Power system inertia online evaluation method based on frequency space correlation

Abstract

The invention discloses a power system inertia online evaluation method based on frequency spatial correlation. The method comprises the following steps: step 1, configuring synchronous phasor measurement devices at an interconnection point transformer substation of a power plant and a power grid and other redundant transformer substations; step 2, acquiring frequency, active power and current measured by the synchronous phasor measurement device on line, acquiring real-time topology and parameters of the system on line, and counting data quality of each measurement point PMU; step 3, calculating a frequency space correlation matrix, and calculating the rotating speed of the generator in the whole network on line according to the measured frequency; step 4, calculating the active power of the generator end on line according to the measured active power and the current; 5, calculating an inertia constant of each generator in each inertia evaluation window by using a parameter identification method; and step 6, calculating the total inertia of the system on line. The inertia of the power system can be accurately measured in real time, and the frequency stability of the power system is ensured.

Description

technical field [0001] The invention belongs to the field of power system frequency stability control, in particular to an online evaluation method for power system inertia based on frequency-space correlation. Background technique [0002] Inertia is the most important index to measure the ability of AC power system to resist disturbance, which mainly comes from the mechanical rotating shafting of synchronous generator. Wind power is connected to the grid through power electronic equipment. The mechanical rotor behind it is decoupled from the system and cannot provide inertia for the system. Photovoltaics itself does not have mechanical inertia. Therefore, new energy power sources have the characteristics of zero inertia and weak inertia. [0003] In recent years, with the large-scale construction of large onshore new energy bases and large offshore wind farms, the inertia level of the power system is gradually decreasing. The lack of inertia will not only increase the max...

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Problems solved by technology

However, considering that there is a step-up transformer and a transmission line between the PMU measuring point and the generator, the electrical frequency of the PMU measuring point is different from the rotor speed of the generator behind it, resulting in the inertia estimation results. large error

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