JP6470003B2 - Uninterruptible power supply and uninterruptible power supply system - Google Patents

Description

  The present invention intervenes between a commercial AC power supply and a load device to which power is supplied from the commercial AC power supply, performs charging in a storage battery unit built in at the time of normal power supply to the load device of the commercial AC power supply, and stops power supply The present invention relates to a constant commercial type uninterruptible power supply (hereinafter referred to as UPS) having a function of discharging a storage battery unit to a load device and backing up power supply for a long time, and a UPS system.

  In recent years, as a lesson from the Great East Japan Earthquake, if a blackout occurs in a wide area due to the occurrence of a large-scale disaster, etc., power supply using commercial AC power to load devices (especially devices with base station functions) such as electrical devices, electronic information processing devices, and communication devices In view of the situation that caused a great deal of damage due to the occurrence of troubles in various fields of the industry along with this, even when the power supply by commercial AC power supply was stopped, the storage battery as a secondary battery to the load device On the other hand, the application of a UPS having a function of backing up power supply has attracted attention.

  In this UPS, stable power supply to the load device is continued even when power supply from the commercial AC power supply is stopped, but the time for backing up the power supply (backup time) is determined by the capacity of the storage battery installed. In general UPS, the power outage time that can be handled is as short as several minutes to 30 minutes, but by increasing the total capacity of the storage battery and increasing the capacity, a device that enables backup time in units of several hours A configuration has also been developed.

  As a well-known technique related to a UPS with such a long backup time, for example, by providing an opportunity to start saving the execution state of an application or the like before activating forced shutdown by multiplex connection of UPS, the save time "Uninterruptible power supply connection method" (see Patent Document 1) to ensure the battery, DC battery backup function for easy battery replacement work and for the deterioration of some of the directly connected storage batteries "Uninterruptible power supply" (refer to Patent Document 2), and "DC uninterruptible power supply" (refer to Patent Document 3) that supplies DC backup power when a power supply trouble occurs in a load device that operates with DC power Can be mentioned.

JP-A-10-97354 Japanese Patent Laid-Open No. 5-260682 JP 2005-176461 A

  In the technology according to Patent Document 1 described above, a plurality of UPSs are cascade-connected to increase the number of UPSs having a function of converting direct current (DC) power from a battery pack into alternating current (AC) power by an inverter (power converter). Therefore, a method that can extend the backup time as desired is proposed.

  However, with such a functional configuration, not only does the installation floor area for adding UPS increase and an occupied space is required, but also the cost is increased, and the cable for connecting the UPSs to each other is also required. Since the influence of the voltage drop due to the impedance cannot be avoided, there is a risk that it is difficult to stably supply power to the load device. Also in the basic operation, for example, the UPS on the commercial AC power supply side is in the backup operation. When other UPS shifts to charging for power storage, the UPS on the commercial AC power supply side also bears the charge energy, so that the situation that the backup time is reduced due to this cannot be avoided, or the existing system Assuming that all UPSs are charged all at once, the UPS on the commercial AC power supply side Breaker provided on the input side (required as a relay function to prevent reverse power flow to the commercial AC power supply in the event of a power failure if the UPS is a commercial type bidirectional type) There is a case where the battery is tripped (blocked) due to excess, and there is a problem that charging cannot be stably performed under such a situation.

  Further, in the technology according to Patent Document 2, a plurality of battery packs having a configuration in which a predetermined number of storage batteries are connected in series are connected in series to be divided into n groups for each battery pack, and a diode is connected in parallel for each of the divided n groups of battery packs. Proposal of a method that can connect and replace the battery pack for each n group so that the UPS can be hot-wired while the power is on, achieve high reliability without stopping the system, and facilitate battery replacement work. Yes.

  However, in the case of a UPS in which a plurality of battery packs according to Patent Document 2 are connected in series, it is expected to extend the backup time by replenishing a fully charged battery pack during the backup operation. In addition to the problem that the battery voltage fluctuates greatly when the pack is inserted / removed, the replacement timing is limited in system operation. In addition, the battery pack is closer to the positive terminal side. Since this is dangerous, there is a problem that safety measures are not sufficiently implemented during hot line maintenance.

