Charging controller, machine and method for regulating a soc level of an energy storage

Abstract

A method performed by a charging controller for regulating a State of Charge, SOC, level of an energy storage in an electrically powered mining and / or construction machine is provided. The energy storage provides electrical energy to at least one electrical motor comprised in the electrically powered mining machine. The energy storage is charged with energy received from an external energy source. The charging controller determines (301) a set of parameters related to a duty cycle of the electrically powered mining and / or construction machine. Each time the electrically powered mining and / or construction machine connects to the external energy source, the charging controller determines (302) a charging power for charging the energy storage. The charging power is determined based on the set of parameters and a current SOC level of energy storage in order to meet a SOC level criterion. The charging controller regulates (303) the SOC level of the energy storage by charging the energy storage according to the determined charging power.

Description

[0001] CHARGING CONTROLLER, MACHINE AND METHOD FOR REGULATING A SOC LEVEL OF AN ENERGY STORAGE.

[0002] TECHNICAL FIELD

[0003] Embodiments herein relate to a method, an arrangement and a machine for regulating a State Of Charge (SOC) level of an energy storage in a mining and / or construction machine.

[0004] BACKGROUND

[0005] In mining and tunneling, there is a constant ongoing process of improving efficiency, productivity and safety. Examples of changes and / or improvements that are carried out to an increasing extent, especially in mining, is the automation, fully or partly, of various processes occurring in mining. Methods for localization, mapping, control and motion planning have enabled development and deployment of fully or partly autonomous vehicles and / or mobile machines, hereinafter denoted as machines. Further, a transition to electrically powered machines is ongoing. This is an important step to reduce emissions of e.g., carbon dioxide. Further, with electrically powered machines, exhaust fumes decrease in the mines and tunnels. This may lead to an improved work environment and lower ventilation requirements.

[0006] Electrically powered machines introduce new requirements for charging infrastructure, electrical capacity and energy storage in machines. Charging and discharging of an energy storage on a machine may have impact on the energy storage capacity, and the energy storage may be degraded over time. Further, electrical infrastructure is expensive, and it requires high capacity to handle charging of a large number of electrically powered machines.

[0007] Consequently, there is a need for improvements in handling the charging of electrically powered machines.

[0008] SUMMARY

[0009] 1

[0010] SUBSTITUTE SHEET (Rule 26) As part of developing embodiments herein a problem has been identified and will first be discussed.

[0011] A problem with electrically powered mining and / or construction machines relates to charging an energy storage comprised in the machines. More specifically, to regulating a State of Charge (SOC) level of the energy source when the energy source is charged by an external energy source, such as e.g., a trolley line, while driving. When charging the energy storage from the external energy source, the energy storage is usually charged with a maximum charging power in order to achieve as high SOC level as possible. This may lead to a high load of the electric infrastructure. Further, charging with a higher charging power results in an increased wear of the energy storage as well as the charging electronics connected to the energy storage. One solution would e.g., be to limit the allowed charging power. However, this may lead to insufficient SOC levels of the energy storage in the electrically powered mining and or construction machines, which may result in of electrically powered mining and or construction machines standing still due to empty energy storages.

[0012] An object of embodiments herein is to provide a mechanism that improves the SOC level regulation of electrically powered mining and or construction machines and reduces the wear of energy storage in the electrically powered mining and or construction machines. The object is achieved by the independent claims.

[0013] According to a first aspect, the object is achieved by a method performed by a charging controller for regulating a State of Charge, SOC, level of an energy storage in an electrically powered mining and / or construction machine. The energy storage provides electrical energy to at least one electrical motor comprised in the electrically powered mining machine. The energy storage is charged with energy received from an external energy source.

[0014] The charging controller determines a set of parameters related to a duty cycle of the electrically powered mining and / or construction machine.

[0015] Each time the electrically powered mining and / or construction machine connects to the external energy source, the charging controller determines a charging power for charging the energy storage. The charging power is determined based on the set of parameters and a current SOC level of energy storage in order to meet a SOC level criterion. The charging controller regulates the SOC level of the energy storage by charging the energy storage according to the determined charging power.

[0016] According to a second aspect, the object is achieved by a charging controller configured to regulate a State of Charge, SOC, level of an energy storage in an electrically powered mining and / or construction machine. The energy storage is adapted to provide electrical energy to at least one electrical motor comprised in the electrically powered mining machine. The energy storage is adapted to be charged with energy received from an external energy source., the charging controller further being configured to:

[0017] Determine a set of parameters adapted to be related to a duty cycle of the electrically powered mining and / or construction machine, each time the electrically powered mining and / or construction machine connects to the external energy source, determine a charging power for charging the energy storage, wherein the charging power is adapted to be determined based on the set of parameters and a current SOC level of energy storage in order to meet a SOC level criterion, and regulate the SOC level of the energy storage by charging the energy storage according to the determined charging power.

