scholarly journals Time-Sharing Control Strategy for Multiple-Receiver Wireless Power Transfer Systems

Energies ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 599 ◽  
Author(s):  
Weikun Cai ◽  
Dianguang Ma ◽  
Xiaoyang Lai ◽  
Khurram Hashmi ◽  
Houjun Tang ◽  
...  
Keyword(s):  
Control Strategy ◽  
Output Voltage ◽  
High Efficiency ◽  
Coupling Effect ◽  
Cross Coupling ◽  
Time Sharing ◽  
Voltage Control Strategy ◽  
Bridge Rectifier ◽  
The Cross ◽  
Target Output

The cross-coupling effect between the induction coils of a multiple-receiver wireless power transfer (MRWPT) system severely weakens its overall performance. In this paper, a time-sharing control strategy for MRWPT systems is proposed to reduce the cross-coupling between receiver coils. An active-bridge rectifier is introduced to the receivers to replace the uncontrollable rectifier to achieve synchronization of the time-sharing control. The synchronization signal generated by an active-bridge rectifier can be directly used to realize the synchronization of time-sharing control and hence saved the traditional zero-crossing point detection circuits for time-sharing circuits. Moreover, the proposed time-sharing system has the advantages of both operating under a resistance-matching condition and providing target output voltage for each receiver. Furthermore, a voltage control strategy was developed to provide both high efficiency and a target output voltage for each receiver. Finally, the simulation and experimental results show that the time-sharing MRWPT system reduced the cross-coupling effect between the receiver coils, and the voltage control strategy provided both a high efficiency and a target output voltage for each receiver.

scholarly journals Interleaved Buck Converter for Inductive Wireless Power Transfer in DC–DC Converters

Electronics ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 949
Author(s):  
Marco Carbajal-Retana ◽  
Leobardo Hernandez-Gonzalez ◽  
Jazmin Ramirez-Hernandez ◽  
Juan Gerardo Avalos-Ochoa ◽  
Pedro Guevara-Lopez ◽  
...  
Keyword(s):  
Control Strategy ◽  
Output Voltage ◽  
High Efficiency ◽  
Wireless Power Transfer ◽  
Power Converter ◽  
Buck Converter ◽  
Power Transfer ◽  
Wireless Power ◽  
Operating Modes ◽  
Bridge Rectifier

The use of Inductive Wireless Power Transfer (IWPT) varies from low-power applications such as mobile phones and tablets chargers to high-power electric vehicles chargers. DC–DC converters are used in IWPT systems, and their design needs to consider the demand of high efficiency in the power transfer. In this paper, a DC–DC power converter for IWPT is proposed. Its topology uses a DC–AC converter in the transmitter circuit and an AC–DC converter in the receptor. The transmitter has an interleaved coupled-Buck converter that integrates two Buck converters connected to a half inverter bridge and a parallel resonant load. The control strategy implemented for the semiconductor switching devices allows two operating modes to obtain a sinusoidal output voltage with a low distortion that makes it suitable in high-efficiency power transfer systems. To obtain a DC output voltage, a full wave bridge rectifier is used in the receptor circuit. The proposed topology and the control strategy are validated with simulation and experimental results for a 15 W prototype.

scholarly journals Lyapunov Stability and Performance Analysis of the Fractional Order Sliding Mode Control for a Parallel Connected UPS System under Unbalanced and Nonlinear Load Conditions

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3475 ◽  
Author(s):  
Muhammad Ali ◽  
Muhammad Aamir ◽  
Hussain Sarwar Khan ◽  
Asad Waqar ◽  
Faheem Haroon ◽  
...  
Keyword(s):  
Sliding Mode Control ◽  
Critical Load ◽  
Lyapunov Stability ◽  
Control Strategy ◽  
Power Supply ◽  
Output Voltage ◽  
Sliding Mode ◽  
Voltage Control Strategy ◽  
Nonlinear Load ◽  
Load Conditions

Parallel-connected uninterruptible power supply (UPS) systems have been used to maintain power supply to the critical load in order to increase power capacity and system reliability. This paper presents a robust and precise voltage control strategy for parallel-connected UPS systems. Each parallel-connected UPS system consists of a three-phase inverter with an output inductor-capacitor (LC) filter directly connected to an AC common bus in order to feed the critical load. Fractional-order sliding mode control (FOSMC) is proposed to maintain the quality of the output voltage despite linear, unbalanced and/or nonlinear load condition. The Riemann-Liouville (RL) fractional derivative is employed in designing the sliding surface. The voltage control strategy effectively eliminates the parametric uncertainties, external disturbances, and reduce the total harmonic distortion (THD) of the output voltage. Furthermore, it also maintains very good voltage regulation such as dynamic response and steady-state error under the nonlinear or unbalanced load conditions. The stability of the proposed controller is proven by applying Lyapunov stability theory. Droop control approach and virtual output impedance (VOI) loop are investigated to guarantee the accurate active and reactive power-sharing for parallel-connected UPS system. Finally, the implementation of the control scheme is carried out by using MATLAB/Simulink real-time environment.

