Janusz Hetmańczyk

Computer analysis of high‐speed PM BLDC motor properties

Purpose – The purpose of this paper is to elaborate a method of computer analysis of high‐speed motor with specific parameters and verifying the obtained results, i.e. computer models by experimental (laboratory) tests.Design/methodology/approach – In order to determine motor properties from the viewpoint of energy conversion, a model using FEM was worked out with the help of Maxwell software. To determine static and dynamic properties of both motor and drive, Matlab/Simulink models were used; one of these models was a built‐in (library) model, the other one was proposed by the authors.Findings – The new analysis method and model of high‐speed motor have been carried out.Research limitations/implications – The permanent magnet brushless direct current high‐speed motor was the subject of the research. In the first part of the research, the properties of the motor were determined by using finite element method.Practical implications – The laboratory prototype can be a starting point in establishing the prod...

Impact of windings switching on torque‐speed curves of PM BLDC motor

Purpose – When phase windings of brushless DC motor are switched, additional voltage drops across inductances of main circuit appear. These drops lead to, among other effects, increase of torque‐speed curve slope. The discussed research has been aimed at working out a simple and precise method of identifying torque‐speed characteristic of PM BLDC motor. The elaborated method takes into account the influence of windings switching and motor inductances on motor torque‐speed characteristic. In order to assess the results, extensive test simulations of models implemented in Matlab/Simulink software have been run. Results of analysis and test simulations have been compared with lab test results of two real PM BLDC motors.Design/methodology/approach – Analytical calculations take into consideration phenomena occurring during windings switch‐overs and impact of inductance on emerging voltage and rotational speed drops. It has been pointed out that on account of main circuit inductance, the average value of sourc...

A validated numerical model of heat and mass transfer in a PM BLDC electric motor

In the paper, a validated numerical model describing heat transfer and air flow phenomena in a PM BLDC motor is presented. Validation was performed using the results of multiple velocity and temperature measurements. The air velocity was measured by constant temperature anemometers (CTA) and using Laser Doppler Anemometry (LDA) outside and inside the motor casing, respectively. The temperature measurements were conducted involving over 40 thermocouples located on the stator winding, internal and external casing walls and in the surrounding air. The numerical and experimental results were in a satisfactory agreement.

An experimental and numerical analysis of temperature and velocity field in PM BLDC motor

In this paper, a validated numerical model was introduced to determine the temperature and velocity fields outside the electric motor. The analysed object was a brushless permanent magnet motor (PM BLDC) having a rated power of 431 W with neodymium permanent magnets located on the rotor. The temperature and velocity measurements were conducted using thermocouples and constant-temperature anemometers. The numerical model covered the investigated motor and the same unit working as a generator and the air volume around them in order to improve the heat dissipation conditions. The numerical results show a satisfactory agreement with the values obtained during the measurements. Streszczenie. W pracy przedstawiono zwalidowany eksperymentalnie model numeryczny do wyznaczenia pola temperatury oraz predkości na obudowie oraz wokol bezszczotkowego silnika elektrycznego malej mocy. Pomiary temperatury i predkości przeprowadzono na stanowisku badawczym za pomocą termopar oraz anemometrow stalotemperaturowych i posluzyly one do walidacji modelu. Model numeryczny obejmowal silnik wraz z obciązającą go prądnicą oraz bryle powietrza wokol obu maszyn w celu dokladniejszego odwzorowania warunkow wymiany ciepla. Wyniki otrzymane z modelu numerycznego wykazaly satysfakcjonującą zgodnośc z wartościami otrzymanymi podczas pomiaru. Wyznaczania pola temperatury oraz predkości na obudowie oraz wokol bezszczotkowego silnika elektrycznego malej mocy

Amorphous Soft Magnetic Core for the Stator of the High-Speed PMBLDC Motor With Half-Open Slots

