Tsinghua University

Zedong Zheng

Kui Wang

Yongdong Li

Lie Xu

A circuit for controlling a DC voltage source current includes a low-voltage DC bus capacitor, a first set of power electronics half-bridge units, a first set of branch circuit inductors, and a first set of DC switches. All of the first set of power electronics half-bridge units are connected in parallel between a positive pole and a negative pole of a low-voltage DC bus and are also connected in parallel with the low-voltage DC bus capacitor, an output neutral point of each power electronics half-bridge unit is connected in series with one of the first set of branch circuit inductors and one of the first set of DC switches to form one of a first set of current-sharing branch circuits, and each power electronics half-bridge unit and the corresponding current-sharing branch circuit are used to be connected with a DC voltage source to form a DC voltage source branch circuit.

Circuit for controlling current of direct current voltage source and control method

The present disclosure provides a multi-level converter with triangle topology and control method thereof, related to the technical field of multi-level converters. In the converter, n DC capacitors connected in series form a vertical edge of a triangle and are as a DC bus, n switching tubes connected in series form a bevel edge of the triangle, switching tubes each connected between a neutral point of the DC bus corresponding to each layer and a point for connecting the switching tube on the bevel edge form a horizontal edge. Each time the layer is expanded by one, the number of levels increases by one. When a voltage across each capacitor is E, an AC output terminal Xn may output a total of n+1 levels.

Multi-level converter with triangle topology and control method thereof

The present disclosure provides a single carrier based multilevel modulation method, a single carrier based multilevel modulation device, and a storage medium. In each control period, a modulated wave value corresponding to each of n switch pairs is obtained according to a reference voltage to obtain n modulated wave values, a triangular carrier having an amplitude of n is generated and compared with each of the n modulated wave values to obtain control signals for each of the n switch pairs, and for each phase, the control signals are input to the corresponding switch pairs of the phase bridge.

Single carrier based multilevel modulation method and device, and storage medium

A method and a device for voltage balancing of DC bus capacitors of an NPC four-level inverter are disclosed. The method includes: determining an optimal zero-sequence voltage, determining an actual reference voltage of each phase based on the optimal zero-sequence voltage; comparing respectively three preset carrier signals with the actual reference voltage of each phase to obtain three first control signals; determining three duty-cycle adjustment values based on a voltage of the intermediate bus capacitor; adjusting correspondingly the three first control signals based the three duty-cycle adjustment values to obtain three second control signals; inputting correspondingly the three second control signals to three first switches of an upper bridge corresponding to each phase; and inputting correspondingly complementary signals of the three second control signals to three second switches of a lower bridge corresponding to each phase.

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Beijing, China

Zedong Zheng