JP2018074623A - Uninterruptible power supply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an uninterruptible power supply device capable of suppressing erroneous detection of a ground fault detection section.SOLUTION: An uninterruptible power supply device 100 is a V-connection uninterruptible power supply device in which one phase of three phases of an input power supply 1 is grounded and which is connected to a load 101 via a connection point M. The device comprises: a control section 6 constituted so that power can be supplied from each of the input power supply 1, a bypass power supply 5 which is a system different from the input power supply 1 and in which one phase of three phases is grounded, and a power storage section 4; a ground fault detection section 10 for applying monitoring voltage to a ground line 1a of the input power supply 1 and a ground line 5a of the bypass power supply 5; a first path 7 for connecting the input power supply 1 and the control section 6; a second path 8 for connecting the bypass power supply 5 and the control section 6; and a relay section 11 for setting the second path 8 in a non-conductive state when power is supplied from the input power supply 1 to the control section 6.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an uninterruptible power supply, and more particularly to an uninterruptible power supply that is supplied with power from a bypass power supply different from an input power supply.

  Conventionally, an uninterruptible power supply apparatus in which power is supplied from a bypass power supply different from the input power supply is known (see, for example, Patent Document 1).

  The uninterruptible power supply described in Patent Document 1 includes a power converter (a three-level converter and a three-level inverter) that converts AC power from a three-phase AC power source (hereinafter referred to as a first power source) and outputs the AC power to a load. ) And a bypass circuit for outputting bypass power from an AC power source (hereinafter referred to as second power source) different from the first power source to the load. And it is comprised so that the electric power output to load can be switched to the electric power from a 1st power supply, or the electric power from a 2nd power supply by switching the switch provided in the load side of a power converter and a bypass circuit.

  Here, in the conventional uninterruptible power supply as in Patent Document 1, a configuration in which a control unit that performs operation control such as a power conversion unit of the uninterruptible power supply can be considered. The control unit needs to control the operation of the power conversion unit or the like even when one of the first power source and the second power source is in an inoperative state. Both of the electric power and the electric power from the second power source are supplied.

  Furthermore, in the uninterruptible power supply, a V-connection type is configured in which one phase of each of the first power supply and the second power supply is grounded and the grounded phase of the first power supply is directly connected to the load. Can be considered. In this case, the structure which provides the ground fault detection part which detects ground faults, such as a peripheral installation, by applying a monitoring voltage to the ground line of a 1st power supply and the ground line of a 2nd power supply is considered.

Japanese Patent Laid-Open No. 2006-63731

  In this case, when the power supplied to the control unit from one of the first power supply or the second power supply is returned to the other of the first power supply or the second power supply, the ground line of the first power supply and the second power supply are supplied. There is an inconvenience that current flows through the ground between the power supply and the ground line. In this case, the monitoring voltage applied to the ground line by the ground fault detection unit is superimposed in the control unit via a path between the first power source and the second power source and the control unit. Therefore, when detecting the power returned from the control unit, the ground fault detection unit detects a voltage component for monitoring that has increased due to the superposition of power in the control unit, and erroneously detects that a ground fault has occurred. There is a problem of detecting.

  The present invention has been made to solve the above-described problems, and one object of the present invention is to provide an uninterruptible power supply capable of suppressing erroneous detection of a ground fault detection unit. It is.

  An uninterruptible power supply according to an aspect of the present invention includes a power conversion unit including a converter unit and an inverter unit, a power storage unit connected to a neutral point between the converter unit and the inverter unit, and a plurality of phases Is a V-connection type uninterruptible power supply, in which one phase of the input power supply is grounded and connected to the load through a neutral point, and is separate from the input power supply and the input power supply. And a bypass power source in which one of a plurality of phases is grounded, a control unit configured to be able to supply power from each of the power storage units, a ground line for grounding the input power source, and a bypass power source. A ground fault detection unit that detects a ground fault by applying a monitoring voltage to a grounding line to be grounded, a first path that connects the input power source and the control unit, and a bypass power source and the control unit are connected. Control from the second path and input power supply A conduction control unit that places the second path in a non-conducting state when power is supplied to the control unit, or a power source that supplies power to the control unit from the bypass power supply; Is provided.

