Redundancy control method and system for wind power converter

Abstract

The invention relates to the technical field of wind power converters, and discloses a wind power converter redundancy control method and system, and the method comprises the following control steps: collecting a current distortion rate DJ, harmonic current data XD and temperature data WD when a converter main body works, calculating an open circuit health value KJ in a forced manner, and when the open circuit health threshold value KJ is zero or a negative number, determining that the current distortion rate DJ, the harmonic current data XD and the temperature data WD are zero or negative; the redundant module replaces a module in the converter main body to operate; collecting bus ripple data MX, total working time SJ and voltage data DY during working, and calculating an aging health value L; when the redundancy control of the converter is carried out, the possible problems of the converter are divided into two types, the first type is the open circuit problem of the converter, the second type is the aging problem of the converter, and different detection modes and judgment standards are adopted for the two problems, so that the problems can be found in time when the converter has the problems; and sudden stop is not easy to occur.

Description

Technical Field

[0001] This invention relates to the field of wind power converter technology, and more specifically to a redundancy control method and system for wind power converters. Background Technology

[0002] A wind power converter is an excitation device applied to the rotor side in a doubly-fed wind turbine. Its main function is to control the amplitude, phase, and frequency of the excitation through the converter when the rotor speed n changes, so that the stator side can input constant frequency electricity to the grid. A wind power converter includes a power module, a control module, and a grid connection module. To ensure the long-term use of converters, redundancy is generally implemented. Converter redundancy refers to introducing an additional converter as a backup in the system to ensure that the system can still operate normally when the main converter fails. The design of converter redundancy aims to improve the reliability and stability of the system and prevent system interruption caused by the failure of a single converter.

[0003] As the core equipment for power conversion, the failure of the converter will directly lead to the interruption of power generation. Although modern converters are equipped with redundant systems to replace the work in time when there is a failure, the current redundant systems cannot use different judgment methods according to the problems that occur in the converter, so they cannot accurately control the converter. Summary of the Invention

[0004] In order to overcome the above-mentioned defects of the prior art, the embodiments of the present invention provide a redundancy control method and system for wind power converters to solve the technical problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a redundancy control method for a wind power converter, comprising the following control steps: Step S1: Collect the current distortion rate DJ, harmonic current data XD, and temperature data WD of the main body of the converter during operation, and calculate the open circuit health value KJ. Step S2: When the open-circuit health threshold KJ is zero or negative, the redundant module replaces the module in the main body of the converter to operate. Step S3: When the open circuit health value KJ is not zero or negative, no instruction is sent when the open circuit health value KJ ≤ the open circuit threshold KY, and a replacement instruction is sent when the open circuit health value KJ > the open circuit threshold KY, and the redundant module performs the replacement work. Step S4: Collect bus ripple data MX, total working time SJ, and voltage data DY during operation, and calculate the aging health value L; Step S5: When the aging health value LJ < the first aging threshold LY1, no instruction is sent. When the first aging threshold LY1 ≤ the aging health value LJ ≤ the second aging threshold LY2, a reduction instruction is sent, and the system operating power decreases. When the aging health value LJ > the second aging threshold LY2, a replacement instruction is sent, and the redundant module works. Step S6: Perform periodic self-tests on redundant modules. During the self-test, a replacement command is sent to replace the redundant module with a new one.

[0006] A redundant control system for a wind power converter includes a converter body, a data acquisition unit, an open-circuit unit, an aging unit, a health unit, a backup unit, and a self-testing unit. The converter body is used for wind power generation conversion. The data acquisition unit is used to acquire data information during the operation of the converter body. The open-circuit unit is used to calculate the open-circuit health value KJ. The aging unit is used to calculate the aging health value LJ. The health unit receives the open-circuit health value KJ and the aging health value LJ and makes a judgment. The backup unit uses redundant modules to replace modules in the converter body. The self-testing unit is used for self-testing of the redundant modules in the backup unit. The acquisition unit collects the current distortion rate DJ, harmonic current data XD, and temperature data WD within each module of the converter during operation. The acquisition unit then sends the collected data to the open-circuit unit. The open-circuit unit receives the data and calculates the open-circuit health value KJ. The formula for calculating the open-circuit health value KJ is as follows: In the formula, sgn is the floor function, XB is the allowable harmonic current of the converter, and k1, k2 and k3 are all weights. The open circuit unit sends the calculated open circuit health value KJ to the health unit.

