Go to the main menu
Skip to content
Go to bottom
REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
The Transactions of the Korean Institute of Power Electronics
Journal Basic Information
Journal DOI :
The Korean Institute of Power Electronics
Editor in Chief :
Volume & Issues
Volume 3, Issue 4 - Dec 1998
Volume 3, Issue 3 - Sep 1998
Volume 3, Issue 2 - Jun 1998
Volume 3, Issue 1 - Mar 1998
Selecting the target year
Improvement of Step-charging Characteristic for Ni-MH Battery by Selective Cut-off Method
The Transactions of the Korean Institute of Power Electronics, volume 3, issue 4, 1998, Pages 273~279
In this paper, the proposed charging system consists of step charging mode and time-sharing equalization charging mode. As
V=O point is detected, the proposed cut-off method will selectively cut off the only battery to reach the
V=O point, preventing serial-connected batteries from undercharging. In the start of each step, the equalization charging mode is performed to reduce the capacity difference among the batteries. Though it is added to simple circuit for selective cut-off, comparing with recently used step-charging method, this system can improve the life cycle of battery and charging efficiency, and be also very effective for preventing the batteries from overcharging and undercharging.
Reduction of Torque Ripple due to Current-Sensing Errors in Inverter-Fed AC Motor Systems
The Transactions of the Korean Institute of Power Electronics, volume 3, issue 4, 1998, Pages 280~286
This paper proposes a novel method to reduce the torque ripple due to the non-ideality of the current sensing parts in vector-controlled inverter-fed AC motor drive systems. For PMSM(Permanent Magnet Synchronous Motor), motor output torque equations are derived in terms of their offset voltages and different voltage transducing gains. And the effects of phase current errors on motor torque are analyzed for both salient PMSM and non-salient PMSM. The proposed method can eliminate the torque ripple by nulling the offset voltages and setting the voltage transducing gains to the same value. To verify the proposed method, digital simulations are carried out for non-salient PMSM.
Reduction of Audible Switching Noise in Induction Motor Drives Using Random Position PWM
The Transactions of the Korean Institute of Power Electronics, volume 3, issue 4, 1998, Pages 287~297
RPWM(Random Pulse Width Modulation) is a switching technique to spread the voltage and current harmonics on wide frequency area. Using randomly changed switching frequency of the inverter, the power spectrum of the electromagnetic acoustic noise can be spread into the wide-band area. And the wide-band noise is much more comfortable and less annoying than the narrow-band one. So RPWM have been attracting an interest as an excellent reduction method of acoustic noise on the inverter drive system. In this paper a new RPPWM(Random Position PWM) is proposed and implemented. Each of three pulses is located randomly in each switching intervals. Along with the randomization of PWM pulses, the space vector modulation is processed on the C167 microcontroller also. The experimental results show that the voltage and current harmonics were spread into wide band area and that the audible switching noise was reduced by proposed RPPWM method.
High-Power-Factor Boost Rectifier with a Passive Energy Recovery Snubber
Kim, Marn-Go ;
The Transactions of the Korean Institute of Power Electronics, volume 3, issue 4, 1998, Pages 298~306
High Power Factor Dual Half Bridge Series Resonant Inverter for an Induction Heating Appliance with Multiple Loads
The Transactions of the Korean Institute of Power Electronics, volume 3, issue 4, 1998, Pages 307~314
A novel high power factor Dual Half Bridge Series Resonant Inverter (DHB-SRI) for an induction heating appliance with multiple loads is proposed to remove the interferential acoustic noise caused by the difference between operating frequencies of adjacent loads. The circuit enables independent full power range control of two induction heating elements by one inverter circuit and has minimum switching losses due to the zero voltage switching characteristic. According to the mode analysis, I will explain the operation of the proposed circuit. To evaluate the required cooling capacity, loss analysis is performed through deriving some loss equations. In order to obtain the power factor correction capability and to lessen the system size, suitable design guides are given. Using the designed values, the proto-type circuit with 2.8kW power consumption for each induction heating element is built and tested to verify the operation of the proposed circuit.
converter of high efficiency by partial resonant switching using lossless snubber
The Transactions of the Korean Institute of Power Electronics, volume 3, issue 4, 1998, Pages 315~322
Power conversion system must increase switching frequency in order to achieve small size, light weight and low noise. However, the switches of converter are subject to high switching power losses and switching stresses. As a result, the power system has a lower efficiency. In this paper, the authors propose an AC-DC boost converter of high efficiency by partial resonant switching mode. The switching devices in the proposed circuit are operated with soft switching and the control technique of those is simplified for switch to drive in constant duty cycle. The partial resonant circuit makes use of a inductor using step up and a condenser of loss-less snubber. Besides, by regenerating energy, that is charged in a loss less snubber condenser of a snubber adopted to a common circuit, toward an input source part, this circuit can get increased efficiency. as merit. The result is that the switching loss is very low, the efficiency and power factor of system is high. The proposed converter is deemed the most suitable for high power applications where the power switching devices are used.
