A Novel Synthetization Approach for Multi Coupled Line Section Impedance Transformers in Wideband Applications

In this paper, a novel synthetization approach is proposed for filter-integrated wideband impedance transformers (ITs). The original topology consists of N cascaded coupled line sections (CLSs) with 2N characteristic impedance parameters. By analyzing these characteristic impedances, a Chebyshev response can be derived to consume N + 2 design conditions. To optimize the left N − 2 variable parameters, CLSs were newly substituted by transmission lines (TLs) to consume the remaining variable parameters and simplify the circuit topology. Therefore, there are totally 2N − N − 2 substituting possibilities. To verify the proposed approach, 25 cases are listed under the condition of N = 5, and 7 selected cases are compared and discussed in detail. Finally, a 75–50 Ω IT with 100% fractional bandwidth and 20 dB bandpass return loss (RL) is designed and fabricated. The measured results meet the circuit simulation and the EM simulation accurately.

THE PROSPECTS OF USING THE MATLAB PACKAGE FOR MODELING LIGHTNING DISCHARGES IN POWER TRANSMITTING LINES

The possibilities of a simulation model of a power line section with a rated voltage of 220 kV created in the Matlab package under the influence of lightning discharges are described.

TECHNICAL MEANS FOR SUPPRESSION OF RESONANCE PHENOMENA IN ELECTRICAL NETWORKS

The self-excitation phenomenon of generators connected to an unloaded power line is considered. Accordingly, the selected values of the conductivity of the controlled shunt reactors, following the control range (especially in the overload mode), avoid the occurrence of self-excitation of the generators. The physical analysis of the processes occurring at self-excitation of the synchronous generator is given, and the calculated models are developed. It is established that in the case of artificial support along the entire length of the voltage line at the nominal value using controlled compensating devices, the transmission will have properties characteristic of relatively short lines (up to 500 km) regardless of its geometric length. It is determined that the length of the line section at the ends of which the DC voltage is maintained is much less than 500 km. Therefore, less than the natural voltage along the section length will exceed the nominal value at the transmitted power, and the line will have excess reactive power. Consumption in intermediate compensation devices (compensation current must be inductive). Ref.8, fig. 4, tables 4.

Algorithm for adaptive correction of the ship's movement along the trajectory in the presence of a sea current

В статье предложен алгоритм адаптивной коррекции движения судна по траектории при наличии морского течения. В основе предлагаемого подхода лежит алгоритм градиента вспомогательных функций. Показаны преимущества предложенного алгоритма адаптивной коррекции движения судна по траектории. Сущность предлагаемого подхода заключается в замене прямолинейного участка маршрута судна, новой виртуальной траекторией и использовании ее во вспомогательной функции и при вычислении соответствующего вектора градиента. Компьютерное моделирование подтвердило эффективность предложенного алгоритма адаптивной коррекции. Адаптивные свойства разработанного алгоритма выражаются в том, что он обеспечивает асимптотически точное движение по участкам запланированной траектории, не используя информации о скорости и направлении морского течения. Предполагается использование предложенного адаптивного алгоритма при разработке систем автоматического управления движением судна по маршруту. The article proposes an algorithm for adaptive correction of the ship's movement along the trajectory in the presence of a sea current. The proposed approach is based on the gradient algorithm of auxiliary functions. The advantages of the proposed algorithm for adaptive correction of the ship's motion along the trajectory are shown. The essence of the proposed approach is to replace the straight-line section of the ship's route with a new virtual trajectory and use it in an auxiliary function and in calculating the corresponding gradient vector. Computer simulation has confirmed the effectiveness of the proposed adaptive correction algorithm. The adaptive properties of the developed algorithm are expressed in the fact that it provides asymptotically accurate movement along sections of the planned trajectory, without using information about the speed and direction of the sea current. It is supposed to use the proposed adaptive algorithm in the development of systems for automatic control of the ship's movement along the route.

BASE SINGLE PART PRODUCT QUALITY CONTROL USING STATISTICAL QUALITY CONTROL (SQC) METHOD IN PT DIRGANTARA INDONESIA MACHINING DEPARTMENT

Base Single Part is the main component of the cable installation that functions as a connector between cables in the aircraft. As a critical part, the Base Single Part is the most important sub-component that must be completed to be installed in the aircraft part. Base Single Part is a part that is used in all types of aircraft which are specially produced at PT. Dirgantara Indonesia, in one aircraft this component can be installed in the amount of 8000-9000 Base Single Part. In relation to the request from the Final Assembly Line section regarding the request for the Base Single Part component, there are still some products that do not meet the specifications so that they have to be repaired, such as holes that do not match the size, this causes the delivery order process to the Final Assembly Line section to be hampered and disruptive smooth production. The purpose of this research is to control the quality of the Base Single Part product by using a p control chart, and a causal diagram.The results of the study conclude that the calculation of the percentage level of defect in the Base Single Part component using the p control chart, there are 3 percentage points that are outside the control limit, namely in August with a disability percentage of 15.11%, in September 10.32%, and October 15.60%. Factors causing defects in Base Single Part components consist of 3 factors, human factors, method factors and machine factors. The human factor is workers who are less productive. Furthermore, the method factor is regarding the fluctuating production schedule and the last cause is the machine factor that lacks maintenance.

Compact 3-bit Frequency Reconfigurable Monopole Antenna Realized with a Switchable Three-Line Section

This work proposes a compact 3-bit frequency-reconfigurable monopole antenna covering a broad reconfigurable range by inserting a switchable three-line section (STLS). The design starts with a conventional quarter-wavelength monopole line antenna, which is then replaced by a novel structure, the STLS. The STLS is composed of three parallel-connected lines with different lengths. Accordingly, three RF p–i–n diodes are introduced in the STLS to achieve binary reconfiguration. After all parameters of the antenna have been optimized, it will eventually output 2N = 8 (N is the number of switches) independent working states with different equivalent lengths and a reconfigurable working frequency. The number of states in a binary reconfigurable antenna is optimally large in relation to the number of switches used, which means that it can be extremely convenient for digital control of switching all the states and capable of decreasing the number of RF p–i–n diodes we used, thereby minimizing the manufacturing cost and loss of diodes. A prototype antenna is fabricated and tested, and the measurement results agree well with the simulation results, validating the good features, such as a large reconfigurable switchable frequency range from 0.95 GHz to 2.45 GHz with considerable working bandwidth varying from 40 MHz to 540 MHz for each state, simple structure, and a compact size of 70 × 40 mm2, which can be appropriately used for a multi-radio wireless system and handheld devices. All the states have a similar monopole radiation pattern with a good maximum efficiency and an acceptable peak gain according to its compact size.

Control of mobile equipment for the processing of marine shaft lines

The purpose of the research is to develop solutions for mobile equipment control in the processing of marine shaft lines; to solve the issues of geometric accuracy of processing; to create a corrective program to address the issues of accuracy of the geometric parameters processing; to give reasons for the application of linear electrohydraulic step drive (LEHSD) in mobile equipment control. The analysis of schemes and mathematical dependencies for calculating the trajectory of the tool movement of a mobile machine when processing shaft lines is carried out; the choice of the optimal zone for finishing the shaft line, taking into account the beats. The object of the study is a ship shaft line. The paper presents an original scheme of rotation of the shaft line section, as well as schemes for changing the position of the shaft line during processing; justifies the possibility of using a linear electrohydraulic step drive (LEHSD) with a corrective program for processing taking into account automatic measurements and a specified error.