[0007] In a preferred embodiment, the health unit receives and identifies the calculated open-circuit health value KJ. When the health unit identifies that the open-circuit health threshold KJ is zero or negative, the health unit directly sends a replacement command and the corresponding converter module data to the standby unit. The standby unit receives the replacement command and the module data and controls the standby module to start, replacing the module in the converter body whose open-circuit health threshold KJ is zero or negative.

[0008] In a preferred embodiment, when the health unit identifies that the open-circuit health value KJ is not zero or is negative, the health unit compares the open-circuit health value KJ with its internal open-circuit threshold KY. When the open-circuit health value KJ ≤ the open-circuit threshold KY, the health unit does not send an instruction. When the open-circuit health value KJ > the open-circuit threshold KY, the health unit sends a replacement instruction and the converter module data corresponding to the open-circuit health value KJ to the backup unit, and the backup unit performs redundant module replacement processing.

[0009] In a preferred embodiment, the acquisition unit acquires bus ripple data MX, total operating time SJ, and voltage data DY during operation. The acquisition unit sends the acquired data to the aging unit, which receives the acquired data and calculates the aging health value LJ. The formula for calculating the aging health value LJ is as follows: In the formula, MB is the standard bus ripple, MS is the standard operating time of the converter, and the aging unit sends the calculated aging health value LJ to the health unit.

[0010] In a preferred embodiment, the health unit receives an aging health value LJ and compares it with its internal first aging threshold LY1 and second aging threshold LY2, wherein the first aging threshold LY1 < the second aging threshold LY2, and when the aging health value LJ < the first aging threshold LY1, the health unit does not send an instruction.

[0011] In a preferred embodiment, when the first aging threshold LY1 ≤ aging health value LJ ≤ second aging threshold LY2, the health unit sends a reduction command to the converter body, the converter body receives the reduction command and controls the system operating power to decrease, and when the aging health value LJ > the second aging threshold LY2, the health unit sends a replacement command and the converter internal module data corresponding to the aging health value LJ to the backup unit, the backup unit performs redundant module replacement processing.

[0012] In a preferred embodiment, the main body of the converter is composed of N modules with different functions. Each of the N modules in the main body of the converter has a corresponding redundant module in the standby unit. The redundant modules in the standby unit are synchronized and connected to the grid within 1ms.

[0013] In a preferred embodiment, the self-test unit is used for periodic self-testing of the redundant modules in the standby unit. When the standby unit is self-testing, it connects the redundant modules to the main body of the converter for load operation. When the standby unit is under load operation, the open-circuit unit and the aging unit calculate the open-circuit health value KJ and the aging health value LJ. When the redundant modules are working, and the health unit sends a replacement command, the self-test unit directly issues a fault alarm. When the self-test unit issues a fault alarm, it replaces the redundant modules with new ones.

[0014] The technical effects and advantages of this invention are as follows: When performing redundant control of the converter, this invention first divides the possible problems of the converter into two categories: the first is the open circuit problem of the converter, and the second is the aging problem of the converter. Different detection methods and judgment criteria are used for the above two problems. Therefore, when the converter has a problem, it can be detected in time, ensuring that the overall power generation process is more stable and less likely to stop suddenly. This invention collects current distortion rate DJ, harmonic current data XD, and temperature data WD. When the harmonic current data XD exceeds the constrained harmonic current, redundant units are directly used for replacement to ensure the stability of the converter. When the open circuit health value KJ > the open circuit threshold KY, the converter body may be damaged. Therefore, timely replacement with redundant modules can cool down the converter body and prevent damage, allowing this application to be used for a long time. This invention directly reflects the aging status of the converter by collecting bus ripple data MX, total operating time SJ, and voltage data DY during operation. The larger the collected values, the more severe the aging. Therefore, the larger the calculated aging health value LJ, the more severe the aging. When the aging health value LJ < the first aging threshold LY1, there is no aging and no treatment is needed. When the first aging threshold LY1 ≤ the aging health value LJ ≤ the second aging threshold LY2, there is slight aging, which can be addressed by slightly reducing the power. When the aging health value LJ > the second aging threshold LY2, the aging is more severe, requiring replacement work. After a period of replacement work, maintenance is needed, and the aging modules need to be replaced. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall method steps of the present invention.

