CN116137444A - Double-fed fan additional active control system for optimizing system frequency response - Google Patents
Double-fed fan additional active control system for optimizing system frequency response Download PDFInfo
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
- F03D—WIND MOTORS
- F03D7/00—Controlling wind motors
- F03D7/02—Controlling wind motors the wind motors having rotation axis substantially parallel to the air flow entering the rotor
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
- F03D—WIND MOTORS
- F03D7/00—Controlling wind motors
- F03D7/02—Controlling wind motors the wind motors having rotation axis substantially parallel to the air flow entering the rotor
- F03D7/022—Adjusting aerodynamic properties of the blades
- F03D7/0224—Adjusting blade pitch
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/24—Arrangements for preventing or reducing oscillations of power in networks
- H02J3/241—The oscillation concerning frequency
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
- H02J3/46—Controlling of the sharing of output between the generators, converters, or transformers
- H02J3/48—Controlling the sharing of the in-phase component
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J2300/00—Systems for supplying or distributing electric power characterised by decentralized, dispersed, or local generation
- H02J2300/20—The dispersed energy generation being of renewable origin
- H02J2300/28—The renewable source being wind energy
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/70—Wind energy
- Y02E10/76—Power conversion electric or electronic aspects
Abstract
The invention discloses an additional active control system of a doubly-fed wind turbine for optimizing the frequency response of a system, wherein a frequency measurement module acquires the frequency of a power grid; the droop controller calculates a fan power signal based on the difference value between the power grid frequency and the power grid reference frequency; the frequency optimization compensation controller calculates and obtains an initial compensation signal based on the power grid frequency; the pitch angle compensation controller calculates a pitch angle compensation signal based on the electromagnetic power acquired in real time and the additional power of the fan; the additional power of the fan is the difference value between the sum of the fan power signal and the initial compensation signal and the fan reference power; the pitch angle controller calculates a pitch angle instruction value based on the fan rotating speed reference value; the wind power controller calculates and obtains a mechanical power reference signal based on the pitch angle compensation signal and the pitch angle command value; the rotor side controller calculates to obtain a rotor side driving signal; and the rotor side PWM converter of the doubly-fed wind machine is controlled by the rotor side driving signal. The invention effectively improves the dynamic performance of the frequency response of the system.
Description
Technical Field
The invention belongs to the technical field of wind power generation, and particularly relates to an additional active control system of a doubly-fed wind turbine for optimizing the frequency response of the system.
Background
With the wide application and rapid development of new energy power generation technologies represented by wind power generation, new energy power generation equipment such as wind power generation is obviously different from the dynamic characteristics of a traditional synchronous machine, the voltage and frequency dynamic behavior of a power system is deeply changed, a great threat is formed to the safe and stable operation of the power system, and the frequency dynamic problem is one of the most important power grid problems.
The frequency dynamic problem is mainly to study whether the system frequency can be within an acceptable range under the conditions of large load or fault disturbance and the like. As a widely used fan type, a doubly fed fan contributes almost zero to the inertia of the system under conventional control. Therefore, in order to restrain the system frequency fluctuation of wind power generation in a large-scale alternative to the traditional synchronous unit, an effective measure is to improve the control of the wind driven generator so that the wind driven generator has the capacity of inertial support. The additional frequency optimization control is an active frequency support control strategy of the wind turbine in the industry.
In patent 201910413508.7, an additional control method for optimizing the frequency dynamics of a system is disclosed, wherein the active power command of the doubly-fed fan is adjusted according to a change rate signal of the power grid frequency, and meanwhile, the frequency dynamics of the system is optimized by adding a frequency correction signal to a reactive branch, so that the effect of inhibiting the system oscillation is achieved. The additional control design concept utilizes the change rate signal of the power grid frequency to adjust the active power instruction or the active current instruction of the doubly-fed fan, so that the doubly-fed fan can be controlled to generate additional active power or electromagnetic torque to provide inertial response in the dynamic process of the system. However, in the dynamic process, changing the active power or active current command of the doubly fed fan inevitably causes impact on the mechanical system of the fan.
In patent 202010557790.9, a method and a system for improving frequency dynamic optimization control of a power system are disclosed, wherein only the reactive power control of a virtual synchronous fan is added with the frequency-based front-stage control, and after the power system is disturbed, the change of a frequency signal is transmitted to a reactive power instruction to cause the change of the voltage of the end of the virtual synchronous fan, and finally the change of the active power of the power system is correspondingly caused, so that the frequency dynamic of the power system is optimized. The control method transmits the change of the frequency signal to the reactive power, and the reactive power can correspondingly cause the terminal voltage change when changing, thereby affecting the frequency dynamic of the power grid. When the load fluctuation is large, the reactive power fluctuation is also large, and the intelligent requirement is high.
