JPWO2019123800A1 - Crane and power electronics equipment - Google Patents

Abstract

The power electronics device 200 includes a DC link capacitor 220 and an inrush current prevention circuit 210. The determination device 244 gives a cutoff command or a continuity command to the switches RY1 and MC1 during the determination period, and the abnormality of the switches RY1 and MC1 is based on the voltage VDC of the DC link capacitor 220 or the current IIN flowing through the inrush current prevention circuit 210 at that time. Is detected.

Description

The present invention relates to cranes and power electronics equipment.

1. 1. In a work machine such as a crane, an AC power source, an AC motor, and a storage battery are connected to each other via a DC bus (for example, Patent Document 1). The AC power supply is connected to the DC bus via a converter device that converts AC power into DC power. The storage battery is connected to the DC bus via a charge / discharge controller that controls the charge / discharge timing and electric energy of the storage battery. The AC motor is connected to the DC bus via an inverter that converts DC power into AC power.

Japanese Unexamined Patent Publication No. 2006-131311 Japanese Unexamined Patent Publication No. 2007-295699 Japanese Unexamined Patent Publication No. 2005-116485

1. 1. Power electronics equipment is used to hybridize cranes. The power electronics equipment mainly consists of a capacitor and a converter, and is connected to the DC bus of the crane. Power electronics equipment is also activated by starting the crane. When electrically connecting the DC bus and the capacitor, a power electronics device with high safety and reliability is desirable.

2. 2. FIG. 1 is a block diagram of a conventional power electronics device. The power electronics device 100R includes a load motor 102, a converter device 110, and a load drive device 120. Converter 110 generates a DC link voltage _{V DC} boosts the DC voltage _{V E} from the DC power source 104, such as a battery, supplies to a load driving device 120 via a DC link 130. The load drive device 120 is, for example, a motor drive device, and includes an inverter 122 that drives the motor 102, which is a load. A large-capacity DC link capacitor 132 is connected to the DC link 130. A large-capacity smoothing capacitor 124 is also connected to the input of the inverter 122.

When the power electronics device 100R is started, the charges of the DC link capacitor 132 and the smoothing capacitor 124 are zero. When a DC voltage _VE is applied to such a capacitor, an inrush current flows. To prevent this, charging resistor _{R J,} relays RY1, electromagnetic contactor MC1 is provided. Introduction relay RY1 is turned on, DC link capacitor 132 is charged slowly via a charging resistor _{R J} and a diode D11. Further, the smoothing capacitor 124 is slowly charged via the charging resistor R2.

When the DC link capacitor 132 and the smoothing capacitor 124 are charged to some extent, or when their charging is completed, the magnetic contactor MC1 and the magnetic contactor MC2 are turned on.

Since relays and magnetic contactors (hereinafter collectively referred to as switches) have mechanical contacts, they deteriorate over time due to oxidation and wear.

In the power electronics device 100R of FIG. 1, deterioration over time of the relay RY1 and the magnetic contactor MC1 becomes a problem. Therefore, in general, a component with an auxiliary contact is adopted for these switches, and failure detection (welding or opening detection) using an answerback signal is widely performed.

FIG. 2 is a block diagram of a conventional power electronics device. The power electronics device 100S of FIG. 2 further includes a redundant switch RY2 on the negative electrode (N pole) side instead of using a switch having no auxiliary contact. Then, the switch RY1 (MC1) on the positive electrode side and the switch RY2 on the negative electrode side are sequentially conducted or cut off, and when the voltage or current in each state deviates from the expected value in the normal state, it is determined as abnormal.

The switch with an auxiliary contact used in the power electronics device 100R of FIG. 1 is generally expensive and often large in size, which may hinder its adoption.

Further, in the power electronics device 100S of FIG. 2, since it is necessary to add a redundant switch RY2, the size of the power electronics device 100S becomes large and the cost becomes high.

The present invention has been made in such a situation, and one of the exemplary purposes of the embodiment is a crane equipped with a power electronics device that is safer at startup, and a power electronics device mounted on the crane. Is to provide. Further, one of the exemplary purposes of the embodiment is to provide a power electronic device capable of detecting deterioration of a switch.

One aspect of the present invention relates to a crane. The crane includes a main body unit, a suspension work unit, a traveling unit, a drive unit that drives the suspension work unit, and a power storage system that supplies electric power to the drive unit. The crane has a function of diagnosing an abnormality in the power storage system at the time of starting or ending.

