کنترل تحمل پذیر خطا

Fault detection and tolerable control of wind turbine increases its reliability and availability. One of the electrical components of the wind turbine with a high error rate is the power converter. In this paper, a new method for fault tolerant (FT) control of the wind turbine back-to-back converter based on Dual Feed Induction Generator (DFIG) is presented. When a open circuit fault occurs in each of the IGBTs of the wind turbine converter, the performance of the converter is distorted and part of the current signal of each leg of the converter is lost. The classical controller cannot completely correct this change in current behavior, and for this reason, it has an abnormal performance. As a result, power generation will be accompanied by many fluctuations. In order to compensate, a new method based on sliding mode control is presented in this article. First, when an error occurs, the fault detection system identifies the faulty leg, and after reconfiguring the hardware, the proposed control system based on sliding mode control replaces the classic control system and switching operation. The fault detection method presented in this article is based on artificial neural network and it was developed based on matching with the functional parameters of the wind turbine. The proposed FT method is evaluated using a hardware simulator in a laboratory loop with a 90 kW DFIG generator. The experimental results show the proper accuracy of the fault detection method and on the other hand, the proposed FT method was able to compensate the open circuit fault of the IGBT.

One of the most common types of wind turbines (WTs) is the Doubly-Fed Induction Generator (DFIG) with a back-to-back converter. The power converter with an Insulated Gate Bipolar Transistor (IGBT) switch is essential equipment for power regulation and grid connection in WTs. The converter IGBT open-circuit causes a drawback in output current and as a result, the production performance of the turbine is reduced. Condition Monitoring (CM), Fault Diagnostic (FD), and Fault-Tolerant Control (FTC) of a WT increase the reliability and availability of the turbine and are typical methods to reduce energy production costs and WT downtime. The IGBT switch’s open-circuit failure rate is significant compared to the overall fault rate in WTs. This paper discusses IGBT open-circuit FTC in back-to-back DFIG converters. In the proposed structure, the converter switch fault is first diagnosed using a fast and numerical method. In the first part, a method based on normalized phase currents, the absolute of the phase currents, and an adaptive threshold is used. The FTC system can be divided into two classes of redundancy and non-redundancy or into active and inactive classes. In this article, the proposed method is active and non-redundancy. In the second step, the FTC process is activated to compensate for the system degradation. In this method, the faulty leg is removed with the gate opening of both IGBTs in one leg by the controller, and one of the legs is positioned as a common leg between the two grid side and rotor side converters. The conventional method in this structure is to use Pulse Width Modulation (PWM) with a zero sequence signal. The novelty of the paper is the use of the proposed SVM vector control. The proposed structure is inexpensive. Furthermore, the fault diagnostic structure operates without additional sensors and the FTC structure operates with minimal hardware. To evaluate the proposed structure, a 2.5 MW turbine software simulator based on real data is used. The simulations show that the proposed method is effective and robust in FD and FTC and that the proposed method is successful in detecting multiple defects of the grid-side and rotor-side converters, as well as the defects of one leg. The proposed method can compensate for the open switch fault to construct three-phase output currents by comparing the numerical parameters. The ability of the proposed method is specified.