PSCAD (Power System Computer Aided Design)-based mechanical complex torque coefficient scanning method

Abstract

The invention discloses a PSCAD (Power System Computer Aided Design)-based mechanical complex torque coefficient scanning method, and belongs to the field of stable control of power systems. The method comprises the following steps: (1) loading a mechanical complex torque coefficient scanning module onto electromagnetic transient software; (2) inputting a generator parameter and an axis coefficient, and establishing an axis motion equation; (3) inputting a scanning parameter; (4) bringing the scanning frequency into the axis motion equation, calculating a mechanical complex torque coefficient under the frequency, and separating the mechanical complex torque coefficient into a real part serving as a mechanical elastic coefficient and a virtual part serving as a mechanical damping coefficient; (5) judging whether the frequency surpasses a cut-off frequency or not, if the frequency does not surpasses the cut-off frequency, adding a scanning step length to the frequency, returning to the step 4), and calculating the mechanical complex torque coefficient of a next frequency point; if the frequency surpasses the cut-off frequency, stopping calculating and finishing scanning. By adopting the PSCAD-based mechanical complex torque coefficient scanning method, the mechanical complex torque coefficient of a generator to be researched and developed on a PSCAD platform can be scanned automatically, a high scanning speed and an accurate result are achieved, and research of the problem of subsynchronous oscillation is facilitated.

Description

technical field [0001] The invention belongs to the field of power system stability control, in particular to a PSCAD-based mechanical complex torque coefficient scanning method. Background technique [0002] Subsynchronous Oscillation (SSO) in power system is a serious stability problem, which will lead to the accumulation of fatigue and even fracture of the main shaft of the generator set, which seriously threatens the safe operation of the power system. Series capacitance compensation for transmission lines or DC transmission systems may cause undesirable interactions between generator sets and the grid leading to subsynchronous oscillations. In the 1970s, during the debugging process of the Square Butte HVDC transmission project in the United States, the SSO problem of the turbogenerator set caused by HVDC was discovered for the first time. Later, in the HVDC transmission projects such as CU and IPP in the United States, Rihand-Deli in India, and Fenno-Skan in Sweden, i...

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Problems solved by technology

However, the calculation of the complex torque coefficient obtained by the analytical method is huge, and the research is inconvenient, and because the accurate mathematical model of the multi-FACTS device in the sub-frequency range has not been established, the application is limited, and the time domain response curve can be obtained through the test of the physical system , can also be calculated in the time domain by simulation software. The simulation method is fast, low in cost, and not affected by multiple FACTS devices in the system, and has been used more and more

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