Identifying EMC-critical devices by monitoring and classifying operating region transitions

2017 ◽  
Author(s):  
Lammert Duipmans ◽  
Dusan Milosevic ◽  
Arnoud van der Wel ◽  
Peter Baltus
Keyword(s):  
Operating Region

On the Study of Cognitive Bidirectional Relaying with Asymmetric Traffic Demands

Frequenz ◽  
2015 ◽  
Vol 69 (5-6) ◽  
Author(s):  
Xiaodong Ji
Keyword(s):  
Ergodic Capacity ◽  
Base Station ◽  
Transmission Protocol ◽  
Splitting Algorithm ◽  
Performance Simulation ◽  
Information Theoretic ◽  
Primary Users ◽  
Operating Region ◽  
Bidirectional Relaying ◽  
Outage Probabilities

AbstractIn this paper, we consider a cognitive radio network scenario, where two primary users want to exchange information with each other and meanwhile, one secondary node wishes to send messages to a cognitive base station. To meet the target quality of service (QoS) of the primary users and raise the communication opportunity of the secondary nodes, a cognitive bidirectional relaying (BDR) scheme is examined. First, system outage probabilities of conventional direct transmission and BDR schemes are presented. Next, a new system parameter called operating region is defined and calculated, which indicates in which position a secondary node can be a cognitive relay to assist the primary users. Then, a cognitive BDR scheme is proposed, giving a transmission protocol along with a time-slot splitting algorithm between the primary and secondary transmissions. Information-theoretic metric of ergodic capacity is studied for the cognitive BDR scheme to evaluate its performance. Simulation results show that with the proposed scheme, the target QoS of the primary users can be guaranteed, while increasing the communication opportunity for the secondary nodes.

Nonlinear Vibration Analysis of a Flexible Rotor Supported by a Flexure Pivot Tilting Pad Journal Bearing in Comparison to a Fixed Profile Journal Bearing with Experimental Verification

2021 ◽  
Author(s):  
Nuntaphong Koondilogpiboon ◽  
Tsuyoshi Inoue
Keyword(s):  
Hopf Bifurcation ◽  
Journal Bearing ◽  
Flexible Rotor ◽  
Maximum Test ◽  
Operating Region ◽  
Stable Operating ◽  
Subcritical Hopf Bifurcation ◽  
Tilting Pad ◽  
Calculation Results ◽  
Tilting Pad Journal Bearing

Abstract In this paper, an efficient numerical method consisting of the real mode component mode synthesis (CMS) model reduction, shooting method with parallel computing, and Floquet analysis was developed for nonlinear rotordynamics analysis of a flexible rotor supported by a 4-lobe flexure pivot tilting pad journal bearing (FPTPJB) in load-on-pad (LOP) and load-between-pad (LBP) orientations in comparison to a fixed profile journal bearing (JB) of the same pad geometry. The method used the rotor's finite elements and bearing forces obtained from directly solving the Reynolds equation to determine the limit cycles and Hopf bifurcation types. For the investigated rotor and bearing parameters, the numerical results indicated that the onset speed of instability (OSI) of FPTPJB is considerably higher than that of JB of the same orientation. Also, FPTPJB in LOP orientation yielded higher OSI than the LBP one, whereas the OSI of JB in LOP orientation was substantially higher than the LBP counterpart. Nonlinear calculation results indicated that all bearing types and orientations gave subcritical Hopf bifurcation. The FPTPJB in LOP orientation produced the largest stable operating region, whereas the JB in LBP configuration yield the smallest one. The experiment showed subcritical Hopf bifurcation occurred at speed close to the calculated OSI in all cases except FPTPJB in LOP orientation that the OSI is higher than the maximum test rig speed. The whirling orbit had the same frequency as the first critical speed and precessed in the direction of shaft rotation.

Sensorless Control of IPMSM Using Modified Current Slope Estimation Method

2012 ◽  
Vol 150 ◽  
pp. 100-104
Author(s):  
Tao Zhang ◽  
Wei Ni ◽  
Hui Ping Zhang ◽  
Sha Sha Wu
Keyword(s):  
Permanent Magnet ◽  
Digital Signal Processor ◽  
Permanent Magnet Synchronous Motor ◽  
Estimation Method ◽  
Digital Signal ◽  
Synchronous Motor ◽  
Low Speed ◽  
Rotor Position ◽  
Operating Region ◽  
Interior Permanent Magnet

