JP5274787B2 - Crane equipment - Google Patents

Abstract

A controller (7) outputs an operational instruction (10A), which represents a new engine speed, to an engine generator (1) based on power supply conditions from the engine generator (1) to a common bus (9) or on operating conditions of a crane device. As a result, the engine speed is regulated in response to a variation in the load side devices such as electric motors (30-33). This significantly reduces operational costs of the crane device.

Description

  The present invention relates to a crane apparatus, and more particularly to an engine-driven power generation type crane apparatus that generates power by driving an engine.

  In a yard such as a harbor, a crane apparatus that loads and unloads a cargo such as a container with respect to a ship or a trailer uses a plurality of electric motors to perform operations such as raising and lowering the cargo, and further running and traversing a gantry. Further, in order to supply operating electric power to these electric motors, the engine-driven electric power generation system is configured to supply necessary electric power to each electric motor using an engine power generator that drives the electric generator using a diesel engine.

  In such a crane apparatus, the load is maximum when the load is lifted or the like, but there is a case where almost no electric power is required when the load is suspended and the load fluctuation is large. Therefore, a large-scale diesel engine or generator is required to supply the appropriate power from the generator at the maximum load, but the equipment scale exceeds the average load, so in terms of equipment costs and operating costs. It was inefficient.

  Conventionally, such a crane device is provided with a power storage device, and the engine power generator always generates power, and power is supplied in parallel from the power storage device at the time of maximum load, and surplus power generated during regeneration is supplied to the power storage device. What is charged has been proposed (see, for example, Patent Document 1). Thereby, since electric power is temporarily supplied from the power storage device to the electric motor, the scale of the diesel engine and the generator can be reduced, and the efficiency can be improved in terms of equipment cost and operation cost.

JP 2001-163574 A

  However, in such a conventional technology, since the power storage device itself is relatively expensive, a relatively large amount of power cannot be supplied from the power storage device over a long period until the crane operation ends. Most of the power needs to be supplied. Therefore, even when the load is reduced, it is necessary to operate the diesel engine of the engine power generator at a constant rotation, and there has been a problem that a significant reduction in operating cost cannot be realized.

  The present invention is intended to solve such problems, and an object thereof is to provide a crane apparatus that can realize a significant reduction in operating cost.

In order to achieve such an object, the crane apparatus according to the present invention supplies electric power generated by engine driving to a common bus, thereby driving an electric motor connected to the common bus via an inverter. A crane device that loads and unloads an engine power generator that outputs AC power generated by driving a generator with an engine, and converts AC power from the engine power generator into DC power that is output to the common bus side. An inverter and a controller that calculates a new engine rotation speed of the engine power generation device based on the power supply status from the engine power generation device to the common bus or the operation status of the crane device and instructs the engine power generation device , If the DC voltage of the common bus is lower than the lower threshold, increase the engine speed and If pressure is higher than the upper threshold value is obtained so as to reduce the engine speed.

  At this time, an engine power generator that generates AC power by driving an AC motor with the engine is provided as an engine power generator, and the inverter generates regenerative power output from the motor to the common bus to AC power to generate engine power. You may make it drive an alternating current motor by outputting to an apparatus.

  In addition, the battery may further include a power storage device that has a storage battery such as a battery or a capacitor, and charges and discharges the common bus with the storage battery according to the power supply status from the engine power generation device to the common bus.

  In addition, when the battery has a storage battery such as a battery or a capacitor, and the DC voltage of the common bus drops below a predetermined discharge threshold, the DC power stored in the storage battery is supplied to the common bus, and the DC of the common bus You may further provide the electrical storage apparatus which charges direct-current power to a storage battery from a common bus line when a voltage rises more than a predetermined charging threshold value.

  According to the present invention, there is provided an engine power generator that outputs AC power generated by driving a generator with an engine, and an inverter that converts AC power from the engine power generator into DC power and outputs it to the common bus side. The controller calculates the new engine rotation speed of the engine power generator based on the power supply status from the engine power generator to the common bus or the operation status of the crane device, and instructs the engine power generator. The engine rotation speed is adjusted according to the fluctuation on the load side. For this reason, the operating cost can be greatly reduced, and the environmental impact can be greatly reduced.

