Проектування вимірювача індуктивності
| dc.contributor.advisor | Витязь, Олег Олексійович | |
| dc.contributor.author | Дакал, Богдан Олександрович | |
| dc.date.accessioned | 2023-08-29T12:55:33Z | |
| dc.date.available | 2023-08-29T12:55:33Z | |
| dc.date.issued | 2021 | |
| dc.description.abstract | Об’єктом дослідження є новий метод вимірювання індуктивності двополюсників. Предмет дослідження – схемна реалізація та метрологічні характеристики методу вимірювання невідомої індуктивності. Метою роботи є розробка методу вимірювання індуктивності, який оснований на отриманні реакції RL-ланки на експоненціальний сигнал, та його схемна реалізація на базі аналого-цифрових пристроїв. У першому розділі детально розглянуто визначення поняття індуктивності та повного опору, що з себе представляє котушка індуктивності, існуючі методи вимірювання індуктивності, похибки вимірювань, та основні шляхи автоматичної реєстрації та математичної обробки виміряного сигналу. У другому розділі розроблено метод вимірювання невідомої індуктивності за реакцією RL-інтегратора на експоненціальний сигнал при нульових початкових умовах. Розроблено схему вимірювання індуктивності з функцією автоматичної реєстрації та математичної обробки результатів на мікроконтролері. Розраховано операторну схемну функцію розробленої схеми та визначено перехідну характеристику системи. У третьому розділі була проведена симуляція вимірювання індуктивності в середовищах EveryCircuit і Matlab та проведена оцінка результатів вимірювання, отриманих від двох симуляторів. Досліджено вплив періоду дискретизації реєстратора сигналу та допусків елементів схеми на похибку вимірювання (обчислення) індуктивності. | uk |
| dc.description.abstractother | The object of research is to find a new method of measuring the inductance of inductors. The subject of the work is the influence of systematic errors of the developed measuring scheme on the measurement error of unknown inductance. The aim of the work is to develop a new method of measuring inductance, which is based on obtaining the reaction of the RL-link, which contains an inductor of unknown denomination, to an exponential signal. Also the purpose of work is automation of registration of a signal of the developed scheme on the basis of digital devices for the further calculation of value of inductance. The need to measure the value of the inductor arises at the final stage of production: it is necessary to verify whether the actual value of the inductance is acceptable. The inductance measurement is performed to obtain the result of measuring the inductance of the coil with acceptable accuracy, which can then be used in various electronic devices and affect their functionality. The first section discusses in detail the definition of inductance and impedance. Inductance is a physical quantity that characterizes the ability of a bipolar to accumulate energy in a magnetic field when current flows through the bipolar. Inductors are used in electrical circuits of medium and high power rectifiers based on inductive smoothing filter, pulse regulators using inductive L- or inductive-capacitive LC-filters, stand-alone inverters, frequency converters. Determined which components make up the equivalent circuit of the inductor. Familiarized with the main parameters of the coil: the nominal value of the inductor, resistance to losses, the maximum current of the coil, its own capacity, the allowable deviation of the inductor, the nominal quality factor, the operating temperature range. The dependence of the inductance value on the parameters of the equivalent coil circuit and the dependence of the impedance on the reactive and active resistance of the inductor are analyzed. The existing methods of inductance measurement are considered: ammeter and voltmeter method, resonance method, bridge method. Measurements by ammeter and wattmeter, using Ohm's laws for electrical circuits, is to measure the current in the coil and the voltage at its terminals. To calculate the unknown inductance, it is necessary to know the active resistance of the coil and the frequency of the current, and the shape of the voltage curve must be sinusoidal. Of the three methods considered, the ammeter and voltmeter methods are the easiest to measure, but the measurement accuracy may not be sufficient in some cases as a result of the total error of the readings of the ammeter and voltmeter and the methodological error caused by neglecting the active resistance of the coil. Resonance method is a method that is based on the appearance of the phenomenon of electrical resonance in an oscillating LC circuit. To determine the resonance, measure the voltage across the resistor with a voltmeter, changing either the frequency of the generator or the value of the capacitor. At the maximum value of the voltage in the circuit there is a resonance of voltages. At resonance, we can find the desired value of the unknown inductance, knowing the frequency of the generator and the capacitance of the electrical circuit. The measurement accuracy of this method depends on the tolerances of the circuit elements, the accuracy of the calibration scale, the calibration of the device and the accuracy of reading the readings. The bridge method is the most accurate of the three main methods, but it has a large number of radio elements. Measurement by this method is a direct comparison of the impedances of the measured value with the sample resistance. There are several factors that affect the accuracy of bridge measurements: signal frequency, zero-indicator sensitivity, resistance of connecting contacts and wires, stability of the sample impedances used in the arms of the bridge. In addition, the influence of systematic errors of measuring instruments