JP2023166291A - Operation control method for engine-driven power generator and engine-driven power generator - Google Patents

Abstract

[Problem] To start multiple motor devices with different starting times using one engine-driven generator while suppressing the starting current. [Solution] One of the motor devices M1 to M3 (for example, M1) is connected to an inverter device 2, and a starting process is performed in which the frequency is gradually increased while starting, and then the motor device M1 is connected to the inverter device 2. An operation continuation process is performed in which the generator is shut off, connected to the generator main body 4, and the operation is continued by the output from the generator main body 4. Due to the transition to operation continuation processing, inverter device 2 enters a standby state with output stopped, and inverter device 2 is also used when additionally starting another motor device (M2 or M3) during operation continuation processing of motor device M1. The motor can be started while gradually increasing the frequency, and both motor devices can be started while suppressing the starting current. [Selection diagram] Figure 1

Description

The present invention relates to a method of controlling the operation of an engine-driven generator and an engine-driven generator, and more particularly, the present invention relates to a method of controlling the operation of an engine-driven generator in which the output frequency is variable by being equipped with an inverter device, and a method of controlling the operation of the engine-driven generator. The present invention relates to an engine-driven generator for carrying out the method.

An engine-driven generator that includes a generator main body and an engine that drives the generator main body, especially an engine-driven power generator that is packaged for portability by housing the generator main body together with the engine in a soundproof box. These machines are widely used as power sources at construction sites, event venues, and disaster-stricken areas.

An example of electrical equipment driven by the electric power generated by this engine-driven generator is an electrical equipment equipped with a three-phase induction motor, such as a drainage pump (hereinafter, electrical equipment equipped with such a three-phase induction motor is referred to as "motor equipment"). ).

When such motor equipment is directly started (full voltage starting), a starting current that is 3 to 6 times (or more) than the rated current is generated, so for example, a 25 kVA class engine-driven generator is used. In this case, only motor equipment with a maximum capacity of 7.5kW can be directly started.

On the other hand, once the motor equipment is started, the rotational speed of the motor increases and the current decreases to approach the rated current, which is normal operation. Type generators have excessive performance.

As a result, the load factor of the engine-driven generator during normal operation (load capacity/rated output of the engine-driven generator) decreases, and the fuel consumption rate [(fuel consumption amount/load capacity)/time] decreases. As a result, running costs increase when engine-driven generators are used as power sources for motor equipment, and the burden on the environment increases.

Therefore, in order to reduce running costs and reduce environmental impact when used as a power source for motor equipment, it is possible to suppress the starting current and start even larger motor equipment with an engine-driven generator of the same class. It is desired that motor equipment of the same class be started using a lower output engine-driven generator.

For the purpose of suppressing such starting current, Patent Document 1 listed below states that as shown in FIG. An engine-driven generator 100 has been proposed that includes an inverter device 102 configured to gradually increase the frequency from a predetermined low frequency at the time of output start, and then reach a set frequency and maintain the output at the set frequency. (See FIG. 1 and claim 1 of Patent Document 1).

In this way, the inverter device 102 starts the motor while gradually increasing the frequency applied to the motor device (not shown) connected to the three-phase output terminal block 151. (hereinafter referred to as "soft start"), it is possible to suppress the starting current, and as a result, with a conventional engine-driven generator, a 25kVA class engine-driven generator can only handle motor equipment with a maximum capacity of 7.5kW. However, if starting is performed by the above-mentioned soft start using the inverter device 102, it is possible to start the motor equipment with twice the power of 15 kW using the same 25 kVA class engine-driven generator. (paragraph [0058] of Patent Document 1).

Note that the engine-driven generator (see FIG. 7) shown in FIG. 1 of Patent Document 1 mentioned above was equipped with a single inverter device 102, but in Patent Document 2 mentioned below, the engine-driven generator shown in FIG. As shown in 8, in a pump car in which a generator body 104 driven by an engine 103 drives a plurality of pumps (motor equipment) P1, P2...Pn, the number of pumps P1, P2...Pn is A configuration is disclosed in which a corresponding number of inverter devices 102 ₁ , 102 ₂ . . . 102 _n are provided (see FIG. 3 of Patent Document 2).

Japanese Patent Application Publication No. 2012-110098 Japanese Patent Application Publication No. 2014-187753

With engine-driven generators, multiple motor devices with different starting conditions may be connected to one engine-driven generator, and in this case, each motor device starts at a different timing. , a case may occur in which an additional motor device is started while one or more motor devices are operating.

As an example of such usage, FIG. 9 shows three independent water sources (first to third water sources) 161 to 163 and three drainage pumps that operate and stop according to changes in the water level in each water source 161 to 163. (First to third drainage pumps) P1 to P3 are provided, respectively, and an engine-driven generator 100 is used as a common power source for the three drainage pumps P1 to P3.

In the configuration shown in FIG. 9, the first to third drainage pumps P1 to P3 are controlled ON and OFF by the first to third float switches F1 to F3, respectively, so that the water level in the water sources 161 to 163 is maintained at a predetermined level. When the water level reaches the upper limit water level HL, the float switches F1 to F3 are turned on, and the drainage pumps P1 to P3 start to start draining water, while the water in the water sources 161 to 163 progresses and the water level in the water sources 161 to 163 reaches the lower limit water level LL. When the water level decreases to this level, the float switches F1 to F3 are turned OFF, the drain pumps P1 to P3 are stopped, and drainage is completed.

Since the first to third water sources 161 to 163 mentioned above are each independent and the water level changes independently, the first to third drainage pumps P1 to P3 arranged in the first to third water sources 161 to 163 are Each of these will be started under different starting conditions.

Therefore, in the configuration of FIG. 9, the inverter device 102 mounted on the engine-driven generator 100 gradually increases the frequency from a predetermined low frequency at the start of output, reaches the set frequency, and maintains the output at the set frequency. When the inverter device 102 described in the above-mentioned Patent Document 1 configured as above is employed, each drainage pump is started in the following manner according to the starting order.

