CN-115021243-B - Subsynchronous oscillation suppression method, subsynchronous oscillation suppression system and subsynchronous oscillation suppression device

Abstract

The invention discloses a subsynchronous oscillation suppression method, a subsynchronous oscillation suppression system and a subsynchronous oscillation suppression device, wherein the subsynchronous oscillation suppression method comprises the steps of extracting a power angle deviation signal of a doubly-fed induction wind driven generator; and the sub-synchronous component signal of the power angle deviation is superposed to the voltage of a rotor side q-axis control loop of the doubly-fed wind driven generator for carrying out compensation control on the rotor q-axis voltage and inhibiting sub-synchronous oscillation. The invention can effectively inhibit subsynchronous oscillation caused by grid connection of the doubly-fed wind power plant through the series compensation circuit, and ensure the stability of the power system.

Inventors

• GU KANGHUI
• Sun Shunxiang
• FENG SHIRUI
• ZHA SHENSEN
• ZHANG SHITAO
• WANG QIUDONG
• WANG ZHENQUAN
• NIU TAO
• ZHEN HONGNING
• LI JINKE
• YANG BIN

Assignees

• 中国能源建设集团江苏省电力设计院有限公司
• 中国能源建设集团江苏省电力设计院有限公司

Dates

Publication Date

20260421

Application Date

20220606

Priority Date

20220606

Claims (4)

1. 1. A method of subsynchronous oscillation suppression, comprising: extracting a power angle deviation signal of the doubly-fed induction wind power generator, wherein the extracting the power angle deviation signal of the doubly-fed induction wind power generator comprises: Obtaining components of transient potential, stator current, stator voltage and rotor voltage of the doubly-fed induction wind driven generator on a d-q axis according to a 5-order electromagnetic transient model of the doubly-fed induction wind driven generator in a d-q coordinate system; converting a 5-order electromagnetic transient model of the doubly-fed induction wind power generator in a d-q coordinate system into polar coordinates to obtain a 5-order electromagnetic transient equation of the doubly-fed induction wind power generator in the polar coordinates by taking the amplitude and the phase of stator current and transient potential as state variables, wherein the phase of the transient potential is a power angle deviation signal of the doubly-fed induction wind power generator; Modulating the generated angle deviation subsynchronous component signal according to the power angle deviation signal of the doubly-fed induction wind driven generator, wherein the modulating the generated angle deviation subsynchronous component signal comprises the following steps: The method comprises the steps of inputting a power angle deviation signal of a doubly-fed induction wind driven generator into a filtering link, extracting to obtain a subsynchronous signal, wherein the filtering link adopts a band-pass filter to extract the subsynchronous signal, sets a characteristic frequency omega c as a subsynchronous oscillation mode frequency, extracts a signal of a subsynchronous frequency domain segment by adjusting the bandwidth of the filter, and is represented by a transfer function of: (1) In the formula (1), G 1 (s) is a band-pass filter, K 1 is a filter gain, s is a complex variable, ζ is a damping coefficient, and ω c is a characteristic angular frequency; The method comprises the steps of sequentially inputting a secondary synchronous signal into a proportion link and a phase shifting link, adjusting the amplitude and the phase of the secondary synchronous signal, and generating a power angle deviation secondary synchronous component signal for inhibiting secondary synchronous oscillation, wherein the phase shifting link comprises a plurality of lead-lag correction links, and simultaneously adjusting the amplitude and the phase of the secondary synchronous signal, and the phase shifting link is represented by a transfer function of the following formula: (2) In the formula (2), G 2 (s) is a transfer function of a moving term link, s is a complex variable, T 1 is a lead time constant, and T 2 is a lag time constant; And superposing the power angle deviation subsynchronous component signal to the voltage of a rotor side q-axis control loop of the doubly-fed wind driven generator, and performing compensation control on the rotor q-axis voltage to inhibit subsynchronous oscillation.
2. 2. A subsynchronous oscillation suppression system, comprising: The extraction module is used for extracting a power angle deviation signal of the doubly-fed induction wind driven generator, and extracting the power angle deviation signal of the doubly-fed induction wind driven generator, wherein the power angle deviation signal comprises the components of transient potential, stator current, stator voltage and rotor voltage of the doubly-fed induction wind driven generator on a d-q axis according to a 5-order electromagnetic transient model of the doubly-fed induction wind driven generator in a d-q coordinate system; The generation success angle deviation subsynchronous component signal module is used for modulating the generation success angle deviation subsynchronous component signal according to the power angle deviation signal of the doubly-fed induction wind driven generator, wherein the modulation generation success angle deviation subsynchronous component signal comprises the following components: The method comprises the steps of inputting a power angle deviation signal of a doubly-fed induction wind driven generator into a filtering link, extracting to obtain a subsynchronous signal, wherein the filtering link adopts a band-pass filter to extract the subsynchronous signal, sets a characteristic frequency omega c as a subsynchronous oscillation mode frequency, extracts a signal of a subsynchronous frequency domain segment by adjusting the bandwidth of the filter, and is represented by a transfer function of: (1) In the formula (1), G 1 (s) is a band-pass filter, K 1 is a filter gain, s is a complex variable, ζ is a damping coefficient, and ω c is a characteristic angular frequency; The method comprises the steps of sequentially inputting a secondary synchronous signal into a proportion link and a phase shifting link, adjusting the amplitude and the phase of the secondary synchronous signal, and generating a power angle deviation secondary synchronous component signal for inhibiting secondary synchronous oscillation, wherein the phase shifting link comprises a plurality of lead-lag correction links, and simultaneously adjusting the amplitude and the phase of the secondary synchronous signal, and the phase shifting link is represented by a transfer function of the following formula: (2) In the formula (2), G 2 (s) is a transfer function of a moving term link, s is a complex variable, T 1 is a lead time constant, and T 2 is a lag time constant; the data processing module is used for superposing the power angle deviation subsynchronous component signal to the voltage of the rotor side q-axis control loop of the doubly-fed wind driven generator, and is used for carrying out compensation control on the rotor q-axis voltage and inhibiting subsynchronous oscillation.
3. 3. A subsynchronous oscillation suppression device, comprising an additional damping controller, wherein the system of claim 2 is installed in the additional damping controller, and the additional damping controller is arranged on a rotor-side frequency converter of a doubly-fed induction wind generator.
4. 4. A subsynchronous oscillation suppression verification method, characterized by comprising: Building a simulation model of the doubly-fed wind power system which is connected with the grid through a series compensation circuit in PSCAD or EMTDC simulation software, and adopting the subsynchronous oscillation suppression method of claim 1 after exciting subsynchronous oscillation; and outputting the waveform of active power and reactive power of the wind power plant, the waveform of the power angle amplitude of the doubly-fed induction wind power generator and the waveform of the internal potential amplitude, comparing with the waveform when subsynchronous oscillation suppression is not performed, and verifying the effectiveness of subsynchronous oscillation suppression.

