67,645 research outputs found
Special section on high speed electrical machines and drives
The use of high-speed electrical machines and drives is in continuous evolution for a number of engineering applications, including electrical spindles for milling cutters and grinding, turbochargers, electrical turbo-compounding systems, aeroengine spools, helicopter and racing engines, and fuel pumps. The academic and industrial interests in this topic are growing very fast, pushing their research toward improvements in the involved technologies with a significant impact in many application areas. One of the main advantages of high-speed machines and drives is the reduction of system weight for a given power conversion. This is particularly desirable in all transportation applications where a weight reduction directly results in reduced fuel consumption and emissions. The electric transportation system is one of main topics with a significant push for advancing high-speed technologie
Power factor correction of an electrical drive system based on multiphase machines
International audienceThis paper deals with the energy efficiency improvement of an electrical drive which can be used both in wind energy conversion or motor drive applications. A power factor (PF) control scheme is presented allowing energy efficiency enhancement and optimization in high power variable-speed drives based on multiphase machines. Thus, the double-star induction machine is taken, as an example of multiphase machines, to introduce the principle of the study presented in this paper. In fact, the purpose of this paper is to maintain the PF of the power-winding, of the double star induction machine, in vicinity of unity whatever the drive operating point. Also, this control scheme can be generalized for several kinds of multiphase machines
Flux switching machine design for high-speed geared drives
Electrical machines capable of high-speed operation are key technology used in many modern applications, such as gas turbine electrical systems, high-speed fly-wheels, turbochargers, and computer numerical control (CNC) machines. The use of geared high-speed machines to replace low-speed high torque drives has not been adequately researched to-date. The rationale of this thesis is to investigate a candidate high speed machine, namely flux switching machines to be used together with new types of core material with mechanical gearing to deliver high-torque and low speeds. Modern developments in advanced material technology have produced new magnetic materials capable of dealing with high resulting in very low losses in high speed machines. However, such metals typically have low mechanical strength, and they are found to be brittle. In order to manufacture electromechanical device with such new materials, it has to be reinforced with a mechanically strong structure. The use of multiple types of magnetic materials referred as a MMLC has been proposed in this thesis for high-speed machine design. In this research, a generic method using magnetic equivalent circuit to model flux switching machines (FSMs) is investigated. Moreover modeling, based on machine dimensions for multiphase FSMs having any pole and slot number has been introduced. The air-gap permeance modeling to simplify the magnetic circuit calculation of FSMs was also investigated in this thesis. It is shown that the permeability of magnetic material can be adjusted with the use of MMLC material. Using this feature, the FSM mathematical model is used to show the impact on electromagnetic performance using MMLCs and is shown to be beneficial. In order the evaluate the weight benefits of using geared high speed FSMs, the planetary gear systems are studies and their design constraints have been identified. An abstract form of weight estimation for given torque and speed requirements has been developed and validated using commercially available planetary gear specifications. FSMs together with gear boxes have been considered and it is shown that significant weight savings can be achieved at higher diameter and at high speeds
Energy efficiency measurement procedure for gearboxes in their entire operating range
Over the last decade, forced regulations and a growing social awareness with respect to energy efficiency have resulted in a renewed interest in the research for high efficient electrical machines. When an electrical motor is coupled to a machine, in many cases a gearbox or belt transmission is used. Research shows a lack of information on energy efficiency of these components. In comparison to electrical motors and drives, there is very few regulation and if efficiency values can be found in catalogues, there is no regulated test procedure available to validate the data. As a result, the reliability of these efficiency values is unknown and comparison between manufacturers and technologies is impossible. In this paper a test bench is proposed to measure the energy efficiency of a gearbox with an accuracy up to 0.4%. The test bench is used to measure the efficiency of gearboxes in their entire speed and torque range. Contour maps are used to visualize these measurement results. Moreover, a measurement campaign using different gearboxes is carried out to compare the energy efficiency in the manufacturers catalogue and the measured efficiency
Design And Implementation Of Speed Regulator For A PMSM Using Genetic Algorithm
Abstract--Power electronics plays an important role in controlling the drives. Digital control technology has been rapidly developed for power electronics and electrical drives, and it has been the impetus to the widespread use of a permanent magnet synchronous motor in many industrial applications such as chip mount machines, semiconductor production machines, high-resolution computerized numerically controlled machine tools, robotics, and hard disk drives. A PMSM has low noise, low inertia, high torque-tocurrent ratio, high efficiency, robustness, and low maintenance cost. We propose a genetic algorithm (GA) based speed regulator system for a permanentmagnet synchronous motor. By using the GA the motor acceleration observer as well as a speed regulator is designed. In terms of linear matrix inequalities, sufficient conditions for the existence of the regulator and observer are derived. Simulation and experimental results are given to verify that the proposed digital control method can be successfully used for a PMSM under model parameter and load torque variations
