Soft starter for big powered electrical motor with built in bypass

Abstract

The invention comprises a CPU, a thyristor and its control circuit, a high power magnetic latching relay, a start key and its signal inputting circuit, and a stop key and its signal inputting circuit. The anode and cathode of the thyristor is connected to the moving contact and the fixed contact of the high power magnetic latching relay in parallel, and the attracting signal and the cut-off signal of the relay are respectively controlled by the signals outputted from the CPU. The output of the start key and the output of the stop key are respectively connected to the signal input of the CPU. The thyristor and the control circuit are packaged in one module, and the current on the contact of the relay keeps 60A-1000A.

Description

technical field [0001] The invention relates to a soft starter, in particular to a soft starter with a high-power built-in bypass motor. Background technique [0002] The soft starter is a motor control device. Its main components are the three-inverse parallel connection between the power supply and the controlled motor and its electronic control circuit. It is a device for voltage regulation and speed regulation of thyristors. , its anode and cathode are connected to the power supply and load to form the main circuit of the thyristor, and the gate and cathode of the thyristor are connected to the device for controlling the thyristor to form the control circuit of the thyristor. By changing the trigger delay angle of the thyristor, the output voltage of the thyristor is adjusted. When the motor is started with a soft starter, the output voltage of the thyristor gradually increases, and the motor gradually accelerates until the thyristor is fully turned on and the voltage re...

AI Technical Summary

Problems solved by technology

Although the external bypass solves the function of the thyristor to stop running after the motor starts, it needs to add an AC contactor of the same power used in conjunction with the motor

In this way, the installation work is increased, the size of the switchboard is increased, and the one-time investment is also increased; at the same time, the wiring of the external bypass, especially the greater the power, the more difficult it is to install, and some high-power bypasses require copper bars. Or aluminum row wiring, which brings great difficulties to installation and transformation, and is easy to cause errors and short-circuit accidents; in addition, AC contactors have high contact resistance, high power consumption, high noise, electromagnetic pollution, and heat radiation, so they are not suitable for use in flammable environments. Use in explosive situations

Images