AC power source advantages and applications
The governor of the variable frequency power supply, first, according to the required speed with energy-saving. It is mainly based on the following factors:
1) Frequency Control System loss and high efficiency.
2) motor always keep running in the low slip to reduce the rotor losses.
3) can be realized soft-start, brake function, reducing the starting current impact.
Speed ??control in ac power source, the need to process requirements, and consider all aspects of the conservation benefits, the payback period. If only from the technological requirements, the savings are to consider the following situations to choose the more advantage Frequency Control:
According to process requirements, production line or single equipment needs according to the procedure required to adjust the motor speed. Such as: packaging machine conveyor system, according to the different varieties of products, need to change the transmit speed, using the frequency control allows the speed control system is simple, accurate control, and easy to implement process control.
Frequency Control instead of a mechanical transmission. Such as: machine tools, not only eliminates the need for a complicated gearbox, but also improve the accuracy to meet the requirements of process control.
Frequency Control suitable for fans, pumps, compressors, etc. instead of gates or baffles to adjust flow. Such as: boiler, pumps, blowers, induced draft fan to implement Frequency Control, which removes the servo amplifier, electric actuator, electric actuator and the water supply valve (or wind deflector), and makes the whole boiler boiler control system has been fast dynamic response, high control accuracy and stability.
1970s, the development of LSI and computer control technology, as well as modern control theory, making the AC electric drive system gradually with a wide speed range, high steady speed range, high steady speed precision fast dynamic response as well as four-quadrant reversible operation of good technical performance, in terms of speed control performance can drag with the DC power comparable to AC variable speed frequency control has an absolute advantage, and constantly improve its speed performance and reliability, falling prices, especially frequency control power-saving effect is obvious and easy to automate the process by the industrial sector of all ages.
1 The outstanding features of an AC power source
1) speed, smoothness, and high efficiency. Low speed, the characteristics of static high clearance rate, relative stability is good.
2) wide speed range, high precision.
3) The low starting current, no impact on the system and power grid, energy-saving effect.
4) variable frequency power supply, small size, easy installation, commissioning, maintenance is simple.
5) easy to implement process automation.
6) There must be a dedicated variable frequency power supply voltage regulator, the current higher cost.
7) In the constant torque speed, low speed of the motor overload is greatly reduced.
2 Compared with other speed control methods
Motor speed control have three ways: pole-changing speed control to change the slip speed and frequency control. Among them, the frequency control most advantageous. It is only in respect of the variable frequency drive system with DC speed control system to do a comparison.
Exchange drag inherent in the energy-saving potential can be tapped. AC variable speed system, the selection of the motor is often left a certain margin, the motor is not always run at maximum load; if the use of variable frequency power conversion technology, light load, the motor speed control, you can save power. Extensive use of industrial fans, pumps, compressors, etc., its about 50% of industrial consumption of electricity consumption; variable frequency power supply speed control technology, can greatly improve their efficiency, and reduces electricity consumption by 10%.
