A power supply start-up sequence design method and system for avoiding electro-mechanical oscillation

Abstract

The application discloses a power supply starting sequence design method and system for avoiding electrical-mechanical oscillation. Firstly, in the unstarted power generation unit, the power generation unit with the maximum capacity is selected as the initial power generation unit of the current starting sequence; then, the i-th power generation unit is subjected to starting checking, the i-th power generation unit is added to the current starting sequence, and the i-th power generation unit and other units in the same sequence are started together; when all the power generation units are traversed and started, the starting sequence of each stage at this time is output. The design method of the application can guarantee that, in the starting process of the power supply, the frequency mode value is stable, and all possible resonance frequencies in the system are avoided, so that the effect of avoiding electrical-mechanical oscillation is realized. The application can be used for safety checking of the existing power supply aerodynamic scheme.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of wind power generation, and relates to a power source starting sequence design method and system for avoiding electrical-mechanical oscillation. BACKGROUND

[0002] Electrical-mechanical oscillation is a kind of dangerous phenomenon that occurs when the electrical-mechanical system oscillates in equal amplitude or super-amplitude when the components of the electrical system and the mechanical system are simultaneously connected and operated, because the fluctuation frequency of the electrical quantity reaches the vicinity of the natural oscillation frequency of the mechanical structure.

[0003] The operation of the modern power system simultaneously brings problems in electrical and mechanical coupling. One of the important problems is how to avoid the resonance of the mechanical system caused by the fluctuation of the electrical quantity when the power system is operated. The main triggering factor of the resonance is that the vibration frequency of the electrical quantity reaches a certain natural frequency of the mechanical system, thereby causing the mechanical system to oscillate with an increase in amplitude, bringing positive gain to the oscillation of the electrical quantity, and finally causing uncontrollable electrical-mechanical oscillation of the whole system.

[0004] At present, in order to prevent such oscillation, on the one hand, the natural frequency of the inertia generator set is specially designed to avoid the actual operating frequency of the power system as much as possible; on the other hand, for the link that may cause electrical oscillation, a related virtual inertia control link is added to the link, so that the operating vibration frequency is offset and the natural frequency of the mechanical system is avoided.

[0005] In the prior art, the natural frequency of the inertia generator set is specially designed, which increases the design cost of the unit, and as the scale of the power network increases, it is impossible to take into account all the special vibration frequencies of all links, and the frequency coincidence area may still be produced. The virtual inertia link belongs to the control system of the power electronic system, and is not suitable for components that are directly connected to the grid without power electronic control. At the same time, since the control system itself still has a control response process, the actual effect of avoiding the characteristic frequency is not stable. SUMMARY

[0006] The purpose of the present application is to solve the problems in the prior art and provide a power source starting sequence design method and system for avoiding electrical-mechanical oscillation.

[0007] To achieve the above purpose, the following technical solutions are adopted in the present application:

[0008] The power source starting sequence design method for avoiding electrical-mechanical oscillation provided by the present application is characterized by comprising the following steps:

[0009] Step 1, in the unstarted power generation unit, select the power generation unit with the maximum capacity as the initial power generation unit of the starting sequence of this round;

[0010] Step 2, the i-th power unit is subjected to a start-up check, and if the check is passed, the i-th power unit is added to the current start-up sequence and the i-th power unit is started together with other units in the same sequence; if the check is not passed, the i-th power unit is not added to the current start-up sequence;

[0011] Step 3, after all the power units are traversed, if all the power units are not started, step 1 is continued to be executed; if all the power units are started, the sequence design is ended and the start-up sequence of each level at this time is output.

[0012] Preferably, the specific operation steps of the start-up check of the i-th power unit are as follows:

[0013] According to the vibration frequency set N and all the frequencies in the vibration frequency Ni, a frequency set NN is obtained.

[0014] According to the frequency set NN, the vibration frequency set N and the vibration frequency Ni, a frequency set NM is obtained.

[0015] If the frequency set NM and the set M of natural frequencies have an intersection, the start-up check fails; if the frequency set NM and the set M of natural frequencies have no intersection, the start-up check succeeds.