Disclosure of Invention
The invention aims to solve the defects in the background technology, and provides an additional active control system of a doubly-fed fan for optimizing the dynamic response of the system frequency, which adjusts the active power instruction of the doubly-fed fan by utilizing the change rate signal of the power grid frequency, increases the positive damping of the frequency range of the frequency response mode of the system, thereby reducing the maximum frequency deviation of the system under the power disturbance and improving the dynamic response performance of the system frequency.
The technical scheme adopted by the invention is as follows: an additional active control system of a doubly-fed wind turbine for optimizing the frequency response of the system comprises a frequency measurement module, a sagging control module, a frequency optimization compensation controller, a pitch angle controller, a wind power controller and a rotor side controller;
the frequency measurement module is used for collecting the frequency of the power grid;
the droop controller calculates a fan power signal based on a difference value between the power grid frequency and the power grid reference frequency;
the frequency optimization compensation controller calculates and obtains an initial compensation signal based on the power grid frequency;
the pitch angle compensation controller calculates a pitch angle compensation signal based on the electromagnetic power acquired in real time and the additional power of the fan; the additional power of the fan is the difference value between the sum of the fan power signal and the initial compensation signal and the fan reference power;
the pitch angle controller calculates a pitch angle instruction value based on a fan rotating speed reference value;
the wind power controller calculates and obtains a mechanical power reference signal based on the pitch angle compensation signal and the pitch angle command value;
the rotor side controller calculates and obtains a rotor side driving signal according to active power, reactive power, three-phase voltage and a mechanical power reference signal output by the fan; and the rotor side PWM converter of the doubly-fed wind machine is controlled by the rotor side driving signal.
In the above technical scheme, the frequency optimization compensation controller comprises a dead zone judging device, a proportion regulator, a high-pass filter, a phase compensation link and a limiter;
the dead zone judging device judges whether the power grid frequency is outside the dead zone; if not, the initial compensation signal output by the frequency optimization compensation controller is zero; if yes, the power grid frequency is transmitted to a proportional regulator;
the proportion regulator calculates and amplifies the conditioning signal through damping control gain based on the power grid frequency and outputs the conditioning signal to the high-pass filter;
the high-pass filter filters the direct current signals contained in the conditioning signals and outputs the direct current signals to the phase compensation link;
the phase compensation link modulates the phase shift of the damping control link at the frequency oscillation frequency, generates a compensation signal and outputs the compensation signal to the amplitude limiter;
the limiter judges whether the compensation signal is in the limiting range, if yes, the limiter directly outputs the limiting boundary value, and if no, the limiter outputs the compensation signal through the phase compensation link.
In the above technical solution, the mathematical expression of the transfer function G(s) of the frequency optimization compensation controller is:
wherein: k represents the damping control gain of the proportioner; sT/(1+sT) is the DC component isolated by the high-pass filter, and is used for isolating the AC and DC components in the frequency range below the frequency oscillation; t representsA filter time constant; t (T) 1 、T 2 Time constant representing phase compensation element, (1+sT) 1 ) m /(1+sT 2 ) m And the phase compensation link is represented, m is a phase compensation series, and the compensation angle of each phase is smaller than 45 degrees.
In the above technical solution, the phase compensation link generates the compensation signal according to the frequency oscillation frequency λ of the transfer functions of the frequency measurement, the proportional regulator and the high-pass filter i The phase shift phi is 180 degrees and the phase shift is different, and the specific parameter design is selected according to the following formula:
wherein omega i The frequency representing the frequency oscillation may be generally chosen to be an angular frequency corresponding to 0.05 Hz.
In the technical scheme, the wind turbine controller comprises an adder, a subtracter, a proportional integrator and a limiter;
the adder acquires a pitch angle command value and a pitch angle compensation signal, adds the pitch angle command value and the pitch angle compensation signal to obtain a pitch angle correction reference signal, and sends the pitch angle correction reference signal to the subtracter;
the subtracter is used for obtaining an error signal by making a difference between the pitch angle signal acquired in real time and the received pitch angle correction reference signal, and sending the error signal to the proportional integrator;
the proportional integrator calculates an initial mechanical power reference signal based on the error signal and sends the initial mechanical power reference signal to the limiter;
and the limiter carries out limiting operation on the initial mechanical power reference signal to obtain the mechanical power reference signal and outputs a value of the rotor side controller.
