JP2556974Y2 - Uninterruptible power system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an uninterruptible power supply. Conventionally, the commercial power supply is connected to the load during normal operation when the commercial power supply is energized, and the DC power supply is connected via an inverter circuit during a power failure.
There is an uninterruptible power supply connected to the load. Also, during a power outage,
There has also been proposed an uninterruptible power supply that multiplies the output voltage by connecting a multiplied voltage rectifier to the output side of an inverter circuit.

The present invention particularly relates to an improvement of an uninterruptible power supply to which the above-mentioned multiplied voltage rectifier is connected.

FIG. 1 is a circuit example of a conventional uninterruptible power supply. In the figure, EB is a storage battery, S1, S2, S3, and S4 are switch elements of a first inverter circuit, S5, S6, S7, and S8 are switch elements of a second inverter circuit, and 6 is a multiplier voltage rectifier shown in FIG. An example of the circuit is shown. Of FIG. 3 (a) is 3 times voltage rectifier circuit, (b) the circuit of Cockcroft, (c) is known as a circuit Schenkel, D ₁ to D _n are rectifying diodes, C ₁ -C _n Is a multiplying voltage capacitor.

In FIG. 1, S9 is a changeover switch such as a relay or a magnet, and 1 and 2 are input terminals for receiving commercial power, 3,
Reference numeral 4 denotes an AC output terminal, and reference numeral 5 denotes a power failure detection circuit that monitors a commercial power failure or momentary interruption.

While receiving the commercial power, the commercial power is sent directly to the output. A power failure detection circuit 5 detects when a commercial power supply fails, and detects switching elements of the first inverter circuit and the second inverter circuit.
A switching command is given to S1 to S8 at a predetermined timing, and a power supply switching instruction is given to the relay in S9 to switch to the output side of the second inverter circuit.

The voltage Ei of the storage battery EB is converted into AC by the first inverter circuit, and the rectified output voltage is charged to nEi = Ed by the multiplied voltage rectifier 6 including D1 to Dn and C1 to Cn. This DC voltage becomes an input voltage of the second inverter circuit, is converted into an AC voltage having a peak value of nEi by a switching operation, and is supplied to the AC output terminals 3 and 4. At the time of power failure, the switching time from the commercial voltage to the inverter voltage requires high speed for the load.
Charging C1 to Cn has a disadvantage that a time delay occurs.

The present invention relates to a capacitor of the multiplying voltage rectifier 6 during commercial power reception.
It is an object of the present invention to provide an uninterruptible power supply which solves the conventional disadvantage by adding a charging circuit for charging C1 to Cn.

FIG. 2 is a circuit diagram showing an embodiment of the present invention.

EB is a DC power supply S1, S2, S3, S4 is a switch element of the first inverter circuit, S5, S6, S7, S8 is a switch element of the second inverter circuit, 6 is a multiplying voltage rectifier and a circuit example in FIG. Is shown. In FIG. 3, D1 to Dn are rectifying diodes C1 to Cn are multiplying voltage capacitors, and the rectifying circuit is known as a multiplying voltage rectifier as described above. S9 is a switch such as a relay or magnet, S10 is a switch such as a relay,
7 is a transformer circuit for arbitrarily transforming the commercial voltage.
Figure shows a circuit example, T1 is a transformer, R1 and R2 are resistors, DZ
1, DZ2 is a constant voltage element such as a Zener diode, 1, 2 is an input terminal for receiving commercial power, 3, 4 is an AC output terminal, 5
Is a power failure detection circuit for monitoring a commercial power failure or momentary interruption. Next, the operation will be described.

While receiving commercial power, the commercial voltage is sent directly to the output. Further, the commercial voltage is transformed by the transformer circuit 7 and each capacitor of the multiplied voltage rectifier 6 is charged from the AC output terminal point of the first inverter circuit. Usually, since the inverter circuit is connected to a feedback diode in reverse parallel to the switching element, is suitable because only the capacitor is not battery charging if the relationship EB ≧ √2e ₂ or EB ≧ e _z is charged. Also, while receiving commercial power,
Relay contact S10 is in a closed state.

