Електромеханічна система сервопреса на базі електричної машини з поперечним полем

Abstract

Дисертація на здобуття наукового ступеня кандидата технічних наук за спеціальністю 05.09.03 «Електротехнічні комплекси та системи». – Державний вищий навчальний заклад «Національний гірничий університет», Дніпро, 2017. У дисертаційній роботі вирішено наукову задачу обґрунтування науково- технічних рішень і визначення закономірностей, що забезпечують створення, високомоментного електропривода з високими енергетичними, динамічними, регулювальними характеристиками та мінімізацію коливань його моменту. Було визначено, що найперспективнішим для застосування в сервопресі є електропривод на базі електричної машини з поперечним полем з циліндричним ротором, одним повітряним проміжком та з поверхневими постійними магнітами. Користуючись запропонованим методом розрахунку був отриманий електромеханічний перетворювач з втратами, які приблизно у 4 рази менші ніж у аналога. В роботі автором запропонована система керування електроприводом сервопреса з контуром швидкості, налаштованим на модульний оптимум та з компенсатором статичного моменту навантаження з модифікованим законом компенсації зубцевого моменту, що дозволило підвищити динаміку роботи ЕМС сервопреса, набагато краще компенсувати коливання моменту у всьому діапазоні робочих швидкостей ніж класичний метод. Все це призвело до підвищення виробничої потужності, енергоефективності промислового сервопреса та якості обробки металу. Були проведені експериментальні дослідження, які підтвердили відповідність результатів розрахунку результатам виміру.

Диссертация на соискание ученой степени кандидата технических наук по специальности 05.09.03 «Электротехнические комплексы и системы». – Государственное высшее учебное заведение «Национальный горный университет», Днепр, 2017. В диссертационной работе решена научная задача обоснования научно- технических решений и определения закономерностей, которые обеспечивают создание высокомоментного электропривода с высокими энергетическими, динамическими, регулировочными характеристиками и минимизацию колебаний его момента. Было определено, что самым перспективным для применения в сервопрессе является электропривод на базе электрической машины с поперечным полем с цилиндрическим ротором, одним воздушным зазором и с поверхностно наклеенными магнитами. Пользуясь предложенным в работе методом расчета, был получен электромеханический преобразователь с меньшими, по сравнению с аналогом, в 4 раза потерями. В работе автором предложена система управления электроприводом сервопресса с контуром скорости, настроенным на модульный оптимум и с компенсатором статического момента нагрузки с модифицированным законом компенсации зубцового момента, что позволило повысить динамику работы ЭМС сервопресса, намного лучше компенсировать колебания момента во всем диапазоне рабочих скоростей, чем классический метод. В результате была получена повышенная производственная мощность, энергоэффективность промышленного пресса и качества обработки металла. Были проведены экспериментальные исследования, которые подтвердили соответствие результатов расчета результатам измерения.

Dissertation for a Candidate of technical sciences degree (PhD) in specialty 05.09.03 "Electrotechnical complexes and systems". - State Higher Education Institution "National Mining University", Dnipro, 2017. 18 The dissertation faced the scientific challenge of creating a compact high-torque electric drive of servopress with high energetic, dynamic and control characteristics, and with minimal ripple torque in a wide speed control range of adjustment of its speed. The work deals with the existing types of presses and their drives, which are classified in three main modes: hammer mode, pressing mode with constant power and mode with fixed trace of press slide. Unlike typical presses, in which the implementation of each operation mode is performed by specialized press for its construction, electromechanical system (EMS) of servopress based on modern non- reductor high- torque electric drive allows to implementate all major modes. Considering the analysis of modes features of servopresses performance and the latest developments of electric machines, it is determined that the most promising for use in servopress is electric drive, which is based on electric machine with transverse field (TFM) with a cylindrical rotor, one air gap and surface permanent magnets, particularly, due to a better efficiency than in other machines.It was compared the developed electric machine with a transverse field to the typical synchronous machine with excitation from permanent magnets with the same mechanical parameters. This comparative analysis showed that the developed TFM has approximately 4 times smaller losses than the analogue. Having reliance on an analysis of existing control systems and by reference to the requirements of the electromechanical system of press, a vector control in dq- coordinates of the rotor position sensor has been selected for a basic system. Electric machine with a transverse field is a type of permanent-magnet synchronous motors (PMSM) because its mathematical model is identical with the PMSM model. It was found that the system with proportional speed controller, unlike the system with proportional plus reset speed controller, provides the necessary speed and quality of the transition process working in the hammer mode, that has a higher operational speed than the system with proportional plus reset speed controller by much smaller transient time and overshoot values. The disadvantage of using the P-controller of speed is the static error during surge load. In the paper it was proposed to solve this problem by adding the error value to the signal of setting the speed controller. For this it was created a static error compensator that includes an observer of the load torque. It is possible to fully compensate the error. The research has been carried out to find the presence of pulsations and their nature in the developed electric machine with a transverse field using the special software package for determining electromagnetic fields. Torque deviations have a negative effect on the accuracy of control, lead to the occurrence of acoustic rumble and vibration, which in many cases is unacceptable when using gearless electric drive. It was found that the developed TFM has large ripples, which are caused by the presence of cogging torque. Dependence function of cogging torque on the rotor rotation angle is found, and the frequency analysis of this function was held, what allowed adding this function in Fourier series. The amplitude of the torque deviation is 19 about 4% of the nominal value, while limitations according to European standards are 2%. To prevent these torque deviations it has been proposed scientific and technological solution, which is a further development of the known methods. Compensation for the modified method, as in the case of classical compensation, occurs by a current signal, which is attached to the main tasks for current, has the same harmonic structure and is in opposite phase to cogging torque. The difference of the proposed modified method is the consideration of the frequency characteristics of the circuit current, module and phase (argument). The equation of compensating current taking into account the frequency characteristics of the circuit current was generated. Simulations of designed machine with both methods of compensation at rated speed and at a speed that is close to zero (one rotation per minute) were conducted to confirm the modified compensation benefits compared to classical one. Both methods are equally effective at zero speed and allow the full compensation for the torque deviation. At rated speed the use of the modified compensation of cogging torque also allows to almost completely offset the torque deviation unlike the classical way of compensation, which reduces deviations almost twice. That is, the modified proposed method allows compensating the torque deviation much better in the entire range of operating speeds than the classic method of compensation. It was considered a collaboration of the proportional speed control system with static error compensator with the modified compensation of cogging torque in servopress mode, which operates in the hammer mode and in the mode with constant pressing force at the provided maximum load and operational speed for each mode. Modeling of electromechanical systems of servopress with classic settings and the proposed technical solutions in both modes confirmed that only the using the last ones will ensure the implementation of the necessary technological requirements and high quality of manufacturing process, especially high speed and lack of torque deviations. To confirm the fidelity of calculations and the adequacy of the mathematical model experimental studies were conducted. A measuring stand measuring stand for this, it allows to measure mechanical, electrical and temperature of electrical machines with excitation from permanent magnets in real time. The results of experimental studies confirmed the appropriateness and high accuracy of calculation results with measurement results.