Voltage tracking method, control equipment, UPS system

Abstract

The present invention provides a voltage tracking method, control device, and UPS system. The method performs the following steps in each capture cycle: after determining a first voltage cycle, if the first voltage cycle is within a preset range, voltage tracking is performed using the first voltage cycle; if the first voltage cycle is not within the preset range, a number of abnormalities is counted. If the number of abnormalities does not exceed the preset number, voltage tracking is performed using the voltage cycle used for voltage tracking in the previous capture cycle; if the number of abnormalities exceeds the preset number, the grid voltage cycle is determined to be abnormal, and voltage tracking is stopped. The present invention takes into account the impact of grid harmonics and can effectively implement grid voltage tracking. Based on this, the present invention can be effectively applied to the nuclear power field, ensuring the stable operation of nuclear power electrical equipment and, therefore, the stable operation of the nuclear power system through effective voltage tracking.

Description

Technical Field

[0001] The present invention belongs to the field of circuit technology, and more specifically, relates to a voltage tracking method, a control device, and a UPS system. Background Art

[0002] In the circuit field, there are many scenarios requiring grid voltage tracking. In existing technologies, when tracking grid voltage, to prevent errors in capturing the grid voltage cycle or abnormalities in the grid voltage itself, which could affect subsequent circuit control and, in turn, normal circuit operation, the captured grid voltage cycle is typically verified. If verification is successful, voltage tracking is performed based on the acquired grid voltage cycle. If an abnormality is detected in the grid voltage cycle, tracking is stopped.

[0003] Based on this, the inventors of this application considered that the power grid will have a certain amount of harmonics. When the amount of grid harmonics is large, it may cause anomalies in the captured grid voltage cycle. However, the existing technology stops tracking the grid voltage when an anomaly is detected in the grid voltage cycle. In other words, once the amount of grid harmonics is large, the existing technology stops tracking the grid voltage. This approach is obviously not conducive to the implementation of voltage tracking. Summary of the Invention

[0004] The purpose of the present invention is to provide a voltage tracking method, a control device, and a UPS system to solve the technical problem in the prior art that when the amount of grid harmonics is large, grid voltage tracking stops, which is not conducive to grid voltage tracking.

[0005] To achieve the above object, the technical solution adopted by the present invention is to provide a voltage tracking method, which is used to track the grid voltage. The voltage tracking method performs the following steps in each capture cycle:

[0006] Determine a first voltage period based on a target time parameter and a first time parameter acquired in a current capture period; wherein the target time parameter is a time parameter stored in a preset storage space;

[0007] determining whether the first voltage cycle is within a preset range; if the first voltage cycle is within the preset range, performing voltage tracking with the first voltage cycle, replacing a time parameter stored in a preset storage space with the first time parameter, and setting the number of abnormalities to zero if the number is not zero; wherein the number of abnormalities refers to the number of times the first voltage cycle is abnormal;

[0008] If the first voltage cycle is not within the preset range, the number of abnormalities is counted and it is determined whether the number of abnormalities exceeds the preset number; if the number of abnormalities does not exceed the preset number, voltage tracking is performed according to the voltage cycle adopted during voltage tracking in the previous capture cycle; if the number of abnormalities exceeds the preset number, it is determined that the cycle of the grid voltage is abnormal, and voltage tracking of the grid voltage is stopped.

[0009] In a possible implementation, the voltage tracking method further includes: acquiring a first time parameter of a current capture period;

[0010] The obtaining of the first time parameter of the current capture period includes:

[0011] Acquire a square wave signal sent by a target conditioning circuit in a current capture cycle; wherein the target conditioning circuit is used to convert a grid voltage signal into a square wave signal;

[0012] The edge of the square wave signal is captured, and the time parameter corresponding to the edge of the square wave signal is used as the first time parameter of the current capture period.

[0013] In one possible implementation, the edges of the square wave signals captured in each capture period have consistent attributes; and determining the first voltage period based on the target time parameter and the first time parameter obtained in the current capture period includes:

[0014] The difference between the target time parameter and the first time parameter obtained in the current capture period is determined as the first voltage period.

