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The aim of this paper is to study the dynamics of a permanent magnet direct current (PMDC) brushed motor while two crucial space-domain effects, namely, slotting effect and commutation phenomenon are taken into account. Semi-analytical dynamic time-domain PMDC brushed motor model inclusive of these space-domain effects is used to analyze and investigate the dynamics. Pulse width modulation operated discontinuous current PMDC brushed motor drive with steady duty cycle is employed to acquire the bifurcation patterns. The chaotic nature due to slotting effect and commutation is identified from the bifurcation patterns and reported. It also has to be admired that such nonlinear dynamical behavior with the same set of parameters at similar operating condition has not been observed when a conventional PMDC brushed motor dynamic model is considered. These space-domain effects, namely, slotting effect and commutation also have a prominent impact to make some time-domain states of a PMDC brushed motor drive chaotic. The role of slotting effect and commutation phenomenon to analyze the chaos over time-domain state variables of the PMDC brushed motor drive is investigated and validated experimentally in this paper. [ABSTRACT FROM PUBLISHER]

Thermal comfort standards are required to provide comfortable indoor condition which has a positive effect on the occupant. However, the Predicted Mean Vote – Percentage People Dissatisfied (PMV-PPD) model which is used to determine the indoor comfort in most of the international standards fails often, especially in naturally ventilated buildings. Several field studies were conducted elsewhere to determine the comfort condition, but very few are reported for the cold and cloudy type of climate and in hilly region. In this paper, the results of field studies conducted in 10 buildings of different types located in varying elevation are presented. A total of 2608 responses of thermal comfort were collected from 436 subjects between January and December 2015. The mean clothing insulation of the subjects were found to increase with the increase in the elevation of the location and this difference was statistically significant, t  = −94.05 (df = 2607, p  < 0.001). The yearly mean clothing insulation in S0135 was 0.640 clo, K1420 was 0.722 clo, M1640 was 0.947 clo, S1950 was 1.055 clo and T2565 was 0.907 clo, respectively. Whereas, the mean comfort temperature decreased with the elevation of the location and this difference was also statistically significant, t  = −92.34 (df = 2607, p  < 0.001). The yearly mean comfort temperature for the location S0135 was 28.37   °C, K1420 was 20.59   °C, M 1640 was 20.07   °C, S1950 was 19.72   °C and T2565 was 17.35   °C, respectively, where the digits in the locations (i.e. 0135 in S0135, 1420 in K1420, 1640 in M1640, 1950 in S1950 and 2565 in T2565) represents the elevation of the location under study in meters above mean sea level. A relation of the indoor comfort temperature with the outdoor environmental conditions and with the elevation of the location under study is obtained. [ABSTRACT FROM AUTHOR]

This paper proposes a novel fuzzified mechanical sensorless speed estimation technique for permanent magnet direct current (PMDC) brushed motor operated with pulse width modulation (PWM) based terminal voltage. For replacement of conventional mechanical speed sensors, few mechanical sensorless speed estimation techniques have been reported recently in the field of PMDC brushed motor. In this paper, a novel technique is applied over a recently reported semianalytical dynamic time-domain PMDC brushed motor model incorporating space-domain effects, namely slotting effect and commutation phenomenon to simulate the proposed estimation process. Ripple and back electromotive force based standalone estimation approaches are hybridized in order to eliminate uncertainties in all regions of estimation. In this paper, a discrete fuzzified hybrid speed estimation model has been proposed with adequate dynamic simulation responses. Further the proposed discrete speed estimation model has been applied experimentally over a PWM-driven 24-V, 12-teeth, 100-W PMDC brushed motor and various dynamic real-time responses have been compared with conventionally captured speed samples to validate the proposed model. [ABSTRACT FROM PUBLISHER]