As an example, as shown in FIG. 9A, when the water levels in the second and third water sources 162 and 163 are at the lower limit position LL and the second and third drainage pumps P2 and P3 are stopped, the first When only the water level in the water source 161 reaches the upper limit water level HL and the first float switch F1 is turned on, the inverter device 102 and the first drain pump P1 are electrically connected, and the inverter device 102 outputs an output to the first drain pump P1. is started.

Therefore, the inverter device 102 gradually increases the frequency from a predetermined low frequency as shown in the waveform diagram in FIG. 9, and then reaches the set frequency and maintains the output at the set frequency. In this case, the first drainage pump P1 that is started first is started by the soft start described above, so that it is possible to start with a suppressed starting current.

However, this inverter device 102 is configured to maintain the output at the set frequency after the output frequency reaches a predetermined set frequency.

Therefore, as shown in FIG. 9(B), after the water level in the first water source 161 once reaches the upper limit water level HL, before it decreases to the lower limit water level LL, the normal operation of the first drainage pump P1 is continued. When the water level in the second water source 162 reaches the upper limit water level HL and the second float switch F2 is turned ON, the second drain pump P2 receives the same frequency as the frequency applied to the first drain pump P1, i.e. , the set frequency is applied.

As a result, the second drainage pump P2 will be started directly (full voltage start), and a large starting current of three to six times the rated current will be generated during starting.

In this way, when power is supplied to multiple motor devices with different operation start conditions via a single inverter device 102, the first motor device to be started can be soft-started, but the second motor device can be soft-started. The starting of the motor equipment that starts after the first start is a direct start (full voltage start), and the starting current cannot be suppressed.

As a result, in order to be able to start the second and subsequent motor devices, it becomes necessary to use an engine-driven generator with an output that is excessively large relative to the rated capacity of the motor device.

The pump truck described in Patent Document 2 mentioned above is equipped with inverter devices 102 ₁ , 102 ₂ ... 102 _n corresponding to the number of pumps P1, P2...Pn, so each inverter By causing the devices 102 ₁ , 102 ₂ . . . 102 _n to output an output that gradually increases the output frequency at the time of output start, similar to the inverter device described in Patent Document 1 mentioned above, any of the pumps P1, P2 . . . Both Pn and Pn can be soft-started, and the starting current can be suppressed.

However, in this configuration, it is necessary to install as many expensive inverter devices 102 ₁ , 102 ₂ . . . 102 _n as there are pumps P 1 , _{P 2 .} Since a high-performance electronic control device is required to enable complex control that individually controls each operation of _the Decrease price competitiveness.

In addition, in the above example, multiple drainage pumps that start and stop depending on changes in the water level in independent water sources are used as an example of multiple motor devices with different operation start conditions. I explained the problem in doing so.

However, the above-mentioned problems are not limited to the example of using an engine-driven generator described with reference to FIG. For example, drainage systems that operate an increasing number of drainage pumps in response to rising water levels in a single water source, ventilation fans that operate in response to increases in room temperature, etc. Air conditioning systems that increase the number of motor-driven compressors (motor equipment), and compressed gas supply systems that increase the number of motor-driven compressors operated in response to the increase in compressed gas consumption on the consumer side. A similar problem can occur in various systems in which "number of machines is controlled".

Therefore, the present invention has been made to eliminate the drawbacks of the above-mentioned prior art, and even when starting multiple motor devices with different starting conditions using one inverter device, it is possible to Operation of an engine-driven generator that is capable of starting motor equipment with the starting current suppressed and, therefore, capable of starting larger motor equipment than conventional engine-driven generators of the same class. It is an object of the present invention to provide a control method and an engine-driven generator that can execute the operation control method.

Means for solving the problem will be described below along with the symbols used in the detailed description. This code is written to clarify the correspondence between the description of the claims and the description of the mode for carrying out the invention, and needless to say, it does not limit the interpretation of the technical scope of the invention. It is not used.

In order to achieve the above object, a method for controlling the operation of an engine-driven generator 1 of the present invention includes:
An engine-driven power generator comprising an engine 3, a generator main body 4 driven by the engine 3, and an inverter device 2 that converts the output of the generator main body 4 into direct current and then converts it into alternating current of an arbitrary frequency and outputs it. In machine 1,
an inverter output circuit 7 that performs output via the one inverter device 2;
A direct output circuit 8 is provided for directly outputting the output from the generator main body 4 without going through the inverter device 2, and
Each of the plurality of motor devices M1 to M3 is arranged so as to be connected to or disconnected from the inverter output circuit 7 and the direct output circuit 8,
One of the motor devices M1 to M3 in a stopped state (for example, the second motor device M2) is set as the motor device to be started, and the motor device to be started (here, the second motor device M2) is connected to the direct output circuit 8. is connected to the inverter output circuit 7 with the connection of a startup process to
After the inverter device 2 starts outputting, when a predetermined condition (for example, a predetermined time has elapsed since the inverter device 2 started outputting, the inverter device 2 outputs a set frequency, etc.), the inverter output circuit 7 and the inverter output circuit 7 and the The connection of the motor device to be started (here, the second motor device M2) is cut off, and the motor device to be started (here, the second motor device M2) is connected to the direct output circuit 8, and the generator main body 4 is connected. Performing operation continuation processing to directly apply an output to continue the operation of the motor device to be started (here, the second motor device M2),
The present invention is characterized in that each time one of the motor devices M1 to M3 is started as the motor device to be started, the starting process and the operation continuation process are executed, respectively (claim 1).

In the operation control method having the above configuration, an operation start condition is set in advance for each of the motor devices M1 to M3, and when the operation start condition for any of the motor devices M1 to M3 is satisfied, the operation start condition is satisfied. The motor device may be configured to be started as the motor device to be started (Claim 2).

