Application of Fieldbus and Frequency Conversion Technology in Air-Condition VWV System

2011 ◽  
Vol 90-93 ◽  
pp. 3068-3072
Author(s):  
Gui Rong Wang ◽  
Cong Zhi Zhang

This paper presents a method which uses LonWorks control system and frequency converter in Central Air-Condition chilled water variable flow system. In this system, the output of frequency converter can be altered by augmenter PID control rule which is used in control of invariable difference in temperature between water supply and backwater, and the rotating speed of water pump can be changed correspondingly, so when the user load is small ,the electric energy consume can be reduced. The effect of energy-saving was visible comparing with the conventional Air-Condition chilled water constant flow system.

2014 ◽  
Vol 551 ◽  
pp. 509-513
Author(s):  
Song Liu ◽  
Lian Zhi Jiang

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.


2013 ◽  
Vol 325-326 ◽  
pp. 271-276 ◽  
Author(s):  
Yu Sheng Zhou ◽  
Long Zeng ◽  
Pei Yao Chen ◽  
Zheng Pan

High-frequency and high-voltage excitation melting ice device is mainly composed of the excitation power supply and the notch filter device, which can realize the power transmission line melting ice without power cut. This paper applied power electronic frequency conversion technology to design a excitation melting ice device with 18KV/40KHZ.This device is adopted PWM control technology, and is mainly composed of the rectifier, controller and inverter. For the small frequency converter, the high-voltage frequency conversion function can be achieved through each phase in series divided voltage method. According to the 1000 kV AC ultrahigh voltage transmission lines, a melting ice model is set up by using SIMULINK simulation. The results show that this device can generate stable 18KV/40KHZ excitation melting ice electric energy in 30ms,and the control method is convenient and simple, the range of frequency and voltage modulation is big characteristics.


2012 ◽  
Vol 516-517 ◽  
pp. 1235-1239
Author(s):  
Gang Guo ◽  
Rui Li

The application of frequency conversion technique in secondary pump and variable flow system is expounded in this essay. In the view of energy conservation, the secondary frequency conversion pump in variable flow system is in favor of energy conservation due to its variability on power according to the end load change, the principle of frequency conversion pump is also analysed. Combined with actual project case, he energy saving potential of secondary pump and variable flow system is discussed.


2010 ◽  
Vol 2 (5) ◽  
pp. 109-114
Author(s):  
Andrius Timofejevas ◽  
Kęstutis Čiuprinskas

The paper analyses a cooling system installed using 268 fan coils and having an area of 7900 m2 in a public building situated in Vilnius city. A comparison between a constant flow system having three way valves, a variable flow system having manually balanced valves and a variable flow system having automatically balanced control valves is made. The analysis has been performed to find out initial investments, installation costs and operating costs during 10 year period. Calculation has showed advantages of the variable flow. The overall cost of the system having manually balanced and two way control valves is 20% lower than that of the constant flow system. The overall cost of the system having automatically balanced control valves is 37% lower than that of the constant flow system. The marked differences may increase in case of growth in electricity price.


Open Physics ◽  
2020 ◽  
Vol 18 (1) ◽  
pp. 408-418
Author(s):  
Yonghong Deng ◽  
Quanzhu Zhang

AbstractIn order to solve the problem that the long cable variable voltage and variable frequency (VVVF) system does not adopt an effective capacitor voltage sharing control method, resulting in a poor effect of resonance overvoltage control, the resonance overvoltage control algorithm of the long cable VVVF system based on discrete mathematics is studied. First, the long cable frequency conversion drive system is established. In order to ensure voltage loss in the range of motor requirements, a frequency converter–cable–motor (ICM) system connection mode is used to maintain the system operation. Based on the research of the capacitor voltage balance control strategy of a long cable frequency conversion drive system, the discrete mathematical model of the AC side of the ICM system is established by using this control strategy. The improved constant active power controller is obtained by establishing the mathematical model, and the resonant overvoltage in a long cable frequency conversion drive is realized by using the constant active power controller. The experimental results show that the algorithm can effectively control the resonance overvoltage phenomenon in the long cable frequency control system, and the control accuracy is over 97%. It has good performance and can be applied in practice.


Author(s):  
Bambang Sumantri ◽  
Eko Henfri Binugroho ◽  
Ilham Mandala Putra ◽  
Rika Rokhana

The two-wheeled electric skateboard (TWS) is designed for a personal vehicle. A Fuzzy-PID control strategy is designed and implemented for controlling its motion. Basically, motions control of the TWS is performed by balancing the pitch position of the TWS. Performance of the designed controller is demonstrated experimentally. The Fuzzy algorithm updates the PID gains and therefore it can handle the changing of the TWS load. Contribution of Fuzzy-PID in reducing the electric energy consumption, which is an important issue in electrical system, is also evaluated. The Fuzzy-PID successes to reduce the electric energy consumption of the TWS compared to the conventional PID.


2020 ◽  
Author(s):  
David Moss

We report a broadband microwave frequency converter based on a coherent Kerr optical micro-comb generated by an integrated micro-ring resonator. The coherent micro-comb displays features that are consistent with soliton crystal dynamics with an FSR of 48.9-GHz. We use this to demonstrate a high-performance millimeter-wave local oscillator at 48.9-GHz in the Q-band for microwave frequency conversion. We experimentally verify the microwave performance up to 40 GHz, achieving a ratio of −6.8 dB between output RF power and IF power and a spurious suppression ratio of > 43.5 dB. The experimental results show good agreement with theory and verify the effectiveness of microwave frequency converters based on coherent optical micro-combs, with the ability to achieve reduced size, complexity, and potential cost.


1963 ◽  
Vol 18 (1) ◽  
pp. 158-165 ◽  
Author(s):  
John A. Sirs ◽  
F. J. W. Roughton

A stopped-flow method is described to measure spectrophotometrically the rates of uptake of CO and O2 by the hemoglobin of intact sheep erythrocytes. A comparison of the results obtained with the constant flow system has led to further refinement of the latter procedure. A linear relation is found between the rate of uptake and the concentration of the dissolved gas, and the initial percentage rate of saturation is independent of the concentration of the erythrocytes. Submitted on September 21, 1961


Sign in / Sign up

Export Citation Format

Share Document