Variable-speed Permanent Magnet Synchronous Generator Research Articles

Wind energy management of a standalone system operating at maximum power point

In this paper, the management and control of a standalone wind energy system versus variations of wind speed and load are investigated. The system includes a wind turbine coupled to a variable-speed permanent magnet synchronous generator (PMSG), rectifier, boost converter, power inverter, and an energy storage system (ESS). The ESS is a very important part to achieve system stability and support the maximum power point tracking (MPPT) operation. A simple off-line MPPT algorithm is introduced that can be accomplished using the boost converter. The system dynamic model is derived then the control and energy management algorithms are introduced to improve the system performance. The MATLAB platform has been utilized to simulate the proposed system under different disturbances in the load power and wind speed. The results show perfect management of the system energy, good performance of the DC link voltage, stable load voltage, and load frequency.

Synchronous Control Strategy with Input Voltage Feedforward for a Four-Switch Buck-Boost Converter Used in a Variable-Speed PMSG Energy Storage System

The four-switch Buck-Boost (FSBB) converter can produce voltage conversion within a wide input voltage range, which is suitable for variable-speed permanent magnet synchronous generator (PMSG) energy storage systems with AC inputs and DC outputs. To reduce the interference of input voltage fluctuation on the performance of the FSBB converter, an input voltage feedforward (IVFF) compensation method is proposed in this paper. The switching synchronization strategy is simple. Using the switching average model, the small signal model of a non-ideal FSBB converter in all working modes is established. The effects of input voltage, load current, damping coefficient and right half plane (RHP) zero on the stability of the control system are analyzed in detail. The transfer function of the IVFF of the FSBB converter is derived, and the relationship between input voltage, load current and duty cycle is analyzed. Finally, the design of the parameters of the converter control system is presented. The simulation and experimental results show that this FSBB converter has high efficiency and a good transient response.

Modeling and Control Design of an Autonomous Hybrid Wind/Energy Storage Generation Unit

The purpose of the present paper is to investigate a controller design and simulations of autonomous hybrid wind turbine system with variable-speed permanent magnet synchronous generator (PMSG) and a system for storing energy. The proposed system is mainly composed of a wind turbine drives permanent magnet synchronous generator, uncontrolled rectifier, DC/DC converter, DC/AC inverter and static loads. Furthermore, the mathematical model of the studied sub-systems and two control loops are considered. The first one is the controller which needed to preserve the DC-link voltage fixed at its desired value. The second one is the controller which needed to regulate the charge/discharge modes of the storage battery. The suggested hybrid wind/energy storage power generation model is considered and analyzed in case of without controller firstly. Then, the considered hybrid wind/energy storage power generation unit with the proposed controller is examined through a step change in wind speed. Digital simulation results show that the power desired by the linked loads may be successfully supplied and transported by the presented hybrid wind turbine and energy storage power generation system based on proportional-integral-derivative (PID) controller. Also, the emulation results show that there a good foretelling of the electrical variable waveforms and good achievement in case of the presented controller emulated with the case of without controller as maintaining the load voltage fixed at its reference values

Variable speed PMSG design and implementation for wind driven welding power source

PurposeThe purpose of this paper is the attempt to model a variable speed permanent magnet synchronous generator (PMSG) for extracting a standalone power source to assuage the needs of a welding application. The emphasis orients to evolve a framework for the effective exploration of renewable energy resource and prevent the injection of grid harmonics.Design/methodology/approachThe system involves the use of self-commutated dc-dc converter interfaces to extradite the current and voltage requirements of the welding attributes. The philosophy incites a pulse width formulation for reducing the voltage ripples in the dc output and improving the time response characteristics.FindingsThe proper selection of closed loop Fuzzy tuned PI control ensures the restriction on the magnitude of the current drawn from the source, enhances the dynamic response and betters steady state response.Originality/valuePMSG-based welding power source with parallel-connected cascaded buck fed cuk converters. MATLAB-based simulation of the methodology offer interesting results in the sense it orchestrates the range of converter operation and the ability to provide a high-quality weld without polluting the ac mains. The experimental prototype further proliferates to validate the simulated performance and claims a space for its use in the real-world utilities.