  In the uninterruptible power supply according to one aspect of the present invention, as described above, when the conduction control unit supplies power to the control unit from the input power supply, the second path is made non-conductive, or When power is supplied from the bypass power source to the control unit, the first path is made non-conductive so that power from one of the input power source and the bypass power source is supplied to the other power source via the control unit. It is possible to suppress the return to Thereby, it is possible to suppress the power from returning to the power output source via the ground line that grounds the input power supply, the ground line that grounds the bypass power supply, and the ground between the ground lines. In this case, the monitoring voltage applied by the ground fault detection unit is suppressed from being superimposed in the control unit via the first path and the second path. As a result, when the ground fault detection unit detects the power returned from the control unit, it can be suppressed to detect the voltage component for monitoring increased due to the superposition of the power in the control unit. Thereby, it can suppress that a ground fault detection part misdetects a ground fault.

  In the uninterruptible power supply according to the above aspect, preferably, the conduction control unit supplies a power to the control unit, and a relay unit driven by power supplied from one of the input power supply and the bypass power supply is provided. Including. With this configuration, the relay unit can be driven by the input power source or the bypass power source without providing a separate power source for the relay unit, so that power can be supplied from the input power source to the control unit with a simple configuration. In this case, the second path can be made non-conductive, and the first path can be made non-conductive when electric power is supplied from the bypass power supply to the control unit.

  In this case, preferably, the first path includes a first supply wiring for supplying power to the control unit, and a first return wiring for returning power from the control unit, and the second path to the control unit. A second supply wiring for supplying electric power and a second return wiring for returning electric power from the control unit, and the relay unit supplies the electric power from the input power source to the control unit. And the second return wiring are both disconnected, or both the first supply wiring and the first return wiring are disconnected when power is supplied to the control unit from the bypass power supply. It is configured. According to this configuration, the monitoring voltage applied by the ground fault detection unit is compared with the case where either the power supply wiring or the power return wiring is disconnected. However, it can suppress more reliably that it is superimposed in a control part via a 1st path | route and a 2nd path | route.

  In the uninterruptible power supply device in which the first and second supply wirings and the first and second return wirings are provided, preferably, when the relay unit supplies power to the control unit from the input power source, A first switch for disconnecting the supply wiring and a second switch for disconnecting the second return wiring are included. With this configuration, when power is supplied from the input power source to the control unit, the power supplied from the input power source to the control unit by the second switch being disconnected by the second switch. However, it can suppress returning to a bypass power supply. In addition, since the second supply wiring is disconnected from the first switch, the power from the bypass power supply can be prevented from being supplied to the control unit and can be prevented from being returned to the input power supply. be able to. Thus, when power can be supplied to the control unit from both the input power supply and the bypass power supply, the monitoring voltage applied by the ground fault detection unit is prioritized while giving priority to the power supply from the input power supply. It is possible to suppress overlapping in the control unit via the first route and the second route.

  In the uninterruptible power supply device in which the first and second supply wirings and the first and second return wirings are provided, preferably, the relay unit supplies the power from the bypass power source to the control unit. A third switch for disconnecting the supply wiring and a fourth switch for disconnecting the first return wiring are included. With this configuration, when power is supplied from the bypass power source to the control unit, the power supplied from the bypass power source to the control unit by the first switch being disconnected by the fourth switch. However, it can suppress returning to an input power supply. In addition, since the first supply wiring is disconnected by the third switch, the power from the input power supply can be suppressed from being supplied to the control unit and can be prevented from being returned to the bypass power supply. be able to. As a result, when power can be supplied to the control unit from both the input power supply and the bypass power supply, the monitoring voltage applied by the ground fault detection unit is given priority over the supply of power from the bypass power supply. It is possible to suppress overlapping in the control unit via the first route and the second route.

  ADVANTAGE OF THE INVENTION According to this invention, as mentioned above, the uninterruptible power supply device which can suppress the misdetection of a ground fault detection part can be provided.

It is the figure which showed the structure of the uninterruptible power supply device by 1st Embodiment of this invention. It is a figure for demonstrating operation | movement of the uninterruptible power supply by 1st Embodiment of this invention. It is the figure which showed the structure of the uninterruptible power supply device by 2nd Embodiment of this invention. It is a figure for demonstrating operation | movement of the uninterruptible power supply by 2nd Embodiment of this invention.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying the present invention will be described below with reference to the drawings.

[First Embodiment]
First, the configuration of the uninterruptible power supply 100 according to the first embodiment will be described with reference to FIGS. 1 and 2.

(Configuration of uninterruptible power supply)
As shown in FIG. 1, the uninterruptible power supply 100 is supplied with power from the input power supply 1. The input power source 1 is a three-phase AC power source composed of an R phase, an S phase, and a T phase. The S phase of the input power supply 1 is grounded by the ground line 1a. The ground line 1a is an example of the “ground line for grounding the input power supply” in the claims.

