Voltage Source Inverter Drive Using Error-compensated Pulse Width Modulation

Keng-Yuan Chen,Jwu-Sheng Hu,Jau-Nan Lin 전력전자학회 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.1

An error-compensated pulse width modulator (ECPWM) is proposed to improve the baseband harmonic performance and the switching loss of voltage source inverters (VSIs). Selecting between harmonic distortion and switching loss is a design tradeoff in the conventional space vector pulse width modulation. In this work, an accumulated difference in produced and desired phase voltages is considered to adjust the reference signal. This mechanism can compensate for the voltage error in the previous carrier period. With error compensation every half-carrier period, the proposed ECPWM allows one-half reduction in carrier frequency without scarifying baseband harmonic distortion. The proposed modulator is applied to a three-phase VSI with R–L load and a motor-speed-control system for experiments. The measured efficiency and operating temperature of switches confirm the effectiveness of the proposed scheme.

Voltage Source Inverter Drive Using Error-compensated Pulse Width Modulation

Chen, Keng-Yuan,Hu, Jwu-Sheng,Lin, Jau-Nan The Korean Institute of Power Electronics 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.1

An error-compensated pulse width modulator (ECPWM) is proposed to improve the baseband harmonic performance and the switching loss of voltage source inverters (VSIs). Selecting between harmonic distortion and switching loss is a design tradeoff in the conventional space vector pulse width modulation. In this work, an accumulated difference in produced and desired phase voltages is considered to adjust the reference signal. This mechanism can compensate for the voltage error in the previous carrier period. With error compensation every half-carrier period, the proposed ECPWM allows one-half reduction in carrier frequency without scarifying baseband harmonic distortion. The proposed modulator is applied to a three-phase VSI with R-L load and a motor-speed-control system for experiments. The measured efficiency and operating temperature of switches confirm the effectiveness of the proposed scheme.

Interleaved DC-DC Converters with Partial Ripple Current Cancellation

Bor-Ren Lin,Huann-Keng Chiang,Chih-Yuan Cheng 전력전자학회 2012 JOURNAL OF POWER ELECTRONICS Vol.12 No.2

An interleaved PWM converter is proposed to implement the features of zero voltage switching (ZVS), load current sharing and ripple current reduction. The proposed converter includes two ZVS converters with a common clamp capacitor. With the shared capacitor, the charge balance of the two interleaved parts is automatically regulated under input voltage and load variations. The active-clamping circuit is used to realize the ZVS turn-on so that the switching losses on the power switches are reduced. The ZVS turn-on of all of the switching devices is achieved during the transition interval. The interleaved pulse-width modulation (PWM) operation will reduce the ripple current and the size of the input and output capacitors. The current double rectifier (CDR) is adopted in the secondary side to reduce output ripple current so that the sizes of the output chokes and capacitor are reduced. The circuit configuration, operation principles and design considerations are presented. Finally experimental results based on a 408W (24V/17A) prototype are provided to verify the effectiveness of the proposed converter.

A New Switching Strategy for Field Oriented Control of Motor Driver Using Multi-Dimensional Feedback Quantization Modulation

Jwu-Sheng Hu,Keng-Yuan Chen,Chi-Him Tang,Te-Yang Shen 전력전자학회 2011 ICPE(ISPE)논문집 Vol.2011 No.5

This work proposes a new switching strategy for field oriented control of a motor driver to minimize the power of filtered error induced by finite bit resolution of the gating signal. It is shown that the conventional space vector pulse width modulation (SVPWM) is a special case of the proposed general switching strategy which has infinite bit resolution within one input period. Another special case, multi-dimensional feedback quantization modulator: MDFQM, is proposed and compared with SVPWM. The experiments in this study compared mean-square-error of motor speed, switching number of the three-phase voltage source inverter, and current waveforms. The experimental results show that MDFQM can reduce the switching number as well as the heat dissipation of the power transistors.

A General Actuator Array Amplifier Design Using MIMO Optimal Feedback Quantization

Jwu-Sheng Hu,Keng-Yuan Chen 제어로봇시스템학회 2008 제어로봇시스템학회 국제학술대회 논문집 Vol.2008 No.10

This paper proposes a novel switch-mode power stage architecture for actuator array. When the number of actuator is large, the associated power amplifier becomes costly and bulky if each actuator is controlled by an independent amplifier. The proposed architecture allows sharing of the power amplifier among actuators, and thereby reducing the number of switching devices. The architecture is mapped into the graph theorem and the acceptable actuation states are analyzed. The switching method is controlled by an MIMO optimal feedback quantization, which is designed to minimize a weighted measure of the quantization distortion. Simulation results are provided to illustrate the effectiveness of the proposed scheme.

