Alessandro Lidozzi

SVM PMSM Drives with Low Resolution Hall-Effect Sensors

In this paper a back-EMF-based method is used in conjunction with three very low-cost integrated circuits based on the Hall-effect to estimate the rotor position of the direct-drive PMSMs to be used for traction purpose of an electric wheelchair. A speed estimator based on rotor frame machine model (SERF) has been implemented for the PMSM drives, and then the rotor position estimation is achieved by means of a discrete integration of the estimated speed. The three Hall effect sensors are used to detect the rotor initial position as well to reset the error on the rotor position estimation every 60 electrical degrees. In the specific application, SVM technique has been implemented together with the field oriented control. Simulations and experimental results are shown in the paper

Implementation and Sensorless Vector-Control Design and Tuning Strategy for SMPM Machines in Fan-Type Applications

This paper presents a complete design methodology for the sensorless vector control of permanent magnet synchronous machine (PMSM) motor drives in fan-type applications. The proposed strategy is built over a linear asymptotic state observer used to estimate the PMSM back-EMF, and a novel tracking controller based on a phase-locked loop (PLL) system, which by synchronizing the estimated and actual d-q frames estimates the rotor speed and position. The paper presents the complete derivation of all associated control-loops, namely state observer, tracking controller, d-q axes current regulator, speed controller, an anti-saturation control loop - which provides inherent operation in the flux-weakening region, and all corresponding anti-windup loops. Detailed design rules are provided for each of these loops, respectively verified through time-domain simulations, frequency-response analysis, and experimental results using a 300 Vdc 3.5 kW PMSM PWM motor-drive, validating both the design methodology and the excellent performance attained by the proposed control strategy

Power balance control of multiple-input DC-DC power converter for hybrid vehicles

In this paper design of voltage and current conditioning system is proposed for a multiple input dc-dc power electronic converter (MIPEC) devoted to combine hybrid-electric vehicles (HEV) different on-board energy sources; the proposed arrangement for the propulsion system includes fuel cell (FC), ultra-capacitor (UC) tank, and battery unit system (BU). In terms of power sources, the proton exchange membrane fuel cells (FCs) are being increasingly accepted as the most appropriate supply for electric vehicles (EVs) because they offer clean and efficient energy without penalizing performance or driving range. The FC generator, that is the main energy source, has poor efficiency at light load thus the BU is devoted to supply the power at such situation in order to save total efficiency. The UC tank is used to satisfy acceleration and regenerative braking requirements accomplishing the system load transients and improving the on-board BU life time. The paper is mainly focused on modeling the converter for both steady-state and dynamic behavior. Regulators tuning is also carried out, as well complete control system implementation on DSP board is accomplished. Information on carried on experimental test campaign are provided. Achieved results show power balancing appropriate to characteristics of generation and storage units.

High-Speed Generator and Multilevel Converter for Energy Recovery in Automotive Systems

This paper deals with the design solution adopted for a high-speed axial-flux permanent-magnet generator devoted to supplementing power in automotive 42 V electrical systems through a low-voltage multilevel neutral-point-clamped converter. The axial-flux permanent-magnet generator is suitably designed to be directly coupled with a radial turbo-expander which provides recovery of kinetic energy available from the exhaust gases of an internal-combustion engine. The multilevel converter is properly sized for systems having low voltage and high first-order harmonic frequency. The paper describes the proposed 4-kW power rating generating system and discusses various issues resulting from electromagnetic, thermal, and mechanical design of the high-speed axial-flux permanent-magnet generator. As well, investigations on modulation strategy, total harmonic distortion, and power losses are presented for the low-voltage neutral-point-clamped power electronic converter.