  The uninterruptible power supply apparatus 100 includes a power conversion unit 2 that receives AC power from the input power source 1 and outputs AC power to a load 101. Specifically, the power conversion unit 2 includes a converter unit 20 that converts AC power from the input power source 1 into DC power. The converter unit 20 includes a switching element unit 20a including a plurality of switching elements. The power conversion unit 2 includes an inverter unit 21 that converts the DC power converted by the converter unit 20 into AC power and outputs the AC power to the load 101. The inverter unit 21 includes a switching element unit 21a including a plurality of switching elements. Note that a plurality (three in the first embodiment) of capacitors and a plurality of (two in the first embodiment) reactors are provided on the input power source 1 side of the switching element unit 20a and the load 101 side of the switching element unit 21a. Is provided.

  Moreover, the converter part 20 has the bidirectional | two-way switching element part 20b arrange | positioned at the inverter part 21 side of the switching element part 20a. The bidirectional switching element portion 20b is provided with a plurality of (two in the first embodiment) bidirectional switches in which reverse blocking IGBTs are connected in parallel in opposite directions. Moreover, the inverter part 21 has the bidirectional | two-way switching element part 21b arrange | positioned at the converter part 20 side of the switching element part 21a. Similar to the bidirectional switching element unit 20b, the bidirectional switching element unit 21b is provided with a plurality of bidirectional switches (two in the first embodiment) in which reverse blocking IGBTs are connected in parallel in opposite directions. . The bidirectional switching element unit 20b and the bidirectional switching element unit 21b convert three levels of output to the load 101 (the voltage level at the connection point P, the voltage level at the connection point M, and the voltage level at the connection point N, which will be described later). It is configured to be possible.

  Moreover, the converter part 20 and the inverter part 21 are comprised by the V connection type. That is, the S phase of the input power supply 1 is connected to the S phase input of the load 101 via a connection point M described later. The connection point M is an example of a “neutral point” in the claims.

  Further, the uninterruptible power supply 100 is provided with an intermediate section 3 disposed between the converter section 20 and the inverter section 21. The intermediate part 3 includes a connection point P, a connection point M, and a connection point N that are connected in series. A capacitor 30 is connected between the connection point P and the connection point M. A capacitor 31 is connected between the connection point M and the connection point N.

  Uninterruptible power supply 100 includes power storage unit 4 connected to connection point P, connection point M, and connection point N. The power storage unit 4 includes a battery 40 and a DC / DC converter 41. The battery 40 is charged with DC power output from the converter unit 20 via the DC / DC converter 41. In the uninterruptible power supply 100, when an abnormality such as a power failure occurs in the input power supply 1, the operation of the converter unit 20 is stopped. At this time, direct-current power from the battery 40 is supplied to the inverter unit 21 via the DC / DC converter 41. In this case, the switch unit 102 between the input power source 1 and the converter unit 20 is turned off.

  The uninterruptible power supply 100 is configured to be able to supply power from a bypass power supply 5 that is a separate system from the input power supply 1. The bypass power supply 5 is a three-phase AC power supply including an Rc phase, an Sc phase, and a Tc phase. The Sc phase of the bypass power supply 5 is grounded by the ground line 5a. The ground line 5a is an example of the “ground line for grounding the bypass power supply” in the claims.

  In the uninterruptible power supply 100, when an abnormality occurs in the converter unit 20 or the inverter unit 21, the switch unit 103 between the bypass power supply 5 and the load 101 is turned on. Thereby, AC power from the bypass power supply 5 is output to the load 101. In this case, the switch unit 104 between the inverter unit 21 and the load 101 is turned off.

  The uninterruptible power supply 100 includes a control unit 6. The control unit 6 is configured to be able to supply power from the input power source 1, the bypass power source 5, and the power storage unit 4. The control unit 6 sends signals to the converter unit 20 and the inverter unit 21 and the like, and controls the operation of the converter unit 20 and the inverter unit 21 and the like. In FIG. 1, wiring for transmitting a control signal from the control unit 6 to the converter unit 20 and the inverter unit 21 is omitted for simplification.

  Specifically, the uninterruptible power supply 100 includes a first path 7 that connects the input power supply 1 and the control unit 6. The first path 7 includes a first supply wiring 70 for supplying power from the input power supply 1 to the control unit 6. The first supply wiring 70 connects the R phase of the input power supply 1 and the control unit 6. The first path 7 includes a first return wiring 71 for returning power from the control unit 6 to the input power supply 1. The first return wiring 71 connects the S phase of the input power supply 1 and the control unit 6.