  Furthermore, in the technology according to Patent Document 3, when a plurality of battery packs are connected in parallel, a charging switch is provided on a charging line for each battery pack, and only the battery pack whose life is determined by the power management unit is removed and replaced, charge control is performed. We proposed a method that facilitated maintenance work in an energized state by turning off the corresponding charge switch at the unit to enable easy and safe replacement of a deteriorated battery pack at an arbitrary timing. ing.

  However, in the case of a UPS in which a plurality of battery packs according to Patent Document 3 are connected in parallel, the battery pack can be safely replaced more safely than the case of Patent Document 2, and the battery is fully charged during the backup operation. Although it is expected to extend the backup time by replenishing the pack, the circuit configuration is actually complicated, and immediately after replacement, the battery pack enters the other battery pack from a fully charged battery pack. Since current (so-called cross current) flows, there is a concern that the system operation may be reduced due to overcurrent depending on the situation, and there is a problem that the battery pack cannot be replaced with stability during hot-line maintenance.

  The present invention has been made to solve such problems, and the main technical problem thereof is that an occupied space is not required, and the power supply to the load device is stabilized for a long time when the power supply of the commercial AC power supply is stopped. Another object of the present invention is to provide a UPS and UPS system that can perform backup with high reliability.

  Another technical problem of the present invention is to provide a UPS and a UPS system that can safely replace the battery pack in the storage battery unit with good stability without disturbing the charge / discharge function during hot-line maintenance.

In order to solve the above technical problem, the present invention is a continuous commercial type uninterruptible power supply device that is connected between a commercial AC power source and a load device to which power is supplied by the commercial AC power source. A plurality of storage batteries that are charged in a normal time when power is supplied to the load device from a commercial AC power supply and are discharged to the load device when power supply from the commercial AC power supply is stopped are connected in series and parallel. A storage battery unit configured by connecting a plurality of battery packs connected in parallel, and charging by converting AC power from the commercial AC power source to DC power and supplying the DC power to the storage battery unit, and DC from the storage battery unit comprising a power conversion unit which performs discharge by supplying to the load device by converting power into AC power, and a control unit for controlling the operation of charging and discharging of the storage battery unit and the power converting unit, The power conversion unit boosts the voltage to a voltage higher than the DC voltage in the storage battery unit and outputs the voltage to the internal high-voltage DC path, and outputs the high-voltage DC voltage supplied to the high-voltage DC path in the storage battery unit. A bidirectional DC-DC converter that steps down to a DC voltage and outputs it to the storage battery unit is connected between the high-voltage DC path and the commercial AC power source, and the commercial AC unit is charged when charging the storage battery unit. The AC power from the power supply is converted into the DC power by converting the AC power to the high-voltage DC path, and then output to the DC-DC converter. When discharging from the storage battery unit, the DC power in the high-voltage DC path A bi-directional inverter that converts the AC power into the AC power and supplies it to the load device. The DC-DC converter electrically disconnects the high-voltage DC path side and the storage battery unit side. A high-frequency transformer having a function to perform the operation, and the storage battery unit is configured such that the plurality of parallel-connected battery packs are electrically insulated from the input / output of the device by the DC-DC converter. The battery pack can be inserted / removed at the time of replacement with respect to any of the battery packs at the time of hot-line maintenance performed according to the result of monitoring the use state of the battery pack, and the control unit is connected to the DC-DC converter and the inverter. Controlled bidirectional transmission operation, and after replacing any of the battery packs from a discharge end state to a fully charged state, the replaced fully charged battery in a state where the input voltage of the device has disappeared After starting the device using DC power from the pack or DC power supplied from a power supply means with external power conversion function, forcibly discharge It has a forced discharge function for backup .

