Zhejiang University

China Southern Power Grid Csg Electric Power Research Institute

China Southern Power Grid Co., Ltd.

Alibaba Group Holding Limited

Ying Huang

Zheng Xu

Wentao Liu

Guoteng Wang

Zheren Zhang

Yan Li

Baorong Zhou

Wangqianyun Tang

Ye Zhang

Yiyan Dong

Yan Chen

Dong Wang

Pengfei Hu

Yanxue Yu

Quansen Rong

Longyue Wang

Ping Ju

Daozhuo Jiang

Yujing Li

Jianfa Zou

Huanhai Xin

A method for enhancing transient stability of a renewable energy power system is performed as follows. An external subsystem corresponding to the renewable energy power system is constructed. A first matrix corresponding to the external subsystem based on voltage control is constructed. A second matrix corresponding to the renewable energy power system is generated. A transient stability Lyapunov function corresponding to the renewable energy power system is constructed in real time based on the first matrix and the second matrix. A first control signal corresponding to the renewable energy power system is generated based on Lyapunov's second method. The transient stability of the renewable energy power system is controlled and enhanced in real time based on the first control signal. The first control signal is an adaptive voltage control signal of the renewable energy power system.

Method and system for enhancing transient stability of power system with renewable energy

A method and system for evaluating strength of a voltage source converter (VSC)-penetrated power grid based on voltage stiffness are provided. First data corresponding to a to-be-analyzed power grid is acquired in real time, and processed to generate a first admittance matrix corresponding to the to-be-analyzed power grid. The first admittance matrix is processed to generate device impedance data of each VSC and a second admittance matrix corresponding to the to-be-analyzed power grid. Rows and columns where a grid-forming VSC node and a rated alternating-current (AC) bus voltage grid-following VSC node are located are removed from the second admittance matrix to generate a third admittance matrix, which is processed to generate second data and third data corresponding to the VSC node. Strength evaluation data corresponding to the to-be-analyzed power grid is generated based on the third data in combination with the second data.

Method and system for evaluating strength of voltage source converter (VSC)-penetrated power grid based on voltage stiffness

A dynamic stability control method for power systems with renewable energy, in which a non-linear system of a grid-forming inverter corresponding to a renewable energy power system is created. An external subsystem corresponding to the grid-forming inverter is constructed based on a Lie derivative. According to the external subsystem, a linear sliding surface corresponding to the external subsystem is constructed, and a dynamic stability control unit corresponding to the external subsystem is generated based on sliding mode control. A first instruction data corresponding to the dynamic stability control unit is generated to control dynamic stability of the renewable energy power system in real time. The voltage instruction value of the grid-forming inverter is modified to improve the dynamic stability of the renewable energy power system. A system for implementing such method is also provided.

Method and system for dynamic stability control of power systems with renewable energy

A measurement method for the impedance of the converter at multiple operating points based on the secondary-side disturbance includes the following steps: superimposing the positive sequence current disturbance in the current sampling value; superimposing the positive sequence voltage disturbance in the voltage sampling value; determining whether measurement data of the converter at two or more current operating points are obtained, if so, based on the measurement data of the converter at two current operating points, calculating values of A(s) and B(s); further calculating values of coefficients at each frequency point, and obtaining the impedance value of the converter at multiple current operating points by calculation. The above-mentioned measurement method overcomes the disadvantages of high cost and complicated operation of the impedance measurement method based on the primary-side disturbance, and solves the problem of lacking the pre-judgment function.

Measurement method for impedance of converter at multiple operating points based on secondary-side disturbance

A distributed voltage clamping method for a 100% renewable-energy sending-end grid, including: selecting key nodes from the 100% renewable-energy sending-end grid, including their voltage levels and positions; installing a dynamic reactive power compensation device on each key node, where the dynamic reactive power compensation device is controlled by a constant alternating-current (AC) voltage effective value, and the instruction value of the constant AC voltage effective value is adjustable according to an operation mode; according to AC voltage variation of the sending-end grid under a typical working condition, judging whether the key nodes meet the checking requirements; if not, selecting more key nodes.

Distributed voltage clamping method for 100% renewable-energy sending-end grid

A backup voltage and frequency support method for a 100%-renewable energy sending-end grid, including: (S) selecting a plurality of support nodes in the 100%-renewable energy sending-end grid; (S) mounting a backup voltage and frequency support device at each support node; and (S) dynamically adjusting an active power output of a renewable energy station of the 100%-renewable energy sending-end grid according to a frequency of a grid-connection point.

Backup voltage and frequency support method for 100%-renewable energy sending-end grid

An example method for positioning feature points of a human face edge including fitting a profile edge curve of a human face edge in a human face image according to the human face image; calculating by using a preset human face edge feature point calculation model to obtain feature points of the human face edge in the human face image; calculating by using a preset convergence algorithm to obtain feature information of a convergence feature point corresponding to each feature point; determining respectively whether a distance from each feature point to the profile edge curve is greater than a distance from a respective corresponding convergence feature point to the profile edge curve; and determining whether a magnitude of overall position change of all the feature points of the human face edge in the human face image before and after the above determination is less than a preset threshold.

Positioning feature points of human face edge

Growing community of inventors

Hangzhou, China

Ying Huang