38 results about "Energy margin" patented technology

This invention relates to a method of determining stability of unstable equilibrium point (UEP) computed by using BCU method, comprising selecting UEP computed by using BCU method, obtaining a test vector Xtest for the selected UEP, say XUEP using the following equation:Xtest=Xspost+0.99(XUEP−Xspost)where Xspost is the SEP, and checking boundary condition of XUEP by simulating system trajectory of post-fault original system starting from Xtest.

A power distribution system is dynamically and adaptively configured in real-time to improve energy efficiency, reliability and power quality, particularly if the system includes renewable sources and storages. An optimal multi-objective scheduling and partitioning method is provided to partition the system into self-sufficient sections (SSS) through optimally combination of adjacent basic switching sections (BSS). The SSSs enable system operating at a lower cost, with less power losses, more energy efficiency, improved power quality, and sufficient transient security. The method uses two storage based transient security indices, storage compensation power margin (SCPM) and storage compensation energy margin (SCEM) evaluate the transient stability margin of distribution system. A minimal stability margin is used to ensure that the system remains stable when subject to large unexpected load deviations.

The invention relates to the technical field of electric power system transient stability analysis, and discloses a voltage online coordination control method based on energy margin constraint. The voltage online coordination control method based on energy margin constraint comprises the following steps that (2) a system potential energy function model Ep is built, and an energy margin Em is calculated on the basis of the lie derivative; (2) an approximate linear programming problem is formed by using the energy margin Em as an objective function and using the reactive margin and the voltage allowable change range as constraint conditions; (3) a coordination control strategy is obtained to accomplish coordination of various voltage control modes. According to the voltage online coordination control method based on energy margin constraint, various voltage control modes are brought into a uniform energy function frame, the lie derivative is introduced to calculate changes of the energy margin, the approximate linear programming problem is formed by using the situation that the energy margin is larger than or equal to zero as the objective function and using the reactive margin and the voltage change range as the constraint conditions, and the solution of the approximate linear programming problem serves as the coordination control strategy. According to the voltage online coordination control method based on energy margin constraint, the calculation speed can be increased, generation of the online coordination control strategy of various voltage control modes is facilitated, and the safe operation level of a power grid is improved.

A memory device, and method of operation are disclosed. The device includes an array of non-volatile memory cells and a controller. The controller is configured to perform an operation (e.g. erase, program, etc.) on a first plurality of the non-volatile memory cells using operational voltages with a first energy margin, and perform the same operation on a second plurality of the non-volatile memory cells using operational voltages with a second energy margin that is greater than the first energy margin. The operations of varying energy margins are based on the required storage longevity of thedata being stored (lower energy margins for data being stored for shorter periods of time) to save energy and wear.

The invention discloses a critical cluster identifying method for transient stability analysis of a power system. The critical cluster identifying method comprises the following steps: obtaining a critical clearing time of a fault by using time domain simulation; obtaining a critical stable track and a critical unstable track of the power system according to the critical clearing time; determining a leading unstable balance point according to the critical stable track and the critical unstable track so as to obtain a power angle of each generator at the leading unstable balance point; carrying out simulation according to the actual clearing time of the fault so as to obtain a fault track; calculating the sensitivity of an energy margin to the mechanical power of each generator according to the fault track and the power angle of each generator at the leading unstable balance point; and identifying generators of a predetermined number in the generators, of which the calculation results of the sensitivities are negative values, as the critical cluster. According to the critical cluster identifying method for transient stability analysis of the power system, the critical cluster is identified according to the sensitivity of the mechanical power of each generator based on the energy margin; the identification accuracy is improved; and the situation of misjudgment is reduced.

An optical approximation correction method, comprising: determining a figure with forbidden distance; forming a plurality of jagged or rectangular protrusions on both sides of the forbidden space figure; inserting a plurality of auxiliary scattering bars between the forbidden space figures. The photomask pattern corrected by optical approximation can form a pattern with high resolution, large depth of focus and energy margin.

The present invention discloses a power grid transient stability energy function analysis method and system containing a detailed generator model. The method comprises the following steps of: establishing a power system model containing the detailed generator model; determining a failure mode; calculating an angular point CRN; calculating a generator equivalent parameter; solving an accurate controlling unstable equilibrium point (CUEP); and calculating an energy margin according to a system energy difference value of the CUEP and a failure clearing moment. The system comprises apparatuses used for implementing the method. The problem of a relatively large deviation between a transient stability analysis result and an actual situation, caused by a too simplified model in an existing energy function method entering a practical stage, is solved, so that the reliability of power system security analysis can be improved.