Common-mode voltage by switching pattern of space vector pulse width modulation excites parasitic capacitance coupling in interior permanent magnet synchronous motors, and it finally causes a shaft-to-frame voltage. Among all parasitic capacitances, winding-to-rotor parasitic capacitance has the greatest effect on the shaft-to-frame voltage, which means the winding-to-rotor parasitic capacitance must be suppressed for noticeable mitigation of the shaft-to-frame voltage. This paper proposes two suppression methods by changing the stator winding-to-rotor and end winding-to-rotor capacitances. First, modified winding shape is utilized for the suppression of stator winding-to-rotor capacitance. Second, a copper shield is applied to suppress the end winding-to-rotor parasitic capacitance. Finally, both methods are applied together to mitigate the effect of the stator winding-to-rotor and end winding-to-rotor capacitances on the shaft-to-frame voltage.

The present in vehicle 14 V DC power system is being pushed to the maximum limits to meet the high power loads. In the mean time, the 42 V power nctwork("powernet") in future automobiles enables a number of new features that require high power loads including electric power steering, engine cooling fan system, electric compressors etc. This paper presents a design and implementation of brushless DC (BLDC) motor and controller for engine Cooling fan system for 42 V automotive applications. Experimental results from a laboratory prototype are presented to validate the feasibility of the proposed BLDC Motor and Drive.

This paper presents an improved micro-step voltage-fed actuator for an automobile active grill shutter (AGS) system. A novel structured stepper motor, which contains both the main and auxiliary teeth in the stator, is proposed for the actuator. In a normal permanent magnet (PM) motor coils are generally wound on all the stator teeth, however, in the proposed motor, the winding is only on the main teeth. Because of the absence of coils in the auxiliary teeth, the proposed stepper motor possesses the following advantages: simple structure, lighter weight, smaller volume, and less time consumption. The unique auxiliary poles in the stepper motor supply the flux path to increase the step resolution even without any coils. The characteristics of the proposed stepper motor were investigated using finite element analysis. In particular, the effect of the magnetization distribution of the PM on the motor performance was investigated during the analysis. Cogging torque, which causes noise and vibration issues, was minimized by the tooth-shape optimization. In addition, a micro-step voltage-fed algorithm was implemented for a high-resolution position control. By employing a current close to a sine wave using space vector pulse-width modulation, a high-quality current waveform with a high resolution was obtained. Finally, the proposed prototype was fabricated, and the cogging torque, back-electromotive force, and current characteristics were measured by mounting the prototype on the AGS system. Both the analysis and experimental results validate the performance improvement from the proposed motor and its possible application for the flap control of the AGS system.

A lot of conventional automotive components driven by mechanical power source are being replaced with electrical ones to comply with the demands of market and customer, therefore the amount of electric energy used in a vehicle will be increased continuously. The increment of electric power demand causes interest on new higher power system such as 42V Power Net, and furthermore necessity for development of energy storage device is highlighted recently. The electro- hydraulic power steering (EHPS) system is one of them. This paper presents the development of the electric driven pump unit for EHPS system of 42V automobile, which is to install interior type permanent magnet synchronous motor.

This paper investigates the performance of the line start permanent magnet (LSPM) motor which needs a high efficiency characteristic in a wide operation region. LSPM motor's performance indexes, such as efficiency, motor current, load angle and synchronous torque, have complex relationship with each other according to the main and auxiliary windings distribution, and the selection of running capacitor. The output characteristics can be defined by the winding structure which is calculated by d-q equivalent circuit and finite element method. The efficiency characteristic is verified by simulation as well as by experiment on the designed LSPM motor. From the results, we show that the redesigned model considering the winding structure and capacitor matching has a wide operating region.

This paper presents the dynamic characteristic analysis of a small sized permanentmagnet (PM) type stepping motor with newly structured claw-poles. First, the motor parameter is derived by PM analyzing torque and back-EMF using the 3-D finite element analysis (FEA) taking account magnetization of PM. Next, the dynamic characteristic of a small sized motor is calculated by magnetic circuit equation coupled with 3-D FEA. Specially, we propose a test method of step response for a small sized PM type stepping motor using a position sensitive detection (PSD) sensor. From the simulation and test results, it is shown that the proposed dynamic characteristic analysis method has usability for a very small sized motors.