Description

Subsynchronous oscillation suppression method, subsynchronous oscillation suppression system and subsynchronous oscillation suppression device Technical Field The invention relates to a subsynchronous oscillation suppression method, a subsynchronous oscillation suppression system and a subsynchronous oscillation suppression device, and belongs to the technical field of grid-connected stability analysis and control of wind power systems. Background In recent years, subsynchronous oscillation caused by grid connection of a wind power system becomes one of serious threats of safe and stable operation of the power system. With the construction and grid-connected operation of more and more large wind power plants, subsynchronous oscillation accidents occur for many times in various power grids. The subsynchronous oscillation has high divergence speed, and relates to a wide area, which is easy to cause the consequences of damage to a crowbar circuit of a wind turbine generator, off-grid of the wind turbine generator, complete cutting of a wind power plant and the like, thereby seriously affecting the safe and stable operation of a large-scale wind power system. Depending on the mechanism of subsynchronous oscillation suppression, methods based on wind farm self-frequency converter control systems and methods based on primary electrical equipment are generally adopted, the former mainly uses additional damping controllers designed in doubly-fed wind turbine control systems to suppress subsynchronous oscillation, and the designed dampers mainly use proper feedback signals as inputs of damping controllers, such as rotor rotation speed, rotor current or series capacitor voltage, and the like. The definition of the power angle of the doubly-fed wind power generator shows that the magnitude of the power angle is related to the rotor and exciting current of the doubly-fed wind power generator, and the magnitude of the power angle is better reflected on one of the electric quantity and the mechanical quantity of the doubly-fed wind power generator, so that the doubly-fed wind power generator has the advantages of being convenient to control, sensitive to detect and the like when being used as a damping control signal. Disclosure of Invention The invention aims to overcome the defects in the prior art and provides a subsynchronous oscillation suppression method, a subsynchronous oscillation suppression system and a subsynchronous oscillation suppression device, which can effectively suppress subsynchronous oscillation caused by grid connection of a series compensation circuit of a doubly-fed wind power plant and ensure the stability of a power system. In order to achieve the above purpose, the invention is realized by adopting the following technical scheme: in a first aspect, the present invention provides a method for subsynchronous oscillation suppression, the method comprising: extracting a power angle deviation signal of the doubly-fed induction wind power generator; modulating and generating a secondary synchronous component signal of the angle deviation according to the power angle deviation signal of the doubly-fed induction wind driven generator; And superposing the power angle deviation subsynchronous component signal to the voltage of a rotor side q-axis control loop of the doubly-fed wind driven generator, and performing compensation control on the rotor q-axis voltage to inhibit subsynchronous oscillation. With reference to the first aspect, further, the extracting a power angle deviation signal of the doubly-fed induction wind generator includes: Obtaining components of transient potential, stator current, stator voltage and rotor voltage of the doubly-fed induction wind driven generator on a d-q axis according to a 5-order electromagnetic transient model of the doubly-fed induction wind driven generator in a d-q coordinate system; converting a 5-order electromagnetic transient model of the doubly-fed induction wind power generator in a d-q coordinate system into polar coordinates to obtain a 5-order electromagnetic transient equation of the doubly-fed induction wind power generator in the polar coordinates by taking the amplitude and the phase of stator current and transient potential as state variables, wherein the phase of the transient potential is a power angle deviation signal of the doubly-fed induction wind power generator. With reference to the first aspect, further, the generating the secondary synchronization component signal includes: Inputting the power angle deviation signal of the doubly-fed induction wind driven generator into a filtering link, and extracting to obtain a secondary synchronization signal; And sequentially inputting the subsynchronous signals into a proportion link and a phase shifting link, and adjusting the amplitude and the phase of the subsynchronous signals to generate a power angle deviation subsynchronous component signal for inhibiting subsynchronous oscillation. In com