Optimal design of digital IIR filters by model-fitting frequency response data

1995 ◽  
Vol 42 (11) ◽  
pp. 702-710 ◽  
Author(s):  
A.K. Shaw
Keyword(s):  
Optimal Design ◽  
Frequency Response ◽  
Model Fitting ◽  
Iir Filters ◽  
Response Data

Estimation of Transformer Winding Capacitances through Frequency Response Analysis – An Experimental Investigation

2013 ◽  
Vol 14 (6) ◽  
pp. 549-559 ◽  
Author(s):  
Krupa Shah ◽  
K. Ragavan
Keyword(s):  
Frequency Response ◽  
Wide Frequency Range ◽  
Response Analysis ◽  
Voltage Distribution ◽  
Response Data ◽  
Non Invasive ◽  
Transformer Winding ◽  
Invasive Method ◽  
Ladder Network ◽  
Good Agreement

Abstract This article focuses on developing a non-invasive method for determining capacitances using frequency response data. The proposed methodology involves acquiring driving-point impedance of the winding under consideration over wide frequency range. With certain terminal conditions and using the terminal impedance measured at specific frequencies, input and shunt capacitances are determined. For the purpose of estimating series capacitance of the winding, an algorithm is proposed. To demonstrate the capability of the method, initially model coils that have provisions for connecting external capacitances are considered. Then, it is found that the estimated values of capacitances are nearly same as those of connected capacitances. The method is, then, extended to transformer winding, and a capacitive ladder network is constructed. To assess the accuracy of estimation, capacitive voltage distribution is utilized. That is, the voltage distribution in the winding is compared with that of synthesized circuit. A good agreement between those data reveals that the estimated capacitance values are accurate.

Mechanical Contact Frequency Response Measurements

2000 ◽  
Vol 122 (4) ◽  
pp. 828-833 ◽  
Author(s):  
S. S. Kupchenko ◽  
D. P. Hess
Keyword(s):  
Frequency Response ◽  
Phase Lag ◽  
Lithium Grease ◽  
Mineral Oils ◽  
Vibration Data ◽  
Response Data ◽  
Lubricated Contacts ◽  
Wide Range ◽  
Contact Frequency ◽  
Dry Conditions

This paper presents friction frequency response measurements taken from a planar steel contact subjected to controlled random broadband normal vibration. Data are included from both dry and various lubricated contact conditions under different vibration input levels and different sliding velocities. Frequency response data for dry contacts are found to have nearly steady magnitude and negligible phase lag over a relatively wide range of frequencies. This suggests a coefficient of friction, independent of frequency but dependent on levels of normal acceleration and sliding velocity, may adequately define the dry contact frequency response. The frequency response data for lubricated contacts are mixed. For example, with MoS2 grease the frequency response may adequately be defined by a constant, as with dry conditions. However, frequency response data for contacts with pure mineral oils, mineral oils with additives, and lithium grease are found to be dependent on frequency. [S0742-4787(11)00101-9]

Sign in / Sign up

Export Citation Format

Share Document