JP2012105497A - Uninterruptible power supply apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an uninterruptible power supply apparatus, capable of achieving space saving and cost reduction.SOLUTION: An uninterruptible power supply apparatus includes: a positive-electrode side capacitor 3 and a negative-electrode side capacitor 4 that are connected in series, which are charged by a first power conversion section 2 when an AC power supply 1 is normal; a power storing section 7 that is charged by connecting to one end of a positive electrode or a negative electrode at a connection point of the positive-electrode side capacitor 3 and the negative-electrode side capacitor 4; a charging/discharging section 8 that charges either the positive-electrode side capacitor 3 or the negative-electrode side capacitor 4 from the power storing section 7; and a control power supply 9 that receives power from the capacitor charged by the charging/discharging section 8 or from the AC power supply 1.

Description

  The present invention relates to an uninterruptible power supply apparatus that supplies AC power from an AC power source to a load, and converts DC power stored in a power storage unit into AC power and supplies the AC power to a load in the event of a power failure of the AC power source. .

  The conventional uninterruptible power supply supplies stable power from the AC power source to the load when the AC power source is in a normal voltage range, detects voltage fluctuations that cause the AC power source voltage to fall below the set value, When detecting the situation where the voltage of the capacitor holding the operating power of the conversion circuit falls below a predetermined value, it is determined that the AC power supply is abnormal, and AC power is supplied from the battery as the power storage unit to the load via the power conversion circuit. .

  In order to perform these uninterruptible operations, a control power supply for the control circuit is required. The control power source is a DC power source configured by connecting a circuit in which a battery and a diode are connected in series and a DC output circuit rectified from an AC power source in parallel. A control power supply circuit of an uninterruptible power supply that supplies power from a higher one is disclosed (for example, see Patent Document 1).

Japanese Utility Model Laid-Open No. 5-11751

  As described above, in the conventional uninterruptible power supply, power is supplied to the control power supply from a battery or an AC power supply. In the case of an uninterruptible power supply that outputs AC100V, the AC power supply needs to perform normal operation, for example, between AC80V and AC120V. 113V to 170V) is applied.

  When the AC power supply is interrupted and performing backup operation, the control power supply is supplied from the battery. The voltage of the battery is generally DC24V to DC48V, and this voltage is applied to the control power supply. Patent Document 1 shows an example in which the battery voltage exceeds 170V, which corresponds to a large-capacity uninterruptible power supply apparatus in which the load power exceeds 3500 W. As a general uninterruptible power supply, a small capacity device that backs up a computer of 500 W to 1000 W is often used. As batteries for these small-capacity uninterruptible power supply devices, a lead battery having a rated voltage of DC12V is often used in series to back up a load of about 250W for 5 to 10 minutes. Are connected in series, and 500 W to 1000 W are supplied, so the battery voltage is generally DC24V to DC48V.

In addition, since the battery deteriorates with age, the user of the uninterruptible power supply periodically replaces the battery. Considering the safety of electric shock when replacing the battery, the battery voltage is often set to a low voltage.
From the above, it is necessary for the control power supply to obtain a predetermined performance in a wide voltage range from 24V of the battery to 170V of the AC power supply, and the control power supply circuit becomes large and expensive.
In order to reduce the voltage difference between the battery and the AC power supply, a DC / DC converter may be provided to boost the 24V of the battery to about 170V of the AC power supply. However, a circuit space for the DC / DC converter is separately provided. In addition, there was a problem that costs were required.

  The present invention has been made in order to solve the above-described problems. By supplying power to the control power supply from an AC power supply or a capacitor that holds the operating power of the power converter, the present invention is small and inexpensive. The purpose is to obtain a power failure power supply.

  An uninterruptible power supply according to the present invention is connected in series to a first power conversion unit that is connected to an AC power source and converts AC power into DC power, and is charged by the first power conversion unit when the AC power source is healthy. The positive-side capacitor and the negative-side capacitor, the second power conversion unit that converts the DC power of the positive-side capacitor and the negative-side capacitor into AC power, and one end of the positive or negative electrode is connected to the positive-side capacitor and the negative-side capacitor. A power storage unit connected to the connection point and charged when the AC power source is healthy; a charge / discharge unit that charges one of the positive side capacitor and the negative side capacitor from the power storage unit when the AC power source is not healthy; A control power source for a control circuit that controls the power conversion unit, the second power conversion unit, and the charge / discharge unit, the control power source being a capacitor or an AC power source on the side supplied with power by the charge / discharge unit Is that supplied Luo power.

  According to the present invention, a small-sized and low-cost uninterruptible power supply can be obtained by supplying power to the control power supply from the capacitor that holds the operating power of the AC power supply or the power converter.

It is a block diagram which shows the whole structure of the uninterruptible power supply in Embodiment 1 of this invention. It is a circuit diagram which shows the 1st power conversion part of the uninterruptible power supply in Embodiment 1 of this invention. It is a circuit diagram which shows the 2nd power conversion part of the uninterruptible power supply in Embodiment 1 of this invention. It is a circuit diagram which shows the charging / discharging part of the uninterruptible power supply in Embodiment 1 of this invention. It is a circuit diagram which shows the starting part of the uninterruptible power supply in Embodiment 1 of this invention. It is a block diagram which shows the whole structure of the uninterruptible power supply in Embodiment 2 of this invention. It is a block diagram which shows the whole structure of the uninterruptible power supply in Embodiment 3 of this invention. It is a block diagram which shows the whole structure of the uninterruptible power supply in Embodiment 4 of this invention. It is a circuit diagram which shows the starting part of the uninterruptible power supply in Embodiment 4 of this invention.