2. 2. One aspect of the present invention relates to a power electronics device. The power electronics device gives an inrush current prevention circuit including a capacitor and a switch provided between the DC power supply and the capacitor, and a cutoff command or a continuity command to the switch during the determination period to prevent the voltage or inrush current of the capacitor at that time. It is provided with a judgment device that detects an abnormality of the switch based on the current flowing through the circuit.

It should be noted that any combination of the above components or components and expressions of the present invention that are mutually replaced between methods, devices, systems, and the like are also effective as aspects of the present invention.

According to an aspect of the present invention, it is possible to provide a crane equipped with a power electronics device having a higher safety at the time of starting, and a power electronics device mounted on the crane. Further, according to an aspect of the present invention, deterioration of the switch can be detected.

It is a block diagram of a conventional power electronics device. It is a block diagram of a conventional power electronics device. It is a block diagram of the electronic device which concerns on embodiment. It is a figure explaining the abnormality detection by a determination device. It is a figure explaining the abnormality detection by a determination device. It is a block diagram which shows the power electronics apparatus which concerns on the modification. 7A and 7B are a schematic front view and a schematic side view of the crane system according to the present embodiment, respectively. FIG. 8 is a power system diagram of the crane system.

(Outline of Embodiment)
One embodiment disclosed herein relates to a crane. The crane includes a main body unit, a suspension work unit, a traveling unit, a drive unit that drives the suspension work unit, and a power storage system that supplies electric power to the drive unit. The crane has a function of diagnosing an abnormality in the power storage system at the time of starting or ending.

The crane may be provided with an abnormality notification unit that detects an abnormality at the time of starting and notifies the existence of the abnormality, or detects an abnormality at the end and notifies the existence of the abnormality.

In the case of remote control, the abnormality notification unit is used as a notification means provided in the remote control means, in the case of automatic operation, via a communication means, as a notification means provided in the management building, and in the case of manual operation, operation. An abnormality may be notified to a notification means provided in the room.

The abnormality notification unit may change the notification content according to the type of abnormality. In the case of an abnormality at a level where work is restricted, a predetermined abnormality at the first level is notified, and replacement or maintenance is recommended, but when an abnormality at a level where work is not restricted occurs, from the first level A lower level second level anomaly may be signaled.

In a state where it is determined that an abnormality has occurred and the abnormality is notified or the work is restricted, the work may be started in a work mode that does not use the power storage system by a predetermined mode change operation.

In the work mode that does not use the power storage system, at least one of the traveling speed and the operating speed of the suspension portion may be limited.

One embodiment disclosed herein relates to a power electronics device. The power electronics device gives an inrush current prevention circuit including a capacitor and a switch provided between the DC power supply and the capacitor, and a cutoff command or a continuity command to the switch during the determination period to prevent the voltage or inrush current of the capacitor at that time. It is provided with a judgment device that detects an abnormality of the switch based on the current flowing through the circuit. According to this embodiment, deterioration of the switch can be detected without using a switch with an auxiliary contact or a redundant switch. In addition, the cost of power electronics equipment can be reduced.

The judgment device gives a continuity command to the switch to charge the capacitor. During the charging period, the switch is temporarily given a cutoff command, and the presence or absence of an abnormality is judged based on the change in the current flowing through the inrush current prevention circuit at that time. You may. If the switch is normally shut off while the switch is given a cutoff command, the current will be zero. On the contrary, if the switch is deteriorated by welding or the like, the current continues to flow. Therefore, it is possible to determine the abnormality of the switch based on the current state of the switch (conduction / interruption) and the change in the current.

The determiner may give a continuity command to the switch to charge the capacitor, temporarily give a cutoff command to the switch during the charging period, and judge the presence or absence of an abnormality based on the change in the voltage of the capacitor at that time. .. If the switch is normally shut off while the cutoff command is given to the switch, charging of the capacitor is stopped, so the change in voltage becomes zero. On the contrary, when the switch is deteriorated by welding or the like, the charging current to the capacitor continues to flow, so that the voltage of the capacitor continues to increase. Therefore, it is possible to determine the abnormality of the switch based on the current state of the switch (conduction / interruption) and the voltage change of the capacitor.