  In addition, the uninterruptible power supply 100 includes a second path 8 that connects the bypass power supply 5 and the control unit 6. The second path 8 includes a second supply wiring 80 for supplying power from the bypass power supply 5 to the control unit 6. The second supply wiring 80 connects the Rc phase of the bypass power supply 5 and the control unit 6. The second path 8 includes a second return wiring 81 for returning power from the control unit 6 to the bypass power supply 5. The second return wiring 81 connects the Sc phase of the bypass power supply 5 and the control unit 6.

  In addition, the power storage unit 4 and the control unit 6 are connected by a third path 9 via the intermediate unit 3. Third path 9 includes a third supply wiring 90 for supplying power from power storage unit 4 to control unit 6. The third supply wiring 90 connects the power storage unit 4 and the control unit 6 via the connection point P of the intermediate unit 3. The third path 9 includes a third return wiring 91 for returning power from the control unit 6 to the power storage unit 4. The third return wiring 91 connects the power storage unit 4 and the control unit 6 via the connection point M of the intermediate unit 3. In addition, when the 3rd return wiring 91 passes through the connection point M, it is possible to suppress that the input voltage to the control part 6 becomes larger than the case where it passes through the connection point N.

  The currents flowing through the first supply wiring 70, the second supply wiring 80, and the third supply wiring 90 are diodes provided in the respective wirings (the first supply wiring 70, the second supply wiring 80, and the third supply wiring 90). Therefore, it flows only in the direction of the control unit 6 side. Further, the current flowing through the first return wiring 71, the second return wiring 81, and the third return wiring 91 is provided in each wiring (the first return wiring 71, the second return wiring 81, and the third return wiring 91). The diodes flow only in the direction opposite to the direction of the control unit 6 side.

  The control unit 6 includes a DC / DC converter 60. The current that has passed through the first supply wiring 70, the second supply wiring 80, and the third supply wiring 90 is input to the DC / DC converter 60. Then, a current is output from the DC / DC converter 60 to the first return wiring 71, the second return wiring 81, and the third return wiring 91. A capacitor 61 is connected to the DC / DC converter 60 in parallel.

  The uninterruptible power supply 100 also includes a ground fault detection unit 10 that detects a ground fault by applying a monitoring voltage (for example, a voltage of 3 V and about 20 Hz) to the ground line 1a and the ground line 5a. Prepare. Specifically, the ground fault detection unit 10 includes a first ground fault detector 10a that applies a monitoring voltage to the ground line 1a, and a second ground that applies a monitoring voltage to the ground line 5a. And a fault detector 10b. The first ground fault detector 10a and the second ground fault detector 10b perform so-called ZCT detection in which ground fault detection is performed by detecting a current that flows when a monitoring voltage is applied. The first ground fault detector 10a and the second ground fault detector 10b are examples of the “ground fault detector” in the claims.

  That is, when a ground fault occurs in peripheral equipment or the like, a current flows through the first ground fault detector 10a and the second ground fault detector 10b. A ground fault is detected by detecting this current. The first ground fault detector 10a and the second ground fault detector 10b are configured to issue an alarm when a current is detected.

  Here, in 1st Embodiment, the uninterruptible power supply 100 is provided with the relay part 11 which makes the 2nd path | route 8 a non-conduction state, when supplying the electric power from the input power supply 1 to the control part 6. FIG. That is, the relay unit 11 is configured to be driven by electric power supplied from the input power supply 1. Specifically, the relay unit 11 is connected to the R phase and the S phase of the input power supply 1 and is configured to be able to supply power from the input power supply 1. The relay unit 11 is an example of the “conduction control unit” in the claims.

  In the first embodiment, when the relay unit 11 supplies power from the input power supply 1 to the control unit 6, both the second supply wiring 80 and the second return wiring 81 are disconnected. Specifically, the relay unit 11 includes a switch 11 a that switches the connection state of the second supply wiring 80. In addition, the relay unit 11 includes a switch 11 b that switches the connection state of the second return wiring 81. When power is supplied from the input power supply 1 to the relay unit 11, the second supply wiring 80 and the second return wiring 81 are disconnected from each other by turning off the switch 11a and the switch 11b. The switch 11a and the switch 11b are examples of the “first switch” and the “second switch” in the claims, respectively.

