HK1229781B - Crane device, power supply unit, and modification method - Google Patents

Description

Crane device, power supply unit and modification method

Technical Field

The invention relates to a crane device, a power supply unit and a transformation method.

Background

As an environment-friendly RTG (Rubber Tired Gantry Crane), an electric RTG without a generator and a ground power supply is now rapidly popularized in a new port and a dock. On the other hand, when the ground power supply facility construction is performed at an existing port, the loading and unloading operations are greatly affected, and therefore, a hybrid RTG using a diesel engine is selected.

Several techniques have been proposed with respect to hybrid RTG. For example, a hybrid power supply device for a crane described in patent document 1 is a hybrid power supply device for a crane including an engine generator, a power storage device, and a control device that controls the power storage device and the engine generator, wherein the control device includes: a load power calculation unit that obtains an engine load power from a requested power supplied to the outside and a charging power of the power storage device; and a command signal transmitting unit that calculates an output torque and a rotational speed from the engine load power calculated by the load power calculating unit, and generates a torque command signal and a rotational speed command signal.

Patent document 1 thus provides a hybrid power supply device for a crane and a control method for the hybrid power supply device for a crane, which can prevent deterioration of the fuel consumption rate of an engine generator even when a load is suddenly increased.

Prior art documents

Patent document

Patent document 1: international publication No. WO2010/146854

Disclosure of the invention

Technical problem to be solved by the invention

In the hybrid RTG using a diesel engine, the effect of reducing exhaust gas to some extent can be obtained from the point that the diesel engine generator can be downsized, but it is desired to further improve the environmental performance.

The invention provides a crane device capable of further improving environmental protection performance and a transformation method.

Means for solving the technical problem

According to the 1 st aspect of the present invention, a crane apparatus includes: a motor; an inverter that operates the motor; auxiliary machines, which are composed of a plurality of auxiliary machines; and a power supply unit configured to supply power to the inverter and the auxiliary devices, the power supply unit including: a power supply that generates power by a gas fuel; a storage battery; and a charge/discharge control unit that is provided between the battery and the power supply and controls charge/discharge of the battery.

The crane apparatus may further include a power supply side output control unit that switches the electric power output from the power supply to either one of a 1 st rated power larger than a maximum auxiliary-equipment-required power required by the auxiliary equipment and a 2 nd rated power smaller than the 1 st rated power.

According to the 2 nd aspect of the present invention, a power supply unit is attached to a crane apparatus, the crane apparatus including: a motor; an inverter that operates the motor; and auxiliary machines each including a plurality of auxiliary machines, and the power supply unit supplies power to the inverter and the auxiliary machines, wherein the power supply unit includes: a power supply that generates power by a gas fuel; a storage battery; and a charge/discharge control unit that is provided between the battery and the power supply and controls charge/discharge of the battery.

According to the 3 rd aspect of the present invention, there is provided a method of modifying a crane apparatus, the crane apparatus including: an engine generator; a motor; an inverter that operates the motor; auxiliary machines, which are composed of a plurality of auxiliary machines; and a power conversion unit that converts power output from the engine generator into dc power and outputs the dc power to the inverter, wherein the modification method includes: a dismantling step of dismantling the engine generator; a unit installation step of installing, in an installation part where the engine generator is installed, a power supply unit including a power supply that generates power by a gas fuel, a battery, and a charge/discharge control part that is provided between the battery and the power supply and controls charge/discharge of the battery; and a connection step of connecting the charge/discharge control unit of the power supply unit to the inverter.

Effects of the invention

According to the crane device, the power supply unit and the modification method, the environmental protection performance can be further improved.

Drawings

Fig. 1 is a schematic configuration diagram showing a configuration example of an electrical system of a crane apparatus according to embodiment 1 of the present invention.

Fig. 2 is a graph showing an example 1 of the power output mode of the generator in the same embodiment.

Fig. 3 is a graph showing an example 2 of the power output pattern of the generator in the same embodiment.

