The soft switch technologies defined in the broad sense, which are different from the traditional resonant mode ZUS and ZCS soft switch, have been adopted to reduce the switch consumption and improve the switch frequency. The soft switch is a damage-free buffer circuit, which can soften the switching process. Meanwhile, it has a simple circuit, requiring no additional resonant network. Therefore, the soft switch is low in cost. The efficient input filter and the active power factor calibrator can be added to the input terminal, and the series-parallel connection technology can be adopted to lower the distortion of the input current, reduce the pollution caused by UPS to the electric power, and turn the electric power supply into green power supply.

Advantages of operating principle of power frequency UPS
Power frequency UPS ensures rapid and flexible measurement data with digital signal processing technology, thus producing fast control variables to ensure real-time control for chargers and inverters.
Power frequency UPS has stronger short-circuit protection ability and overload ability than high frequency UPS.
As the power grid is not stable and is easy to be affected by external conditions, it has higher short-circuit protection ability and overload ability. Power frequency UPS would greatly improve the security and stability of load equipment.

1. Before starting the machine, make sure that the polarity of the input mains wiring is correct. The requirements of the UPS system for the positive and negative poles of the power supply are very strict, and the consequences are unpredictable.
2. Pay full attention to the total load capacity can not be greater than the rated power of the UPS. If the total load capacity is too large, the battery in the UPS will be overloaded. Over time, the battery will be damaged or even damaged.

Constant current charging:
Constant current charging is performed by a piecewise constant current method. It is generally achieved by the adjustment of the charging device itself. The charging current can be arbitrarily selected and adjusted, and the adaptability is strong, and is particularly suitable for long-time charging of a small current, and is also advantageous for charging a battery with a slower capacity recovery.

Under normal use, the UPS power supply has little maintenance work, mainly dustproof and regular dust removal. Especially in areas with dry climate, there are more ash particles in the air. The fan inside the machine will bring dust into the machine for deposition. When the air is wet, it will cause the host to control the disorder and cause the host to work abnormally, and an inaccurate alarm will occur. A lot of dust can also cause poor heat dissipation in the device. It should be thoroughly cleaned every quarter.

UPS power supply host does not require high ambient temperature, +5 °C ~ 40 °C can work normally, but requires indoor cleaning, less dust, otherwise dust and moisture will cause the host to work disorderly. The energy storage battery has higher temperature requirements. The standard operating temperature is 25 °C, and it should not exceed +15 °C to +30 °C. If the temperature is too low, the battery capacity will drop. Its discharge capacity increases with increasing temperature, but its life is reduced. If used at high temperatures for a long time, the battery life is reduced by about half for every 10 °C temperature.

UPS is divided into three types according to the working principle: backup, online and online.
1. Backup UPS: When the utility power is normal, the utility power supplies power directly to the load. When the utility power exceeds its working range or power failure, it is converted into battery inverter power supply through the transfer switch. The utility model has the advantages of simple structure, small volume and low cost, but the input voltage range is narrow, the output voltage stability and precision are poor, there is switching time, and the output waveform is generally a square wave.