The Sliding Mode Control For DC-DC Converter

The switching power supplies have gradually replaced the traditional linear ones and become the mainstream products, because of their small size, light weight, high efficiency and so on. The technology of power electronic converters is the core of the switching power supply. With the increasing requirements to the performance of the switching power supply from different high-tech field, the design of the power electronic converter control system has become a hot issue. In this paper, several control sliding mode variable structure schemes are proposed for buck converter and boost converter which are two basic forms of DC-DC converters.First of all, because of that the sliding mode control method is only robust to the mismatched disturbance and uncertainty when the state variables are on the sliding surface, in this paper, two global sliding mode controllers, time-varying sliding controller and the optimal sliding controller are designed for buck converter to deal with the disturbance of input voltage ripple. This method can eliminate the reaching phase of sliding mode control so that the buck converter can get global robustness.Secondly, the terminal sliding mode controller with strong robustness, faster response speed and dynamic performance, was designed for the buck converter with an uncertain load. At the same time, the adaptive terminal sliding mode controller is also designed to eliminate the steady-state error caused by the uncertainty of the load.Finally, it was designed that the robust backstepping sliding mode controller for boost converter to deal with the uncertainty of the load, combining the backstepping and sliding mode control method, and giving the robustness analysis; taking into account the disturbance of the input voltage to boost converter and jitter problem of the traditional sliding mode control, the robust smooth sliding mode controller with backstepping design for boost converter was proposed to weak the jitter of the sliding mode control; since the derivation of the virtual control in backstepping method could cause the expansion of controller coefficients, making the controller complex, at the same time, taking into account the non-linear attenuation of the input voltage and the uncertainty of the load, a smooth sliding mode backstepping controller with a filter is designed for buck converter to simplify the controller.In the end, the content of the article has been concluded. And the direction of research has been given.