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In recent years, environmental problems are being serious and renewable energy has attracted attention as their solutions. However, the electricity generation using the renewable energy has a demerit that the output becomes unstable because of intermittent characteristics such as variations of wind speed or solar radiation intensity. Therefore, it can cause frequency fluctuations or voltage fluctuations...
In view of the appearance of parallel stator winding open circuit fault in large capacity permanent magnet wind turbines, the negative sequent current is caused in stator windings, which may endanger the stability of the wind turbine. With the 2-D transient electromagnetic field, the negative sequence current with the rated condition and fault condition is calculated. Further more, the change rule...
Wind energy have for many years been a growing alternative to fossil energy. The sizes of turbines are increasing to megawatt level. Wind turbines operate in a wide range of wind speeds but are shot down for high wind speeds. Traditional concepts are relatively stiff and have a cause stress on the gearbox. The turbine described in this paper overcomes some of these challenges by having flexibly and...
This study demonstrates the use of two types of pendulums on a vortex bladeless wind (VBW) turbine: arc-shaped and disc-shaped. Here, the kinetic energy of the wind as input to the VBW turbine gets converted into useful electrical energy for both types of pendulums. Permanent magnets are attached to the pendulums and act as a piston to the generator, while a coil is made as the stator with 2,200 turns...
In last ten years many developed and developing countries move towards green power. Most of them installed green power like wind generator and solar cell with storage device at distribution level. Interconnecting and facilitating the distribution power system with advanced control, communication and information technology is challenging task. The aim of Integrating Green Power Generators in microgrid...
This paper proposes the use of an active yaw system to protect small and medium wind turbines in the high wind zone from overloading. The active yaw system turns the rotor partially out of the wind to decrease the turbine power. The dependency of the power on the yaw angle is modeled by the third power of the cosine of the yaw angle. A proper controller is configured based on on-off control of the...
The goal of this paper is to design a wind turbine generator operated under variable speed with intelligent pitch angle control capability under variable wind conditions. The control scheme for the variable speed wind turbines has been discussed and analysed using wind turbines driven by the permanent magnet generators connected to the grid. Main strategies of conventional control and intelligent...
An increased share of variable speed wind turbines reduces the inertia of the power system due to the decoupling of mechanical rotor frequency and grid frequency. In the recent years, a lot of research has been done about exploitation of the rotating mass of a wind turbine for participation in the primary frequency regulation of the power system. This paper proposes a linearized general variable speed...
With more wind power integrating into power grid, a lot of issues are caused by its uncertainty and variability. In order to analysis wind characters, this paper proposes a method to model wind power. This method bases on stochastic Burgers equation. It turns wind power model from three dimension to one dimension in order to simplify the physical model and generate more wind speed data to improve...
The traditional PID controller is difficult to reach good performances of a variable pitch control wind power system in a wide range of wind speed with changes momentarily and randomly. To deal with this problem, a strategy of fuzzy — PI and fuzzy feedforward compound control for variable pitch systems is proposed. When the wind speed is above its rated value, the fuzzy feedforward controller can...
More accurate dynamic models of wind turbines are of great importance in validating simulation results of their interaction with the network (micro-grid), and thus the reliability of the network (micro-grid) is improved. The first of this paper is an overview of wind power and wind energy conversion system structures. In addition, network requirements in the presence of wind energy conversion systems...
In this paper, the problem of Soft-stall power control design for a small wind turbine is considered. Passive stalling and furling methods are widely used to limit the output power of small wind turbines at above-rated wind speed conditions. However, these methods have substantial limitations, for instance, related to tracking the maximum power at some wind speed levels, limited variable speed operation...
this study evaluates the impact of wind power generation connected to distribution systems. Three load profiles (residential, commercial and industrial) connected to the distribution network were analyzed considering the impact on voltage levels for different wind speeds and wind generator control strategies. The wind generator model is based on doubly fed induction generator (DFIG) and were developed...
This paper reviews three types of storage assisted wind power conversion systems (WPCS) that harvest the entirety of their wind power with assistance from an added compressed air or hydraulic subsystem. Configurations of a compressed-air assisted wind power conversion system (CA-WPCS) and a hydraulic wind power conversion system (H-WPCS) are explained and compared. The results of a numerical simulation...
Feasibility study on implementing wind energy harvesting system on moving train is discussed in this study. Wind turbines installation over the train roof is suggested and tested from different aspects. Practical aspects of wind energy utilization are discussed and challenges are highlighted. Calculations of wind power generation for wagon roof mounted turbine are provided and air drag of turbine...
With the increasing size of the wind farms, the impact of the wake effect on the energy yields and lifetime consumption of wind turbine can no longer be neglected. In this paper, the affecting factors like the wind speed and wind direction are investigated in terms of the single wake and multiple wakes. As the power converter is the most fragile component among the turbine system, its lifetime estimation...
This paper proposes a frequency regulation strategy applied to wind turbine generators (WTGs) in an isolated grid. In order to complement active power shortage caused by sudden load or wind speed change, an improved deloading method is proposed to solve inconsistent regulation capabilities in different speed regions and provide WTGs a certain capacity of power reserves. Considering the torque compensation...
Squirrel-cage induction generator wind power plant requires the provision of reactive power for self-excitation and to sustain the generated voltage. The Katsina wind power plant comprising of several squirrel cage generators, each has a fixed capacitor bank connected in shunt to the wind turbine generator provide the needed reactive power. These capacitors are selected to enable the excitation of...
The paper deals with implementation of maximum torque per ampere (MTPA) control strategy for a permanent magnet synchronous generator as a part of a wind energy conversion system (WESC). The variable speed wind turbines require appropriate control of the generator power, toque and speed in order to maximize the energy production under varying wind speed using appropriate MPPT algorithms. The power...
This paper work develops the dynamic model of a wind system based on a permanent magnet synchronous generator (PMSG). The dynamic modeling of the system requires prior knowledge of the parameters of the turbine, of the machine and of the static converters which are controlled by the pulse width modulation (PMW) to ensure the interconnection between the generator and the grid. Using a control approach...
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