Yong-Ho Yoon

A 3 kW fuel cell generation system using the fuel cell simulator

Fuel cell system includes a fuel processor and subsystems Io manage air, water, thermal energy, and power. The overall system is high-priced and needs to peripheral devices. In this paper, the fuel cell simulator designed and manufactured as electrical characteristic of fuel cell generation system uses a simple buck converter to overcome these disadvantages. Characteristic of voltage and current (V-I) curve for fuel evil simulator is controlled by the linear function of being simplified, and we designed the fuel cell simulator. In addition, to verify fuel cell generation system performance and operation, full-bridge DC/DC converter and single-phase DC/AC inverter are designed and manufactured for fuel cell applications. The close agreement between the simulation and the experimental results confirms the validity and usefulness of the proposed fuel cell simulator.

A New Cost Effective SRM Drive using Commercial 6-Switch IGBT Modules

The main purpose of this paper is to describe six-switch inverters for cost effective Switched Reluctance Motor (SRM) drive used in commercial applications. For effective utilization of the developed system, a novel direct current controlled PWM scheme is designed and implemented to produce the desired dynamic and static speed-torque characteristic. Compared with the conventional split typed asymmetric converter topology, it can minimize the entire system size and cost and can increase the efficiency. Therefore, it may pave a new way for SRM to compete with other ac motors, such as induction motors, brushless dc motors, and so on. The validity of the proposed method is verified by theoretical explanation, simulation, and experimental results.

New Approach to Rotor Position Detection and Precision Speed Control of the BLDC Motor

This paper presents particular methods for deployment of the sensorless permanent magnet brushless DC (PM BLDC) motor drive system. The waveform of the motor internal voltages (or back emf) contains fundamental and higher order frequency harmonics. Therefore the third harmonic component is extracted from the stator phase voltage. The resulting third harmonic signal maintains a constant phase relationship with the rotor flux at any motor speed and load condition. In addition, in this paper, a simple starting method and speed estimation approach are also proposed. Experimental results are provided, to demonstrate the validity of the proposed control method

PLL control algorithm for precise speed control of the slotless PM brushless DC motor Using 2 Hall-ICs

The high performance drives of the slotless permanent magnet brushless DC (PM BLDC) motor can be achieved by the current control, where the currents flow according to the rotor position and the current phase is suitably controlled according to the operation condition. Rotor position information can be provided by Hall-IC or sensorless algorithm. However, basically sensorless algorithm is not suitable for the complicated operation conditions of PM BLDC. So, the Hall-ICs are set up in this motor to detect the main flux from the rotor. Instead of using three Hall-ICs and encoder, this paper uses only two Hall-ICs for the permanent magnet rotor position and the speed feedback signals, and uses a microcontroller of 16-bit type (80C196KC) with the 3-phase slotless PM BLDC whose six stator and two rotor designed. Two Hall-ICs H/sub A/ and H/sub B/ are placed on the endplate at 120 degree phase difference. With these elements, we estimate information of the others phase in sequence through a revolving rotor. Also because of low resolution obtained by using Hall-IC even low-cost and simple structure, to improve the wide range of speed response characteristic more exactly, we propose the rotor position signal synthesizer using PLL circuit based on two Hall-ICs.

High performance switched reluctance motor drive for automobiles using C-dump converters

Small electric motors in an automobile perform various tasks such as engine cooling, pumping, and in heating, ventilating, and air-conditioning (HVAC) system. At present, most of DC motors are supplied by 12 V or 24 V batteries. However, DC motors suffer from lack of efficiency, low life cycles and unreliability. Therefore, there is a growing interest in substituting DC motors for advanced AC motors including switched reluctance motors. Although there are several other forms SRM converters, they are either unsatisfactory to the control performance or unsuitable for the 12 V-battery powered 3-phase SRM drives. Taking into account the requirement for effective operation and simplicity structure of converter in the limited internal environment of automobiles, the author inclines toward selecting the modified C-dump converter as well as the energy efficient C-dump converter. This is so that more economical and efficient converter topology in automobile industries can be utilized. This paper describes the foundation for the design and development of a 12 V-250 W-3000 rpm SRM drives for automobiles. Furthermore, complete circuit, computer simulation and experiment results are presented to verify the performance of the C-dump converters.

Precise speed control of the PM brushless DC motor for sensorless drives

This paper describes the method of precise speed control for the sensorless PM BLDC motor drives using the PLL. The method using the third harmonic voltage component between the networking resister of the stator phase voltage and the motor neutral point is applied for the sensorless PM BLDC motor drives. As a result, we obtained that it results of achieving a good performance over a wide speed range because it is not sensitive to the filtering delays. In addition to the estimated Hall-ICs signal circuit by the Johnson counter, the estimated Hall-ICs signal haves the identical period and frequency like sticked Hall-ICs signal in the PM BLDC motor. Also, we proposed the rotor position signal synthesizer using the PLL based 6-pulse. Because of high resolution obtained by using the PLL circuit, we can improve the wide range of speed response characteristic more exactly. Some experimental results are provided to demonstrate the validity of the proposed control method.

Autonomous Underwater Vehicles with Modeling and Analysis of 7-Phase BLDC Motor Drives

In this paper, a simulation model for 7-phase BLDC motor drives for an Autonomous Underwater Vehicles (AUV) is proposed. A 7-phase BLDC motor is designed and the electrical characteristics are analyzed using FEA program and the power electronics drives for the 7-phase BLDC motor are theoretically analyzed and the actual implementation has been accomplished using Matlab Simulink. PI controller and fuzzy controller are compared for verifying the validity of the proposed model and the informative results are described in detail. Especially A fuzzy controller is used to characterize 7-phase BLDC motor, drive systems under normal and fault operating conditions.

Rotor Position Estimation of 3-Phase PM BLDC Motor by 2Hall-IC, 1Hall-IC

Generally, Permanent Magnet Brushless DC Motor(PM BLDC) is necessary the Hall-IC to detect the rotor position. But it will take place the operation standstill of motor or error of rotor position detection according to the circumference temperature, humidity, or limited surroundings. This paper propose the algorithm of rotor position detection only using one or two Hall-IC. Therefore we can estimate information of the others phase in sequence through a rotor instead of using three Hall-IC at 3 phase motor. This paper identify the same characteristics, performance and function of protection circuit by the proposed algorithm with the 3 phase PM BLDC motor in comparison with general method.

Current hysteresis controlled resonant C-dump converter for switched reluctance motor drive

The speed at which the SRM makes a transition from chopping control to single pulse operation, (i.e., low speed to high speed operation). It is unsatisfied with performance at all operational regimes. In this paper, the operational performance of SRM can be improved by using current hysteresis control method. This method maintains a generally flat current waveform. At the high speed, the current chopping capability is lost due to the development of the back-EMF. Therefore SRM operates in single pulse mode. By using zero-current switching and zero-voltage switching technique, the stress of power switches can be reduce in chopping mode. When the commutation from one phase winding to another phase winding, the current can be zero as fast as possible in this period because several times negative voltage of DC-source voltage produce in phase winding. This paper is compared to performance based on conventional C-dump converter topology and the proposed resonant C-dump converter topology. Simulation and experimental results are presented to verify the effectiveness of the proposed circuit.

Photovoltaic system application performance in extreme environments like desert conditions

The increased penetration of PV is impacting on grid operation and in particular the voltage within the local grid can be significantly influenced by the various PV systems. Especially extreme clim...