Wyniki wyszukiwania - BazTech

1

Quick-response protection system against electric shock in distributed generation systems

Shkrabets Fedir, Plaksin Sergej, Ostapchuk Oleksandr, Kuznetsov Valeriy, Tymchenko Irina, Muntian Antonina

Diagnostyka

|

2021

|

Vol. 22, No. 3

59--65

EN

The peculiarities of the operation of distributed generation systems lead to a change in the requirements for the reliability and safety of the power distribution systems in which they are integrated. To meet the increased requirements, continuous monitoring of the insulation parameters (active resistance and capacitance to ground) is often used with operating artificial non-industrial frequency operational signals introduced into the network. In the case of a sudden touch, such a system is not effective, since the response time of the protection device, which consists of the signal processing time and the operating of the actuator, is crucially important. For the used operational signals with a frequency of 100 and 200 Hz, the processing time using the Fourier transform is 10 ms for 100 Hz and 5 ms for 200 Hz. Considering that the response time of the fastest actuators (based on vacuum switches) is from 3 to 7 ms, this is a rather significant period of time. To develop an effective resolver system, the capabilities of the Matlab environment were used to determine the most successful design of an analog prototype (Butterworth, Bessel, Chebyshev and Cauer of 6th order) for an operational signal with a frequency of 200 Hz. As a result, the processing time was established, which varies widely from 3.5 to 19 ms. Taking into account the known indicators, namely the frequency and number of operational signals, a signal processing system was developed using the vector-matrix analysis method. As a result of modeling the processing characteristics of functional signals (at a sampling rate of 1 kHz), the system quick-response was 3 ms, with the possibility of its further decrease as its productiveness increases.

2

Prototype constructions of magnetorheological dampers with energy harvesting capability

Sapiński B., Szydło Z.

Czasopismo Techniczne. Mechanika

|

2014

|

R. 111, z. 2-M

45--52

EN

The paper briefly summarises the design structure of a prototype linear and rotary magnetorheological (MR) damper with energy recovery capability, engineered by the authors, and provides selected characteristics of those devices based on laboratory testing.

PL

W artykule opisano budowę zaprojektowanych i wykonanych przez autorów prototypowych konstrukcji liniowego i obrotowego tłumika magnetoreologicznego (MR) z odzyskiem energii. Przedstawiono również wybrane charakterystyki tych urządzeń wyznaczone na podstawie badań laboratoryjnych.

3

Signal processing system in cavity enhanced spectroscopy

Wojtas J., Bielecki Z.

Opto-Electronics Review

|

2008

|

Vol. 16, No. 4

420-427

EN

The paper presents a signal processing system used for nitrogen dioxide detection employing cavity enhanced absorption spectroscopy. In this system, the absorbing gas concentration is determined by the measurement of a decay time of a light pulse trapped in a cavity. The setup includes a resonance optical cavity, which was equipped with spherical and high reflectance mirrors, the pulsed diode laser (414 nm) and electronic signal processing system. In order to ensure registration of low-level signals and accurate decay time measurements, special preamplifier and digital signal processing circuit were developed. Theoretical analyses of main parameters of optical cavity and signal processing system were presented and especially signal-to-noise ratio was taken into consideration. Furthermore, investigation of S/N signal processing system and influence of preamplifier feedback resistance on the useful signal distortion were described. The aim of the experiment was to study potential application of cavity enhanced absorption spectroscopy for construction of fully optoelectronic NO₂ sensor which could replace, e.g., commonly used chemical detectors. Thanks to the developed signal processing system, detection limit of NO₂ sensor reaches the value of 0.2 ppb (absorption coefficient equivalent = 2.8 x 10 ⁻⁹ cm⁻¹ ).