[0015] In a possible implementation, the attributes of the edges of the square wave signals captured in two adjacent capture cycles are inconsistent; and determining the first voltage period based on the target time parameter and the first time parameter obtained in the current capture cycle includes:

[0016] Two times the difference between the target time parameter and the first time parameter acquired in the current capture period is determined as the first voltage period.

[0017] In a possible implementation, the voltage tracking method further includes: determining the preset number of times; the determining the preset number of times includes:

[0018] Obtaining the harmonic content of the grid voltage according to a preset time interval;

[0019] The preset order is determined according to the harmonic amount, and the preset order is positively correlated with the harmonic amount.

[0020] In a possible implementation, determining the preset order according to the harmonic amount includes:

[0021] Obtaining a linear relationship between a pre-calibrated preset order and a harmonic amount;

[0022] The preset order corresponding to the currently acquired harmonic amount is determined according to the linear relationship.

[0023] In a possible implementation, the voltage tracking method further includes: determining the preset number of times; the determining the preset number of times includes:

[0024] Determine the preset time period to which the current moment belongs;

[0025] The preset number of times corresponding to the current moment is determined according to the preset time period to which the current moment belongs.

[0026] In a possible implementation, before determining the preset number of times, the voltage tracking method further includes:

[0027] Obtain the harmonic content of the grid voltage;

[0028] Each day is divided into a plurality of preset time periods according to the magnitude of the harmonic amount, and preset times corresponding to the plurality of preset time periods are determined.

[0029] In another aspect of the present invention, a control device is provided, 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 voltage tracking method described above when executing the computer program.

[0030] In another aspect of the present invention, a UPS system is provided, comprising:

[0031] The control device described above.

[0032] The voltage tracking method, control device, and UPS system provided by the present invention have the following beneficial effects:

[0033] Unlike the prior art method of directly stopping grid voltage tracking when a grid voltage cycle anomaly is detected, the present invention will first count the number of voltage cycle anomalies when it is determined that the first voltage cycle is not within a preset range, rather than directly stopping grid voltage tracking. This method can effectively avoid the impact of grid harmonics on grid voltage tracking and ensure the effective implementation of grid voltage tracking.

[0034] On this basis, when it is determined that the first voltage cycle is not within the preset range, the present invention will continue to use the voltage cycle adopted in the previous capture cycle for voltage tracking to ensure the accuracy of voltage tracking and avoid affecting subsequent circuit control and circuit operation.

[0035] Furthermore, considering the overall solution of the present invention, it can be seen that the present invention updates the target time parameter only when the first voltage cycle is normal, and temporarily does not update the target time parameter when the first voltage cycle is abnormal and the number of abnormalities in the first voltage cycle does not exceed a preset number. In other words, when the first voltage cycle is abnormal and the number of abnormalities in the first voltage cycle does not exceed a preset number, the present invention will determine that harmonics have been detected. In this case, the present invention will choose not to update the target time parameter and will continue to obtain a more accurate first time parameter, thereby obtaining a more accurate grid voltage cycle. From this perspective, the present invention also improves the accuracy of grid voltage tracking. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. 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 paying any creative work.

[0037] Figure 1 A schematic flow chart of a voltage tracking method provided in one embodiment of the present invention;

[0038] Figure 2 A schematic diagram of a square wave corresponding to the grid voltage when harmonics exist in the grid according to an embodiment of the present invention;

[0039] Figure 3 A schematic structural diagram of a control device provided in one embodiment of the present invention. DETAILED DESCRIPTION

[0040] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0041] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0042] Please refer to Figure 1 , Figure 1 This is a flow chart of a voltage tracking method provided by one embodiment of the present invention. This voltage tracking method is used to track grid voltage and is applicable to any scenario requiring grid voltage tracking. For example, in a UPS system, the voltage tracking solution provided by an embodiment of the present invention can be used when the inverter circuit tracks the bypass voltage. The voltage tracking method performs the following steps during each capture cycle:

[0043] S101: Determine a first voltage period based on a target time parameter and a first time parameter acquired during a current capture period, wherein the target time parameter is a time parameter stored in a preset storage space.