  According to the UPS of the present invention, with the above configuration, it is possible to stably and reliably back up the power supply to the load device for a long time when the commercial AC power supply is stopped, without requiring an occupied space. Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

1 is a functional block diagram showing a basic configuration of a UPS system in which two UPSs according to Embodiment 1 of the present invention are cascade-connected. FIG. 2 is a schematic diagram illustrating an operation state of the UPS system illustrated in FIG. 1 according to a stage according to an operation state of each UPS. It is the external appearance perspective view which showed schematic structure of the UPS system which cascade-connected three UPS based on Example 2 of this invention. FIG. 4 is a schematic diagram illustrating an input / output connection relationship between interface circuits in each UPS of the UPS system illustrated in FIG. 3. FIG. 5 is a diagram for explaining signal level control when exclusive charge control is performed by the UPS control unit on the commercial AC power supply side in the input / output connection relationship between the interface circuits shown in FIG. The figure regarding the case where the storage battery part of UPS of the AC power supply side is charging, (b) is the figure regarding the case where the storage battery part of UPS of the commercial AC power supply side is discharging.

  Hereinafter, the UPS and the UPS system of the present invention will be described in detail with reference to the drawings by giving some examples.

  FIG. 1 is a functional block diagram showing a basic configuration of a UPS system in which two UPSs according to Embodiment 1 of the present invention are cascade-connected.

  Referring to FIG. 1, in the UPS system according to the first embodiment, two UPS 100 and 200 are cascade-connected, and a commercial AC power source (noted) is shown and power is supplied from this. In the UPS 100, 200, the switching connection operation is performed at the relays (RY) 101, 201 provided between the input / output terminals. The storage battery units 102 and 202 built in during normal power supply to the load device of the commercial AC power supply are used and discharged from the storage battery units 102 and 202 to the load device when the power supply of the commercial AC power supply is stopped. In addition to the commercial type that has a function to back up the power supply, the commercial AC power supply in the power failure state on the input side of the UPS 100 on the commercial system side Breaker relay function of preventing reverse power flow (BRK) 11 are provided for.

  Here, each UPS 100, 200 is connected to the positive and negative sides of the battery packs 103, 203 connected in parallel in the storage battery units 102, 202 and the commercial AC power supply and load device, respectively, and the AC power from the commercial AC power supply. Is converted into DC power and supplied to the storage battery units 102 and 202, and charging is performed. At the same time, DC power from the storage battery units 102 and 202 is converted into AC power and supplied to the load device to perform discharge. Units 104 and 204, control units 107 and 207 for controlling charging / discharging operations of the storage battery units 102 and 202 and the power conversion units 104 and 204, and interface circuits 108 and 208 for cascading the devices. I have.

  In addition, the power conversion units 104 and 204 in each UPS 100 and 200 boost the voltage to a voltage higher than the DC voltage in the storage battery units 102 and 202, output the voltage to the internal high-voltage DC path, and supply the high-voltage DC path to the high-voltage DC path. A direct current voltage is stepped down to a direct current voltage in the storage battery units 102 and 202 and output to the storage battery units 102 and 202. The bidirectional DC-DC converters 105 and 205 are connected between the high voltage direct current path and the commercial alternating current power source. At the time of charging the storage battery units 102 and 202, the AC power from the commercial AC power source is converted into DC power by converting the AC power to the high-voltage DC path, and then output to the DC-DC converters 105 and 205. Bi-directional inverters 106 and 206 that convert DC power in the high-voltage DC path into AC power and supply the load device when discharging from 102 and 202 are provided. Composed of Te. The control units 107 and 207 in each UPS 100 and 200 control bi-directional transmission operations in the DC-DC converters 105 and 205 and the inverters 106 and 206. Incidentally, for the DC-DC converters 105 and 205 described above, it is preferable to use a high-frequency transformer having a function of electrically insulating the high-voltage DC path side and the storage battery units 102 and 202 side. With such a configuration, a total conversion efficiency of 90% or more can be realized, which can contribute to the downsizing of the device configuration of the UPS 100, 200.