[0018] According to a third aspect, the object is achieved by an electrically powered mining and / or construction machine configured to comprise an energy storage and at least one electrical motor. The energy storage is adapted to provide electrical energy to at least one electrical motor. The electrically powered mining and / or construction machine is further configured to comprise a charging controller according to the second aspect.

[0019] According to a fourth aspect, it is furthermore provided herein a computer program comprising instructions, which, when executed on at least one processor, cause the at least one processor to carry out the method above.

[0020] Embodiments herein may bring the advantage of improved SOC level regulation of electrically powered mining and or construction machines. This may e.g., be achieved by, as mentioned above, determining a charging power for regulating the SOC level each time the electrically powered mining and / or constriction machine connects to the external power source. The charging power is determined to meet a SOC level criterion based on a set of parameters related to the duty cycle and a current SOC level of the energy storage in the electrically powered mining and / or constriction machine. This leads to an improved SOC level regulation of electrically powered mining and or construction machines, since by determining the charging power, it is possible to efficiently regulate the SOC level.

[0021] Further, embodiments herein may bring the advantage of a decreased wear of the energy storage, since by determining a charging power based on the set of parameters and the current SOC level in order to regulate the SOC level of the energy storage, it is possible to reduce the wear of the energy storage e.g., by avoiding unfavorable SOC levels and charging powers.

[0022] BRIEF DESCRIPTIONS OF DRAWINGS

[0023] Examples of embodiments herein are described in more detail with reference to attached drawings in which:

[0024] Figure 1 shows an electrically powered mining and / or construction machine system according to embodiments herein.

[0025] Figure 2 shows an example of a worksite according to embodiments herein.

[0026] Figure 3 shows a flowchart depicting embodiments of a method according to embodiments herein.

[0027] Figures 4a to 4b show schematic block diagrams illustrating embodiments of a charging controller.

[0028] It should be noted that the drawings have not necessarily been drawn to scale and that the dimensions of certain features may have been exaggerated for the sake of clarity. Like reference signs in the drawings refer to the same or similar element, unless expressed otherwise.

[0029] DETAILED DESCRIPTION

[0030] As mentioned above, an object of embodiments herein is to provide mechanisms that improve the SOC level regulation of an energy storage providing electrical energy to an electrically powered mining and / or construction machine, reduce wear of the energy storage, charging of the energy storage based on a duty cycle of the mining and / or construction machine, and minimize the load of electrical infrastructure providing electrical energy to the energy storage. This e.g., by an improved mechanism for regulating the SOC level of the energy storage of the electrically powered mining and of construction machine.

[0031] Embodiments herein may bring the advantage of a reduced wear of the energy storage providing electrical energy to the electrically powered mining and / or construction machine. This may be achieved by regulating the SOC level of the energy storage, e.g., determining a charging power that meets a SOC level criterion. In this way unfavorable SOC levels will be avoided. Further, embodiments herein may bring the advantage of minimizing the load of the electrical infrastructure, e.g., by determining the charging power based on a set of parameters related to the duty cycle of the mining and / or construction machine. In this way, the charging power used to regulate the SOC level may be adaptively determined based on the duty cycle, instead of always using a maximum charging power.

[0032] Fig. 1 shows an example of a mining and / or construction machine 1 according to embodiments herein, mining and / or construction machine comprises a charging controller 10, at least one energy storage 11 and at least one electrical motor 12. The charging controller 10 controls the charging of the at least one energy storage 11. This may comprise regulating a SOC level of the at least one energy storage 11 , e.g., by determining a charging power to be used for charging the at least one energy storage 11. The charging power may be larger than zero, zero or smaller than zero. A charging power larger than zero, such as a positive charging power, may mean that electrical energy is supplied to the at least one energy storage 11 from an external power source. A charging power smaller than zero, such as a negative charging power, may mean that electrical energy is supplied from the at least one energy storage 11 to the external power source. The external power source may e.g., be a trolley line the mining and / or construction machine 1 may connect to.