Fig. 4 is a schematic configuration diagram showing a configuration example of an electrical system of a crane apparatus before modification according to embodiment 2 of the present invention.

Fig. 5 is an explanatory diagram showing an example of arrangement of each part in a crane apparatus before modification according to the same embodiment.

Fig. 6 is a schematic configuration diagram showing a configuration example of an electric system of a modified crane apparatus according to the same embodiment.

Fig. 7 is an explanatory diagram showing an example of arrangement of each part in the modified crane apparatus according to the same embodiment.

Fig. 8 is a schematic configuration diagram showing a configuration of a power supply unit according to modification 1.

Fig. 9 is a schematic configuration diagram showing a configuration of a power supply unit according to modification 2.

Detailed Description

Hereinafter, embodiments of the present invention will be described, but the following embodiments do not limit the invention according to the claims. In addition, not all combinations of features described in the embodiments are essential to the solution of the present invention.

< embodiment 1 >

Fig. 1 is a schematic configuration diagram showing a configuration example of an electrical system of a crane apparatus according to embodiment 1 of the present invention. In the figure, the crane apparatus 1 includes a power supply unit 110, an inverter 121, an inverter 131, a motor 122, a motor 132, and an auxiliary machine 141. The power supply unit 110 includes a CNG (Compressed Natural Gas) engine 111, a generator 112, a converter 113, a battery 114, a DC/DC converter 115, an inverter 116, and a power supply side output control unit 119.

The crane apparatus 1 is a hybrid crane including an engine generator and a battery. The Crane device 1 may be, for example, an RTG (Rubber tire Gantry Crane) installed at a port terminal, but is not limited thereto.

The power supply unit 110 supplies power to each unit of the crane apparatus 1.

The CNG engine 111 generates a rotational force using compressed natural gas as fuel, and drives the generator 112 (rotates a Rotor) by the generated rotational force.

The generator 112 is driven by the rotational force from the CNG engine 111 and generates electricity.

In this way, the combination of the CNG engine 111 and the generator 112 constitutes a power source and generates electric power.

Here, the power supply in the crane apparatus 1 is not limited to the combination of the CNG engine 111 and the generator 112, and may be various power supplies that generate power (generate electric power) by using gas fuel. For example, the crane apparatus 1 may be provided with an engine generator using a gas other than compressed natural gas as a fuel as a power source. Alternatively, the crane apparatus 1 may be provided with a fuel cell using a gas such as hydrogen gas as a fuel as a power source.

The converter 113 outputs electric power generated by the power supply (combination of the CNG engine 111 and the generator 112) as direct-current electric power. In particular, the output side of the converter 113 is connected to the inverter 116, the inverter 121, the inverter 131, and the DC/DC converter 115 via a DC bus, and the converter 113 outputs the electric power generated by the power source at a predetermined DC bus voltage.

The battery 114 is connected to a DC bus via a DC/DC converter 115, and is charged and discharged under the control of the DC/DC converter 115. The battery 114 may be various batteries. For example, the battery 114 may be a lithium ion battery or a lead battery.

The DC/DC converter 115 is provided between the battery 114 and the output side (DC bus side) of the converter 113, and controls charging and discharging of the battery 114. In particular, DC/DC converter 115 converts the voltage between the DC bus voltage and the voltage of battery 114. At this time, when the DC bus voltage is high, DC/DC converter 115 charges battery 114. When the DC bus voltage is low, DC/DC converter 115 discharges battery 114. The DC/DC converter 115 corresponds to an example of the charge/discharge control unit.

Specifically, the DC/DC converter 115 performs constant voltage control so that the DC bus voltage becomes the rated voltage. Thus, when the battery 114 is to be charged, the dc bus voltage rises, and therefore, a current flows to the battery 114 side, and the battery 114 is charged.

The inverter 116 supplies the electric power output from the generator 112 and the battery 114 to the auxiliary machines 141. In particular, the inverter 116 converts the electric power flowing through the dc bus from the dc bus voltage to the rated voltage of the auxiliary device 141, and outputs the converted electric power to the auxiliary device 141.