In this case, the operation stop conditions are further set in advance for each of the motor devices M1 to M3, and among the motor devices for which the operation continuation process is performed, the motor devices M1 to M3 that satisfy the operation stop conditions and the direct output A configuration may be adopted in which a stop process is performed in which the connection between the circuits 8 is cut off and the motor device is stopped (claim 3).

The motor devices M1 to M3 are drain pumps P1 to P3 installed at the water sources 61 to 63, and the operation start condition is set to the water level of the water sources 61 to 63 reaching a predetermined water level. The filled drain pumps P1 to P3 may be configured to be the motor equipment to be started (claim 4).

Further, the engine-driven generator 1 of the present invention that executes the above operation control method includes:
An engine-driven power generator comprising an engine 3, a generator main body 4 driven by the engine 3, and an inverter device 2 that converts the output of the generator main body 4 into direct current and then converts it into alternating current of an arbitrary frequency and outputs it. In machine 1,
an inverter output circuit 7 that performs output via the one inverter device 2;
In addition to providing a direct output circuit 8 that outputs directly from the generator main body 4 without going through the inverter device 2,
A switching mechanism (starting switches SW1a, SW2a, SW3a; operation continuation switches SW1b, SW2b, SW3b) and
A control device 9 is provided for controlling the operation of the switching mechanism (starting switches SW1a, SW2a, SW3a; operation continuation switches SW1b, SW2b, SW3b) and the inverter device 2,
When operating any of the motor devices M1 to M3 (for example, the second motor device M2) in a stopped state as a motor device to be started, the control device 9:
The switching mechanism (starting switches SW1a, SW2a, SW3a; operation continuation switches SW1b, SW2b, SW3b) is configured to cut off the connection between the motor device to be started (second motor device M2 here) and the direct output circuit 8 (Fig. In example 1, the motor device (second motor device M2 in this case) is connected to the inverter output circuit 7 (in the illustrated example, the second start switch SW2a is turned off), At the same time, the inverter device 2 outputs an output that gradually increases the frequency from a predetermined low frequency (zero frequency as an example) to a predetermined set frequency to connect the motor equipment to be started (here, the second a starting process for starting the motor device M2);
After the inverter device 2 starts outputting, when a predetermined condition (a predetermined time has elapsed since the inverter device 2 started outputting, the inverter device 2 outputs a set frequency, etc.), the switching mechanism (starting switch SW1a, SW2a, SW3a; operation continuation switches SW1b, SW2b, SW3b) to cut off the connection between the inverter output circuit 7 and the motor device to be started (here, the second motor device M2) (in the illustrated example, the second starting switch SW2a is turned off) At the same time, the motor device to be started (second motor device M2 in this case) is connected to the direct output circuit 8 (in the illustrated example, connected by turning on the second operation continuation switch SW2b), and the generator main body is connected. performs an operation continuation process in which the output of No. 4 is directly applied to continue the operation of the motor to be started (here, the second motor device M2);
Each time the control device 9 starts any one of the motor devices M1 to M3 as the motor device to be started, the control device 9 executes the start process and the operation continuation process, respectively (claim 5). ).

In the engine-driven generator 1 having the above configuration,
An operation start condition is set in advance for each of the motor devices M1 to M3, and an operation condition detection device (float switches F1 to F3 in the embodiment) is provided to detect whether or not the set operation start condition is satisfied.
The control device 9
When the operation condition detection device (for example, float switches F1 to F3) detects that the operation start condition set for any of the motor devices M1 to M3 is satisfied, the operation start condition is satisfied. The starting process and the operation continuation process may be performed using a motor device as the starting target motor device (Claim 6).

In this case, operation stop conditions are further set in advance for each of the motor devices M1 to M3, and the operation condition detection devices (F1 to F3 as an example) are used to detect whether or not the set operation stop conditions are satisfied. In addition to configuring it to be possible,
The control device 9
Among the motor devices undergoing the operation continuation process, the connection between the motor device that satisfies the operation stop condition and the direct output circuit 8 is cut off (in the illustrated example, by turning off the operation continuation switches SW1b, SW2b, and Sw3b). (Claim 7).

The inverter device 2 is provided with a switch 23 for starting or stopping the output of the inverter device 2,
The control device 9
The switching mechanism (starting switches SW1a, SW2a, SW3a; operation continuation switches SW1b, SW2b, SW3b) is operated to connect the motor to be started and the inverter output circuit (in the illustrated example, the starting switches SW1a, SW2a, SW3a are connected). When the switch 23 of the inverter device 2 is turned ON to cause the inverter device 2 to start outputting,
After turning off the switch 23 of the inverter device 2, the switching mechanism (start switches SW1a, SW2a, SW3a; operation continuation switches SW1b, SW2b, SW3b) is operated to connect the motor to be started and the inverter output circuit 7. The output of the inverter device 2 may be stopped by shutting off (in the illustrated example, shutting off by turning off the start switches SW1a, SW2a, and SW3a) (claim 8).

Note that the motor equipment M1 to M3 can be drain pumps P1 to P3 installed at the water sources 61 to 63, and in this case, the operating condition detection device is a level sensor (implemented) that detects the water level of the water source. In the example, float switches F1 to F3) are provided, and
When the control device 9 detects that the level sensors (float switches F1 to F3) have reached the predetermined water levels of the water sources 61 to 63, The start process and the operation continuation process may be performed using the drain pumps P1 to P3, which have the water levels of the water sources 61 to 63 as the operation start condition, as the motor equipment to be started (claim 9).