[0033] The at least one energy storage 11 may e.g., be a battery configured to store electrical energy. The at least one energy storage 11 may supply electrical energy to the at least one electrical motor 12 in the electrically powered mining and / or mining machine 1. The current level of electrical energy in the at least one energy storage may be expressed as the SOC level. Thus, the SOC level of the at least one energy storage 11 the current level of electrical energy in the at least one energy storage, e.g., as a percentage of the maximum capacity of the at least one energy storage. The at least one energy storage 11 may be supplied, such as charged, with electrical energy from the external power source, or from the at least one electrical motor 12 e.g., by regenerative braking of the mining and / or construction machine 1.

[0034] Fig. 2 shows an example of a worksite for the electrically powered mining and or construction machine 1. The electrically powered mining and / or construction machine 1 may operate according to a duty cycle that in example comprises driving from A to B and back to A again. Along the path from A to B, there are two sections where an external energy source 20 is available. The electrically powered mining and / or construction machine 1 may connect to the external energy source 20 and then charge the at least one energy storage 11 according to a charging power e.g., determined by the charging controller 10. The worksite and duty cycle shown in Fig. 2 are simplified for an easier understanding of embodiments herein.

[0035] In the following examples, the worksite referred to in Fig. 2 is referred to as a mine, or mining environment. The mine or mining environment may be above ground, or it may be an underground mine or mining environment. This is not to be seen as limiting, and the examples may be correspondingly applied to other type of worksites, such as e.g., a construction site.

[0036] According to an example of embodiments herein, the mining and / or construction machine 1 may be located at position A, at the bottom of the mine. The at least one energy storage 11 may have a SOC level that equals a SOC reference level. The mining and / or construction machine 1 may connect to the external energy source 20 and start moving in accordance with a duty cycle. According to this example, the charging controller 10 may determine a charging power that provides energy to the at least one energy storage 11 that equals the amount energy consumed by the mining and / or construction machine 1 , this since the SOC level equals the SOC reference level. This way the SOC level may be regulated to stay at the same level as the SOC reference level.

[0037] According to some other examples of embodiments herein, the SOC level of the at least one energy storage 11 is 5% when the mining and / or construction machine 1 connects the external energy source 20. A lower threshold may be configured in the charging controller 10 for the lowest allowed SOC level. The lower threshold may also be referred to as a second threshold. In this example, the second threshold is configured to a SOC level of 15%. The charging controller 10 may then determine the charging power to be a maximum charging power, i.e. , as much energy as possible is to be supplied to the at least one energy storage 11 in as short time as possible. The maximum charging power may e.g., be used until the SOC level of the at least one energy storage 11 reaches the second threshold. When the SOC level has reached the second threshold, the charging controller 10 may change, or adapt, the charging power. The charging controller 10 may determine to decrease the charging power, and the decreased charging power may e.g., be used until the SOC level has reached another threshold, also referred to as a fourth threshold, that is higher than the second threshold. When the SOC level has reached the fourth threshold, the charging power may be determined, or adapted, such that energy provided to the at least one energy storage 11 that equals the amount energy consumed by the mining and / or construction machine 1. It should be noted that the embodiments herein are not limited to only using two thresholds where the charging power is adapted, more or less thresholds may be used. This example may be altered to reflect a scenario where the SOC level e.g., starts at 95% and an upper threshold, also referred to as a first threshold, is configured to a level of e.g., 85%. Here, the charging controller 10 may determine the charging power to be lower than or equal to zero. In this way the SOC level of the at least one energy storage 11 may be decreased. When the SOC level has reached the first threshold, the charging controller 10 may adapt the charging power, e.g., by determining to increase the charging power. By this, the decrease SOC level becomes slower. Further, when the SOC level has reached another threshold, also referred to as a third threshold, that is lower than the first threshold, the charging power may be determined, or adapted, such that energy provided to the at least one energy storage 11 that equals the amount energy consumed by the mining and / or construction machine 1. Once again, it should be noted that the embodiments herein is not limited to only using two thresholds where the charging power is adapted, more or less thresholds may be used.

[0038] According to another example of embodiments herein, the SOC level is at e.g., 20%. The mining and / or construction machine 1 drives down a ramp, and by regenerative braking, the at least one electrical motor 12 provides, or supplies, energy to the at least one energy source 20. In this example, the SOC level has increases to 60% when the mining and / or construction machine 1 connects to the external energy source 20. The charging controller 10 may determine the charging power to use while connected to the external energy source 20, e.g., based on a set of parameters related to the duty cycle, which may comprise the SOC reference level. If the SOC reference level e.g., is 50%, the charging controller 10 may determine the charging power such that the SOC level decreases to 30% while the mining and / or construction machine 1 is connected to the external energy source 20. This since the natural variation of the SOC level here is 40%, 60%-20%= 40%. While driving up the ramp, the mining and / or construction machine 1 may be disconnected from the external energy source 20. When reconnecting, the charging controller 10 may determine a new, such as adapt the, charging power such that the SOC level is 30% once reaching the top of the ramp.

[0039] According to another example of embodiments herein, the mine may comprise external energy source 20 where the mining and / or construction machine 1 may connect both when the mining and / or construction machine 1 drive up a ramp and down a ramp. In this example, the SOC reference level is 50%. The energy consumption of the mining and / or construction machine 1 during this duty cycle may be 12% when disconnected from the external energy source 20, and the current SOC level may be 45%. The largest natural variance during the duty cycle may be 10%. The charging controller 10 may determine the charging power such that the SOC level is 51% when the mining and / or construction machine 1 reaches the bottom the ramp and disconnects from the external energy source 20, given that the time to drive down the ramp equals the time to drive up the ramp. The mining and / or construction machine 1 drives according to its duty cycle and when once again connects to the external energy source 20, the SOC level is at 49%. The charging controller 10 may determine a new charging power which results in that the SOC level is at 55% when the mining and / or construction machine 1 reaches the top of the ramp. The mining and / or construction machine 1 drives according to its duty cycle and when returning to drive down the ramp, the SOC level is at 45 %.

[0040] Fig. 3 shows an example embodiment of a method performed by the charging controller 10 for regulating the SOC level of the energy storage 11 in the electrically powered mining and / or construction machine 1. The energy storage 11 provides electrical energy to at least one electrical motor 12 comprised in the electrically powered mining machine 1. The energy storage 11 is charged with energy received from an external energy source 20. The external energy source 20 may e.g., be a trolly line. The energy storage 11 may e.g., be a battery. The method comprises the following actions, which may be taken in any suitable order. Optional actions are referred to as dashed boxes in Fig. 3.

[0041] Action 301

[0042] The charging controller 10 determines a set of parameters related to a duty cycle of the electrically powered mining and / or construction machine 1. Determining the set of parameters may e.g., comprise obtaining the set of parameters from a memory in the charging controller 10. Alternatively, or additionally, the set of parameters may be continuously, or repeatedly, determined. E.g., the charging controller 110 may evaluate and update the set of parameters according to a time and / or distance interval. This may mean that the set of parameters are adapted, or adaptively determined, during the duty cycle, e.g., based on new information such as e.g., energy consumption, changes in the route of the duty cycle, queueing, unexpected stops, accidents and / or non-availability of the external energy source 20. Further, in some examples, the set of parameters may be determined, or adapted, each time the electrically powered mining and / or construction machine 1 connects to the external energy source 20.

[0043] The set of parameters may comprise a SOC reference level. The SOC reference level may e.g., be determined based on the duty cycle.

[0044] SOC reference level when used herein, may e.g., mean a preferred SOC level that, during a duty cycle, the SOC level of the energy storage varies, such as that the natural variance of the SOC level varies around the SOC reference level.

[0045] In some embodiments, the set of parameters may comprise any one or more out of:

[0046] - A first amount of energy consumed when the electrically powered mining and / or construction machine 1 is disconnected from the external energy source 20 during a duty cycle. The first amount of energy may e.g., be calculated as an average of the energy consumed during one or more previous duty cycles. In case the of only one previous duty cycle, the first amount of energy may be the energy consumption during this one previous duty cycle.

[0047] - A second amount of energy generated when the electrically powered mining and / or construction machine 1 is disconnected from the external energy source 20 during the duty cycle. The second amount of energy may e.g., be generated when driving downhill. The second amount of energy may e.g., be calculated as an average of the energy generated during one or more previous duty cycles. In case the of only one previous duty cycle, the second amount of energy may be the energy generated during this one previous duty cycle.

[0048] - A ratio between a time period the electrically powered mining and / or construction machine 1 is connected to the external energy source 20 and a time period when it is disconnected from the external energy source 20. The ratio may e.g., be calculated as an average ratio during one or more previous duty cycles. In case the of only one previous duty cycle, the ratio may be the ratio during this one previous duty cycle.

[0049] - A third amount of energy consumed by the electrically powered mining and / or construction machine 1 during a most recent time period disconnected from the external energy source 20. In other words, the third amount of energy may comprise the energy consumed the last time the mining and / or construction machine 1 was disconnected from the external energy source 20. This may mean that the third amount of energy was taken from the battery of the mining and / or construction machine 1.

[0050] - A fourth amount of energy comprising a current amount of energy supplied to the at least one electrical motor 12. In other words, the fourth amount of energy may comprise a momentary amount of energy supplied to the at least one electrical motor 12.

