A5057916835- HVDC Systems and Fault Protection
- High-Voltage Power Transmission Systems
- Silicon Carbide Semiconductor Technologies
- Cardiac Structural Anomalies and Repair
- Radioactive element chemistry and processing
- Geological and Geochemical Analysis
- Spectroscopy and Chemometric Analyses
- Geochemistry and Geologic Mapping
- Advanced Algorithms and Applications
- Superconductivity in MgB2 and Alloys
- Sensorless Control of Electric Motors
- Water Quality Monitoring and Analysis
- Power Systems Fault Detection
- Electric Motor Design and Analysis
- Magnetic Bearings and Levitation Dynamics
Xi'an Jiaotong University
2016-2019
The modular multilevel converter is one of the most attractive topologies for high-voltage dc transmission systems, but it needs at least 10 min during system uncontrolled precharge stage to verify stability and reliability submodules (SMs), making capacitor static voltage balancing a key issue. This paper proposes novel method based on self-power supply control voltage. Because influence supplies voltages, can keep balanced by controlling input characteristic SMs supplies. signals have...
As one of the most potential converter topologies, modular multilevel (MMC) is widely used in high‐voltage direct current (HVDC) transmission systems. The capacitor static voltage imbalance during HVDC system start‐up stage has become a key issue. This study presents new balance method based on auxiliary‐power supply (APS) pulse width control for MMC. signal APS can be generated by comparing modulation closed‐loop with carrier fixed frequency. An AND gate circuit to improve Metal oxide...
Recently, with the rapid development and application of modular multilevel converter (MMC) in high voltage direct current (HVDC) transmission system, motor drive other fields, more attention has been paid to it's safe reliable operation. This paper proposed a semi-hot reserved redundancy method under MMC sub-modules (SMs) failure. In this method, redundant SMs participate uncontrolled precharge as ordinary SMs. After precharge, are controlled balance state normal If an SM failed, faulty will...
This paper pays attention to magnetic flux linkage optimization of a direct-driven surface-mounted permanent magnet synchronous generator (D-SPMSG). A new compact representation the D-SPMSG nonlinear dynamic differential equations reduce system parameters is established. Furthermore, characteristics in process varying are considered, which illustrated by Lyapunov exponent spectrums, phase orbits, Poincaré maps, time waveforms and bifurcation diagrams, stable region acquired concurrently....
Based on the background of VSC-HVDC system, we analyze sub-module static voltage balancing feature modular multilevel converter (MMC). Through analysis existing research results, sub-modules capacitors are related to parameters equalizing resistance. In this paper, a detailed design method resistance is presented. studying main factors which influencing balance, testing input and current data power supply, fitting test supply sub-module, can get exact curve function, using it calculate in...
This paper presents a modified modular multilevel converter (MMC) topology and simple voltage balancing scheme that consists of intra‐ inter‐arm methods. Each arm the MMC comprises several half‐bridge submodules (SMs), one full‐bridge SM, some clamping diodes. By adding diode to each two adjacent SMs, capacitor SM will be clamped by neighboring SMs when is in operation. Based on diode‐clamped circuit, simplify intra‐arm method, which needs only sensors, proposed, it takes up very little time...
The modular multilevel converter (MMC) is a promising topology for high-voltage direct current (HVDC) system. However, typical half bridge sub-module (HBSM) based MMC vulnerable to dc-side short circuit fault. To protect power-electronic devices from the damage of current, protective thyristors with small on-resistance connected in anti-parallel lower insulated gate bipolar transistor (IGBT) HBSM are applied. use large number will bring higher costs and losses In allusion this problem, paper...
Recently, the clamp double sub-module (CDSM) topology with its DC fault clearance ability has become more attractive for use in modular multilevel converter (MMC)-based high-voltage transmission systems. However, capacitor voltage imbalance caused by discreteness of device parameters during uncontrolled pre-charging process seriously affects system's safe start-up. To solve this problem, study provides a novel CDSM-MMC static balance method. Since power supplies obtaining energy from CDSM...
Spectroscopy is an important component analysis method and full spectrum prediction may be complicated inaccurate. In order to find out the irrelevant variables, a variable selection based on frequent pattern tree(FP-tree) proposed in this paper. The firstly formulates orthogonal array generate wavelength plans, which makes more reasonable. Then, partial least square(PLS) performed spectral data selected by array, root-mean-square error of cross validation adopted as evaluation criteria...