A Method for Accuracy Analysis of MMC Digital-Analog Mixed Simulation System

Abstract

The invention provides a method for analyzing the accuracy of an MMC digital-analog hybrid simulation system. The MMC digital-analog hybrid simulation system includes a digital simulation system, a power interface and a physical system under test, and the digital simulation system and the physical system under test are connected through the power interface; the analysis method Concretely include the following steps: establish the MMC digital-analog hybrid simulation equivalent model, and determine the open-loop transfer function of the MMC digital-analog hybrid simulation system; determine the disturbance error of the non-ideal interface and the disturbance error of the interface noise; judge the disturbance error of the non-ideal interface according to the upper limit of the error and interface noise disturbance error meet the requirements. The invention solves the problem of lack of reference standards for the accuracy evaluation of the MMC digital-analog hybrid simulation system at present. By analyzing the accuracy of the MMC digital-analog hybrid simulation system, we can pre-judge whether the MMC digital-analog hybrid simulation system is reasonable and improve it, thereby providing a basis for MMC engineering construction, which has great theoretical and practical significance.

Description

technical field [0001] The invention belongs to the technical field of flexible direct current transmission, and in particular relates to an accuracy analysis method for an MMC digital-analog hybrid simulation system. Background technique [0002] The flexible high voltage direct current (HVDC) system based on the modular multilevel modular converter (MMC) has the advantages of power supply to islands, no commutation failure, high waveform quality, and strong fault handling capabilities, etc. Many advantages. In recent years, the number and scale of projects of MMC-HVDC systems have been greatly increased worldwide. Therefore, it is extremely important to conduct certain simulation experiments. Due to the complexity of the MMC-HVDC system, traditional digital simulation and physical simulation can no longer meet the requirements. It is necessary to use digital-analog hybrid simulation that takes into account the advantages of both, also known as hardware-in-the-loop simula...

AI Technical Summary

Problems solved by technology

Ideally, the power interface is a unit gain unit without delay and phase distortion to ensure that the digital-analog hybrid simulation system is consistent with the original system, which cannot be achieved in practical applications

Therefore, the non-ideal power interface inevitably has problems such as delay, noise, non-ideal transfer function, limited bandwidth, etc., resulting in certain errors in the simulation results

If the error is too large, the reliability of the simulation will be reduced or even meaningless. It is very important to analyze the accuracy of the MMC digital-analog hybrid simulation system

[0005] However, when performing MMC digital-analog hybrid simulation, the original system as the only system that can produce correct results cannot be used as a reference for simulation results (otherwise simulation is unnecessary)

Therefore, it is very difficult to evaluate the accuracy of the MMC digital-analog hybrid simulation system

Due to the lack of reference standards for evaluating accuracy, its accuracy can only be analyzed through the simulation system itself

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