Automotive electrical and electronic systems, e.g. EHV, FCV, future X-By-Wire, have recently been introduced or planned in place of mechanical systems. Drivers are demanding environmental performance (fuel consumption and weight reduction), safety and comfort. For general use of the new technologies, evolution of the automotive technology is required, including energy conversion efficiency improvement, size and weight reduction of components, cost reduction and high reliability. This paper discusses and summarizes the next generation power systems, the future vehicle image, power source combinations, and problems to be solved for development of automotive electronics.

抄録全体を表示

Generally, vector controllers in induction motors tend to suffer from the influence of rotor resistance variation caused by temperature and load torque conditions. Several rotor resistance identification methods have been proposed in the literature. In this paper, a novel rotor resistance identification technique is proposed based on variables in the magnetic suspension control loops. When static force, for example, a shaft weight is applied, force commands are automatically generated in the opposite direction to satisfy the force equilibrium. However, the amplitude and direction of the force command vary in accordance with the rotor resistance variation. Thus, the rotor resistance can be identified from the suspension force command. In addition, influence of temperature drift in gap sensors is investigated. The effectiveness is confirmed experimentally.

抄録全体を表示

In this paper, a current sensorless MPPT control method for a stand-alone-type PV generation system is proposed. This control method offers advantages of the simplified hardware configuration and the low cost, by using only one sensor to measure the PV output voltage.
In the application to stand-alone-type with a battery load, the experimental results show that the estimated values of PV output current are accurate, and the use of the proposed MPPT control increases the PV generated energy by 16.3% compared to the conventional system. Furthermore, it is clarified that the proposed method has extremely high UUF (Useful utilization factor) of 98.7%.

抄録全体を表示

An AC photovoltaic module system is recognized as a novel photovoltaic power generating system. However, serious EMI troubles caused by the photovoltaic inverters are suspected, because many inverters operate simultaneously. This paper discusses common-mode conducted EMI and its a reduction method of parallel operation of grid connectable inverters. In the case of parallel operation of inverters, the characteristic impedance of the series resonant circuit in a common-mode equivalent circuit decreases and it increases a noise voltage on grid lines. When a common-mode inductor is connected in series to the total output line, the reduction effect of common-mode noise is larger compared to when individual inductors are connected to each inverter output.

抄録全体を表示

We have already proposed the anti-slip re-adhesion control based on disturbance observer and sensor-less vector control at acceleration mode. This paper proposes a new anti-skid re-adhesion control based on disturbance observer at braking mode. The numerical simulation and experimental results point out that the proposed anti-skid re-adhesion control system has the desired driving wheel torque response for the tested bogie system of electric train.
An actual train uses both electric brake and air brake in the high-speed range. Hence, this paper proposes a new anti-skid re-adhesion control considering the air brake, which carries out the cooperation control of electric brake and air brake in order to realize a fine re-adhesion control. The numerical simulation results point out that the proposed system has the desired driving wheel torque response and a fine anti-skid re-adhesion control.

抄録全体を表示

We made a prototype rear-view mirror with built in an image sensor. Useful driver assistance systems, image-processing is one of the best approach and it is necessary to develop a suitable image sensor for acquiring driver's images. We developed an image sensor that could acquire driver's image under several environments and investigated the methods to detect driver's eye blink for the “Driver's Monitor System" that estimated driver awareness level. Described in this paper, are the superior characteristics and evaluation results of the prototype rear-view mirror.

抄録全体を表示

An autonomous control for redundant parallelism of uninterruptible power supplies (UPS) connected in parallel has successfully been proposed and discussed in theoretical and experimental terms. This independent control only requires the measurement of the output current. With the computation of the active and reactive currents, proportional-integral-based controllers provide the phase angle and amplitude, respectively, of the output voltage. However, when voltage difference between UPS exists, there is a flow of reactive lateral current, which makes the load sharing disproportional. A preliminary approach to reduce this circulating current considers a high proportional gain in the control equation for output voltage amplitude in order to reduce the offset error. Nevertheless it implies in high variation of the voltage amplitude, so that voltage levels easily reaches the limit, and the respective control equation becomes incapable to compensate any voltage difference. This paper proposes a compensator to counterbalance the voltage drop caused by the proportional gain of the control equation for the voltage amplitude. Implementation in an experimental setup with three UPS with different output rating connected in parallel shows significant reduction of the reactive lateral current, and consequent improvement of the current distribution, including employment of voltage limiters (1%), under various conditions.

抄録全体を表示

Recently, finite element method (FEM) that is one of the calculation method of non-linear electromagnetic equation used for analysis of a motor characteristic. It is important to analyze the motor by using FEM as well as the equivalent circuit analysis for its design and applications. We have proposed a new-type induction motor that has free-rotating magnets inside the rotor (IMFM). IMFM has a squirrel-cage type rotor and a magnet rotor inside the rotor. The rotor and the inner magnet rotor are driven at different rotational speed. Therefore, it is difficult to analyze IMFM by using FEM. In this paper, we propose a new FEM application technique for analyzing IMFM. In this method, we gave different speeds to the inner magnet rotor and the rotor respectively, and adjusted the phase of the applied voltage so that the magnet rotor does not generate the output torque. The characteristic between the torque and the rotational speed obtained by the magnetic field analysis of IMFM was matched well with that of the experimental results in the practical slip range.

抄録全体を表示

The spread of wind energy converter is progressing in recent years and its capacity is becoming larger and larger. In order to capture more energy from the wind, it is important to analyze loss characteristics of wind generators for operating speed which is determined dependent on the wind speed. This paper presents a method to evaluate various losses in wind generator as a function of wind speed, which is based on the steady state analysis and thus the calculation can be performed quickly. By using the proposed method, wind turbine power, generator output, various losses, and the total energy efficiency are calculated for three types of wind speed data which are represented by a weibull function.

抄録全体を表示