In the above technical solution, the rotor side controller includes a power converter, an active controller, a reactive controller, a current controller, a signal generator, and a phase-locked loop module;
the power converter calculates an active power instruction value of the fan based on the mechanical power reference signal and sends the active power instruction value to the active controller;
the active controller makes a difference between the fan active power instruction value and the collected fan active power value, obtains a d-axis current reference signal through calculation and conditioning, and sends the d-axis current reference signal to the current controller;
the reactive power controller receives the reactive power signal and makes a difference with the reactive power instruction value, and a q-axis current reference signal is obtained through calculation and conditioning and is sent to the current controller;
the phase-locked loop module receives the three-phase voltage signal, obtains a terminal voltage phase signal through phase-locked control and transmits the terminal voltage phase signal to the current controller;
the current controller calculates a conditioning signal based on the d-axis current reference signal, the q-axis current reference signal and the terminal voltage phase signal, and sends the conditioning signal to the signal generator; the signal generator calculates a driving signal according to the modulation signal and sends the driving signal to the rotor-side PWM converter.
The invention also provides an additional active control method of the doubly-fed fan for optimizing the frequency response of the system, which comprises the following steps: the frequency measurement module collects the power grid frequency and sends the power grid frequency to the sagging controller; the droop controller calculates a fan power signal based on the difference value between the power grid frequency and the power grid reference frequency; the frequency optimization compensation controller calculates and obtains an initial compensation signal based on the power grid frequency;
the pitch angle compensation controller calculates a pitch angle compensation signal based on the electromagnetic power acquired in real time and the additional power of the fan; the additional power of the fan is the difference value between the sum of the fan power signal and the initial compensation signal and the fan reference power; the pitch angle controller calculates a pitch angle instruction value based on the fan rotating speed reference value; the wind power controller calculates and obtains a mechanical power reference signal based on the pitch angle compensation signal and the pitch angle command value; the rotor side controller calculates and obtains a rotor side driving signal according to active power, reactive power, three-phase voltage and a mechanical power reference signal output by the fan; and the rotor side PWM converter of the doubly-fed wind machine is controlled by the rotor side driving signal.
The beneficial effects of the invention are as follows: the invention discloses a doubly-fed wind turbine additional active control system for optimizing system frequency response, which consists of a traditional primary frequency modulation control link and a parallel transient power compensation link. The primary frequency modulation control link introduces a response channel of frequency disturbance-pitch angle compensation control output on the basis of reserved load shedding, and improves or reduces electromagnetic power output of a fan when the frequency disturbance occurs in the system, so that the wind turbine generator actively supports power grid frequency modulation. The transient power compensation link provided by the invention is connected in parallel with the traditional primary frequency modulation link to increase the positive damping of the frequency band of the frequency response mode of the system, thereby reducing the maximum frequency deviation of the system under power disturbance and improving the dynamic performance of the frequency response of the system; the transient compensation control does not affect the steady-state power-frequency characteristic of the doubly-fed fan, and the function distinction from the traditional primary frequency modulation is realized. The wind turbine generator system has good stability when connected into a power grid, and on the basis of the primary frequency modulation design of the traditional doubly-fed wind turbine generator system, a certain standby power is reserved for the wind turbine generator system by adopting droop control, and meanwhile, a transient power compensation loop is connected in parallel on the traditional primary frequency modulation link, so that the positive damping of the system in the frequency band is increased, the low-frequency oscillation generated when the wind turbine generator system is connected into the power grid is effectively restrained, and the stability of grid connection of the wind turbine generator system is improved.
The invention discloses an additional active control method of a doubly-fed fan for optimizing the frequency response of a system. The transient power compensation link is connected with the primary frequency modulation control link in parallel to increase positive damping of a frequency band of a system frequency response mode, so that maximum frequency deviation of the system under power disturbance is reduced, and frequency response dynamic performance of the system is improved; the transient compensation control does not affect the steady-state power-frequency characteristic of the doubly-fed fan, and the function distinction from the traditional primary frequency modulation is realized.
Drawings
Fig. 1 is a schematic structural view of the present invention.
FIG. 2 is a schematic diagram of a primary frequency modulation control scheme of a doubly fed wind turbine participation system.
