scholarly journals Strategy for Switchover between the Ground Return and the Metallic Return Operation Modes of MTDC Systems

2021 ◽  
Author(s):  
Manxi Huang ◽  
Hengyi Pan ◽  
Gen Li ◽  
Jianzhong Xu ◽  
Xiufang Jia
Keyword(s):  
Operation Modes

Whole body 3T MRI system with eight parallel RF transmit/receive channels and dual operation modes

2007 ◽  
Vol 179 (03) ◽  
Author(s):  
I Graesslin ◽  
P Vernickel ◽  
J Schmidt ◽  
C Findeklee ◽  
P Röschmann ◽  
...  
Keyword(s):  
Whole Body ◽  
3T Mri ◽  
Operation Modes

THE ANALYSIS OF OPERATION MODES OF ENERGY STORES IN AUTONOMOUS HYBRID POWER PLANTS WITH RENEWABLE ENERGY RESOURCES

2018 ◽  
pp. 55-67
Author(s):  
S. G. Obukhov ◽  
I. A. Plotnikov ◽  
V. G. Masolov
Keyword(s):  
Renewable Energy ◽  
Power Systems ◽  
Low Frequency ◽  
Rechargeable Batteries ◽  
Energy Resources ◽  
Renewable Energy Resources ◽  
Hybrid Power ◽  
Operation Modes ◽  
Energy Stores ◽  
Energy Store

The paper presents the results of the comparative analysis of operation modes of an autonomous hybrid power complex with/without the energy store. We offere the technique which defines the power characteristics of the main components of a hybrid power complex: the consumers of the electric power, wind power and photo-electric installations (the last ones have been constructed). The paper establishes that, in order to compensate the seasonal fluctuations of power in autonomous power systems with renewable energy resources, the accumulative devices are required, with a capacity of tens of MWh including devices that are capable to provide energy storage with duration about half a year. This allows abandoning the storage devices for smoothing the seasonal fluctuations in the energy balance.The analysis of operation modes of energy stores has shown that for a stock and delivery of energy on time intervals, lasting several hours, the accumulative devices with rather high values of charging and digit power aren't required. It allows using the lead-acid rechargeable batteries of the deep category for smoothing the daily peaks of surplus and a capacity shortage. Moreover, the analysis of operation modes of energy stores as a part of the hybrid complexes has demonstrated that in charging/digit currents of the energy store the low-frequency and high-frequency pulsations of big amplitude caused by changes of size of output power of the renewable power installations and loading are inevitable. If low-frequency pulsations (the period of tens of minutes) can partially be damped due to the restriction of size of the maximum charging current of rechargeable batteries, then it is essentially impossible to eliminate high-frequency pulsations (the period of tens of seconds) in the power systems with the only store of energy. The paper finds out that the combined energy store having characteristics of the accumulator in the modes of receiving and delivery of power on daily time intervals, and at the same time having properties of the supercondenser in the modes of reception and return of impulses of power on second intervals of time is best suited to requirements of the autonomous power complexes with renewable energy resources.

ENERGY SAVING OPERATION MODES OF TRANSCEIVERS IN ULTRA-WIDEBAND SENSOR NETWORKS

2012 ◽  
Vol 1 (1) ◽  
Author(s):  
Yu. V. Andreev ◽  
E. V. Efremova ◽  
V. A. Lazarev ◽  
V. A. Kotelnikov
Keyword(s):  
Sensor Networks ◽  
Energy Saving ◽  
Ultra Wideband ◽  
Operation Modes

ПРОЕКТИРОВАНИЕ ВЫСОКОТОЧНЫХ СВЧ КВАДРАТУРНЫХ МОДУЛЯТОРОВ И ДЕМОДУЛЯТОРОВ И ИССЛЕДОВАНИЕ ВОЗМОЖНОСТИ ПОДСТРОЙКИ ДИНАМИЧЕСКИХ ПАРАМЕТРОВ С ПОМОЩЬЮ ЦИФРОВОЙ РЕГУЛИРОВКИ

2020 ◽  
Vol 96 (3s) ◽  
pp. 337-342
Author(s):  
И.И. Мухин ◽  
Р.С. Шабардин ◽  
Л.В. Недашковский ◽  
Д.Н. Морозов
Keyword(s):  
Dynamic Parameters ◽  
Operation Modes ◽  
Measurement Results ◽  
Quadrature Modulators ◽  
Functional Blocks

В работе представлены результаты проектирования четырех микросхем квадратурных модуляторов и демодуляторов, в которых реализована коррекция динамических параметров цифровым способом, что достигается регулировкой режимов работы отдельных функциональных блоков схемы. Разработаны опытные образцы квадратурных модуляторов и демодуляторов на основе SiGe технологического процесса и приведены результаты измерений. Показано, что при регулировке изменение фазового разбаланса может достигать значений до 5°, амплитудный разбаланс - до 2,8 дБ, а подавление паразитных составляющих может быть больше 50 дБ. The paper presents four quadrature modulators and demodulators circuits design results. In these circuits the dynamic parameters are digitally corrected, which is achieved by adjusting the operation modes of separate functional blocks. Prototypes of quadrature modulators and demodulators manufactured on SiGe process were produced and the measurement results are presented. It is shown that during adjustment the change in phase imbalance can reach values up to 5 degrees, amplitude imbalance up to 2.8 dB, and suppression of spurious components can be more than 50 dB.

scholarly journals The simulation model for a flood management by flood control facilities

2018 ◽  
Vol 245 ◽  
pp. 15002 ◽  
Author(s):  
Roman Davydov ◽  
Valery Antonov ◽  
Dmitry Molodtsov ◽  
Alexey Cheremisin ◽  
Vadim Korablev
Keyword(s):  
Mathematical Models ◽  
Flood Control ◽  
Flood Management ◽  
Hydroelectric Power Station ◽  
Hydroelectric Power ◽  
Operating Characteristics ◽  
Hydro Power ◽  
Operation Modes ◽  
Wide Range ◽  
Environmental Requirements

The rapid spread of storm floods over large areas requires flood management throughout the river basin by the creation an innovative system of flood control facilities of various functional purposes distributed in the area. The central part of the system is the hydro system with hydro power plant. In addition, the flood control facilities on the side tributaries with self-regulating reservoir are included in the system. To assess the effect of controlling extreme water discharges by flood control facilities, it is necessary to develop special mathematical models reflecting the specifics of their operation. Unified mathematical models of the operation modes of a hydro complex with hydroelectric power station and flood control facility are created. They are implemented in a computer program that provides the ability to determine the main parameters and operating characteristics of hydro systems when performing multivariate calculations in a wide range of initial data. This makes possible specifying the parameters and operation modes of each hydro system with the current economic and environmental requirements, to assess the energy-economic and environmental consequences in the operation of the system of flood control facilities distributed in the area. The article analyses the results of the extreme water discharge’s regulation by the hydro system on the main river and flood control facilities on the side tributaries, considering environmental requirements.

scholarly journals Design of Self-Reconfigurable Multiarm Robot Mechanism Based on Deployable Kinematic Chains

2020 ◽  
Vol 33 (1) ◽  
Author(s):  
Fu-Qun Zhao ◽  
Sheng Guo ◽  
Hai-Jun Su ◽  
Hai-Bo Qu ◽  
Ya-Qiong Chen
Keyword(s):  
Parallel Mechanism ◽  
Parallel Mechanisms ◽  
Kinematic Chains ◽  
Assembly Method ◽  
Operation Modes ◽  
Object Based ◽  
Switch Operation ◽  
Storage Area ◽  
Mechanism Theory

Abstract As the structures of multiarm robots are serially arranged, the packaging and transportation of these robots are often inconvenient. The ability of these robots to operate objects must also be improved. Addressing this issue, this paper presents a type of multiarm robot that can be adequately folded into a designed area. The robot can achieve different operation modes by combining different arms and objects. First, deployable kinematic chains (DKCs) are designed, which can be folded into a designated area and be used as an arm structure in the multiarm robot mechanism. The strategy of a platform for storing DKCs is proposed. Based on the restrictions in the storage area and the characteristics of parallel mechanisms, a class of DKCs, called base assembly library, is obtained. Subsequently, an assembly method for the synthesis of the multiarm robot mechanism is proposed, which can be formed by the connection of a multiarm robot mechanism with an operation object based on a parallel mechanism structure. The formed parallel mechanism can achieve a reconfigurable characteristic when different DKCs connect to the operation object. Using this method, two types of multiarm robot mechanisms with four DKCs that can switch operation modes to perform different tasks through autonomous combination and release operation is proposed. The obtained mechanisms have observable advantages when compared with the traditional mechanisms, including optimizing the occupied volume during transportation and using parallel mechanism theory to analyze the switching of operation modes.

scholarly journals A Bus-Sectionalized Hybrid AC/DC Microgrid: Concept, Control Paradigm, and Implementation

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3508
Author(s):  
Jing Li ◽  
Hongda Cai ◽  
Pengcheng Yang ◽  
Wei Wei
Keyword(s):  
Hierarchical Control ◽  
Mode Switching ◽  
Stable Operation ◽  
Service Reliability ◽  
Test Results ◽  
Dc Microgrid ◽  
Dc Microgrids ◽  
Operation Modes ◽  
Control Paradigm ◽  
Operational Data

In the last several years, the coordination control of hybrid AC/DC microgrids (HMGs) has been gaining increasingly more attention. However, most of these discussions are focused on single-bus HMGs whose AC or DC bus is not sectionalized by AC or DC breakers. Compared with these single-bus HMGs, the bus-sectionalized HMG has more flexible topologies, more diverse operation modes, and consequently higher service reliability. However, meanwhile, these benefits also bring challenges to the stable operation of bus-sectionalized HMGs, particularly for mode switching. Relying on the national HMG demonstrative project in Shaoxing, China, this paper makes efforts to present the hierarchical control paradigm of a typical bus-sectionalized HMG toward standardization. The test results demonstrate that the proposed system provides seamless switching and uninterrupted power supply without controller reconfiguration among different operation modes. The operational data are also brought forth and analyzed to provide significant and useful experiences for designing and developing similar HMGs in the future.

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