Linni Jian

Regulated Charging of Plug-in Hybrid Electric Vehicles for Minimizing Load Variance in Household Smart Microgrid

With the advent of the plug-in hybrid electric vehicles (PHEVs), the vehicle-to-grid (V2G) technology is attracting increasing attention recently. It is believed that the V2G option can aid to improve the efficiency and reliability of the power grid, as well as reduce overall cost and carbon emission. In this paper, the possibility of smoothing out the load variance in a household microgrid by regulating the charging patterns of family PHEVs is investigated. First, the mathematic model of the problem is built up. Then, the case study is conducted, which demonstrates that, by regulating the charging profiles of the PHEVs, the variance of load power can be dramatically reduced. Third, the energy losses and the subsidy mechanism are discussed. Finally, the impacts of the requested net charging quantities and the battery capacity of PHEVs on the performance of the regulated charging are investigated.

ELECTROMAGNETIC DESIGN AND ANALYSIS OF A NOVEL MAGNETIC-GEAR-INTEGRATED WIND POWER GENERATOR USING TIME-STEPPING FINITE ELEMENT METHOD

This paper presents a novel permanent-magnet (PM) machine for wind power generation. In order to achieve high power/torque density as well as get rid of the nuisances aroused by the mechanical gearbox, a coaxial magnetic gear (CMG) is engaged. Difierent from the existing integrated machine in which armature windings are deployed in the inner bore of the CMG as an individual part, stator windings are directly inserted among the slots between the ferromagnetic segments in this proposed machine. Thus, it can ofier several merits, such as simpler mechanical structure, better utilization of PM materials and lower manufacturing cost. Moreover, by artfully designing the connection of the armature windings, the electromagnetic coupling between the windings and the outer rotor PMs can be dramatically decreased, and the electromechanical energy conversion can be achieved by the fleld interaction between the inner rotor PMs and the armature windings.

OPTIMUM DESIGN FOR IMPROVING MODULATING- EFFECT OF COAXIAL MAGNETIC GEAR USING RESPONSE SURFACE METHODOLOGY AND GENETIC ALGORITHM

Coaxial magnetic gear (CMG) is a non-contact device for torque transmission and speed variation which exhibits promising potential in several industrial applications, such as electric vehicles, wind power generation and vessel propulsion. CMG works lying on the modulating-efiect aroused by the ferromagnetic segments. This paper investigates the optimum design for improving the modulating-efiect. Firstly, the operating principle and the modulating-efiect is analyzed by using 1-D fleld model, which demonstrates that the modulating- efiect is essential for the torque transmission capacity of CMGs, and the shape of the ferromagnetic segments have impact on the modulating- efiect. Secondly, the fltted model of the relationship between the maximum pull-out torque and the shape factors including radial height, outer-edge width-angle and inner-edge width-angle is built up by using surface response methodology. Moreover, FEM is engaged to evaluate its accuracy. Thirdly, the optimum shape of the ferromagnetic segment is obtained by using genetical algorithm.

A Novel Dual-Permanent-Magnet-Excited Machine for Low-Speed Large-Torque Applications

This paper proposes a novel dual-permanent-magnet-excited (DPME) machine, in which two sets of permanent magnets (PMs) are employed, one on stator and the other on rotor. Bi-directional field modulation effect (BFME) is artfully engaged to guarantee the effective coupling between the magnetic field excited by the armature windings and those excited by the two sets of PMs. Machine configuration and its operating fundaments are elaborated. Finite element analysis demonstrates that the proposed DPME machine can offer much higher torque capability than its existing counterparts, which allows it a strong competitor for low-speed large-torque applications.

Integrated Magnetic-Geared Machine With Sandwiched Armature Stator for Low-Speed Large-Torque Applications

This paper proposes a novel integrated magnetic-geared machine for low-speed large-torque applications. By embedding the armature windings into the air slots adjacent to the modulating segments, a complex component which can serve as the armature stator and the modulating stator simultaneously is achieved. Therefore, the proposed integrated machine is with simpler mechanical structure than the existing integrated machine. Since the permanent magnets on the two rotors are all effectively involved in the energy conversion process, high torque density can be achieved. Moreover, the proposed machine exhibits high power factor due to the week armature-excited field.