Fig. 3 is a schematic diagram of a frequency optimized compensation control strategy.
FIG. 4 is a schematic diagram of a wind turbine controller.
Fig. 5 is a schematic diagram of a rotor side controller principle.
Fig. 6 is a graph of the frequency response of the conventional control and the present invention.
Detailed Description
The invention will now be described in further detail with reference to the drawings and specific examples, which are given for clarity of understanding and are not to be construed as limiting the invention.
As shown in fig. 1, the doubly-fed wind turbine includes: fan blades, a multi-stage gearbox, a generator, a power grid, a rotor side PWM converter, a grid side controller and a grid side PWM converter; the generator is electrically connected with the fan blade through a multi-stage gear box; the power grid is connected with the generator; the output end of the rotor side PWM converter is electrically connected with the control end of the generator; the grid-side PWM converter is electrically connected with the output end of the power grid; the rotor side PWM converter is connected with the network side PWM converter through a direct current bus capacitor; the network side controller is used for controlling the network side PWM converter.
As shown in fig. 1, the present invention provides a doubly-fed wind turbine additional active control system for optimizing the frequency response of the system, the overall system comprising a wind turbine blade 1, a multi-stage gearbox 2, a frequency optimization compensation control 22, a generator 31, a rotor side PWM converter 32, a dc bus capacitor 33, a grid side PWM converter 34, a filter inductance 35, a pitch angle controller 41, a pitch angle compensation controller 42, a wind turbine controller 43, a rotor side controller 44, a grid side controller 45, a transformer 5 and a power grid.
The frequency measurement 21 in the primary frequency modulation link of the fan participation system is used for collecting the power grid frequency f in real time and is matched with the reference frequency f N In comparison, the error signal is amplified, calculated and processed by the droop control module 23 to obtain a power signal ΔP e 23.1. Reference power signal P ref And power signal DeltaP e The difference is 23.1 to obtain the additional power delta P of the fan.
Pitch angle compensation controller 42 receives electromagnetic power P collected in real time meas And the difference value of the additional power delta P of the fan, and obtaining a compensation signal dbeta of the pitch angle through calculation and processing based on the signal ref 42.1 and then compensating signal dβ of pitch angle ref To the wind turbine controller 43. The pitch angle controller 41 is used for receiving the rotation speed reference value omega in real time ref And calculating a pitch angle command value beta ref I.e. signal 41.1, then commands this pitch angle to the value beta ref To the wind turbine controller 43. The wind turbine controller 43 receives the compensation signal dβ for the pitch angle ref And a pitch angle command value beta ref By calculation, the mechanical power reference signal P is obtained mref I.e. signal 43.1, and will be a mechanical power reference signal P mref To the rotor-side controller 44.
The rotor-side controller 44 is used for collecting active power P output by the fan in real time e Reactive power Q and three-phase voltage u abc In combination with an output signal 43.1 of the wind turbine controller 43. Based on the above signals, a drive signal 44.1 is obtained by calculation and processing, and then control of the rotor-side converter 32 is achieved by the drive signal 44.1.
The rotor side converter is used for collecting three-phase voltages of active power, reactive power and grid connection points sent by the fan, and correspondingly adjusting driving signals of the rotor side PWM converter by combining mechanical power reference signals sent by the wind turbine controller. Two control targets of the rotor side PWM converter and the rotor side controller are provided, namely, current required by excitation is provided for the DFIG rotor so as to regulate reactive power output by the stator; secondly, the torque of the DFIG or the output active power of the stator is controlled through the torque component of the rotor current, so that the unit operates on the optimal power curve of the wind turbine, and the maximum wind energy tracking operation is realized.
Through the control thought, compared with the traditional control without adding a primary frequency modulation and frequency optimization compensation control method, the invention introduces the power grid frequency f, obtains the compensation signal 42.1 of the pitch angle through the calculation of a primary frequency modulation link and the pitch angle compensation controller, outputs the compensation signal to the wind turbine controller 43, and changes the mechanical power of the wind turbine fromWhile changing the active power. Thus, the active force P of the fan can be reduced e In relation to the grid frequency f, the active power P of the fan is regulated according to the grid frequency f e Thereby effectively suppressing active power low frequency oscillations of the power grid.