In the operation control method of the present invention described above, the inverter output circuit 7 is connected to the inverter device 2 and performs output via the inverter device 2, and the inverter output circuit 7 is connected to the generator main body 4 without going through the inverter device 2. A direct output circuit 8 that outputs directly from the generator main body 4 is provided, and a motor device to be started is connected to the inverter output circuit 7 with the connection to the direct output circuit 8 cut off, and the inverter By performing a starting process in which the device 2 outputs an output that gradually increases the frequency from a predetermined low frequency (for example, zero frequency) to a predetermined set frequency, the motor equipment to be started can be started by increasing the starting current. We were able to achieve a soft start that could be suppressed.

On the other hand, when a predetermined condition (elapse of a predetermined time from the start of output of the inverter device 2, output of a set frequency by the inverter device 2, etc.) after the output of the inverter device 2 is started, the inverter output circuit 7 and the connection between the motor equipment to be started and the motor equipment to be started is connected to the direct output circuit 8 to directly apply the output of the generator main body 4 to continue the operation of the motor equipment to be started. By shifting to operation continuation processing, power can be directly supplied from the generator main body 4 to the motor equipment that has shifted to operation at or near the rating (normal operation) after startup.

As a result, even if one or more motor devices are already in operation, the inverter device 2 can be used to start a new motor device to be additionally started. All were able to be started using soft start, which suppresses the starting current.

As a result, the engine-driven generator that implements the operation control method of the present invention was able to start larger motor equipment than conventional engine-driven generators of the same class.

Operation start conditions are set in advance for each of the motor devices M1 to M3, and when the operation start conditions for any of the motor devices are met, the motor device that satisfies the operation start conditions is started as the motor device to be started. and a configuration in which operation stop conditions are set in advance for each of the motor devices M1 to M3, and among the motor devices for which the operation continuation processing is performed, the motor devices M1 to M3 that satisfy the operation stop conditions and the direct In a configuration in which the connection between the output circuits is cut off and the motor equipment is stopped, automatic control is performed to sequentially operate the motor equipment drain pumps P1 to P3 in response to changes in the water levels of the water sources 61 to 63, for example. The engine-driven generator of the present invention could be suitably used in, etc.

Similarly, for example, an air conditioning system that increases or decreases the number of fans (motor equipment) that operate in response to changes in room temperature, or a compressed gas supply that increases or decreases the number of motor-driven compressors that operate in response to changes in compressed gas consumption. The present invention can be used as a power source in various systems in which a new motor device is additionally started while one or more motor devices are in operation, such as various systems in which so-called "number control" is performed. An engine-driven generator can be suitably used.

FIG. 1 is a schematic explanatory diagram of an engine-driven generator of the present invention. FIG. 2 is an explanatory diagram showing an example in which the engine-driven generator of the present invention is used as a common power source for a plurality of drainage pumps (with all drainage pumps stopped). An explanatory diagram showing an example of using the engine-driven generator of the present invention as a common power source for a plurality of drainage pumps (in a state where the first drainage pump P1 is being started). FIG. 2 is an explanatory diagram showing an example in which the engine-driven generator of the present invention is used as a common power source for a plurality of drainage pumps (a state in which the first drainage pump P1 is transitioned from startup processing to continuous operation processing). An explanatory diagram showing an example in which the engine-driven generator of the present invention is used as a common power source for a plurality of drainage pumps (while the first drainage pump P1 continues to operate, the second drainage pump P2 is started) processing has started). An explanatory diagram showing an example in which the engine-driven generator of the present invention is used as a common power source for a plurality of drainage pumps (a state in which the second drainage pump P2 is transitioned from startup processing to continuous operation processing). FIG. 1 is an explanatory diagram of a conventional engine-driven generator including an inverter device (corresponding to FIG. 1 of Patent Document 1). An explanatory diagram of a conventional engine-driven generator equipped with an inverter device (corresponding to FIG. 3 of Patent Document 2). It is an explanatory diagram assuming a case where a plurality of motor devices with different starting conditions are connected to a single inverter device, where (A) is when the first drainage pump P1 is started, and (B) is when the second drainage pump is started. Time.

An example of the configuration of an engine-driven generator for carrying out the operation control method of the present invention will be described below with reference to the accompanying drawings.

Reference numeral 1 in FIG. 1 is an engine-driven generator of the present invention, and this engine-driven generator 1 includes an engine 3, a generator main body 4 driven by the engine 3, and an output to the generator main body 4. An inverter device 2 connected via a line 5, an inverter output circuit 7 connected to the inverter device for taking out the output via the inverter device 2, and an inverter device 2 connected to the generator main body 4. It has a direct output circuit 8 for directly extracting the output from the generator main body 4 without going through the It is equipped with a switching mechanism (start switches SW1a, SW2a, SW3a, and operation continuation switches SW1b, SW2b, SW3b) that perform communication and cutoff.

The aforementioned generator main body 4, which is one of the main components of the engine-driven generator 1, can be of various known types, and in this embodiment, as an example, is equipped with an exciter 42. A self-excited three-phase alternating current generator (three-phase 200V) is used as the generator main body 4.

In the generator main body 4 equipped with such an exciter 42, an automatic voltage regulator (AVR) 43 adjusts the exciter according to increases and decreases in the output voltage so that the voltage output from the main generator 41 becomes the set value. The excitation current supplied to 42 is controlled.

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

The inverter device 2 described above includes a converter section 21 that converts alternating current from the generator main body 4 into direct current, an inverter section 22 that converts the direct current obtained by the converter section 21 into alternating current of an arbitrary frequency, and an output of the inverter device 2. It is equipped with a switch 23 for starting or stopping the alternating current of an arbitrary frequency set by a frequency setting means (not shown) consisting of a dial switch etc. provided on an operation panel etc., for example, by a known PWM (Pulse Width Modulation) method etc. It is configured to be able to generate an output, and the output voltage is adjusted as the frequency increases or decreases so that when the output frequency is relatively low, the output voltage is low and when the output frequency is relatively high, the output voltage is high. is also set to change.

The operation of this inverter device 2 is controlled by an inverter control section 91 of a control device 9 composed of an electronic control device, etc., and upon receiving an output start command from the control device 9, a predetermined low frequency is set at the time of starting output. It is configured to output an output that gradually increases the frequency from (for example, zero frequency) to a predetermined set frequency, and is configured to maintain output at a constant frequency until the set frequency is reached as necessary. .

The aforementioned set frequency may be adjustable by operating a frequency setting means (not shown) provided on an operation panel (not shown), etc., and preferably matches the output frequency of the generator main body 4. let In this embodiment, in order to enable such setting of the output frequency, for example, the set frequency is set to be variable within a predetermined range while the rotational speed of the engine is kept constant.

The inverter output circuit 7 is connected to the inverter device 2 configured as described above, and the first to third motor devices M1 to M3 are connected to each of the branch paths 71 to 73 provided in the inverter output circuit 7. are configured to be connectable via a switching mechanism (starting switches SW1a, SW2a, SW3a provided in the switching mechanism) to be described later.

Furthermore, a direct output circuit 8 is connected to the aforementioned output line 5 that connects the aforementioned generator body 4 and the inverter device 2 to directly take out the output of the generator body 4 without going through the inverter device 2. , motor devices M1 to M3 are connected to each of branch paths 81 to 83 provided in this direct output circuit 8 via a switching mechanism (operation continuation switches SW1b, SW2b, SW3b provided in the switching mechanism), which will be described later. configured to be possible.

The connection and disconnection between each motor device M1 to M3 and the branch paths 71 to 73 provided in the inverter output circuit 7, and the connection and disconnection between the branch paths 81 to 83 provided in the direct output circuit 8 are as described above. This is done by a switching mechanism.

This switching mechanism includes a first start switch SW1a that connects or disconnects the first motor device M1 to the first branch path 71 of the inverter output circuit 7, and a first start switch SW1a that connects or disconnects the first motor device M1 to the first branch path 81 of the output circuit 8. A first operation continuation switch SW1b connects or disconnects the second motor device M2 to or disconnects the second branch 72 of the inverter output circuit 7, a second start switch SW2a connects or disconnects the second motor device M2 to the second branch 72 of the inverter output circuit 7, and directly outputs the second motor device M2. A second operation continuation switch SW2b connects or disconnects the second branch 82 of the circuit 8, and a third start switch SW3a connects or disconnects the third motor device M3 to the third branch 73 of the inverter output circuit 7. and a third operation continuation switch SW3b that connects or disconnects the third motor device M3 to the third branch path 83 of the direct output circuit 8.

These switches (SW1a, SW2a, SW3a, SW1b, SW2b, SW3b) are configured to be able to operate independently, so that each motor device M1 to M3 can be started by connecting them to the inverter output circuit 7. processing, operation continuation processing performed by connecting directly to the output circuit 8, and stop processing in which the motor devices M1 to M3 are stopped without being connected to either the inverter output circuit 7 or the direct output circuit 8. It is composed of

Each switch (SW1a, SW2a, SW3a, SW1b, SW2b, SW3b) provided in the switching mechanism may be manually operated by an operator, but preferably these switches (SW1a, SW2a, SW3a, SW1b, SW2b, The SW 3b) may be configured to include a conductor (electromagnetic switch) so as to be automatically controlled by an electric signal from the switching control section 92 of the control device 9.

Note that although the example in FIG. 1 shows a configuration example in which the inverter control section 91 and the switching control section 92 are realized by a common control device 9, the inverter control section 91 and the switching control section 92 are implemented by separate control devices. It may also be realized by

In this way, when the switching control unit 92 of the control device 9 controls the operation of each switch (SW1a, SW2a, SW3a, SW1b, SW2b, SW3b), each of the three motor devices M1 to M3 described above starts operating. In addition to setting the conditions and operation stop conditions in advance, the conditions for switching between start control and operation continuation control are also set in advance, and furthermore, the operation that detects whether the operation start conditions and operation stop conditions are satisfied. A condition detection device (float switches F1 to F3 in the embodiment) is provided, and the switching control unit 92 of the control device 9 detects each switch (SW1a, SW2a, SW3a, SW1b, SW2b, SW3b) based on the condition detected by the operating condition detection device. ) may be configured to be able to automatically control opening and closing.

As a result, when the operating condition detection device (float switches F1 to F3 in the embodiment) detects that the operation start condition of any motor device (for example, the first motor device M1) is satisfied, the control device 9 A predetermined starting process is executed with the device (here, the first motor device M1) as the motor device to be started.

In this starting process, the switching control unit 92 of the control device 9 turns on the starting switch (here, the first starting switch SW1a) corresponding to the starting motor equipment (here, the first motor equipment M1), thereby turning on the starting switch (here, the first starting switch SW1a) to Here, the first motor device M1) is connected to the inverter output circuit 7, and the inverter control unit 91 of the control device 9 gradually increases the frequency from a predetermined low frequency (for example, zero frequency) to a predetermined set frequency. This is done by producing an output that increases the

Then, a predetermined signal indicating that the starting of the motor device to be started (here, the first motor device M1) is completed, such as the elapse of a predetermined time after the start of output from the inverter device 2 or the output of a set frequency by the inverter device 2, is detected. When the switching conditions are satisfied, the inverter control section 91 of the control device 9 stops the output of the inverter device 2, and the switching control section 92 turns off the corresponding starting switch (here, the first starting switch SW1a), and further, Turn on the corresponding operation continuation switch (first operation continuation switch SW1b here) and perform operation continuation processing by directly inputting the output of the generator main body 4 to the motor device to be started (here first motor device M1). Start.

