JP5735780B2 - Engine-driven generator - Google Patents

Description

  The present invention relates to an engine-driven generator used as a power source for electrical equipment outdoors and the like.

  When it is necessary to secure a power supply, such as at a construction site or event venue, especially outdoors, the engine and the generator body driven by the engine can be moved, for example, by housing them in a common package. An engine-driven generator is used.

  In such an engine-driven generator, as an example, in order to be able to supply power to various devices regardless of the type of device to which power is to be supplied, three-phase 200V or three An engine-driven generator that includes both a three-phase terminal block that outputs a phase of 400 V and a single-phase terminal block that outputs a single-phase of 100 V has been proposed. In such an engine-driven generator, Different devices can be connected to the three-phase and single-phase terminal blocks at the same time (see Patent Document 1).

JP 2006-87242 A

  At construction sites in rivers, as an example, steel sheet piles are isolated from rivers by placing steel sheet piles and surrounding the work places to prevent water from entering the work places. There are cases where work is carried out while pumping out the water accumulated in the part enclosed by the submersible pump.

  And in such a work site, in order to ensure the brightness and safety in the work place surrounded by the steel sheet pile, it is also performed to install and illuminate the work place.

  Therefore, when using the engine-driven generator described above at such work sites, a submersible pump is connected to the three-phase output terminal block of this engine-driven generator, and a lighting fixture is connected to the single-phase output terminal block. Thus, it is used as a power source for both the submersible pump and the lighting fixture.

  However, when a plurality of devices are connected to one engine-driven generator in this way, one of them is a device equipped with a three-phase induction motor such as a submersible pump (hereinafter referred to as such If the device is called a “motor device”), the change in the operating state of the motor device may greatly affect the operation of other devices (“lighting equipment” in the above example). .

  That is, the three-phase induction motor used as a drive source for the above-described submersible pump, for example, has a starting current of 4 to 6 times (or more) the rated current. The voltage at the three-phase output terminal block drops, the engine speed decreases, the output frequency decreases with this, and the supplied power becomes unstable.

  As a result, when the device connected to the engine-driven generator together with the motor device is the above-described lighting fixture, for example, the flickering of the illumination, the brightness is reduced, or the light is temporarily turned off in some cases. , The operation may be abnormal.

  The motor equipment described above is operated at a substantially constant rotational speed corresponding to the output frequency of the three-phase output terminal block when the rotational speed is increased and the operating state is stabilized after startup. In the example, when the amount of water entering the work place from the river side is small, if the submersible pump is driven at a rotational speed that generates a drainage volume that greatly exceeds this amount, the work place will eventually run out of water and the submersible pump will run idle. If the pump is overheated without being cooled and continues to operate, the submersible pump may be damaged.

  Therefore, it is convenient if the output frequency of the three-phase output terminal block of the engine-driven generator can be made variable and the submersible pump can be driven at a rotational speed balanced with the amount of water entering from the river side.

  However, if the output frequency is changed in a conventional engine-driven generator, the rotation speed of the generator body is changed by changing the rotation speed of the engine. In this case, the three-phase output terminal block Not only the motor device connected but also all other devices connected to the engine-driven generator are changed, which is not preferable.

  Therefore, it is convenient if the frequency can be varied only for the output from the three-phase output terminal block to which the motor equipment is connected.

  Furthermore, since the starting current of a three-phase induction motor is 4 to 6 times (or more) the rated current as described above, a conventional motor drive generator of 25 kVA class has a motor device of up to 7.5 kW. Can only be started.

  Therefore, once the motor equipment is started up and the motor rotation speed increases and the current decreases to approach the rated current, only the state after the transition to normal operation can be seen. The engine drive generator of 25kVA class has excessive performance. If a larger motor device can be started by the engine drive generator of the same class, the load factor of the engine drive generator (load capacity / engine The rated output of the drive generator can be increased, and the fuel consumption rate [(fuel consumption / load capacity) / time] can be reduced to improve the efficiency, thereby reducing the cost. In addition, the load on the environment can be reduced.