Embodiment 1 FIG.
Hereinafter, the uninterruptible power supply in Embodiment 1 of this invention is demonstrated based on FIGS. 1 is a block diagram showing the overall configuration of the uninterruptible power supply, FIG. 2 is a circuit diagram showing a first power converter, FIG. 3 is a circuit diagram showing a second power converter, and FIG. 4 is a charge / discharge unit. FIG. 5 is a circuit diagram showing an activation unit.

In FIG. 1, an uninterruptible power supply 100 is connected to an AC power source 1, a first power conversion unit 2 that converts an AC voltage into a DC voltage, and a predetermined value (for example, DC 170 V) by the first power conversion unit 2. A positive-side capacitor 3 and a negative-side capacitor 4 that are charged to the second side, and a second side that is connected to the positive-side capacitor 3 and the negative-side capacitor 4 and converts a DC voltage into an AC voltage (for example, AC 100 V) and supplies power to the load 6. Power converter 5, power storage unit 7 such as a battery that supplies power to positive side capacitor 3 and negative side capacitor 4 when AC power supply 1 is abnormal, and power from negative side capacitor 4 when AC power source 1 is healthy Is charged in the power storage unit 7, the power of the power storage unit 7 is discharged when the AC power source 1 is abnormal, and the charge / discharge unit 8 that supplies power to the negative side capacitor 4 is stored. 7 and the input switching relay 12 that closes the first power converter 2, the bypass relay 13 that is closed when the AC power source 1 and the load 6 are directly connected, the high potential side of the negative side capacitor 4, and the AC power source. 1 is connected to the other end 20 of the AC power supply 1 via the diode 11 and the relay 14, and the other end 23 is connected to the low potential of the negative capacitor 4. A control power source 9 connected to the side through a diode 10, a starter 15 connected to the power storage unit 7, acting on the charge / discharge unit 8 and supplying the power of the power storage unit 7 to the negative capacitor 4, a second An output relay 16 that outputs the output of the power converter 5 to a load is provided.
The control power source 9 is a power source for operating a control circuit (not shown) for controlling the first power conversion unit 2, the second power conversion unit 5, the charge / discharge unit 8, the relays 12 to 14, and the like. is there.

  As shown in FIG. 2, the first power converter 2 is connected in parallel with the reactor 2a, the half bridge diode 2b, the diodes 2c1, 2c2, 2c3, 2c4 constituting the diode bridge 2c, and the diode bridge 2c. When the AC power source 1 is healthy, the AC power of the AC power source 1 is rectified to DC power by the half-bridge diode 2b and boosted by the reactor 2a, the diode bridge 2c and the transistor 2d to be positive. Power is supplied to the side capacitor 3 and the negative side capacitor 4. When the AC power supply 1 is abnormal, the DC power of the power storage unit 7 is boosted by the reactor 2a, the half-bridge diode 2b, and the switch 2c and supplied to the positive-side capacitor 3.

  As shown in FIG. 3, the second power converter 5 includes a first transistor 5a whose collector is connected to the positive voltage line P, a diode 5b connected in antiparallel with the first transistor 5a, a collector Is connected to the emitter of the first transistor 5a, the second transistor 5c having the emitter connected to the negative voltage line N, the diode 5d connected in antiparallel with the second transistor 5c, and the first transistor 5a And an AC filter 5e formed of a reactor 5e1 and a capacitor 5e2.

As shown in FIG. 4, the charging / discharging unit 8 includes a first transistor 8a having a collector connected to the positive electrode side of the power storage unit 7, a diode 8b connected in reverse parallel to the first transistor 8a, and a collector having a first collector A second transistor 8c connected to the emitter of one transistor 8a, the emitter of which is connected to the negative voltage line N, a diode 8d connected in antiparallel with the second transistor 8c, and one end of the first transistor 8a. And a reactor 8e connected to the common line at the other end.
Note that the transistors 2d, 5a, 5c, 8a, and 8c are not limited to IGBTs that are self-extinguishing type semiconductor switching elements, but are also forcedly switched by MOSFETs, GCTs, GTOs, transistors, or thyristors that have no self-extinguishing function. It is sufficient if the flow operation is possible.

The electrical storage part 7 should just be able to store energy, such as a lead battery, for example.
Further, the relay 14 has a b-contact that closes when the control power supply 9 is not operating.

As shown in FIG. 5, the starting unit 15 may have two circuit configurations shown in FIGS. 5 (a) and 5 (b). FIG. 5 (a) includes only the control circuit 15a. b) is composed of a control circuit 15b and a power transistor 15c.
The control circuit 15a in FIG. 5A is a circuit that controls on / off of the transistor 8a of the charging / discharging unit 8.
The control circuit 15b in FIG. 5B is a circuit that controls on / off of the power transistor 15c.

