Wind field synchronous phase modifier transient stability control method and device

Abstract

The invention provides a transient stability control method and device for a wind field synchronous phase modifier. The method comprises the following steps: constructing a comprehensive performance index function of a wind field grid-connected system according to a state feedback accurate linearization method; inputting a weight coefficient of the comprehensive performance index function, and solving an optimal additional control law; after it is detected that low voltage ride through control exits, the power angle, the angular speed and the electromagnetic power of a wind field synchronous phase modifier and the rotating speed of a draught fan in the wind field are measured and obtained in real time, and the optimal additional control rate serves as an optimal active power additional control instruction of the draught fan; and superposing the optimal active power additional control instruction of the fan with the original MPPT control instruction of the fan, generating a final active power control instruction of the fan, and adjusting the active output of the fan. According to the method, the power angle stability of the new energy station synchronous phase modifier is effectively improved, and meanwhile, the problem that the rotating speed of a fan is too high due to excessive limitation of fan output in similar methods is solved.

Description

Technical Field

[0001] The present invention relates to the field of wind power technology, and in particular to a method and device for controlling transient stability of synchronous phase regulators in a wind farm. Background Art

[0002] At present, the rapid growth of installed capacity and proportion of new energy represented by wind power has brought many challenges to the stability and safety of the power system, including transient overvoltage after fault clearance, repeated high and low voltage caused by voltage fluctuations, and broadband oscillation. In severe cases, it can cause the new energy unit to be disconnected from the grid, thus causing a chain of failures. Synchronous condenser is a dynamic reactive power compensation device. Its dynamic compensation effect is better than other reactive power compensation equipment, which can effectively improve the voltage support strength of the power grid at the sending end of renewable energy. However, as a special synchronous motor, synchronous condenser has voltage source characteristics, which makes it bear the power disturbance in the transient process of the system together with the synchronous generator. When the grid powered by conventional synchronous generators is disturbed, the static stability margin of the synchronous condenser connected to it is large and generally will not lose step. However, the condenser configured at the wind farm station is very close to the wind farm electrical distance, and its static stability limit and rotor dynamics will be deeply affected by wind power injection, making it possible for the condenser to experience transient accelerated instability. Existing studies have shown that adding synchronous condensers to wind farms can significantly increase the output limit of wind farms under voltage safety or short-circuit ratio constraints, but it will also introduce new power angle stability constraints. The wind farm power limit under the power angle stability constraint is highly sensitive to controllable factors such as wind farm transient control. Therefore, improving the transient output characteristics of wind farms to enhance the transient power angle stability of synchronous condensers has great potential for improving the power limit of renewable energy transmission.

[0003] While improving the stability of the synchronous phase condenser power angle, it is also necessary to ensure that the wind farm output is restored as soon as possible. If the active output of the wind farm is too low for a long time, on the one hand, it may cause the wind turbine speed to accelerate beyond the limit, thereby threatening the safety of the unit; on the other hand, at this time, the frequent and large-scale actions of the wind turbine pitch angle control will aggravate the wear of the machine parts, and the unloading resistor will also be difficult to operate at high power for a long time. Therefore, how to coordinate the recovery of the active output of the wind turbine and the stability of the power angle of the adjacent synchronous phase condenser has become an urgent problem to be solved. At present, there is no wind power low-penetration control optimization solution that combines the safety of wind turbine units with the stability of phase condenser units. Summary of the invention

[0004] In view of this, the present invention provides a method and device for transient stability control of a synchronous condenser in a wind farm to solve at least one of the above-mentioned problems.

