MOBILE ELECTRIC ENERGY SUPPLY DEVICE

Abstract

The invention relates to a mobile electric energy supply device, comprising at least one energy supply connector for drawing energy from the energy supply device, a ground grounding device adapted to cooperate with a ground of the installation site of the energy supply device to provide grounding for the energy supply device, and a touch safety monitoring device adapted to monitor at least one touch point disposed on or electrically connected to the energy supply device for touch safety.

Claims

1. Mobile electric energy supply device, comprising at least one energy supply connector for drawing energy from the energy supply device, a ground grounding device adapted to cooperate at an installation site with a ground of the installation site of the energy supply device to provide grounding for the energy supply device, and a touch safety monitoring device adapted to monitor at least one touch point disposed on or electrically connected to the energy supply device for touch safety.

2. Energy supply device according to claim 1, wherein the ground grounding device comprises at least one grounding floor space arranged and adapted to be in touching contact with the ground at the installation site.

3. Energy supply device according to claim 1, wherein the touch safety monitoring device comprises at least one contact plate arranged and adapted to be in touching contact with the ground at the installation site, wherein the touch safety monitoring device preferably comprises a measuring device which is operatively connected to the at least one contact plate on the one hand and to the at least one touch point on the other hand.

4. Energy supply device according to claim 3, wherein the measuring device is adapted to measure at least one electrical measurand between the at least one touch point and the at least one contact plate, wherein the at least one electrical measurand is selected from a group, consisting of a voltage and a current.

5. Energy supply device according to claim 4, wherein the touch safety monitoring device is adapted to compare a measured value of the at least one electrical measurand to a threshold value, and to evaluate the touch safety based on the comparison.

6. Energy supply device according to claim 4, wherein the measuring device is adapted to detect the at least one electrical measurand as time dependent, and wherein the touch safety monitoring device is adapted to evaluate the touch safety on the basis of the at least one electrical measurand detected as time dependent.

7. Energy supply device according to claim 1, wherein the touch safety monitoring device comprises as the at least one contact plate two contact plates which are spaced apart from each other and are adapted to be in touching contact with the ground at the installation site, wherein the two contact plates are preferably electrically connected in parallel with each other to the measuring device.

8. Energy supply device according to claim 7, wherein the measuring device is operatively connected to the two contact plates and adapted to measure an impedance between the contact plates.

9. Energy supply device according to claim 1, wherein the energy supply device is formed as a device selected from a group consisting of: An electrical energy storage, a charging station, in particular for charging electrically driven motor vehicles, and an electronic power converter.

10. Energy supply device according to claim 1, wherein the energy supply connector has a charging cable comprising a protective conductor, wherein the touch safety monitoring device, in particular the measuring device, is electrically connected to the protective conductor.

11. Energy supply device according to claim 1, wherein the touch safety monitoring device comprises a measuring device which has a common contact point and a measuring circuit, wherein a first contact plate of two contact plates is electrically connected to a common contact point via a first connection conductor, wherein a second contact plate of the two contact plates is electrically connected to the common contact point via a second connection conductor, and wherein the measuring circuit is electrically connected to at least one touch point and to the common contact point and is adapted to measure at least one electrical measurand between the at least one touch point and the common contact point.

12. Energy supply device according to claim 11, wherein the measuring device is adapted to measure the impedance between the two contact plates, in particular between the first connection conductor and the second connection conductor, wherein a first decoupling device is arranged in the first connection conductor, and wherein a second decoupling device is arranged in the second connection conductor.

13. Energy supply device according to claim 12, wherein at least one decoupling device selected from said first decoupling device and said second decoupling device is formed as a decoupling resistor, or switch.

14. Energy supply device according to claim 11, wherein a first measuring resistor is integrated in the measuring circuit, or wherein the first contact plate is electrically connected in parallel with the first connection conductor and the measuring circuit via a second measuring resistor to the at least one touch point, wherein the second contact plate is electrically connected in parallel with the second connection conductor and the measuring circuit via a third measuring resistor to the at least one touch point.

15. Energy supply device according to claim 11, wherein a first contact plate of the two contact plates is electrically connected to the at least one touch point via a first measuring conductor, wherein a second contact plate of the two contact plates is electrically connected to the at least one touch point via a second measuring conductor, a fourth measuring resistor being arranged in the first measuring conductor, a fifth measuring resistor being arranged in the second measuring conductor, and the measuring device being adapted to measure a first electrical voltage drop across the fourth measuring resistor and to measure a second electrical voltage drop across the fifth measuring resistor.

