Graded frequency conversion stepless voltage regulating soft starting device based on non-speed sensor

Abstract

The invention discloses a graded frequency conversion stepless voltage regulating soft starting device based on a non-speed sensor, and belongs to the technical field of starting of motors, and the device is mainly used for solving the problems that the existing soft starting device has reduced starting voltage, consequently the starting torque is seriously reduced, and the heavy-duty starting is hard. The graded frequency conversion stepless voltage regulating soft starting device is mainly characterized by being composed of a main loop which is composed of five groups of sequentially-connected antiparallel controllable silicon groups, and a main loop control circuit, wherein the main loop control circuit comprises a DSP (digital signal processor) controller, a current signal zero cross detection circuit, a voltage sampling circuit, a current sampling circuit, a synchronous signal collection circuit and a driving circuit; and the voltage sampling circuit and the synchronous signal collection circuit are connected between the main loop and a DSP, the current sampling circuit and the current signal zero cross detection circuit are connected between the main loop and the DSP, and the driving circuit is connected between each silicon controlled end and the DSP. The graded frequency conversion stepless voltage regulating soft starting device provided by the invention has the characteristics that the starting current is small, the starting torque is high, the frequency division section switching is smooth, and the graded frequency conversion stepless voltage regulating soft starting device is mainly used for a three-phase asynchronous motor belt heavy-duty starting occasion.

Description

technical field [0001] The invention belongs to the technical field of motor starting. In particular, it relates to a step-by-step frequency conversion stepless voltage regulation device for soft starting. Background technique [0002] As an electromagnetic mechanical device for electromechanical energy conversion, electric motors are widely used in various fields such as industrial and mining enterprises, transportation, and national defense industry. Among them, among various motors that drive loads, induction motors have been widely used due to their high and stable performance. Three-phase induction motor soft start controller is a control device specially designed for motor starting. Its main circuit uses cheap (compared with other power devices) thyristors (SCR) as power devices. The whole set of equipment is low in cost and easy to use. It is based on the thyristor voltage regulation principle, by adjusting the firing angle of the thyristor, thereby controlling its ...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to provide a soft starter with graded frequency conversion and stepless voltage regulation based on no speed sensor to solve the problem of large starting current when the existing soft starter starts heavy loads, so that it has small starting current and high starting torque , while introducing no speed sensor to ensure smooth switching of each sub-frequency band, and the device is cheap

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