JPH01186123A - Parallel power converter - Google Patents

Abstract

PURPOSE:To reduce the extension of a pulse width of a control signal, to effectively identify wide and narrow pulses, and to obtain a parallel power converter having high reliability by providing a means for transmitting the signal as an optical signal. CONSTITUTION:A clock pulse output from the oscillator 11a of an inverter 1a is input to an OR circuit 15a. Clock pulses output from the oscillators 11b, 11c of inverters 1b, 1c are input through electro-optical converters 12b, 12c and photoelectric converters 13a, 14a to the circuit 15a. Then, the OR of the clock pulses is obtained. OR circuits 15b, 15c are similarly operated. That is, since ring counters 10a, 10b, 10c are all operated by the same clock pulse, the inverters 1a, 1b, 1c are operated by AC outputs having the same phase. Thus, a parallel power converter having high reliability is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a parallel power conversion device that transmits control signals, such as clock pulses, for a plurality of power conversion devices using optical signals.

(Prior Art) A conventional parallel power conversion device will be explained using FIG. 5.

In this case, the parallel power conversion device is a device that operates two or more inverter devices (inverter device 11a, inverter device 1b, and inverter device fllc in FIG. 5) in parallel, and each inverter device, that is, inverter device 1
1a, inverter device 1b, and inverter device [ilc are operated in the same phase. Each inverter device is composed of a plurality of unit inverters. The inverter device 1a shown in FIG. 5 is an 18-pulse inverter device, and the unit inverter 2
a, a unit inverter 3a, and a unit inverter 4a. As the main circuit, alternating current is input to terminal 5a, and converted to direct current by converter 6a. The output of converter 6a is input to unit inverters 2a, 3a, and 4a, converted into alternating current, and input to transformer 7a, transformer 8a, and transformer 9a, respectively.

The secondary sides of transformer 7a, transformer 8a, and transformer 9a are connected and output as one alternating current. Inverter device 11
Since 1a is an 18-pulse inverter device consisting of three unit inverters 2at, 3a and 4a, each unit inverter generates alternating current with a phase shift of 20 degrees.

The switching signal of each unit inverter is outputted from the ring counter 10a.The zero oscillation circuit 11a outputs a clock pulse having a frequency (18f>) that is 18 times the frequency f of the output AC. , are input to the ring counter 10a, and the clock pulse of 18f is distributed as a switching pulse to each unit inverter.

Although the inverter device 1a has been described, the same applies to the inverter device tlb and the inverter device 1c.

The outputs of the inverter devices 1a, lb, and lc are all connected to the own load 16 by 0 oscillation circuits 11a, 11b*ll
c is an oscillation circuit with the same frequency, but (a) in Fig. 2
,(b).

As shown in (C), the clock pulse output from the 0 oscillation circuit 11a with a slight deviation is input to the pulse transformer 18b and pulse transformer 18c via the pulse transformer 18a, and is output from the oscillation circuit 11b. The generated flock pulse is transmitted through the pulse tone 18b,
The clock pulse is input to the pulse transformer 18a and the pulse transformer 18c, and on the other hand, the clock pulse output from the oscillation circuit 11c is input to the pulse transformer 18a and the pulse transformer 18b via the pulse transformer 180. That is, on the secondary side 19a of the pulse transformer 18a, the OR of the clock pulses oscillated from the oscillation circuits 11a, llb, and llc is taken, and the oscillation circuit is reset by the first clock pulse, and the oscillation circuit is reset as shown in FIG. 2(d). Similarly, on the secondary side 19b of the pulse transformer 18b and the secondary side 19c of the pulse transformer 18c, the clock pulses oscillated from the oscillation circuit 11 a t 11 b *11c are ORed, And the oscillation circuit is reset by the first clock pulse as shown in Figure 2 (
The waveform becomes d). That is, the ring counter 10a,
10b and 10c all operate with the same clock pulse. As a result, the inverter devices 1a, lb, and lc output alternating current with the same phase.

(Problems to be Solved by the Invention) However, the conventional parallel inverter device described above has the following problems. U, V of 3-phase output of inverter device
, W, in the 18-pulse inverter device, a wide pulse with a large pulse duty is output from the oscillation circuit once every 18 pulses. Other pulses are narrow pulses.

Since a pulse transformer is used to transmit the clock pulse, the pulse width of the clock pulse is 10μ to 20μse.
Also, due to the difference in impedance of the transmission circuit by the pulse transformer when operating in parallel and when operating alone, there is no effect, but at 500Hz
In high-frequency inverter devices with a large number of pulses, the clock pulse width increases,
It becomes difficult to distinguish between wide and narrow pulses.

