http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Yash (검색결과 25 건)
- 무료
- 기관 내 무료
- 유료
-
Yash Pal,A. Swarup,Bhim Singh 전력전자학회 2011 JOURNAL OF POWER ELECTRONICS Vol.11 No.4
This paper presents a novel control strategy for selective compensation of power quality (PQ) problems, depending upon the limited rating of voltage source inverters (VSIs), through a unified power quality conditioner (UPQC) in a three-phase four-wire distribution system. The UPQC is realized by the integration of series and shunt active power filters (APFs) sharing a common dc bus capacitor. The shunt APF is realized using a three-phase, four-leg voltage source inverter (VSI), while a three-leg VSI is employed for the series APF of the three-phase four-wire UPQC. The proposed control scheme for the shunt APF, decomposes the load current into harmonic components generated by consumer and distorted utility. In addition to this, the positive and negative sequence fundamental frequency active components, the reactive components and harmonic components of load currents are decomposed in synchronous reference frame (SRF). The control scheme of the shunt APF performs with priority based schemes, which respects the limited rating of the VSI. For voltage harmonic mitigation, a control scheme based on SRF theory is employed for the series APF of the UPQC. The performance of the proposed control scheme of the UPQC is validated through simulations using MATLAB software with its Simulink and Power System Block set toolboxes.
-
A Novel Control Strategy of Three-phase, Four-wire UPQC for Power Quality Improvement
Yash Pal,A. Swarup,Bhim Singh 대한전기학회 2012 Journal of Electrical Engineering & Technology Vol.7 No.1
The current paper presents a novel control strategy of a three-phase, four-wire Unified Power Quality (UPQC) to improve power quality. The UPQC is realized by the integration of series and shunt active power filters (APF) sharing a common dc bus capacitor. The realization of shunt APF is carried out using a three-phase, four-leg Voltage Source Inverter (VSI), and the series APF is realized using a three-phase, three-leg VSI. To extract the fundamental source voltages as reference signals for series APF, a zero-crossing detector and sample-and-hold circuits are used. For the control of shunt APF, a simple scheme based on the real component of fundamental load current (I CosΦ) with reduced numbers of current sensors is applied. The performance of the applied control algorithm is evaluated in terms of power-factor correction, source neutral current mitigation, load balancing, and mitigation of voltage and current harmonics in a three-phase, four-wire distribution system for different combinations of linear and non-linear loads. The reference signals and sensed signals are used in a hysteresis controller to generate switching signals for shunt and series APFs. In this proposed UPQC control scheme, the current/voltage control is applied to the fundamental supply currents/voltages instead of fast-changing APF currents/voltages, thus reducing the computational delay and the required sensors. MATLAB/Simulink-based simulations that support the functionality of the UPQC are obtained.
-
Pal, Yash,Swarup, A.,Singh, Bhim The Korean Institute of Power Electronics 2011 JOURNAL OF POWER ELECTRONICS Vol.11 No.4
This paper presents a novel control strategy for selective compensation of power quality (PQ) problems, depending upon the limited rating of voltage source inverters (VSIs), through a unified power quality conditioner (UPQC) in a three-phase four-wire distribution system. The UPQC is realized by the integration of series and shunt active power filters (APFs) sharing a common dc bus capacitor. The shunt APF is realized using a three-phase, four-leg voltage source inverter (VSI), while a three-leg VSI is employed for the series APF of the three-phase four-wire UPQC. The proposed control scheme for the shunt APF, decomposes the load current into harmonic components generated by consumer and distorted utility. In addition to this, the positive and negative sequence fundamental frequency active components, the reactive components and harmonic components of load currents are decomposed in synchronous reference frame (SRF). The control scheme of the shunt APF performs with priority based schemes, which respects the limited rating of the VSI. For voltage harmonic mitigation, a control scheme based on SRF theory is employed for the series APF of the UPQC. The performance of the proposed control scheme of the UPQC is validated through simulations using MATLAB software with its Simulink and Power System Block set toolboxes.
-
A Novel Control Strategy of Three-phase, Four-wire UPQC for Power Quality Improvement
Pal, Yash,Swarup, A.,Singh, Bhim The Korean Institute of Electrical Engineers 2012 Journal of Electrical Engineering & Technology Vol.7 No.1
The current paper presents a novel control strategy of a three-phase, four-wire Unified Power Quality (UPQC) to improve power quality. The UPQC is realized by the integration of series and shunt active power filters (APF) sharing a common dc bus capacitor. The realization of shunt APF is carried out using a three-phase, four-leg Voltage Source Inverter (VSI), and the series APF is realized using a three-phase, three-leg VSI. To extract the fundamental source voltages as reference signals for series APF, a zero-crossing detector and sample-and-hold circuits are used. For the control of shunt APF, a simple scheme based on the real component of fundamental load current (I $Cos{\Phi}$) with reduced numbers of current sensors is applied. The performance of the applied control algorithm is evaluated in terms of power-factor correction, source neutral current mitigation, load balancing, and mitigation of voltage and current harmonics in a three-phase, four-wire distribution system for different combinations of linear and non-linear loads. The reference signals and sensed signals are used in a hysteresis controller to generate switching signals for shunt and series APFs. In this proposed UPQC control scheme, the current/voltage control is applied to the fundamental supply currents/voltages instead of fast-changing APF currents/voltages, thus reducing the computational delay and the required sensors. MATLAB/Simulink-based simulations that support the functionality of the UPQC are obtained.
