Schematic diagram of motor full-wave energy consumption braking control circuit

Schematic diagram of motor full-wave energy consumption braking control circuit

Many production machinery hope to have appropriate braking effect when parking, so that moving parts can stop quickly. Parking brakes include mechanical braking and electrical braking. Dynamic braking is a widely used electrical braking method.

Energy-consuming braking means to cut off the running motor from the AC power supply and immediately connect it to the DC power supply. When the stator winding is connected to the DC power supply, the DC current will generate a static DC magnetic field in the stator, and the rotor will move in the magnetic field due to inertia. The rotor rotates internally and generates an induced potential in the rotor conductor and an induced current flows through it. It interacts with the constant magnetic field to consume the inertial energy of the motor rotor to generate braking torque, causing the motor to rapidly decelerate and finally stop rotating.

1. Close the air switch QF and connect the three power supplies

2. Press the start button SB2, the contactor KM1 coil is energized and self-locked, the main contact is closed, and the motor is connected to the three-phase power supply to start operation.

3. When it is necessary to stop, press the stop button SB1, the KM1 coil will be powered off, and its main contacts will all release the motor and disconnect from the power supply.

4. At this time, the coils of contactor KM2 and time relay KT are energized and self-locked. KT starts timing. The main contact of KM2 is closed and the DC power supply is connected to the stator winding of the motor. The motor stops quickly under energy consumption braking.

In addition, when the normally closed contact of the time relay KT is delayed and disconnected, the contactor KM2 coil is deenergized, and the KM2 normally open contact disconnects the DC power supply, disconnects from the power supply and the stator winding, and the energy consumption braking ends in time, ensuring accurate stopping. .

5. The overload protection of this circuit is completed by a thermal relay

6. Interlocking links:

⑴ The KM2 normally closed contact is connected in series with the KM1 coil circuit, and the KM1 normally closed contact is connected in series with the KM2 coil circuit. It is guaranteed that the KM1 and KM2 coils cannot be energized at the same time, that is, when the motor is not disconnected from the three-phase AC power supply, the DC power supply cannot be connected to the stator winding.

⑵ The normally closed contact of button SB1 is connected to the KM1 coil loop, and the normally open contact of SB1 is connected to the KM2 coil loop. This is button interlocking and ensures that KM1 and KM2 cannot be powered on at the same time. dots have the same effect.

7. The DC power supply adopts a diode single-phase bridge rectifier circuit, and the resistor R is used to adjust the braking current and change the braking force.

Motor full-wave energy consumption braking control wiring diagram