Обзор и классификация пространственно-временных векторов дискретных состояний семифазного преобразователя

The subject of the research is the control algorithms for a seven-phase converter that implement space-vector voltage modulation of a seven-phase motor as an alternative to a three-phase engine in modern electric traction. The study used elements of set theory, combinatorics, Fourier series expansion and vector analysis. Checking research results was implemented on a special stand for experimental studies of spatial vector voltage modulation of a seven-phase motor.

Residual flux impact in controlled switching of HVDC converter transformer

Converter transformers are an interface point of HVDC frameworks and are basic hardware from activity and reliability view point. Converter transformers are turned off intentionally under planned support and un-deliberately during fault conditions. Random energization of HVDC Converter transformer delivers high inrush currents due to core saturation asymmetries and endanger equipment health. In this paper, charging approach has been proposed. By utilizing point on wave exchanging for moderation of charging drifters during charging of 888 MVA 400/325 kV Converter Transformer of ±800 kV HVDC Sub-station. The proposed procedure has been applied on HVAC electrical Circuit Breaker furnished with Pre-Insertion Resistor considering diverse degree of residual flux. Performance of proposed philosophy has been affirmed by field tests and reproduction in PSCAD programming package and is found very viable. Near investigation is done in this paper and shows that with the use of proposed system, the switching transient during stimulation and field tests of coupled three phase converter transformers is decreased to worthy level.

HIL Simulation of a Tram Regenerative Braking System

Regenerative braking systems are an efficient way to increase the energy efficiency of electric rail vehicles. During the development phase, testing of a regenerative braking system in an electric vehicle is costly and potentially dangerous. For this reason, Hardware-In-the-Loop (HIL) simulation is a useful technique to conduct the system’s testing in real time where the physical parts of the system are replaced by simulation models. This paper presents a HIL simulation of a tram regenerative braking system performed on a scaled model. First, offline simulations are performed using a measured speed profile in order to validate the tram, supercapacitor, and power grid model, as well as the energy control algorithm. The results are then verified in the real-time HIL simulation in which the tram and power grid are emulated using a three-phase converter and LiFePO4 batteries. The energy flow control algorithm controls a three-phase converter which enables the control of energy flow within the regenerative braking system. The results validate the simulated regenerative braking system, making it applicable for implementation in a tram vehicle.

NON LINEAR CONTROL OF MULTI FED INDUCTION GENERETOR BASED OFFSHORE WIND TURBINE SYSTEM

Novel technique is used to improve the voltage ride of wind turbine system by using LVRT System. In most of the turbines sequence operation is a proper way to increase the capacity of electronic devices in PMDD wind power generation system. Direct Current Link are regulated in this system. Because it causes the ZSCC, which brings current oscillation, distortion of waveform, reduction in power, and interruption of Electromagnetic waves, and so on. This system gives a different methodology for offshore wind turbine system which are composed of the various control strategies applied to the multi- phase converter which can deal with mostly imbalanced. Apart from averagemodels of the turbine system MVF is used to compensate highly imbalance load but not affecting the static and dynamic response of the system. Based on the above topology, the schematic diagram of the proposed system is constructed. The simulated results of offshore wind turbine system will show the advantages of the proposed system and control strategies.