UPS (Uninterrupted Power Supply) module, UPS system and fault detection method of UPS system

Abstract

The invention discloses a UPS module, a UPS system and a fault detection method of the UPS system, which are used for accurately identifying a faulted UPS module. The UPS module comprises a plurality of first switches, a plurality of second switches, a plurality of detection modules, a plurality of third switches, a plurality of fourth switches, a first conversion module, a second conversion module and a controller. One end of the first switch is connected with one input end, and the second end is connected with the first end of a third switch; the first end of the second switch is connected with an input end, and the second end is connected with the first end of a fourth switch; the second end of the third switch is connected with the anode of the battery pack; the second end of the fourth switch is connected with the cathode of the battery pack; the discharging module is connected with the second end of one first switch or the second switch; the detection module detects voltage at two ends of a first switch or a second switch; and when receiving the first signal, the controller controls the third switch, the fourth switch and the first conversion module to be switched off, and determines the fault state of the UPS module according to the numerical value detected by the detection module.

Description

Technical Field

[0001] The present application relates to the field of power electronics, and in particular to a UPS module, system and a fault detection method for a UPS system. Background Art

[0002] Uninterruptible Power Supply (UPS) is a core component of the data center and plays a vital role in maintaining the power reliability of the data center. UPS mainly works in grid power supply mode or battery power supply mode. When UPS works in grid power supply mode, the rectifier and inverter in the UPS convert the electric energy transmitted from the grid into the electric energy required by the load. When UPS works in battery power supply mode, the discharger and inverter in the UPS convert the electric energy stored in the battery pack into the electric energy required by the load. In order to improve the utilization rate of the devices in the UPS, the rectifier required for the UPS to work in grid power supply mode and the discharger required for the UPS to work in battery power supply mode are reused.

[0003] In order to increase the power supply of the UPS device, multiple UPS modules are generally connected in parallel inside the UPS device, and each UPS module can work independently. When the discharger and rectifier in the UPS module are reused and the UPS device works in battery power mode, if the relay or other connector connected to the grid is short-circuited, the battery pack is directly connected to the grid connection side, and there is a backfeed voltage on the grid connection side. This backfeed voltage will bring certain safety hazards to UPS maintenance personnel. In order to protect the safety of maintenance personnel, when a backfeed voltage is detected in the UPS system, the industry usually considers disconnecting the entire machine switch. This method will affect the normal power supply of the UPS system, and in serious cases, there will be load operation safety issues. Summary of the invention

[0004] The present application provides a UPS module, a system and a fault detection method for a UPS system, which are used to accurately identify a faulty UPS module of a UPS system when a backfeed fault occurs in the UPS system.

[0005] In a first aspect, an embodiment of the present application provides a UPS module, which can be applied to a UPS system, wherein the UPS system includes a plurality of the above UPS modules connected in parallel. Each UPS module may include: a plurality of first switches, a plurality of second switches, a plurality of detection modules, a third switch corresponding to each first switch, a fourth switch corresponding to each second switch, a first conversion module, a second conversion module, and a controller.

[0006] Specifically, the first end of each first switch is connected to an input end of the UPS module to which it belongs, and the second end of each first switch is connected to the first end of the corresponding third switch and the first conversion module; the first end of each second switch is connected to an input end of the UPS module to which it belongs, and the second end of each second switch is connected to the first end of the corresponding fourth switch and the first conversion module; multiple input ends of the UPS module are connected to input ends of other UPS modules in the UPS system and an AC power supply; the second conversion module is connected to the first conversion module, and the second conversion module is also used to connect to the load; the second end of each third switch is used to connect to the positive electrode of the battery pack; the second end of each fourth switch is used to connect to the negative electrode of the battery pack; each load The electrical module is connected to the second end of a first switch or the second end of a second switch in the UPS module to which it belongs; each detection module is connected to both ends of a first switch or a second switch in the UPS module to which it belongs, and is used to detect a first voltage at the first end and a second voltage at the second end of the connected switch, and output the detected voltages to the controller; the controller is used to control each third switch, each fourth switch and the first conversion module in the UPS module to be turned off when receiving a first signal indicating that the fault detection is completed and sent by the previous UPS module connected in parallel to the UPS module to which it belongs, receive the voltage output by each detection module, and determine the fault state of the UPS module to which it belongs according to the value detected by each detection module.

[0007] With the above design, each UPS module is configured with a detection module for detecting the voltage across each first switch and the second switch. When the UPS system works in the battery power supply mode, the UPS modules of the UPS system will perform fault detection in sequence according to the set order. Specifically, when the controller in the current UPS module receives the first control signal, it indicates that the fault detection of the previous UPS module is completed, and the current UPS module can start the fault detection. The controller can control each third switch and the fourth switch in the UPS module to be turned off, and control the first conversion module to stop working, so as to control the UPS module to stop receiving the electric energy output by the battery pack. At this time, the discharge operation of the discharge module connected to the first switch and the second switch will reduce the absolute value of the voltage at the second end of the above two switches. Therefore, during the discharge process of the discharge module, if the first switch or the second switch has a short circuit fault, resulting in a reverse voltage on the input side, the voltage difference across the first switch and the second switch is close to zero, and the fault condition of the current UPS module can be accurately judged by detecting the voltage difference across the above switches.

[0008] In a possible design, the controller is specifically configured to: when the UPS system operates in the battery pack power supply mode and receives a first signal sent by the previous UPS module to which the UPS module belongs and is connected in parallel, control each third switch, each fourth switch, and the first conversion module in the UPS module to turn off, receive the voltages output by each detection module after a preset duration from the turn-off of each third switch and fourth switch, and determine that the UPS module to which it belongs is a faulty UPS module when the absolute value of the difference between the first voltage and the second voltage output by any detection module is less than or equal to a first preset voltage. By adopting the above method, after the third switch and the fourth switch are turned off, the voltages at the second ends of the first switch and the second switch respectively connected to the third switch and the fourth switch will change with the discharge of the discharge module. Therefore, each UPS module can accurately identify whether the UPS module to which it belongs is a faulty UPS module based on the voltage difference across the first switch and the second switch during the discharge process of the discharge module.

[0009] In a possible design, the controller is further configured to: when it is determined that the absolute value of the difference between the first voltage and the second voltage output by each detection module is greater than the first preset voltage, determine that the UPS module to which it belongs is a normal module, and control each third switch, each fourth switch, and the first conversion module in the UPS module to turn on.

