With the rapid development of industry and Commerce in China, the demand for frequency converters is also getting higher and higher. Today Xiaobian takes you to know the functions and functions of frequency converters.
Frequency converter is an electrical device that converts the power frequency power to any frequency and any voltage AC power. The use of frequency converter mainly adjusts the power of the motor and realizes the variable speed operation of the motor. The main components of frequency converter consist of two parts: control circuit and main circuit. The main circuit also includes rectifier and inverter.
1. frequency conversion energy saving
The energy saving of the frequency converter is mainly shown in the application of the fan and the pump. In order to ensure the reliability of production, all kinds of production machines have a certain amount of surplus when they are designed to drive power. When the motor can not run under full load, in addition to the requirements of the power drive, the excess torque increases the consumption of active power and causes the waste of electric energy. The traditional way of speed regulation for fans and pumps is to regulate the air volume and water supply by adjusting the inlet or outlet baffle and valve opening. The input power is large, and a large amount of energy is consumed in the process of the closure of the baffle and valve. When using frequency conversion speed control, if the flow requirement is reduced, the speed of the pump or fan can be reduced by reducing the speed of the pump or the fan.
The function of the motor using the frequency converter is to speed up and reduce the starting current. In order to produce variable voltage and frequency, the device first changes the AC power of the power supply to DC, which is called rectifying. For inverters, inverters with adjustable frequency and adjustable voltage are called inverters. The waveform of the frequency converter is the analog sine wave, which is mainly used in the three phase asynchronous motor speed control, also called the frequency conversion governor. For variable frequency inverters, which require high waveform in instruments used for instrumentation, we need to sort out waveforms, and output standard sine wave, called frequency conversion power supply.
Frequency conversion can not save electricity everywhere, there are many field combined frequency conversion does not necessarily save electricity. As an electronic circuit, the converter itself also needs to consume power (about 3-5% of the rated power). A 1.5 air-conditioning power consumption is also 20-30W, the equivalent of a pilot. The operation of the transducer under high frequency, with a power saving function, is a fact. But his precondition is:
First, high power and load of fan / pump.
Second. The device itself has a power saving function (software support).
Third, continuous operation for a long time.
This is the three conditions that embody the power saving effect. In addition, it does not mean that it is not saving electricity, and there is no meaning. If the frequency conversion of frequency converter is energy-saving without precondition, it is exaggerated or commercial hype. Knowing the original, you will use it to serve you skillfully. We must pay attention to the use of the situation and the use of the conditions to correct the application, otherwise it is blind, credulous and deceived.
1. power factor compensation and energy saving
The reactive power will not only increase the heating power loss and equipment, more important is to reduce the power factor of the power grid leads to the decrease of active power, reactive power consumption in a large number of lines, low efficiency, serious waste of equipment, the use of frequency control devices, the inverter internal filter capacitor, thereby reducing the reactive power loss, increase active power grid.
2. soft start energy saving
The hard start of the motor will cause serious impact on the power grid, and it will also require too much capacity of the power grid. The large current and vibration caused by the startup will cause great damage to the baffle and valve, which will be extremely unfavorable for the life of the equipment and pipeline. With the use of frequency conversion energy saving device, the soft starting function of converter will start the current from zero, and the maximum value will not exceed the rated current. It will reduce the impact on the power grid and the power supply capacity, and extend the service life of the equipment and valve. The maintenance cost of the equipment is saved.
Theoretically, the inverter can be used in all mechanical equipment with electric motor, the motor starts, current will be 5-6 times higher than the rated current, will not only affect the service life of the motor, but also consume more power. In the design of the system in the motor selection will leave some margin, the motor speed is fixed, but in actual use, sometimes running at low or high speed, so the frequency transformation is very necessary. Frequency converter can realize motor soft start and compensation power factor, and achieve the purpose of energy saving and speed regulation by changing the frequency of input voltage, and it can provide overcurrent, pressure and overload protection functions for the device.