Mean flow regulation of a high frequency combustion control valve based on pulse width modulation and system identification

2005 ◽  
Author(s):  
Tongxun Yi ◽  
M. Cornwell ◽  
E.J. Gutmark
Keyword(s):  
System Identification ◽  
High Frequency ◽  
Pulse Width ◽  
Pulse Width Modulation ◽  
Control Valve ◽  
Flow Regulation ◽  
Combustion Control ◽  
Mean Flow

Sequential Control of Multichannel On–Off Valves for Linear Flow Characteristics Via Averaging Pulse Width Modulation Without Flow Meter: An Application for Pneumatic Valves

2018 ◽  
Vol 141 (1) ◽  
Author(s):  
Kanchit Pawananont ◽  
Thananchai Leephakpreeda
Keyword(s):  
Flow Rate ◽  
Pulse Width ◽  
Pulse Width Modulation ◽  
Single Channel ◽  
Flow Characteristics ◽  
Volumetric Flow Rate ◽  
Operating Conditions ◽  
Mean Flow ◽  
Flow Meter ◽  
Linear Flow

Control of on–off valves for linear flow characteristics is a challenging design problem due to nonlinearity of valve mechanism and fluidic properties under various operating conditions. In this study, averaging pulse width modulation (PWM) is proposed as a control valve signal by implementing PWM with predetermined duty period so that overflow at the open position and underflow at the closed position are divided proportionately around desired mean flow rates during entire cycle periods. Multichannels in a parallel pattern are implemented to yield linear flow characteristics with higher resolution than a single channel. With pressure and temperature measurements, the volumetric flow rate is determined by an empirical model of flow characteristics across flow control valves at given operating conditions. The experimental results on achieving the desired volumetric flow rate of air under actual flow conditions without a flow meter are presented for viability of the proposed methodology in practical uses.

A Hydraulic Rotary Switched-Inertance Servo-Transformer

1988 ◽  
Vol 110 (2) ◽  
pp. 144-150 ◽  
Author(s):  
F. T. Brown ◽  
S. C. Tentarelli ◽  
S. Ramachandran
Keyword(s):  
Steady State ◽  
High Frequency ◽  
Pulse Width ◽  
Pulse Width Modulation ◽  
Complete Solution ◽  
Partial Solution ◽  
State Theory ◽  
Novel Approach ◽  
Flow Through ◽  
Theory And Experiments

Switched-reactance hydraulics represents a radically novel approach to the control of fluid power, since the proportional metering of flow through adjustable orifices is eliminated, and the inertive properties of the fluid substituted. Potential advantages in bandwidth, linearity, and efficiency have been indicated. This paper presents the first steady-state theory and experiments with a rotary fluid switch, which accomplishes the needed pulse-width modulation at a desirably high frequency. Cavitation problems are observed, means of their partial solution are implemented, and means of a more complete solution are indicated.

Performance of a flow control valve with pilot switching valve

2017 ◽  
Vol 232 (2) ◽  
pp. 178-194 ◽  
Author(s):  
Xiaoyan Xiong ◽  
Jiahai Huang
Keyword(s):  
Flow Control ◽  
Pulse Width ◽  
Pulse Width Modulation ◽  
Control Valve ◽  
Duty Ratio ◽  
Main Stage ◽  
Flow Control Valve ◽  
Average Pressure ◽  
Switching Valve ◽  
Outlet Flow

In digital fluid power, fast switching valve is a potential digital hydraulic component because of less throttling loss, reliability, low price, and so on. But its outlet flow is usually small and discontinuous. In this article, a two-stage proportional flow control valve is presented, in which the main stage is a flow amplifying valve, and the pilot stage consists of several switching valves with pulse width modulation control strategy. Peak and hold technique is adopted to improve the dynamic performance of the pilot stage. Benefits of the proposed configuration are continuous outlet flow and large flow capacity. The valve performance is investigated by theoretical analysis, simulation, and test. It is shown that both poppet displacement and outlet flow fluctuate around a stable value because of the discontinuous pilot flow, but the average outlet flow as well as poppet displacement of the main stage can be approximately proportionally regulated by changing pulse width modulation duty ratio. Average outlet flow of the main stage is an amplification of that of pilot stage. Increasing the average pressure drop not only increases outlet flow but also increases the severity of flow pulsations because pressure fluctuation becomes more serious as the average pressure difference increases. In theory, higher carrier frequency leads to smoother outflow; however, tested outflow profile of the proposed valve at 50 Hz is not significantly smoother than that at 30 Hz. This phenomenon may be due to the asynchrony of the four switching valves and the pressure fluctuations during the testing process.

