Method for ascertaining an energy consumption value during the charging of an electrical device

Abstract

The invention relates to a method for ascertaining an energy consumption value during the charging of an electrical device (7). According to the invention, measurement value blocks (8) are continuously measured and are transmitted to a central computing unit (2) after predefined interval steps; evaluation cycles are carried out by the central computing unit (2), in which evaluation cycles mean values of different mean value types are calculated, prognosis values associated with the mean values are ascertained, durations are determined, the mean values are updated, the mean values are compared with the associated prognosis values, the mean values having the smallest deviations from the respective ascertained prognosis values are selected, the prognosis values for which the associated mean values were updated are updated, energy values are determined from durations and selected mean values; and the individual energy values of the evaluation cycles are summed to form the energy consumption value.

Description

[0001] Method for determining an energy consumption value when charging an electrical device

[0002] The invention relates to a method for determining an energy consumption value when charging an electrical device according to claim 1.

[0003] Accurate energy consumption measurements for charging electrical appliances are essential for accurately billing and meticulously recording energy usage for accounting purposes. The accuracy of these measurements is particularly crucial for tax purposes.

[0004] Furthermore, the shift from fossil fuel-powered vehicles to electric vehicles has made determining the energy required for charging electric vehicles extremely important, especially for businesses. It has become apparent that there are differences in energy consumption measurements when charging electric vehicles with external charging devices, and these differences vary depending on the charging time. Since electric vehicles typically have longer charging times, there is a need for precise energy consumption measurements.

[0005] The object of the invention is therefore to provide a method of the type mentioned above, with which the aforementioned disadvantages can be avoided, and with which the amount of energy used when charging an electrical device can be accurately determined.

[0006] According to the invention, this is achieved by the features of claim 1.

[0007] By using averages of different types of averages, along with the corresponding forecast values, the amount of energy consumed when charging an electrical device, particularly an electric vehicle, can be precisely determined. This reduces the effect of various measurement errors during charging, which have varying degrees of impact on different types of averages, thus improving measurement accuracy. Studies have shown that this method allows for a more accurate determination of the amount of energy consumed during charging than previously known charging devices.The use of different averaging methods and their associated forecast values ​​led to an improvement in the accuracy of energy consumption measurement of several percent compared to previously known charging devices, with these differences accumulating as the charging time increases. The method according to the invention enables a precise calculation to be reliably performed and fulfills currently known tax requirements of national countries. In summary, this improves the measurement accuracy of a conventional charging device without requiring any structural modifications to the device.This allows for the use of a simple and robust device to determine energy consumption values ​​when charging an electrical appliance, which is particularly important for energy consumption measurement devices that often need to be transported and are exposed to highly changing environmental conditions, such as temperature fluctuations.

[0008] The invention further relates to an energy consumption measurement device according to claim 14.

[0009] The invention therefore further aims to provide an energy consumption measurement device of the type mentioned above, with which the aforementioned disadvantages can be avoided and with which the amount of energy used when charging an electrical device can be accurately determined.

[0010] According to the invention, this is achieved by the features of claim 14.

[0011] The advantages of the energy consumption measurement device correspond to those of the aforementioned method. This allows for the creation of an energy consumption measurement device that accurately determines energy consumption values ​​when charging an electrical appliance.

[0012] The dependent claims relate to further advantageous embodiments of the invention.

[0013] The invention is described in more detail with reference to the enclosed drawings, in which only preferred embodiments are shown by way of example. These show:

[0014] Fig. 1 shows a preferred embodiment of an energy consumption measurement device designed as a charging cable,

[0015] Fig. 2 shows a schematic representation of determined measurement blocks for at least one current phase, which measurement blocks are transmitted to a central computing unit over time.

[0016] Fig. 3 shows a schematic representation of how to determine the mean values ​​of different types of means over time.

[0017] Fig. 4 shows a flowchart of a preferred sequence of the method according to the invention.

[0018] Fig. 4 shows at least parts of a method for determining an energy consumption value when charging an electrical device 7, wherein measurement blocks 8 for at least one current phase are continuously measured and transmitted to a central processing unit 2 at predetermined interval steps, wherein each measurement block 8 comprises three measurement values ​​for each current phase, the three measurement values ​​depending on the electric current 9, the electric voltage 10 and the phase shift 11, wherein after receiving a predetermined first number of measurement blocks 8, the central processing unit 2 executes a first evaluation cycle of the method, which first evaluation cycle comprises the following steps: i. calculation of at least one first mean value according to a first mean value type 13 and at least one second mean value according to a second mean value type 14 from the measurement blocks 8 of the first number, ii.Determination of at least one first forecast value and at least one second forecast value, iii. Determination of a first time period, iv. Determination of a first energy value from the first time period and the at least one first mean value, wherein further evaluation cycles of the procedure are executed following the first evaluation cycle as soon as a predefinable second number of measurement blocks 8 have been transmitted to the central processing unit 2, wherein each further evaluation cycle comprises the following steps: a. Updating the at least one first mean value according to the first mean value type 13 and / or the at least one second mean value according to the second mean value type 14, provided that sufficient measurement blocks 8 for updating the mean value of the respective mean value type 13, 14 have been transmitted to the central processing unit 2, b.a. Comparison of the at least one first mean value with the at least one first forecast value and of the at least one second mean value with the at least one second forecast value; c. Selection of the at least one first mean value or the at least one second mean value taking into account the smallest deviation from the respective determined first or second forecast value; d. Updating the at least one first forecast value if the first mean value associated with the first forecast value has been updated and updating the at least one second forecast value if the mean value associated with the second forecast value has been updated; e. Determination of a further energy value from a further time period and the at least one selected mean value, wherein the individual energy values ​​of the evaluation cycles are summed to obtain the energy consumption value.