[0010] In a possible design, the controller is further configured to: when it is determined that the UPS module is faulty, compare the first voltage and the second voltage output by each detection module with a second preset voltage respectively; when it is determined that the absolute values of the first voltage and the second voltage output by any detection module are both greater than the second preset voltage, determine that the number of faulty UPS modules in the UPS system is greater than 1. By adopting the above design, after it is detected that the UPS module to which it belongs is a faulty module, if the UPS system also has other faulty UPS modules, since multiple UPS modules are connected in parallel, the other faulty UPS modules will clamp the potential of the input side of all UPS modules. Therefore, it is possible to determine whether there are other faulty UPS modules in the system by detecting the voltage across the first switch and the second switch during the discharge process of the discharge module.

[0011] In a possible design, the controller is further configured to: when determining that the absolute values of the first voltage and the second voltage output by any detection module are both greater than a second preset voltage, control each third switch, each fourth switch, and the first conversion module in the UPS module to which it belongs to remain off, and send a first signal indicating that the fault detection is completed to the next UPS module; and when determining that the absolute values of the first voltage and the second voltage output by each detection module are both less than or equal to the second preset voltage, control each third switch, each fourth switch, and the first conversion module in the UPS module to which it belongs to remain off, and send a second signal indicating to stop the fault detection to the next UPS module. With the above design, the UPS module with a fault can be accurately identified and the connection between the faulty UPS module and the battery pack can be quickly disconnected, and in the above manner, it is not necessary to perform fault detection on all UPS modules in the UPS system, which helps to reduce the fault detection duration of the UPS system.

[0012] In a possible design, the controller is further configured to: when determining that the absolute values of the first voltage and the second voltage output by any detection module are both greater than a second preset voltage, control each third switch, each fourth switch, and the first conversion module in the UPS module to which it belongs to conduct, and send a first signal indicating that the fault detection is completed to the next UPS module; when determining that the fault detection of other UPS modules in the UPS system is completed, if the number of non-faulty UPS modules in the UPS system is less than a set value, control each third switch, each fourth switch, and the first conversion module in the UPS module to which it belongs to conduct. With the above design, when determining that there are multiple faulty UPS modules in the UPS system, in order to prevent all the electric energy from being transmitted through the non-faulty UPS modules and causing the non-faulty UPS to be unable to operate due to overload, when the controller detects that there are other faulty UPS modules in the system in addition to the UPS module to which it belongs, it does not directly disconnect the connection between the UPS module to which it belongs and the battery pack, but waits until the fault detection of all UPS modules is completed and then performs corresponding processing according to the number of faulty UPS modules.

[0013] In a second aspect, an embodiment of the present application provides a UPS system, which includes a battery pack and the UPS module provided in the first aspect and any possible design thereof in the embodiments of the present application.

[0014] Among them, the battery pack is connected to each UPS module and is used to supply power to each UPS module when the AC power source connected to the UPS module fails.

[0015] In a possible design, the UPS system further includes a main controller, and the main controller is connected to the controllers in each UPS module. In the above manner, the fault detection of multiple UPS modules in the UPS system is controlled by the main controller.

[0016] In a third aspect, an embodiment of the present application provides a method for fault detection of a UPS system. The method for fault detection of the UPS system can be applied to the UPS system provided in the second aspect and any possible design thereof in the embodiment of the present application, and is executed by a controller in the UPS module or a master controller in the UPS system.

[0017] Specifically, the method for fault detection of the UPS system mainly includes the following steps:

[0018] When it is determined that the UPS system is operating in the battery power supply mode and a first signal indicating that the fault detection of the previous UPS module is completed is received, control each third switch, each fourth switch, and the first conversion module in the UPS module to turn off; determine the fault state of the UPS module according to the first voltage and the second voltage output by each detection module.

[0019] In a possible design, determining the fault state of the UPS module according to the first voltage and the second voltage output by each detection module includes: receiving the voltages output by each detection module at a preset time period after each third switch, each fourth switch, and the first conversion module in the UPS module are turned off; when the absolute value of the difference between the first voltage and the second voltage output by any detection module is less than or equal to a first preset voltage, determine that the UPS module is a faulty UPS module.

[0020] In a possible design, the method further includes: when it is determined that the absolute value of the difference between the first voltage and the second voltage output by each detection module is greater than the first preset voltage, control each third switch, each fourth switch, and the first conversion module in the UPS module to turn on.

[0021] In a possible design, the method further includes: when it is determined that the UPS module is a faulty UPS module, compare the first voltage and the second voltage output by each detection module with a second preset voltage respectively; when it is determined that the absolute value of the first voltage and the second voltage output by any detection module is greater than the second preset voltage, determine that the number of faulty UPS modules in the UPS system is greater than 1.

[0022] In a possible design, the method further includes: when it is determined that the absolute value of the first voltage and the second voltage output by any detection module is greater than the second preset voltage, control each third switch, each fourth switch, and the first conversion module in the UPS module to remain off, and send a first signal indicating that the fault detection is completed to the next UPS module; and when it is determined that the absolute value of the first voltage and the second voltage output by each detection module is less than or equal to the second preset voltage, control each third switch, each fourth switch, and the first conversion module in the UPS module to remain off, and send a second signal indicating to stop the fault detection to the next UPS module.

[0023] In a possible design, the method further includes: when it is determined that the absolute values of the first voltage and the second voltage output by any detection module are both greater than the second preset voltage, controlling each third switch, each fourth switch, and the first conversion module in the UPS module to conduct, and sending a first signal indicating that the fault detection is completed to the next UPS module; when it is determined that the fault detection of other UPS modules in the UPS system is completed, if the number of non-faulty UPS modules in the UPS system is less than the set value, controlling each third switch, each fourth switch, and the first conversion module in the UPS module to conduct.

[0024] Fourthly, an embodiment of the present application further provides a computer-readable storage medium, in which a computer program is stored. When the computer program runs on a computer, it executes the fault detection method of the UPS system provided in the third aspect and any design thereof in the embodiments of the present application.

[0025] In addition, for the technical effects brought by the second aspect to the fourth aspect and any possible design thereof, reference may be made to the technical effects brought by different designs in the first aspect of the embodiments of the present application, which will not be elaborated herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0027] Figure 1 It is a schematic structural diagram of a UPS module provided by an embodiment of the present application;

[0028] Figure 2 It is a schematic structural diagram of a UPS system provided by an embodiment of the present application Figure 1 ;

[0029] Figure 3 It is a schematic structural diagram of a UPS system provided by an embodiment of the present application Figure 2 ;

[0030] Figure 4 It is a schematic flowchart of a fault detection method for a UPS system provided by an embodiment of the present application Figure 1 ;

[0031] Figure 5 It is a schematic flowchart of a fault detection method for a UPS system provided by an embodiment of the present application Figure 2 ;

[0032] Figure 6 Flow schematic of a fault detection method for a UPS system provided by an embodiment of the present application Figure 3 ;

[0033] Figure 7 Flow schematic of a fault detection method for a UPS system provided by an embodiment of the present application Figure 4 。 Specific implementation manners

[0034] The embodiments of the present application will be described in detail below in conjunction with the accompanying drawings.

