Bypass state detection method and apparatus, and uninterruptible power supply

Abstract

The bypass state detection method, device and uninterruptible power supply are disclosed. The bypass state detection method comprises the following steps: determining that a bypass voltage meets a detection condition; generating a bypass driving pulse at a detection time; sampling a bypass current; and judging a state of the bypass based on the bypass current.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power systems, in particular to a bypass state detection method and device and an uninterruptible power supply. BACKGROUND

[0002] An uninterruptible power supply (UPS) is a power supply containing an energy storage device, mainly used to provide uninterrupted power supply for devices with high requirements for power supply stability. When the mains (i.e. power frequency alternating current) input is normal, the UPS supplies the mains after voltage stabilization to the load, and at the same time, the UPS also charges the battery in the machine. When the mains is interrupted (for example, accidental power failure), the UPS immediately switches and converts the direct current power of the battery to continue to supply the same alternating current as the mains to the load, so that the load maintains normal operation, thereby protecting the software / hardware of the load from damage.

[0003] The UPS is provided with a main path and a bypass. Among them, the UPS normally operates in the mains state, that is, it is powered by the main path. When the mains and the main path cannot supply power, the UPS operates in the bypass state and supplies power to the load by the bypass to perform the last power protection for the load. However, since the bypass is not running at ordinary times, if the bypass exception is not detected in time and effectively, the bypass cannot be used when it is needed, causing the load to lose power. SUMMARY

[0004] Therefore, the embodiments of the present application provide a bypass state detection method and device and an uninterruptible power supply, which can detect bypass exceptions in time and effectively and ensure the power supply safety of the load.

[0005] The technical scheme of the embodiments of the present application is as follows:

[0006] The bypass state detection method provided by the embodiments of the present application is applied to an uninterruptible power supply and includes the following steps: determining that a bypass voltage meets a detection condition; generating a bypass drive pulse at a detection time, wherein the bypass drive pulse is used to turn on the bypass; sampling a bypass current; and judging the state of the bypass based on the bypass current.

[0007] In the above scheme, the detection condition includes that the bypass voltage is in phase with an inverter voltage.

[0008] In the above scheme, the detection condition further includes that the difference between the bypass voltage and the inverter voltage is greater than a voltage difference threshold.

[0009] In the above scheme, the bypass drive pulse is used to turn on a controllable switch of the bypass to turn on the bypass.

[0010] In the above scheme, sampling the bypass current includes: sampling the bypass current until the bypass voltage crosses zero.

[0011] In the above scheme, the detection time includes: a first time and / or a second time; wherein, the first time is located in the positive phase region of the bypass voltage; and the second time is located in the negative phase region of the bypass voltage.

[0012] In the above scheme, the first moment is the time period between the positive phase maximum value of the bypass voltage and zero; the second moment is the time period between the negative phase maximum value of the bypass voltage and zero.

[0013] In the above scheme, determining the state of the bypass based on the bypass current includes: if the bypass current is greater than a first current threshold, then determining that the state of the bypass is normal; and / or, if the bypass current is less than a second current threshold, then determining that the state of the bypass is abnormal; wherein, the first current threshold is greater than or equal to the second current threshold.

[0014] This application embodiment also provides a bypass state detection device, including: a determination module configured to determine that the bypass voltage meets the detection conditions; a driving module configured to generate a bypass driving pulse at the detection time, wherein the bypass driving pulse is used to turn on the bypass; a sampling module configured to sample the bypass current; and a judgment module configured to judge the state of the bypass based on the bypass current.

[0015] This application also provides an uninterruptible power supply, including: the bypass status detection device described in the above solution.

[0016] Therefore, the embodiments of this application can detect bypass anomalies in a timely and effective manner, thereby enabling timely maintenance and repair of the bypass. This avoids power outages caused by bypass anomalies and ensures the safety of the load's power supply. Attached Figure Description

[0017] Figure 1 A schematic diagram of an optional structure of the uninterruptible power supply provided in an embodiment of this application;

[0018] Figure 2 A schematic diagram of an optional implementation flow of the bypass state detection method provided in the embodiments of this application;

[0019] Figure 3 A schematic diagram of an optional waveform for the bypass state detection method provided in the embodiments of this application;

[0020] Figure 4 This is a schematic diagram of an optional structure of the bypass status detection device provided in an embodiment of this application. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application are further described in detail below with reference to the accompanying drawings and embodiments. The described embodiments should not be regarded as limitations on this application. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0022] In the following description, references to "some embodiments" refer to a subset of all possible embodiments. It is understood that "some embodiments" may be the same or different subsets of all possible embodiments and may be combined with each other without conflict. The terms "first / second / third" are used merely to distinguish similar objects and do not represent a specific ordering of objects. It is understood that "first / second / third" may be interchanged in a specific order or sequence where permitted, so that the embodiments of this application described herein can be implemented in an order other than that illustrated or described herein.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. The terminology used herein is for descriptive purposes only and is not intended to limit the scope of this application.

