285 research outputs found
Position Sensor-less and Adaptive Speed Design for Controlling Brush-less DC Motor Drives
This paper proposes a method for direct torque control of Brushless DC (BLDC)
motors. Evaluating the trapezium of back-EMF is needed, and is done via a
sliding mode observer employing just one measurement of stator current. The
effect of the proposed estimation algorithm is reducing the impact of switching
noise and consequently eliminating the required filter. Furthermore, to
overcome the uncertainties related to BLDC motors, Recursive Least Square (RLS)
is regarded as a real-time estimator of inertia and viscous damping
coefficients of the BLDC motor. By substituting the estimated load torque in
mechanical dynamic equations, the rotor speed can be calculated. Also, to
increase the robustness and decrease the rise time of the system, Modified
Model Reference Adaptive System (MMRAS) is applied in order to design a new
speed controller. Simulation results confirm the validity of this recommended
method
Hybrid Field Oriented and Direct Torque Control for Sensorless BLDC Motors Used in Aerial Drones
In this study, a sensorless hybrid control scheme for brushless direct current (BLDC) motors for use in multirotor aerial vehicles is introduced. In such applications, the control scheme must satisfy high-performance demands for a wide range of rotor speeds and must be robust to motor parameter uncertainties and measurement noise. The proposed controller combines field-oriented control (FOC) and direct torque control (DTC) techniques to take benefit of the advantages offered by each of these techniques individually. Simulation results demonstrate the effectiveness of the proposed control scheme over a wide range of rotor speeds as well as good robustness against parameter uncertainties within -5to + 10% for inductance and -5to + 5% for resistance parameters. The proposed hybrid controller is robust also against noise in voltage and current measurements. In order to verify the results from simulation, the proposed hybrid controller is implemented in hardware using the TI C2000 Piccolo Launchpad and TI BOOSTXL-DRV8305EVM BoosterPack. Testing is done with a Bull Running motor typically used in aerial drones. Testing experiments demonstrate that the hybrid controller reduces the rotor speed ripple when compared to DTC while operating in steady-state mode and decreases the response time to desired speed changes when compared to FOC
Sensorless flux-weakening control of permanent-magnet brushless machines using third harmonic back EMF
The sensorless control of brushless machines by detecting the third harmonic back electromotive force is a relatively simple and potentially low-cost technique. However, its application has been reported only for brushless dc motors operating under normal commutation. In this paper, the utility of the method for the sensorless control of both brushless dc and ac motors, including operation in the flux-weakening mode, is demonstrated
Precision Control of a Sensorless Brushless Direct Current Motor System
Sensorless control strategies were first suggested well over a decade ago with the aim of
reducing the size, weight and unit cost of electrically actuated servo systems. The
resulting algorithms have been successfully applied to the induction and synchronous
motor families in applications where control of armature speeds above approximately one
hundred revolutions per minute is desired. However, sensorless position control remains
problematic.
This thesis provides an in depth investigation into sensorless motor control strategies for
high precision motion control applications. Specifically, methods of achieving control of
position and very low speed thresholds are investigated. The developed grey box
identification techniques are shown to perform better than their traditional white or black
box counterparts. Further, fuzzy model based sliding mode control is implemented and
results demonstrate its improved robustness to certain classes of disturbance. Attempts to
reject uncertainty within the developed models using the sliding mode are discussed.
Novel controllers, which enhance the performance of the sliding mode are presented.
Finally, algorithms that achieve control without a primary feedback sensor are
successfully demonstrated. Sensorless position control is achieved with resolutions
equivalent to those of existing stepper motor technology. The successful control of
armature speeds below sixty revolutions per minute is achieved and problems typically
associated with motor starting are circumvented.Research Instruments Ltd
Some Permanent Magnet Synchronous Motor (PMSM) Sensorless Control Methods based on Operation Speed Area
This paper compares some sensorless Permanent Magnet Synchronous Motor (PMSM) controls for driving an electric vehicle in terms of operating speed. Sensorless control is a type of control method in which sensors, such as speed and position sensors, are not used to measure controlled variables. The controlled variable value is estimated from the stator current measurement. Sensorless control performance is not as good as a sensor-based system. This paper aims are to recommend a control method for the PMSM sensorless controls that would be used to drive an electric vehicle. The methods that we will discuss are divided into four categories based on the operation speed area. They are a startup, low speed, high speed, and low and high-speed areas. The low and high-speed area will be divided into with and without switching. If PMSM more work at high speed, the most speed area that is used, we prefer to choose the method that works at high speed, that is, the modification or combination of two or more conventional methods
Sensorless Control of Switched-Flux Permanent Magnet Machines
This thesis investigates the sensorless control strategies of permanent magnet synchronous machines (PMSMs), with particular reference to switched-flux permanent magnet (SFPM) machines, based on high-frequency signal injection methods for low speed and standstill and the back-EMF based methods for medium and high speeds
Sensorless SVPWM-FADTC of a new flux-modulated permanent-magnet wheel motor based on a wide-speed sliding mode observer
published_or_final_versio
- …