[0019] Figure 1 shows at least parts of an energy consumption measurement device.

[0020] I comprising a central processing unit 2, an analog-to-digital converter 3, an input 4 and an output 5, wherein the input 4 is configured for connection to a socket 6 and the output 5 for connection to an electrical device 7, wherein the analog-to-digital converter 3 transmits measurement blocks 8 for at least one current phase to the central processing unit 2 at predetermined interval steps, wherein each measurement block 8 comprises three measurement values ​​for each current phase, wherein the three measurement values ​​are of the electric current 9, the electric voltage 10 and the phase shift

[0021] II depend, and wherein the central computing unit 2 is designed to execute the method according to the invention.

[0022] By using mean values ​​of different mean types 13, 14, 15 and the associated forecast values, the amount of energy consumed when charging an electrical device 7, particularly an electric vehicle, can be precisely determined. This reduces the effect of various measurement errors during charging of the electrical device 7, which have varying degrees of influence on different mean types 13, 14, 15. Studies have shown that the amount of energy consumed during charging of the electrical device 7 can be determined more accurately than with previously known charging devices.The use of different mean value types 13, 14, 15 and the associated forecast values ​​led to an improvement in the accuracy of the energy consumption measurement of several percent compared to previously known charging devices, with these differences accumulating with increasing charging time. The method according to the invention enables a precise calculation to be reliably performed and fulfills currently known tax requirements of national countries. In summary, this improves the measurement accuracy of a conventional charging device without requiring any structural modification of the charging device.This allows a simple and robust device to be used to determine an energy consumption value when charging an electrical device 7, which is particularly important for energy consumption determination devices 1 that often have to be transported and are exposed to highly changing environmental conditions, such as temperature fluctuations.

[0023] This allows an energy consumption measurement device 1 to be created, which accurately determines energy consumption values ​​when charging an electrical device 7.

[0024] Preferably, the input 4 is connected to a first power cable 17 for plugging into the socket 6 and / or the output 5 is connected to a second power cable 18 for plugging into the electrical device 7, either directly or permanently.

[0025] Preferably, socket 6 can be a low-voltage socket, in particular with a voltage of 230V or 400V.

[0026] Preferably, socket 6 can be a household socket or a high-voltage socket.

[0027] Preferably, socket 6 can be a three-phase socket.

[0028] Preferably, the energy consumption measurement device comprises a relay, current dividers, and current transformers for the individual current phases, and in particular for the neutral conductor. For example, in order to measure the entire output voltage range of a current sensor, the zero level of the output signal can be raised by means of a voltage divider, in particular to 3.3 V / 2, so that both the positive and negative half-waves of a 50 Hz signal can be digitally recorded.

[0029] Preferably, the energy consumption measurement device 1 can have a compact form, and in particular be designed to be portable.

[0030] It is particularly preferred that the energy consumption measurement device 1 is designed as a charging cable 12. This is shown by way of example in Fig. 1. This allows the charging cable 12 to be easily transported, particularly in a motor vehicle. Because the charging cable 12 can be used to determine the energy consumption value, the energy consumption value can always be determined according to the same method, i.e., the method according to the invention, regardless of the charging location, thereby eliminating dependence on external charging devices and preventing differences due to different evaluation algorithms.

[0031] Preferably, the input 4 of the energy consumption measurement device 1 is configured to be plugged into the socket 6 or to be connected to the first power cable 17. Preferably, a first end of the first power cable 17 is permanently connected to the input 4, and a second end of the first power cable 17 is configured to be connected to the socket 6. Preferably, the second end of the power cable 17 can have a plug for insertion into the socket 6.

[0032] Preferably, a first end of the second power cable 18 is permanently connected to the output 5, and a second end of the second power cable 18 is designed for connection to the electrical device 7. The second end of the second power cable 18 may preferably have a power plug.

[0033] The method according to the invention is designed for determining energy consumption values ​​during the charging of electrical appliances 7. The electrical appliance 7 is a device with a rechargeable energy storage device. The electrical appliance 7 comprises a rechargeable accumulator, hereinafter referred to as a battery. During the charging of the energy storage device, the method according to the invention determines the amount of energy with which the energy storage device is charged.

[0034] Preferably, the electrical device 7 is an electric vehicle, i.e., a means of transport powered by electrical energy. Preferably, the electric vehicle can be a road vehicle, a rail vehicle, a watercraft, and / or an aircraft. Preferably, the electric vehicle can be an electric motor vehicle, an electric bicycle (also known as an e-bike), and / or an electric scooter.

[0035] Preferably, the energy consumption value can be determined by summing energy values ​​in watts per second.

[0036] According to the invention, measurement blocks 8 are measured. The measurement blocks 8 are determined from at least one current phase. The measurement blocks 8 are measured continuously. Continuous measurement is understood to mean a continuous, uninterrupted measurement. The current signal can be digitized using conventional, known devices. An analog-to-digital converter 3 transmits the measurement blocks 8 to the central processing unit 2 at predetermined intervals. The predetermined intervals are specified by the analog-to-digital converter 3 and the power grid. In the European power grid with 50 Hz, for example, a measurement block 8 can be transmitted to the central processing unit 2 every 20 ms. The transmission of the measurement block 8 can be carried out in known ways, for example, via a circuit connection or wirelessly.

[0037] Preferably, an analog-to-digital converter 3 can be provided for each current phase, and in particular for the neutral conductor. Preferably, the energy consumption measurement device 1 can comprise an analog-to-digital converter 3 for each current phase, and in particular for the neutral conductor.

[0038] For example, the input signals can be digitized using a sampling rate of essentially 12 kHz via the analog-to-digital converter 3.

