Blade pitch control malfunction simulation in a wind energy conversion system with MPC five-level converter

Abstract

This paper is on a wind energy conversion system simulation of a transient analysis due to a blade pitch control malfunction. The aim of the transient analysis is the study of the behavior of a back-to-back multiple point clamped five-level full-power converter implemented in a wind energy conversion system equipped with a permanent magnet synchronous generator. An alternate current link connects the system to the grid. The drive train is modeled by a three-mass model in order to simulate the dynamic effect of the wind on the tower. The control strategy is based on fractional-order control. Unbalance voltages in the DC-link capacitors are lessen due to the control strategy, balancing the capacitor banks voltages by a selection of the output voltage vectors. Simulation studies are carried out to evaluate not only the system behavior, but also the quality of the energy injected into the electric grid. © 2015 Elsevier Ltd. All rights reserved.Keywords: Wind energy; five-level power converter; drive train; fractional-order control; simulation. IntroductionEnvironmental problems such as global warming and habitat preservation have to be faced by the society in nowadays in order to achieve a sustainable development. One of the causes for the global warming is said to be the increase on the level of CO 2 in the atmosphere due to fossil fuel burning [1]. However, nowadays fossil fuel burning is needed for supplying the majority of the energy demand [2]. Research and development is on the way to achieve lower pollutants emissions on conversion of energy to convenient forms of usage in order to achieve a sustainable development. Conversion of energy from renewable energy sources are in nowadays a political attractive option [3] and a wind energy conversion system (WECS) is an economically viable exploitation [4], experiencing a significant expansion [5,6]. Although, onshore WECS deployments are cheaper than offshore ones, new suitable available onshore sites for deployments are becoming scarce, particularly in Europe [7]. So, the offshore WECS is becoming a further attractive option.

Intelligent robust pitch control of wind turbine using brain emotional learning

“…In real‐world wind turbine applications, there are many different types of generators installed in wind turbines, such as the doubly‐fed induction generator (DFIG) 34,35 . Since the focus of this article is on pitch control, the common first‐order model of the generator is used 11 : where t g is time constant, P ref is reference power, η g is generator efficiency, T g is generator torque, and Pout is generated power.…”

Fractional Control of an Offshore Wind System

“…Figure 2 shows the wind speed u(t) and wave elevation η(t) impacting the system. For model details see [10] and the references therein. Parameters are given in Table I.…”

“…where ρ is air density, R is the radius of the area covered by the blades, r is the radius of the area covered by the rigid part of the blades, and c p is a numerically calculated power coefficient [10].…”

“…was developed according to the method of [4]. The difference between the voltage U dc and the reference voltage U * dc is numerically processed by the controller to determine a reference for the stator currents [8], [10] (see Figure 5; the Crone approximation was followed for implementation). The difference between the stator current and the reference stator current is corrected using sliding mode control; the final control action consists in pulse-width modulation by space vector modulation, since the IGBTs have on/off switching states.…”

“…Furthermore, abnormal behaviour in the operation which is not avoided in due time can lead to a fault going into a failure, needing human intervention on the wind system, which in the case of offshore platforms is difficult and expansive. In this paper a fractional PI controller controls in simulation an offshore wind system where a vanadium redox flow battery (VRFB) [2] is used to store energy, and to replace during a short time span the delivery of energy coming from the generator interrupted by a fault in the rectifier converter [1], preserving the connection to the electric grid until the recovery of the full operation, and thus avoiding a failure implying the disconnection of the wind system [10]. The novelty herein presented is the usefulness of the VRFB.…”