  Furthermore, the storage battery units 102 and 202 in each UPS 100 and 200 are configured by connecting in parallel a plurality of battery packs 103 and 203 having a configuration in which a plurality of lithium ion battery cells are connected in series and parallel as storage batteries (secondary batteries). High reliability of the backup function by considering that the capacity can be reduced to a minimum even when either of 103 or 203 is in failure or life-degraded state, compared to the configuration in which the battery packs of such configuration are connected in series and parallel. Is secured. Further, in the storage battery units 102 and 202, the battery packs 103 and 203 are electrically insulated by DC-DC converters 105 and 205 with respect to the input / output of the device, respectively. It is possible to safely carry out insertion / extraction at the time of replacement with respect to any one of the battery packs 103 and 203 at the time of hot-line maintenance performed according to the result of monitoring the use state at a dangerous voltage (60 Vdc) or less. The number of battery packs 103 and 203 connected in parallel in the storage battery units 102 and 202 may be expanded according to the system to be applied. For example, the battery packs 103 and 203 can be expanded in units of 0.62 kWh up to a maximum of 7.4 kWh. . Incidentally, when any of the battery packs 103 and 203 has a trouble such as a failure or a life deterioration state, the control units 107 and 207 display the result on the display unit or turn on a lighting unit of a specific color. It is possible to warn the maintenance manager by a method such as lighting.

  In addition, the control units 107 and 207 in the UPSs 100 and 200 replace any of the battery packs 103 and 203 in the storage battery units 102 and 202 from those in a discharge end state to those in a fully charged state, and then the input voltage of the device DC power from the fully charged battery packs 103 and 203 when the battery disappears, or power supply means having an external power conversion function (power conversion connected to an outlet provided exclusively for each UPS 100, 200) In addition to having a forcible discharge function for forcibly discharging and backing up after starting the apparatus using DC power supplied from a power supply apparatus having a function, signals in the input circuits and output circuits of the interface circuits 108 and 208 By controlling the level, the charging operation is performed exclusively when charging with the storage battery unit 102, 202 of the own device Both the in backup operation during discharge from the battery portion 102, 202 of its own device has exclusive charge control function to be executed to instruct the charge suppression in the other device backup inoperative.

  In this UPS system, the connection between the interface circuits 108 and 208 of the two UPS 100 and 200 is realized by using the I / O cable 13, but in order to improve noise resistance, the use of a coaxial cable or a shielded cable is required. desirable. A plurality of cables are used, the input circuit of the interface circuit 208 is connected to the output circuit of the interface circuit 108, and the input circuit of the interface circuit 108 is connected to the output circuit of the interface circuit 208. . Incidentally, the specific configuration of the input circuit and output circuit of the interface circuits 108 and 208 will not be described in detail because a well-known technique can be applied, but a signal transmission system circuit constituted by an insulating circuit using a photocoupler or the like is applied. And has a function of processing so as to maintain the signal level from the control units 107 and 207 at High or Low.

  That is, the input circuits and the output circuits of the interface circuits 108 and 208 of the UPS 100 and 200 are maintained high or low by the exclusive charge control function of the control units 107 and 207 described above. For example, when the storage battery unit 102 in the UPS 100 is being charged, the output circuit of the interface circuit 108 is maintained at Low indicating charging or discharging, and the input circuit is maintained at High indicating charging is possible. At this time, the output circuit of the interface circuit 208 in the UPS 200 in the standby state (backup non-operation state) in the commercial bypass operation is maintained at High indicating standby, and the input circuit is maintained at Low indicating charging prohibition. On the other hand, the same control is performed even when the storage battery unit 102 in the UPS 100 is discharging, the output circuit of the interface circuit 108 is maintained at Low indicating charging or discharging, and the input circuit is set to High indicating charging is possible. Maintained. At this time, the output circuit of the interface circuit 208 in the UPS 200 in the standby state in the commercial bypass operation is maintained at High indicating standby, and the input circuit is maintained at Low indicating charging prohibition.

  However, in the UPS system according to the first embodiment, the exclusive charging control function by the control units 107 and 207 as described above works on the backup operation, but in actuality, a power failure of the commercial system (commercial AC power source) by the UPS 100 occurs. The detection is divided into a case where the detection is earlier than the case of the UPS 200 and a case where the detection is late.

