Analysis of oscillatory tanks of resonant inverner in power source mode

Проведено порівняльний аналіз трьох основних послідовно-паралельних коливальних контурів резонансного інвертора в режимі джерела потужності: 1) контур, в якому навантаження під’єднано паралельно до першого конденсатора через другий конденсатор; 2) контур, в якому навантаження під’єднано паралельно до першого конденсатора, а через другий конденсатор – до дроселя контура; 3) контур, який за топологією відповідає першому або другому із вказаних вище контурів, але другий конденсатор якого, як роздільний, має безмежну ємність. Встановлено залежності похибки підтримання потужності від діапазону опору навантаження. Показано, що контури мають однакову здатність щодо параметричного підтримання потужності, але кращим серед розглянутих контурів є перший контур, який забезпечує найвищий коефіцієнт корисної дії. Запропоновано методику розрахунку параметрів контурів на мінімальну похибку підтримання потужності при заданому діапазоні зміни опору навантаження.The problems of power maintenance in variable load by means of voltage resonant inverters with various serial-parallel resonant tanks by the way of corresponding selection of its parameters is considered. A comparative analysis of three basic series-parallel oscillatory tanks of resonant inverter is accomplished. The inverter load is connected in parallel to the capacitance section of oscillatory tank and in series with inductance to half-bridge switching section. These resonant tanks are the next: 1) the tank with load connected in parallel to the first capacitor through the second capacitor;2) the tank with load connected in parallel to the first capacitor directly and through the second capacitor to the tank inductance; 3) the tank which topology corresponds to both above appointed tanks but differs from them by infinity capacitance of second capacitor. Analysis consists in establishing of analytical expressions which describe the connections between minimum and maximum power in variable load and corresponding values of oscillatory tank quality factor. On the basis of these expressions the equations for power relative deviations and parameters of resonant inverter are obtained. The dependency of power maintenance error vs. load resistance range is established. It is appointed that in case of equality of power for minimum and maximum loads, the maximum power deviation from given power in load range will reach its minimum value. It is showed that all considered tanks have practically equal possibilities in power maintenance but the first tank has highest efficiency and it is a best choice among these tanks. For all tanks the next assertion is established: the square of the quality factor which corresponds to the maximum load power level is equal to the multiplication of two quality factors which correspond to some less load power level. To ensure a small switching loss in resonant inverter, the parameters of oscillatory tanks are calculated taking into account the zero-voltage switching condition. Therefore the inverter resonant frequency which reaches its maximum value at maximum load resistance mustn’t exceeds the inverter switching frequency. The design sequence for calculation of each oscillatory tank parameters is proposed. This design sequence is based on a numerical solution of two equations set relative to tank parameters and parameter of inverter dc voltage. Calculated inductance, first and second capacitances, dc voltage of the inverter and its switching frequency ensure minimum value of maximum power deviation in given load resistance range. Calculated dependence of maximum deviation of relative power as a function of ratio of a maximum load resistance to its minimum value and the dependence of load power vs. load resistance verify the obtained results. It is shown that resonant inverter designed as open loop circuit is able to achieve the power deviations about of 6% of its nominal value for a double change in load resistance

Forming of characteristic curve of high pressure sodium lamp by electronic ballast

Проаналізовано чотири варіанти формування характеристичної кривої натрієвої лампи високого тиску високочастотним електронним пускорегулювальним апаратом упродовж усього терміну її служби. Варіанти відрізняються розташуванням та значеннями максимальних додатних та від’ємних відхилень потужності відносно номінальної потужності лампи. Формування таких кривих базується на властивостях коливального контуру резонансного інвертора напруги. Запропоновано варіант характеристичної кривої, використання якої зменшить інтенсивність деградації лампи та дасть змогу забезпечити регламентований термін її служби.The problems of reducing the influence of high pressure sodium (HPS) lamp resistance variations during the lamp aging on lamp power taking advantage of electronic ballast with open-loop structure is considered. The four variants of characteristic curves forming as a «power-voltage» dependences for HPS lamp with electronic ballast are analyzed. The curves differ from each other in locations and values of positive and negative power deviations from the nominal lamp power. These characteristic curves are the following: 1) the curve with start lamp power equal to a nominal lamp power and specified power positive deviation from the nominal power; 2) the curve with start and finish powers, which are equal to the nominal lamp power; 3) the curve with start power negative deviation and equal to its maximum power positive deviation from the nominal power and finish power equal to the nominal lamp power; 4) the curve with equal start and finish power negative deviations and equal to the maximum power positive deviation from the nominal power. The forming of such curves is based on the properties of parametric power maintenance by the resonant voltage inverter operating at frequency a little higher than its resonant frequency. The resonant inverter in the power source mode as an output stage of electronic ballast is analyzed. In this mode the resonant inverter maintains the power delivered to the lamp in the limits of «power-voltage» admissible values. This analysis deals with the determination of analytical expressions, which describe the interrelations between start, nominal, maximum, finish lamp powers and corresponding values of resonant tank quality factor. On the basis of these expressions the equations for power relative deviation and parameters of resonant inverter are obtained. As the result of analysis it was found that the second characteristic curve provides the minimum lamp power positive deviation from its nominal power. The third characteristic curve decreases the lamp degradation intensity and makes possible to increase the lamp lifetime. The fourth characteristic curve provides with equal minimum power negative and positive deviations from the nominal power and can be used in some applications of resonant inverter as a power source

