JPS61116937A - Parallel redundancy synchronous operation system inverter device - 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 Industrial Application] The present invention relates to an inverter device configured as a parallel redundant system, and particularly relates to an inverter device configured as a parallel redundant system.
This invention relates to an inverter device using a so-called parallel redundant synchronous operation method, which has a power direct transmission circuit from a power source (source 1111) and operates a plurality of inverter devices in parallel while synchronizing with the power source 1111.

[Conventional technology]

Conventionally, if it falls over, there is no PP1I constant voltage constant frequency (CVCF) used as a power source for broadcasting equipment, communication equipment, computers, etc.
) In the power supply device, an inverter tit of parallel redundant operation type is generally adopted. In parallel redundant synchronous operation systems that require particularly high reliability, if a failure occurs in the semiconductor switching elements (e.g. transistors, thyristors) that make up each of the multiple inverter devices, the load You can directly send power from a synchronized commercial power source or rotating machine power source (backup power source) via a pie bus circuit (backup energized line) without stopping the power supply to the inverter, or selectively shut off a failed inverter device and install a backup power source. Countermeasures are being taken, such as switching between the m source device 2 (standby inverter device) and

Multiple inverter devices operated in parallel with the above uninterruptible CVCFI power source device are operated as the rated maximum output P w + ax of the uninterruptible CvCF power source device, where the total maximum output of n-1 devices is usually the sum of the maximum outputs of n-1 devices, where n is the number of inverter devices installed. control is in place.

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, #1. #
2. ...#n is an inverter device that performs parallel operation, 1 (1-+, 1-2...1-n) is an inverter, 2 < 2- +, 2-2, "" 2-n
) is inverter device #1. #2.・・・・・・ Parallel operation selection cutoff switch #n, 3 common output line of parallel operation inverter device (hereinafter referred to as r main energized line), 4
is an input terminal for connecting a backup power supply, 5 is a backup energizing line (bypass circuit), 6 <6-1.6-2...6-
7 (7-117-2) is an oscillator that synchronizes with the standby power source and operates each of the parallel operation inverter devices as a tlI unit;
> is the main energization $1 each! etc. 3 and a energizing line switching switch provided on the preliminary energizing line 5, and 8 an output terminal for connecting a load.

The above-mentioned parallel operation selection/cutoff switch 2 (2-+).

2-2. ...2-n) and the energized line switching switch 7 (7-1, 7-2>) are static switches configured using, for example, thyristors, and are connected to the switch control circuit (not shown). Open/close operations are performed according to command signals.

Moreover, the above oscillation B6 (6-t, 6-z,...
...6-n) is synchronized with the standby power supply and inverter 1
This is a so-called synchronous operation gate control circuit that generates a signal to control semiconductor switching elements (for example, thyristors, transistors, etc.) constituting (1-+, 1-2, . . . 1-n).

In a conventional power supply system configured in this way,
Normally, a maintenance circuit is equipped with an allowable output current monitoring circuit that monitors the maximum allowable output current and a failure detection circuit that detects inverter failure. 1 device (not shown), so that necessary measures can be taken immediately when an overload condition or an accident occurs in the parallel operation inverter device (hereinafter referred to as the "main power source").

C. Problems to be solved] In the conventional uninterruptible power supply equipped with the above bypass circuit,
Regardless of the load IF flow value, if a failure occurs in one of the multiple (n) inverter devices and the number of inverter devices that can be operated in parallel becomes n -2 or less, the main power is disconnected. A switch was made to the standby energized line side, and power from the standby power supply was supplied to the load.

Therefore, even if the load is light and the remaining inverter units that can operate normally can supply sufficient power, the
Since it switched to iwi, it lost its function as a non-stop 1CVCF power supply.

The present invention has been made to solve the above problems, and even if one or more inverters operating in parallel fail, the remaining number of inverters that can operate normally will be enough to handle the load. Install an inverter to the maximum power that can be supplied! It is an object of the present invention to provide a power supply system that allows the operation of NvA (main 1!i) to continue and switches to standby NvA only when power supply to the load becomes impossible.

[Means for solving problems]

In order to achieve the above object, the device of the present invention monitors the occurrence of an overload condition based on the load current and the power supply capacity according to the number of inverter devices in normal operation, and immediately It is equipped with a standby power supply synchronous switching control circuit that provides a switch switching signal to the energized line switching switch. That is, the backup 1 source synchronous switching control circuit receives the operation signals from each inverter Vta performing parallel redundant synchronous operation,
The inverter is in normal operation by inputting the load N flow signal from the Rin-Ai output current detection circuit installed on the general output line! fI
The role is to judge the state of the load on the side, and to immediately switch the switch to the pre*mi side if an overload occurs.

(Function) As described above, since the device of the present invention is equipped with a comprehensive output current detection circuit and a standby power supply synchronous switching control circuit, one or more of the plurality of inverter HIMs performing parallel redundant synchronous operation When a failure occurs in one of the inverter devices, the remaining healthy inverter devices determine whether or not to supply power to the active load, and if power cannot be supplied, the backup power source I
If the inverter device is capable of supplying power, the inverter device can continue to supply power to the load.

