A Master and Slave Control Strategy for Parallel Operation of Three-Phase UPS Systems with Different Ratings Woo-Cheol Lee, Taeck-Ki Lee Sang-Hoon Lee, Kyung-Hwan Kim, Dong-Seok Hyun In-Young Suh-Department of Electrical Engineering HanKyong National University-Seoul, Korea

AEG POWER SOLUTIONS NEW TRAINING DATES FOR 2015 AVAILABLE - POWER SUPPLIES SYSTEM

The Service Training Center in Belecke serves as the basis for professional training in technical service support. Owing to the long years of experience in training at AEG Power Solutions, we have been able to continually improve our competence. We are considered nowadays to be the training facility for service experts. We hold training sessions in all AEG PS technologies and our trainees achieve a high degree of expertise. Target groups for our training sessions include staff from service departments, testing fields, application engineering, R&D and sales. Prerequisite for trainees is that they are skilled electrical.
LINK

http://www.aegps.com/en/services/training/

Development of a Compact 750KVA Three-phase NPC Three-level Universal Inverter Module with Specifically Designed Busbar Jun Wang, Binjian Yang, Jing Zhao, Yan Deng, Xiangning He College of Electrical Engineering Zhejiang University Hang Zhou, China

Abstract—This paper presents the bus bar design of a 750kVA three-phase Neutral Point Clamped three-level universal inverter module (PEBB) of high power density. ANSOFT Q3D is used in comparative evaluation for three types of multi-layer bus bar structures and a novel low inductive laminated configuration with divided connections is proposed for this inverter modules. Combined with specially arranged snubber capacitors distribution, reduced voltage overshoots across IGBTs at turned-off and lower loss within the electrolytic capacitors are achieved without any RC snubbers, along with optimized high frequency current equalization. The stray inductance of the bus bar is simulated as a contrast to the test results. Feasibility and improved performance are confirmed by experiments.

34- The flyback converter 14 28 UNIVERSITY OF COLORADO BOUDER

Performance Improvement of PWM Converter-Inverter System for AC Supplied Electric Train -HYUNGCHUL KIM -CHUNGBUK NATIONAL UNIVERSITY

ABSTRACT

Domestically in 1994, both Gwacheon and Bundang line used the GTO converter/inverter system instead of the resistance control system, which started active research on AC supplied vehicle.[3] Addition to this, introduction of high-speed railway vehicles such as KTX and tilting train has developed interest about PWM converter-inverter system and its control method.[9] PWM converter which converts AC power into DC power has been used to maintain the sinusoidal current waveform and unity power factor in AC side. This means that the AC current controller of PWM converter has to produce very low AC current tracking error and no phase delay even though the load changes abruptly.[10-17] The PWM converter system with feedback controller is generally constructed with double feedback loop, which consists of an inner AC current-feedback loop and an outer DC voltage-feedback loop.[7][22] These feedback loops are usually designed with PI controller, but the close interconnection between the loops complicates the frequency analysis to the design controller. When a digital controller is used, the control performance is limited to a certain value due to the low sampling rate. Therefore, the system characteristics depend on various situation, and the gain tuning of each PI controller has been basing on trial and error method conventionally considering switching frequency, sampling frequency, parameter variation, and etc. This research proposes a robust digital current controller for a single phase AC/DC PWM converter in electric train under two main considerations. One is that overall system keeps very low AC current tracking error without any phase delay over the different load conditions, and the other is that the digital controller is designed at a fixed sampling rate. First, we design a continuous-time controller for a continuous-time plant and then discretize the controller with the given sampling frequency. This kind of process has some disadvantages because its fidelity depends on the sampling rate and the discrete method, but it has sufficient and valuable design method in developing continuous-time linear systems. The error-space feedback control scheme to carry out the robust AC current tracking is used, which is well known as an analytic state-feedback method to give a controller the ability to track a non-decaying input perfectly and to reject a non-decaying disturbance such as a sinusoidal input. And to achieve the time response requirements, the characteristic ratio assignment (CRA) is introduced, which has the ability to deal directly with the overshoot and speed of step response in an all-pole system with arbitrary order.[25] This method is based on certain relationships between the coefficients of characteristic polynomial and the transient responses. The CRA design formulates a model matching method whose reference model is selected from a target polynomial. In this paper, the state feedback gains are determined by the CRA instead of the pole-placement method.
LINK
http://www.mediafire.com/view/sxc1dk8mmveiyzp/Performance_Improvement_of_PWM_Converter-Inverter_System_for_AC_Supplied_Electric_Train.pdf