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Sequence impedance modeling method and system for double-fed wind generator

A doubly-fed wind power generation and modeling method technology, applied in wind power generation, electrical components, circuit devices, etc., can solve the problems of not considering the influence of excitation and the inability to accurately analyze the stability of the DFIG grid-connected system, and achieve the effect of accurate analysis

Active Publication Date: 2021-06-18
STATE GRID HENAN ELECTRIC POWER ELECTRIC POWER SCI RES INST +2
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The existing technical solutions using the impedance method do not consider the influence of excitation on the DFIG sequence impedance, so the stability of the DFIG grid-connected system cannot be accurately analyzed

Method used

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  • Sequence impedance modeling method and system for double-fed wind generator
  • Sequence impedance modeling method and system for double-fed wind generator
  • Sequence impedance modeling method and system for double-fed wind generator

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0056] like figure 1 As shown, the present invention provides a doubly-fed wind turbine sequence impedance modeling method, comprising the following steps:

[0057] S1: Construct the stator and rotor voltage and current positive sequence relation and the stator and rotor voltage and current negative sequence relation.

[0058] S2: Determine the phase a rotor positive sequence voltage and the phase a rotor negative sequence voltage in the abc coordinate system.

[0059] S3: Determine the positive-sequence output impedance of the rotor side considering excitation according to the stator and rotor voltage-current positive-sequence relationship formula and the a-phase rotor positive-sequence voltage in the abc coordinate system.

[0060] S4: Determine the rotor-side negative-sequence output impedance considering excitation according to the stator and rotor voltage-current negative-sequence relational formula and the a-phase rotor negative-sequence voltage in the abc coordinate sy...

Embodiment 2

[0129] like image 3 As shown, the present invention also provides a doubly-fed wind generator sequence impedance modeling system, said system comprising:

[0130] The parameter equation construction module 301 is used to construct the stator and rotor voltage and current positive sequence relational expression and the stator and rotor voltage and current negative sequence relational expression;

[0131] A-phase rotor sequence voltage determination module 302 in the abc coordinate system, used to determine the a-phase rotor positive sequence voltage and a-phase rotor negative sequence voltage in the abc coordinate system;

[0132] The rotor-side positive-sequence output impedance determination module 303 is used to determine the rotor-side positive-sequence output impedance considering excitation according to the stator and rotor voltage-current positive-sequence relationship formula and the a-phase rotor positive-sequence voltage in the abc coordinate system;

[0133] The ro...

Embodiment 3

[0148] Embodiment 1 and Embodiment 2 deduce the DFIG sequence impedance considering excitation, and its accuracy can be verified by simulation. The present invention adopts the double-fed fan grid-connected system as the research object, and simulates and verifies the correctness of the model in MATLAB through the method of harmonic voltage injection. The specific parameters are shown in Table 1. The parameters in Table 1 are used to study the sequence impedance of excitation to DFIG, and the rotor speeds at different wind speeds are shown in Table 2.

[0149] Table 1 Grid-connected system parameters of double-fed fan

[0150]

[0151]

[0152] Table 2 Rotor speed at different wind speeds

[0153] Wind speed V ω (m / s)

Rotor speed f r / Hz

5.0 33.33 6.0 42.22 7.0 51.11 7.5 55.56 9.0 60

[0154] Using the parameters in Table 1 to study the influence of excitation on the sequence impedance of DFIG, in Figure 4 The DFIG seq...

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Abstract

The invention discloses a sequence impedance modeling method and system for a double-fed wind generator. The method comprises the following steps of: constructing a stator and rotor voltage and current positive sequence relational expression and a stator and rotor voltage and current negative sequence relational expression; determining an a-phase rotor positive sequence voltage and an a-phase rotor negative sequence voltage under an abc coordinate system; determining rotor side positive sequence output impedance considering excitation according to the stator and rotor voltage and current positive sequence relational expression and the a-phase rotor positive sequence voltage under the abc coordinate system; determining rotor side negative sequence output impedance considering excitation according to the stator and rotor voltage and current negative sequence relational expression and the a-phase rotor negative sequence voltage under the abc coordinate system; obtaining grid-side converter GSC sequence impedance which comprises GSC positive sequence impedance and GSC negative sequence impedance; determining DFIG sequence impedance considering the excitation according to the rotor side negative sequence output impedance, the rotor side positive sequence output impedance and the GSC sequence impedance considering the excitation. According to the method and system of the invention, the DFIG sequence impedance is determined under the condition that the excitation is comprehensively considered, so that the stability of a DFIG grid-connected system can be accurately analyzed.

Description

technical field [0001] The invention relates to the technical field of impedance modeling, in particular to a method and system for modeling sequence impedance of a doubly-fed wind power generator. Background technique [0002] In recent years, my country's wind power industry has continued a good momentum of development. In 2019, my country's wind power industry has a cumulative grid-connected capacity of 210GW, making it the third largest source of electricity in my country. However, due to the reverse distribution pattern of wind power bases and main loads in my country, it is necessary to send wind power to the main load center for consumption. In order to increase the transmission capacity of the line and improve the transient stability, it is often used in long-distance high-voltage transmission lines Install a series capacitor for compensation. As large-scale wind turbines are connected to the grid, the problem of sub-synchronous resonance (SSR) becomes more and more...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H02J3/38
CPCH02J3/381H02J2203/20H02J2300/28Y02E10/76
Inventor 李程昊高泽崔惟田春笋方舟高昆刘轶王景钢李晓萌刘明洋
Owner STATE GRID HENAN ELECTRIC POWER ELECTRIC POWER SCI RES INST
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