Therefore, in view of the above-mentioned problems, it is an object of the present invention to provide a parallel power conversion device that can reliably transmit a control signal, such as a clock pulse, even in high-frequency output.

[Structure of the invention]

(Means for Solving the Problems) Therefore, in order to achieve the above object, the present invention provides an oscillation means for generating an electric signal that becomes a phase signal of a plurality of power conversion devices, and an electric signal output from the oscillation means. A power conversion device based on an electro-optical conversion means that converts a signal into an optical signal, a photoelectric conversion means that converts an optical signal outputted by the electro-optical conversion means into an electrical signal, and an electric signal output from the photoelectric conversion means. A parallel power converter is provided, which includes a control signal generating means for converting the power into a switching signal and outputting a control signal to each power converter.

(Function) In the parallel power converter configured as above,
The oscillation means outputs an electrical signal to the electro-optical conversion means, which converts the electrical signal into an optical signal and transmits it to the photo-electric conversion means. The optical signal received by the photoelectric conversion means is converted into an electric signal, and this electric signal is output to each power conversion device by the control signal generation means, and the power conversion device is operated based on it.

(Example) An embodiment of the present invention will be described below with reference to FIG.

As shown in FIG. 1, the parallel power conversion device of this embodiment is
The unit power conversion device is an inverter device, and is composed of a plurality of inverter devices including an inverter device 1a, an inverter device 1b, and an inverter device 1c.

18 shows an example of an inverter, so the inverter family [
1a is a unit inverter device 2a, a unit inverter 3a
, unit inverter 4a, inverter device 1b, unit inverter 2b, unit inverter 3b, unit inverter 4b, inverter group! 1c is a unit inverter 2c,
Each unit is composed of a unit inverter 3c and a unit inverter 4c. In the inverter device 1a, AC power is input to a terminal 5a (terminal 5b in the inverter device 1b, terminal 5c in the inverter device 1c), and a converter 6a (converter 6b in the inverter device 1b, converter 6c in the inverter device 1c) converts the alternating current to direct current. )
, each outputs an alternating current whose output phase is shifted by 20 degrees. Unit inverter 2a (inverter device 1b
In this case, the unit inverter 2b, the unit inverter 2C in the inverter device 1c), the unit inverter 3a (the unit inverter 3b in the inverter device 1b, the inverter i1
c, unit inverter 3C), unit inverter 4a (
In the inverter device 1b, the unit inverter 4b, the inverter device! lc is connected to a unit inverter 4c), and each unit inverter 2a, unit inverter 3a, and unit inverter 4a is connected to a transformer 7a (inverter device 1b).
In the case of the transformer 7b, and in the inverter device 1c, the transformer 7c)
, transformer 8a (in the inverter device 1b, transformer 8b,
In the inverter device 11c, transformer 8c) transformer 9a (
In the inverter device 1b, the transformer 9b and the inverter group W1
In 1c, transformers 9c) are connected, each transformer 8
a, the secondary sides of transformer 9a and transformer 10a are connected,
Output as one alternating current. Inverter device i1a,
The outputs of lb and lc are both connected to a load 16. A ring counter 10a that sends a switching signal to each unit inverter (in the inverter device 1b, a ring counter 1
0b, ring counter 10c in the inverter device 1c)
is installed, and a ring counter 10a (inverter device 1
The ring counter 10b (in the case of b, the ring counter 10C in the inverter device 1c) receives the clock pulse of 18f output from the oscillation circuit 11a (the oscillation circuit 11b in the inverter device 1b, and the oscillation circuit 11C in the inverter device 1c) and The oscillation circuit 11c in the device 1b, the oscillation circuit 11a in the inverter device IC) is connected to the photoelectric conversion circuit 13a (in the inverter device The 18f clock pulse output from the photoelectric conversion circuit 13b in 1b and the photoelectric conversion circuit 13C in inverter device 1c) and the oscillation circuit 11C (oscillation circuit 11a in inverter device 1b, oscillation circuit 11b in inverter device 1C)
) from the photoelectric conversion circuit 14a (the photoelectric conversion circuit 14b in the inverter device 1b, the photoelectric conversion circuit 14b in the inverter device 1c) via the photoelectric conversion circuit 12c (the photoelectric conversion circuit 12a in the inverter device 1b, the photoelectric conversion circuit 12b in the inverter device 1c).
Then, the OR circuit 15a (OR circuit 15b for the inverter device 1b, OR circuit 15b for the inverter device 1c) with the clock pulse of 18f output from the photoelectric conversion circuit 14c)
A clock pulse taken by circuit 15c) is input. Also, the OR circuit 15a (in the inverter device 1b, the
R circuit 15b, inverter device! ! In 1c, OR circuit 1
5c) The clock pulse output from the oscillation circuit 11a
(Input to the oscillation circuit 11b in the inverter device 1b, and the oscillation circuit 11c in the inverter device 1c).

