Efficient simulation modeling method for full-bridge cascading type multi-level converter

Abstract

The invention relates to an efficient simulation modeling method for a full-bridge cascading type multi-level converter, and belongs to the technical field of power transmission and distribution. The efficient simulation modeling method is characterized in that equivalence is carried out on a sub-module of the full-bridge cascading type multi-level converter and a Dommel equivalent calculation model for a bridge arm, and the problem that in the locking stage of the full-bridge cascading type multi-level converter, a switch tube conducting state changes during two simulation moments is processed by adding a switch element. Due to the fact that the calculated quantity in simulation operation is reduced by reducing the number of variable impedance circuit braches in electromagnetic transient simulation software, the efficient simulation of the full-bridge cascading type multi-level converter is achieved. The efficient simulation modeling method is clear in principle, and stable and reliable in calculation result.

Description

technical field [0001] The invention relates to a high-efficiency simulation modeling method for a full-bridge cascaded multilevel converter, belonging to the technical field of power transmission and distribution. Background technique [0002] For the sake of sustainable development, using renewable energy such as solar energy and wind energy to generate electricity has become the development direction of the future power system. These power generation methods have the characteristics of being far away from the main grid and fluctuating greatly over time. The flexible DC transmission system is based on Voltage Source Converter (Voltage Source Converter, VSC) and Pulse Width Modulation (Pulse Width Modulation, PWM) technology to invert DC voltage into AC voltage with controllable amplitude and phase, and can independently and quickly Controlling the transmitted active power and reactive power greatly enhances the flexibility of power transmission and becomes the most potent...

AI Technical Summary

Problems solved by technology

In the algorithm of the current general-purpose electromagnetic transient simulation software (ElectroMagnetic Transient Program, EMTP), the switching device is equivalent to a two-state variable resistor. Therefore, if a detailed device model is used in the simulation research, each simulation At any time, there are many equivalent calculated admittances of power electronic switching device branches that need to update the state, which will cause a large number of rows of the node admittance matrix to be re-triangulated at each simulation time, and in order to eliminate It is necessary to interpolate the state variables at the exact switching time, which will cause the simulation speed of the full-bridge cascaded multilevel converter model to be very slow. The device model simulates the full-bridge cascaded multilevel converter model of the practical engineering cascade level, and the simulation time will be almost unacceptable

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