Relay Adhesion Detection Method, Control Device, UPS

Abstract

The present invention provides a method for detecting relay adhesion, a control device, and a UPS. The relay in this method refers to the relay in the UPS that is used to conduct the inverter output side of the power module. The method for detecting relay adhesion includes: after the UPS is powered on, during the process of tracking the phase of the UPS input voltage in the bypass of the UPS, when it is detected that the phase of the UPS input voltage is at a preset phase, controlling the bypass switch of the UPS to conduct at a preset conduction angular velocity; obtaining the inverter output parameters of the UPS during the conduction process of the bypass switch, and judging whether the relay is adhered based on the inverter output parameters. The present invention can simply and quickly judge the adhesion situation of the relay, and has a relatively low cost.

Description

Technical Field

[0001] The present invention belongs to the field of circuit technology, and more specifically, relates to a method for detecting relay adhesion, a control device, and a UPS. Background Art

[0002] For a UPS (Uninterruptible Power System), after the system is powered on, the power module usually needs to wait for the rectifier to start working and complete before it can perform inverter output, which takes a long time. Therefore, before powering on, the system first performs bypass output after powering on. At this time, if the inverter output relay of the power module sticks, it will cause current to flow back from the inverter to the power module bus, generating a large current and leading to a blown machine. Therefore, it is particularly necessary to detect the adhesion state of the inverter output relay.

[0003] In the prior art, an additional detection circuit is usually set up to detect the adhesion of the aforementioned relay. However, this method has a high cost and is not very convenient. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for detecting relay adhesion, a control device, and a UPS, so as to solve the technical problems of inconvenient and costly relay adhesion detection in the prior art.

[0005] To achieve the above object, the technical solution adopted by the present invention is to provide a method for detecting relay adhesion. The relay refers to a relay used to conduct the inverter output side of the power module in the UPS. The method for detecting relay adhesion includes:

[0006] After the UPS is powered on, during the process of tracking the phase of the UPS input voltage in the bypass of the UPS, when it is detected that the phase of the UPS input voltage is at a preset phase, control the bypass switch of the UPS to conduct at a preset conduction angular velocity;

[0007] Obtain the inverter output parameters of the UPS during the conduction process of the bypass switch, and judge whether the relay is adhered based on the inverter output parameters.

[0008] In a possible implementation manner, the range of the preset phase is (180° - e1, 180° + e2) or (360° - e3, 360° + e4);

[0009] Wherein, e1, e2, e3, and e4 are all preset error values.

[0010] In a possible implementation manner, the judging whether the relay is adhered based on the inverter output parameters includes:

[0011] Determine whether the inverter output parameter is greater than a preset parameter value;

[0012] If the inverter output parameter is greater than the preset parameter value, determine that the relay is stuck;

[0013] If the inverter output parameter is not greater than the preset parameter value, determine that the relay is not stuck;

[0014] Wherein, the preset parameter value is positively correlated with the input voltage of the UPS.

[0015] In a possible implementation, the method for determining the preset parameter value is:

[0016] Obtain the acquisition moment of the inverter output parameter;

[0017] Obtain the input voltage of the UPS and the conduction angle of the bypass switch at the acquisition moment;

[0018] Determine the theoretical output parameter of the bypass according to the input voltage and the conduction angle;

[0019] Determine the preset parameter value based on the theoretical output parameter and a preset proportional value.

[0020] In a possible implementation, the inverter output parameter is the inverter output current or the inverter output voltage, the theoretical output parameter is the theoretical output voltage or the theoretical output current corresponding to the inverter output parameter, and the preset parameter value is the preset current value or the preset voltage value corresponding to the inverter output parameter;

[0021] When the inverter output parameter is the inverter output voltage, the method for determining the preset voltage value is: U thd =U sd ×k1, where U thd is the preset voltage value, k1 is the preset proportional value when the inverter output parameter is the inverter output voltage, and U sd is the theoretical output voltage;

[0022] When the inverter output parameter is the inverter output current, the method for determining the preset current value is: I thd =I sd ×k2 + I e where I thd is the preset current value, k2 is the preset proportional value when the inverter output parameter is the inverter output current, I sd is the theoretical output current, and I e is a current value positively correlated with the capacitance of the capacitor in the power module.

[0023] In a possible implementation, obtaining the inverter output parameters of the UPS during the conduction of the bypass switch includes:

[0024] Obtaining at least two inverter output parameters of the UPS during the conduction of the bypass switch.

[0025] In a possible implementation, determining whether the relay is stuck based on the inverter output parameters includes:

[0026] Determining the growth rate of the inverter output parameters according to the at least two inverter output parameters;

[0027] If the growth rate is greater than a preset rate, it is determined that the relay is stuck;

[0028] If the growth rate is not greater than the preset rate, it is determined that the relay is not stuck;

[0029] Wherein, the preset rate is positively correlated with the conduction angular velocity.

