Umer Amir Khan

King Fahd University of Petroleum and Minerals | KFUPM · Department of Electrical Engineering

Polymer based composite high voltage insulators (HVIs) due to their hydrophobic surfaces have consistently outperformed the traditional ceramic insulators in highly contaminating coastal-desert environments. However, the harsh environment causes polymer surfaces of these HVIs undergo rapid ageing leading to permanent loss of hydrophobicity. In this...

The Photovoltaic (PV) module converts only a small portion of irradiance into electrical energy. Most of the solar energy is wasted as heat, resulting in a rise in PV cell temperature and a decrease in solar cell efficiency. One way to harvest this freely available solar thermal energy and improve PV cell efficiency is by integrating PV systems wit...

The increasing deployment of inertia-less power electronic converters poses serious concerns on power system frequency stability. Synchronverter has certain features like virtual inertia, damping and voltage regulation embedded in its controller. Therefore, it can support system frequency and voltage in power grids. Like synchronous generator, it h...

The rapidly increasing demand for electrical energy and the depletion of fossil fuels ignited research in renewable energy generation and management. Thermoelectric generation (TEG) systems as a green energy resource are designed to recover waste heat recovery. Concentrated solar tackles the disadvantages of low power generation efficiency. This pa...

The diminishing of conventional energy sources such as fuel, oil, and coal has shifted researchers’ focus towards more cost-effective and sustainable energy sources. The conventional energy sources leave the Carbon footprint and Sulphur contents in the atmosphere, which are not only harmful to the environment but also to human health. These issues...

A new fault detection system is proposed in this study for large-scale grid-tied PV power plants. The fault detection system performs string level comparison of DC power of Actual PV Plant and a simulated PV plant, referred as Theoretical PV Plant. The comparison is performed with a statistical tool which distinguishes a faulty condition and identi...

Non-uniform irradiance levels, and drastically changing weather and climate conditions cause PV systems to fall in partial shading (PS) category. Under uniform irradiance conditions, conventional MPPT techniques provide a viable solution, however under PS conditions, such techniques fail to perform. Many bio-inspired MPPT control techniques are pre...

Solar energy is a viable solution to the damage caused by the conventional power sources to the environment. Temperature and irradiance levels have a high impact on the power generation of photovoltaic modules, but due to non-uniform irradiance levels, PV modules generate non-linear P-V curves. Maximum power point tracking control is introduced to...

Superconducting Fault Current Limiters (SFCL) have been used in power systems for many years, however the best possible positioning of different SFCL still needs a lot of work. Resistive and Inductive are two types of SFCL used in power system. Function of both these current limiters is to control the fluctuations and abnormalities in the system by...

A multi-terminal high voltage DC (MTDC) grid, is an optimum and cost-effective transmission network to minimize the energy crisis worldwide largely. However, the core demand for a fast DC protection scheme with an extraordinary strict fault clearance time of a few milliseconds, is a key research gap in this network, holding back its development and...

The demand of energy usage is increasing rapidly and to meet the energy requirements, best possible transmission systems should be adopted to avoid energy losses in our transmission systems. In Pakistan’s WAPDA (Water & Power Development Authority) system, the rapid increase in load and less generation capacity has increased load shedding thought t...

Growing urbanization coupled with increased power demands have led to an increasing use of mixed power transmission lines with sections of overhead lines (OHL) and the underground cables. Due to differences in surge impedance of cables and OHL, voltage surges experience reflections and refractions at their boundaries which make the transient behavi...

The aim of this paper is to perform fundamental simulation for design of 1.5 kV DC circuit breaker of high speed. The simulation was focused on methods for improvement of the arc driving force. Considering that design for arc runner is a main component which affects the arc driving force, two main design parameters of arc runner: slope of arc runne...

Recently, studies on HVDC circuit breaker (CB) prototypes have shown successful test results. Nevertheless, effective and reliable solutions regarding massive fault energy during dc fault interruption have not yet been commercialized, and dc current breaking topologies on methods of achieving artificial zero should be somewhat modified. As an alter...

