Speed regulation mode

Variable pole speed adjusting method

The speed regulation method is to change the stator winding connection mode to change the cage motor stator pole number to achieve the speed regulation

The characteristics are as follows:

1, with a hard mechanical properties, good stability;

2, no slip loss, high efficiency;

3, wiring is simple, easy to control, low prices;

4, speed, bigger, can not get smooth speed;

5, can be used with the voltage regulator, electromagnetic slip clutch with high efficiency, smooth speed regulation characteristics.

The method is applicable to the production of machines without the need of stepless speed regulation, such as metal cutting machine tools, elevators, lifting equipment, fans, pumps, etc..

Variable frequency speed regulation method

Variable frequency speed regulation is the speed control method to change the frequency of the motor stator power supply, so as to change the synchronous speed. The main equipment of frequency conversion system is to provide variable frequency power supply inverter, the inverter can be divided into AC DC AC inverter and AC AC converter into two categories, most of the domestic use of AC-DC-AC frequency converter. Its characteristics:

1, high efficiency, no additional loss in the speed regulation process;

2, a wide range of applications, can be used for cage asynchronous motor;

3, speed range, hard, high precision;

4, complex technology, high cost, maintenance difficulties.

The method is suitable for high accuracy and good speed regulation.

Cascade speed regulation method

Cascade speed regulation refers to the winding motor rotor circuit can be adjusted into the additional potential to change the motor rotation, to achieve the purpose of speed regulation. Most of the differential power is absorbed by the additional potential which is connected in series, and then an additional device is used to return the absorbed differential power to the power grid or to convert the energy to be utilized. According to the difference of power absorption and utilization, cascade speed regulation can be divided into motor cascade speed control, mechanical cascade speed control and thyristor cascade speed regulation, the use of thyristor cascade speed regulation, which is characterized by:

1, can be in the process of speed difference between the loss of feedback to the power grid or production machinery, high efficiency;

2, equipment capacity and speed range is proportional to the investment, suitable for the production of mechanical speed range at rated speed 70%90%;

3, speed control device failure can switch to full speed operation, avoid production;

4, thyristor cascade speed control power factor is low, the influence of harmonic.

The method is suitable for the use of fan, water pump, rolling mill, mine hoist and extruder.

Resistance speed regulation method

Wirewound asynchronous motor rotor string into additional resistance, the motor slip up motor in low speed

Function。 The greater the resistance, the lower the speed of the motor. This method is simple and easy to control, but the differential power is consumed in the form of heat. Is a class speed control, mechanical characteristics of soft.

Stator voltage regulating speed regulating method

When changing the stator voltage of the motor, a group of different mechanical characteristics curves can be obtained. Due to the torque of the motor is proportional to the square of the voltage, the maximum torque is decreased, and the speed range is small. In order to expand the range of speed, pressure and speed adjustment should be rotorresistance value cage motors such as large torque motor, speed regulator for use, or frequency sensitive resistors in series wound motor. In order to expand the scope of stable operation, when the speed of 2:1 or more occasions should be used to control the feedback to achieve the purpose of automatic speed adjustment.

The main device of voltage regulation and speed regulation is a kind of power supply which can supply voltage variation. The commonly used methods of voltage regulation are series saturable reactor, self coupling transformer and thyristor voltage regulator. Thyristor voltage regulation is the best. Characteristics of voltage regulation and speed regulation:

1, the voltage regulating circuit is simple, easy to achieve automatic control;

2, in the process of adjusting the pressure difference in the form of power consumption in the rotor resistance, low efficiency.

3, pressure regulating speed is generally applicable to the following production machinery 100KW.

Motor speed regulating method

The electromagnetic speed regulating motor is composed of three parts: a cage motor, an electromagnetic slip clutch and a direct current excitation power supply (controller)

A. The DC excitation power supply is small, usually composed of single phase half wave or full wave thyristor rectifier.

The electromagnetic clutch is composed of three parts: the armature, the magnetic pole and the exciting winding. There is no mechanical connection between the armature and the latter. The rotor of the motor armature and the coaxial connection called active part, driven by the motor; magnetic pole for coupling with load docking said driven part. When the armature and the magnetic pole are all static, such as the excitation winding is connected with the direct current, a plurality of poles with alternating polarity of N and S are formed along the circumference of the air gap. When the armature rotates with the drive motor, the armature and pole between relative movement and makes electric armature inductionproduced eddy thiseddy and flux produced by the interaction of torque to drive the rotor poles rotating in the same direction, but its speed constant below the armature speed of N1, it is a slip speed control mode of DC excitation the current change slip clutch, clutch can change the output torque and speed. Speed regulation characteristics of electromagnetic speed regulating motor:

Device structure and control circuit is simple, reliable operation, easy maintenance;

1, speed smooth, stepless speed regulation;

2, the impact on the power grid;

3, speed loss, low efficiency.

The method is suitable for medium and small power, and requires the production of flat sliding, short time and low speed operation.

Coupler speed regulating method

Hydraulic coupler is a kind of hydraulic transmission device