Method for determining an electrical fault contact in an electrically driven vehicle and electrical system

Abstract

The invention relates to a method for determining an electrical fault contact in an electrically driven vehicle and to an electrical system of a vehicle. The method has the following steps: determining (100) a gradient (G) from a plurality of measured values (V) of at least one electrical quantity of an electrical system of the vehicle, including the battery; comparing (200) the determined gradient (G) with a predefined threshold value (T) of the gradient (G); and outputting (300) a fault signal if the gradient (G) is continuously above the predefined threshold value (T) of the gradient (G) for a first predefined time period or alternately above and below the predefined threshold value (T) of the gradient (G) with a value greater than a predefined minimum frequency for a second predefined time period.

Description

Technical Field

[0001] The present invention relates to a method for determining electrical fault contacts in a battery-powered vehicle and the electrical system of such a vehicle. Background Technology

[0002] Electrically driven vehicles are known in the prior art, and these vehicles have a battery and an electric motor powered by the battery for driving the vehicle. Particularly in relation to electrically driven two-wheeled vehicles, such as electric bicycles, batteries that can be removed from the battery receiving device of the two-wheeled vehicle are often used, allowing the battery to be charged remotely from the vehicle. For this purpose, such batteries and / or their corresponding battery receiving devices have corresponding contact devices through which an electrical connection is established between the two components when the battery is in use.

[0003] Contact failures may occur between such contacts via such contact devices and / or other electrical contacts between the energy storage device and the electric motor in the corresponding vehicle, for example due to wear and / or aging of such electrical contacts and / or due to vibrations caused during driving. Such contact failures may affect the performance of the entire electrical system. Summary of the Invention

[0004] According to a first aspect of the invention, a method is provided for determining electrical fault contacts in a battery-powered vehicle.

[0005] In the first step of the method of the present invention, a gradient is obtained based on multiple measurements of at least one electrical parameter of the vehicle's electrical system, including the battery. In principle, the battery is not limited in terms of the battery technology on which it is based and / or its corresponding characteristic parameters (e.g., the battery's rated capacity, the battery's rated voltage, etc.). For example, at least one electrical parameter may be obtained in an electrical appliance (e.g., a drive unit) and / or with the aid of the battery's battery management system and / or with the aid of a vehicle component that deviates from the battery management system. This component is preferably connected in information technology to a sensing device configured to sense at least one electrical parameter of the battery. Preferably, the measured value of at least one electrical parameter is converted into a digital measurement and is also used as the measurement value for calculating the gradient. However, alternatively or additionally, it is also possible to receive and process the measurement values ​​in analog form.

[0006] In the second step of the method of the present invention, the obtained gradient is compared with a predetermined threshold for the gradient. This predetermined threshold is stored, for example, in the vehicle's storage unit and is preferably determined such that the required functional capabilities of the vehicle's electrical system using the battery are not limited or substantially not limited, provided that the threshold is not exceeded.

[0007] In the third step of the method of the present invention, a fault signal is output if the gradient is continuously higher than a predetermined threshold for a first predetermined time period, or alternately higher and lower than the predetermined threshold for a second predetermined time period at a frequency greater than a predetermined minimum frequency. By correspondingly determining the first time period (preferably guided by the minimum technical requirements of the respective electrical system), for example with a very short first time period, a fault signal can be output immediately after the threshold is exceeded for the first time. This allows for an immediate response to such threshold exceedances. Alternatively, by selecting a longer first time period, it is possible to output a fault signal only when the gradient exceeds the threshold within a correspondingly longer time period. The latter offers the advantage that no fault signal is output when the gradient individually and briefly exceeds the threshold without causing substantial damage to the electrical system. Alternatively, as described above, it is possible to always output a fault signal when the gradient exceeds the threshold at a predetermined frequency within the second time period.

[0008] The method of this invention offers the particular advantage that, by examining the gradient of at least one electrical parameter to be monitored, the individual changes in the curve of that parameter's variation can be sensed and used for the output of a fault signal. Thus, particularly accurate and flexibly coordinated fault monitoring can be achieved in electrical systems where electrical parameters deviate at least partially from their intended values, for example, due to fault contact. Furthermore, this method enables early identification of electrical system degradation, thereby allowing for the prevention of damage to the electrical system, for example, through early intervention with appropriate measures.