[0030] In a possible implementation, the relay stuck detection method further includes:

[0031] Detecting whether there is a charging current in the battery of the UPS;

[0032] If there is a charging current in the battery, it is determined that the relay is stuck.

[0033] On the other hand, the present invention also provides a control device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the relay stuck detection method described above are implemented.

[0034] On yet another aspect, the present invention also provides a UPS, including:

[0035] The control device described above.

[0036] The beneficial effects of the relay stuck detection method, control device, and UPS provided by the present invention are as follows:

[0037] First, the present invention creatively proposes a relay adhesion detection scheme based on bypass switch control. On this basis, the present invention can be directly implemented based on the existing data acquisition devices and control devices of the UPS without additional detection devices, thus effectively reducing the cost of relay adhesion detection. Moreover, the present invention can perform adhesion judgment according to the inverter output parameters during the conduction process of the bypass switch, without collecting data for several cycles for calculation, so it is also more convenient. That is to say, the present invention overcomes the problems in the prior art, effectively reduces the detection cost, improves the detection efficiency, and can effectively ensure the safe operation of the UPS. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the following-described drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0039] Figure 1 is a schematic flowchart of a relay adhesion detection method provided by an embodiment of the present invention;

[0040] Figure 2 is a schematic diagram of an application scenario of relay adhesion detection provided by an embodiment of the present invention;

[0041] Figure 3 is a schematic structural diagram of a control device provided by an embodiment of the present invention;

[0042] Figure 4 is a schematic diagram of the starting point of bypass switch opening provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0043] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the following further details the present invention in conjunction with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0044] The following further details the present invention in conjunction with the drawings and specific embodiments.

[0045] Please refer to Figure 1 and Figure 2 , Figure 1 which is a schematic flowchart of a relay adhesion detection method provided by an embodiment of the present invention, Figure 2 and is a schematic diagram of an application scenario of relay adhesion detection provided by an embodiment of the present invention (it should be noted here that Figure 2Taking a modular UPS as an example, a group of rectifiers + inverters form a power module of the UPS. In actual implementation, non-modular UPSs are also applicable to the present invention. In the present invention, the relay in the relay adhesion method refers to the relay in the UPS that conducts the inverter output side of the power module (i.e., Figure 2 the relay in

[0046] S101: After the UPS is powered on, during the process of the UPS bypass tracking the phase of the input voltage, when it is detected that the phase of the UPS input voltage is at the preset phase, control the bypass switch of the UPS to conduct at the preset conduction angular velocity.

[0047] S102: Obtain the inverter output parameters of the UPS during the conduction process of the bypass switch, and determine whether the relay is stuck based on the inverter output parameters.

[0048] After the system is powered on, the power module usually needs the rectifier to complete the startup before it can perform inverter output, which takes a long time. Therefore, before powering on, the system first performs bypass output after powering on. On this basis, it is usually necessary to control the bypass of the UPS to track the phase of the UPS input voltage. During this phase tracking process, the embodiments of the present invention can detect the phase of the UPS input voltage. When it is detected that the phase of the UPS input voltage reaches the preset phase, the bypass switch is controlled to slowly open in a way of gradually increasing the conduction angle. During the opening process of this bypass switch, the embodiments of the present invention can determine whether the relay on the inverter output side is stuck by detecting the inverter output parameters of the power module in the UPS.

[0049] In this embodiment, determining whether the relay is stuck based on the inverter output parameters can be detailed as determining whether the relay is stuck based on the inverter output parameters and the preset parameter values corresponding to the inverter output parameters. Among them, the preset parameter values are related to the UPS input voltage and the conduction angular velocity.

[0050] In this embodiment, if it is detected that the relay is not stuck, the conduction state of the bypass switch can be maintained. If it is detected that the relay is stuck, the bypass switch can be turned off to prohibit bypass output, thereby ensuring the safe operation of the UPS.

[0051] In a possible implementation, the range of the preset phase is (180° - e1, 180° + e2) or (360° - e3, 360° + e4).

[0052] Wherein, e1, e2, e3, and e4 are all preset error values, and each error value can be equal or unequal, and no limitation is made here.

[0053] In this embodiment, to facilitate the phase synchronization between the bypass voltage and the UPS input voltage, the bypass switch can be turned on near the zero-crossing point of the UPS input voltage (i.e., near phase 180° or 360°). Here, reference can be made to Figure 4 ( Figure 4 the input voltage mentioned in

[0054] Figure 4 is the input voltage of the UPS), and the bypass switch can be directly turned on at phase 180° or phase 360°.

