Powered parafoil systems are nonlinear systems that are easily affected by the surrounding complex environment. In this study, an eight-degree-of-freedom (DOF) model of a powered parafoil was established based on the ...
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Powered parafoil systems are nonlinear systems that are easily affected by the surrounding complex environment. In this study, an eight-degree-of-freedom (DOF) model of a powered parafoil was established based on the Lagrange equation and dynamic constraints. A control methodology was then designed based on an extended state observer (ESO) and sliding mode control (SMC). By accurately estimating the influences of the complex environment using the ESO, the estimated disturbances could be compensated for in the SMC. Finally, the simulation results showed that this method could effectively overcome the influence of environmental disturbances and achieve accurate trajectory tracking control. Compared with the traditional proportional-integral-derivative (PID) controller and active disturbance rejection control (ADRC), this method has a higher control accuracy and better robustness.& nbsp;(c) 2022 Elsevier Masson SAS. All rights reserved.
In a hydrogen-based DC microgrid (MG), the integration of hydrogen subsystem increases the system complexity and flexibility. Effective power split, bus voltage stability and reliable operation become significant cont...
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In a hydrogen-based DC microgrid (MG), the integration of hydrogen subsystem increases the system complexity and flexibility. Effective power split, bus voltage stability and reliable operation become significant control issues of hydrogen-based DC MG. This paper proposes a simple and effective decentralized energy management strategy based on a mode-triggered droop scheme for an islanded PV/hydrogen/battery DC MG. In a decentralized manner, the proposed decentralized energy management strategy is implemented through two control steps: mode divisions and droop control. For practical implementation purposes of the proposed energy management strategy, the mode divisions scheme autonomously divides this DC MG into eight operating modes based on the system local information;the adaptive droop control method controls the distributed generation units based on their droop relationships under different operating modes. In addition, an islanded DC MG hardware-in-the-loop (HIL) RT-LAB simulation platform and a lab-scaled experimental platform are built to validate the effectiveness of the proposed decentralized strategy. The simulation and experiment results show that the proposed energy management strategy has an efficient power distribution ability without communication link under various operating modes. (C) 2020 Elsevier Ltd. All rights reserved.
Vehicle fuel economy is poor, because the urban traffic is congested, the auto is constantly in the idle condition resulting in the increase of fuel consumption. In order to improve the vehicle fuel economy, the exper...
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Vehicle fuel economy is poor, because the urban traffic is congested, the auto is constantly in the idle condition resulting in the increase of fuel consumption. In order to improve the vehicle fuel economy, the experimental scheme was designed through analyzing the work mechanism of automobile Idling Stop＆start System（ISS）. Engine working conditions were simulated by drive motor, the road resistance was simulated through electromagnetic brake controlled current to achieve the control of braking torque. The models of ISS were established, which consists of drive motor, regenerative braking, braking pedal and road resistant simulation. The test system was verified based on hardware in the loopsimulation test system. The test results show that the models and the experimental scheme are rational and effective. It is a good testing and simulation platform for the further research on energy-saving mechanism and control technology.
Modular multilevel converters (MMC) are used in the applications such as medium voltage multi-megawatt drives and in HVDC power transmission. The converter has several sub-modules connected in series that are switched...
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ISBN:
(纸本)9781467371520
Modular multilevel converters (MMC) are used in the applications such as medium voltage multi-megawatt drives and in HVDC power transmission. The converter has several sub-modules connected in series that are switched appropriately to regulate the pole voltage. Besides regulation of output voltage, it is also essential to regulate the individual sub-module capacitor voltages. In this paper, a novel modulation scheme for an MMC converter based on carrier phase shifted PWM is proposed. The proposed modulation scheme balances the sub-module capacitor voltages without distortions in output voltage. The scheme combines the best features of the two well-known modulation approaches, namely, carrier-based modulation approach and sub-module insertion approach. Real-time simulation results modeling a single leg MMC converter using a Typhoon HIL system are presented to validate the performance of the proposed modulation scheme.
A direct self-repairing controller based on adaptive sliding mode control technique designed for the quadrotor helicopter with actuator faults is studied in this *** any fault diagnosis,such adaptive sliding mode-base...
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ISBN:
(纸本)9781479946983
A direct self-repairing controller based on adaptive sliding mode control technique designed for the quadrotor helicopter with actuator faults is studied in this *** any fault diagnosis,such adaptive sliding mode-based fault-tolerant control is implemented to track the desired output signal,when any actuator of the quadrotor loses ***,the Lyapunov stability theory applied can guarantee the stability of the whole system and the convergence of the tracking ***,the availability of the proposed method is verified by the numerical simulation and HIL (hardware-in-loop) simulation on Qball-X4 to ensure the tracking performance of this nonlinear system under both normal and faulty conditions.
It has been shown that high seasonal energy efficiency ratio (SEER) air conditioner compressor motors will stall during a voltage sag of 30% or greater such as during a sub-transmission fault. When these motors stall,...
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ISBN:
(纸本)9781479936571
It has been shown that high seasonal energy efficiency ratio (SEER) air conditioner compressor motors will stall during a voltage sag of 30% or greater such as during a sub-transmission fault. When these motors stall, they draw two to three times their rated current and reactive power. The motor stall affects the entire power system beyond the duration of voltage drop of the fault resulting in a system-wide impact. This phenomenon is known as fault induced delayed voltage recovery (FIDVR) or slow voltage recovery (SVR). The FIDVR or SVR event is not only influenced by the air conditioner motor penetration but also by the voltage sensitivity of the load composition in the distribution system. In this study, the single-phase induction machine model that is available in the real time digital simulator (RTDS) is used to simulate the stall nature of these high SEER machines. This paper also addresses the effect of distribution system loads on FIDVR and analyzes the effect using RTDS. A group of the machine models are installed in a test power system along with constant impedance (Z), constant current (I), and constant power (P) load models to study the effect of these loads on the stall nature of the single phase induction machines.
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