JPS61207138A - Power failure-free constant voltage/constant frequency powersource unit - 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] (Industrial Application Field) The present invention is a constant voltage constant frequency power supply device NF with an uninterruptible function.
(CVCF inverter!l1l), which has a direct power transmission circuit from a standby power source (commercial AC power supply or rotating machine power supply), and operates multiple inverter devices in parallel while synchronizing with the standby power source. Configured WIW
This concerns device A.

[Conventional technology]

BACKGROUND ART Conventionally, in an uninterruptible constant voltage constant frequency (CVCF) power supply device used as a power source for, for example, broadcast equipment 1 communication equipment, computers, etc., an inverter device of a parallel redundant operation type is generally employed in order to improve reliability. Each inverter device operated in parallel is operated manually! F!
In case of a power outage (commercial input), a battery is provided that can temporarily replace the power outage.

Figure 2 shows the simplest configuration of the inverter Pi = in the above parallel redundant operation system, where two constant voltage constant frequency <
CVCF>Impark device (#1>1-+,<Zeng2)2
= is operated redundantly in parallel. In the figure, 2 is the input terminal for connecting the commercial input (commercial frequency power supply), and 3 is the input terminal for connecting the commercial input (commercial frequency power supply).
, 4 is a charger for charging a battery included in the auxiliary power source, and 5 is an output terminal for connecting a load.

The above two inverter units f! IF1-+, 1-:. are operated synchronously, and their outputs are commonly connected.

The load connected to the output terminal 5 (or the inverter device 1 mentioned above)
limited to the allowable load capacity of the machine. In other words, the system is operated with a margin for one inverter II!, and a so-called hot standby system is used to ensure that there is no problem even if one of the inverters fails.

In the parallel redundant synchronous operation system that requires particularly high reliability, semiconductor switching elements (e.g. transistors,
In the event that a failure occurs in a thyristor, etc., a commercial power supply or a rotating machine power supply with a good Q.
Reserve 1! You can send power directly from the source (source) or selectively shut off the failed inverter device to create a spare one! +! @t! (Countermeasures are being taken, such as switching between inverters that are on standby.

2. Multiple inverter devices operated in parallel with the non-stop CVCF1i source device are usually n-1, where n is the number of inverter devices installed.
Operation M control is performed with the total maximum output of the units as the rated maximum output p laX of the uninterruptible CVCF power supply device.

FIG. 3 shows an example of the configuration of the main parts of an uninterruptible power supply system equipped with the above-mentioned bypass circuit, and in the figure, the same reference numerals as those described above indicate the same or equivalent parts. #1. #2. . . . #n (one inverter device 1-:, . . . 1-n) which performs parallel operation, and 6 is an inverter device 91. #2.・・・・・・N's parallel operation selection/cutoff switch, 7 is the common output line of the parallel operation inverter device (referred to as the "main energized line" under 1χ), 8 is the input terminal for connecting the backup power supply, 9 is the Direct energized line (bypass circuit), 1
0 is a direct transmission transformer, 11 is a synchronous circuit that synchronously follows the backup lI'R source and synchronously controls each of the parallel operation inverter devices, and 12 (12-+, 12-2) are the main lines 1!
The switch for switching 11 lines provided on the crossroads 7 and the direct feed line 9, and 13 are the switches for each inverter device! Detection circuit, 1
4 is a protection circuit for the impark device, and 15 is a switch control circuit.

Upper parallel operation selection Tsuji Dango switch 6 (6-+.

6-:,...6-n) and energized line switching switch 12 (12-1, 12-1,...l2-n)
) are static switches constructed using, for example, Cyrisk, and perform opening/closing operations in response to command signals from the protection circuit 14 and the switch control circuit 15.

Although not shown in the drawings, there is also an input switching circuit that monitors power outages in the commercial AC input and switches to supply input from the auxiliary 'I11'm (battery) 3 to the inverter in the event of a power outage.

In a conventional power supply system configured in this way,
Normally, a parallel operation inverter device (hereinafter referred to as "main power supply" ), necessary measures can be taken immediately when an overload condition or accident occurs.