[0055] Optionally, for the convenience of subsequent detection, when the phase of the UPS input voltage corresponding to the turn-on of the bypass switch is 180°, the inverter output parameters can be detected at 270° for relay adhesion detection. When the phase of the UPS input voltage corresponding to the turn-on of the bypass switch is 360°, the inverter output parameters can be detected at 90° for relay adhesion detection.

[0056] In a possible implementation, determining whether the relay is adhered based on the inverter output parameters includes:

[0057] Judging whether the inverter output parameters are greater than a preset parameter value.

[0058] If the inverter output parameters are greater than the preset parameter value, it is determined that the relay is adhered.

[0059] If the inverter output parameters are not greater than the preset parameter value, it is determined that the relay is not adhered.

[0060] In this embodiment, during the process of gradually increasing the conduction angle, the instantaneous voltage peak value of the bypass output will gradually increase. At this time, if the inverter output parameters exceed the preset parameter value, it indicates that the relay is adhered and the current has started to backfeed from the inverter. Correspondingly, if the inverter output parameters are not greater than the preset parameter value, it is determined that the relay is not adhered.

[0061] In a possible implementation, the method for determining the preset parameter value is:

[0062] Obtain the acquisition moment of the inverter output parameters.

[0063] Obtain the UPS input voltage and the conduction angle of the bypass switch at the acquisition moment.

[0064] Determine the theoretical output parameters of the bypass according to the input voltage and the conduction angle.

[0065] Determine the preset parameter value based on the theoretical output parameters and a preset proportional value.

[0066] In this embodiment, the conduction angle of the bypass switch at the acquisition moment can be calculated based on a preset conduction angular velocity and the conduction time of the bypass switch.

[0067] In this embodiment, the theoretical output voltage or theoretical output current of the bypass can be calculated based on the input voltage of the UPS and the conduction angle of the bypass switch, and then the preset voltage value or preset current value can be correspondingly calculated based on the theoretical output voltage and theoretical output current.

[0068] In a possible implementation manner, the inverter output parameter is the inverter output current or inverter output voltage, the theoretical output parameter is the theoretical output voltage or theoretical output current corresponding to the inverter output parameter, and the preset parameter value is the preset current value or preset voltage value corresponding to the inverter output parameter.

[0069] When the inverter output parameter is the inverter output voltage, the method for determining the preset voltage value is: U thd = U sd × k1, where U thd is the preset voltage value, k1 is the preset proportional value when the inverter output parameter is the inverter output voltage, and U sd is the theoretical output voltage.

[0070] When the inverter output parameter is the inverter output current, the method for determining the preset current value is: I thd = I sd × k2 + I e , where I thd is the preset current value, k2 is the preset proportional value when the inverter output parameter is the inverter output current, I sd is the theoretical output current, and I e is the current value that is positively correlated with the capacitance of the capacitor in the power module.

[0071] In this embodiment, the preset voltage value can take a preset proportion of the theoretical output voltage. Regarding the preset current value, considering the existence of the energy storage element (capacitor) in the power module (which may generate a small current), this embodiment will consider the compensation amount related to the capacitance of the capacitor (i.e., the current value I e ) when setting the threshold to ensure the accuracy of the relay adhesion detection.

[0072] In this embodiment, k1 and k2 can be equal or unequal, and no limitation is made here.

[0073] In a possible implementation manner, the inverter output parameter of the UPS is obtained during the conduction process of the bypass switch, including:

[0074] At least two inverter output parameters of the UPS are obtained during the conduction process of the bypass switch.

[0075] In this embodiment, obtaining at least two inverter output parameters can support the calculation of the growth rate of subsequent inverter output parameters, and then adhesion detection can be performed based on this growth rate. It can also support obtaining at least two detection results based on at least two inverter output parameters, and then obtaining the final detection result by synthesizing each detection result. No matter which detection method is used, the accuracy of relay adhesion detection can be improved.

[0076] In a possible implementation manner, determining whether a relay is adhered based on inverter output parameters includes:

[0077] Determine the growth rate of the inverter output parameters according to at least two inverter output parameters.

[0078] If the growth rate is greater than a preset rate, it is determined that the relay is adhered.

[0079] If the growth rate is not greater than the preset rate, it is determined that the relay is not adhered.

[0080] Among them, the preset rate is positively correlated with the conduction angular velocity.

[0081] In this embodiment, the greater the conduction angular velocity, the greater the preset rate. On this basis, the embodiment of the present invention performs adhesion detection based on the growth rate of inverter output parameters, which can effectively reduce the influence of external environmental factors on relay adhesion detection (for example, there is already a part of small current in the power module, and the detection method using the growth rate in the embodiment of the present invention can effectively reduce the influence of the existing current on the detection accuracy), thereby improving the accuracy of relay adhesion detection.

[0082] In a possible implementation manner, the relay adhesion detection method further includes:

[0083] Detect whether there is a charging current in the battery of the UPS.