As further preferable, as shown in fig. 2, the schematic diagram of the primary frequency modulation control of the system of the doubly fed fan is divided according to the wind speed working condition, the fan operation mainly comprises two intervals of a power tracking area and a constant power area, and the primary frequency modulation control of the fan comprises a load shedding operation and a speed regulator control link; wherein the load shedding operation reserves standby power for the speed regulation control, i.e. the mechanical power reference signal P mref The speed regulation control is to start work after the frequency deviation is larger than a threshold value so as to adjust the output power of the fan to restrain the frequency fluctuation of the system for supporting. The invention selects a standby mode for increasing the pitch angle in both working areas, and in the frequency adjustment dynamic process, a frequency optimization compensation controller is added, and the frequency optimization compensation controller acts in parallel with a conventional speed regulator to promote frequency dynamic response.
The additional control of the wind turbine generator is realized by collecting frequency and power, modifying a compensation power command value of the pitch angle, adjusting the pitch angle, and changing the power command value compensated by the pitch angle into load shedding power P del To realize load shedding operation. The primary frequency modulation link of the wind turbine participation system comprises a frequency measurement module 21 and a sagging control module 23, and the proportion adjustment of the frequency error signal is included. Wherein the frequency measurement module 21 is used for collecting the power grid frequency f, and then based on the signal, the droop control module 23 calculates and processes the power signal DeltaP e 23.1, an initial pitch angle compensation signal 42.1 is obtained by calculation and processing by the pitch angle compensation controller 42 and is fed to the wind turbine controller 43.
As a further preferred, based on the improved concept proposed above, a frequency optimized compensation control strategy is employed as shown in fig. 3. Namely, a transient power compensation loop is connected in parallel with the traditional primary frequency modulation link so as to lead dP introduced by the transient power compensation loop e The/dω phase appears negative in the frequency response band (i.e., the ultra-low frequency oscillation band) to increase the positive damping of the system in that band.
The internal controller 211 in the frequency optimization compensation controller specifically includes a dead zone determiner 2111, a proportional regulator 2112, a high pass filter 2113, a phase compensation link 2114, and a limiter 2115.
The dead zone determiner 2111 determines whether the signal is outside the dead zone, if not, the input grid frequency f is transmitted to the proportioner 2112 for amplification, and then the output signal 2112.1 passes through the high pass filter 2113, the high pass filter 2113 is used for receiving the conditioning signal, and the direct current signal contained in the conditioning signal is filtered. Then the phase compensation signal is output to a phase compensation link 2114, the phase compensation link 2114 receives the conditioning signal, and the angle to be compensated is represented by the transfer function of three links of frequency measurement, a filtering link and a high-pass filter at lambda i The phase shift at the oscillation frequency outputs the compensation signal 2113.1 to the limiter 2115 by modulating the phase shift of the entire damping control element at the low frequency oscillation frequency. The limiter 2115 determines whether the compensation signal 2113.1 is within the limiter, if so, outputs the initial compensation signal 211.1, and if not, outputs the compensation signal after the limiter.
Specifically, the mathematical expression of the frequency optimization compensation controller is:
wherein: k represents damping control gain of the proportional regulator, T represents filter time constant, and the recommended value is 0.01s; sT/(1+sT) represents the DC component isolated by the high-pass filter element; t (T) 1 、T 2 Time constant representing phase compensation element, (1+sT) 1 ) m /(1+sT 2 ) m And representing phase compensation links, wherein m is the phase compensation progression, and the control parameter setting mainly relates to parameters related to the three links. The angle to be compensated in the phase compensation link is the frequency measurement, the ratio regulator and the high-pass filter, and the transfer function is shown in lambda i The phase shift at the oscillation frequency is such that,
for a difference of 180 ° and its phase shift, a specific time constant α design can be selected as follows.
Further preferably, the wind turbine controller 43 comprises an adder 431, a subtractor 432, a proportional integrator 433 and a limiter 434, as schematically shown in fig. 4. Wherein adder 431 collects pitch angle command value signal beta ref And a pitch angle compensation signal dβ output by the damping controller ref The pitch angle correction reference signal 431.1 is added to the two and is supplied to the subtractor 432. The subtractor receives the pitch angle signal β and the pitch angle correction reference signal 431.1, and subtracts the two signals to obtain an error signal 432.1, and sends the error signal to the proportional integrator 433. The proportional integrator 433 receives the error signal 432.1, calculates and processes the initial mechanical power reference signal 433.1, and provides it to the limiter 434. Limiter 434 performs a limiting operation on the initial mechanical power reference signal 433.1 to obtain the mechanical power reference signal 43.1.