[0009] The preferred embodiments illustrate preferred extensions of the invention. In an advantageous configuration of the invention, a fault signal is used to output information about a fault condition of the electrical system to the vehicle user. This information may be output, for example, in the form of prompt text and / or prompt symbols on the vehicle's display and / or by activating the vehicle's warning lights. Alternatively or additionally, it is also conceivable that this information may be output in the form of audible prompts (e.g., warning tones) and / or tactile prompts (e.g., steering wheel vibration). Further alternatively or additionally, based on this fault signal, it is possible to reduce energy extraction from the battery. This is preferably achieved by shutting off the vehicle's electrical appliances and / or by limiting the maximum driving speed used.

[0010] Furthermore, it is advantageous to determine the cause of electrical fault contacts based on gradients and / or other measurement parameters. This can be achieved, for example, by analyzing and evaluating the frequency at which the gradient alternately exceeds and falls below a threshold within a third predetermined time period. For example, it is conceivable in this way to distinguish fault contacts caused by vehicle vibrations due to motion from persistent fault contacts (e.g., due to contaminated contact parts). It is also conceivable to identify batteries that are not properly inserted into the battery receiving device, as contact faults in this case may have a more significant impact on the gradient than when the battery is properly inserted. For example, measurement parameters from vibration sensors, etc., can be considered as additional measurement parameters mentioned above.

[0011] In a particularly advantageous embodiment of the invention, the method additionally includes the steps of: comparing a measured value of at least one electrical parameter with a predefined (maximum permissible) range of the measured value, and, if the measured value is outside the predefined range, placing the electrical system in a safe state. Regardless of the performance of the corresponding gradient, values ​​above or below this range can be considered in this way, values ​​that might, for example, cause critical system conditions (e.g., overheating of electrical components and / or battery damage).

[0012] Preferably, the calculated gradients are normalized before being compared with a predefined threshold for the gradients. This simplifies subsequent processing of each gradient, as they each have a uniform reference.

[0013] Advantageously, at least one electrical parameter is voltage, current, resistance, power, or frequency. Depending on the electrical parameter used, a corresponding sensor is used to sense the corresponding parameter.

[0014] Particularly advantageously, multiple gradients are calculated based on multiple corresponding measurements of different electrical parameters, wherein a fault signal is output if at least one of the multiple gradients is higher than a corresponding associated threshold. By considering the gradients of different electrical parameters in this way, the reliability and / or sensitivity of the method of the invention can be further improved. This is particularly advantageous when the gradient of a single electrical parameter is insufficient to reliably identify contact faults within an electrical system.

[0015] According to a second aspect of the invention, an electrical system for a battery-powered vehicle is provided. The vehicle is, for example, an electrically powered road transport vehicle (e.g., a motorcycle, passenger car, light truck, truck), an electrically powered rail transport vehicle, or an electrically powered air transport vehicle / aircraft and / or water transport vehicle. Particularly preferred is an electrically powered bicycle (electric bicycle) or an electrically powered scooter. The electrical system is, for example, a system for supplying energy to the electric drive unit of the vehicle and / or a communication system for the vehicle (e.g., a bus system). The electrical system comprises: a battery having a first electrical terminal, an electrical appliance having a second electrical terminal, electrical contact elements, and an analysis and evaluation unit. The electrical contact elements are preferably contact springs, which can be used in any embodiment (e.g., as a stamped bending element, a compression spring, a spring ring, etc.). Alternatively, the contact elements are, for example, screw contact elements, locking contact elements, clamping contact elements, or contact elements deviating from these contact elements. The electrical contact elements are configured to electrically connect the first electrical terminal of the battery to the second electrical terminal of the electrical appliance. The analysis and evaluation unit is configured, for example, as an ASIC, FPGA, processor, digital signal processor, microcontroller, or the like, and is part of the vehicle's drive unit, part of the existing battery management system of the battery, part of a vehicle component that deviates from the existing battery management system of the battery, or a separate vehicle component. Furthermore, the analysis and evaluation unit is preferably informationally connected to an internally and / or externally connected storage unit, in which data received and / or processed by the analysis and evaluation unit is stored. The analysis and evaluation unit is configured to calculate a gradient based on multiple measurements of at least one electrical parameter of the vehicle's electrical system, compare the calculated gradient with a predetermined threshold for the gradient, and output a fault signal if the gradient is consistently higher than the predetermined threshold for a first predetermined time period. Alternatively, if the gradient alternately exceeds and falls below the predetermined threshold for the gradient at a frequency greater than a predetermined minimum frequency during a second predetermined time period, a fault signal is output. Furthermore, the analysis and evaluation unit is generally configured to implement the methods of the invention described above in all currently disclosed variations (e.g., based on computer programs implementing the various method steps). The features, combinations of features, and advantages derived from these features and combinations of features are so clearly corresponding to those features, combinations of features, and advantages achieved by combining the inventive aspects first proposed, that reference be made to the above embodiments to avoid repetition.

[0016] Preferably, the battery of the electrical system of the present invention is a removable battery, which is configured to be securely fastened in the vehicle's battery receiving device and electrically contacted through the battery receiving device in the state of use. The battery is, for example, a lithium-ion battery, which preferably has a voltage in the range of 12V to 60V, without limiting the battery to such a battery type and such a voltage range.

[0017] Particularly preferably, the battery of the electrical system of the present invention is also a traction battery, and the electrical appliance is preferably an electric drive motor of a vehicle, which is further preferably an electrically driven two-wheeled vehicle. Attached Figure Description

[0018] Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. As shown herein: Figure 1 A flowchart illustrating the steps of the method of the present invention; and Figure 2 A schematic overview of the components of the electrical system of the present invention, which incorporates an electrically driven two-wheeled vehicle. Detailed Implementation

[0019] Figure 1 A flowchart illustrating the steps of the method of the present invention is shown. The method begins at node S in the flowchart. In step 400 of the method of the present invention, a measured value V representing the voltage of a voltage sensor of the electrical system of the vehicle 20 is first sensed and compared with a predetermined value range B. The electrical system includes, in particular, a battery 10 and an electric motor 30 electrically connected to the battery. In step 500 of the method of the present invention, if at least one of these measured values ​​V is higher or lower than the predetermined value range B, the electrical system is placed in a safe state. Here, the safe state is achieved by preventing energy from being drawn from the battery 10 using a controllable circuit breaker element.

[0020] If the measured value V does not exceed a predetermined value range B, in step 100, a gradient G is calculated based on multiple measured values ​​V, and this gradient is normalized in step 150. In step 200, the calculated gradient G is compared with a predetermined threshold T for gradient G. If the gradient G is consistently higher than the predetermined threshold T within a first predetermined time period, or alternately higher and lower than the threshold at a frequency greater than a predetermined minimum frequency within a second predetermined time period, a fault signal is output in step 300. In step 320, the fault signal is received by the vehicle's onboard computer, and in response, a warning is output on a display connected to the onboard computer in information technology, informing the user of the vehicle 20 of the current contact problem of the battery 10. Furthermore, in step 340, energy drawn from the battery 10 is reduced to avoid damage to the electrical system.

[0021] If the gradient G does not exceed the threshold T in step 200, the method continues in step 400.

[0022] Furthermore, the cause of electrical fault contact can be determined based on this gradient.

[0023] Preferably, in addition to the measured value V representing voltage, another measured value Vs representing current is sensed. In this case, the gradient Gs obtained with respect to the other measured value Vs is also analyzed and evaluated in relation to the output fault signal, wherein this analysis and evaluation is performed in a similar manner to the analysis and evaluation of gradient G described above.

[0024] Figure 2 A schematic overview of the components of the electrical system of the present invention, incorporated into an electrically driven two-wheeled vehicle, here an electric bicycle 20, is shown. The electric bicycle's electrical system includes a traction battery 10, which is inserted into a battery receiving device 12 of the electric bicycle 20. The battery 20 has a first electrical connector 15, which is electrically connected to a second electrical connector 35 of the electric motor 30 (drive motor) of the electric bicycle 20 via a contact spring 40. The electrical system also includes an analysis and evaluation unit 50, which is integral to the electric motor 30. The analysis and evaluation unit 50 is electrically connected to the second electrical connector 35 of the electric motor 30 and is configured in such a way as to sense the voltage between the two contacts of the second electrical connector 35. Based on the current configuration, the analysis and evaluation unit 50 is configured to perform the aforementioned steps of the method of the present invention and, based on the method of the present invention, identify potential faulty contacts between the first electrical connector 15 and the second electrical connector 35 and respond to these faulty contacts in a suitable manner.

Claims

1. A method for determining electrical fault contacts in a battery-powered vehicle (20), the method comprising the steps of: - The gradient (G) of (100) is obtained from multiple measurements (V) of at least one electrical parameter of the electrical system of the vehicle (20), including the battery (10). - Compare the obtained gradient (G) with a predefined threshold (T) for the gradient (G) (200), and - If the gradient (G): If the gradient (G) remains consistently higher than a predetermined threshold (T) within a first predetermined time period, or If, during a second predetermined time period, the frequency alternates between being higher and lower than the predetermined threshold (T) of the gradient (G) at a frequency greater than the predetermined minimum frequency, then a fault signal (300) is output.

2. The method according to claim 1, wherein, The fault signal is used for: - Output (320) information about the fault condition of the electrical system to the user of the vehicle (20), and / or - Reduce (340) the energy obtained from the battery (10).

3. The method according to claim 2, wherein, The cause of electrical fault contact is determined based on the gradient (G) and / or other measurement parameters.

4. The method according to claim 1 or 2, further comprising the following steps: - Compare the measured value (V) of the at least one electrical parameter with a predetermined value range (B) of the measured value (V) (400), and - If the measured value (V) is outside the predetermined value range (B), the electrical system is placed in a (500) safe state.

5. The method according to claim 1 or 2, wherein, The obtained gradient (G) is normalized (150) before being compared with a predefined threshold (T) of the gradient (G).

6. The method according to claim 1 or 2, wherein, The at least one electrical parameter is: • Voltage, or • Electric current, or • Resistor, or • Power, or • Frequency.

7. The method according to claim 1 or 2, wherein, Multiple gradients (G) are obtained based on multiple corresponding measured values ​​(V) of different electrical parameters. If at least one of the multiple gradients (G) exceeds the corresponding threshold (T), the fault signal is output.

8. An electrical system for a battery-powered vehicle (20), said electrical system having: • A battery (10) having a first electrical connector (15). • An appliance (30) having a second electrical connector (35). • Electrical contact element (40), and • Analysis and evaluation unit (50) in, • The electrical contact element (40) is configured to electrically connect the first terminal (15) of the battery to the second electrical terminal (35) of the electrical appliance (30). • The analysis and evaluation unit (50) is configured for, - The gradient (G) is obtained from multiple measurements of at least one electrical parameter of the electrical system of the vehicle (20). - Compare the obtained gradient (G) with a predefined threshold (T) for the gradient (G), and -If the gradient (G) a) Continuously exceeding a predetermined threshold (T) of the gradient (G) within a first predetermined time period, or b) During the second predetermined time period, the gradient (G) is alternately higher and lower than the predetermined threshold (T) at a frequency greater than the predetermined minimum frequency. Then a fault signal will be output.

9. The electrical system according to claim 8, wherein, The battery (10) is a removable battery, which is configured to be secured in the battery receiving device (12) of the vehicle (20) in the use state and to be electrically contacted by the battery receiving device (12).

10. The electrical system according to claim 8 or 9, wherein, • The battery (10) is a traction battery, and • The electrical appliance (30) is the electric drive motor of the vehicle (20), wherein the vehicle (20) is in particular an electrically driven two-wheeled vehicle.

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