[0016] Preferably, the vibration frequency set N and all the frequencies in the vibration frequency Ni are subjected to greatest common divisor calculation two by two to obtain the frequency set NN.

[0017] Preferably, the frequency set NN, the vibration frequency set N and the vibration frequency Ni are taken as a union set to obtain the frequency set NM.

[0018] Preferably, the vibration frequency set N and the vibration frequency Ni are obtained by the following method:

[0019] Suppose that the set M of natural frequencies of the mechanical system of all the inertia power units is M;

[0020] The power curve of all the determined start-up units in the current sequence is transformed to obtain a vibration frequency set N of the start-up of all the determined start-up units in the current sequence.

[0021] The power curve of the i-th power unit is transformed to obtain a vibration frequency Ni of the start-up of the i-th power unit.

[0022] Preferably, the power curve of all the determined start-up units in the current sequence is subjected to Fourier transform.

[0023] Preferably, the power curve of the i-th power unit is subjected to Fourier transform.

[0024] The application provides a system for a power supply starting sequence design method for avoiding electrical-mechanical oscillation, which comprises the following steps of:

[0025] An initial power generation unit acquisition module is used for selecting a power generation unit with the maximum capacity from the power generation units that are not started as an initial power generation unit of the current starting sequence;

[0026] A power generation unit checking module is used for starting checking on the i-th power generation unit, and if the checking is passed, the i-th power generation unit is added to the current starting sequence and is started together with other units in the same sequence; if the checking is not passed, the i-th power generation unit is not added to the current starting sequence;

[0027] A power generation unit starting sequence acquisition module is used for traversing all the power generation units, and if all the power generation units are not started, the step 1 is continuously executed; if all the power generation units are started, the sequence design is ended, and the starting sequence of each level at this time is output.

[0028] A computer device comprises a memory and a processor, the memory stores a computer program, and the processor implements the steps of the power supply starting sequence design method for avoiding electrical-mechanical oscillation when executing the computer program.

[0029] A computer readable storage medium stores a computer program, and the computer program implements the steps of the power supply starting sequence design method for avoiding electrical-mechanical oscillation when executed by a processor.

[0030] Compared with the prior art, the application has the following beneficial effects:

[0031] The power supply starting sequence design method for avoiding electrical-mechanical oscillation can guarantee that all possible resonance frequencies in the perfect avoidance system are avoided during the starting process of the power supply, so that the effect of avoiding electrical-mechanical oscillation is achieved. The power generation unit with the maximum capacity is selected as the initial power generation unit of the current starting sequence, and the power generation units meeting the requirements are added to the current starting sequence, and after all the power generation units are traversed and started, the starting sequence table of the power generation units is obtained. The design method ignores the size of the power grid and the number of power supply components, does not need the assistance of the power electronic control system, does not need the power supply to have the power electronic converter link, can be used for the safety checking of the existing power supply aerodynamic scheme, allows the power supplies meeting the conditions to be started at the same time, saves the starting time, and accurately avoids the oscillation phenomenon through the starting checking on the i-th power generation unit.

[0032] Further, it is judged whether all superimposed vibration frequencies caused by all power generation devices will intersect with inherent frequencies of all inertia power generators when the i-th power generation unit joins the starting sequence of the current round, if the intersection is generated, it means that the i-th power generation unit joining the starting sequence of the current round will have the possibility of causing resonance of the whole system, and then the i-th power generation unit should not start in the current round.

[0033] The system for the power supply starting sequence design method for avoiding electrical-mechanical oscillation provided by the application divides the system into an initial power generation unit acquisition module, a power generation unit checking module and a power generation unit starting sequence acquisition module, adopts the modularization idea to make each module independent of each other, and facilitates unified management of each module. BRIEF DESCRIPTION OF DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiments, and it should be understood that the following drawings only show some embodiments of the application, and therefore should not be regarded as a limitation to the scope, and for those skilled in the art, other related drawings can also be obtained without creative labor on the basis of the drawings.

