Research Groups

In the late 1960s, Power Electronics Laboratory was founded by the late professor Min-Ho Park. Since 1991, under the leadership of professor Seung-Ki Sul, 6 PhD, 6 master's courses students, a foreign postdoctoral researcher, 2 intern undergraduated senior students have been researching on electric motor drive and power conversion system such as AC-DC, AC-AC etc. In these fields, our Lab. has carried out a lot of projects with foreign companies as well as domestic companies, and achieved excellent results. Especially by commercializing our research results through sponsor companies, we are directly contributing to domestic and international sponsoring industries. Therefore, most of students who graduated from our laboratory have been leading an advance of power electronics in industry and academia. Like this, our lab has been well known as the leading technology research group at home and abroad. Recently due to emerging environmental issues, power conversion research related to green technology has been received much attention, because power conversion plays an important role in renewable energy industry. Study on this field is actively ongoing in our Lab. Furthermore, AC motor drive system including Hybrid/Electric Car, electric propulsion ship etc. also have been researched for over ten years. Through this study, 3 doctors who graduated from our Lab were employed in GM Advanced Technology Center, USA. Also, we annually give a chance to study abroad for a year to 2 graduated students investigating power electronics, by supporting scholarship based on the fund, five hundred million, which the late professor Min-Ho Park donated.

▶ Research Area
- New Ac-AC, AC-DC converter topology
- Motor drive algorithm, in particular the best technology and original patent reserved in terms of position sensorless AC motor drive
- Power Conversion System (PCS) design and control, Power Quality(PQ) improvement for renewable energy
- Modular Multilevel voltage source Converter(MMC) for high voltage DC transmission system (HVDC)
- Converter and System controlled by FPGA, DSP

▶ Recent main research project
- AC/DC/AC converter system having regenerative capability for multi megawatt medium voltage motor drive
- High performance sensorless algorithm for ac motor drive
- Fault detection algorithm applicable to Hybrid/Electric Car
- Grid connected photovoltaic converter system
- Control algorithm and PCS development for grid connected multi megawatt Energy Storage System
- PQ improvement with MMC

- Typical papers
[1] Jae-Jung Jung, Hak-Jun Lee, Seung-Ki Sul
Control strategy for improved dynamic perform ance of variable-speed drives with modular Mu ltilevel converter,
IEEE JOURNAL OF EMERGING AND SELECTED TOPICS IN POWER ELECTRONIC, 2015. 6, Volume: 3, Issue: 2, Pages: 371 - 380

[2] Myoungho Kim, Seung-Ki Sul, Junggi Lee
Compensation of current measurement error for current-controlled PMSM drives,
IEEE Transactions on Industry Applications, 2014. 10, Volume: 50, Issue: 5, Pages: 3365 - 3373

[3] Yong-Cheol Kwon, Sungmin Kim, Seung-Ki Sul
Six-Step operation of PMSM with instantaneous current control,
IEEE Transactions on Industry Applications, 2014. 8, Volume: 50, Issue: 4, Pages: 2614 - 2625

[4] Young-Doo Yoon, Seung-Ki Sul
Sensorless control for induction machines based on square-wave voltage injection,
IEEE Transactions on Power Electronics, 2014. 7, Volume: 29, Issue: 7, Pages: 3637 - 3645

[5] Sehwa Choe, Eunsoo Jung, Seung-Ki Sul
Sensorless control of synchronous machine with an inverter integrated rotor,
IEEE Transactions on Industry Applications, 2014. 7, Volume: 50, Issue: 4, Pages: 2584 - 2591

[6] Yongsoon Park, Seung-Ki Sul
Sensorless control method for PMSM based on F requency-adaptive disturbance observer,
IEEE JOURNAL OF EMERGING AND SELECTED TOPICS IN POWER ELECTRONIC, 2014. 6, Volume: 2, Issue: 2, Pages: 143 - 151

[7] Yong-Cheol Kwon, Seung-Ki Sul, Baloch, N.A., Murakami, S., Morimoto, S.
Design and control of IPMSM sensorless drive for mechanical rotor position estimation capability,
IEEE JOURNAL OF EMERGING AND SELECTED TOPICS IN POWER ELECTRONIC, 2014. 6, Volume: 2, Issue: 2, Pages: 152 - 158

[8] Yongsoon Park, Seung-Ki Sul
Implementation schemes to compensate for inverter nonlinearity based on trapezoidal voltage,
IEEE Transactions on Industry Applications, 2014. 3 Volume: 50, Issue: 2, Pages: 1066 - 1073

[9] Yongsoon Park, Seung-Ki Sul, Woo-Chull Kim, Hyun-young Lee
Phase-Locked loop based on an observer for grid synchronization,
IEEE Transactions on Industry Applications, 2014. 3, Volume: 50, Issue: 2, Pages: 1256 - 1265

[10] Hyun-Sam Jung, Seung-Jun Chee, Seung-Ki Sul, Young-Jae Park, Hyun-Soo Park, Woo-Kyu Kim
Control of three-phase inverter for AC motor drive with small DC-link capacitor fed by single-phase AC source,
IEEE Transactions on Industry Applications, 2014. 3, Volume: 50, Issue: 2, Pages: 1074 - 1081

[11] Wook-Jin Lee, Seung-Ki Sul
DC-Link voltage stabilization for reduced DC- link capacitor inverter,
IEEE Transactions on Industry Applications, 2014. 1, Volume: 50, Issue: 1, Pages: 404 - 414

[12] Yongsoon Park, Seung-Ki Sul, Chun-Ho Lim, Woo-Chull Kim, Seong-Hun Lee
Asymmetric control of DC-link voltages for separate MPPTs in three-level Inverte rs,
IEEE Transactions on Power Electronics, 2013. 6, Volume: 28, Issue: 6, Pages: 2760 - 2769

[13] Hak-Jun Lee, Sungho Jung, Seung-Ki Sul
A current controller design for current source inverter-fed AC machine drive Sys tem,
IEEE Transactions on Power Electronics, 2013. 3, Volume: 28, Issue: 3, Pages: 1366 - 1381

[14] Sungmin Kim, Young-Doo Yoon, Seung-Ki Sul, Ide, K.
Maximum torque per ampere (MTPA) control of an IPM machine based on signal injection considering inductance saturation,
IEEE Transactions on Power Electronics, 2013. 1, Volume: 28, Issue: 1 , Pages: 488 – 497

- Typical patents