[0044] S102: Determine whether the first voltage cycle is within a preset range. If the first voltage cycle is within the preset range, perform voltage tracking using the first voltage cycle, replace the time parameter stored in the preset storage space with the first time parameter, and reset the number of abnormalities to zero if it is not zero. The number of abnormalities refers to the number of abnormalities in the first voltage cycle.

[0045] S103: If the first voltage cycle is not within the preset range, the number of abnormalities is counted and a determination is made as to whether the number of abnormalities exceeds the preset number. If the number of abnormalities does not exceed the preset number, voltage tracking is performed according to the voltage cycle used for voltage tracking in the previous capture cycle. If the number of abnormalities exceeds the preset number, the grid voltage cycle is determined to be abnormal, and grid voltage tracking is stopped.

[0046] In this embodiment, the first voltage cycle is the voltage cycle determined in the current capture cycle. If the first voltage cycle is normal (i.e., within a preset range), voltage tracking can be performed directly using the first voltage cycle. If the first voltage cycle is abnormal (i.e., not within the preset range), voltage tracking is first performed using the normal voltage cycle used in the previous capture cycle.

[0047] An analysis of the solution of the embodiment of the present invention shows that, without considering the situation where the influence of harmonics is present (that is, the determined first voltage period is always normal), the time parameters stored in the preset storage space are essentially the time parameters of the previous capture period. On this basis, the first voltage period is essentially determined based on the time parameters obtained in the current capture period and the time parameters obtained in the previous capture period.

[0048] On this basis, considering the influence of harmonics, if the first voltage cycle is detected to be abnormal and the number of abnormal voltage cycles does not exceed the preset number, the present invention will determine that harmonics may be captured. At this time, the target time parameter will not be updated first. On this basis, if in a subsequent capture cycle, the number of voltage cycle abnormalities does not exceed the number of abnormalities, the determined first voltage cycle becomes normal. At this time, the present invention will determine that the cycle capture process has passed the stage of harmonic influence and captured the normal first voltage cycle. At this time, voltage tracking can be performed based on the normal first voltage cycle. On this basis, the target time parameter can be updated to the first time parameter in the current capture cycle.

[0049] In this embodiment, if the number of abnormal voltage cycles exceeds a preset number, the present invention will determine that the tracked grid voltage itself has an abnormality. At this time, the tracking of the grid voltage can be stopped and an alarm can be issued.

[0050] In this embodiment, tracking the grid voltage may include tracking the frequency of the grid voltage and tracking the phase of the grid voltage.

[0051] As can be seen from the above description, unlike the prior art method of directly stopping tracking the grid voltage when a grid voltage cycle abnormality is detected, the embodiment of the present invention will first count the number of voltage cycle abnormalities when it is determined that the first voltage cycle is not within a preset range, rather than directly stopping tracking the grid voltage. This method can effectively avoid the impact of grid harmonics on grid voltage tracking and ensure the effective implementation of grid voltage tracking.

[0052] On this basis, when it is determined that the first voltage cycle is not within the preset range, the embodiment of the present invention will continue to use the voltage cycle adopted in the previous capture cycle for voltage tracking to ensure the accuracy of voltage tracking and avoid affecting subsequent circuit control and circuit operation.

[0053] Furthermore, considering the overall solution of the embodiment of the present invention, it can be seen that the embodiment of the present invention only updates the target time parameter when the first voltage cycle is normal, and temporarily does not update the target time parameter when the first voltage cycle is abnormal and the number of abnormalities in the first voltage cycle does not exceed a preset number. In other words, when the first voltage cycle is abnormal and the number of abnormalities in the first voltage cycle does not exceed a preset number, the embodiment of the present invention will determine that harmonics have been detected. In this case, the embodiment of the present invention will choose not to update the target time parameter, but will continue to obtain a more accurate first time parameter, thereby obtaining a more accurate grid voltage cycle. From this perspective, the embodiment of the present invention also improves the accuracy of grid voltage tracking.

