Method for reducing UPS component stresses during transition from inverter to green / bypass operation

Abstract

To provide uninterruptible power supply (UPS) systems, methods, and computer-readable mediums utilizing electromechanical bypass relays to switch from an on-line mode of operation to a green / bypass mode of operation.SOLUTION: A first UPS 100 includes a controller to adaptively adjust timing when a UPS inverter is made to turn off to prevent backfeeding a utility. After the UPS is instructed to transition from an on-line mode to a green mode, a monitoring period begins. During the monitoring period, a parameter related to output current of the inverter is monitored and compared to a predetermined threshold. If the parameter exceeds the predetermined threshold before a fixed period time elapses, the inverter is turned off early. If the inverter current does not exceed the predetermined value within the fixed period time, the inverter is turned off.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] This application is incorporated herein by reference in its entirety. The patent application filed on the 11th, "SYSTEM AND METHOD FOR PREVENTING DAMAGE TO BYPASS RELAYS IN POWER SUPPLY" U.S. Provisional Application No. 10 / 10 / 2009, entitled "A Method for Preventing Bypass-Relay Damage in a Power Supply," Priority is claimed to be from No. 62 / 914,034.

[0002] TECHNICAL FIELD The present disclosure relates generally to systems and methods for controlling uninterruptible power supplies (UPS). Summary of the Invention [Problem to be solved by the invention]

[0003] sensitive and / or critical loads such as computer systems and other data processing systems Such as uninterruptible power supplies (UPS) that provide regulated and / or uninterrupted power to a load. Known uninterruptible power supplies include online UPS, off-line There are line UPS as well as other devices. Online UPS is a device that provides power to the AC power supply when the primary power source is interrupted. The offline UPS provides regulated AC power and backup AC power. Generally, they do not regulate the input AC power when the primary AC power is interrupted, but they do regulate the backup AC power. C. A line-interactive UPS provides power when a power outage occurs. It is similar to an offline UPS in that it switches to a power source, but generally does not require a The inverter has a multi-tap transformer that adjusts the output voltage. [Means for solving the problem]

[0004] According to one embodiment, an uninterruptible power supply (UPS) is configured to receive input power. and a backup power supply configured to receive backup power from the backup power source. an input section, and an output section for receiving at least one of the input power and the backup power; an output configured to supply power to a load; the input; and the backup input; and an inverter connected to the output and configured to provide an inverter output current. and a sensor configured to detect a parameter indicative of the inverter output current. a relay connected between the input and output, and a relay connected to the sensor at least one controller configured to determine when the relay is closed; configured to turn off the inverter based on a determination that the relay is closed. The controller.

[0005] In one embodiment, the at least one controller controls the inverter output current. and determining that the relay is closed based on the indicated parameters. .

[0006] In another embodiment, the at least one controller controls the inverter output current and determining that the relay is closed based on the differential value of

[0007] In one embodiment, the at least one controller is connected to the relay; and detecting that the inverter output current exceeds a threshold value. and determining that the relay is closed based on detecting a threshold being exceeded. do.

[0008] In another embodiment, the at least one controller is configured to close the relay. to determine that the relay has closed based on the lapse of a predetermined period of time after commanding the relay to close. It is structured as follows.

[0009] In one embodiment, the UPS includes a power factor correction (PFC) circuit and the sensor includes: As a parameter indicating the inverter output current, The sensor is configured to detect a current passing through the sensor.

[0010] In another embodiment, the uninterruptible power supply further receives a second input power and A second input configured to provide a second input power to the relay.

[0011] In one embodiment, the sensor is connected to the inverter output at the output of the inverter. The sensor is configured to detect a force current.

[0012] In another embodiment, the sensor detects a parameter indicative of the inverter output current. and configured to sense the current at the input of the inverter.

[0013] According to one embodiment, a method of operating an uninterruptible power supply (UPS) includes: receiving backup power from a backup power source; and supplying output power to a load from at least one of the input power and the backup power. and supplying a parameter indicating an inverter output current from the inverter of the UPS. detecting a meter; determining that a relay is closed; and turning off the included inverter based on the determination of closure. can.

[0014] In one embodiment, the method further comprises: obtaining a parameter indicative of the inverter output current; determining that the relay is closed based on the data.

[0015] In another embodiment, the method further comprises commanding the relay to close. and detecting that a parameter indicative of the inverter output current exceeds a threshold value in response to the and detecting the inverter output current exceeding a threshold value. and determining that the relay is closed.