A Utility Interactive Photovoltaic Generation System using PWM Chopper and Current Source Inverter
The Transactions of the Korean Institute of Power Electronics, volume 3, issue 4, 1998, Pages 323~329
In this paper, we compose of the utility interactive photovoltaic(PV) generation system with a PWM stepdown chopper and a current source inverter. The stepdown chopper is controlled by the several gate pulses (twice frequency of utility voltage, square pulse and without the chopper) of chopper part to reduce pulsation of DC current and size of DC reactor. PV current only is measured for maximum power point tracking without any influence on the variation of insolation and temperature. Therefore, we can control modulation factor of the chopper to operate at maximum power point of solar cell. And, the utility interactive photovoltaic generation system supplies an AC power to the load and the utility power system.
Duty Cycle Modeling for Average Model of Buck Converter Employing Hysteresis Control
The Transactions of the Korean Institute of Power Electronics, volume 3, issue 4, 1998, Pages 330~337
A duty cycle average model is mathematically developed for an average model of buck converter employing hysteresis c control. The derived model is able to simultaneously deal with both the continuous conduction mode (CCM) and the d discontinuous conduction mode (DCM) in the time domain. Also. taking advantage of the MAST language of SABER. a t template of the proposed duty cycle average model is built for the time and frequency domain analyses. The accuracy of t this template is verified through the computer simulations.
Small Signal Modeling of Current Mode Control
The Transactions of the Korean Institute of Power Electronics, volume 3, issue 4, 1998, Pages 338~345
The mathematical interpretation of a practical sampler which is useful to obtain the small signal models for the peak and average current mode controls is proposed. Due to the difficulties in applying the Shannons sampling theorem to the analysis of sampling effects embedded in the current mode control, several different approaches have been reported. However, these approaches require the information of the inductor current in a discrete expression, which restricts the application of the reported method only to the peak current mode control. In this paper, the mathematical expressions of sampling effects on a current loop which can directly apply the Shannons sampling theorem are newly proposed, and applied to the modeling of the peak current mode control. By the newly derived models of a practial smapler, the models in a discrete time domain and a continuous time domain are obtained. It is expected that the derived models are useful for the control loop design of power supplies. The effectiveness of the derived models are verified through the simulation and experimental results
Speed-Sensorless Vector Control of an Induction Motor Using Neural Network Speed Estimation Scheme
The Transactions of the Korean Institute of Power Electronics, volume 3, issue 4, 1998, Pages 346~352
A Study on the Development of Stand-Alone Model for Power Converter Circuit Simulation
The Transactions of the Korean Institute of Power Electronics, volume 3, issue 4, 1998, Pages 353~364
This paper presents a systematic approach to the modeling of power electronic circuits with systemlongrightarrowlevel simulation l languages. It is shown that a circuit model reduces to one of four basic types according to input/output conditions. The e elementary models for single series components and shunt components are derived which are integrated to develop a m model of given converter circuit. The constraints imposed on the model development-matching input/output conditions a and avoiding algebraic loop-are discussed in relation to the realization example of a buck converter circuit model. It is s shown that the constraints can always be fullfilled by introducing fictitious interface blocks, which is generalized to the c concept of model transformation.
Approximate SHE PWM for Real-Time Control of 2-Level Inverter
The Transactions of the Korean Institute of Power Electronics, volume 3, issue 4, 1998, Pages 365~374
The SHE(Selected Harmonic Elimination) PWM scheme which eliminates specific lower order harmonics can generate h high quality output waveforms in 3-level PWM inverters. However. its application has limited since SHE switching a angles cannot be calculated on-line by a microprocessor-implemented control system. Based on off-line optimization. in which multiple SHE solutions were found and analysed for 2 to 5 switching angles per quarter in the 3-level SHE PWM pattern. this paper presents an algebraic algorithm for an ordinary microprocessor to calculate approximate SHE S switching angles on-line with such high resolution that it makes no practical difference between the accurate and the a approximate SHE switching angles. By employing the variable of the dc-link voltage Vdc' the proposed SHE PWM p pattern can ideally compensate the dc input fluctuation together with selected harmonics eliminated.
ZVS PWM Converter For Battery Charger
The Transactions of the Korean Institute of Power Electronics, volume 3, issue 4, 1998, Pages 375~381
Zero Voltage Switched (ZVS) Pulse Width Modulation (P~마1) converter which operates a fixed frequency is proposed in this paper. The main switches of the converter are always switched at zero voltage, and the auxiliaη switches are s softly switched, The voltage and current stresses of the switches are minimized as low as in conventional PWM converters, The suggested buck typed converter is analyzed. designed for a battery charger. The designed characteristics are experimentally verified by the results of the buck type converter.
A Method for Adaptive Hysteresis Current Control of PWM Inverter Using Neural Network
The Transactions of the Korean Institute of Power Electronics, volume 3, issue 4, 1998, Pages 382~387
The adaptive hysteresis band current control method using neural network is proposed to hold the switching frequency of PWM inverter constant at any operating points of ac motor. The adaptive hysteresis band equation is derived as the teaching signal of neural network. and then the structure and learning algorithm of the neural network a are suggested. The simulation results show that the switching frequency of PWM inverter is held constant at any operating conditions of ac motor and the proposed method has good transient performance of stator current.
The Look-up table Plus-Minus Tuning Method of Fuzzy Control Systems
The Transactions of the Korean Institute of Power Electronics, volume 3, issue 4, 1998, Pages 388~398
In constructing fuzzy control systems. there are many parameters such as rule base. membership functions. inference m method. defuzzification. and I/O scaling factors. To control the system in properly using fuzzy logic. we have to consider t the correlation with those parameters. This paper deals with self-tuning of fuzzy control systems. The fuzzy controller h has parameters that are input and output scaling factors to effect control output. And we propose the looklongleftarrowup table b based self-tuning fuzy controller. We propose the PMTM(Plus-Minus Tuning Method) for self tuning method, self-tuning the initial look-up table to the appropriate table by adding and subtracting the values.
A Study on Novel High Performance SRM Drive
The Transactions of the Korean Institute of Power Electronics, volume 3, issue 4, 1998, Pages 399~406
This paper proposes an instantaneous torque control method for the high performance SRM drive. In first, we e establish SRM model with the characte1istics of the torque. phase current and rotor position which were measured in t the experimental SRM. Based on this model. the reference torque waveform to minimize torque ripple is obtained by t the control of resultant torque considering phase torque overlap according to the variation of load and speed. And the r reference current waveform for the tracking of reference torque are decided. The control method for tracking the r reference current is used the delta modulation technique. The proposed method is validated by the comparing with S simulation and experimental results.
Novel Dual-Carrier PWM and It's Implementation
The Transactions of the Korean Institute of Power Electronics, volume 3, issue 4, 1998, Pages 407~411
Traditional carrier-based PWM method cannot produce maximum output voltage due to dead-time compensation, w which results in degradation of voltage utilization factor compared with ideal PWM inverters, Dual-carrier PWM has b been proposed as an alternative method to solve this problem. But this method requires paying attentition to changing r reference voltage in the vicinity of maximum voltage to ensure enough dead-time. Novel dual-carrier PWM method and i it's practical implementation is proposed in this paper. The reference voltage can be changed without any restriction in t this method.
A Study on the Drive Characteristics of SRM by 2-Phase Excitation Method
The Transactions of the Korean Institute of Power Electronics, volume 3, issue 4, 1998, Pages 412~417
This paper suggests the drive characteristics of a Switched Reluctance Motor(SRM) by 2-phase excitation method. T This scheme excites 2 phases simultaneously, which is similar to 2-phase excitation method of a step motor. In this s scheme. the torque is produced by mutual inductances as well as self inductances. The abrupt change of a phase e excitation produces mechanical stresses and it results in vibration and noise. The acoustic noise is reduced remarkably t through the sequential phase excitation in the 2-phase excitation. Operational principle and characteristic comp없1son t to that of the conventional SRM show that this excitation scheme has some advantages including torque ripple and n noise reduction.
Determination of Optimal Turn-off Angle for SRM Converter Using Self-Tuning Method
The Transactions of the Korean Institute of Power Electronics, volume 3, issue 4, 1998, Pages 418~425
In this paper. determination method of turn-off angle in the SRM drives is proposed to maintain the high torque at a any turn-on angle, which is realized by using selHuning control method, During the sampling time. a number of P pulses from encoder are checked by using one-chip microprocessor. and compared with pre-checked a number of pulses A After calculating difference between two data, the turn-off angle moves forward or backward direction by the self-tuning m method, As repeating such process, the optimal turn-off angle is determined and the maximum torque is maintained T Though experiments, it is observed that motor speed is almost maintained if turn-off angle is adjusted automatically by s selHuning method when turn-ηn angle is changed.
An Improved Short Circuit Protection Scheme for IGBT Inverters
The Transactions of the Korean Institute of Power Electronics, volume 3, issue 4, 1998, Pages 426~436
Identification of fault current during the operation of a power semiconductor switch and activation of suitable remedial actions are important for reliable operation of power converters. A short circuit is a basic and severe fault situation in a circuit structure such as voltage source converters. This paper presents a new active protection circuit for fast and precise clamping and safe shutdown of fault currents of the IGBTs. This circuit allows operation of the IGBTs with a higher on-state gate voltage, which can thereby reduce the conduction loss in the device without compromising the short circuit protection characteristics. The operation of the circuit is studied under various conditions, considering variation of temperature, rising rate of fault current, gate voltage value, and protection circuit parameters. An evaluation of the operation of the circuit is made using IGBTs from different to confirm the effectiveness of the protection circuit.