[0035] The embodiments described in the implementation manner part of the present application are only a part of the embodiments of the present application, not all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts fall within the scope of protection of the present application.

[0036] The application scenarios of the technical solutions in the embodiments of the present application will be introduced below.

[0037] The UPS system provided by the embodiment of the present application is applied to devices that need to maintain power supply for a period of time when the power supply is disconnected. For example, the UPS system can be applied in a data center. When a fault occurs in the external power supply of the data center, the UPS system can still maintain power supply for the data center for a period of time so that the data center can store data.

[0038] In actual use, the UPS system is connected to at least one AC power supply. When the connected AC power supply can supply power normally, the UPS system can convert the electric energy output by the above AC power supply into the electric energy required by the load and supply it to the load. When the connected AC power supply cannot supply power normally, the UPS system disconnects the connection with the AC power supply and converts the electric energy stored in the internal battery pack into the power supply electric energy required by the load and supplies it to the load.

[0039] In order to achieve high-power power supply, multiple UPS modules with the same function are generally set in the UPS system. The input end of each UPS module is connected to the AC power supply, and the output end of the UPS module is connected to the load, that is, multiple UPS modules are connected in parallel. Each UPS module receives a part of the electric energy output by the AC power supply, converts the received electric energy into the electric energy required by the load, and outputs it to the load after converging on the output side of the UPS module, so as to achieve high-power power supply. In actual use, the UPS system generally has switching devices such as relays and contactors that can perform high-power transmission at the input side. When the AC power supply fails and cannot supply power normally, the connection between the UPS system and the AC power supply is disconnected by turning off the main switch, thereby ensuring the safe operation of the UPS system.

[0040] At present, in order to improve the utilization rate of components in the UPS system, the discharger required for battery pack power supply and the rectifier required for AC power supply are multiplexed. This multiplexing method causes the electrical energy output by the battery pack and the electrical energy output by the AC power supply to be transmitted to the input side of the UPS system. When the UPS system operates in the battery pack power supply mode, if the switching device has a short-circuit fault in its mechanical contact due to contact adhesion, wear, aging, dust and other debris, the electrical energy output by the battery pack will be reversely transmitted to the AC power supply side, which will pose a safety hazard to the operator and may also cause damage to the components on the AC power supply side. If the connection between the battery pack and all UPS modules is directly turned off, the UPS system cannot continue to supply power to the load. Therefore, it is necessary to quickly and accurately identify the faulty UPS module in the UPS system.

[0041] In view of this, the present application provides a UPS module, a system and a fault detection method for a UPS system, which are used to accurately detect the faulty UPS module.

[0042] The UPS module provided by the embodiment of the present application can be applied to a UPS system, and the UPS system can include multiple UPS modules connected in parallel. Refer to Figure 1 As shown, the UPS module provided by the embodiment of the present application includes: a plurality of first switches K1, a plurality of second switches K2, a plurality of detection modules, third switches K3 corresponding to each first switch K1 one by one, fourth switches K4 corresponding to each second switch K2 one by one, a first conversion module, a second conversion module and a controller.

[0043] Specifically, the first end of each first switch K1 is connected to an input terminal of the corresponding UPS module, and the second end of each first switch K1 is connected to the first end of the corresponding third switch K3 and the first conversion module. Among them, the first end of each first switch K1 is connected to a phase wire of the AC power supply through the connected input terminal, and the phase wires connected to the first end of each first switch K1 are different. The first end of each second switch K2 is connected to an input terminal in the corresponding UPS module, and the second end of each second switch K2 is connected to the first end of the corresponding fourth switch K4 and the first conversion module. Among them, the first end of each second switch K2 is connected to a phase wire of the AC power supply through the connected input terminal, and the phase wires connected to the first end of each second switch K2 are different. The second conversion module is connected to the first conversion module, and the output terminal of the second conversion module is used for connecting to the load; the second end of each third switch K3 is used for connecting to the positive pole of the battery pack in the UPS system. The second end of the fourth switch K4 is used for connecting to the negative pole of the battery pack. Each discharge module is connected to the second end of a first switch or the second end of a second switch in the corresponding UPS module. The number of discharge modules in a single UPS module is equal to the sum of the number of first switches and second switches in the corresponding UPS module, and the switches connected by each discharge module are different. Each detection module is connected to both ends of a first switch or both ends of a second switch in the corresponding UPS module, and is used for detecting the first voltage at the first end and the second voltage at the second end of the connected switch, and outputting the detected first voltage and second voltage to the controller; the controller is connected to the control terminals of each third switch K3 and each fourth switch K4 in the corresponding UPS module.

[0044] Among them, the multiple input terminals of the above UPS module are connected to the input terminals of other UPS modules in the UPS system and the AC power supply, that is, the input terminals of all UPS modules in the UPS system are connected and receive the electric energy output by the AC power supply.

[0045] It should be understood that Figure 1 the structure of the shown UPS module is only an example. In actual application, the UPS module may have more components than Figure 1 shown. For example, in addition to the above-mentioned devices, the UPS module may further include protection devices for short-circuit or overload protection when the UPS module operates in the AC power supply mode or the battery power supply mode. Among them, Figure 1 the various components shown can be implemented in hardware, software, or a combination of hardware and software including one or more signal processing and / or application specific integrated circuits.

[0046] In practical applications, the UPS module can be fixed to the UPS system. In another implementation, the UPS module can also be configured in a flexible and detachable form, that is, each UPS module in the UPS system is provided with a fixed interface to achieve the connection of the UPS module to the AC power supply, the battery pack, and the load. In this case, the UPS module can be regarded as a device independent of the UPS system.