High-order sliding mode control for variable speed PMSG wind turbine based disturbance observer

This paper introduces a model-based control system for variable speed wind energy conversion system (VSWECS)-based permanent magnet synchronous generator (PMSG). Comparing to traditional wind turbines operating methods, these variable speed systems have the advantages of increasing the energy capture and reducing the mechanical stress. In order to exploit this latest advantage, a high order sliding mode (HOSM) control strategy has been developed to enhance system performances, ensure the maximum power point tracking (MPPT) and track the generator reference speed. Moreover, for the WT system, the turbine torque is considered as an immeasurable disturbance. Therefore, using a modified disturbance observer will allow direct tracking of the maximum power point. The stability analysis of the system has been proved using the Lyapunov theory. Finally, simulation results have been presented to verify the proposed approach efficiency.

Adaptive SRF-PLL Based Voltage and Frequency Control of Hybrid Standalone WECS with PMSG-BESS

Abstract The variable-speed Permanent Magnet Synchronous Generator (PMSG) based Wind Energy Conversion System (WECS) attracts the maximum power from wind, but voltage-regulation and frequency-control of the system in standalone operation is a challenging task A modern-control-based-tracking of power from wind for its best utilization is proposed in this paper for standalone PMSG based hybrid-WECS comprising Battery Energy Storage System (BESS). An Adaptive Synchronous Reference Frame Phase-Locked-Loop (SRF-PLL) based control scheme for load side bi-directional voltage source converter (VSC) is presented for the system. MATLAB/Simulink model is developed for simulation study for the proposed system and the effectiveness of the controller for bi-directional-converter is discussed under different operating conditions: like variable wind-velocity, sudden load variation, and load unbalancing. Converter control scheme enhances the power smoothening, supply-load power-matching. Also it is able to regulate the active & reactive power from PMSG-BESS hybrid system with control of fluctuations in voltage & frequency with respect to varying operating conditions. Proposed controller successfully offers reactive-power-compensation, harmonics-reduction, and power-balancing. The proposed scheme is based on proportional & integral (PI) controller. Also system is experimentally validated in the laboratory-environment and results are presented here.

Power Smoothening of Grid Connected Direct- Driven Permanent Magnet Synchronous Generator (PMSG) Wind Turbines

Objectives: The main objective of this paper is smoothening of the power fluctuation of a variable speed PMSG wind generator with the help of Energy Capacitor System (ECS). ECS consists of a voltage source inverter, dc-dc converter and an ultra-capacitor bank including their control strategies. Methods/Analysis: In this paper two back-to-back voltage source Insulated Gate Biopolar Transistor (IGBT) converters controlled through highly efficient variable frequency drive control method is considered. By using this method, efficiency of wind farm can be improved and voltage regulation for interconnecting the wind farm with grid can be achieved. Findings: Recent application of power electronic devices and scaling up of MegaWatt (MW) wind turbines, Low-speed high torque Permanent Magnet Synchronous Generator (PMSG) has become the ultimate choice for wind power extraction. At present, a commercial PMSG based wind generator primarily makes use of a rectifier followed by an IGBT converter. Novelty /Improvement: The real power reference for ECS is generated accurately. Simulation is carried out through MATLAB/SIMULINK.

