Method for operating an electric vehicle during a start-up situation

Abstract

Method for operating an electric vehicle during a starting situation comprising the steps: AA) Providing an electric vehicle 0 with at least one axle 3a driven by a first electric motor 1a via a first multi-speed transmission 2a, at least one axle 3b driven by a second electric motor 1b via a second multi-speed transmission 2b, and either: A) Driving at least one axle 3a by providing a first power La to the first electric motor 1a and driving at least one axle 3b by providing a second power Lb to the second electric motor 1b, or: A) Driving at least one axle 3a by providing a first power La to the first electric motor 1a, wherein the first multi-speed transmission 2a is shifted into a torque-transmitting gear G1a, G2a and the second multi-speed transmission 2b is shifted into neutral position N.

Description

[0001] The invention relates to a method for operating an electric vehicle during a starting situation.

[0002] The invention lies in the technical field of methods for operating electric vehicles, in particular electrically powered trucks or cars, with several electric motors each driven by a multi-speed transmission.

[0003] Electric vehicles are known from the state of the art that comprise two drivable axles, each with an associated electric motor and a multi-speed transmission. These typically provide significantly more drive power than comparable models with only a single electric motor. Electric vehicles with a multi-speed transmission also typically reach higher speeds than comparable models with only one gear.

[0004] The range of an electric vehicle depends on how much electrical energy its power supply (battery) can store and on how much power is required to drive it over a certain distance. The starting process (the starting situation) plays a key role, as the electric vehicle usually accelerates from a standstill (i.e., the motor speed is zero) and therefore must generate high power and / or torque for the short distance covered during starting. To increase the range of an electric vehicle, an efficient starting process is also necessary.

[0005] In the aforementioned well-known electric vehicles, each of the multi-gear transmissions is in the lowest torque-transmitting gear. Therefore, the maximum possible torque of the drive axles is available for propulsion during start-up. During start-up, both multi-gear transmissions are then shifted successively or simultaneously into a higher gear.

[0006] This method has the disadvantage of being inefficient, especially when the high torque provided in this way is not needed to achieve the desired acceleration during acceleration. On the other hand, it requires unnecessarily frequent gear shifts during acceleration, resulting in uneven acceleration and reducing ride comfort.

[0007] It is the object of the present invention to overcome the disadvantages of the prior art and in particular to provide a method for operating an electric vehicle during a starting situation which is efficient and comprises few switching operations.

[0008] This object is achieved by a method for operating an electric vehicle during a starting situation according to the independent claim. Advantageous aspects of the invention form the subject matter of the dependent claims.

[0009] The invention comprises a method for operating an electric vehicle (electrically powered truck or car) during a starting situation (from a standstill) comprising the steps: AA) Providing an electric vehicle with at least one (first) axle drivable by a first electric motor via a first multi-speed transmission (with at least two torque-transmitting gears), at least one (second) axle drivable by a second electric motor via a second multi-speed transmission (with at least two torque-transmitting gears), a power supply (battery) for supplying power to the first electric motor and to the second electric motor, a control unit for controlling the power supplied to the first electric motor and the second electric motor and for controlling the switching of the first multi-speed transmission and the second multi-speed transmission, wherein the sum of the peak power of the first electric motor and the peak power of the second electric motor is greater than the power that can be provided by the power supply.

[0010] The procedure further includes either the following steps: A) driving at least one axle by providing a first power to the first electric motor and driving at least one axle by providing a second power to the second electric motor, wherein the first multi-speed transmission is shifted into a torque-transmitting gear and the second multi-speed transmission is shifted into a torque-transmitting gear; B) Shifting (only) the second multi-speed gearbox into a (different) torque-transmitting gear or into neutral; C) increasing the first power supplied to the first electric motor and decreasing the second power supplied to the second electric motor during step B);or the steps: A) driving at least one axle by providing a first power to the first electric motor, wherein the first multi-speed transmission is shifted into a torque-transmitting gear and the second multi-speed transmission is shifted into neutral; B) Shifting (only) the second multi-speed transmission into a torque-transmitting gear; C) Increasing the first power supplied to the first electric motor during step B).

[0011] The electric vehicle can be an electrically powered truck or car (electric car). The electric vehicle can have a first axle that can be driven by the first electric motor via the first multi-speed transmission, and a second axle that is different from the first axle and can be driven by the second electric motor via the second multi-speed transmission. The first axle can be a front axle and the second axle a rear axle, or the first axle is a rear axle and the second axle a front axle, or the first axle and the second axle are each a rear axle or each a front axle. Alternatively, the electric vehicle can have multiple axles, one of which can be driven by both the first electric motor via the first multi-speed transmission and the second electric motor via the second multi-speed transmission.

[0012] Torque-transmitting gears (first gear, second gear, and higher gears) are those that can transmit torque from an electric motor to an axle. The second gear of the respective multi-speed transmission is designed to result in a smaller torque ratio or a larger speed ratio from an electric motor to an axle than the first gear of the respective multi-speed transmission. For example, a first gear of a multi-speed transmission can have a speed ratio of 6:1 from an electric motor to an axle, and a second gear of the same multi-speed transmission can have a smaller speed ratio of 4:1 from an electric motor to an axle, so that the electric vehicle can reach higher speeds in second gear than in first gear. In the neutral position, no torque is transmitted. Therefore, the neutral position is not a torque-transmitting gear.

[0013] An electric motor can only provide peak power for a few seconds, for example up to 10 seconds. In contrast to peak power, an electric motor can provide continuous power for a longer period than the peak power, from several minutes to hours, for example at least 30 minutes. The power supply is designed such that the power that can be provided by the power supply is less than the sum of the peak power of the first electric motor and the peak power of the second electric motor. The power supply can further be designed such that the power that can be provided by the power supply is greater than or equal to the sum of the continuous power of the first electric motor and the continuous power of the second electric motor.

[0014] The method enables starting that only involves shifting the second multi-speed transmission. This enables smooth starting and a high level of driving comfort. The method also enables efficient starting by (selectively) increasing or decreasing the power supplied to the first electric motor and second electric motor. By increasing the first power supplied to the first electric motor while shifting the second multi-speed transmission, the drive power can be maintained (or supported).

[0015] According to a preferred aspect, in step A), the first multi-speed transmission and / or the second multi-speed transmission is shifted into a torque-transmitting gear that is different from the respective first torque-transmitting gear. By shifting the first multi-speed transmission and / or the second multi-speed transmission into a torque-transmitting gear that is different from the respective first torque-transmitting gear in step A), gear changes during the start-up process can be avoided and the start-up process can be made more efficient, especially when the maximum possible torque is not required.

[0016] According to another preferred aspect, either: - in step A) the first multi-speed transmission is shifted into a second gear and the second multi-speed transmission into a first gear, and in step B) the second multi-speed transmission is shifted into a second gear; or - in step A) the first multi-speed transmission is shifted into a second gear and the second multi-speed transmission is shifted into a first gear and in step B) the first multi-speed transmission is shifted into a first gear; or - in step A) the first multi-speed transmission is shifted into a first gear or a second gear and the second multi-speed transmission is shifted into a neutral position and in step B) the second multi-speed transmission is shifted into a first gear or a second gear.

[0017] The first alternative is particularly advantageous for efficient starting from a standstill on gentle gradients. The second alternative is particularly advantageous for efficient starting from a standstill on steep gradients. The third alternative is particularly advantageous for efficient starting from a standstill on steep gradients.

[0018] According to a particularly preferred aspect, the method comprises the step: D) Decreasing the first power supplied to the first electric motor after switching the second multi-speed transmission in step B) (and simultaneously increasing the second power supplied to the second electric motor by the amount by which the first power to the first electric motor was decreased).

[0019] This takes into account that after the second multi-speed transmission has been switched in step B), the second electric motor can again contribute to the drive.

[0020] According to an advantageous aspect, in step A) the first multi-speed transmission is shifted into a first gear or into a second gear and the second multi-speed transmission is shifted into a first gear and in step B) the second multi-speed transmission is shifted into a neutral position.

[0021] According to a further advantageous aspect, in step A), the first multi-speed transmission is shifted into a first gear and the second multi-speed transmission into a first gear, and in step B), the second multi-speed transmission is shifted into a second gear. Furthermore, the method comprises the steps: E) switching (only) the first multi-speed transmission to a second gear after step D); F) Increasing the second power supplied to the second electric motor during step E).

[0022] According to a particularly advantageous aspect, in step C), the first power provided to the first electric motor is increased to at least 75%, preferably to at least 85%, particularly preferably to at least 95%, of the peak power of the first electric motor, and / or in step F), the second power provided to the second electric motor is increased to at least 75%, preferably to at least 85%, particularly preferably to at least 95%, of the peak power of the second electric motor. As a result, the first electric motor or the second electric motor can provide increased power during a shift of the second multi-speed transmission or the first multi-speed transmission for the (short) duration of the shift.

[0023] According to a preferred aspect, in step C), the second power provided to the second electric motor is reduced to a maximum of 25%, preferably to a maximum of 15%, particularly preferably to 0%, of the peak power of the second electric motor. A reduction to 0% is particularly necessary in dog-claw transmissions.

[0024] According to a particularly preferred aspect, the electric vehicle has at least one sensor which is designed to measure at least one drive parameter selected from: - the speed of an axle; - the speed of another axis; - the speed of the electric vehicle; - the acceleration of the electric vehicle; - the drive power of an axle; - the drive power of another axle; - the drive torque of an axle; - the drive torque of another axle; - Measure the power output of the power supply and provide it to the control unit in real time. "Real time" can mean that the power is provided at intervals of tenths of a second, hundredths of a second, or even faster.

[0025] According to a further preferred aspect, the method comprises the steps: G) measuring at least one drive parameter and providing the at least one drive parameter to the control unit in real time; H) Controlling in real time the first power provided to the first electric motor and / or the second power provided to the second electric motor and / or controlling in real time the switching of the first multi-speed transmission and / or the second multi-speed transmission based on the at least one drive parameter.

[0026] While the provision of the at least one drive parameter to the control unit occurs in real time, the measurement of the at least one drive parameter occurs either in real time or not in real time. If the measurement of the at least one drive parameter also occurs in real time, control can be carried out based on the current drive parameter. If the measurement of the at least one drive parameter does not occur in real time, a derived drive parameter can be provided by calculation based on this drive parameter and used for control. The control unit can comprise a processor to perform the calculation.

[0027] According to a particularly preferred aspect, the electric vehicle comprises at least one further electric motor, which is configured (in each case) via a further multi-speed transmission to drive an axle. In this case, an additional power (Lc) provided by the power supply to the at least one further electric motor is increased during the shifting of the first multi-speed transmission (2a) and / or during the shifting of the second multi-speed transmission (2b). As a result, the drive power is supported by the at least one further electric motor during the shifting of the first multi-speed transmission (2a) and / or during the shifting of the second multi-speed transmission (2b).

[0028] The invention is explained in more detail below using exemplary embodiments. In the following, the following are shown: Fig. 1 Schematic sectional view of an electric vehicle provided in step AA); Fig. 2 - 5 Diagrams of the course of the first power provided to the first electric motor and the second power provided to the second electric motor during a preferred method for operating the electric vehicle from Fig. 1 during a start-up situation AF from a standstill. Fig. 6a, Fig. 6b Schematic sectional views of further embodiments of electric vehicles provided in step AA).

[0029] Fig. 1 shows a schematic sectional view of an electric vehicle 0 provided in step AA). The electric vehicle 0, an electrically powered passenger car, comprises a first axle 3a as the rear axle and a second axle 3b as the front axle. The first axle 3a is driven by a first electric motor 1a via a first multi-speed transmission 2a, and the second axle 3b is driven by a second electric motor 1b via a second multi-speed transmission 2b. The first multi-speed transmission 2a has two torque-transmitting gears G1a, G2a and a neutral position N, and the second multi-speed transmission 2b also has two torque-transmitting gears G1b, G2b and a neutral position N.

[0030] The electric vehicle 0 has a battery as a power supply 4. This battery provides a first power La to the first electric motor 1a and a second power Lb to the second electric motor 1b. The sum of the peak power SLa of the first electric motor 1a and the peak power SLb of the second electric motor 1b is greater than the power that can be provided by the power supply 4.

[0031] Furthermore, the electric vehicle 0 comprises a control unit 5 which controls the powers La, Lb provided to the first electric motor 1a and the second electric motor 1b and the switching of the first multi-speed transmission 2a and the second multi-speed transmission 2b.

[0032] A sensor 6a is arranged on the first axis 3a, which measures the drive parameter AP of the rotational speed AP1 of the first axis 3a in real time and provides it in real time to the control unit 5. Real time means at intervals of one hundredth of a second.

[0033] Fig. 2 - 5 each show diagrams of the curve of the first power La provided to the first electric motor 1a and the second power Lb provided to the second electric motor 1b during a preferred method for operating the electric vehicle from Fig. 1 during a start-up situation AF from a standstill. In Fig. 2 - 5, the starting situation AF from standstill is completed when the respective continuous power DLa, DLb is constantly supplied to the first electric motor 1a and the second electric motor 1b (for example, for more than 30 seconds). The diagrams are also described below with reference to the Fig. 1 shown reference numerals.

[0034] The drive parameter AP provided in real time, i.e., the rotational speed AP1 of the first axis 3a, is plotted on the horizontal axis, and the first power La provided to the first electric motor 1a, the second power Lb provided to the second electric motor 1b, and the total power L of the first power La and second power are plotted on the vertical axis. The first power La is represented by a dashed line, the second power Lb by a dotted line, and the total power L by a solid line. The intersection point of the horizontal axis with the vertical axis is zero in each case.

[0035] During the starting situation AF, during step G), the speed AP1 of the first axle 3a is measured and this drive parameter AP is provided to the control unit 5 in real time. Furthermore, during the starting situation AF in step H), the first power La provided to the first electric motor 1a and the second power Lb provided to the second electric motor 1b are controlled in real time, as well as the switching of the first multi-speed transmission 2a and the second multi-speed transmission 2b is controlled in real time depending on the speed AP1 of the first axle 3a.

[0036] In Fig. 2, at the beginning of the starting situation AF from a standstill in step A), the first multi-speed transmission 2a is shifted into the second gear G2a and the second multi-speed transmission 2b is shifted into the first gear G1b. Thus, in step A), the first axle 3a is driven by providing a first power La to the first electric motor 1a, and the second axle 3b is driven by providing a second power Lb to the second electric motor 1b.

[0037] In step B), the second multi-speed transmission 2b is shifted to the second gear G2b. During step B), in step C), the first power La provided to the first electric motor 1a is increased to 100% of the peak power SLa of the first electric motor 1a and the second power Lb provided to the second electric motor 1b is reduced to 0% of the peak power SLb of the second electric motor 1b. After the second multi-speed transmission 2b is shifted in step B), in step D), the first power La provided to the first electric motor 1a is reduced.

[0038] In Fig. 3, at the beginning of the starting situation AF from a standstill in step A), the first multi-speed transmission 2a is shifted into the first gear G1a and the second multi-speed transmission 2b is shifted into the first gear G1b. Thus, in step A), the first axle 3a is driven by providing a first power La to the first electric motor 1a, and the second axle 3b is driven by providing a second power Lb to the second electric motor 1b.

[0039] In step B), the second multi-speed transmission 2b is shifted to the second gear G2b. During step B), in step C), the first power La provided to the first electric motor 1a is increased to 100% of the peak power SLa of the first electric motor 1a and the second power Lb provided to the second electric motor 1b is reduced to 0% of the peak power SLb of the second electric motor 1b. After the second multi-speed transmission 2b is shifted in step B), in step D), the first power La provided to the first electric motor 1a is reduced.

[0040] After step D), in step E) the first multi-speed transmission 2a is switched to the second gear G2a, wherein during step E the second power Lb provided to the second electric motor 1b is increased.

[0041] In Fig. 4, at the beginning of the starting situation AF from a standstill in step A), the first multi-speed transmission 2a is shifted into the first gear G1a and the second multi-speed transmission 2b is shifted into the first gear G1b. Thus, in step A), the first axle 3a is driven by providing a first power La to the first electric motor 1a, and the second axle 3b is driven by providing a second power Lb to the second electric motor 1b.

[0042] In step B), the second multi-speed transmission 2b is switched to neutral position N. During step B), in step C), the first power La provided to the first electric motor 1a is increased to the continuous power DLa of the first electric motor 1a and the second power Lb provided to the second electric motor 1b is reduced to 0% of the peak power SLb of the second electric motor 1b.

[0043] In Fig. 5, at the beginning of the starting situation AF from a standstill in step A), the first multi-speed transmission 2a is shifted into the first gear G1a and the second multi-speed transmission 2b is shifted into the neutral position N. Thus, in step A), the first axle 3a is driven by providing a first power La to the first electric motor 1a and the second axle 3b is driven by providing a second power Lb to the second electric motor 1b.

[0044] In step B), the second multi-speed transmission 2b is shifted to the second gear G2b. During step B), in step C), the first power La provided to the first electric motor 1a is increased to 100% of the peak power SLa of the first electric motor 1a, and the second power Lb provided to the second electric motor 1b is increased to the continuous power DLb of the second electric motor 1b. After the second multi-speed transmission 2b is shifted in step B), the first power La provided to the first electric motor 1a is reduced in step D.

[0045] Fig. Figure 6a shows a schematic sectional view of another electric vehicle 0 provided in step AA). The electric vehicle 0, an electrically powered passenger car, comprises a first axle 3a as the rear axle and a second axle 3b as the front axle. The first axle 3a is driven by both a first electric motor 1a via a first multi-speed transmission 2a and a second electric motor 1b via a second multi-speed transmission 2b.

[0046] The electric vehicle 0 has a battery as a power supply 4. This battery provides a first power La to the first electric motor 1a and a second power Lb to the second electric motor 1b. Furthermore, the electric vehicle 0 includes a control unit 5, which controls the powers La and Lb provided to the first electric motor 1a and the second electric motor 1b and the switching of the first multi-speed transmission 2a and the second multi-speed transmission 2b.

[0047] Fig.Figure 6b shows a schematic sectional view of another electric vehicle 0 provided in step AA). The electric vehicle 0, an electrically powered truck, comprises a first axle 3a as the rear axle, a second axle 3b as the further rear axle, and a third axle 3c as the front axle. The first axle 3a is driven by a first electric motor 1a via a first multi-speed transmission 2a, and the second axle 3b is driven by a second electric motor 1b via a second multi-speed transmission 2b. The third axle 3c is driven by a further electric motor 1c via a further multi-speed transmission 2c.

[0048] The electric vehicle 0 has a battery as a power supply 4. This provides a first power La to the first electric motor 1a, a second power Lb to the second electric motor 1b, and a further power Lc to the further electric motor 1c. The electric vehicle 0 further comprises a control unit 5, which controls the provided powers La, Lb, Lc to the first electric motor 1a, the second electric motor 1b, and the further electric motor, and the switching of the first multi-speed transmission 2a, the second multi-speed transmission 2b, and the further multi-speed transmission 2c. The further power Lc provided by the power supply 4 to the further electric motor 1c is increased during the switching of the first multi-speed transmission 2a or during the switching of the second multi-speed transmission 2b in order to support the drive power during the switching. Reference symbol 0 electric vehicle 1a first electric motor 1b second electric motor 1c additional electric motor 2a first multi-speed gearbox 2b second multi-speed gearbox 2c additional multi-speed gearbox 3a first axis 3b second axis 3c third axis 4 Power supply 5 Control 6 Sensor G1a first torque-transmitting gear of the first multi-speed transmission G2a second torque-transmitting gear of the first multi-speed transmission G1b first torque-transmitting gear of the second multi-speed transmission G2b second torque-transmitting gear of the second multi-speed transmission N Neutral position The first performance Lb second power Lc additional performance L Total power

Claims

[1] Procedure for operating an electric vehicle during a starting situation comprising the steps: AA) Providing an electric vehicle (0) with at least one axle (3a) driven by a first electric motor (1a) via a first multi-speed transmission (2a), at least one axle (3b) driven by a second electric motor (1b) via a second multi-speed transmission (2b), a power supply (4) for providing power (La, Lb) to the first electric motor (1a) and to the second electric motor (1b), a control unit (5) for controlling the power (La, Lb) provided to the first electric motor (1a) and the second electric motor (1b) and for controlling the switching of the first multi-speed transmission (2a) and the second multi-speed transmission (2b), wherein the sum of the peak power (SLa) of the first electric motor (1a) and peak power (SLb) of the second electric motor (1b) is greater than the power that can be provided by the power supply (4); and either: A) Driving at least one axle (3a) by providing a first power (La) to the first electric motor (1a) and driving at least one axle (3b) by providing a second power (Lb) to the second electric motor (1b), wherein the first multi-speed transmission (2a) is engaged in a torque-transmitting gear (G1a, G2a) and the second multi-speed transmission (2b) is engaged in a torque-transmitting gear (G1b, G2b); B) Switching the second multi-speed transmission (2b) into a torque-transmitting gear (G1b, G2b) or into neutral (N); C) Increasing the first power supplied (La) to the first electric motor (1a) and decreasing the second power supplied (Lb) to the second electric motor (1b) during step B); or: A) Driving at least one axle (3a) by providing a first power (La) to the first electric motor (1a), wherein the first multi-gear transmission (2a) is engaged in a torque-transmitting gear (G1a, G2a) and the second multi-gear transmission (2b) is engaged in neutral (N); B) Switching the second multi-speed transmission (2b) into a torque-transmitting gear (G1b, G2b); C) Increasing the initial power supplied (La) to the first electric motor (1a) during step B). [2] Method according to claim 1, wherein in step A) the first multi-speed transmission (2a) and / or the second multi-speed transmission (2b) is switched into a torque-transmitting gear (G2a; G2b) different from the respective first torque-transmitting gear (G1a; G1b). [3] Method according to claim 2, wherein either: - in step A) the first multi-speed transmission (2a) is shifted into second gear (G2a) and the second multi-speed transmission (2b) into first gear (G1b), and in step B) the second multi-speed transmission (2b) is shifted into second gear (G2b); or - in step A) the first multi-speed transmission (2a) is shifted into second gear (G2a) and the second multi-speed transmission (2b) into first gear (G1b), and in step B) the first multi-speed transmission (2a) is shifted into first gear (G1a); or - in step A) the first multi-speed transmission (2a) is shifted into a first gear (G1a) or into a second gear (G2a) and the second multi-speed transmission (2b) is shifted into a neutral position (N) and in step B) the second multi-speed transmission (2b) is shifted into a first gear (G1b) or into a second gear (G2b). [4] Method according to any of the preceding claims, comprising the step of: D) Reducing the first power supplied (La) to the first electric motor (1a) after switching the second multi-speed transmission (2b) in step B). [5] Method according to one of claims 1 or 2, wherein in step A) the first multi-gear transmission (2a) is shifted into a first gear (G1a) or into a second gear (G2a) and the second multi-gear transmission (2b) is shifted into a first gear (G1a) and in step B) the second multi-gear transmission (2b) is shifted into a neutral position (N). [6] Method according to claims 1 and 4, wherein in step A) the first multi-speed transmission (2a) is shifted into a first gear (G1a) and the second multi-speed transmission (2b) is shifted into a first gear (G1b) and in step B) the second multi-speed transmission (2b) is shifted into a second gear (G2b), further comprising the steps: E) Shifting the first multi-speed transmission (2a) into a second gear (G2a) after step D); F) Increase the second power (Lb) supplied to the second electric motor (1b) during step E). [7] Method according to one of the preceding claims, wherein in step C) the first power supplied (La) to the first electric motor (1a) is increased to at least 75%, preferably to at least 85%, particularly preferably to at least 95%, of the peak power (SLa) of the first electric motor (1a) and / or in step F) the second power supplied (Lb) to the second electric motor (1b) is increased to at least 75%, preferably to at least 85%, particularly preferably to at least 95%, of the peak power (SLb) of the second electric motor (1b). [8] Method according to one of the preceding claims, wherein in step C) the power supplied (L) to the second electric motor (1b) is reduced to a maximum of 25%, preferably to a maximum of 15%, particularly preferably to 0%, of the peak power (SLb) of the second electric motor (1b). [9] Method according to any of the preceding claims, wherein the electric vehicle (0) has at least one sensor (6) configured to select at least one drive parameter (AP) from: - the rotational speed (AP1) of an axis (3a); - the rotational speed (AP2) of another axis (3b); - the speed (AP3) of the electric vehicle (0); - the acceleration (AP4) of the electric vehicle (0); - the drive power (AP5) of an axle (3a); - the drive power (AP6) of another axle (3b); - the drive torque (AP7) of an axle (3a); - the drive torque (AP8) of another axle (3b); - to measure the output power (AP9) of the power supply (4) and to provide it to the control unit (5) in real time. [10] The method of claim 9, comprising the steps: G) Measuring at least one drive parameter (AP) and providing the at least one drive parameter (AP) to the control unit in real time (5); H) Real-time control of the first power supplied (La) to the first electric motor (1a) and / or the second power supplied (Lb) to the second electric motor (1b) and / or real-time control of the switching of the first multi-speed transmission (2a) and / or the second multi-speed transmission (2b) based on at least one drive parameter (AP). [11] Method according to one of the preceding claims, wherein the electric vehicle (0) comprises at least one further electric motor (1c) which is configured via a further multi-speed transmission (2c) for driving an axle (3a, 3b, 3c), and wherein a further power (Lc) supplied by the power supply (4) to the at least one further electric motor (1c) is increased during the switching of the first multi-speed transmission (2a) and / or during the switching of the second multi-speed transmission (2b).

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