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 Optimal Current Trajectory Control Strategy of IPMSM Considering the Cross Saturation Effects

Energies ◽  
2017 ◽  
Vol 10 (10) ◽  
pp. 1460 ◽  
Author(s):  
Huimin Li ◽  
Jian Gao ◽  
Shoudao Huang ◽  
Peng Fan
Keyword(s):  
Control Strategy ◽  
Trajectory Control ◽  
Optimal Current ◽  
The Cross ◽  
Saturation Effects

scholarly journals Improved Direct Torque Control strategy for Wide Range Speed Control of Induction Motor Drives

2020 ◽  
Vol 8 (5) ◽  
pp. 2113-2117
Keyword(s):  
Induction Motor ◽  
Control Strategy ◽  
Direct Torque Control ◽  
Motor Drives ◽  
Torque Control ◽  
Switching Frequency ◽  
Induction Motor Drives ◽  
Wide Range ◽  
Speed Range ◽  
Level Variable

Induction Motor is popular option for most of the drives applications. It has simple construction but complex control. DC motor like decoupled control of induction motor drives similar to Field Oriented control is possible using Direct Torque Control (DTC) method which is very simple control strategy compared to vector control. The DTC strategy is very useful for automobile and traction applications using IM but due to use of hysteresis band controllers, DTC has problems of torque ripples, variable switching frequency and poor low speed performance. Because of these reasons, DTC is used in such applications for high speed range and not for the whole speed range. An improved DTC strategy suitable for wide range speed control is suggested in this paper which is based on a performance index calculated on the basis of what is the value of THD of stator current, value of operating speed and switching frequency. It uses new five level variable width torque hysteresis band controller and two level variable width hysteresis band flux controller along with new hybrid model for stator flux estimation. This improved strategy is designed to maintain simplicity of conventional DTC and give better performance than it. This new strategy is simulated using Matlab/Simulink

DTC of reconfigured three level inverter fed IM drives following a leg failure

2016 ◽  
Vol 35 (2) ◽  
pp. 764-781 ◽  
Author(s):  
Tarek Gallah ◽  
Badii Bouzidi ◽  
Ahmed Masmoudi
Keyword(s):  
Design Methodology ◽  
Experimental Validation ◽  
Direct Torque Control ◽  
Cost Benefit ◽  
Torque Control ◽  
Content Type ◽  
Speed Range ◽  
Bus Voltage ◽  
The One ◽  
Inverter Topology

Purpose – The purpose of this paper is to deal the adaptation of a direct torque control (DTC) strategy, originally dedicated to three level three leg inverter fed induction motor (IM) drives, following a leg failure that required the reconfiguration of the inverter from three to two legs. Design/methodology/approach – In case of troubles with one leg of a three level inverter, it is interesting in some applications to keep operating using the two remaining legs. So, after the detection and isolation of the faulty leg, the drive connection should be rearranged with the connection of the motor phase, previously linked to the faulty leg, to the mid point of the DC-bus voltage, leading to a three level two leg inverter topology (also called bridge B8-inverter). Findings – It has been found that the IM drive exhibits better performances under the proposed DTC strategy dedicated to the reconfigured inverter than those yielded by the DTC of the IM drive under healthy operation of the inverter. It has been noticed that the only drawback affecting the reconfigured inverter fed IM drive is the speed range limitation. Research limitations/implications – This work should be extended by an experimental validation of the proposed DTC strategies. Originality/value – The power factor of the reconfigured three level inverter fed IM drive is higher than the one yielded by the three level three leg inverter fed one. This represents a crucial cost benefit.

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.