Further preferably, the rotor side controller 44 includes a power converter 441, an active controller 442, a reactive controller 443, a current controller 444, a signal generator 445, and a phase-locked loop 446 as shown in fig. 5. The power converter 441 receives the mechanical power reference signal and calculates the fan active power command finger P eref And the active power instruction is denoted as P eref Is sent to the active controller 442, and the active controller 442 receives the power command value P eref And the collected active power value P e The difference is subtracted, calculated and conditioned to obtain the d-axis current reference signal 442.1, which is fed to the current controller 444. The reactive controller 443 receives the reactive power signal Q and the reactive power command value Q ref Make difference byThe q-axis current reference signal 443.1 is calculated and conditioned and supplied to the current controller 444. The phase-locked loop 446 receives a three-phase voltage signal u abc The terminal voltage phase signal 446.1 is obtained by phase lock control and is sent to the current controller 444; the current controller 444 receives the d-axis current reference signal 442.1, the q-axis current reference signal 443.1, and the terminal voltage phase signal 446.1, calculates and processes the conditioned signal 444.1, and supplies the signal to the signal generator 445. The signal generator 445 derives a drive signal from the received modulated signal and delivers the drive signal 44.1 to the rotor side PWM converter 32.
In a typical two-zone four-machine system, one synchronous machine is replaced by a wind farm with equal capacity, and a frequency response comparison chart of conventional control and addition of optimized control is shown in fig. 6, it can be seen that the addition of optimized control can increase the damping of the frequency response mode and reduce the lowest frequency drop point. The additional control method of the doubly-fed fan adopts droop control to realize load shedding operation of the fan, and simultaneously, frequency optimization compensation control is added on the traditional primary frequency modulation link, and the active power instruction of the doubly-fed fan is regulated by utilizing the change rate signal of the power grid frequency, so that the positive damping of the frequency band of the frequency response mode of the system is increased, the maximum frequency deviation of the system under power disturbance is reduced, and the frequency response dynamic performance of the system is improved.
The invention discloses an additional active control system and method for a doubly-fed fan, which adopt droop control to realize load shedding operation of the fan, and simultaneously add frequency optimization compensation control on a traditional primary frequency modulation link, adjust an active power instruction of the doubly-fed fan by utilizing a change rate signal of a power grid frequency, increase positive damping of a frequency response mode frequency band of the system, and have the advantages of simple additional frequency optimization compensation control structure in practical application, obviously reduced oscillation degree of low-frequency oscillation of the system after adding the additional frequency optimization compensation control, and more stable system. And the optimal control effect is gradually enhanced along with the increase of the permeability, and the oscillation peak value of 0.2Hz can be maximally reduced when the permeability of the fan is higher, so that the requirement of optimal control is met, the maximum frequency deviation of the system under power disturbance is effectively reduced, and the frequency response dynamic performance of the system is improved.
According to the invention, the fan is connected into the power grid with good stability, and on the basis of the primary frequency modulation design of the traditional doubly-fed fan participating in the system, the droop control is adopted to ensure that the wind turbine is kept with certain standby power, and meanwhile, a transient power compensation loop is connected in parallel on the traditional primary frequency modulation link, so that the positive damping of the system in the frequency band is increased, the low-frequency oscillation generated when the fan is connected into the power grid is effectively restrained, and the stability of the fan grid connection is improved.
What is not described in detail in this specification is prior art known to those skilled in the art.
Claims (7)
1. An additional active control system of a doubly-fed wind turbine for optimizing the frequency response of the system, which is characterized in that: the device comprises a frequency measurement module, a sagging control module, a frequency optimization compensation controller, a pitch angle controller, a wind power controller and a rotor side controller;
the frequency measurement module is used for collecting the frequency of the power grid;
the droop controller calculates a fan power signal based on a difference value between the power grid frequency and the power grid reference frequency;
the frequency optimization compensation controller calculates and obtains an initial compensation signal based on the power grid frequency;
the pitch angle compensation controller calculates a pitch angle compensation signal based on the electromagnetic power acquired in real time and the additional power of the fan; the additional power of the fan is the difference value between the sum of the fan power signal and the initial compensation signal and the fan reference power;
the pitch angle controller calculates a pitch angle instruction value based on a fan rotating speed reference value;
the wind power controller calculates and obtains a mechanical power reference signal based on the pitch angle compensation signal and the pitch angle command value;
the rotor side controller calculates and obtains a rotor side driving signal according to active power, reactive power, three-phase voltage and a mechanical power reference signal output by the fan; and the rotor side PWM converter of the doubly-fed wind machine is controlled by the rotor side driving signal.
