JP2008190212A - Tunnel work method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tunnel work method of suppressing the capacity of a selected power generator in use of such a power-operated equipment as an excavator, mucking machine, concrete spraying machine, and ventilation equipment with power supply from the generator. <P>SOLUTION: According to the tunnel work method, such power-operated equipments as the excavator 11, mucking machine 12, concrete spraying machine 13, and a dust collector 14 are used as a load equipment 1, and power is supplied from a generator 2. A power-factor control type reactive power compensating device 3 is connected in parallel with the load equipment 1 to a power circuit 4 connecting the generator 2 to the load equipment 1, and the load equipment 1 is operated. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a tunnel construction method in which electric power is supplied from a generator and electric devices such as an excavator, a sliding machine, a concrete spraying machine, and a ventilation facility are used.

  In tunnel construction, excavators, sliding machines, concrete spraying machines, and ventilation equipment are used. Specifically, the excavator excavates the soil, cuts the stones, and discharges the earth and sand excavated by the extruding machine. Immediately, the concrete spraying machine sprays concrete against the wall surface exposed by excavation and fixes the wall surface. In addition, a dust collector is operated as a ventilation facility. These electric devices are inductive loads using an induction motor as a drive source, and are operated while being repeatedly started and stopped.

  In tunnel construction in mountainous areas, etc., power cannot be supplied from the commercial power system, so power is supplied from the generator.

  By the way, when a load with a large starting capacity such as an induction motor is applied to the generator, the voltage from the generator may drop rapidly, and the load may not operate normally. For this reason, the capacity of the generator is selected in consideration of the efficiency of the induction motor, the power factor, and the converted value of the generator output at the start of the induction motor (for example, Japan Internal Power Generation Equipment Association standard NEGA D 201 etc.). However, in tunnel construction in which an electric device is operated while being repeatedly started and stopped, a plurality of load devices are always started indefinitely and indefinitely, so that reactive power is likely to be generated when these load devices are started. For this reason, when selecting the generator capacity, considering the influence of the voltage drop in the power circuit when starting up multiple induction motors on the load equipment in other operating states (steady operation state), I had to select something significantly larger than the generator output. In addition, an increase in the capacity of the generator leads to an increase in fuel costs.

  The present invention has been made in view of such circumstances, and an object thereof is to provide tunnel construction in which electric power is supplied from a generator and electric devices such as an excavator, a sliding machine, a concrete spraying machine, and a ventilation facility are used. The method consists in suppressing the capacity of the generator to be selected.

Hereinafter, means for achieving the above-described object and its operation and effects will be described.
The invention according to claim 1 is a tunnel construction method in which an electric device such as an excavator, a sliding machine, a concrete spraying machine, and a ventilation facility is used as a load device, and electric power is supplied from the generator. The reactive power compensator of the power factor control method is connected in parallel with the load device to the power circuit connecting the load device and the load device, and the gist thereof is operated.

  According to this configuration, in tunnel construction that uses electric equipment such as excavators, slide-out machines, concrete spraying machines, and ventilation equipment as load equipment, it is operated while being repeatedly started and stopped. By providing the reactive power compensator of the control method in parallel with the load device, the voltage drop in the power circuit due to the start of each device can be alleviated, and the reactive power in the generator can be reduced. As a result, the voltage drop on the power circuit at the start-up of the load device can be suppressed, and power generation in the operating state of the load device can be performed without considering the voltage drop at the start-up of the load device when selecting the capacity of the generator. Since the capacity of the generator can be selected based on the converted value of the machine output, the capacity of the generator to be selected can be suppressed from the capacity of the conventional generator. Further, by suppressing the capacity of the generator to be selected, not only can the equipment be reduced in size, but also the amount of fuel consumed can be reduced, so that the cost for tunnel construction can be reduced.

The reactive power compensator includes a series circuit of a connected reactor and a waveform shaping circuit.
The invention according to claim 3 is the tunnel construction method according to claim 1 or 2, wherein the reactive power compensator is installed close to the load device.

