JPH09200974A - Dc power supply equipment having backup storage battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to freely select a voltage of a storage battery and to enhance the power factor and efficiency of input commercial AC. SOLUTION: A DC power supply equipment is constituted using a commercial AC power supply 1, a rectifier circuit 2, a DC-DC converter 3 and a switching diode 4 as the main power source. The output power of the DC-DC converter 3 is branched to a charging circuit 6 for charging a plurality of batteries 7. Outputs from a plurality of these batteries are incorporated with the main power supply through respective switching diodes 8, backup DC-DC converter 9 and a switching diode 10. Setting voltage of the backup DC-DC converter 9 is set slightly lower than the steady-state voltage of the main power supply. Power is supplied only from the main power supply during steady state, and the backup DC-DC converter is operated under no-load condition. The DC-DC converter 9 supplies the power during power service interruption.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a DC power supply device equipped with a backup storage battery.

[0002]

2. Description of the Related Art Since a DC power supply device for a communication device is required to have high reliability to supply power continuously and stably, power from a commercial AC power supply and a storage battery for backup are arranged in parallel. In preparation for a power failure of the commercial AC power supply.
As a DC power supply device for this purpose, for example, JP-A-4-30
It is disclosed in Japanese Patent No. 4160. As shown in FIG. 3, this circuit normally obtains a DC voltage from a commercial AC input through a rectifying / smoothing circuit and then outputs this DC voltage to a DC-D for the main power supply.
Power is supplied to the load by the C converter. This power is also branched to charge the backup storage battery.
When the commercial AC input is cut off, the backup storage battery is set to a voltage lower than the input voltage of the main power supply DC-DC converter by the power failure detection switch.
-Switching to the input side of the DC converter, the DC-DC converter for the main power supply is continuously driven through the switching diode which is turned on based on the relation of the input / output voltage at this time. This DC power supply device has high power efficiency because the DC-DC converter for the main power supply directly supplies power to the load during normal times. Also, in the event of a power failure, the backup storage battery passes through the backup DC-DC converter, and the specified DC power is supplied from the main power supply DC-DC converter, so the power efficiency is only the loss of the backup DC-DC converter from normal times. Will decrease. This DC power supply device has a simple structure and high efficiency, and the voltage of the backup storage battery can be freely selected, which is extremely useful.

[0003]

Meanwhile, in equipment using a commercial AC power source, there is a concern about an increase in harmonics caused by the fact that the input current is not a sine wave and a failure caused in the equipment of the power system due to the increase. There is. This problem becomes a problem in the conventional configuration in which the commercial AC power supply is rectified and smoothed.

According to the present invention, in a DC power supply device equipped with a backup storage battery, the input current of the commercial AC input is converted into a sine wave to bring the power factor close to 1 and improve the power conversion efficiency.
The challenge is to freely select the storage battery voltage and type.

[0005]

In order to solve this problem, the present invention proposes the following means. A circuit for rectifying a commercial AC input to generate a pulsating flow output, a DC-DC converter for a main power supply for converting the pulsating flow output into a predetermined DC output and supplying a predetermined DC output power to a load, and this DC -A charging circuit that branches from the DC converter to give a charging current, a backup storage battery that is charged by this charging circuit, and power is supplied from this backup storage battery that is slightly lower than the DC output voltage of the main power supply DC-DC converter. Backup DC-DC converter for converting low voltage DC power, and this backup DC-DC converter
A switching diode connected between the output of the DC converter and the output of the DC-DC converter for the main power supply, which is a backup DC-D due to a power failure of the commercial AC input.
When the output of the C converter exceeds the output voltage of the DC-DC converter for the main power supply, it is turned on and is composed of a switching diode connected to the polarity that supplies power to the load from the backup DC-DC converter. The present invention proposes a DC power supply device equipped with a characteristic storage battery for backup.

Regarding the structure of the DC-DC converter for the main power supply, it is proposed that the DC-DC converter is composed of a high frequency switching section for switching at a frequency sufficiently higher than the frequency of the commercial AC input, a transformer and a rectifying / smoothing section. is there.

