Dual-mode disturbance broadband impedance measurement method and dual-mode disturbance device

Abstract

The invention discloses a dual-mode disturbance broadband impedance measurement method and a dual-mode disturbance device. The measurement method comprises the following steps: measuring the impedance in a voltage disturbance mode, measuring the impedance in a current disturbance mode, and respectively combining the impedance of the VSC type equipment or the power network in the voltage disturbance mode and the impedance of the VSC type equipment or the power network in the current disturbance mode to obtain the impedance of the VSC type equipment or the power network. The dual-mode disturbance device comprises a first transformer, a harmonic power module, a mode selector and a coupling transformer; and the secondary side of the first transformer is connected to the input end of the harmonic power module, and the output end of the harmonic power module is connected to the primary side of the coupling transformer through the mode selector. According to the invention, the high-precision impedance measurement requirements of the VSC type equipment and the power network are met, the measurement requirements of the impedance of the VSC type equipment and the impedance of the power network during time varying can be met, and the blank in dual-mode and controllable broadband high-precision impedance measurement methods and disturbance devices is filled up.

Description

technical field [0001] The invention relates to the technical field of impedance measurement of power networks and VSC equipment, in particular to a dual-mode disturbance broadband impedance measurement method and a dual-mode disturbance device. Background technique [0002] With the rapid development of power electronic conversion technology, high-power voltage source converter (VSC) has become the core converter equipment of wind power generation equipment, photovoltaic power generation equipment, and high-speed trains. These non-linear power electronic converters have brought a series of vibration and instability problems while exerting their excellent performance, seriously interfering with the safe and stable operation of major power grids. Existing studies have pointed out that the mismatch of impedance characteristics between VSC equipment and power network will cause oscillation or instability of VSC control system. Using impedance analysis to analyze system stabili...

AI Technical Summary

Problems solved by technology

In the actual impedance measurement process, due to the difference in the influence of different parameters on the frequency-domain impedance, the impedance-frequency characteristic curves of VSC-type equipment and power networks often interact in a wide frequency range, causing the respective impedances in a specific frequency band to appear large and small. Small characteristics, only using a single disturbance method of voltage disturbance injection or current disturbance injection cannot accurately measure the impedance characteristics of broadband VSC equipment and power networks at the same time

In addition, the traditional single-frequency scanning impedance measurement method takes a long time to measure and cannot meet the measurement requirements of time-varying impedance

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