  According to this configuration, since the reactive power compensator is installed close to the load device, it is possible to respond more quickly to the voltage drop of the power circuit by the load device, and to reduce the reactive power in the generator. it can.

  According to the present invention, the capacity of a generator to be selected is suppressed in a tunnel construction method in which electric power is supplied from a generator and electric devices such as an excavator, a sliding machine, a concrete spraying machine, and a ventilation facility are used. Can do.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a schematic configuration diagram showing the configuration of equipment and the like used for tunnel construction.
As shown in FIG. 1, the tunnel construction of the present embodiment is performed using a load device 1 such as an excavator 11, a sliding machine 12, a concrete spraying machine 13, and a dust collector 14 as a ventilation facility. Specifically, the excavator 11 digs up the soil, cuts the stone, and discharges the earth and sand excavated by the scraping machine 12 (squeezing out). And the concrete spraying machine 13 sprays concrete with respect to the wall surface exposed by excavation, and fixes the same wall surface. The dust collector 14 is operated to ventilate the tunnel. The load machine 1 such as the excavator 11, the sliding machine 12, the concrete spraying machine 13, and the dust collector 14 as a ventilation facility is an inductive load that uses an induction motor as a drive source and operates while being repeatedly started and stopped. Is done. In addition to the excavator 11, the sliding machine 12, the concrete spraying machine 13, and the dust collector 14 as a ventilation facility, another electric device is added as the load device 1 as necessary. The load device 1 is connected to the end of the power circuit 4 from the generator 2, and power is supplied to the load device 1 by the generator 2.

  A reactive power compensator (SVG: Static Var Generator) 3 is provided in parallel with the load device 1 between the generator 2 and the load device 1. The reactive power compensator 3 includes a series circuit in which a waveform shaping circuit 32 including an inverter circuit 33 and a capacitor 34 is connected to the power circuit 4 via the interconnection reactor 31. The reactive power compensator 3 includes a control circuit 30 that calculates the voltage and current of the power circuit 4 and controls the waveform shaping circuit 32. Specifically, a current detection current transformer CT is attached to the load device 1 side from the connection point P. Further, a transformer PT for measuring the voltage of the power circuit 4 on the load device 1 side from the connection point P is connected. The control circuit 30 calculates the power factor of the power circuit 4 from the current detected by the current transformer CT and the voltage detected by the transformer PT, and controls the waveform shaping circuit 32 so as to be a predetermined power factor. Then, the reactive power is injected into the power circuit 4 so as to cancel the reactive power of the power circuit 4, and the power factor is controlled to be constant.

  Here, it will be described that the reactive power compensator 3 selects not the constant voltage control but the constant power factor control. Normally, the generator 2 has an automatic voltage control function, and when the reactive power compensator 3 performs reactive power compensation with constant voltage control, the generator 2 and the reactive power compensator 3 try to control the voltage with each other. Since reactive power compensation by the reactive power compensation device 3 may not be performed, the reactive power compensation device 3 selects constant power factor control.

Next, an operation mode of the reactive power compensator 3 configured as described above will be described.
The reactive power compensator 3 synchronizes the output voltage of the inverter circuit 33 with the phase of the voltage of the power circuit 4 and changes the magnitude. As a result, a 90-degree delayed / advanced current flows from the voltage of the power circuit 4 to the interconnection reactor. As a result, the reactive power compensator 3 operates as if a variable phase advance capacitor and a shunt reactor are connected when viewed from the power circuit 4 side.

  The reactive power compensator 3 adjusts the voltage of the power circuit 4 by changing the reactive power to be output. That is, when the voltage of the power circuit 4 decreases due to fluctuations in the load device 1, an operation similar to that of the phase advance capacitor is performed as viewed from the power circuit 4 to increase the voltage. As a result, as shown in FIG. 2, the reactive power on the generator 2 side is reduced from the connection point P of the reactive power compensator 3 in the power circuit 4. Further, when the voltage of the power circuit 4 rises, the same operation as that of the shunt reactor is performed as seen from the power circuit 4, and the voltage is lowered. Thereby, the power factor in the generator 2 is improved and the power supply efficiency is increased. Moreover, in order to cancel the reactive power generated by the load device 1 at high speed, the voltage fluctuation generated by the load device 1 is reduced.

