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Commutation failure prevention control method and controller based on DC current change rate

A DC current and commutation failure technology, applied in the direction of power transmission AC network, etc., can solve the problems of prominent contradictions of AC voltage drop at firing angle, deterioration of commutation conditions, low prediction accuracy, etc., and achieve a balance between the increase of firing angle and the contradiction of voltage drop , Commutation failure is good, the effect of strong predictive ability

Active Publication Date: 2022-04-29
HUAZHONG UNIV OF SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0015] Most of the existing commutation failure prevention control (CFPREV) has the following disadvantages: (1) low prediction accuracy: start, input, and control are only based on AC voltage; (2) poor flexibility: once a certain gain or time constant is selected, it is very difficult to Difficult to make flexible adjustments according to actual working conditions; (3) The increase of trigger angle and the drop of AC voltage are prominent, or the commutation conditions will be deteriorated

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  • Commutation failure prevention control method and controller based on DC current change rate
  • Commutation failure prevention control method and controller based on DC current change rate
  • Commutation failure prevention control method and controller based on DC current change rate

Examples

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Embodiment 1

[0072] A commutation failure prevention control method based on the rate of change of DC current, such as figure 1 shown, including:

[0073] At the beginning of the current control cycle, detect whether various preset faults occur according to the real-time detected inverter side parameters including DC current;

[0074] When any type of fault occurs, according to the DC current variation ΔI dci Predict the firing angle α on the inverter side cv0 , and calculate the firing angle α of the inverter side output by the system controller o , so the firing angle compensation amount on the inverter side is Δα cv0 = α cv0 -α o ; DC current variation ΔI dci is the sum of the first-order differential item to the M-order differential item of DC current, the higher the order of the differential item, the smaller the time constant; M is a positive integer, and M≥2;

[0075] Using the trigger angle compensation amount Δα on the inverter side cv0 The trigger angle of the inverter si...

Embodiment 2

[0104] A commutation failure prevention controller based on the rate of change of DC current, such as figure 2 As shown, it includes: a signal detection module, a fault prediction module, a DC current variation calculation module, a firing angle compensation calculation module and a compensation module;

[0105] The signal detection module is used to continuously detect inverter side parameters including DC current;

[0106] DC current variation calculation module, used to calculate DC current variation ΔI dci ; DC current variation ΔI dci is the sum of the first-order differential item to the M-order differential item of DC current, the higher the order of the differential item, the smaller the time constant; M is a positive integer, and M≥2;

[0107] The fault prediction module is used to detect whether various preset faults have occurred according to the inverter side parameters detected in real time by the signal detection module at the beginning of the current control ...

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Abstract

The invention discloses a commutation failure prevention control method and a controller based on the rate of change of direct current current, which belong to the field of high-voltage direct current transmission, including: at the beginning moment of the current control cycle, according to the real-time detection of the inverter side including the direct current The parameters detect whether various preset faults occur; when any type of fault occurs, according to the DC current variation ΔI dci Predict the firing angle α on the inverter side cv0 , and calculate the firing angle α of the inverter side output by the system controller o , so the firing angle compensation amount on the inverter side is Δα cv0 = α cv0 ‑α o ; DC current variation ΔI dci It is the sum of the first-order differential item to the M-order differential item of the DC current. The higher the order of the differential item, the smaller the time constant; M is a positive integer, and M≥2; use the trigger angle compensation amount Δα on the inverter side cv0 The trigger angle of the inverter side actually output by the system controller is compensated, and the commutation failure prevention control of the current control cycle is completed. The invention can improve the commutation margin, suppress or alleviate the commutation failure, and promote the recovery of the power grid.

Description

technical field [0001] The invention belongs to the field of high voltage direct current transmission, and more specifically relates to a commutation failure prevention control method and a controller based on the rate of change of direct current current. Background technique [0002] Commutation failure is one of the most common faults in HVDC systems based on grid-commutated converters. After the commutation failure occurs, the DC voltage drops rapidly and the DC current increases sharply, causing serious impact on the system and even causing interruption of transmission power. With the successive investment in high-voltage direct current transmission projects, the characteristics of "strong direct current and weak alternating current, multi-circuit direct current centralized feed-in" of my country's power grid have become increasingly prominent, and the supporting capacity of the receiving end power grid has declined, and AC system failures may induce multiple phase commu...

Claims

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Application Information

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IPC IPC(8): H02J3/36
CPCH02J3/36Y02E60/60
Inventor 姚伟周泓宇艾小猛文劲宇
Owner HUAZHONG UNIV OF SCI & TECH