The power output control unit 119 controls the output of the CNG engine 111 according to the charging rate of the battery 114.

The motor 122 and the motor 132 are power sources for operating the crane apparatus 1, and consume electric power output from the generator 112 and the battery 114 to operate the crane apparatus 1. The motor 122 and the motor 132 are loads that consume electric power together with the auxiliary machine 141.

The motors 122 and 132 generate regenerative electric power, respectively.

In fig. 1, the motor 122 and the motor 132 are illustrated to show that the crane apparatus 1 may include a plurality of motors, but the number of the motors included in the crane apparatus 1 may be 1 or more. For example, the crane apparatus 1 may include 3 or more motors such as a traveling motor, a transverse traveling motor, and a hoisting motor.

The inverter 121 outputs electric power flowing through the dc bus to the motor 122, thereby operating the motor 122. The inverter 121 causes the regenerative power generated by the motor 122 to flow to the dc bus.

The inverter 121 outputs electric power flowing through the dc bus to the motor 132, thereby operating the motor 132. The inverter 121 causes the regenerative power generated by the motor 132 to flow to the dc bus.

The auxiliary device 141 is a device that consumes power and is provided in the main body of the crane apparatus 1, such as a lighting device, a control device, and a communication device.

Hereinafter, the plurality of auxiliary machines 141 provided in the crane apparatus 1 are collectively referred to as "auxiliary machines".

Next, the power generation by the CNG engine 111 and the generator 112 will be described with reference to fig. 2 and 3.

Fig. 2 is a graph showing an example 1 of the power output mode of the generator 112. The horizontal axis of the graph shown in the figure represents time, and the vertical axis represents electric power. Line L11 represents the power consumption or the regenerative power of motor 122, motor 132, and auxiliary devices. Specifically, when the value of the line L11 is positive (on the horizontal axis), it indicates power consumption. On the other hand, when the value of the line L11 is negative (below the horizontal axis), regenerative power is represented. And, a line L12 represents the output power of the generator 112.

At time T11, the crane apparatus 1 is started and the auxiliary devices consume electric power. At this point, the CNG engine 111 and the generator 112 are not operated, and the battery 114 supplies the consumed electric power (base electric power) of the auxiliary machinery.

In general, a power supply using a gas as a fuel has low responsiveness and is difficult to follow a required output variation at the time of starting or the like in the power supply alone. In contrast, in the crane apparatus 1, the battery 114 compensates for the characteristic that the load variation of the power supply (the CNG engine 111 and the generator 112) is weak. Thus, a small power supply can be used.

At time T12, the CNG engine 111 and the generator 112 start operating, and the output power is increased in a predetermined pattern. For example, the CNG engine 111 increases the rotation speed at a constant rate, and the generator 112 increases the output power at a constant rate according to the rotation speed of the CNG engine 111, and the operation modes of the CNG engine 111 and the generator 112 are not limited to increasing the rotation speed and the output power at a constant rate. For example, the output power of the generator 112 may be changed in S-words.

As the output power of the generator 112, power E11 and power E12(E11 > E12) are set in advance. Electric power E11 is set to an electric power larger than the auxiliary machinery maximum required electric power required by the auxiliary machinery. The electric power E11 corresponds to the 1 st rated electric power. The power E12 corresponds to the 2 nd rated power example.

The power supply side output control unit 119 switches the electric power output to the generator 112 to either one of the electric power E11 and the electric power E12. Specifically, when the power supply side output control unit 119 detects that the charging rate is low (lower than the power increase threshold) from the charging rate of the battery 114, the power supply side output control unit sets the power to be output to the generator 112 as the power E11. When the power supply side output control unit 119 detects that the charging rate of the battery 114 is high (equal to or higher than the power reduction threshold), the power supply side output control unit sets the power to be output to the generator 112 to the power E12. In addition, the power increase threshold is less than or equal to the power decrease threshold. In particular, by setting hysteresis between the power increase threshold and the power decrease threshold, it is possible to suppress frequent switching of the output of the generator 112.

At time T12, the power supply side output control unit 119 detects that the charging rate of the battery 114 is lower than the power increase threshold, and increases the output of the generator 112 to the power E11.

The output power of the generator 112 (the amount of electric power that is insufficient is compensated by the battery 114 when the required electric power is not satisfied), on the other hand, when the output power of the generator 112 exceeds the required electric power, a surplus is charged to the battery 114, and the battery 114 also charges a surplus when the surplus is generated by the regenerative electric power.

The generator 112 outputs electric power to the electric power E11 at time T13, and thereafter, continues to output the electric power E11.

At time T14, power supply side output control unit 119 detects that the charging rate of battery 114 is equal to or greater than the power reduction threshold, and sets the output of generator 112 to power E12. As a result, the generator 112 reduces the output in a predetermined pattern, and the output power becomes the power E12 at time T15. Thereafter, the generator 112 continues to output the electric power E12.

In this way, the power supply side output control unit 119 switches the output power of the generator 112 in 2 stages. For example, the power supply side output control unit 119 calculates the electric power to be borne by the generator 112 (borne electric power), and determines the output mode of the generator 112 to be any one of 2 stages in consideration of the output change mode (slope at the time of transition) of the generator 112 and the charging rate of the battery.

The power supply side output control unit 119 controls the converter 113 to output the determined output power according to the power command. In the power command control, the power supply side output control unit 119 monitors the dc bus voltage V and calculates the output current command value I according to the formula (1).

[ formula 1]

I＝P/V…(1)

Here, P denotes electric power output to the converter 113. The power supply side output control unit 119 outputs the obtained output current command value I to the converter 113, and outputs a current corresponding to the current command value, thereby outputting the electric power P.

In this way, the generator 112 generates power by the 2 output powers of the power E11 and the power E12, and can generate power efficiently.

Here, it is considered that a power source such as an engine generator generally has a relatively high-efficiency output belt. Therefore, the output of the power source is set to include the power of the high-efficiency output band as the output of the generator 112, and the power source is generated with any set power. This power supply can efficiently generate power.

Further, since the output fluctuation mode of the generator 112 is set to be constant in advance, it is not necessary to perform complicated rotation control of the engine generator (the CNG engine 111 and the generator 112).

Fig. 3 is a graph showing an example 2 of the power output mode of the generator 112. The horizontal axis in the figure represents time and the vertical axis represents power. Line L21 represents the power consumption or the regenerative power of motor 122, motor 132, and auxiliary devices. Specifically, when the value of the line L21 is positive (on the horizontal axis), it indicates power consumption. On the other hand, when the value of the line L21 is negative (below the horizontal axis), regenerative power is represented. Line L22 represents the output power of the generator 112.

Unlike the case of fig. 2, in the example of fig. 3, the low-side setting value of the output power of the generator 112 (power E22) is set to 0.

In the example of fig. 3, the output of the generator 112 at the times T21 to T24 is the same as that at the times T11 to T14 of fig. 2.

On the other hand, the generator 112 whose output has decreased from the time T24 has the output set to 0 at the time T25, which is different from the case at the time T15 in fig. 2.

When the output power of the generator 112 becomes E22(═ 0), the CNG engine 111 and the generator 112 can be stopped. This can further improve the operation efficiency (output with respect to fuel consumption) of the crane apparatus 1 and reduce the exhaust gas.

As described above, the crane apparatus 1 includes: a power supply (CNG engine 111 and generator 112) that generates power by using a gas fuel; a battery 114; and a DC/DC converter 115 that is provided between the battery 114 and the power supply and controls charging and discharging of the battery 114.

Power supply responsiveness is low when gas is used as fuel, such as the CNG engine 111 and the generator 112, and on the other hand, the battery 114 compensates for the characteristic that the load variation of the power supply (the CNG engine 111 and the generator 112) is weak, so that a small power supply can be used.

In the crane apparatus 1, CO2, NOx, SOx, and the like can be reduced by using a gas fuel such as compressed natural gas, for example, and the environmental performance can be further improved. In this connection the crane means 1 is not susceptible to environmental regulations and the like.

Also, the compressed natural gas can be supplied at a stable price. The crane apparatus 1 can use compressed natural gas and can stabilize fuel consumption.

The power supply side output control unit 119 switches the electric power output from the power supply (the CNG engine 111 and the generator 112) to either the 1 st rated electric power larger than the auxiliary maximum required electric power for the auxiliary or the 2 nd rated electric power smaller than the 1 st rated electric power.

In this way, the generator 112 can generate power by 2 output powers of the electric powers E11 and E12, and can generate power efficiently.

Further, since the output fluctuation mode of the generator 112 is set to be constant in advance, it is not necessary to perform complicated rotation control of the engine generator (the CNG engine 111 and the generator 112).

< embodiment 2 >

When the configuration described in embodiment 1 is applied to an existing crane apparatus, a portion corresponding to the power supply unit 110 (fig. 1) is packaged, whereby the crane apparatus can be modified relatively easily. This point will be described in embodiment 2.

Fig. 4 is a schematic configuration diagram showing a configuration example of an electric system of the crane apparatus before modification. In the figure, the crane apparatus 2 includes a diesel engine 211, a generator 212, an inverter 121 and an inverter 131, a motor 122 and a motor 132, a rectifier circuit 223 and a rectifier circuit 233, a regenerative resistor 224 and a regenerative resistor 234, and an auxiliary machine 141.

In this figure, parts having the same functions are denoted by the same reference numerals (121, 122, 131, 132, 141) corresponding to the respective parts in fig. 1, and the description thereof is omitted.

The crane apparatus 2 is an existing crane apparatus, and unlike the crane apparatus 1 (fig. 1), does not include a battery. The crane device 2 may be, for example, an RTG installed at a port terminal, but is not limited thereto.

The diesel engine 211 generates rotational force using diesel oil as fuel, and drives the generator 212 by the generated rotational force.

The generator 212 is driven by the rotational force from the diesel engine 211 and generates electricity.

In this manner, the diesel engine 211 and the generator 212 are combined to form a power source and generate electric power.

The rectifier circuit 223 and the rectifier circuit 233 rectify output power of the generator 212 and convert the rectified output power into dc power.

The regenerative resistor 224 consumes power when regenerative power is returned from the motor 122. The regenerative resistor 234 consumes power when regenerative power is returned from the motor 132.

Fig. 5 is an explanatory diagram showing an arrangement example of each part in the crane apparatus 2.

In the drawing, a diesel engine 211 and a generator 212 are provided in one leg portion of the crane body 12, and an inverter 121 and an inverter 131, and a regenerative resistor 224 and a regenerative resistor 234 are provided in the other leg portion.

The generator 212 is connected to the inverter 121 and the inverter 131 via a power path (wiring) passing through the overhead portion, and the output power from the generator 212 is supplied to auxiliary machines provided in the inverter 121 and the inverter 131 and each part of the crane main body 12. The inverter 121 and the inverter 131 are connected to the regenerative resistor 224 and the regenerative resistor 234, respectively, and output electric power to the regenerative resistor 224 and the regenerative resistor 234 and consume the electric power when regenerative electric power returns during braking or the like.

Fig. 6 is a schematic configuration diagram showing a configuration example of an electric system of the modified crane apparatus. In the figure, the crane apparatus 3 includes a power supply unit 110, an inverter 121 and an inverter 131, a motor 122 and a motor 132, a rectifier circuit 223 and a rectifier circuit 233, and an auxiliary machine 141. The power supply unit 110 includes a CNG engine 111, a generator 112, a converter 113, a battery 114, a DC/DC converter 115, an inverter 116, and a power supply side output control unit 119.

In fig. 6, the same reference numerals (111 to 116, 119, 121, 122, 131, 132, 141) are given to the parts having the same functions corresponding to the parts in fig. 1, and the description thereof is omitted. In fig. 6, the same reference numerals (223, 233) are given to the parts having the same functions corresponding to the parts in fig. 4, and the description thereof is omitted.

The crane apparatus 3 includes a rectifier circuit 223 and a rectifier circuit 233 in addition to the structure of the crane apparatus 1 shown in fig. 1. Here, the output side of the rectifying circuit 223 is connected to the inverter 121, and the input side is not connected to any component. Therefore, the rectifier circuit 223 does not function in the state of fig. 6. Likewise, the output side of the rectifying circuit 233 is connected to the inverter 121, and the input side is not connected to any component. Therefore, the rectifier circuit 233 does not function in the state of fig. 6. Therefore, the crane apparatus 3 has substantially the same configuration as the crane apparatus 1.

The configuration shown in fig. 6 can be obtained by removing the diesel engine 211, the generator 212, the regenerative resistor 224, and the regenerative resistor 234 from the configuration shown in fig. 4, adding the power supply unit 110, and changing the wiring. Therefore, the power supply unit 110 is packaged and prepared in advance as a replacement unit (power supply unit), and the crane apparatus can be modified more easily and smoothly. The power supply unit 110 in fig. 6 corresponds to an example of a power supply means.

Fig. 7 is an explanatory diagram showing an arrangement example of each part in the crane apparatus 3.

In the figure, each part of the power supply unit 110 is provided on one leg of the crane body 13. Specifically, the CNG engine 111, the generator 112, and the electrical components (the converter 113, the battery 114, the DC/DC converter 115, and the inverter 116) are provided. The other leg is provided with an inverter 121 and an inverter 131.

The electric components (particularly, the converter 113, the DC/DC converter 115, and the inverter 116) are connected to the inverter 121 and the inverter 131 via power paths (wires) passing through the overhead portion, and output power from the generator 112 and the battery 114 is supplied to the inverter 121 and the inverter 131. The power path constitutes a part of the dc bus. The regenerative power generated in the motor 122 and the motor 132 is output from the inverter 121 and the inverter 131 to a power path (dc bus). When the electric power is surplus, surplus electric power is supplied to the battery 114 in the electric component.

The inverter 116 is connected to auxiliary machines provided in each part of the crane body 13, and supplies electric power to the auxiliary machines.

The arrangement of fig. 7 can be obtained by removing the diesel engine 211, the generator 212, the regenerative resistor 224, and the regenerative resistor 234 from the arrangement of fig. 5, providing the packaged power supply unit 110 as a power supply unit, and changing the wiring. The power supply unit 110 is provided at a location where the diesel engine 211 and the generator 212 are provided, for example.

In this way, the power supply unit is packaged and applied to an existing crane apparatus, and thus the crane apparatus can be modified more easily and smoothly.

In this case, the crane apparatus is modified by, for example, performing the following steps: a dismantling step of dismantling the engine generator (the diesel engine 211 and the generator 212); a unit installation step of installing, in an installation part where the engine generator is installed, a power supply unit including a power source (CNG engine 111 and generator 112) for generating power by the gas fuel, a storage battery 114, and a DC/DC converter 115 provided between the storage battery 114 and the power source and controlling charging and discharging of the storage battery 114; and a connection step of connecting the DC/DC converter 115 to the inverter 121 and the inverter 231.

The configuration of the power supply unit is not limited to the configuration shown in fig. 6. Next, a modified example of the structure of the power supply unit will be described with reference to fig. 8 and 9. These modifications are also applicable to embodiment 1.

Fig. 8 is a schematic configuration diagram showing a configuration of a power supply unit according to modification 1.

In the figure, the crane apparatus 4 includes a power supply unit 410, an inverter 121 and an inverter 131, a motor 122 and a motor 132, a rectifier circuit 223 and a rectifier circuit 233, and an auxiliary machine 141. The power supply unit 410 includes the CNG engine 111, the generator 112, the converter 113, the battery 114, the inverter 116, and the power supply side output control unit 119.

In fig. 8, parts having the same functions are denoted by the same reference numerals (111 to 114, 116, 119, 121, 122, 131, 132, 141, 223, and 233) as those in fig. 6, and description thereof will be omitted. Unlike the crane apparatus 3 (fig. 6), the DC/DC converter 115 is not required in the crane apparatus 4, and the battery 114 is directly connected to the converter 113 and the inverter 116. When the voltage variation range of the battery 114 is considered to be within the voltage variation allowable range of the dc bus, the configuration of fig. 8 is assumed.

In the case of the configuration of the crane apparatus 4, the control by the power supply side output control unit 119 is the same as that described for the crane apparatus 1. The charging and discharging of the battery 114 can be controlled by the increase or decrease of the dc bus voltage, as in the case of the crane apparatus 1.

Fig. 9 is a schematic configuration diagram showing a configuration of a power supply unit according to modification 2.

In the figure, the crane apparatus 5 includes a power supply unit 510, an inverter 121 and an inverter 131, a motor 122 and a motor 132, a rectifier circuit 223 and a rectifier circuit 233, and an auxiliary machine 141. The power supply unit 510 includes the CNG engine 111, the generator 112, the storage battery 114, the DC/DC converter 115, the inverter 116, and an output control unit 519.

In fig. 9, parts having the same functions are denoted by the same reference numerals (111, 112, 113 to 116, 121, 122, 131, 132, 141, 223, and 233) corresponding to the parts in fig. 6, and description thereof is omitted. The crane apparatus 5 is different from the crane apparatus 3 (fig. 6) in that the converter 113 is not required and the output power of the generator 112 is input to the rectifier circuit 223 and the rectifier circuit 233. In this way, the configuration of fig. 9 is a configuration using the rectifier circuit 223 and the rectifier circuit 233.

The output control unit 519 controls the output power of the power supply (the CNG engine 111 and the generator 112) in the same manner as the power supply side output control unit 119 (fig. 6). The output control section 519 controls the output of the DC/DC converter 115.

In the case of the configuration of the crane apparatus 5, the output control section 519 measures load power. Specifically, the output controller 519 measures the electric power supplied to the inverter 116, the inverter 121, and the inverter 131 (electric power at each of the points P11, P12, and P13), and calculates the total value of the measured electric power as the load electric power.

The output control unit 519 switches the output power of the generator 112 in 2 stages, similarly to the power supply side output control unit 119 (fig. 1). For example, the output control unit 519 calculates the electric power to be applied to the generator 112 (applied electric power), and determines the output mode of the generator 112 to be any one of 2 stages in consideration of the output change mode (gradient at the time of transition) of the generator 112 and the charging rate of the battery.

The output control unit 519 outputs the determined output power to the converter 113 by power command control, similarly to the power supply side output control unit 119. In the power command control, the CNG engine 111 monitors the dc bus voltage V, and calculates the output current command value I according to the formula (1).

The output control unit 519 calculates the difference between the load power and the load power of the generator 112 as the load power of the battery 114 (the power to be borne by the battery 114). Then, output control unit 519 outputs the calculated load power of battery 114 to DC/DC converter 115 by power command control. In the power command control, the output current command value for the DC/DC converter 115 is calculated by dividing the load power of the battery 114 by the DC bus voltage. Then, the output control unit 519 outputs the obtained output current command value to the DC/DC converter 115 to output a current corresponding to the output current command value, thereby outputting the load power.

While the embodiments of the present invention have been described in detail with reference to the drawings, the specific configuration is not limited to the embodiments, and design changes and the like are included within a range not departing from the gist of the present invention.

Industrial applicability

The present invention relates to a crane device including: a motor; an inverter that operates the motor; auxiliary machines, which are composed of a plurality of auxiliary machines; and a power supply unit configured to supply power to the inverter and the auxiliary devices, the power supply unit including: a power supply that generates power by a gas fuel; a storage battery; and a charge/discharge control unit that is provided between the battery and the power supply and controls charge/discharge of the battery.

