JP2795950B2 - Inverter optical transmission device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention relates to a constant voltage / constant frequency output inverter device, and in particular, improves an optical transmission system of a control signal applied to inverter phase control. The invention relates to an optical transmission device for an inverter device.

(Prior Art) FIG. 4 is a block diagram showing an example of a conventional parallel operation system of an uninterruptible power supply having an optical transmission function of a parallel control signal. FIG. 4 shows a commercial synchronous parallel system comprising a switching device CHG having a switching circuit for switching between a common bus connecting the outputs of two uninterruptible power supply devices CV1 and CV2 and a direct power commercial power supply. In addition to the parallel redundant operation of the power supply system, it is a highly reliable system configuration that has a function of instantaneous interruption switching with the direct power commercial power supply.

In FIG. 4, 1 is a commercial power supply, 2A and 2B are rectifiers, 3A and
3B is an inverter that converts the converted DC power back to AC, 4A and 4B are inverter transformers, 5A and 5B are AC filter circuits, and 6A and 6B are storage batteries that supply power during a commercial power failure. Outputs of the uninterruptible power supply devices CV1 and CV2 are connected by a common bus CB, and supply power to a load 9 via a switching circuit 8 with a direct power supply 7. The voltage and phase of the inverter, which is one of the important technical points of parallel control, is controlled as follows. Active power deviations ΔP _A , ΔP _B at active power deviation detectors 11A, 11B and reactive power deviations at reactive power deviation detectors 12A, 12B, based on the deviation of output current detectors 10A, 10B and output voltage of the UPS. ΔQ _A and ΔQ _B are detected. Active power deviation ΔP _A , ΔP _B
Performs a phase control so as to correct the deviation by interrupting the PLL circuits 13A and 13B with a minor loop, while the reactive power deviations ΔQ _A and ΔQ _B are interrupted by the voltage control circuits 14A and 14B to output the uninterruptible power supply. The load imbalance caused by the voltage difference is corrected.

Voltage reference generation circuits 15A and 15B generate a sine wave voltage reference signal whose amplitude is set by a phase reference set by PLL circuits 13A and 13B and a voltage command set by voltage control circuits 14A and 14B, and a PWM control circuit. Inverter circuit 3A, 3B through 16A, 16B
Drive.

FIG. 5 shows an embodiment of the PLL circuits 13A and 13B. The phase difference detector 17 detects an inverter phase signal INVFB synchronized with the phase reference signal PHO and the inverter phase, interrupts the effective deviation ΔP, and outputs a voltage-controlled oscillator 19 through a low-pass filter 18.
A clock signal with a frequency that is an integral multiple of the sine wave output at
Convert to CPS. The clock signal CPS generated by the voltage controlled oscillator 19 is used as a reference clock for determining the phase in the voltage reference generating circuit 15 and is also frequency-divided by the frequency divider 20 to become an inverter phase signal INVFB, which is fed back to the phase difference detector 17. Is done.

The above-mentioned phase reference signal PHO is synchronized with the direct power commercial power supply 7 in the commercial synchronous system as shown in FIG. 4, and this synchronous control is performed by the PL in the switching device having the same configuration as that of FIG.
Performed by the L circuit 13. If an abnormality occurs in the direct power commercial power supply 7, the internal oscillation circuits 21A and 21B are provided in the uninterruptible power supply units CV1 and CV2.
And backup is performed by the phase reference switching circuits 22A and 22B. The phase reference switching command signals CHA and CHB of the phase reference switching circuits 22A and 22B are detected by the direct power supply synchronous control monitoring circuit 23 of the switching device CHG and transmitted to the uninterruptible power supply devices CV1 and CV2.

In the commercial synchronous parallel system of FIG. 4 described above, the phase signals PHA and PHB synchronized with the direct power supply, the phase signals PHA and PHB transmitted when the direct power supply is abnormal, and the internal pulse signals PHIA and PHIB generated by the internal oscillation circuit are used. And two types of phase reference switching command signals CHA and CHB are transmitted from the switching device to the uninterruptible power supply.

In FIG. 4, since a high speed is required for signal transmission, a system in which light is insulated for control signal transmission is employed. 24C ~ 24F is optical transmitter, 25C ~ 25F is optical fiber, 26
C to 26F are optical receivers.

(Problems to be Solved by the Invention) The optical transmission system of the phase synchronization control signal of the uninterruptible power supply as described above is more externally received on a wiring path and the like than the conventional transmission system using pulse transformer insulation. , For example, there is a merit that reliability against noise is increased, but there are also the following problems.