For Line Commutated Converter based HVDC system, the occurrence of commutation failure is inevitable. Generally, thyristor valves are turned on by a firing signal but turn off control is governed by the external applied ac voltage from surrounding network nearby LCC-HVDC system. When the fault occurs in ac system, especially in inverter end of LCC-...

The key obstacle in integrating high-voltage direct current (HVDC) point-to-point networks into meshed multiterminal HVDC networks (MTDC) is the absence of dc circuit breakers (DCCBs), which can timely and reliably isolate the faulty HVDC network from the MTDC. In this paper, a novel hybrid-type superconducting DCCB model (SDCCB) is proposed. The S...

High-voltage direct current (HVDC) technology is considered to have some important advantages over traditional high-voltage alternating current, such as higher overall efficiency and smaller power losses for long-distance transmission. In addition, applications of superconducting cables in dc electric power networks may realize real zero impedance,...

Voltage source converter-based HVDC systems (VSC-HVDC) are a better alternative than conventional thyristor-based HVDC systems, especially for developing multi-terminal HVDC systems (MTDC). However, one of the key obstacles in developing MTDC is the absence of an adequate protection system that can quickly detect faults, locate the faulty line and...

High Voltage Direct Current (HVDC) system has been evaluated as the optimum solution for the renewable energy transmission and long-distance power grid connections. In spite of the various advantages of HVDC system, it still has been regarded as an unreliable system compared to AC system due to its vulnerable characteristics on the power system fau...

In the design of DC superconducting cables, the electrical insulation design is a critical factor in the cable's performance and reliability. To evaluate the insulation design of DC superconducting cables, DC electric field analysis and experimental verifications should be performed. Wrapped polypropylene laminated paper (PPLP) tape has generally b...

Due to fewer risk of commutation failures, harmonic occurrences and reactive power consumptions, Voltage Source Converter (VSC) based HVDC system is known as the optimum solution of HVDC power system for the future power grid. However, the absence of suitable fault protection devices for HVDC system hinders the efficient VSC-HVDC power grid design....

In a smart grid, various kinds of distributed generation (DG) sources could be connected into the main power grid in order to enhance the reliability of the power system. The combination of ac and dc distribution grid are also considered for the efficient connection of renewable power resources. In this case, one of the critical problems due to the...

Partial discharge (PD) measurement is one of the effective diagnostic techniques to predict abnormal high voltage dielectric insulation conditions of the electric equipments. PD diagnostic techniques were also could be utilized to evaluate the conditions of cryogenic dielectric insulation media of high temperature superconducting electric equipment...

Superconducting electric equipments have a lot of advantages over the conventional devices such as improvements in overall efficiency, size reduction, high current carrying capability, and also environment-friendly products. Owing to these advantages, many research institutes have been tried to develop commercial superconducting devices, which coul...

DC fault current limitation in DC distribution network is one of the critical issues which need to be taken care of before they can be practically implemented. High temperature superconductors could be efficiently installed to cope with the problem of DC fault currents. In this paper, a generalized DC high temperature superconducting fault current...

Conventional protection devices installed for the protection of excessive fault current in the electric power system have a certain response time delay resulting in power system to pass initial peaks of fault current. Superconducting Fault Current Limiter (SFCL) is a novel technology which has negligible power loss and capability to quench initial...

One of the most important topics regarding the application of superconducting fault current limiters (SFCL) for upcoming smart grid is related to its possible effect on the reduction of abnormal fault current and the suitable location in the micro grids. Due to the grid connection of the micro grids with the current power grids, excessive fault cur...

Highvoltagecryogenicinsulationissuesneedtobead- dressed in order to promote the commercialization of high temper- ature superconducting (HTS) equipment. One of the critical com- ponents for superconducting devices is the bushing whose role is to safely supply high current to the device. Due to a steep tem- peraturegradient,commercialbushingswhichha...

A considerable amount of research material discussing designs and properties of High Temperature Superconducting Fault Current Limiter (HTS FCL) is available. However, a shortage of research concerning positioning of HTS FCL in power grid is felt. In this paper a feasibility study of HTS FCL positioning in Smart Grid through simulation analysis is...