Description

[0062] The invention is explained in more detail below with reference to the drawing. Thereby showing:

[0063] FIG. 1 a schematic illustration of an embodiment of a mobile electric energy supply device;

[0064] FIG. 2 a schematic illustration of a first embodiment of a measuring device of the energy supply device;

[0065] FIG. 3 a schematic illustration of a second embodiment of a measuring device of the energy supply device;

[0066] FIG. 4 a schematic illustration of a third embodiment of a measuring device of the energy supply device, and

[0067] FIG. 5 a schematic illustration of a fourth embodiment of a measuring device of the energy supply device.

[0068] FIG. 1 shows a schematic illustration of an embodiment of a mobile electric energy supply device 1, which has at least one energy supply connector 3, indicated here only schematically, for drawing energy from the energy supply device 1. The energy supply connector 3 may be designed as a junction box or as a charging cable 4, in particular connected to a plug 6. It is possible that the energy supply device 1 has a plurality of energy supply connectors 3, for example in order to be able to charge a plurality of electric motor vehicles at the same time. The energy supply device 1 comprises a ground grounding device 5, which is adapted to cooperate with a ground 9 of the installation site 7 of the energy supply device 1 to provide a grounding for the energy supply device 1. To ensure electrical touch safety for a user 11, the energy supply device 1 comprises a touch safety monitoring device 13 adapted to monitor at least one touch point 15 disposed on or electrically connected to the energy supply device 1 for touch safety. Advantageously, this makes it possible for the user 11 to operate the energy supply device 1 without risk even at an installation site 7 where there is no possibility of a connection to a main grounding rail, a foundation grounding electrode, a depth grounding electrode or the like.

[0069] In the case illustrated here, the touch point 15 is arranged on a housing 17 of the energy supply device 1. Additionally or alternatively, it is possible that the touch point 15 is arranged on another device external to the energy supply device 1 but electrically connected to the energy supply device 1, for example an electric motor vehicle. In particular, it is possible that a charging cable of the energy supply connector 3 has a protective conductor 8, in which case the touch safety monitoring device 13 is electrically connected to the protective conductor 8.

[0070] In a manner not explicitly shown here, the energy supply device 1 has at least one electrical or electronic device for providing electrical energy, which is electrically connected to the energy supply connector 3 and is preferably arranged in the housing 17. The electrical or electronic device may in particular be in the form of a battery and/or a power converter circuit. The energy supply device 1 is preferably formed as a device selected from a group consisting of: An electrical energy storage, a charging station, in particular for charging electrically driven motor vehicles, and an electronic power converter, in particular an inverter, a rectifier, a boost converter, or a buck converter.

[0071] The ground grounding device 5 preferably has at least one grounding floor space 19, in this case in particular two grounding floor spaces 19 spaced apart from each other, wherein the at least one grounding floor space 19 is arranged and adapted to be in touching contact with the ground 9 at the installation site 7. Schematically, the grounding floor spaces 19 each have a partial grounding resistance to an imaginary grounding point 21, indicated here as 2R.sub.E, so that a total grounding resistance for the energy supply device 1 results due to the electrical parallel connection of the two partial grounding resistances of the grounding floor spaces 19 to R.sub.E. The individual partial ground resistances 2R.sub.E and thus also the total ground resistance R.sub.E depend on the specific installation conditions of the electrical energy supply device 1 at the installation site 7, in particular on at least one installation parameter, in particular on an impedance or an electrical resistance of the ground at the installation site, a chemical composition of the ground, a physical condition of the ground, a moisture or a water content of the ground, and a ground flatness at the installation site.

[0072] The touch safety monitoring device 13 has at least one contact plate 23, in this case two contact plates 23 arranged spaced apart from each other, namely a first contact plate 23.1 and a second contact plate 23.2. The contact plates 23 are arranged and adapted to be in contacting engagement with the ground 9 at the installation site 7. Each contact plate 23 of the contact plates 23 preferably has an area of 200 cm.sup.2 and a mass of 25 kg, resulting in a total summed contact area of 400 cm.sup.2 and a total contact force of 500 N on the ground 9 for the contact plates 23 of the touch safety monitoring device 13. In particular, in this way, the contact plates 23 replicate the contact of the feet of the human user 11 with the ground 9. The contact plates 23 each have a contact resistance, denoted R.sub.ME, to the imaginary grounding point 21. The contact resistances of the contact plates 23 are indicated here as equal, in particular for the sake of simplicity. They may well be the same—not least depending in particular on the specific installation conditions—but it is also possible for the contact resistances of the contact plates 23 to be different from one another.

[0073] The touch safety monitoring device 13 also has a measuring device 25 which is operatively connected, that is in particular electrically connected, on the one hand to the contact plates 23 and on the other hand to the touch point 15. In particular, the contact plates 23 are electrically connected to the measuring device 25 in parallel with one another. The measuring device 25 is adapted to monitor the touch safety at the touch point 15 by measuring and preferably evaluating at least one electrical measurand.

