UPS Module and Control Method thereof

Abstract

The uninterruptible power supply module of the present invention is characterized in that it includes: an AC-DC converter for converting the current of a commercial power supply; a DC-DC converter for converting the current of a battery; a common output terminal, the output terminals of the AC-DC converter and the DC-DC converter are connected through a link capacitor with a preset bus voltage to form the common output terminal; a first blocking part for opening or closing the circuit between the common output terminal and the load; a second blocking part for opening or closing the circuit between the commercial power supply and the AC-DC converter; a third blocking part for opening or closing the circuit between the battery and the DC-DC converter; and a control part. When the UPS module is started, the control part connects the common output terminal and the load and charges the link capacitor. If the bus voltage is formed, the control part closes the second blocking part and the third blocking part in sequence.

Description

Technical Field

[0001] The present invention relates to an uninterruptible power supply (UPS) module and a control method for the same. Background Art

[0002] Currently, with the development of technology, industrial systems are tending towards advancement, and automated and high-speed industrial equipment is operating according to these advanced industrial systems.

[0003] In the case where problems occur in the power system supplying power to these industrial devices due to the automation and high-speed operation of these industrial devices, significant damage caused by power outages may occur. Additionally, since the problems in the power system may damage these industrial devices themselves that receive power, the damage may further increase.

[0004] Therefore, in the case of power system problems such as sudden power outages or abnormal currents, a UPS module that supplies alternative power to loads, i.e., these industrial devices, using a battery charged with a specified amount of current, is introduced, so that stable power can also be supplied in the case of abnormalities in the commercial power supply system.

[0005] In the case of such a UPS module, it generally has a dual structure composed of a commercial power supply module connected to the commercial power supply to supply the current applied from the commercial power supply to the load and a battery module connected to the battery power supply to supply the current applied from the battery to the load. In the case of a UPS module having such a dual structure, the commercial power supply module and the battery module can be controlled by independent control units respectively.

[0006] However, in the case of controlling in the integrated form of such a dual module, there are problems that the structure and control of the UPS module become complex. In addition, such complex structure and control cause a time delay required for the UPS module to connect to an alternative power supply (battery) when a problem occurs in the commercial power supply, so there is a problem that it may become a factor hindering the uninterrupted power supply.

[0007] To solve such problems, research is currently actively underway to simplify the structure and control of the UPS module by unifying the UPS module.

[0008] On the other hand, in the case of using one UPS module, one UPS module undertakes all the current supplied to the load, so the current load increases. Moreover, in the case of using only one UPS module, there is a problem that the UPS function cannot be maintained when the UPS module is under repair or fails.

[0009] Therefore, research is actively underway to connect multiple UPS modules together to reduce the current load and enable the UPS function even when a certain UPS module fails or is under repair. Summary of the Invention

[0010] Problems to be Solved by the Invention

[0011] An object of the present invention is to provide a UPS module in which a commercial power supply module and a battery module are integrated, and a control method for the UPS module.

[0012] In addition, an object of the present invention is to provide a UPS module that can be connected to a load together with other UPSs, and a control method for the UPS module that connects the UPS to other UPSs.

[0013] Technical Solutions for Solving the Problems

[0014] According to one aspect of the present invention for achieving the above or other objects, the UPS module of an embodiment of the present invention is characterized in that it includes: an AC-DC converter that converts the AC current of a commercial power supply into a DC current; a DC-DC converter that converts the DC current of a battery into a DC current of a different voltage; a common output terminal, the output terminal of the AC-DC converter and the output terminal of the DC-DC converter are connected through a link capacitor having a preset bus voltage; a first blocking unit formed between the common output terminal and the load to open or close the circuit between the common output terminal and the load; a second blocking unit that opens or closes the circuit between the commercial power supply and the AC-DC converter; a third blocking unit that opens or closes the circuit between the battery and the DC-DC converter; an initial charging unit for charging the link capacitor; and a control unit. When the UPS module starts, the control unit closes the first blocking unit to connect the common output terminal and the load, charges the link capacitor by controlling the initial charging unit, and if the bus voltage is formed as the link capacitor is charged, the control unit closes the second blocking unit and the third blocking unit in sequence.

[0015] In one embodiment, the initial charging unit is characterized in that it includes: a first charging unit that receives an AC current and charges the link capacitor; and a second charging unit that receives a DC current and charges the link capacitor.

[0016] In one embodiment, the first charging unit is configured to receive the current of any one of the polyphase AC currents supplied from the commercial power supply and charge the link capacitor, and the second charging unit is configured to receive the positive current in the output terminal of the UPS module connected to the load and charge the link capacitor.

[0017] In one embodiment, it is characterized in that when the UPS module is started, the control unit controls the initial charging unit to charge the link capacitor through different charging units according to whether there is a DC current supplied to the load.

[0018] In one embodiment, it is characterized in that when the UPS module is started, the control unit controls the initial charging unit to charge the link capacitor through the first charging unit when there is no current supplied to the load from other UPS modules, and the control unit controls the initial charging unit to charge the link capacitor through the second charging unit when there is current supplied to the load from other UPS modules.

[0019] In one embodiment, it is characterized in that if the second blocking unit is closed to connect the circuit between the commercial power supply and the AC-DC converter, the control unit interrupts the current supply to the link capacitor by turning off the initial charging unit before the third blocking unit is closed. If the initial charging unit is turned off, the control unit connects the circuit between the battery and the DC-DC converter by closing the third blocking unit.

