UPS Development
In the early days, it was a dynamic uninterruptible power supply. The mains electricity drove the generator, and the motor drove the engine to generate AC power. The flywheel inertia was used. When the mains electricity changed, the flywheel’s huge inertia did not react to the instantaneous change in voltage, thus ensuring the stability of the output voltage. (Relying on the flywheel with kinetic energy storage to extend the power supply time when the mains electricity is cut off is bound to be limited)
After the mains electricity is rectified, one path is used to charge the battery, and the other path is used to power the DC motor, which in turn drives the AC generator to output stable, frequency-stabilized AC power. (This type of system has the disadvantages of high noise, low efficiency, long switching time, and bulkiness.)
Static UPS relies on electromagnetic energy storage and converts electrical energy through a static inverter to maintain load power supply. (Small size, light weight, low noise, easy operation, high efficiency, long backup time)
UPS Classification
There are many ways to classify UPS. According to the output capacity, it can be divided into: Small capacity ( below 10kV·A) UPS, medium capacity (10~100kV·A) UPS and large capacity (above 100kV·A) UPS; according to the number of phases of input and output voltage, it can be divided into single-input single-output UPS, three-input three-output UPS and three-input single-output UPS; according to the output waveform, it can be divided into: square wave UPS, trapezoidal wave UPS and sine wave UPS; but people are accustomed to classifying UPS according to their various structural forms, which can be divided into backup UPS, interactive UPS and online UPS.
Backup UPS
When the AC power is normal, the voltage stabilizer supplies power to the load; when it is abnormal, the battery supplies power to the load through the inverter. (The original form of static UPS) Mainly powered by AC power.
Online UPS
When the AC power is normal, the load is powered by the rectifier and inverter; when it is abnormal, the battery supplies power to the load through the inverter. (Also known as double conversion online or series adjustment UPS)
Interactive UPS
When the AC power is normal, the load is powered by the voltage stabilizer and the converter only charges the battery; when the AC power is abnormal, the battery supplies power to the load through the converter. (Also known as online interactive UPS or parallel compensation UPS)