[0005] In order to achieve the above object, the present invention adopts the following scheme:

[0006] According to a first aspect of the present invention, a method for transient stability control of synchronous phase regulators in a wind farm is provided, the method comprising: constructing a comprehensive performance index function of a wind farm grid-connected system according to a state feedback precise linearization method; inputting a weight coefficient of the comprehensive performance index function to solve an optimal additional control law; after detecting that low voltage ride-through control is exited, measuring and acquiring the power angle, angular velocity, electromagnetic power and speed of wind turbines in the wind farm in real time, and using the optimal additional control rate as an optimal active power additional control instruction for the wind turbine; superimposing the optimal active power additional control instruction for the wind turbine with the original maximum power point tracking (MPPT) control instruction of the wind turbine to generate a final active power control instruction for the wind turbine, and adjusting the active output of the wind turbine.

[0007] As an embodiment of the present invention, the above method further includes: determining whether the power angle and angular velocity errors are both zero, or whether the control duration exceeds a time limit, and if so, exiting the control.

[0008] As an embodiment of the present invention, the method of constructing a comprehensive performance index function of a wind farm grid-connected system according to a state feedback precise linearization method includes: performing coordinate mapping on an affine nonlinear system formed by a wind farm and a synchronous condenser transmission system to convert it into a controllable linear system, and constructing a quadratic comprehensive performance index function according to the linear quadratic optimal control theory as follows:

[0009]

[0010] In the above formula, J is the quadratic comprehensive performance index; δ and δ d are the measured value and expected value of the synchronous condenser power angle respectively; ω SC and ω d are the synchronous condenser angular velocity and synchronous speed respectively; ω WF and ω dWF are the measured value and expected value of the fan speed respectively; K1, K2, K3 as well as H1, H2 are weight coefficients.

[0011] As an embodiment of the present invention, in the above method, the weight coefficient of the comprehensive performance index function is inputted, and solving the optimal additional control law includes:

[0012] Input weight coefficients K1, K2, K3 and H1, H2, and satisfy K1, K2, K3>H1, H2>0, and construct weight matrices Q and R respectively by the following formulas:

[0013]

[0014] Substitute the weight matrices Q, R into the Riccati equation shown below:

[0015] A T P+PA-PR -1 B T P+Q=0;

[0016]

[0017] In the above formula, P is the solution of Riccati;

[0018] Solve the Riccati equation and keep the positive solution P * ;

[0019] The mapped wind field and the input v of the synchronous condenser transmission system are solved according to the following formula:

[0020]

[0021] In the above formula, v is the system input after mapping, and v1 and v2 are the two components of the input;

[0022] The mapping result is inversely transformed, and the optimal additional control rate is obtained according to the following formula:

[0023] u=M eq v1+P eSC +P mWF -P eWF -Mv2;

[0024] Where, u is the optimal additional control rate; M eq is the inertia time constant of the synchronous condenser, M is the equivalent inertia time constant of the fan; P mWF is the mechanical power of the fan; P eWF and P eSC are the electromagnetic powers of the fan and synchronous condenser respectively.

[0025] According to a second aspect of the present invention, there is provided a transient stability control device for a synchronous phase regulator in a wind farm, the device comprising: an exponential function construction unit, for constructing a comprehensive performance index function of a wind farm grid-connected system according to a state feedback precise linearization method; an additional control law acquisition unit, for inputting a weight coefficient of the comprehensive performance index function to solve an optimal additional control law; an optimal control instruction acquisition unit, for measuring and acquiring the power angle, angular velocity, electromagnetic power and speed of a synchronous phase regulator in the wind farm in real time after detecting that a low voltage ride-through control has been exited, and using the optimal additional control rate as an optimal active power additional control instruction for the wind turbine; an adjustment unit, for superimposing the optimal active power additional control instruction for the wind turbine with the original MPPT control instruction for the wind turbine to generate a final active power control instruction for the wind turbine, and adjusting the active output of the wind turbine.

[0026] As an embodiment of the present invention, the above-mentioned device also includes: a judgment unit, used to judge whether the power angle and angular velocity errors are both zero, or whether the control time exceeds the time limit, and if so, exit the control.

