Overall fuzzy logic control strategy of direct driven PMSG wind turbine connected to grid

The fuzzy logic strategies reported in the literature about the control of direct drive permanent magnet synchronous generator (PMSG) connected to grid are limited in terms of inclusiveness and efficiency. So an overall control based on fuzzy logic and anti-windup compensation is proposed in this paper. Aiming at the inadequate of hill climb search (HCS) MPPT with fixed step size, the fuzzy logic is introduced in the stage of "generating rotor speed reference" to overcome the oscillations and slowness in traditional method. PI controllers are replaced by anti-windup fuzzy logic controllers in the "machine side control" stage and in "grid side control" stage to pertinently regulate the reference parameters. Then comparison tests with classical methods are implemented under varying climatic conditions. The results obtained demonstrate that the developed control is superior to other methods in response time (less than 4.528E-04 s), precision (an overshoot about 0.41%) and quality of produced energy (efficiency is 91%). The study verifying the feasibility and effectiveness of this algorithm in PMSG wind turbine connected to grid

Development of a photovoltaic characteristics generator based on mathematical models for four PV panel technologies

A good study of photovoltaic system requests to have very precise current-voltage characteristic curves of photovoltaic modules for different technologies. The photovoltaic emulator provides an efficient solution to maintain the same current-voltage output of photovoltaic module. It includes three parts: the PV model, the control strategy, and the power converter. This paper provides three classes of modeling and simulation of photovoltaic arrays and presents the synthesis results of the current-voltage characteristic performances obtained by the modeling approaches. The models of the first class are based on electrical circuit model, those of the second class are based on multiple straight lines model, and for the third class, it is based on the look up table. The mathematical model is built using MATLAB/ Simulink, and an experimental bench was carried out to acquire an up-to-date and representative experimental database of four PV panels. This database is used for the validation of these models for the different PV panel technologies under Moroccan meteorological conditions. Following this comparative study, we came to a high agreement between the experimental and simulated current-voltage characteristics for the emulator under study

Enhanced Three-Phase Inverter Faults Detection And Diagnosis Approach - Design And Experimental Evaluation

Efficiency, reliability, high power quality and continuous operation are important aspects in electric vehicle attraction system. Therefore, quick fault detection, isolation and enhanced fault-tolerant control for open-switches faults in inverter driving systems become more and more required in this filed. However, fault detection and localization algorithms have been known to have many performance limitations due to speed variations such as wrong decision making of fault occurrence. Those weaknesses are investigated and solved in this paper using currents magnitudes fault indices, current direct component fault indices and a decision system. A simulation model and experimental setup are utilized to validate the proposed concept. Many simulation and experimental results are carried out to show the effectiveness of the proposed fault detection approach

H infini dynamic observer design for discrete-time linear systems with time varying delays based on generalized reciprocally convex matrix inequality

International audienceIn this work, we have studied the problem of designing dynamic observers (HDO) for discrete-time linear systems (DTLS) with time-varying delay (TVD) and disturbance. By designing an augmented Lyapunov-Krasovskii functional (LKF) with double summation terms using the Generalized reciprocally convex matrix inequality (GRCMI), as well as the Jensen-based inequality (JBI) and the Wirtinger-based inequality (WBI) that derive new less conservative time-dependent conditions. The resulting algebraic conditions form a set of linear matrix inequalities (LMIs) which can be solved by the LMI or YALMIP toolboxes. Furthermore, the observer under consideration has more degrees of freedom to be estimated, and is known as a generalized observer, where the proportional and proportional-integral observers are particular cases. Finally, two examples are given to demonstrate the validity and effectiveness of the findings

An Experimental Study of P&O MPPT Control for Photovoltaic Systems

Tracking the maximum power point plays an important role for the optimization of the solar energy. The objective here is to study experimentally optimizing photovoltaic (PV) systems connected to a DC-DC converter (Boost) and a resistive load. For this, tests were conducted to determine the law of open loop control (power versus the duty cycle) for different solar irradiance values and load with an approximately constant cell temperature. The obtained results showed that the power passes through a maximum point. In order to extract the maximum power, for different values of solar irradiance and load, an MPPT control "Perturb and Observe" P & O has been implemented on a DSPACE 1104. The experimental results showed the performance of the method suggested

Four-Switch Three-Phase PMSM Converter with Output Voltage Balance and DC-Link Voltage Offset Suppression

High power quality, efficiency, complexity, size, cost effectiveness and switching losses of the direct current to alternating current (DC–AC) conversion system are crucial aspects in industrial applications. Therefore, the four-switch three-phase inverter (4S3P) has been proposed as an innovative inverter design. However, this topology has been known to have many performance limitations in the low-frequency region, because of the generation of an unbalanced voltage leading to an unbalanced current due to the fluctuation and offset of the centre tap voltage of the DC-link capacitors. Those drawbacks are investigated and solved in this paper in order to provide pure sinusoidal output voltages. The generated output voltages are controlled using proportional-integral (PI) controllers to follow the desired voltages. Furthermore, the DC-link capacitor voltage offset is mitigated by subtracting the direct component from the control reference voltage using low pass filters, where this direct voltage component provides the direct current component which leads to DC-link capacitor voltage divergence. A simulation model and experimental setup are used to validate the proposed concept. Many simulation and experimental results are carried out to show the effectiveness of the proposed control scheme

Sliding-Mode Speed Control of PMSM with Fuzzy-Logic Chattering Minimization—Design and Implementation

In this paper a Sliding Mode Control scheme (SMC) applied to the Permanent Magnet Synchronous Motor (PMSM) speed control is designed and improved. A Fuzzy logic algorithm is added to mitigate chattering caused by discontinuous term in steady states, and to ensure good performances of the controller in transient states. The proposed Fuzzy-SMC performance is tested in simulation and experimental results are obtained using eZdsp F28335