The power electronics device may further include a converter device provided between the inrush current protection circuit and the capacitor. The converter device may be switched in a state where a cutoff command is given to the switch, and the presence or absence of an abnormality may be determined based on the current flowing through the inrush current prevention circuit at that time.

If the switch is normally shut off when the cutoff command is given to the switch, the current flowing through the inrush current prevention circuit is zero even if the converter device is switched. On the contrary, when the switch is deteriorated by welding or the like, a current flows through the inrush current prevention circuit. Therefore, the presence or absence of abnormality can be determined based on the current.

The power electronics device may further include a converter device provided between the inrush current protection circuit and the capacitor. The converter device may be switched in a state where a cutoff command is given to the switch, and the presence or absence of an abnormality may be determined based on the voltage of the capacitor at that time.

If the switch is normally shut off while the cutoff command is given to the switch, the current flowing through the inrush current prevention circuit is zero even if the converter device is switched, and therefore the voltage of the capacitor does not rise. On the other hand, if the switch is deteriorated due to welding or the like, the current flows through the inrush current prevention circuit, so that the voltage of the capacitor rises. Therefore, the presence or absence of abnormality can be determined based on the voltage of the capacitor.

(Embodiment)
Hereinafter, the present invention will be described with reference to the drawings based on preferred embodiments. The same or equivalent components, members, and processes shown in the drawings shall be designated by the same reference numerals, and redundant description will be omitted as appropriate. Further, the embodiment is not limited to the invention but is an example, and all the features and combinations thereof described in the embodiment are not necessarily essential to the invention.

In the present specification, the "state in which the member A is connected to the member B" means that the member A and the member B are physically directly connected, and that the member A and the member B are electrically connected to each other. It also includes the case of being indirectly connected via other members, which does not substantially affect the connection state, or does not impair the functions and effects performed by the combination thereof.

Similarly, "a state in which the member C is provided between the member A and the member B" means that the member A and the member C, or the member B and the member C are directly connected, and their electricity. It also includes the case of being indirectly connected via other members, which does not substantially affect the connection state, or does not impair the functions and effects performed by the combination thereof.

The vertical and horizontal axes of the waveform charts and time charts referred to in the present specification are appropriately enlarged or reduced for ease of understanding, and each of the waveforms shown is also simplified for ease of understanding. Or exaggerated or emphasized.

FIG. 3 is a block diagram of the electronic device according to the embodiment. The power electronics device 200 includes a DC power supply 202, an inrush current prevention circuit 210, a DC link capacitor 220, and a converter device 230.

DC power supply 202 is a battery or a capacitor or an external converter, generates a DC voltage (also referred to as input voltage) V _E. A DC link capacitor 220 is connected to the DC link 204. Although not shown in FIG. 3, a load driving device as shown in FIGS. 1 and 2 is connected to the DC link 204. The type of load is not particularly limited.

Immediately after activation of the power electronics equipment 200, less charge the DC link capacitor 220, a rush current in the DC link voltage _{V DC} is low, the input voltage _{V E} is applied to the DC link capacitor 220 via a low impedance path Flows. In order to prevent this, an inrush current prevention circuit 210 is provided between the DC power supply 202 and the DC link capacitor 220.

The inrush current prevention circuit 210 includes at least one switch provided between the DC power supply 202 and the DC link capacitor 220. In the present embodiment, the inrush current preventing circuit 210 includes a first switch MC1, the charging resistor _{R J} and the second switch RY1 is provided in series with the parallel paths to the first switch MC1. For example, the first switch MC1 is an electromagnetic contactor and the second switch RY1 is a relay.

The converter device 230 is provided between the inrush current prevention circuit 210 and the DC link capacitor 220. Converter device 230 in the operating state, boosts the input voltage _{V E,} to generate a high DC link voltage _{V DC} from the DC voltage _{V E} to the DC link 204 (a power running operation). The controller 240 includes a converter controller 242 that controls the converter device 230. The converter controller 242 generates a control signal _CTRL that defines the duty ratio of the gate signal of the converter device 230.

The controller 240, the digital feedback signal _{D VDC} indicating the DC link voltage _{V DC} is fed back. The controller 240, feedback signal _{D VDC} is, so as to approach the target value _{D REF} defining a target voltage of the DC link voltage _{V DC,} to adjust the duty ratio by the feedback.

The gate driver 232 drives the transistors M1 and M2 of the converter device 230 based on the duty ratio indicated by the control signal _CTRL .

The current sensor 234 is, for example, current transformer, for detecting a current _{I L} flowing through the reactor L1. The controller 240, and a digital value _{D IL} showing the current _{I L,} the digital value _{D VE} indicating the input voltage _{V E} is input. The feedback control in the converter controller 242, and the input voltage _{V E,} may reflect the current _{I L} flowing through the reactor L1 of the converter device 230.

When the DC power supply 202 includes a rechargeable battery or a capacitor, the converter device 230 can be regeneratively operated, and the excess energy on the DC link 204 side may be recovered to the DC power supply 202.

The controller 240 has a function of controlling on / off of the switches MC1 and RY1 included in the inrush current prevention circuit 210 and detecting an abnormality of the switches MC1 and RY1.

In the charging period immediately after the start of the power electronics device 200, the controller 240 stops the converter device 230 and turns on the second switch RY1. Thus, the resistance _{R J,} the second switch RY1, the charging current _{I CHG} through the diode D11 flows, DC link capacitor 220 is charged.

When the DC link voltage _VDC rises to such an extent that there is no risk of inrush current to the DC link capacitor 220, the first switch MC1 is turned on. After that, the controller 240 starts the operation of the converter device 230.

Abnormality detection of the switch of the inrush current prevention circuit 210 will be described. The controller 240 includes a determination device 244. The judgment device 244 gives a cutoff command or a continuity command to the switches MC1 and RY1 during the judgment period, and flows through the command (switch usage status) and the voltage _VDC or inrush current prevention circuit 210 of the DC link capacitor 220 at that time. Abnormality of switches MC1 and RY1 is detected based on the combination of currents.

The current sensor 234 can be grasped as detecting the current (referred to as input current) I _IN flowing through the inrush current prevention circuit 210. Input current _{I IN} is nothing but the reactor current _{I L} in the operating state of the converter device 230, during the charging period, nothing but the charging current _{I CHG.}

Hereinafter, the abnormality detection by the determination device 244 will be described with reference to three examples.

(First Example)
FIG. 4 is a diagram illustrating abnormality detection by the determination device 244.
At time _{t 0,} the controller 240 starts the charging of the DC link capacitor 220 provide a conduction command to the second switch RY1. The controller 240 inserts the determination period τ _DET1 into the charging period, and temporarily (t _{1 to} t ₂ ) gives a cutoff command to the second switch RY1 during the determination period τ _DET1 . The determination device 244 determines whether or not there is an abnormality based on the change in the input current I _IN flowing through the inrush current prevention circuit during the determination period τ _DET1 .

If the second switch RY1 is normally shut off while the cutoff command is given to the second switch RY1, the input current I _IN becomes zero as shown by the solid line. On the contrary, when deterioration such as welding occurs in the second switch RY1, the non-zero input current I _IN continues to flow as shown by the alternate long and short dash line. Therefore, the determination device 244 can determine the abnormality of the switch based on the input current I _IN in the determination period τ _{DET 1} . For example determiner 244, when the digital value DI _L in the determination period tau _DET1 is higher than a predetermined threshold abnormality may be determined to be normal when low.

The end time _{t 2} of the determination period tau _DET1, a second switch RY1 may be on again. The increased DC link voltage V _DC until the input voltage V _E is substantially equal to the voltage level at time t ₃ when there is no possibility of inrush current may provide a conduction command to the first switch MC1. Then, the converter device 230 at time _{t 4} is started operation.

Incidentally, the end time _{t 2} of the determination period tau _DET1, if DC link voltage _{V DC} is sufficiently high to the extent there is no risk of inrush current, and turned immediately first switch MC1 at time _{t 2,} the first switch The DC link capacitor 220 may be charged via the MC1.

(Second Example)
Continue to refer to FIG. In decision 244 the second embodiment determines the presence or absence of abnormality on the basis of the change in the DC link voltage _{V DC} in the determination period tau _DET1. If the second switch RY1 is normally shut off while the second switch RY1 is given a cutoff command, charging of the DC link capacitor 220 is stopped, so that the increase in the DC link voltage _VDC stops as shown by the solid line. However, the voltage change becomes zero. On the contrary, when the second switch RY1 is deteriorated by welding or the like, the charging current _ICHG continues to flow in the DC link capacitor 220, so that the DC link voltage _VDC continues to increase as shown by the alternate long and short dash line. Therefore, the determination device 244 can determine the abnormality of the second switch RY1 based on the DC link voltage _VDC in the determination period τ _DET1 . For example, the determination device 244 may determine that the change amount of the digital value D _VDC in the determination period τ _{DET 1} is normal when it is substantially zero, and abnormal when it is non-zero. More specifically, at the start time t ₁ and the end time t ₂ of the judgment period, the digital value _DVDC is sampled, and when the difference between them is larger than a predetermined threshold value, it is judged as abnormal, and when it is smaller, it is judged as normal. You may.

Subsequently, the determination period τ _DET1 in the first embodiment or the second embodiment will be described. For example, the determination period τ _{DET 1} may be set to the start time t ₁ of the determination period τ after a predetermined delay time has elapsed from the charging start time t ₀ .

Or to monitor the input voltage _{V E} immediately after startup, to determine the threshold K × _{V E} multiplied by the coefficient K (K <1) to an input voltage _{V E,} DC link voltage _{V DC} reaches the threshold The time may be set as the start time t ₁ of the determination period τ.

Or to monitor the input current I _IN in the charging period, after the input current I _IN is passed through the peak, the time when lowered to a predetermined reference value may be a starting time t ₁ of the determination period tau.

(Third Example)
FIG. 5 is a diagram illustrating abnormality detection by the determination device 244. The determination period τ _{DET 2} is inserted during the non-charging period after the end of the charging period. During this determination period τ _DET2 , the controller 240 is given a cutoff command to both the first switch MC1 and the second switch RY1. Then, the converter device 230 is put into an operating state.

For example, the determination period τ _{DET 2} may be inserted in the vicinity of the time t ₃ in FIG. In this case, DC link voltage _{V DC} is substantially equal to the input voltage _{V E.} If the switches MC1 and RY1 of the inrush current prevention circuit 210 are normally turned off when the converter device 230 is switched, the DC link voltage _VDC does not rise and the original voltage is shown as shown by the solid line. Maintain the level (here _VE ). If any of the switches MC1 and RY1 has an abnormality, the DC link voltage _VDC rises as a result of the boosting operation of the converter device 230, as shown by the alternate long and short dash line. Therefore, the determination device 244 can detect the abnormality of the switches MC1 and RY1 based on the amount of voltage change in the determination period τ _DET2 .

For example, the determination device 244 may determine that the change amount of the digital value D _VDC in the determination period τ _{DET 2} is normal when it is substantially zero, and abnormal when it is non-zero. More specifically, at the start time t ₁ and the end time t ₂ of the judgment period, the digital value _DVDC is sampled, and when the difference between them is larger than a predetermined threshold value, it is judged as abnormal, and when it is smaller, it is judged as normal. You may.

(Fourth Example)
Continue to refer to FIG. In the fourth embodiment, the determination device 244 determines the presence or absence of an abnormality based on the change in the input current I _IN during the determination period τ _{DET 2} . If both the first switch MC1 and the second switch RY1 are normally cut off in the determination period τ _DET2 , the input current I _IN is zero as shown by the solid line. On the contrary, when an abnormality occurs in either the first switch MC1 or the second switch RY1, the input current I _IN becomes non-zero as shown by the alternate long and short dash line. Therefore, the determination device 244 can determine the abnormality of the switch based on the input current I _IN in the determination period τ _{DET 2} . For example determiner 244, when the digital value DI _L in the determination period tau _DET2 is higher than a predetermined threshold abnormality may be determined to be normal when low.

In the third embodiment and the fourth embodiment, the determination period τ _DET 2 may be inserted at the end of the power electronics device 200. In this case, the initial value of the DC link voltage _VDC is a high voltage after boosting.

(Modification example)
In the embodiment, the abnormality detection of the switch of the inrush current prevention circuit 210 provided in the front stage of the converter device 230 has been described, but the application of the present invention is not limited thereto. As shown in FIGS. 1 and 2, an inrush current prevention circuit including a resistor R2 and a switch MC2 is provided in front of the load drive device 120, and the present invention can also be applied to anomaly detection of the switch MC2. FIG. 6 is a block diagram showing a power electronics device 300 according to a modified example. DC power supply 302 includes a converter for generating a DC link voltage _{V DC} to the DC link 304.

The inrush current prevention circuit 310 is provided between the DC power supply 302 and the smoothing capacitor 320. In this modification, the inrush current prevention circuit 310 includes a resistor R2, switches MC2, and RY2. The load drive device 330 drives a load 306 such as a motor based on the DC voltage generated in the smoothing capacitor 320.

The controller 340 controls the switches MC2 and RY2 and the load drive device 330, and detects an abnormality in the switches MC2 and RY2. As the detection method, the same methods as those in the first to fourth embodiments described above can be adopted.

First, if employing the second embodiment, the _{V E} of the above description and FIG. 4 read as _{V DC,} it may be read as a _{V DC} and _{V IN.} Third, in the case of employing the fourth embodiment, during the determination period tau _DET2, given cutoff command to switch MC2, RY2, operates the load driving device 330, the voltage _{V IN} of the change or the current _{I 1} at that time The change may be detected.

The power electronics equipment applied to the industrial machine, the construction machine, and the transport vehicle may be started in response to the start of the industrial machine, the construction machine, and the transport vehicle. At the time of start-up, the capacitor voltage is 0 V, and the power electronics The device may charge the capacitor after booting.

The present invention can be applied to a power electronics device having a switch with an auxiliary contact and a redundant switch RY2 from the viewpoint of duplication of protection, but a switch with an auxiliary contact and a redundant switch RY2 are used. It is understood that if there is no power electronics device, the effects such as simple configuration, size reduction, and cost reduction will be even more remarkable.

When a power electronics device detects what is called an abnormality, it notifies the upper controller mounted on the industrial machine or the like, displays the abnormality on the display unit provided on the industrial machine or the like, or displays the abnormality on the industrial machine or the like. If such things are stopped, it will contribute to the improvement of safety. Further, it may be notified preliminaryly or forecastly, and in this case, it is excellent from the viewpoint of failure prediction that does not stop the industrial machine or the like.

The applications of power electronics equipment are not particularly limited, but for example, industrial machines such as injection molding machines and presses, construction machines such as excavators and cranes, and transport vehicles such as forklifts and automatic guided vehicles (generalized industry). It can be applied to machines, etc.).

7A and 7B are a schematic front view and a schematic side view of the crane system according to the present embodiment, respectively. A plurality of pillars 40 support the girder 41. A gate-shaped frame is formed by the pillar 40 and the girder 41. Wheels 42 are attached to the lower ends of the pillars 40, and the gate-shaped frame runs along the rails 43. The direction perpendicular to the paper surface of FIG. 4A and the left-right direction of FIG. 4B correspond to the traveling direction. A trolley 45 is mounted on the girder 41. The hoisting machine 46 is mounted on the trolley 45. The main body is composed of a portal frame and wheels 42, and the working part is composed of a trolley 45, a hoisting machine 46, and a hanging work part (hanging tool 47 and wire).

A plurality of electric actuators drive each operating unit. For example, a traveling motor 51 mounted on a gantry frame drives the wheels 42. The traversing motor 52 mounted on the trolley 45 moves the trolley 45 in the traversing direction. The left-right direction of FIG. 4A and the direction perpendicular to the paper surface of FIG. 4B correspond to the transverse direction. The hoisting machine 46 includes a hoisting motor 53, and winds and unwinds a wire to which a hanging tool 47 such as a hook is attached to the tip thereof. In this way, the electric actuators such as the hoisting motor 53, the traversing motor 52, and the traveling motor 51 operate the suspending tool 47, the trolley 45, and the wheels 42, respectively.

An AC power supply 60, a power converter (DC-DC converter) 65, a power storage device 67, and a power converter (DC-DC converter) 68 are mounted on the portal frame. The AC power source 60 includes an engine 61 and a generator 62. The AC power supply 60 supplies driving power to the hoisting motor 53, the traversing motor 52, and the traveling motor 51. Further, the power storage device 67 is charged by the electric power supplied from the AC power source 60.

The power conversion device 68 and the power storage device (capacitor) 67 are attached to the DC bus 70 (DC bus) as a power storage system (power electronics device) 90. It can also be retrofitted to a crane that does not have such a power storage system (power electronics device) 90.

FIG. 8 is a power system diagram of the crane system. The AC power supply 60 is connected to the DC bus 70 via the rectifier 63 and the power converter 65. The power conversion device 65 converts the DC power output from the AC power supply 60 and rectified by the rectifier 63 into DC power of a target voltage and supplies the DC power to the DC bus 70. A smoothing capacitor 72 is connected between the positive bus 70P and the negative bus 70N of the DC bus 70.

The power storage device 67 is connected to the DC bus 70 via the power conversion device 68. The power conversion device 68 controls charging / discharging of the power storage device 67. When the power storage device 67 is discharged, the power conversion device 68 boosts the output voltage of the power storage device 67 to supply power from the power storage device 67 to the DC bus 70. When charging the power storage device 67, the power conversion device 68 lowers the voltage of the DC bus 70 to supply power from the DC bus 70 to the power storage device 67.

The traveling motor 51 is connected to the DC bus 70 via the inverter 54 and the power converter (DC-DC converter) 57. The traversing motor 52 is connected to the DC bus 70 via an inverter 55 and a power converter (DC-DC converter) 58. The hoisting motor 53 is connected to the DC bus 70 via an inverter 56 and a power converter (DC-DC converter) 59. The power converters 57, 58, and 59 boost the voltage of the DC bus 70, respectively, and supply the boosted power to the inverters 54, 55, and 56.

The controller 80 controls the power converters 57, 58, 59, 65, 68, and the inverters 54, 55, 56 to power the traveling motor 51, the traversing motor 52, and the hoisting motor 53 from the DC bus 70. To supply. The controller 80 controls the power converters 57, 58, 59, 65, and 68 so as to maintain the voltage of the DC bus 70 at a preset target value. When the hoisting motor 53 performs the hoisting operation, the controller 80 controls the inverter 56 and the power conversion device 59 to step down the regenerated power generated by the hoisting motor 53 and supply it to the DC bus 70. The power storage device 67 can be charged by this regenerative power.

An inrush current prevention circuit 76A is provided between the power conversion device 68 and the power storage device 67.

The controller 80 has a function of diagnosing an abnormality of the power storage system 90 at the start or end of the crane. The crane system is triggered by a start-up operation. The activation operation may be configured by activation means such as an activation button and an activation key. The start-up operation can be performed by the operator in the driver's cab. In the case of remote control, the starting means may be provided in a control room (control room) that remotely controls the crane, or may be provided in a remote control means that can be used outside the cab. The crane may be terminated by a termination operation to the starting means, or may be provided with a separate dedicated button (terminating means).

The abnormality of the power storage system to be diagnosed is not particularly limited, but may be, for example, an abnormality of the power storage means (battery, capacitor, combination thereof) (internal resistance abnormality, deterioration abnormality, temperature abnormality, voltage abnormality) or connection. The means (switch) or resistance or capacitor abnormality may be included. When a plurality of power storage means connected in series are provided, the life may be extended if the voltage is evenly balanced in each power storage means, so that the voltage state may be detected at the start or end. At this time, by measuring the internal resistance and temperature of each storage means, it is possible to detect the internal resistance abnormality and the temperature abnormality prior to the operation of the crane.

The crane system further includes an abnormality notification unit 92. The abnormality notification unit 92 detects an abnormality at startup and notifies the existence of the abnormality, or detects an abnormality at the end and notifies the existence of the abnormality.

The abnormality notification unit 92 is provided to the notification means provided in the remote control means in the case of remote control, to the notification means provided in the management building in the case of automatic operation, via the communication means, and in the case of manual operation. The abnormality is notified to the notification means provided in the driver's cab.

The abnormality notification unit 92 can change the notification content according to the type of abnormality or the degree of urgency. For example, in the case of an abnormality at a level where work is restricted, a predetermined first level abnormality is notified, and replacement or maintenance is recommended, but when an abnormality at a level where work is not restricted occurs, the first level is detected. A second level anomaly at a level lower than the level may be notified.

The crane may start work in a work mode that does not use the power storage system 90 by performing a predetermined mode change operation in a state where it is determined that an abnormality has occurred and the abnormality is notified or work is restricted. .. In the work mode in which the power storage system 90 is not used, at least one of the traveling speed and the operating speed of the suspension portion may be limited.

The crane system of FIG. 8 and the power electronics device 300 of FIG. 3 can be associated with each other as follows.
Fig. 8 Fig. 3
Controller 80 Controller 240, Gate driver 232
Power storage device 67 DC power supply 202
Inrush current prevention circuit 76A Inrush current prevention circuit 210
Power converter 68 Converter device 230
Smoothing capacitor 72 DC link capacitor 220
Positive bus 70P DC link 204

One of the abnormalities monitored by the controller 80 may be deterioration or failure of the relay or magnetic contactor of the inrush current prevention circuit 76A. In this case, the controller 80 may detect deterioration or failure of the relay or the magnetic contactor by the method described with reference to FIGS. 3 and 4.