(Description of uninterruptible power supply operation)
(Comparative example)
(When relay part is not arranged)
As shown in FIG. 2, the power from the input power supply 1 is supplied to the control unit 6 through the route A by the first supply wiring 70. When the relay unit 11 is not disposed, a part of the power supplied from the input power source 1 to the control unit 6 is returned to the bypass power source 5 through the route B by the second return wiring 81. At this time, the electric power returned to the bypass power supply 5 is route C (in the direction from the bypass power supply 5 to the input power supply 1) by the ground line 1a, the ground line 5a, and the ground between the ground line 1a and the ground line 5a. Route) to the input power source 1. That is, the power from the input power source 1 returns to the input power source 1 while propagating in the order of route A, route B, and route C. For this reason, the monitoring voltage applied by the first ground fault detector 10 a and the second ground fault detector 10 b is superimposed in the control unit 6. In FIG. 2, the arrow of each route means the direction of the flowing current.

  Further, the electric power from the power storage unit 4 is supplied to the control unit 6 through the route D by the third supply wiring 90. Here, when the relay unit 11 is not arranged, part of the power supplied from the power storage unit 4 to the control unit 6 is route B and route C (from the bypass power source 5 to the input power source 1 as described above). And return to the input power source 1. In this case, since the switch unit 102 is on, the power returned to the input power source 1 is returned to the power storage unit 4 through the route E via the switch unit 102. That is, the power from the power storage unit 4 returns to the power storage unit 4 while propagating in the order of route D, route B, route C, and route E. For this reason, the monitoring voltage applied by the first ground fault detector 10 a and the second ground fault detector 10 b is superimposed in the control unit 6.

  When the relay unit 11 is not arranged, the power from the bypass power supply 5 is supplied to the control unit 6 through the route F by the second supply wiring 80. Part of the power supplied from the bypass power supply 5 to the control unit 6 is returned to the input power supply 1 through the route G by the first return wiring 71. At this time, the electric power returned to the input power supply 1 passes through the ground line 1a, the ground line 5a, and the ground between the ground lines through the route C (route in the direction from the input power supply 1 to the bypass power supply 5). Returned to 5. That is, the power from the bypass power source 5 returns to the bypass power source 5 while propagating in the order of the route F, the route G, and the route C. For this reason, the monitoring voltage applied by the first ground fault detector 10 a and the second ground fault detector 10 b is superimposed in the control unit 6.

(When relay part is arranged)
By arranging the relay unit 11, when power is being supplied from the input power supply 1 to the control unit 6, the route B and the route F are blocked. That is, the power from the input power source 1 supplied to the control unit 6 through the route A is suppressed from being returned to the bypass power source 5 through the route B. Further, it is possible to suppress the power from the power storage unit 4 supplied to the control unit 6 through the route D from being returned to the bypass power source 5 through the route B.

  Further, the supply of power from the bypass power supply 5 through the route F to the control unit 6 is suppressed. As a result, the power from the bypass power supply 5 is suppressed from returning to the input power supply 1 through the route G via the control unit 6.

  As a result, conduction of electric power via the route C is suppressed between the input power supply 1 and the bypass power supply 5.

  In addition, when the input power source 1 is out of power, the route B and the route F are not cut off. Therefore, a part of the power supplied from the power storage unit 4 to the control unit 6 through the route D is routed to the route B. And is returned to the bypass power supply 5. Then, the electric power returned to the bypass power supply 5 is returned to the input power supply 1 through the route C (route in the direction from the bypass power supply 5 to the input power supply 1). Here, at the time of a power failure of the input power supply 1, the switch unit 102 is turned off. Thereby, since the route E is interrupted, the power returned to the input power source 1 is suppressed from being returned to the power storage unit 4. As a result, the monitoring voltage applied by the first ground fault detector 10 a and the second ground fault detector 10 b can be suppressed from being superimposed in the control unit 6.

(Effect of 1st Embodiment)
In the first embodiment, the following effects can be obtained.

  In the first embodiment, as described above, the uninterruptible power supply 100 includes the relay unit 11 that brings the second path 8 into a non-conductive state when power is supplied from the input power supply 1 to the control unit 6. Thus, uninterruptible power supply 100 is constituted. Thus, when the relay unit 11 supplies power from the input power source 1 to the control unit 6, the power from the input power source 1 passes through the control unit 6 by setting the second path 8 in a non-conductive state. Thus, the return to the bypass power source 5 can be suppressed. As a result, the power is prevented from returning to the input power supply 1 via the ground line 1a for grounding the input power supply 1, the ground line 5a for grounding the bypass power supply 5, and the ground between the ground lines. Can do. In this case, the monitoring voltage applied by the ground fault detection unit 10 is suppressed from being superimposed in the control unit 6 via the first path 7 and the second path 8. As a result, when the ground fault detection unit 10 detects the electric power returned from the control unit 6, the detection of the voltage component for monitoring that has increased due to the superposition of the electric power in the control unit 6 is suppressed. be able to. Thereby, it can suppress that the ground fault detection part 10 misdetects a ground fault.

