A5007026193- HVDC Systems and Fault Protection
- Power Systems Fault Detection
- High-Voltage Power Transmission Systems
- Wind Turbine Control Systems
- Power System Optimization and Stability
- Optimal Power Flow Distribution
- Magnetic Properties and Applications
- Power Quality and Harmonics
- Power Systems and Technologies
- Islanding Detection in Power Systems
- Electric Motor Design and Analysis
- Network Traffic and Congestion Control
- Power System Reliability and Maintenance
- Smart Grid and Power Systems
- Non-Destructive Testing Techniques
Tianjin University
2020-2023
Shandong University
2016
The distributed capacitance of the line becomes larger as scale wind farms, transmission voltage level, and distance increase. Hence, error traditional time-domain protection scheme based on R-L model, which ignores line, unacceptable. Therefore, fault location method especially maximum range, is theoretically analyzed in this paper. On basis, a novel Bergeron models proposed. Then, fast designed. In proposed scheme, fitting calculation used to construct weight matrix, an algorithm for...
The frequency of the fault current fed by wind farm may deviate from fundamental after line fault. This characteristic seriously affects performance traditional distance protection. paper proposes an improved protection method based on dynamic estimation. After is started, estimated multiple signal classification algorithm firstly. criterion not activated until close to frequency. Accordingly, influence deviation prevented. delay time can be significantly shorted compared with fixed-delay...
A rapiddevelopment of the permanent magnetic synchronous generator (PMSG)-based offshore wind farm has been witnessed in past decade. To prevent farms from being disconnected during a fault, many countries have proposed specification requirements for fault ride-through (FRT). Traditional FRT scheme Chopper circuit PMSG needs to consume all mismatching energy and impulse current is too high which will even affect safe PMSG. In this paper, superconducting limiter (SFCL) applied enhance ability...
Soft open point (SOP) is applied to the power service restoration of distribution network because advantages flexible control mode and optimizing operation network. Taking advantage parallel collaborative between independent peer smart terminals unit (STU) in information interaction ways working, distributed method considering soft put forward, which brings superiority SOP aspect into full play avoids problem large collection calculation centralized method. Firstly, structure, model are...
The protection is one of the most important techniques for modular multilevel converter (MMC) high-voltage dc (HVdc) system. existing single-ended line protections are mainly based on boundary characteristics, which not suitable condition with no element terminal. In this article, variation characteristics different electric variables fault distance changing analyzed in MMC-HVdc system reactors. On basis, a novel segmented-change-of-voltage-based algorithm proposed, element. addition...
In view of the problems existing in traditional centralized power service restoration method a distributed for smart distribution grid is proposed. The based on terminal unit (STU) arranged at each measuring point grid, and through information interaction cooperation between STU, task completed. Combined with characteristics system requirements restoration, management network topology information, equivalence method, searching simplified calculation constraint conditions are analyzed...
A scheme of restraining transformer inrush current based on control by closing voltage amplitude is proposed analyzing the influence factors and deriving mathematical relationship between factors. In this scheme, in order to making sure that magnetic flux produced no-load does not exceed saturated flux, should be controlled selecting appropriate curve, thus attaining goal current. The function derived from inequality attenuation law transient component, upper lower limitation initial value...
The amplitude and phase of the equivalent positive sequence impedance wind farm considerably fluctuate during a fault, extraction fault component is affected by frequency deviation. As result, operating performance traditional directional relay affected. This paper proposes based on polarity comparison traveling waves. First, polarities voltage current waves are analyzed under forward reverse faults. Second, an improved wavelet transform algorithm complementary detail coefficients adjacent...
This paper puts forward a new idea of wide-area back-up protection. Firstly it establishes distributed system architecture whose basic structure and functional unit is circuit breaker centered IED (Intelligent Electronic Device). Second The principle division protection range based on proposed. types in the are classified into three kinds structures: "Line-Bus", "Line-Transformer" "Bus-Transformer". process which confirming information interactive objects structures analyzed explained....
Doubly fed induction generators (DFIG) have become widely applied in wind power generation, but they suffer from high sensitivity to grid disturbances, particularly faults. In this paper, a fault ride-through method based on the dynamic impedance for DFIG-based turbines. The impedance, integrated at rotor side of DFIG, can effectively limit current help DFIG ride through faults side. And be flexibly adjusted precisely different levels current. inductance reduce peak value initial stage...