When the permanent magnet synchronous motor is operated at a low speed. The rotor position and speed are very difficult to estimate using the extended flux or back EMF method. A novel modified current slope estimating method is used to estimate the rotor position and speed in low speed in this paper. The mathematical models of an interior permanent magnet synchronous motor (IPMSM) are deduced. The basic principle of modified current slope method is introduced. The simulation control system is built based on Matlab and a TMS320LF2407 digital signal processor is used to execute the rotor position and speed estimation. The experimental and simulation results have shown that the rotor position and speed can be accurately estimated in a low-speed operating region.

scholarly journals Misalignment-Tolerant Series Hybrid with Active Adjustable Constant Current and Constant Voltage Output Wireless Charging System

Energies ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7594
Author(s):  
Zhao-Wei Gong ◽  
Jin-Gang Li ◽  
Xiang-Qian Tong
Keyword(s):  
Constant Current ◽  
Outer Diameter ◽  
Wireless Charging ◽  
Constant Voltage ◽  
Load Variations ◽  
Charging System ◽  
Voltage Output ◽  
Operating Region ◽  
Constant Output ◽  
Output Characteristics

This paper presents a series hybrid wireless charging system with an active adjustable circuitry offering constant current and constant voltage output characteristics. The series hybrid system consists of the inductor–capacitor–capacitor (LCC) and series-series (SS) networks are used for improving charging pad misalignment tolerance. An active switch is employed to provide an adjustable CC and CV output for different battery charging stages. To demonstrate the performance of the proposed method, a 310 W prototype was built. A systematic optimization in the parameter of the proposed topology to achieve relative constant output was analyzed within a certain range of the designed operating region. The experimental results indicate that the output current fluctuation is less than 5% with load variations, and the output voltage fluctuation is less than 5% with load varying from 19 to 70 Ω, as the pick-up pads misaligned within 50% of the pad outer diameter.

Research on Surveillance Risk Index System of Unified and Interconnected Electricity Market in China

2014 ◽  
Vol 1070-1072 ◽  
pp. 1516-1523
Author(s):  
Chun Cheng Gao ◽  
Shu Hong Shi
Keyword(s):  
Electricity Market ◽  
Index System ◽  
Risk Index ◽  
First Grade ◽  
Risk Level ◽  
Electricity Trading ◽  
Operating Region ◽  
Market State ◽  
Grid Operation ◽  
And Control

After the establishment of the unified and interconnected electricity market in China, electricity trading range will cover the entire State Grid operating region, and headquarters market and provincial market will become interconnected, unified and coordinated operation. Aiming at the surveillance risk under the unified and interconnected electricity market, a relatively complete surveillance risk index system is proposed. The proposed risk index system includes six first grade indices, i.e., market state, transaction plan, contract and settlement, market coordination, energy efficiency and power grid operation. The risk index system can reasonably and overall reflect the risk level of the electric power transaction under the unified and interconnected electricity market circumstances. It is useful for State Grid to achieve risk management and control of electricity trading surveillance, rectify the irregularities, and maintain a fair and impartial market order.

Leveraging Flow Regeneration in Individual Energy-Efficient Hydraulic Drives

2021 ◽  
Author(s):  
Damiano Padovani
Keyword(s):  
Natural Frequency ◽  
Dynamic Properties ◽  
Poor Performance ◽  
Control Techniques ◽  
Lower Natural Frequency ◽  
Operating Region ◽  
Depth Analysis ◽  
Study Case ◽  
Boom Crane ◽  
Circuit Configuration

Abstract The current demand for energy efficiency in hydraulics directs towards the replacement of centralized, valve-controlled actuators with individual, throttleless drives. The resulting solutions often require an undesirable sizing of the key components to expand the system’s operating region. Using flow regeneration (i.e., shortcutting the actuator’s chambers) mitigates this issue. Such an option, already stated for individual drives, lacks an in-depth analysis from the control perspective since the dynamic properties are changed (e.g., the natural frequency is decreased to about 60% of the original value). Therefore, this research paper studies a representative single-pump architecture arranged in a closed-circuit configuration. Linear control techniques are used to understand the system dynamics and design a PI-control algorithm that also adds active damping. The outcomes are validated via high-fidelity simulations referring to a single-boom crane as the study case. The results encompassing diverse scenarios indicate that flow regeneration is only interesting in those applications where the dynamic response is not demanding. In fact, the lower natural frequency reduces the system’s bandwidth to about 69% of the original value and affects the closed-loop position tracking drastically. This poor performance becomes evident when medium-to-high actuation velocity is commanded with respect to the maximum value.

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