  Specifically, in the former case, when a power failure occurs in a commercial system (commercial AC power supply) at a certain time, the power failure is detected by the UPS 100 somewhat later than that point, and then the relay (RY) 101 is turned on. Then, the backup operation in the UPS 100 is performed for a predetermined period by supplying DC power from the storage battery unit 102 by discharging immediately after the switching. Further, if the power failure detection of the commercial system (commercial AC power supply) by the UPS 200 is performed immediately before the backup in the UPS 100, the relay (RY) 201 is switched from on to off for a short time after the backup in the UPS 100 is started. Immediately after that, the UPS 200 simply outputs a signal indicating that the next backup is performed, and does not immediately shift to the backup. The UPS (100) in a state where the relay (RY) 201 is switched from OFF to ON during the backup in the UPS 100. The relay (RY) 201 is reactivated by a predetermined timing after the end of the discharge of the backup (for example, a case where a predetermined time delayed by the backup time related to the UPS 100 after detection of a power failure in the UPS 200 is used as a trigger and immediately after that) Immediately after switching from on to off, the storage battery unit 202 Backup operation in UPS200 by supplying DC power by discharge is performed. Incidentally, in this operation, there is a slight time lag from the end of the backup operation in the UPS 100 to the start of the backup operation in the UPS 200 in signal processing, but the battery packs 103 of the actual storage battery units 102 and 202, The continuity of power supply by the backup operation to the load device after discharging from 203 is not hindered, and it may be considered that the power supply to the load device is continuously performed. The reason for this is that even if it is considered that the backup operation in the UPS 100 has ended in a state where the voltage drops below a predetermined voltage threshold, the power supply is actually powered down to the load device while the voltage is dropped due to a transient phenomenon of discharge. This is because the probability that the load device that has been supplied with power by the backup operation before that point in time continues to consume the maximum power and the power supply demand is high is considered to be extremely low.

  On the other hand, in the latter case, the power failure detection of the commercial system (commercial AC power supply) is performed first in the UPS 200, and the relay (RY) 201 is switched from on to off at the timing when the power failure is detected in the UPS 100 thereafter. Immediately after switching, the UPS 200 simply outputs a signal indicating that the next backup is performed for a little longer, and does not immediately shift to the backup. In operation, the switching of the relay (RY) 101 after the power failure is detected in the UPS 100, the UPS 100 Backup operation immediately after switching of the relay (RY) 101 in the UPS, switching of the relay (RY) 201 in the UPS 200 during the backup operation related to the UPS 100, relay in the UPS 200 at a predetermined timing after the discharge of the backup operation related to the UPS 100 is completed (RY) 201 again switching, Again a backup operation immediately after switching of the relay (RY) 201 in beauty UPS200 are respectively performed similarly to the former case. That is, when the power failure detection of the commercial system (commercial AC power supply) by the UPS 100 is later than the UPS 200, the power failure detection at the UPS 200, and the relay (RY) 201 at the timing when the power failure is detected at the UPS 100 at the UPS 200 is turned off. Is different from the former case in that the signal output state for performing backup next in the UPS 200 is slightly extended.

  As described above, in the UPS system according to the first embodiment, regardless of whether the power failure detection of the commercial system (commercial AC power supply) by the UPS 100 is earlier or later than the UPS 200, the UPS 100 is caused by the discharge from the battery pack 103 of the storage battery unit 102. After the backup operation is performed, the backup operation by discharging from the battery pack 203 of the storage battery unit 202 in the UPS 200 is continuously performed.

  FIG. 2 is a schematic diagram illustrating the operation of the UPS system according to the first embodiment for each of the stages A to D according to the operation states of the UPSs 100 and 200.

  Referring to FIG. 2, in this UPS system, in stage A, the UPS 100 is in a backup operation by discharging from the battery pack 103 of the storage battery unit 102 and the capacity of the storage battery unit 102 is slightly reduced. Is in a standby (standby) state, and the battery pack 203 of the storage battery unit 202 is in a fully charged state and shows a state in which the capacity of the storage battery unit 202 is maintained at a rating.

