Working principle, advantages and disadvantages of apcups

UPS power supply system consists of rectifier module, inverter, voice battery, static switch, phase locked loop and other components. The rectifier module is energy conversion device (AC / DC), inverter is also energy conversion device (DC / AC), and battery is energy storage device. Generally, the up5 with capacity greater than 5kV. A is equipped with bypass device

Working principle, advantages and disadvantages of UPS

UPS power supply system consists of rectifier module, inverter, voice battery, static switch, phase locked loop and other components. The rectifier module is energy conversion device (AC / DC), inverter is also energy conversion device (DC / AC), and battery is energy storage device. Generally, the up5 with capacity greater than 5kV. A is equipped with bypass device. Because the rectifier and inverter circuits have been involved in the professional basic courses, and their principles are similar, so we will not introduce them in detail here, but simply describe the working principle of UPS system, static switch, phase-locked loop and power storage. Next, the principle block diagram of several common UPS is introduced.

(1) Basic working principle

When the mains power supply is normal, the power frequency alternating current supplies power to the load through the filter, automatic voltage regulator and relay contact SL. When the municipal power supply is stopped, the load is supplied by the battery and inverter, and the DC power supply is changed into AC power supply by the inverter, and the load is supplied by the relay contact s.

In the figure, the control circuit is used to detect the voltage at the input side and output side of the inverter, and generate PWM modulation pulse to provide driving signal to the power switch of the inverter, so that the inverter can output stable frequency and stable voltage AC for the load. The discharge time of the battery is determined by the load capacity. Usually, there are detailed instructions and diagrams in the product manual. When the market power is restored, the battery will be supplemented by the rectifier.

(2) Advantages and disadvantages

The biggest advantage of this kind of UPS is its simple structure, low cost and low noise. But the essential characteristic of backup UPS is inverter high wire, so the reverse deformation is usually in standby state. Moreover, because of the small capacity, the switching switch mostly selects the relay (2-5mg) for fast switching rather than static switch for higher speed switching. Therefore, the switching time is relatively long. When the power supply is normal, ups will directly connect the power supply to the load end, so it has no rectification, filtering and other functions, and is easily affected by the grid voltage and harmonic current. Only when the mains power input is stopped or the power supply quality exceeds the normal input range of UPS, the inverter will be switched to the battery discharge state, and the ups will output quasi square wave. Because of its narrow input range, small capacity and poor output power supply quality, this kind of UPS is only suitable for the common power supply maintenance of single PC and other non important occasions, such as home computer maintenance.