Papers by A Hasib Chowdhury
Parameterization of active disturbance rejection controller for load frequency control
8th International Conference on Electrical and Computer Engineering, 2014
Six mode control strategy for a stand-alone hybrid power system
2012 7th International Conference on Electrical and Computer Engineering, 2012
Abnormal condition in a power system generally leads to a fall in system frequency, and it leads ... more Abnormal condition in a power system generally leads to a fall in system frequency, and it leads to system blackout in an extreme condition. This paper presents a technique to develop an auto load shedding and islanding scheme for a power system to prevent blackout and to stabilize the system under any abnormal condition. The technique proposes the sequence and conditions of the applications of different load shedding schemes and islanding strategies. It is developed based on the international current practices. It is applied to the Bangladesh Power System (BPS), and an auto load-shedding and islanding scheme is developed. The effectiveness of the developed scheme is investigated simulating different abnormal conditions in BPS.
Technique to Develop Auto Load Shedding and Islanding Scheme to Prevent Power System Blackout
IEEE Transactions on Power Systems, 2012
Abnormal condition in a power system generally leads to a fall in system frequency, and it leads ... more Abnormal condition in a power system generally leads to a fall in system frequency, and it leads to system blackout in an extreme condition. This paper presents a technique to develop an auto load shedding and islanding scheme for a power system to prevent blackout and to stabilize the system under any abnormal condition. The technique proposes the sequence and conditions of the applications of different load shedding schemes and islanding strategies. It is developed based on the international current practices. It is applied to the Bangladesh Power System (BPS), and an auto load-shedding and islanding scheme is developed. The effectiveness of the developed scheme is investigated simulating different abnormal conditions in BPS.
Interconnection planning of power systems requires the evaluation of location and capacity of tie... more Interconnection planning of power systems requires the evaluation of location and capacity of tie lines that ensure optimum operating cost and optimum rate of return on the investment. Tie line planning is a complicated combinational problem to select a solution from a finite set of possible outcomes. This paper presents a tie line planning method using probabilistic load model. This method decomposes the planning problem into a number of smaller optimization problems those are solved using AC optimal power flow (OPF) technique. At first, at every load level, the OPF is used to evaluate the optimum capacity and location of a tie line. The cost function includes both the tie line cost and the energy production cost for a particular load level. The energy production cost for the whole planning period is evaluated in the next stage considering the evaluated optimum tie line obtained for a particular load level. Appropriate penalty cost is introduced if the tie capacity determined at a particular load level is over or under sized with respect to the optimum capacity obtained for other load levels. The costs associated with each load level are then compared to choose the tie line with minimum overall cost. The proposed methodology is applied on IEEE Two Area Reliability Test System (RTS) 1996 to determine the tie line capacity and location.
Conventional solar photo voltaic (PV) systems for pumping are designed with panel overcapacity of... more Conventional solar photo voltaic (PV) systems for pumping are designed with panel overcapacity of 30 to 40 percent so that pumping can be continued during low insolation. This adds much to the cost of such a system. In this paper a new concept for optimum utilization of photovoltaic output for irrigation is presented. The designed system eliminates overcapacity requirement of PV modules by using a combination of pumps where load become variable with the change of PV power output. The developed system can continue pumping even during low solar insolation. Directly fed DC motors used to drive the pumps avoid design complexity and eliminate battery and its maintenance cost. The designed system is superior to existing systems, increasing the water output for the same installed PV module capacity. A practical irrigation system based on the concept is implemented in the field. Field testing shows that the system improves the total output of water over conventional PV powered irrigation system by maximum utilization of available photovoltaic output and maximum utilization of the duration for which solar power is available.
The use of smart card is rapidly increasing to pay different type of utility bills like electrici... more The use of smart card is rapidly increasing to pay different type of utility bills like electricity or gas bill for prepaid electricity meter or prepaid gas meter respectively. It is time consuming for the consumer to recharge smart card from the vending station if it is far away from home. It is costly to increase the number of vending station too. This paper presents a low cost portable vending system for recharging smart card. It is a micro-controller based embedded system interfaced with GPRS modem, slip printer, memory card, smart card, RTC, LCD and keypad. The system is tested for prepaid electricity and gas meters developed by the Institute of Information and Communication Technology of Bangladesh University of Engineering and Technology. Performance of the developed system is very satisfactory.
Digital equipment and devices have become most essential tools for disseminating knowledge in edu... more Digital equipment and devices have become most essential tools for disseminating knowledge in educational institutions. The use of such equipment has now become more effective with the inclusion of contents available in the Internet. All of these tools and means have created a great opportunity for spreading teaching and learning in distance educational mode. But for a developing country, the main hindrances for spreading distance education are the cost of the equipment and availability of Internet access over all parts of the country. A research has been carried out on how the cost of useful digital gadgets and their accessories can be brought down to an affordable price and how the access to the Internet can be made easy for the students in general. This paper starts with the description of the challenges for reaching the objectives and then it explains how they are overcome by different indigenous technical solutions. Moreover, work on how the power requirement for the commonly used digital equipment has been minimized is reported in the paper. Finally it shows the techniques of applying solar power to supply the energy requirement for the gadgets to be used for distance learning. This has made a break through in education sector for a vast community in developing countries.
In power system voltage collapse is considered as a very complex subject that has been challengin... more In power system voltage collapse is considered as a very complex subject that has been challenging the power system engineers in the recent past two decades. In respect to voltage collapse phenomenon, information based on loading capability is highly important for the secure operation of the power system. As interconnection between independent power systems is found to be economically attractive to provide with a background for the expansion planning, the complexity of voltage collapse problem is increased. Voltage collapse is generally caused by either of the two types of system disturbances: load variations and contingencies. When a bulk power transmission network (generation and transmission system) is operated close to the voltage stability limit, it becomes difficult to control the reactive power demand for that system. As a result, the system voltage stability will be affected, which if undetected may lead to voltage collapse.