Design and analysis of new fault-tolerant permanent magnet motors for four-wheel-driving electric vehicles

In this paper, a novel in-wheel permanent-magnet (PM) motor for four-wheel-driving electrical vehicles is proposed. It adopts an outer-rotor topology, which can help generate a large drive torque, in order to achieve prominent dynamic performance of the vehicle. Moreover, by adopting single-layer concentrated-windings, fault-tolerant teeth, and the optimal combination of slot and pole numbers, the proposed motor inherently offers negligible electromagnetic coupling between different phase windings, hence, it possesses a fault-tolerant characteristic. Meanwhile, the phase back electromotive force waveforms can be designed to be sinusoidal by employing PMs with a trapezoidal shape, eccentric armature teeth, and unequal tooth widths. The electromagnetic performance is comprehensively investigated and the optimal design is conducted by using the finite-element method.

A compact integrated switched reluctance motor drive with bridgeless PFC converter

This paper presents a compact integrated switched reluctance motor(SRM) drive with bridgeless PFC converter. A novel SRM converter topology which integrated a battery charger in the SRM drive is proposed. The motor drive is rebuilt as a battery charger in the charging function. In order to obtain the balance force, the two freewheeling diodes are instead of two thyristors to inject the same magnitude current in two phases. For the driving function, the proposed SRM drive operates as an asymmetric converter. In the charging mode, all phase winding are used as inductances. The two phase windings are used to a bridgeless boost converter to satisfy the power quality requirement. The other winding is constructed be a buck-boost converter to charging the battery. The operation modes are introduced in detail. Due to ac and dc current will flow into the phase winding of SRM, the magnetic field and torque will be analyzed by FEM. Also, the charging position which is proved by mathematical method is found to keep the rotor at still and improve the charging efficiency. The control strategy of the proposed system is presented. Some simulation results are done to verify performance of proposed converter.

Anti-skid for Electric Vehicles based on sliding mode control with novel structure

It is prone to skid or slip for wheel vehicles when driving on the low adherent surfaces. Due to the high nonlinearity of time-varying parameters and uncertainties, the anti-skid control is usually very difficult. A robust anti-skid control based on the sliding mode control and friction coefficient estimation is proposed. Furthermore, a novel anti-skid control structure utilizing the drivers demanded slip ratio is adopted to coordinate the automatic control and the mans operation on foot pedal. Co-simulations with SIMULINK and CarSim show the effectiveness.

A Novel Targeted Magnetic Fluid Hyperthermia System Using HTS Coil Array for Tumor Treatment

This paper presents a concept of a novel targeted magnetic fluid hyperthermia system for tumor treatment. A copper solenoid is engaged to generate an oscillating high-frequency magnetic field in the tumor area to heat the injected nano-particles to kill the tumor cells. In addition, a high temperature superconductor (HTS) coil array consisting of six HTS coils deployed symmetrically in the space surrounding the patient, is used to excite a static magnetic field in the area around the tumor cells to protect the healthy tissues from thermal damage. The design considerations on the HTS coil array and the copper solenoid are introduced. Their performances are quantitatively analyzed by using 3-D finite-element method.

Analysis parking position of integrated switched reluctance motor drive system with on-board charger for EV

Analysis parking position of integrated switched reluctance motor drive with on-board charger for EV is proposed in this paper. The switched reluctance motor drive and battery charger are integrated in the EV application. A novel topology converter is proposed. The operation modes are introduced in detail. Due to the charging current is injected to phase windings, the rotor will produce the torque to rotate or rock, so the mechanical loss is increased in charging mode. The parking position can be controlled to reduce the mechanical loss. The special parking positions are found from different charging modes. And the magnetic field and torque are analyzed by FEM when the sine-wave current flows in the winding. Some simulation results are done to verify the performance of proposed converter.