Centrifuge frequency-converting control circuit and control method thereof

Abstract

The invention discloses a centrifuge frequency-converting control circuit and a control method thereof. The centrifuge frequency-converting control circuit comprises a variable frequency power supply circuit and a power frequency power supply circuit. The variable frequency power supply circuit comprises a frequency converter and the power input end of the frequency converter is connected with a power frequency three-phase power supply via the normally-opened switch of a contactor KM6. The power output end of the frequency converter is used for powering up a centrifuge via the normally-opened switch of a contactor KM5. The frequency converter is also connected with the normally-opened switch of a relay KA1. The power frequency power supply circuit comprises a normally-opened switch of a contactor KM7 and an FR fuse. The coil power supply circuit of the contactor KM6 and the contactor KM5 is connected in series with the normally-opened switch of a relay KA5 and the normally-closed switch of the contactor KM7. The coil power supply circuit of the contactor KM7 is connected in series with the normally-opened switch of a relay KA6 and the normally-closed switch of the contactor KM5. The relay KA1, the relay KA5, the relay KA6 and the frequency converter are controlled by a PLC. The centrifuge frequency-converting control circuit is small in start-up current, and the impact to the power grid is avoided. Meanwhile, the service life of an electric motor is prolonged. Moreover, the circuit is simple in structure, reliable in operation and strong in overload capability.

Description

technical field [0001] The invention relates to an electric control device for starting and working of a centrifuge, in particular to a frequency conversion control circuit of a centrifuge and a control method thereof. Background technique [0002] Centrifuges are widely used in food, pharmaceutical, agrochemical, chemical and other industries, using centrifugal force to separate solid particles in suspension from liquid, or to separate two immiscible liquids with different densities in emulsion; It can also be used to remove liquid in wet solids. At present, the control device of horizontal centrifuge mainly adopts PLC programmable logic control as microprocessor control, real-time display and input adjustment of various parameters, protection circuit, and frequency conversion mode. Through the analysis of existing products in the current market, it is found that although the frequency conversion method can be used to adjust the speed, the current is large and the motor hea...

AI Technical Summary

Problems solved by technology

Through the analysis of existing products in the current market, it is found that although the frequency conversion method can be used to adjust the speed, the current is large and the motor heats up, which poses a large safety hazard; with the continuous change of the motor speed, the centrifuge starts to vibrate. cause loud noise

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