[0016] In one embodiment, the method further comprises determining whether the relay is determining that the lock has been closed.

[0017] According to one embodiment, the non-transitory computer readable medium is configured to receive input power. and a backup power supply configured to receive backup power from a backup power source. a backup input section, and an output section from at least one of the input power and the backup power. an output configured to supply power to a load; the input; and the backup input. and an inverter connected to the output section, and an inverter output current of the inverter. a sensor connected between the input and the output, the sensor being configured to detect a parameter related to the input; a relay connected to the sensor and configured to provide output power; and a computer that controls an uninterruptible power supply (UPS) including at least one controller. a non-transitory computer-readable medium storing a sequence of computer-executable instructions, said The sequence of computer-executable instructions for the at least one controller Detecting a parameter related to the inverter output current and determining that the relay is closed and commanding the inverter to turn off based on a determination that the relay is closed. This is what we do.

[0018] In one embodiment, the sequence of computer executable instructions comprises: For each controller, the previous This command determines that the relay is closed.

[0019] In another embodiment, the at least one controller is connected to the relay; and The sequence of computer-executable instructions may be transmitted to the at least one controller. and indicating the inverter output current in response to a command to close the relay. and detecting that a parameter exceeds a threshold value, and that the inverter output current exceeds a threshold value. determining that the relay is closed based on the detection of This is an order to

[0020] In one embodiment, the UPS includes a power factor correction (PFC) circuit and the computer A sequence of data executable instructions for the at least one controller to The current at the input of the PFC circuit is detected as a parameter related to the inverter output current. It commands the government to

[0021] In another embodiment, the sequence of computer executable instructions comprises: For one controller, the relay is closed based on the passage of a predetermined period of time. It is an order to make a decision.

[0022] In one embodiment, the sequence of computer executable instructions comprises: For each controller, the inverter output current at the output of the inverter is calculated by It commands the detection.

[0023] In another embodiment, the sequence of computer executable instructions comprises: For one controller, the parameters related to the inverter output current are It commands the inverter to sense the current at its input.

[0024] Various aspects of at least one embodiment are not intended to be drawn to scale. Reference is now made to the accompanying drawings, which illustrate and further illustrate various aspects and embodiments. The present invention is incorporated herein by reference in its entirety to provide an understanding of the present invention. These figures are not intended to define the limits of the present disclosure. Each identical or nearly identical component shown in the various figures is designated by a like reference numeral. For purposes of clarity, not every component may be labeled in every figure. [Brief explanation of the drawings]

[0025] [Figure 1] FIG. 2 is a block diagram of an online UPS in an online mode according to an embodiment described herein. [Figure 2] FIG. 1 is a block diagram of an online UPS transitioning to green / bypass mode according to aspects described herein. [Figure 3] FIG. 2 is a block diagram of an online UPS in an online mode according to an embodiment described herein. [Figure 4]FIG. 1 is a block diagram of an online UPS transitioning to green / bypass mode according to aspects described herein. [Figure 5] 1 is a logic flow diagram illustrating operations for controlling an inverter of a UPS according to aspects described herein. [Figure 6] 6 is a timing diagram illustrating a transition from online mode to green / bypass mode according to embodiments described herein without utilizing the logic flow chart of FIG. 5. [Figure 7] 10 is a timing diagram illustrating a transition from online mode to green / bypass mode according to embodiments described herein. DETAILED DESCRIPTION OF THE INVENTION

[0026] Examples of the methods and systems described herein are set forth in the following description or illustrated in the accompanying drawings. No limitation is imposed on the details of construction and arrangement of components shown in the figures. The methods and systems are capable of implementation in other embodiments and of being practiced or performed in various ways. The specific embodiment examples are for illustrative purposes only and are not intended to be limiting. In particular, any one or more embodiments are presented herein as though they were not part of the invention. The illustrated acts, components, elements and features may function similarly in any other embodiment. It is not intended to be exclusionary.

[0027] Further, the phraseology and terminology used herein is intended to be descriptive and not limiting. Examples and embodiments of the systems and methods mentioned herein alone Any reference to a component, element, or act includes embodiments including plurals. and a plurality of any embodiment, component, element or act. Any reference to can include embodiments including only the singular. Any reference to the systems or methods, their components, acts or The term "including" as used herein is not intended to limit the elements. "comprising," "having," "containing" The use of "involving" and its variations is listed thereafter. "or / if" is intended to cover items and their equivalents, as well as additional items. References to "or" can be construed as inclusive and therefore It can refer to a single item, more than one item, and all of the items. In the event of a discrepancy in terminology between the literature and the literature incorporated herein, the incorporated The terminology used in the cited references is supplemental to that used in this specification and should not be construed as inconsistent. The term "match" governs the use of the term herein.