[0047] In the UPS module provided by the embodiment of the present application, the first conversion module can be a circuit that multiplexes a rectifier and a discharger commonly used in the industry. The first conversion module can convert the alternating current output by the AC power supply into direct current, or perform voltage regulation on the DC electrical energy output by the battery pack. The second conversion module can be a circuit with an inversion function. The second conversion module can convert the DC electrical energy output by the first conversion module into the AC electrical energy required for powering the load connected to the backend and provide the AC electrical energy to the load. Each detection module can include two voltage sensors. The first voltage sensor is connected to the first end of the switch connected to the detection module to which it belongs, and the second voltage sensor is connected to the second end of the switch connected to the detection module to which it belongs. The detection module can detect the voltage across the connected switch through the two internal voltage sensors and transmit it to the controller. The controller can be the controller in the first conversion module for controlling the operation of the first conversion module. This controller can also control the conduction and cutoff of the third switch K3 and the fourth switch K4 connected to the battery pack in the UPS module, thereby controlling the UPS module to enter and exit the battery power supply state. Among them, the voltage sensor can be any circuit or chip that can achieve voltage detection. For example, the voltage sensor can be, but is not limited to: sampling resistor, Hall sensor, and voltage transformer.

[0048] By using the UPS module provided by the embodiment of the present application, the controller can control the conduction of each third switch K3 and fourth switch K4 when the AC power supply cannot supply power normally. At this time, the UPS module enters the battery power supply state, and the first conversion module and the second conversion module in the UPS module use the electrical energy stored in the battery pack to power the load. By using the above method, all UPS modules in the UPS system can be controlled to work in the battery power supply state to meet the power supply requirements of the load.

[0049] After receiving the first signal indicating the completion of detection sent by the previous UPS module, the controller in the UPS module can control each third switch K3 and each fourth switch K4 in the current UPS module to turn off, and control the first conversion module to stop working, so as to control the UPS module to stop receiving the electric energy output by the battery pack. Before each third switch K3 and fourth switch K4 are turned off, since each third switch K3 is connected to the positive pole of the battery pack and each fourth switch K4 is connected to the negative pole of the battery pack, when the third switch K3 and the fourth switch K4 are turned off, the potential of the second end of the first switch K1 connected to the third switch K3 is the potential of the positive pole of the battery pack, and the potential of the second end of the second switch K2 connected to the fourth switch K4 is the potential of the negative pole of the battery pack. After the third switch K3 and the fourth switch K4 are turned off, the discharge module connected to the second end of the first switch K1 and the second end of the second switch K2 performs a discharge operation, and the voltage at the second end of the first switch K1 and the voltage at the second end of the second switch K2 will gradually decrease as the discharge duration of the discharge module increases. If there is no reverse power injection fault in the UPS module, the first voltage U1 at the first end of the above two switches remains stable, and the voltage at the second end of the switch decreases with the discharge of the discharge module. Therefore, there will be a voltage difference between the voltage U1 at the first end of the switch and the voltage U2 at the second end of the switch. Therefore, when it is determined that the absolute value of the voltage difference between the first voltage U1 at the first end of the switch and the second voltage U2 at the second end of the switch is less than the first preset voltage, it can be determined that there is a short circuit fault in the switch connected to the AC power supply in the current UPS module, that is, there is reverse power injection in the main circuit where the UPS module is connected to the AC power supply. By adopting the above method, each UPS module in the UPS system can detect whether it is a faulty module by itself and accurately detect the faulty UPS module in the UPS system.

[0050] In one example, in an ideal situation, the voltage difference across the first switch K1 is zero. Therefore, the first preset voltage can be set to a value close to zero. For example, the first preset voltage can be set to 1V. Of course, the first preset voltage can also be set to other values, and the specific value can be set according to the application scenario of the UPS module and the operating experience of the operator.

[0051] In another example, when the current UPS module has no fault, the voltage at the first ends of the first switch K1 and the second switch K2 mainly shows two situations. One is 0V output by the AC power supply of the UPS module without fault in the UPS system, and the other is when there is a fault in the UPS module in the UPS system, the potential of the first ends of all UPS modules of the faulty UPS module is clamped to the potential of the positive pole or the negative pole of the battery pack. And the potential at the second end of the switch will change fixedly with the discharge parameters and discharge duration of the discharge module. Therefore, the first preset voltage can be set to a value less than the voltage difference of the switch in the above two situations.

[0052] In actual application, after the controller detects that the UPS module to which it belongs is a faulty UPS module, it can directly turn off the current UPS module. Therefore, all UPS modules in the UPS system can complete the fault detection function in the above manner and timely disconnect the connection between the faulty UPS module and the power supply. The controller can also determine that the UPS module to which it belongs is a faulty UPS module, and first does not perform the turn-off operation of the faulty UPS module, but waits until all UPS modules have been detected and then uniformly processes the faulty UPS module.

[0053] Next, the fault detection working process of the UPS module in the UPS system of the present application will be described in conjunction with embodiments.

[0054] Embodiment 1

[0055] After the controller receives the first signal indicating that the fault detection of the previous UPS module is completed, it controls each third switch K3 and each fourth switch K4 in each UPS module to which it belongs to turn off, and controls the first conversion module to stop working, so as to control the UPS module to which it belongs to stop receiving the electric energy output by the battery pack. Refer to Figure 1 As shown, before each third switch K3 and each fourth switch K4 are turned off, since each third switch K3 is directly connected to the positive electrode of the battery pack and each fourth switch K4 is directly connected to the negative electrode of the battery pack, the potential of the second end of the first switch K1 connected to the third switch K3 is the positive electrode potential of the battery pack, and the potential of the second end of the second switch K2 connected to the fourth switch K4 is the negative electrode potential of the battery pack. After each third switch K3 and the fourth switch K4 are turned off, the discharge module connected to the second ends of the first switch K1 and the second switch K2 performs a discharge operation, and the potential of the second ends of each first switch K1 and the second switch K2 gradually changes with the increase of the discharge duration of the discharge module. The controller can control each detection circuit to detect the voltage across the first switch K1 and the voltage across the second switch K2 after the discharge duration reaches the preset duration T, and when the absolute value of the voltage difference across the switch is greater than the first preset voltage, it is determined that the UPS module to which it belongs is normal, otherwise it is determined that the UPS module to which it belongs is a faulty UPS module. After the controller detects that the UPS module to which it belongs is a faulty UPS module, it directly controls each third switch K3 and each fourth switch K4 in the UPS module to which it belongs to remain off, disconnecting the UPS module to which it belongs from the power supply, so as to quickly cut off the UPS module with reverse power injection fault in the UPS system. In addition, since a discharge module is provided at the second ends of the first switch K1 and the second switch K2 of each UPS module, the discharge module can drop the input-side voltage to zero, thus protecting the safety of the operator.

[0056] After the controller controls each third switch K3 and each fourth switch K4 in the UPS module to which it belongs to remain off, it sends a first signal indicating that the current UPS module has been detected to the controller in the next UPS module, so that the next UPS module can perform fault detection in the same manner until all UPS modules in the UPS system have been detected, and disconnect all faulty UPS modules from the power supply.

[0057] Embodiment 2

[0058] After receiving the first signal indicating that the fault detection is completed sent by the previous UPS module, the controller controls each third switch K3 and each fourth switch K4 in the UPS module to which it belongs to turn off, and controls the first conversion module to stop working, and determines whether the UPS module to which it belongs has a fault by using the absolute value of the pressure difference across each first switch K1 and the second switch K2. When it is determined that the UPS module to which it belongs is a faulty UPS module, the controller controls each third switch K3 and each fourth switch K4 in the UPS module to which it belongs to remain off, and detects whether there are other faulty UPS modules in the UPS system. When it is determined that there are no other faulty UPS modules in the UPS system, the controller sends a second signal to stop detection to the next UPS module. The controller is also used to send a first signal indicating that the detection is completed and continue the detection to the next UPS module when it is determined that there are other faulty UPS modules in the UPS system.

[0059] Specifically, the controller can set a second preset voltage according to the parameters of the discharge module and the discharge duration, and compare the voltages across each first switch K1 and the second switch K2 with the second preset voltage respectively. If there is only one faulty UPS module, which is the UPS module to which it belongs, in the UPS system, the voltages across the first switch K1 and the second switch K2 will both change with the increase of the discharge duration of the discharge module, and the voltage drop values of the voltages across the first switch K1 and the second switch K2 are consistent with the voltage values corresponding to the discharge rate of the discharge module. Therefore, when it is determined that the absolute values of the voltages across the first switch K1 and the second switch K2 are both less than or equal to the second preset voltage, it can be determined that only the current UPS module in the UPS system has a fault. When it is determined that the absolute values of the voltages across the first switch K1 and the second switch K2 are both greater than the second preset voltage, it can be determined that there are other faulty UPS modules in the UPS system in addition to the current UPS module being a faulty UPS module. Therefore, after the controller detects that the current UPS module is a faulty UPS module, it will not only control the third switch K3 and the fourth switch K4 in the UPS module to which it belongs to turn off, but also send a first signal to continue the detection after the fault detection is completed to the next UPS module until the last faulty UPS module is disconnected from the power supply.

[0060] It should be noted that when the fault detection method provided in the second embodiment is adopted, the number of UPS modules for which fault detection is performed in the UPS module is the number of UPS modules between the first UPS module and the last faulty UPS module. Therefore, by adopting the above fault detection method, it is not necessary to detect all the UPS modules in the UPS system, which can reduce the fault detection time of the UPS system.

[0061] Embodiment 3

[0062] After receiving the first signal indicating that the fault detection is completed sent by the previous UPS module, the controller controls each third switch K3 and each fourth switch K4 in the UPS module to turn off, and controls the first conversion module to stop working, and determines whether the UPS module has a fault by using the absolute value of the voltage difference across each first switch K1 and second switch K2. When it is determined that the UPS module is a faulty UPS module, the controller controls the third switch K3 and the fourth switch K4 in the UPS module to turn on, and controls the first conversion module to resume working, and detects whether there are other faulty UPS modules in the UPS system. When it is determined that there are no other faulty UPS modules in the UPS system, the controller sends a second signal for stopping detection to the next UPS module. The controller is further configured to send a first signal indicating that the detection is completed and continue the detection to the next UPS module when it is determined that there are other faulty UPS modules in the UPS system.

[0063] Specifically, the controller can set a second preset voltage according to the parameters of the discharge module and the discharge duration, and compare the voltages across each first switch K1 and second switch K2 with the second preset voltage respectively. If there is only one faulty UPS module, which is the UPS module itself, in the UPS system, the voltages across the first switch K1 and the second switch K2 will both change with the increase of the discharge duration of the discharge module, and the voltage drop values of the voltages across the first switch K1 and the second switch K2 are consistent with the voltage value corresponding to the discharge rate of the discharge module. Therefore, when it is determined that the absolute values of the voltages across the first switch K1 and the second switch K2 are both less than or equal to the second preset voltage, it can be determined that only the current UPS module in the UPS system has a fault. When it is determined that the absolute values of the voltages across the first switch K1 and the second switch K2 of the current UPS module are both greater than the second preset voltage, it can be determined that there are other faulty UPS modules in the UPS system in addition to the current UPS module. Therefore, after the controller detects that the current UPS module is a faulty UPS module, it will control the third switch K3 and the fourth switch K4 in the UPS module to turn on, and control the first conversion module to resume working, and also send a first signal for continuing the detection after the fault detection is completed to the next UPS module until all the UPS modules in the UPS system are detected.

[0064] Specifically, the controllers in each UPS module communicate with each other and inform the detection status of all UPS modules in the UPS system and the faults of the faulty UPS modules in the UPS system. After the controller in the current UPS module determines that all UPS modules in the UPS system have been detected, when it determines that the number of non-faulty UPS modules in the UPS system is greater than or equal to the set value and the current UPS module is a faulty UPS module, it controls the third switch K3 and the fourth switch K4 in the faulty UPS module to turn off, and controls the first conversion module to stop working. When the controller in the current UPS module determines that the number of non-faulty UPS modules in the UPS system is less than the set value, it controls the third switch K3 and the fourth switch K4 in the faulty UPS module to remain conducting and supplies power to the load.

[0065] Among them, the set value can be the ratio between the load demand power and the maximum operating power of a single UPS module. Therefore, when the number of non-faulty UPS modules in the UPS system is less than the set value, the non-faulty UPS modules in the UPS module will be damaged due to overload, resulting in the inability to supply power to the load.

[0066] It should be noted that by using the fault detection method provided in the third embodiment, while accurately identifying the faulty UPS modules in the UPS system, the safe operation of the UPS system can also be ensured.

[0067] In practical applications, when using the fault detection methods shown in the first to third embodiments, when the first switches in two or more UPS modules all have short-circuit faults, or the second switches in two or more UPS modules all have faults, the faulty UPS modules will clamp the voltage on the input side of the UPS module. Therefore, the controller in a single UPS module can determine whether there are multiple faulty UPS modules in the UPS system by comparing the absolute value of the voltage across the first switch and the second switch with the second voltage. When the first switch in one UPS module has a short-circuit fault and the second switch in another UPS module has a short-circuit fault, the positive and negative poles of the battery pack are short-circuited, and the short-circuit protection device connected between the battery pack and each UPS module will automatically disconnect one or more UPS modules causing the battery pack short-circuit. The non-disconnected UPS modules execute the fault detection method provided in the above embodiments of the present application for fault detection.