[0074] In particular, the measuring device 25 is adapted to measure the at least one electrical measurand between the touch point 15 and the contact plates 23. The at least one electrical measurand is thereby selected from a group consisting of: A voltage and a current.

[0075] The touch safety of the user 11 is determined, on the one hand, by a touch voltage U.sub.B which drops across the body of the user 11, represented here by a body resistance R.sub.k, between the touch point 15 and the ground 9, and, on the other hand, by a touch current intensity I.sub.d which flows through the body, that is, in the equivalent circuit diagram, the body resistance R.sub.k and a location resistance R.sub.st. The feet of the user 11 are thereby electrically connected to the imaginary grounding point 21 via the location resistor R.sub.st.

[0076] The touch voltage U.sub.B is preferably to be less than a threshold voltage of 50 V as a threshold value. The touch current I.sub.d shall preferably be smaller than a threshold current of 30 mA as threshold value. Especially if both conditions are fulfilled, the touch safety is given. In particular, the threshold values can also be chosen to be lower.

[0077] By means of the touch safety monitoring device 13, the electrical conditions are virtually simulated for the user 11, and in particular an attempt is made to estimate at least one touch safety parameter selected from the touch voltage U.sub.B and the touch current intensity I.sub.d, preferably both touch safety parameters, on the basis of a suitable measurement.

[0078] The touch safety monitoring device 13, in particular the measuring device 25, is preferably adapted to compare a measured value of the at least one electrical measurand with a threshold value, in particular the threshold values specified above or derived therefrom, and to evaluate the touch safety on the basis of the comparison. The threshold value can be predetermined, in particular fixed, or variable, in particular depending on the at least one installation parameter.

[0079] Preferably, the measuring device 25 is adapted to acquire the at least one electrical measurand in a time-dependent manner, in particular as a signal. Preferably, the touch safety monitoring device 13, in particular the measuring device 25, is adapted to evaluate the touch safety on the basis of the at least one electrical measurand acquired in a time-dependent manner, in particular by means of signal evaluation.

[0080] In a preferred embodiment, the touch safety monitoring device 13 has, in addition to the measuring device 25, a computing device 27 which is operatively connected to the measuring device 25 and is adapted to evaluate the touch safety as a function of the at least one electrical measurand detected by the measuring device 25, in particular to perform the comparison with the threshold value and/or to perform the evaluation of the touch safety on the basis of the at least one electrical measurand detected as a function of time, in particular by means of signal evaluation.

[0081] The measuring device 25 is preferably adapted to measure an impedance between the two contact plates 23, in particular to obtain information therefrom about the at least one installation parameter and thus at least indirectly about the contact resistances R.sub.ME, the total earth resistance R.sub.E, and thus ultimately also the site resistance R.sub.st.

[0082] FIG. 2 shows a schematic illustration of a first embodiment of the measuring device 25 of the energy supply device 1.

[0083] Identical and functionally identical elements are provided with the same reference numerals in all figures, so that reference is made in each case to the preceding description.

[0084] The measuring device 25 has a common contact point 29 and a measuring circuit 31. The first contact plate 23.1 is electrically connected to the common contact point 29 via a first connection conductor 33. The second contact plate 23.2 is electrically connected to the common contact point 29 via a second connection conductor 35. The measuring circuit 31 is electrically connected to the at least one touch point 15 and to the common contact point 29, and is adapted to measure the at least one electrical measurand between the touch point 15 and the common contact point 29. In particular, the measuring device 25 comprises a first terminal a electrically connected to the first contact plate 23.1, a second terminal b electrically connected to the second contact plate 23.2, and a third terminal c electrically connected to the touch point 15, the measuring circuit 31 being adapted to measure the at least one electrical measurand between the third terminal c and the common contact point 29.

[0085] In particular, the measuring circuit 31 comprises a measuring resistor 36 having the resistance value R.sub.M and a voltage measuring device 37, in particular a voltmeter, which is arranged and adapted to measure a voltage U dropping across the measuring resistor 36. Preferably, the measuring circuit 31 further comprises a current measuring device 39, in particular an amperemeter, which is adapted to measure a current I flowing through the measuring resistor 36. The measuring device 25 or the computing device 27 is preferably adapted to compare the voltage U with a limit voltage U.sub.max, and/or to compare the current I with a limit current I.sub.max, and to evaluate the touch safety based on the comparison.

[0086] The measuring device 25 is further preferably adapted to measure an impedance Z between the contact plates 23, in particular between the first connection conductor 33 and the second connection conductor 35. For this purpose, the measuring device 25 preferably comprises an impedance measuring device 41 arranged and adapted to measure the impedance Z.