[0028] In existing UPS systems, parallel operation of the inverter and commercial power supply is simply an online This occurs momentarily during the transition from the operating mode to the bypass operating mode after the bypass relay is closed. After the bypass relay is closed, the inverter, inverter relay, and bypass relay A conductive path can be formed between the commercial line connected to the bypass relay and the commercial line connected to the bypass relay. During this time of parallel connection of the utility line and inverter, the power supply in the UPS components The current can continue to increase until the inverter is turned off. This puts stress on the components and requires more robust and expensive components to handle the increased current. This can result in the use of a bypass that is used to transition from online mode to bypass mode. If the increasing current is not properly controlled, it can melt the relay and In addition, if the inverter is not connected to the mains during this parallel connection, There is a risk of backfeeding the power supply.

[0029] At least some embodiments of the present disclosure are configured to prevent power or A method for adaptively adjusting the timing of turning off the inverter output of a UPS is disclosed. and a non-transitory computer-readable medium. The embodiment of the present invention provides variable relay timing without the use of additional hardware circuitry. and time to accommodate timing variations between units and to generate parallel operations. Improve existing UPS systems by reducing

[0030] One embodiment of an uninterruptible power supply 100 according to the present disclosure is described below with reference to FIG. FIG. 1 shows a functional block diagram of a first UPS 100. This UPS 100 is an online UPS. S, and includes a controller 12, a rectifier / power factor correction (PFC) circuit 14, a DC-DC converter inverter 16, battery 18, polarized capacitor 20, DC bus 22, inverter 24, Inductor 26, current sensor 28, backfeed line relay 32, backfeed no Pole relay 34, bypass relay 36, inverter relay 38, input section 101, neutral input section 103, an output section 104, and a neutral output section 105. The UPS 100 includes an input section 101. Powering the load 110 based on the input power received and / or power from the battery 18 .

[0031] In some embodiments, the inductor 26 may be an air-core inductor, an iron-core inductor, or It is one of the ferrite core inductors.

[0032] The input 101 is connected to a backfeed line relay 32 which is connected to the PFC circuit 14. Each output of the PFC circuit 14 is connected to an inverter 24. are connected to each other by a polarized capacitor 20 and connected to the anode of the polarized capacitor 20. The output of the PFC circuit forms a DC bus 22 that is connected to the DC-DC converter 16. The DC bus 22 is further connected to the battery 18 via the DC-DC converter 16. The battery 18 also acts as a backup input that receives power from the The cathode of the polarized capacitor 20 is connected to the PFC circuit 14, the inverter 24 and the DC-DC converter 16. The power supply is connected to the anode of the battery 18 and the other output of the DC-DC converter 16. The inverter 24 is connected to the cathode and ground terminals of the battery 18. It has an output connected to the inverter 26 and another output connected to the neutral output 105. The output section 105 includes a PFC circuit 14, an inverter 24, a backfeed non-polarized relay 34, and the load 110. The inductor 26 is connected to the inverter relay 38. The inverter relay 38 is connected to the bypass relay 36 and the load. The load 110 is connected to both the output 104 and the center The bypass relay 36 is connected between the input 101 and the backfire output 105. Connect to the power line relay 32.

[0033] In FIG. 1, the controller 12 includes a PFC circuit 14, a DC-DC converter 16, an inverter circuit 17, an inverter circuit 18, an inverter circuit 19, an inverter circuit 20, an inverter circuit 21, an inverter circuit 22, an inverter circuit 23, an inverter circuit 24, an inverter circuit 25, an inverter circuit 26, an inverter circuit 27, an inverter circuit 28, an inverter circuit 29, an inverter circuit 29, Inverter 24, current sensor 28, backfeed relay 32, backfeed non-polarized relay 34, bypass relay 36, and inverter relay 38. Each solid line connected to the controller 12 transmits a signal from the controller 12 or Receive signals from one or more internal components of S100 at controller 12 Each of the relays 32, 34, 36, and 38 shown in FIG. The valve is configured to switch between an open position and a closed position when commanded by the controller 12. In the closed position, a conductive path is formed between the first and second terminals of a given relay. For example, when the bypass relay 36 is open (as shown in FIG. 1), the current In the relay 36, the input 101 and the output 104 are not electrically connected. When the terminal 6 is closed, the load 110 is connected between the output terminal 104 and the neutral output terminal 105. If power is present at input 101, current flows through the relay connection to input 101 and through output 10 Conduction is achieved by connecting a relay to 4.

