Multi-gear transformer type voltage drop device

Abstract

The invention discloses a multi-gear transformer type voltage drop device which comprises a voltage drop device, a signal measuring module and a device protective module. The voltage drop device comprises a primary side controlled current source, a secondary side controlled current source, a primary side field winding, a secondary side field winding, a drop characteristic setting module, a three-phase impedance calculation module and a three-phase current calculation module. The primary side controlled current source is connected with voltage of power supply grid through a breaker, the secondary side controlled current source is connected with the input end of a tested device, the drop characteristic setting module is used for setting the voltage drop depth, a failure type, the drop speed and the drop time, the three-phase impedance calculation module is used for calculating impedance of a transformer three-phase winding, the three-phase current calculation module is used for calculating the current of the transformer three-phase winding, electrical parameters collected by the signal measuring module are sent to the device protective module, and the signal measuring module is used for protecting the device against the possibly-occuring faults. The multi-gear transformer type voltage drop device can simulate voltage drop experiments with different depths under various faults, and meet the penetrating testing requirements of low voltage of a wind motor set.

Description

technical field [0001] The invention relates to the technical field of testing, in particular to a multi-level transformer-type voltage drop device suitable for wind power low-voltage ride-through testing. Background technique [0002] The voltage drop device is widely used in the low voltage ride-through test of wind power. When the power grid fails and the voltage at the grid-connected point of the wind farm drops, within the range of the voltage drop, the wind turbine can run uninterruptedly connected to the grid. [0003] According to the national standard wind turbine needs to meet the low voltage ride through capability, before the wind turbine leaves the factory or is connected to the grid, the low voltage ride through test must be carried out to judge whether it meets the requirements. Therefore, it is necessary to develop a voltage drop device as a test method. [0004] At present, domestic transformer-type wind power voltage drop devices are implemented in two form...

AI Technical Summary

Problems solved by technology

Its main disadvantage is that most of the switches connected to the transformer are contactors and relays, which will generate large voltage and current peaks, which is very unfavorable to the system under test; and the voltage drop depth is fixed, which is difficult to meet the requirements of actual testing

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