[0016] Figure 2 This is a schematic diagram of the overall system composition of the present invention. Detailed Implementation

[0017] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. In addition, the forms of the various structures described in the following embodiments are merely illustrative. The wind power converter redundancy control method and system involved in the present invention are not limited to the structures described in the following embodiments. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] Reference Figure 1 This invention provides a redundancy control method for wind power converters, comprising the following control steps: Step S1: Collect the current distortion rate DJ, harmonic current data XD, and temperature data WD of the main body of the converter during operation, and calculate the open circuit health value KJ. Step S2: When the open-circuit health threshold KJ is zero or negative, the redundant module replaces the module in the main body of the converter to operate. Step S3: When the open circuit health value KJ is not zero or negative, no instruction is sent when the open circuit health value KJ ≤ the open circuit threshold KY, and a replacement instruction is sent when the open circuit health value KJ > the open circuit threshold KY, and the redundant module performs the replacement work. Step S4: Collect bus ripple data MX, total working time SJ, and voltage data DY during operation, and calculate the aging health value L; Step S5: When the aging health value LJ < the first aging threshold LY1, no instruction is sent. When the first aging threshold LY1 ≤ the aging health value LJ ≤ the second aging threshold LY2, a reduction instruction is sent, and the system operating power decreases. When the aging health value LJ > the second aging threshold LY2, a replacement instruction is sent, and the redundant module works. Step S6: Perform periodic self-tests on redundant modules. During the self-test, a replacement command is sent to replace the redundant module with a new one.

[0019] In this embodiment of the application, when performing redundant control of the converter, the possible problems of the converter are first divided into two categories: the first is the open circuit problem of the converter, and the second is the aging problem of the converter. Different detection methods and judgment criteria are used for the above two problems. Therefore, when the converter has a problem, it can be detected in time, ensuring that the overall power generation process is more stable and less likely to suddenly stop.

[0020] Reference Figure 2 A redundant control system for a wind power converter includes a converter body, a data acquisition unit, an open-circuit unit, an aging unit, a health unit, a backup unit, and a self-testing unit. The converter body is used for wind power generation conversion. The data acquisition unit is used to acquire data information during the operation of the converter body. The open-circuit unit is used to calculate the open-circuit health value KJ. The aging unit is used to calculate the aging health value LJ. The health unit receives the open-circuit health value KJ and the aging health value LJ and makes a judgment. The backup unit uses redundant modules to replace modules in the converter body. The self-testing unit is used for self-testing of the redundant modules in the backup unit.

[0021] In this embodiment of the application, when performing redundancy control, the application first collects different data information within the main body of the converter through the acquisition unit. After collecting the data information, it sends it to the open circuit unit and the aging unit respectively. Based on the received data, the two units automatically calculate the open circuit health value KJ and the aging health value LJ. The health unit judges the open circuit health value KJ and the aging health value LJ respectively, and promptly detects when different problems occur in the main body of the converter. The redundant modules in the backup unit are then replaced in a timely manner to ensure that the converter will not have problems even after long-term use.

[0022] Reference Figure 2 The acquisition unit collects the current distortion rate DJ, harmonic current data XD, and temperature data WD within each module of the converter during operation. The acquisition unit then sends the collected data to the open-circuit unit. The open-circuit unit receives the data and calculates the open-circuit health value KJ. The formula for calculating the open-circuit health value KJ is as follows: In the formula, sgn is the floor function, XB is the allowable harmonic current of the converter, and k1, k2, and k3 are all weights. The open-circuit unit sends the calculated open-circuit health value KJ to the health unit. The health unit receives the calculated open-circuit health value KJ and identifies it. When the health unit identifies that the open-circuit health threshold KJ is zero or negative, the health unit directly sends a replacement command and the corresponding module data in the converter to the backup unit. The backup unit receives the replacement command and the module data and controls the backup module to start, replacing the module in the converter body whose open-circuit health threshold KJ is zero or negative.

[0023] In this embodiment, the current distortion rate DJ, harmonic current data XD, and temperature data WD are first collected. The larger the values ​​of the current distortion rate DJ, harmonic current data XD, and temperature data WD, the greater the possibility of problems with the converter. When the harmonic current data XD exceeds the constrained harmonic current, the converter itself already has certain fixed problems. The sgn rounding function of this application outputs 1 when the input is positive, 0 when the input is 0, and -1 when the input is negative. Therefore, when the harmonic current data XD is greater than the allowable harmonic current of the converter, sgn will output 0 and -1, making the calculated open-circuit health threshold KJ zero or negative. At this time, redundant units are directly used for replacement to ensure the stability of the converter.

[0024] Reference Figure 2When the health unit identifies that the open-circuit health value KJ is not zero or is negative, the health unit compares the open-circuit health value KJ with its internal open-circuit threshold KY. When the open-circuit health value KJ ≤ the open-circuit threshold KY, the health unit does not send an instruction. When the open-circuit health value KJ > the open-circuit threshold KY, the health unit sends a replacement instruction and the converter module data corresponding to the open-circuit health value KJ to the backup unit, and the backup unit performs redundant module replacement processing.