  In addition, if it is possible to start up a large motor device in this way, when using it as a power source for a motor device, it is possible to select a smaller one compared to the conventionally selected engine-driven generator. In addition, the economic burden of purchasing an engine-driven generator can be reduced, and the cost and labor for transportation, installation, storage, etc. can be reduced.

  Therefore, the present invention has been made in view of the above-mentioned drawbacks of the prior art, and even when both the motor device described above and other devices are connected to the same engine-driven generator, the motor device is provided. It is possible to prevent other devices from being affected by the start-up of the motor, and to change only the output frequency for the motor device described above, and to make the motor device larger than the conventional one. Another object of the present invention is to provide an engine-driven generator that can be activated.

  Hereinafter, means for solving the problem will be described together with reference numerals used in the embodiment for carrying out the invention. This code is used to clarify the correspondence between the description of the scope of claims and the description of the mode for carrying out the invention. Needless to say, it is used in a limited manner for the interpretation of the technical scope of the present invention. It is not a thing.

In order to achieve the above object, an engine-driven generator 1 of the present invention is driven by an engine 3 that is operated at a set constant rotational speed (for example, 1500 min ⁻¹ or 1800 min ⁻¹ ), and the engine 3. In the engine-driven generator 1 having the generator body 4 that outputs a predetermined voltage and a predetermined commercial frequency (50 Hz or 60 Hz) ,
The provided generator body 4 simultaneously taken out Shi possible plurality of terminal blocks power generated by the 6 (61 to 63),
The plurality of terminal blocks 6 (61 to 63) are set so as to reach the set frequency and maintain the output of the set frequency after gradually increasing the frequency from a predetermined low frequency at the start of output. and at least one three-phase output terminal block 61 is connected before Symbol generator body 4 through the generator body 4 is three-phase and / or single-phase output without varying the frequency and voltage output With terminal blocks (62, 63),
A start command means (start / stop switch 22) for instructing the inverter device 2 to start output is provided (claim 1).

  The engine-driven generator 1 having the above-described configuration can further be provided with a frequency setting means 21 that makes the set frequency variable (claim 2).

  Further, the three-phase output line 51 connected to the generator body 4 is branched, and the three-phase output terminal block 61 is connected to any one of the branched three-phase output lines 51a via the inverter device 2. In addition, the other three-phase output terminal block 62 may be connected to the other branched three-phase output line 51b.

  Further, the plurality of terminal blocks 61 to 63 may include a single-phase output terminal block 63 (Claim 4).

  Moreover, it is preferable to provide the breaker 91 which establishes and cancels | releases the connection between both between the said inverter apparatus 2 and the said generator main body 4. (Claim 5).

  With the configuration of the present invention described above, according to the engine-driven generator 1 of the present invention, the following remarkable effects can be obtained.

  By providing the three-phase output terminal block 61 connected to the generator body 4 via the inverter device 2 in the plurality of output terminal blocks 6 (61 to 63), the three-phase output terminal block 61 , For example, by using a device (motor device) equipped with a three-phase induction motor such as a submersible motor, it was possible to suppress an increase in the starting current of the motor device.

  As a result, the activation of the motor device affects the operation of other devices connected to the other output terminal blocks 62 and 63 of the common engine-driven generator 1, for example, as in the above-described example. When other equipment is lighting equipment, it was possible to prevent problems such as flickering of lighting, reduction of brightness, and extinction.

  In addition, as described above, since the increase in the starting current of the motor device is suppressed, it is possible to start a larger motor device as compared with the conventional engine-driven generator.

  As a result, the load factor of the engine-driven generator can be increased, the fuel consumption rate can be reduced and the efficiency can be improved, the cost during power generation can be reduced, and the environmental load can be reduced. By selecting a smaller engine-driven generator, the purchase cost of the engine-driven generator can be reduced, and the labor required for transportation, installation, and storage can be greatly reduced.

