THE HIGH-FREQUENCY BASE CONVERTERS WITH VARIABLE CIRCULATING CURRENT

Mikihiko MATSUI,Sejin SEONG,Tadashi FUKAO 전력전자학회 1989 ICPE(ISPE)논문집 Vol.- No.-

" High frequency (HP) base " or " HF" link " power conversion techniques are now expected to be applied for very large capacity power conversions in the future, because they can be realized by using conventional commutation turn-off thynstors which have merits in costs and reliabilities compared with GTOs. This paper summarizes a novel series of HF base power converters named "HFbase-VCC(HF base converters with variable circulating current)", that are characterized by the variable circulating current and its control scheme which the authors have been researching on. Basic principles of operation are explained through a dc source dual-converter system, then they are extended to the applications using ac source HF cycloconverter systems.<br/>

Single Phase PWM Converters with Active Filter Functions Both on AC-Input and DC-Output Sides

Mikihiko MATSUI,Talsuya KITANO 전력전자학회 1998 ICPE(ISPE)논문집 Vol.- No.-

A comparative study of single-phase PWM converters having active filtering functions both on ac-input and dc-output sides have been carried out. Based on the func­tion of the dc-output side active filter, two types of configu­rations, the RPM (npple power managing) type and the APM (average power managing) type are compared to show their contrastive characteristics. The prototype system using DSP based control algorithms, 1 e deadbeet current control and voltage sensor-less technique using full-order observer, show the availability of the proposed systems.<br/>

SOFT-SWITCHED NON-RESONANT TYPE HF LINK CONVERTER AND ITS APPLICATIONS

Mikihiko Matsui 전력전자학회 1995 ICPE(ISPE)논문집 Vol.1995 No.10

The research on soft-switching power conver­ters is becoming popular not only for making the operating frequency higher but also reducing the EMI problems. The approach toward the ideal soft-switching is classified into two which are based on the snubber circuits and the resonant circuits. Author proposed a totally soft-switched non-resonant type HF link conver­ter based on the former approach. In this paper, the derivation of such circuit topology and basic principle are explained in detail with two application systems.

Education of Power Electronics in Japan

Matsui, Mikihiko,Ueda, Akiteru,Oguch, Kuniomi The Korean Institute of Power Electronics 2002 JOURNAL OF POWER ELECTRONICS Vol.2 No.4

Power electronics is an interdisciplinary area that is interstitial to all of the major disciplines of electrical engineering including power, electronics and control. Today, the covering field of power electronics has more widely spread out with the help of ever evolving microelectronics and computer science. Whereas, in Japan the tendency is becoming remarkable nowadays that science, especially "mathematics" and "hardware work", are falling into disfavor with the young people. For these reasons, it has become a very important problem to find out "what are the truest essentials of power electronics\ulcorner" and "How to give students incentives to learn power electronics\ulcorner " from an educational point of view In under-graduate and graduate courses in universities. On the other hand, the power electronics engineers in companies are always required to comply with the ever changing trend of global and open market. However, it takes long time to cultivate their skills. Against the background, "The Cooperative Research Committee on Education of Power Electronics" was established in the IEEJ Industry Applications Society during 2000-2001. The present status of the power electronics education in Japan is surveyed in this paper, and some problems with remedy are pointed out based on the discussions performed in the committee.sed on the discussions performed in the committee.

A Solar Battery Charging Module by Means of Limit-Cycle MPPT Control

Mikihiko Matsui,Kanghoon Koh,Byunggyu Yu,Tatsuya Kitano 전력전자학회 2007 ICPE(ISPE)논문집 Vol.- No.-

The objective of this paper is to develop a power converter module that charges a battery with solar power, and the design technique at the product level is introduced to realize a compact size and light weight. The main circuit is a buck-boost chopper so that it can cover wide range of charging voltage. The MPPT control is realized by a very simple algorithm of Limit-Cycle MPPT (LCMPPT) proposed by authors previously. All control functions are implemented in digital algorithm and a HITACHI H8 microprocessor is used for the control. In addition to the battery, a load can be directly connected also, which is automatically disconnected in the case of detecting a low voltage condition of the battery. RS-232C port is also available for observing the internal variables such as input/output voltages and currents through a PC. An example of obtained test results showing the relations of output power versus input/output voltages and efficiency are given. The efficiency is about 70-72% in a wide range of output power.