[0024] Figure 1 This is a schematic diagram of an optional structure of the UPS in the embodiments of this application, which will be combined with Figure 1 Please provide an explanation.

[0025] refer to Figure 1 If the voltage and frequency of the AC power (mains power) input to the UPS are within the allowable range, the UPS is in normal operating mode. In normal operating mode, the AC power input to the UPS is converted to DC power by a rectifier; the converted DC power then charges the battery. Simultaneously, the DC power is converted back to AC power by an inverter for output. In other words, in normal operating mode, the AC power input to the UPS, after conversion by the rectifier and inverter, supplies power to the load (i.e., AC output) and simultaneously charges the battery.

[0026] Continue to refer to Figure 1 If the voltage or frequency of the AC input to the main circuit becomes abnormal, the UPS will enter stored energy mode of operation. In this mode, the battery provides DC power, which is converted to AC power by the inverter and then output. In other words, in this mode, the battery supplies power to the load through the inverter.

[0027] Continue to refer to Figure 1 If the voltage or frequency of the AC power input to the main circuit becomes abnormal and the battery cannot provide power, the UPS will enter bypass mode of operation. In bypass mode, the AC power input to the bypass circuit supplies power to the load via the bypass circuit.

[0028] Figure 2 This is a schematic diagram illustrating the implementation process of a bypass state detection method provided in an embodiment of this application, as shown below. Figure 2 As shown, the method includes steps S101 to S104.

[0029] S101. Confirm that the bypass voltage meets the detection conditions.

[0030] In this embodiment, the bypass status can be detected even when the bypass is not running, i.e., when the UPS is not in bypass mode. This detection can be performed periodically, with the period set to daily or weekly.

[0031] In this embodiment of the application, before detecting the bypass state, it is necessary to first determine whether the bypass voltage meets the detection conditions. The bypass voltage and the inverter voltage can be compared to determine whether the bypass voltage meets the detection conditions.

[0032] Among them, reference Figure 1 The bypass voltage is the AC voltage input to the bypass, which can be sampled at the input terminal of the bypass; while the inverter voltage is the AC voltage output by the inverter, which can be sampled at the output terminal of the inverter.

[0033] In some embodiments of this application, the detection conditions include: the bypass voltage and the inverter voltage are in phase.

[0034] It should be noted that in most cases, the phase of the bypass voltage is the same as the phase of the inverter voltage. Since the bypass state detection method provided in this application requires the bypass to be turned on during UPS operation, if the phase of the bypass voltage is different from the phase of the inverter voltage, it may cause significant voltage fluctuations after being turned on, affecting the load power supply. Therefore, ensuring that the bypass voltage and inverter voltage are in phase helps to avoid voltage fluctuations and ensure the stability of the load power supply.

[0035] In some embodiments of this application, the detection condition further includes: the difference between the bypass voltage and the inverter voltage is greater than a voltage difference threshold. For example, if the effective value of the inverter voltage is 220V, then the effective value of the bypass voltage needs to reach 225-235V, that is, the difference between the bypass voltage and the inverter voltage needs to be greater than 5V.

[0036] It should be noted that, since the bypass state detection method provided in this application requires sampling the bypass current after the bypass is turned on, if the difference between the bypass voltage and the inverter voltage is too small, the voltage difference across the bypass will be too small, making it difficult to form an effective bypass current. Therefore, determining that the difference between the bypass voltage and the inverter voltage is greater than the voltage difference threshold is beneficial for forming a bypass current that can be sampled, thus ensuring the accuracy of the detection.

[0037] Figure 3 This is a waveform diagram provided for an embodiment of this application. (Reference) Figure 3 Bypass voltage ( Figure 3 The sine wave drawn with a solid line in the middle) and the inverter voltage ( Figure 3 The sine waveform drawn by the dashed line is in phase, and the bypass voltage and the inverter voltage have a certain voltage difference, that is, the bypass voltage meets the above detection conditions.

[0038] S102. At the detection time, a bypass drive pulse is generated.

[0039] In this embodiment of the application, after determining that the bypass voltage meets the detection conditions, a bypass drive pulse can be generated. The bypass drive pulse is used to activate the bypass.

[0040] In some embodiments of this application, a bypass drive pulse is used to turn on the controllable switch of the bypass, thereby enabling the bypass to conduct. The controllable switch may be an SCR (Silicon Controlled Rectifier) ​​in the bypass.