After that, when the operating condition detection device (here, the first float switch F1) detects that the operation stop condition of the motor device (here, the first motor device M1) that is in the process of continuing operation is satisfied, the inverter of the control device 9 The control unit 91 turns off the switch 23 of the inverter device 2 to stop the output of the inverter device 2, and the switching control unit 92 of the control device 9 turns off the corresponding operation continuation switch (here, the first operation continuation switch SW1b). Then, a stop process is performed to stop the corresponding motor device (here, the first motor device M1).

In the engine-driven generator 1 of the present invention, each time the control device 9 starts one of the motor devices M1 to M3 as a motor device to be started, the above-mentioned starting process and operation continuation process are executed. Both devices M1 to M3 can be started using a soft start with the starting current suppressed.

The manner in which each motor device is started by soft start in this manner will be explained in detail with further reference to FIGS. 2 to 6.

In the configuration example shown in FIGS. 2 to 6, the motor equipment M1 to In this example, the condition for starting operation of the first drainage pump P1 is that the water level in the first water source 61 is equal to or higher than the predetermined upper limit water level HL, and the water level in the second water source 62 is equal to or higher than the predetermined upper limit water level HL. It is set as a condition for starting operation of the second drain pump P2, and a condition for starting operation of the third drain pump P3 is that the water level in the third water source 63 becomes equal to or higher than a predetermined upper limit water level HL.

Then, when the operation start conditions set for any of the drainage pumps P1 to P3 are satisfied, the output from the inverter device 2 is applied to the drainage pump that has satisfied the operation start conditions as the motor device to be started. When a predetermined period of time has elapsed since the start of the output of the inverter device 2, the connection between the motor equipment to be started and the inverter device is cut off, and the output of the generator main body 4 is started. It is configured to execute continuous operation processing, which continues operation by directly applying voltage to the target motor device.

In addition, in the examples shown in Figures 2 to 6, the drainage pumps P1 to P3 that have been started and are undergoing the above-mentioned continuous operation process must satisfy the operation stop conditions set for each of the drainage pumps P1 to P3. In this embodiment, when the water level in the first water source 61 is below the predetermined lower limit water level LL, the operation stop condition for the first drainage pump P1 is determined as the condition for stopping the operation of the first drainage pump P1. The condition for stopping the operation of the second drain pump P2 is that the water level has become below the predetermined lower limit water level LL, and the operation stop condition for the third drain pump P3 is that the water level in the third water source 63 has become below the predetermined lower limit water level LL. Each was set as a condition.

Level sensors that detect the water levels in the first to third water tanks 61 to 63, in the illustrated example, first to third float switches F1 to F3 are used as operating condition detection devices in the first to third water sources 61 to 63. When the first to third float switches F1 to F3 detect that the water level in the first to third water sources 61 to 63 has exceeded the predetermined upper limit water level HL, the control that received this detection signal The device 9 operates the switching mechanism and the inverter device to start the corresponding drainage pump, and also indicates that the water level in the first to third water sources 61 to 63 has become below the predetermined lower limit water level LL. When the float switches F1 to F3 are detected, the control device 9 that receives this detection signal controls the switching mechanism and the inverter device 2 to stop the corresponding drainage pump.

In the engine-driven generator 1 having the above configuration shown in FIGS. 2 to 6, as an example, the water level of the first water source 61 and the second water source 62 rises in order and reaches the upper limit water level HL, so that the first Taking as an example the case where the drainage pump P1 is started and then the second drainage pump P2 is added and started while the first drainage pump P1 continues to operate, the steps from the start to the continued operation of each drainage pump P1 and P2 are as follows. The process will be explained as follows.

As shown in FIG. 2, the water levels in the first to third water sources 61 to 63 are all below the upper limit water level HL (in the illustrated example, the lower limit water level LL), and the water levels in the first to third water sources 61 to 63 are lower than the upper limit water level HL (lower limit water level LL in the illustrated example), and When everything is stopped, the switch 23 of the inverter device 2 is OFF and no output is produced from the inverter device 2, and the first to third start switches SW1a and SW2a that constitute the switching mechanism are turned off. , SW3a and the first to third operation continuation switches SW1b, SW2b, and SW3b are all OFF, and the first to third drainage pumps P1 to P3 are cut off from both the inverter output circuit 7 and the direct output circuit 8. is in a state of being

When the water level of the first water source 61 rises from the above-mentioned state shown in FIG. 2 to reach the upper limit water level HL as shown in FIG. outputs a detection signal.

The switching control unit 92 of the control device 9, which has received the detection signal of the first float switch F1, turns on the first start switch SW1a and connects the first drainage pump P1 to the first branch path 71 of the inverter output circuit 7. , the inverter control unit 91 of the control device 9 turns on the switch 23 of the inverter device 2, and outputs an output to the inverter device 2 that gradually increases the frequency from a predetermined low frequency to a predetermined set frequency and maintains the set frequency constant. Executes startup processing.

As a result, the first drainage pump P1 is soft-started with the starting current suppressed.

The inverter control unit 91 of the control device 9 determines that the first drainage pump P1 has entered a stable operating state when the timer counts that a predetermined time has elapsed since the inverter device 2 started outputting. As shown in FIG. 4, by turning off the switch 23 of the inverter device 2 and stopping the output of the inverter device 2, the inverter device 2 is placed in a standby state until the other drain pumps P2 and P3 that are stopped are started. shall be.

With the output of the inverter device 2 stopped in this manner, the switching control unit 92 of the control device 9 turns off the first start switch SW1a and turns on the first operation continuation switch SW1b to control the first drainage pump. P1 is directly connected to the first branch path 81 of the output circuit 8, and an operation continuation process is executed in which the output of the generator main body 4 is directly applied to the first drainage pump P1 to continue the operation.

Note that in this embodiment, the switching from the above-mentioned startup process to the operation continuation process is performed on the condition that a predetermined time has elapsed since the inverter device 2 started outputting, but for example, if the inverter device 2 The start process may be switched to the continuation process when the output frequency of the pump P1 increases to the set frequency, or when a predetermined period of time has elapsed since the output frequency has increased to the set frequency, and when the start of the first drainage pump P1 is completed, Various configuration changes are possible as long as the switching is preferably carried out after the start has been completed and when normal operation has entered a stable state.