영구자석형 풍력-디젤-BESS 복합발전시스템 모델링 및 운전제어 알고리즘에 관한 연구

Nowadays high-cost energy storage system using flywheel or secondary battery is applying to hybrid generation system with WT(Wind Turbine) and diesel generator in island areas for stable operation. This paper proposes an operating algorithm and modeling method of the hybrid generation system that can operate for variable wind speed and load, which is composed of energy storage system, variable-speed PMSG(Permanent Magnet Synchronous Generator) WT and diesel generator applied in island areas. Initially, the operating algorithm was proposed for frequency and voltage to be maintained within the proper ranges for load and wind speed changes. Also, the modeling method is proposed for variable speed PMSG WT, diesel generator and BESS(Battery Energy Storage System). The proposed operating algorithm and modeling method were applied to a typical island area. The frequency and voltage was kept within the permissible ranges and the proposed method was proven to be appropriate through simulations.

Stabilization of a Fixed Speed IG Based Wind Farm using Variable Speed PMSG

To optimize the output power and reduce the frequency fluctuation in conventional fixed speed Induction Generator (IG) based wind farm, various controlling devices are used. But, this paper proposes that Permanent Magnet Synchronous Generator (PMSG) can work both as a power producing device and as a controlling device for IG. In this paper a more practical case has been considered where a wind farm is operated with a set of Synchronous Generators (SG). Thermal, Hydro and Nuclear Governors have been used for SGs. Wind farm has a capacity of 20% of the total SG’s capacity. Both two-level and three-level converter-inverter based PMSG have been considered. Comparative results between IG and IG with PMSG are shown. Simulation results prove the effectiveness of the proposed system. Simulations have been carried out by using the laboratory standard power system software package, PSCAD/EMTDC.

A Novel Topology Design for Integration of Offshore Wind Farm via High-voltage DC Transmission

A novel configuration for offshore wind farms based on variable-speed permanent magnet synchronous generator integration via high-voltage DC transmission is proposed. Each permanent magnet synchronous generator is equipped with a full-bridge diode rectifier and a DC/DC boost chopper, which constitutes a cascaded submodule. Quite a number of submodules are series-parallel connected to form a DC collector system for the offshore wind farm. Any unit that needs maintenance or that undergoes fault in a series-connected branch can be isolated from the system by the natural commutated process without influencing other normal units in the same branch. The proposed submodule has several prominent features, such as low cost, low power loss, and simple control strategy. A maximum power point tracking algorithm of each wind turbine is realized by controlling the current through the inductor of each DC/DC boost circuit in one submodule. The proposed topology and control strategy are verified by simulations in Power Systems Computer Aided Design/Electromagnetic Transients including Direct Current (PSCAD/EMTDC; Manitoba HVDC Research Centre, Manitoba, Canada).

Modeling and Control of Standalone Direct-Driven PMSG WECS for Grid Compatibility at Varying Wind Speeds

Wind energy is one of the most available and exploitable forms of renewable energy. Variable speed PMSG based Wind Energy Conversion System (WECS) offers many advantages compared to the fixed speed squirrel cage induction generators such as improved stator output operation at better power factor, no maintenance cost for gear box (as it is direct-driven) reduction in weight and losses, higher efficiency and ability to run at low speeds. The elimination of the gear box and brushes can enhance the efficiency of wind turbine by 10%. In this paper a Permanent Magnet Synchronous Generator (PMSG) is modeled whose stator is connected to the constant single phase load (in place of grid) through AC/DC thyristors based rectifier followed by capacitor (dc-link) and DC/DC converter control. Overall arrangement provides constant output to connected load if applied with proper controlling techniques. Hence this proposed wind generation system design can be extended for grid connection also via DC/AC inverter control. Results are simulated and verified in MATLAB/Simulink platform at constant rated (12m/s) and varying (stepped) wind speed for smooth and constant output voltage. DOI: http://dx.doi.org/10.11591/telkomnika.v13i3.7097

Load parameter waveforms improvement of a stand‐alone wind‐based energy storage system and Takagi–Sugeno fuzzy logic algorithm

