JP2002191126A - Power supply system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power supply system capable of indirect load-leveling concurrently with backup of a DC feeding system. SOLUTION: This power supply system comprises a storage device (a storage battery 17A) for backup, and a storage device for load-leveling (a booster converter 17B, a current detector 17C, a storage battery 17D, a charger 17E, an integrator 17F, a charging and discharging pattern table 17G, and a load sharing control circuit 17H). The storage device for backup is connected in parallel with a DC feeding system which is a feeding system constituted by mixing an AC feeding system with a DC feeding system, charged by a rectifier 14, and conducts discharging if an abnormality occurs in an utility power supply. The storage device for load-leveling is connected in parallel with the DC feeding system, charged by the rectifier 14 under an off-peak load condition of power demand, and conducts discharging under a peak load condition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a power supply system for supplying power to a load.

[0002]

2. Description of the Related Art A power supply system receives DC power and supplies DC power and AC power to various loads.
Such a power supply system is disclosed in Japanese Unexamined Patent Publication No. 9-285037.
No. in the official gazette. According to the technique described in this publication, a storage battery is installed on the commercial AC side of the rectifier. A method is shown in which power is supplied from a commercial power supply to a load in a normal state, and wiring is switched from a storage battery side in an abnormal state.

Some power supply systems supply power to, for example, a communication device as a load. From a power supply system for communication, both DC power required by an exchange or a transmission device and AC power required by an air conditioner or a lighting device are supplied. For DC power, usually
A storage battery is used for backup. Since the storage battery is heavy and bulky, the installation space and floor load of the storage battery are limited.

However, since the storage battery has high responsiveness, the storage battery supplies energy for a short time (for example, about 30 minutes). Then, when the time elapses, the standby power generation device, which is not very responsive but can supply a large amount of power, starts up, starts AC power supply to the power receiving device, and stops power supply from the storage battery. The storage battery is normally floatingly charged in a standby state,
In the event of a power outage, it is used to connect the standby power generator until it starts.

[0005] As described above, the power supply system using the storage battery and the standby power generation device is based on the Advanced Telecommunication Air C.
onditioning Systems in the Multimedia Era (Intele
c'94,) pp. 14-20. The power supply system in this document usually receives commercial power from a power receiving device, and then draws the commercial power into an AC branching device. And the power supply system is an AC branching device that uses AC as it is, such as an air conditioner,
Energy is supplied separately to a device that converts alternating current to direct current, such as a rectifier. Hereinafter, a wiring system that converts AC into DC by a rectifier or the like and feeds the power is referred to as a DC power feeding system.

FIG. 11 shows a power supply system according to the above document. In the power supply system of FIG. 11, the power receiving device 101 including a circuit breaker or the like normally receives the supply of the commercial power 201,
It is drawn into the AC branching device 102. AC branching device 102
Supplies commercial power to the air conditioner 202 and the rectifier 103 separately. The air conditioner 202 is a device that uses alternating current as it is, and the rectifier 103 is a device that converts alternating current to direct current.

[0007] The rectified power from the rectifier 103 is
DC / DC converter 104, DC / AC converter 1
05 and the communication device 203. The DC / DC converter 104 converts the voltage level of the rectified power to generate DC power, and the DC / AC converter 105 converts the rectified power to AC again to generate AC power.

On the other hand, a storage battery 106 is connected to the output side of the rectifier 103, and a standby power generator 107 is connected to a power receiving device. The storage battery 106 is a short-term energy supply source that supplies DC power to the DC / DC converter 104, the DC / AC converter 105, and the communication device 203 when the commercial power supply 201 loses power. Backup power generator 10
7 is a power receiving device 10 when the commercial power supply 201 is out of power.
1 is a long-term energy supply source that supplies AC power to the AC branching device 102 via the AC power supply 1. As such a standby power generation device 107, there is one using an engine.

Next, the operation of the power supply system will be described with reference to FIG.
2 will be described. Usually, the power supply system is a commercial power supply 2
01 is supplied to the air conditioner 202, and DC power and AC power are supplied to the communication device 203. In the power supply system, the storage battery 106 is floatingly charged (step S101).

Since the communication device 203 is an important device that is not too much to say at the heart of information communication, an instantaneous interruption of power supply is not allowed. For this reason, the power supply system monitors the occurrence of an abnormality in the commercial power supply 201 (step S10).
2). If the commercial power supply 201 is normal, the power supply system returns the process to step S101.

