Abstract
Nowadays high performance becomes the destination of the development of UPS; therefore taking the research of digital controlled UPS is very important and meaningful。
A digital controlled UPS is presented here. Firstly, the topology of the system is studied. The principle of PFC rectifier is described in detail, with the average current mode controlled circuit as an example. And some problems should be given attention to are noticed here. The model of the half-bridge inverter is studied both in the continuous field and the discrete field, for the convenience of simulation and analysis. And the result that inverter is a double input, single output nonlinear model is pointed output then nonlinear of the model only presented by the nonlinearity of the load disrupt。
The phase-lock between the line input and inverter output is discussed here and the theoretic basis of the phase lock technique. Finally two algorithms are summed with implementation respectively. And the most widely used PID controller is used to improve the dynamic response of the inverter. The design of controller parameters is Introduce and the result was validated through simulation. The RMS control is added to the system as a result that Pm controller can't trace the sinusoidal signal without
steady-state error. The monitor system and the switching circuit are mentioned for the entirety of the system。
Keywords: Uninterruptible Power Supply Power Factor Correction average current mode control Phase lock Instantaneous feedback PID Digital control