The charging circuit is proposed to be supplied with power from a transformer and connected to a backup storage battery via a second rectifying / smoothing unit. With this configuration, the voltage of the storage battery can be freely selected and the efficiency of the charging circuit can be increased.

Further, regarding the backup storage battery, it is proposed that the storage battery units having different characteristics can be exchanged, and that the storage battery units are provided with identification terminals and the charging circuit is provided with identification terminals corresponding to the identification terminals. Is. With this configuration, when the storage battery unit is replaced, the charging circuit can automatically set the charging control mode corresponding to the connected storage battery unit.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of a DC power supply device equipped with a backup storage battery according to the present invention. The commercial AC power supply 1 is connected to the rectifier circuit 2 to obtain a pulsating flow waveform. This pulsating flow waveform is supplied to the input of the DC-DC converter 3 for the main power source without passing through the smoothing circuit. This DC-DC converter 3
The inside of is configured to generate a target DC voltage via a high frequency switching unit 31 that switches at a frequency sufficiently higher than that of the commercial AC power supply 1, a transformer 32, and a rectifying / smoothing unit 33. In addition, another winding of the transformer 32 and the rectifying and smoothing unit 34
To obtain another DC voltage output. This DC voltage output charges the storage battery 7 via the charging circuit 6. This charging circuit 6
A plurality of circuits of the storage battery 7 and the storage battery 7 are configured in parallel, and each of the storage batteries 7 has a disconnection circuit and a spare for maintenance and the like.
Each of the storage batteries 7 is connected to a backup DC-DC converter 9 via a diode 8. This D
The C-DC converter 9 merges with the output of the DC-DC converter 3 for the main power source through the switching diode 10 and is connected to the load 5. DC-D for this backup
The set output voltage of the C converter 9 is DC-D for the main power supply.
It is set to be slightly lower than the steady voltage of the C converter 3. Therefore, in the steady state, only the DC-DC converter 3 for the main power supply supplies power to the load 5, and the backup DC-DC converter 3
The DC converter 9 is operating without load. And in the event of a power failure, there is no interruption in the backup DC-DC converter 9
Powers the load 5.

The operation of the DC power supply device configured as described above will be described. First, the case where the commercial AC power supply 1 is normally supplied with power will be described. Since there is no smoothing circuit having a large capacitance in the subsequent stage of the rectifier circuit 2, the input current flows uniformly over the entire phase angle of the commercial AC power supply 1. As shown in the waveform in FIG. 1, the high-frequency switching unit 31 has a contour of the commercial AC power supply 1
In the waveform of, switching is finely cut by high frequency. The rectifying / smoothing unit 33 converts this waveform into a direct current with a constant for smoothing the so-called low-frequency component of the commercial AC power supply 1. Therefore, the input current of the commercial AC power supply 1 becomes sinusoidal and the power factor becomes substantially equal to 1, and at the same time, a flat DC output can be generated. In this way, the DC-DC converter 3 for the main power supply has the switching diode 4
A predetermined DC power is supplied to the load 5 via In this power supply path, the high-frequency switching unit 31 is a main element that may cause power loss, but it is possible to sufficiently reduce this power loss by optimizing the selection of switching elements and design conditions. .

Next, when the commercial AC power supply 1 fails, the DC-DC converter 3 for the main power supply stops the power supply. At this time, the backup DC-DC converter 9 which is supplied with power from the storage battery 7 and is in the idling operation turns on the switching diode 10 to supply power to the load 5. It should be noted that the diode 4 is not always an essential element, and the circuit of the DC-DC converter 3 for the main power supply may have a circuit configuration such that a backflow from the backup DC-DC converter 9 causes no trouble. The diode 4 is unnecessary.

Regarding the selection of the storage battery 7, D on the charging side
The circuit of the transformer 32, the rectifying / smoothing unit 34, and the charging circuit 6 in the C-DC converter 3 can be freely selected according to the voltage and type of the storage battery 7. On the discharge side, D for backup
By stepping up and down in the C-DC converter 9,
It is possible to freely cope with the required voltage of the load 5.