-
-
CAPITAL STRUCTURE CONVERGENCE AND A DOMINANT-COUNTRY EFFECT: A CASE STUDY OF THE EUROPEAN UNION
Dev Prasad,Yash R Puri,Walayet A Khan,H Kent Baker People&Global Business Association 2007 Global Business and Finance Review Vol.12 No.1
This exploratory study examines the impact of the formation of the European Union (EU) at the microeconomic level. Specifically, the study investigates the impact on a firm's capital structure by investigating whether capital structures are becoming more homogeneous across 10 EU countries over time, and whether a dominant-country effect exists. The results suggest movement toward convergence in capital structures across EU economies during the period examined. This evidence, which is particularly true for industrial firms, indicates an increase in homogeneity for companies in this economic community. The evidence also indicates the presence of a dominant-country effect. Specifically, the capital structures in the smaller EU economies lend to converge on the French capital structure. These changes in capital structure have implications for investors due to changes in the value of the firm as well as policy makers due to the changed needs of the market microstructure.
-
Three new species of genus Myrmica (Hymenoptera: Formicidae) from Himalaya
Himender Bharti,Yash Paul Sharma 한국응용곤충학회 2013 Journal of Asia-Pacific Entomology Vol.16 No.2
Three new species of the genus Myrmica are described from the Himalayas. Myrmica curvispinosa sp. nov.,Myrmica kothiensis sp. nov. and Myrmica religiosa sp. nov. belong to the Myrmica inezae species group, which is earlier represented by 4 species. Myrmica curvispinosa sp. nov. is described based on worker and gyne, with a report of ergatoid aswell.Myrmica kothiensis sp. nov. andMyrmica religiosa sp. nov. are described based onworker caste only. A key to the species of the Myrmica inezae species group has been provided in the following.
-
-
김재헌,정인갑,Yash S. Khandwala,Tina Hernandez-Boussard,James D. Brooks,Benjamin I Chung 대한배뇨장애요실금학회 2021 International Neurourology Journal Vol.25 No.3
Purpose: This study aimed to examine the prevalence of surgery for postprostatectomy incontinence (PI) following minimally invasive surgery compared to conventional open surgery for prostate cancer. Methods: This retrospective cohort study used the Florida State Ambulatory Surgery and State Inpatient Databases, 2008 to 2010, radical prostatectomy (RP) patients were identified using International Classification of Diseases (ICD)-9/10 procedure codes and among this cohort, PI was identified also using ICD-9/10 codes. Surgical approaches included minimally invasive (robotic or laparoscopic) versus open (retropubic or perineal) RP. The primary outcome was the overall prevalence of surgery for PI. The secondary outcome was the association of PI requiring anti-incontinence surgery with the surgical approach for RP. Results: Among the 13,535 patients initially included in the study (mean age, 63.3 years), 6,932 (51.2%) underwent open RP and 6,603 (49.8%) underwent minimally invasive RP. The overall prevalence of surgical procedures for PI during the observation period among the all patients who had received RP was 3.3%. The rate of PI surgery for patients receiving minimally invasive surgery was higher than that for patients receiving open surgery (4.8% vs. 3.0%; risk difference, 1.8%; 95% confidence interval, 0.3%–3.4%). The adjusted prevalence of PI surgery for patients who had undergone laparoscopic RP was higher than that for those with retropubic RP (8.6% vs. 3.7%). Conclusions: Among patients undergoing RP for prostate cancer, the prevalence of PI surgery is not negligible. Patients undergoing minimally invasive RP had higher adjusted rates for PI surgery compared to open approaches, which was attributed to high rate of PI surgery following laparoscopic approach and low rate of PI surgery following perineal approach. More studies are needed to establish strategies to reduce the rate of PI surgery after RP.
-
Comparative Study of Rapid Ice Investment Casting Vs Rapid Casting Processes of Aluminium Alloy
Rajendra Hodgir,Yash Gopal Mittal,Pushkar Kamble,Gopal Gote,Yogesh Patil,Ashik Kumar Patel,K. P. Karunakaran 한국정밀공학회 2023 International Journal of Precision Engineering and Vol.24 No.5
Rapid casting (RC) is a phrase that refers to a specific casting process technique that reduces total production lead time. The technique for achieving it is Additive Manufacturing (AM) or Rapid Prototyping (RP). AM techniques were employed for RC to create complex shapes and sand a 3D mould from a CAD model. This article aimed to examine the performance of Rapid Ice Investment Casting (RIIC) compared with other RC processes such as Direct Wax Investment Casting (Direct Wax IC), Lost Foam Casting (LFC), Lost PLA Casting (LPC), and Rapid Sand Casting (RSC). This investigation examines the part which has various geometric features. Each casting route's procedure is described in detail; pattern development, slurry preparation and mould making. Comparison of RIIC with other RC processes is studied based on the cast specimen's dimensional accuracy and surface finish. According to the findings, RIIC is preferable in terms of smooth surface finish, whereas Direct Wax IC and LFC are superior in dimensional accuracy. The article also addresses, the shortcomings of RIIC are discussed in this article, as well as proposed methods to overcome them.
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