When it is detected that an abnormality has occurred in the commercial power supply 201, a start signal is transmitted to the standby power generation device 107 and, at the same time, the supply of DC from the storage battery 106 is started (step S103). Then, the power supply system checks whether or not the standby power generator 107 has been started (step S10).
4). Upon detecting that the standby power generator 107 has been activated in step S104, the power supply system sets the standby power generator 10
7 from the DC / DC converter 104 and the DC / DC converter 104 and the DC / DC
The DC power and the AC power generated by the AC converter 105 are supplied to the communication device 203. At the same time, the power supply system performs floating charging of the storage battery 106 (step S106).

Normally, the standby power generator 107 is not very responsive, so in step S104, the standby power generator 107
Is not activated, the power supply system converts the DC power from the storage battery 106 into the DC / DC converter 104,
The power is supplied to the DC / AC converter 105 and the communication device 203 (step S105).

After step S106, the power supply system monitors whether the commercial power supply 201 has recovered (step S107). Upon detecting that the commercial power supply 201 has recovered in step S107, the power supply system returns the process to step S101. If the commercial power supply 201 has not recovered, the power supply system continues the process of step S106.

Thus, when the commercial power supply 201 fails,
DC power supply from storage battery 106 to communication device 203 is performed first.

[0015]

SUMMARY OF THE INVENTION Incidentally, NEDO
(New Energy and Industrial Technology Development Organization) has been developing high-efficiency batteries and distributed battery power storage systems aiming at load leveling in order to equalize power demand since 1994. We are developing. These are specialized in leveling different power demands depending on the time of day, and the configuration in combination with the backup of the load device has not been studied.

Further, the above-mentioned Japanese Patent Application Laid-Open No. 9-285037 is disclosed.
The technology disclosed in the above publication does not disclose a configuration for performing a leveling operation. Further, the power supply system of FIG. 11 is fully equipped with a backup system by a DC power supply system, but does not perform a load leveling operation completely corresponding to recent power saving.

Incidentally, a backup of a load device is an essential condition for a communication device. In addition, a circuit configuration for realizing energy saving by load leveling is also required.
For example, if the load leveling operation is performed with a circuit configuration that considers only backup, when the power failure occurs immediately after discharging the storage battery during peak load, the capacity of the storage battery for backup becomes insufficient, and before the backup power generator starts up. Power supply to the communication device is interrupted.

In the load leveling operation, it is conceivable to leave a backup capacity in the storage battery when discharging at the time of peak load. However, if a certain type of battery is not completely discharged from time to time, a memory effect may occur. There is a problem that the capacity is reduced. In addition, since the storage battery deteriorates, the capacity changes with time, and it is difficult to accurately estimate the remaining capacity.

The power supply system for communication uses both DC power required by the exchanges and transmission devices and AC power required by air conditioning and lighting. A storage battery is normally connected to DC power for backup. For load leveling, DC power from a fuel cell, NaS (sodium sulfur) battery, or the like is temporarily converted to AC power by an inverter and is used together with commercial AC power to level energy.

However, in this load leveling method, it is necessary to intensively supply the AC power of the inverter to the inflow section of the commercial power supply. As a result, a large-scale device is required for the energy storage device and the inverter. If the inverter fails, load leveling becomes impossible. In addition, load leveling via the inverter is not optimal because of the loss of the inverter.

An object of the present invention is to solve the above-mentioned problems and to provide a power supply system for performing backup of a DC power supply system and indirectly leveling loads.

[0022]

According to a first aspect of the present invention, there is provided a power supply system connected to a power supply system in which an AC power supply system and a DC power supply system are mixed in parallel with the DC power supply system. And a backup power storage device that is charged by the rectifier and is discharged when an abnormality occurs in the commercial power supply. And a load leveling power storage device that discharges at times.

According to a second aspect of the present invention, in the power supply system according to the first aspect, the load leveling power storage device includes a storage battery, a current detector for detecting a current of the storage battery, and the storage battery. And a booster converter for use in series connection, and a battery charger for charging is connected to the storage battery.

According to the power supply system having the above structure, the voltage of the storage battery is designed to be lower than the voltage of the rectifier,
When the operation of the booster converter is stopped, DC power supply to a load such as a communication device is performed only from the rectifier. When the boosted voltage of the booster converter is added to the voltage of the storage battery, DC power is supplied from the storage battery to the communication device, and the DC power from the rectifier can be reduced.