[0027] As an embodiment of the present invention, the exponential function construction unit is specifically used to: perform coordinate mapping on the affine nonlinear system composed of the wind farm and the synchronous condenser transmission system, convert it into a controllable linear system, and construct a quadratic comprehensive performance index function according to the linear quadratic optimal control theory as follows:

[0028]

[0029] In the above formula, J is the quadratic comprehensive performance index; δ and δ d are the measured value and expected value of the synchronous condenser power angle respectively; ω SC and ω d are the synchronous condenser angular velocity and synchronous speed respectively; ω WF and ω dWF are the measured value and expected value of the fan speed respectively; K1, K2, K3 as well as H1, H2 are weight coefficients.

[0030] As an embodiment of the present invention, the above-mentioned optimal control instruction acquisition unit is specifically used for:

[0031] Input weight coefficients K1, K2, K3 and H1, H2, and satisfy K1, K2, K3>H1, H2>0, and construct weight matrices Q and R respectively by the following formulas:

[0032]

[0033] Substitute the weight matrices Q, R into the Riccati equation shown below:

[0034] A T P+PA-PR -1 B T P+Q=0;

[0035]

[0036] In the above formula, P is the solution of the Riccati equation;

[0037] Solve the Riccati equation and keep the positive solution P * ;

[0038] The mapped wind field and the input v of the synchronous condenser transmission system are solved according to the following formula:

[0039]

[0040] In the above formula, v is the system input after mapping, and v1 and v2 are the two components of the input;

[0041] The mapping result is inversely transformed, and the optimal additional control rate is obtained according to the following formula:

[0042] u=M eq v1+P eSC +P mWF -P eWF -Mv2;

[0043] Where, u is the optimal additional control rate; M eq is the inertia time constant of the synchronous condenser, M is the equivalent inertia time constant of the fan; P mWF is the mechanical power of the fan; P eWF and P eSC are the electromagnetic powers of the fan and synchronous condenser respectively.

[0044] According to a third aspect of the present invention, there is provided an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the above method when executing the computer program.

[0045] According to a fourth aspect of the present invention, there is provided a computer-readable storage medium having a computer program stored thereon, wherein the computer program implements the steps of the above method when executed by a processor.

[0046] The method and device for controlling the transient stability of synchronous condensers in wind farms proposed in the present invention can adjust the active output of wind turbines in real time according to the measured feedback signal. Compared with the traditional method of setting the control value in advance, the present invention has stronger adaptability to different faults and operation scenarios and lower costs. It effectively improves the power angle stability of synchronous condensers in new energy stations, and avoids the problems of excessive wind turbine speed caused by excessive restriction of wind turbine output in similar methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0048] Figure 1 It is a flow chart of a method for controlling transient stability of a synchronous phase regulator in a wind farm provided by an embodiment of the present invention;

[0049] Figure 2 It is a topological diagram of a wind farm grid-connected system equipped with a synchronous condenser;

[0050] Figure 3 is a control structure block diagram provided by an embodiment of the present invention;

[0051] Figure 4 It is a waveform diagram of the wind turbine active current changing with time under the conventional strategy of restoring normal operation after the end of low voltage ride-through and after adopting the control strategy of the present invention;

[0052] Figure 5 It is a waveform diagram of the change of the phase-modulation power angle over time under the conventional strategy of restoring normal operation after the end of low voltage ride-through and after adopting the control strategy of the present invention;

[0053] Figure 6 It is a structural schematic diagram of a wind farm synchronous phase regulator transient stability control device provided by an embodiment of the present invention;

[0054] Figure 7 It is a structural schematic diagram of a wind farm synchronous phase regulator transient stability control device provided by another embodiment of the present invention;

[0055] Figure 8 It is a structural schematic diagram of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0056] To make the purpose, technical solution and advantages of the embodiments of the present invention more clear, the embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings. Here, the exemplary embodiments of the present invention and their descriptions are used to explain the present invention, but are not intended to limit the present invention.

