Four-isolated single-phase motor speed controller

Abstract

The invention discloses a four-isolation single-phase motor speed regulator, and relates to the technical field of motor speed regulators. A power source is connected with an isolation transformer and an SCR power output and protection module. The isolation transformer is connected with a direct current voltage stabilizing filtering module connected with a speed regulating and indicating module and an isolation zero-cross detecting module, the speed regulating and indicating module and the isolation zero-cross detecting module are connected with an integrated speed regulating module, the integrated speed regulating module, an isolation triggering module and the SCR power output and protection module are connected in sequence, the SCR power output and protection module is connected with an isolation speed measuring feedback module through a motor, a first isolation capacitor and a second isolation capacitor, and the isolation speed measuring feedback module is connected with the integrated speed regulating module. The four-isolation single-phase motor speed regulator is smaller in size, easy to install, low in fault rate, safe, reliable, low in cost, long in service life and capable of being widely applied to the industrial control fields such as the single-phase alternating current speed regulating field, and the regulating performance of the speed regulator is improved.

Description

technical field [0001] The invention relates to the technical field of motor speed controllers, in particular to a four-isolation single-phase motor speed controller. Background technique [0002] Most of the common single-phase motors on the market use SCRs for voltage regulation and speed feedback with tachogenerators, and bidirectional SCRs are connected in series in the motor control loop to control the conduction angle of SCRs. In order to control the terminal voltage of the motor, when the external power supply voltage or load fluctuations cause the speed to change, the output signal of the tachometer generator coaxially connected with the motor is compared with the given speed signal through the integrator, and the error is amplified and the zero-crossing trigger signal, The voltage is automatically adjusted by driving the phase-shift trigger, and the set speed is adjusted with the potentiometer. However, due to the lack of isolation and interference measures, this ad...

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Problems solved by technology

[0002] Most of the common single-phase motors on the market use SCRs for voltage regulation and speed feedback with tachogenerators, and bidirectional SCRs are connected in series in the motor control loop to control the conduction angle of SCRs. In order to control the terminal voltage of the motor, when the external power supply voltage or load fluctuations cause the speed to change, the output signal of the tachometer generator coaxially connected with the motor is compared with the given speed signal through the integrator, and the error is amplified and the zero-crossing trigger signal, The voltage is automatically adjusted by driving the phase-shift trigger, and the set speed is adjusted with the potentiometer. However, due to the lack of isolation and interference measures, this adjustment method is vulnerable to power supply-control-speed regulation-zero-crossing detection-speed feedback. Motor leakage, power supply common mode / differential mode interference, power surge, and the influence of thyristor transient spikes cause out of control, reduce accuracy, cause fault damage and reduce life expectancy. Based on this, a four-isolation single-phase motor speed controller is designed. Still have great market application prospect

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