  In the next stage B, the battery pack 103 of the storage battery unit 102 in the UPS 100 is discharged, and once the backup is stopped, the battery pack 103 is replaced with a fully charged battery by hot-line maintenance. Shows a state in which the capacity of the storage battery unit 202 is slightly reduced during a backup operation by discharging from the battery pack 203 of the storage battery unit 202.

  In the subsequent stage C, from the fully charged battery pack 103 in which the storage battery unit 102 has been replaced by the forced discharge function of the control unit 107 when it is determined that the input voltage of the device in the UPS 100 has disappeared after the replacement operation in the stage B. During the backup operation by discharging, the capacity of the storage battery unit 102 is slightly reduced. At this time, the UPS 200 shifts to a standby (standby) state. It shows how the capacity remains slightly reduced.

  In the further stage D, since the UPS 100 continues the backup operation by the discharge from the battery pack 103 of the storage battery unit 102 in the stage C, the capacity of the storage battery unit 102 in the UPS 100 becomes empty and the operation is stopped. At this time, the backup operation by discharging from the battery pack 203 of the storage battery unit 202 in the UPS 200 is performed, and the capacity of the storage battery unit 202 is further reduced.

  In any case, in the UPS system according to the first embodiment, after the backup operation by the discharge from the storage battery unit 102 in the UPS 100 is performed, the backup operation by the discharge from the storage battery unit 202 in the UPS 200 is continuously performed. Even when a commercial AC power supply that requires a long time for power recovery due to the occurrence of a major disaster does not require an occupied space, the power supply to the load device can be stably backed up for a long time with high reliability. . For example, if the storage battery used for the battery packs 103 and 203 is a lithium ion battery cell and the total weight of the UPS system is about 100 kg, it is possible to continuously supply 1 kW to 2 kW for over 3 hours during backup. become.

  In the UPS system according to the first embodiment, the battery units 102 and 202 in the UPSs 100 and 200 are electrically insulated from each other by DC-DC converters 105 and 205 with respect to the input / output of the device. , 203 even if the battery has reached the end of discharge due to a life deterioration or failure and needs to be replaced, the battery packs 103 and 203 can be easily and safely charged without stopping the system operation by hot-line maintenance. Can be exchanged for something. Furthermore, if it is determined at this time that the input voltage of the apparatus has disappeared by the forced discharge function of the control units 107 and 207 in each UPS 100 and 200, the DC power from the replaced battery packs 103 and 203 in a fully charged state, or In order to perform backup by forcibly discharging using DC power supplied from a power supply means having an external power conversion function, the battery pack 103, with good stability during hot-line maintenance, without system operation being down, 203 can be exchanged.

  In addition, in the UPS system according to the first embodiment, the signal levels of the input circuits and the output circuits of the interface circuits 108 and 208 connected to each other are controlled by the exclusive charge control function of the control units 107 and 207 in each UPS 100 and 200. In order to exclusively control the charging operation in the storage battery units 102 and 202 in the own device, and to suppress the charging operation of other devices during the backup operation by the discharge from the storage battery units 102 and 202 in the own device, As in the prior art (Patent Document 1), simultaneous charging is performed and the breaker (BRK) 11 is tripped (cut off) due to excess power and charging is not stably performed. The battery packs 103 and 203 in the storage battery units 102 and 202 can be stably stabilized without hindering the charge / discharge function. Well it will be able to exchange.

  In addition, regarding the configuration of each of the UPS 100 and 200 in the UPS system according to the first embodiment, if the required functional configuration is selected and renewed without fundamentally changing the existing device environment and equipment, the minimum It can be applied at a limited introduction cost so as to have an equivalent processing function and to have an equivalent effect.

  FIG. 3 is an external perspective view showing a schematic configuration of a UPS system in which three UPSs according to Embodiment 2 of the present invention are cascade-connected.

