Papers by Keyword: Frequency Converter

Abstract: The article presents results of studies of electromagnetic modes of side stirrer composed of multi-melting unit, based on the induction crucible furnace. Using induction crucible furnaces as highly efficient smelting unit in combination with an electromagnetic stirrer and heat control means electrodynamic effect on the molten metal at all stages of melting. The aim of this approach is to reduce the time of melting and improve the quality characteristics of the metal. This article describes the design of basic units, calculation of energy parameters and the study of stirrer modes when powered by a frequency converter.

Abstract: The article presents the comparative analysis of influence frequency regulated electric drive and current electric drive to harmonic structure of voltage of power grid. There was obtained the dependence of total harmonic distortion (THD) of curve on loading power for 2 types of valve converters. The effectiveness is shown in use of filter compensating device, connected at low side of converting transformer. There were defined the ranges of filter adjusting for improving THD of voltage curve. The described solutions are performed by the structural modeling method of Simulink packet in Matlab environment.

Abstract: The dynamic development of devices that use electrical and electronic components makes it necessary to eliminate sources of interference occurring in circuits with systems of this type. These disturbances adversely affect the correct functioning other systems that work together as a network, as well as equipment located in neighbouring systems. The article presents a method of the analysis of the sources of faults occurring in electrical circuits, using a frequency converter. The discussed principle of the operation of the frequency converter and the impact of disturbances generated by these installations are presented in this article. The evaluation methodology of the installation is presented using the requirements of the Harmonized Standards and the authors’ own solutions. The verification of the method was conducted by applying it to a real electrical circuit. The potential sources of electrical faults were identified that were caused by the frequency converters and its circuit. The developed and presented analysis method of the faults sources can be used for evaluating other circuits of this type in which one of subsystems is a frequency converter circuit.

Abstract: This article describes the main advantages and disadvantages of electric drive TVR-IM compared with a frequency converter. The necessity to use electric drives TVR-IM and angular velocity observers to solve technological problems is substantiated. Promising directions in the field of constructing closed-loop by the speed observer systems TVR-IM are shown.

Abstract: With the rapid growth of the Internet, the interest for connecting devices such as frequency converters into Internet has increased. Web browser is used by remote operator to control and monitor frequency converters via Internet and this application will be widely utilized. This article makes a study of web-based monitoring for frequency converters with USS interface. It is based on TCP/IP stack and the real time operating systemμC/OS-II. Then this paper presents a detailed analysis of the Web server, and the interactive method of the browser and the Web server. In the design of the server, it emphasizes the USS protocol telegram processing method. The architecture of embedded monitoring system, hardware and software implementation are also described in this article.

Abstract: This paper introduces a kind of motor frequency conversion energy-saving controller used for fan and water pump loads. Motor energy-saving controller mainly consists of two parts, controller and driver. The main functions of the controller are data collection, control algorithm and communication. The driver is mainly composed of inverter, switch and display instrument. According to the actual situation, if it needs a remote control, we can configure the remote console in the control room, in order to realize the remote control.

Abstract: The leakage protection system usually trends to make a misjudgment and tripping in normal operation after applying the converter in the coal mine power system. This seriously affects the safety in coal production. Based on the research of the structure and working principle of the converter, it has obtained the definite reason for the converter interfere the leakage protection system. It is the higher harmonics and pulses that generate the zero sequence current through the ground capacitance. Combined with the actual situation in coal mine, it has proposed two corresponding solutions: one is adding the isolation transformer in the output lines of the converter; another is modifying criterion of the leakage protection system. Both methods have their own characteristics, and have verified the feasibility of the methods through the MATLAB simulation.

Abstract: Foaming machine is a piece of important equipment in the production process of the foam concrete. This paper designed the control system with singlechip as the core of the digital processing. The communication between the singlechip and frequency converter was realized through RS485 port and the automatic control of the working process of the air compression double-bubble foaming machine can come true. The high performance-cost ratio of the single ratio enables the system control to be economical and practical; the touchscreen interface makes it simple to use; and the multi-gear setting also is easy to adjust and control. All these improve the overall performance of the foaming machine.

Abstract: In view of the traditional double motor constant pressure water supply system without tower in the operation process of the problem of short service life, the design of a new type of dual voltage no tower water supply control system. The control system uses PLC, soft starter and frequency converter technology, the soft starter can make the motor to realize soft start and soft stop, no impact on the motor, can extend the service life of the motor, avoid pumping station "door" damage, reduce repair costs and repair work. The running results show that, after the reformation of water supply system can save more than 21% energy, but also improve the quality and reliability of the water supply.

Abstract: This paper explains and demonstrates how to construct a constant pressure water supply system with an integrated intelligent inverter controller (CPS-20B type) based on fuzzy control. This system can automatically adjust the mode of operation in accordance with different working conditons. The controller can choose the number of working pumps and change the motor speed to achieve constant pressure water supply. The PID regulator is set in the CPS-20B1 controller to adjust the output of the inverter, and the automatic regulating system is formed into a closed loop. The simulation results and practical application show that this system used in the water supply network can keep the water pressure stable. This system has been used in a number of industrial and civil water supply service since 2009, which improved efficiency and saved cost.