Large-grid wide-area asynchronous coordination control method

Abstract

The invention relates to a large-grid wide-area asynchronous control method, which belongs to the field of emergency control of power systems. The method comprises the following steps of (1): real-time state computation of a main network frame of a wide area measurement system (WAMS)-based power grid, which is to eliminate the false and retain the truth through data pre-treatment, inhibit or eliminate noises to the largest extent, and highlight the useful information of the wide area measurement system in a grid dynamic process to provide characteristic quantity for stable analysis and control; (2) real-time analysis of stability of grid power angle, which is to detect and predict asynchronous process of the system based on the synchronous phasor of the integral main power grid by combining a system analysis method, and find out an asynchronous section in space; and (3) presentation of a coordinate control strategy for asynchronous disconnection, which is to present a backup disconnection control measure when the asynchronous section deviates to the section which is not controlled by disconnection and guarantee reliable disconnection when the large-grid becomes asynchronous. According to the method, a WAMS-based wide area asynchronous emergency control is provided, the running state of the power system can be monitored and controlled in real time, possible power angle instability of the power system can be predicted, the chain reactions of large-grid resistance is guaranteed, and influences of grid accidents on national economy and people's live are avoided.

Description

technical field [0001] The invention belongs to the field of power systems, in particular to a method for emergency control of a large power grid, and in particular to a method for wide-area out-of-step protection of a large power grid. Background technique [0002] Out-of-step protection is a key measure to avoid chain reactions in the power grid. At present, traditional out-of-step protection has encountered challenges in large power grids with complex structures and operating modes, mainly reflected in: (1) The process of out-of-step development in large power grids is complicated: regional power grids The center of the out-of-synchronization oscillation generally falls on the tie line and its vicinity, and at this time, the decoupling device based on the local quantity may operate. However, accidents in the power system often do not develop in the direction people imagined. For example, due to climate reasons (gale, lightning, dense fog) the main line tripped one after a...

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Problems solved by technology

(2) Traditional out-of-step protection cannot carry out large-scale coordinated control: the detection criterion of out-of-step protection is based on the parameter change of the out-of-step state. The current criterion includes: the change of voltage, current and phase angle at the monitoring point; the impedance measurement of the monitoring point and its changes; monitoring point output power and its changes; monitoring oscillation center voltage changes, etc.

[0003] The current criterion has the following problems: the principle of measuring impedance is easy to misoperate. When this algorithm is reclosing or switching faults, the measured impedance may change in a jump. This situation is easy to be confused with asynchronous operation.

In order to prevent misjudgment, some devices use multi-level impedance sequence actions to detect asynchronous operation; based on local detection quantities, the current out-of-step disassembly device measures the electrical quantity of the plant station, and cannot macroscopically observe changes in the entire power system

When large-area power grids oscillate and lose synchronization, they cannot be analyzed from a global perspective; the out-of-step oscillation mode of the large-area interconnected grid often has multiple oscillation modes during the grid disturbance process, and most of the current The vibration splitting device is based on a two-machine model and cannot fully adapt to the detection of multi-machine oscillation modes

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