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The purpose of the paper is to investigate the application of a Switched Reluctance Generator (SRG) for future wave energy converters. This machine presents some favourable features as compared to others. The machine optimal operation can be obtained after a detailed assessment of the control strategy. For this purpose, a SRG model is implemented in Matlab® Simulink® environment to find out the values...
By aggregating renewable sources as main generators, storage systems, diesel generator, and loads, microgrids can achieve high level renewable energy penetration and efficiency in electricity distribution systems. The difference between loads consumption and renewable generation causes fluctuations in the microgrid bus voltage. For off-grid operating mode or limited public grid availability, power...
The efficiency of the wind power conversions systems can be greatly improved using an appropriate control algorithm. In this work, an adaptive control scheme based on sliding mode control theory is proposed. In the control scheme, a robust aerodynamic torque observer based on super twisting algorithm is designed in order to avoid the wind speed sensors. The proposed robust observer is based on the...
This paper considers the control of a 7-leg back-to-back Voltage Source Inverter (VSI) arrangement feeding a 4-wire load from a 3-phase Permanent Magnet Synchronous Generator (PMSG) operating at variable speed. The 7-leg converter is regulated using Resonant Controllers (RCs) at the load side and self-tuning resonant controllers at the generator side. The control system is augmented by a feed-forward...
This paper includes a control strategy for the fault-ride-through performance of wind turbines connected to the grid by means of fully rated converter. The proposed control strategy does not require the use of PLLs or FLLs for grid connection. The effects of the proposed control strategy on the low speed shaft and the gearbox has been studied on the NREL 5 MW reference wind turbine, modeled with the...
Nowadays, electricity is mainly produced by large central generation plants. However, generators with lower capacities are increasingly used for distributed generation (DG). Distributed generators are applicable for improving supply reliability with considerations of renewable energy, environmental protection, peak load shaving and deferred investments in network expansion. Comparing to central generation,...
Distributed generation causes new challenges in medium voltage networks. Especially voltage stability is becoming an issue. Conventional planning measures, like network expansion, can be used to address this challenge, but they should be planned with great care due to their high costs. Power factor control of distributed generators is an alternative to such measures. Therefore it should also be considered...
This paper presents a system using a supercapacitor storage device to smoothen the output power fluctuation of a variable-speed wind generator. This kind of system is a multiconverter structure and exhibits nonlinear behavior. In this paper, a nonlinear control algorithm based on the flatness properties of the system is proposed. Utilizing the flatness principle, we propose simple solutions to the...
The paper presents a study for determination the optimal control law for a small horizontal axis windgenerator. Experimentally, using a mixed physical-analog laboratory model, were determined the state variables, corresponding to different wind speed values, for the optimum regimes of the wind turbine, based on the turbine theoretical estimated mathematical model. From a large multitude of possible...
In this paper, a multivariable control strategy is proposed for variable speed wind turbines operating in the two primary regimes, below-rated and above-rated wind speeds. A torque controller, based on the achievement of zero speed-tracking error, is developed to follow a trajectory that allows the wind turbine to operate with maximum power extraction in below-rated regime. The turbine torque is unknown...
With the growing of electrical energy demand, wind energy gains higher potential and plays a vital role in energy sectors. Direct driven permanent magnet synchronous generator (PMSG) with a full size back-to-back converter set is one of the promising technologies employed with wind power generation. This paper focuses on developing a control scheme of PMSG-based wind turbines to obtain maximum wind...
Pitch control system plays an important role in large wind turbine generator (LWTG) because of the direction and intensity of wind is changing every moment. Therefore, the system of pitch control is difficult to be set up the tuning parameters of controller. Conventional PID controller is not suit for all operating point. Because, tuning parameters of conventional PID controller are not consistently...
This paper analyzed the structure of a direct-drive wind power generation, The mathematical model of the wind power generation system is complex, strongly affected by the varying parameter and exterior disturbing, and has the features of nonlinear, time changing and coupling. According to the above characteristics, the fuzzy-logic control is introduced into the wind power system. By using the fuzzy...
As a renewable, clean energy, wind energy has attract more and more attention. It has become a common understanding of the world to vigorously develop wind energy. In order to guarantee the safety and reliability for wind power integration operation, it is of great significance to establish an appropriate wind power generator system model and analyze its electromagnetic transient characteristics....
The wind turbines used for power generation should enable to produce maximum power, making best use of available energy in the wind. A specific known terminology: Maximum Power Point Tracking (MPPT) must be introduced to obtain maximum energy efficiency. The strategy from this command is to control the electromagnetic torque to adjust the speed mechanics to maximize the electrical power generated...
In this paper, a two-level reconfiguration action is used to design an Active Fault Tolerant Control (AFTC) system. The first level of the procedure is triggered when the impact of the fault on the system performance is limited. The reconfigurable controller is updated by the new post-fault system model. At the second level a dynamic reference modification based on Reference Governor (RG) is proposed...
In this paper, a new control strategy is proposed to improve the performance of a wind generator system composed of a three-phase PMSG and a Back-to-Back three-phase to single phase converter. With the use of the large inductance of the synchronous generator, the control method minimizes the generator torque ripple when the system supplies a single-phase load. The problem arises from the fact that...
The low-voltage ride-through (LVRT) capability of a MW-Level variable speed wind turbine with a direct-driven permanent magnet synchronous generator (PMSG) is a hot topic these days. To prevent over-rated dc-link dynamic voltage, a novel dc-link voltage control scheme is proposed. In this paper comparing with traditional control method, the generator-side converter uses a doubly closed loop namely...
In this paper a hybrid distributed generation (DG) system connected to isolated load is studied. The DG system consisting of photo voltaic (PV) system, fuel cells, aqua electrolyzer, diesel engine generator and a battery energy storage system. The ambient temperature value of PV is taken as constant to make the output power of PV is directly proportional to the radiation and output power of other...
Deregulation is, restructuring the rules and economic incentives that the government setup to control and drive the Electric Supply Industry (ESI). It is also called as open power market, competitive power market, vertically unbundled market etc. With the introduction of deregulation, the electric power industry needs changes in various power system operation, control and planning activities. In this...
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