  In the first embodiment, as described above, the uninterruptible power supply 100 is configured such that the relay unit 11 is driven by the power supplied from the input power supply 1 that supplies power to the control unit 6. To do. As a result, the relay unit 11 can be driven by the input power source 1 without providing a separate power source for the relay unit 11, and therefore, power is supplied from the input power source 1 to the control unit 6 with a simple configuration. The second path 8 can be turned off.

  In the first embodiment, as described above, the first path 7 includes the first supply wiring 70 for supplying power to the control unit 6 and the first return wiring for returning power from the control unit 6. The second path 8 includes a second supply wiring 80 for supplying power to the control unit 6 and a second return wiring 81 for returning power from the control unit 6. And when the relay part 11 is supplying electric power from the input power supply 1 to the control part 6, the uninterruptible power supply apparatus 100 is set so that both the second supply wiring 80 and the second return wiring 81 are disconnected. Configure. Thereby, the monitoring voltage applied by the ground fault detection unit 10 is compared with the case where either the second supply wiring 80 or the second return wiring 81 is disconnected. 7 and the second route 8 can be more reliably suppressed from being superimposed in the control unit 6.

  In the first embodiment, as described above, when the relay unit 11 supplies power from the input power supply 1 to the control unit 6, the switch 11 a and the second switch 11 a that disconnects the second supply wiring 80. The uninterruptible power supply 100 is configured so as to include the switch 11b that disconnects the two return wirings 81. Thus, when power is supplied from the input power source 1 to the control unit 6, the power supplied from the input power source 1 to the control unit 6 by the second return wiring 81 being disconnected by the switch 11 b. However, return to the bypass power supply 5 can be suppressed. In addition, since the second supply wiring 80 is disconnected by the switch 11a, the power from the bypass power supply 5 can be suppressed from being supplied to the control unit 6 and returned to the input power supply 1. Can be suppressed. As a result, when power can be supplied to the control unit 6 from both the input power source 1 and the bypass power source 5, the power supply from the input power source 1 is prioritized and the monitoring is applied by the ground fault detection unit 10 Can be suppressed from being superimposed in the control unit 6 via the first path 7 and the second path 8.

[Second Embodiment]
Next, the configuration of the uninterruptible power supply 200 according to the second embodiment will be described with reference to FIGS. 3 and 4. The uninterruptible power supply 200 in the second embodiment differs from the first embodiment in which the second path 8 is turned off by the power from the input power supply 1, and the first path 7 is powered by the power from the bypass power supply 5. It is configured to be in a non-conductive state. In addition, in the figure, the same code | symbol is attached | subjected to the part of the structure similar to the said 1st Embodiment.

(Configuration of uninterruptible power supply)
As shown in FIG. 3, in the second embodiment, when the relay unit 51 supplies power from the bypass power supply 5 to the control unit 6, the relay unit 51 brings the first path 7 into a non-conductive state. That is, the relay unit 51 is configured to be driven by electric power supplied from the bypass power supply 5. Specifically, the relay unit 51 is connected to the Rc phase and the Sc phase of the bypass power supply 5 and is configured to be able to supply power from the bypass power supply 5. The relay unit 51 is an example of the “conduction control unit” in the claims.

  In the second embodiment, when the relay unit 51 supplies power from the bypass power supply 5 to the control unit 6, both the first supply wiring 70 and the first return wiring 71 are disconnected. Specifically, the relay unit 51 includes a switch 51 a that switches the connection state of the first supply wiring 70. The relay unit 51 also includes a switch 51 b that switches the connection state of the first return wiring 71. When power is supplied from the bypass power supply 5 to the relay unit 51, the first supply wiring 70 and the first return wiring 71 are disconnected by turning off the switch 51a and the switch 51b. The switch 51a and the switch 51b are examples of the “third switch” and the “fourth switch” in the claims, respectively.

