Abstract: The application involves a stability evaluation method and system of direct-drive wind turbine generator, which belongs to the technical field of wind power generation. It solves the problems of poor stability of direct-drive wind turbine generator, low safety performance, failure to realize mutual cooperation between online stability evaluation and parameter adjustment in the existing technology. Firstly, the variation of direct-drive wind turbine generator terminal voltage, current, power and PLL angle of direct-drive wind turbine generator is measured, the terminal energy and the energy negative gradient of direct-drive wind turbine generator is calculated. Then, the system stability is assessed according to the value of energy negative gradient, the influence of the critical parameters on system stability is analyzed and the preliminary adjustment strategy is proposed.

Abstract: The application involves a stability evaluation method and system of direct-drive wind turbine generator, which belongs to the technical field of wind power generation. It solves the problems of poor stability of direct-drive wind turbine generator, low safety performance, failure to realize mutual cooperation between online stability evaluation and parameter adjustment in the existing technology. Firstly, the variation of direct-drive wind turbine generator terminal voltage, current, power and PLL angle of direct-drive wind turbine generator is measured, the terminal energy and the energy negative gradient of direct-drive wind turbine generator is calculated. Then, the system stability is assessed according to the value of energy negative gradient, the influence of the critical parameters on system stability is analyzed and the preliminary adjustment strategy is proposed.

Abstract: The method for measuring a time stamp unit of a remote device includes: obtaining m sets of sampled data, m is a positive integer, and m>1; calculating m estimated time stamp units according to the time stamps when packets are transmitted and the time points when the previously transmitted data packets and the subsequently transmitted data packets arrive at the measuring point; selecting, from the m estimated time stamp units, an estimated time stamp unit; and calculating a time stamp unit of the remote device according to the selected estimated time stamp unit.

Abstract: The method for measuring a time stamp unit of a remote device includes: obtaining m sets of sampled data, m is a positive integer, and m>1; calculating m estimated time stamp units according to the time stamps when packets are transmitted and the time points when the previously transmitted data packets and the subsequently transmitted data packets arrive at the measuring point; selecting, from the m estimated time stamp units, an estimated time stamp unit; and calculating a time stamp unit of the remote device according to the selected estimated time stamp unit.