Search

Recently, modular multi-level converters (MMC) are attracting attention as the next generation of high-capacity power converters. For the control method, PI control is widely applied. On the other hand, the deadbeat control and the model predictive control, which are known as a model based digital control methods, was applied to improve the tracking accuracy, and the superior characteristics have been reported for these methods. In this paper, a quasi multi-rate deadbeat control (QMDB control) with the PWM hold method based on FPGA based hardware controller for MMC was proposed. The advantages of the proposed method were verified through the simulations and the experiments.

EVs (Electric Vehicles) and HEVs (Hybrid Electric Vehicles) have electric motor drive system, and its quick and smooth response is one of advantage in electric motor drive system. In order to utilize potential performance of control response, this paper introduces MSDB (Multi Sampling Deadbeat control) of PMSM (Permanent Magnet Synchronous Motor) drive system for EVs and HEVs using a FPGA (Field Programmable Gate Array). The proposed deadbeat control using a FPGA can realize good response and robustness, especially for electric motor drive system using low carrier frequency of PWM (Pulse Width Modulation) inverter like as EVs and HEVs.

The field of electric drives in general, and medium-voltage high-power drives in particular, has recently experienced considerable progress. Numerous interesting developments have been reported in the literature. Various reliable, efficient, and cost-effective medium voltage drive topologies, handling high powers up to 120 MW, have been proposed in the literature. This paper provides a detailed overview of the current state-of-the-art in medium-voltage high-power drives and the challenges facing them.

Currently, modular multi-level converters (MMC) are attracting attention as the next generation of high-capacity power converters. For the control of the MMC, PI control is widely used. On the other hand, the deadbeat control and/or the model predictive control was applied as for the model based digital control method, and the superior characteristics were obtained. In this paper, a quasi multi-rate deadbeat control for MMC was proposed using a PWM hold method. Applying FPGA based hardware controller, instantaneous control calculation can be carried out which result in the ideal digital control feedback system. The advantages of the proposed method were verified through simulations and experiments.

A new digital control method for permanent magnet synchronous motor based on deadbeat control with multisampling method using FPGA based hardware controller is proposed. Adopting FPGA based hardware controller, all the control calculation can be finished within around 800 nano second, which result in the realization of the ideal digital control feedback without any sampling compensation method, and superior transient characteristics can be obtained. In this paper, weighted moving average 1MHz multisampling deadbeat control was proposed and compared with the conventional deadbeat control method through simulations and experiments. The advantages of the proposed method was verified.

A power packet dispatching system for the robot arm operation is discussed. The power packet dispatching system is the power distribution system which DC voltage is delivered with the information tag in the same power line. To include the information into the packet, switching speed of the switching device is desired over MHz range. SiC or GaN device is attracting solution to realize the power packet system. Six arm robot operation with the power packet dispatching system using GaN device is designed and evaluated. Design concept is described to interface the power and the information in simultaneously. Realization of the proposed method was verified.

In recent years, the switching frequency of power converter is increased due to the progress of the power devices. As the result, passive elements used in power converters can be reduced in the volume. The inductors using dust core material is applied to the PWM inverter to downsize the filter component. In the case of using the dust core inductors, the flux density is saturated for the large inductance current and the inductance parameter is rapidly varied widely due to the inductance current variations. The output characteristics is deteriorated in the case of the conventional control. Two kinds of the deadbeat control methods combined with the disturbance compensation and the inductance estimation with 1MHz multisampling method were proposed to adjust the control gains for the inductance parameter variations. In this paper, the effect of the two kinds methods were verified through simulations and experiments.

This paper investigates the solid state transformer applied for the HVDC transmission from the offshore windfarm. The 3kHz, 5kVA transformers with some different core materials are manufactured. Dependency of the loss in the transformer to frequency is investigated. From the measurement, hysteresis loss and eddy current loss are separately considered for the higher frequency loss estimation. Copper loss is also considered by using the measured resistance at various frequencies. In this investigation, the difference of the core materials does not affect the loss largely but the copper loss does.