[0034] The UPS 100 shown in FIG. 1 is a single-phase power supply with a double-conversion (AC-DC, DC-AC) topology. In another embodiment, the UPS 100 is a multi-phase UPS, such as a three-phase UPS. The UPS 100 operates in the online mode in FIG. In this case, the UPS utilizes an inverter 24 to provide output power to a load 110. As shown in FIG. 1, the backfeed line relay 32 is configured to The input unit 101 is connected to the PFC circuit 14. The bypass relay 36 is in the open position. The backfeed non-polarized relay 34 and the inverter relay 38 are in the closed position. Backfeed line relay 32, backfeed non-polarized relay 34, bypass relay 36, and inverter relay 38 are configured in these positions. When the power is turned on, the UPS100 operates in online mode. To proceed to the bypass mode, the controller 12 must turn on the bypass relay 36. It activates (closes) and turns off the inverter 24.

[0035] In some embodiments, the backfeed line relay 32, the backfeed non-polarized relay One or more of the relay 34, bypass relay 36 and inverter relay 38 are Electromechanical relays (EMRs) convert magnetic flux into mechanical force, This mechanical force operates the electrical contacts in a relay that uses a spring. On the other hand, solid-state relays (SSRs) have no moving parts and rely on semiconductors for their functionality. Due to its mechanical properties, the internal switch lifts off one contact and then settles on the other. The time it takes to repair a fault depends on the age of the EMR, the type of EMR, spring force, contact wear, coil damage, temperature, and Therefore, when the EMR is closed, the How long does it take for the R internal switch to move from one position to the other? Therefore, the bypass relay 36 is commanded to close. After the controller 12 has completed the process, it will only take a fixed amount of time to interrupt the output of the inverter 24. In this case, the inverter 24 supplies power to the input 101 via the bypass relay 36. It is possible.

[0036] FIG. 2 shows a functional block diagram of the UPS 100 transitioning to the bypass operation mode. The difference from FIG. 1 is that the bypass relay 36 is closed, and the inverter relay 38 and the bypass relay 36. Under normal operation of the UPS 100, the current 120 is present online. During the transition from the operating mode to the bypass operating mode, the controller 12 activates the bypass relay 36 to close, which in turn disables (turns off) the inverter 24, thereby Allows input AC power to be fed directly to output line 104 via bypass relay 36 After the inverter 24 is commanded off, the inverter relay 38 is commanded open. In some embodiments, the controller 12 turns off the inverter 24. After commanding the power supply to be turned on, the controller 12 prevents the power from backfeeding into the power grid. To prevent this, the backfeed line relay 32 and the backfeed non-polarized relay 34 are and command it to open.

[0037] In an ideal scenario, the optimal transition from online to bypass mode is When the bypass relay 36 is closed, the inverter 24 stops. However, the controller 12 may shut down the inverter 24 too early (bypass relay 36 may shut down) If the load 110 is turned off (before the load is turned off), the load 110 may drop and / or the load input capacitor may drain. This results in a large inrush current when the bypass relay 36 is grounded. If the controller 12 runs the inverter 24 too slowly (bypass relay 36 If the power supply is stopped after a long time has elapsed since landing, parallel connection of the commercial power supply and inverter power supply is required. The inverter 24 may cause stress or damage to the internal components of the UPS 100. In such a scenario, the device may source or pass large currents that could Therefore, the inverter 24 attempts to supply (backfeed) power to the connected commercial power source. 3 and 4 are the same as the first UPS except that the second UPS 200 includes a second input unit 102. The second UPS 200 is substantially identical to the first UPS 100. The second input 102 is connected to the bypass relay 36. As shown in FIGS. 3 and 4, the second input unit 102 can receive input power. and is separate from input unit 101. In some embodiments, input unit 101 and The second input 102 may be adapted to receive power from a different power source for additional redundancy. In one embodiment, one of the input unit 101 and the second input unit 102 is connected to a commercial power source. One receives power from a power source and the other receives power from an alternative energy source. In terms of form, alternative energy sources are one of the following: solar power, wind power, and hydroelectric power. One or more.