Analysis of Crankcase Flow of an Automobile ECV for Air Conditioning Control System

2013 ◽  
Vol 373-375 ◽  
pp. 421-426 ◽  
Author(s):  
Md. Iqbal Mahmud ◽  
Haeng Muk Cho
Keyword(s):  
Control System ◽  
Experimental Test ◽  
Input Signal ◽  
Pulse Width ◽  
Air Conditioning ◽  
Pulse Width Modulation ◽  
Control Valve ◽  
Electromagnetic Control ◽  
Pressure Controlled ◽  
Conditioning Control

Electromagnetic control valve (ECV) controls an automobile vehicle air conditioning compressor based on a pulse width modulation (PWM) input signal that supplied from an external controller. For maintaining a suitable range of temperatures inside the vehicle, suction and crankcase port pressure controls the swash (wobble) plate at certain angle. Suction and crankcase port pressure controlled in ECV can be analyzed by experimental test by considering different technical assumptions. This research paper highlights the flow of air from crankcase port with correspondence with amount of variable supply of current to obtain the experimental test data which is important to maintain the vehicle temperature inside the compartment for passengers comfort.

scholarly journals Analysis of Sinusoidal Pulse Width Modulation Parameter Settings in High Precission Closed Loop Full Bridge Bipolar Inverters for High Voltage High Frequency Generator

Teknik ◽  
2020 ◽  
Vol 41 (1) ◽  
pp. 55-61
Author(s):  
Abdul Syakur ◽  
Arifin Wibisono
Keyword(s):  
High Voltage ◽  
High Frequency ◽  
Pulse Width ◽  
Large Scale ◽  
Closed Loop ◽  
Pulse Width Modulation ◽  
Waste Treatment ◽  
Electrical Energy ◽  
Loop Control ◽  
Sinusoidal Pulse Width Modulation

The application of high voltage becomes more important and wider. High voltage is needed in the process of reducing air contaminants, waste treatment, sanitation, disinfecting microorganisms, testing for insulating high voltage equipment, and transmitting electrical energy. The problem of high voltage AC generation system is still in a large scale, static, not portable, and very expensive. This paper presents an analytical design of a high-voltage AC high-frequency based on power electronic. It is portable, less expensive, and eaasier to control the amplitudo and frequency. The application of the Full Bridge Bipolar Inverter topology with the Sinusoidal Pulse Width Modulation switching method provides variable sinusoidal AC voltage outputs (Vo) on its amplitude and frequency. The Tesla Coil Transformer amplifies the amplitude in accordance with the classification of the high voltage AC in the order of Kilo Volt. The Closed Loop control system in the Bipolar Inverter Full Bridge topology provides high accuracy results between the given setting values and the actual amplitude output and the expected high-frequency AC voltage. Analysis of the SPWM switching pattern parameter settings shows stability for several loading variations

scholarly journals Common-Mode Reduction SVPWM for Three-Phase Motor Fed by Two-Level Voltage Source Inverter

Energies ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3884
Author(s):  
Jian Zheng ◽  
Mingcheng Lyu ◽  
Shengqing Li ◽  
Qiwu Luo ◽  
Keyuan Huang
Keyword(s):  
High Frequency ◽  
Pulse Width ◽  
Pulse Width Modulation ◽  
Voltage Source ◽  
Switching Frequency ◽  
Voltage Source Inverter ◽  
Large Magnitude ◽  
Common Mode ◽  
Common Mode Voltage ◽  
Three Phase

Aiming at the problem of large magnitude and high frequency of common-mode voltage (CMV) when space vector pulse width modulation (SVPWM) is used in a three-phase motor fed by a two-level voltage source inverter, a common-mode reduction SVPWM (CMRSVPWM) is studied. In this method, six new sectors are obtained by rotating six sectors of conventional SVPWM by 30°. In odd-numbered sectors, only three non-zero vectors with odd subscripts are used for synthesis, while in even-numbered sectors, only three non-zero vectors with even subscripts are used for synthesis. The actuation durations of three non-zero vectors in each switching period in each sector are given. Simulation and experimental results show that, compared with the conventional SVPWM, the CMV magnitude of CMRSVPWM is reduced by 66.67% and the CMV frequency of CMRSVPWM is reduced from the original switching frequency to the triple fundamental frequency. At the same time, the current, torque and speed of the motor are still good.

The Design of 25KV High-Frequency High-Voltage Power Supply

2014 ◽  
Vol 912-914 ◽  
pp. 927-930
Author(s):  
Qiang Jiang
Keyword(s):  
Power Supply ◽  
High Frequency ◽  
Pulse Width ◽  
Pulse Width Modulation ◽  
Single Chip ◽  
Single Chip Microcomputer ◽  
High Voltage Power Supply ◽  
Switch Power Supply ◽  
Switch Power ◽  
Inverter Topology

In this paper, a HV and HF switch power supply was designed, which was controlled through a single chip microcomputer, also the MOSFET was used as the switch power tube. The PWM (pulse width modulation) technique and half-bridge inverter topology have been used to invert AC into the DC that can be adjust from 0V~25KV and the operating frequency is 35KHz, Through the simulation with the Saber software and practical use, the feasibility of the scheme and the correctness of the design have been verified.

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