Energy-effective electrotechnical systems of operation and control for multiple fluorescent lamps

Обгрунтовано метод побудови енергоефективних ресурсоекономних електротехнічних систем високочастотного живлення та керування для багатолампових люмінесцентних світильників. Метод базується на поєднанні дискретного регулювання потужності шляхом комутації окремих ламп та наступного неперервного регулювання потужності на міжкомутаційних інтервалах потужності. За рахунок нової структури системи зекономлено N силових ключів та їх драйверів, де N – кількість ламп світильника.The method of design of energy- and resourse-efficient electrical systems for high-frequency operation of multiple fluorescent lamps lighting installations with their continous-discrete power control is presented in this paper. The method is based on a combination of discrete power control by changing the amount of on-off lamps and further continuous power control on the intercommutation intervals. If the installation running power can be provided by the number of lamps which is smaller than N (N is a lamp number in the installation), the redundant lamps are switched off. Thus the unproductive power consumption for redundant lamps electrode heating is eliminated and the system efficiency is increased. The total power control range is divided into N power intervals. Within each interval the power control is continuous, and the intervals change is discrete by the way of fluorescent lamps tuning on-off. The extention of the first ( lowest) interval, which is enabled only for one lamp, is equal to a half of effective power of fluorescent lamp, which is indicated as the nominal lamp power minus power heating of its electrodes. The remaining (N-1) intervals, which is enabled for more than one lamp, have the same extentions, which are equal to the effective power of one lamp. The control range of each lamp, regardless of the number of lamps in installation, is equal to a half of lamp effective power, which ensures the high quality control. Hysteresis is introduced to ensure the lamps accurate tuning on-off in commutation regions. The analytical expressions for lighting installation power and its efficiency as a functions of running power and number of turn-on lamps are established. Comparison of continous and continous-discrete power control testifies the increasing of system efficiency up to 1,8 times in the case of use of proposed continous-discrete control in 4-lamps installation. To achieve high quality of electric energy and system component reduction the single-stage approach to the system structure design is implemented by combining the stage of power factor corrector and the N stages of high-frequency half-bridge resonance inverters. One inverter is a master inverter and others are slave inverters (semiinverters). Each semiinverter has only one own active switch and utilizes the active switch which is common to all semiinverters and master inverter. Thus N active power switches and their drivers are saved due to such system structure

Electronic ballast for high pressure sodium lamp as a power source

Проаналізовано резонансний інвертор напруги як вихідний каскад електронного пускорегулювального апарата (ЕПРА) для живлення натрієвих ламп високого тиску (НЛВТ). Розглянуто підтримання потужності НЛВТ в області допустимих значень за допомогою ЕПРА, побудованого за розімкненою структурою, впродовж усього терміну її експлуатації.The voltage resonant inverter is an output stage of electronic ballast for high-pressure sodium lamps operation is analyzed. The maintenance of power of high pressure sodium lamp in operation area during the lamp aging by electronic ballast with open-loop structure is considered

Power factor corrector on the basis of modified buck converter

Застосовано модифікований знижувальний перетворювач в коректорі коефіцієнта потужності, що дало змогупокращити якість електроенергії та забезпечило ефективність, кращу ніж при використанні традиційного знижувального перетворювача напруги.Applied a modified downward converter power factor corrector, which helped improve the quality of electricity and provide performance better than using traditional of trigger voltage converter

Electronic ballasts with eliminating of acoustic resonance in high pressure discharge lamps

Розглянуто однокаскадні електронні пускорегулювальні апарати для живлення розрядних ламп високого тиску низькочастотними прямокутними імпульсами струму, які усувають акустичний резонанс та забезпечують високий коефіцієнт потужності.A single-stage low-frequency square-wave electronic ballasts for high-pressure discharge lamps operation with acoustic resonance eliminating and high power factor are considered

The operator of the transformation of the scale in the tasks of modeling and analysis of cycle signals

У роботі дано означення ізоморфних відносно порядку та значень циклічних функціональних відношень, досліджено дію оператора перетворення шкали на циклічні детерміновані та випадкові функції, а також досліджено дві його форми – оператор динамічного масштабування та оператор динамічного зсуву. Записано аналітичні співвідношення між функціями ритму циклічних функціональних відношень, що пов’язані через закони динамічного зсуву та масштабування.The definition of the isomorphous cycle functional relations in sense of order and the meanings is given in the papers. The action of the operator of scale transformation on the cycle determined and random functions is studied. Two its forms – the dynamical scaling operator and dynamical displacement operator are studied also. The analytical dependences between the functions of the rhythm of the cycle functional relations by the laws of the dynamical displacement and scaling are written in this work

Agrarian sector of Ukraine in the global world

Characterization of Ukraine as a “bread basket” for the world have been done. In our study using database of State statistical service of Ukraine and FAO we showed changes of harvest areas and volume of production of cereals and protein-oil crops during this century. As a result we showed that Ukraine has increased its share in the world gross harvest of cereals up to 2.17% and protein-oil crops up to 3.4%. Each economically active agrarian produced 22.6 tons of cereals and 3.5 tons of protein-oil crops, increasing this index in comparing to 2000 in 11 and 12 times accordingly. Ukraine has a great potential for increasing crop production because of use genetic potential of varieties only for 60–70%. Here are shown changes in cattle, poultry breeding and dynamic of livestock production. We also included export of cereals and livestock production