When the first drainage pump P1 is in the state of continuous operation in this way, if the water level in the second water source 62 rises to exceed the predetermined upper limit water level HL as shown in FIG. The second float switch F2 detects the rise in the water level and outputs a detection signal to the control device 9.

The switching control unit 92 of the control device 9, which has received the detection signal from the second float switch F2, turns on the second start switch SW2a and connects the second drainage pump P2 to the second branch path 72 of the inverter output circuit 7. At the same time, the inverter control unit 91 of the control device 9 turns on the switch 23 of the inverter device 2, causing the inverter device 2 to gradually increase the frequency from a predetermined low frequency to a predetermined set frequency, and maintain the frequency constant at the set frequency. Executes startup processing that causes output to be output.

As a result, the second drainage pump P2 can be started by soft start with suppressed starting current.

After the second drainage pump P2 is started and a predetermined period of time has elapsed since the inverter device 2 started outputting, the inverter control unit 91 of the control device 9 turns off the switch 23 of the inverter device 2, as shown in FIG. After the output of the inverter device 2 is stopped, the switching control section 92 of the control device 9 turns off the second start switch SW2a and turns off the second operation continuation switch SW2b. Turn on the second drainage pump P2, directly connect it to the second branch 82 of the output circuit 8, and directly apply the output of the generator main body 4 to the second drainage pump P2 to continue operation. The points to be executed are the same as the processing for the first drainage pump P1.

The above-mentioned startup processing and operation continuation processing are performed in the same way when starting the third drainage pump P3, and as a result, all of the first to third drainage pumps P1 to P3 use software that suppresses the starting current. It can be started at the start.

Although illustration is omitted, by continuing to operate the first drainage pump and the second drainage pump as described above, drainage in each of the water sources 61 and 62 progresses, and the water level of the first water source 61 increases. When the water level drops below a predetermined lower limit LL, the switching control unit 92 of the control device 9, which has received the detection signal from the first float switch that detected this, turns off the first operation continuation switch SW1b and turns off the first drain pump P1. A stop process is performed in which communication between the first branch paths 81 of the direct output circuit 8 is cut off and the first drainage pump P1 is stopped.

Additionally, when the water level in the second water source 62 progresses and the water level in the second water source 62 lags behind the first water source 61 and falls below the predetermined lower limit water level LL, a detection signal from the second float switch F2 that detects this is received. The switching control unit 92 of the control device 9 turns off the second operation continuation switch SW2b, cuts off the communication between the second drainage pump P2 and the second branch path 82 of the direct output circuit 8, and restarts the second drainage pump P2. Perform the stop processing to stop the .

Then, when the water level of any one of the first to third water sources 61 to 63 rises again to the predetermined upper limit water level HL or higher, the above-described process is repeated.

As described above, in the operation control method of the present invention, the output of the inverter device 2 is applied to each of the drainage pumps P1 to P3 only when starting the drainage pumps P1 to P3 to be started, and When the starting of the pumps P1 to P3 is completed, a transition is made to an operation continuation process in which the operation of the motor equipment is continued by directly applying the output of the generator main body 4.

As a result, when one inverter device 2 starts multiple drainage pumps (motor equipment) with different operation start conditions and, therefore, different start timings, the operation of one or more drainage pumps (motor equipment) may be delayed. Even when starting a new drainage pump (motor equipment), the soft start enabled it to be started while suppressing the starting current.

In this way, since a soft start is possible with all drainage pumps (motor equipment) suppressing the starting current, an engine-driven generator that implements the operation control method of the present invention can be used with a conventional engine-driven generator of the same class. It is possible to start a drainage pump (motor equipment) that consumes more power than a type generator.

Table 2 below shows the case (example) in which the engine-driven generator and motor equipment with the performance shown in Table 1 below are used to start the motor equipment using the operation control method of the present invention. This figure shows the results of a comparison of how the number of motor devices that can be started differs between cases where starting is performed using the conventional method (Comparative Examples 1 and 2).

Furthermore, as shown in Table 1, when only the inverter is connected to the generator main body, the output upper limit of the inverter is 37kW, but in the method of the present invention, the power is generated directly through the output circuit 8 in the continuous operation process. A load with a rating of 11 kW or 22 kW will be connected to the machine body in parallel with the inverter, and the output upper limits of the inverter in this case will be 29 kW and 18 kW, respectively.

In addition, Comparative Example 1 assumes that three motor devices are started by directly inputting the output (50 Hz, 200 V) from the generator itself without going through an inverter. After starting the first motor equipment directly (full voltage start), start the second motor equipment directly (full voltage start) while the first motor equipment is running normally without stopping, and then , it is assumed that the third motor device is directly started (full voltage start) while the first and second motor devices are operated normally without stopping.

In addition, in Comparative Example 2, all three motor devices are started by output from an inverter device, and the output frequency of the first motor device is gradually increased from a predetermined low frequency to a set frequency. After starting with soft start, the inverter outputs output to the second motor while the first motor continues to operate normally without stopping. Directly start (full voltage start) by applying the frequency and set voltage (50Hz, 200V) as they are, and connect the inverter to the third motor while the first and second motors are operating normally. This assumes that the output set frequency and set voltage (50 Hz, 200 V) are directly applied to cause a direct start (full voltage start).

As shown in Table 2, when motor equipment is started using the methods of Comparative Example 1 and Comparative Example 2, the second and subsequent motor equipment must be started no matter which method is used. However, when starting the motor devices using the operation control method of the present invention, all three motor devices could be started.

