Design and analysis of a control strategy approach for a smooth transition between battery and ultracapacitor

2017 ◽  
Vol 19 (5-6) ◽  
pp. 313-339 ◽  
Author(s):  
Raghavaiah KATURI ◽  
Srinivasa Rao GORANTLA
Author(s):  
Lucas Ginzinger ◽  
Heinz Ulbrich

In this contribution, a new approach to control a rubbing rotor by applying an active auxiliary bearing is presented. The auxiliary bearing is attached to the foundation via two unidirectional actuators. The control force is applied indirectly using the auxiliary bearing, only in case of rotor rubbing. During a normal operation state, the feedback control does not interfere with the rotor system at all. A robust control system has been developed which significantly reduces the intensity of rubbing by stabilizing the rotor system and assuring an optimal rubbing state in case of a too large rotor amplitude. The two-phase control strategy guarantees a smooth transition from free rotor motion to the state of synchronous full annular rub. A test rig has been developed to experimentally verify the control system. Various experiments show the success of the control strategy. In case of rubbing, the contact forces are reduced up to 80 per cent, which results in significantly lower loads. At the same time, the rotor deflection is decreased too. For industrial applications, the activation of the control system can be operated fully automatically. The high efficiency of the control algorithm allows an implementation on microcontrollers. The developed control of the auxiliary bearing reduces the load and the noise of the system during rotor rubbing significantly.


Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 2031
Author(s):  
Yang Yang ◽  
Yundong He ◽  
Zhong Yang ◽  
Chunyun Fu ◽  
Zhipeng Cong

The electro-hydraulic composite braking system of a pure electric vehicle can select different braking modes according to braking conditions. However, the differences in dynamic response characteristics between the motor braking system (MBS) and hydraulic braking system (HBS) cause total braking torque to fluctuate significantly during mode switching, resulting in jerking of the vehicle and affecting ride comfort. In this paper, torque coordination control during mode switching is studied for a four-wheel-drive pure electric vehicle with a dual motor. After the dynamic analysis of braking, a braking force distribution control strategy is developed based on the I-curve, and the boundary conditions of mode switching are determined. A novel combined pressure control algorithm, which contains a PID (proportional-integral-derivative) and fuzzy controller, is used to control the brake pressure of each wheel cylinder, to realize precise control of the hydraulic brake torque. Then, a novel torque coordination control strategy is proposed based on brake pedal stroke and its change rate, to modify the target hydraulic braking torque and reflect the driver’s braking intention. Meanwhile, motor braking torque is used to compensate for the insufficient braking torque caused by HBS, so as to realize a smooth transition between the braking modes. Simulation results show that the proposed coordination control strategy can effectively reduce torque fluctuation and vehicle jerk during mode switching.


IEEE Access ◽  
2020 ◽  
Vol 8 ◽  
pp. 142159-142172
Author(s):  
Yaran Li ◽  
Long Fu ◽  
Ke Meng ◽  
Zhao Yang Dong ◽  
Kashem Muttaqi ◽  
...  

2013 ◽  
Vol 441 ◽  
pp. 240-244
Author(s):  
Ji Hong Shi ◽  
Kai Xia ◽  
Ren Jie Zhu ◽  
Jiang Yu

As microgrid is a significant part in the development of smart grid, researches focusing on operation efficiency, intelligent control and smooth transition with the main distribution network are very important in advancing micro-grid technology. This paper studies multi-microgrid control strategy based on IP and MAS and divided microgrid to three levels which are important, less important and unimportant. Then simulation experiments are designed to realize seamless transition between connected mode and island mode, intelligent management of microgrid by priority when the output power of main grid decrease.


2022 ◽  
Vol 14 (1) ◽  
pp. 168781402110709
Author(s):  
Mingfang Chen ◽  
Kangkang Hu ◽  
Yongxia Zhang ◽  
Fengping Qi

The parallel leg of the quadruped robot has good structural stiffness, accurate movement, and strong bearing capacity, but it is complicated to control. To solve this problem, a series connection of parallel legs (SCPL) was proposed, as well as a control strategy combined with the central pattern generator (CPG). With the planar 5R parallel leg as the research object, the SCPL analysis method was used to analyze the leg structure. The topology of CPG network was built with the Hopf oscillator as the unit model, and the CPG was the core to model the robot control system. By continuously adjusting the parameters in the CPG control system and changing the connection weight, and the smooth transition between gaits was realized. The simulation results show that the SCPL analysis method can be effectively used in the analysis of parallel legs, and the control system can realize the smooth transition between gaits, which verifies the feasibility and effectiveness of the proposed control strategy.


2017 ◽  
Vol 68 (6) ◽  
pp. 405-414
Author(s):  
Niancheng Zhou ◽  
Chunyan Li ◽  
Fangqing Sun ◽  
Qianggang Wang

AbstractCompared with other kinds of fuel cells, solid oxide fuel cell (SOFC) has been widely used in microgrids because of its higher efficiency and longer operation life. The weakness of SOFC lies in its slow response speed when grid disturbance occurs. This paper presents a control strategy that can promote the response speed and limit the fault current impulse for SOFC systems integrated into microgrids. First, the hysteretic control of the bidirectional DC-DC converter, which joins the SOFC and DC bus together, is explored. In addition, an improved droop control with limited current protection is applied in the DC-AC inverter, and the active synchronization control is applied to ensure a smooth transition of the microgrid between the grid-connected mode and the islanded mode. To validate the effectiveness of this control strategy, the control model was built and simulated in PSCAD/EMTDC.


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