[0068] Specifically, when a short-circuit fault occurs in the first switch of some UPS modules and a short-circuit fault occurs in the second switch of another UPS module, the number of UPS modules to be disconnected and the specific UPS modules can be set according to the action value of the short-circuit protection device. For example, when the action value of the short-circuit protection device connected between the battery pack and each UPS module is the same, if the first switches in both UPS modules have a short-circuit fault and the second switch in one UPS module has a short-circuit fault, the short-circuit currents of the two UPS modules with the first switch faults converge and flow through the UPS module with the second switch fault, and the short-circuit protection device connected to the UPS module with the second switch fault first starts to disconnect the UPS module from the battery pack.

[0069] By adopting the fault detection method shown in Examples 1 to 3, the faulty UPS module can be accurately identified, and after cutting off the connection between the faulty UPS and the battery pack, the voltage on the input side of the UPS module can be reduced to a safe voltage through the discharge module set in each UPS module, thereby protecting the safety of the operator.

[0070] In one example, in order to reduce the cost of the UPS module, the safety capacitor in the UPS module can be used as a discharge module.

[0071] In another example, in order to protect the safety of operators and quickly reduce the voltage on the input side of the faulty UPS module to a safe voltage, the discharge module may also use other discharge devices, for example, the discharge module may use an RC discharge circuit. At this time, the RC circuit in the discharge module and the safety capacitor in the UPS module can both be used as discharge branches to discharge the input side of the UPS module, thereby accelerating the drop speed of the voltage on the input side of the UPS module.

[0072] Based on the same inventive concept, the present application also provides a UPS system, see Figure 2 As shown, the UPS system may include a battery pack and a plurality of the aforementioned UPS modules. The battery pack may include a plurality of storage batteries, and the plurality of storage batteries may be connected in series or in parallel.

[0073] In a possible implementation, multiple UPS modules are directly connected and communicate with each other through an internal controller, and each UPS is controlled in turn to perform fault detection according to the sequence number of each UPS module. The sequence number of each UPS module can be set according to the installation position of multiple UPS modules in the UPS system, or can be set in other ways, which is not limited in this application.

[0074] In another possible implementation, see Figure 3As shown, the UPS system may also include a main controller connected to multiple UPS modules. The main controller may be connected to the controller in each UPS module. The main controller may monitor the fault detection process of each UPS module and store the fault detection results of each UPS module.

[0075] Specifically, after detecting that the current UPS module fault detection is completed, the main controller may send a first signal indicating that the current UPS module fault detection is completed to a UPS module, so that the controller in the next UPS module performs fault detection until the last UPS module fault detection is completed.

[0076] Based on the same inventive concept, the embodiment of the present application also provides a UPS system fault detection method, which can be applied to the aforementioned UPS system and executed by a controller in a UPS module, see Figure 4 As shown, the fault detection method mainly includes the following steps:

[0077] Step 401: When it is determined that the UPS system is operating in the battery power supply mode and a first signal indicating that the fault detection of the previous UPS module is completed is received, each third switch and each fourth switch in the corresponding UPS module are controlled to be turned off, and the first conversion module is controlled to stop working. The first signal may be sent by a controller in the previous UPS module or by a main controller in the UPS system.

[0078] In a possible implementation, the fault detection sequence of multiple UPS modules in the UPS system may be set according to the installation positions of the UPS modules, and the fault detection process may be started from the first UPS module.

[0079] In another possible implementation, in order to speed up the fault detection speed of the UPS system, multiple UPS modules of the UPS system can be arranged into multiple groups according to the installation positions of the UPS modules, each group includes at least two UPS modules, and fault detection is performed on multiple UPS modules in a group each time.

[0080] Step 402: Determine the fault status of the UPS module according to the first voltage and the second voltage output by each detection module in the UPS module.

[0081] Specifically, the controller receives the voltages output by each detection module during a preset duration after each third switch and fourth switch are turned off. When the absolute value of the difference between the first voltage and the second voltage output by any detection module is less than or equal to a first preset voltage, it is determined that the UPS module to which it belongs is a faulty UPS module. When the controller determines that the absolute value of the difference between the first voltage and the second voltage output by each detection module in the UPS module to which it belongs is greater than the first preset voltage, it is determined that the target UPS module is a normal UPS module.

[0082] In a possible implementation, after the controller determines that the UPS module to which it belongs is faulty, it controls the third switch and the fourth switch in the UPS module to which it belongs to remain off, and sends a first signal indicating that the fault detection is completed to the next UPS module. The controller is also used to control the third switch and the fourth switch in the UPS module to which it belongs to conduct after determining that the UPS module to which it belongs is a normal module, and control the first conversion module to resume operation, and send a first signal indicating that the fault detection is completed to the next UPS module. After the controller in the next UPS module receives the first signal, the controller in the next UPS module repeats the above fault detection process. By using the above fault detection method, the fault detection of all UPS modules can be completed, and the connection between the faulty UPS module and the battery pack can be quickly disconnected.

[0083] In a possible implementation, in order to reduce the number of UPS modules for fault detection in the UPS system, after the controller determines that the UPS module to which it belongs is faulty, it compares the first voltage and the second voltage output by each detection module with a second preset voltage respectively; when it is determined that the absolute value of the difference between the first voltage and the second voltage output by any detection module is greater than the second preset voltage, it is determined that there are other faulty UPS modules in the UPS system.

[0084] In an example, when the controller determines that there are other faulty UPS modules in the UPS system, it controls each third switch and fourth switch in the UPS module to which it belongs to remain off, and sends a first signal indicating that the fault detection is completed to the next UPS module, so that the next UPS module continues to perform fault detection until the control in one of the UPS modules determines that the absolute value of the difference between the first voltage and the second voltage output by each detection module is less than or equal to the second preset voltage, and then controls each third switch and fourth switch in the UPS module to which it belongs to remain off, and sends a second signal indicating to stop the fault detection to the next UPS module. By using the above method, the last UPS module detected is the last faulty UPS module, rather than the last UPS module in the UPS system. Therefore, the fault detection time of the UPS system can be reduced.

[0085] In another example, to prevent an excessive number of faulty UPS modules in the UPS system, directly shutting down the faulty UPS modules may cause the non-faulty UPS modules to be unable to operate due to overload. When the controller determines that the number of faulty UPS modules in the UPS system is greater than 1 and determines that the absolute values of the first voltage and the second voltage output by any detection module are both greater than the second preset voltage, it controls each third switch and fourth switch in the UPS module to conduct, and controls the first conversion module to resume operation, and sends a first signal indicating that a fault detection is to be performed to the next UPS module; when it determines that the fault detection of other UPS modules in the UPS system is completed, if the number of non-faulty UPS modules in the UPS system is less than the set value, it controls each third switch and fourth switch in the UPS module to remain conducting. If the number of non-faulty UPS modules in the UPS system is greater than or equal to the set value and the UPS module belongs to a faulty UPS module, it controls each third switch and fourth switch in the UPS module to turn off, and controls the first conversion module to stop working.