This paper investigates the solid state transformer applied for the HVDC transmission from the offshore windfarm. The 5kVA experimental setup is developed and comparison of up to 1200Hz operation. Dependency of the loss in the transformer with different core materials to frequency is investigated. Frequency loss dependency of nano-crystaline and amorphous core materials are compared in experimental measurement. Nano-crystaline material called "FINEMET" is the best performance, although amorphous seems to have better cost performance. It is also indicated that the converter voltage causes the larger loss in the transformer than the sinusoidal power supply.

Recently, multi-level inverters were widely applied to grid connect system to downsize the filter component and reduce the harmonic distortions of the output voltage and the current. In these systems, the conventional PI control is widely used for the inverter control, and the dynamic performance should be considered in the case of FRT conditions. In this paper, a new deadbeat control method for multi-level inverters is proposed based on PWM hold technique. Three level inverters are investigated to achieve the fast transient response in the FRT conditions. 1MHz multisampling method was also applied to improve the dynamic response. The advantages of the proposed method was verified through simulations.

The demand of the UPS system is highly recommended for the power system of the important infrastructure. The precise output voltage control for the load variations are required. In the case of large scale UPSs, the power rating of the inverter becomes several hundred kVA or more, the switching frequency of the inverter is limitted under several kHz range. The carrier interval becomes rather large, so the robustness for the load condition is deteriorated. The deadbeat control with disturbance compensation with 1MHz multisampling method for three phase PWM inverter system is proposed. Using FPGA based hardware controller, 1MHz sampling is realized while the carrier interval of the PWM pulse, the robustness for the load variation can be improved compared with the conventional deadbeat control method. Through simulations and experiments, the output characteristics were verified.

In recent years, the switching frequency is increased in power converters due to improvement of the switching devices, which result in the reduction of the size of the passive components. The dust core material is used for the inductance core of the PWM inverter to downsize the filter component. In that case, the flux density is saturated for the large inductance current and the inductance parameter is varied widely due to the inductance current variations. The output characteristics is deteriorated with the conventional control. The deadbeat control method combined with the disturbance compensation and the inductance estimation methods were proposed. Also 1 MHz multisampling method was applied to adjust the control gains for the inductance parameter variations. The advantage of the proposed method was verified through simulations and experiments.

In recent years, permanent magnet synchronous motor is widely used due to its high efficiency and maintenance free features in the industry. high accuracy position control and speed control performance in the servo system is required, so the high response performance in the current control system is required. In this paper, the moter drive system applying the 2-degree-of-freedom deadbeat control with disturbance compensation method is propsed to realize high tracking accuracy and robustness to the system parameters variations. The advantages of the proposed method was compared with the conventional deadbeat control method through simulations and experiments.

A power packet dispatching system for the robot arm operation is discussed. Recent wide-band-gap power semiconductor technology realizes high speed and low switching loss devices such as SiC and GaN. The power packet dispatching system is the power distribution system in which DC voltage is delivered with the information tag in the same power line. To include the information into the packet, switching speed of the switching device is desired over MHz range. SiC or GaN device is attracting solution to realize the power packet system. Six arm robot operation with the power packet dispatching system is designed and evaluated. Design concept is described to interface the power and the information in simultaneously. Realization of the proposed method was evaluated.

This paper investigates the solid state transformer applied for the HVDC transmission from the offshore windfarm. The 5kVA experimental setup is developed and comparison of 50Hz, 400Hz and 1000Hz operation. Dependency of the loss in the transformer with different core materials to frequency is investigated. Frequency loss dependency of several core materials are compared with experimental measurement. Nano crystaline material called “FINEMET” is the best performance, although amorphous seems to have better cost performance.