1 Engine-driven generator 2 Inverter device 21 Converter section 22 Inverter section 23 Switch 3 Engine 4 Generator body 41 Main generator 42 Exciter 43 Automatic voltage regulator (AVR)
5 Output lines 61 to 63 1st to 3rd water sources 7 Inverter output circuits 71 to 73 (1st to 3rd) branch paths 8 Direct output circuits 81 to 83 (1st to 3rd) branch paths 9 Control device 91 Inverter control Section 92 Switching control section 100 Engine-driven generator 102, 102 ₁ , 102 ₂ , 102 _n Inverter device 103 Engine 104 Generator main body 151 Three-phase output terminal block 161 to 163 First to third water sources SW1a, SW2a, SW3a ( 1st to 3rd) starting switch SW1b, SW2b, SW3b (1st to 3rd) operation continuation switch P1 to P3, Pn (drainage) pump F1 to F3 Operating condition detection device (1st to 3rd float switch)
M1 to M3 Motor equipment HL Upper limit water level LL Lower limit water level

Claims (9)

An engine-driven generator that includes an engine, a generator main body driven by the engine, and an inverter device that converts the output of the generator main body into direct current and then converts it into alternating current of an arbitrary frequency and outputs it,
an inverter output circuit that performs output via one of the inverter devices;
A direct output circuit is provided for directly outputting the output from the generator main body without going through the inverter device, and
Each of the plurality of motor devices is arranged so as to be able to be connected to or disconnected from the inverter output circuit and the direct output circuit,
One of the motor devices in a stopped state is set as a motor device to be started, and the motor device to be started is connected to the inverter output circuit with the connection to the direct output circuit cut off, and the motor device is connected to the inverter device in a predetermined manner. A starting process in which the engine is started by outputting an output that gradually increases the frequency from the low frequency to a predetermined set frequency;
After the output of the inverter device starts, when a predetermined condition is met, the connection between the inverter output circuit and the motor device to be started is cut off, and the motor device to be started is connected to the direct output circuit to start the power generation. Performs operation continuation processing that continues the operation of the motor equipment to be started by directly applying the output of the machine main body,
An operation control method for an engine-driven generator, characterized in that each time any one of the motor devices is started as the motor device to be started, the start process and the operation continuation process are respectively executed. Operation start conditions are set in advance for each of the motor devices, and when the operation start conditions for any of the motor devices are met, the motor device that satisfies the operation start conditions is started as the motor device to be started. The method for controlling the operation of an engine-driven generator according to claim 1. Operation stop conditions are set in advance for each motor device, and among the motor devices for which the operation continuation processing is being performed, the connection between the motor device that satisfies the operation stop condition and the direct output circuit is cut off, and the 3. The method for controlling the operation of an engine-driven generator according to claim 2, further comprising performing a stop process to stop a motor device. The motor equipment is a drainage pump installed at a water source, and the operation start condition is that the water level of the water source reaches a predetermined water level, and the drainage pump that satisfies the operation start condition is set as the motor equipment to be started. The method for controlling the operation of an engine-driven generator according to claim 2 or 3, characterized in that: An engine-driven generator that includes an engine, a generator main body driven by the engine, and an inverter device that converts the output of the generator main body into direct current and then converts it into alternating current of an arbitrary frequency and outputs it,
an inverter output circuit that performs output via one of the inverter devices;
Providing a direct output circuit that outputs directly from the generator main body without going through the inverter device,
a switching mechanism that connects and disconnects each of the plurality of motor devices, the inverter output circuit, and the direct output circuit;
a control device for controlling operations of the switching mechanism and the inverter device;
When operating one of the motor devices in a stopped state as a motor device to be started, the control device:
The switching mechanism is configured to connect the motor device to the inverter output circuit while cutting off the connection between the motor device to be started and the direct output circuit, and to set the inverter device at a predetermined low frequency to a predetermined setting. a starting process of starting the target motor device by outputting an output that gradually increases the frequency up to the starting frequency;
After the inverter device starts outputting, when a predetermined condition is satisfied, the switching mechanism disconnects the inverter output circuit from the motor device to be started, and connects the motor device to be started to the direct output circuit. and performs an operation continuation process in which the output of the generator main body is directly applied to continue operation of the motor to be started,
An engine-driven generator characterized in that the control device executes the starting process and the operation continuation process each time one of the motor devices is started as the motor device to be started. An operating condition detection device is provided for setting operation start conditions for each motor device in advance and detecting whether or not the set operation start conditions are satisfied.
The control device includes:
When the operating condition detection device detects that the operation start condition set for any of the motor devices is satisfied, the motor device that satisfies the operation start condition is set as the motor device to be started and the motor device is started. The engine-driven generator according to claim 5, wherein the engine-driven generator performs the processing and the operation continuation processing. Setting operation stop conditions for each motor device in advance, and configuring the operation condition detection device to be able to detect whether or not the set operation stop conditions are satisfied,
The control device includes:
Among the motor devices undergoing the operation continuation process, the connection between the motor device that satisfies the operation stop condition and the direct output circuit is cut off, and a stop process is performed to stop the motor device. The engine-driven generator according to claim 6. The inverter device is provided with a switch for starting or stopping the output of the inverter device,
The control device includes:
When the switching mechanism is operated to connect the motor to be started and the inverter output circuit, the switch of the inverter device is turned on to cause the inverter device to start outputting;
After turning off the switch of the inverter device, the switching mechanism is operated to cut off the motor to be started and the inverter output circuit, thereby stopping the output of the inverter device. 7. The engine-driven generator according to any one of item 7. The motor device is a drainage pump installed at a water source,
A level sensor for detecting the water level of the water source is provided as the operating condition detection device, and
When the level sensor detects that the water level of the water source has reached a predetermined water level, the control device sets the drainage pump to be started, with the water level of the water source detected by the level sensor as the operation start condition. The engine-driven generator according to claim 6 or 7, wherein the engine-driven generator performs the starting process and the operation continuation process as a motor device.

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