[0086] Next, the centralized fault detection method for the UPS system provided by the embodiments of the present application will be introduced separately.

[0087] See Figure 5 As shown, it is a fault detection method for a UPS module provided by an embodiment of the present application. This fault detection method for the UPS module can be executed by the controller in the UPS module. See Figure 5 As shown, it mainly includes the following steps:

[0088] S501. After receiving the first signal indicating that the detection is completed sent by the previous UPS module, control each third switch and fourth switch in the UPS module to turn off, and control the first conversion module to stop working.

[0089] S502. After a preset time period after each third switch and fourth switch are turned off, receive the first voltage and the second voltage output by each detection module. Among them, the first voltage is the voltage at the first end of the switch connected to each detection module, and the second voltage is the voltage at the second end of the switch connected to each detection module.

[0090] S503. Detect whether the absolute value of the pressure difference between the first voltage and the second voltage output by each detection module is less than or equal to the first preset voltage. If so, execute step 505; otherwise, execute step 504.

[0091] S504. Control each third switch and fourth switch in the UPS module to conduct, and control the first conversion module to resume operation.

[0092] S505. Send a first signal indicating that the detection is completed to the next UPS module.

[0093] See Figure 6 shown in the figure, a fault detection method for a UPS module provided by an embodiment of the present application. This fault detection method for the UPS module can be executed by a controller in the UPS module. See Figure 6 shown in the figure, which mainly includes the following steps:

[0094] S601. After receiving the first signal indicating the completion of detection sent by the previous UPS module, control each third switch and fourth switch in the UPS module to turn off, and control the first conversion module to stop working.

[0095] S602. After a preset time period after each third switch and fourth switch are turned off, receive the first voltage and second voltage output by each detection module. Among them, the first voltage is the voltage at the first end of the switch connected to each detection module, and the second voltage is the voltage at the second end of the switch connected to each detection module.

[0096] S603. Detect whether the absolute value of the voltage difference between the first voltage and the second voltage output by each detection module is less than or equal to the first preset voltage. If so, execute step 605; otherwise, execute step 604.

[0097] S604. Control each third switch and fourth switch in the UPS module to turn on, and control the first conversion module to resume working.

[0098] S605. Detect whether the absolute value of the first voltage and the second voltage output by each detection module is less than the second preset voltage. If so, execute step 606; otherwise, execute step 607.

[0099] S606. Send a second signal indicating the stop of detection to the next UPS module.

[0100] S607. Send a first signal indicating the completion of fault detection to the next UPS module.

[0101] See Figure 7 shown in the figure, a fault detection method for a UPS module provided by an embodiment of the present application. This fault detection method for the UPS module can be executed by a controller in the UPS module. See Figure 7 shown in the figure, which mainly includes the following steps:

[0102] S701. After receiving the first signal indicating the completion of detection sent by the previous UPS module, control each third switch and fourth switch in the UPS module to turn off, and control the first conversion module to stop working.

[0103] S702. Receive the first voltage and the second voltage output by each detection module after a preset time period after each third switch and fourth switch are turned off. Here, the first voltage is the voltage at the first end of the switch connected to each detection module, and the second voltage is the voltage at the second end of the switch connected to each detection module.

[0104] S703. Detect whether the absolute value of the voltage difference between the first voltage output by each detection module and the second voltage at the second end is less than or equal to the first preset voltage. If so, execute step 704; otherwise, execute step 707.

[0105] S704. Detect whether the absolute value of the first voltage and the second voltage output by each detection module is less than the second preset voltage. If so, execute step 705; otherwise, execute step 706.

[0106] S705. Send a second signal indicating the stop of detection to the next UPS module.

[0107] S706. Denote the UPS module to which it belongs as a faulty UPS module, control the third switch and the fourth switch in the UPS module to which it belongs to conduct, and control the first conversion module to resume operation.

[0108] S707. Send a first signal indicating that the fault detection is completed to the next UPS module.

[0109] S708. When it is determined that all UPS modules in the UPS system have been detected, detect whether the number of non-faulty UPS modules in the UPS system is greater than or equal to the set value. If so, execute step 709; otherwise, execute step 710.

[0110] S709. When it is determined that the UPS module to which it belongs is a faulty UPS module, control the third switch and the fourth switch in the UPS module to which it belongs to turn off, and control the first conversion module to stop working.

[0111] S710. When it is determined that the UPS module to which it belongs is a faulty UPS module, control the third switch and the fourth switch in the UPS module to which it belongs to remain conducting.

[0112] Based on the above embodiments, the embodiments of the present application further provide a computer-readable storage medium, in which a computer program is stored. When the computer program is executed by a computer, the computer is enabled to implement Figures 4 to 6The method provided in the illustrated embodiment. Among them, the storage medium can be any available medium that can be accessed by a computer. Taking this as an example but not limited to: the computer-readable medium can include RAM, read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM1), CD-ROM or other optical disc storage, magnetic disk storage medium or other magnetic storage devices, or any other medium that can be used to carry or store the desired program code in the form of instructions or data structures and can be accessed by a computer.

[0113] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0114] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory produce a manufactured article including an instruction device, and the instruction device implements the functions specified in one process Figure 1 one process or multiple processes and / or blocks Figure 1 specified in one block or multiple blocks.

[0115] These computer program instructions can also be loaded onto a computer or other programmable data processing device, so that a series of operation steps are performed on the computer or other programmable device to generate a computer-implemented process. Thus, the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one process Figure 1 one process or multiple processes and / or blocks Figure 1 specified in one block or multiple blocks.

[0116] In each embodiment of the present application, if there is no special explanation and logical conflict, the terms and / or descriptions between different embodiments are consistent and can be referenced to each other. The technical features in different embodiments can be combined to form new embodiments according to their inherent logical relationships.

[0117] Obviously, those skilled in the art can make various changes and modifications to this application without departing from the scope of protection of this application. Thus, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalent technologies, this application is also intended to cover these modifications and variations.