(Description of uninterruptible power supply operation)
(Comparative example)
(When relay part is not arranged)
As shown in FIG. 4, the power from the bypass power supply 5 is supplied to the control unit 6 through the route F by the second supply wiring 80. When the relay unit 51 is not disposed, part of the power supplied from the bypass power supply 5 to the control unit 6 is returned to the input power supply 1 through the route G by the first return wiring 71. At this time, the electric power returned to the input power source 1 is route C (in the direction from the input power source 1 to the bypass power source 5) by the ground line 1a, the ground line 5a, and the ground between the ground line 1a and the ground line 5a. Route) to the bypass power supply 5. That is, the power from the bypass power source 5 returns to the bypass power source 5 while propagating in the order of the route F, the route G, and the route C. For this reason, the monitoring voltage applied by the first ground fault detector 10 a and the second ground fault detector 10 b is superimposed in the control unit 6. In FIG. 4, the arrow of each route means the direction of the flowing current.

  Further, the electric power from the power storage unit 4 is supplied to the control unit 6 through the route D by the third supply wiring 90. Here, when the relay unit 51 is not arranged, a part of the power supplied from the power storage unit 4 to the control unit 6 is route G and route C (from the input power source 1 to the bypass power source 5 as described above). The route is returned to the bypass power source 5 through the route in the direction of travel. Then, the electric power returned to the bypass power supply 5 is supplied again to the control unit 6 through the route F, and then returned to the power storage unit 4 through the route H by the third return wiring 91. That is, the power from the power storage unit 4 returns to the power storage unit 4 while propagating in the order of route D, route G, route C, route F, and route H. For this reason, the monitoring voltage applied by the first ground fault detector 10 a and the second ground fault detector 10 b is superimposed in the control unit 6.

  When the relay unit 51 is not arranged, the power from the input power source 1 is supplied to the control unit 6 through the route A by the first supply wiring 70. Part of the electric power supplied from the input power source 1 to the control unit 6 is returned to the bypass power source 5 through the route B by the second return wiring 81. At this time, the electric power returned to the bypass power source 5 is route C (in the direction from the bypass power source 5 to the input power source 1) by the ground line 1a, the ground line 5a, and the ground between the ground line 1a and the ground line 5a. Route) to the input power source 1. That is, the power from the input power source 1 returns to the input power source 1 while propagating in the order of route A, route B, and route C. For this reason, the monitoring voltage applied by the first ground fault detector 10 a and the second ground fault detector 10 b is superimposed in the control unit 6.

(When relay part is arranged)
By arranging the relay unit 51, when power is supplied from the bypass power supply 5 to the control unit 6, the route A and the route G are blocked. Thereby, the power from the bypass power supply 5 supplied to the control unit 6 through the route F is suppressed from being returned to the input power supply 1 through the route G. Further, it is possible to suppress the power from the power storage unit 4 supplied to the control unit 6 through the route D from being returned to the input power source 1 through the route G.

  Further, the supply of power from the input power source 1 through the route A to the control unit 6 is suppressed. As a result, the power from the input power source 1 is suppressed from returning to the bypass power source 5 through the route B via the control unit 6.

  As a result, conduction of electric power via the route C is suppressed between the input power supply 1 and the bypass power supply 5.

  Other configurations of the second embodiment are the same as those of the first embodiment.

(Effect of 2nd Embodiment)
In the second embodiment, the following effects can be obtained.

  In the second embodiment, as described above, the uninterruptible power supply device 200 includes the relay unit 51 that brings the first path 7 into a non-conductive state when power is supplied from the bypass power supply 5 to the control unit 6. Configure. Thereby, when power is supplied from the bypass power supply 5 to the control unit 6, the power from the bypass power supply 5 is supplied to the input power supply 1 through the control unit 6 by making the first path 7 nonconductive. Return can be suppressed. As a result, similarly to the first embodiment, the ground fault detection unit 10 can be prevented from erroneously detecting a ground fault.

  In the second embodiment, the uninterruptible power supply 200 is configured such that the relay unit 51 is driven by the power supplied from the bypass power supply 5 that supplies power to the control unit 6. As a result, the relay unit 51 can be driven by the bypass power source 5 without providing a separate power source for the relay unit 51. Therefore, when the power is supplied from the bypass power source 5 to the control unit 6 with a simple configuration. The first path 7 can be turned off.

  In the second embodiment, when the relay unit 51 supplies power from the bypass power supply 5 to the control unit 6, both the first supply wiring 70 and the first return wiring 71 are disconnected. The uninterruptible power supply 200 is configured. As a result, the monitoring voltage applied by the ground fault detection unit 10 is less than the first path in comparison with the case where either the first supply wiring 70 or the first return wiring 71 is disconnected. 7 and the second route 8 can be more reliably suppressed from being superimposed in the control unit 6.