Next, the operation of the uninterruptible power supply 100 will be described.
First, when the AC power supply 1 is applied from the state in which the uninterruptible power supply device 100 has stopped operating (the control power supply 9 has stopped operating), the control power supply 9 is connected to the AC power supply 1 via the diode 11 and the relay 14. A voltage (a voltage peak value of 141 V when the AC power supply 1 is AC 100 V) is applied, the control power supply 9 starts operating, and a control circuit (not shown) starts operating. In the control circuit, when the AC power source 1 is healthy, the input switching relay 12 closes the AC power source 1 and the first power conversion unit 2 (connection between the terminals bc), and the first power conversion unit 2 serves as an input. The applied AC voltage of the AC power source 1 is rectified and boosted, and the positive-side capacitor 3 and the negative-side capacitor 4 are supplied with power and charged so as to have a predetermined voltage (for example, DC 170 V).

Hereinafter, the charging operation of the positive capacitor 3 and the negative capacitor 4 will be described in detail with reference to FIG.
When the voltage of the AC power source 1 is positive, the transistor 2d of the first power converter 2 is turned on, the AC power source 1 → the input switching relay 12 → the reactor 2a → the diode 2c1 of the diode bridge 2c → the transistor 2d → the diode bridge 2c. The energy is stored in the reactor 2a through the route of the diode 2c4 → the AC power source 1.
Subsequently, the transistor 2d is turned off, and the energy stored in the reactor 2a is routed through the route of the reactor 2a → the half-bright diode 2b → the positive capacitor 3 → the AC power source 1 → the input switching relay 12 → the reactor 2a. 3 is charged, and the positive side voltage line P is formed with respect to the common line.

When the AC power source 1 is negative, the transistor 2d of the first power converter 2 is turned on, the AC power source 1 → the diode 2c2 of the diode bridge 2c → the transistor 2d → the diode 2c3 of the diode bridge 2c → the reactor 2a → the input switching relay. 12 → Accumulate energy in the reactor 2a through the AC power supply 1 route.
Subsequently, the transistor 2d is turned off, and the energy stored in the reactor 2a is routed through the route of the reactor 2a → the input switching relay 12 → the AC power supply 1 → the negative side capacitor 4 → the half bristle diode 2b → the reactor 2a. 4 is charged to form a negative voltage line N for the common line.

  The second power conversion unit 5 converts the DC voltage of the positive side capacitor 3 and the negative side capacitor 4 into a predetermined AC voltage (for example, AC 100 V). The output relay 16 is closed by an output ON command by an ON button (not shown) operation or the like, and AC power is supplied to the load 6.

Hereinafter, the power conversion operation of the second power conversion unit 5 will be described in detail with reference to FIG.
When the first transistor 5a of the second power converter 5 is turned on, the route of the positive capacitor 3 → the first transistor 5a → the reactor 5e1 → the capacitor 5e2 and the load 6 via the output relay 16 → the positive capacitor 3 To supply power to the load 6.
When the second transistor 5c is turned on, power is supplied to the load 6 through the route of the negative capacitor 4 → the capacitor 5e2 and the load 6 via the output relay 16 → the reactor 5e1 → the second transistor 5c → the negative capacitor 4. Supply. In this way, the DC voltage of the positive side capacitor 3 and the negative side capacitor 4 is converted into a predetermined AC voltage and supplied to the load 6.

The charging / discharging unit 8 supplies the power storage unit 7 with a predetermined voltage (for example, DC24) by the electric power of the negative side capacitor 4.
Charge to V).
Hereinafter, the operation of the charging / discharging unit 8 will be described in detail with reference to FIG.
When the transistor 8c of the charging / discharging unit 8 is turned on, current flows through the negative capacitor 4 → reactor 8e → transistor 8c → negative capacitor 4 and when the transistor 8c is turned off, the current is changed to the reactor 8e → diode 8b → storage. Part 7 → Reactor 8e flows to charge power storage unit 7.

The above operation is hereinafter referred to as normal operation. At this time, a voltage across the negative-side capacitor 4 (for example, DC 170 V) is applied to the control power supply 9 via the diode 10.
If the peak value of the AC power supply 1 is higher than 170V, a voltage is applied to the control power supply 9 via the AC power supply 1, the diode 11, and the relay 14. That is, in the normal operation, the control power source 9 is supplied with power from the negative side capacitor 4 or the AC power source 1 whichever is larger.

  If the AC power source 1 deviates from a predetermined normal range (for example, AC 80 V to 120 V), it is determined that the AC power source 1 has entered an abnormal state such as a momentary voltage drop or a power failure, and the input switching relay 12 is connected to the first power source. The converter 2 and the power storage unit 7 are switched so as to be closed (connection between terminals a and c), and the power of the power storage unit 7 is converted into DC / DC power by the first power converter 2 to the positive capacitor 3. Then, the voltage across the positive electrode side capacitor 3 is maintained at a predetermined voltage (for example, DC 170 V).

The operation in the case where the power of the power storage unit 7 is converted by the first power converter 2 and supplied to the positive capacitor 3 will be described in detail with reference to FIG.
When the transistor 2d of the first power converter 2 is turned on, a current flows through the power storage unit 7 → the input switching relay 12 → the reactor 2a → the diode 2c1 → the transistor 2d → the diode 2c4 → the power storage unit 7 and the transistor 2d is turned off. The current flows through the reactor 2a → the diode 2b1 → the positive capacitor 3 → the power storage unit 7 → the input switching relay 12 → the reactor 2a and supplies power to the positive load capacitor 3.

Further, the power of the power storage unit 7 is converted by the charging / discharging unit 8 and supplied to the negative capacitor 4, and the voltage across the negative capacitor 4 is maintained at a predetermined voltage (for example, DC 170 V).
An operation in the case where the power of the power storage unit 7 is converted by the charge / discharge unit 8 and supplied to the negative capacitor 4 will be described in detail with reference to FIG.
When the transistor 8a of the charge / discharge unit 8 is turned on, a current flows through the power storage unit 7 → the transistor 8a → the reactor 8e → the power storage unit 7, and when the transistor 8a is turned off, the current is changed to the reactor 8e → the negative capacitor 4 → diode. 8d → Reactor 8e flows to supply power to the load side capacitor 4.
Thus, the electric power held by the positive side capacitor 3 and the negative side capacitor 4 is converted by the second power conversion unit 5 to output an AC voltage (for example, AC 100 V) to the load 6.
The above operation is hereinafter referred to as backup operation.

When the backup operation is continued, the voltage of the power storage unit 7 gradually decreases. When the voltage of the power storage unit 7 reaches a predetermined value (for example, DC 19 V), the stored energy of the power storage unit 7 is depleted and power is supplied to the load 6. The operation is stopped, the operation of the control circuit by the control power supply 9 is stopped, and the uninterruptible power supply 100 stops operating.
If the AC power supply 1 returns to a predetermined normal range (for example, AC 80 V to 120 V) during the backup operation, it is determined that an abnormal state such as an instantaneous voltage drop or a power failure has been recovered, and the normal operation is resumed.

Next, when the AC power supply 1 has a power failure, the uninterruptible power supply 100 stops operating (control power supply 9
A case will be described in which the operation is started using the electric power of the power storage unit 7 from the state where the operation is stopped.
When the start unit 15 receives a start command by an on button (not shown) operation or the like, the control circuit 15a of the start unit 15 operates to turn on / off the transistor 8a of the charge / discharge unit 8. Thus, the electric power of the power storage unit 7 is supplied to the negative electrode side capacitor 4 through the charging / discharging unit 8, and the voltage across the negative electrode side capacitor 4 is increased. The voltage across the negative electrode side capacitor 4 is applied to the control power supply 9 via the diode 10, and when the applied voltage reaches the operable voltage of the control power supply 9 (for example, DC 100V), the control power supply 9 starts its operation.

  When the control power supply 9 starts operating, a control circuit (not shown) starts operating. The control circuit supplies the power of the power storage unit 7 to the negative capacitor 4 through the charging / discharging unit 8, and maintains the voltage across the negative capacitor 4 at a predetermined voltage (for example, DC 170V). The power storage unit 7 is connected to the first power conversion unit 2 via the input switching relay 12, and the control circuit supplies the power of the power storage unit 7 to the positive capacitor 3 by the first power conversion unit 2, The voltage across the positive electrode side capacitor 3 is maintained at a predetermined voltage (for example, DC 170 V). The electric power held in the positive side capacitor 3 and the negative side capacitor 4 is converted by the second power conversion unit 5, the output relay 16 is closed, and an AC voltage (for example, AC 100 V) is output to the load 6.

  According to the first embodiment, the control power supply 9 is supplied with power from the AC power supply 1 or the negative electrode side capacitor 4, and the power of the power storage unit 7 is supplied to the negative electrode side capacitor 4 by the charging / discharging unit 8 by the starting unit 15. Therefore, the control power supply 9 can be operated with a space-saving and low-cost configuration without using a DC / DC conversion circuit for adjusting the voltage difference.

Embodiment 2. FIG.
Next, the uninterruptible power supply in Embodiment 2 of this invention is demonstrated based on FIG. FIG. 6 is a block diagram showing an overall configuration of uninterruptible power supply 101 according to Embodiment 2 of the present invention.
The uninterruptible power supply apparatus 101 in FIG. 6 has one end 20 of the AC power supply 1 by the first power conversion unit 2 having a normally closed contact of the input switching relay 19 (closed when the control power supply 9 is not operating). And a contact 18 between the connection point of the positive side capacitor 3 and the negative side capacitor 4 and the other end 21 of the AC power source 1 and a normally open contact (open when the control power source 9 is not operating). Are connected in parallel, and the control power supply 9 is connected in parallel to the negative-side capacitor 4. A normally open contact of the input switching relay 19 (opened when the control power supply 9 is not operating) is connected to the power storage unit 7 and the first power conversion unit 2. Other configurations are the same as those of the first embodiment shown in FIG. 1, and the same or corresponding parts are denoted by the same reference numerals, and description thereof is omitted.

Next, the operation of the uninterruptible power supply 101 will be described.
First, when the AC power source 1 is applied from the state where the uninterruptible power supply device 101 has stopped operating (the control power source 9 has stopped operating), the AC power source 1 → the input switching relay 19 → the first power converter 2 (reactor 2a And the half bridge diode 2b) → the positive side capacitor 3 → the resistor 18 → the AC power source 1 is charged, and at the same time, the AC power source 1 → the resistor 18 → the negative side capacitor 4 → the first power converter 2 ( Reactor 2a and half-bridge diode 2b) → input switching relay 19 → AC power supply 1 is charged to negative electrode side capacitor 4.

  Here, the resistor 18 is a current limiting resistor that suppresses an excessive current that charges the positive-side capacitor 3 and the negative-side capacitor 4 from flowing. Since the control power supply 9 is connected in parallel to the negative-side capacitor 4, the control power supply 9 starts operating when the voltage across the negative-side capacitor 4 reaches the operable voltage of the control power supply 9 (for example, DC 100 V).

When the control power supply 9 starts operating, a control circuit (not shown) starts operating. When the AC power supply 1 is healthy, the control circuit closes the resistance short-circuit relay 17 and supplies power to the positive-side capacitor 3 and the negative-side capacitor 4 by the first power converter 2, and the voltage across both capacitors is set to a predetermined voltage (for example, DC 170V).
The operation in which the first power conversion unit 2 rectifies and boosts the AC voltage of the AC power supply 1 to charge the positive side capacitor 3 and the negative side capacitor 4 is the same as that of the first embodiment.

  An operation of supplying the AC power to the load 6 by converting the DC voltage of the positive side capacitor 3 and the negative side capacitor 4 into a predetermined AC voltage by the second power conversion unit 5, and the AC power source 1 has a voltage drop, a power failure The operation of the backup operation when an abnormal state is caused by the above is the same as that of the first embodiment, and the description thereof is omitted.

Next, a description will be given of a case where the operation of the uninterruptible power supply device 101 is stopped using the power of the power storage unit 7 from the state where the operation of the uninterruptible power supply device 101 is stopped (the control power supply 9 stops operating) when the AC power supply 1 is interrupted. To do.
When the start unit 15 receives a start command by an on button (not shown) operation or the like, the control circuit 15a of the start unit 15 operates to turn on / off the transistor 8a of the charge / discharge unit 8. Thus, the electric power of the power storage unit 7 is supplied to the negative electrode side capacitor 4 through the charging / discharging unit 8, and the voltage across the negative electrode side capacitor 4 is increased. The voltage across the negative electrode side capacitor 4 is applied to the control power supply 9, and when the applied voltage reaches the operable voltage of the control power supply 9 (for example, DC 100V), the control power supply 9 starts its operation.

  When the control power supply 9 starts operating, a control circuit (not shown) starts operating. The control circuit supplies the power of the power storage unit 7 to the negative capacitor 4 through the charging / discharging unit 8, and maintains the voltage across the negative capacitor 4 at a predetermined voltage (for example, DC 170V). The control circuit closes the power storage unit 7 and the first power conversion unit 2 by the input switching relay 19 (connection between terminals a and c), and supplies the power of the power storage unit 7 to the positive side capacitor by the first power conversion unit 2. 3 and the voltage across the positive electrode side capacitor 3 is maintained at a predetermined voltage (for example, DC 170 V). Since other operations are the same as those in the first embodiment, description thereof is omitted.

  According to the second embodiment, the control power supply 9 is supplied with power from the negative side capacitor 4, and the starter 15 supplies the power of the power storage unit 7 to the negative side capacitor 4 through the charge / discharge unit 8. Therefore, the control power supply 9 can be operated with a space-saving and low-cost configuration without using a DC / DC conversion circuit for adjusting the voltage difference.

Embodiment 3 FIG.
Next, the uninterruptible power supply in Embodiment 3 of this invention is demonstrated based on FIG. FIG. 7 is a block diagram showing an overall configuration of uninterruptible power supply 102 according to Embodiment 3 of the present invention.
In the second embodiment, assuming that the N-phase of the uninterruptible power supply 101 is not the ground phase but is connected to the live phase side by mistake, the input switching relay 19, the output relay 16, and the resistance short-circuit relay 17 are opened. There is a problem that a phase potential occurs at the battery terminal.

Therefore, in the uninterruptible power supply 102 of the third embodiment, as shown in FIG. 7, the first power conversion unit 2 is normally closed of the input switching relay 19 (closed when the control power supply 9 is not operating). Is connected to one end 20 side of the AC power supply 1 by a contact, and a parallel body of a resistor 24 and a normally open relay 25 is connected in series with the input switching relay 19. Between the connection point of the positive electrode side capacitor 3 and the negative electrode side capacitor 4 and the other end 21 of the AC power supply 1, a relay 26 having a normally closed contact (closed when the control power supply 9 is not operating) is connected. The control power supply 9 is connected in parallel to the negative-side capacitor 4. A normally open contact of the input switching relay 19 (opened when the control power supply 9 is not operating) is connected to the power storage unit 7 and the first power conversion unit 2. Other configurations are the same as those of the first embodiment shown in FIG. 1, and the same or corresponding parts are denoted by the same reference numerals, and description thereof is omitted.

  When the AC power supply 1 is applied from the state where the uninterruptible power supply 102 stops operating (the control power supply 9 stops operating), the AC power source 1 → the resistor 24 → the relay 19 → the first power conversion unit 2 (with the reactor 2a) The half-bridge diode 2b) → the positive side capacitor 3 → the relay 26 → the AC power source 1 is charged through the path, and the AC power source 1 → the relay 26 → the negative side capacitor 4 → the first power conversion unit 2 (reactor). 2a and half-bridge diode 2b) → relay 19 → resistor 24 → AC power supply 1 is charged in the negative side capacitor 4.