[0025] In this embodiment, when the open-circuit health value KJ is not zero or is negative, the converter is not yet damaged. However, when the open-circuit health value KJ is greater than the open-circuit threshold KY, the converter body may be damaged. Therefore, timely replacement with redundant modules can cool down the converter body and prevent damage, allowing this application to be used for a long time.

[0026] Reference Figure 2 The acquisition unit collects bus ripple data MX, total operating time SJ, and voltage data DY during operation. The acquisition unit sends the collected data to the aging unit. The aging unit receives the data and calculates the aging health value LJ. The formula for calculating the aging health value LJ is as follows: In the formula, MB represents the standard bus ripple, and MS represents the standard operating time of the converter. The aging unit sends the calculated aging health value LJ to the health unit. The health unit receives the aging health value LJ and compares it with its internal first aging threshold LY1 and second aging threshold LY2. The first aging threshold LY1 < the second aging threshold LY2. When the aging health value LJ < the first aging threshold LY1, the health unit does not send an instruction. When the first aging threshold LY1 ≤ the aging health value LJ ≤ the second aging threshold LY2, the health unit sends a reduction instruction to the converter body. The converter body receives the reduction instruction and controls the system's operating power to decrease. When the aging health value LJ > the second aging threshold LY2, the health unit sends a replacement instruction and the corresponding converter module data to the backup unit. The backup unit performs redundant module replacement processing. In this embodiment, the bus ripple data MX, total operating time SJ, and voltage data DY collected by this application directly reflect the aging status of the converter. The larger the collected values, the more severe the aging. Therefore, the larger the aging health value LJ calculated by this application, the more severe the aging. When the aging health value LJ < the first aging threshold LY1, there is no aging and no processing is required. When the first aging threshold LY1 ≤ the aging health value LJ ≤ the second aging threshold LY2, there is slight aging. If a replacement operation is performed at this time, a permanent replacement is required, which will not reduce costs. Therefore, it is sufficient to slightly reduce the power. When the aging health value LJ > the second aging threshold LY2, the aging is more severe. Replacement work is required at this time. After a period of replacement work, maintenance is required to replace the aging modules.

[0027] Reference Figure 2 The converter body consists of N modules with different functions. Each of the N modules in the converter body has a corresponding redundant module in the standby unit. The redundant modules in the standby unit perform synchronous grid-connected operation within 1ms. The self-test unit is used for periodic self-testing of the redundant modules in the standby unit. When the standby unit performs self-testing, it connects the redundant modules to the converter body for load operation. When the standby unit is under load operation, the open-circuit unit and the aging unit calculate the open-circuit health value KJ and the aging health value LJ. When the redundant module is working, if the health unit sends a replacement command, the self-test unit directly issues a fault alarm. When the self-test unit issues a fault alarm, it replaces the redundant module.

[0028] In this embodiment, each of the N modules within the converter body has a corresponding redundant module in the backup unit. Therefore, when any module in the converter malfunctions, a corresponding redundant module can replace it. The redundant module synchronizes and connects to the grid within 1ms, which is timely enough to avoid converter malfunction due to excessive replacement time. Furthermore, the redundant module performs self-checks to promptly detect its operating status. When the self-check detects a problem in its operating status, i.e., when the healthy unit sends a replacement command, the redundant module needs to be replaced. This prevents the redundant module from malfunctioning when a problem occurs in the converter body and a replacement module is used.

[0029] The above embodiments can be implemented, in whole or in part, by software, hardware, firmware, or any other combination thereof. When implemented in software, the above embodiments can be implemented, in whole or in part, as a computer program product. The units and algorithm steps of the various examples described in the embodiments can be implemented in electronic hardware or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0030] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0031] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0032] In conclusion, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A wind power converter redundancy control method, characterized by: The method comprises the following control steps: Step S1, collecting the current distortion rate DJ, harmonic current data XD, and temperature data WD of the converter main body during operation, and calculating the open circuit health value KJ; Step S2, when the open circuit health threshold KJ is zero or negative, the redundant module replaces the module in the converter main body to operate; Step S3, when the open circuit health value KJ is not zero and negative, if the open circuit health value KJ is less than or equal to the open circuit threshold KY, no instruction is sent, and if the open circuit health value KJ is greater than the open circuit threshold KY, a replacement instruction is sent, and the redundant module operates to replace; Step S4, collecting the bus ripple data MX, the total operation time SJ, and the voltage data DY during operation, and calculating the aging health value L; Step S5, when the aging health value LJ is less than the first aging threshold LY1, no instruction is sent, when the first aging threshold LY1 is less than or equal to the aging health value LJ and less than the second aging threshold LY2, a reduction instruction is sent, the system operation power is reduced, and when the aging health value LJ is greater than the second aging threshold LY2, a replacement instruction is sent, and the redundant module operates; Step S6, the redundant module is regularly self-checked, and when the redundant module is self-checked, a replacement instruction is sent, and a new redundant module is replaced.