[0020] In one embodiment, it is characterized in that when both the first blocking unit and the second blocking unit are closed, the control unit drives the DC-DC converter to a standby state. The control unit controls the DC-DC converter in a state where the first blocking unit is closed to convert the DC current of the battery into a DC current having the bus voltage when the second blocking unit is open.

[0021] In one embodiment, it is characterized in that it further includes a discharging unit capable of discharging the charging voltage of the link capacitor. When the first blocking unit to the third blocking unit are all open, the control unit discharges the current charged in the link capacitor by connecting the discharging unit to the link capacitor.

[0022] According to an aspect of the present invention for achieving the above or other purposes, the control method of the UPS module according to an embodiment of the present invention includes: a first step of connecting the output terminal of the UPS module and the load by controlling a first blocking portion formed between the output terminal of the UPS module and the load when the UPS module is started; a second step of charging the link capacitor to a preset bus voltage by controlling an initial charging portion for charging the link capacitor; a third step of connecting the commercial power supply and the AC-DC converter by controlling a second blocking portion formed between the commercial power supply and the AC-DC converter that converts the AC current input from the commercial power supply into a DC current if the link capacitor is charged to the bus voltage; a fourth step of interrupting the current supply to the link capacitor by turning off the initial charging portion if the commercial power supply and the AC-DC converter are connected; a fifth step of converting the AC current of the commercial power supply into a DC current having a voltage corresponding to the bus voltage by controlling the AC-DC converter; a sixth step of connecting the battery and the DC-DC converter by controlling a third blocking portion formed between the battery and the DC-DC converter that converts the DC current input from the battery into a DC current having a voltage corresponding to the bus voltage; and a seventh step of driving the DC-DC converter to a standby state if the DC-DC converter and the battery are connected.

[0023] In one embodiment, the second step includes: a 2-1 step of determining whether there is a DC current supplied to the load; and a 2-2 step of controlling the initial charging portion according to the determination result to charge the link capacitor with the DC current supplied to the load if there is a DC current supplied to the load, and controlling the initial charging portion to charge the link capacitor with the AC current supplied from the commercial power supply if there is no DC current supplied to the load.

[0024] In one embodiment, it further includes: an eighth step of controlling the DC-DC converter to convert the DC current of the battery into a DC current having the bus voltage if the second blocking portion is opened to disconnect the commercial power supply; a ninth step of further detecting whether the commercial power supply is restored if the current of the battery is converted into a DC current of a different voltage by the DC-DC converter; a tenth step of connecting the commercial power supply and the AC-DC converter by closing the first blocking portion if the commercial power supply is restored; and an eleventh step of restoring the DC-DC converter to the standby state.

[0025] In one embodiment, it is characterized in that the ninth step includes: the 9-1 step of further detecting the discharge state of the battery; the 9-2 step of opening the first blocking part according to the discharge state of the battery so that the output end of the UPS module is disconnected from the load; the 9-3 step of, if the first blocking part is open, disconnecting the battery from the DC-DC converter by opening the third blocking part; and the 9-4 step of, if the third blocking part is open, discharging the voltage charged to the link capacitor by connecting a discharging part including at least one resistor or grounding to the link capacitor.

[0026] In one embodiment, it is characterized in that the tenth step includes: the 10-1 step of, when the commercial power supply is restored, charging the link capacitor to a preset bus voltage by controlling the initial charging part; and the 10-2 step of, if the link capacitor is charged to the bus voltage, connecting the commercial power supply and the AC-DC converter by controlling the second blocking part.

[0027] Advantages of the Invention

[0028] The effects of the UPS module and the control method of the UPS module according to the present invention are as follows.

[0029] According to at least one embodiment of the present invention, the present invention is controlled by a control part to connect a load to a commercial power supply or a battery, thereby simplifying the structure of the UPS module and making its control easier.

[0030] In addition, according to at least one embodiment of the present invention, the present invention enables a plurality of UPS modules to be connected to a load and enables the UPS modules to be easily loaded and unloaded, so that the UPS function can also be realized when any one of the UPS modules fails or needs to be repaired. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a block diagram showing each component of the UPS module for explaining an embodiment of the present invention.

[0032] Figure 2 It shows Figure 1 The circuit diagram showing the circuit structure of the UPS module of the embodiment of the present invention shown.

[0033] Figure 3 It is a flowchart showing the operation process of performing initial startup in the UPS module of the embodiment of the present invention.

[0034] Figure 4 It is a flowchart showing the operation process in the case where the commercial power supply is cut off in the UPS module of the embodiment of the present invention.

[0035] Figure 5 It is a circuit diagram showing the circuit structure in which a plurality of UPS modules according to embodiments of the present invention are connected to a load together. Detailed implementation manners

[0036] Hereinafter, embodiments disclosed in this specification will be described in detail with reference to the accompanying drawings. The same or similar components are denoted by the same reference numerals, and redundant descriptions thereof will be omitted. The suffixes "module" and "section" of the components used in the following description are given or mixed only for the ease of writing the specification, and they do not have meanings or functions to distinguish each other. Also, when describing the embodiments disclosed in this specification, if it is determined that a detailed description of related well-known technologies may obscure the gist of the embodiments disclosed in this specification, the detailed description thereof will be omitted. Also, the drawings are only for facilitating the understanding of the embodiments disclosed in this specification, and it should be understood that the technical ideas disclosed in this specification are not limited by the drawings, but cover all modifications, equivalents, and alternatives included in the spirit and technical scope of the present invention.

