Papers by Keyword: Frequency Conversion

Abstract: Due to a reduced structural weight, composite parts offer the possibility to increase the eco-efficiency of any mobility devices during their lifetime. Due to the mold-based production of composite parts, their surfaces are contaminated with release agent residues (e.g. silicones). Thus, the adhesion of the part’s surface is lowered, which prevent structural adhesive bonding of untreated parts. To enable this joining technology and guarantee a sufficient adhesion during part’s lifetime, a surface pre-treatment prior to the bonding process has to be performed. A laser treatment shows a high potential for an integration in an industrial process chain, but unfortunately, common laser sources lower this potential due to high investment costs (excimer laser) or the risk of causing material damage (lasers emitting in the range of 1 μm wavelength). To solve this challenge, laser radiation at 3 μm wavelength, which has several advantages (high absorption within epoxy resin, less thermal interaction concluding less risk to cause delaminations and the possibility to be guided through a fiber) was generated by frequency conversion of an industrial ND:YAG laser (at 1064 nm) and applied to the composite. The results show a good and sensitive treatment of the surface, resulting in high bonding strengths and providing a robust pre-treatment method.

Abstract: In this paper, on basis of DPMZM (Dual-Parallel Mach-Zehnder Modulator), an approach for microwave photonic frequency conversion using DSSC(double-sideband suppressed-carrier) and balance detection is demonstrated. DSSC and balance detection were used to realize high harmonic suppression, and achieve frequency conversion signal with high power and high spectrum purity. In addition, theoretical analysis and simulation results show that the optimal modulation index is m1=2, m2=1.81, and the harmonic suppression is greater than 30dB.

Abstract: Glasses are very versatile materials, also because of the ease of doping them with various elements and compounds. In particular, rare-earth-doped glasses have greatly contributed to the development of optical amplifiers, lasers, active optical waveguides and white-light-emitting devices. White light emitting diodes (W-LEDs) and color LEDS obtained by the combination of an UV emitting LED, such as AlGaN-based LED, with a glass phosphor exhibit very interesting properties. In the present contribution we report the luminescence characteristics of zinc-sodium-aluminosilicates glasses variously doped, namely either singly doped with Eu3⁺, Tb³⁺ or Sm³⁺, or co-doped with Tb³⁺-Eu³⁺, Tb³⁺-Sm³⁺ and Tb³⁺-Ce³⁺. These glasses have also proved to be suitable for ion exchange and therefore for the production of active optical waveguides.

Abstract: The rope haulage monorail transport system is an important kind of subsidiary transport system in the underground mine. We propose a control system using frequency conversion on rope haulage monorail transport system in this paper, which consists of PLC control console, AC inverter, speed sensor, over-wind protection switch, sound-light alarm, leakage monitoring device, etc. Our control system can realize the start-stop control, the forward and backward control, the frequency conversion control, the over-wind protection, and so on. This control system can also real-timely detect and display the status information of transport system. The field experiments have showed that our control system using frequency conversion can well satisfy the needs of automatic operation of rope haulage monorail transport system.

Abstract: In view of the traditional way of painting by using brush, wearing protective clothing and breathing harmful gas, etc. problems, The bottleneck of traditional manual approach to health, safety and social progress should be solved. By analyzing the relationship between innovative structure, strength analysis, recycling of resources and environmental protection,A comprehensive solution is put forward which includes the structure design of quadruple adjustment and twofold recycling, integration of roll-spray, automatic control and frequency conversion for speed regulation. The results of the enterprise’s practical application indicate that this device is effective on ensuring human health, environmental protection, resource utilization, improving productivity and creating economic benefit, Its market application prospect is very broad.

Abstract: In a power plant of 300MW, the power consumption of its axial Induced Draft Fan (IDF) and Flue Gas Desulfurization (FGD) booster fan was high on the whole. So it is necessary to take measures to reduce the power consumption by energy-saving retrofit. Firstly, a series of test and optimization are carried out on its operational performances. Furthermore, several retrofit schemes are worked out. Then, based on a series of test about its operational characters, an evaluation on potential to save energy is carried out for the IDF and the FGD booster fan. Finally, according to the comprehensive analysis including technical economic, difficulty and reliability, it is of the best scheme to carry out the frequency conversion retrofit for IDF. In fact, its effect is good after the retrofit is conducted, namely, the energy-saving index is almost the same as from evaluation. Obviously, the evaluation as for performance test is quite accurate and can avoid several problems likely to occur in frequency conversion retrofit.

Abstract: The principle of double-input and single-output fuzzy controller has been analyzed in detail. Aimed at the frequency conversion system of the pump in wastewater treatment we has conducted the research of fuzzy control algorithm, In frequency control system we adopt double input and single output basic fuzzy controller. The simulation results show that using the fuzzy controller to control frequency converter to realize AC variable speed of motor can achieve value quickly, and control effete is smooth, the dynamic characteristics of system are also good, reaching the design requirements well, which has a very broad application prospects. Keywords: sewage treatment; frequency conversion; fuzzy control; pump; double input and single output

Abstract: The microwave frequency conversion technology, also known as mixers, RF and microwave system is the transmitter and the receiver have the basic functions. Microwave photon system, instead of the traditional high-speed optoelectronic devices electronic device to overcome the conventional signal processing electronics in the electronic bottleneck. In this paper, respectively, modulators and optical devices based on nonlinear effects of microwave photon frequency conversion methods are summarized, research and verify the bandpass filter can achieve frequency conversion scheme.

Abstract: The direct digital frequency synthesis (DDS) technology has high frequency resolution, fast frequency switching, low phase noise and higher frequency stability, so it is widely used in communications, aerospace, instrumentation and other fields. In this paper, the DDS system was designed based on Field Programmable Gate Array (FPGA) and hardware design language (VHDL). The experimental and simulation results show that the system has stable output frequency, high frequency accuracy, adjustable frequency and phase.

Abstract: The realization method of the explosion-proof three-level frequency conversion equipment for coal mine is introduced in this paper. The frequency conversion equipment uses diode clamped three-level inverter unit topology structure, it overcomes some disadvantages of two-level converter that harmonic content of voltage output is higher, electromagnetic interference is serious and on-off loss is higher. The frequency conversion equipment is suitable for coal mine high voltage and large power devices such as draught fan, pumps and belt conveyers.