Here, the resistor 24 suppresses an excessive current that charges the positive-side capacitor 3 and the negative-side capacitor 4 from flowing. Since the control power supply 9 is connected in parallel to the negative-side capacitor 4, the control power supply 9 starts operating when the voltage across the negative-side capacitor 4 reaches the operable voltage of the control power supply 9 (for example, DC 100 V).
When the control power supply 9 starts operating, a control circuit (not shown) starts operating. When the AC power supply 1 is healthy, the control circuit supplies power to the positive-side capacitor 3 and the negative-side capacitor 4 by the first power converter 2, and maintains the voltage across both capacitors at a predetermined voltage (for example, DC 170V).
The operation in which the first power conversion unit 2 rectifies and boosts the AC voltage of the AC power supply 1 to charge the positive side capacitor 3 and the negative side capacitor 4 is the same as that of the first embodiment.

  An operation of supplying the AC power to the load 6 by converting the DC voltage of the positive side capacitor 3 and the negative side capacitor 4 into a predetermined AC voltage by the second power conversion unit 5, and the AC power source 1 has a voltage drop, a power failure The operation of the backup operation when an abnormal state is caused by the above is the same as that of the first embodiment, and the description thereof is omitted.

Next, when the AC power supply 1 has a power failure, the operation of the uninterruptible power supply 102 is stopped using the power of the power storage unit 7 from the state where the operation of the uninterruptible power supply 102 is stopped (the control power supply 9 stops operating). explain.
When the start unit 15 receives a start command by an on button (not shown) operation or the like, the control circuit 15a of the start unit 15 operates to turn on / off the transistor 8a of the charge / discharge unit 8. Thus, the electric power of the power storage unit 7 is supplied to the negative electrode side capacitor 4 through the charging / discharging unit 8, and the voltage across the negative electrode side capacitor 4 is increased. The voltage across the negative electrode side capacitor 4 is applied to the control power supply 9, and when the applied voltage reaches the operable voltage of the control power supply 9 (for example, DC 100V), the control power supply 9 starts its operation.

When the control power supply 9 starts operating, a control circuit (not shown) starts operating. The control circuit supplies the power of the power storage unit 7 to the negative capacitor 4 through the charging / discharging unit 8, and maintains the voltage across the negative capacitor 4 at a predetermined voltage (for example, DC 170V). The control circuit closes the power storage unit 7 and the first power conversion unit 2 by the input switching relay 19 (connection between terminals a and c), and supplies the power of the power storage unit 7 to the positive side capacitor by the first power conversion unit 2. 3 and the voltage across the positive electrode side capacitor 3 is maintained at a predetermined voltage (for example, DC 170 V).
When the battery (power storage unit 7) is to be replaced while the AC power source 1 is healthy, the relay 13 is closed, the relay 25 is opened, the relay 19 is opened from the AC power source 1 side, the relay 26 is opened, and the relay 16 is turned on. If it is opened, the potential of the AC power supply 1 is not generated in the power storage unit 7. Since other operations are the same as those in the first embodiment, description thereof is omitted.

  According to the third embodiment, the control power supply 9 is supplied with electric power from the negative electrode side capacitor 4, and the starting unit 15 supplies the electric power of the power storage unit 7 to the negative electrode side capacitor 4 through the charging / discharging unit 8. Therefore, the control power supply 9 can be operated with a space-saving and low-cost configuration without using a DC / DC conversion circuit for adjusting the voltage difference.

Embodiment 4 FIG.
Next, the uninterruptible power supply in Embodiment 4 of this invention is demonstrated based on FIG. FIG. 8 is a block diagram showing the overall configuration of the uninterruptible power supply 103 according to Embodiment 4 of the present invention, and FIG. 9 is a circuit diagram showing an activation unit.
In the first to third embodiments, the negative electrode side of power storage unit 7 is connected to common line N, power storage unit 7 is provided on the positive electrode side (upper side of common line N), and charging / discharging unit 8 supplies power of power storage unit 7. The negative electrode side capacitor 4 was supplied. In the invention of Embodiment 4, the power storage unit 7 is provided on the negative electrode side (below the common line N),
The charging / discharging unit 8 supplies power from the power storage unit 7 to the positive capacitor 3.
In other words, the charging / discharging unit 8 of the present invention may supply power to at least one of the positive-side capacitor 3 and the negative-side capacitor 4 that has a different polarity from the connection side of the power storage unit 7.