[0037] Ordinal terms such as first, second, etc. may be used to describe various components, but the components are not limited by the terms. The terms are only used to distinguish one component from other components.

[0038] When referring to any component "connected" or "coupled" to another component, it should be understood that it can be directly connected or coupled to the other component, or there may also be other components between them. On the contrary, when referring to any component "directly connected" or "directly coupled" to another component, it should be understood that there are no other components between them.

[0039] Unless otherwise clearly stated in the context, singular expressions include plural expressions.

[0040] In this application, it should be understood that terms such as "including" or "having" are intended to indicate the existence of features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and cannot preclude the existence or addition of one or more other features or numbers, steps, actions, components, parts, or combinations thereof in advance.

[0041] First, Figure 1 It is a block diagram for explaining each component of the UPS module according to the embodiment of the present invention.

[0042] Refer to Figure 1, the UPS (Uninterruptible Power Supply) module 10 of the embodiments of the present invention may include a control unit 100, and a DC blocking unit 110, an AC blocking unit 120, a battery blocking unit 130, an initial charging unit 140, a discharging unit 150, an AC-DC converter 160, and a DC-DC converter 170 that are connected to the control unit 100 and controlled by the control unit 100.

[0043] First, the DC blocking unit 110 may be a blocking unit formed at an output terminal for outputting a DC (Direct Current) current from the UPS module 10 of the embodiments of the present invention to a load. The DC blocking unit 110 may include at least one DC circuit breaker, and at least one of the DC circuit breakers is used to disconnect the UPS module in which an abnormality has occurred from the load to protect the load and the internal circuit in the case of an abnormality in the UPS module.

[0044] On the other hand, the AC blocking unit 120 may include at least one AC circuit breaker, and at least one of the AC circuit breakers is used to protect the internal circuit from damage such as overcurrent or arc by disconnecting the commercial power supply in the case of an abnormal state such as a short circuit in the alternating current (AC: Alternating Current) current (three-phase (R, S, T) alternating current) input from the commercial power supply.

[0045] On the other hand, the battery blocking unit 130 may include at least one DC circuit breaker, and at least one of the DC circuit breakers is used to protect the internal circuit from damage such as overcurrent or arc by disconnecting the battery in the case of an abnormal state in the battery.

[0046] On the other hand, the circuit breaker for alternating current or direct current included in the DC blocking unit 110, the AC blocking unit 120, or the battery blocking unit 130 may include at least one MCCB (Molded CirCuit Breaker) or ACB (Air Circuit Breaker). In addition, in the following description, when each blocking unit is turned on, the circuit is closed to connect the circuit, and when each blocking unit is turned off, the circuit is opened to disconnect or cut off the circuit.

[0047] On the other hand, the AC-DC converter 160 can be a converter that is connected to a commercial power supply and converts a three-phase alternating current input from the commercial power supply into a direct current. The AC-DC converter 160 can include a bridge rectifier circuit to which a plurality of rectifying elements are connected. The plurality of rectifying elements can be diodes or silicon controlled rectifiers (SCRs). In the following description, for ease of explanation, it is assumed that the rectifying element is a diode.

[0048] In addition, the DC-DC converter 170 can be a converter that is connected to a battery and converts a direct current of a primary voltage input from the battery into a direct current of a secondary voltage. The secondary voltage is a voltage higher than the primary voltage and can be the same voltage as the direct current voltage output from the AC-DC converter 160. In this case, the output terminal voltage of the AC-DC converter 160 can be a preset bus link voltage, and the DC-DC converter 170 can be configured to convert a high-voltage current output from the battery into a current of the bus link voltage so that the output terminal of the AC-DC converter 160 and the output terminal of the DC-DC converter 170 are connected to each other.

[0049] On the other hand, the UPS module according to an embodiment of the present invention can include a DC link capacitor to connect the output terminal of the AC-DC converter 160 and the output terminal of the DC-DC converter 170 to each other through the bus link voltage.

[0050] To charge the DC link capacitor, the UPS module 10 according to an embodiment of the present invention can include an initial charging unit 140. For the safe charging of the capacitor, the initial charging unit 140 can include at least one resistor to adjust the charging speed of the DC link capacitor through at least one of the resistors, thereby enabling the capacitor to be safely charged.

[0051] In addition, the discharging unit 150 can discharge the current of the charged DC link capacitor. The discharging unit 150 can include at least one resistor or a ground, and the resistor or the ground discharges according to the control of the control unit 100 to safely discharge the current charged into the DC link capacitor through the resistor or the ground.

[0052] On the other hand, the control unit 100 connects the UPS module 10 to a load by sequentially controlling each connected component and connects the commercial power supply and the battery, so that an alternating current or a direct current input from the connected commercial power supply or battery can be converted into a direct current with a specific voltage and output to the load.

[0053] To this end, the control unit 100 can control the initial charging unit 140 to charge the provided DC link capacitor until it reaches a specific voltage, and can control the AC blocking unit 120, the DC blocking unit 110, the AC-DC converter 160, and the DC-DC converter 170 based on the voltage charged in the DC link capacitor, thereby connecting the battery and the commercial power supply to the load together.

[0054] Figure 2 It shows Figure 1 The circuit diagram of the circuit structure of the UPS module 10 according to the embodiment of the present invention shown.

[0055] Referring to Figure 2 In the embodiment of the present invention, the UPS module 10 can supply a direct current from the commercial power supply 200 or the battery 201 to the load or the power conversion unit connected to the load through the DC output terminals (DC+, DC-). In addition, the supplied direct current is input to the load or is converted into an alternating current again through the power conversion unit connected to the load, so that it can become the driving source of the load.

