scholarly journals Inertial Gyro Wave Energy Conversion Nonlinear Modeling and Power-Index Predictive Control for Autonomous Ship

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Nailong Wu ◽  
Xinyuan Chen ◽  
Shaonan Chen ◽  
Haodong Yuan ◽  
Jie Qi ◽  
...  
Keyword(s):  
Predictive Control ◽  
Wave Energy ◽  
Control Method ◽  
Nonlinear Modeling ◽  
Electric Energy ◽  
Coupling Model ◽  
High Energy ◽  
Energy Evaluation ◽  
Unmanned Ship

The complex marine environment and the high energy consumption of shipboard equipment pose challenges to the long-term navigation of autonomous unmanned ships. In wave-induced motion, inertial gyro antirolling technology is used to offset the energy transmitted by waves, but the massive consumption of energy is not conducive to long-term navigation of the unmanned ships. This paper attempts to exploit the wave energy transmitted by the gyro to improve the power supply of the unmanned ship. Firstly, a nonlinear coupling model of the gyro antirolling device and the unmanned ship is established. Secondly, considering various model constraints and physical constraints of the equipment, the energy evaluation objective function of nonlinear model predictive control (NMPC) is designed. In the simulation, the proposed control method can effectively extract electric energy from different waves.

Long Term Voltage Stability Enhancement by Model Predictive Control

2012 ◽  
Vol 157-158 ◽  
pp. 1553-1557
Author(s):  
Pei Jia Yu ◽  
Ting Ting Jiang ◽  
Jing Zhang
Keyword(s):  
Model Predictive Control ◽  
Power System ◽  
New England ◽  
Predictive Control ◽  
Voltage Stability ◽  
Control Method ◽  
Proper Time ◽  
Time Instant ◽  
Load Shedding

Power system load shedding has been used as an emergency control method to prevent possible power system instability problems. In this paper, a model predictive control based load shedding scheme is proposed to enhance long term voltage stability of a power system. The main advantage of this method is the capability to handle control actions with proper time instant. A new cost function is defined for the model predictive control scheme. The proposed scheme is tested on the New England 39-bus system to validate its efficiency and effectiveness in preventing system long term voltage stability problems.

A Load Shedding Scheme for Long Term Voltage Stability Enhancement by Multi-Stage Model Predictive Control

2011 ◽  
Vol 383-390 ◽  
pp. 4735-4741
Author(s):  
Yu He ◽  
Jing Zhang ◽  
Zhi Wei Peng ◽  
Zhao Yang Dong
Keyword(s):  
Model Predictive Control ◽  
Power System ◽  
New England ◽  
Predictive Control ◽  
Voltage Stability ◽  
Control Method ◽  
Load Shedding ◽  
Stage Model ◽  
Multi Stage

Power system load shedding has been used as an emergency control method to prevent possible power system instability problems. In this paper, a new multi-stage model predictive control based load shedding scheme is proposed to enhance long term voltage stability of a power system. The main advantage of this new method is the capability of the scheme to handle multi-stage control actions, which may also be disturbances to a power system at a critical status toward instability. A new cost function is defined for the model predictive control scheme. The proposed scheme is tested on the New England 39-bus system to validate its efficiency and effectiveness in preventing system long term voltage stability problems.

Application of Neural Network for Nonlinear Predictive Control

2012 ◽  
Vol 562-564 ◽  
pp. 1964-1967 ◽  
Author(s):  
Zhi Cheng Xu ◽  
Bin Zhu ◽  
Qing Bin Jiang
Keyword(s):  
Neural Network ◽  
Model Predictive Control ◽  
Linear Model ◽  
Predictive Control ◽  
Control Method ◽  
Nonlinear Modeling ◽  
Nonlinear Process ◽  
Effective Control ◽  
Nonlinear Predictive Control ◽  
The Stability

A novel model predictive control method was proposed for a class of dynamic processes with modest nonlinearities in this paper. In this method, a diagonal recurrent neural network (DRNN) is used to compensate nonlinear modeling error that is caused because linear model is regarded as prediction model of nonlinear process. It is aimed at offsetting the effect of model mismatch on the control performance, strengthening the robustness of predictive control and the stability of control system. Under a certain assumption condition, linear model predictive control method is extended to nonlinear process, which doesn’t need solve nonlinear optimization problem. Consequently, the computational efforts are reduced drastically. The simulation example shows that the proposed method is an effective control strategy with excellent tracing characteristics and strong robustness.

scholarly journals Hydrodynamic Analysis of 3-SPS Wave Energy Conversion Device

2021 ◽  
Vol 271 ◽  
pp. 01013
Author(s):  
Zhifei Ji ◽  
Xiaodong Yuan ◽  
Min Lin ◽  
Jianyu Fan
Keyword(s):  
Kinetic Energy ◽  
Energy Conversion ◽  
Wave Energy ◽  
Electric Energy ◽  
High Energy ◽  
Energy Utilization ◽  
Utilization Efficiency ◽  
High Energy Density ◽  
Wave Energy Conversion ◽  
Linear Waves