2. An additional active control system for a doubly-fed wind turbine optimizing system frequency dynamic response as defined in claim 1 wherein: the frequency optimization compensation controller comprises a dead zone judging device, a proportion regulator, a high-pass filter, a phase compensation link and a limiter;
the dead zone judging device judges whether the power grid frequency is outside the dead zone; if not, the initial compensation signal output by the frequency optimization compensation controller is zero; if yes, the power grid frequency is transmitted to a proportional regulator;
the proportion regulator calculates and amplifies the conditioning signal through damping control gain based on the power grid frequency and outputs the conditioning signal to the high-pass filter;
the high-pass filter filters the direct current signals contained in the conditioning signals and outputs the direct current signals to the phase compensation link;
the phase compensation link modulates the phase shift of the damping control link at the frequency oscillation frequency, generates a compensation signal and outputs the compensation signal to the amplitude limiter;
the limiter judges whether the compensation signal is in the limiting range, if yes, the limiter directly outputs the limiting boundary value, and if no, the limiter outputs the compensation signal through the phase compensation link.
3. An additional active control system for a doubly-fed wind turbine for optimizing system frequency dynamic response as defined in claim 2 wherein: the mathematical expression of the transfer function G(s) of the frequency optimization compensation controller is as follows:
wherein: k represents the damping control gain of the proportioner; sT/(1+sT) is the DC component isolated by the high-pass filter, and is used for isolating the AC and DC components in the frequency range below the frequency oscillation; t represents the filter time constant; t (T) 1 、T 2 Time constant representing phase compensation element, (1+sT) 1 ) m /(1+sT 2 ) m And the phase compensation link is represented, m is a phase compensation series, and the compensation angle of each phase is smaller than 45 degrees.
4. A doubly-fed wind turbine additional active control system for optimizing system frequency dynamic response according to claim 3, wherein: the phase compensation link generates compensation signals as three link transfer functions of frequency measurement, a proportion regulator and a high-pass filter at the frequency oscillation frequency lambda i The phase shift phi is 180 degrees and the phase shift is different, and the specific parameter design is selected according to the following formula:
wherein omega i Representing the frequency of the frequency oscillation.
5. A doubly-fed wind turbine additional active control system for optimizing system frequency dynamic response according to claim 3, wherein: the wind turbine controller comprises an adder, a subtracter, a proportional integrator and a limiter;
the adder acquires a pitch angle command value and a pitch angle compensation signal, adds the pitch angle command value and the pitch angle compensation signal to obtain a pitch angle correction reference signal, and sends the pitch angle correction reference signal to the subtracter;
the subtracter is used for obtaining an error signal by making a difference between the pitch angle signal acquired in real time and the received pitch angle correction reference signal, and sending the error signal to the proportional integrator;
the proportional integrator calculates an initial mechanical power reference signal based on the error signal and sends the initial mechanical power reference signal to the limiter;
and the limiter carries out limiting operation on the initial mechanical power reference signal to obtain the mechanical power reference signal and outputs a value of the rotor side controller.
6. An additional active control system for a doubly-fed wind turbine optimizing system frequency dynamic response as defined in claim 5 wherein: the rotor side controller comprises a power converter, an active controller, a reactive controller, a current controller, a signal generator and a phase-locked loop module;
the power converter calculates an active power instruction value of the fan based on the mechanical power reference signal and sends the active power instruction value to the active controller;
the active controller makes a difference between the fan active power instruction value and the collected fan active power value, obtains a d-axis current reference signal through calculation and conditioning, and sends the d-axis current reference signal to the current controller;
the reactive power controller receives the reactive power signal and makes a difference with the reactive power instruction value, and a q-axis current reference signal is obtained through calculation and conditioning and is sent to the current controller;
the phase-locked loop module receives the three-phase voltage signal, obtains a terminal voltage phase signal through phase-locked control and transmits the terminal voltage phase signal to the current controller;
the current controller calculates a conditioning signal based on the d-axis current reference signal, the q-axis current reference signal and the terminal voltage phase signal, and sends the conditioning signal to the signal generator; the signal generator calculates a driving signal according to the modulation signal and sends the driving signal to the rotor-side PWM converter.