Claims

1. A UPS module, characterized in that, Applied to a UPS system, the UPS system includes a plurality of UPS modules connected in parallel, and each UPS module includes: a plurality of first switches, a plurality of second switches, a plurality of detection modules, a third switch corresponding to each first switch one by one, a fourth switch corresponding to each second switch one by one, a first conversion module, a second conversion module, and a controller; The first end of each first switch is connected to an input terminal of the corresponding UPS module, and the second end of each first switch is connected to the first end of the corresponding third switch and the first conversion module; The first end of each second switch is connected to an input terminal of the corresponding UPS module, and the second end of each second switch is connected to the first end of the corresponding fourth switch and the first conversion module; the plurality of input terminals of the UPS module are connected to the input terminals of other UPS modules in the UPS system and an AC power supply; The second conversion module is connected to the first conversion module, and the second conversion module is further used to be connected to a load; The second end of each third switch is used to be connected to the positive pole of the battery pack; The second end of each fourth switch is used to be connected to the negative pole of the battery pack; Each discharge module is connected to the second end of a first switch or the second end of a second switch in the corresponding UPS module; Each detection module is connected to both ends of a first switch or a second switch in the corresponding UPS module, and is used to detect the first voltage at the first end and the second voltage at the second end of the connected switch, and output the detected voltages to the controller; When receiving a first signal indicating that the fault detection of the previous UPS module connected in parallel with the corresponding UPS module is completed, the controller is used to control each third switch, each fourth switch, and the first conversion module in the corresponding UPS module to turn off, receive the voltages output by each detection module, and determine the fault status of the corresponding UPS module according to the values detected by each detection module.

2. The UPS module according to claim 1, wherein Specifically, when the UPS system operates in the battery pack power supply mode and receives the first signal sent by the previous UPS module connected in parallel with the corresponding UPS module, the controller is used to control each third switch, each fourth switch, and the first conversion module in the corresponding UPS module to turn off, receive the voltages output by each detection module after a preset duration when each third switch and each fourth switch are turned off, and determine that the corresponding UPS module is a faulty UPS module when the absolute value of the difference between the first voltage and the second voltage output by any detection module is less than or equal to a first preset voltage.

3. The UPS module according to claim 2, wherein, The controller is further used to: When it is determined that the absolute value of the difference between the first voltage and the second voltage output by each detection module is greater than the first preset voltage, control each third switch, each fourth switch, and the first conversion module in the corresponding UPS module to turn on.

4. The UPS module according to claim 2, wherein The controller is further used to: When it is determined that the corresponding UPS module is faulty, compare the first voltage and the second voltage output by each detection module with a second preset voltage respectively; When it is determined that the absolute values of the first voltage and the second voltage output by any detection module are both greater than the second preset voltage, it is determined that the number of faulty UPS modules in the UPS system is greater than 1.

5. The UPS module according to claim 4, characterized in that, The controller is further configured to: When it is determined that the absolute values of the first voltage and the second voltage output by any detection module are both greater than the second preset voltage, control each third switch, each fourth switch, and the first conversion module in the affiliated UPS module to remain off, and send a first signal indicating that the fault detection is completed to the next UPS module; And When it is determined that the absolute values of the first voltage and the second voltage output by each detection module are both less than or equal to the second preset voltage, control each third switch, each fourth switch, and the first conversion module in the affiliated UPS module to remain off, and send a second signal indicating to stop the fault detection to the next UPS module.

6. The UPS module according to claim 4, wherein The controller is further configured to: When it is determined that the absolute values of the first voltage and the second voltage output by any detection module are both greater than the second preset voltage, control each third switch, each fourth switch, and the first conversion module in the affiliated UPS module to turn on, and send a first signal indicating that the fault detection is completed to the next UPS module; When it is determined that the fault detection of other UPS modules in the UPS system is completed, if the number of non-faulty UPS modules in the UPS system is less than the set value, control each third switch, each fourth switch, and the first conversion module in the affiliated UPS module to turn on.

7. A UPS system, characterized in that, Comprising a battery pack and a plurality of UPS modules as described in any one of claims 1 to 6; The battery pack is connected to each UPS module and is used to supply power to each UPS module when the AC power supply connected to the UPS module fails.

8. The system according to claim 7, wherein The UPS system further includes a main controller, and the main controller is connected to the controllers in each UPS module.

9. A method for detecting faults in a UPS system, characterized in that, Applied to the UPS system as described in claim 7 or 8, including: When it is determined that the UPS system is operating in the battery power supply mode and receives a first signal indicating that the fault detection of the previous UPS module is completed, control each third switch, each fourth switch, and the first conversion module in the affiliated UPS module to turn off; Determine the fault status of the affiliated UPS module according to the first voltage and the second voltage output by each detection module.

10. The method according to claim 9, characterized in that, The determining the fault status of the affiliated UPS module according to the first voltage and the second voltage output by each detection module includes: Receive the voltages output by each detection module after a preset time period after each third switch, each fourth switch, and the first conversion module in the affiliated UPS module are turned off. When the absolute value of the difference between the first voltage and the second voltage output by any detection module is less than or equal to the first preset voltage, determine that the affiliated UPS module is a faulty UPS module.

11. The method according to claim 10, wherein The method further includes: When it is determined that the absolute value of the difference between the first voltage and the second voltage output by each detection module is greater than the first preset voltage, control each third switch, each fourth switch, and the first conversion module in the affiliated UPS module to turn on.

12. The method according to claim 10, wherein The method further includes: When determining that the UPS module belongs to a faulty UPS module, the first voltage and the second voltage output by each detection module are respectively compared with a second preset voltage; When determining that the absolute values of the first voltage and the second voltage output by any detection module are both greater than the second preset voltage, it is determined that the number of faulty UPS modules in the UPS system is greater than 1.

13. The method according to claim 12, wherein The method further includes: When determining that the absolute values of the first voltage and the second voltage output by any detection module are both greater than the second preset voltage, controlling each third switch, each fourth switch, and the first conversion module in the UPS module to which it belongs to remain off, and sending a first signal indicating that the fault detection is completed to the next UPS module; and When determining that the absolute values of the first voltage and the second voltage output by each detection module are both less than or equal to the second preset voltage, controlling each third switch, each fourth switch, and the first conversion module in the UPS module to which it belongs to remain off, and sending a second signal indicating to stop the fault detection to the next UPS module.

14. The method according to claim 12, wherein The method further includes: When determining that the absolute values of the first voltage and the second voltage output by any detection module are both greater than the second preset voltage, controlling each third switch, each fourth switch, and the first conversion module in the UPS module to which it belongs to turn on, and sending a first signal indicating that the fault detection is completed to the next UPS module; When determining that the fault detection of other UPS modules in the UPS system is completed, if the number of non-faulty UPS modules in the UPS system is less than a set value, controlling each third switch, each fourth switch, and the first conversion module in the UPS module to which it belongs to turn on.

15. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, which when executed, causes the method according to any one of claims 9-14 to be executed.

Images