FIG. 2 is a partial detailed view showing the connection relationship between the charging circuit and the storage battery. As the storage battery connected to the charging circuit 6, a sealed lead storage battery unit 7L and NiCd are used.
There are two types of storage battery unit 7N. The sealed lead acid battery unit 7L includes the necessary number of sealed lead acid batteries 711,
Connect the positive poles of 712 etc. to terminals 701, 702 etc. respectively, and
Commonly connect the poles to terminal 709. Then, terminals A, B, and C for identifying the type of the storage battery are provided, and A and B among them are provided.
Make a short-circuit connection between them. Also, NiCd storage battery unit 7N
Is the number of NiCd storage batteries 731,732 etc.
Connect the poles to terminals 721 and 722, etc., and connect each − pole to terminal 72.
Connect to 9 in common. Then, terminals A, B and C are provided, and B and C among them are short-circuited and connected. And the charging circuit 6
Terminals 601, 602 ... 609 and A, B, C are provided so that they can be connected and connected to both of the sealed lead acid battery unit 7L and the NiCd battery unit 7N. The difference in the type of storage battery is identified by which of the terminals A, B, and C is short-circuited, and the charging control mode is switched correspondingly.

[0014]

EFFECTS OF THE INVENTION Since the present invention has the characteristics as described above, in a DC power supply device equipped with a backup storage battery, the input current of the commercial AC input is made into a sine wave to bring the power factor close to 1. The power conversion efficiency can be improved, and the storage battery voltage and type can be freely selected. It is also highly reliable and economical because it does not require a special power failure detection switch.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of a DC power supply device equipped with a backup storage battery according to the present invention.

FIG. 2 is a diagram showing a connection relationship between a charging circuit and a storage battery.

FIG. 3 shows an example of a DC power supply device including a conventional backup storage battery.

[Explanation of symbols]

1 ... Commercial AC power supply 2 ... Rectifier circuit 3 ... DC-DC converter 4 ... Diode 5 ... Load 6 ... Charging circuit
7 ... Storage battery 7L ... Sealed lead storage battery unit 7N ... NiCd storage battery unit 8 ... Diode 9 DC-DC converter 10 ... Diode

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshio Nagasaka 1-18-1 Takada, Toshima-ku, Tokyo Inside Origin Electric Co., Ltd. No. 2 Nippon Telegraph and Telephone Corporation

Claims (4)

[Claims] 1. A circuit for rectifying a commercial AC input to generate a pulsating flow output, and a DC-DC for a main power supply for converting the pulsating flow output into a predetermined DC output and supplying a predetermined DC output power to a load.
A converter, a charging circuit that branches from the DC-DC converter to give a charging current, a backup storage battery charged by the charging circuit, and power is supplied from the backup storage battery to the main power supply DC-DC converter. A backup DC-DC converter for converting DC power having a voltage slightly lower than the DC output voltage, and switching connected between the output of the backup DC-DC converter and the output of the main power supply DC-DC converter A diode, which is turned on when the commercial AC input fails and the output of the backup DC-DC converter exceeds the output voltage of the main power supply DC-DC converter.
A DC power supply device comprising a backup storage battery, comprising a switching diode connected in a polarity for supplying power from the C converter to the load. 2. The main power supply DC-DC converter is configured by a high frequency switching unit that switches at a frequency sufficiently higher than the frequency of the commercial AC input, a transformer and a rectifying / smoothing unit. A DC power supply device comprising the backup storage battery according to claim 1. 3. A DC power supply device having a backup storage battery according to claim 2, wherein power is supplied from the transformer and is connected to the charging circuit via a second rectifying / smoothing unit. 4. A configuration in which storage battery units having different characteristics are replaced with respect to the backup storage battery, identification terminals are provided on these storage battery units, and identification terminals are also provided on the charging circuit corresponding to the identification terminals. A DC power supply device comprising the backup storage battery according to any one of claims 1 to 3.