Analysis of operating modes of the novel isolated interface converter for PMSG based wind turbines (original) (raw)

Switched Inductor Quasi-z-source Inverter for PMSG based Wind Energy Conversion System

For standalone wind energy conversion system Permanent magnet synchronous generator is best suited because of no need of separate excitation, maintenance free and available in moderate ratings up to 50 Kilowatts. The main objective of this paper is to improve the wind energy conversion system by implementing Switch inductor quasi-z-source inverter and Battery storage system. Switch inductor quasi-z-source inverter has high efficiency and the input current is continuous, suppress inrush current and avoid shoot through fault in inverter when compared to Z-source inverter based wind energy conversion system. An effective control technique for the inverter, based on the pulse width modulation (PWM) method, has been developed to make the line voltages at the point of common coupling (PCC) balanced when the load is unbalanced. By proper control of battery current through dc–dc converter has been done to reduce the electrical torque pulsation of the PMSG under an unbalanced load condition Keywords-Wind Energy Conversion System (WECS), Battery Storage system (BSS), Permanent-magnet Synchronous generator (PMSG), Switched Inductor quasi-Z-Source inverter (SL-q-ZSI)

A Review on DC-DC Converters for PMSG based Standalone Variable Speed Wind Turbine System

International Journal of Engineering Research & Technology, 2016

Lack of conventional resources across the globe and its effects of green house emissions track an ideal path towards renewable energy sectors. The deploying conventional energy resources cause uneven climatic changes and there by confront to the innovators in making the transition towards non conventional energy resources. Among the renewable system, wind energy systems which is considered to be the promising resource, track an ideal path and meets the expectation to the demand in the recent decades. Quantity (Real & Reactive Power) and quality (Harmonic pollutants) of power output are the challenging issues faced by the wind energy harvesters. This paper deals with the review of various power electronic DC-DC converters employed for a permanent magnet synchronous generator (PMSG) based variable speed wind turbine system (VSWTS). The output power is analyzed in correlating the voltage gain, voltage stress and circuit complexity. Pulse width modulation inverters (PWM) are used to control the load voltage in terms of magnitude and frequency. Modeling is performed at each section of conversion. The performance comparison of the chart is presented in pertaining to the discussion.

Operation and Control of a Direct-Driven PMSG-Based Wind Turbine System with an Auxiliary Parallel Grid-Side Converter

In this paper, based on the similarity, in structure and principle, between a grid-connected converter for a direct-driven permanent magnet synchronous generator (D-PMSG) and an active power filter (APF), a new D-PMSG-based wind turbine (WT) system configuration that includes not only an auxiliary converter in parallel with the grid-side converter, but also a coordinated control strategy, is proposed to enhance the low voltage ride through (LVRT) capability and improve power quality. During normal operation, the main grid-side converter maintains the DC-link voltage constant, whereas the auxiliary grid-side converter functions as an APF with harmonic suppression and reactive power compensation to improve the power quality. During grid faults, a hierarchical coordinated control scheme for the generator-side converter, main grid-side converter and auxiliary grid-side converter, depending on the grid voltage sags, is presented to enhance the LVRT capability of the direct-driven PMSG WT. The feasibility and the effectiveness of the proposed system's topology and hierarchical coordinated control strategy were verified using MATLAB/Simulink simulations.

Mathematical modeling, dynamic response analysis, and control of PMSG-based wind turbines operating with an alternative control structure in power control mode

This paper deals with the detailed mathematical modeling, in-depth stability analysis, and control of PMSG-based wind turbine (WT), when PMSG works with an alternative control structure. In the alternative control structure, machine-side converter (MSC) is used for control of the dc-link voltage and grid-side converter (GSC) for control of the output power. In this way, full linearized dynamics of the dc-link model is achieved by using the equivalent current based model of the MSC and GSC. Based on the system detailed linearized representation , it is shown that the dc-link dynamics is non-minimum phase with a right half plane (RHP) zero, where the RHP zero depends on operating point and changes under wind speed variation. Hence, due to stability issue, careful considerations are considered for selection of the dc-link controller parameters, and necessary conditions are proposed to guarantee the closed-loop system stability at all operating conditions. Then, the dc-link control system is modified by introducing an auxiliary compensation block which virtually adds a positive damping resistor in parallel with the dc-link capacitor. Next design considerations for selection of the auxiliary compensation term are proposed, and finally response of the system is examined by the several time domain simulations. KEYWORDS auxiliary compensation term, dc-link dynamics, equivalent current based model, PMSG-based wind turbine, stability analysis 1 | INTRODUCTION Recently, variable speed wind turbines (VSWT) have attracted significant interest in electric power generation systems. 1 Two most popular types of VSWTs are wind energy conversion systems with doubly fed induction generators (DFIGs) and permanent magnet synchronous generators (PMSGs). However, WT systems with PMSG have instinct advantages over other types of WTs due to low maintenance cost, reliability, and optimum power generation capability. 2-4 Figure 1 depicts the wind energy system with PMSG connected to the grid via back-to-back voltage source converters (VSCs), known as machine-side converter (MSC), and grid-side converter (GSC). 5