[0057] like Figure 1 FIG. 1 is a flow chart of a method for controlling transient stability of a synchronous phase regulator in a wind farm provided by an embodiment of the present invention. The method comprises the following steps:

[0058] Step S101: constructing a comprehensive performance index function of a wind farm grid-connected system according to a state feedback precise linearization method.

[0059] The state feedback exact linearization method is a technique for controlling nonlinear systems. Through appropriate coordinate transformation and feedback control, the nonlinear system is transformed into a linear system, so that the linear control theory can be applied to the original nonlinear system. The core idea of ​​this method is to make the dynamic behavior of the system appear linear in the new coordinate system through nonlinear transformation and feedback.

[0060] like Figure 2 The figure shows a topological diagram of a wind farm grid-connected system equipped with a synchronous condenser. In this step, the comprehensive performance index function of the wind farm grid-connected system is constructed by using the state feedback precise linearization method, which specifically includes:

[0061] right Figure 2 The wind farm grid-connected system with synchronous condenser is mathematically modeled as shown below:

[0062]

[0063] In the above formula, δ is the synchronous phase condenser power angle, ω SC is the angular velocity of the synchronous condenser, M eq is the inertia time constant of the synchronous condenser, M is the equivalent inertia time constant of the doubly fed wind turbine; ω WF is the speed of the doubly-fed fan; P mWF is the mechanical power of the doubly-fed wind turbine; P eWF and P eSC are the electromagnetic powers of the doubly-fed wind turbine and the synchronous phase condenser respectively, and u is the optimal additional control rate.

[0064] The affine nonlinear system composed of the wind farm and the synchronous condenser transmission system is mapped to transform it into a controllable linear system. According to the linear quadratic optimal control theory, the quadratic comprehensive performance index function is constructed as follows:

[0065]

[0066] In the above formula, J is the quadratic comprehensive performance index; δ and δ d are the measured value and expected value of the synchronous condenser power angle respectively; ω SC and ω d are the synchronous condenser angular velocity and synchronous speed respectively; ω WF and ω dWF are the measured value and expected value of the fan speed respectively; K1, K2, K3 as well as H1, H2 are weight coefficients.

[0067] Step S102: inputting the weight coefficient of the comprehensive performance index function to solve the optimal additional control law.

[0068] Preferably, this step may further specifically include the following steps:

[0069] Input weight coefficients K1, K2, K3 and H1, H2, and satisfy K1, K2, K3>H1, H2>0, and construct weight matrices Q and R respectively by the following formulas:

[0070]

[0071] Substitute the weight matrices Q, R into the Riccati equation shown below:

[0072] A T P+PA-PR -1 B T P+Q=0;

[0073]

[0074] In the above formula, P is the solution of the equation;

[0075] Solve the Riccati equation and keep the positive solution P * ;

[0076] Solve the mapped system input v according to the following formula:

[0077]

[0078] In the above formula, v is the mapped system input, v1 and v2 are the two components of the input, and z is the nonlinear system Exactly linearized diffeomorphisms;

[0079] The mapping result is inversely transformed, and the optimal additional control rate is obtained according to the following formula:

[0080] u=M eq v1+P eSC +P mWF -P eWF -Mv2;

[0081] Where u is the optimal additional control rate; M eq is the inertia time constant of the synchronous condenser, M is the equivalent inertia time constant of the fan; P mWF is the mechanical power of the fan; P eWF and P eSC are the electromagnetic powers of the fan and synchronous condenser respectively.

[0082] Step S103: after detecting that the low voltage ride-through control is exited, the power angle, angular velocity, electromagnetic power of the synchronous condenser in the wind farm and the speed of the wind turbines in the wind farm are measured and obtained in real time, and the optimal additional control rate is used as the optimal active power additional control instruction of the wind turbine.

