A Possible Method of Impedance Testing Aircraft Power Control Units

1955 ◽  
Vol 59 (534) ◽  
pp. 432-433
Author(s):  
F. T. Davies
Keyword(s):  
Power Control ◽  
Power Unit ◽  
Constant Velocity ◽  
Control Unit ◽  
Aircraft Control ◽  
Aircraft Structure ◽  
Control Units ◽  
Impedance Testing ◽  
Air Speed ◽  
Control Surfaces

Knowledge of the motions of aircraft control surfaces due to oscillating hinge moments is of great importance for flutter investigations. While the impedance of the power control unit may play a large part in determining these motions, it is not their only cause. The elasticity of the power unit mounting and the effect on the input of distortion of the aircraft structure, an effect which may depend on air speed, may also be important. Nevertheless the influence of the power unit itself is of major importance. No very satisfactory methods appear to have been devised yet, however, for making such tests. The difficulty lies chiefly in applying the large oscillatory loads to the output of the power control unit, which are necessary if the test is to be realistic. The facts that the oscillating loads must be applied to the jack while it is moving, and that a non-oscillatory opposing load is also desirable, add to the difficulties. For convenience in assessing the characteristics of the unit, it is desirable that the oscillating load should be superimposed on a constant opposing load and that the basic jack motion should be of constant velocity.

scholarly journals Investigation on Thermal Resistance and Capacitance Characteristics of a Highly Integrated Power Control Unit Module

Electronics ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 958
Author(s):  
Maosheng Zhang ◽  
Yu Bai ◽  
Shu Yang ◽  
Kuang Sheng
Keyword(s):  
Thermal Resistance ◽  
Power Control ◽  
Electric Vehicles ◽  
Low Cost ◽  
Control Unit ◽  
Underlying Mechanism ◽  
Power Converter ◽  
Liquid Cooling ◽  
Integration Density ◽  
Unit Module

With the increasing integration density of power control unit (PCU) modules, more functional power converter units are integrated into a single module for applications in electric vehicles or hybrid electric vehicles (EVs/HEVs). Different types of power dies with different footprints are usually placed closely together. Due to the constraints from the placement of power dies and liquid cooling schemes, heat-flow paths from the junction to coolant are possibly inconsistent for power dies, resulting in different thermal resistance and capacitance (RC) characteristics of power dies. This presents a critical challenge for optimal liquid cooling at a low cost. In this paper, a highly integrated PCU module is developed for application in EVs/HEVs. The underlying mechanism of the inconsistent RC characteristics of power dies for the developed PCU module is revealed by experiments and simulations. It is found that the matching placement design of power dies with a heat sink structure and liquid cooler, as well as a liquid cooling scheme, can alleviate the inconsistent RC characteristics of power dies in highly integrated PCU modules. The findings in this paper provide valuable guidance for the design of highly integrated PCU modules.

scholarly journals D-PMU and 5G-Network-Based Coordination Control Method for Three-Phase Imbalance Mitigation Units in the LVDN

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2754
Author(s):  
Mengmeng Xiao ◽  
Shaorong Wang ◽  
Zia Ullah
Keyword(s):  
Mobile Networks ◽  
Control Method ◽  
Low Voltage ◽  
Control Unit ◽  
Distribution Networks ◽  
Optimal Operation ◽  
Positive Sequence ◽  
Measurement Unit ◽  
Control Units ◽  
Three Phase

Three-phase imbalance is a long-term issue existing in low-voltage distribution networks (LVDNs), which consequently has an inverse impact on the safe and optimal operation of LVDNs. Recently, the increasing integration of single-phase distributed generations (DGs) and flexible loads has increased the probability of imbalance occurrence in LVDNs. To overcome the above challenges, this paper proposes a novel methodology based on the concept of "Active Asymmetry Energy-Absorbing (AAEA)" utilizing loads with a back-to-back converter, denoted as “AAEA Unit” in this paper. AAEA Units are deployed and coordinated to actively absorb asymmetry power among three phases for imbalance mitigation in LVDNs based on the high-precision, high-accuracy, and real-time distribution-level phasor measurement unit (D-PMU) data acquisition system and the 5th generation mobile networks (5G) communication channels. Furthermore, the control scheme of the proposed method includes three control units. Specifically, the positive-sequence control unit is designed to maintain the voltage of the DC-capacitor of the back-to-back converter. Likewise, the negative-sequence and zero-sequence control units are expected to mitigate the imbalanced current components. A simple imbalanced LVDN is modeled and tested in Simulink/Matlab (MathWorks, US). The obtained results demonstrate the effectiveness of the proposed methodology.