Although the present invention has been described using specific terms and phrases based on the embodiments, the embodiments merely indicate the principles and applications of the present invention, and the embodiments are defined in the claims. Many modifications and arrangement changes are permitted without departing from the ideas of the present invention.

200 Power Electronics Equipment 202 DC Power Supply 204 DC Link 210 Rush Current Prevention Circuit 220 DC Link Capacitor 230 Converter Device 232 Gate Driver 234 Current Sensor 240 Controller 242 Converter Controller 244 Judge MC1 1st Switch RY1 2nd Switch 300 Power Electronics Equipment 302 DC Power supply 304 DC link 306 Load 310 Inrush current prevention circuit 320 Smoothing capacitor 330 Load drive device 332 Load

The present invention can be used for industrial machines.

Claims (13)

With the main body
Suspended work part and
A drive unit that drives the traveling unit and the suspension work unit,
A power storage system that supplies power to the drive unit,
With
A crane having a function of diagnosing an abnormality in the power storage system at the time of starting or ending. The crane according to claim 1, further comprising an abnormality notification unit that detects an abnormality at startup and notifies the existence of the abnormality, or detects an abnormality at the end and notifies the existence of the abnormality. The abnormality notification unit is
In the case of remote control, the notification means provided in the remote control means
In the case of automatic operation, via communication means, the notification means provided in the administration building
In the case of manual operation, the notification means provided in the driver's cab
The crane according to claim 2, which notifies an abnormality. The abnormality notification unit changes the notification content according to the type of abnormality, and changes the notification content.
In the case of an abnormality at a level where work is restricted, a predetermined first level abnormality is notified and
The crane according to claim 2, wherein when replacement or maintenance is recommended, but work is not restricted, a second level abnormality lower than the first level is notified. The first aspect of the present invention, wherein the work is started in a work mode that does not use the power storage system by a predetermined mode change operation in a state where it is determined that an abnormality has occurred and the abnormality is notified or the work is restricted. Crane. The crane according to claim 5, wherein in the work mode that does not use the power storage system, at least one of a traveling speed and an operating speed of a suspension portion is limited. With a capacitor
An inrush current prevention circuit including a switch provided between the DC power supply and the capacitor,
A determination device that gives a cutoff command or a continuity command to the switch during the determination period and detects an abnormality of the switch based on the voltage of the capacitor or the current flowing through the inrush current prevention circuit at that time.
A power electronics device characterized by being equipped with. The determination device temporarily gives a cutoff command to the switch during the charging period in which the switch is given a continuity command to charge the capacitor, and is based on a change in the current flowing through the inrush current prevention circuit at that time. The power electronics device according to claim 7, wherein the presence or absence of the abnormality is determined. The determination device temporarily gives a cutoff command to the switch during the charging period in which the switch is given a continuity command to charge the capacitor, and the presence or absence of the abnormality is based on a change in the voltage of the capacitor at that time. The power electronics device according to claim 8, wherein the power electronics device is characterized in that. A converter device provided between the inrush current prevention circuit and the capacitor is further provided.
The seventh aspect of claim 7, wherein the converter device is switched in a state where a cutoff command is given to the switch, and the presence or absence of the abnormality is determined based on the current flowing through the inrush current prevention circuit at that time. Power electronics equipment. A converter device provided between the inrush current prevention circuit and the capacitor is further provided.
The power electronics device according to claim 7, wherein the converter device is switched in a state where a cutoff command is given to the switch, and the presence or absence of the abnormality is determined based on the voltage of the capacitor at that time. .. Further equipped with a load drive device connected to the capacitor
The seventh aspect of claim 7, wherein the load drive device is operated in a state where a cutoff command is given to the switch, and the presence or absence of the abnormality is determined based on the current flowing through the inrush current prevention circuit at that time. Power electronics equipment. Further equipped with a load drive device connected to the capacitor
The power electronics device according to claim 7, wherein the load drive device is operated in a state where a cutoff command is given to the switch, and the presence or absence of the abnormality is determined based on the voltage of the capacitor at that time. ..

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