[0051] - A fifth amount of energy comprising an estimated amount of energy to be supplied to the at least one electrical motor 12 until the electrically powered mining and / or construction machine 1 is disconnected from external energy source 20. In other words, the fifth amount of energy may comprise an estimation of the amount of total amount energy needed to by the mining and / or construction machine 1 until it disconnects from the external energy source 20.

[0052] Action 302

[0053] Each time the electrically powered mining and / or construction machine 1 connects to the external energy source 20, the charging controller 10 determines a charging power for charging the energy storage 11. The charging power is determined based on the set of parameters and a current SOC level of the energy storage 11 in order to meet a SOC level criterion. In other words, in order to meet the, e.g., one or more, SOC level criterion, the charging controller 10 determines the charging power each time the mining and / or construction machine 1 connects to the external energy source 20. Thus, the charging power may be adaptively determined based on the set of parameters and the current SOC level. This may mean that the charging power is determined several times during a duty cycle, where the charging power may not always be determined to be the same.

[0054] Meeting the SOC level criterion may comprise meeting one or more SOC level criterion. Therefore, in some embodiments, meeting the SOC level criterion may comprise that any one or more out of:

[0055] - An average SOC level of the energy storage 11 during the duty cycle equals the SOC reference level. In other words, the average SOC level of the duty cycle is the same as the SOC reference level. This may mean that the SOC level of the external energy source 20 may vary during the duty cycle, e.g., since the mining and / or construction machine 1 is not always connected to the external energy source 20. The variation of the SOC level may be around the SOC reference level, meaning e.g., that sometimes it is above and sometimes below the SOC reference level, but the average SOC level during the duty cycle equals the SOC reference level, in some examples, equals may mean that that average SOC level is within a certain percentage of the reference SOC level.

[0056] - The SOC level of the energy storage 11 equals the SOC reference level when the electrically powered mining and / or construction machine 1 disconnects from the trolley line. This may mean that the charging level may be determined such that, when the mining and / or construction machine 1 disconnects from the external energy source 20, the SOC level equals the SOC reference level. As mentioned above, equals may mean that that SOC level is within a certain percentage of the reference SOC level.

[0057] - During a duty cycle, the energy consumed by the electrically powered mining and / or construction machine 1 when disconnected from the trolley line equals the energy charged to the energy storage 11 when the electrically powered mining and / or construction machine 1 is connected to the trolley line. This may mean that the mining and / or construction machine 1 starts and ends the duty cycle with the same SOC level.

[0058] In some embodiments, the charging power is further determined to be as low as possible while still meeting the SOC level criterion. In other words, determining the respective charging power may comprise minimizing the charging power for charging the energy storage 11. The minimized charging power is determined to still meet, or fulfill, the SOC level criterion. By this, the load of the power grid supplying electric energy to the external energy source 20, and the mining and / or construction machine 1, may decrease. Further, a lower charging power may reduce the wear of the energy storage 11 , as well as on the charging electronic on the mining and / or construction machine 1.

[0059] In some embodiments, the charging power is further determined such that any one or more out of:

[0060] - The SOC level remains below a first threshold. The first threshold may also be referred to a maximum allowed SOC level. Alternatively, or additionally, the charging power is determined such that SOC level decreases in order to lower the SOC level so it becomes less than the first threshold. Thus, the charging power may be determined such that the SOC level remains below the first threshold and / or such that the SOC level decreases at least until it is below the first threshold.

[0061] - The SOC level remains above a second threshold. The second threshold may also be referred to a minimum allowed SOC level. Alternatively, or additionally, the charging power is determined such that SOC level increases in order to increase the SOC level so it becomes higher than the second threshold. Thus, the charging power may be determined such that the SOC level remains above the second threshold and / or such that the SOC level increases at least until it is above the second threshold. The first and second thresholds may be configured in the charging controller 10.

[0062] In some embodiments, when the current SOC level approaches the first threshold, the charging controller 10 determines the charging power to be lower than or equal to zero. The charging controller 10 adapts the charging power based on changes to the current SOC level. The charging power being lower than zero may mean that electrical energy is supplied from the energy storage 11 to the external energy source 20. The charging power being equal to zero means that no electrical energy is supplied in either direction between the energy storage 11 and the external energy source 20. As an example, the current SOC level approaches the first threshold, i.e. , the SOC level is increasing and is within a certain percentage of the first threshold. In order to lower the current SOC level, the charging controller 10 determines that the charging power is to be lower than or equal to zero. This way, the SOC level in the energy storage 11 may decrease, either by supplying electrical energy from the energy storage 11 to the external energy source 20, or by that no electrical energy is supplied in either direction between the energy storage 11 and the external energy source 20. According to the last option, the SOC level is decreased by the electrical energy used by the machine and / or construction machine 1. In some examples of the above, approaches the first threshold may comprise, or be changed to, that the current SOC level is above the first threshold. Thus, in some examples, when the current SOC level is above the first threshold, the charging controller 10 determines the charging power to be lower than or equal to zero. The charging controller 10 may adapt the charging power based on changes to the current SOC level. E.g., the charging controller 10 may adapt the charging power when the SOC level has decreased to equal the first threshold. The charging controller 10 may adapt the charging power by determining to increase the charging power to be higher than the previously determined charging power, while still low enough to decrease the SOC level. Low enough to decrease the SOC level may mean that less energy is supplied to the energy storage 11 from the external energy source 20 than is consumed by the mining and / or construction machine 1. The charging controller 10 may adapt the charging power based on changes to the current SOC level. The charging power may here be the charging power used for charging the energy storage 11 as explained in Action 303.

[0063] In some embodiments, when the current SOC level approaches the second threshold, the charging controller 10 determines the charging power to be a maximum charging power. The charging controller 10 adapts the charging power based on changes to the current SOC level. The maximum charging power may e.g., be the maximum charging power the energy storage 11 and / or the charging electronic in the machine and / or construction machine 1 is able to handle and / or receive. As an example, the current SOC level approaches the second threshold, i.e. , the SOC level is decreasing and may be within a certain percentage of the second threshold. In order to increase the current SOC level, the charging controller 10 may determine that the charging power is the maximum charging power. Alternatively, the charging controller 10 may determine the charging power such that the SOC level increases, while not being the maximum charging power. This way, the SOC level in the energy storage 11 may increase by supplying electrical energy from the external energy source 20 to the energy storage 11 to the external energy source 20. In some examples of the above, approaches the second threshold may comprise, or be changed to, that the first current SOC level is below the second threshold. Thus, in some examples, when the current SOC level is below the second threshold, the charging controller 10 may determine the charging power to be a maximum charging power. The charging controller 10 may adapt the charging power based on changes to the current SOC level. E.g., the charging controller 10 may adapt the charging power when the SOC level has increased to equal the second threshold. The charging controller 10 may adapt the charging power by determining to decrease the charging power to be lower than the maximum charging power, while still high enough to increase the SOC level. High enough to increase the SOC level may mean that more energy is supplied to the energy storage 11 from the external energy source 20 than is consumed by the mining and / or construction machine I .The charging power may here be the charging power used for charging the energy storage 11 as explained in Action 303.

[0064] In some embodiments, adapting the charging power comprises repeatedly evaluating the current SOC level. The charging controller 10 may adapt the charging power by any one out of: Increasing the charging power or decreasing the charging power. Repeatedly evaluating the current SOC level may e.g., mean monitoring the SOC level of the energy storage 11 and based on the monitored SOC level, adapt the charging power by e.g., determine to increase and / or decrease the charging power. Repeatedly may e.g., mean at certain time and / or distance intervals, or it may mean continuously.

[0065] In some embodiments, adapting the charging power may comprise determining the charging power to equal the current energy consumption when the current SOC level has reached a third threshold that is lower than the first threshold. Referring to the example above where the current SOC level is approaching, or is above, the first threshold, this may e.g., mean that the charging controller 10 e.g., monitors the current SOC level, and when the SOC level has reached the third threshold, determines the charging power to equal the current energy consumption. Alternatively, or additionally, adapting the charging power may comprise determining the charging power to equal the current energy consumption when the current SOC level has reached a fourth threshold that is higher than the second threshold. Referring to the example above where the current SOC level is approaching, or is below, the second threshold, this may e.g., mean that the charging controller 10 e.g., monitors the current SOC level, and when the SOC level has reached the fourth threshold, determines the charging power to equal the current energy consumption. Thus, the charging controller 10 may adapt the charging power in a stepwise manner e.g., by monitoring the current SOC level of the energy storage and redetermining the charging power at different SOC level thresholds. In the above examples, four different thresholds are discussed. Embodiments herein may however be implemented with any number of thresholds.

[0066] In some examples, the third threshold and the fourth threshold may be the same, or equal. The first, second, third and fourth thresholds may also be referred to as the first, second, third and fourth SOC level thresholds. That is, the first, second, third and fourth thresholds may correspond to certain SOC levels.

[0067] Action 303

[0068] The charging controller 10 regulates the SOC level of the energy storage 11 by charging the energy storage 11 according to the determined charging power. In other words, when the charging controller 10 has determined a charging power, the determined charging power is used to charge the energy storage 11. As described above, the charging controller 10 may continuously, or adaptively, determine the charging power, even while charging the energy storage 11. Thus, in some embodiments, the charging controller 10 may change the charging power currently used to a new determined, such as the latest determined, charging power.

[0069] Fig. 4a disclose an example configuration of the charging controller 10 configured to regulate the SOC level of the energy storage 11 in the electrically powered mining and / or construction machine 1. The energy storage 11 is adapted to provide electrical energy to at least one electrical motor 12 comprised in the electrically powered mining machine 1. The energy storage 11 is adapted to be charged with energy received from an external energy source 20.

[0070] The charging controller 10 may comprise an input and output interface 400 configured to communicate with, e.g., the energy storage 11, the at least one electrical motor 12 and / or units, controllers or entities located in or outside the charging controller 10.

[0071] Fig. 4b discloses an example configuration of processing circuitry for a charging controller, e.g., the processing circuitry 450 disclosed in Fig. 4a. The processing circuitry may comprise a determining unit 410 and a regulating unit 420 configured to perform the methods above.

[0072] The charging controller 10 determines a set of parameters adapted to be related to a duty cycle of the electrically powered mining and / or construction machine 1.

[0073] Each time the electrically powered mining and / or construction machine 1 connects to the external energy source 20, the charging controller 10 determines a charging power for charging the energy storage 11. The charging power is adapted to be determined based on the set of parameters and a current SOC level of energy storage 11 in order to meet a SOC level criterion.

[0074] The charging controller 10 charges the energy storage 11 according to the determined charging power.

[0075] The embodiments herein may be implemented through the processing circuitry 450 in the charging controller 10 depicted in Figure 4a, together with respective computer program code for performing the functions and actions of the embodiments herein. The processing circuitry 450 may comprise one or more processors and one or more memory units. The memory units may be the memory 460. The program code mentioned above may also be provided as a computer program product, for instance in the form of a data carrier carrying computer program code for performing the embodiments herein when being loaded into the charging controller 10. One such carrier may be in the form of a CD ROM disc, a USB flash drive, and / or an Over-the-Air (OTA) carrier. It is however feasible with other data carriers such as a memory stick. The computer program code may furthermore be provided as pure program code on a server and downloaded to the battery charge management unit 101.

[0076] The memory 460 of the charging controller 10 may further comprise one or more memory units. The memory 460 is configured to store instructions executable by the processing circuitry 450. The memory 460 is arranged to be used to store e.g., information, messages, indications, configurations, thresholds, SOC levels, charging power, locations, positions and applications to perform the methods herein when being executed in executed in the charging controller 10. In some embodiments, a computer program 470 comprises instructions, which when executed by the processing circuitry 450, e.g., of the respective at least one processor of the processing circuitry 450, cause the processing circuitry 740 of the charging controller 10 to perform the actions above.

[0077] In some embodiments, a respective carrier 480 comprises the respective computer program 470, wherein the carrier 480 is one of an electronic signal, an optical signal, an electromagnetic signal, a magnetic signal, an electric signal, a radio signal, a microwave signal, or a computer-readable storage medium.

[0078] Those skilled in the art will appreciate that the units in the charging controller 10 described above may refer to a combination of analogue and digital circuits, and / or one or more processors configured with software and / or firmware, e.g., stored in the charging controller 10, that when executed by the respective one or more processors such as the processors described above. One or more of these processors, as well as the other digital hardware, may be included in a single Application-Specific Integrated Circuitry (ASIC), or several processors and various digital hardware may be distributed among several separate components, whether individually packaged or assembled into a system-on-a- chip (SoC).

[0079] It will be appreciated that the foregoing description and the accompanying drawings represent non-limiting examples of the methods and apparatus taught herein. As such, the apparatus and techniques taught herein are not limited by the foregoing description and accompanying drawings. Instead, the embodiments herein are limited only by the following claims and their legal equivalents.

Claims

CLAIMS1. A method performed by a charging controller (10) for regulating a State of Charge, SOC, level of an energy storage (11) in an electrically powered mining and / or construction machine (1), which energy storage (11) provides electrical energy to at least one electrical motor (12) comprised in the electrically powered mining machine (1), wherein the energy storage (11) is charged with energy received from an external energy source (20), the method comprising: determining (301) a set of parameters related to a duty cycle of the electrically powered mining and / or construction machine (1), each time the electrically powered mining and / or construction machine (1) connects to the external energy source (20), determining (302) a charging power for charging the energy storage (11), wherein the charging power is determined based on the set of parameters and a current SOC level of energy storage (11) in order to meet a SOC level criterion, and regulating (303) the SOC level of the energy storage (11) by charging the energy storage (11) according to the determined charging power.

2. The method according to claim 1 , wherein the set of parameters comprises a SOC reference level, wherein the SOC reference level is determined based on the duty cycle, and wherein meeting the SOC level criterion comprises that any one or more out of:- an average SOC level of the energy storage (11) during the duty cycle equals the SOC reference level,- the SOC level of the energy storage (11) equals the SOC reference level when the electrically powered mining and / or construction machine (1) disconnects from the trolley line, and- during a duty cycle, the energy consumed by the electrically powered mining and / or construction machine (1) when disconnected from the trolley line equals the energy charged to the energy storage (11) when the electrically powered mining and / or construction machine (1) is connected to the trolley line.

3. The method according to any of claims 1-2, wherein the charging power is further determined to be as low as possible while still meeting the SOC level criterion.

4. The method according to any of claims 1-3, wherein the charging power is further determined such that any one or more out of:- the SOC level remains below or becomes below a first threshold.- the SOC level remains above or becomes above a second threshold.

5. The method according to claim 4, wherein when the current SOC level approaches the first threshold, determining the charging power to be lower than or equal to zero, and adapting the charging power based on changes to the current SOC level.

6. The method according to claim 5, wherein a charging power lower than zero comprises supplying energy from the energy storage (11) to the trolley line.

7. The method according to claim 5-6, wherein adapting the charging power comprises determining the charging power to equal the current power consumption when the current SOC level has reached a third threshold that is lower than the first threshold.

8. The method according to claim 4, wherein when the current SOC level approaches the second threshold, determining the charging power to be a maximum charging power, and adapting the charging power based on changes to the first current SOC level, / / or is above in description.

9. The method according to claim 8, wherein adapting the charging power comprises determining the charging power to equal the current power consumption when the current SOC level has reached a fourth threshold that is higher than the second threshold.

10. The method according to any of claims 5-9, wherein adapting the charging power comprises repeatedly evaluating the current SOC level, and adapting the charging power by any one out of:- increasing the charging power, or- decreasing the charging power.

11. The method according to any one of claims 1-10, wherein the set of parameters comprises any one or more out of:- a first amount of energy consumed when the electrically powered mining and / or construction machine (1) is disconnected from the external energy source (20) during a duty cycle,- a second amount of energy generated when the electrically powered mining and / or construction machine (1) is disconnected from the external energy source (20) during the duty cycle,- a ratio between a time period the electrically powered mining and / or construction machine (1) is connected to the external energy source (20) and a time period disconnected from the external energy source (20),- a third amount of energy consumed by the electrically powered mining and / or construction machine (1) during a most recent time period disconnected from the external energy source (20),- a fourth amount of energy comprising a current amount of energy supplied to the at least one electrical motor (12), and- a fifth amount of energy comprising an estimated amount of energy to be supplied to the at least one electrical motor (12) until the electrically powered mining and / or construction machine (1) is disconnected from the external energy source (20).

12. A computer program (580) comprising instructions, which when executed by a processing circuitry (550), causes the processing circuitry (550) to perform actions according to any of the claims 1-11.

13. A charging controller (10) configured to regulate a State of Charge, SOC, level of an energy storage (11) in an electrically powered mining and / or construction machine (1), which energy storage (11) is adapted to provide electrical energy to at least one electrical motor (12) comprised in the electrically powered mining machine (1), wherein the energy storage (11) is adapted to be charged with energy received from an external energy source (20), the charging controller (10) further being configured to: determine a set of parameters adapted to be related to a duty cycle of the electrically powered mining and / or construction machine (1), each time the electrically powered mining and / or construction machine (1) connects to the external energy source (20), determine a charging power for charging the energy storage (11), wherein the charging power is adapted to be determined based on the set of parameters and a current SOC level of energy storage (11) in order to meet a SOC level criterion, and regulate the SOC level of the energy storage (11) by charging the energy storage (11) according to the determined charging power.

14. The charging controller (10) according to claim 13, wherein the charging controller (10) is further configured to perform the method according to claims 2-(11).

15. An electrically powered mining and / or construction machine (1) configured to comprise an energy storage (11) and at least one electrical motor (12), the energy storage (11) adapted to provide electrical energy to at least one electrical motor (12), wherein the electrically powered mining and / or construction machine (1) is further configured to comprise a charging controller according to claims 13-14.

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