According to the crane device, the environmental protection performance can be further improved.

Description of the symbols

1. 3, 4, 5-crane device, 111-CNG engine, 112-generator, 113-converter, 114-storage battery, 115-DC/DC converter, 116, 121, 131-inverter, 119-power supply side output control section, 122, 132-motor, 141-auxiliary machine.

Claims (3)

1. A crane device is provided with:

a motor;

an inverter that operates the motor;

auxiliary machines, which are composed of a plurality of auxiliary machines; and

a power supply unit configured to supply power to the inverter and the auxiliary machines,

the power supply unit includes:

a power supply that generates power by a gas fuel;

a storage battery;

a charge/discharge control unit that is provided between the battery and the power supply and controls charge/discharge of the battery; and

a power supply side output control unit that switches power output from the power supply to either 1 st rated power larger than maximum auxiliary power required by the auxiliaries or 2 nd rated power smaller than the 1 st rated power,

the charge/discharge control unit controls the storage battery to supply the electric power consumed by the auxiliary machines during a period from when the crane apparatus is started and the auxiliary machines start to require the electric power to when the power supply operates to output the required electric power,

the power supply side output control unit sets the power output from the power supply as the 1 st rated power when a charging rate of the battery is lower than a power increase threshold set in advance,

the power supply side output control unit sets the power output from the power supply as the 2 nd rated power when a charging rate of the battery is equal to or higher than a power reduction threshold set in advance.

2. A power supply unit for a crane device, which is attached to the crane device, the crane device comprising: a motor; an inverter that operates the motor; and auxiliary machines each including a plurality of auxiliary machines, and the power supply unit supplies power to the inverter and the auxiliary machines, wherein the power supply unit for the crane device includes:

a power supply that generates power by a gas fuel;

a storage battery;

a charge/discharge control unit that is provided between the battery and the power supply and controls charge/discharge of the battery; and

a power supply side output control unit that switches power output from the power supply to either 1 st rated power larger than maximum auxiliary power required by the auxiliaries or 2 nd rated power smaller than the 1 st rated power,

the charge/discharge control unit controls the storage battery to supply the electric power consumed by the auxiliary machines during a period from when the crane apparatus is started and the auxiliary machines start to require the electric power to when the power supply operates to output the required electric power,

the power supply side output control unit sets the power output from the power supply as the 1 st rated power when a charging rate of the battery is lower than a power increase threshold set in advance,

the power supply side output control unit sets the power output from the power supply as the 2 nd rated power when a charging rate of the battery is equal to or higher than a power reduction threshold set in advance.

3. A method for modifying a crane device, the crane device comprising:

an engine generator;

a motor;

an inverter that operates the motor;

auxiliary machines, which are composed of a plurality of auxiliary machines; and

a power conversion unit that converts power output from the engine generator into dc power and outputs the dc power to the inverter, wherein the modification method includes:

a dismantling step of dismantling the engine generator;

a unit installation step of installing a power supply unit in an installation portion where the engine generator is installed, the power supply unit including: a power supply that generates power by a gas fuel; a storage battery; a charge/discharge control unit that is provided between the battery and the power supply and controls charge/discharge of the battery; and a power supply side output control unit that switches the electric power output from the power supply to either a 1 st rated power larger than a maximum auxiliary power demand required by the auxiliary devices or a 2 nd rated power smaller than the 1 st rated power; and

a connection step of connecting the charge/discharge control unit of the power supply unit to the inverter,

the charge/discharge control unit controls the storage battery to supply the electric power consumed by the auxiliary machines during a period from when the crane apparatus is started and the auxiliary machines start to require the electric power to when the power supply operates to output the required electric power,

the power supply side output control unit sets the power output from the power supply as the 1 st rated power when a charging rate of the battery is lower than a power increase threshold set in advance,

the power supply side output control unit sets the power output from the power supply as the 2 nd rated power when a charging rate of the battery is equal to or higher than a power reduction threshold set in advance.