[0056] To supply the direct current as the driving source of the load, the UPS module 10 can include: the commercial power supply 200; and an AC-DC converter 160 that converts the three-phase (R phase, S phase, T phase) alternating current input from the commercial power supply 200 into a direct current with a preset voltage. In addition, an AC blocking unit 120 can be provided between the AC-DC converter 160 and the commercial power supply 200, and the AC blocking unit 120 can protect the AC-DC converter 160 and the internal circuit when an abnormality occurs in the commercial power supply 200.

[0057] The AC blocking unit 120 can close the circuit between the commercial power supply 200 and the AC-DC converter 160 to connect the commercial power supply 200 and the AC-DC converter 160, or can open the circuit between the commercial power supply 200 and the AC-DC converter 160 to disconnect the connection between the commercial power supply 200 and the AC-DC converter 160.

[0058] On the other hand, at least one DC link capacitor 210 can be formed at the output terminal of the AC-DC converter 160. Here, the DC link capacitor 210 can be connected to the initial charging unit 140 and can be charged with the current supplied from the initial charging unit 140 until it reaches a specific voltage.

[0059] On the other hand, the initial charging unit 140 may receive the current of any one phase (the first-phase current, e.g., the R-phase current) of the three-phase alternating current of the commercial power supply 200. In addition, the first-phase current may be supplied to the DC link capacitor 210, so that the DC link capacitor 210 can be charged.

[0060] More specifically, the initial charging unit 140 may include a switch and at least one rectifying element (e.g., a diode), and close or open the circuit between the commercial power supply (the first phase) and the DC link capacitor 210 under the control of the control unit 100, whereby the first-phase current rectified by the rectifying element can be supplied to the DC link capacitor 210, or the first-phase current supplied to the DC link capacitor 210 can be disconnected.

[0061] Herein, the DC link capacitor 210 may further include a discharging unit 150. The discharging unit 150 may be connected to the DC link capacitor 210 and may include at least one resistor or a ground. In addition, under the control of the control unit 100, it closes the circuit between the DC link capacitor 210 and the resistor or the ground, thereby connecting the DC link capacitor 210 and the resistor or the ground, so that the current charged in the DC link capacitor 210 can be discharged through the resistor or the ground.

[0062] In addition, the UPS module 10 according to an embodiment of the present invention may include: a battery 201; and a DC-DC converter 170 that converts the direct current having a first voltage input from the battery 201 into a direct current having a preset second voltage. In addition, a battery blocking unit 130 may be provided between the DC-DC converter 170 and the battery 201, and the battery blocking unit 130 can protect the DC-DC converter 170 and the internal circuit when an abnormality occurs in the battery 201.

[0063] The battery blocking unit 130 may close the circuit between the battery 201 and the DC-DC converter 170 to connect the battery 201 and the DC-DC converter 170, or may open the circuit between the battery 201 and the DC-DC converter 170 to disconnect the connection between the battery 201 and the DC-DC converter 170.

[0064] On the other hand, the output end of the DC-DC converter 170 may be connected to the output end of the AC-DC converter 160 in which the DC link capacitor 210 (or the DC link capacitor 210 having the discharging unit 150) is formed to form a common output end.

[0065] On the other hand, the second voltage, which is the output voltage of the DC-DC converter 170, may be the same voltage as the charging voltage of the DC link capacitor 210 that is charged by the initial charging unit 140. In this case, the charging voltage of the DC link capacitor 210 may be the DC bus voltage. When the output voltage of the DC-DC converter 170 reaches the DC bus voltage, the output terminal of the DC-DC converter 170 and the output terminal of the AC-DC converter 160 may be connected to each other. Thus, through the shared output terminal, the commercial power supply 200 and the battery 201 can be simultaneously connected to the load.

[0066] On the other hand, a DC blocking unit 110 may be provided between the shared output terminal and the DC output terminals (DC+, DC-). When an abnormality occurs in the UPS module 10, the DC blocking unit 110 can protect the load and the internal circuit by disconnecting the output terminals (DC output terminals: DC+, DC-) of the UPS module 10 and the load.

[0067] The DC blocking unit 110 can connect the shared output terminal and the DC output terminals (DC+, DC-) by closing the circuit between the shared output terminal and the DC output terminals (DC+, DC-), or can disconnect the connection between the shared output terminal and the DC output terminals (DC+, DC-) by opening the circuit between the shared output terminal and the DC output terminals (DC+, DC-).

[0068] Figure 3 Yes, it shows the Figure 2 flowchart of the operation process in which the commercial power supply 200 and the battery 201 are all connected to the load through initial startup in the UPS module 10 according to an embodiment of the present invention having the

[0069] Refer to Figure 3 , the control unit 100 of the UPS module 10 according to an embodiment of the present invention may first turn on the DC blocking unit 110 in a state where both the commercial power supply 200 and the battery 201 are separated from the load. Then, a shared output terminal formed by connecting the output terminal of the AC-DC converter 160 having the DC link capacitor 210 and the output terminal of the DC-DC converter 170 may be connected to the load or the DC output terminals (DC+, DC-) of the power conversion unit connected to the load (S300).

[0070] On the other hand, if the common output terminal is connected to the DC output terminal through the step S300, the control unit 100 can first turn on the initial charging unit 140, thereby connecting the circuit between the commercial power supply (first phase) 200 and the DC link capacitor 210. Then, the first-phase current is supplied to the DC link capacitor 210, so that the DC link capacitor 210 can be charged (S301).