  Referring to FIG. 3, in the UPS system according to the second embodiment, three UPSs 100, 200, and 300 are cascade-connected to be connected between the commercial AC power supply 10 and the load device 12 to which power is supplied. In each UPS 100, 200, 300, as in the case described in the first embodiment, the normal operation for the load device 12 of the commercial AC power supply 10 is performed using the switching operation of the relay provided between the input and output terminals. In addition to being a regular commercial type that has a function to back up the power supply by discharging the storage device from the storage battery unit when the power supply of the commercial AC power supply 10 is stopped, Again, a breaker (BRK) 11 is provided on the input side of the UPS 100 on the commercial system side.

  In the case of the UPS system according to the second embodiment, the basic configuration of each UPS 100, 200, 300 is the embodiment except for the connection relationship of the interface circuit and the details related to the control of the signal level by the exclusive charge control function by the control unit. Since it is the same as the case of 1, the reference numerals of the detailed configuration are omitted, and different points will be described.

  FIG. 4 is a schematic diagram illustrating an input / output connection relationship between interface circuits in the UPS 100, 200, and 300 of the UPS system according to the second embodiment.

  Referring to FIG. 4, the output circuit OUT of the interface circuit of the UPS 100 is connected to the part IN0 of the input circuit of the interface circuit of the UPS 200 and the part IN0 of the input circuit of the interface circuit of the UPS 300 using the I / O cable 13. The output circuit OUT of the interface circuit of the UPS 200 is connected to a part IN0 of the input circuit of the interface circuit of the UPS 100 and the other part IN1 of the input circuit of the interface circuit of the UPS 300 by using the same I / O cable 13. The output circuit OUT of the interface circuit is connected to the other part IN1 of the input circuit of the interface circuit of the UPS 100 and the other part IN1 of the input circuit of the interface circuit of the UPS 200 using the same I / O cable 13.

  FIG. 5 is a diagram for explaining signal level control when exclusive charge control is performed by the control unit of the UPS 100 on the commercial AC power supply 10 side in such an input / output connection relationship between the interface circuits. The figure (a) is a figure regarding the case where the storage battery part of UPS100 by the side of commercial AC power supply 10 is charging, The figure (b) is the figure regarding the case where the storage battery part of UPS100 by the side of commercial AC power supply 10 is discharging.

  Referring to FIG. 5A, when the storage battery unit in the UPS 100 is being charged, the output circuit OUT of the interface circuit is maintained at Low indicating charging or discharging, and a part IN0 and the other part IN1 of the input circuit are It is maintained at High indicating that charging is possible. At this time, the output circuit OUT of the interface circuit in the UPS 200, 300 in the standby state in the commercial bypass operation is maintained at High indicating standby, and a part of the input circuit IN0 is maintained at Low indicating charging prohibition. The other part IN1 is maintained at a chargeable high level. Incidentally, since the input circuit of the interface circuit has an inversion processing function, even if the other part IN1 is set to be chargeable High, as a result, if either one of the parts IN0 or the other part IN1 is Low, charging is prohibited. Processed as Low.

  Referring to FIG. 5B, the same control is performed even when the storage battery unit in the UPS 100 is discharging, and the output circuit OUT of the interface circuit is maintained at Low indicating charging or discharging, and the input circuit The part IN0 and the other part IN1 are maintained at High indicating that charging is possible. At this time, the output circuit OUT of the interface circuit in the UPS 200, 300 in the standby state in the commercial bypass operation is maintained at High indicating standby, and a part of the input circuit IN0 is maintained at Low indicating charging prohibition. The other part IN1 is maintained at a chargeable high level. Here again, due to the inversion processing function of the input circuit of the interface circuit, the other portion IN1 is processed as “Low” indicating that charging is prohibited even if the other portion IN1 is “High” that can be charged.

  Even in the UPS system according to the second embodiment, the UPS 100 was backed up by the discharge from the storage battery unit regardless of whether the power failure detection of the commercial system (commercial AC power supply) was earlier or slower than the UPS 200, 300. After that, it is possible to construct a function in which backups are sequentially performed by discharging from the storage battery unit in the UPS 200, 300, so that the UPS system 300 for an additional time is longer than the UPS system according to the first embodiment (for example, about 24 hours). It becomes possible to continue power supply at the time of backup, and the other effects are equivalent.