[0035] Figure 1 The flow chart of the power supply starting sequence design method for avoiding electrical-mechanical oscillation of the application.

[0036] Figure 2 The specific flow chart of the power supply starting sequence design method for avoiding electrical-mechanical oscillation of the application.

[0037] Figure 3 The system diagram of the power supply starting sequence design system for avoiding electrical-mechanical oscillation of the application. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solutions and advantages of the embodiments of the application more clear, the following will combine the drawings in the embodiments of the application to clearly and completely describe the technical solutions in the embodiments of the application, and obviously, the described embodiments are some embodiments of the application, but not all the embodiments. The components of the embodiments of the application described and shown in the drawings can be arranged and designed in various different configurations.

[0039] Therefore, the following detailed description of the embodiments of the application provided in the drawings is not intended to limit the scope of the claimed application, but only represents selected embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the application.

[0040] It should be noted that like reference numerals and characters refer to like elements throughout the several views of the drawings, and that, unless otherwise indicated, like reference numerals and characters in different figures indicate like elements throughout the several views of the drawings.

[0041] In the description of the embodiments of the present application, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "horizontal", "inner", etc. is based on the orientation or positional relationship shown in the drawings or the orientation or positional relationship in which the product of the present application is usually placed, and is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", etc. are only used for differentiation in description and cannot be understood as indicating or implying relative importance.

[0042] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly inclined. For example, "horizontal" only means that its direction is relatively more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0043] In the description of the embodiments of the present application, it should also be noted that, unless otherwise explicitly specified and limited, if the terms "arrangement", "installation", "connection", "connection" appear, they should be understood in a broad sense, for example, they can be fixedly connected, or can be detachably connected, or integrally connected; can be mechanically connected, or can be electrically connected; can be directly connected, or can be indirectly connected through an intermediate medium; can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0044] The present application will be described in further detail below in conjunction with the accompanying drawings:

[0045] The present application proposes a power supply start-up sequence design method for avoiding electrical-mechanical oscillation, as shown in Figure 1 The method comprises the following steps:

[0046] Step 1, in the unstarted power generation unit, select the power generation unit with the largest capacity as the initial power generation unit of the current start-up sequence;

[0047] Step 2, start-up checking is performed on the i-th power generation unit, if the checking is passed, the i-th power generation unit is added to the current start-up sequence, and the i-th power generation unit is started together with other units in the same sequence; if the checking is not passed, the i-th power generation unit is not added to the current start-up sequence;

[0048] Step 3, after traversing all power generation units, if the power generation units are not all started, continue to execute step 1; if the power generation units are all started, the sequence design is ended, and the starting sequence of each level at this time is output.

[0049] As shown in Figure 2 Fig. 1 is a flow chart of a power supply starting sequence design method for avoiding electrical-mechanical oscillation, and the optimization method of the present application will be described in detail below in combination with the flow chart.

[0050] 1) Set n as a dynamic variable, representing the number of all power generation units not added to the starting list in the power grid at this time. Among the unstarted power generation units, select the power generation unit with the largest capacity as the initial power generation unit of the starting sequence of this round.

[0051] The variable n is always changing during the entire method, and always equals the number of all power generation units not added to the starting list in the power grid at this time.

[0052] 2) Let variable i = 1, and perform starting check on the i-th power generation unit. If the check passes, let the i-th power generation unit join the starting sequence of this round and start together with other units in the same sequence; if the check fails, do not add the i-th power generation unit to the starting sequence of this round.

[0053] The starting check method is as follows:

[0054] Suppose the set of mechanical system natural frequencies of all inertia power generation units is M;

[0055] Perform Fourier transform on the power curve of all determined starting units in this sequence to obtain the vibration frequency set N of the starting of all determined starting units in this sequence;

[0056] Perform Fourier transform on the power curve of the i-th power generation unit to obtain the vibration frequency Ni of the starting of the i-th power generation unit;

[0057] Calculate the greatest common divisor of all frequencies in the vibration frequency set N and the vibration frequency Ni, to obtain the frequency set NN; at the same time, take the union of the frequency set NN, the vibration frequency set N and the vibration frequency Ni, to obtain the frequency set NM;

[0058] Determine whether there is an intersection between the frequency set NM and the set of natural frequencies M, if there is an intersection, the starting check fails; if there is no intersection, the starting check succeeds.