[0084] If there is a charging current in the battery, it is determined that the relay is adhered.

[0085] Considering the situation where the battery of the UPS is directly connected to the bus, the embodiment of the present invention can also directly detect the charging current of the battery. If there is a charging current in the battery, it means that the current is back-fed to the bus. At this time, it can be directly determined that the relay is adhered, and this method is more convenient.

[0086] On the other hand, the present invention also provides a control device 300, including: one or more processors 301, one or more input devices 302, one or more output devices 303 and one or more memories 304. The above-mentioned processors 301, input devices 302, output devices 303 and memories 304 complete the communication with each other through a communication bus 305. The memory 304 is used to store computer programs, and the computer programs include program instructions. The processor 301 is used to execute the program instructions stored in the memory 304. Among them, 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 so-called 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 fingerprint information and the direction information of the fingerprint) of the user, a microphone, etc., and the output device 303 may include a display (such as an LCD), a speaker, etc. The memory 304 may include a read-only memory and a random access memory, and provide instructions and data to the processor 301. A part 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 processors 301, input devices 302, and output devices 303 described in the embodiments of the present invention may execute the implementation manners described in the first and second embodiments of the relay adhesion detection method provided by the embodiments of the present invention.

[0087] In still another aspect of the present invention, a UPS is also provided, including:

[0088] The control device described above.

[0089] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of various equivalent modifications or substitutions, and these modifications or substitutions should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A method for detecting relay adhesion, characterized in that, The relay refers to the relay used to conduct the inverter output side of the power module in the UPS, and the relay adhesion detection method includes: After the UPS is powered on, during the process of tracking the phase of the UPS input voltage on the bypass of the UPS, when it is detected that the phase of the UPS input voltage is at a preset phase, control the bypass switch of the UPS to conduct at a preset conduction angular velocity; Obtain the inverter output parameters of the UPS during the conduction process of the bypass switch, and determine whether the relay is adhered based on the inverter output parameters; The determining whether the relay is adhered based on the inverter output parameters includes: Determine whether the inverter output parameter is greater than a preset parameter value; If the inverter output parameter is greater than the preset parameter value, it is determined that the relay is adhered; If the inverter output parameter is not greater than the preset parameter value, it is determined that the relay is not adhered; Wherein, the preset parameter value is positively correlated with the input voltage of the UPS; The method for determining the preset parameter value is: Obtain the acquisition moment of the inverter output parameter; Obtain the input voltage of the UPS and the conduction angle of the bypass switch at the acquisition moment; Determine the theoretical output parameter of the bypass according to the input voltage and the conduction angle; Determine the preset parameter value based on the theoretical output parameter and a preset ratio value.

2. The relay adhesion detection method according to claim 1, wherein, The range of the preset phase is (180° - e1, 180° + e2) or (360° - e3, 360° + e4); Wherein, e1, e2, e3, and e4 are all preset error values.

3. The relay adhesion detection method according to claim 1, characterized in that, The inverter output parameter is the inverter output current or the inverter output voltage, the theoretical output parameter is the theoretical output voltage or the theoretical output current corresponding to the inverter output parameter, and the preset parameter value is the preset current value or the preset voltage value corresponding to the inverter output parameter; When the inverter output parameter is the inverter output voltage, the method for determining the preset voltage value is: U thd = U sd × k1, where U thd is the preset voltage value, k1 is the preset proportional value when the inverter output parameter is the inverter output voltage, and U sd is the theoretical output voltage; When the inverter output parameter is the inverter output current, the method for determining the preset current value is: I thd = I sd × k2 + I e , where, I thd is the preset current value, k2 is the preset proportional value when the inverter output parameter is the inverter output current, I sd is the theoretical output current, and I e is the current value positively correlated with the capacitance of the capacitor in the power module.

4. The relay adhesion detection method according to claim 1, wherein, The obtaining the inverter output parameters of the UPS during the conduction process of the bypass switch includes: Obtain at least two inverter output parameters of the UPS during the conduction process of the bypass switch.

5. The relay adhesion detection method according to claim 4, characterized in that, The determining whether the relay is adhered based on the inverter output parameters includes: Determine the growth rate of the inverter output parameter according to the at least two inverter output parameters; If the growth rate is greater than a preset rate, it is determined that the relay is adhered; If the growth rate is not greater than the preset rate, it is determined that the relay is not adhered; Wherein, the preset rate is positively correlated with the conduction angular velocity.

6. The relay adhesion detection method according to any one of claims 1 to 5, characterized in that The relay adhesion detection method further includes: Detect whether there is a charging current in the battery of the UPS; If there is a charging current in the battery, it is determined that the relay is adhered.

7. A control device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 6.

8. A UPS, characterized in that, Includes: The control device according to claim 7.

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