  In the configuration provided with the frequency setting means 21 that makes the set frequency output from the inverter device 2 variable, the rotational speed of the motor device during normal operation can be made variable. For example, the motor device is a submersible pump. In this case, it was possible to select the operating state of the motor device according to the situation, such as driving the submersible pump at a rotational speed that generates a drainage amount balanced with the amount of water entering the work place.

  Further, the three-phase output line 51 connected to the generator main body is branched, and the three-phase output terminal block 61 is connected to any one of the branched three-phase output lines 51a and the other branched In the configuration in which the other three-phase output terminal block 62 is connected to the three-phase output line 51b, in addition to the three-phase output terminal block 61 whose output is controlled by the inverter device 2, power generation is not performed via the inverter device 2. Since the three-phase output terminal block 62 from which the output from the machine body 4 can be taken out is provided, other three-phase output terminal blocks 62 are conventionally used for devices that do not require the output controlled by the inverter device 2. The power could be supplied via

  Furthermore, by providing the engine-driven generator 1 with the single-phase output terminal block 63, not only equipment driven by a three-phase AC power supply but also equipment driven by a single-phase AC power supply can be connected simultaneously. It was.

  Further, in the configuration in which the breaker 91 for establishing and releasing the connection between the inverter device 2 and the generator body 4 is provided, when the output through the inverter device 2 is not performed By disconnecting the communication between the inverter device 2 and the generator body 4 by operating the breaker 91, the capacitor in the inverter device 2 is not charged and the life of the inverter device 2 can be extended. It was.

Explanatory drawing of the engine drive type generator of this invention.

  The engine-driven generator according to the present invention will be described below with reference to the accompanying drawings.

  In FIG. 1, reference numeral 1 denotes an engine-driven generator according to the present invention. This engine-driven generator 1 includes an engine 3, a generator main body 4 driven by the engine 3, and a generator body 4. Necessary equipment such as an output line 5 (51, 52) for taking out the electric power generated by the generator body 4 is accommodated, and the generator body 4 is connected to the generator body 4 via the output line 5 (51, 52). A control panel 7 equipped with switches and instruments for controlling the operation of the connected output terminal block 6 (61, 62, 63), the engine 3, the generator body 4, the inverter device 2 to be described later, etc. , For example, is attached to a position where it can be operated from outside the soundproof box 8.

  The above-described generator body 4 that is one of the main components of the engine-driven generator can use various known types. In the present embodiment, an exciter 42 is provided as an example. A self-excited three-phase AC generator is used as the generator body 4.

  In the present embodiment, the generator main body 4 includes windings capable of simultaneously obtaining a three-phase AC output (three-phase 200 V) and a single-phase AC output (single-phase 100 V), and a three-phase output terminal. Electric power can be simultaneously supplied to the electric devices connected to the bases 61 and 62 and the single-phase output terminal base 63.

  As described above, the generator main body 4 used in the present embodiment includes the exciter 42 and an automatic voltage regulator (AVR) so that the voltage output from the main generator 41 becomes a set value. The excitation current supplied to the exciter 42 is controlled according to the increase / decrease of the output voltage by 43.

  The engine-driven generator 1 configured as described above is provided with an output line 5 (51, 52) for taking out the electric power generated in the generator body 4, and as described above, this embodiment includes the output line 5 (51, 52). In this case, since the generator main body 4 is capable of generating a three-phase AC output (three-phase 200 V) and a single-phase AC output (single-phase 100 V) at the same time, this output line 5 (51, 52), two types of a three-phase output line 51 and a single-phase output line 52 are provided.

  Of these output lines, the single-phase output line 52 is connected to a single-phase output terminal block 63 via, for example, a breaker 93 that supplies or cuts off power, and is connected to a terminal provided on the single-phase output terminal block 63. This can be activated by connecting a device driven by a single-phase AC power source, such as a lighting device.

  Of the output lines connected to the generator body 4, the aforementioned three-phase output line 51 branches as shown in FIG. 1, and one branched three-phase output line 51a is supplied with power. Alternatively, the three-phase output terminal block 61 is connected to one of the three-phase output terminal blocks 61 via the breaker 91 and the inverter device 2 to be shut off, and the other three-phase output line 51b is connected to the above-described three-phase output terminal via the same breaker 92. It is connected to a three-phase output terminal base 62 provided separately from the base 61.

The engine 3 that drives the generator body 4 is configured to be able to be operated at a constant rotational speed so that a predetermined commercial frequency (50 Hz or 60 Hz) is obtained in the generator body 4. In the configuration of the embodiment, when the rotational speed of the engine 3 is set to 1500 min ⁻¹ , an output with a frequency of 50 Hz can be obtained from the generator body 4 and the rotational speed of the engine 3 is set to 1800 min ^−1. When set to, an output with a frequency of 60 Hz can be obtained from the generator body 4.

  The inverter device 2 described above has a converter unit that converts input power into direct current, and an inverter unit that converts direct current obtained by the converter unit into alternating current of a predetermined frequency and voltage. For example, a known PWM (pulse (Width modulation) method, etc., so that an AC output at an arbitrary frequency set by the frequency setting means 21 can be generated. When the output frequency is relatively low, the output voltage is low and the output frequency is compared. The output voltage is set so as to change as the frequency increases or decreases so that the output voltage increases when the frequency is high.

  This inverter device 2 outputs a start command means for instructing the inverter device 2 to start, based on an electric signal generated by operating a start / stop switch 22 provided in the control panel 7 in the illustrated embodiment. It is configured to start and stop output, and at the start of output, the output frequency is increased from a predetermined low frequency, in this embodiment from zero frequency to a set frequency gradually, When the set frequency is reached, the output at this set frequency is maintained.

  The set frequency is configured to be adjustable by operating the frequency setting means 21, and is configured to take various values in relation to the use of the engine-driven generator and the connected device. Yes.

  This set frequency may be set to be higher or lower than the commercial frequency (50 Hz or 60 Hz). In the present embodiment, the set frequency is set with the engine speed kept constant as an example. It was set to be variable in the range of 30-60 Hz.

  The predetermined low frequency is a frequency that is sufficiently lower than the commercial frequency (50 Hz or 60 Hz) and the lower limit setting value of the set frequency (30 Hz in the present embodiment), and is a zero frequency. Is preferred.

  In the engine-driven generator 1 configured as described above, a three-phase induction motor such as a submersible pump is connected to one three-phase output terminal block 61 connected to the generator body 4 via the inverter device 2. Connect a device (motor device) equipped with

  The other three-phase output terminal block 62 and / or the single-phase output terminal block 63 are connected to electrical devices other than the motor device described above. In the above-described example, the lighting device is connected to the single-phase output terminal block 63. Connect.

  In this state, the engine 3 of the engine-driven generator 1 is started, and after the rotational speed of the engine 3 reaches the rated rotational speed, the breakers 92 and / or 93 are operated to operate the electrical equipment other than the motor equipment described above. If, for example, power is supplied to the lighting fixture, then the breaker 91 is operated to supply power to the inverter device 2, and the start / stop switch 22 is operated to instruct the inverter device 2 to start output, the inverter device 2 starts output to the motor device via one of the three-phase output terminal blocks 61.

  The inverter device 2 gradually increases the frequency from the start of the output according to the output start command until the predetermined set frequency is reached from the zero frequency according to a preset rule, and responds to this frequency increase. And gradually increase the output voltage.

  As a result, the synchronous speed increases in accordance with the increase in the rotational speed of the motor device, so that an excessive increase in the starting current can be suppressed, and the trip of the inverter device 2, the decrease in the rotational speed of the engine 3, the power generation The output voltage drop of the machine body 4 is prevented.

  Further, although the output to one of the three-phase output terminal blocks 61 to which the motor device is connected is controlled by the inverter device 2, the frequency and voltage output from the other terminal blocks 62 and 63 are as follows. For example, even when a lighting fixture is connected to the single-phase output terminal block 63 as described above, the lighting fixture flickers when the motor device starts up, the brightness decreases, or the lamp is turned off. Such a problem does not occur.

