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In recent years, distributed generation (DG) and renewable energies source (RES) are attracting special attention to distribution systems. Renewable energy such as photovoltaic system and wind turbine generator are used as the sources of green energy. However, the large amount of distributed generation causes voltage deviation beyond the statutory range in distribution systems. This paper proposes...
This paper proposes the hybrid power source with electric double layer capacitor (EDLC) and battery. The charge and discharge control in this system is executed so as to reduce repetitive charge and discharge operation of battery. This operation makes the battery have a long time. Computer simulation results illustrates that the utilization ratio of battery is reduced by the strategic support of EDLC.
Recently, operational cost for diesel generator such as fossil cost, transport cost, and storage cost are expensive in isolated island. Consequently, renewable energy generation is advanced in the world. Furthermore, all-electric house and electric vehicle carrying a storage battery is increasing. Controllable load in the grid can be installed using all-electric house and electric vehicle carrying...
To reduce the impact of large output power fluctuations of a wind turbine generator (WTG) integrated in a power system, a battery energy storage system (BESS) is installed with the WTG. However, if a large battery is installed, the capital cost of the wind turbine system will increase. Hence, the smaller size of battery is preferable to reduce the capital cost and the battery should be utilized effectively...
This paper proposes an optimal PAM control which can adjust the inverter DC-link voltage by using the buck-boost DC-DC converter. At low speed range, the proposed system can reduce the distortion of the voltage commands, and then the stator currents waveforms would be improved. Also, the allowable speed range would be extended. In order to verify the proposed method, experimental results are provided...
Wind energy conversion systems have become important in the research of renewable energy sources. This is not a small part due to the rapid advances in the size of wind generators as well as the development of power electronics and their applicability in wind energy extraction. However, wind energy has a drawback of having only 1/800 density as compared to that of water energy, and it does not remain...
Recently, dispersed generators have been installed in distribution network to supply power to commercial facilities. Renewable energy generation contains output power fluctuations and distributed generator produces sluggish response for power demand. In order to overcome these problems, an ultra capacitor energy storage system is used for compensating instantaneous power imbalance. However, large...
Recently, CO2 emissions from residential sector are increasing rapidly due to the proliferation of all-electric houses. Therefore, it is expected that renewable energy is installed in all-electric houses. The solar heater system, as a kind of renewable energy, is assumed to be installed in a typical residence. However, solar radiation is not constant and collected thermal energy of solar heater system...
The output power fluctuation of renewable energy power plants such as wind turbine generator and photovoltaic system result in frequency deviation and terminal voltage fluctuation. Furthermore, these power fluctuations also affect the turbine shafting of diesel generator and gas-turbine generators which are the main power generation systems in isolated islands. This paper presents a control strategy...
The output power fluctuation of renewable energy power plants such as wind turbine generator and photovoltaic system result in frequency deviation and terminal voltage fluctuation. Furthermore, these power fluctuations also affect the turbine shafting of diesel generator and gas-turbine generators which are the main power generation systems in isolated islands. This paper presents a control strategy...
This paper presents a methodology of short term generation scheduling (unit commitment) for thermal units integrated with wind energy system considering the unexpected deviation on load demand. The deviation in load demand occurs mainly due to variation in temperature which in turns yields error in load forecasting. Since the usual unit commitment (UC) scheduling as well as economic power dispatch...
Generally, a back electro-motive-force or flux observer is used for position sensorless drive of permanent magnet synchronous motors from middle to high speed range. Thus, the estimation accuracy of the observer influences position sensorless drive performance. This paper proposes a position sensorless drive system using the Hinfin flux observer in which the observer gain is designed by using the...
Generally, PWM voltage source inverter (VSI) has been used for the variable speed permanent magnet synchronous motor (PMSM) drives. However, the PWM-VSI fed PMSMs has two disadvantages. Firstly, PMSMs cannot operate at the speed at which the motor terminal voltage exceeds voltage constraint imposed by the DC-link voltage. Secondly, the distortion of the voltage commands increase at the low speed,...
Nowadays, wind turbine generator (WTG) is increasingly required to provide control capabilities regarding output power. Under this scenario, this paper proposes an output power control of WTG using pitch angle control connected to small power systems. By means of the proposed method, output power control of WTG considering states of power system becomes possible, and in general both conflicting objectives...
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, and there is the advantage that this decreases transmission losses. However, output of natural energy power...
Operation of variable speed wind turbine generator (WTG) in the above-rated region characterized by high turbulence intensities demands a trade-off between two performance metrics: maximization of energy harvested from the wind and minimization of damage caused by mechanical fatigue. This paper presents a learning adaptive controller for output power leveling and decrementing cyclic loads on the drive...
Price forecasting has become a very valuable tool in the current upheaval of electricity market deregulation. It plays an important role in power system planning and operation, risk assessment and other decision making. This paper provides a method for predicting hourly prices in the day-ahead electricity market using recursive neural network (RNN) technique, which is based on similar days approach...
The parameter variation problem in controller design for wind turbine generator (WTG) systems due to wind speed fluctuations is addressed in this paper. The wind speed is generated by an auto-regressive and moving average (ARMA) model while drive-train components are modelled as a two- mass system described by non-linear equations for accurate dynamic performance assessment. The control of the unit...
Short-term price forecasting in competitive electricity markets is critical for consumers and producers in planning their operations and managing their price risk. This paper adopts artificial neural network (ANN) model based on similar days methodology in order to forecast weekly electricity prices in the PJM market. To demonstrate the superiority of the proposed model, extensive analysis is conducted...
Output power from wind turbine generators occurs a large frequency fluctuation on small power systems. In order to solve this problem, we propose an oscillation frequency control for a new power supply system with using renewable energy facilities in isolated island. The proposed system can supply a high-quality power using aqua electrolyzers, fuel cells, renewable energy, and diesel generators. The...
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