One is that optical transmission equipment is expensive and the number of uninterruptible power supplies increases in parallel, so the cost for optical transmission increases, and optical fibers concentrate on the switching device CHG, which is a switching command generation means provided outside. Therefore, there is a problem that restrictions on the internal structure design are increased due to wiring. Also, phase reference switching command CH
A and CHB are always off without sending a signal when the direct power supply is normal, which is the normal operation mode of the UPS. Optical transmission equipment is optimally applied with a pulse train signal having a predetermined duty, and when turned off at all times, the reliability of the light emitting element and the like is not necessarily improved compared to the case where the pulse train signal is transmitted and applied. It doesn't matter. Furthermore, even if an error occurs in the transmission system during normal operation, it cannot be detected, and if the signal is not transmitted when it should be operating normally, a failure may occur in switching the phase reference signal, and in the worst case, the system may go down. is there.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an optical transmission system for transmitting a phase control synchronization signal of the inverter device, in which the number of optical fibers is increased to increase the cost, the workability is deteriorated, and the optical signal is transmitted only in an emergency state in an always off state. The present invention has been made in view of the problem of reliability of various application methods, and provides an optical transmission device of an inverter device that can reduce the cost and components of the transmission device while ensuring the reliability of the transmission system. is there.

[Means for Solving the Problems] In order to achieve this object, the present invention provides a synchronization control circuit for generating a phase control signal synchronized with a frequency reference signal supplied from outside such as a direct power commercial power supply, Two types of signals, a phase reference signal and a phase reference switching command, to be transmitted to each inverter device from a switching device provided outside the inverter device having an abnormality detection circuit for phase synchronization control are transmitted by the same optical fiber, A phase reference switching command generated due to an external phase synchronization control abnormality is superimposed while constantly transmitting a phase reference signal, and is switched to phase control means inside the inverter device.

(Operation) In the present invention, the phase reference switching command signal is superimposed on the optical signal of the pulse train transmitting the phase reference signal PH transmitted from the switching device CHG to each uninterruptible power supply, and the rising edge of the transmitted pulse signal Alternatively, the phase reference signal information is transmitted at the falling timing and the phase reference switching command information is transmitted at the pulse width, so that a single optical signal realizes the same function as the conventional two types of optical transmission systems. In addition, it is possible to reduce the cost of the apparatus by reducing the number of optical fibers, and to always transmit a pulse signal to the optical fiber for a signal that is not always transmitted, such as a phase reference switching command signal. Can be enhanced.

(Embodiment) An embodiment of the present invention will be described below with reference to FIG.
In FIG. 1, the same elements as those in FIG. 4 are denoted by the same reference numerals, and description thereof will be omitted.

In FIG. 1, 28 is a transmission signal generator, 24A and 24B are transmitters, 25A and 25B are light guides, 26A and 26B are receivers, 29A,
29B is a reception signal discrimination circuit.

FIG. 2 shows an embodiment of the received signal discriminating circuit 29, in which 30 is a timer circuit, 31 is an AND circuit, 21 is an internal oscillator, 32 is a frequency divider, 33 is an OR circuit, and 34 is a pulse width discriminating circuit. It is.

The transmission pulse signal including the phase information and the control circuit information transmitted from the switching device is output from the PW reception signal determination circuit. The phase signal is PH, the internal pulse signal generated by the internal oscillator is PHI, and the phase reference of the PLL circuit is PHO.

The received signal discriminating circuit 29 shown in FIG. 2 is transmitted from the transmitting signal generating circuit 28 in the switching device CHG to the transmitters 24A and 24B and the optical fibers 25A and 2A.
The transmission pulse signal PW, which is the phase information, is
, And outputs a phase signal PH to the PLL circuit 13. A function for preventing a sudden change in the phase signal and a backup circuit when the transmission pulse signal is lost are provided.

Reference numeral 30 denotes a timer circuit for prohibiting the input of the next phase reference signal via the AND circuit 31 for a predetermined time determined by the allowable frequency range of the system after the input of the phase signal. On the other hand, the clock pulse signal generated by the internal oscillator 21 is divided by the frequency divider 32 into (1/1 /
N) to generate a clock signal of the system output frequency. At this time, an OR of the output of the frequency divider 32 and the transmission pulse signal PW is obtained by an OR circuit, and the output is output from the OR circuit. Reset the container 32. As a result, the internal pulse signal PH1 almost constantly synchronized with the phase reference PH can be generated. In addition, as the frequency division ratio N of the frequency divider 32 is increased, the phase accuracy is improved. By setting the output of the frequency divider 32 and the output of the AND circuit 31 as the phase signal PH of the PLL circuit 13 via the OR circuit 33, even if the transmission pulse signal PW from the switching board CHG suddenly disappears, the phase signal PH can be secured.

