JPS62193515A - Service interruption free electric source - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an uninterruptible power supply, and more particularly to a charging circuit for a spare battery.

B1 Overview of the Invention The present invention provides an uninterruptible W1 power supply device that obtains a constant voltage, constant frequency AC output from an inverter with a spare battery on the DC side, in which DC power necessary for battery charging is obtained from the output side of the inverter. 1: The charging circuit is more cost-reduced and more compact (2).

C1 Conventional technology Uninterruptible power supply (i'a) A known method is to achieve uninterrupted power supply by supplying DC power from a battery to an inverter during a power outage of an AC power source such as a commercial power source. The reverse current circuit of the uninterruptible power supply at the platform has the main circuit configuration shown in Fig. 3.DC power is obtained from an AC power source 1 via a rectifier 2, and this DC power is connected to an accelerator 3 and a filter circuit of a capacitor 4. is converted into constant 18 voltage, constant frequency AC power by the inverter 5, and taken out via the output transformer 6.Meanwhile, DC power is taken out from the AC power supply 1 through the charger 7, and this DC power powers the battery. 8 is preliminarily charged. When a power outage occurs in the AC power supply 1, the inverter 5 (=DC power) is supplied from the battery 8 via the switch 9, resulting in an uninterrupted state.

D0 Problems to be Solved by the Invention Conventional battery charging circuits have a configuration in which the alternating current from the alternating current power supply 1 is rectified and made constant voltage by the charger 7 to charge the battery 8 to its rated voltage. U requires a rectifier and a constant voltage circuit, and a constant voltage circuit (: Therefore, AC power supply 1
This will stabilize the charging voltage against voltage fluctuations. At this time, in order to obtain a stabilized output even when the voltage of the AC power source 1 fluctuates (10% of the rating), the constant voltage circuit requires a large power loss due to the control element I, such as a transistor, and is costly and dimensional. There was a problem.

It should be noted that when the stabilizing circuit 1 nitswitching method is adopted, there is a problem that the circuit becomes complicated and expensive.

Means and Function for Solving Problem E1 The present invention has been made in view of the problem I above, and includes a charging circuit that obtains DC power from the output side of the inverter to charge the battery. DC power can be obtained from voltage and constant frequency output (: Therefore, the power loss in the charging circuit does not change depending on the state of charge of the battery, resulting in small and low power loss.

F. Example FIG. 1 is a circuit diagram showing an embodiment of the present invention.

The difference between this figure and FIG. 3 lies in the charging circuit configuration of the battery 8. This charging circuit includes a transformer 10 whose primary input is the secondary output of the output transformer 6, a rectifier 11 which rectifies the AC output of the transformer 10, a capacitor 12 which smoothes the rectified output of the rectifier 11, and a capacitor 12 on the side of the capacitor 12. The charger 13 obtains charging power for the battery 8 from DC power.

The charger 13 includes a transistor TR connected in series between the DC input terminal P and the battery 8, and the transistor TR.
A constant current diode C provided between the collector and base of
OD, a Zener diode ZD provided between the base of the transistor and the DC input @N, and a transistor T
Collector of R.

A diode D is provided in anti-parallel between the emitters.

In a charging circuit with such a configuration, a constant voltage, constant frequency AC output is taken out to the output transformer 6 during device operation.
A part of this AC output is transferred to the transformer 10° rectifier 11. It is taken out as rectified and smoothed DC power through a capacitor 12. This DC power allows the charger 13 to charge the battery 8
charge down to its rated voltage. In other words, the charger 13 is designed so that the Zener voltage of the Zener diode ZD falls to approximately the rated voltage of the battery 8, and when there is a difference between the voltage between the terminals P and N and the battery voltage, the voltage of the constant current diode CCD is Constant 1. current flows, this current becomes the pace current of the transistor TH, and the transistor TR
The battery 8 is charged with a constant current according to the first current amplification factor. supply a stream of water. Then, when the battery 8 is charged to the rated normal pressure, C2 is the constant current diode CCD 1! The current is bypassed to the Zener diode Z D and the transistor TR is turned off to prevent overcharging of the battery 8 . The diode D protects the transistor TR from its reverse voltage, and also reverse charges the capacitor 12 from the battery 8 before starting the device operation.
．． This prevents the initial charging current from the rectifier 11 to the capacitor 12 from becoming excessive.

What should be noted here is that since the constant voltage output of the inverter 5 is used as a charging voltage source, the transformer 10. Rectifier 11. The DC voltage of the rectifier circuit consisting of the capacitor 12 always drops at a constant level. Therefore, the charger 13 can have a small difference between the DC voltage and the rated voltage of the battery 8, and lightning and power loss within the charger 13 (in the figure, between the collector current of the transistor TR and the collector-emitter voltage product)
It is possible to use a device with a low power rating for the voltage burden element (transistor TR in the figure) and a small device for the heat dissipation means.

In particular, in this embodiment, since the charger 13 is a constant current charger, the power loss range becomes narrow and the charging current becomes constant regardless of the state of charge of the battery 8, and the charger 13 and the rectifier circuit It is possible to increase the side margin, reduce costs, and downsize.

FIG. 2 is a circuit diagram showing another embodiment 1 of the present invention. The difference between this figure and FIG. 1 lies in that the output of the rectifier 11 is configured to charge the battery 8 into U[ via the reactor 14'.

Also in this embodiment, the output voltage of the inverter 5 is constant 1
: Since it is controlled, the voltage obtained by rectifying the output with the transformer 10 and the rectifier 11 becomes constant, and by adding the peak voltage 1 of the rectified waveform to the rated voltage of the battery 8, constant voltage charging to a constant voltage can be performed. can. In addition, the reactor 14 is full! It improves voltage ripple and can be replaced by other filter circuits such as resistors and capacitors.

Since this embodiment uses constant voltage charging, it is a simple charging circuit that does not require a charger, and can be applied to a relatively small capacity uninterruptible power supply to reduce power loss and cost.

Excellent in miniaturization.

In the embodiment, if ripples in battery charging and PL pressure are not a problem, the filter means such as the lever 14 can be omitted.

G0 Effects of the Invention As described above, according to the present invention, in order to obtain the DC power necessary for battery charging from the output side of the inverter, the voltage difference borne by the charging circuit is reduced, and the fluctuation in power loss is small and low. It is effective in reducing the cost and size of the charging circuit.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing a first embodiment of the present invention, FIG. 2 is a circuit diagram showing another embodiment of the present invention, and FIG. 3 is a conventional main circuit diagram. 1... AC power supply, 2... Rectifier, 5... Inverter, 6... Output transformer, 8... Battery, 9...
・Switch, 10...transformer, 11...rectifier,
12... Capacitor, 13... Charger, 14...
Reactor, COD...constant current diode, ZD...
・Zener diode, TR...transistor, D・
··diode. Figure 1! Marei) ω [3rd route map

Claims (3)

[Claims] (1) An uninterruptible power supply that obtains constant voltage, constant frequency AC output from an inverter having a spare battery on the DC side, comprising a charging circuit that obtains DC power from the output side of the inverter to charge the battery. An uninterruptible power supply device characterized by: (2) In claim 1, the charging circuit is characterized by comprising a transformer that receives the output of an inverter as an input, and a rectifier that rectifies the output of the transformer and supplies charging current to the battery. Uninterruptible power supply. (3) In claim 1, the charging circuit includes a transformer that receives the output of an inverter as an input, a rectifier that rectifies the output of the transformer, and supplies a constant charging current to the battery from the output of the rectifier. What is claimed is: 1. An uninterruptible power supply device comprising a charger for supplying power.