Variable carrier single rate deadbeat control method for low carrier frequency was proposed. In the large capacity inverter system, the carrier frequency range is limited to relatively lower frequency range, the trade off between the control accuracy and the efficiency should be considered. Digital hysteresis control was applied to the inductor current, suitable carrier frequency was adopted in every carrier period, the control accuracy could kept in the tolerable range with low carrier frequency. 2.4MHz multi-sampling method and space vector modulation was also applied to improve the characteristics.

Network technology realizes ultra high speed digital data transmission system. FPGA based hardware controller can utilize this technology in the power electronics fields. Nano seconds order data transmission can be realized. In this paper, Rocket I/O protocol was applied to the FPGA based hardware controller, the network based high speed feedback implementation can be realized. 1MHz multi sampling quasi multi-rate deadbeat control with disturbance compensation method was applied to the digital control of PWM inverter, the advantage of the proposed method was verified through simulations and experiments.

Recently, a power packet dispatching system was proposed as one of the new power distribution systems, which realizes various power transmission through one common power line. Multi-path routing for power packet dispatching system is realized using a new protocol which is included in the power packet, and the electric power is transferred with information. FPGA based hardware controller is used to realize a fast data transmission. In this paper, MHz order packet dispatching system was realized using FPGA based hardware controller. The proposed system was applied to the lighting control of LEDs and the multi-hop system. The basic performance was verified experimentally.

Memantine is a non-competitive antagonist of the N-methyl-D-aspartate (NMDA) receptor, and is an approved drug for the treatment of moderate-to-severe Alzheimer’s disease. We identified a mouse strain with a naturally occurring mutation and an ataxic phenotype that presents with severe leg cramps. To investigate the phenotypes of these mutant mice, we screened several phenotype-modulating drugs and found that memantine (10 mg/kg) disrupted the sense of balance in the mutants. Moreover, the mutant mice showed an attenuated optokinetic response (OKR) and impaired OKR learning, which was also observed in wild-type mice treated with memantine. Microsatellite analyses indicated that the Grid2 gene-deletion is responsible for these phenotypes. Patch-clamp analysis showed a relatively small change in NMDA-dependent current in cultured granule cells from Grid2 gene-deleted mice, suggesting that GRID2 is important for correct NMDA receptor function. In general, NMDA receptors are activated after the activation of non-NMDA receptors, such as AMPA receptors, and AMPA receptor dysregulation also occurs in Grid2 mutant mice. Indeed, the AMPA treatment enhanced memantine susceptibility in wild-type mice, which was indicated by balance sense and OKR impairments. The present study explores a new role for GRID2 and highlights the adverse effects of memantine in different genetic backgrounds.

3MHz multi sampling deadbeat control for 100kHz carrier single phase PWM 3.verter using FPGA based hardware controller was proposed. 3MHz sampling for the feedback signals was realized while the carrier interval to recalculate the PWM pulse pattern, the tracking accuracy to the reference was much improved for the disturbance and the parameter variations. Design concept and high calculation capability of FPGA based hardware controller was indicated. The robustness of the proposed method were verified through simulations and experiments. And 3MHz multi sampling method using the FPGA based hardware controller realize the robust system.

A new digital control method for permanent magnet synchronous motor based on deadbeat control using FPGA based hardware controller is proposed. Adopting FPGA based hardware controller, all the control calculation can be finished within around 1 µ second, which result in the realization of the ideal digital control feedback without any sampling compensation method. In this paper, 1MHz multi-sampling deadbeat control with disturbance compensation method was proposed and compared with the conventional deadbeat control method through simulations and experiments, the advantages of the proposed method was verified.

