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Article
Publication date: 3 January 2017

Guangming Zhang, Xiaojun Liu, Lei Mei, Huimin Ouyang and Xin Deng

This paper aims to describe a simple low-pass filter to suppress torque pulsation and current harmonics in permanent magnet synchronous motor (PMSM) drives.

Abstract

Purpose

This paper aims to describe a simple low-pass filter to suppress torque pulsation and current harmonics in permanent magnet synchronous motor (PMSM) drives.

Design/methodology/approach

For the control of the PMSM, a field-oriented control algorithm is always used. The proposed filter is actually a resistance, inductance, capacitance (RLC) filter. At the output of the inverter and the input of PMSM, an RLC filter is connected. This filter suppresses current harmonics through filtering phase voltage harmonics. Analysis of the filter is achieved through frequency characteristics analysis.

Findings

This filter can effectively filter out the harmonic of phase voltage. Both the simulation and experiment results show that the proposed filter can effectively suppress torque pulsation and current harmonics in PMSM drives. Also, the method of selecting filter parameters and the whole control system are very simple.

Research limitations implications

The filter increases the design cost of the system.

Practical implications

The harmonics and torque ripple of phase current are greatly suppressed. Also, the loss of the PMSM reduced.

Originality/value

The method of selecting filter parameters and the analysis of the proposed filter are proposed for the first time.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 36 no. 1
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 1 December 1958

R.T. Beazley

The effectiveness of an oil filter and of the method in which it is employed is judged by the level of lubricating quality it maintains in the bearings and other sliding parts of…

Abstract

The effectiveness of an oil filter and of the method in which it is employed is judged by the level of lubricating quality it maintains in the bearings and other sliding parts of the engine. The word “quality” here includes freedom from dirt (particularly from those dirt particles which, by their size and composition, are likely to cause abrasive wear) and the presence in sufficient quantity of those additives which the modern refiner incorporates in Heavy Duty oils to reduce oxidation, piston‐ring sticking and other ills.

Details

Industrial Lubrication and Tribology, vol. 10 no. 12
Type: Research Article
ISSN: 0036-8792

Article
Publication date: 1 October 1998

A.J. Bannan and B.J. Inglis

Melt filtration systems are widely employed across polymer production industries. It is common for the filters used in such systems to be chemically cleaned and reinstalled for…

Abstract

Melt filtration systems are widely employed across polymer production industries. It is common for the filters used in such systems to be chemically cleaned and reinstalled for repeat process application. These “regenerable” filters can be characterised by their performance and reliability and their selection is a major issue, in terms of both plant economics and technical justification. This paper considers the factors surrounding the economics of filter cleaning together with a case study on recycling efficiency and filter failure modes.

Details

Pigment & Resin Technology, vol. 27 no. 5
Type: Research Article
ISSN: 0369-9420

Keywords

Article
Publication date: 1 March 2013

Chang Jiang You, Xiao Wei Zhu and Zhen Hai Shao

The purpose of this paper is to propose an improved reconfigurable zero‐IF RF receiver with anti‐interference improvement used in dynamic spectrum resource sharing system at UHF…

Abstract

Purpose

The purpose of this paper is to propose an improved reconfigurable zero‐IF RF receiver with anti‐interference improvement used in dynamic spectrum resource sharing system at UHF band based on tunable filter array computation. Measured results show that the anti‐interference competence of improved zero‐IF RF receiver is enhanced greatly by employing two tunable filter arrays.

Design/methodology/approach

The anti‐interference reconfigurable zero‐IF RF receiver is based on fully differential I/Q demodulation structure and employs two same tunable filter arrays to meet the requirement on adjacent channel suppression imposed by systems coexisting. The performance requirement of each filter in tunable filter arrays is computed and derived according to the needs of anti‐interference.

Findings

The anti‐interference competence of zero‐IF RF receiver could be enhanced greatly by employing two tunable filter arrays.

Originality/value

The paper provides a method to design zero‐IF RF receivers with anti‐interference competence used in dynamic spectrum resource sharing systems.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 32 no. 2
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 5 May 2015

Yijiu Zhao, Houjun Wang and Zhijian Dai

The purpose of this paper is to present a model calibration technique for modulated wideband converter (MWC) with non-ideal lowpass filter. Without making any change to the system…

Abstract

Purpose

The purpose of this paper is to present a model calibration technique for modulated wideband converter (MWC) with non-ideal lowpass filter. Without making any change to the system architecture, at the cost of a moderate oversampling, the calibrated system can perform as the system with ideal lowpass filter.

Design/methodology/approach

A known test sparse signal is used to approximate the finite impulse response (FIR) of the practical non-ideal lowpass filter. Based on the approximated FIR filter, a digital compensation filter is designed to calibrate the practical filter. The calibrated filter can meet the perfect reconstruction condition. The non-ideal sub-Nyquist samples are filtered by a compensation filter.

Findings

Experimental results indicate that, by calibrating the MWC with the proposed algorithm, the impaction of non-ideal lowpass filter could be avoided. The performance of signal reconstruction could be improved significantly.

Originality/value

Without making any change to the MWC architecture, the proposed algorithm can calibrated the non-ideal lowpass filter. By filtering the non-ideal sub-Nyquist samples with the designed compensation filter, the original signal could be reconstructed with high accuracy.

Details

COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering, vol. 34 no. 3
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 6 August 2019

Karthie S. and Salivahanan S.