[0071] In addition, if the charging voltage of the DC link capacitor 210 reaches a preset voltage, that is, the DC link bus voltage, the control unit 100 can first turn on the AC blocking unit 120 (S302). Then, the commercial power supply 200 and the AC-DC converter 160 can be connected to each other through the AC blocking unit 120. Thus, the current of the commercial power supply 200, that is, the three-phase alternating current, can be supplied to the AC-DC converter 160.

[0072] In addition, if the current of the commercial power supply 200 is supplied to the AC-DC converter 160, the control unit 100 can disconnect the connection between the DC link capacitor 210 and the commercial power supply (first phase) 200 by turning off the initial charging unit 140. Then, the current supply to the DC link capacitor 210 can be interrupted.

[0073] In addition, the control unit 100 can convert the current input from the commercial power supply 200 into a direct current with a preset voltage by controlling the AC-DC converter 160 (S303). Here, the preset voltage can be the DC link bus voltage. In this case, through the DC link capacitor 210, a direct current with the same voltage as the DC link bus voltage can be output. In addition, the current of the DC link bus voltage output from the AC-DC converter 160 can be conducted to the DC output terminal (DC+, DC-) through the DC blocking unit 110. In addition, it can be supplied to the load or the power conversion unit of the load through the DC output terminal (DC+, DC-).

[0074] On the other hand, if the AC-DC converter 160 is driven, the control unit 100 can turn on the battery blocking unit 130 (S304). Then, the battery 201 and the DC-DC converter 170 can be connected to each other through the battery blocking unit 130. Thus, the direct current of the battery 201 can be supplied to the DC-DC converter 170.

[0075] Then, the control unit 100 can control the DC-DC converter 170 so that the DC-DC converter 170 is driven to the standby state (S305). In addition, the control unit 100 can control the DC-DC converter 170 to perform current conversion according to whether the current supply from the commercial power supply 200 is disconnected.

[0076] That is, when the current is supplied from the commercial power supply 200 without abnormality, the control unit 100 drives the DC-DC converter 170 to the standby state. When the current supply from the commercial power supply 200 is disconnected due to an abnormality or a failure of the commercial power supply 200, the control unit 100 can convert the current (current having a primary voltage) of the battery 201 into a current having the DC link bus voltage by driving the DC-DC converter 170.

[0077] Then, the direct current converted in the DC-DC converter 170 can be conducted to the DC output terminals (DC+, DC-) via the common output terminal and the DC blocking unit 110, and can be supplied to the load or the power conversion unit of the load via the DC output terminals (DC+, DC-).

[0078] On the other hand, Figure 4 is a flowchart showing the operation process when the commercial power supply 200 is disconnected due to an abnormality or a failure after the initial start-up drive of the UPS module 10 according to Figure 3 the embodiment of the present invention.

[0079] As an example, in the case of a power abnormality such as an overcurrent or a failure in the system of the commercial power supply 200, the AC blocking unit 120 is turned off, so that the connection between the commercial power supply 200 and the AC-DC converter 160 can be disconnected. Then, the control unit 100 can convert the direct current supplied from the battery 201 into a current having the DC link bus voltage by driving the DC-DC converter 170 (S400). Then, as described above, the direct current converted in the DC-DC converter 170 can be supplied to the load or the power conversion unit of the load through the DC blocking unit 110.

[0080] As described above, when the current for supplying to the load is supplied from the battery 201, the control unit 100 can detect the remaining power of the battery 201. As an example, the control unit 100 can measure the voltage of the battery 201 and judge the discharge state of the battery 201 according to the measured voltage (S401).

[0081] According to the judgment result in step S401, if the remaining voltage of the battery 201 exceeds a preset level, the control unit 100 can detect whether the commercial power supply 200 is restored while the current supplied from the battery 201 is being supplied to the load (S402). For example, the control unit 100 can detect the current input from the commercial power supply 200 through a current sensor provided at the input end of the AC blocking unit 120, and can judge whether the commercial power supply 200 is restored based on the detected current.

[0082] On the other hand, according to the detection result of step S402, in the case where the commercial power supply 200 is not restored (when the commercial power supply 200 is in the off state), the control unit 100 can repeatedly execute steps S400 to S402. Therefore, the current state of the battery 201 supplied to the load can be continuously maintained.

[0083] On the contrary, according to the judgment result of step S402, if the commercial power supply 200 is in a restored state, the control unit 100 can connect the commercial power supply 200 by turning on the AC blocking unit 120 (S403). As an example, when it is detected by the current sensor that there is a current input from the commercial power supply 200, the control unit 100 can first turn on the AC blocking unit 120 to connect the commercial power supply 200. In this case, when the current supplied from the commercial power supply 200 is a normal current, the AC blocking unit 120 can remain in the on state. Therefore, the commercial power supply 200 can be connected to the AC-DC converter 160. However, in the case where there is a problem with the current supplied from the commercial power supply 200 (e.g., overcurrent), the AC blocking unit 120 can be turned off again. In this case, the commercial power supply 200 can be disconnected again.

[0084] On the other hand, when the AC blocking unit 120 is turned on, the commercial power supply 200 and the AC-DC converter 160 can be connected again. Then, the control unit 100 can control to drive the AC-DC converter 160 to convert the three-phase alternating current supplied from the commercial power supply 200 into a direct current corresponding to the voltage of the DC link bus (S404). Then, the direct current output from the AC-DC converter 160 can be supplied to the load or the power conversion unit of the load through the DC blocking unit 110.

