Circuit and method for switching from power frequency of high-voltage inverter to variable frequency without disturbance

Abstract

The invention discloses a circuit and a method for switching from power frequency of a high-voltage inverter to variable frequency without disturbance. The circuit comprises the high-voltage inverter, wherein an input end of the high-voltage inverter is connected with a power grid through a wire inlet switch QF1; an output end of the high-voltage inverter is connected to a load motor sequentially through a three-phase reactor L and a wire outlet switch QF2; an input end of the load motor is connected with the power grid sequentially through a power frequency bypass switch QF3 and a current sampling CT; and the current sampling CT is connected with the high-voltage inverter and is used for collecting the current during power-frequency operation and controlling the power-frequency current to be zero during switching. By the circuit and the method for switching from power frequency of the high-voltage inverter to variable frequency without disturbance, undisturbed switching from power frequency of the high-voltage inverter to variable frequency can be guaranteed, the production continuity is guaranteed, impact to the high-voltage inverter in the switching process is avoided, and meanwhile, failure of the high-voltage inverter in the switching process is avoided.

Description

technical field [0001] The invention relates to the field of control of high-voltage frequency converter switching between power frequency and frequency conversion, and more specifically, relates to a method for undisturbed switching between power frequency and frequency conversion of a high-voltage frequency converter. Background technique [0002] With the wide application of energy-saving technologies for high-voltage frequency converters in power, metallurgy, petroleum, chemical and other important occasions, higher requirements are put forward for the stability and energy-saving effect of high-voltage frequency converters. Since the load of high-voltage inverters in various industries is a very critical link in the entire production process, it is not allowed to stop. The non-disruptive switching of high-voltage inverters from power frequency to frequency conversion is very important for the continuity of user equipment and production. and safety are of great importance...

AI Technical Summary

Problems solved by technology

[0007] The purpose of the present invention is to solve the problem of undisturbed switching from power frequency to variable frequency, and to provide a method of undisturbed switching from power frequency to variable frequency of high-voltage inverters, which can realize the undisturbed switching of high-voltage inverters from power frequency to variable frequency , to avoid the shutdown failure of the high-voltage inverter during the switching process from industrial frequency to variable frequency, to ensure the continuity of production, and to avoid the impact on the high-voltage inverter during the switching process, which improves the reliability of the entire system, thereby ensuring the maximum benefit of users

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