Active Rectifier With Integrated System Control for Microwind Power Systems

Abstract

This paper presents simple and effective control strategies for the active rectifier stage (AC/DC stage) of a grid-connected low power system for micro wind applications employing Permanent Magnet Synchronous Generator (PMSG). In particular a novel algorithm for the estimation of the rotor angle of the PMSG, based on flux estimators, was implemented using an adaptive low-pass filter coupled with a feed-forward compensator. This enabled a very smooth start-up operation of the PMSG, obtained by pre-loading the values of the flux\ud estimator and using a single voltage transformer (VT) transducer. The solution for the power flow control between the active rectifier and the other(s) power converters connected to the common DC link was implemented without any digital communication between them, in order to obtain a solution suitable for modular architectures (e.g. to be used in conjunction with a grid-connected converter and/or an energy storage system). Simulation and experimental results confirmed the effectiveness of the proposed solutions. The experimental validation was conducted using a grid-connected converter as load for the proposed active rectifier

Comparison of flux observers for sensorless control of permanent magnet assisted SynRel motors

“…The adopted vector control scheme needs the knowledge of the rotor angular position and speed. In sensored solutions these come from a physical sensor, typically an encoder or a resolver, while in sensorless schemes they must be obtained with some type of software observer able to track the rotor position [11]. Three sensorless methods were investigated, as reported in Section IV.…”

Optimal Power Control Strategy of Maximizing Wind Energy Tracking and Different Operating Conditions for Permanent Magnet Synchronous Generator Wind Farm

“…This power is maximized at the particular rotational speed for various wind and it is obligatory to keep the rotor velocity at an optimum value of the tip speed ratio, opt O . As a result, the variable velocity WECS can operate at the peak of the ( ) m P Z curve when the wind speed changes and the maximum power is extracted continuously from the wind (MPPT control) [17]. That is shown in Fig.…”

“…Thus, when the wind velocity changes, the speed of PMSG is controlled to follow the maximum power point trajectory and, the optimum rotational speed of the generator can be simply estimated as follows [17]:…”

Power Extraction Control of Variable Speed Wind Turbine Systems Based on Direct Drive Synchronous Generator in All Operating Regimes

“…In the area of wind power generation technology, Variable Speed Wind Power Generation System (VS-WPGS) has many advantages over fixed speed ones such as better power quality, higher overall efficiency, lower mechanical stress, and increased energy capture. So, it can be controlled to enable the turbine to operate at its maximum coefficient of power and to ensure the Maximum Power Tracking (MPT) ability [20][21][22]. To control the VS-WPGS based DDSG, full scale power electronic converter systems are generally used as the interface between the VS-WPGS and the electrical network for satisfying the new standards and grid connection requirements [23,24].…”

“…On the other hand, to increase the annual energy yield of VS-WPGS, MPT control is essential under the rated wind velocity. Then, by changing the rotor velocity of DDSG according to the varying wind velocity, maximum power is extracted from available wind [21,22,32,33]. Also, variable speed wind turbines frequently employ pitch control system, either active stall or pitch to feather, to reduce the aerodynamic power captured [34,35].…”