Next, an operation mode of the tunnel construction method configured as described above will be described.
When the excavation of the tunnel starts, the excavator 11, the sliding machine 12, and the concrete spraying machine 13, which are the load devices 1, are operated while being repeatedly started and stopped. Specifically, the excavator 11 changes in the rotational speed of the face depending on the hardness of the ground. Moreover, the concrete spraying machine 13 greatly differs in the driving of the compressor when concrete is sprayed and when it is not performed. Each time the device is activated, a voltage drop occurs in the power circuit 4, but the reactive power compensation device 3 quickly compensates the reactive power, thereby relaxing the voltage fluctuation of the power circuit 4.

As described above, according to the embodiment described above, the following effects can be obtained.
(1) In tunnel construction in which an electric device such as the excavator 11, the sliding machine 12, the concrete spraying machine 13, and the dust collector 14 is used as the load device 1, it is operated while being repeatedly started and stopped. A power factor control type reactive power compensator 3 is provided in parallel with the load device 1. Thereby, the voltage drop in the power circuit 4 due to the start of each device can be alleviated, and the reactive power in the generator 2 can be reduced. As a result, it is possible to suppress a voltage drop on the power circuit 4 when the load device 1 is started, and the load device 1 can be selected without considering the voltage drop when the load device 1 is started when selecting the capacity of the generator 2. Since the capacity | capacitance of the generator 2 can be selected based on the conversion value of the output of the generator 2 in this operating state, the capacity | capacitance of the generator 2 to select can be suppressed rather than the capacity | capacitance of the conventional generator. Further, by suppressing the capacity of the generator 2 to be selected, not only can the equipment be reduced in size, but also the amount of fuel consumption can be suppressed, so that the cost for tunnel construction can be suppressed.

  (2) Furthermore, since the output is adjusted by the inverter circuit, the response speed is fast, and it is possible to compensate for a steep voltage drop, and to compensate for flicker caused by voltage fluctuations for periodically generated load equipment with severe output fluctuations. be able to.

In addition, the said embodiment can be implemented with the following forms which changed this suitably.
In the above configuration, the reactive power compensator 3 may be moved inside a tunnel by moving it on a moving body, such as a truck, and provided close to the load device 1. According to this configuration, since the reactive power compensator 3 is installed close to the load device 1, it is possible to respond quickly to a voltage drop caused by the load device 1, and to reduce the reactive power in the generator 2. it can.

  In the above embodiment, the present invention is applied to the mountain tunnel construction method. However, the present invention is not limited to this, and may be applied to other tunnel construction methods such as a shield method.

The schematic block diagram of the apparatus used for tunnel construction. The figure which shows the reactive power compensation by this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Load apparatus, 2 ... Generator, 3 ... Reactive power compensator, 4 ... Power circuit, 11 ... Excavator, 12 ... Extruding machine, 13 ... Concrete spraying machine, 14 ... Dust collector, 30 ... Control circuit, 31 ... interconnected reactor, 32 ... waveform shaping circuit, 33 ... inverter circuit, 34 ... capacitor, CT ... current transformer, PT ... transformer, P ... connection point.

Claims (3)

In the tunnel construction method of using electric equipment such as excavators, sliding machines, concrete spraying machines and ventilation equipment as load equipment and supplying power from the generator,
A power circuit connecting the generator and the load device is connected to a power factor control reactive power compensator in parallel with the load device, and the load device is operated. Tunnel construction method. In the tunnel construction method according to claim 1,
The reactive power compensator includes a series circuit of a connected reactor and a waveform shaping circuit. In the tunnel construction method according to claim 1 or 2,
The reactive power compensator is installed close to the load device. A tunnel construction method, wherein:

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