In the embodiment configured in this way, (a
), (b), and (c), the 0 oscillation circuit 11a (the oscillation circuit 11b for the inverter device 1b and the oscillation circuit 11c for the inverter device 1c) is slightly shifted.
) is input to the OR circuit 15a (OR circuit 15b in the inverter device 1b, OR circuit 15c in the inverter device i1c). Also, the oscillation circuit 11b (the oscillation circuit 11c in the inverter device 11b, the oscillation circuit 11a in the inverter device 11c)
The 18f clock pulse output from
c. In the inverter device 1c, it is converted into an optical signal by the electro-optical conversion circuit 12a) and sent to the photoelectric conversion circuit 13a (inverter device 1).
1b, the photoelectric conversion circuit 13b, and the inverter device 1c, the photoelectric conversion circuit 13c) convert the signal into an electric signal again, and input it to the OR circuit 15a. In addition, the oscillation circuit 11C
The 18f clock pulse output from the oscillation circuit 11a in the inverter device 1b and the oscillation circuit 11b in the inverter device 1c is output from the electro-optical conversion circuit 12c (the electro-optical conversion circuit 12a in the inverter device llb, and the electro-optic conversion circuit 12b in the inverter device 1c). The photoelectric conversion circuit 14a (in the inverter device 1b, the photoelectric conversion circuit 1
4b, in the inverter device 1c, the photoelectric conversion circuit 14c) converts the signal into an electrical signal again, and inputs it to the OR circuit 15a. The OR circuit 15a performs an OR operation on the clock pulses, and the oscillation circuit is reset by the first clock pulse, resulting in the waveform shown in FIG. 2(d). Similarly, OR
The clock pulses are also ORed in the circuit 15b and the OR circuit 15c, and the first clock pulse resets the oscillation circuit 11b and the oscillation circuit 11c as shown in FIG.
) waveform. That is, the ring counters 10a, 1
0b and 10c all operate with the same clock pulse.

As a result, the inverter devices 1a, lb, and lc output alternating current with the same phase.

As described above, in this embodiment, since the clock pulse is transmitted as an optical signal, even in a high-frequency inverter with a large number of pulses, the clock pulse width does not increase much and it is possible to reliably distinguish between wide and narrow pulses. Width pulses can be identified.

Another embodiment of the present invention will be described below with reference to FIG.

As shown in FIG. 3, the parallel power conversion device of this embodiment is
The unit power conversion device is an inverter device.

It is composed of a plurality of inverter devices including an inverter group [1a, an inverter group M1b, and an inverter device 1c.

Since this is an example of an 18-pulse inverter device, the inverter device 1a includes a unit inverter 2a, a unit inverter 3a, and a unit inverter 4a, and the inverter device lb includes:
The inverter device 1c includes the unit inverter 2b, the unit inverter 3b, and the unit inverter 4b.
c, a unit inverter 3c, and a unit inverter 4c. In the inverter device 1a, AC power is input to a terminal 5a (terminal 5b in the inverter device 11b, terminal 5c in the inverter device 1c), and a converter 6a (converter 6b in the inverter family fib, converter 6c in the inverter group fib) that converts the alternating current to direct current. ), each outputs an alternating current whose output phase is shifted by 20°. Unit inverter 2a (In inverter device 1b, unit inverter 2b, inverter device IC
In this case, unit inverter 2C), unit inverter 3a (unit inverter 3b in inverter device 1b, unit inverter 3c in inverter device IC), unit inverter 4a
(Connected to unit inverter 4b in inverter device 1b, unit inverter 4c in inverter device IC),
Each unit inverter 2a.

A transformer 7 is connected to the unit inverter 3a and the unit inverter 4a.
a (transformer 7b in inverter device 1b, transformer 7C in inverter device 1c), transformer 8a (transformer 8b in inverter device 1b, transformer 8c in inverter device 1c), transformer 9a (transformer 9a in inverter device 1b) 9b and the inverter device 1c are connected to the transformer 9c), and the respective transformers 8a, 9a, and 10a
The secondary side of is connected and output as one alternating current.