[0038] Some embodiments may include a neutral output 105 in each of FIGS. 1, 2, 3, and 4. An optional electrical wiring connected between the sensor 28 and the conductive line connecting the inverter relay 38. Includes a capacitor.

[0039] As shown in FIGS. 1 and 2, a current sensor is provided between the inductor 26 and the inverter relay 38. 28 is connected to the inverter 24, and the inverter 24 is used as a parameter indicating the current being output. In some embodiments, the inverter output current of the inverter 24 is measured. Alternatively, the UPS 200 may include one or more current sensors, including the current sensor 28. Each of the one or more current sensors is connected to a different location within the UPS 100 or UPS 200. In one embodiment, the inductor 26 and the inverter relay 38 In addition to or instead of the current sensor 28 connected to the DC bus 22, a current sensor may be connected to the DC bus 22. The input of the inverter 24 is received as a parameter indicating the output current of the inverter 24. In some embodiments, the output current of the inverter 24 is estimated. Apply a scaling factor to the current received to one or more other current sensors. Other scaling factors can be applied to the PFC circuit 14 as well. A current sensor is provided at the input of the PFC circuit 14, which is connected to both the backfeed line relay 32 and the PFC circuit 14. The multiplication factor or individual threshold is connected to the current sensor 28 at the input of the PFC circuit 14. 8 to determine whether the bypass relay 36 is closed. In an embodiment, a plurality of one or more sensors is used, the plurality including a current sensor. 28, and the parameter indicating the output current is the current measurement value of each current sensor. The weighted average is calculated as follows:

[0040] In Figures 1 to 4, the lines that intersect or cross each other are not electrical connections. The overlapping black circles indicate that the lines below the circles are electrically connected. Backfeed line relay 32, backfeed non-polarized relay 34, bypass relay 3 Within each of the relays 6 and 38, there are three electrical contacts, shown as circles. A line connecting one of the circles to a component outside the corresponding relay indicates a connection. For example, the input 101 is connected to the PFC circuit 14 via the backfeed relay 32. The operation of the first UPS 100 will be explained below. The second UPS 200 has an additional input section 1 The input power applied to all points of the first UPS 100 is It works almost the same way to receive.

[0041] The operation of the first UPS 100 is illustrated as a logic flow chart in FIG. 5 in accordance with method 500. The method 500 includes at least three acts 502, 506, and 506a. and two conditions 504 and 508. In some embodiments, the controller 12 Each act and condition in the method 500 is performed. This method is similar to a firmware algorithm stored as program instructions in a memory device. Implement Law 500.

[0042] In the method 500, the current sensor 28 is utilized so that the controller 12 converts the ADC measurement The inverter output current is converted to an ADC measurement to allow for detection of an increase in A The increase in DC measurement is due to the landing of the bypass relay 36 and the bypass of the current 120 to the utility power supply. Indicates the start of a feed.

[0043] In a first act 502 of the method 500, the controller 12 turns on the UPS 100. Command to transition from line mode to bypass mode. Therefore, the controller 12 commands the bypass relay 36 to close. After the current sensor 28 is commanded to close, the controller 12 In some embodiments, the controller 12 begins monitoring the current. The system waits a predetermined period of time before monitoring the current with sensor 28. In another embodiment, the predetermined time is in the range of about 0.1 ms to about 5 ms. In one embodiment, the predetermined time is in the range of about 0.01 ms to about 10 ms. The predetermined time is within a range of about 0.001 ms to about 50 ms.

[0044] Next, the controller 12 sets the most recent current detected by the current sensor 28 as a first condition 504. In some embodiments, the predetermined value is 4. In some embodiments, this predetermined value is The current threshold is adjusted for a constant load 110. In one embodiment, the load is a server load. The maximum capacity of the inverter 24 is about 30A, and the current consumption is about 5.5kW. The threshold is set at approximately 24 A, which is approximately 80% of the maximum capacity. In another embodiment, the current threshold is In some embodiments, this range is about 3 to about 5 times the RMS value. For example, if the RMS value is about 30A, a range of roughly 100A is reasonable. In some embodiments, this range is about 30 A to 100 A. The range is about 24 A to 30 A. In some embodiments, the range is about 10 A to 50 A. If the current value detected by the sensor 28 exceeds the predetermined value (YES), the first condition 504 is If this is true, the method 500 proceeds to a second act 506. If the current value detected by the sensor 28 exceeds the predetermined value, the method 500 proceeds to a second act 506. If not (NO), the method 500 proceeds to evaluate the second condition 508. In the embodiment, the first condition 504 is a current increase per unit time detected by the sensor 28. is compared to a threshold value representing a predetermined derivative of the current.

