Trade-off between torque ripple and vibration in an IPMSM by examining the temporal and spatial harmonics of flux density

Despite continuous effort to minimize torque ripple, the reduction of vibration has not been yet achieved due to the lack of link between these two performances. The difficulty of investigating the relationship stems from the fact that torque is solely influenced by tangential force whereas vibration is directly tied to radial force. In this paper, the correlation between torque ripple and vibration in an IPMSM (Interior Permanent Magnet Synchronous Motor) is established by examining the air-gap flux density in both radial and tangential directions. Its temporal and spatial harmonics are analyzed. A six-pole nine-slot IPMSM is used as a base configuration, and the air-gap flux density is varied by changing the height of a stator tooth tip. In the previous study, the same approach has been done to observe how to reduce torque ripple effectively. In this study, however, it is found that the trend of torque ripple is not the same as that of vibration with respect to the height of a pole tip, and the relation between the two is thoroughly observed and explained

Investigation of electromagnetic noise in an induction cooktop by examining circular membrane vibration modes in terms of their harmonics

In this study, the mechanism of vibration and noise is analytically investigated in an induction cooktop (IC). By employing the method of an electric motor in estimating its vibration performance, it is found that air-gap force normal to the glass surface is a main source in an IC. Three different types of a cookware in terms of its material are compared as a part of load, and the pattern of their vibration is scrutinized by means of a membrane. It is noted that the mode of vibration in an IC is the circular shape of a membrane. Spatial and temporal harmonics in normal force are obtained through a three-dimensional Fast Fourier transform. This study is focused on spatial harmonic orders in a cylindrical coordinate to determine the dominant mode of vibration, and experimental verification has been performed to prove the feasibility of this proposal

Analysis of Vibration and Noise in a Permanent Magnet Synchronous Motor Based on Temperature-Dependent Characteristics of Permanent Magnet

Interior permanent magnet synchronous motors (IPMSMs) are widely utilized due to their high power density. However, noise and vibration issues are often encountered in these motors. While researchers have extensively investigated individual aspects such as noise, vibration, and heat generation in PMSMs, there has been a lack of comprehensive studies examining the interrelationships among these factors. In this paper, a novel approach is proposed for predicting vibration by considering the radial force in the air gap as the exciting force, while also accounting for the changes in the permanent magnet (PM) characteristics caused by heat generation during motor operation. The method involves decomposing and identifying vibration components associated with each vibration mode and predicting noise based on the sound radiation efficiency of each mode. By constructing a vibration map based on current and temperature at a specific frequency, the components most affected by current variations and PM characteristics can be identified. This allows for the proposal of design improvements aimed at reducing vibration. Furthermore, by comparing the vibration map with the noise map, it is confirmed that vibration serves as a source of noise and influences its generation. However, it is found that vibration and noise are not strictly proportional. Overall, a comprehensive analysis of the correlations between vibration, noise, and other factors in IPMSMs is presented in this study. The proposed method and findings contribute to the understanding of the complex dynamics involved and provide valuable insights for the design of quieter and more efficient motor systems

Design of a Single-Phase BLDC Motor for a Cordless Vacuum Cleaner Considering the Efficiency of Airflow

This paper discusses an inverter-driven single-phase brushless direct-current (BLDC) motor assembled by a housing for a cordless vacuum cleaner. Air gap in the single-phase BLDC motor is asymmetrically designed to satisfy starting and continuous torque by considering voltage fluctuation in a battery. By varying both advance and conduction angles in response to the change of battery voltage, the proposed single-phase BLDC motor with asymmetric air gap is able to maintain sufficient output power. The system efficiency of a vacuum cleaner driven by the proposed motor assembly is estimated by means of fluid dynamics in air watt, and it is also verified experimentally. From the results of the condition of 100,020 r/min, it was confirmed that the motor efficiency was in good agreement with the estimated efficiency, and air flow efficiency of 45.7% and system efficiency of 41.8% were achieved

Control of Output and Circulating Current of Modular Multilevel Converter Using a Sliding Mode Approach

The modular multilevel converter (MMC) has been prominently used in medium- and high-power applications. This paper presents the control of output and circulating current of MMC using sliding mode control (SMC). The design of the proposed controller and the relation between control parameters and validity condition are based on the system dynamics. The proposed designed controller enables the system to track its reference values. The controller is designed to control both output current and circulating current along with suppression of second harmonics contents in circulating current. Furthermore, the capacitor voltage and energy of the converter are also regulated. The control of output current is carried out in d q -axis as well as in α β − a x i s with first-order switching law. However, a second-order switching law-based super twisting algorithm is used for controlling circulating current and suppression of its second harmonics contents. The stability of the controlled system is numerically calculated and verified by Lyapunov stability conditions. Moreover, the simulation results of the proposed controller are critically compared with the conventional proportional resonant (PR) controller to verify the effectiveness of the proposed control strategy. The proposed controller attains faster dynamic response and minimizes steady-state error comparatively. The simulation of the MMC model is carried out in MATLAB/Simulink

A Blended SPS-ESPS Control DAB-IBDC Converter for a Standalone Solar Power System

In sustainable energy applications, standalone solar power systems are mostly preferred for self-powered energy zones. In all standalone renewable power systems, batteries are still preferred as the common energy storage device. On the other hand, batteries are not applicable for high peak power demand applications because of their low power density. A supercapacitor is a preferable high-power density energy storage device for high peak power applications. A 2 kW, 50 kHz digital control dual active bridge isolated bi-directional dc-dc converter (DAB-IBDC) was developed for interfacing the supercapacitor bank in standalone solar power system. This paper proposes a blended SPS-ESPS digital control algorithm for a DAB-IBDC converter instead of using a traditional single-phase shift (SPS) control algorithm, which is commonly used for large input to output voltage varying applications. This proposed blended SPS-ESPS control algorithm achieved high power conversion efficiency during a large input to output voltage variation, over a traditional phase shift control algorithm by reducing the back-power flow and current stress in a circuit. This system also achieved maximum power point for solar modules and enhanced rapid charging-discharging for a supercapacitor bank. Both SPS and the blended SPS-ESPS control algorithms were verified experimentally using 2 kW DAB-IBDC topology implemented with standalone power system that combination of 2000 W input solar module and 158 Wh supercapacitor bank