(Problem to be solved) As mentioned above, with conventional equipment, one extra inverter is installed for the actual load, and the extra inverter equipment is not normally fully utilized. However, the problem is that the equipment cost increases relative to the load capacity of the device.

In addition, in conventional uninterruptible power supplies equipped with a direct flow path (bypass circuit), a failure occurs in one of the multiple (n) inverter devices, regardless of the load 'R current value. When the number of inverter devices that can be operated in parallel becomes n -2 or less, the main power supply is disconnected and the direct power supply is turned on.
The load was being supplied with power from the standby power source.

Therefore, even if the load is light and sufficient power can be supplied only by the remaining inverter devices that can operate normally, there are loads that require completely uninterrupted FIP power (hereinafter referred to as "completely uninterruptible loads"). ) and you wish to supply power from the remaining inverter device (healthy Va) that can operate normally, it will switch to the backup power source, so no power supply
It had lost its function as a VCF I source device.

The present invention has been made to solve the above-mentioned problems, and it divides the load into a completely uninterruptible load and a load that can survive a power outage (hereinafter referred to as "power outage allowable load"). An inverter system that allows normal operation even when one inverter unit running in parallel fails and becomes overloaded! I! (Healthy machines) continue to operate, their remaining units are used to supply power to completely uninterruptible loads, power is supplied to power outage-permissible loads from the standby II source, and failed inverter equipment (faulty The object of the present invention is to provide a power supply system that can restore the original state after a long period of time.

[Means for solving problems]

In order to achieve the above object, in the present invention, as described above, the load is divided in advance into a completely uninterruptible load and a power outage allowable load (corresponding to the capacity of one inverter device), and the load is A static switch (AC switch) is installed on the line connecting the allowable load and the main power source with multiple inverters, and on the line connecting the allowable load during power outage and the standby power source, for seamless switching between the standby power source and the standby power source. When operating normally, we use the so-called 100% load parallel operation method, which uses the total output capacity of all inverters - the total load capacity of completely uninterruptible load and power outage allowable load, but if one unit breaks down during operation. In such a case, the load for one machine (allowable load during power outage) is immediately cut off and connected to the standby 'R source side, and the healthy machine is restarted. The system was then integrated to supply power to the remaining load (completely uninterruptible load).

(Function) According to the power supply device of the present invention, when any one of the inverter devices operating in parallel fails, the failed device is selectively shut off, and the power outage allowable load is supplied with backup power by non-instantaneous switching. Electricity is supplied from the uninterrupted load, and power is continuously supplied from the healthy load to completely uninterruptible loads. When the failure of the faulty machine is corrected, the inverter device is put into parallel operation, and then the power outage allowable load that was connected to the standby power source can be switched back to the main power source side without a momentary interruption to restore the system.

(Example) Hereinafter, the present invention will be explained in detail with reference to Examples.

FIG. 1 is a block diagram showing the configuration of an embodiment of the HM of the present invention. In order to simplify the drawings and explanations, the case is shown in which the number of inverter devices operated in parallel is two (#1. Since the configuration of the ! section is almost the same as the conventional device shown in FIG. 3, the sections improved by the present invention will be mainly explained.

Note that the inverter device 11. which constitutes the main power supply of the present invention.
Although not shown, #2 is internally equipped with a rectifier for rectifying the commercial AC input, a DC filter, an impark, an inverter control unit, an AC filter, and the like. Further, when the selective cutoff switches 6-+ and 6-2 are cut off, when any of the inverter devices fails and the failure detection circuit 13 outputs a failure detection signal, the protection circuit 14 stops the operation of the failed machine. However, as shown in FIG. 1, the protection circuit 14 issues a command to operate the switch, and the signal that actually drives the switch in response to the command is sent to the switch control circuit. 15 may be output. In this case, the switch control circuit 15 cuts off the failed inverter and at the same time switches the energized line.