[0039] The central processing unit 2 preferably comprises a microcontroller. The processing unit 2 can be operated according to the method of the invention. The central processing unit 2 is configured to execute the method of the invention. The central processing unit 2 is configured to evaluate the blocks of measured values ​​8 received by the analog-to-digital converter 3.

[0040] It is provided that a measurement block 8 is continuously determined for at least one current phase, in particular for each current phase, and preferably for the neutral conductor. Each measurement block 8 comprises three measured values, which depend on the electric current 9, the electric voltage 10, and the phase shift 11. Preferably, the electric current 9, the electric voltage 10, and the phase shift 11 are measured, such that each measurement block 8 comprises one value each for the electric current 9, the electric voltage 10, and the phase shift 11. Figure 2 shows an exemplary schematic representation of determined measurement blocks 8 for at least one current phase, which are transmitted to the central processing unit 2 over time. The triangular arrows schematically indicate the transmission of the measurement blocks 8 to the central processing unit 2. As shown in Figure 2, the measurement blocks 8 are transmitted to the central processing unit 2.As can be seen in section 2, each is determined according to the time period t. a A measurement block 8 is transmitted to the central processing unit 2. The time duration t a is constant. As already explained above, the time duration t can a For example, in a 50 Hz power grid, this would be 20 ms. Therefore, in this example, the central processing unit 2 receives 50 new measurement blocks (8) every second.

[0041] With three current phases and one neutral conductor, for example, four measurements can be taken for the electric current 9, four measurements for the electric voltage 10, and four measurements for the phase shift 11. Thus, for a first current phase, one measurement for the electric current 9, one measurement for the electric voltage 10, and one measurement for the phase shift 11; for a second current phase, one measurement for the electric current 9, one measurement for the electric voltage 10, and one measurement for the phase shift 11; for a third current phase, one measurement for the electric current 9, one measurement for the electric voltage 10, and one measurement for the phase shift 11; and for a neutral conductor, one measurement for the electric current 9, one measurement for the electric voltage 10, and one measurement for the phase shift 11.

[0042] The method according to the invention comprises a first evaluation cycle and further evaluation cycles which are executed after the first evaluation cycle. The evaluation cycles are executed by the central processing unit 2. The calculations and determinations according to the invention are performed by the central processing unit 2. The first evaluation cycle is executed, i.e., begins, when a predefinable first number of measurement blocks 8 have been received by the central processing unit 2.

[0043] The initial number of measurement blocks 8 is predefined. For example, the first evaluation cycle can begin after 200 ms. If a measurement block 8 is transmitted to the central processing unit 2 every 20 ms, the first evaluation cycle begins, for example, after 10 measurement blocks. Preferably, the initial number of measurement blocks 8 comprises more than five measurement blocks 8, in particular more than eight measurement blocks 8, and preferably more than ten measurement blocks 8.

[0044] Preferably, the first set of measurement blocks comprises 8 ten measurement blocks.

[0045] As can be seen by way of example in Fig. 4, the first evaluation cycle comprises steps i., ii., iii. and iv.

[0046] In step i., at least one first mean value according to a first mean value type 13 and at least one second mean value according to a second mean value type 14 are calculated from the measurement blocks 8 of the first number. If, for example, the first evaluation cycle begins after ten measurement blocks 8, these means, i.e., the first mean value according to the first mean value type 13 and the second mean value according to the second mean value type 14, are determined from the ten measurement blocks 8.

[0047] Preferably, the first type of mean (13) can be the arithmetic mean. The arithmetic mean is a well-known type of mean, which is why further explanation is omitted here.

[0048] It may be particularly preferred that the second type of mean 14 is a moving average.

[0049] For the moving average, a data series is created from a predefined number of measurements, and the arithmetic mean is calculated from this predefined number of measurements. The predefined number of measurements required for the initial calculation of the moving average corresponds to the first number of measurement blocks 8. Preferably, after each new measurement block 8 is transmitted, the oldest measurement is removed from the data series, and the new measurement from the newly transmitted measurement block 8 is added to the data series. The arithmetic mean is then calculated again from this new data series. Preferably, the moving average is updated after each additional measurement block 8 transmitted to the central processing unit 2. Consequently, the data series consists of, for example, ten measurements if the initial number of measurement blocks 8 comprises ten measurement blocks 8.

[0050] In step ii., at least one first forecast value and at least one second forecast value are determined. The at least one first forecast value corresponds to the at least one first mean, and the at least one second forecast value corresponds to the at least one second mean. Each forecast value is an expected value, i.e., the value expected for the respective mean.

[0051] Due to network quality, the continuously measured values, i.e., the three values ​​in measurement block 8, are subject to fluctuations. To account for these fluctuations when determining the energy consumption value, the respective average values ​​are updated during the process. This update involves replacing the value of the respective average. The forecast value therefore indicates the next expected value for that average.

[0052] In step iii, an initial time duration is determined. This initial duration can be the runtime for evaluating the process steps and / or the time between transmitted measurement blocks (8). It has been shown that the algorithm can be adapted by using different durations. It is important to ensure that a continuous time calculation is taken into account for calculating the energy consumption value.

[0053] It is particularly preferred that the first time period comprises an initial measurement data transmission period and an initial evaluation period. The measurement data transmission period is the time required to transmit the first number of measurement data blocks 8 to the central processing unit 2. Figure 3 shows a schematic representation of the determination of average values ​​of different average value types 13, 14, 15 over time. The reference numeral 16 denotes the program run time 16, i.e., the runtime from when the measurement data blocks 8 are transmitted to the central processing unit 2 and the evaluation cycles are executed until the energy consumption value determination is completed. In Figure 3, block A denotes the start of the energy consumption measurement. In this case, for example, the electric vehicle is connected to the energy consumption value determination device 1 via a circuit, so that an energy flow to the electric vehicle is ensured.Starting with block A, measurement blocks 8 are transmitted to the central processing unit 2. The time interval to is the measurement transmission duration. In block B, the first number of measurement blocks 8 were transmitted to the central processing unit 2, so the first evaluation cycle begins. The short vertical lines along the timelines for the averaging methods 13, 14, 15 show, by way of example, when enough measurement data are available for this averaging method. The runtime for the first evaluation cycle, i.e., the program runtime 16 comprising steps i. and ii., is preferably the first evaluation duration for the first evaluation cycle. In Fig. 3, the first evaluation duration for the first evaluation cycle is preferably the duration ti. Therefore, in Fig. 3, the first duration is composed, for example, of the durations to and ti.