Development of New IGBT to Reduce Electrical Power Losses and Size of Power Control Unit for Hybrid Vehicles

2017 ◽  
Vol 6 (2) ◽  
pp. 303-308 ◽  
Author(s):  
Keisuke Kimura ◽  
Tasbir Rahman ◽  
Tadashi Misumi ◽  
Takeshi Fukami ◽  
Masafumi Hara ◽  
...  
Keyword(s):  
Power Control ◽  
Electrical Power ◽  
Control Unit ◽  
Hybrid Vehicles ◽  
Power Losses

Optimisation of a Polarisation Nephelometer

2021 ◽  
pp. 87-95
Author(s):  
Victor G. Oshlakov ◽  
Anatoly P. Shcherbakov
Keyword(s):  
Personal Computer ◽  
Position Control ◽  
Control Unit ◽  
Numerical Control ◽  
Radiation Beam ◽  
Drive Control ◽  
Control Units ◽  
Smooth Motion ◽  
Approximation Errors ◽  
Scattering Volume

An analysis of the influence caused by polarization nephelometer parameters on the scattering matrix measurement accuracy in a non-isotropic medium is presented. The approximation errors in the actual scattering volume and radiation beam by an elementary scattering volume and an elementary radiation beam are considered. A formula for calculating the nephelometer base is proposed. It is shown that requirements to an irradiation source of a polarizing nephelometer, i.e. mono-chromaticity and high radiation intensity and directivity in a wide spectral range can be satisfied by a set of high brightness LEDs with a radiating (self-luminous) small size body. A 5-wavelength monochromatic irradiation source, with an emission flux of (0.15–0.6) W required for a polarization nephelometer, is described. The design of small-sized polarizing phase control units is shown. An electronic circuit of a radiator control unit based on an AVR-Atmega 8-bit microcontroller with feedback and drive control realized by means of an incremental angular motion sensor and a software PID controller is presented. Precise and smooth motion of the radiator is ensured by standard servo-driven numerical control mathematics and the use of precision gears. The system allows both autonomous adjustment of the radiator’s reference positions and adjustment by means of commands from a personal computer. Both the computer and microcontroller programs were developed with the use of free software, making it possible to transfer the programs to Windows‑7(10), Linux and embedded Linux operating systems. Communication between the radiator’s position control system and the personal computer is realised by means of a standard noise immune USB-RS485 interface.

scholarly journals Water Environmental Capacity Calculation and Allocation of the Taihu Lake Basin in Jiangsu Province Based on Control Unit

2019 ◽  
Vol 16 (19) ◽  
pp. 3774 ◽  
Author(s):  
Huang ◽  
Zhang ◽  
Tong
Keyword(s):  
Taihu Lake ◽  
Water Environment ◽  
Control Unit ◽  
Jiangsu Province ◽  
Lake Basin ◽  
Environmental Capacity ◽  
Taihu Lake Basin ◽  
Control Units ◽  
Water Environmental Capacity ◽  
Capacity Calculation

The water quality target management of the control unit is a convenient and direct technology for water environment management and the development direction of water environment management in China, involving control unit division and water environment capacity calculation. Taking the Taihu Lake Basin in Jiangsu Province as an example, we propose herein the basic principle of the division of a regional control unit in a plain river network and the method of analyzing the rationality of the control unit division. On this basis, the Taihu Lake Basin in Jiangsu Province was divided into 70 control units. To calculate the water environmental capacity in the plain river network area, we established a water environmental capacity calculation framework based on multiple targets of lakes and rivers, and proposed the goal of water quality "double compliance" of the water environmental functional zone and the assessment section. For this study, we calculated the regional water environmental capacity using the mathematical model of the Taihu Lake Basin’s water environmental capacity, and the water environmental capacities of the 70 control units were allocated by the weight coefficient method, which established water area and functional division length. The research results described herein were applied to the pollution permit management of the Taihu Lake Basin in Jiangsu Province. It provides important technical support for the establishment of a pollution permit system based on the total capacity to improve environmental quality.

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