[0085] In addition, the control unit 100 can switch the DC-DC converter 170 to the standby state again (S405). Therefore, the DC-DC converter 170 can stop converting the current of the battery 201, and thus can interrupt the power consumption of the battery 201.

[0086] On the other hand, in the above description, it is assumed that the DC link capacitor 210 remains in a charged state. However, when the commercial power supply 200 is disconnected, obviously, at least a part of the voltage charged in the DC link capacitor 210 can also be discharged. Therefore, in step S403, before turning on the AC blocking unit 120, the control unit 100 can first execute a process for charging the DC link capacitor 210.

[0087] In this case, step S403 may include: when the commercial power supply 200 is restored in step S402, first turning on the initial charging unit 140 and charging the DC link capacitor 210. In addition, it may also include: if the DC link capacitor 210 is charged to a preset voltage, that is, the DC link bus voltage, then turning on the AC blocking unit 120 to connect the commercial power supply 200 and the AC-DC converter 160, and turning off the initial charging unit 140 after the AC blocking unit 120 is turned on, thereby disconnecting the connection between the commercial power supply 200 and the DC link capacitor 210.

[0088] On the other hand, according to the detection result of step S401, if the remaining voltage of the battery 201 is below a preset level, the control unit 100 can disconnect the UPS module 10 from the load by turning off the DC blocking unit 110 (S410). Thus, when the commercial power supply 200 has an abnormality and the current supply is disconnected, and the battery 201 discharges and cannot supply more current from the UPS module 10, the load can receive current through a power supply module connected to another power source (for example, a backup power source).

[0089] On the other hand, when the UPS module 10 is disconnected from the load in step S410 through the DC blocking unit 110, the control unit 100 can disconnect the connection between the discharged battery 201 and the DC-DC converter 170 by turning off the battery blocking unit 130 (S411).

[0090] In addition, the control unit 100 can turn on the discharge unit 150 to connect the DC link capacitor 210 and at least one resistor included in the discharge unit 150 or ground to the DC link capacitor 210 (S412). Thus, the current charged in the DC link capacitor 210 is gradually discharged, and thereby the charging voltage of the DC link capacitor 210 can also be reduced.

[0091] On the other hand, if the voltage of the DC link capacitor 210 discharges to a preset safe voltage (e.g., 0 V or a voltage close to 0 V) as the DC link capacitor 210 discharges, the control unit 100 may turn off the discharge unit 150 (S413). Therefore, the discharge unit 150 and the DC link capacitor 210 can be disconnected.

[0092] As described above, in the UPS module 10 according to the embodiment of the present invention, when the driving of the UPS module 10 is stopped, the high voltage charged in the DC link capacitor 210 is discharged, thereby being able to prevent damage or accidents caused by the high voltage of the DC link capacitor 210 in advance.

[0093] On the other hand, the above Figures 1 to 4 configuration shows the configuration in which one UPS module 10 of the embodiment of the present invention is connected to a load or a power conversion unit of the load. However, differently, obviously, a plurality of UPS modules of the embodiment of the present invention can be connected to the load together.

[0094] Figure 5 is a circuit diagram showing the circuit structure in which a plurality of UPS modules of the embodiment of the present invention are connected to the load together in this case.

[0095] Referring to Figure 5 , Figure 5 shows an example of some of the UPS modules 500 and 501 among the plurality of UPS modules connected to one DC output terminal (DC +, DC -). The common output terminals of each UPS module can be connected through a plurality of DC blocking units 512 and 552 formed in each of the UPS modules 500 and 501. Here, the common output terminal can be formed by connecting the output terminal of the AC - DC converter and the output terminal of the DC - DC converter to each other in each UPS module.

[0096] As described above, when a plurality of UPS modules are connected to the load together, the current required by the load, that is, the current load, can be shared by the plurality of UPS modules. Therefore, when a plurality of UPS modules are driven together, a more stable power supply can be provided by reducing the current load.

[0097] On the other hand, when a plurality of UPS modules are driven in this way, at least one UPS module may be disconnected due to a fault or maintenance.

[0098] For example, as Figure 5As shown, when the first module 500 and the second module 501 are jointly connected to the DC output terminals (DC+, DC-), in the case where the connection of the first module 500 is released due to maintenance or a fault, the first AC blocking unit 518 and the battery blocking unit 522 can be sequentially turned off first, so that the current supply from the commercial power supply 510 and the battery 511 can be interrupted.

[0099] Then, similar to the process from Figure 4 step S410 to step S413, the control unit (not shown) of the first module 500 can first turn off the first DC blocking unit 512, thereby disconnecting the first module 500 from the DC output terminals (DC+, DC-). Then, the current can be supplied to the load through the remaining UPS modules including other UPS modules except the first module 500, that is, the second module 501.

[0100] On the other hand, if the first DC blocking unit 512 is turned off, the control unit (not shown) of the first module 500 can connect at least one resistor or ground of the discharge unit 526 to the first DC link capacitor 516 of the first module 500 by turning on the discharge unit 526. Then, the current charged in the first DC link capacitor 516 can be discharged.

[0101] Then, if the inspection or maintenance of the first module 500 is completed, the first module 500 can reconnect the output terminal of the first module 500 and the DC output terminals (DC+, DC-) by turning on the first DC blocking unit 512.

[0102] However, as described above, the UPS module according to the embodiment of the present invention can connect the output current of the battery and the output current of the commercial power supply to each other according to the DC link bus voltage formed by the DC link capacitor. Therefore, in a state where the DC link bus voltage is not formed by the DC link capacitor, when the AC current of the input commercial power supply is input, a voltage lower than the DC link bus voltage may be output through the AC-DC converter.