[0054] In step iv., a first energy value is determined from the first time period and at least one first mean value.

[0055] Preferably, the at least one mean value can be a power value, in particular a first power value. Preferably, the power value is determined from the three measured values ​​of the measured value block 8. Preferably, the power value is determined from the measured values ​​for the electric current 9, the electric voltage 10, and the phase shift 11 by multiplying the value of the electric current 9 by the value of the electric voltage 10 and the cosine of the value of the phase shift 11. By taking the phase shift 11 into account, it is preferably possible to calculate the active power, whereby the apparent power and the reactive power no longer need to be considered.

[0056] Preferably, the energy value, in particular the first energy value, is a value in watts per unit of time, especially in watts per second.

[0057] Following the first evaluation cycle, further evaluation cycles of the procedure are executed. The central processing unit 2 consequently executes further evaluation cycles after the first evaluation cycle. These further evaluation cycles are executed when a predefined second number of measurement blocks 8 have been transmitted to the central processing unit 2. This predefined second number of measurement blocks 8 does not have to be the same as the first number of measurement blocks 8.

[0058] The second number of specified measurement blocks (8) depends on the averaging methods used. This will be illustrated in the following two examples.

[0059] If, for example, the arithmetic mean is used as the first mean type (13) and the moving average as the second mean type (14), the configurable second number of measurement blocks (8) can, for example, be only one measurement block (8). In this case, another evaluation cycle is executed after each transmitted measurement block (8), because the second mean is updated, specifically replaced, after each new measurement block (8).

[0060] If, for example, the arithmetic mean (13) is used as the first mean type and the median (14) as the second mean type, the configurable second number of measurement blocks (8) will be greater than one measurement block (8). For example, the configurable second number of measurement blocks (8) could comprise ten measurement blocks (8). In this case, another evaluation cycle is executed after ten measurement blocks (8) have been transmitted.

[0061] As can be seen by way of example in Fig. 4, the further evaluation cycles comprise steps a., b., c., d., and e.

[0062] In step a., at least one first mean value according to the first mean value type 13 and / or at least one second mean value according to the second mean value type 14 is updated, provided that sufficient measurement blocks 8 for updating the mean value of the respective mean value type have been transmitted to the central processing unit 2. This is illustrated by the following two examples.

[0063] If, for example, the arithmetic mean is used as the first mean type 13 and the moving average as the second mean type 14, another evaluation cycle is executed after each new transmitted measurement block 8. If the arithmetic mean was only recalculated previously, i.e., in the previous evaluation cycle, and a new evaluation cycle is executed after this calculation of the arithmetic mean because a new measurement block 8 is transmitted to the central processing unit 2 and therefore the moving average is calculated, the arithmetic mean is not recalculated, for example, in step a., since more than just one measurement is preferably required for the calculation of the arithmetic mean. In this case, only the moving average is calculated.If the last update of the arithmetic mean is further in the past and enough measurement blocks 8 have been transmitted to the central processing unit 2 for the update of the arithmetic mean, both means of the two mean types 13, 14 are preferably updated, i.e. the first mean according to the first mean type 13, in this example the arithmetic mean, and the second mean according to the second mean type 14, in this example the moving average.

[0064] If, for example, the arithmetic mean (13) is used as the first mean type and the median (14) as the second mean type, both means are recalculated, since the median is the middle value of the data series. Preferably, the measured values ​​are sorted in ascending order for the median. Thus, for example, after ten transmitted measurement blocks (8), a new arithmetic mean and a new median are calculated, where the median is the sum of the 5n and 6n values ​​divided by 2.

[0065] In step b., the at least one first mean is compared with the at least one first forecast value, and the at least one second mean is compared with the at least one second forecast value. "Comparison" preferably means that the difference between the respective mean and the corresponding forecast value is determined. The comparison preferably yields a value for the deviation between the at least one first mean and the at least one first forecast value, and a value for the deviation between the at least one second mean and the at least one second forecast value.

[0066] In step b., the respective mean value is compared with the corresponding forecast value to identify which mean value, for example, has not been updated. If, for instance, the arithmetic mean is used as the first mean type (13) and the moving average as the second mean type (14), the updated moving average and the unchanged, i.e., unupdated, arithmetic mean can be used in step b. Thus, the unchanged, unupdated arithmetic mean is compared with the corresponding forecast value, and the updated moving average is compared with the corresponding forecast value. This allows for improved energy consumption measurement during grid fluctuations.

[0067] In step c, at least one first mean or at least one second mean is selected. The selection takes into account the deviation from the respective first or second forecast value. For example, in step b, a value of 5 is determined as the first deviation value for the first mean from the first forecast value, and a value of 7 is determined as the second deviation value for the second mean from the second forecast value. The deviation of the second mean from the second forecast value is therefore greater than the deviation of the first mean from the first forecast value. In this case, for example, the first mean is selected.

[0068] In step d., at least one first forecast value is updated if the first mean corresponding to that first forecast value has been updated, and at least one second forecast value is updated if the second mean corresponding to that second forecast value has been updated. Therefore, only those forecast values ​​are updated in step d. for which the corresponding mean was updated in step a.