Background G protein-coupled receptors (GPCRs) are ubiquitous surface proteins mediating various biological responses and thus, important targets for therapeutic drugs. GPCRs individually produce their own signaling as well as modulate the signaling of other GPCRs. Real-time observation of GPCR signaling and modulation in living cells is key to molecular study of biological responses and pharmaceutical development. However, fluorescence imaging, the technique widely used for this purpose, requires a fluorescent dye which may inhibit biological responses or a fluorescent-tagged target protein created through time-consuming genetic manipulation. In this study, we applied two-dimensional surface plasmon resonance (SPR) imaging to monitoring the translocation of protein kinase C (PKC), a major GPCR-coupled signaling molecule in the widely used HEK293 cell lines and examined whether the signaling of, and, modulation between heterologously expressed GPCRs can be measured without fluorescent labeling. Results We cultured HEK293 cells on the gold-plated slide glass and evoked SPR at the interface between the cell’s plasma membrane and the gold surface with incident light. The translocation of activated native PKC to the plasma membrane is expected to alter the incident angle-SPR extent relation, and this could be detected as a change in the intensity of light reflection from the specimen illuminated at a fixed incident angle. Direct activation of PKC with 12-O-tetradecanoylphorbol-13-acetate increased the reflection intensity. This increase indeed reported PKC translocation because it was reduced by a pre-treatment with bisindolylmaleimide-1, a PKC inhibitor. We further applied this technique to a stable HEK293 cell line heterologously expressing the GPCRs type-1 metabotropic glutamate receptor (mGluR1) and adenosine A1 receptor (A1R). (RS)-3,5-dihydroxyphenylglycine, a mGluR1 agonist, increased the reflection intensity, and the PKC inhibitor reduced this increase. A pre-treatment with (R)-N6-phenylisopropyladenosine, an A1R-selective agonist suppressed mGluR1-mediated reflection increase. These results suggest that our technique can detect PKC translocation initiated by ligand binding to mGluR1 and its modulation by A1R. Conclusions SPR imaging turned out to be utilizable for monitoring GPCR-mediated PKC translocation and its modulation by a different GPCR in a heterologous expression system. This technique provides a powerful yet easy-to-use tool for molecular study of biological responses and pharmaceutical development.

A current control method for the utility interactive inverter based on multi-rate deadbeat control method with FPGA based hardware controller is verified for 100kHz carrier PWM inverter. As the distributed power systems spread, the requirement of the control accuracy for the utility interactive inverter becomes more precise. Deadbeat control is one method to ensure the output voltage or current matches to the references at the sampling instant, so adopting this control law to the utility interactive inverter, the response of the system is much improved with small LC filter component compared with the conventional PI control. A current control method for the utility interactive inverter based on multi-rate deadbeat control, single-rate deadbeat control and PI control were compared. Multi-rate deadbeat control improves the tracking accuracy to the reference compared with the conventional single-rate deadbeat control and PI control. The advantages and disadvantages are discussed through simulations and experiments.

In this paper, a new control method is proposed for the utility interactive inverter based on the deadbeat control with the FPGA-based hardware controller to improve the control response of an utility current.Deadbeat control is one method to ensure the output voltage or current matches with the references at the sampling instant; therefore, by adopting this control law to the utility interactive inverter, the response of the system is much improved compared with the conventional PI control. The utility interactive inverter is linked to the commercial source via the interactive inductor, and so the inverter controls the output voltage based on the deadbeat control to regulate the output current through the interactive inductor. As a result, a very fast transient response of the utility current can be achieved.The current control method using voltage deadbeat control and PLL control with quasi dq transformation with multisampling parallel processing method are implemented in the FPGA-based hardware controller for the single phase utility interactive inverter.