According to a third aspect of the present invention, in the power supply system according to the second aspect, the load leveling power storage device controls the charge / discharge state of the storage battery and controls the charge / discharge state of the storage battery.
A charge / discharge pattern table that records information on a discharge state, an integrator that calculates the storage battery capacity by integrating the discharge current of the storage battery detected by the current detector, and the information of the charge / discharge pattern table, A load sharing control circuit for controlling a boosted voltage of the booster converter and adjusting a discharge current of the storage battery.

According to the power supply system having the above-described configuration, the capacity of the storage battery in the charge / discharge pattern table is updated with the previous measured value of the discharge capacity and used in the next charge / discharge cycle of load leveling. With this configuration, the state of deterioration of the storage battery can be measured, and peak and off-peak times can be predicted to charge and discharge the storage battery.

According to a fourth aspect of the present invention, in the power supply system according to the third aspect, there is provided a selection circuit for switching the functions of the backup power storage device and the load leveling power storage device in a constant cycle, The backup power storage device includes a series circuit of a storage battery, a current detector, and a booster converter, an integrator, a charge / discharge pattern table, and a load sharing control circuit. And a power failure detection circuit for detecting the power failure.

According to the power supply system having the above-described structure, one of the storage batteries is not used exclusively for backup and the other is used exclusively for leveling, so that the life of the storage batteries is improved, and the capacity of each storage battery is measured at regular intervals. be able to.

[0029]

Next, embodiments of the present invention will be described with reference to the drawings.

The power supply system according to this embodiment is provided with distributed energy storage devices for leveling the load only with the DC power supply system, and the DC power supply system is backed up as usual. Hereinafter, two embodiments will be described.

[First Embodiment] FIG. 1 is a block diagram showing a first embodiment of the present invention. In the power supply system 1 shown in FIG. 1, an AC power supply system and a DC power supply system are mixed.
That is, the power supply system 1 receives the supply of the commercial power 201 and supplies AC power to the air conditioner 202 and supplies DC power and AC power to the communication device 203.

The power supply system 1 includes a power receiving device 11, a standby power generating device 12, an AC branching device 13, a rectifying device 14,
A C / DC converter 15, a DC / AC converter 16, and a backup device 17 are provided. In the power supply system 1, the power receiving device 11, the standby power generation device 12, and the AC branching device 13 form an AC supply system, and the rectifier 14 and the backup device 17 form a DC supply system. Note that the power receiving device 11, the standby power generation device 12, the AC branching device 13, the rectifier 14, the DC / DC converter 15, and the DC / AC converter 16 in FIG.
01, standby power generator 107, AC branching device 102, rectifier 103, DC / DC converter 104 and DC / DC converter 104.
Since they are the same as the AC converter 105, respectively, description thereof is omitted.

The backup device 17 has a load leveling and is used as a short-time energy supply source. The backup device 17, as shown in FIG.
Storage batteries 17A, 17D, booster converter 17B, current detector 17C, charger 17E, integrating device 17F,
Discharge pattern table section 17G, load sharing control circuit 17
H, input terminals 17J, 17K and output terminals 17L, 1
7M.

In the backup device 17, the input terminal 17
J and 17K are connected to output terminals 17L and 17M, respectively. Input terminal 17 to which rectifier 14 is connected
A storage battery 17A and a charger 17E are connected between J and the input terminal 17K. Booster converter 17B, current detector 17C, and storage battery 17D are connected in series, and the series connection circuit is connected between input terminal 17J and input terminal 17K.

The integrator 17F and the charge / discharge pattern table 17G are connected. An output terminal of the integrator 17F is connected to an input terminal of the load sharing control circuit 17H,
The output terminal of the current detector 17C is connected to the input terminal of the integrator 17F. Each output terminal of the charge / discharge pattern table section 17G is connected to the input terminal of the charger 17E and the input terminal of the load sharing control circuit 17H.

The backup device 17 comprises a backup power storage device and a load leveling power storage device.

The storage battery 17A is a backup power storage device. The storage battery 17 </ b> A is exclusively used for back-up, and is constantly floating-charged at the output of the rectifier 14 to supplement self-discharge. Since the storage battery 17A is constantly charged, the storage battery 17A is likely to be overcharged. For this reason, if a battery that is resistant to overcharging, such as a lead storage battery, is used as the storage battery 17A, floating charging can be directly performed using the output of the rectifier 14.