Wave energy has the advantages of high energy density, renewability, and wide distribution, and has been highly valued by many coastal countries. The wave energy conversion device can convert wave energy into electric energy, which is of great significance for alleviating problems such as energy crisis and greenhouse effect. The traditional wave energy conversion device can only gain the energy along the heave direction, and the kinetic energy of the buoy is not fully utilized. To improve the energy utilization efficiency of the wave energy conversion device, this paper proposed a new type of 3-SPS wave energy conversion device. Based on linear waves and Lagrangian equation, a hydrodynamic model of the device was established. The displacement and velocity of the device float under the action of linear waves were analyzed. The results show that the 3-SPS wave energy conversion device can collect the kinetic energy of the buoy in its heaving, surging and pitching movement at the same time; the kinetic energy of the buoy in the heaving direction is much greater than the kinetic energy in the surging and pitching directions; the buoy can capture kinetic energy in multiple directions of motion, indicating that the 3-SPS wave energy conversion device has a high energy utilization efficiency. This paper provides some useful references for the optimal design of the new wave energy device.

1554: 6 Year Long Term Clinical and Urodynamical Outcome and Retreatment Rates of High Energy Transurethral Microwave Thermotherapy: Multicenter European Pooled Analysis

2004 ◽  
Vol 171 (4S) ◽  
pp. 410-410
Author(s):  
Christian Seitz ◽  
Bob Djavan ◽  
Michael Dobrovits ◽  
Matthias Waldert ◽  
Saeid Alavi ◽  
...  
Keyword(s):  
High Energy ◽  
Pooled Analysis ◽  
Transurethral Microwave Thermotherapy

Efficient Co-Harvesting of Solar Energy and Low-Grade Heat by Molecular Photoswitches for High Energy Density, Long-Term Stable Solar Thermal Battery

2019 ◽  
Author(s):  
Zhao-Yang Zhang ◽  
Tao LI
Keyword(s):  
Energy Density ◽  
Solar Energy ◽  
High Performance ◽  
High Energy ◽  
Solar Thermal ◽  
High Energy Density ◽  
Low Grade ◽  
Thermal Battery ◽  
Low Grade Heat

Solar energy and ambient heat are two inexhaustible energy sources for addressing the global challenge of energy and sustainability. Solar thermal battery based on molecular switches that can store solar energy and release it as heat has recently attracted great interest, but its development is severely limited by both low energy density and short storage stability. On the other hand, the efficient recovery and upgrading of low-grade heat, especially that of the ambient heat, has been a great challenge. Here we report that solar energy and ambient heat can be simultaneously harvested and stored, which is enabled by room-temperature photochemical crystal-to-liquid transitions of small-molecule photoswitches. The two forms of energy are released together to produce high-temperature heat during the reverse photochemical phase change. This strategy, combined with molecular design, provides high energy density of 320-370 J/g and long-term storage stability (half-life of about 3 months). On this basis, we fabricate high-performance, flexible film devices of solar thermal battery, which can be readily recharged at room temperature with good cycling ability, show fast rate of heat release, and produce high-temperature heat that is >20<sup> o</sup>C higher than the ambient temperature. Our work opens up a new avenue to harvest ambient heat, and demonstrate a feasible strategy to develop high-performance solar thermal battery.

Efficient Co-Harvesting of Solar Energy and Low-Grade Heat by Molecular Photoswitches for High Energy Density, Long-Term Stable Solar Thermal Battery

2019 ◽  
Author(s):  
Zhao-Yang Zhang ◽  
Tao LI
Keyword(s):  
Energy Density ◽  
Solar Energy ◽  
High Performance ◽  
High Energy ◽  
Solar Thermal ◽  
High Energy Density ◽  
Low Grade ◽  
Thermal Battery ◽  
Low Grade Heat

Solar energy and ambient heat are two inexhaustible energy sources for addressing the global challenge of energy and sustainability. Solar thermal battery based on molecular switches that can store solar energy and release it as heat has recently attracted great interest, but its development is severely limited by both low energy density and short storage stability. On the other hand, the efficient recovery and upgrading of low-grade heat, especially that of the ambient heat, has been a great challenge. Here we report that solar energy and ambient heat can be simultaneously harvested and stored, which is enabled by room-temperature photochemical crystal-to-liquid transitions of small-molecule photoswitches. The two forms of energy are released together to produce high-temperature heat during the reverse photochemical phase change. This strategy, combined with molecular design, provides high energy density of 320-370 J/g and long-term storage stability (half-life of about 3 months). On this basis, we fabricate high-performance, flexible film devices of solar thermal battery, which can be readily recharged at room temperature with good cycling ability, show fast rate of heat release, and produce high-temperature heat that is >20<sup> o</sup>C higher than the ambient temperature. Our work opens up a new avenue to harvest ambient heat, and demonstrate a feasible strategy to develop high-performance solar thermal battery.

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