7. An additional active control method of a doubly-fed wind turbine for optimizing the frequency response of a system is characterized by comprising the following steps of: the method comprises the following steps: the frequency measurement module collects the power grid frequency and sends the power grid frequency to the sagging controller; the droop controller calculates a fan power signal based on the difference value between the power grid frequency and the power grid reference frequency; the frequency optimization compensation controller calculates and obtains an initial compensation signal based on the power grid frequency;
the pitch angle compensation controller calculates a pitch angle compensation signal based on the electromagnetic power acquired in real time and the additional power of the fan; the additional power of the fan is the difference value between the sum of the fan power signal and the initial compensation signal and the fan reference power; the pitch angle controller calculates a pitch angle instruction value based on the fan rotating speed reference value; the wind power controller calculates and obtains a mechanical power reference signal based on the pitch angle compensation signal and the pitch angle command value; the rotor side controller calculates and obtains a rotor side driving signal according to active power, reactive power, three-phase voltage and a mechanical power reference signal output by the fan; and the rotor side PWM converter of the doubly-fed wind machine is controlled by the rotor side driving signal.
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Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101834446A (en) * | 2010-03-23 | 2010-09-15 | 浙江大学 | Sub-synchronous oscillation suppression method based on controlled series compensation |
| CN108599253A (en) * | 2018-05-25 | 2018-09-28 | 国家电网公司西北分部 | A kind of combination control method of Wind turbines field grade primary frequency modulation and damping control |
| CN110048440A (en) * | 2019-05-29 | 2019-07-23 | 国网陕西省电力公司电力科学研究院 | A kind of wind power generating set participates in the control method and model of primary frequency regulation of power network |
| CN113612263A (en) * | 2021-07-15 | 2021-11-05 | 国网江苏省电力有限公司电力科学研究院 | Low-frequency oscillation suppression method and system for multi-port alternating current-direct current hybrid power distribution network |
| CN113890115A (en) * | 2021-09-28 | 2022-01-04 | 杭州意能电力技术有限公司 | New energy power station control system for restraining power oscillation of power grid |
| CN114024304A (en) * | 2021-10-29 | 2022-02-08 | 南京理工大学 | Additional damping control method based on oscillation suppression of doubly-fed wind generator |
| CN114427514A (en) * | 2022-01-18 | 2022-05-03 | 武汉理工大学 | Local damping control system of double-fed fan for inhibiting system low-frequency oscillation |
| CN115241894A (en) * | 2022-07-29 | 2022-10-25 | 华中科技大学 | Method, system and medium for controlling primary frequency modulation of double-fed fan |
| US20230031575A1 (en) * | 2021-07-29 | 2023-02-02 | General Electric Company | System and method for power control of an inverter-based resource with a grid-forming converter |
-
2023
- 2023-02-14 CN CN202310110670.8A patent/CN116137444A/en active Pending
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101834446A (en) * | 2010-03-23 | 2010-09-15 | 浙江大学 | Sub-synchronous oscillation suppression method based on controlled series compensation |
| CN108599253A (en) * | 2018-05-25 | 2018-09-28 | 国家电网公司西北分部 | A kind of combination control method of Wind turbines field grade primary frequency modulation and damping control |
| CN110048440A (en) * | 2019-05-29 | 2019-07-23 | 国网陕西省电力公司电力科学研究院 | A kind of wind power generating set participates in the control method and model of primary frequency regulation of power network |
| CN113612263A (en) * | 2021-07-15 | 2021-11-05 | 国网江苏省电力有限公司电力科学研究院 | Low-frequency oscillation suppression method and system for multi-port alternating current-direct current hybrid power distribution network |
| US20230031575A1 (en) * | 2021-07-29 | 2023-02-02 | General Electric Company | System and method for power control of an inverter-based resource with a grid-forming converter |
| CN113890115A (en) * | 2021-09-28 | 2022-01-04 | 杭州意能电力技术有限公司 | New energy power station control system for restraining power oscillation of power grid |
| CN114024304A (en) * | 2021-10-29 | 2022-02-08 | 南京理工大学 | Additional damping control method based on oscillation suppression of doubly-fed wind generator |
| CN114427514A (en) * | 2022-01-18 | 2022-05-03 | 武汉理工大学 | Local damping control system of double-fed fan for inhibiting system low-frequency oscillation |
| CN115241894A (en) * | 2022-07-29 | 2022-10-25 | 华中科技大学 | Method, system and medium for controlling primary frequency modulation of double-fed fan |
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