2. A wind power converter redundancy control system, characterized by: The method comprises a converter main body, a collection unit, an open circuit unit, an aging unit, a health unit, a backup unit, and a self-checking unit. The converter main body is used for wind power generation conversion operation. The collection unit is used for collecting data information during operation of the converter main body. The open circuit unit is used for calculating the open circuit health value KJ. The aging unit is used for calculating the aging health value LJ. The health unit receives the open circuit health value KJ and the aging health value LJ and judges. The backup unit uses the redundant module to replace the module in the converter main body. The self-checking unit is used for self-checking of the redundant module in the backup unit. The collection unit collects the current distortion rate DJ, harmonic current data XD and temperature data WD in each module during the operation of the converter main body, and sends the collected data information to the open circuit unit. The open circuit unit receives the data information collected by the collection unit and calculates the open circuit health value KJ. The calculation formula of the open circuit health value KJ is , wherein sgn is an integral function, XB is the allowable harmonic current of the converter, k1, k2 and k3 are weights, and the open circuit unit sends the calculated open circuit health value KJ to the health unit.

3. The wind power converter redundancy control system of claim 2, wherein: The health unit receives the calculated open circuit health value KJ and identifies. When the health unit identifies that the open circuit health threshold KJ is zero or negative, the health unit directly sends a replacement instruction and the module data corresponding to the open circuit health value in the converter to the backup unit. The backup unit receives the replacement instruction and the module data and controls the backup module to start, replacing the module corresponding to the open circuit health threshold KJ that is zero or negative in the converter main body to operate.

4. The wind power converter redundancy control system of claim 3, wherein: When the health unit identifies that the open circuit health value KJ is not zero and negative, the health unit compares the open circuit health value KJ with the open circuit threshold KY in the health unit. When the open circuit health value KJ is less than or equal to the open circuit threshold KY, the health unit does not send an instruction. When the open circuit health value KJ is greater than the open circuit threshold KY, the health unit sends a replacement instruction and the module data corresponding to the open circuit health value in the converter to the backup unit, and the backup unit replaces the redundant module.

5. The wind power converter redundancy control system of claim 2, wherein: The collecting unit collects bus ripple data MX, working total time SJ and voltage data DY in working time, and sends the collected data information to the aging unit, the aging unit receives the data information collected by the collecting unit and calculates aging health value LJ, and the calculation formula of the aging health value LJ is , wherein MB is a standard bus ripple, MS is a standard use time of the converter, and the aging unit sends the calculated aging health value LJ to the health unit.

6. The wind power converter redundancy control system of claim 5, wherein: The health unit receives the aging health value LJ and compares it with the first aging threshold LY1 and the second aging threshold LY2 in the health unit. When the aging health value LJ is less than the first aging threshold LY1, the health unit does not send an instruction.

7. The wind power converter redundancy control system of claim 6, wherein: When the first aging threshold LY1 ≤ the aging health value LJ ≤ the second aging threshold LY2, the health unit sends a reduction instruction to the converter main body, the converter main body receives the reduction instruction and controls the system to run power down, when the aging health value LJ > the second aging threshold LY2, the health unit sends a replacement instruction and the converter internal module data corresponding to the aging health value LJ to the backup unit, the backup unit performs redundant module replacement processing.

8. The wind power converter redundancy control system of claim 2, wherein: The converter main body is composed of N different functional modules, the N modules in the converter main body are provided with corresponding redundant modules in the backup unit, and the redundant modules in the backup unit are synchronized and connected to the grid within 1ms.

9. The wind power converter redundancy control system of claim 8, wherein: The self-checking unit is used for periodic self-checking of the redundant modules in the backup unit, when the backup unit is self-checked, the backup unit connects the redundant modules to the converter main body for load operation, when the backup unit is in load operation, the open circuit unit and the aging unit calculate the open circuit health value KJ and the aging health value LJ, when the health unit sends a replacement instruction, the self-checking unit directly performs a fault alarm, and when the self-checking unit performs a fault alarm, a new redundant module is replaced.

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