High gear ratio mechanical transmissions for actuators: Simplified models for efficiency under opposing and aiding loads
Planetary gear drives are widely employed in electrical and hydraulic actuation systems, to adapt a high speed, low torque motor to a low speed, high torque user, within strict weight and volume constraints. During the early design phases of these devices, accurate yet simple simulation models are required to evaluate the performance of a given configuration of the device. Similar models are also useful within diagnostic and health monitoring analyses of existing machines, as a discrepancy between the actual behaviour of the physical system and that predicted by its digital twin may be the effect of a damage. This work compares different models available in literature for the efficiency of high gear ratio mechanical transmissions; the models are applied to multiple arrangements common for planetary drives, and the results in form of an efficiency map for the transmissions are compared and discussed. The simulations provide different levels of detail, and require different levels of knowledge about the specific architecture of the system. All of them are able to deal with dry friction; additionally, the different behaviour of the transmission under the effect loads aligned in the same direction of speed or in the opposite one is accounted for
Lightweight High-Efficiency Power Train Propulsion with Axial- Flux Machines for Electric or Hybrid Vehicles
The aim of this chapter is to present a new type of powertrain with dimensions and low weight, for vehicles with reduced carbon emissions, which have an axial synchronous machine with one stator and two rotor, with static converter that is simple and inexpensive, a broadcast transmission system using an electric differential, with the control of the two rotors so that they can operate as motor/generator, at the same rotational direction or in opposite directions, at the same speed value, at slightly different speeds or at much different speeds by using an original dual vector control with operating on dual frequency. This is a major concern of hybrid and electric vehicle manufacturers. Expected results: a lighter power train with 20% and an increase in 5% of electric drive efficiency, low inertia rotor at high speed, a compact electric drive system with high torque and simple control, intelligent energy management system with a new vision of technological and innovation development, and equal importance of environment protection. The electrical machines for hybrid (HEV) or electric (EV) drives include a variety of different topologies. According to outcomes of literature survey, induction machines alongside synchronous machines take the major place in HEV or EV power trains
High-frequency issues using rotating voltage injections intended for position self-sensing
The rotor position is required in many control schemes in electrical drives. Replacing position sensors by machine self-sensing estimators increases reliability and reduces cost. Solutions based on tracking magnetic anisotropies through the monitoring of the incremental inductance variations are efficient at low-speed and standstill operations. This inductance can be estimated by measuring the response to the injection of high-frequency signals. In general however, the selection of the optimal frequency is not addressed thoroughly. In this paper, we propose discrete-time operations based on a rotating voltage injection at frequencies up to one third of the sampling frequency used by the digital controller. The impact on the rotation-drive, the computational requirement, the robustness and the effect of the resistance on the position estimation are analyzed regarding the signal frequency
Low-cost, high-resolution, fault-robust position and speed estimation for PMSM drives operating in safety-critical systems
In this paper it is shown how to obtain a low-cost, high-resolution and fault-robust position sensing system for permanent magnet synchronous motor drives operating in safety-critical systems, by combining high-frequency signal injection with binary Hall-effect sensors. It is shown that the position error signal obtained via high-frequency signal injection can be merged easily into the quantization-harmonic-decoupling vector tracking observer used to process the Hall-effect sensor signals. The resulting algorithm provides accurate, high-resolution estimates of speed and position throughout the entire speed range; compared to state-of-the-art drives using Hall-effect sensors alone, the low speed performance is greatly improved in healthy conditions and also following position sensor faults. It is envisaged that such a sensing system can be successfully used in applications requiring IEC 61508 SIL 3 or ISO 26262 ASIL D compliance, due to its extremely high mean time to failure and to the very fast recovery of the drive following Hall-effect sensor faults at low speeds. Extensive simulation and experimental results are provided on a 3.7 kW permanent magnet drive
New 5-Phase Concentrated Winding Machine with Bi-Harmonic Rotor for Automotive Application
For a power range from 10 to 30 kW, 5-phase machines are well adapted to low-voltage (48V) supply thanks to their reduced current per phase. For three-phase machines but with higher voltages (>120V), machines with a number of slots per pole and per phase spp equal to 0.5 (as the 12slots/8poles combination) are widely used in hybrid automotive applications when a wide speed range is required. The reason is that the value of spp=0.5 guarantees no sub-harmonics and thus induces low level of permanent magnet rotor losses. In this paper a 20slots/8poles/5phases machine is chosen. With a winding factor of only 0.588 for the first harmonic, this machine is only interesting if its high third harmonic winding factor (0.951) is used. Thus, a new bi-harmonic rotor structure is presented. Thanks to adequate control with flux-weakening and ratio r between first and third harmonic currents, the maximum torque versus speed characteristic is determined.Projet ADEME/MHYGAL
- …