Interleaved DC-DC Converters with Partial Ripple Current Cancellation

Lin, Bor-Ren,Chiang, Huann-Keng,Cheng, Chih-Yuan The Korean Institute of Power Electronics 2012 JOURNAL OF POWER ELECTRONICS Vol.12 No.2

An interleaved PWM converter is proposed to implement the features of zero voltage switching (ZVS), load current sharing and ripple current reduction. The proposed converter includes two ZVS converters with a common clamp capacitor. With the shared capacitor, the charge balance of the two interleaved parts is automatically regulated under input voltage and load variations. The active-clamping circuit is used to realize the ZVS turn-on so that the switching losses on the power switches are reduced. The ZVS turn-on of all of the switching devices is achieved during the transition interval. The interleaved pulse-width modulation (PWM) operation will reduce the ripple current and the size of the input and output capacitors. The current double rectifier (CDR) is adopted in the secondary side to reduce output ripple current so that the sizes of the output chokes and capacitor are reduced. The circuit configuration, operation principles and design considerations are presented. Finally experimental results based on a 408W (24V/17A) prototype are provided to verify the effectiveness of the proposed converter.

Treatment outcomes of patients with stage II pure endometrioid-type endometrial cancer: a Taiwanese Gynecologic Oncology Group (TGOG-2006) retrospective cohort study

Hung-Chun Fu,Jen-Ruei Chen,Min-Yu Chen,Keng-Fu Hsu,Wen-Fang Cheng,An Jen Chiang,Yu-Min Ke,Yu-Chieh Chen,Yin-Yi Chang,Chia-Yen Huang,Chieh-Yi Kang,Yuan-Yee Kan,Sheng-Mou Hsiao,Ming-Shyen Yen 대한부인종양학회 2018 Journal of Gynecologic Oncology Vol.29 No.5

Objective: Choice of hysterectomy and adjuvant treatment for International Federation of Gynecology and Obstetrics (FIGO) 2009 stage II endometrioid endometrial cancer (EEC) is still controversial. Aims of this study were to evaluate survival benefits and adverse effects of different hysterectomies with or without adjuvant radiotherapy (RT), and to identify prognostic factors. Methods: The patients at 14 member hospitals of the Taiwanese Gynecologic Oncology Group from 1992 to 2013 were retrospectively investigated. Patients were divided into simple hysterectomy (SH) alone, SH with RT, radical hysterectomy (RH) alone, and RH with RT groups. Endpoints were recurrence-free survival (RFS), overall survival (OS), disease-specific survival (DSS), adverse effects and prognostic factors for survival. Results: Total of 246 patients were enrolled. The 5-year RFS, OS, DSS and recurrence rates for the entire cohort were 89.5%, 94.3%, 96.2% and 10.2%, respectively. Patients receiving RH had more adverse effects including blood loss (p<0.001), recurrent urinary tract infections (p=0.013), and leg lymphedema (p=0.038). Age over 50-year (HR=9.2; 95% confidence interval [CI], 1.2–70.9) and grade 3 histology (HR=7.28; 95% CI, 1.45–36.6) were independent predictors of OS. Grade 3 histology was an independent predictor of RFS (HR=5.13; 95% CI, 1.38–19.1) and DSS (HR=5.97; 95% CI, 1.06–58.7). Patients receiving adjuvant RT had lower locoregional recurrence (p=0.046), but no impact on survival. Conclusion: Different treatment modalities yield similar survival outcomes. Patients receiving SH with RT had lower locoregional recurrent with acceptable morbidity. Age and tumor grading remained significant predictors for survival among patients with FIGO 2009 stage II EEC.

Changes in prostate-specific antigen kinetics during androgen-deprivation therapy as a predictor of response to abiraterone in chemonaïve patients with metastatic castration-resistant prostate cancer

Chung-Lin Lee,Ying-Hsu Chang,Chung-Yi Liu,Ming-Li Hsieh,Liang-Kang Huang,Yuan-Cheng Chu,Hung-Cheng Kan,Po-Hung Lin,Kai-Jie Yu,Cheng-Keng Chuang,Chun-Te Wu,See-Tong Pang,I-Hung Shao 대한비뇨의학회 2022 Investigative and Clinical Urology Vol.63 No.5

Purpose: Metastatic castration-resistant prostate cancer (mCRPC) has a poor prognosis. Abiraterone acetate (AA), enzalutamide, and chemotherapy are first-line treatments for patients with mCRPC. This study examined prognostic factors for AA response in the form of prostate-specific antigen (PSA) kinetics throughout androgen-deprivation therapy (ADT) in chemonaïve patients with mCRPC. Materials and Methods: We retrospectively included data from 34 chemonaïve patients with mCRPC who had received AA at some point between January 2017 and December 2018. We separated patients into two study arms according to the decrease in PSA percentages after use of AA for 3 months. We correlated PSA kinetics parameters with response and compared the two study groups with respect to PSA kinetics. Results: The patients’ median age was 77 years. In the total group of patients, 64% had a response to AA, whereas 35% did not. The ratio of the PSA level at nadir to the level during ADT was significantly higher in the AA-sensitive group (19.78 vs. 1.03, p=0.019). Conclusions: Patients who experienced a dramatic change in PSA level during ADT were more likely to be resistant to AA after progression to mCRPC. Chemotherapy rather than AA might be more suitable as a first-line treatment for these patients.