The application of the Takagi–Sugeno (TS) fuzzy approach for voltage and frequency control of an isolated wind turbine (WT) system with variable-speed permanent magnet synchronous generator (PMSG) and a system for storing energy during wind speed and load variations is investigated. Energy storage systems are needed for power balance and power quality in autonomous wind energy systems. Initially, the holistic model of the entire system is achieved, including the PMSG, the uncontrolled rectifier, the buck converter and the storage system. The power absorbed by the connected loads can be effectively delivered and supplied by the proposed WT and energy storage systems, subject to TS-fuzzy control. The main purpose is to supply 230-V/50-Hz through a three-phase inverter. The performance of the proposed system is compared with the system without storage system. Moreover, the proposed system performance with the TS-fuzzy control is compared with the conventional proportional–integral–derivative (PID) controller. The simulation results show that the proposed system with the TS-fuzzy controller has good prediction of the electrical parameter waveforms compared with the case of absence of the storage system and the conventional PID controller.

Control methods for PWM rectifier cooperating with variable speed PM generator

Abstract The paper deals with cooperation between pulse width modulation (PWM) rectifier and variable speed synchronous generator which is applied especially in small water or wind plants. In such applications, the synchronous generator, which is usually permanent magnet (PM) generator, rotates at a variable speed which depends on water or wind energy. Therefore, this energy should be converted to the parameters of the three-phase power grid with the use of a power electronic unit. The main aim of the control strategy is to transfer a maximum possible amount of energy produced by the water turbine or the wind turbine connected to a synchronous generator. The second purpose of the control method is to decrease the amount of higher harmonics of generator currents. The paper describes two basic methods which are used in control systems of the PWM rectifiers. The first one is the sinusoidal PWM method, and the second method relates to the hysteresis switching of the PWM rectifier transistors. A significant part of the paper is devoted to control principles of the PWM rectifier which cooperates with a variable speed PM synchronous generator. Special attention is paid to higher harmonics of PM generator currents with respect to individual methods.

Control Structure for Single-Phase Stand-Alone Wind-Based Energy Sources

This paper is analyzing the operation of a stand-alone wind turbine system with variable-speed permanent-magnet synchronous generator (PMSG) and a system for storing energy during wind speed and load variations. Energy storage devices are required for power balance and power quality in stand-alone wind energy systems. Initially, the holistic model of the entire system is achieved, including the PMSG, the boost converter, and the storage system. The power absorbed by the connected loads can be effectively delivered and supplied by the proposed wind turbine and energy storage systems, subject to an appropriate control method. The main purpose is to supply 230-V/50-Hz domestic appliances through a single-phase inverter. The simulation results, validated by experimental testing, show a good prediction of the electrical parameter waveforms. The control system is implemented on a dSPACE DS1103 real-time board. Furthermore, the results confirm the stability of the supply.

Optimization Design of a Permanent Magnet Synchronous Generator for a Potential Energy Recovery System

Potential energy recovery is an encouraging way to save energy in a hydraulic lifting system and a variable-speed permanent magnet synchronous generator (PMSG) is one of the key components. In this paper, an optimization design of the PMSG is given based on the analysis of working conditions and requirements. The rotor configuration of the PMSG employs a segmented Halbach permanent magnet (PM) array, for it is beneficial to the airgap flux density distribution. A parameterized design approach, which combines analytical and finite element analysis, is proposed to improve the efficiency and accuracy of the design procedure. The main part of the procedure is divided into two steps. First, the losses are minimized by optimizing the dimensions and flux density distributions of the stator with an analytical model. Second, the geometry of the PM array is designed with a finite element method to satisfy the flux requirement determined in the first step. Temperature rise, armature reaction, and demagnetization are also calculated. A prototype of the new designed PMSG has been fabricated and tested on the experimental platform. Expected experimental results are achieved, verifying the effectiveness of the design.

Modeling and Operational Testing of an Isolated Variable Speed PMSG Wind Turbine with Battery Energy Storage

This paper presents the modeling and operational testing of an isolated permanent magnet synchronous generator (PMSG), driven by a small wind turbine with a battery energy storage syst ...