Protection setting calculation model for high-voltage variable-frequency motor

Abstract

The invention discloses a protection setting calculation model for a high-voltage variable-frequency motor. The protection setting calculation model for the high-voltage variable-frequency motor comprises a protection setting calculation model for the high-voltage variable-frequency motor with a phase-shifting transformer and a protection setting calculation model for the high-voltage variable-frequency motor without the phase-shifting transformer, and each of the two protection setting calculation models comprises a long start protection setting calculation model, a current quick-breaking protection setting calculation model, an overcurrent protection setting calculation model, a negative-sequence current protection setting calculation model, an overheat protection setting calculation model, a ground protection setting calculation model and a low-voltage protection setting calculation model; the protection setting calculation model for the high-voltage variable-frequency motor without the phase-shifting transform further comprises a locked-rotor protection setting calculation model. The protection setting calculation model for the high-voltage variable-frequency motor provides reference basis for the protection setting calculation of the high-voltage variable-frequency motor, and therefore, the protection functions are more complete, the protection set value is more reasonable, and the high-voltage frequency converter and the high-voltage motor can be protected to the utmost extent.

Description

technical field [0001] The invention relates to a protection setting calculation model of a high-voltage variable-frequency motor, which belongs to the technical field of relay protection. Background technique [0002] In recent years, due to the impact of load structure changes, the peak-to-valley difference of the power grid has become larger and larger. For this reason, many generating sets, even large-capacity, high-parameter generating sets must participate in peak-shaving operation. Frequent peak shaving tasks increase the number of starts and stops of the high-voltage auxiliary motor, and the insulation damage of the motor due to impact is increasing year by year; on the other hand, the output is adjusted by adjusting the baffle and the valve opening, resulting in Long-term operation in a low-efficiency work area causes serious energy waste. In order to improve the operating environment of the electric motor and reduce the power consumption rate of the plant, the "I...

AI Technical Summary

Problems solved by technology

[0003] At present, there are many articles at home and abroad on the analysis of energy-saving benefits brought by high-voltage frequency converters, but there are relatively few studies on the setting and protection of high-voltage motors after frequency conversion, and many articles only propose general setting methods, but for real applications that can be used in practice And there are few discussions on setting calculations to solve practical problems

After the motor is equipped with a frequency converter, it has a great impact on the traditional protection method of the motor

At present, the protection configuration of high-voltage variable-frequency motors is insufficient, and it is necessary to study a new protection configuration scheme suitable for wide-range frequency-modulated high-voltage motors

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