[0083] like Figure 3 As shown, it is a control structure block diagram of this application. Figure 3 In this case, s is the Laplace operator; T des is the time constant of the delay link; K1, K2, K3 are adjustment parameters, which can be obtained by solving v. Figure 3 A closed-loop control system is described. By measuring the synchronous machine power angle, angular velocity, electromagnetic power, fan speed, and output power, the error signal is calculated and feedback is processed to finally obtain the optimal additional control rate u. This control rate is superimposed on the original fan MPPT control command and used as the optimal active power control command to achieve optimal control of the system.

[0084] Step S104: superimposing the optimal active power additional control instruction of the wind turbine with the original MPPT control instruction of the wind turbine to generate a final active power control instruction of the wind turbine, and adjusting the active output of the wind turbine.

[0085] After this step, the final active power control instruction of the fan is

[0086] P eWF * =P MPPT +u;

[0087] In the above formula, P eWF * is the final active power control instruction of the wind turbine; P MPPT It is the original MPPT control instruction of the fan.

[0088] Preferably, after this step, the method of the present application may further include: determining whether the power angle and angular velocity errors are both zero, or whether the control duration exceeds the time limit, and if so, exiting the control. The wind turbine active power control time limit here can be preferably set to 2s, and of course the time limit setting can also be adjusted according to actual conditions, and the present application does not limit this.

[0089] From the above, it can be seen that the transient stability control method of synchronous condensers in wind farms proposed by the present invention can adjust the active output of wind turbines in real time according to the measurement feedback signal. Compared with the traditional method of setting the control value in advance, the present invention has stronger adaptability to different faults and operation scenarios and lower cost. It effectively improves the power angle stability of synchronous condensers in new energy stations, and avoids the problems of excessive wind turbine speed caused by excessive restriction of wind turbine output in similar methods.

[0090] In order to verify the implementation effect of the above control method, a simulation platform is built as follows: Figure 2 The wind farm plus synchronous condenser transmission system model shown in the figure was then simulated and verified according to the following parameters:

[0091] The actual output of the direct-drive wind turbine is 600MW; the capacity of the synchronous condenser at the sending end is 180MVA, and the inertia time constant is 4s; the receiving end is an infinite power grid; the adjustment parameters are: K1=2, K2=10, K3=1, H1=10, H2=1.

[0092] At 0.5s, a three-phase permanent short circuit occurred in one of the double-circuit lines. After 200ms, the protection action disconnected the faulty line, and the reclosing was successful after another 1s.

[0093] If the conventional control is used, i.e. the fan resumes normal operation immediately after the low voltage ride-through control is completed, the effect of the design scheme of the present invention is compared with that of the conventional control. Figure 4 and Figure 5 shown. Figure 4is the curve of wind turbine active current changing with time, Figure 5 This is the curve of the power angle of the synchronous phase regulator in the wind farm changing with time.

[0094] contrast Figure 4 and Figure 5 It can be seen that compared with restoring normal control immediately after the low penetration ends, the method proposed in the present invention can effectively improve the transient power angle stability of the synchronous phase regulator in the wind farm, and can also ensure the timely recovery of the active output of the wind farm.

[0095] like Figure 6 FIG. 1 is a schematic diagram of a structure of a wind farm synchronous phase regulator transient stability control device provided by an embodiment of the present application, comprising Figure 6 It can be seen that the device includes: an exponential function construction unit 610, an additional control law acquisition unit 620, an optimal control instruction acquisition unit 630 and an adjustment unit 640, which are connected in sequence.

[0096] The exponential function construction unit 610 is used to construct a comprehensive performance index function of the wind farm grid-connected system according to the state feedback precise linearization method.

[0097] The additional control law acquisition unit 620 is used to input the weight coefficient of the comprehensive performance index function to solve the optimal additional control law.

[0098] The optimal control instruction acquisition unit 630 is used to measure and obtain the power angle, angular velocity, electromagnetic power and wind turbine speed of the wind farm synchronous phase regulator in real time after detecting the exit of low voltage ride-through control, and use the optimal additional control rate as the optimal active power additional control instruction of the wind turbine.