[0069] In step e., a further energy value is determined from a further time period and the at least one mean value selected in step c. This further time period preferably comprises a further measurement transmission period and / or a further evaluation period. It is preferably provided that the evaluation period is long enough for a new measurement block 8 to be transmitted to the central processing unit 2, so that the next evaluation cycle is executed immediately following the completed evaluation cycle. However, it is also possible that the evaluation period is short enough that a waiting period is required until a sufficient number of measurement blocks 8, i.e., the predefinable second number of measurement blocks 8, have been transmitted to the central processing unit 2. In this case, the further evaluation period can be subtracted from the further measurement transmission period to ensure that no time period is counted twice in the process.

[0070] Following step e., a further evaluation cycle is executed as soon as a predefined second number of measurement blocks 8 have been transmitted to the central processing unit 2. This is illustrated in Fig. 4 by the arrow pointing from step e. to step a.

[0071] Preferably, the predefinable second number of measurement blocks 8 can be adjusted between further evaluation cycles, in particular increased or decreased.

[0072] The plan is to sum the individual energy values ​​from the evaluation cycles—that is, the energy value from the first evaluation cycle and the subsequent energy values ​​from the following evaluation cycles—to obtain the total energy consumption value. This energy consumption value indicates, for example, how many watts of energy were required to charge electrical device 7, i.e., during the charging time.

[0073] The individual energy values ​​can be summed up after step e., so that the energy value calculated in step e. is always added to the previously determined energy value, or the individual energy values ​​can be summed up after the electrical device 7 has finished charging.

[0074] Preferably, the accumulated energy values, in particular the accumulated energy consumption value, can be transmitted to an on-board computer of the electrical device, in particular of the electric vehicle.

[0075] Preferably, the accumulated energy values, in particular the accumulated energy consumption value, can be stored in a memory of the energy consumption measurement device 1. Preferably, the stored accumulated energy values, in particular the accumulated energy consumption value, can be read out using a readout device. Preferably, the readout device can be connected to the energy consumption measurement device 1. Preferably, the readout device can be a smartphone and / or a computer and / or a tablet.

[0076] Particularly preferably, it can be provided that the at least one first mean value according to the first mean type 13 is updated after a predefinable first update number of measurement blocks 8, and the at least one second mean value according to the second mean type 14 is updated after a predefinable second update number of measurement blocks 8, wherein the predefinable second update number is less than the predefinable first update number. The predefinable update number of measurement blocks 8 is the number of measurement blocks 8 required to update the mean value of the respective mean type 13, 14. For example, if the mean value is the arithmetic mean and the update number is ten, a new arithmetic mean value can be determined after ten measurement blocks 8.

[0077] Preferably, the predefinable second update number of measurement blocks 8 can be a maximum of 500 measurement blocks 8, in particular a maximum of 300 measurement blocks 8, preferably a maximum of 200 measurement blocks 8.

[0078] Preferably, the specified number of second updates can be kept constant across the evaluation cycles.

[0079] Preferably, if the second update count is smaller than the first update count, the configurable second update count corresponds to the configurable second number of measurement blocks 8 for the subsequent evaluation cycles. This is the case, for example, if the arithmetic mean 13 is used as the first mean type and the moving mean 14 as the second mean type. In this case, the moving mean is preferably updated after each newly transmitted measurement block 8, which is why the second number of measurement blocks 8 and the second update count each represent a measurement block 8.

[0080] It is particularly preferred that the predefinable first update number of measurement blocks 8 is reduced if, during an evaluation cycle, the difference between the deviation between the at least one first mean value and the at least one first forecast value, and the deviation between the at least one second mean value and the at least one second forecast value, is greater than a predefinable difference value. This improves the efficiency of the calculations by reducing the number of calculations required, thereby shortening the runtime for evaluating the process steps, and also allows network fluctuations to be easily taken into account in the process.In this case, a first deviation value is determined between the at least one first mean value and the at least one first forecast value, as well as a second deviation value between the at least one second mean value and the at least one second forecast value, and the first deviation value is compared with the second deviation value. If the difference between the first deviation value and the second deviation value is greater than the predefined difference value, the predefined number of updates can be reduced.

[0081] Preferably, the difference value can be greater than a maximum of 60 percent, in particular a maximum of 40 percent, and preferably a maximum of 20 percent. It can preferably be provided that the predefinable first update number of measurement blocks 8 is reduced if, during an evaluation cycle, the difference between the deviation between the at least one first mean value and the at least one first forecast value and the deviation between the at least one second mean value and the at least one second forecast value is greater than a maximum of 60 percent, in particular a maximum of 40 percent, and preferably a maximum of 20 percent.

[0082] Preferably, the number of updates for the first time can be increased if the difference between the deviation between the at least one first mean and the at least one first forecast value, and the deviation between the at least one second mean and the at least one second forecast value, is smaller than a predefinable second difference value. For example, the number of updates for the first time can be increased by at least 10 percent, preferably at least 20 percent, and in particular at least 30 percent.

[0083] The number of updates will be explained in more detail using the following example.

[0084] For example, the first mean type 13 is the arithmetic mean and the second mean type 14 is the moving average. For example, the arithmetic mean is recalculated after ten measurement blocks 8. The moving average is recalculated after each new measurement block 8 is transmitted. After ten measurement blocks 8, the arithmetic mean is recalculated, and the difference between the deviation between the arithmetic mean and the corresponding forecast value, as well as the deviation between the moving average and the corresponding forecast value, is determined.If the difference value, i.e., the difference, is greater than, for example, a maximum of 20 percent, i.e., if the deviation between the arithmetic mean and the corresponding forecast value differs from the deviation between the moving mean and the corresponding forecast value by more than 20 percent, the first number of updates can be reduced by at least 20 percent, for example.

