Abstract: A display apparatus and a display method for a multi-layer superimposition are provided. When a display presents a user interface, a touch trajectory from a user can be detected via a touch component, and a touch trajectory pattern is present in a first layer; upon obtaining the touch trajectory pattern, an interpolation operation can also be performed on the touch trajectory pattern in the first layer according to a background pattern in a second layer; finally, a converted pattern obtained after the interpolation operation and the background pattern are superimposed and presented on the display.

Abstract: A method for minimizing DC capacitance of a cascade multilevel converter is provided. On the basis of balancing of capacitor voltages, the method estimates instantaneous value of the DC side capacitor voltages in a circuit through an energy conservation law, and uses a proportional resonance controller to control a grid-connected current to realize adjustment of the grid-connected current without static difference, such that the cascade multilevel converter can operate in a small capacitance mode, the system volume is greatly reduced, the system cost is reduced, the control is easy to be implemented, and the capacitor voltage is free from overshoot and the system has a better rapidity.

Abstract: A method for minimizing DC capacitance of a cascade multilevel converter is provided. On the basis of balancing of capacitor voltages, the method estimates instantaneous value of the DC side capacitor voltages in a circuit through an energy conservation law, and uses a proportional resonance controller to control a grid-connected current to realize adjustment of the grid-connected current without static difference, such that the cascade multilevel converter can operate in a small capacitance mode, the system volume is greatly reduced, the system cost is reduced, the control is easy to be implemented, and the capacitor voltage is free from overshoot and the system has a better rapidity.