[0099] The adjustment unit 640 is used to superimpose the wind turbine optimal active power additional control instruction with the wind turbine original MPPT control instruction to generate a final wind turbine active power control instruction to adjust the wind turbine active output.

[0100] Preferably, Figure 7 As shown, the device of this embodiment also includes: a judgment unit 650, which is used to judge whether the power angle and angular velocity errors are both zero, or whether the control time exceeds the time limit, and if so, exit the control.

[0101] Preferably, the exponential function construction unit 610 is specifically used for:

[0102] The affine nonlinear system composed of the wind farm and the synchronous condenser transmission system is mapped to transform it into a controllable linear system. According to the linear quadratic optimal control theory, the quadratic comprehensive performance index function is constructed as follows:

[0103]

[0104] In the above formula, J is the quadratic comprehensive performance index; δ and δ d are the measured value and expected value of the synchronous condenser power angle respectively; ω SC and ω d are the synchronous condenser angular velocity and synchronous speed respectively; ω WF and ω dWF are the measured value and expected value of the fan speed respectively; K1, K2, K3 as well as H1, H2 are weight coefficients.

[0105] Preferably, the above-mentioned optimal control instruction acquisition unit 630 is specifically used for:

[0106] Input weight coefficients K1, K2, K3 and H1, H2, and satisfy K1, K2, K3>H1, H2>0, and construct weight matrices Q and R respectively by the following formulas:

[0107]

[0108] Substitute the weight matrices Q, R into the Riccati equation shown below:

[0109] A T P+PA-PR -1 B T P+Q=0;

[0110]

[0111] In the above formula, P is the solution of the equation;

[0112] Solve the Riccati equation and keep the positive solution P * ;

[0113] Solve the mapped system input v according to the following formula:

[0114]

[0115] In the above formula, v is the system input after mapping, and v1 and v2 are the two components of the input;

[0116] The mapping result is inversely transformed, and the optimal additional control rate is obtained according to the following formula:

[0117] u=M eq v1+P eSC +P mWF -P eWF -Mv2;

[0118] Where, u is the optimal additional control rate; M eq is the inertia time constant of the synchronous condenser, M is the equivalent inertia time constant of the fan; P mWF is the mechanical power of the fan; PeWF and P eSC are the electromagnetic powers of the fan and synchronous condenser respectively.

[0119] The detailed description of the above-mentioned units and modules can be found in the corresponding description in the aforementioned method embodiment, which will not be further elaborated here.

[0120] From the above, it can be seen that the wind farm synchronous phase condenser transient stability control device proposed by the present invention can adjust the active output of the wind turbine in real time according to the measurement feedback signal. Compared with the traditional method of setting the control value in advance, the present invention has stronger adaptability to different faults and operation scenarios and lower cost. It effectively improves the power angle stability of the synchronous phase condenser in the new energy station, and avoids the problem of excessive wind turbine speed caused by excessive restriction of wind turbine output in similar methods.

[0121] Figure 8 is a schematic diagram of an electronic device provided by an embodiment of the present invention. Figure 8 The electronic device shown is a general data processing device, which includes a general computer hardware structure, which at least includes a processor 801 and a memory 802. The processor 801 and the memory 802 are connected via a bus 803. The memory 802 is suitable for storing one or more instructions or programs executable by the processor 801. The one or more instructions or programs are executed by the processor 801 to implement the steps in the above-mentioned IGBT internal defect location method based on the current rise transient process.

