Voltage following device and method and variable frequency drive control loop

Abstract

The invention provides a voltage following device and method, and a variable frequency drive control loop. The voltage following device comprises a rectification module, an inversion driving module, avoltage reduction module, a voltage sampling module, a current sampling module and a voltage following control module, wherein the output end of the inversion driving module is connected with the current sampling module, the current sampling module is used for collecting present current, the voltage sampling module is used for collecting a current bus voltage, and the voltage following control module is used for calculating the current running rotating speed of a load according to the present current and executing voltage boosting operation or voltage reducing operation according to the current running rotating speed and the current bus voltage. According to the invention, the reference bus voltage for controlling the rectification module to execute voltage boosting and the voltage reduction module to execute voltage reducing is determined by judging different rotating speeds of a load, so that the bus voltage is adjusted in real time, and the bus voltage of the variable frequency driving control loop is ensured to be in an optimal state in real time so as to improve the driving efficiency and reliability.

Description

technical field [0001] The invention belongs to the field of air conditioners, and in particular relates to a voltage following device, method and frequency conversion drive control loop. Background technique [0002] With the increasing energy efficiency requirements of various commercial air-conditioning inverters, more and more air-conditioning compressor manufacturers are looking for a combination of compressors and variable frequency drives with higher overall efficiency. Compressors with high back EMF have high load efficiency and drive The advantage of small current is gradually being widely used. [0003] In order to drive high back electromotive force compressors, the bus voltage of the variable frequency drive is also designed to be higher accordingly. The frequency converter with three-phase PWM rectifier has the advantage of being able to adjust the bus voltage to a high back electromotive force compressor. The power frequency conversion industry has attracted m...

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Problems solved by technology

[0004] In view of the above-mentioned shortcomings of the prior art, the object of the present invention is to provide a voltage following device, method and variable frequency drive control circuit, which are used to solve the problem that the bus voltage in the variable frequency drive circuit in the prior art remains higher than the natural rectified voltage for a long time. state, it is impossible to realize real-time adjustment, resulting in the problem of reduced driving efficiency and reliability

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