With the development of social economy, people’s lives are increasingly inseparable from the use of electricity. Whether the power supply is normal or not directly affects the social and economic benefits. In addition to the normal industrial power grid, it is often necessary to be equipped with a UPS power supply system to prepare for it from time to time Need. Let us briefly understand the application of UPS uninterruptible power supply in production and life.

Uninterruptible power supply system (UPS for short), it refers to the equipment that can continue to supply power to the load when the AC grid input is abnormal, and the quality of the power supply is guaranteed, so that the power supply of the load is not affected. In daily production and life, due to the complex quality of the power grid, voltage instability and interruption, etc., it has caused a series of interferences to the power electronic system, and the electronic components may also be damaged. In order to maintain the normal, continuous and stable use of power, UPS is increasingly It has received attention and has gradually developed into a power protection system with functions such as voltage stabilization, frequency stabilization, filtering, anti-electromagnetic and radio frequency interference, and anti-voltage surge. Uninterruptible power supply can be divided into AC uninterruptible power supply and DC uninterruptible power supply system according to whether the load provides AC or DC.

UPS uninterruptible power supply

UPS power system is mainly composed of inverter, static switch, rectifier, and battery. Its main component is an inverter, which is used to convert DC power into AC power at the required voltage and frequency. It contains energy storage equipment to maintain a stable voltage and stable frequency power supply protection. The rectifier (charger) is responsible for providing a stable DC voltage to the inverter and charging the battery.

UPS as a kind of AC uninterrupted power supply equipment, its functions are: when the mains power supply is interrupted, it can continue to provide the load with the required AC power; second, it can be used when the mains power supply is not interrupted but the power supply equipment cannot meet the load requirements , It has the purifying function of AC power such as voltage stabilization and frequency stabilization, that is, UPS processes the electric energy that does not meet the load requirements of the mains grid into AC power that meets the requirements of the load. Mains abnormalities are affected by complex power grid conditions such as voltage spikes, voltage transients, wire noise, voltage notches, voltage drops, voltage surges, and mains interruptions.

People are accustomed to divide the UPS circuit structure into two major categories: backup and online. When the backup UPS power supply is normally supplied by the mains, the mains directly supplies power to the load through the AC bypass channel and then through the transfer switch, and the inverter in the machine is in a stopped working state. This UPS power supply is essentially equivalent to a mains voltage stabilizer with poor voltage stabilization performance. The effects of frequency instability, waveform distortion, and interference from the power grid on the mains voltage have basically not been improved.

Schematic diagram of backup UPS

The advantages of backup UPS power supply are high operating efficiency, simple circuit, low noise, and relatively cheap price. It is mainly suitable for occasions where the mains power fluctuation is not large and the quality of power supply is not high. Normally the capacity of the backup sine wave output UPS is below 2kV·A, while the capacity of the backup square wave output UPS is usually below 1kV·A.

Online UPS schematic diagram

On-line UPS power supply is when the mains power is normally supplied, the mains AC power is first converted into a DC power, and then pulse width modulation and filtering are performed, and then the DC power is turned into an AC power again, that is, it is usually After the AC power is rectified, it provides AC power to the load in the form of an inverter. For the online UPS power supply, under normal circumstances, regardless of whether there is commercial power, it is always powered by the inverter of the UPS power supply to the load, thus avoiding the influence of the voltage fluctuation and interference of the mains power grid.

Obviously, the power supply quality of the online UPS power supply is better than that of the backup UPS power supply, because it can achieve stable frequency and stable power supply to the load, and the conversion time is zero when the power supply is switched from the mains power to the battery power supply. .

After continuous development, UPS has continuously enhanced its performance and adaptability, and its application fields have been continuously expanded. The future development tends to be high-frequency, green and intelligent. The development of UPS pursues high frequency and green, and requires high conversion rate. The choice of low loss and high saturation magnetic flux density materials can effectively reduce the volume and weight of the device and increase the switching frequency of the inverter. The use of high frequency conversion technology makes the UPS highly energy-efficient, environmentally friendly and pollution-free. The uniform distribution of the air gap of the platinum metal powder core is characterized by the use of inorganic bonding insulation, no aging problems, low loss, and can meet the low loss requirements of various high-frequency applications.