[0122] The processor 801 may be an independent microprocessor or a collection of one or more microprocessors. Thus, the processor 801 executes the commands stored in the memory 802 to execute the method flow of the embodiment of the present invention as described above to realize the processing of data and the control of other devices. The bus 803 connects the above-mentioned multiple components together, and at the same time connects the above-mentioned components to the display controller 804 and the display device and the input / output (I / O) device 805. The input / output (I / O) device 805 may be a mouse, a keyboard, a modem, a network interface, a touch input device, a somatosensory input device, a printer, and other devices known in the art. Typically, the input / output (I / O) device 805 is connected to the system via an input / output (I / O) controller 806.

[0123] The memory 802 may store software components such as an operating system, a communication module, an interaction module, and an application program. Each of the modules and applications described above corresponds to a set of executable program instructions that implement one or more functions and methods described in the embodiments of the invention.

[0124] An embodiment of the present invention further provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the steps of the above-mentioned IGBT internal defect location method based on the current rise transient process are implemented.

[0125] An embodiment of the present invention further provides a computer program product, including a computer program / instruction, which, when executed by a processor, implements the steps of the above-mentioned IGBT internal defect location method based on the current rise transient process.

[0126] From the above, it can be seen that the IGBT internal defect location method and device based on the current rise transient process proposed by the present invention can accurately analyze and locate the defect position inside the IGBT, including collector defects, gate defects and emitter defects, by observing the gate-emitter voltage and collector current of the IGBT device. It significantly improves the accuracy and reliability of IGBT status monitoring, which is of great practical significance for ensuring the safe and stable operation of the equipment.

[0127] The preferred embodiments of the present invention are described above with reference to the accompanying drawings. Many features and advantages of these embodiments are clear from this detailed description, and therefore the claims are intended to cover all such features and advantages of these embodiments that fall within their true spirit and scope. In addition, since many modifications and changes are easily conceivable to those skilled in the art, it is not intended to limit the embodiments of the present invention to the precise structure and operation illustrated and described, but all suitable modifications and equivalents falling within its scope may be covered.

[0128] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0129] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1A device that provides the functions specified in a block or multiple blocks.

[0130] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0131] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0132] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for transient stability control of synchronous phase regulator in a wind farm, characterized in that: The method comprises: The comprehensive performance index function of the wind farm grid-connected system is constructed based on the state feedback precise linearization method; Inputting the weight coefficient of the comprehensive performance index function to solve the optimal additional control law; After detecting that the low voltage ride-through control is exited, the power angle, angular velocity, electromagnetic power of the synchronous condenser in the wind farm and the speed of the wind turbines in the wind farm are measured and obtained in real time, and the optimal additional control rate is used as the optimal active power additional control instruction of the wind turbine; The optimal additional active power control instruction of the wind turbine is superimposed on the original MPPT control instruction of the wind turbine to generate a final active power control instruction of the wind turbine, and the active output of the wind turbine is adjusted.

2. The method for controlling transient stability of synchronous phase condenser in a wind farm according to claim 1, characterized in that: The method further includes: determining whether the power angle and angular velocity errors are both zero, or whether the control duration exceeds a time limit, and if so, exiting the control.

3. The method for controlling transient stability of synchronous phase condenser in a wind farm according to claim 1, characterized in that: The comprehensive performance index function of the wind farm grid-connected system constructed according to the state feedback precise linearization method includes: The affine nonlinear system composed of the wind farm and the synchronous condenser transmission system is mapped to transform it into a controllable linear system. According to the linear quadratic optimal control theory, the quadratic comprehensive performance index function is constructed as follows: In the above formula, J is the quadratic comprehensive performance index; δ and δ d are the measured value and expected value of the synchronous condenser power angle respectively; ω SC and ω d are the angular velocity and synchronous speed of the synchronous condenser respectively; v WF and ω dWF are the measured value and expected value of the fan speed respectively; K1, K2, K3 as well as H1, H2 are weight coefficients.

