Variable-Frequency Drive (VFD) is an application for frequency conversion technology and microelectronics technology. The power control equipment for AC motor by changing the frequency of motor working power.The inverter is mainly composed of rectifier (AC DC), filtering, inverse (DC communication), braking unit, driving unit, and micro -processing unit of detection unit.The inverter adjusts the voltage and frequency of the output power supply by the internal IGBT opening, and provides the power supply voltage according to the actual needs of the motor to achieve the purpose of energy saving and speed regulation.
Mitsubishi inverter
The Mitsubishi inverter is a electrical control device that transforms the power supply power supply to another frequency by using the through breakdown effect of the power semiconductor device.The Mitsubishi inverter mainly adopts the interchange -direct -transmission method (VVVF frequency conversion or vector control inverter). First, the industrial AC power supply is converted into a DC power supply through the rectifier, and then the DC power supply is converted into a frequency and voltage of AC power supply.Supply motor.The circuit of Mitsubishi inverter is generally composed of four parts: rectification, middle DC link, inverter and control.The rectifier part is a three -phase bridge -type irreplaceable rectifier, the inverter part is the IGBT three -phase bridge inverter, and the output is PWM waveform. The middle DC link is filtering, DC energy storage and cushioning powerless power.I. Introduction Mitsubishi inverter is one of the world -renowned inverters. It is produced by Mitsubishi Electric Co., Ltd., and has a high share in the world.Mitsubishi inverter has a history of more than 20 years. In the domestic market, Mitsubishi has a broad market because of its stable quality and strong brand influence, and has been widely used in various fields.
The function of the frequency frequency
1. Control the startup current of the motor. When the motor is directly activated by the motor frequency, it will generate a rated current of 7 to 8 times.This current value will greatly increase the electrical stress of the motor winding and generate heat, thereby reducing the life of the motor.The variable frequency speed adjustment can be activated at zero -speed and zero voltage (can also be increased by proper torque).Once the relationship between frequency and voltage is established, the inverter can drive the load to work according to the V/F or vector control mode.The use of variable frequency speed adjustment can fully reduce the start -up current and improve the endurance of the winding. The most direct advantage of the user is that the maintenance cost of the motor will be further reduced and the life of the motor will increase accordingly.
Inverter repair
1. Common methods Static test 1. Test the results of the rectifier circuit to find the results of the circuit.P, Black Watch sticks depend on R, S, T, respectively, with a resistance value of dozens of euros in normal times, and basically balance.On the contrary, the black watch stick is connected to the P end, and the red watch stick receives R, S, T, with a resistance value close to infinitely.Repeat the red watch stick to the N -terminal, and repeat the above steps, and the same results should be obtained.If there is a three -phase imbalance with the resistance value, it means that when there is a fault in the rectifier bridge .b. When the red table rod is connected to the P end, the resistance is infinite, and the fault of the rectifier bridge or starting the resistance can be determined.
Inverter working principle
The main circuit is the power transformation part of the influence of regulating frequency and frequency -regulating power supply for asynchronous motors. The main circuit of the inverter can be divided into two categories: the voltage type is to transform the DC of voltage sources into a conversion inverter. The filter of the DC circuit is a capacitor.EssenceThe current type is the inverter of the current source to the inverter of the current, and its DC circuit filter is an inductance.It consists of three parts, transforming the power frequency power to a "rectifier" with a DC power, and absorb the voltage pulse generated by the variable and inverter.The power frequency power supply is converted to a DC power supply.

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