Sensor-less Approaches for Maximum Photovoltaic Power Tracking Control

Mikihiko Matsui,Tatsuya Kitano 전력전자학회 2001 ICPE(ISPE)논문집 Vol.2001 No.10

MPPT (maximum power point tracking) control is very important for the practical PV (photovoltaic) systems to maintain efficient power generating conditions irrespective of the deviation in the PV array insolation or/and temperature conditions. Although a plenty of researches have been done so far, most of them are too costly because of being too dependant on expensive sensors for measuring photovoltaic power and micro-processors for achieving elaborate and complicated control strategies. From this point of view, authors have been researching on sensor-less approaches for MPPT control, and have proposed two types of new control schemes "Power Equilibrium Scheme" and "Limit Cycle Scheme". This paper summarises these two schemes with focussing on their operating principles and some results of simulation and experiments.<br/>

Proposal of a Simple MPPT Control Technique Using Current Minor-Loop Error Information

Mikihiko Matsui,Tatsuya Kitano 전력전자학회 2004 ICPE(ISPE)논문집 Vol.- No.-

The MPPT (maximum power point tracking) control is one of the important techniques required for a recycle energy system such as PV (photovoltaic) or WTG (wind turbine generator) system that have an output power characteristic curve with an unimodal convex function and a maximum power point under the given operating condition inherently. From the view point of developing a practical home use system, the authors have been focusing on the simplification of the MPPT control system by reducing the sensor numbers and simplifying the algorithm, and have proposed several types of new power sensor-less MPPT schemes. This paper summarizes the general basic ideas of MPPT first, then reviews the authors' research works in three steps. Finally, a current minor-loop error based new MPPT scheme is proposed and its application is shown to prove its validity and usefulness.

A Novel Single-Voltage-Sensor-Based Maximum Power Point Tracking Method

Xiang-Dong Sun,Mikihiko Matsui,Kouji Yanagimura 전력전자학회 2007 ICPE(ISPE)논문집 Vol.- No.-

A novel maximum power point tracking method for photovoltaic systems based on a single voltage sensor is proposed in this paper. By means of the simulation studies with PSIM software, it has been found that there are similar relationship curves between the expression (C-d)ㆍ(-ΔVPV)and the actual power PPV of a photovoltaic array regardless of the chopper stage topology connected to the array. Therefore the maximum power point tracking based on PPV is replaced with the expression (C-d)ㆍ(-ΔVPV). For the purpose of diminishing the power fluctuation in the steady state, the averaged voltages of a photovoltaic array and the average duty ratios are used for the calculation. Experimental results obtained on a 50W prototype of a lead acid battery charger show high performance such as the less power fluctuation and the less ambient, i.e. irradiation and temperature, influence.

A Novel Islanding Detection Method Based on Minute Asymmetrical Current Injection for Three-Phase Grid-Connected PV Inverters

Xiang-Dong Sun,Mikihiko Matsui,Byung-Gyu Yu 전력전자학회 2007 ICPE(ISPE)논문집 Vol.- No.-

An active anti-islanding method based on the current control for a three-phase grid-connected PV inverter is proposed in this paper. The current of phase a is synchronous with the corresponding voltage at the common coupling point in its positive half cycle, and a zero-current zone is inserted into the end of the cycle in a negative half cycle. As for phase c, the zero-current zone is inserted in the positive half cycle of the current, and the current of phase c in a negative half cycle is synchronous with the corresponding voltage. Therefore the currents of phase a and c in one cycle become asymmetrical slightly. Before the islanding takes place, because of the operation of utility voltage the positive and negative half cycles of three-phase voltages are symmetrical. While the islanding occurs, the time differences between the positive and negative half cycles of the voltages of phase a and c will generate and the islanding is detected in accordance with the repetitive cycles fulfilling the conditions of the time differences. On the basis of the above analysis for three-phase four-wire power systems, three-phase three-wire systems are designed. The experiment on a 0.3㎾ PV inverter system connected to 200V/50㎐ utility are carried out, and it is verified that the method can detect the islanding for the parallel RLC loads even if the voltage frequency is within the non-detection zone. It is seen from the analysis of the detecting principle that there is no influence on the proposed method even if a large load connected in parallel frequently starts up or stops.

유효전력변동방식을 이용한 새로운 단독운전 검출기법 연구

유병규(Byung-Gyu Yu),정영석(Young-Seok Jung),미키히코 마츠이(Mikihiko Matsui),유권종(Gwon-Jong Yu) 전력전자학회 2006 전력전자학술대회 논문집 Vol.- No.-

Islanding phenomenon is undesirable because it lead to a safety hazard to utility service personnel and may cause damage to power generation and power supply facilities as a result of unsynchronized reclosure. In order to prevent the phenomenon, various anti-islanding methods have been studied. This paper proposes the variation method of inverter output current magnitude to prevent the islanding phenomenon as a novel method, which causes the large frequency variation of inverter output voltage after islanding. Unlike most active anti-islanding method deteriorating power quality, this novel method will have high performance of islanding detection and good power quality. For the verification of the proposed method, the simulated result and analyses are presented.