Accuracy analysis method for MMC (Multilevel Modular Converter) digital-analog hybrid simulation system

Abstract

The invention provides an accurate analysis method for an MMC (Multilevel Modular Converter) digital-analog hybrid simulation system. The MMC digital-analog hybrid simulation system comprises a digital simulation system, a power interface and a physical tested system, wherein the digital simulation system is connected with the physical tested system through the power interface. The analysis method specifically comprises the following steps: building an MMC digital-analog hybrid simulation equivalent model, and determining an open-loop transfer function of the MMC digital-analog hybrid simulation system; determining a non-ideal interface agitation error and an interface noise agitation error; and judging whether or not the non-ideal interface agitation error and the interface noise agitation error are consistent with requirements according to error upper limits. The problem of lack of an accuracy evaluation reference standard for the MMC digital-analog hybrid simulation system is solved. A judgment on whether or not the MMC digital-analog hybrid simulation system is rational can be made through analysis of the accuracy of the MMC data-analog hybrid simulation system, and improvements are made, so that a basis is laid for engineering construction of an MMC, and great theoretical significance and practical significance are achieved.

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

Images