Gas is an important source of energy in this world. At this age of energy crisis, gas must be uti... more Gas is an important source of energy in this world. At this age of energy crisis, gas must be utilized wisely and carefully. In this paper, a design of a smart card based prepaid gas metering system has been presented. Prepaid gas meter will make the consumers more conscious to utilize gas carefully and also it promises easy, fast and accurate billing scheme. The entire system is designed with the state-of-the-art digital and information technology. A prototype of the system has been developed and tested.
Power system oscillations involving interactions of generating units from interconnected areas ar... more Power system oscillations involving interactions of generating units from interconnected areas are crucial, as these oscillations may appear significantly in tie-line power flow by adding up the effects from all participating units. Considerable research has been evident in the industry to design stabilization measures to mitigate inter-area oscillations. TCSC, a member of FACTS controller family, has been identified as one of the major candidates for this purpose. Bangladesh Power System consists of greater Eastern and Western Grid, interconnected by the East-West Interconnectors. Application of TCSC in damping inter-area oscillations in this interconnected system has been studied in this work.
Evaluation of optimum capacity and location of east west interconnector using tie line planning approach
Bangladesh is physically divided into two parts, Eastern and Western, by the combined flow of Jam... more Bangladesh is physically divided into two parts, Eastern and Western, by the combined flow of Jamuna-Meghna river system. Because of the availability of natural gas in Eastern part, most of the generating plants of the country are installed here. Therefore, it is important for the utility to search optimum interconnection(s), connecting Eastern and Western parts, for capacity transaction such that
Electric Power Systems Research, 1998
Torque developed during a short circuit of an alternator is considered as the most severe case fo... more Torque developed during a short circuit of an alternator is considered as the most severe case for the design of the shaft by engineers. But studies show that shaft torque during a faulty synchronization may exceed the torque developed during a short circuit at certain conditions. Accurate prediction of the shaft torque in faulty synchronization process is therefore important in the design stage to ensure the safe operation of ac generators. In the reported simulations the effects of saturation is either neglected or taken into consideration in the form of mutual path saturation only. The procedure may provide underestimated values of shaft torque because the current involved in such a situation may become significantly high at certain synchronizing angle. Hence, simulations should consider leakage path saturation during shaft torque evaluation particularly during short circuits and faulty synchronization. This paper describes a method of simulating faulty synchronization of a generator to a power system considering a detail generator model in mathematical and state space form. A method of incorporating saturation effects both in the mutual and leakage path is proposed. Simulations have been carried out for different synchronizing angles to evaluate the instantaneous and the peak shaft torques with and without saturation effects. Finally, a typical comparative study between faulty synchronization and short circuit faults of ac generators is provided in this paper, where, the results of faulty synchronization conditions were evaluated by proposed simulation method presented in this paper. © 1998 Elsevier Science S.A.
Power system load switching monitoring using wavelet transform based multiresolution signal decomposition
This paper presents a wavelet transform based multiresolution signal decomposition technique for ... more This paper presents a wavelet transform based multiresolution signal decomposition technique for monitoring power system load switching. The proposed method depends on the standard deviations of wavelet coefficients calculated at different resolution levels. Power system signals are decomposed using discrete wavelet transform based filter bank. The simulation results of the study clearly demonstrate that proposed method can efficiently detect and localize power system load switching in time domain. The method can also give information on the magnitude of the load switched and its distance from the observation point.
Savings of electricity consumption cost in residential sector of Bangladesh
This paper presents the savings of electricity consumption cost in residential sector of Banglade... more This paper presents the savings of electricity consumption cost in residential sector of Bangladesh through replacing the instantaneous power supply (IPS) units with solar photovoltaic (PV) system. In Bangladesh, presently total electrical demand is about 6000 MW with total generation of about 4500 MW. About 1500 MW or 25% of total demand is unserved with current generation. To get rid
Design and cost benefit analysis of grid connected solar PV system for the AUST campus
... [6] Sunny Mini Central 11000TL datasheet, SMA Solar Technology, USA. [7] Midnite Solar MNP... more ... [6] Sunny Mini Central 11000TL datasheet, SMA Solar Technology, USA. [7] Midnite Solar MNPV3 datasheet, Midnight Solar, USA. [8] Master Price List, U-LA, Unirac, 2008. [9] M. RezwanKhan, M. Fayyaz Khan, Design considerations for solar PV home systems in ...
Information on loading capability is highly important for secure operation of a power system, and... more Information on loading capability is highly important for secure operation of a power system, and also provide with a background for expansion planning. Loadability studies based on voltage collapse, considered as one of the severe limiting factors in system loading, can be used to obtain practical insights on the operational regime of an existing system. Findings of a preliminary level voltage collapse study on Bangladesh Power System Network (BPSN) have been presented in this paper. The complete network model of BPSN, represented in this work by a 166 bus system, has been used. Voltage collapse constrained maximum loading point at the base case -created with a recent peak-time operational data set, and with several selected contingencies have been determined and presented. Usefulness of additional information obtained from voltage collapse studies, such as identification of weak buses and their effectiveness in network performance improvement has also been discussed.
Abnormal condition in a power system generally leads to a fall in system frequency and it leads t... more Abnormal condition in a power system generally leads to a fall in system frequency and it leads to system blackout in an extreme condition. Bangladesh Power System (BPS) experienced three blackouts in it recently. This paper develops an auto load shedding scheme to prevent frequent blackout and stabilize the BPS under any abnormal condition. The effectiveness of the developed auto load shedding scheme is investigated simulating different abnormal conditions in BPS.
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Papers by A Hasib Chowdhury