Direct Torque Control Methods of EMU during All Speed Range

2012 ◽  
Vol 462 ◽  
pp. 891-896
Author(s):  
Na Wang ◽  
Heng Bin Cui ◽  
Xiao Yun Feng
Keyword(s):  
Control Strategy ◽  
Control Method ◽  
Direct Torque Control ◽  
Torque Control ◽  
Low Velocity ◽  
Flux Control ◽  
Torque Control Strategy ◽  
Speed Range ◽  
Static Performance ◽  
Velocity Zone

This paper theoretically analyzes the principle of the direct torque control method, then builds the direct torque control scheme of electric multiple-units(EMU) running during all speed range: indirect torque control in low velocity zone, eighteen polygon flux control method in moderate velocity zone and weakening hexagonal flux control strategy in high velocity zone. Simulation results show that the EMU direct torque control strategy in all speed range is feasible, and the system has good dynamic and static performance. All of the researches are available in the EMU controller research.

Investigation of cross-coupling effect and its restraining methods of a 3-DOF hybrid magnetic bearing

2018 ◽  
Vol 37 (6) ◽  
pp. 2195-2210 ◽  
Author(s):  
Yunlong Zhong ◽  
Lijian Wu ◽  
Youtong Fang ◽  
Xiaoyan Huang
Keyword(s):  
Degrees Of Freedom ◽  
Coupling Effect ◽  
Cross Coupling ◽  
Magnetic Bearing ◽  
Axial Thrust ◽  
Content Type ◽  
The Cross ◽  
Saturation Effects ◽  
And Control ◽  
Force Characteristics

Purpose The purpose of this paper is to investigate and restrain the cross-coupling effect among X, Y and Z-axes of a three degrees of freedom hybrid magnetic bearing (3-DOF HMB). The influence of the cross-coupling effect on the force characteristics and stiffnesses are analysed. Two additional methods are proposed to eliminate the cross-coupling effect. Design/methodology/approach Analysis with finite element method (FEM) is time-consuming because of the requirement of a 3D model for the studied 3-DOF HMB. Hence, an improved magnetic circuit model considering the leakage, cross-coupling and saturation effects is used to investigate the cross-coupling effect in this paper. In addition, two restraining methods are proposed. One is adding an auxiliary coil between radial and axial stators. The other is adding an iron ring between the PM and radial or axial stator. Findings The X-axis (or Y-axis) force characteristics and stiffnesses are significantly influenced by the Z-axis current, while other axes force characteristics and stiffnesses do not show the cross-coupling effect. Moreover, this cross-coupling effect is inversely related to the distance between axial thrust disk and radial MB part. Besides, adding an auxiliary coil can effectively eliminate the cross-coupling effect in whole work range and adding an iron ring can reduce the cross-coupling effect. Originality/value The cross-coupling effect and its restraining methods of a 3-DOF HMB are investigated, which is beneficial to the design and control of such 3-DOF HMB.

scholarly journals Capacitive Wireless Power Transfer with Multiple Transmitters: Efficiency Optimization

Energies ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 3482
Author(s):  
Ben Minnaert ◽  
Alessandra Costanzo ◽  
Giuseppina Monti ◽  
Mauro Mongiardo
Keyword(s):  
Maximum Output Power ◽  
Cross Coupling ◽  
Wireless Power Transfer ◽  
Maximum Efficiency ◽  
Maximization Problem ◽  
Maximum Output ◽  
System Efficiency ◽  
Power Transfer ◽  
Wireless Power ◽  
The Cross

Wireless power transfer with multiple transmitters can have several advantages, including more robustness against misalignment and extending the mobility and range of the receiver(s). In this work, the efficiency maximization problem is analytically solved for a capacitive wireless power transfer system with multiple coupled transmitters and a single receiver. It is found that the system efficiency can be increased by adding more transmitters. Moreover, it is proven that the cross-coupling between the transmitters can be eliminated by adding shunt susceptances at the input ports. Optimal values for the input currents and receiver load are determined to achieve maximum efficiency. As well the optimal load, the optimal input currents and the maximum efficiency are independent on the cross-coupling. By impedance-matching the internal conductances of the generators, the maximum-efficiency solution also becomes the one that provides the maximum output power. Finally, by expressing each transmitter–receiver link with its kQ-product, the maximum system efficiency can be calculated. The analytical results are verified by circuital simulation.

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