Quick estimation algorithm for valve loss of modularized multi-level current converter

Abstract

The invention discloses a quick estimation algorithm for the valve loss of a modularized multi-level current converter, and the algorithm comprises the steps: 1, building a MMC rapid simulation model according to system parameters and a control method; 2, enabling a submodule capacitor voltage, a switching device trigger pulse and a bridge arm current in the simulation results to be stored as a readable data file; 3, building a mathematic model for switching device loss calculation and PN junction temperature estimation according to the characteristic parameters of a switching device in an MMC submodule; 4, enabling the data file to be imported into a loss calculation program, and calculating the valve loss of a single IGBT and a diode at each data step; 5, carrying out superposition to obtain the valve loss power of the MMC through iterative computation according to the relation between the valve loss power of the IGBT and the diode and the junction temperature. The method solves a problem that the voltage and current of the MMC submodule and the working temperature of a converter valve cannot be calculated precisely through analysis, and can be widely used for the technical field of flexible DC power transmission.

Description

technical field [0001] The invention relates to the technical field of flexible power transmission and distribution of electric power systems, in particular to a fast valve loss evaluation algorithm of a modular multilevel converter. Background technique [0002] At present, Modular Multilevel Converter (MMC, Modular Multilevel Converter) occupies a dominant position in the field of high-voltage flexible direct current transmission. Compared with two-level or three-level inverters modulated by PWM (pulse width modulation, pulse width modulation), MMC avoids the consistent triggering caused by direct series connection of IGBT (Insulated Gate Bipolar Transistor, insulated gate bipolar transistor), etc. It is applicable to various HVDC transmission occasions. With the increase in the number of sub-modules connected in series, that is, the number of levels, MMC can significantly increase the voltage level and power capacity, and the voltage sine degree of the AC side is higher ...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to overcome the above-mentioned deficiencies in the background technology, provide a modular multilevel converter valve loss rapid evaluation algorithm, and solve the problem that the MMC sub-module voltage, current and converter valve operating temperature cannot be accurately calculated by analytical means Compared with the original pure analytical calculation method, it has higher accuracy and stronger adaptability

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