New discrete reactive power factor definition of the two-terminal network

2017 ◽  
Vol 65 (3) ◽  
pp. 369-373
Author(s):  
M. Siwczyński ◽  
M. Jaraczewski

Abstract This paper describes a new method of determining the reactive power factor. The reactive power factor herein is calculated on the basis of time samples and not] with the Fourier transform of signals, like it was done previously. The new reactive power factor calculation results from the receiver admittance-operator decomposition into the product of self-adjoint and unitary operators. This is an alternative decomposition to another one, namely into a sum of the Hermitian and skew-Hemiitian operators.

2021 ◽  
pp. 204-268
Author(s):  
Victor Lazzarini

This chapter now turns to the discussion of filters, which extend the notion of spectrum beyond signals into the processes themselves. A gentle introduction to the concept of delaying signals, aided by yet another variant of the Fourier transform, the discrete-time Fourier transform, allows the operation of filters to be dissected. Another analysis tool, in the form of the z-transform, is brought to the fore as a complex-valued version of the discrete-time Fourier transform. A study of the characteristics of filters, introducing the notion of zeros and poles, as well as finite impulse response (FIR) and infinite impulse response (IIR) forms, composes the main body of the text. This is complemented by a discussion of filter design and applications, including ideas related to time-varying filters. The chapter conclusion expands once more the definition of spectrum.


2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Mawardi Bahri ◽  
Ryuichi Ashino

A definition of the two-dimensional quaternion linear canonical transform (QLCT) is proposed. The transform is constructed by substituting the Fourier transform kernel with the quaternion Fourier transform (QFT) kernel in the definition of the classical linear canonical transform (LCT). Several useful properties of the QLCT are obtained from the properties of the QLCT kernel. Based on the convolutions and correlations of the LCT and QFT, convolution and correlation theorems associated with the QLCT are studied. An uncertainty principle for the QLCT is established. It is shown that the localization of a quaternion-valued function and the localization of the QLCT are inversely proportional and that only modulated and shifted two-dimensional Gaussian functions minimize the uncertainty.


2021 ◽  
pp. 106-155
Author(s):  
Victor Lazzarini

This chapter is dedicated to exploring a form of the Fourier transform that can be applied to digital waveforms, the discrete Fourier transform (DFT). The theory is introduced and discussed as a modification to the continuous-time transform, alongside the concept of windowing in the time domain. The fast Fourier transform is explored as an efficient algorithm for the computation of the DFT. The operation of discrete-time convolution is presented as a straight application of the DFT in musical signal processing. The chapter closes with a detailed look at time-varying convolution, which extends the principles developed earlier. The conclusion expands the definition of spectrum once more.


2014 ◽  
Vol 989-994 ◽  
pp. 3993-3996 ◽  
Author(s):  
Yan Jun Wu ◽  
Gang Fu ◽  
Fei Liu

The fractional Fourier transform (FRFT) is a generalization of the Fourier transform. The article first introduces the definition of FRFT transformation; then analyzed FRFT Chirp signal based on this humble proposed restoration Chirp signal in a noisy background in two ways: one is based on parameter estimation, and the other is based on the scores Fourier domain filtering to achieve signal reconstruction; Finally, simulation verify the feasibility of the above analysis.


2021 ◽  
Vol 8 (3) ◽  
pp. 59-64
Author(s):  
Sulistyowati Sulistyowati ◽  
Muhammad Fahmi Hakim ◽  
Heri Sungkowo ◽  
Ikfi Asmaul Husna

Power factor is the ratio between active power (W) and apparent power (VA). In an electrical installation, the quality of electric power can be said to be good if the value of the power factor is above a predetermined standard of 0.85 according to the Minister (ESDM) Number 30 of 2012 [1]. From the research that has been done at the Blitar Square Shopping Center, it was found that the power factor value is still below the standard with an average value of 0.711. With the low power factor value, this shopping center gets a penalty from PT. PLN (Persero) due to the use of reactive power. Therefore, it is necessary to make efforts to improve the power factor by installing a capacitor bank. The installation of this capacitor bank is expected to be able to increase the power factor value with a power factor target of 0.98 and reduce the charge for reactive power usage penalties. The calculation results show that global compensation requires 12 capacitor banks with a rating of 10.4 kVAR, while sectoral compensation on the chiller load panel requires 7 capacitor banks with a rating of 10.4 kVAR and the foodmart load panel requires a capacitor bank with a rating of 10. 4 kVAR is 6 pieces. In simulating the installation of a capacitor bank using the ETAP application, it is known that the installation of a capacitor bank can increase the power factor value. In addition, the installation of a capacitor bank also results in an increase in the voltage value in the system, this voltage increase is still below the permissible standard of ± 5%. The simulation of installing a capacitor bank on global compensation can improve the power factor value from 72.99% to 96.97%, with a voltage increase of 0.479% from the initial value of 397 V to 398.9 V, and a decrease in the current value of 24.645% from the initial value. 330.7 A to 249.2 A. While the simulation of installing a capacitor bank in sectoral compensation can improve the power factor value from 72.99% to 93.57%, with a voltage increase of 0.401% from the initial value of 397 V to 398.6 V , and a decrease in the value of current by 21.593% from the initial value of 330.7 A to 258.1 A. The cost of installing a capacitor bank in global compensation was Rp. 189,897,500 while the sectoral compensation is Rp. 211.305.600. It can be concluded that the installation of a capacitor bank using the global compensation method is more effective.


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