  In FIG. 8, an uninterruptible power supply 103 is connected to an AC power source 1, a first power conversion unit 2 that converts an AC voltage into a DC voltage, and a predetermined value (for example, DC 170 V) by the first power conversion unit 2. A positive-side capacitor 3 and a negative-side capacitor 4 that are charged to the second side, and a second side that is connected to the positive-side capacitor 3 and the negative-side capacitor 4 and converts a DC voltage into an AC voltage (for example, AC 100 V) and supplies power to the load 6. Power conversion unit 5, power storage unit 7 that supplies power to positive side capacitor 3 and negative side capacitor 4 when AC power supply 1 is abnormal, and power supply from positive side capacitor 3 to power storage unit 7 when AC power supply 1 is healthy. Charging and discharging unit 8 that charges and discharges power of power storage unit 7 when AC power supply 1 is abnormal and supplies power to positive-side capacitor 3; power storage unit 7 and first power conversion unit 2 when AC power supply 1 is abnormal When the input switching relay 12 to be closed, the AC power source 1 and the load 6 are directly connected, the bypass relay 13 to be closed, the low potential side of the positive capacitor 3 and one end 21 of the AC power source 1 are connected at one end. 22 is connected, the other end 23 is connected to the other end 20 of the AC power source 1 via the diode 11 and the relay 14, and the other end 23 is connected to the high potential side of the positive capacitor 3 via the diode 10. The control power supply 9 is connected to the power storage unit 7 and works on the charge / discharge unit 8 to supply the power of the power storage unit 7 to the positive-side capacitor 3. The output of the second power converter 5 is used as a load. An output relay 16 is provided for output.

In addition, the circuit structure of the 1st power conversion part 2, the 2nd power conversion part 5, and the charging / discharging part 8 is the same as FIGS. The circuit configuration of the activation unit 27 is shown in FIG.
As shown in FIG. 9, the starting unit 27 may have two circuit configurations of FIG. 9A and FIG. 9B, and FIG. 9A includes only the control circuit 27a. b) is composed of a control circuit 27b and a power transistor 27c.
The control circuit 27a in FIG. 9A is a circuit that controls on / off of the transistor 8c of the charging / discharging unit 8.
The control circuit 27b in FIG. 9B is a circuit that controls on / off of the power transistor 27c.
However, the operation of the first power conversion unit 2 is the same as that of the first embodiment when the AC power supply 1 is healthy, but when the AC power supply 1 is abnormal, the DC power of the power storage unit 7 is converted to the first power conversion unit. DC / DC power is converted by 2 and power is supplied to the negative capacitor 4.

In the charge / discharge unit 8, the collector of the first transistor 8a is connected to the positive voltage line P, the emitter of the second transistor 8c is connected to the negative side of the power storage unit 7, and the other end of the reactor 8e is common. It becomes the structure connected to a line.
That is, the first transistor 8a whose emitter is connected to the collector of the second transistor 8c, the collector is connected to the positive voltage line, the diode 8b connected in antiparallel with the first transistor 8a, and the emitter is charged The second transistor 8c connected to the negative side of the unit 7, the diode 8d connected in antiparallel with the second transistor 8c, and one end connected to the emitter of the first transistor 8a and the collector of the second transistor 8c The other end of the reactor 8e is connected to a common line.

Next, the operation of the uninterruptible power supply 103 will be described.
First, when the AC power source 1 is applied from the state where the uninterruptible power supply device 103 has stopped operating (the control power source 9 has stopped operating), the control power source 9 starts operating, and a control circuit (not shown) operates. Start and perform normal operation. This normal operation is the same as in the first embodiment.
During this normal operation, the control power supply 9 has a higher voltage (for example, DC 170 V) supplied from both ends of the positive capacitor 3 via the diode 10 and a voltage supplied from the AC power supply 1 via the diode 11. A voltage is applied.

During this normal operation, the charging / discharging unit 8 charges the power storage unit 7 to a predetermined voltage (for example, DC 24 V) with the electric power of the positive electrode side capacitor 3.
Hereinafter, the operation of the charging / discharging unit 8 will be described in detail with reference to FIG.
When the transistor 8a of the charging / discharging unit 8 is turned on, a current flows through the positive side capacitor 3 → the transistor 8a → the reactor 8e → the positive side capacitor 3 and when the transistor 8a is turned off, the current is changed to the reactor 8e → the power storage unit 7 → The current flows from the diode 8d to the reactor 8e, and the power storage unit 7 is charged.

During the backup operation, the power of the power storage unit 7 is converted into DC / DC power by the first power converter 2 and supplied to the negative capacitor 4 and the voltage across the negative capacitor 4 is maintained at a predetermined voltage (for example, DC 170 V). To do.
The operation in the case where the power of the power storage unit 7 is converted by the first power converter 2 and supplied to the negative capacitor 4 will be described in detail with reference to FIG.
When the transistor 2d of the first power converter 2 is turned on, a current flows through the power storage unit 7 → the diode 2c2, the transistor 2d, the diode 2c3, the reactor 2a, the input switching relay 12 and the power storage unit 7, and the transistor 2d is turned off. The current flows through the reactor 2 a → the power storage unit 7 → the negative capacitor 4 → the diode 2 b 2 → the reactor 2 a and supplies power to the load capacitor 4.

Moreover, the electric power of the electrical storage part 7 is DC / DC-power-converted by the charging / discharging part 8, and is supplied to the positive electrode side capacitor | condenser 3, and the both-ends voltage of the positive electrode side capacitor | condenser 3 is maintained at predetermined voltage (for example, DC170V).
An operation in the case where the power of the power storage unit 7 is converted by the charge / discharge unit 8 and supplied to the positive capacitor 3 will be described in detail with reference to FIG.
When the transistor 8c of the charging / discharging unit 8 is turned on, a current flows through the power storage unit 7 → the reactor 8e → the transistor 8c → the power storage unit 7, and when the transistor 8c is turned off, the current is changed to the reactor 8e → the diode 8b → the positive side capacitor. 3 → Reactor 8e flows to supply power to the positive load side capacitor 3.
Then, the second power converter 5 converts the electric power held by the positive capacitor 3 and the negative capacitor 4 and outputs an AC voltage (for example, AC 100 V) to the load 6.