that occur during measurements has been studied. The main factors influencing the measurement result are considered: precision, resolution, range and bandwidth, sensitivity, accuracy, noise. Accuracy shows how close the measured value is to the true value of the measured value. The quantitative measure of measurement accuracy is the absolute error and the relative error. Precision shows how close to each other the measurement results obtained on different instruments with different graduated scales. The range of the device is determined by the minimum and maximum values of the input signal. The range is selected so that the reading of the device is large enough and meets the requirements of precision. The bandwidth of a measuring device is the difference between the minimum and maximum frequencies for which it is intended. The resolution of the instrument is the smallest change (delta) of the measured value to which the instrument will respond. The sensitivity of the measuring device is defined as the ratio of the output signal or reading of the device to the input signal or the measured value. Mastered the algorithm for recording analog continuous signals due to automatic registration and mathematical processing of measurement information. In the second section a new method of measuring inductance is developed. To do this, the reaction of the integrating link to the exponential signal was studied. Integrating RL links are used in electronics as a low-pass filter, ie when it is necessary for the circuit to pass low frequencies and cut off high frequencies. The main circuit of the RL integrator is a resistor that is connected in series with the inductance and the signal source. To simplify the calculations, the paper uses the operator method of analysis of transients. This method is based on the Laplace transform and belongs to the class of symbolic methods, the essence of which is the analysis of the electric circuit in the field of functions of a complex variable. The function-reaction of the integrator to the exponential signal is obtained and on its basis the graph of the dependence of the voltage at the output of the RL-link on time is constructed. To reduce the measurement error, it is necessary to increase the rate of change of the output signal within the time where we observe the peak voltage. To do this, use the derivative of the output signal over time. Based on the obtained derivative, a graph of the dependence of the differentiating voltage at the output on time is constructed. This was done to find the time tmax at the peak value of the voltage at the output of the RL-link. To accurately determine this value, it was proposed to differentiate the signal at the output of the integrator. The electric schematic diagram of the inductance meter with the function of automatic registration and mathematical processing of the results on the microcontroller is developed and on its basis the transmission coefficient of each stage is determined by the operator method. The circuit function of the inductance meter was obtained by multiplying the calculated transmission factor of each stage of the circuit. Each stage of the electrical circuit, the function of which is performed by the stage, is considered and the transmission coefficient of the link is calculated. The circuit function of the developed circuit and the transient characteristic of the system by the operator method when applying a single step signal to the input are calculated. By switching from the operator view to the original image of the reaction, we obtained the voltage versus time when applying to the input of the circuit of a single step signal. In the third section, the measurement scheme was analyzed using two simulators EveryCircuit and Matlab. Graphs of the dependence of the output voltage on the time of each stage are derived. Based on the obtained dependences, the functionality of each simulator was evaluated and the obtained results were compared. Metrological indicators of a new method of inductance measurement were investigated and calculated: calculation of measurement error depending on the sampling period of the signal recorder; the effect of the error of measuring the inductance from the tolerance of the elements used in the measurement scheme. The errors of inductance measurement at different periods of time discreteness and at inductance measurement with different degrees of nominal values are calculated. Measurement errors at different values of tolerances of elements of the electric circuit are calculated. It is investigated which elements affect the output signal of the whole circuit, and which do not. For elements that affect the measurement result, the total measurement error at an element tolerance of 1% was investigated. The list of elements of the electric scheme of measurement is made. | uk |
| dc.format.extent | 113 с. | uk |
| dc.identifier.citation | Дакал, Б. О. Проектування вимірювача індуктивності : дипломна робота … бакалавра : 153 Мікро- та наносистемна техніка / Дакал Богдан Олександрович. – Київ, 2021. – 113 с. | uk |
| dc.identifier.uri | https://ela.kpi.ua/handle/123456789/59621 | |
| dc.language.iso | uk | uk |
| dc.publisher | КПІ ім. Ігоря Сікорського | uk |
| dc.publisher.place | Київ | uk |
| dc.subject | вимірювання індуктивності | uk |
| dc.subject | метрологічні показники | uk |
| dc.title | Проектування вимірювача індуктивності | uk |
| dc.type | Bachelor Thesis | uk |
Файли
Контейнер файлів
1 - 1 з 1
Вантажиться...
- Назва:
- Dakal_bakalavr.pdf
- Розмір:
- 2.75 MB
- Формат:
- Adobe Portable Document Format
- Опис:
Ліцензійна угода
1 - 1 з 1
Ескіз недоступний
- Назва:
- license.txt
- Розмір:
- 9.1 KB
- Формат:
- Item-specific license agreed upon to submission
- Опис: