A power circuit for a mining / construction machine and a method thereof

Abstract

The disclosure relates to a power circuit for a mining / construction machine (300). The power circuit (100) comprises: a first power bus (110) configured to be connected to a first power source (200) configured to provide a first power (P1 ) in a first voltage (V1 ); at least one second power bus (120) configured to be connected to a second power source (200') configured to provide a second power (P2) in a second voltage (V2) different to the first voltage (V1 ); an interconnection circuit (130) connected between the first power bus (110) and the second power bus (120); and a controller (140) configured to: set the interconnection circuit (130) in a first circuit configuration (C1 ) in which the first power bus (110) and the second power bus (120) are electrically disconnected from each other so that a first load (310) of the mining / construction machine (300) is powered by the first power source (200) and a second load (310') of the mining / construction machine (300) is powered by the second power source (200'), respectively. Furthermore, the disclosure also relates to a corresponding method and a mining / construction vehicle comprising such a power circuit (100).

Description

[0001] A POWER CIRCUIT FOR A MINING / CONSTRUCTION MACHINE AND A METHOD THEREOF

[0002] Technical Field

[0003] The disclosure relates to a power circuit for a mining / construction machine. Furthermore, the disclosure also relates to a corresponding method and a mining / construction machine comprising such a power circuit.

[0004] Background

[0005] Electrified mining / construction machines and vehicles provide an opportunity to reduce the environmental footprint and create a healthier work environment in mining / construction environments.

[0006] The electrified mining / construction machine is driven by one or more electric motors which in turn may be powered by an electric grid system and / or an on-board electrical storage system (ESS) comprising e.g., battery packs etc. Compared to diesel machines / vehicles, the electrified mining / construction machines / vehicles are emission free and can hence bring considerable savings, especially for ventilation and cooling in mining / construction environments.

[0007] However, the electrified mining / construction machines need electrical power for their functioning and operation. That is, for powering electrical motors, batteries, etc. of the electrified mining / construction machines. In this respect the electrical loads of the mining / construction machine may be powered by a power grid or a battery via a so- called electrical bus or busbar.

[0008] A power bus may be considered as an arrangement having an input for receiving power from a power source such as a power grid or a battery. Further, a plurality of loads may be connected to the power bus so that the loads may be powered by the power source via the power bus thereby being able to operate. Conventional power buses have the drawback of unreliable operation of the loads during fault as all the connected loads are impacted.

[0009] Summary An objective of embodiments of the disclosure is to provide a solution which mitigates or solves the drawbacks of conventional solutions.

[0010] Another objective of embodiments of the disclosure is to provide a power bus with safe and reliable operation. Especially, when the power quality of the supplied power of the power source varies.

[0011] According to a first aspect of the disclosure, the above mentioned and other objectives are achieved with a power circuit for a mining / construction machine, the power circuit comprising: a first power bus configured to be connected to a first power source configured to provide a first power in a first voltage; at least one second power bus configured to be connected to a second power source configured to provide a second power in a second voltage different to the first voltage; an interconnection circuit connected between the first power bus and the second power bus; and a controller configured to: set the interconnection circuit in a first circuit configuration in which the first power bus and the second power bus are electrically disconnected from each other so that a first load of the mining / construction machine is powered by the first power source and a second load of the mining / construction machine is powered by the second power source, respectively.

[0012] The first power source and the second power source may provide AC power or DC power depending on the load application of the mining / construction machine. Thus, the power buses may be AC buses or DC buses.

[0013] An advantage of the power circuit according to the first aspect is that by the segmentation of the power buses of the power circuit a general solution is provided which can handle different conditions at the input side and also at the output side, i.e. , conditions of the power sources and the conditions of the loads. Thereby, secure operation of the loads is possible since different voltage levels may be provided for different loads, etc. Further, the energy usage can be optimized due to the flexibility provided by the segmentation of power buses in the present power circuit.

[0014] In an embodiment of a power circuit according to the first aspect, the first power source is configured to provide the first power in the first voltage in a first frequency; and the second power source is configured to provide the second power in the second voltage in a second frequency different to the first frequency.

[0015] An advantage with this embodiment is that also different frequencies of the voltages for different AC loads are provided thereby further improving the flexibility and increasing the applicable use cases for the present power circuit.

[0016] In an embodiment of a power circuit according to the first aspect, the controller is configured to: set the interconnection circuit in a second circuit configuration in which the first power bus and the second power bus are electrically connected to each other so that the first load and the second load are powered by the first power source and the second power source.

[0017] An advantage with this embodiment is that when needed, plural power sources can be interconnected so as to deliver a common power to the loads. Thereby, the common power of the first and second power sources can be distributed between the loads in a flexible manner.

[0018] In an embodiment of a power circuit according to the first aspect, the controller is configured to: set the interconnection circuit in a third circuit configuration in which the first power bus and the second power bus are electrically disconnected from each other so that the first load is fed by the second power source and the second load is powered by the first power source, respectively.

[0019] An advantage with this embodiment is that more flexibility of the power circuit is provided since the interconnection circuit also make it possible for interconnection between crosswise connections, i.e. , between the first power source and the second load, and between the second power source and the first load.

[0020] In an embodiment of a power circuit according to the first aspect, the interconnection circuit comprises at least one connection line arranged between the first power bus and the second power bus via at least one breaker.

[0021] An advantage with this embodiment is that a simple interconnection circuit solution is provided. The interconnection circuit solution is also cheap to produce and cost effective compared to conventional solutions.

[0022] In an embodiment of a power circuit according to the first aspect, the controller is configured to: set the interconnection circuit in the first circuit configuration based on an electrical measurement of the first power source and / or the second power source.

[0023] An advantage with this embodiment is that relevant parameters related to the power source for controlling the interconnection circuit in different circuit configurations is used thereby improving the robustness and energy usage of the power circuit.

[0024] In an embodiment of a power circuit according to the first aspect, the measurement of the first power source and / or the second power source comprises any of: a voltage measurement, a frequency measurement, and an oscillation measurement.

[0025] An advantage with this embodiment is that these measurements are particularly relevant for controlling the interconnection circuit in different circuit configurations.

[0026] In an embodiment of a power circuit according to the first aspect, the controller is configured to: set the bus interconnection circuit in the first circuit configuration based on a forecast of the first power source and / or the second power source.

[0027] An advantage with this embodiment is that further relevant parameters are considered for controlling the interconnection circuit in different circuit configurations thereby improving the robustness and energy usage of the power circuit. By using forecasts of the power sources, the power circuit can be prepared for coming changes in the input conditions.

[0028] In an embodiment of a power circuit according to the first aspect, the forecast of the first power source and / or the second power source comprises any of: a forecast on a power generation from a renewable source, a forecast on an available power grid capacity, and a forecast on a remaining energy in a battery.

[0029] An advantage with this embodiment is that these input forecast parameters are particularly relevant for controlling the interconnection circuit in different circuit configurations.

[0030] In an embodiment of a power circuit according to the first aspect, the controller is configured to: set the interconnection circuit in the first circuit configuration based on a work schedule for the mining / construction machine.

[0031] An advantage with this embodiment is that the work schedule may have an impact on how the interconnection circuit may be controlled due to the power consumption used by the loads of the mining / construction machine when the work schedule is applied.

[0032] In an embodiment of a power circuit according to the first aspect, the work schedule for the mining / construction machine comprises any of: a required energy based on mine schedule, a shift plan, and a travel path.

[0033] An advantage with this embodiment is that relevant work schedule parameters are considered for planning the power and / or energy consumption of the loads and therefore also how the interconnection circuit may be controlled.

[0034] In an embodiment of a power circuit according to the first aspect, the controller is configured to: set the interconnection circuit in the first circuit configuration based on a measurement of the first load and / or the second load. An advantage with this embodiment is that further relevant parameters related to the loads may be considered for improving the knowledge on the actual power consumption need by the loads.

[0035] In an embodiment of a power circuit according to the first aspect, the measurement of the first load and / or the second load comprises a power consumption pattern of the first load and / or the second load.

[0036] An advantage with this embodiment is that the power consumption pattern of the load directly impacts the energy usage therefore also impacting how the interconnection circuit may be controlled.

[0037] In an embodiment of a power circuit according to the first aspect, the power consumption pattern of the first load and / or the second load comprises a fault indication of the first load and / or the second load.

[0038] An advantage with this embodiment is that the fault indication is especially relevant since faulty loads will directly impact the energy usage and hence the power transfer over the segmented power buses.

[0039] In an embodiment of a power circuit according to the first aspect, the first power source is a first power grid or a first battery; and the second power source is a second power grid or a second battery.

[0040] An advantage with this embodiment is that power sources including, for example, power grids and batteries can be combined as so to provide any types of power, to the loads, via the segmented power buses.

[0041] In an embodiment of a power circuit according to the first aspect, the interconnection circuit is connected between the first power bus and a plurality of second power buses, wherein different second power buses are configured to be connected to different second power sources. An advantage with this embodiment is that multiple power sources and loads can be interconnected using the power circuit. Thus, it is possible to build a complex power bus and load structure meeting different application requirements.

[0042] In an embodiment of a power circuit according to the first aspect, the controller is configured to: set the bus interconnection circuit in the first circuit configuration in a sequential order for the plurality of second power buses.

[0043] An advantage with this embodiment is that different sequential orders may be adapted to different conditions. Thus, the sequential order ensures reliability and power surety for different scenarios.

[0044] In an embodiment of a power circuit according to the first aspect, the controller is configured to: set the bus interconnection circuit in the first circuit configuration in the sequential order for the plurality of second power buses based on a fault indication of the first load and / or the plurality of second loads.

[0045] An advantage with this embodiment is that the fault indication of loads is especially relevant for triggering the sequential order.

[0046] In an embodiment of a power circuit according to the first aspect, the sequential order is predetermined.

[0047] An advantage with this embodiment is that the sequential order can be done promptly when an event is detected. The event may e.g., be a fault in the grid or a failure of a load such as a motor. This provides faster segmentation and low impact on the loads.

[0048] According to a second aspect of the disclosure, the above mentioned and other objectives are achieved with a mining / construction machine comprising: a first load; at least one second load; and a power circuit according to any one of the preceding claims connected to the first load and the second load.

[0049] According to a third aspect of the disclosure, the above mentioned and other objectives are achieved with method for a power circuit comprising: a first power bus configured to be connected to a first power source configured to provide a first power in a first voltage; at least one second power bus configured to be connected to a second power source configured to provide a second power in a second voltage different to the first voltage; an interconnection circuit connected between the first power bus and the second power bus; wherein the method comprises: set the interconnection circuit in a first circuit configuration in which the first power bus and the second power bus are electrically disconnected from each other so that a first load of the mining / construction machine is powered by the first power source and a second load of the mining / construction machine is powered by the second power source, respectively.

[0050] The method may be adapted in accordance with the above-mentioned embodiments of the power circuit. The advantages of the method are the same as the advantages of the corresponding embodiments of the power circuit.

[0051] According to further aspects of the present disclosure, the herein described methods are implemented by use of computer program products comprising instructions which, when the programs are executed by a computer, such as e.g., a control unit, cause the computer to carry out the steps of the methods according to any one of the herein described embodiments.

[0052] Further applications and advantages of embodiments of the disclosure will be apparent from the following detailed description.

[0053] Brief Description of the Drawings

[0054] The appended drawings are intended to clarify and explain different embodiments of the disclosure, in which: - Fig. 1 shows a power circuit where an interconnection circuit is set in a first circuit configuration according to embodiments of the disclosure;

[0055] - Fig. 2 shows a power circuit where an interconnection circuit is set in a second circuit configuration according to embodiments of the disclosure;

[0056] - Fig. 3 shows a power circuit where an interconnection circuit is set in a third circuit configuration according to embodiments of the disclosure;

[0057] - Fig. 4 shows an example of an interconnection circuit according to embodiments of the disclosure;

[0058] - Fig. 5 and 6 show an interconnection circuit comprising multiple breakers according to embodiments of the disclosure;

[0059] - Fig. 7 illustrates how a controller is configured to control an interconnection circuit based on one or more input parameters according to embodiments of the disclosure;

[0060] - Fig. 8 shows a power circuit comprising multiple second power buses and loads according to embodiments of the disclosure;

[0061] - Fig. 9 shows a detailed flow chart according to embodiments of the disclosure;

[0062] - Fig. 10 shows a general flow chart of a method for a power circuit according to embodiments of the disclosure; and

[0063] - Fig. 11 illustrates examples of a mining / construction machine according to embodiments of the disclosure.

[0064] Detailed Description

[0065] As aforementioned, a power bus is a common device for transferring power from power sources to loads. However, conventional power buses do not consider conditions at the power source side or the load side resulting in unreliable operation. This is partially due to the fact that conventional power buses are not capable of segmenting and / or isolating different power sources from each other if necessary.

[0066] Thus, a novel power bus architecture is disclosed herein providing segmentation of multiple power buses for improved robustness and energy efficiency compared to conventional power buses.

[0067] Fig. 1 shows a power circuit 100 where an interconnection circuit 130 is set in a first circuit configuration C1 according to embodiments of the disclosure. The power circuit 100 comprises a first power bus 110 configured to be connected to a first power source 200 and configured to provide a first power P1 in a first voltage V1 , and at least one second power bus 120 configured to be connected to a second power source 200' and configured to provide a second power P2 in a second voltage V2 different to the first voltage V1. The power circuit 100 further comprises an interconnection circuit 130 connected between the first power bus 110 and the second power bus 120. The power circuit 100 comprises a controller 140 configured to set the interconnection circuit 130 in a first circuit configuration C1 in which the first power bus 110 and the second power bus 120 are electrically disconnected from each other so that a first load 310 of the mining / construction machine 300 is powered by the first power source 200 and a second load 310' of the mining / construction machine 300 is powered by the second power source 200', respectively.

[0068] Hence, it is provided a power circuit architecture having two or more segmented power buses having a first side coupled to power sources and a second side coupled to loads. The segmentation means that plural power buses can be disconnected or interconnected with each other so as to form different power fed configurations meeting different power source conditions and load requirements.

[0069] The first voltage V1 may also be denoted a first voltage level and the second voltage V2 may be denoted a second voltage level. Thus, the first voltage level and the second voltage level are different voltage levels. In DC applications this implies that the first voltage and the second voltage have different voltage levels e.g., 12V and 24V, respectively.

[0070] However, the present power circuit 100 is also applicable in AC applications which means that in embodiments of the disclosure, the first power source 200 is configured to provide the first power P1 in the first voltage V1 in a first frequency f1 and the second power source 200' is configured to provide the second power P2 in the second voltage V2 in a second frequency f2 different to the first frequency f1 . This is applicable when the first power bus 110 and the second power bus 120 are electrically disconnected from each other, i.e., in the first circuit configuration C1. The power sources are AC power sources in these examples. The frequency may be standard grid frequency of 50 Hz or 60 Hz. However, the first frequency f1 and the second frequency f2 are not limited thereto.

[0071] In embodiments of the disclosure, the first power source 200 is a first power grid or a first battery and correspondingly the second power source 200' is a second power grid or a second battery which is common set up for battery vehicles. When one power source is a power grid and another power source is a battery, the battery can charge and discharge in low and peak load conditions. Also, the battery helps to tram (i.e., move the machine / vehicle) to another location without being connected to the grid.

[0072] Fig. 2 shows a power circuit 100 where an interconnection circuit 130 is set in a second circuit configuration C2 according to embodiments of the disclosure. In the second circuit configuration C2, the first power bus 110 and the second power bus 120 are electrically connected to each other which means that the first load 310 and the second load 310' are powered by the first power source 200 and the second power source 200'. Thus, the second circuit configuration C2 is the opposite case to the first circuit configuration C1 in which the first power bus 110 and the second power bus 120 are electrically disconnected from each other. Thereby, the power sources 200, 200' are interconnected with each other which means that they shared the loads in regards of power distribution.

[0073] Fig. 3 shows a power circuit 100 where an interconnection circuit 130 is set in a third circuit configuration C3 according to embodiments of the disclosure. In the third circuit configuration C3, the first power bus 110 and the second power bus 120 are electrically disconnected from each other so that the first load 310 is fed by the second power source 200 and the second load 310' is powered by the first power source 200', respectively. In other words, the third circuit configuration C3 implies a cross coupling between power sources and loads.

[0074] Fig. 4 shows an example of a power bus interconnection circuit 130 according to embodiments of the disclosure. The interconnection circuit 130 comprises at least one connection line 132 arranged between the first power bus 110 and the second power bus 120 via at least one breaker 134. This configuration of the interconnection circuit 130 is a low complex and low-cost design. The interconnection circuit 130 in Fig. 4 is suitable for the first C1 and second C2 circuit configurations for connecting and disconnection the first 110 and second 120 power bus to or from each other.

[0075] Fig. 5 and 6 show an interconnection circuit 130 comprising multiple breakers according to embodiments of the disclosure. The design in Fig. 5 and 6 is more complex than the shown in Fig. 4 but still achievable and cheap to produce. The interconnection circuit 130 comprises in this particular example two separate connection lines 132. Each connection line comprises of two breakers 134 connected on each side of a junction point to which a power source 200, 200' is connected. Thus, the power source 200, 200' may be connected to a first load 310 or a second load 310' depending on the state of the breakers. A black breaker 134 illustrates that it is in nonconducting state, i.e., the current cannot pass through the breaker, while a white breaker 134 illustrates that it is in conducting state, i.e., the current can pass through the breaker 134. By setting multiple breakers 134 in different conductive / non- conductive configurations multiple electrical paths may be provided in the interconnection circuit 130.

[0076] In Fig. 5, multiple electrical paths are created so that the first power source 200 feds the first load 310 with a first power P1 via the interconnection circuit 130, while the second power source 200' feds the second load 310' with a second power P2 via the interconnection circuit 130. The first P1 and second P2 power have different voltage levels and possibly different frequencies in AC applications.

[0077] In Fig. 6, the revers case is shown when compared to Fig. 5, i.e., in that electrical paths are created so that the first power source 200 feds the second load 310' with the first power P1 via the interconnection circuit 130, while the second power source 200' feds the first load 310 with the second power P2 via the interconnection circuit 130.

[0078] The breakers 134 herein used in the interconnection circuit 130 may be any suitable breakers capable of handling the currents passing through and voltages generated across the power circuit 100. Thus, the breakers may be mechanical breakers with actuators, or power electronics breakers with semiconductor switches. Fig. 7 illustrates how the controller 140 of the power circuit 100 is configured to control an interconnection circuit 130 based on one or more input parameters according to embodiments of the disclosure. The controller 140 may comprises a processor, memory, control logic, control interface and control lines for controlling the interconnection circuit 130.

[0079] The controller 140 may be configured to execute a control algorithm which receives input parameters and outputs control signals, control instructions or control elements for controlling the interconnection circuit 130 and other parts of the power circuit 100. By controlling the interconnection circuit 130, the breakers 134 of the interconnection circuit 130 may be switched between conductive and non-conductive state. Also, other components and elements of the interconnection circuit 130 may be controlled by the controller 140 via suitable control interfaces.

[0080] In embodiments of the invention, the controller 140 is configured to set the interconnection circuit 130 in the first circuit configuration C1 based on an electrical measurement of the first power source 200 and / or the second power source 200'.

[0081] The measurement of the first power source 200 and / or the second power source 200' comprises any of:

[0082] • a voltage measurement at the output terminal of the power source;

[0083] • a frequency measurement of the power source; and

[0084] • an oscillation measurement of the output power or current.

[0085] In embodiments of the invention, the controller 140 is configured to set the bus interconnection circuit 130 in the first circuit configuration C1 based on a forecast of the first power source 200 and / or the second power source 200'.

[0086] The forecast of the first power source 200 and / or the second power source 200' comprises any of:

[0087] • a forecast on a power generation from a renewable source e.g., solar or wind power;

[0088] • a forecast on an available power grid capacity; and • a forecast on a remaining energy in a battery to know how much energy the battery will be able to supply.

[0089] In embodiments of the invention, the controller 140 is configured to set the interconnection circuit 130 in the first circuit configuration C1 based on a work schedule for the mining / construction machine 300.

[0090] The work schedule for the mining / construction machine 300 comprises any of:

[0091] • a required energy based on a mine schedule including process load, electric and battery electric machines;

[0092] • a shift plan which defines the operation shift works of the mining / construction machine 300, e.g., where and when to perform a certain task; and

[0093] • a travel path of the battery electric or electric machines within a mine.

[0094] In embodiments of the invention, the controller 140 is configured to set the interconnection circuit 130 in the first circuit configuration C1 based on a measurement of the first load 310 and / or the second load 31 O'.

[0095] The measurement of the first load 310 and / or the second load 310' comprises a power consumption pattern of the first load 310 and / or the second load 310'. Thus, by monitoring the power consumption pattern useful information about the load may be derived. This information may be used for setting the interconnection circuit 130 in the first circuit configuration C1 .

[0096] The power consumption pattern of the first load 310 and / or the second load 310' may comprise a fault indication of the first load 310 and / or the second load 31 O'. The fault indication of the load is especially relevant due to the direct impact on the power consumption of the load.

[0097] It is noted that all the previous mentioned input parameters, i.e., measurement of the first power source 200 and / or the second power source 200', forecast of the first power source 200 and / or the second power source 200', work schedule for the mining / construction machine 300, and measurement of the first load 310 and / or the second load 310', may also be used to set the bus interconnection circuit 130 in the second C2 and third C3 circuit configuration. Hence, in embodiments of the invention, the controller 140 is configured to set the interconnection circuit 130 in the second C2 and third C3 circuit configuration based on any of: measurement of the first power source 200 and / or the second power source 200', forecast of the first power source 200 and / or the second power source 200', work schedule for the mining / construction machine 300, and measurement of the first load 310 and / or the second load 310'.

[0098] Moreover, the mentioned input parameters may also be used to switch the interconnection circuit 130 between the first C1 , second C2 and third C3 circuit configurations. This means that the controller 140, in embodiments of the invention, is configured to switch the interconnection circuit 130 between the first C1 , second C2 and third C3 circuit configurations based on any of: measurement of the first power source 200 and / or the second power source 200', forecast of the first power source 200 and / or the second power source 200', work schedule for the mining / construction machine 300, and measurement of the first load 310 and / or the second load 310'.

[0099] Fig. 8 shows a power circuit 100 comprising multiple second power buses 120 and second loads 310' according to embodiments of the disclosure. In other words, the interconnection circuit 130 is in these embodiments connected between the first power bus 110 and a plurality of second power buses 120. The second power buses 120 are configured to be connected to second power sources 200'. Hence, a more advanced power bus architecture is provided which can support and power multiple loads with different power requirements.

[0100] In embodiments of the invention, the controller 140 is therefore configured to set the bus interconnection circuit 130 in the first circuit configuration C1 in a sequential order for the plurality of second power buses 120.

[0101] The power bus interconnection circuit 130 may be set in the first circuit configuration C1 in the sequential order for the plurality of second power buses 120 based on a fault indication of the first load 310 and / or the plurality of second loads 31 O'.

[0102] In embodiments of the invention, the sequential order is predetermined which means that when the interconnection circuit 130 is triggered the sequence in which the segmentations will take place, i.e. , the order of how the breakers opens and closes, is already determined.

[0103] Fig. 9 shows a detailed flow chart according to further embodiments of the disclosure. The flow chart especially shows when to open and close a breaker 134 of the interconnection circuit 130 so as to disconnect and connect two or more power buses from each other, i.e., the transitions from the first circuit configuration C1 to the second circuit configuration C2, and vice versa. In this particular example, one power source is a power grid while another power source is an energy source such as a battery.

[0104] In 1 ) in Fig. 9, a quality issue with the power grid is detected. Thus, it is checked in 2) if there is enough power in the energy storage to supply all loads connected to the power circuit 100.

[0105] If there is enough power to supply all loads, the power grid is disconnected from the power circuit 100 in 3). However, if there is not enough power to supply all loads it is checked in 4) whether there is enough power in the energy storage to supply a part of the loads which implies that not all loads may be connected at the same time.

[0106] If the answer is negative in 4) a quality issue with the power grid is detected in 5). However, if the answer is positive in 4) the following is performed in 6): initiate segmentation of the power buses and determine the voltage to be controlled, set the ESS in grid forming, and open the breaker 134 in a non-conductive state.

[0107] In 7) in Fig. 9, it is checked for a need of resynchronization. If no resynchronization is needed in 7), the flow chart returns to 1 ) in Fig. 9. If resynchronization is needed in 7), the flow chart continues to 8) where resynchronization is performed together with matching of voltage, phase and frequency.

[0108] Resynchronization may be considered as a process or procedure to connect the first and second power buses. If a breaker 134 is suddenly closed, there will be voltage oscillation due to sudden power exchange. So, the voltage is matched in the DC case and then the breaker is closed. In case of AC, it is voltage magnitude, frequency and phase angle that are matched. This matching is done by a control method called resynchronization and will be performed by the energy storage in this particular example.

[0109] In 9) in Fig. 9, it is checked whether the matching of voltage, phase and frequency have been achieved in 8). If No, the flow chart returns back to 8) for a new resynchronization. Else, if Yes the breaker 134 is closed in 10).

[0110] Fig. 10 shows a flow chart of a general method for a power circuit 100 according to embodiments of the disclosure. The power circuit 100 as previously mentioned comprises a first power bus 110 configured to be connected to a first power source 200 configured to provide a first power P1 in a first voltage V1 ; at least one second power bus 120 configured to be connected to a second power source 200' configured to provide a second power P2 in a second voltage V2 different to the first voltage V1 ; and an interconnection circuit 130 connected between the first power bus 110 and the second power bus 120.

[0111] The method 400 comprises: setting 402 the interconnection circuit 130 in a first circuit configuration C1 in which the first power bus 110 and the second power bus 120 are electrically disconnected from each other so that a first load 310 of the mining / construction machine 300 is powered by the first power source 200 and a second load 310' of the mining / construction machine 300 is powered by the second power source 200', respectively.

[0112] Embodiments of the method 400 may fully correspond to all embodiments of the power circuit 100 herein disclosed.

[0113] According to embodiments of the disclosure the controller 140 may comprise one or more control devices / units arranged / configured / programmed with instruction to carry out the method 400.

[0114] Fig. 11 illustrates examples of a mining / construction machine that may be used with the power circuit 100. The mining / construction machine comprises a first load 310; at least one second load 310'; and a power circuit 100 according to embodiments of the invention connected to the first load 310 and the second load 310'. The mining / construction machine 300 may be any type of electrified machine or vehicle used in a mining and / or construction environment / site such as e.g., a drill rig, a truck, a loader, a digging machine, etc.

[0115] With reference to Fig. 11 , the mining / construction machine 300 may e.g., be a drill rig, a loading, hauling and dumping (LHD) machine or a mine truck but is not limited thereto. Finally, it should be understood that the invention is not limited to the embodiments described above, but also relates to and incorporates all embodiments within the scope of the appended independent claims.

Claims

CLAIMS1 . A power circuit (100) for a mining / construction machine (300), the power circuit (100) comprising: a first power bus (110) configured to be connected to a first power source (200) configured to provide a first power (P1 ) in a first voltage (V1 ); at least one second power bus (120) configured to be connected to a second power source (200') configured to provide a second power (P2) in a second voltage (V2) different to the first voltage (V1 ); an interconnection circuit (130) connected between the first power bus (110) and the second power bus (120); and a controller (140) configured to: set the interconnection circuit (130) in a first circuit configuration (C1 ) in which the first power bus (110) and the second power bus (120) are electrically disconnected from each other so that a first load (310) of the mining / construction machine (300) is powered by the first power source (200) and a second load (310') of the mining / construction machine (300) is powered by the second power source (200'), respectively.

2. The power circuit (100) according to claim 1 , wherein the first power source (200) is configured to provide the first power (P1 ) in the first voltage (V1 ) in a first frequency (f1 ); and the second power source (200') is configured to provide the second power (P2) in the second voltage (V2) in a second frequency (f2) different to the first frequency (f1 ).

3. The power circuit (100) according to claim 1 or 2, wherein the controller (140) is configured to: set the interconnection circuit (130) in a second circuit configuration (C2) in which the first power bus (110) and the second power bus (120) are electrically connected to each other so that the first load (310) and the second load (310') are powered by the first power source (200) and the second power source (200').

4. The power circuit (100) according to any one of the preceding claims, wherein the controller (140) is configured to: set the interconnection circuit (130) in a third circuit configuration (C3) in which the first power bus (110) and the second power bus (120) are electrically disconnected from each other so that the first load (310) is fed by the second power source (200) and the second load (310') is powered by the first power source (200'), respectively.

5. The power circuit (100) according to any one of the preceding claims, wherein the interconnection circuit (130) comprises at least one connection line (132) arranged between the first power bus (110) and the second power bus (120) via at least one breaker (134).

6. The power circuit (100) according to any one of the preceding claims, wherein the controller (140) is configured to: set the interconnection circuit (130) in the first circuit configuration (C1 ) based on an electrical measurement of the first power source (200) and / or the second power source (200').

7. The power circuit (100) according to claim 6, wherein the measurement of the first power source (200) and / or the second power source (200') comprises any of: a voltage measurement, a frequency measurement, and an oscillation measurement.

8. The power circuit (100) according to any one of the preceding claims, wherein the controller (140) is configured to: set the bus interconnection circuit (130) in the first circuit configuration (C1 ) based on a forecast of the first power source (200) and / or the second power source (200').

9. The power circuit (100) according to claim 8, wherein the forecast of the first power source (200) and / or the second power source (200') comprises any of: a forecast on a power generation from a renewable source, a forecast on an available power grid capacity, and a forecast on a remaining energy in a battery.

10. The power circuit (100) according to any one of the preceding claims, wherein the controller (140) is configured to:set the interconnection circuit (130) in the first circuit configuration (C1 ) based on a work schedule for the mining / construction machine (300).11 . The power circuit (100) according to claim 10, wherein the work schedule for the mining / construction machine (300) comprises any of: a required energy based on mine schedule, a shift plan, and a travel path.

12. The power circuit (100) according to any one of the preceding claims, wherein the controller (140) is configured to: set the interconnection circuit (130) in the first circuit configuration (C1 ) based on a measurement of the first load (310) and / or the second load (310').

13. The power circuit (100) according to claim 12, wherein the measurement of the first load (310) and / or the second load (310') comprises a power consumption pattern of the first load (310) and / or the second load (310').

14. The power circuit (100) according to claim 13, wherein the power consumption pattern of the first load (310) and / or the second load (31 O') comprises a fault indication of the first load (310) and / or the second load (310').

15. The power circuit (100) according to any one of the preceding claims, wherein the first power source (200) is a first power grid or a first battery; and the second power source (200') is a second power grid or a second battery.

16. The power circuit (100) according to any one of the preceding claims, wherein the interconnection circuit (130) is connected between the first power bus (110) and a plurality of second power buses (120), wherein different second power buses (120) are configured to be connected to different second power sources (200').

17. The power circuit (100) according to claim 16, wherein the controller (140) is configured to: set the bus interconnection circuit (130) in the first circuit configuration (C1 ) in a sequential order for the plurality of second power buses (120).

18. The power circuit (100) according to claim 17, wherein the controller (140) is configured to: set the bus interconnection circuit (130) in the first circuit configuration (C1 ) in the sequential order for the plurality of second power buses (120) based on a fault indication of the first load (310) and / or the plurality of second loads (31 O').

19. The power circuit (100) according to claim 17 or 18, wherein the sequential order is predetermined.

20. A mining / construction machine (300) comprising: a first load (310); at least one second load (310'); and a power circuit (100) according to any one of the preceding claims connected to the first load (310) and the second load (310').21 . A method (400) for a power circuit (100) comprising: a first power bus (110) configured to be connected to a first power source (200) configured to provide a first power (P1 ) in a first voltage (V1 ); at least one second power bus (120) configured to be connected to a second power source (200') configured to provide a second power (P2) in a second voltage (V2) different to the first voltage (V1 ); an interconnection circuit (130) connected between the first power bus (110) and the second power bus (120); wherein the method (400) comprises: setting (402) the interconnection circuit (130) in a first circuit configuration (C1 ) in which the first power bus (110) and the second power bus (120) are electrically disconnected from each other so that a first load (310) of the mining / construction machine (300) is powered by the first power source (200) and a second load (310') of the mining / construction machine (300) is powered by the second power source (200'), respectively.

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