Several papers have appeared in recent years on the application of the amorphous soft magnetic materials in the stators of the electric motors. In our previous work, we demonstrated that the replacement of a slotless stator from the FeSi electrical steel with the stator from an amorphous alloy Metglas 2605 SA1 in a high-speed permanent magnet brushless direct current (PMBLDC) motor resulted in a substantial decrease of power losses in this stator, even by three times at the rotary frequency of 70 000 r/min. This paper was concentrated on the development of the cores for stators with half-open slots, which are technologically more difficult to produce than the slotless cores. The cores were made by cutting out suitable amount of 25μm-thick rings from the FeSiB amorphous ribbon by a laser technique, followed by stacking up the rings and their consolidation, and suitable heat treatment of the compressed stacks. Next, the measurements of the magnetic properties of the sample cores with half-open slots were made using the Remacomp C-1200 hysteresisgraph and the Lakeshore 450 Gaussmeter. Based on the results of measurements, the sample cores of different heights (17.5 and 10 mm) were selected for application in a stator of the prototype high-speed PMBLDC motor, 800 W in rated power and with a maximum rotary speed of 60 000 r/min. The preliminary performance tests with this prototype motor showed that after 1 h of uninterrupted operation, the temperature of a motor housing did not exceed 60 °C. It was also found that the operating efficiency of the PMBLDC motor incorporating a stator with half-open slots, made from an amorphous material, was almost 90% over a wide range of torques (from 40 to 140 mN · m).

Constant Current Models of Brushless DC Motor

Abstract Two constant current models of Permanent Magnet Brushless Direct Current Motor (PM BLDC) are presented in the paper. In the first part of the paper principle of operation, basic properties and mathematical equations describing PM BLDC models are given. Then, two different constant current models of PM BLDC motor are considered: In the first model, PM BLDC motor is approximated with dc motor; in the second model, modified constant current model is applied with additional block, which is used to take into account the impact of inductance on torque-speed characteristics. In order to verify these models, torque-speed characteristics have been determined and compared for different motor supply voltages. After running a series of simulation and laboratory tests, we have found that this modified model (which makes allowance for the influence of inductance on torque-speed characteristics) ensures obtaining torque-speed characteristics identical to those of the real motor. Therefore, this model may be recommended for those simulation tests which do not consider effects occurring inside the electronic commutator-motor circuit. However, approximation of PM BLDC motor with dc motor is not recommended in computer tests.

Development of parallel manipulator control system for simulation of selected means of transport

The paper presents the control system of 6-DOF parallel manipulator based on linear actuators driven by PM BLDC motors. The manipulator and its control system have been developed by the authors. The geometric parameters of the manipulator are presented as well as the control system structure. The motors are controlled by CAN-bus interface. The control system of the manipulator has been developed using rapid prototyping approach in Matlab/Simulink environment. The real time operation of the control system is possible thanks to xPC Target platform, which is an extension of the abovementioned software. An example of the parallel manipulator motion recorded on the laboratory stand is presented. The final part of the article discusses the application of the 6-DOF manipulator for simulation of search and rescue ship motion in order to evaluate the performance of the motion compensation system of electro-optical turret. The manipulator has been loaded with different masses up to 60 kg. Finally on the laboratory stand the real electro-optical turret has been mounted. The range of the manipulator motion obtained during the test leads to the conclusion that the manipulator can be used as a ship motion simulator.

Application of 6-DOF parallel manipulator for simulation of selected manoeuvres of emergency vehicles

The paper presents application of a Stewart-Gouch platform parallel manipulator, developed by the authors, as a laboratory stand for simulating forces acting on the load of the car. As it comes from the analysis of existing literature, particular kind of oscillations and shocks reduction is an important issue for transport of new born babies. For further research it is intended to develop and evaluate motion compensation or stabilization method, which could be applied in medical emergency transport. The research described in the paper focuses on two situations during transport, when particular shocks appear. The first situation appears when driving over a speed bump and the second situation is a manoeuvre to avoid an obstacle on the road. In both cases measurements of the vertical and lateral accelerations have been carried out and then simulations of such motions have been conducted on the 6-DOF platform laboratory stand. Assuming the limited range of motion frequency, it is possible to state that parallel manipulator based on the linear actuators powered by PM BLDC motors could be applied as a vehicle motion simulator.