[0059] The core purpose of this step is to determine whether all superimposed vibration frequencies caused by the i-th power generation unit joining the current starting sequence and all current power generation devices will intersect with the inherent frequency of all inertia power generation units, if the intersection is generated, it means that the i-th power generation unit joining the current starting sequence will have the possibility of causing resonance of the whole system, and then the i-th power generation unit should not start in the current round.

[0060] 3) whether i is equal to n, if i is not equal to n, then i is equal to i+1, and step 2) is returned; if i is equal to n, it is determined whether there is a power generation unit that has not been started, that is, whether n is equal to 0, if n is equal to 0, step 1) is returned, if n is not equal to 0, the sequence design is ended, and the starting sequence of each level at this time is output.

[0061] The purpose of this step is to determine whether all n power generation units have been checked in the current sequence. If it has been checked, it is determined whether all power generation units in the scheme have been arranged in the starting sequence, if not, step 1) is returned, and the next sequence of the power generation unit is checked.

[0062] The system for avoiding electrical-mechanical oscillation power supply starting sequence design method provided by the application, as shown in Figure 3 , comprises:

[0063] An initial power generation unit acquisition module is configured to select a power generation unit with the maximum capacity from the unstarted power generation units as an initial power generation unit in the current starting sequence.

[0064] A power generation unit checking module is configured to perform starting checking on the i-th power generation unit, if the checking is passed, the i-th power generation unit is added to the current starting sequence, and the i-th power generation unit is started together with other units in the same sequence; if the checking is not passed, the i-th power generation unit is not added to the current starting sequence.

[0065] A power generation unit starting sequence acquisition module is configured to traverse all power generation units, if the power generation units are not all started, step 1) is continued to be executed; if the power generation units are all started, the sequence design is ended, and the starting sequence of each level at this time is output.

[0066] The terminal device provided by the embodiment of the application comprises a processor, a memory, and a computer program stored in the memory and executable on the processor. The processor implements the steps in each method embodiment described above when executing the computer program. Alternatively, the processor implements the functions of each module / unit in each device embodiment described above when executing the computer program.

[0067] The computer program can be divided into one or more modules / units, which are stored in the memory and executed by the processor to complete the present application.

[0068] The terminal device can be a desktop computer, a notebook computer, a palm computer, a cloud server, and the like. The terminal device can include, but is not limited to, a processor, a memory.

[0069] The processor can be a central processing unit (CPU), and can also be other general-purpose processors, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, and the like.

[0070] The memory can be used to store the computer program and / or modules, and the processor realizes various functions of the terminal device by running or executing the computer program and / or modules stored in the memory, and calling data stored in the memory.

[0071] The modules / units integrated in the terminal device, if realized in the form of software function units and sold or used as independent products, can be stored in a computer readable storage medium. Based on this understanding, all or part of the processes in the above-mentioned embodiment methods can also be completed by a computer program instructing related hardware, and the computer program can be stored in a computer readable storage medium. The computer program can realize the steps of the above-mentioned various method embodiments when executed by a processor. The computer program includes computer program code, which can be in the form of source code, object code, executable files or some intermediate forms, etc. The computer readable medium can include any entity or device capable of carrying the computer program code, recording medium, U disk, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal and software distribution medium, etc. It should be noted that the computer readable medium can include appropriate contents according to the requirements of legislation and patent practice in the jurisdiction, for example, in some jurisdictions, according to legislation and patent practice, the computer readable medium does not include electrical carrier signals and telecommunication signals.