This paper aims to present the design of a novel triangular-shaped wideband microstrip bandpass filter implemented on a low-cost substrate with a notched band for interference…

87

Abstract

Purpose

This paper aims to present the design of a novel triangular-shaped wideband microstrip bandpass filter implemented on a low-cost substrate with a notched band for interference rejection.

Design/methodology/approach

The conventional dual-stub filter is embedded with simple fractal-based triangular-circular geometries through various iterations to reject wireless local area network (WLAN) signals with a notched band at 5.8 GHz.

Findings

The filter covers a wide frequency band from 3.1 to 8.8 GHz and has a fractional bandwidth of 98 per cent with the lower passband of 57.5 per cent and upper passband of 31.6 per cent separated by a notched band at 5.8 GHz. The proposed wideband prototype bandpass filter is fabricated in FR-4 substrate using PCB technology and the simulation results are validated with measurement results which include insertion loss, return loss and group delay. The fabricated filter has a sharp rejection of 28.3 dB at 5.8 GHz. Measured results show good agreement with simulated responses. The performance of the fractal-based wideband filter is compared with other wideband bandpass filters.

Originality/value

In the proposed work, a fractal-based wideband bandpass filter with a notched band is reported. The conventional dual-stub filter is deployed with triangular-circular geometry to design a wideband filter with a notched band to suppress interference signals at WLAN frequency. The proposed wideband filter exhibits smaller size and better interference rejection compared to other wideband bandpass filter designs implemented on low-cost substrate reported in the literature. The aforementioned wideband filter finds application in wideband wireless communication systems.

Details

Circuit World, vol. 45 no. 3
Type: Research Article
ISSN: 0305-6120

Keywords

Article
Publication date: 1 January 1958

E.A. STOKES and G.H. VOKES

Wear can be minimised by good lubrication. We have travelled far since lubrication meant just “oil”; refining processes have improved, oils are more “oily”, and additives reduce…

Abstract

Wear can be minimised by good lubrication. We have travelled far since lubrication meant just “oil”; refining processes have improved, oils are more “oily”, and additives reduce the effects of gums, oxidation, acid formation, etc., over a useful service life. Extreme pressure agents and detergents allow operation under conditions of load and temperature not possible with straight oils. Yet all these advances count for little, unless abrasives are excluded.

Details

Industrial Lubrication and Tribology, vol. 10 no. 1
Type: Research Article
ISSN: 0036-8792

Article
Publication date: 1 February 1980

Filter media used for full‐flow filtration are made of paper, woven wire cloth and monofilament fabrics. The main characteristic of paper is a high retention rate of small…

Abstract

Filter media used for full‐flow filtration are made of paper, woven wire cloth and monofilament fabrics. The main characteristic of paper is a high retention rate of small particles. An absolute filter fineness is difficult to guarantee. Woven filter cloth can today be produced within a mesh tolerance less than 5 per cent. This makes it possible to remove excessively large particle sizes in the oil. It is possible to range lubricating oil systems into classes depending on the increasing amounts of solid matter. For each stage of contamination exists an optimal filter and filter arrangement.

Details

Industrial Lubrication and Tribology, vol. 32 no. 2
Type: Research Article
ISSN: 0036-8792

Article
Publication date: 1 March 2013

Hu Xia, Yan Fu, Junlin Zhou and Qi Xia

The purpose of this paper is to provide an intelligent spam filtering method to meet the real‐time processing requirement of the massive short message stream and reduce manual…

Abstract

Purpose

The purpose of this paper is to provide an intelligent spam filtering method to meet the real‐time processing requirement of the massive short message stream and reduce manual operation of the system.

Design/methodology/approach

An integrated framework based on a series of algorithms is proposed. The framework consists of message filtering module, log analysis module and rules handling module, and dynamically filters the short message spam, while generating the filtering rules. Experiments using Java are used to execute the proposed work.

Findings

The experiments are carried out both on the simulation model (off‐line) and on the actual plant (on‐line). All experiment data are considered in both normal and spam real short messages. The results show that use of the integrated framework leads to a comparable accuracy and meet the real‐time filtration requirement.

Originality/value

The approach in the design of the filtering system is novel. In addition, implementation of the proposed integrated framework allows the method not only to reduce the computational cost which leads to a high processing speed but also to filter spam messages with a high accuracy.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 32 no. 2
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 1 March 1997

Leszek Fracckowiak and Ryszard Strzelecki

Examines some basic aspects of hybrid filters, operating effectively when current pulsations of a non‐linear variable load occur. The operation of two hybrid filter systems, each…

Abstract

Examines some basic aspects of hybrid filters, operating effectively when current pulsations of a non‐linear variable load occur. The operation of two hybrid filter systems, each equipped with an active power filter, working as: a) a controlled additional current source, b) a controlled additional voltage source, recognized by the authors in previous publications as the most advantageous solution has been examined. For both systems, vectorial equations in α,β co‐ordinates, describing their operation, have been presented. On the basis of these equations a common frequency model of three‐phase three‐wire hybrid filters has been elaborated. This model has been used for the evaluation of the filtration efficiency of line current harmonics, taking into consideration the applied methods and algorithms to separate filtered harmonics, above all at a pulsating load current. Some conclusions from the theoretical analysis have been verified by simulation of a line loaded by converter with an output current pulsating at frequencies 10 and 20Hz.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 16 no. 1
Type: Research Article
ISSN: 0332-1649

Keywords

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