A device including the storage battery 17D, ie, a booster converter 17B, a current detector 17C, and a storage battery 17D
D, the charger 17E, the integrator 17F, the charge / discharge pattern table 17G, and the load sharing control circuit 17H constitute a power storage device dedicated to load leveling.

The booster converter 17B includes a storage battery 17
The voltage of D is boosted and added to the voltage of storage battery 17D.
Booster converter 17B is used for adjusting the discharge current of storage battery 17D. Booster converter 17
One example of B is shown in FIG. The booster converter of FIG.
Forward type, transformer 21, switch element 2
2. Diodes 23 and 24, smoothing filter 25, output current detector 26, output voltage detector 27 and PWM (Puls
e Width Modulation) control circuit 28.

In this booster converter, the transformer 2
Switch element 2 connected in series to one primary winding 21A
2 repeatedly turns on and off under the control of the PWM control circuit 28. As a result, the DC voltage of the storage battery 17D is converted into a pulsed AC voltage. The AC voltage induces an AC voltage in the secondary winding 21B of the transformer 21, and the induced voltage is rectified by the rectifying diode 23 and the circulating diode 24. The rectified voltage is smoothed by a smoothing filter 25 including a coil 25A and a capacitor 25B, and becomes a DC voltage.
The DC voltage is applied to output terminals 17L and 17M.

When the DC voltage is output, the output current detector 26 of the booster converter detects the value of the current flowing by the DC voltage, and the output voltage detector 27 detects the DC voltage. The PWM control circuit 28 controls the opening / closing timing of the switch element 22 based on the detection result from the output current detection unit 26, the detection result from the output voltage detection unit 27, and the control signal a from the load sharing control circuit 17H. I do. As a result of this control, pulses having different duty ratios are generated by the switch element 22. That is, the boost voltage output from the booster converter can be freely adjusted by adjusting the on / off ratio of the switch element 22 by the booster converter of FIG.

FIG. 4 shows another example of the booster converter. The booster converter of FIG. 4 is a full-bridge type and includes a switch element 3 having switches 31A to 31D.
1, transformer 32, diodes 33A and 33B, smoothing filter 34, output current detector 35, output voltage detector 36
And a PWM control circuit 37.

In this booster converter, the switches 31A to 31D connected in a bridge form are repeatedly turned on and off under the control of the PWM control circuit 37. At this time, when the switches 31A and 31D are turned on, the switches 31B and 31C are turned off. These switches 31A
31D converts the DC voltage of the storage battery 17D into a pulsed AC voltage. At this time, a voltage approximately twice as high as the voltage generated in the primary winding 21A of FIG. 3 is generated in the primary winding 32A of the transformer 32.

The transformer 3 is operated by the generated AC voltage.
An AC voltage is induced in the second secondary winding 32B, and the induced voltage is rectified by rectifying diodes 33A and 33B. The rectified voltage is applied to the coil 34A and the capacitor 3A.
4B and a DC voltage. The DC voltage is output terminal 17L,
Added to 17M.

Hereinafter, the output current detection unit 35, the output voltage detection unit 36, and the PWM control circuit 37 correspond to the output current detection unit 26, the output voltage detection unit 27, and the PWM control circuit 2 of FIG.
8 perform the same operations as those of the switches 31A to 31D.
Control the opening and closing timing of the

It should be noted that a normal converter can be used as the booster converter of FIGS. Since the on / off ratio of the switch element is adjusted by the booster converters of FIGS. 3 and 4, the boosted voltage can be adjusted freely. Even if these converters should fail, the storage battery 17D can be discharged through the freewheel diode or the rectifier diode.

The storage battery 17D is charged by the charger 17E during the off-peak of power demand. The charging voltage of the charger 17E is set to be equal to or lower than the output voltage of the rectifier 14 in the full load state of the rectifier 14. Therefore, unless the booster converter 17B performs a boosting operation, the storage battery 17
D cannot discharge.

The current detector 17C detects a discharge current flowing from the storage battery 17D, and outputs the detected current value to the integrating device 17C.
Send to F.

The charger 17E charges the storage battery 17D. The charging voltage of the charger 17E is set to be equal to or lower than the output voltage of the rectifier 14 in the full load state of the rectifier 14. The charger 17E includes a charge / discharge pattern table unit 17
The necessary information of the storage battery 17D is read from G. Charger 1
7E checks the off-peak time of the power demand from the read information, and charges the storage battery 17D at the off-peak time.

When the charging capacity is determined by integrating the discharge current value detected by the current detector 17C during charging by the charger 17E, insufficient charging occurs when the charging efficiency of the storage battery 17D is low. For this purpose, it is effective to combine known charging methods such as a method of performing supplementary charging for a certain period of time, a method of detecting ΔV, and a method of detecting a peak value of the charging voltage as a charging method by the charger 17E. Note that the charging current of the charger 17E may be a constant current or a pulse current.

When receiving the value of the discharge current of the storage battery 17D from the current detector 17C, the integrating device 17F integrates this current value. Integrator 17F calculates the capacity of storage battery 17D by integrating the current.

The charge / discharge pattern table unit 17G stores information on the storage battery 17D in the charge / discharge pattern table, and also updates the charge / discharge pattern table.
FIG. 5 shows information necessary for the charge / discharge pattern table.
The information of the charge / discharge pattern table 17PT shown in FIG. 5 includes the number of cycles for performing the load leveling. In the number of load leveling cycles, one cycle includes daytime (for example, 7:00 am to 11:00 pm) and nighttime (for example, 11:00 pm to 7:00 am).

Further, the charge / discharge pattern table 17P
The information of T includes storage battery capacity, discharge start time and discharge end time, charge start time and charge end time. The storage battery capacity is data of the (N + 1) th cycle updated by the measurement data of the Nth cycle. The discharge start time and the discharge end time are estimated from the time period during which the peak load occurs. The charging start time and the charging end time are reference, and may be the times to which the seasonal hourly rate discount is applied.

The charge / discharge pattern table section 17G
These six data are written in the discharge pattern table. Past similar data is input to the charge / discharge pattern table as an initial value. Then, each time load leveling is performed, the charge / discharge pattern table unit 17G updates the charge / discharge pattern for performing the next load leveling with the value.

The load sharing control circuit 17H performs control for load leveling. That is, the load sharing control circuit 17H
Sends a control signal a based on the integrated value of the integrator 17F and information of the charge / discharge pattern table section 17G to control the booster converter 17B. At the time of control, the load sharing control circuit 17H controls the charge / discharge pattern table 1
The necessary information is read from the charge / discharge pattern table of the storage battery 17D stored in 7G. For example, at the time when the peak load is predicted, the load sharing control circuit 17H
The booster converter 17B sends a boost signal as a control signal a to the PWM control circuit of the booster converter 17B.
Of the communication device 203. When the current time passes the peak load or when the storage battery 17D reaches the end voltage earlier than expected, the load sharing control circuit 17H transmits a stop signal to the booster converter 17B as a control signal a.

Embodiment 1 has the above configuration. Next, the operation of the first embodiment will be described. Commercial power supply 2
01 is normal, the commercial power supply 201
1 and the air conditioner 202 via the AC branching device 13. Further, the AC power supplied from the AC branching device 13 to the rectifier 14 is converted into DC and the DC power is supplied to the communication device 20.
3 is supplied. DC from the rectifier 14 is DC / D
The DC power is converted into DC power having different levels by the C converter 15 and supplied to the communication device 203. The DC / AC converter 16 converts the DC power into AC power again and the communication device 2.
03.

In such a state, the backup device 17 performs the processing shown in FIG. That is, the load sharing control circuit 17H reads the charge / discharge pattern table of the charge / discharge pattern table unit 17G, and reads the storage battery capacity and the discharge information of the discharge cycle (step S1). When the reading is completed, the load sharing control circuit 1
7H calculates the discharge current using the following equation (step S2). Discharge current = storage battery capacity / (discharge end time-discharge start time) In steps S1 and S2, a discharge current is determined using a charge / discharge pattern table, and load leveling is started at a peak load occurrence time. Road leveling
The load sharing control circuit 17H starts by sending a boost signal to the booster converter 17B. The load sharing amount with the rectifier 14 is determined by the rectifier 14 and the booster converter 17B.
Is the stable operating point. This is shown in FIG. According to FIG. 7, the regulation of the rectifier 14 and the booster converter 17B determines the load sharing. By changing the boosted voltage of the booster converter 17B while the load curve of the rectifier 14 is constant, it is possible to change the intersection (stop point) of both output voltages,
The load sharing amount can be adjusted freely.

When the storage battery 17D is discharged, as shown in FIG. 8, the supply current of the rectifier 14 is reduced by that amount, and the input current of the rectifier 14 can be reduced indirectly. Since the communication device 203 is almost computerized at present, the current of the communication device 203 is almost constant regardless of day or night. By using the storage battery 17D, it becomes possible to reduce the power in the daytime when the load such as air conditioning is increased, and load leveling is achieved.

After calculating the discharge current, the load sharing control circuit 17H determines whether the peak load is expected, that is, the discharge start time (step S3). If it is not the discharge start time, the standby state is maintained (step S4), and the process returns to step S3. When the discharge start time comes, the load sharing control circuit 17H transmits a boost signal and a discharge current setting signal indicating a discharge current to the booster converter 17B (step S5).

When the storage battery 17D starts discharging by the booster converter 17B, the current detector 17C detects the discharge current, and the integrator 17F integrates the detected discharge current (step S6). It is determined whether the integrated value of the discharge current has reached the storage battery capacity or whether the storage battery voltage has reached the end voltage (step S7). If the capacity remains or the storage battery voltage is higher than the end voltage, the standby state is maintained (step S8), and the process returns to step S7.

When the integrated value of the discharge current reaches the storage battery capacity or when the storage battery voltage reaches the end voltage, the load sharing control circuit 17H transmits a step-down signal to the booster converter 17B. At the same time, the charge / discharge pattern table unit 17G
Replace the storage battery capacity in the discharge pattern table with the integrated value, and replace the discharge end time with the actual time (step S
9).

In steps S5 to S9, the storage battery 17 is discharged to the final voltage, and the storage battery capacity is calculated. Rewrite the capacity of the next charge / discharge pattern table.

Thereafter, it is determined whether or not it is the charging start time (step S10). If it is not the charging start time, the standby state is maintained (step S11), and the processing is performed in step S10.
Return to When the charge start time comes, a charge start signal for the storage battery 17D is transmitted from the charge / discharge pattern table unit 17G to the charger 17E (step S12).

Upon receiving the signal, charger 17E charges storage battery 17D (step S13). Charging of the storage battery 17D is performed during the night power hours. It is determined whether the charging of the storage battery 17D has been completed (step S1).
4). When the charging is completed, a stop signal is transmitted from the charge / discharge pattern table unit 17G to the charger 17E. At the same time, the load sharing control circuit 17H advances the number of load leveling cycles in the charge / discharge pattern table of the charge / discharge pattern table unit 17G by one (step S15).
When step S15 ends, the process returns to step S1.

In steps S12 to S15, the storage battery is charged with midnight power, and after the charging is completed, the standby mode is set to prepare for the next load leveling operation.

As described above, according to the first embodiment, each DC power supply system is provided with an energy storage device that performs load leveling only by the DC power supply system, and backup of the DC power supply system is performed as before. , Backup and load leveling.

According to the first embodiment, even if the booster converter 17B fails, the storage battery can be discharged through the freewheeling diode or the rectifier diode. In the worst case, the storage battery can be used as a substitute for a backup storage battery.

Further, according to the first embodiment, there is an advantage that even if the load leveling backup device 17 is connected to the DC power supply system, the wiring of other parts is not changed. When the device is connected in series to the DC power supply system,
Although there is a point that the backup power supply is interrupted when the backup device fails, the first embodiment can cope with the conventional connection, and has an advantage that the influence on the reliability of the power supply system is small.

[Second Embodiment] In the second embodiment, FIG.
Instead of the backup device 17, the backup device 18 shown in FIG. 9 is used. Backup device 1
8 is an input terminal 18A, 18B, an output terminal 18C, 18
D, power storage devices 50 and 60, and a selection circuit 70.

Power storage device 50 includes booster converter 5
1, a current detector 52, a storage battery 53, a charger 54, an integrating device 55, a charge / discharge pattern table section 56, and a load sharing control circuit 57. The power storage device 60
Booster converter 61, current detector 62, storage battery 6
3, a charger 64, an integrating device 65, a charge / discharge pattern table section 66, and a load sharing control circuit 67.
Booster converters 51, 61 of power storage devices 50, 60,
Current detectors 52 and 62, storage batteries 53 and 63, charger 5
4, 64, the integrators 55 and 65 and the charge / discharge pattern table units 56 and 66 are the booster converter 17B and the current detector 17 of the backup device 17 of the first embodiment.
C, the storage battery 17D, the charger 17E, the integrator 17F, and the charge / discharge pattern table section 17G, and thus the description thereof is omitted.

In the backup device 18, the input terminal 18
A, 18B and output terminals 18C, 18D, a booster converter 51 of the power storage device 50, a current detector 52, a storage battery 53, a charger 54, an integration device 55, a charge / discharge pattern table section 56, and a load sharing control circuit 57. A booster converter 61 of the power storage device 60, a current detector 62,
The storage battery 63, the charger 64, the integrating device 65, the charge / discharge pattern table section 66, and the load sharing control circuit 67
It is connected in the same way as the backup device 17 of the first embodiment.

Further, in the backup device 18, the input terminal of the selection circuit 70 is connected to the power failure detection circuit 14A,
The output terminals of the selection circuit 70 are load sharing control circuits 57 and 67.
Connected to each other. The power failure detection circuit 14A is provided in the rectifier 14. Then, a power failure of the commercial power supply 201 is detected.

The selection circuit 70 sets the power storage device 50 for backup and the power storage device 60 for load leveling, or sets the power storage device 50 for load leveling and sets the power storage device 60 for load leveling. Is set for backup. Then, the selection circuit 70
Switches between the first setting and the second setting at a constant cycle. The selection circuit 70 is connected to the power failure detection circuit 14 of the rectifier 14.
Monitor if A has run. Power failure detection circuit 14A
Detects the power failure, the selection circuit 70 maintains the current setting without switching.

When the load sharing control circuits 57 and 67 are set for backup by the selection circuit 70, they transmit a stop signal to the booster converters 51 and 61 to stop the booster converters 51 and 61. When the load sharing control circuits 57 and 67 are set for load leveling by the selection circuit 70, they perform the same load leveling control as the backup device 17.

Embodiment 2 has the above configuration. Next, the operation of the second embodiment will be described. The normal operation is the same as in the first embodiment, and the description of the normal operation will be omitted.

During the normal operation, the backup device 18 performs the processing shown in FIG. That is, the selection circuit 70 is connected to one of the power storage devices, for example, the power storage device 5.
The first setting is made such that the storage battery 53 of 0 is used for backup and the storage battery 63 of the power storage device 60 is used for load leveling (step S21). Thereby, booster converter 51 stops, and at the same time, power storage device 60 performs the process shown in FIG. 6 (step S22).

During the operation of one cycle of load leveling, the selection circuit 70 operates the power failure detection circuit 14 of the rectifier 14.
It is determined whether or not A has operated (step S23).
When the power failure detection circuit 14A operates, the selection circuit 70 does not switch between the backup storage battery 53 and the load leveling storage battery 63 in the next operation cycle,
Keep settings. At the same time, the selection circuit 70 rewrites the charge / discharge pattern table for load leveling (step S24).

If no power failure is detected in step S23, the selection circuit 70 switches to the second setting in the next operation cycle, switches the storage battery 53 for load leveling, and replaces the storage battery 63 for backup. At the same time, the charge / discharge pattern table for load leveling is rewritten (step S25). After steps S24 and S25, the process returns to step S22.

As described above, according to the second embodiment, load leveling can be achieved by using storage batteries 53 and storage batteries 63 alternately. In addition, since one of the storage batteries is not used exclusively for backup and the other is used exclusively for leveling, the life of the storage batteries 53 and 63 can be improved, and the capacity of each of the storage batteries 53 and 63 can be measured at regular intervals.

Further, in the second embodiment, the power failure detection circuit 1
4A, and a selection circuit 70 for switching between a backup storage battery and a load leveling storage battery.
The selection circuit 70 mechanically switches between the backup storage battery and the load leveling battery for each cycle. However, when a power failure or accident occurs, if the backup storage battery is switched for load leveling before charging, the storage battery capacity that can be used for load leveling becomes insufficient. In order to avoid this, in the second embodiment, when a power failure is detected during one cycle operation, the switching operation by the selection circuit 70 is stopped and the operation is continued as it is, so that stable power supply is realized. can do.

[0081]

As described above, according to the present invention, the following effects can be achieved. (1) By using a power storage device for backup,
Backup can be performed on the load side such as a communication device, and load leveling can be performed on the supply side of the commercial power supply by using the load leveling power storage device. It is possible to realize a power supply system in consideration of energy saving and energy saving.

(2) Since the load leveling operation is performed while constantly updating the capacity of the storage battery, reliable energy saving can be realized.

[Brief description of the drawings]

FIG. 1 is a block diagram showing Embodiment 1 of the present invention.

FIG. 2 is a block diagram showing a backup device of FIG. 1;

FIG. 3 is a circuit diagram illustrating an example of a booster converter of FIG. 2;

FIG. 4 is a circuit diagram showing another example of the booster converter of FIG. 2;

FIG. 5 is a configuration diagram illustrating an example of a charge / discharge pattern table.

FIG. 6 shows a load leveling function of a backup device.
It is a flowchart which shows the charge / discharge operation for every cycle.

FIG. 7 is a diagram showing a load sharing curve.

FIG. 8 is a diagram conceptually showing supply currents of a storage battery and a rectifier.

FIG. 9 is a block diagram illustrating an example of a backup device used in the second embodiment.

FIG. 10 is a flowchart illustrating a process performed by the backup device according to the second embodiment;

FIG. 11 is a block diagram showing a conventional power supply system.

12 is a flowchart showing the operation of the power supply system of FIG.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 power supply system 11 power receiving device 12 standby power generation device 13 AC branching device 14 rectifier 14A power failure detection circuit 15 DC / DC converter 16 DC / AC converter 17, 18 backup device 17A, 17D, 53, 63 storage battery 17B, 51, 61 Booster converters 17C, 52, 62 Current detectors 17E, 54, 64 Chargers 17F, 55, 65 Integrators 17G, 56, 66 Charge / discharge pattern table sections 17H, 57, 67 Load sharing control circuits 17J, 17K, 18A, 18B Input terminal 17L, 17M, 18C, 18D Output terminal 17PT Charge / discharge pattern table 21, 32 Transformer 21A Primary winding 21B Secondary winding 22, 31 Switch element 23, 24, 33A, 33B Diode 25, 34 Smoothing filter 25A Ko Le 25B capacitors 26 and 35 output current detection unit 27, 36 the output voltage detecting section 28 and 37 PWM control circuit 31A~31D switches 50, 60 storage device 70 select circuit 201 commercial power supply 202 air conditioning system 203 the communication device

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Masamichi Onozaki 2-3-1 Otemachi, Chiyoda-ku, Tokyo F-term (reference) in Nippon Telegraph and Telephone Corporation 5G003 AA01 BA02 CA02 CA12 DA03 DA06 DA16 GB04 5G015 GA03 GA07 GA17 HA02 HA04 JA32 JA34 JA35 JA53 JA55 5G066 BA03 CA07 CA08 DA08 HA11 HA15 HB02 HB09 JA02 JA12 JA13 JB03

Claims (4)

[Claims] 1. A backup power storage device that is connected in parallel to a DC power supply system of a power supply system in which an AC power supply system and a DC power supply system coexist, is charged by a rectifier, and discharges when an abnormality occurs in a commercial power supply. And a load leveling power storage device connected in parallel to the DC power supply system, charged by the rectifier at off-peak load of power demand, and discharged at peak load. 2. The power storage device for load leveling comprises a series connection circuit of a storage battery, a current detector for detecting a current of the storage battery, and a booster converter for the storage battery. The power supply system according to claim 1, wherein the charger is connected. 3. The charge / discharge pattern table for controlling the charge / discharge state of the storage battery and recording information on the charge / discharge state, wherein the load leveling power storage device detects An integrator that integrates the discharge current of the storage battery to calculate the storage battery capacity, and a load sharing control circuit that controls the boosted voltage of the booster converter based on the information of the charge / discharge pattern table and adjusts the discharge current of the storage battery. The power supply system according to claim 2, further comprising: 4. A backup circuit comprising: a selection circuit for switching a function of the backup power storage device and the function of the load leveling power storage device in a constant cycle; When,
4. The power supply system according to claim 3, further comprising an integrator, a charge / discharge pattern table, and a load sharing control circuit, wherein the DC power supply system includes a power failure detection circuit for detecting a power failure of a commercial power supply.
A power supply system according to claim 1.