Modeling and Analysis of Hysteretic Current Mode Control Inverter

In this paper, a small signal model of hysteretic current mode control with variable frequency and fixed hysteretic band is presented, based on three terminal averaged switch cell of buck converter in continuous current mode. This model reveals that the averaged current is the control target of hysteretic control. And phase lag of current loop with high switching frequency is quite small that makes current loop equivalent power stage be a proportional component. The conclusion is also valid in large signal analysis. Then an averaged linear model of single phase inverter is derived. The order of the system closed loop characteristic equation is reduced due to hysteretic current control introduced. And compensation principles of a single phase inverter are investigated with Routh criterion, which is easy to implement in practice and a good comprise between stability and stable/dynamic performance could be achieved.