[0054] In a possible implementation, the voltage tracking method further includes: acquiring a first time parameter of a current capture cycle.

[0055] Get the first time parameters of the current capture cycle, including:

[0056] Acquire the square wave signal sent by the target conditioning circuit during the current capture cycle. The target conditioning circuit is used to convert the grid voltage signal into a square wave signal.

[0057] The edge of the square wave signal is captured, and the time parameter corresponding to the edge of the square wave signal is used as the first time parameter of the current capture cycle.

[0058] In this embodiment, the voltage tracking method may further include a process of obtaining the first time parameter of the current capture cycle. Figure 2When actually obtaining the first time parameter, an ECAP module in a related control device (i.e., the executor of the voltage tracking method provided by an embodiment of the present invention) can capture the square wave edge corresponding to the grid voltage, and the count value of the time reference counter when the ECAP module captures the square wave edge of the grid voltage is used as the first time parameter of the current capture period.

[0059] In this embodiment, it can be combined with Figure 1 and Figure 2 , an analysis of the solution of the embodiment of the present invention shows that the solution of the present invention of "not updating the target time parameter when detecting that the first voltage cycle is abnormal and the number of abnormal voltage cycles does not exceed the preset number" is essentially to calculate the harmonic cycle when determining the first voltage cycle (that is, according to the solution of the embodiment of the present invention, when the first voltage cycle becomes normal under the influence of harmonics, it includes the harmonic cycle). This method can ensure that the accurate grid voltage cycle is obtained, thereby improving the accuracy of grid voltage tracking.

[0060] In one possible implementation, the edges of the square wave signals captured in each capture period have the same attributes. Determining the first voltage period based on the target time parameter and the first time parameter obtained in the current capture period includes:

[0061] The difference between the target time parameter and the first time parameter obtained in the current capture period is determined as the first voltage period.

[0062] In this embodiment, the edge attribute is used to describe whether a certain edge is a rising edge or a falling edge. Based on this, if the edges of the square wave signal captured in each capture cycle are all rising edges, or if the edges of the square wave signal captured in each capture cycle are all falling edges, the difference between the target time parameter and the first time parameter obtained in the current capture cycle can be directly determined as the first voltage period.

[0063] That is, in this embodiment, when the attributes of the edges of the square wave signals captured in each capture period are consistent, the difference between the time parameters in two adjacent capture periods is essentially one grid voltage period.

[0064] In one possible implementation, the edges of the square wave signals captured in two adjacent capture cycles have different attributes. Determining the first voltage cycle based on the target time parameter and the first time parameter obtained in the current capture cycle includes:

[0065] Two times the difference between the target time parameter and the first time parameter acquired in the current capture period is determined as the first voltage period.

[0066] In this embodiment, the edge attribute is used to describe whether a certain edge is a rising edge or a falling edge. Based on this, if the edge of the square wave signal captured in the previous capture cycle is a rising edge and the edge of the square wave signal captured in the current capture cycle is a falling edge, then twice the difference between the target time parameter and the first time parameter obtained in the current capture cycle is determined as the first voltage cycle. Alternatively, if the edge of the square wave signal captured in the previous capture cycle is a falling edge and the edge of the square wave signal captured in the current capture cycle is a rising edge, then twice the difference between the target time parameter and the first time parameter obtained in the current capture cycle is also determined as the first voltage cycle.

[0067] That is, in this embodiment, when the attributes of the edges of the square wave signals captured in two adjacent capture periods are inconsistent, the difference between the time parameters in the two adjacent capture periods is essentially half a grid voltage period.

[0068] In a possible implementation, the voltage tracking method further includes: determining a preset number of times. Determining the preset number of times includes:

[0069] The harmonic content of the grid voltage is obtained at preset time intervals.

