Gul Ahmad Ludin

Frequency control using real-time pricing for isolated power systems

Recently, generators using renewable energy have increased in usage within the power system. These continual increase of these generators is expected in future. Within the power system, output fluctuations of generators using renewable energy causes frequency and voltage fluctuations. Consequently, in the near future, power consumption will have the requirement to track the supply power by a demand-response system. Further, faster power fluctuations that cannot be tracked by demand-response will need to be compensated by battery systems. This paper describes a technique of frequency and voltage control by using demand-response and battery control for isolated power systems, which includes wind generators. Demand-response is executed corresponding to fluctuations in electric power price using real-time pricing. The H∞ control method installed in batteries is adopted as improvement over the conventional Droop control method. The H∞ control method is compared with the conventional improved Droop control method. The effectiveness of the proposed method is verified by simulation results in the Matlab/Simulink environment.

System frequency control using emergency demand response in power systems with large-scale Renewable Energy Sources

Recently, the introduction of Renewable Energy Sources (RESs) has been remarkable. However, the RESs are the cause of output power fluctuation which depends upon the weather condition. It also causes system frequency to deviate that means reliability of system is decreased. In particular, RESs output power which varies steeply and significantly is a cause of concern. Due to these output power fluctuations, the supply-demand balance gets worse, in the worst case, massive blackout can occur. In this paper, we propose emergency demand response (EDR) method to prevent the steep output power fluctuation of the RESs. The EDR adjusts the supply-demand balance by changing the consumed power of controllable load depending on system frequency drop. When the system frequency drops steeply, the system frequency is restored rapidly within acceptable range using the EDR.

Uninterruptible smart house equipped with a single-phase dq-transformation system

This paper proposes an uninterruptible all-electric smart house equipped with photovoltaic system and storage battery. There is a control delay in the conventional control system, because the system uses root mean square or average values for the control method. Therefore, it causes transient currents when load variation and system faults occur. The transient current adversely affects the in-house loads (e.g., precision equipment). In this paper, the control delay is reduced by using a control system with single-phase dq-transformation information. Therefore, the smart house achieves a reduction of the transient current caused by load variation and system faults through the use of instantaneous inverter control. The effectiveness of the proposed method is verified by simulation results given by the Matlab/SimPowerSystems® environment.

Multi-Terminal High Voltage Direct Current Transmission System with DC Resonant Semiconductor Breakers

Abstract In consideration of the natural environment and depletion of energy resources, the widespread use of electric power system is expected in which the power is generated from sources of renewables such as wind and solar. When these plants are introduced in large scale, the use of broad land is required. Due to low transmission losses and small stability problems, multi-terminal high voltage direct current (MTDC) transmission becomes advantageous as long-distance power transmission system. Since DC current does not incorporate a zero cross point, therefore it’s blocking is difficult. This paper proposes a DC resonant semiconductor breaker which enables rapid fault clearance for self-excited HVDC transmission. This circuit breaker is connected as a semiconductor switch, in parallel with a group of capacitors, and resistors in the DC transmission line. The capacitor is charged to a higher voltage from the DC transmission line. For generating reverse current to allow the zero cross point in the transmission line, the semiconductor switch turns on to open the circuit breaker. After blocking, the inductance of the line is demagnetized by the resistor and fault clearing is achieved. The system except fault point can continue its normal operation.

Electricity Sector Development Trends in an After-war Country: Afghanistan Aspiration for an Independent Energy Country

The rapid change in economic growth and human civilization has led to a dramatic increase in energy utilization and electricity demand. That faces nations with the challenge of maintaining cost-effective and clean power energy production. This paper aims to present Afghanistan electricity sector development and energy resources exploitation in a broad context. With the global growing interest in Afghanistan rehabilitation, this paper presents energy development trends in Afghanistan. Besides, the future outlook up to 2032 and the challenges that face electricity sector are highlighted. This study tries to emerge the historical development, current status, and future direction of Afghanistan electricity sector till 2032, in a precise collection.

Hybrid PV/Wind/Diesel Based Distributed Generation for an Off-Grid Rural Village in Afghanistan

Afghanistan has a tremendous resource potential of renewable energy especially solar and the wind. Therefore, utilization of these resources has a special rule for the remote areas where access to the electrical grid or secure power supply is a dream for most of the people. This paper presents a feasibility and usefulness of hybrid power generation based on PV/wind/diesel generator for an off-grid rural village that feeds the load at a rate of average 7.9 kWh/day with 1.32 kW peak load. GsT (geospatial toolkit) is used to obtain the solar and wind data of the site. Windographer software is used to analyze the wind resource data of the site. HOMER Pro software package is used to select the suitable and reliable hybrid generation system and calculate the optimal capacities and costs of the components. Through the study, it is found that this state of the art adaptation could provide vast opportunities for off-grid rural communities such as in Afghanistan where enough high penetration of renewable energy is available.

Electricity Sector Transitions in an after War Country: A Review of Afghanistan’s Electricity

Afghanistan electricity sector has experienced many ups and downs of transitions from 1893 to date. With the growing global interest in Afghanistan rehabilitation, this paper presents an over view of Afghanistan electricity sector which includes the historical development trends, power generation potential, sustainable energy exploitation, electricity policy transition and immature policies experiences, and the legacy of the war. The lack of access to the basic information about Afghanistan power sector was one of the serious concerns of international donors and investors. Still, this information somehow has been kept in official documents wrap up. In this collection, the Afghanistan’s electricity sector is pictured as a reference for Afghanistan electricity. It can be opening toward primary sources of Afghanistan electricity sector of the lessons learned and asset for researchers interesting in this topic.

Torsional oscillation damping control for wind turbine generator under strong wind conditions

This paper proposed the control system that torsional oscillation damping control for wind turbine generator under strong wind conditions. It is assumed that wind turbine is permanent magnet synchronous generators and consisted of two mass system, which is wind turbine and generator. The blades and generator are connected to the shaft and due to the different inertia of blades and generator, a torsion occurs in the shaft In general, torsions are reduced over time because of wind turbine mechanical losses. However, shaft systems have resonance frequency that amplify torsions, and did not damp the oscillation. As a result, the shaft may be damaged or broken. The proposed method is damping the response at resonant frequency by using H∞ controller and considering rotating speeds controlling method.