[0085] Particularly preferably, the predefinable first update number can be reduced by at least 25 percent, in particular at least 35 percent, preferably at least 50 percent, especially if, during an evaluation cycle, the difference between the deviation between the at least one first mean value and the at least one first forecast value, and the deviation between the at least one second mean value and the at least one second forecast value, is greater than the predefinable difference value. The reduction by at least 25 percent has proven particularly advantageous in tests for increasing the accuracy of energy consumption measurement.

[0086] Particularly preferably, it can be provided that the at least one first mean value is a first mean value vector, that the first mean value vector comprises a first mean value of the first mean value type 13 for each measured value, that the at least one second mean value is a second mean value vector, and that the second mean value vector comprises a second mean value of the second mean value type 14 for each measured value. Each mean value vector comprises a mean value for the measured values ​​of the electric current 9, a mean value for the measured values ​​of the electric voltage 10, and a mean value for the phase shift 11. Thus, there are three measured values ​​per phase, and in particular for the neutral conductor, and for each mean value vector.This allows the accuracy of the procedure to be improved, since, for example, a power value can be calculated for each current phase from the voltage value of the first mean value type 13 and the current value and phase shift value of the second mean value type 14, and an energy value can be determined from this power value and a time duration.

[0087] Particularly preferably, it can be provided that the at least one first forecast value is a first forecast value vector, that the first forecast value vector comprises an associated first forecast value for each calculated first mean value, that the at least one second forecast value is a second forecast value vector, and that the second forecast value vector comprises an associated second forecast value for each calculated second mean value. Since each mean value vector comprises three measured values, each forecast value vector associated with the respective mean value vector can also comprise three measured values, namely a forecast value for the expected current value, a forecast value for the expected voltage value, and a forecast value for the expected phase shift.

[0088] It may be particularly preferred that

[0089] - that in addition, in step i) at least a third mean value according to a third mean type 15 is calculated from the measurement blocks 8 of the first number,

[0090] - that in addition, at least a third forecast value is determined in step ii),

[0091] - that in step a) at least one first mean value according to the first mean type 13 and / or at least one second mean value according to the second mean type 14 and / or at least one third mean value according to the third mean type 15 is updated, provided that sufficient measured value blocks 8 for updating the mean of the respective mean type 13, 14, 15 have been transmitted to the central processing unit 2,

[0092] - that in addition, in step b) at least one third mean value is compared with at least one third forecast value,

[0093] - that in step c) at least one first mean or at least one second mean or at least one third mean is selected taking into account the smallest deviation from the respective determined first or second or third forecast value,

[0094] - that in addition, in step d) at least one third forecast value is updated, provided that the third mean value associated with the third forecast value has been updated.

[0095] This allows the accuracy of the measurement to be further improved, since instead of two mean value types 13, 14, three mean value types 13, 14, 15 can be used. For example, for a current phase and the determination of the energy value, the mean value for the electric current 9 from the first mean value type 13, the mean value for the electric voltage 10 from the second mean value type 14, and the mean value for the phase shift 11 from the third mean value type 15 can be used.

[0096] The third type of mean, 15, is preferably the median. Preferably, in this third type of mean, 15, the measured values ​​used to determine the mean are sorted in ascending order. The median is the middle value among the sorted measured values ​​and is determined in a known manner, which is why a further explanation of how to determine the median is omitted here.

[0097] Preferably, it may be provided that at least one third mean value according to the third mean value type 15 is updated after a predefinable third update number of measurement blocks 8.

[0098] Preferably, the second update count is smaller than the third update count. It is particularly preferred that the at least one third mean is a third mean vector, and that the third mean vector comprises a third mean of the third mean type 15 for each measured value.

[0099] Particularly preferred, it may be provided that the at least one third forecast value is a third forecast value vector, and that the third forecast value vector includes a corresponding third forecast value for each calculated third mean.

[0100] It is particularly preferred that the respective forecast value be determined taking into account a trend line, in particular a polynomial function. Preferably, the trend line can be a polynomial function, especially of the first or second order. However, preferably any other polynomial function suitable as a trend line can also be used. The use of the trend line can facilitate the determination of the respective forecast value.

[0101] It is particularly preferred that the central processing unit 2 takes a measured ambient temperature into account when determining the respective energy value. The measured ambient temperature can be used for temperature compensation. This makes temperature compensation particularly easy when determining the energy value. Preferably, the temperature compensation is performed using an algorithm. Preferably, correction values ​​can be stored in the central processing unit 2, which are used for the temperature compensation. It can be provided that at a specific temperature, the energy value is to be adjusted by a certain amount, in particular increased or decreased. In particular, the temperature compensation can be performed after determining a power value from the measured values ​​for the electric current 9, the electric voltage 10, and the phase shift 11.

[0102] Preferably, the ambient temperature can be measured anew at each evaluation cycle, or preferably, it can be provided that the ambient temperature is measured after a predefinable temperature duration. Preferably, the predefinable temperature duration can be at least 30 seconds, in particular at least one minute, preferably at least 5 minutes.

[0103] The inventive method and device will now be explained using an example and Fig. 3.

[0104] For example, a person drives their electric vehicle home from work. Upon arrival, the person connects the energy consumption measurement device 1, designed as a charging cable 12, to the electric vehicle and the socket 6 available at home. This could be, for example, a standard household socket or a high-voltage socket. The person chooses, for instance, a household socket, which has one live wire and one neutral wire. Once plugged into the household socket, the electric vehicle begins charging. For this example, only the live wire is used.

[0105] The energy consumption measurement device 1 determines measurement blocks 8 for the current phase, each comprising one measurement for the electric current 9, one measurement for the electric voltage 10, and one measurement for the phase shift 11. The measurement blocks 8 are generated by the analog-to-digital converter 3 and transmitted to the central processing unit 2. This measurement transmission time is shown in Fig. 3 as time duration to.

[0106] After the central processing unit 2 has received the predefined first number of measurement blocks 8, for example after ten received measurement blocks 8, the first evaluation cycle of the procedure is executed. This start is shown as block B in Fig. 3.

[0107] In step i., three mean values ​​for the current phase are preferably determined for each mean type 13, 14, 15. For example, the mean types 13, 14, 15 are the arithmetic mean, the median, and the moving average. In Fig. 3, the shorter continuous lines for mean types 13, 14, 15 for block B indicate that sufficient measured values ​​are available for these mean types 13, 14, 15. Thus, a mean value is determined for each of the measured values ​​of the electric current 9, the electric voltage 10, and the phase shift 11 for the first, second, and third mean types 13, 14, 15 for the current phase.

[0108] Following step i., in step ii., three forecast values ​​for the three mean value types 13, 14, 15 for the current phase are preferably determined.

[0109] Following step ii, a first time duration is determined in step iii. Preferably, the measurement transmission time to for the transmitted ten measurement blocks 8 and the first evaluation duration for steps i and ii are determined. The first evaluation duration is shown as ti in Fig. 3.

[0110] Following step iii, in step iv, an initial energy value is determined from the first time period and the first average values. To do this, a power value is calculated from the first average values ​​for the electric current 9, the electric voltage 10, and the phase shift 11 by multiplying the value of the electric current 9 by the value of the electric voltage 10 and the cosine of the value of the phase shift 11. The phase shift 11 is therefore required to account for the active power, thus eliminating apparent and reactive power.

[0111] Following the first evaluation cycle, further evaluation cycles are performed as soon as the predefined second number of measurement blocks (8) have been transmitted to the central processing unit (2). In the present example, for instance, the moving average for the three measurement blocks is recalculated after each transmitted measurement block (8). This occurs in step a.

[0112] As can be seen in Fig. 3, the previous evaluation cycle in block C is complete. Two new moving averages have already been transmitted to the central processing unit 2. Therefore, a new moving average is available for the next evaluation cycle.

[0113] For example, the first and second update counts are set to 3, as shown in Fig. 3. Therefore, for every third transmitted measurement block 8, enough measurement values ​​are available to calculate the three mean types 13, 14, and 15. In step a., the three mean values ​​according to the first mean type 13, the three mean values ​​according to the second mean type 14, and the three mean values ​​according to the third mean type 15 for the current phase are updated. This applies to the measured values ​​of the electric current 9, the electric voltage 10, and the phase shift 11, respectively.

[0114] Starting with block C, for example, not enough measurement blocks 8 have yet been transmitted for the first mean type 13 and the second mean type 14. Therefore, in step a., only at least one mean of the third mean type 15 is updated.

[0115] The respective mean values ​​are compared with the respective forecast values ​​in step b, and in step c the respective mean value is selected. For example, for the current phase, the mean value for the electric current 9 is selected from the first mean value type 13, the mean value for the electric voltage 10 from the second mean value type 14, and the mean value for the phase shift 11 from the third mean value type 15.

[0116] In step d., the forecast value corresponding to at least one third mean value is updated, and in step e., the further energy value is determined. The energy value is preferably calculated by determining a power value from the selected mean values ​​for the electric current 9, the electric voltage 10, and the phase shift 11, as well as the further time duration. Preferably, temperature compensation is also performed when determining the energy value. The time duration t2 is chosen as an example.

[0117] After completion of the evaluation cycle from block C to block D, the next evaluation cycle begins with block D, with enough measurement blocks (8) available for all three mean types (13, 14, 15). The subsequent time duration is, for example, the duration tß. After completion of the evaluation cycle from block D to block E, the next evaluation cycle begins with block E, with enough measurement blocks (8) available only for the third mean type (15).

[0118] It should be noted that Fig. 3 is only intended to illustrate the process flow by way of example, with durations being exaggerated.

[0119] Studies have shown that the evaluation time for one evaluation cycle can be, for example, between 2 and 3 ms. The mean values ​​used in the present invention are averages calculated using different methods. An average is a number determined from a specific set of numbers according to a specific calculation procedure. Known mean values ​​include, for example, the arithmetic mean, the geometric mean, and / or the root mean square. According to the invention, different mean values ​​can be used, and the method is not limited to the use of the mean values ​​given in the examples.

[0120] Preferably, the calculation rule for the first mean type 13 may differ from the calculation rule for the second mean type 14, and / or in particular from the calculation rule for the third mean type 15.

[0121] Preferably, at least one type of mean, in particular two types of mean, of the types of mean 13, 14, 15, takes into account the sum of the measurement blocks 8 and in particular the number of measurement blocks 8. Such types of mean are, for example, the arithmetic mean and / or the moving average.

[0122] Preferably, at least one type of average can be used to calculate a moving average from the measurement blocks 8. For example, a moving average can be calculated iteratively from the measurement blocks 8. The moving average can be understood as a kind of "window" that shifts by one measurement block 8 with each new measurement block 8. The oldest measurement block 8 is removed from the "window," with the first value being determined for the first time after the "window" has been filled with measurement blocks 8.

[0123] Preferably, at least one type of average can take into account a predefinable number of updates, and in particular be recalculated after the predefinable number of updates. Preferably, at least one type of average can take into account a predefinable number of measured value blocks (8) for determination. The following are principles for understanding and interpreting this disclosure.

[0124] Characters are usually introduced with an indefinite article "ein, eine, eines, einer". Unless the context indicates otherwise, "ein, eine, eines, einer" should therefore not be understood as a numeral.

[0125] The phrase "essentially" in conjunction with a numerical value includes a tolerance of ± 10% around the stated numerical value, unless otherwise indicated by the context.

[0126] Value ranges include the endpoints unless the context indicates otherwise.

Claims

P A T E N T A N S P R Ü C H E 1. Method for determining an energy consumption value when charging an electrical device (7), wherein measurement blocks (8) for at least one current phase are continuously measured and transmitted to a central processing unit (2) at predetermined interval steps, wherein each measurement block (8) comprises three measurement values ​​for each current phase, the three measurement values ​​depending on the electric current (9), the electric voltage (10) and the phase shift (11), wherein after receiving a predetermined first number of measurement blocks (8), the central processing unit (2) executes a first evaluation cycle of the method, which first evaluation cycle comprises the following steps: i. calculation of at least one first mean value according to a first mean value type (13) and at least one second mean value according to a second mean value type (14) from the measurement blocks (8) of the first number, ii.Determination of at least one first forecast value and at least one second forecast value, iii. Determination of a first time period, iv. Determination of a first energy value from the first time period and the at least one first mean value, wherein further evaluation cycles of the procedure are executed following the first evaluation cycle as soon as a predefinable second number of measurement blocks (8) have been transmitted to the central computing unit (2), wherein each further evaluation cycle comprises the following steps: a. Updating the at least one first mean value according to the first mean value type (13) and / or the at least one second mean value according to the second mean value type (14), provided that sufficient measurement blocks are available. Blocks (8) for updating the mean of the respective mean type (13, 14) of the central computing unit (2) were transmitted, b. comparison of the at least one first mean with the at least one first forecast value and of the at least one second mean with the at least one second forecast value, c. selection of the at least one first mean or the at least one second mean taking into account the smallest deviation from the respective determined first or second forecast value, d. updating the at least one first forecast value if the first mean associated with the first forecast value has been updated and updating the at least one second forecast value if the mean associated with the second forecast value has been updated, e.Determination of a further energy value from a further period of time and at least one selected mean value, whereby the individual energy values ​​of the evaluation cycles are summed to obtain the energy consumption value.

2. Method according to claim 1, characterized in that the first time period comprises a first measurement transmission time period and a first evaluation time period.

3. Method according to claim 1 or 2, characterized in that the at least one first mean value according to the first mean type (13) is updated after a predefinable first update number of measurement blocks (8) and the at least one second mean value according to the second mean type (14) is updated after a predefinable second update number of measurement blocks (8), wherein the predefinable second update number is smaller than the predefinable first update number.

4. Method according to one of claims 1 to 3, characterized in that, that the second type of mean (14) is a moving average.

5. Method according to claim 3, characterized in that the predefinable first update number of measurement blocks (8) is reduced if, during an evaluation cycle, the difference between the deviation between the at least one first mean value and the at least one first forecast value and the deviation between the at least one second mean value and the at least one second forecast value is greater than a predefinable difference value.

6. Method according to claim 5, characterized in that the predefinable first update number is reduced by at least 25 percent, in particular at least 35 percent, preferably at least 50 percent.

7. Method according to one of claims 1 to 6, characterized in that the at least one first mean value is a first mean value vector, that the first mean value vector comprises a first mean value of the first mean value type (13) for each measured value, that the at least one second mean value is a second mean value vector, that the second mean value vector comprises a second mean value of the second mean value type (14) for each measured value.

8. Method according to claim 7, characterized in that the at least one first forecast value is a first forecast value vector, that the first forecast value vector comprises an associated first forecast value for each calculated first mean value, that the at least one second forecast value is a second forecast value vector, that the second forecast value vector comprises an associated second forecast value for each calculated second mean value.

9. Method according to any one of claims 1 to 8, characterized in that, - that in addition, in step i) at least a third mean is calculated according to a third mean type (15) from the measurement blocks (8) of the first number, - that in addition, at least a third forecast value is determined in step ii), - that in step a) at least one first mean according to the first mean type (13) and / or at least one second mean according to the second mean type (14) and / or at least one third mean according to the third mean type (15) is updated, provided that sufficient measurement blocks (8) for updating the mean of the respective mean type (13, 14, 15) have been transmitted to the central processing unit (2), - that in addition, in step b) at least one third mean value is compared with at least one third forecast value, - that in step c) at least one first mean or at least one second mean or at least one third mean is selected taking into account the smallest deviation from the respective determined first or second or third forecast value, - that in addition, in step d) at least one third forecast value is updated, provided that the third mean value associated with the third forecast value has been updated.

10. Method according to claim 9, characterized in that the at least one third mean value is a third mean value vector, and that the third mean value vector comprises a third mean value according to the third mean value type (15) for each measured value.

11. Method according to claim 10, characterized in that the at least one third forecast value is a third forecast value vector, and that the third forecast value vector comprises an associated third forecast value for each calculated third mean value.

12. Method according to one of claims 1 to 11, characterized in that the respective forecast value is determined taking into account a trend line, in particular a polynomial function.

13. Method according to one of claims 1 to 12, characterized in that the central computing unit (2) takes into account a measured ambient temperature when determining the respective energy value.

14. Energy consumption measurement device (1) comprising a central processing unit (2), an analog-to-digital converter (3), an input (4) and an output (5), wherein the input (4) is designed for connection to a socket (6) and the output (5) is designed for connection to an electrical device (7), characterized in that the analog-to-digital converter (3) transmits blocks of measured values ​​(8) for at least one current phase to the central processing unit (2) at predetermined interval steps, that each block of measured values ​​(8) comprises three measured values ​​for each current phase, wherein the three measured values ​​depend on the electric current (9), the electric voltage (10) and the phase shift (11), and that the central processing unit (2) is configured to perform the method according to claims 1 to 13.

15. Energy consumption measurement device (1 ) according to claim 14, characterized in that the energy consumption measurement device (1 ) is designed as a charging cable (12).

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