Md Tanbhir Hoq

Md Tanbhir Hoq is an electrical engineer and worked as a doctoral student at KTH the Royal Institute of Technology from 2018-2022. His work involved distance protection of series compensated transmission lines. The supervisors for this project were Nathaniel Taylor and Jianping Wang.

Project Abstract

Series compensation is widely used in long power transmission lines, the main reasons behind this are increased power transfer capability, improved voltage profile, reduce transmission losses, improved transient stability. Fixed capacitors are connected in series with the transmission line for series compensation. These capacitors are protected from faults by using varistor, spark gaps etc. Fault currents activate the protection devices and during any external or internal fault, the compensated line demonstrates highly nonlinear and time-varying characteristics. Distance protection is a popular method for protecting transmission lines, it can operate locally and is independent of the communication link between the protected line segments. Distance protection operates based on measuring line impedance and by comparing it with pre-fault values, but the nonlinear behaviour of the series compensated line due to the protection devices of the capacitor poses a challenge in measuring the line impedance accurately. The distance relay faces directional and reach problems in this situation. There are existing methods implemented in protection relays to solve this problem but increased use of higher levels of series compensation requires further investigations, mainly to find the limits of using distance protection in highly compensated lines, to improve current methods and possibly develop new techniques to use distance protection.

Background

Md Tanbhir Hoq obtained B.Sc. in Electrical & Electronic Engineering from Islamic University of Technology (IUT), Bangladesh in 2011. later he completed EIT KIC InnoEnergySENSE double degree M.Sc. from KU Leuven, Belgium and KTH, Sweden in 2014. He has worked with ABB HVC in Karlskrona (now NKT cables) for a master thesis on the topic ''Effect of Heat Treatment on Morphology and Dielectric Properties of Polyethylene''.

After completing M.Sc. Tanbhir worked at KTH high voltage laboratory for a brief period. Then from 2015 to 2017, he worked in the Swedish power industry for ABB Capacitors (Ludvika), ABB FACTS (Västerås), FMTP Power AB (Stockholm) in several projects. In 2017 he returned to academia & research and worked as a lecturer at the University of Asia Pacific (UAP), Bangladesh for a year before coming back to KTH as a Doctoral Student in November 2018.