[0103] Thus, in order to prevent the output of a DC current having a voltage lower than the DC link bus voltage, it is necessary to charge the DC link capacitor first before connecting the commercial power supply.

[0104] To this end, the first module 500 may further include a configuration of an initial charging unit connected to the positive terminal DC+ of the DC output terminals (DC+, DC-) connected to the load. In this case, the initial charging unit for receiving any one phase current (the first-phase alternating current) of the alternating current of the commercial power supply 510 may rectify the first-phase alternating current according to the control of a control unit (not shown) of the first module 500 and supply it to the first DC link capacitor 516; another initial charging unit connected to the positive terminal DC+ of the DC output terminals (DC+, DC-) may supply the direct current of the positive terminal to the first DC link capacitor 516 according to the control of the control unit (not shown) of the first module 500.

[0105] Hereinafter, the initial charging unit 514 that supplies the alternating current of the commercial power supply 510 to the first DC link capacitor 516 is referred to as an AC initial charging unit, and the initial charging unit 515 that supplies the direct current of the positive terminal DC+ of the DC output terminals (DC+, DC-) to the first DC link capacitor 516 is referred to as a DC initial charging unit.

[0106] As described above, the initial charging unit of the UPS modules 500 and 501 according to the embodiments of the present invention may have a configuration including the AC initial charging unit 514 and the DC initial charging unit 515. In this case, as described above, for inspection or repair, when the connection between the first module 500 and the load is disconnected and then reconnected, since the first AC blocking unit 518 and the battery blocking unit 522 are in a closed state, the DC output terminals (DC+, DC-) have a higher voltage.

[0107] In this case, the control unit of the first module 500 may close the circuit between the positive terminal DC+ of the DC output terminals (DC+, DC-) and the first DC link capacitor 516 by turning on the DC initial charging unit 515. Then, the positive terminal DC+ and the first DC link capacitor 516 are connected, and the DC voltage may be supplied from the positive terminal DC+ to the first DC link capacitor 516.

[0108] On the other hand, when the first DC link capacitor 516 is charged to a preset DC link bus voltage, the control unit of the first module 500 may connect the commercial power supply 510 to the AC-DC converter 520 by turning on the first AC blocking unit 518. Then, the AC-DC converter 520 may convert the alternating current input from the commercial power supply 510 into a direct current having the DC link bus voltage through the first DC link capacitor 516 and output it.

[0109] On the other hand, if the first AC blocking unit 518 is turned on, the control unit of the first module 500 can turn off the DC initial charging unit 515. In addition, the current of the battery 511 can be input to the first DC-DC converter 524 by turning on the first battery blocking unit 130, and the first DC-DC converter 524 can be driven to the standby state. Then, a plurality of UPS modules including the first module 500 can share the current required by the load again, that is, the current load.

[0110] As described above, the UPS module according to the embodiment of the present invention can connect the output current of the battery and the output current of the commercial power supply to each other according to the DC link bus voltage formed by the DC link capacitor, so that the internal structure of the UPS module can be unified. On the other hand, in order to implement such a unified structure, the UPS module according to the embodiment of the present invention can charge the DC link capacitor before the commercial power supply is connected.

[0111] On the other hand, the DC link capacitor is charged by an initial charging unit for supplying current to the DC link capacitor. The initial charging unit can receive current from different current supply sources and charge the DC link capacitor according to whether the UPS module is initially started without supplying current to the load or restarted in a state where other UPS modules are connected to the load, that is, in a state where there is direct current flowing to the load. As an example, the control unit of the UPS module determines whether there is another UPS module supplying current to the load, that is, the current flowing to the load, through a feedback signal provided by another UPS module connected to the load or a current sensor formed at the DC output terminals (DC+, DC-).

[0112] More specifically, the UPS module according to the embodiment of the present invention receives current from the commercial power supply and charges the DC link capacitor during the initial start, and can receive the current input to the load and charge the DC link capacitor during the restart. To this end, the initial charging unit may include: a charging unit (AC initial charging unit) for charging the DC link capacitor by including at least one rectifying element capable of rectifying the alternating current of the commercial power supply; and a charging unit (DC initial charging unit) for receiving the current input to the load and charging the DC link capacitor.

[0113] The foregoing invention of the present disclosure may be implemented as code that can be read by a computer on a medium recording a program. A medium readable by a computer includes all kinds of recording devices that store data readable by a computer system. Examples of a medium readable by a computer include HDD (Hard Disk Drive), SSD (Solid State Disk), SDD (Silicon Disk Drive), ROM, RAM, CD-ROM, magnetic tape, floppy disk, optical data storage device, etc. In addition, there is also an example implemented in the form of a carrier wave (for example, transmitted through a network).

[0114] In addition, the computer may further include the control unit 100. Therefore, the above detailed description should not be construed as restrictive in all respects, but rather as exemplary. The scope of the present invention should be determined by a reasonable interpretation of the appended claims, and all changes within the equivalent scope of the present invention are included in the scope of the present invention.

