# 3 Methods to Control UPS Inverter

The ups means uninterruptible power supply, that contains energy storage devices. It is mainly used to provide uninterruptible power supply for some equipment with higher requirements on power stability.

When the mains input is normal, the ups will supply the mains voltage regulator to the load. At this time, the ups is an AC voltage regulator, and it also charges the battery in the machine.

Inverter is the heart of ups. It converts direct current to alternating current required by the user. For ups, the quality of the inverter output voltage determines the overall performance of ups. The following is a brief introduction to the 3 control methods of the ups inverter.

• Hysteresis control. Hysteresis control has fast response speed and high stability, but the switching frequency of hysteresis control is not fixed, so that the reliability of the circuit is reduced, the frequency spectrum of the output voltage is worse, and the system performance of the ups inverter is not good.
• Predictive control. Predictive control can achieve small current distortion and strong anti-noise ability in the ups inverter. However, this algorithm requires accurate load model and circuit parameters, and the delay caused by numerical calculation is also a problem in practical applications.
• Dead-beat control. Dead-beat control was first proposed by Kalman. It is a control method based on the precise mathematical model of the controlled object. The basic idea of beat free control is to calculate the PWM pulse width of the next switching period according to the state equation of the sine wave power inverter and the output feedback signal (usually the voltage and current of the output filter capacitor). The PWM pulse width is calculated from the state vector at the current time and the reference sine at the next sampling time.

Therefore, it is theoretically possible to make the output voltage very close to the reference voltage in both phase and amplitude, and to correct output voltage errors caused by load changes or non-linear loads within one switching cycle. No-beat control requires that the control pulse width must be calculated and output during the beat, otherwise it will not only destroy the control characteristics, but also affect the system stability. Inverter.com provides ups inverter with different power, ups inverter is equipped with pure sine wave output and soft-start technology.