[0041] In some embodiments of this application, reference is made to Figure 3 The detection times include: a first time t1 and / or a second time t2. The first time t1 is located in the positive phase region of the bypass voltage, and the second time t2 is located in the negative phase region of the bypass voltage.

[0042] It is understandable that using the first time t1 and / or the second time t2 as the detection time can assess the bypass state when the bypass voltage is in the positive phase region and / or negative phase region, thereby making the detection results more comprehensive and accurate.

[0043] S103. Sample the bypass current.

[0044] In this embodiment of the application, after the bypass driving pulse turns on the bypass, a bypass current is generated in the bypass, and the bypass current can be sampled.

[0045] In some embodiments of this application, the bypass current is sampled until the bypass voltage crosses zero. That is, the cutoff time for sampling the bypass current is set to the zero point of the bypass voltage.

[0046] Understandably, reference Figure 3 When the bypass voltage reaches zero, the inverter voltage also reaches zero. At this point, the difference between the bypass voltage and the inverter voltage is 0, and there is no voltage difference across the bypass terminals. Consequently, the sampled bypass current is also zero. Simultaneously, when the bypass voltage reaches zero, the controllable switch of the bypass will be completely turned off. Therefore, the cutoff time for sampling the bypass current is set to the zero point of the bypass voltage. This avoids invalid sampling and prevents interference with the detection results.

[0047] In some embodiments of this application, reference is made to Figure 3 The first time point t1 is the period between the positive phase maximum value of the bypass voltage and zero; the second time point t2 is the period between the negative phase maximum value of the bypass voltage and zero.

[0048] It is understandable that the sampling cutoff time for the bypass current is the zero point of the bypass voltage. Therefore, setting the first time t1 to the period between the positive phase maximum value of the bypass voltage and the zero point, and setting the second time t2 to the period between the negative phase maximum value of the bypass voltage and the zero point, can shorten the current sampling time, improve sampling efficiency, and at the same time avoid the impact of prolonged bypass conduction on the load.

[0049] S104. Determine the status of the bypass based on the bypass current.

[0050] In this embodiment, the waveform and magnitude of the sampled bypass current can be used to determine whether the bypass is functioning correctly. Furthermore, if the bypass is determined to be abnormal, it needs to be inspected to determine if the bypass drive or bypass SCR is functioning correctly.

[0051] In some embodiments of this application, if the bypass current is greater than a first current threshold, the bypass state is determined to be normal; and / or, if the bypass current is less than a second current threshold, the bypass state is determined to be abnormal. Wherein, the first current threshold is greater than or equal to the second current threshold.

[0052] In this embodiment, if the bypass current is greater than the first current threshold, it indicates that the bypass can conduct normally. Conversely, if the bypass current is less than the second current threshold, it indicates that the bypass conduction is abnormal (open circuit).

[0053] In some embodiments, the first current threshold and the second current threshold can be set to the same value. In other embodiments, the first current threshold is set to be larger than the second current threshold, so that if the bypass current is between the first current threshold and the second current threshold, the bypass can be detected again to confirm the bypass status.

[0054] It is understood that the embodiments of this application can detect bypass anomalies in a timely and effective manner, thereby enabling timely maintenance and repair of the bypass. This avoids power outages to the load caused by bypass anomalies and ensures the safety of the load's power supply.

[0055] Figure 4 This is a schematic diagram of the composition structure of a bypass state detection device provided in an embodiment of this application, as shown below. Figure 4 As shown, the bypass status detection device 200 includes: a determination module 210, a drive module 220, a sampling module 230, and a judgment module 240.

[0056] The determination module 210 is configured to determine whether the bypass voltage meets the detection conditions. The driving module 220 is configured to generate a bypass driving pulse at the detection time; wherein the bypass driving pulse is used to turn on the bypass. The sampling module 230 is configured to sample the bypass current. The judgment module 240 is configured to determine the state of the bypass based on the bypass current.

[0057] In some embodiments of this application, the detection conditions include: the bypass voltage and the inverter voltage are in phase.

[0058] In some embodiments of this application, the detection condition further includes: the difference between the bypass voltage and the inverter voltage is greater than a voltage difference threshold.

[0059] In some embodiments of this application, a bypass drive pulse is used to turn on the controllable switch of the bypass, thereby enabling the bypass to conduct.

[0060] In some embodiments of this application, the sampling module 230 is also configured to sample the bypass current until the bypass voltage crosses zero.

[0061] In some embodiments of this application, the detection time includes a first time and / or a second time. The first time is located in the positive phase region of the bypass voltage; the second time is located in the negative phase region of the bypass voltage.

[0062] In some embodiments of this application, the first moment is the time period between the positive phase maximum value of the bypass voltage and zero; the second moment is the time period between the negative phase maximum value of the bypass voltage and zero.