(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 a parallel redundant synchronous operation type inverter device of the present invention. In order to simplify the drawing and explanation, the case is shown in which the number of inverter devices operated in parallel is 3 (#1. #2. #3). N(1)@@! ,″″′″
! "I I! G"29゛0°"2~6-Generally used.

Inverter device #1゜#2. constitutes the main power source of the present invention.
Although not shown, #3 is equipped with an oscillator that oscillates in synchronization with an inverter and a standby power supply, as in the conventional device (FIG. 3). In the drawings, the same reference numerals as those described above indicate the same or equivalent parts, and the explanation will be omitted as appropriate.

'9 is a combined output current detection circuit, and 10 is a standby power source synchronous switching control circuit.

The functions of the standby power supply synchronous switching control circuit 10 are as described above, and an example of the specific circuit configuration is shown in the second section.
It looks like the picture. As shown in FIG. 2, the standby power source synchronous switching control circuit 10 controls inverter device #1. #2.
A control signal S1 corresponding to the number of inverter units in operation is input by inputting the operation signal (outputs '1' when in operation and outputs 'O' when stopped) that informs the operation status of #3. 52 (when 2 units are in operation) and 53 (when 3 units are in operation)
Judgment circuit 11 that outputs (when the inverter is in operation) and the allowable output 1 according to the number of inverter units in operation from the reference voltage! A resistor circuit [5(
A threshold generation circuit 12 consisting of a voltage dividing circuit) and a plurality of switches (in this embodiment, three switches SW+
, SW2. SWs>, and a comparator 14 that compares the load current signal detected by the comprehensive output current detection circuit 9 with the am signal from the threshold generation circuit 12tP&.

SW+, SW2, and SW3 of the switch circuit 13 are control signals S+ from the judgment circuit 11, respectively.

S2. It is turned on and off by Sx and plays the role of generating a threshold signal according to the number of inverter devices in operation.

That is, when there are three machines in operation, SW+ and SWz are both turned off, when there are two machines in operation, SW2 is on, and when there is one machine, SW1 is turned on.

The comparator 14 generates a switch switching signal when the load current value exceeds an allowable output current value depending on the number of operating inverter devices. This switch switching signal operates the energizing line switching switch 7, disconnecting the main power source and supplying power from the auxiliary power source to the load.

The above-mentioned embodiment is based on the case where there are three inverter devices, but when increasing the number of inverter devices to be operated in parallel, the logic circuit configuration of the judgment circuit 11 and the threshold value generation circuit 12 may be changed depending on the number of inverter devices operated in parallel. Although it is necessary to change the number of resistors (R>) and the number of switches (SW) in the switch circuit 13,
Since the change can be easily deduced and realized from the configuration of this embodiment, the explanation will be omitted.

(Effects) As explained above, in the parallel redundant synchronous operation type inverter device of the present invention, even if a failure occurs in one or more inverter devices during parallel operation, the inverter device does not easily switch to the auxiliary power source and is able to operate normally. The main power source (inverter device) can be operated up to the limit that can supply power to the load with the remaining number of operable inverter devices, so when the load is relatively light, it is sufficient to provide uninterruptible constant voltage constant frequency 1M. It can be used as a source device.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a parallel redundant synchronous operation type inverter device of the present invention, the second factor is a circuit diagram showing an example of the configuration of the pre-INM synchronous switching control circuit of the present invention, and FIG. 3 is a conventional circuit diagram. 1 is a block diagram showing the main components of the uninterruptible power supply system of FIG. #1. #2. #3. ...#n...Inverter device, 3...Main line 1! Route a, 4...-Input terminal for connecting backup power supply, 5...
・・Preliminary communication msm, 7・・・・・・Communication I! Keyakiji switching switch, 8...
...Output terminal for load connection, 9...Comprehensive output current detection circuit, 10...Pre-Im source synchronization switching #1I
J111 circuit, 11...determination circuit, 12...interval value generation circuit, 13...switch circuit. 14... Comparator.

Claims (1)

[Claims] 1. A commercial frequency power source or a rotating machine power source (hereinafter referred to as a "standby power source"), a standby energized line that directly transmits power from the standby power source to the load, and a cyclic operation possible with the standby power source. a main power source equipped with a plurality of inverter devices, a energized line switching switch for switching to the backup power source when the main power source becomes overloaded, and the output side of the energized line switching switch is connected to the load. In an uninterruptible power supply system configured with a comprehensive output current detection circuit provided on a common output line, the operation signal from each of the plurality of inverter devices and the load current from the comprehensive output current detection circuit are A standby power supply synchronous switching control circuit is provided that inputs the signal and determines the load status relative to the number of inverter units in normal operation, and generates a switch switching signal to the energized line switching switch when overload occurs. A parallel redundant synchronous operation type inverter device characterized by the following.