Next, embodiments of the present invention will be described with reference to the drawings.
[First Embodiment]
First, a crane apparatus according to a first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a functional block diagram showing the configuration of the crane apparatus according to the first embodiment of the present invention.
This crane device 1 is a device that drives electric motors connected to a common bus by supplying electric power generated by engine driving to the common bus, and loads and unloads luggage. 1, an inverter (INV) 13, a main winding motor 30, traveling motors 31 and 32, a traverse motor 33, inverters (INV) 41 to 44, a discharge device 5, a power storage device 6, a controller 7, and a common bus 9 are provided. Yes.

  The present embodiment includes an engine power generation device 1 that outputs AC power generated by driving a generator with an engine, an inverter 13 that converts AC power from the engine power generation device into DC power, and outputs the DC power to the common bus side. The controller 7 calculates a new engine rotation speed of the engine based on the power supply status or the operation status from the engine power generation device 1 for the common bus 9 and instructs the engine power generation device 1.

Hereinafter, the structure of the crane apparatus concerning this Embodiment is demonstrated in detail.
The engine power generator 1 has a diesel engine (DE) 11 and a generator (G) 12, and is a device that generates and outputs AC power by driving the generator 12 with the diesel engine 11. The engine 7 has a function of controlling the engine speed of the diesel engine 11 on the basis of an operation instruction 10A from the controller 7.
The inverter 13 is a power conversion device that is connected between the engine power generator 1 and the common bus 9, converts AC power from the engine power generator 1 into DC power, and outputs the DC power to the common bus 9.

The main winding motor 30 is an AC motor for raising and lowering a load. The traveling motors 31 and 42 are AC motors for traveling the gantry. The traverse motor 33 is an AC motor for traversing the gantry.
Inverter 41 is a DC / AC converter that converts DC power on common bus 9 into AC power and supplies it to main winding motor 30 and traveling motor 31.
The inverter 42 is a DC / AC converter that converts DC power on the common bus 9 into AC power and supplies the AC power to the main winding motor 30 and the traveling motor 32.
The inverter 43 is a DC / AC converter that converts DC power on the common bus 9 into AC power and supplies the AC power to the traverse motor 33.

The inverter 44 is a DC / AC converter that converts the DC power on the common bus 9 into AC power and supplies it as a power source for lighting, air conditioning, and various auxiliary machines.
The discharge device 5 is a circuit device that discharges surplus DC power generated on the common bus 9 at the time of regeneration such as when a load is suspended using a resistor or the like.
The power storage device 6 is a circuit device incorporating a storage battery such as a battery or a capacitor, and has a function of charging / discharging the common bus 9 with the storage battery according to the power supply status from the engine power generator 1 to the common bus 9. doing.

  The controller 7 has a microprocessor such as a CPU and its peripheral circuits, and reads and executes the program from a memory provided in the microprocessor or the peripheral circuit, thereby causing the program and the hardware to cooperate with each other. It has various functions for controlling the entire apparatus.

  The main function of the controller 7 is to control the inverters 41 to 44 on the basis of an operator command input 71 detected through an operation lever or an operation switch, and to perform operations such as lifting / lowering of luggage, running of a gantry and traversing Crane operation function for controlling the power supply, power supply status confirmation function for confirming the power supply status from the engine generator 1 to the common bus 9 and the operation status of the crane device itself, and the input load and command speed, or the confirmed power supply There is a rotation speed control function that calculates a new engine rotation speed based on the situation and instructs the engine power generation device 1 by the operation instruction 10A.

The power supply status from the engine power generator 1 to the common bus 9 can be grasped by monitoring the DC voltage of the common bus 9, for example. In the case of lifting a load based on the command input 71, traveling the frame, or traversing, the DC voltage on the common bus 9 is reduced when the corresponding electric motors 30 to 33 are driven, so that the DC voltage decreases.
Therefore, the power supply status confirmation function detects the DC voltage of the common bus 9 and reads and compares the lower threshold and upper threshold stored in advance in memory, so that the power supply status is excessive or insufficient. Can be confirmed.

[Operation of First Embodiment]
Next, with reference to FIG. 2 and FIG. 3, the engine rotational speed control in the controller 7 will be described in detail as the operation of the crane device according to the first embodiment of the present invention. FIG. 2 is a flowchart showing an engine speed control process of the crane device according to the first embodiment of the present invention. FIG. 3 is an operational characteristic showing the relationship between the power generated by the engine power generator and the engine speed.

The controller 7 starts the engine rotation speed control process of FIG. 2 in response to the detection of the operation start operation by the operator.
First, the controller 7 checks the presence / absence of the command input 71 from the operator using the engine speed control function (step 100). If there is a command input 71 (step 100: YES), the controller 7 inputs the command input 71. The operation instruction 10A indicating the engine rotation speed N corresponding to the load and the command speed is output to the engine power generator 1 (step 101), and the process returns to step 100.

  The engine power generator 1 has operational characteristics as shown in FIG. 3 with respect to the generated power P and the engine rotational speed N. In general, this type of operating characteristic tends to attenuate after the generated power P monotonously increases as the engine speed N increases and reaches a predetermined maximum power value. Therefore, if such operation characteristics are stored in advance in the memory of the controller 7 in the form of a function or a table, the engine speed N required to supply the desired generated power P, that is, the command supply power, can be calculated.

Accordingly, since the command supply power (= load × command speed) can be calculated from the load and the command speed, the engine rotation speed corresponding to the command supply power is calculated with reference to the operation characteristics, and the engine power generation device is determined by the operation instruction 10A. You only need to indicate to 1.
As a result, the diesel engine 11 of the engine power generator 1 is operated at the engine speed N, and the command supply power corresponding to the load and command speed input by the operator is generated by the generator 12.

  On the other hand, when there is no command input 71 from the operator in step 100 (step 100: NO), the controller 7 detects the DC voltage V of the common bus 9 by the power supply status confirmation function (step 102). It is compared with the lower threshold value VL stored in the memory (step 103).

Here, when the DC voltage V is lower than the lower limit threshold VL (step 103: YES), the engine speed acquired by the operation notification 10B from the engine power generator 1 is increased by a predetermined amount, and a new engine speed N is obtained. (Step 104), a driving instruction 10A indicating a new engine speed N is output to the engine power generator 1 (step 105), and the process returns to step 100.
As a result, when the DC power of the common bus 9 is used and the DC voltage is lower than the lower limit threshold, the engine speed of the engine power generator 1 is increased, and more power is generated by the common bus. 9 is supplied.

Further, in step 103, when the DC voltage V is not lower than the lower threshold VL (step 103: NO), the power supply status check function, the upper limit threshold stored DC voltage V of the common bus 9 to memory Compare with the value VH (step 106).

Here, when the DC voltage V is higher than the upper limit threshold value VH (step 106: YES), the engine speed acquired by the operation notification 10B from the engine power generator 1 is reduced by a predetermined amount, and a new engine speed N is obtained. (Step 107), a driving instruction 10A indicating a new engine speed N is output to the engine power generator 1 (step 108), and the process returns to step 100.
As a result, when the DC power of the common bus 9 is not used and the DC voltage is higher than the upper limit threshold value, the engine speed of the engine power generator 1 is reduced, and power generation supplied to the common bus 9 is performed. Power is suppressed.

[Operation Example of First Embodiment]
Next, with reference to FIG. 4, the operation example of the crane apparatus concerning one embodiment of this invention is demonstrated. FIG. 4 is a timing chart showing an operation example of the crane device according to the embodiment of the present invention. Here, the case where the load power 34 increases and the engine rotation speed of the engine power generation device 1 increases, and then the load power 34 decreases and the engine rotation speed of the engine power generation device 1 decreases will be described as an example.

  Before the time T0, the crane operation is not performed, and the diesel engine of the engine power generator 1 is idling at the engine speed Na. At this time, the specified power supply PMa is output from the engine power generator 1, and the DC voltage V of the common bus 9 indicates the specified voltage value Va.

Next, when an arbitrary crane operation is started in response to the command input 71 at time T0, the load power 34 starts to increase according to the start of operation of the corresponding electric motors 30 to 33, and the load power 34 increases. On the other hand, the supply voltage 14 does not catch up and the power supply is insufficient, so the DC voltage V temporarily decreases.
When the DC voltage V falls below the lower limit threshold VL, the controller 7 gradually increases the engine rotation speed by the engine rotation speed control process of FIG. 2, whereby the supply power 14 from the engine power generator 1 is increased. To increase.

  Thereafter, when the load power 34 reaches the maximum load power PLb at time T1, the supply power 14 also reaches the maximum supply power PMb, and the power supply status is balanced. As a result, the DC voltage V rises to the specified voltage value Va, the increase in the engine speed due to the engine speed control process is stopped, and the engine speed N becomes Nb constant.

In addition, when the crane operation is finished at time T2, the load power 34 starts to decrease, and when the output of regenerative power from the electric motors 30 to 33 to the common bus 9 is started at time T3, the DC voltage V is It rises temporarily.
When the DC voltage V rises above the upper limit threshold value VH , the controller 7 gradually decreases the engine speed from Nb to Na by the engine speed control process of FIG. Supplied power 14 from PMb decreases to PMa. At this time, the engine rotation speed is not reduced below Na but is made constant Na.

  After that, at the time T4, when the output of the regenerative power is completed, the diesel engine of the engine power generator 1 is idling at the engine rotation speed Na as before the time T0. As a result, the specified power supply PMa is output from the engine power generator 1, and the DC voltage V of the common bus 9 becomes the specified voltage value Va.

[Effect of the first embodiment]
An engine generator 1 that outputs AC power generated by driving a generator with an engine, and an inverter 13 that converts AC power from the engine generator into DC power and outputs the DC power to the common bus side are provided. Since a new engine rotational speed of the engine is calculated based on the power supply status from the engine power generator 1 to the common bus 9 and the engine power generator 1 is instructed, the power supply status to the common bus 9 or the crane device Since the engine rotation speed of the engine power generator 1 is adjusted according to the driving conditions, the diesel engine can be driven at a rotation speed commensurate with the load, and fuel consumption can be improved.

  In particular, in a large-scale crane apparatus in which a gantry runs, the maximum load power required on the load side corresponds to several times the average load power, and the power generated by the engine power generator 1 is usually less than the average load power. Is enough. Therefore, as compared with the case where the engine power generator 1 generates power at a constant engine speed at which the maximum load power can be obtained, the operating cost can be greatly reduced, and the environmental impact can be greatly reduced.

  Further, in the present embodiment, as shown in FIG. 1, the storage battery 6 is connected to the common bus 9, and the storage battery is connected to the common bus 9 according to the power supply status from the engine power generator 1 to the common bus 9. You may make it perform charging / discharging by.

For example, as shown in FIG. 4 , power supply from the engine power generator 1 to the common bus 9 is continued until time T1 when the power supply 14 reaches the maximum value PMa after power generation at the engine power generator 1 is started at time T0. Sometimes it cannot catch up. In such a case, it is possible to discharge the common bus 9 from the storage battery of the power storage device 6 to make up for the shortage of power. Further, if the surplus power generated in the common bus 9 is charged to the storage battery of the power storage device 6 during regeneration from time T2 or during a period when the power consumption in the electric motors 30 to 33 is low, surplus power can be effectively used.

Regarding the charge / discharge control in the power storage device 6, for example, in the same manner as the operation instruction for the engine power generation device 1, the controller 7 controls the power storage device 6 based on the power supply status from the engine power generation device 1 to the common bus 9. A charge / discharge instruction may be output.
Alternatively, the power storage device 6 is provided with a charge / discharge control function, and when the DC voltage of the common bus 9 drops below a predetermined discharge threshold value, the DC power stored in the storage battery is supplied to the common bus 9 and is shared. When the DC voltage of the bus 9 rises above a predetermined charging threshold, the DC power on the common bus 9 may be charged to the storage battery.

  Thereby, it is possible to avoid applying a large load to the engine power generator 1 during a period in which a lot of electric power is required, such as during rotation acceleration of the electric motors 30 to 33. In addition, since the power storage device 6 is temporarily used only during a period in which the load power reaches a peak, the power storage device 6 does not require a large power storage capacity, and the facility cost required for the power storage device 6 compared to the above-described conventional technology. Can be reduced.

[Second Embodiment]
Next, with reference to FIG. 5, the crane apparatus concerning the 2nd Embodiment of this invention is demonstrated. FIG. 5 is a functional block diagram showing the configuration of the crane apparatus according to the second embodiment of the present invention, and the same or equivalent parts as those in FIG.
In the first embodiment, the case where the engine power generation device 1 generates power by driving the generator 12 with a diesel engine has been described as an example, but in the present embodiment, the AC motor 12A is used instead of the generator 12. A description will be given of a case where the AC motor 12A is driven by a diesel engine to generate power and the diesel engine 11 is driven by the AC motor 12A according to the regenerative power during regeneration.

  The engine generator 1 includes a diesel engine (DE) 11 and an AC electric motor (EM) 12A, and is an apparatus that generates and outputs AC power by driving the AC electric motor 12A with the diesel engine 11, and the engine rotation speed. Based on the operation instruction 10A from the controller 7 indicating the function of controlling the engine rotation speed of the diesel engine 11, and driving the diesel engine 11 by operating the AC motor 12A based on the regenerative power, It has a function to make it a no-load state.

  The inverter 13 is connected between the engine power generator 1 and the common bus 9, converts AC power from the engine power generator 1 into DC power and outputs the DC power to the common bus 9, and an electric motor 30 for the common bus 9. This is a power converter that converts the regenerative power output from ˜33 into AC power based on the synchronous frequency specified by the operation instruction 10 </ b> C from the controller 7 and outputs the AC power to the engine power generator 1.

  In the present embodiment, the controller 7 synchronizes the inverter 13 according to the power supply status from the engine power generator 1 to the common bus 9 in addition to the crane operation function, the power supply status confirmation function, and the engine rotation speed control function described above. It has a synchronous frequency control function for calculating the frequency and instructing the inverter 13 by the operation instruction 10C. In addition, about the other structure of a crane apparatus, it is the same as that of 1st Embodiment, and detailed description here is abbreviate | omitted.

[Operation of Second Embodiment]
Next, with reference to FIG. 6, the engine rotational speed control process in the controller 7 will be described in detail as the operation of the crane device according to the second embodiment of the present invention. FIG. 6 is a flowchart showing an engine rotation speed control process of the crane apparatus according to the first embodiment of the present invention, and the same or equivalent parts as in FIG.

The controller 7 starts the engine rotation speed control process of FIG. 6 in response to the detection of the operation start operation by the operator.
First, the controller 7 checks the presence / absence of the command input 71 from the operator using the engine speed control function (step 100). If there is a command input 71 (step 100: YES), the controller 7 inputs the command input 71. The operation instruction 10A indicating the engine rotation speed N corresponding to the load and the command speed is output to the engine power generator 1 (step 101), and the process returns to step 100.

  The engine power generator 1 has operational characteristics as shown in FIG. 3 with respect to the generated power P and the engine rotational speed N. In general, this type of operating characteristic tends to attenuate after the generated power P monotonously increases as the engine speed N increases and reaches a predetermined maximum power value. Therefore, if such operation characteristics are stored in advance in the memory of the controller 7 in the form of a function or a table, the engine speed N required to supply the desired generated power P, that is, the command supply power, can be calculated.

Accordingly, since the command supply power (= load × command speed) can be calculated from the load and the command speed, the engine rotation speed corresponding to the command supply power is calculated with reference to the operation characteristics, and the engine power generation device is determined by the operation instruction 10A. You only need to indicate to 1.
As a result, the diesel engine 11 of the engine power generator 1 is operated at the engine speed N, and the command supply power corresponding to the load and command speed input by the operator is generated by the generator 12A.

  On the other hand, when there is no command input 71 from the operator in step 100 (step 100: NO), the controller 7 detects the DC voltage V of the common bus 9 by the power supply status confirmation function (step 102). It is compared with the lower threshold value VL stored in the memory (step 103).

  Here, when the DC voltage V is lower than the lower limit threshold VL (step 103: YES), the engine speed acquired by the operation notification 10B from the engine power generator 1 is increased by a predetermined amount, and a new engine speed N is obtained. Is calculated (step 104), and a driving instruction 10A indicating a new engine speed N is output to the engine power generator 1 (step 105).

  Subsequently, the controller 7 calculates a synchronization frequency from the engine rotation speed N by the synchronization frequency control function (step 110). At this time, in order to set the power supply state to the power generation state, the synchronization frequency F is determined so that the slip S = (F−N) / F indicating the relationship between the engine rotation speed N and the synchronization frequency F satisfies S> 1. Thereafter, the operation instruction 10C indicating the new synchronization frequency F is output to the inverter 13 by the synchronization frequency control function (step 111), and the process returns to step 100.

  As a result, when the DC power of the common bus 9 is used and the DC voltage is lower than the lower limit threshold, the engine speed of the engine power generator 1 is increased, and more power is generated by the common bus. 9 is supplied. Further, the slip S becomes S> 1, and even when an AC motor is used instead of the generator, the slip state is reliably controlled to the power generation state.

Further, in step 103, when the DC voltage V is not lower than the lower threshold VL (step 103: NO), the power supply status check function, the upper limit threshold stored DC voltage V of the common bus 9 to memory Compare with the value VH (step 106).

Here, when the DC voltage V is higher than the upper limit threshold value VH (step 106: YES), the engine speed acquired by the operation notification 10B from the engine power generator 1 is reduced by a predetermined amount, and a new engine speed N is obtained. Is calculated (step 107), and a driving instruction 10A indicating a new engine speed N is output to the engine power generator 1 (step 108).

  Subsequently, the controller 7 calculates a synchronization frequency from the engine speed N by the synchronization frequency control function (step 112). At this time, in order to set the power supply state to the regenerative state, the synchronization frequency F is determined so that the slip S = (F−N) / F indicating the relationship between the engine rotation speed N and the synchronization frequency F satisfies S <1. Thereafter, the operation instruction 10C indicating the new synchronization frequency F is output to the inverter 13 by the synchronization frequency control function (step 113), and the process returns to step 100.

  As a result, when the DC power of the common bus 9 is not used and the DC voltage is higher than the upper limit threshold value, the engine speed of the engine power generator 1 is reduced, and power generation supplied to the common bus 9 is performed. Power is suppressed. Further, the slip S becomes S <1, and even when an AC motor is used instead of the generator, the regenerative state is reliably controlled.

[Operation Example of Second Embodiment]
Next, with reference to FIG. 7, the operation example of the crane apparatus concerning the 2nd Embodiment of this invention is demonstrated. FIG. 7 is a timing chart showing an operation example of the crane apparatus according to the second embodiment of the present invention. Here, the case where the load power 34 increases and the engine rotation speed of the engine power generation device 1 increases, and then the load power 34 decreases and the engine rotation speed of the engine power generation device 1 decreases will be described as an example.

  Before the time T0, crane operation is not performed, the diesel engine of the engine power generator 1 is idling at the engine rotation speed Na, and the synchronous frequency of the inverter 13 is Fa. At this time, the specified power supply PMa is output from the engine power generator 1, and the DC voltage V of the common bus 9 indicates the specified voltage value Va.

Next, when an arbitrary crane operation is started in response to the command input 71 at time T0, the load power 34 starts to increase according to the start of operation of the corresponding electric motors 30 to 33, and the load power 34 increases. On the other hand, the supply voltage 14 does not catch up and the power supply is insufficient, so the DC voltage V temporarily decreases.
When the DC voltage V falls below the lower limit threshold VL, the controller 7 gradually increases the engine rotation speed by the engine rotation speed control process of FIG. 2, whereby the supply power 14 from the engine power generator 1 is increased. To increase.

  Thereafter, when the load power 34 reaches the maximum load power PLb at time T1, the supply power 14 also reaches the maximum supply power PMb, and the power supply status is balanced. As a result, the DC voltage V rises to the specified voltage value Va, the increase in the engine rotational speed due to the engine rotational speed control process is stopped, the engine rotational speed N becomes constant at Nb, and the synchronization frequency F also becomes constant at Fb. .

In addition, when the crane operation is finished at time T2, the load power 34 starts to decrease, and when the output of regenerative power from the electric motors 30 to 33 to the common bus 9 is started at time T3, the DC voltage V is It rises temporarily.
When the DC voltage V rises above the upper limit threshold value VH , the controller 7 gradually decreases the engine speed from Nb to Na and changes the synchronization frequency from Fb to Fc by the engine speed control process of FIG. Reduce.

  At this time, since the synchronous frequency Fc satisfies the slip S <1, the AC motor 12A is driven by the regenerative power output from the inverter 13 in the direction opposite to the common bus 9, and the AC motor 12A enters a no-load state. . Thereby, the supply electric power 14 from the engine power generator 1 falls from PMb to 0.

  Thereafter, at time T4, when the output of the regenerative power is completed, the DC voltage V of the common bus 9 becomes the specified voltage value Va, so that the synchronization frequency is changed to Fa. As a result, as before time T0, the specified power supply PMa is output from the engine power generator 1, and the DC voltage V of the common bus 9 becomes the specified voltage value Va.

[Effect of the second embodiment]
As described above, in the present embodiment, an engine generator that generates AC power by driving an AC motor with the engine is provided as the engine generator 1, and output from the motors 30 to 33 to the common bus 9 by the inverter 13. Since the AC motor 12A is driven by converting the generated regenerative power into AC power and outputting it to the engine power generator 1, the diesel engine 11 can be unloaded during regeneration. Thereby, the fuel consumption in the engine power generator 1 can be further reduced, and the operating cost can be further reduced.

  Further, in the present embodiment, as shown in FIG. 5, the storage battery 6 is connected to the common bus 9, and the storage battery is connected to the common bus 9 according to the power supply status from the engine power generator 1 to the common bus 9. You may make it perform charging / discharging by.

  For example, as shown in FIG. 6, power supply from the engine power generator 1 to the common bus 9 is continued until time T1 when the power supply 14 reaches the maximum value PMa after power generation at the engine power generator 1 is started at time T0. Sometimes it cannot catch up. In such a case, it is possible to discharge the common bus 9 from the storage battery of the power storage device 6 to make up for the shortage of power. Further, if the surplus power generated in the common bus 9 is charged to the storage battery of the power storage device 6 during regeneration from time T2 or during a period when the power consumption in the electric motors 30 to 33 is low, surplus power can be effectively used.

Regarding the charge / discharge control in the power storage device 6, for example, in the same manner as the operation instruction for the engine power generation device 1, the controller 7 controls the power storage device 6 based on the power supply status from the engine power generation device 1 to the common bus 9. A charge / discharge instruction may be output.
Alternatively, the power storage device 6 is provided with a charge / discharge control function, and when the DC voltage of the common bus 9 drops below a predetermined discharge threshold value, the DC power stored in the storage battery is supplied to the common bus 9 and is shared. When the DC voltage of the bus 9 rises above a predetermined charging threshold, the DC power on the common bus 9 may be charged to the storage battery.

  Thereby, it is possible to avoid applying a large load to the engine power generator 1 during a period in which a lot of electric power is required, such as during rotation acceleration of the electric motors 30 to 33. In addition, since the power storage device 6 is temporarily used only during a period in which the load power reaches a peak, the power storage device 6 does not require a large power storage capacity, and the facility cost required for the power storage device 6 compared to the above-described conventional technology. Can be reduced.

[Extended embodiment]
In each of the above embodiments, as a specific configuration for confirming the power supply status by the controller 7, the case of detecting a change in the DC voltage of the common bus 9 has been described as an example. However, the present invention is not limited to this. Instead, the power supply status may be confirmed by comparing the power generated by the engine power generator 1 with the load power used on the load side.

  At this time, with respect to the load power, a method of obtaining the fluctuation from the power supplied to the common bus 9, the rotation speed of the motors 30 to 33 (the number of rotations per unit time), or the command input 71 by the operator can be considered. At least one of these three methods may be used.

  For example, the rotation speed 45 of the electric motors 30 to 33 indicating the operation status of the crane apparatus is closely related to the power consumption of each of the electric motors 30 to 33, and can be shown as the operation characteristics of the electric motors 30 to 33. These rotational speeds 45 are equal to the frequency of the AC power output from each of the inverters 41 to 44. Accordingly, the controller 7 refers to the operation characteristics of the respective motors 30 to 33 stored in the memory in advance, obtains the power consumption corresponding to the rotational speed 45 acquired from each of the inverters 41 to 44, and determines the power consumption of these power consumptions. The load power 34 may be calculated from the sum.

  In addition, the lifting and lowering of the load indicating the operation status of the crane device, and the individual crane operations such as traveling and traversing the platform require specific load power, and the relationship between them can be regarded as a fixed relationship to some extent. it can. Therefore, the correspondence relationship between the crane operation and the load power necessary for the operation is stored in the memory of the controller 7 in advance, and the correspondence relationship is referred to according to the command input 71, and is necessary for the crane operation input by the operation. What is necessary is just to acquire load electric power for every crane operation | movement, and to calculate the load electric power required for the crane operation input from these sum totals.

  In the second embodiment, the inverter 13 automatically converts the power conversion direction in the inverter 13 by comparing the power and voltage from the engine power generator 1 side and the common bus 9 side. However, the present invention is not limited to this. For example, since the controller 7 confirms the power supply status by the DC voltage V of the common bus 9, the controller 7 instructs the power conversion direction by the operation instruction 10C, and the inverter 13 performs the power conversion operation in response thereto. May be.

  In the second embodiment, the case where the controller 7 instructs the inverter 13 to specify the synchronization frequency has been described. However, the present invention is not limited to this. For example, the function of calculating the synchronization frequency provided in the controller 7 may be installed in the inverter 13 so that the inverter 13 itself calculates the synchronization frequency based on the engine speed acquired from the engine power generator 1. Thereby, the process of the controller 7 can be simplified and the processing load can be reduced.

It is a functional block diagram which shows the structure of the crane apparatus concerning the 1st Embodiment of this invention. It is a flowchart which shows the engine speed control process of the crane apparatus concerning the 1st Embodiment of this invention. It is an operating characteristic which shows the relationship between the electric power generated by the engine power generator and the engine speed. It is a timing chart which shows the operation example of the crane apparatus concerning the 1st Embodiment of this invention. It is a functional block diagram which shows the structure of the crane apparatus concerning the 2nd Embodiment of this invention. It is a flowchart which shows the engine speed control process of the crane apparatus concerning the 2nd Embodiment of this invention. It is a timing chart which shows the operation example of the crane apparatus concerning the 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Engine power generation device, 10A, 10C ... Operation instruction, 10B ... Operation notification, 11 ... Diesel engine, 12 ... Generator, 12A ... AC motor, 13 ... Inverter, 14 ... Supply power, 30 ... Main winding motor, 31, 32 ... Traveling motor, 33 ... Traverse motor, 34 ... Load power, 41-44 ... Inverter, 45 ... Rotational speed, 5 ... Discharge device, 6 ... Power storage device, 7 ... Controller, 71 ... Command input, 9 ... Common bus.

Claims (4)

A crane device that loads and unloads loads by driving an electric motor connected to the common bus via an inverter by supplying electric power generated by engine driving to the common bus,
An engine generator that outputs AC power generated by driving a generator with an engine; and
An inverter that converts AC power from the engine generator to DC power and outputs the DC power to the common bus;
A controller for calculating a new engine rotation speed of the engine power generation device based on the power supply status from the engine power generation device for the common bus or the operation status of the crane device and instructing the engine power generation device ;
The controller increases the engine speed when the DC voltage of the common bus is lower than a lower threshold, and decreases the engine speed when the DC voltage of the common bus is higher than an upper threshold. crane apparatus characterized by causing. The crane apparatus according to claim 1,
The engine power generator comprises an engine power generator that generates AC power by driving an AC motor with the engine,
The said inverter drives the said AC motor by converting the regenerative electric power output from the said motor to the common bus line into AC power, and outputting it to the said engine generator. The crane apparatus characterized by the above-mentioned. In the crane apparatus of Claim 1 or Claim 2,
A crane apparatus comprising a storage battery such as a battery or a capacitor, and further comprising a power storage device that charges and discharges the common bus with the storage battery in accordance with a power supply status from the engine power generator to the common bus. . In the crane apparatus of Claim 1 or Claim 2,
A storage battery such as a battery or a capacitor, and when the DC voltage of the common bus drops below a predetermined discharge threshold, DC power stored in the storage battery is supplied to the common bus; A crane apparatus further comprising a power storage device that charges DC power from the common bus to the storage battery when the DC voltage of the battery rises above a predetermined charging threshold.

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