[0045] In the embodiment shown in FIGS. 1-4, the current sensor 28 is electrically connected to the output of the inverter 24. The inverter output is connected to an inductor 26, which is connected between the inductor 26 and the inverter relay 38 and is connected to the output of the inverter 224 In other embodiments, the sensor 28 or the attached Additional sensors can be connected to the input of inverter 24. For example, in some embodiments In this state, the current sensor 28 is connected to the DC bus 22. Other locations for the (voltage) sensor are included within the embodiments described herein. The particular value indicating the presence of a current 120 to be monitored depends on the position of the sensor 28 within the UPS 100. The method 500 may vary based on the location, and the acts and conditions of the method 500 may be the same for each location. More specifically, in different embodiments, the UPS 100 switches to bypass mode. To detect the increase in output current after switching, parameters related to the output current from the inverter are Any sensor that determines the current may be used in addition to or in place of the current sensor 28.

[0046] The second condition 508 causes the controller 1 to close the bypass relay 36 in the first action 502. The time that has elapsed since the command was issued to the UPS 100 is compared with a predetermined time threshold. The maximum period of time that can elapse after the bypass relay 36 is commanded to close is According to some embodiments, the predetermined threshold is between about 1 ms and about 2 ms. In some embodiments, the predetermined threshold is 10 ms. ms. The current time (of the second condition 508 currently being evaluated) exceeds a predetermined threshold. If so, the second condition 508 is satisfied (yes) and the method 500 proceeds to the third act 510. If the current time does not exceed the predetermined threshold, the second condition 508 is not met (No); The method 500 then returns to evaluating the first condition 504. In some embodiments, the average relay time Based on the time (for the type of relay used as the bypass relay 36), The inverter 24 is interrupted after the roller 12 commands the bypass relay 36 to close. A fixed relay time is used as the predetermined threshold for closing with a margin to determine the time to close. do.

[0047] In some embodiments, when the second condition is not met (No), the method 500 proceeds to the second Returning to evaluating the second condition 508, in one embodiment, the method 500 evaluates the first condition 508. If condition 4 is not met, the first condition is evaluated one or more times before proceeding to evaluate the second condition 508. 1. The step of evaluating condition 504. Some embodiments may include evaluating the current of inverter 24. The first condition 504 includes a predetermined waiting period before comparing the parameter being measured to a predetermined threshold. and then proceeds to evaluate the second condition 508.

[0048] The time to interrupt the inverter 24 after commanding the bypass relay 36 to close is , must be less than the relay flight time, otherwise a large amount of current will flow from the utility power supply to the load 110. Inrush currents can occur that can damage the relay and / or other UPS components. There is a risk of this happening.

[0049] In some embodiments, the method 500 may result in one of two possible outcomes: In one outcome, the first condition 504 is met and the controller 12 Instructs inverter 24 to turn off early (before the time threshold is exceeded). In the other outcome, the second condition 508 is met and after a predetermined period of time has elapsed, As a result, the controller 12 commands the inverter 24 to turn off. The form may include additional conditions or actions. In one embodiment, a third condition 505 (not shown) may be added. The third condition can be evaluated between the first condition 504 and the second condition 508. The inverter current is evaluated to see if it is different from the value checked in the first condition 504. In an embodiment, the first condition 504 evaluates the current against a first current value and determines whether the current is If the value is not exceeded, a second higher current value is evaluated in third condition 505. If the current is exceeded at 5, the method 500 proceeds to a second act 506; if not, the second condition 5 Go to 08.

