Suppliers of energy feedback devices for frequency converters remind you that many people do not have a clear understanding of the specific differences and uses of frequency converters and energy-saving devices. Most energy-saving devices on the market are power compensation or overvoltage protection products that use high-voltage filtering and energy absorption technology to automatically absorb the energy of the reverse potential of high-voltage power equipment and continuously feedback it back to the load, saving the electricity that the electrical equipment absorbs from the high-voltage grid. The energy-saving effect is average and has little effect.
The frequency converter adjusts the different currents required by electrical equipment due to changes in operating conditions by controlling the frequency. It mainly consists of rectification (AC to DC), filtering, inversion (DC to AC), braking unit, driving unit, detection unit, microprocessor unit, etc. The frequency converter adjusts the voltage and frequency of the output power supply by disconnecting the internal IGBT, providing the required power supply voltage according to the actual needs of the motor, thereby achieving energy saving and speed regulation. In addition, the frequency converter also has many protection functions, such as overcurrent, overvoltage, overload protection, etc. With the continuous improvement of industrial automation, frequency converters have also been widely used.
The reason why frequency converters can achieve energy-saving and energy-saving effects in most cases is that the frequency converter controls the speed of the motor
The prerequisite for a frequency converter to achieve energy saving is its load speed regulation characteristics. For spare parts that have a significant impact on power, such as centrifugal fans and centrifugal water pumps, the adjustment effect of the frequency converter should be significantly better than that after its own speed regulation operation. Under this premise, the frequency converter can actually achieve energy saving and energy saving effects
If the spare parts processed by the frequency converter are constant torque loads or even constant power loads, the power decrease is not significant or the power remains constant when the speed decreases. Therefore, the use of frequency converters cannot achieve the same energy-saving effect as before, and even cannot save electricity at all
The main reason why energy-saving devices are different from frequency converters is that:
Firstly, frequency conversion technology is only one of many energy-saving technologies, which includes various techniques such as voltage regulation and current limiting, power factor compensation, phase controlled power regulation, frequency conversion, chopping, filtering, energy feedback, etc. Even for energy-saving devices that use frequency conversion principles, frequency converters are only one unit in the energy-saving device;
Secondly, the research and design of the energy-saving device takes into account various control requirements of the application site, and has various control functions that are easy to operate on site, such as temperature and pressure closed-loop control;
Thirdly, in many industrial sites, directly wiring and installing frequency converters does not comply with electrical standards and can easily cause various safety accidents. Installing a complete set of energy-saving devices can reduce the occurrence of accidents;
Fourthly, the research and design of the energy-saving device fully considers the safety protection of the built-in frequency converter, setting up lightning protection circuits, overvoltage protection circuits, and fault alarm functions to minimize the accidental damage of the frequency converter itself.
Fifthly, according to the actual needs of the production site, energy-saving devices are generally equipped with high-performance bypass systems, which can ensure the smooth progress of on-site production even in the event of unexpected failures in the speed control unit.
Sixth, as is well known, frequency converters generate certain harmonics during operation. In many production sites, a large amount of harmonic interference often causes equipment misoperation or even damage. When researching and designing energy-saving devices, large energy-saving enterprises generally install harmonic filtering devices inside the energy-saving devices to filter out most of the harmonics on site, which is crucial for the safety production of customers.