When a commercial power supply fails, the power failure detection circuit 5 detects the power failure, gives a switching command to the first inverter circuit and the second inverter circuit, gives a power supply switching instruction to the relay in S9, and outputs the second inverter output. Switch to the side. Further, the transformer circuit 7 is disconnected from the commercial input side by setting S10 to an open circuit state. The voltage Ei of the storage battery EB is converted into AC by the first inverter circuit, and D1 to Dn and C1 to Cn in FIG.
Is charged by the multiplying voltage rectifier 6 consisting of, but has already been charged during the reception of the commercial power, and only the shortage is supplementarily charged. Also, this DC voltage Ed becomes the input voltage of the second inverter circuit, and is switched by the switching operation.
The voltage is converted into an AC voltage having a peak value of nEi and supplied to AC output terminals 3 and 4. Since the relay contact S10 is open, no inverter voltage is applied to the commercial input terminals 1 and 2 at this time.

In the embodiment of the present invention shown in FIG. 2, for example, each inverter circuit has an output control function, an inverter circuit system other than the bridge type is adopted, and a modification or replacement of each part such as a modification of a capacitor pre-charge circuit. Changes such as addition, addition, and the like can be made within the scope of the present invention as necessary.

According to the present invention, at the time of receiving the commercial power, the capacitor of the multiplied voltage rectifier between the first inverter circuit and the second inverter circuit that are not operating is charged in advance with the commercial power voltage, so that the second inverter is provided. The rise time of the circuit output voltage can be shortened, the switching of the load power supply can be speeded up in the event of a commercial power outage, and the overcurrent capability during charging of the capacitor of the first inverter circuit can be reduced. The practical effect as an uninterruptible power supply is great.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a conventional uninterruptible power supply, FIG. 2 is a circuit diagram showing an embodiment of the uninterruptible power supply of the present invention, FIG. 3 is a circuit diagram showing an embodiment of a multiplying voltage rectifier, FIG. Figure, fifth
The figure is a circuit diagram showing an embodiment of a transformer circuit, wherein 1 and 2 are commercial inputs, 3 and 4 are AC outputs, 5 is a power failure detection circuit, 6 is a multiplying voltage rectifier, 7 is a transformer circuit, and S ₁ and S _2. , S ₃ and S ₄ are the switching elements of the first inverter circuit, and S ₅ , S ₆ , S ₇ and S ₈ are the second switching elements.
Switch element of the inverter circuit, S ₉ is a changeover switch,
S10 relay contacts, EB storage battery, D ₁ -Dn is: rectifying diodes, C ₁ -C _n is multiplied voltage capacitors, T ₁ is a transformer, R _1,
R ₂ resistors, D _z 1, D _z 2 is constant-voltage _{element, Ei, Ed, e 1,} e 2,
e ₃ and _ez are specified voltages, a, b, c, d, e, f, g, h
Is a designated terminal.

Claims (1)

(57) [Scope of request for utility model registration] 1. A direct-feed circuit for supplying an AC output to a load via a switch during receiving of commercial voltage, a power-failure detecting circuit for monitoring a power failure or momentary interruption of the commercial voltage, and one end of the changeover switch and a direct-feed circuit. An inverter power supply unit that supplies an AC output between one end, and is configured to supply the AC output of the inverter power supply unit to a load by switching the changeover switch at the time of a power failure or momentary interruption of commercial voltage; Is a storage battery, a first inverter for converting DC power of the storage battery to AC, a voltage doubler rectifier for multiplying and rectifying the output of the inverter, a second inverter having the rectified output voltage as input, and In an uninterruptible power supply having a charging circuit for charging an output capacitor of a voltage rectifier at the time of commercial power reception, a transformer circuit for transforming a commercial power supply is provided on an input side of the charging circuit. Uninterruptible power supply, characterized in that the connection.