[0063] In some embodiments of this application, the determination module 240 is further configured to determine that the bypass state is normal if the bypass current is greater than a first current threshold; and / or, determine that the bypass state is abnormal if the bypass current is less than a second current threshold. Wherein, the first current threshold is greater than or equal to the second current threshold.

[0064] This application also provides an uninterruptible power supply (UPS), which includes the bypass status detection device 200 described in the above embodiments. Therefore, bypass anomalies in the UPS can be detected promptly and effectively.

[0065] It should be understood that the phrase "one embodiment" or "an embodiment" throughout the specification means that a specific feature, structure, or characteristic related to the embodiment is included in at least one embodiment of this application. Therefore, "in one embodiment" or "in an embodiment" appearing throughout the specification does not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. It should be understood that in the various embodiments of this application, the sequence numbers of the above steps / processes do not imply a sequential order of execution; the execution order of each step / process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application. The sequence numbers of the above embodiments of this application are merely descriptive and do not represent the superiority or inferiority of the embodiments.

[0066] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0067] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods, such as: multiple units or components can be combined, or integrated into another system, or some features can be ignored or not executed. In addition, the coupling, direct coupling, or communication connection between the various components shown or discussed can be through some interfaces, and the indirect coupling or communication connection between devices or units can be electrical, mechanical, or other forms.

[0068] The units described above as separate components may or may not be physically separate. The components shown as units may or may not be physical units. They may be located in one place or distributed across multiple network units. Some or all of the units may be selected to achieve the purpose of this embodiment according to actual needs.

[0069] Furthermore, in the various embodiments of this application, all functional units can be integrated into one processing unit, or each unit can be a separate unit, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or in a combination of hardware and software functional units. Those skilled in the art will understand that all or part of the steps of the above method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it performs the steps of the above method embodiments. The aforementioned storage medium includes various media capable of storing program code, such as mobile storage devices, read-only memory (ROM), magnetic disks, or optical disks.

[0070] Alternatively, if the integrated units described above are implemented as software functional modules and sold or used as independent products, they can also be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence or the part that contributes to related technologies, can be embodied in the form of a software product. This computer software product is stored in a storage medium, including instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as mobile storage devices, ROM, magnetic disks, or optical disks.

[0071] The above description is merely an embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

Claims

1. A bypass status detection method, applied to uninterruptible power supplies, characterized in that, include: Confirm that the bypass voltage meets the testing conditions; The detection conditions include: the bypass voltage and the inverter voltage are in phase; At the detection time, a bypass drive pulse is generated; wherein the bypass drive pulse is used to turn on the bypass; the detection time includes: a first time and / or a second time; wherein the first time is located in the positive phase region of the bypass voltage, and the second time is located in the negative phase region of the bypass voltage; The bypass current is sampled until the bypass voltage crosses zero; Based on the bypass current, the state of the bypass is determined; wherein, if the bypass current is greater than a first current threshold, the state of the bypass is determined to be normal; and / or, if the bypass current is less than a second current threshold, the state of the bypass is determined to be abnormal; wherein, the first current threshold is greater than or equal to the second current threshold.

2. The bypass state detection method according to claim 1, characterized in that, The detection conditions also include: the difference between the bypass voltage and the inverter voltage is greater than the voltage difference threshold.

3. The bypass state detection method according to claim 1, characterized in that, The bypass drive pulse is used to turn on the controllable switch of the bypass, thereby enabling the bypass to conduct.

4. The bypass state detection method according to claim 1, characterized in that, The first moment is the time period between the positive in-phase maximum value of the bypass voltage and its zero point; The second moment is the period between the negative phase maximum value of the bypass voltage and zero.

5. A bypass status detection device, characterized in that, include: The determination module is configured to determine whether the bypass voltage meets the detection conditions; The detection conditions include: the bypass voltage and the inverter voltage are in phase; The driving module is configured to generate a bypass driving pulse at a detection time; wherein the bypass driving pulse is used to enable bypass conduction; the detection time includes: a first time and / or a second time; wherein the first time is located in the positive phase region of the bypass voltage, and the second time is located in the negative phase region of the bypass voltage; The sampling module is configured to sample the bypass current until the bypass voltage crosses zero; The judgment module is configured to determine the state of the bypass based on the bypass current; wherein, if the bypass current is greater than a first current threshold, the state of the bypass is determined to be normal; and / or, if the bypass current is less than a second current threshold, the state of the bypass is determined to be abnormal; wherein, the first current threshold is greater than or equal to the second current threshold.

6. An uninterruptible power supply, characterized in that, include: The bypass status detection device according to claim 5.

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