High-Speed Electric Drive for Exhaust Gas Energy Recovery Applications

High-speed electric drives play an important role in the field of power generating units on board vehicles and aircrafts. This paper deals with the solutions for developing the direct coupled electric drive to be used in combination with a radial turbo-expander for exhaust energy recovery in automotive applications. The descriptions of prototypal realization of both the axial-flux permanent-magnet (PM) generator and the three-level boost-rectifier converter, which results as the preferred topology for the controlled rectifier, are given. The high rotational speed of the direct-driven PM generator results in high electric fundamental frequency also, which is challenging for the electric drive control issues. Results of the electric drive prototype experimental activity are finally presented.

Mathematical Model and Control Design for Sensorless Vector Control of Permanent Magnet Synchronous Machines

This paper presents a mathematical model and control design for the sensorless vector control of permanent magnet synchronous machines (PMSM). A detailed motor drive including three-phase PWM voltage-source inverter and PMSM and control system models are presented, providing insight into the frequency response based design of all associated loops, namely back-EMF state observer, rotor speed and position estimator, d-q axes current regulator, and speed controller. The complete design procedure is provided, together with simulation and experimental results with a 3.5 kW PMSM drive, all of which verify the excellent results attained by the proposed model and control design methodology

Design and Evaluation of a PLL-Based Position Controller for Sensorless Vector Control of Permanent-Magnet Synchronous Machines

This paper presents a rotor position controller for sensorless vector control of permanent magnet synchronous machines (PMSM) based on a synchronous d-q frame phase-locked loop (PLL). Extending the capabilities of PLLs for grid-connected converters¿using feedback linearization to ensure a constant dynamic response regardless of the operating region and rotor speed, the proposed controller takes advantage of the sinusoidal and balanced PMSM back-EMF voltages synchronizing the estimated and actual d-q frames. The resultant controller structure is readily linearized providing an accurate design tool based on frequency response specifications. A complete design procedure is provided, together with simulation and experimental results with a 3.5 kW PMSM drive, all of which verify the excellent results attained by the proposed PLL-based position controller.

Adaptive Direct-Tuning Control for Variable-Speed Diesel-Electric Generating Units

This paper deals with an adaptive control method to be used in the dc-link voltage controller of diesel-electric power supply units being arranged with both permanent-magnet generator and three-phase boost rectifier. The proposed control method is based on the suitable manipulation of the overall system transfer function to achieve an adaptive “closed-form” expression for the parameters of the dc-link voltage controller. Such an approach allows overcoming the inherent nonlinear behavior of the system, so that the overall system dynamic performance is not affected by the system load conditions. Moreover, a current feedforward technique based on the estimation of the load current will be introduced to improve the control stiffness to load unbalances.

LC Filter Design for On-Grid and Off-Grid Distributed Generating Units

The paper deals with the design procedure of an LC based output filter for three-phase inverters to be used in both off-grid and on-grid scenarios. The aim of this procedure is to provide guidelines and component selection criteria for reducing the inverter output switching ripple in order to limit the interaction with the control algorithm and to increase the filter stability. A suitable combination of resistive and reactive components is used to realize the complete filter structure. The proposed procedure is applied to the design of the output power filter for a 40 kVA three-phase inverter.

Resonant–Repetitive Combined Control for Stand-Alone Power Supply Units

This paper investigates a combined resonant–repetitive (RR) control structure for a three-phase four-leg dc/ac converter power supply. The RR control configuration is composed by a resonant controller tuned at the system fundamental frequency working in conjunction with a plug-in-type repetitive controller. The resonant part of the control scheme is used to assure prompt tracking of the inverter output voltage and to achieve as fast as possible system response to load variations; to this purpose, it is tuned at the fundamental frequency. At the same time, the resonant controller is able to stabilize the system without the necessity of any further additional controller; the repetitive part of the scheme is implemented for the fine regulation at the system harmonic frequencies. The proposed control configuration is used to regulate the power supply output voltage, providing very good tracking of the output voltage reference even in the presence of a nonlinear load. Experimental validation from a 40-kVA converter prototype is presented to validate the operation of the proposed converter and control.