[0070] The preset order is determined according to the harmonic amount, and the preset order is positively correlated with the harmonic amount.

[0071] In this embodiment, the greater the harmonic content of the grid voltage, the greater the number of abnormalities in the first voltage cycle may be in order to obtain a more accurate grid voltage cycle. Therefore, this embodiment may also obtain the harmonic content of the grid voltage according to a preset time interval and determine the preset number based on the harmonic content of the grid voltage. In other words, the preset number may be adjusted according to the preset time interval to ensure the accuracy of grid voltage tracking.

[0072] In this embodiment, the preset order is positively correlated with the harmonic amount, that is, the greater the harmonic amount, the greater the preset order.

[0073] In a possible implementation, determining the preset order according to the harmonic amount includes:

[0074] A linear relationship between a pre-calibrated preset order and the harmonic amount is obtained.

[0075] The preset order corresponding to the currently acquired harmonic amount is determined according to the linear relationship.

[0076] In this embodiment, the linear relationship between the preset order and the harmonic amount can be pre-calibrated. When the preset order needs to be determined, the preset order corresponding to the currently acquired harmonic amount is determined based on the currently acquired harmonic amount and the preset calibrated linear relationship.

[0077] In a possible implementation, the voltage tracking method further includes: determining a preset number of times. Determining the preset number of times includes:

[0078] Determine the preset time period to which the current moment belongs.

[0079] The preset number of times corresponding to the current moment is determined according to the preset time period to which the current moment belongs.

[0080] In a possible implementation, before determining the preset number of times, the voltage tracking method further includes:

[0081] Get the harmonic content of the grid voltage.

[0082] Each day is divided into a plurality of preset time periods according to the magnitude of the harmonic amount, and the preset times corresponding to the plurality of preset time periods are determined.

[0083] In this embodiment, the harmonic content of the grid voltage exhibits spatiotemporal characteristics in some application scenarios. For example, in certain production areas, each nonlinear device has a specific operating period. During the operating period, the connection of each nonlinear device to the grid causes a significant increase in the harmonic content. However, during the non-operating period, the connection of each nonlinear device decreases, resulting in a decrease in the harmonic content. Therefore, in this embodiment, a day can be pre-divided into multiple time periods based on the harmonic content of the grid voltage in each time period, with each time period assigned a preset number. When determining the preset number during subsequent grid voltage tracking, the preset number corresponding to the current moment can be determined based on the preset time period to which the current moment belongs. In other words, if the current moment belongs to a preset time period, the preset number corresponding to that preset time period is the same as the preset number corresponding to the current moment. This method can effectively ensure the accuracy of grid voltage tracking.

[0084] Another aspect of the present invention is to refer to Figure 3, further provides a control device 300, comprising: one or more processors 301, one or more input devices 302, one or more output devices 303, and one or more memories 304. The processors 301, input devices 302, output devices 303, and memories 304 communicate with each other via a communication bus 305. The memory 304 is used to store computer programs, which include program instructions. The processor 301 is used to execute the program instructions stored in the memory 304. The processor 301 is configured to call the program instructions to execute the steps of the above-mentioned method embodiments. It should be understood that in the embodiments of the present invention, the processor 301 may be a central processing unit (CPU). The processor may also be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor, or the processor may also be any conventional processor, etc. The input device 302 may include a touchpad, a fingerprint sensor (for collecting the user's fingerprint information and fingerprint direction information), a microphone, etc., and the output device 303 may include a display (LCD, etc.), a speaker, etc. The memory 304 may include a read-only memory and a random access memory, and provides instructions and data to the processor 301. A portion of the memory 304 may also include a non-volatile random access memory. For example, the memory 304 may also store information about the device type. In a specific implementation, the processor 301, the input device 302, and the output device 303 described in the embodiment of the present invention may execute the implementation described in the first embodiment and the second embodiment of the voltage tracking method provided in the embodiment of the present invention.