The outputs of inverter devices 1a, lb, and lc are all connected to load 16. A ring counter 10a (ring counter 10b for the inverter device 1b, ring counter 10c for the inverter device IC) that sends a switching signal to each unit inverter is installed.
a (In the inverter family! 1b, the ring counter 10b,
In the inverter device 11c, the ring counter 10C) is
Photoelectric conversion circuit 13a (photoelectric conversion circuit 13b in inverter device 1b, photoelectric conversion circuit 13 in inverter device IC)
0 oscillation circuit 11a (oscillation circuit 11b in inverter device 1b, oscillation circuit 1ie in inverter group [1c) to which the 18f clock pulse output from The clock pulses of the photoelectric conversion circuits 13a to 18f are input as reset signals.In the device i1b, the clock pulses are input to the electro-optical conversion circuit 12b, and in the inverter E1c, the clock pulses of the photoelectric conversion circuits 13a to 18f are input as reset signals. Lightning conversion circuit 12a
, 12b, 12c, the clock pulses converted into optical signals with different wavelengths are transmitted to the common optical signal transmission path 1.
7 and is transmitted on a common optical signal transmission path, so it is OR'ed.

It is converted into an electric signal by the photoelectric conversion circuits 13a, 13b, and 13c, and the oscillation circuit 11a is activated by the first clock pulse.
.

11b, lie is reset. That is, the oscillation circuit 11a outputs the clock pulse shown in FIG. 2(a), the oscillation circuit 11b outputs the clock pulse shown in FIG. 2(b), and the oscillation circuit 11c outputs the clock pulse shown in FIG. 2(C). If so, each oscillator is reset by the first clock pulse, resulting in the clock pulse of FIG. 0(d). As a result, each ring counter 10a.

Since inverters 10b and 10c operate with the same clock pulse, inverter devices 1a, lb, and lc provide AC outputs of the same phase.

In this example, since a common optical signal transmission path is used,
Regardless of the number of oscillators, only one optical fiber is required between the inverters, so both material costs and construction costs can be reduced.

This is noticeable when the distance between the inverters is long.

In both of the above two embodiments, a total of three oscillators were provided, one for each inverter device, but the number does not have to be three, and any number of oscillators may be used as long as there are multiple oscillators.The fourth example uses two oscillators. It is a diagram.

Further, in the above embodiments, an example of an 18-pulse inverter device is shown, but the present invention is not limited to an 18-pulse inverter device. In addition, we configured three inverter devices in parallel,
It goes without saying that the present invention is not limited to this number and can be applied to a parallel configuration of a plurality of inverter devices.

〔Effect of the invention〕

As detailed above, in the present invention, since the control signal (clock pulse, etc.) is transmitted as an optical signal, the pulse width of the control signal can be increased even in a high-frequency power conversion device and a power conversion device with a large number of pulses. It is possible to provide a highly reliable parallel power conversion device in which wide pulses and narrow pulses can be reliably distinguished.

Further, when a common optical signal transmission path is used, regardless of the number of oscillators, only one optical fiber is required between the power converters, so that an inexpensive parallel power converter can be provided.

Since the control signal, for example, the clock pulse, is transmitted as an optical signal, there is no impedance drop of the control signal, for example, the clock pulse, and the distance of the power converter may be increased.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention, FIG. 2 is a time chart of clock pulses of a parallel inverter device which is one embodiment of the present invention, and FIG. 3 is a block diagram showing another embodiment of the present invention. FIG. 4 is a block diagram showing another embodiment of the present invention, and FIG. 5 is a block diagram showing a conventional parallel inverter device. la, lb, lc...inverter devices 2a, 2b, 2
c, 3a, 3b, 3c, 4a, 4b, 4cm unit inverter 10a, 10b, 10cm ring counter 11a,
llb, 1lc - oscillators 12a, 12b, 12cm electro-optical conversion circuits 13a, 13b
, 13c14ae14bt14cm photoelectric conversion circuit 15a
, 15b, 15cm OR circuit 17... Optical signal transmission line Figure 1 Figure 4 Figure 5

Claims (1)

[Claims] In a parallel power conversion device having a plurality of power conversion devices, an oscillation means for outputting an electric signal to the power conversion device;
an electro-optical conversion means that converts the electric signal from the oscillation means into an optical signal; a transmission means that transmits the optical signal; and a control signal is output to the power converter based on the electric signal from the photoelectric conversion means. 1. A parallel power conversion device comprising control signal generation means and photoelectric conversion means for converting the transmitted optical signal from the electro-optical conversion means into an electrical signal.