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A Photovoltaic (PV) systempsilas power output is not constant and fluctuates depending on weather conditions. Fluctuating power causes frequency deviations in the power utilities when PV power penetration is large. Using a battery is the common practice to smooth PV output power fluctuations. In this paper, we propose a new and simple fuzzy based control method for PV-diesel hybrid system to reduce...
This paper presents a methodology for solving unit commitment problem for thermal units integrated with wind and solar energy systems. The renewable energy sources are included in this model due to their low electricity cost and positive effect on environment. The unit commitment problem is solved by a genetic algorithm operated improved binary particle swarm optimization (PSO) algorithm. Unlike trivial...
This paper presents a multi-population binary clustered particle swarm optimization (BCPSO) algorithm to solve short term thermal generation scheduling problem. The potential solution schedules are distributed among several clusters based on their corresponding fitness values. Each cluster contains a cluster best schedule. Each solution of a particular population then flies through to its cluster...
Electric utility deregulation has made it possible for power producers and suppliers (PPSs) to enter the electricity market in Japan. PPSs are supposed to achieve 30-minute balancing control for stable supply of electrical power, in which energy demand and energy supply should be matched within thirty minutes. Meanwhile, load rejection and instantaneous voltage drop greatly affect turbine shafting,...
Wind energy is a significant and powerful natural resource that is safe, clean, and abundant. However, wind energy has a drawback of having only 1/800 density as compared to that of water energy, and it is not constant and wind turbine output is proportional to the cube of wind speed, which causes the generated power of wind turbine generator (WTG) to fluctuate. In this paper, a technique is proposed...
Nicotinic cholinergic receptors play a role in cardiovascular regulation in the lower brain stem. Herein, we present evidence that l-3,4-dihydroxyphenylalanine (DOPA), a putative neurotransmitter in the central nervous system, is involved in the depressor response to microinjection of nicotine into the nucleus tractus solitarii (NTS). Microinjection of nicotine into the medial area of the NTS led...
In recent years, power system has employed many applications of power electronics technologies for power quality improvement. Unified Power Quality Conditioner (UPQC), which consists of double converters connected by a DC capacitor with each other, has great potential because of its high controllability. Various attractive applications for power quality improvement are considered but the active power...
Recently, a small-scale power system has been able to perform autonomous or islanding operation with some distributed generators. But in such a microgrid, it is afraid that serious voltage imbalance may be caused by unbalanced loads during the islanding operation. Fortunately, grid interactive inverters of the distributed generators often have some amount of surplus capacity. This paper deals with...
An active network control method using distributed energy resources in microgrids is shown. Some features of the system were outlined. And also, power system stabilizer to compensate for the fluctuation of active power in microgrid is proposed. The microgrid with these new techniques can contribute to efficient operation of DGs and stable power supply for customers.
Due to the large output power fluctuations of a wind power generator, a battery is installed to smooth these fluctuations. However, if a large battery is installed in the power system, the capital cost for wind power system will increase. Hence the smallest size of battery is preferable to save on capital cost. In this paper, we propose a methodology for controlling combined system output and optimal...
This paper proposes stable operation strategies for gearless wind power generation systems using permanent magnet synchronous generator (PMSG) under line fault. The proposed method uses a chopper circuit in DC-link circuit for gearless wind power generation system. This chopper circuit can avoid DC-link over-voltages under line fault. In addition, the control schemes in this paper include the maximum...
In recent years, focus has been on environmental pollution issue resulting from consumption of fossil fuels, e.g., coal and oil. Thus, introduction of an alternative energy source such as solar energy is expected. However, insolation is not constant and output of photovoltaic (PV) system is influenced by meteorological conditions. In order to predict the power output for a PV system as accurately...
In recent years, distributed generation, as clean natural energy generation and cogeneration system of high thermal efficiency, has increased due to the problems of global warming and exhaustion of fossil fuels. Many of the distributed generations are set up in the vicinity of the customer, with the advantage that this decreases transmission losses. However, output power generated from natural energy...
Strong growth figures prove that wind is now a mainstream option for new power generation. However, wind stochasticity results in fluctuations in output power as well as undesirable dynamic loading of the drive-train during high turbulence. To provide industry with the support it needs to develop technologies capable of cost-effective operation, advanced power electronic components have become increasingly...
This paper investigates availability of Demand-Side Management (DSM) considering Flexible, Reliable and Intelligent Energy Delivery System (FRIENDS) proposed by the authors. The proposed DSM is based on a Real-Time Pricing system (RTP) executed by owners of Quality Control Centers (QCC) in FRIENDS, which are facilities allocated close to consumers. More specifically, QCC owners procure electricity...
The Ministry of Economy, Trade, and Industry in Japan published a target to install 3 GW wind power generation to be connected to grids by 2010. However, as outputs from wind power generation fluctuate time to time and wind power resources are available only in specific areas, deterioration of the quality of utilitypsilas power supply has become an important issue to be solved. As a countermeasure...
Recently, renewable energy technologies such as wind turbine generators and photovoltaic systems have been introduced as distributed generation. The connection of a large amounts of distributed generation causes voltage deviation beyond the statutory range in distribution system. In this paper, we propose a methodology for voltage control using tap changing transformers in distribution system and...
Many single phase distributed generators (DGs) - such as solar cells, small scale gas-engine CHP systems, etc. - are being installed in an electric power distribution system in recent years. These distributed generators are not always generating steady power due to the weather conditions or hot-water demand conditions, etc. Therefore, DGs could make ldquobalanced three-phase loadrdquo unbalanced....
With increased structural flexibilities of modern wind energy conversion systems (WECSs), drive-train torsional oscillations due to high wind disturbances can be hazardous to power systems. It is particularly important to design control schemes that properly account for the flexible modes of the turbine, and maintain stable closed-loop behavior of the WECS. To capture the essential features of the...
With increased structural flexibilities of modern wind energy conversion systems (WECSs), torsional oscillations can be hazardous to the drive train components as well as compromise output power quality. The proposed control paradigm is based on the linear quadratic Gaussian (LQG) to damp these undesired oscillations, and utilizes only one measurable feedback signal: generator speed deviation. An...
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