Mauro Zigliotto

Sensorless full-digital PMSM drive with EKF estimation of speed and rotor position

This paper concerns the realization of a sensorless permanent magnet (PM) synchronous motor drive. Position and angular speed of the rotor are obtained through an extended Kalman filter. The estimation algorithm does not require either the knowledge of the mechanical parameters or the initial rotor position, overcoming two of the main drawbacks of other estimation techniques. The drive also incorporates a digital d-q current control, which can be easily tuned with locked rotor. The experimental setup includes a PM synchronous motor, a pulsewidth modulation voltage-source inverter, and floating-point digital-signal-processor-based control system.

Extended Kalman filter tuning in sensorless PMSM drives

The use of an extended Kalman filter (EKF) as a nonlinear speed and position observer for permanent-magnet synchronous motor drives is a mature research topic. Notwithstanding, the shift from research prototype to a market-ready product still calls for a solution to some implementation pitfalls. The major and still unsolved topic is the choice of the EKF covariance matrices. This paper replaces the usual trial-and-error method with a straightforward matrices choice. These matrices, possibly combined with a novel self-tuning procedure, should put the EKF drive much closer to an off-the-shelf product. The proposed method is based on the complete normalization of the EKF algorithm representation. Successful experimental results are included in the paper.

Experimental fault-tolerant control of a PMSM drive

The paper describes a study and an experimental verification of remedial strategies against failures occurring in the inverter power devices of a permanent-magnet synchronous motor drive. The basic idea of this design consists of incorporating a fourth inverter pole, with the same topology and capabilities of the other conventional three poles. This minimal redundant hardware, appropriately connected and controlled, allows the drive to face a variety of power device fault conditions while maintaining a smooth torque production. The achieved results also show the industrial feasibility of the proposed fault-tolerant control, that could fit many practical applications.

Design and Implementation of Model Predictive Control for Electrical Motor Drives

This paper deals with a model predictive control (MPC) algorithm applied to electrical drives. The main contribution is a comprehensive and detailed description of the controller design process that points out the most critical aspects and also gives some practical hints for implementation. As an example, the MPC is developed for a permanent-magnet synchronous motor drive. Speed and current controllers are combined together, including all of the state variables of the system, instead of keeping the conventional cascade structure. In this way, the controller enforces both the current and the voltage limits. Both simulation and experimental results point out the validity of the design procedure and the potentials of the MPC in the electrical drive field.

Torque-ripple reduction in PM synchronous motor drives using repetitive current control

The paper deals with the torque-ripple reduction in a permanent magnet synchronous motor (PMSM) drive with distorted back electromotive force. A smooth torque is obtained by tracking a modified current reference which is periodic over one-sixth of the electrical time period in the synchronous reference frame. An accurate tracking involves, however, very high current loop bandwidth, which is usually not achievable with conventional linear controllers. In order to improve current tracking in the presence of periodic reference signals and disturbances, the paper proposes the application of repetitive techniques to the current control in a field-oriented PMSM drive, where the q-axis current reference has been modified to achieve constant torque. The paper investigates the advantages and pitfalls of the method, through a mathematical analysis and an experimental validation obtained on a laboratory prototype. Particular emphasis is placed on the adjustments that have been specifically studied to enhance the overall system performance.

Extended-range PMSM sensorless speed drive based on stochastic filtering

The paper describes the design of a high-performance sensorless permanent magnet synchronous motor (PMSM) drive, capable of starting at full torque even from standstill and able to deliver full torque in 1:12 speed range. Experimental setup, hardware circuitry and software implementation are described into details. Particular emphasis is given to the software control algorithms, that were specifically studied to enhance the overall system performance.

Fuzzy logic control of a switched reluctance motor drive

A FLC (fuzzy logic controller) is applied to the speed control of an SRM (switched reluctance motor) drive. The FLC has been designed in terms of state evaluation control rules derived from a rough formulation of a sliding mode control of the drive. The control rules have been selected to force the drive in the sliding regime when the speed error is high and to decrease the reaching of the steady state when the speed error becomes low. In this way the drive dynamics takes advantage of the intrinsic robustness of the sliding mode control, avoiding the problem of both the switching control and the chattering phenomenon in the steady state. The resulting drive has been simulated and significant tests have been carried out. The traces are in line with the expectations, confirming that the FLC represents a powerful tool to give the drive superior performance.<<ETX>>

Novel digital continuous control of SVM inverters in the overmodulation range

A novel technique for space-vector modulation (SVM) inverters in the overmodulation range is presented. A unique algorithm manages the transition from the onset of overmodulation to six-step operation. The technique is suitable for a very simple digital implementation. Experimental results, obtained by a digital signal processor (DSP) board, are also included in this paper.

High performance PM synchronous motor drive for an electrical scooter

In this paper, the design of a full electrical system for an electrical scooter is presented. The paper explains the design choices that have been done to satisfy the typical main requirements for an electrical vehicle. According to them, an interior permanent magnet synchronous motor has been incorporated in a drive able to control the motor both in the constant torque (constant flux) and in the constant volt-ampere (flux-weakening) regions. Experimental results carried out on a system prototype are also included in the final paper.

Analysis of PM synchronous motor drive failures during flux weakening operation

Under flux weakening operation, the phase emf of a PM synchronous motor can be extremely high; this paper investigates the effects on currents, voltages and torque of different drive failures occurring under flux weakening operation, as a starting point for a successful design of an effective system protection and a fault-tolerant control.