  Furthermore, even if the set frequency output from the three-phase output terminal block 61 connected to the inverter device 2 by the frequency setting means 21 is set lower or higher than the commercial frequency (50 Hz or 60 Hz), the other terminal blocks 62 , 63 are output at a predetermined frequency and voltage set according to the number of revolutions of the engine 3, so that there is no influence on the devices connected to the other output terminal blocks 62, 63.

  Thus, by setting the set frequency variable so that it can be set lower or higher than the commercial frequency (50 Hz or 60 Hz), the engine driven generator according to the present invention can be submerged in the river construction example described above. When used as a power source for a pump, the rotation speed of the submersible pump can be varied according to the amount of water entering the space partitioned by steel sheet piles, etc. Can be prevented.

  In addition, since the starting current of the motor device can be kept low by starting the motor device while gradually increasing the frequency by the inverter device 2 as described above, compared with the conventional engine-driven generator. , Larger motor equipment can be started.

  As an example, the maximum submersible pump that can be driven by a 25 kVA class engine-driven generator is 7.5 kW at the maximum. However, the engine-driven generator 1 of the present invention is of the same 25 kVA class, Up to twice the 15kW submersible pump can be started, the load factor during operation of the engine-driven generator is increased, and the fuel consumption is reduced to improve efficiency.

  In the configuration in which the breaker 91 is provided on the primary side of the inverter device 2, when the output through the inverter device 2 is unnecessary, the power supply to the inverter device 2 is cut off so that the capacitor in the inverter device 2 is The battery can no longer be charged and the life of the expensive inverter device can be extended. Similarly, the terminal blocks 61, 62, and 63 that are not used by the operation of the breakers 91, 92, and 93 are cut off. Accidents (electric shock) due to contact can also be prevented.

  Furthermore, in the present invention, the power factor of the induction motor that drives the motor device is improved by supplying the output via the inverter device 2 as compared with the case where the output of the generator body 4 is supplied to the motor device as it is. The reactive current value flowing through the generator body 4 can be reduced, and heat generation can be reduced.

DESCRIPTION OF SYMBOLS 1 Engine drive type generator 2 Inverter apparatus 21 Frequency setting means 22 Start stop switch (start command means)
3 Engine 4 Generator body 41 Main generator 42 Exciter 43 Automatic voltage regulator (AVR)
5 Output line 51 Three-phase output line 51a Three-phase output line (one branched)
51b Three-phase output line (branched other)
52 Single-phase output line 6 Output terminal block 61 Three-phase output terminal block (one side)
62 Three-phase output terminal block (other side)
63 Single-phase output terminal block 7 Control panel 8 Soundproof box 91, 92, 93 Breaker

Claims (5)

In an engine-driven generator including an engine that is operated at a set constant rotational speed and a generator body that is driven by the engine and outputs a predetermined voltage and a predetermined commercial frequency ,
The exit-Shi a plurality of terminal blocks which can take the generator power generated in the body at the same time,
Wherein the plurality of terminal block, after gradually increasing the frequency from a predetermined low frequency in output start, setting the frequency to reach the set inverter before Symbol generator through so as to maintain the output of the set frequency At least one three-phase output terminal block connected to the main body, and a terminal block that outputs the frequency and voltage output from the generator main body without fluctuation,
An engine-driven generator, comprising start instruction means for instructing the inverter device to start output.   2. The engine-driven generator according to claim 1, further comprising frequency setting means for making the set frequency variable.   The three-phase output line connected to the generator body is branched, and the three-phase output terminal block is connected to one of the branched three-phase output lines via the inverter device. 3. The engine-driven generator according to claim 1, wherein another three-phase output terminal block is connected to the three-phase output line.   The engine-driven generator according to any one of claims 1 to 3, wherein the plurality of terminal blocks include a single-phase output terminal block.   The engine-driven generator according to any one of claims 1 to 4, wherein a breaker for establishing and releasing connection between the inverter device and the generator main body is provided.

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