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Chylous leakage is a rare occurrence after breast surgery. Trauma to the thoracic duct and its main distribution may be the main cause of chylous leakage, but the cause of such an injury during breast surgery is unknown. We herein report the first case of chylous leakage from many minimal lymph ducts in a skin flap. In all, four cases of chylous leakage were observed out of 1 096 breast cancer patients...
This paper applies an effective repetitive controller to the Static Synchronous Compensator (STATCOM). This hybrid controller integrated repetitive control with proportional feedback control. This approach can decrease steady-state error and improve robustness. A detailed design method is presented and the mathematical model is introduced. The simulation results demonstrate the validity of the proposed...
This paper applies Boost Converter Control to the parallel operation of APF with multiple inverters. Master-slave control mode is adopted because of its prominent advantages on independent operation, redundancy control and cost-effectiveness. The malfunctioning of one APF will not influence the normal working of other APFs. In Boost Converter Control, the canceling of system harmonic current is equivalent...
This paper chooses the proportional resonant controller for the controlling of Active Power Filter, and proposed a new control topology for dual parallel APF application. The APF_I near the load side employs the proportional resonant controller to compensate the 5th, 11th, 17th and 23rd harmonics; The APF_II near the system side also employs the proportional resonant controller to compensate the 7...
The behavior of credibility theory is analyzed to account for uncertainties on the small signal stability problem of microgrid. Uncertainties such as random fluctuation of power generations and loads in a MG should be taken into consideration for effective analysis of small signal stability of the MG. Based on credibility theory. This paper presents a novel small signal stability fuzzy analysis method...
This paper presents Boost Converter Control strategy for a three-phase four-leg Active Power Filter (APF). In the proposed control method, voltage source model is established for APF system, and the compensation of system current is equivalent to the compensation of the proposed voltage source. This method explains the working principles of the Voltage Source Inverter (VSI) on current compensation...
The repetitive control, which is based on a delay of fundamental period, is widely used in grid-connected voltage-source converters, such as uninterruptible power supply (UPS), photovoltaic (PV) inverter and active power filter (APF). This paper presents four repetitive controllers in rotating frame for APF system, whose repetitive period is T, T/2, T/3, and T/6 respectively. Compared with traditional...
The repetitive control and resonant control are widely used in grid-connected voltage-source converters recently, such as uninterruptible power supplies (UPS), photovoltaic inverter (PV) and active power filter (APF). This paper introduces a new repetitive control strategy in APF system, whose repetitive period is only one half of the traditional and could eliminate all odd harmonics as a bank of...
Nonlinear model of switching power electronic converter using black-box identification method is presented in the paper. The duty cycle and the output voltage are chosen, respectively, as the input and the output of the model. A nonlinear Hammerstein-type mathematical model is considered in order to cope with the well-known limitations of the more common small-signal models. Simulation and experimental...
With the proliferation of alternate power sources such as fuel cells system in the distributed power system, inverter is the key component of the system. Parallel inverter systems can be designed to have the advantages to improve output power and reliability etc. In order to share the load and restrain circumfluence, A power sharing control technique for inverter parallel operation is described in...
Since LCL filter has smaller inductance value comparing to L type filter with the same performance in harmonic suppression. It is gradually used in high-power and low-frequency current-source-controlled grid-connected converters. However design of LCL filter's parameter not only relates switch frequency ripple attenuation, but also impacts on performance of grid-connected current controller. This...
Grid-connected inverters are widely used in the distribution generation (DG) systems for the conversion of renewable energies. These inverters are usually connected to the utility grid through LCL filter to reduce the current harmonics injected to the grid. A LCL network, which can achieve reduced levels of harmonic distortion at low switching frequencies with less inductance, is a good alternative...
As one of the most effective methods to inhibit electric power grid harmonics, the technology of Active Power Filter (APF) has been a key subject in the field of power quality control. Currently, research on APF mainly focuses on topology structure and control strategy. A novel topological structure of APF in alpha-beta coordinate is presented based on transformation of three phase static A-B-C coordinate...
Increasing numbers of wind turbine units are connected to electrical power systems, the full model of wind farms with high number of wind turbines is a high order model which isn't appropriate for online system security analysis and stability margin computation. This paper presents a new way of aggregation of doubly fed induction generators(DFIGs) wind turbine units which have a four-quadrant ac-to-ac...
This paper presents a two-point estimate (TPE) based method for probabilistic analysis of small signal stability of a microgrid (MG) considering uncertainties. The uncertainties may arise from different sources as load demand or generation unit outages. This method combines the TPE method and probabilistic small signal stability analysis. Stability indices and the judgment of unstable types for microgrid's...
An improved time-domain online dynamic equivalent method is presented, which is suitable to shipboard power systems (SPS) and based on the coherency technique. It preserves the structure of the generator, excitation system and governor system, and the time-domain non-iterative algebraic operations process is used to calculate equivalent parameters. Sixth-order generator equation is used to reduce...
A novel topological structure of Active Power Filter (APF) in alpha-beta coordinate is presented based on transformation of three phase static A-B-C coordinate to two phase static alpha-beta coordinate. The topological structure adopts two groups of single-phase inverter as main devices of APF, and can realize transformation of current source from two phases to three phases by using a special transformer...
The research progress in the fields of distributed generation (DG) and micro-grid (MG) are summarized in this paper, which mainly focuses on the schemes of DG islanding detection, DG's relay protection as well as the control strategy of converters. It is beneficial to realize the situation in these aspects and to know the improvements can be made in the future.
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