On the other hand, the phase shift pulse signal PW received by the receiver is input to the pulse width discriminating circuit 34, and when a signal having a pulse width equal to or larger than a predetermined value set on the transmitting side is input, the phase reference switching command CH is transmitted to the phase reference switching circuit. Send to 22.

The above operation is shown in the time chart of FIG. When the pulse width of the phase pulse signal PW exceeds a predetermined value, the phase control signal PHO switches from the transmission pulse signal PW transmitted from the switching device CHG to the internal pulse signal PH1 determined by the internal oscillator according to the phase reference switching command CH. The phase shift is determined by the time difference Δθ between the phase reference PH before the generation of the phase reference switching command CH in FIG. 3 and the internal pulse signal, but Δθ is very small by the above-described clear operation of the frequency divider 32 and can be switched without any problem.

The case where the number of the inverter devices is two has been described above, but the present invention can be implemented with one or three or more inverter devices. Also, the phase control signal transmitted from the switching device having an externally provided phase synchronization control circuit has been described as a signal synchronized with the direct power commercial power supply. The present invention can be applied. Further, the present invention can be applied not only to the uninterruptible power supply device of the inverter device but also to, for example, a variable frequency power supply device that operates in a synchronized phase.

[Effects of the Invention] As described above, a phase signal for synchronization control from a switching device having an externally provided phase synchronization control means to a plurality of inverter devices and a phase control switching due to an abnormality in the phase synchronization control on the switching device side. Since two signals with different commands are superimposed on the same optical transmission path and the function equivalent to the case of split transmission is achieved, the number of optical fibers used for transmission can be halved. The cost can be reduced, and the transmission form of the always-off signal can be eliminated by constantly transmitting the pulse train signal through the optical fiber, so that the reliability of the optical transmission system can be improved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of an optical transmission system of a parallel system of an uninterruptible power supply according to the present invention, FIG. 2 is a block diagram showing an embodiment of a reception signal discriminating circuit of FIG. FIG. 4 is a time chart for explaining the operation of the reception discriminating circuit. FIG. 4 is a block diagram showing an embodiment of an optical transmission system of a parallel system of a conventional uninterruptible power supply, and FIG. 5 is a PLL shown in FIG. FIG. 3 is a block diagram illustrating an example of a circuit. CV1, CV2… Uninterruptible power supply, CH… Switching device, 1… Commercial power supply, 2A, 2B …… Rectifier, 3A, 3B …… Inverter, 4A, 4B …… Inverter transformer, 5A, 5B… ... AC filter circuit, 6A, 6B ... storage battery, 7 ... direct power commercial power supply, 8 ... switching circuit, 9 ... load, 10A, 10B ... output current detector, 11A, 11B ... active power deviation detector , 12A, 12B… reactive power deviation detector, 13A, 13B, 13C… PLL circuit, 14A, 14B… voltage control circuit, 15A, 15B… voltage reference generation circuit, 16A, 16B… PWM control circuit, 21A, 21B ... internal oscillation circuit, 22A, 22B ... phase reference switching circuit, 23 ... direct power supply synchronous control and monitoring circuit, 24A to 24F ... optical transmitter, 25A, 25B ... optical fiber, 26A to 26F ... ... Optical receiver, 28 ... Transmission signal generation circuit, 29A, 29B ... Reception signal discrimination circuit.

Claims (1)

(57) [Claims] 1. A phase synchronization control means for synchronously controlling a first frequency reference signal provided from an external source such as a commercial power supply or a second frequency reference signal output from a built-in oscillator, and said first frequency reference signal. And a phase reference switching means for switching between the first frequency reference signal and the second frequency reference signal, wherein the switching command generation means for giving a switching command to the phase reference switching means in accordance with the state of the first frequency reference signal. Provided externally, the switching command generating means is connected to the phase synchronization control means and the phase reference switching means by an optical transmission line, and the switching command generating means output signal is superimposed on the first frequency reference signal and transmitted. An optical transmission device for an inverter device, characterized in that: