Electric vehicles with central energy monitoring characterizing each component

Abstract

The invention relates to an electric vehicle with a high-voltage battery, at least one electric machine, power electronics, a DC / DC converter and an electronic evaluation unit for central energy monitoring, characterizing each of the predetermined components of the low-voltage vehicle electrical system and / or each of the predetermined components of the high-voltage vehicle electrical system. The evaluation unit is configured in such a way that a load signature specific to each of the predetermined components is stored in the evaluation unit and that outside the predetermined components, total measurement signals detected by a first (only) measurement sensor for the entire low-voltage vehicle electrical system and / or a second (only) measurement sensor for the entire high-voltage vehicle electrical system are separated using the NILM technique in order to identify the load signature. Furthermore, each of the total measurement signals is filtered out of vehicle-specific electrical disturbances by a predetermined correction module before separation.

Description

[Technical field]

[0001] The invention relates to an electric vehicle with a central energy monitoring that characterizes each component. The energy monitoring that characterizes each component is known, for example, in the form of so-called non-intrusive load monitoring (also abbreviated as NILM). Non-intrusive load monitoring of electrical components is a process that analyzes the voltage and / or current changes to determine the components used in the system that consume energy in terms of the total energy consumption of the system and the individual energy consumption of the individual components. This process is used in particular in domestic electrical appliances and involves disentangling ("segregation") the total energy consumption measured at a certain central measuring point of the system into the individual energy consumption of the individual components or devices of the system. [Background technology]

[0002] The core idea of ​​the NILM technology is based on the premise that each electrical component leaves an individual signal, a kind of "load (power) signature" (load pattern) in the energy distribution network. These signals are detected in the aggregated total energy consumption. Using well-known algorithms for pattern recognition (the so-called NILM algorithms) and machine learning methods, the individual signals (hereafter called load signatures) in the total energy consumption are disentangled, i.e. separated. The actual recognition of the components is event- or time-controlled.

[0003] As a result, separation provides detailed insight into what the energy consumption of individual components is and, if necessary, how it changes over time, thus identifying potential energy efficiency improvements and determining equipment-specific diagnostic methods. Summary of the Invention [Problem to be solved by the invention]

[0004] The task of the present invention is to transfer the principle of energy monitoring, which characterizes each component of a household appliance or other device on the public power grid, to electric vehicles. [Means for solving the problem]

[0005] This problem is solved by the features of patent claim 1. Advantageous developments of the invention are the subject matter of the dependent claims.

[0006] The invention relates to an electric vehicle with a high-voltage battery, at least one electric machine, power electronics, a DC / DC converter and an electronic evaluation unit for central energy monitoring characterizing each of the predetermined components of the low-voltage vehicle electrical system and / or the predetermined components of the high-voltage vehicle electrical system, wherein the evaluation unit is configured such that a load (power) signature specific for each of the predetermined components is stored in the evaluation unit and that outside the predetermined components, total measurement signals detected by a first (only) measurement sensor for the entire low-voltage vehicle electrical system and / or a second (only) measurement sensor for the entire high-voltage vehicle electrical system are discriminated using the NILM technique in order to identify the load signatures. Furthermore, each of the total measurement signals is filtered by a certain correction module prior to discriminatory motor vehicle-specific electrical disturbances.

[0007] The present invention is based on the following considerations: Non-Intrusive Load Monitoring (NILM) describes a signal decomposition method to model multiple signal values ​​based on observations. Mathematically this is a highly unspecified "single channel source separation" problem that can be formulated as follows:

number

[0008] Non-intrusive load monitoring has gained importance over the last decade not only in the field of intelligent networks but also for use in heavy industry (ships, pump drives, etc.). Its advantages are cost savings due to the reduction in the number of sensors and wiring required, measurement of quantities that cannot be known via sensor devices, and increased efficiency due to accurate feedback on energy consumption.

[0009] NILM has not yet been implemented in vehicle systems so far. However, its application is becoming more and more interesting as electrification advances and "living spaces" are being created inside vehicles. Its advantages and possibilities are: - Cost savings by replacing redundant sensor devices (central measuring point with additional calculations) - Energy savings by providing feedback to customers on their energy consumption (AC, heating, infotainment, etc.) - Detection of unknown quantities (brush wear in current-controlled electric drives (SSM)) to predict maintenance in advance

[0010] Prior Art - Sensors, Wiring, and Components: In a battery electric vehicle, energy is distributed from the high voltage battery (HVS) to the high voltage vehicle electrical system (HV vehicle electrical system for short) and then via a DC / DC converter to the low voltage vehicle electrical system (LV vehicle electrical system for short). The energy is transmitted via wires. Measuring the currents and voltages on these wires is made possible by sensor devices for two reasons: - Functional necessity (e.g. current measurement for torque control) - Customer information (e.g. HVS charging status) For functional safety, sensors are often used redundantly for certain functions in order to allow limited operation in the event of a simple fault. The redundant sensors can also be realized virtually, for example as calculations.

[0011] Technical issues: Measuring electrical quantities, especially for safety-relevant functions, is costly and laborious (and sometimes not even possible as standard due to inaccessible measuring points). However, the measured quantities are necessary to cover two functions: firstly, functions with functional necessity, and secondly, information to be displayed to the customer via the infotainment to improve the driving experience.

[0012] Basic concept of the present invention: In an electric vehicle, it is proposed to use one central sensor for the HV on-board electrical system with given electrical components and / or one central sensor for the LV on-board electrical system with given electrical components, whose respective sensor signals as the total energy consumption of the HV on-board electrical system and / or the LV on-board electrical system are separated using suitable calculation methods to obtain all the required individual energy consumptions of the given components. Thus, the basic principle of the NILM technology is applied.

[0013] However, in electric vehicles, there is a technical problem that the measurement signal can be corrupted by static and dynamic disturbances depending on where sensors are needed. According to the invention, unlike the prior art, the measurement signal is corrected before sorting using a correction module which again removes these disturbance factors as a so-called "inverse filter".

[0014] For example, static disturbances in the central sensor for measuring the total energy consumption of the LV on-board electrical system are due in particular to the behavior of the DC / DC converter, which has a filtering effect due to its own inductance, since this sensor is located at the outlet and close to the DC / DC converter, i.e. at the “inlet” of the LV on-board electrical system of the electric vehicle.

[0015] For example, dynamic disturbances in the central sensor for measuring the total energy consumption of the hybrid vehicle on-board electrical system are due in particular to the behavior of the electric machine, which depends on its operating state and the switching behavior of the power electronics, since this sensor is located at the outlet of the high-voltage battery, i.e. at the "inlet" of the hybrid vehicle on-board electrical system of the electric vehicle.

[0016] The advantages of the present invention are as follows: - Cost savings by replacing redundant sensor devices (central measuring point with additional calculations) - Energy savings through feedback to customers on energy consumption (air conditioning, heating, infotainment, etc.) - Detection of unknown quantities (SSM brush wear) to predict maintenance in advance

[0017] An embodiment of the present invention is shown in the figures. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 is a schematic diagram showing components important for the understanding of the present invention, including in particular the corresponding evaluation unit of an electric vehicle. [Diagram 2] FIG. 2 shows an implementation of the evaluation unit in detail. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Figure 1 shows an electric vehicle F according to the invention with a high-voltage battery HVS, a first electric machine K3 and a second electric machine K4, power electronics LE, a DC / DC converter W and an electronic evaluation unit A for central energy monitoring, which characterizes certain components K1, K2 of the low-voltage vehicle electrical system NV and certain components K3, K4 (in this example in the form of electric machines) of the high-voltage vehicle electrical system HV.

[0020] The evaluation unit A is configured such that in the evaluation unit, load signatures LS1, LS2, LS3, LS4 specific to each of the given components K1, K2, K3, K4 are stored, and outside the given components, total measurement signals S_NV, S_HV detected by a first measurement sensor S1 for the entire low-voltage vehicle electrical system NV and a second measurement sensor S2 for the entire high-voltage vehicle electrical system HV are separated using the NILM technique in order to identify the load signatures LS1, LS2, LS3, LS4. According to the invention, each of the total measurement signals S_NV, S_HV is then filtered out of vehicle-specific electrical disturbances by a respective given correction module M1, M2 before being separated.

[0021] The first measurement sensor S1 is arranged at the outlet of the DC / DC converter W or at the "inlet" of the low-voltage vehicle electrical system NV. The second measurement sensor S2 is arranged at the outlet of the high-voltage battery HVS.

[0022] The correction module M1 for the total measurement signal S_NV of the first measurement sensor S1 has a behavior opposite to the behavior of the DC / DC converter W stored in the evaluation unit A, since this behavior acts as a filter for electrical disturbances on the load signatures LS1′, LS2′ which are measured incorrectly due to electrical disturbances.

[0023] The correction module M2 for the total measurement signal S_HV of the second measurement sensor S2 has a behavior opposite to that of the power electronics LE stored in the evaluation unit A, since it likewise acts as a filter (albeit in a different way) on the load signatures LS3′, LS4′ which are measured incorrectly due to electrical disturbances.

[0024] The correction module M2 is preferably variably adjustable depending on the current operating parameters of the electric machines K3, K4 and / or the switching states of the power electronics LE before discriminating the total measurement signal S_HV of the second measurement sensor S2.

[0025] In a further development of the invention (shown in FIG. 2), the evaluation unit A outputs the individual energy consumptions V1, V2 of the components K1, K2 on the basis of the separated load signatures LS1, LS2 on a first display D1. The consumptions can be displayed as circles with a diameter proportional to the consumption. The invention is thus used as consumption information and indicates potential savings to the driver if necessary.

[0026] Additionally or alternatively, the evaluation unit A can output maintenance information on the second display D2 relating to a particular component (here K3) as a function of the change ΔLS3 in the individual energy consumption of the component compared to the stored load signature LS3 of the component. Thus, the invention is used here as a diagnostic, for example to detect wear of the brushes of an electric machine K3 to which a current is applied.

[0027] In summary, two central sensors S1 and S2 must be provided: S1 is a current / voltage sensor in the DC / DC converter of the LV onboard electrical system. · S2 is a current / voltage sensor in the HVS of the HV on-board electrical system.

[0028] The signals of these two sensor pairs can be used to model the corresponding LV and HV components:

number

[0029] Examples of possible load signatures: - LS1(NV): Load signature Air conditioning(K1) => feedback to reduce energy consumption, for example - LS2(NV): Load Signature Infotainment (K2) => feedback to reduce energy consumption, for example - LS3(HV): Load signature (current applied) Electric machine K3 => for detection of brush wear - LS4(HV): Load signature (current applied) electric machine K4 => for detection of brush wear

[0030] The load signature may be determined empirically during the design of the vehicle as a model.

Claims

1. An electric vehicle (F) comprising a high-voltage battery (HVS), at least one electric machine (K3, K4), power electronics (LE), a DC / DC converter (W), and an electronic evaluation unit (A) for central energy monitoring, which characterizes predetermined components (K1, K2) of a low-voltage vehicle electrical system (NV) and / or predetermined components (K3, K4) of a high-voltage vehicle electrical system (HV), the evaluation unit (A) is configured such that load signatures (LS1, LS2; LS3, LS4) specific to each of the predetermined components (K1, K2; K3, K4) are stored in the evaluation unit, and total measurement signals (S_NV; S_HV) detected outside the predetermined components (K1, K2, K3, K4) by a first measurement sensor (S1) for the entire low-voltage vehicle electrical system (NV) and / or a second measurement sensor (S2) for the entire high-voltage vehicle electrical system (HV) are separated using NILM techniques in order to identify the load signatures (LS1, LS2; LS3, LS4), An electric vehicle, wherein each of the total measurement signals (S_NV; S_HV) is filtered by a predetermined correction module (M1; M2) to remove electrical disturbances specific to the vehicle before being separated.

2. 2. The electric vehicle (F) according to claim 1, characterized in that the first measurement sensor (S1) is arranged at the outlet of the DC / DC converter (W) or the second measurement sensor (S2) is arranged at the outlet of the high-voltage battery (HVS).

3. 3. The electric vehicle (F) according to claim 1 or 2, characterized in that the correction module (M1) for the total measurement signal (S_NV) of the first measurement sensor (S1) has a behavior opposite to the behavior of the DC / DC converter (W) stored in the evaluation unit (A).

4. 3. The electric vehicle (F) according to claim 1 or 2, characterized in that the correction module (M2) for the total measurement signal (S_HV) of the second measurement sensor (S2) has a behavior opposite to the behavior of the power electronics (LE) stored in the evaluation unit (A).

5. 3. An electric vehicle (F) according to claim 1 or 2, characterized in that the correction module (M2) is variably adjustable depending on the current operating parameters of at least one of the electric machines (K3, K4) and / or the switching state of the power electronics (LE) before separating the total measurement signal (S_HV) of the second measurement sensor (S2).

6. 3. The electric vehicle (F) according to claim 1 or 2, characterized in that the evaluation unit (A) outputs the individual energy consumptions (V1, V2) of the predetermined components (K1, K2) on a first display (D1) based on the classified load signatures (LS1, LS2).

7. 3. An electric vehicle (F) according to claim 1 or 2, characterized in that the evaluation unit (A) outputs maintenance information on a second display (D2) relating to a particular component (K3) as a function of the change (ΔLS3) in the individual energy consumption of that component compared with the stored classified load signature (LS3) of that component.

Images