4. The method for transient stability control of synchronous condenser in a wind farm according to claim 3, characterized in that: The weight coefficient of the input comprehensive performance index function to solve the optimal additional control law includes: Input weight coefficients K1, K2, K3 and H1, H2, and satisfy K1, K2, K3>H1, H2>0, and construct weight matrices Q and R respectively by the following formulas: Substitute the weight matrices Q, R into the Riccati equation shown below: A T P+PA-PR -1 B T P+Q=0; In the above formula, P is the solution of the Riccati equation; Solve the Riccati equation and keep the positive solution P * ; The mapped wind field and the input v of the synchronous condenser transmission system are solved according to the following formula: In the above formula, v is the system input after mapping, v1 and v2 are the two components of input v; The mapping result is inversely transformed, and the optimal additional control rate is obtained according to the following formula: u=M eq v1+P eSC +P mWF -P eWF -Mv2; Where, u is the optimal additional control rate; M eq is the inertia time constant of the synchronous condenser, M is the equivalent inertia time constant of the fan; P mWF is the mechanical power of the fan; P eWF and P eSC are the electromagnetic powers of the fan and synchronous condenser respectively.

5. A wind farm synchronous phase condenser transient stability control device, characterized in that: The device comprises: An exponential function construction unit, used to construct a comprehensive performance index function of a wind farm grid-connected system according to a state feedback precise linearization method; An additional control law acquisition unit, used for inputting a weight coefficient of the comprehensive performance index function to solve an optimal additional control law; The optimal control instruction acquisition unit is used to measure and acquire the power angle, angular velocity, electromagnetic power of the synchronous condenser of the wind farm and the speed of the wind turbine in the wind farm in real time after detecting the exit of the low voltage ride-through control, and use the optimal additional control rate as the optimal active power additional control instruction of the wind turbine; The adjustment unit is used to superimpose the optimal active power additional control instruction of the wind turbine with the original MPPT control instruction of the wind turbine to generate a final active power control instruction of the wind turbine and adjust the active output of the wind turbine.

6. The wind farm synchronous phase condenser transient stability control device according to claim 5, characterized in that: The device further comprises: a judging unit, which is used to judge whether the power angle and angular velocity errors are both zero, or whether the control time exceeds the time limit, and if so, exit the control.

7. The wind farm synchronous phase condenser transient stability control device according to claim 5, characterized in that: The exponential function construction unit is specifically used for: The affine nonlinear system composed of the wind farm and the synchronous condenser transmission system is mapped to transform it into a controllable linear system. According to the linear quadratic optimal control theory, the quadratic comprehensive performance index function is constructed as follows: In the above formula, J is the quadratic comprehensive performance index; δ and δ d are the measured value and expected value of the synchronous condenser power angle respectively; ω SC and ω d are the synchronous condenser angular velocity and synchronous speed respectively; ω WF and ω dWF are the measured value and expected value of the fan speed respectively; K1, K2, K3 as well as H1, H2 are weight coefficients.

8. The wind farm synchronous phase condenser transient stability control device according to claim 7, characterized in that: The optimal control instruction acquisition unit is specifically used for: Input weight coefficients K1, K2, K3 and H1, H2, and satisfy K1, K2, K3>H1, H2>0, and construct weight matrices Q and R respectively by the following formulas: Substitute the weight matrices Q, R into the Riccati equation shown below: A T P+PA-PR -1 B T P+Q=0; In the above formula, P is the solution of the Riccati equation; Solve the Riccati equation and keep the positive solution P * ; The mapped wind field and the input v of the synchronous condenser transmission system are solved according to the following formula: In the above formula, v is the system input after mapping, v1 and v2 are the two components of input v; The mapping result is inversely transformed, and the optimal additional control rate is obtained according to the following formula: u=M eq v1+P eSC +P mWF -P eWF -Mv2; Where, u is the optimal additional control rate; M eq is the inertia time constant of the synchronous condenser, M is the equivalent inertia time constant of the fan; P mWF is the mechanical power of the fan; P eWF and P eSC are the electromagnetic powers of the fan and synchronous condenser respectively.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 4 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 4 are implemented.

Images