[0050] FIG. 6 illustrates the on-line and bypass modes when the second condition 508 of the method 500 is met. Timing of transition between modes in the first UPS 100 and the second UPS 200 6 shows a timing sequence 600. In this timing sequence 600, at a first time point 602 The controller 12 sends a command to the bypass relay 36 to close the bypass relay. After a fixed period of 13 ms, the controller 12 applies The inverter relay 38 is then instructed to turn off at the second time point 604. The first coexistence duration 610 shown is commanded to open at a subsequent zero crossing point 606. The bypass relay 36 starts after it is grounded, and the controller 12 starts after it is grounded. This first concurrent action 610 indicates a duration that ends when the user commands the controller 38 to open. The amount of time this occurs depends on the actual closing time of the bypass relay 36, which varies depending on the relay. During this coexistence duration 610, the inverter 24 and the quotient The utility power supplies are both connected to a load 110, which results in a current 120 being fed into the utility power supply. The resulting current 120 flows through the connected load 110 and Related to the difference between the output voltage of the inverter 24 and the utility voltage at the input 101 This current 120 can damage the bypass relay 36 and / or components of the inverter 24. This may result in stress on the power supply or other components in the UPS. For the second condition, the scenario shown in Figure 6 resembles the operation of a typical UPS. In the embodiment described herein, the UPS operation upon detecting the first condition is associated with the second condition. together or alone to improve the transition time from online mode to bypass mode.

[0051] FIG. 7 illustrates the online and by-operation modes when the first condition 504 of the method 500 is met. Timing of transition between the first UPS 100 and the second UPS 200 7 shows a timing sequence 700. In this timing sequence 700, as shown in FIG. Thus, at a first time point 602, the controller 12 issues a command to close the bypass relay 36. The controller 12 provides a command to the bypass relay 36. After commanding the bypass relay 36 to close, the method 500 begins. The current at 28 begins to rise. Both the second coexistence duration 710 and the detection period 712 The detection period 712 begins when the bypass relay 36 touches the floor. The length of time to detect whether a value exceeds a predetermined threshold in the first condition 504 of the method 500. At the end of the detection period 712, the first condition 5 of the method 500 is satisfied. 04 is met and at a time 704 earlier than the fixed threshold time evaluated in the second condition 508 The second act 506 of the method 500 commands the inverter 24 to turn off. After the controller 12 commands the inverter 24 to turn off, the controller 12 then The inverter relay 38 is commanded to open at the zero crossing point 706. As a result of the first condition 504 being satisfied during the interval 712, the second coexistence duration 710 is The duration is shorter than 610.

[0052] While one or more embodiments have been described above for a UPS device, these and other embodiments may be It should be understood that the device may be equipped with a general purpose power supply instead of or in addition to a UPS device. Some embodiments include using the techniques described herein in other power supply devices. States include, but are not limited to, Standby UPS, Line-Interactive UPS, Standby · Online · Hybrid UPS, Standby · Ferro UPS, Delta Conversion Online The techniques described herein can be used with other types of UPS, including offline UPS. Other embodiments include using the techniques described herein in devices other than relays. This includes:

[0053] Although several aspects of at least one embodiment described herein have been described, it is understood that Nevertheless, various alterations, modifications, and improvements will readily occur to those skilled in the art. Such alterations, modifications, and improvements are intended to be part of this disclosure and are within the spirit and spirit of the present disclosure. Accordingly, the foregoing description and drawings are by way of example only. [Explanation of symbols]

[0054] 12 Controllers 14 Rectifier / power factor correction (PFC) circuit 16 DC-DC converters 18 Battery 20 Polarized Capacitors 22 DC bus 24 inverters 26 Inductor 28 Current Sensor 32 Backfeed line relay 34 Backfeed non-polarized relay 36 Bypass Relay 38 Inverter Relay 100 1st UPS 101 Input section 102 Second input section 103 Neutral input section 104 Output section 105 Neutral output section 110 Load 120 current 200 2nd UPS 500 ways 600 Timing Sequences 700 Timing Sequences

Claims

1. In uninterruptible power supplies (UPS), an input configured to receive input power; A backup input configured to receive backup power from a backup power source Department and Providing output power to a load from at least one of the input power or the backup power an output configured to provide A power supply connected to the input, the backup input, and the output, and also connected to an inverter output an inverter configured to provide a power current; a sensor configured to detect a parameter indicative of the inverter output current; a relay connected between the input and the output; and at least one controller coupled to the sensor, to determine when the relay is closed, and to turn off the inverter based on a determination that the relay is closed. the controller configured An uninterruptible power supply comprising:

2. 2. The uninterruptible power supply according to claim 1, wherein the at least one controller Determining that the relay is closed based on a parameter indicative of inverter output current.

2. An uninterruptible power supply (UPS) configured to:

3. 2. The uninterruptible power supply according to claim 1, wherein the at least one controller and determining that the relay is closed based on a differential value of the inverter output current. Uninterruptible power supply.