  The UPS system according to the first embodiment has a configuration in which two UPS 100, 200 are cascade-connected, and the UPS system according to the second embodiment has a configuration in which three UPS 100, 200, 300 are cascade-connected. It is also possible to configure a UPS system by cascading the above UPSs. In addition, communication between the interface circuits included in each UPS in such a case is configured to transmit and receive wirelessly without using the I / O cable 13 other than connecting by using the I / O cable 13 and performing wired communication. It is also possible. As described above, since the UPS of the present invention can be variously changed in configuration, it is not limited to the form disclosed in each embodiment.

10 Commercial AC power supply 11 Breaker (BRK)
12 Load device 13 I / O cable 100, 200, 300 UPS (uninterruptible power supply)
101, 201 Relay (RY)
102, 202 Storage battery unit 103, 203 Battery pack 104, 204 Power conversion unit 105, 205 DC-DC converter 106, 206 Inverter 107, 207 Control unit 108, 208 Interface circuit

Claims (3)

An uninterruptible power supply of a commercial type that is connected and connected between a commercial AC power supply and a load device to which power is supplied by the commercial AC power supply,
A plurality of storage batteries that are charged in a normal time when power is supplied from the commercial AC power source to the load device and are discharged to the load device when power supply from the commercial AC power source is stopped are connected in series and parallel. A storage battery unit configured by connecting a plurality of battery packs connected in parallel;
Charging by converting AC power from the commercial AC power source to DC power and supplying it to the storage battery unit, and by converting DC power from the storage battery unit to AC power and supplying it to the load device A power converter for discharging,
A control unit for controlling the operation of charging and discharging according to the storage battery unit and the power conversion unit,
The power conversion unit boosts the voltage to a voltage higher than the DC voltage in the storage battery unit and outputs the voltage to an internal high-voltage DC path, and outputs a high-voltage DC voltage supplied to the high-voltage DC path in the storage battery unit. A bidirectional DC-DC converter that steps down to a DC voltage and outputs it to the storage battery unit is connected between the high-voltage DC path and the commercial AC power source, and the commercial AC unit is charged when charging the storage battery unit. The AC power from the power supply is converted into the DC power by converting the AC power to the high-voltage DC path, and then output to the DC-DC converter. When discharging from the storage battery unit, the DC power in the high-voltage DC path A bidirectional inverter that converts the AC power into the alternating current power and supplies it to the load device,
The DC-DC converter uses a high-frequency transformer having a function of electrically insulating the high-voltage DC path side and the storage battery unit side,
In the storage battery unit, the plurality of parallel-connected battery packs are electrically insulated from the input / output of the device by the DC-DC converter, respectively, and a result of monitoring the use state of the battery pack by the control unit Can be inserted or removed when replacing any of the battery packs during hot-line maintenance according to
The control unit controls the bi-directional transmission operation in the DC-DC converter and the inverter, and after replacing any of the battery packs from a discharge end state to a fully charged state, the input voltage of the device After starting the device using DC power from the fully charged battery pack that has been replaced or DC power supplied from a power supply means having an external power conversion function, the battery is forcibly discharged. And has a forced discharge function to perform backup ,
An uninterruptible power supply. In the uninterruptible power supply according to claim 1,
An uninterruptible power supply, wherein a lithium ion battery cell is used for the storage battery. A plurality of uninterruptible power supply devices according to claim 1 or 2 are connected in cascade, and a reverse power flow to the commercial AC power supply in a power failure state is prevented on the input side of the commercial AC power supply device. An uninterruptible power supply system provided with a relay function breaker,
The plurality of uninterruptible power supply devices include an interface circuit for cascading devices together,
The control unit controls a signal level in the input circuit and the output circuit of the interface circuit, so that the charging operation is performed exclusively during charging in the storage battery unit of the own device, and from the storage battery unit of the own device. An uninterruptible power supply system having an exclusive charge control function for instructing and executing charging suppression in other devices in a backup non-operating state during a backup operation at the time of discharging.