Charging the battery of an electric mining vehicle

Abstract

An arrangement (100) for charging the battery (120) of an electric mining vehicle (200) comprising a battery (120) and one or more motors (210, 220) is provided. The arrangement (100) comprises a current supply circuit (110), arranged to supply electric current to the battery (120) for charging it, as well as to the one or more motors (210), (220), and a charge controller (150). The charge controller (150) is arranged to control the current supply circuit (110) to supply electric current to the battery (120) only when the power consumption in the one or more motors (210, 220) is below a predefined charge threshold Tc. This enables the charge controller (150) to prevent charging of the battery (120) simultaneously with mining work conducted by the electric mining vehicle (200). Also provided is a method (300) for charging the battery (120) of an electric mining vehicle (200) comprising a battery (120) and one or more motors (210, 220).

Description

[0001] CHARGING THE BATTERY OF AN ELECTRIC MINING VEHICLE

[0002] TECHNICAL FIELD

[0003] The present disclosure relates generally to the charging of the battery of an electric mining vehicle comprising a battery and one or more motors. The disclosed arrangements and methods may for example be applied in a rock drilling machine.

[0004] BACKGROUND

[0005] An electric mining vehicle is typically equipped with a battery, to allow the supply of energy even when the electric mining vehicle is not connected to an external power supply. This is necessary to enable the electric mining vehicle to move between different work sites, and to be able to operate at work sites where there is no external power supply. The battery can be charged when the electric mining vehicle is connected to an external power supply.

[0006] PROBLEMS WITH THE PRIOR ART

[0007] If the battery is charged simultaneously with mining work conducted by the electric mining vehicle, the power supply system must be dimensioned to simultaneously supply both the power needed for the battery charging and the power needed for the mining work conducted by the electric mining vehicle.

[0008] There is thus a need for improved arrangements and methods for charging the battery of an electric mining vehicle.

[0009] SUMMARY

[0010] The above-described problem is addressed by the claimed arrangement and method for charging the battery of an electric mining vehicle comprising a battery and one or more motors.

[0011] The arrangement preferably comprises a current supply circuit, arranged to supply electric current to the battery for charging it, as well as to the one or more motors, and a charge controller. The charge controller is preferably arranged to control the current supply circuit to supply electric current to the battery only when the power consumption in the one or more motors is below a predefined charge threshold Tc. This enables the charge controller to prevent charging of the battery simultaneously with mining work conducted by the electric mining vehicle, and instead charge the battery only when there is enough unused power.

[0012] The method preferably comprises supplying, using a current supply circuit, electric current to the battery for charging it, as well as to the one or more motors, determining the power consumption in the one or more motors, and controlling, using a charge controller, the current supply circuit to supply electric current to the battery only when the determined power consumption in the one or more motors is below a predefined charge threshold Tc. This enables the charge controller to prevent charging of the battery simultaneously with mining work conducted by the electric mining vehicle, and instead charge the battery only when there is enough unused power.

[0013] The claimed arrangement and method enable the power supply system, and especially the current supply circuit, to be dimensioned only for the maximum power needed for the mining work conducted by the electric mining vehicle.

[0014] In embodiments, the current supply circuit comprises a controllable rectifier, arranged to control whether the battery is charged or discharged based on the output voltage from the controllable rectifier.

[0015] In embodiments, the power consumption in the one or more motors is determined based on the rotational speed of the one or more motors. The rotational speed is easily monitored using sensors in the one or more motors, and a significant increase in the rotational speed may be used to indicate a significant increase in power consumption in the one or more motors.

[0016] In embodiments, the power consumption in the one or more motors is determined based on the power consumption of the electric mining vehicle in its entirety - the power consumption in the other parts of the electric mining vehicle is typically much lower than the power consumption in the one or more motors. The power consumption in the one or more motors may e.g. be defined as the power delivered by the controllable rectifier minus the power used for charging the battery (when the battery is discharged instead of charged, this means that the power discharged from the battery is added to the power delivered by the controllable rectifier, instead of being subtracted). A significant increase in the power consumption of the electric mining vehicle in its entirety may be used to indicate a significant increase in power consumption in the one or more motors.

[0017] In embodiments, the charge controller is arranged to control the current supply circuit to supply electric current from the battery to the one or more motors when the power consumption in the one or more motors is above a predefined peak threshold Tp. This will limit the maximum power supplied from the external power supply, and thus prevent overload in the current supply circuit, by using the battery as support when the power consumption is high.

[0018] The above described problem is further addressed by the claimed use of the above arrangement for charging the battery of an electric mining vehicle, such as a rock drilling machine, comprising a battery and one or more motors.

[0019] The above described problem is also addressed by the claimed rock drilling machine, comprising the above arrangement.

[0020] The battery may comprise any number of battery modules, as well as one or more battery management systems, and / or one or more cooling systems.

[0021] The scope of the invention is defined by the claims, which are incorporated into this section by reference. A more complete understanding of embodiments of the invention will be afforded to those skilled in the art, as well as a realization of additional advantages thereof, by a consideration of the following detailed description of one or more embodiments. Reference will be made to the appended sheets of drawings that will first be described briefly.

[0022] BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Fig. 1 is a schematic illustration of an arrangement for charging the battery of an electric mining vehicle comprising a battery and one or more motors, in accordance with one or more embodiments described herein.

[0024] Fig. 2 schematically illustrates an electric mining vehicle, in accordance with one or more embodiments described herein. Fig. 3 schematically illustrates a method for charging the battery of an electric mining vehicle comprising a battery and one or more motors, in accordance with one or more embodiments described herein.

[0025] Embodiments of the present disclosure and their advantages are best understood by referring to the detailed description that follows. It should be appreciated that like reference numerals are used to identify like elements illustrated in one or more of the figures.

[0026] DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS OF THE DISCLOSURE

[0027] An electric mining vehicle is typically equipped with a battery, to allow the supply of energy even when not connected to an external power supply. If the battery is charged simultaneously with mining work conducted by the electric mining vehicle, the power supply system must be dimensioned to simultaneously supply both the power needed for the battery charging and the power needed for the mining work conducted by the electric mining vehicle. It would therefore be advantageous to be able to ensure that the battery is not charged simultaneously with mining work conducted by the electric mining vehicle.

[0028] The present disclosure relates generally to arrangements and methods for charging the battery of an electric mining vehicle, such as e.g. a rock drilling machine, comprising a battery and one or more motors. Embodiments of the disclosed solution are presented in more detail in connection with the figures.

[0029] Fig. 1 is a schematic illustration of an arrangement 100 for charging the battery 120 of an electric mining vehicle comprising a battery 120 and two motors 210, 220. The arrangement 100 comprises a current supply circuit 110 and a charge controller 150. The current supply circuit 110 is arranged to receive power from an external power supply 180, e.g. an electrical cable providing 1000V AC, and supply electric current to the battery 120 for charging it, as well as to the motors 210, 220. The charge controller 150 is arranged to control the current supply circuit 110 to supply electric current to the battery 120 only when the when the power consumption in the motors 210, 220 is below a predefined charge threshold Tc. This enables the charge controller 150 to prevent charging of the battery 120 simultaneously with mining work conducted by the electric mining vehicle 200. The arrangement 100 schematically illustrated in Fig. 1 also comprises, as a part of the current supply circuit 110, a controllable rectifier 160, which transforms AC to DC. The controllable rectifier 160 is arranged to supply the motors 210, 220 with power from the external power supply 180, and to control whether the battery 120 is charged or discharged. The controllable rectifier 160 may e.g. be arranged to control the charging of the battery 120 based on the output voltage from the controllable rectifier 160, i.e. the voltage in the connection point 130. If the voltage in the connection point 130 is higher than the battery voltage, the battery 120 will be charged, and if the voltage in the connection point 130 is lower than the battery voltage, the battery 120 will be discharged (this principle is described in W02023091059). The controllable rectifier 160 may e.g. be a line converter, or an inverter. The charge controller 150 may control the controllable rectifier 160 to control that the battery 120 receives electric current only when the power consumption in the motors 210, 220 is below a predefined charge threshold Tc. As soon as the power consumption in the motors 210, 220 reaches the predefined charge threshold Tc, the current supply to the battery 120 is preferably stopped, in order to prevent charging of the battery 120 simultaneously with mining work conducted by the electric mining vehicle 200.

[0030] The controllable rectifier 160 may also be arranged to control the battery 120 to supply electric current to the motors 210, 220 if the power consumption in the motors 210, 220 reaches a predefined peak threshold Tp.This will limit the maximum power supplied from the external power supply 180, and thus prevent overload in the current supply circuit 110 by using the battery 120 as support when the power consumption is high.

[0031] The current supply circuit 110 may in embodiments be arranged to control the electric current supplied to and from the battery 120 using other means than one or more controllable rectifiers 160. The current supply circuit 110 may further comprise a number of other components, such as e.g. one or more transformers, and / or one or more filters.

[0032] The battery 120 may comprise any number of battery modules, as well as one or more battery management systems, and / or one or more cooling systems.

[0033] Fig. 2 schematically illustrates an electric mining vehicle 200 in the form of a rock drilling machine. The schematically illustrated electric mining vehicle 200 is supplied with power from an external power supply 180 and comprises a current supply circuit 110 controlled by a charge controller 150, a battery 120, and two motors 210, 220, which may drive different aspects of the electric mining vehicle 200. The first motor 210 may e.g. drive a hydraulic system in the electric mining vehicle 200, and the second motor 220 may e.g. drive a pneumatic system in the electric mining vehicle 200. A hydraulic system typically drives the tools that conduct the mining work, e.g. the ground engaging members 250, which are used for moving the rock drilling machine 200, and the arm 260, which is used for vertical positioning of a drilling arrangement. A pneumatic system typically drives a compressor that supplies compressed air that may be used e.g. for blowing away loose material during the mining work. The electric mining vehicle 200 may alternatively comprise only one motor that drives both a hydraulic system and a pneumatic system. There may also be other motors in the electric mining vehicle 200, such as e.g. small electric motors that drive the windshield wiper and the interior fan.

[0034] In order not to have to simultaneously supply both the power needed for the battery charging and the power needed for the mining work conducted by the electric mining vehicle 200, it needs to be ensured that no electric current is supplied to the battery 120 when the power consumption in the motors 210, 220 is above a predefined charge threshold Tc. This prevents charging of the battery 120 simultaneously with mining work conducted by the electric mining vehicle 200.

[0035] A hydraulic system in an electric mining vehicle is normally not turned off completely at any point during a workday, since it typically takes a long time to start up a hydraulic system. However, in order to save energy, the hydraulic system is preferably configured to enter an idling mode when it has not been used for a predetermined time, such as e.g. 30 seconds, or one minute. Such an idling mode may be entered any time the operator takes a short break in the mining work, such as e.g. for taking a telephone call. Since the first motor 210 uses very little power during an idling mode, and is only run at its idling speed (e.g. around 1000 rpm), there is free capacity in the current supply circuit 110, and this free capacity may be used for charging the battery 120. As soon as the operator activates any part of the hydraulic system, the hydraulic system leaves the idling mode, and the first motor 210 starts driving the hydraulic system, at a higher rotational speed than the idling speed. The charge controller 150 then senses that the power consumption in the motors 210, 220 goes above the predefined charge threshold Tc, and controls the current supply circuit 110 to immediately stop supplying electric current to the battery 120.

[0036] When the first motor 210 is run at idling speed, the second motor 220 may also be running at a low speed, or even be turned off entirely, since it is typically only the hydraulic system that takes a long time to start. The power consumption in the one or more motors 210, 220 at idling speed is typically less than 10kW (such as e.g. 5kW), which means that the predefined charge threshold Tcmay e.g. be 10kW.

[0037] The operator may cause the hydraulic system to leave the idling mode by activating any of the tools that are used to conduct the mining work, such as e.g. the ground engaging members 250, which are used for moving the rock drilling machine 200, or the arm 260, which is used for vertical positioning of a drilling arrangement. The idling mode may thus be left by any operator initiated action, such as by the operator using means such as e.g. a lever, a button or a joystick in the electric mining vehicle 200.

[0038] This enables the charging of the battery 120 during the workday, without the need to dimension the power supply system to simultaneously supply both the power needed for the battery charging and the power needed for the mining work conducted by the electric mining vehicle 200. This enables the power supply system, and especially the components in the current supply circuit 110 (such as e.g. the controllable rectifier 160) to be dimensioned only for the maximum power needed for the mining work conducted by the electric mining vehicle 200.

[0039] In embodiments, the power consumption in the one or more motors 210, 220 is determined based on the rotational speed of the one or more motors 210, 220, in order to detect when the one or more motors 210, 220 leaves its idling speed (e.g. around 1000 rpm) e.g. to reach a rotational speed of more than 1200 rpm. The rotational speed is easily monitored using sensors in the one or more motors 210, 220, and a significant increase in the rotational speed may be used to indicate a significant increase in power consumption in the one or more motors.

[0040] In embodiments, the power consumption in the one or more motors 210, 220 is determined based on the power consumption of the electric mining vehicle 200 in its entirety - the power consumption in the other parts of the electric mining vehicle 200 is typically much lower than the power consumption in the one or more motors 210, 220. The power consumption of the electric mining vehicle 200 in its entirety may e.g. be defined as the power delivered by the controllable rectifier 160 minus the power used for charging the battery 120 (when the battery 120 is discharged instead of charged, this means that the power discharged from the battery 120 is added to the power delivered by the controllable rectifier 160, instead of being subtracted). A significant increase in the power consumption of the electric mining vehicle 200 in its entirety may be used to indicate a significant increase in power consumption in the one or more motors 210, 220.

[0041] Fig. 3 schematically illustrates a method 300 for charging the battery of an electric mining vehicle comprising a battery 120 and one or more motors 210, 220. The method 300 may comprise:

[0042] Step 310: supplying, using a current supply circuit 110, electric current to the battery 120 for charging it, as well as to the one or more motors 210, 220.

[0043] Step 320: determining the power consumption in the one or more motors 210, 220.

[0044] Step 330: controlling, using a charge controller 150, the current supply circuit 110 to supply electric current to the battery 120 only when the determined power consumption in the one or more motors 210, 220 is below a predefined charge threshold Tc.

[0045] This enables the power supply system, and especially the components in the current supply circuit 110 (such as e.g. the controllable rectifier 160) to be dimensioned only for the maximum power needed for the mining work conducted by the electric mining vehicle 200, by not allowing the charging of the battery 120 simultaneously with the mining work conducted by the electric mining vehicle 200.

[0046] In embodiments, the determining 320 of the power consumption in the one or more motors 210, 220 is based on the rotational speed of the one or more motors 210, 220. The rotational speed is easily monitored using sensors in the one or more motors 210, 220, and a significant increase in the rotational speed may be used to indicate a significant increase in power consumption in the one or more motors.

[0047] In embodiments, the determining 320 of the power consumption in the one or more motors 210, 220 is based on the power consumption of the electric mining vehicle 200 in its entirety - the power consumption in the other parts of the electric mining vehicle 200 is typically much lower than the power consumption in the one or more motors 210, 220.

[0048] This may e.g. be defined as the power delivered by the controllable rectifier 160 minus the power used for charging the battery 120 (when the battery 120 is discharged instead of charged, this means that the power discharged from the battery 120 is added to the power delivered by the controllable rectifier 160, instead of being subtracted). A significant increase in the power consumption of the electric mining vehicle 200 in its entirety may be used to indicate a significant increase in power consumption in the one or more motors 210, 220.

[0049] The method 300 may further comprise one or more of:

[0050] Step 340: controlling whether the battery 120 is charged or discharged based on the output voltage from a controllable rectifier 160 comprised in the current supply circuit 110.

[0051] Step 350: controlling, using the charge controller 150, the current supply circuit 110 to supply electric current from the battery 120 to the one or more motors 210, 220 when the determined power consumption in the one or more motors 210, 220 is above a predefined peak threshold Tp. This will limit the maximum power supplied from the external power supply 180, and thus prevent overload in the current supply circuit 110, by using the battery 120 as support when the power consumption is high.

[0052] The foregoing disclosure is not intended to limit the present invention to the precise forms or particular fields of use disclosed. It is contemplated that various alternate embodiments and / or modifications to the present invention, whether explicitly described or implied herein, are possible in light of the disclosure. The steps may be effected in any order that makes technical sense, and some of the steps may be effected simultaneously with each other. Accordingly, the scope of the invention is defined only by the claims.

Claims

CLAIMS1. Arrangement (100) for charging the battery (120) of an electric mining vehicle (200) comprising a battery (120) and one or more motors (210, 220), the arrangement (100) comprising: a current supply circuit (110), arranged to supply electric current to the battery (120) for charging it, as well as to the one or more motors (210, 220); and a charge controller (150), arranged to control the current supply circuit (110) to supply electric current to the battery (120) only when the power consumption in the one or more motors (210, 220) is below a predefined charge threshold Tc.

2. Arrangement (100) according to claim 1 , wherein the current supply circuit (110) comprises a controllable rectifier (160), arranged to control whether the battery (120) is charged or discharged based on the output voltage from the controllable rectifier (160).

3. Arrangement (100) according to claim 1 or 2, wherein the power consumption in the one or more motors (210, 220) is determined based on the rotational speed of the one or more motors (210, 220)4. Arrangement (100) according to any one of claims 1-3, wherein the power consumption in the one or more motors (210, 220) is determined based on the power consumption of the electric mining vehicle (200) in its entirety.

5. Arrangement (100) according to any one of claims 1-4, wherein the charge controller (150) is arranged to control the current supply circuit (110) to supply electric current from the battery (120) to the one or more motors (210, 220) when the power consumption in the one or more motors (210, 220) is above a predefined peak threshold Tp.

6. Method (300) for charging the battery (120) of an electric mining vehicle (200) comprising a battery (120) and one or more motors (210, 220), the method (300) comprising: supplying (310), using a current supply circuit (110), electric current to the battery (120) for charging it, as well as to the one or more motors (210, 220); determining (320) the power consumption in the one or more motors (210, 220); andcontrolling (330), using a charge controller (150), the current supply circuit (110) to supply electric current to the battery (120) only when the determined power consumption in the one or more motors (210, 220) is below a predefined charge threshold Tc.

7. Method (300) according to claim 6, further comprising controlling (340) whether the battery (120) is charged or discharged based on the output voltage from a controllable rectifier (160) comprised in the current supply circuit (110).

8. Method (300) according to claim 6 or 7, wherein the determining (320) of the power consumption in the one or more motors (210, 220) is based on the rotational speed of the one or more motors (210, 220).

9. Method (300) according to any one of claims 6-8, wherein the determining (320) of the power consumption in the one or more motors (210, 220) is based on the power consumption of the electric mining vehicle (200) in its entirety.

10. Method (300) according to any one of claims 6-9, further comprising controlling (350), using the charge controller (150), the current supply circuit (110) to supply electric current from the battery (120) to the one or more motors (210, 220) when the determined power consumption in the one or more motors (210, 220) is above a predefined peak threshold TP.

11. Use of an arrangement (100) according to any one of claims 1-5 for charging the battery of an electric mining vehicle (200), such as a rock drilling machine, comprising a battery (120) and one or more motors (210, 220).

12. Rock drilling machine (200) comprising an arrangement (100) according to any one of claims 1-5.

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