[0085] In another aspect of the present invention, a UPS system is provided, comprising:

[0086] The control device described above.

[0087] In this embodiment, the grid voltage tracking method described in the above embodiment can be used for the inverter circuit to track the bypass voltage. On this basis, the control device described in the above embodiment can be a control device in the inverter circuit, which is used to enable the inverter circuit to track the bypass voltage frequency and phase (that is, track the frequency and phase of the grid voltage).

[0088] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and such modifications or substitutions are intended to be within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of protection of the claims.

Claims

1. A voltage tracking method, characterized in that: The voltage tracking method is used to track the grid voltage. The voltage tracking method performs the following steps in each capture cycle: Determine a first voltage period based on a target time parameter and a first time parameter acquired in a current capture period; wherein the target time parameter is a time parameter stored in a preset storage space; determining whether the first voltage cycle is within a preset range; if the first voltage cycle is within the preset range, performing voltage tracking with the first voltage cycle, replacing a time parameter stored in a preset storage space with the first time parameter, and setting the number of abnormalities to zero if the number is not zero; wherein the number of abnormalities refers to the number of times the first voltage cycle is abnormal; If the first voltage cycle is not within the preset range, the number of abnormalities is counted and it is determined whether the number of abnormalities exceeds the preset number; if the number of abnormalities does not exceed the preset number, it is determined that harmonics are detected, and voltage tracking is performed according to the voltage cycle used in voltage tracking in the previous capture cycle; if the number of abnormalities exceeds the preset number, it is determined that the cycle of the grid voltage is abnormal, and voltage tracking of the grid voltage is stopped.

2. The voltage tracking method according to claim 1, wherein: The voltage tracking method further includes: acquiring a first time parameter of a current capture cycle; The obtaining of the first time parameter of the current capture period includes: Acquire a square wave signal sent by a target conditioning circuit in a current capture cycle; wherein the target conditioning circuit is used to convert a grid voltage signal into a square wave signal; The edge of the square wave signal is captured, and the time parameter corresponding to the edge of the square wave signal is used as the first time parameter of the current capture period.

3. The voltage tracking method according to claim 2, wherein: The edge properties of the square wave signal captured in each capture cycle are consistent; The determining the first voltage period based on the target time parameter and the first time parameter obtained in the current capture period includes: The difference between the target time parameter and the first time parameter obtained in the current capture period is determined as the first voltage period.

4. The voltage tracking method according to claim 2, wherein: The edge properties of the square wave signal captured in each two adjacent capture cycles are inconsistent; The determining the first voltage period based on the target time parameter and the first time parameter obtained in the current capture period includes: Two times the difference between the target time parameter and the first time parameter acquired in the current capture period is determined as the first voltage period.

5. The voltage tracking method according to any one of claims 1 to 4, characterized in that: The voltage tracking method further includes: determining the preset number of times; the determining the preset number of times includes: Obtaining the harmonic content of the grid voltage according to a preset time interval; The preset order is determined according to the harmonic amount, and the preset order is positively correlated with the harmonic amount.

6. The voltage tracking method according to claim 5, wherein: Determining the preset order according to the harmonic amount includes: Obtaining a linear relationship between a pre-calibrated preset order and a harmonic amount; The preset order corresponding to the currently acquired harmonic amount is determined according to the linear relationship.

7. The voltage tracking method according to any one of claims 1 to 4, characterized in that: The voltage tracking method further includes: determining the preset number of times; the determining the preset number of times includes: Determine the preset time period to which the current moment belongs; The preset number of times corresponding to the current moment is determined according to the preset time period to which the current moment belongs.

8. The voltage tracking method according to claim 7, wherein: Before determining the preset number of times, the voltage tracking method further includes: Obtain the harmonic content of the grid voltage; Each day is divided into a plurality of preset time periods according to the magnitude of the harmonic amount, and preset times corresponding to the plurality of preset time periods are determined.

9. A control device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 8 are implemented.

10. A UPS system, characterized in that: include: The control device according to claim 9.

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