Next, a description will be given of a case where the operation of the uninterruptible power supply device 103 is stopped (the control power supply 9 stops operating) using the electric power of the power storage unit 7 when the AC power supply 1 has a power failure. To do.
When the start unit 27 receives a start command by an on button (not shown) operation or the like, the start unit 15 supplies the power of the power storage unit 7 to the positive capacitor 3 by the charge / discharge unit 8, and the voltage across the positive capacitor 3 Increase. The voltage across the positive capacitor 3 is applied to the control power supply 9 via the diode 10, and when the applied voltage reaches the operable voltage of the control power supply 9 (for example, DC 100V), the control power supply 9 starts operation.

  When the control power supply 9 starts operating, a control circuit (not shown) starts operating. The control circuit supplies the electric power of the power storage unit 7 to the positive capacitor 3 by the charging / discharging unit 8, and maintains the voltage across the positive capacitor 3 at a predetermined voltage (for example, DC 170V). The power storage unit 7 is connected to the first power conversion unit 2 via the input switching relay 12, and the control circuit supplies the power of the power storage unit 7 to the negative capacitor 4 by the first power conversion unit 2, The voltage across the negative electrode side capacitor 4 is maintained at a predetermined voltage (for example, DC 170V). The second power converter 5 converts the power held by the positive capacitor 3 and the negative capacitor 4 into power, the output relay 16 is closed, and an AC voltage (for example, AC 100 V) is output to the load 6.

  According to the fourth embodiment, the control power supply 9 is supplied with power from the AC power supply 1 or the positive-side capacitor 3, and the power of the power storage unit 7 is supplied to the positive-side capacitor 3 by the charging / discharging unit 8 by the starting unit 27. Therefore, the control power supply 9 can be operated with a space-saving and low-cost configuration without using a DC / DC conversion circuit for adjusting the voltage difference.

1: AC power supply, 2: First power converter,
3: Positive side capacitor, 4: Negative side capacitor,
5: Second power conversion unit, 6: Load,
7: power storage unit, 8: charge / discharge unit,
9: Control power supply, 10: Diode,
11: Diode, 12: Input switching relay,
13: Bypass relay, 14: Relay,
15: Starter, 16: Output relay,
17: Resistance short-circuit relay, 18: Resistance,
19: Input switching relay, 24: Resistance,
25: Normally closed relay, 26: Relay,
27: Starter,
100, 101, 102, 103: Uninterruptible power supply.

Claims (6)

A first power converter connected to an AC power source and converting AC power to DC power;
When the AC power supply is healthy, the positive-side capacitor and the negative-side capacitor connected in series, which are charged by the first power conversion unit,
A second power converter that converts the DC power of the positive side capacitor and the negative side capacitor into AC power;
One end of a positive electrode or a negative electrode is connected to a connection point between the positive electrode side capacitor and the negative electrode side capacitor, and the power storage unit that is charged when the AC power source is healthy,
When the AC power supply is not healthy, a charging / discharging unit that charges the positive electrode side capacitor or the negative electrode side capacitor from the power storage unit,
A control power source for a control circuit that controls the first power conversion unit, the second power conversion unit, and the charge / discharge unit;
The uninterruptible power supply apparatus, wherein the control power supply is supplied with power from a capacitor on the side supplied with power by the charge / discharge unit or the AC power supply.   2. The power supply / discharge unit according to claim 1, wherein the charge / discharge unit supplies power of the power storage unit to at least a capacitor having a polarity different from a connection side of the power storage unit among the positive electrode side capacitor or the negative electrode side capacitor. Uninterruptible power system.   The charging / discharging unit supplies power to the negative side capacitor when the negative side of the power storage unit is connected to a connection point between a positive side capacitor and a negative side capacitor connected in series, and the positive side of the power storage unit is The uninterruptible power supply according to claim 2, wherein power is supplied to the positive-side capacitor when connected to a connection point between the positive-side capacitor and the negative-side capacitor connected in series. A first input switching relay connected in series between one end of the AC power source and the first power converter, and a connection point between the positive side capacitor and the negative side capacitor and the other end of the AC power source A resistor and a resistor short-circuit relay connected in parallel;
The first input switching relay closes and connects the AC power supply and the first power conversion unit when the control power supply is not operating. Uninterruptible power supply as described in the section.   A second input switching relay connected in series between one end of the AC power supply and the first power converter; a parallel body of a resistor and a resistance short-circuiting relay connected in series to the second input switching relay; 4. A normally closed relay connected between a connection point of the positive side capacitor and the negative side capacitor and the other end of the AC power supply. Uninterruptible power supply described in 1.   An activation unit for controlling the charge / discharge unit is provided, and when the AC power supply is not healthy and the control power supply is not operating, the charge / discharge unit is controlled by the activation unit, and the power of the power storage unit is The uninterruptible power supply according to any one of claims 1 to 5, wherein power is supplied to a capacitor having a polarity different from that of the connection side of the power storage unit.

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