A reliability calculation method for vsc-hvdc grid-connected system based on wind farm

Abstract

The present invention discloses a reliability calculation method for a VSC-HVDC grid interconnection system based on a wind farm. The method comprises the following steps: establishing a multi-state Markov model of timing output power of a wind farm by taking into account of time sequentiality and autocorrelation of a wind velocity, establishing a component Markov model of a VSC-HVDC grid interconnection system by taking into account of a STACOM state, and combining the two reliability models, to obtain a reliability model of the VSC-HVDC grid interconnection system based on the wind farm; and considering the influence of power output intermittency of the wind farm, excluding a component failure indicator that has no effect on the reliability of the VSC-HVDC grid interconnection system; and establishing a reliability indicator of the VSC-HVDC grid interconnection system based on the wind farm. According to the reliability calculation method provided by the invention, the degree of matching among the VSC-HVDC grid interconnection system, the wind farm, and an alternating-current system can be reflected accurately, and configurations of a wind turbine and the VSC-HVDC grid interconnection system can be determined more reasonably.

Description

technical field [0001] The invention relates to the field of power system reliability evaluation, in particular to a wind farm-based VSC-HVDC grid-connected system reliability calculation method. Background technique [0002] With the worsening of environmental pollution and the depletion of traditional energy, my country has gradually attached importance to the development and utilization of renewable energy. Wind energy is the fastest growing renewable energy in recent years, with the advantages of abundant resources, clean and pollution-free, and low development costs. Among the wind power transmission methods, the high voltage direct current transmission (HVDC) technology based on the voltage source converter (VSC) is widely used at present. The international authoritative academic organization named it VSC-HVDC, and the domestic unified name is flexible direct current transmission. Compared with the traditional DC transmission technology based on current source convert...

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Problems solved by technology

The periodical "Electric Power Automation Equipment" 2010, Volume 30, Issue 10 "Analytic Method Based Wind Farm Reliability Model" proposed a wind farm reliability model based on analytical method, but did not fully consider the timing and autocorrelation of wind speed The journal "Power System Protection and Control", Volume 41, Issue 8, 2013, "A multi-state reliability model for wind turbines for sequential Monte Carlo simulation" establishes a multi-state reliability model for wind farms. The Monte Carlo method is used for simulation, but the randomness of the wind speed is transferred to the output of the fan

[0005] At present, the research on the reliability assessment of AC transmission system and traditional DC transmission system is relatively mature, but there is little research on the reliability of wind farms based on VSC-HVDC

Journal "Power System Protection and Control" 2009 Volume 36 Issue 21 "Reliability Assessment of Flexible DC Transmission Based on FD Method and Model Combination" has carried out a reliable VSC-HVDC grid-connected system based on the FD method and model combination However, the STATCOM operating status of the VSC-HVDC grid-connected system is not considered, and the VSC-HVDC grid-connected system is directly regarded as a conventional DC transmission system, and the two-state model is used to model it, which does not reflect the VSC-HVDC grid-connected system at all. advantages and value

Moreover, when the wind farm is connected to the grid using VSC-HVDC, the existing literature does not consider the impact of the intermittent output of the wind farm.

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