Summary In this study, we examined the expression of excision repair cross-complementation group 1 (ERCC1) protein in 90 completely resected lung cancer samples from patients who received adjuvant or neo-adjuvant platinum-based chemotherapy. Epidermal growth factor receptor ( EGFR ) was also studied in these samples. We also examined class III β-tubulin protein expression in 50 patients treated with a platinum-based drug plus paclitaxel. Among 90 patients treated with platinum-based chemotherapy, the loss of ERCC1 protein expression was associated with a better prognosis ( p =0.0068). The effect of ERCC1 expression on survival was not seen in a separate set of 59 patients who underwent curative resection but did not receive adjuvant chemotherapy. Among 50 patients treated with a platinum-based drug plus paclitaxel, loss of class III β-tubulin protein expression was also associated with a better prognosis ( p =0.0303). When combined, patients with a tumor that was negative for both ERCC1 and class III β-tubulin had a significantly longer overall survival than those with a tumor that expressed either ERCC1 or class III β-tubulin ( p =0.0230). There was no relationship between the presence of an EGFR mutation and the patients' survival after the platinum-based chemotherapy. In conclusion, we found that the loss of ERCC1 and class III β-tubulin protein expression were predictors of better survival in patients who received a platinum-based plus taxane chemotherapy.

Background Mutations of the epidermal growth factor receptor (EGFR) gene at kinase domain have been reported in non-small-cell lung cancer (NSCLC), and some common somatic mutations in EGFR have been examined for their ability to predict sensitivity to gefitinib or erlotinib. However, EGFR mutations at exon 20 have been reported to predict resistance to gefitinib therapy. Materials and methods We investigated the EGFR mutations and/or polymorphism statuses at kinase domain in 303 surgically treated non-small cell lung cancer (NSCLC) cases. One hundred ninety-four adenocarcinoma cases were included. The presence or absence of EGFR polymorphism of kinase domains was analyzed by direct sequences. We have also investigated EGFR polymorphism status at exon 20 for 23 NSCLC patients who had undergone surgery followed by treatment with gefitinib at the National Hospital Organization, Kinki-chuo Chest Medical Center. Results EGFR mutations at kinase domain were found in 75 of 303 lung cancer patients. During sequencing of EGFR tyrosine kinase domain in tumors, 86 EGFR polymorphism (G2607A) cases were identified at exon 20. G2067A polymorphism was significantly higher in nonadenocarcinomas (37.4%) than in adenocarcinoma (25.3%, P = 0.0415). The polymorphism status did not correlate with gender, smoking (never smoker versus smoker), and EGFR mutations. In 46 total gefitinib treated NSCLC patients, there was a tendency toward better prognosis in EGFR wild type (GG) patients than AG + AA patients. EGFR polymorphism in Japanese lung cancers seemed to be less frequent than Caucasian lung cancers. Conclusions EGFR-tyrosine kinase polymorphism might be associated with clinicopathological background of lung cancers.

Thymic carcinoma is a rare mediastinal neoplasm with frequent pleural or pericardial dissemination. We retrospectively studied ten such cases and analyzed factors that influenced the survival of the patients.Ten thymic carcinoma patients with dissemination have been treated since 1987. The clinical and pathological data were retrospectively reviewed.Pretreatment tumor biopsy was performed and demonstrated squamous cell carcinomas in nine and small cell carcinoma in one. In six of ten patients pleural or pericardial dissemination was clinically evident (cT4). These patients were basically regarded as inoperable and treated with chemotherapy and/or radiotherapy. Four other patients were diagnosed as cT3 preoperatively but were found to have dissemination at the time of thoracotomy. They underwent total resection of the thymic tumor and all visible pleural dissemination but without pericardial dissemination. Radiotherapy was performed pre-or postoperatively with or without chemotherapy. The 5-year survival rate in all patients was 42.0%. The patients with Masaoka stage IVa showed significantly better prognosis than the patients with stage IVb (MST, 69.7 months vs. 14.5 months; 5-year survival rate, 64.3% vs. 0%) (P = 0.03). The patients with cT3 disease showed significantly better prognosis (P = 0.016) than the patients with cT4 disease (MST, 69.7 months vs. 14.5 months; 5-year survival rate, 100% vs. 16.7%).Among thymic carcinoma patients with pleural or pericardial dissemination, there seem to be some patients who show good prognosis. These candidates are patients who underwent subtotal resection with disseminations that were identified only at the operation and without hematogenous or lymphogenous metastasis.