around April.

■ How effective is in-service training?

In fact, the business of training employees is not easy. Since they have to spend a certain amount of time working at the company to receive training, the will of the CEO and the will of those receiving training are also necessary.

In fact, the satisfaction level after we provide training is very high. Because the training content is structured to meet the needs of the company, the satisfaction level of those who complete the training is very high. Companies that have received training once say they will provide more training.

So, the company that received the training last year is planning to continue the training this year. I think that in-service training is very necessary as a lifelong education concept. Since those who are currently working in the field always feel the need for education, the university is interested in lifelong education, and in the future, we will challenge and win projects implemented by the government, and we plan to display the university's capabilities in lifelong education projects for in-service employees.

■ You will also be providing training for employees at the upcoming e4ds technology conference . Could you please introduce the content?

This conference will cover everything from the basic principles of motors to the principles of power conversion, from basics to applications.

I think the thing I always emphasize when teaching students is the basics. Since a solid foundation is necessary for application, we will cover everything from basic principles to advanced application technologies, including power conversion devices and basic circuit principles, and AC and DC motor control, from the basics to applications, and cover them as conference topics.

■ It is said that the precision control of AC motors is more complicated than that of DC motors. I wonder why.

The DC motor is structurally designed so that the magnetic flux and current form a 90-degree angle. Therefore, the DC motor always operates at maximum torque when current is supplied, and it is easy to control because separate power sources, that is, the power source that generates the magnetic flux and the power source that generates the current that generates the force that goes into the armature, can be used separately.

On the other hand, AC motors generally cannot be controlled separately because the flux current and torque-on current are input at the same time on the input side. That is why AC motors are difficult to control.

■ Scalar control, vector control, etc. are used for motor control, but I am curious about the characteristics and advantages of each control.

In order to control an AC motor, a power conversion device such as an inverter is first required. Therefore, since the power conversion device is made of semiconductor elements, we will briefly examine the switching characteristics of the semiconductor elements. Next, if a power conversion device is equipped, it can be broadly divided into scalar control and vector control.

Scalar control is a method of controlling with one cycle of voltage, since alternating current has one cycle. Scalar control is a representative method and the V/f control method is used.

On the other hand, V/f control cannot be controlled in real time because it controls with one cycle of voltage. Therefore, in order to achieve real-time control, the concept of vector control is needed for control of DC motors, and such vector control is a technique that can achieve real-time control.

■ The future and prospects of the power electronics field

Since we majored in power electronics, for example, when we think of electric vehicles, the first thing that comes to mind is the battery. We think the battery is the most important, but in fact, electric vehicles have to roll, so the technology to turn the motor is what we actually need.

Members of our society who majored in power electronics generally think that the most important thing about electric vehicles is the inverter, or power conversion device. They are very proud of such power conversion technology.

First, power conversion devices need to be operated well to control the motor well, and power devices are developing very rapidly. So, efficiency is increasing, size is getting smaller, and they are becoming more compact. As space develops further in the future, what the space industry needs is electricity. So I think power conversion devices are developing much more.

Another thing is the power grid. Along with the power grid, power electronics technologies are being combined to create smart grids and distributed power supply systems that you all know well. I think that in the future, electric energy will be the energy of the future, so I think that power conversion devices that handle electric energy well are fundamental.

So, if you have a good understanding of power conversion devices and the theory of electric motors as loads, and apply advanced control technology to them, I think you will be able to apply it to all areas of industry and produce good products.

■ A word to our readers

As I said in the beginning, I would like to say again that the basis of all learning is a strong foundation for application. I hope this conference will be a time to lay the foundation. I hope that this foundation will be an opportunity to apply it to your work and practice, and become a momentum. I will see you at the conference.

thank you