4. 2. The uninterruptible power supply according to claim 1, wherein the at least one controller connected to the relay and Detecting when the inverter output current exceeds a threshold; and The relay is closed upon detecting that the inverter output current exceeds a threshold. To determine An uninterruptible power supply configured to:

5. 2. The uninterruptible power supply according to claim 1, wherein the at least one controller The relay closes based on a predetermined period of time having elapsed after the relay is commanded to close.

1. An uninterruptible power supply configured to:

6. 2. The uninterruptible power supply of claim 1, wherein the UPS includes a power factor correction (PFC) circuit. The sensor also detects the inverter output current as a parameter, and 1. An uninterruptible power supply configured to sense a current at an input of a C circuit.

7. 10. The uninterruptible power supply of claim 1, further comprising: a first input power supply; a second input configured to provide a second input power to the relay. Place.

8. 2. The uninterruptible power supply according to claim 1, wherein the sensor detects a voltage at an output of the inverter. and detecting the inverter output current in the uninterruptible power supply.

9. 2. The uninterruptible power supply according to claim 1, wherein the sensor indicates the inverter output current. The inverter is configured to sense the current at the input of the inverter as a parameter. An uninterruptible power supply.

10. 1. A method of operating an uninterruptible power supply (UPS), comprising: receiving input power at an input; receiving backup power from a backup power source; Providing output power to a load from at least one of the input power or the backup power providing the A switch for detecting a parameter indicating an inverter output current from the inverter of the UPS Tep and determining that the relay is closed; A switch is included that turns off the inverter based on a determination that the relay is closed. Tep and A method comprising:

11. 11. The method of claim 10, further comprising: acquiring a parameter indicative of the inverter output current. determining that the relay is closed based on the data.

12. The method of claim 10 further comprising: In response to commanding the relay to close, a signal indicating the inverter output current is output. detecting that a parameter exceeds a threshold; and the relay is closed upon detecting that the inverter output current exceeds a threshold value; determining a A method comprising:

13. 11. The method of claim 10, further comprising: determining whether the relay is turned on or off based on the passage of a predetermined period of time. determining that the closure has occurred.

14. an input configured to receive input power and a backup power supply from a backup power source; a backup input configured to receive power; an output configured to provide an output power to a load from at least one of the power sources; an inverter connected to an input section, the backup input section, and the output section; a sensor configured to detect a parameter related to an inverter output current of the inverter; a relay connected between the input and the output and configured to provide output power; and at least one controller connected to the sensor. A persistent computer that stores a sequence of computer-executable instructions that control the device (UPS). a computer-readable medium, the sequence of computer-executable instructions including: For each controller, Detecting a parameter related to the inverter output current; determining that the relay is closed; and Turning off the inverter based on determining that the relay is closed.

10. A non-transitory computer-readable medium that instructs

15. 15. The non-transitory computer-readable medium of claim 14, wherein the computer-executable instructions A sequence of instructions to the at least one controller to control the inverter output voltage. determining that the relay is closed based on a flow-related parameter.

1. A non-transitory computer-readable medium comprising:

16. 15. The non-transitory computer-readable medium of claim 14, wherein the at least one controller a controller connected to the relay, and the sequence of computer-executable instructions For at least one controller, In response to a command to close the relay, a power supply indicative of the inverter output current is Detects when a parameter exceeds a threshold, and the relay is closed upon detecting that the inverter output current exceeds a threshold value; Determine 10. A non-transitory computer-readable medium that instructs

17. 15. The non-transitory computer readable medium of claim 14, wherein the UPS has a power factor correction (PF C) circuitry, and the sequence of computer-executable instructions comprises: For each controller, the PF is used as a parameter related to the inverter output current. A persistent computer-enabled device that commands the computer to detect the current at the input of the C circuit. Reading medium.

18. 17. The non-transitory computer-readable medium of claim 16, wherein the computer-executable instructions The sequence of instructions may be for the at least one controller to and determining that the relay has closed based on the Data-readable medium.

19. 15. The non-transitory computer-readable medium of claim 14, wherein the computer-executable instructions A sequence of instructions is provided to the at least one controller to control the inverter output. a continuous computer that detects the inverter output current in the Data-readable medium.

20. 15. The non-transitory computer-readable medium of claim 14, wherein the computer-executable instructions A sequence of instructions to the at least one controller to control the inverter output voltage. command to sense the current at the input of the inverter as a parameter relating to the current; 1. A non-transitory computer-readable medium.

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