Claims

1. A UPS module, characterized in that, Comprising: An AC-DC converter that converts the alternating current of a commercial power supply into direct current; A DC-DC converter that converts the direct current of a battery into direct current of a different voltage; A common output terminal, where the output terminal of the AC-DC converter and the output terminal of the DC-DC converter are connected through a link capacitor with a preset bus voltage to form the common output terminal; A first blocking unit formed between the common output terminal and the load, and opening or closing the circuit between the common output terminal and the load; A second blocking unit that opens or closes the circuit between the commercial power supply and the AC-DC converter; A third blocking unit that opens or closes the circuit between the battery and the DC-DC converter; An initial charging unit that charges the link capacitor; A control unit, when the UPS module starts, the control unit connects the common output terminal and the load by closing the first blocking unit, and charges the link capacitor by controlling the initial charging unit. If the bus voltage is formed as the link capacitor is charged, the control unit closes the second blocking unit and the third blocking unit in sequence; And A discharging unit that can discharge the charging voltage of the link capacitor; When the first blocking unit to the third blocking unit are all open, the control unit discharges the current charged into the link capacitor by connecting the discharging unit to the link capacitor.

2. The UPS module according to claim 1, wherein The initial charging unit includes: A first charging unit that receives alternating current and charges the link capacitor; and A second charging unit that receives direct current and charges the link capacitor.

3. The UPS module according to claim 2, wherein The first charging unit is configured to receive the current of any one phase of the polyphase alternating current supplied from the commercial power supply and charge the link capacitor, The second charging unit is configured to receive the positive current in the output terminal of the UPS module connected to the load and charge the link capacitor.

4. The UPS module according to claim 2, wherein When the UPS module starts, the control unit controls the initial charging unit to charge the link capacitor through different charging units according to whether it is in a state where direct current is supplied to the load.

5. The UPS module according to claim 4, wherein When the UPS module starts, in the case where there is no current supplied from other UPS modules to the load, the control unit controls the initial charging unit to charge the link capacitor through the first charging unit, In the case where there is current supplied from other UPS modules to the load, the control unit controls the initial charging unit to charge the link capacitor through the second charging unit.

6. The UPS module according to claim 1, wherein If the second blocking part is closed to connect the circuit between the commercial power supply and the AC-DC converter, the control part interrupts the current supply to the link capacitor by turning off the initial charging part before the third blocking part is closed. If the initial charging part is turned off, the control part connects the circuit between the battery and the DC-DC converter by closing the third blocking part.

7. The UPS module according to claim 1, characterized in that When both the first blocking part and the second blocking part are closed, the control part drives the DC-DC converter to a standby state. When the second blocking part is open while the first blocking part is closed, the control part controls the DC-DC converter to convert the DC current of the battery into a DC current having the bus voltage.

8. A control method for a UPS module, characterized in that, Comprising: When the UPS module is started, the step of connecting the output end of the UPS module and the load by controlling the first blocking part formed between the output end of the UPS module and the load; The step of charging the link capacitor to a preset bus voltage by controlling the initial charging part for charging the link capacitor; If the link capacitor is charged to the bus voltage, the step of connecting the commercial power supply and the AC-DC converter by controlling the second blocking part formed between the commercial power supply and the AC-DC converter for converting the AC current input from the commercial power supply into a DC current; If the commercial power supply and the AC-DC converter are connected, the step of interrupting the current supply to the link capacitor by turning off the initial charging part; The step of converting the AC current of the commercial power supply into a DC current having a voltage corresponding to the bus voltage by controlling the AC-DC converter; The step of connecting the battery and the DC-DC converter by controlling the third blocking part formed between the battery and the DC-DC converter for converting the DC current input from the battery into a DC current having a voltage corresponding to the bus voltage; If the DC-DC converter and the battery are connected, the step of driving the DC-DC converter to a standby state; and If the first blocking part to the third blocking part are all open, the step of discharging the current charged in the link capacitor by connecting a discharging part including at least one resistor or ground to the link capacitor.

9. The control method of the UPS module according to claim 8, characterized in that The step of charging the link capacitor to a preset bus voltage includes: The step of determining whether there is a DC current supplied to the load; and According to the result of determining whether there is a DC current supplied to the load in a directed manner, when there is a DC current supplied to the load in a directed manner, controlling the initial charging unit to charge the link capacitor with the DC current supplied to the load; when there is no DC current supplied to the load in a directed manner, controlling the initial charging unit to charge the link capacitor with the AC current supplied from the commercial power supply.

10. The control method of the UPS module according to claim 8, wherein Further comprising: When the second blocking unit is open and the commercial power supply is disconnected, controlling the DC-DC converter to convert the DC current of the battery into a DC current having the bus voltage. When the current of the battery is converted into a DC current having a different voltage by the DC-DC converter, further detecting whether the commercial power supply is restored. When the commercial power supply is restored, connecting the commercial power supply and the AC-DC converter by closing the second blocking unit. And Restoring the DC-DC converter to the standby state.

11. The control method of the UPS module according to claim 8, characterized in that The step of discharging the current charged in the link capacitor includes: When the second blocking unit is open and the commercial power supply is disconnected, further detecting the discharge state of the battery. According to the discharge state of the battery, disconnecting the output terminal of the UPS module from the load by opening the first blocking unit. When the first blocking unit is open, disconnecting the battery from the DC-DC converter by opening the third blocking unit; and When the first to third blocking units are all open, discharging the voltage charged in the link capacitor by connecting the discharging unit to the link capacitor.

12. The control method of the UPS module according to claim 10, characterized in that The step of connecting the commercial power supply and the AC-DC converter includes: When the commercial power supply is restored, charging the link capacitor to a preset bus voltage by controlling the initial charging unit; and When the link capacitor is charged to the bus voltage, connecting the commercial power supply and the AC-DC converter by controlling the second blocking unit.

Images