  In the second embodiment, when the relay unit 51 supplies power from the bypass power supply 5 to the control unit 6, the switch 51 a and the first return wiring 71 that disconnect the first supply wiring 70 are provided. The uninterruptible power supply 200 is configured to include the switch 51b to be disconnected. Accordingly, when power is supplied from the bypass power supply 5 to the control unit 6, the power supplied from the bypass power supply 5 to the control unit 6 by the first return wiring 71 being disconnected by the switch 51 b. However, it can suppress returning to the input power supply 1. FIG. Further, the first supply wiring 70 is disconnected from the switch 51a, whereby the power from the input power source 1 can be suppressed from being supplied to the control unit 6 and returned to the bypass power source 5. Can be suppressed. As a result, when power can be supplied from both the input power supply 1 and the bypass power supply 5 to the control unit 6, the power supply from the bypass power supply 5 is prioritized and the monitoring is applied by the ground fault detection unit 10. Can be suppressed from being superimposed in the control unit 6 via the first path 7 and the second path 8.

  The remaining effects of the second embodiment are similar to those of the aforementioned first embodiment.

[Modification]
The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiment but by the scope of claims for patent, and further includes all modifications (modifications) within the meaning and scope equivalent to the scope of claims for patent.

  For example, in the said 1st and 2nd embodiment, although the ground fault detection part 10 showed the example which detects a ground fault by ZCT detection, this invention is not limited to this. Any method other than ZCT may be used as long as the ground wires (1a, 5a) are provided.

  In the first and second embodiments, an example of a configuration in which one bypass power supply 5 is provided has been described, but the present invention is not limited to this. For example, a plurality of bypass power supplies 5 may be provided.

  In the first and second embodiments, the example in which the relay unit 11 (51) controls the conduction state between the input power source 1 or the bypass power source 5 and the control unit 6 has been described. However, the present invention is not limited to this. I can't. For example, the conduction state between the input power source 1 or the bypass power source 5 and the control unit 6 may be controlled by an insulating transformer.

1 Input power 1a Grounding wire (grounding wire to ground the input power)
2 Power conversion unit 4 Power storage unit 5 Bypass power supply 5a Ground line (ground line for grounding the bypass power supply)
6 Control Unit 7 First Route 8 Second Route 10 Ground Fault Detection Unit 10a First Ground Fault Detector (Ground Fault Detection Unit)
10b Second ground fault detector (ground fault detector)
11, 51 Relay part (conduction control part)
11a switch (first switch)
11b switch (second switch)
20 Converter unit 21 Inverter unit 51a Switch (third switch)
51b Switch (4th switch)
70 First supply wiring 71 First return wiring 80 Second supply wiring 81 Second return wiring 100, 200 Uninterruptible power supply 101 Load M Connection point (neutral point)

Claims (5)

A power conversion unit including a converter unit and an inverter unit; and a power storage unit connected to a neutral point between the converter unit and the inverter unit, wherein one phase of a plurality of input power sources is grounded A V-connection type uninterruptible power supply unit connected to a load through the neutral point,
A control unit configured to be able to supply power from each of the input power source, a bypass power source that is a system different from the input power source and one of a plurality of phases is grounded, and the power storage unit;
A ground fault detecting unit for detecting a ground fault by applying a monitoring voltage to a ground line for grounding the input power source and a ground line for grounding the bypass power source;
A first path connecting the input power source and the control unit;
A second path connecting the bypass power supply and the control unit;
The second path is turned off when power is supplied from the input power source to the control unit, or the first path is supplied when power is supplied from the bypass power source to the control unit. An uninterruptible power supply device comprising: a conduction control unit that sets the non-conduction state.   2. The uninterruptible power supply according to claim 1, wherein the continuity control unit includes a relay unit that is driven by power supplied from one of the input power source and the bypass power source that supplies power to the control unit. Power supply. The first path includes a first supply wiring for supplying power to the control unit, and a first return wiring for returning power from the control unit,
The second path includes a second supply wiring for supplying power to the control unit, and a second return wiring for returning power from the control unit,
The relay unit disconnects both the second supply wiring and the second return wiring when power is supplied to the control unit from the input power source, or the control is performed from the bypass power source. The uninterruptible power supply according to claim 2, wherein both of the first supply wiring and the first return wiring are disconnected when power is supplied to the unit.   A second switch that disconnects the first switch and the second return wiring when the relay unit supplies power from the input power source to the control unit; The uninterruptible power supply according to claim 3 including a switch.   When the relay unit supplies power from the bypass power source to the control unit, a fourth switch that disconnects the first supply wiring and the third switch that disconnects the first supply wiring. The uninterruptible power supply according to claim 3 including a switch.

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