scholarly journals Dynamic DC-link Voltage Adjustment for Electric Vehicles Considering the Cross Saturation Effects

Energies ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 2046 ◽  
Author(s):  
Huimin Li ◽  
Shoudao Huang ◽  
Derong Luo ◽  
Jian Gao ◽  
Peng Fan
Keyword(s):  
Control Strategy ◽  
Reference Signal ◽  
Cross Coupling ◽  
Torque Control ◽  
Maximum Efficiency ◽  
Magnetic Saturation ◽  
Speed Range ◽  
The Cross ◽  
Bus Voltage ◽  
Saturation Effects

The demands of remarkable reliability and high power density of traction systems are becoming more and more rigorous. The conflicting requirements imposed on the control strategy are higher accuracy and higher efficiency over the whole speed range. However, parameter variations caused by the cross coupling and magnetic saturation effect (omitted from the cross saturation effects in the following) are usually neglected in conventional control strategies, which could reduce the control precision. In order to fully consider the influence of parameter changes on the motor control and derive an approach that could realize the maximum efficiency during the whole speed range, this paper proposes a dynamic DC-link voltage adjustment strategy considering the cross coupling and magnetic saturation effects. The strategy can be categorized into three parts. Firstly, the torque request is transformed to the optimal current reference signal. Secondly, the differences between the setpoint and the real-time feedback signals of torque and voltage can be applied in the linearized function in the did,q coordinate. The solution guides the current vector into the optimal direction under the current and voltage limits to ensure the safety and reliability of the motor. Finally, last, the bus voltage can be modified according to the asked terminal voltage. A 10 kW prototype which instrumented a bidirectional DC-DC converter to regulating the bus voltage has been studied. The simulation and experiment results verify that the proposed control strategy can reduce the inverter losses in low speed region by offering the low bus voltage and track the actual maximum torque control trace more accurately, meanwhile, the flux weakening region can be delayed in high speed region by applying a high bus voltage. It helps the motor realize the high utilization rate of the DC-link voltage and guarantees the system reliability and robustness.

scholarly journals A Novel Control Strategy for DC-Link Voltage Balance and Reactive Power Equilibrium of a Single-Phase Cascaded H-Bridge Rectifier

Energies ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 51 ◽  
Author(s):  
Chengwei Luo ◽  
Derong Luo ◽  
Shoudao Huang ◽  
Gongping Wu ◽  
Hongzhang Zhu ◽  
...  
Keyword(s):  
Working Conditions ◽  
Duty Cycle ◽  
Control Strategy ◽  
Reactive Power ◽  
Coupling Effect ◽  
Active Duty ◽  
Integral Control ◽  
Loop Control ◽  
Voltage Balance ◽  
Bridge Rectifier

The dc-link voltage balance and reactive power equilibrium of the cascaded H-bridge rectifier (CHBR) are the prerequisites for the safe and stable operation of the system. However, the conventional PI (Proportional-Integral) control strategy only puts emphasis on the CHBR dc-link voltage balance without taking into account its reactive power equilibrium under capacitive and inductive working conditions. For this reason, this paper has proposed a novel control strategy for the CHBR that can not only balance dc-link voltage, but also achieve reactive power equilibrium and eliminate the coupling effect between the voltage-balancing controller (VBC) and original system controller (OSC). The control strategy can achieve dc-link voltage balance and the reactive power equilibrium of the CHBR through modifying the active duty cycle by closed loop control, and adjusting the reactive duty cycle relatively according to the modifiable amount of the active duty cycle. Moreover, the strategy can eliminate the coupling effect between the VBC and OSC by the open loop control modification of the active and reactive duty cycle of any H-bridge module in CHBR. Simulations and experiments have shown that the proposed control strategy is feasible and effective in performing the CHBR dc-link voltage balance and reactive power equilibrium under all working conditions and load variations.

Cross-Feedback Stabilization of the Digitally Controlled Magnetic Bearing

1992 ◽  
Vol 114 (1) ◽  
pp. 54-59 ◽  
Author(s):  
Y. Okada ◽  
B. Nagai ◽  
T. Shimane
Keyword(s):  
Pid Control ◽  
High Speed ◽  
Coupling Effect ◽  
Cross Coupling ◽  
Magnetic Bearing ◽  
Feedback Stabilization ◽  
Time Interval ◽  
Rotating Disc ◽  
Digitally Controlled ◽  
The Cross

A method of stabilizing a high speed rotor supported by magnetic bearings is presented. The magnetic bearing is controlled by a digital controller with rotationally synchronized interruption. The main problem with the rotating disc is the cross-coupling effect caused by the gyroscopic or inductive forces which sometimes make the high speed rotor unstable. Standard PID control is carried out with constant time interval interruption, while the rotational interrupt subroutine performs the cross-coupling feedback. The cross-feedback in the x-y directions well compensates for the undesirable coupling effect. This scheme is applied to a four-mass, two-bearing rotor system and its capability is tested.

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