5 results about "Tidal current" patented technology

The invention relates to a method and device for determining the stability of a voltage-source-type converter station connected multi-feed-in system. The method comprises the following steps of: inputting a hybrid generalized short circuit ratio (HGSCR) model according to the power flow information in a power system; comparing the output value of the HGSCR model with the value 1; if the output value is greater than 1, determining that the power system is in a stable state; if the output value is equal to 1, determining that the power system is in a critical stable state; and if the output value is less than 1, determining that the power system is unstable. Compared with the prior art, the method can accurately determine the static voltage stability of the hybrid dual-feed-in system.

The invention discloses a harmonic power flow calculation method containing a VSC (Voltage Source Converter). Firstly, the fundamental wave power flow is calculated to obtain the fundamental wave voltage of each node, and the modulation ratio of the VSC is obtained; secondly, three pieces of input data, namely, the DC voltage, the modulation ratio and the carrier frequency are substituted into theharmonic model formula of the VSC to obtain the content of each harmonic in the AC side voltage of the VSC, and the VSC is regarded as a harmonic voltage source approximately; and thirdly, in order to realize an interface between a VSC harmonic voltage source model and the harmonic power flow, the VSC and the AC side transformer thereof are equivalent to a harmonic current source with internal impedance based on the Norton's equivalence theorem to form a harmonic admittance matrix, and the harmonic power flow is calculated by harmonic current injection.

The embodiment of the present invention provides a method and device for calculating an evaluation index of ideal degree of power grid operation economy, which is used for the technical problem that the average power purchase cost index cannot really reflect the dispatching operation business level. The method in the embodiment of the present invention includes: calculating the optimal power flow for each generator set based on the grid operation data to obtain the economically optimal operating position based on the actual operating data of the grid and the grid operation under the condition of the economically optimal operating position. The required power generation curve of each generator set; calculate the first average power purchase cost corresponding to the optimal position of grid operation economy according to the power generation curve and the preset on-grid electricity price, and calculate the first average power purchase cost corresponding to the actual power generation of the unit in actual operation and the preset The set on-grid electricity price calculates the second average power purchase cost corresponding to the actual operation of the power grid; thus, the evaluation index of the ideal degree of economical efficiency of the power grid operation is calculated, and the evaluation index of the ideal degree of economical efficiency of the power grid operation can accurately reflect the dispatching operation business level.