[0072] The application provides a power supply starting sequence design method for avoiding electrical-mechanical oscillation. The method can ensure that all possible resonance frequencies in a perfect avoidance system are avoided during the starting process of the power supply, so that the function of avoiding electrical-mechanical oscillation is realized. The method has the following advantages: 1) regardless of the size of the power grid and the number of power supply components; 2) the frequency mode value is stable, and the oscillation phenomenon can be accurately avoided; 3) no power electronic control system is needed for assistance, and the power supply does not need to have a power electronic converter link; 4) the method can be used for safety check of an existing power supply aerodynamic scheme; and 5) the power supply can be started at the same time under certain conditions, and the starting time is saved.

[0073] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. The present application can be variously changed and modified by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A power supply start-up sequence design method for circumventing electro-mechanical oscillations, characterized by, The method comprises the following steps: Step 1, in the unstarted generating units, selecting the generating unit with the largest capacity as the initial generating unit of the current starting sequence; Step 2, performing starting checking on the i-th generating unit, if the checking is passed, adding the i-th generating unit into the current starting sequence, and starting the i-th generating unit together with other units in the same sequence; if the checking is not passed, not adding the i-th generating unit into the current starting sequence; Step 3, after traversing all the generating units, if all the generating units are not started, continuing to perform Step 1; if all the generating units are started, ending the sequence design, and outputting the starting sequence of each level at this time; The specific operation steps of performing starting checking on the i-th generating unit are as follows: According to the vibration frequency set N and all the frequencies in the vibration frequency Ni, a frequency set NN is obtained; According to the frequency set NN, the vibration frequency set N and the vibration frequency Ni, a frequency set NM is obtained; If there is an intersection between the frequency set NM and the set M of natural frequencies, the starting checking fails; if there is no intersection between the frequency set NM and the set M of natural frequencies, the starting checking succeeds; The vibration frequency set N and all the frequencies in the vibration frequency Ni are calculated for the greatest common divisor, and a frequency set NN is obtained; The frequency set NN, the vibration frequency set N and the vibration frequency Ni are taken as a union set, and a frequency set NM is obtained; The vibration frequency set N and the vibration frequency Ni are obtained as follows: Suppose that the set M of natural frequencies of the mechanical system of all inertia generating units is M; The power curve of all the determined starting units in the current sequence is transformed to obtain a vibration frequency set N of the starting units in the current sequence; The power curve of the i-th generating unit is transformed to obtain a vibration frequency Ni of the i-th generating unit.

2. The power supply start-up sequence design method for evading electro-mechanical oscillation according to claim 1, wherein The power curve of all the determined starting units in the current sequence is Fourier transformed.

3. The power sequencing design method for circumventing electro-mechanical oscillation according to claim 1, wherein, The power curve of the i-th generating unit is Fourier transformed.

4. The system for the power supply start-up sequence design method for evading electro-mechanical oscillation according to any one of claims 1 to 3, characterized in that, The method comprises: An initial generating unit acquisition module, which is used to select the generating unit with the largest capacity as the initial generating unit of the current starting sequence in the unstarted generating units; A generating unit checking module, which is used to perform starting checking on the i-th generating unit, if the checking is passed, adding the i-th generating unit into the current starting sequence, and starting the i-th generating unit together with other units in the same sequence; if the checking is not passed, not adding the i-th generating unit into the current starting sequence; A generating unit starting sequence acquisition module, which is used to traverse all the generating units, if all the generating units are not started, continuing to perform Step 1; if all the generating units are started, ending the sequence design, and outputting the starting sequence of each level at this time. 5.A computer device, comprising a memory and a processor, wherein the memory stores a computer program, and the computer device is configured to perform the method according to any one of claims 1-4 when the computer program is executed by the processor. The processor executes the computer program to realize the steps of the power starting sequence design method for avoiding electrical-mechanical oscillation in any one of claims 1 to 3.

6. A computer-readable storage medium storing a computer program, the computer program comprising instructions that, when executed by a computer, cause the computer to perform the method of any one of claims 1 to 5. The computer program is executed by the processor to realize the steps of the power starting sequence design method for avoiding electrical-mechanical oscillation in any one of claims 1 to 3.

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