Results 251 to 260 of about 12,500,295 (288)

Determining negative sequence currents of turbine generator rotors

2009 International Conference on Electrical Machines and Systems, 2009
In parallel to their dynamic duty synchronous generators must be capable of bearing permanently an additional negative sequence current of up to 10% of the rated current according to the IEC 60034–1 standard. On turbine generators this does not only charge the damper winding but causes eddy currents and losses in the solid rotor iron in parallel.
T. Bach, D. Wohner, K. Takahashi, K. Hattori, M. Liese, W. Hofmann   +5 more
openaire   +1 more source

Negative-Sequence Current Injection for Fast Islanding Detection of a Distributed Resource Unit

IEEE Transactions on Power Electronics, 2008
This paper presents an active islanding detection method for a distributed resource (DR) unit which is coupled to a utility grid through a three-phase voltage-sourced converter (VSC). The method is based on injecting a negative-sequence current through the VSC controller and detecting and quantifying the corresponding negative-sequence voltage at the ...
Amirnaser Yazdani, Houshang Karimi, Reza Iravani   +2 more
exaly   +3 more sources

Research on Negative-Sequence Electric Current Examination Method

Advanced Materials Research, 2011
This paper based on traditional ip, iq examination's method , introduces one kind of non-phase-locked loop's ip, iq method. this method avoids the mains frequency displacement the influence, causes the examination to be more conveniently. With the MATLAB simulation of software, obtain the satisfactory results, thus proving the usefulness of this method.
Kai Wang, Wen Jin Dai
openaire   +1 more source

A digital distance relay using negative sequence current

IEEE Transactions on Power Delivery, 1990
The configuration and performance of a recently developed digital distance relay using negative sequence current for remote backup protection are described. Since relays for remote backup protection are designed for remote faults, the fault current that is input to the relay is small due to the influence of current distribution factors.
Y. Ohura, T. Matsuda, M. Suzuki, F. Andow, Y. Kurosawa, A. Takeuchi   +5 more
openaire   +1 more source

Negative sequence current reduction for generator/turbine protection

Conference Record of the 1993 IEEE Industry Applications Conference Twenty-Eighth IAS Annual Meeting, 2002
The authors present a feasible method for negative sequence current reduction at the generator terminal through a special function static VAr compensator (SVC). A specially designed fixed-capacitor thyristor-controlled reactor SVC is used. Computer simulation and laboratory test results show that it can effectively reduce negative sequence current at a
W.-J. Lee, T.-Y. Ho, J.-P. Liu, Y.-H. Liu   +3 more
openaire   +1 more source

Harmonic and Negative-Sequence Current Control in an Islanded Multi-Bus MV Microgrid

IEEE Transactions on Smart Grid, 2014
This paper presents a multifunctional control strategy for the autonomous operation of a multi-bus medium voltage (MV) microgrid under nonlinear and unbalanced load conditions. The main objective is to effectively compensate the harmonic currents of nonlinear loads using electronically-coupled distributed generation (DG) units.
Mohsen Hamzeh, Houshang Karimi, Hossein Mokhtari   +2 more
openaire   +2 more sources

Analysis on IIDG's negative-sequence current upon asymmetric fault

2016 China International Conference on Electricity Distribution (CICED), 2016
As a large number of distributed generations (DG) are connected to the distribution network, the fault current of the distribution network has been changed, and the reliable operation of relay protection in the distribution network has been influenced.
Hua Shao, Haobin Zhu, Rong Lin, Guangfu Xu, Qunbing Yu, Chunguang He   +5 more
openaire   +1 more source

Compensation for the negative-sequence currents of electric railway based on SVC

2008 3rd IEEE Conference on Industrial Electronics and Applications, 2008
As a classic unbalanced load, the traction engines of the electric railways result in negative-sequence currents(NSC) in power systems, which cannot be ignored in most cases. SVC is considered as an effective method to reduce or even eliminate NSC, as well as some other power quality problems, such as reactive power compensation.
null Zhu Guiping, null Chen Jianye, null Liu Xiaoyu   +2 more
openaire   +1 more source

Asymmetric Overload of Synchronous Generators with Negative Sequence Currents at Geomagnetic Disturbances

2020 International Conference on Electrotechnical Complexes and Systems (ICOECS), 2020
It is demonstrated that at the occurrence of geomagnetic disturbances the value of quasi-direct current acting on a generator step-up transformer depends on the type and number of blocks "synchronous generator – generator step-up transformer" as parts of a power plant, phase wire parameters, geographic direction of overhead power lines extending away ...
Vera Vakhnina, Aleksey Kuvshinov, Aleksey Chernenko, Dmitry Kretov   +3 more
openaire   +1 more source

Evaluation of negative-sequence-current compensators for high-speed electric railways

2016 IEEE Energy Conversion Congress and Exposition (ECCE), 2016
This paper evaluates three alternative topologies for a static compensator (StatCom), suitable to eliminate the negative-sequence currents in a railway system. The compensator is placed in a transformer substation, which feeds two separate sections of the catenary.
Antonios Antonopoulos, Jan R. Svensson
openaire   +1 more source