In Fig. 1, 16 is a branch board for connecting a completely uninterruptible load, 17 is a branch board for connecting a load that can tolerate N-stops, and an M CB (molded circuit breaker), for example, is inserted in each branch. . 18 is branch board 16
19 is an output terminal of the power supply device to which the branch board 17 is connected.The present invention is characterized by the insertion location of the changeover switch 12 for switching the energization straight path. That is, in the past (see Fig. 3), there was a main power source equipped with multiple inverter units and an output terminal 5 that connected the entire load (main energizing line 7), and an output terminal that connected the standby power source and the entire load. Between 5 (direct energized line 9)
However, in the present invention, a changeover switch 12 (12-1, 12-co) is inserted between the main power source and the output terminal 19 that connects a part of the load (power failure permissible load), and between the 1fIN source and the load. An energizing line switching switch 12 is inserted between the output terminals 19 to which a portion (I9 allowable load) is connected. In addition,
The above-mentioned energizing line switching switch 12 is composed of AC switches A, CS W + and A, which are configured using Cyrisk, for example.
It has CS W 2.

Next, the operation of the power supply device of this embodiment will be explained.

Inverter devices 1-+, 1-:! Assume that the output capacity is, for example, 500 kVA. When these two units are operating normally, AC8W+ is on, AC8W2i
;tt7 and L, load 1000k VA (completely uninterruptible load 500kVA, power outage allowable load 500kVA) is operated with two inverter devices. If any one of the inverter devices fails, the faulty device is shut off using the selective cutoff switch 6-1 or 6-2, and at the same time the A.C.
By turning off S W + and turning on A CS W 2, the power outage allowable load of 500 kVA is switched to the standby power source without momentary interruption. When the faulty machine is restored, after putting it into parallel operation, the load 500k VA that had been switched to standby 'am
is switched back to the main power supply (inverter device) side without any interruption.

In this way, completely uninterruptible loads can be continuously supplied with power by the remaining healthy machine.

〔effect〕

As explained above, in the present invention, it is necessary to divide the load into a completely uninterruptible load and a power outage allowable load, but even if one of the multiple inverter devices operating in parallel fails,
Operation can be continued without stopping either load.

Completely non-stop operation (reliability equivalent to parallel redundant operation for the load can be ensured).

Furthermore, for the 1,000k VA load shown in the above embodiment, it was conventionally necessary to perform parallel redundant operation using three 500k VA inverters, but according to the present invention, two 500k VA inverters are used. Inverter device and one 5
A 00k VA direct transmission transformer (this transformer may be omitted in some cases) allows operation with the same level of reliability as before. Therefore, the cost of the 'R'R device can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the structure of an embodiment of the apparatus of the present invention, and FIGS. 2 and 3 are block diagrams showing the structure of the main parts of the conventional apparatus. 1 (1-+, 1-z,...1-n)...
... Inverter device, 3 ... Auxiliary power supply (battery), 6 (6-+
, 6-= ,...6-n)...Selective cutoff switch, 8...Input terminal for preliminary mvss connection, 9...
...Direct energized line (bypass circuit), 12...
・Electric line switching switch, 16.17... Branch board, 18.19... Output terminal.

Claims (1)

[Claims] 1. A commercial AC power source or a rotating machine power source (hereinafter referred to as a "backup power source"), a direct transmission line that directly transmits power from the standby power source to a part of the load as necessary, and the above-mentioned standby power source. A main power source equipped with a plurality of constant voltage constant frequency inverter devices (n units) capable of synchronized operation with the power supply, and a battery for supplying auxiliary input to each of the plurality of inverter devices in the event of a commercial AC input power outage. Consisting of an auxiliary power source and an energized line switching switch for switching the connection of some of the loads to the standby power source via the direct energized line when one of the plurality of inverter devices breaks down. The loads connected to the above-mentioned uninterruptible power supply are divided into groups in advance into loads that require complete uninterruptibility and loads for which power outages are permitted, and each group is connected to an inverter. -Completely uninterruptible load and inverter device 1 limited to the capacity of one unit
The power outage allowable load is limited to the capacity of the inverter, and the switch for switching the energized line is installed on the line connecting the power outage allowable load and the main power source and standby power source, and is connected to one of the plurality of inverter devices. An uninterruptible constant voltage constant frequency power supply device, characterized in that when a failure occurs, power is supplied from a standby power supply to the power outage allowable load.