[0087] Preferably, a first decoupling device 43 is arranged in the first connection conductor 33, and a second decoupling device 45 is arranged in the second connection conductor 35. The decoupling devices 43, 45 advantageously ensure that by means of the impedance measuring device 41 the impedance Z between the contact plates 23 is actually measured and not, for example, a short circuit or an internal impedance of the measuring circuit 31.

[0088] In the first embodiment of the measuring device 25 according to FIG. 2, the decoupling devices 43, 45 are each formed as decoupling resistors 47, 49.

[0089] FIG. 3 shows a schematic illustration of a second embodiment of the measuring device 25. In this second embodiment, the decoupling devices 43, 45 are each designed as, in particular, controllable switches 51, 53. In particular, the first decoupling device 43 is formed as a first controllable switch 51, and the second decoupling device 45 is formed as a second controllable switch 53. Preferably, the first switch 51 and the second switch 53 are alternately controlled, in particular by the computing device 27. In a first functional state, the first switch 51 is closed, and the second switch 53 is open. In a second functional state, the first switch 51 is open, and the second switch 53 is closed. In this way, a loop impedance can be determined individually for each contact plate 23 via the ground 9, the grounding floor spaces 19, and the measuring circuit 31, with an internal impedance or an internal resistance of the measuring circuit 31 preferably being known, so that ultimately the sum of the total grounding impedance and the respective contact resistance R.sub.E+R.sub.ME is determined and relevant information about the at least one installation parameter is obtained as a result. In this case, the two measurements performed separately for the contact plates 23 in each case can be checked for plausibility against each other. In a third functional state, both switches 51, 53 are preferably open; the impedance between the contact plates can then be determined directly, in particular as 2R.sub.ME. Finally, from a combination of the measurements in the first functional state, the second functional state and the third functional state, the contact resistance R.sub.ME and the total ground resistance R.sub.E alone can also be obtained. Thus, overall, in this second embodiment of the measuring device 25, multiple parasitic components can be detected with the highest precision. For the purpose of monitoring the touch safety in the narrower sense, i.e. in particular for measuring the at least one electrical measurand between the touch point 15 and the contact plates 23, preferably in a fourth functional state both switches 51, 53 are closed.

[0090] Preferably, the switches 51, 53 are designed as semiconductor switches.

[0091] FIG. 4 shows a schematic illustration of a third embodiment of the measuring device 25.

[0092] In the first embodiment example according to FIG. 2 and the second embodiment example according to FIG. 3 of the measuring device 25, the measuring resistor 36, which is referred to as a first measuring resistor 36 for the purpose of differentiation, is virtually integrated in the measuring circuit 31.

[0093] In contrast, in the third embodiment example of the measuring device 25 according to FIG. 4, the first contact plate 23.1, that is to say here in particular the first terminal a, is electrically connected in parallel with the first connection conductor 33 and with the measuring circuit 31 via a second measuring resistor 55 to the touch point 15, that is to say in particular to the third terminal c, and the second contact plate 23.2, that is to say in particular the second terminal b, is electrically connected in parallel with the second connection conductor 35 and the measuring circuit 31 via a third measuring resistor 57 to the touch point 15, that is to say in particular to the third terminal c. Due to the electrical parallel connection of the second measuring resistor 55 and the third measuring resistor 57, these preferably each have twice the resistance value 2R.sub.M compared to the first measuring resistor 36.

[0094] The decoupling devices 43, 45 are shown here by way of example—analogous to the first embodiment according to FIG. 2—as decoupling resistors 47, 49. However, it is of course also possible in the third embodiment example to design the decoupling devices 43, 45 as coils, in particular chokes.

[0095] Compared to the first embodiment example according to FIG. 2, the third embodiment example according to FIG. 4 has the advantage that, on the one hand, the decoupling resistors 47, 49 can be designed with a high impedance, whereby the measuring resistors 55, 57 according to FIG. 4 also have higher resistance values than the decoupling resistors 47, 49 of the first embodiment example shown in FIG. 2. Thus, the impedance between the contact plates 23 can be measured with higher accuracy in the third embodiment example according to FIG. 4 than in the first embodiment example according to FIG. 2. In the latter, the decoupling resistors 47, 49 should be selected much smaller than the first measuring resistor 36 in order not to influence the measurement of the at least one electrical measurand too much, but this in turn has the consequence that the impedance between the contact plates 23 can only be determined with comparatively low accuracy, since the measurement is dominated by the decoupling resistors 47, 49 connected in parallel.

[0096] FIG. 5 shows a schematic illustration of a fourth embodiment of the measuring device 25. In the fourth embodiment, the first terminal a and thus the first contact plate 23.1 is connected to the third terminal c and thus the touch point 15 via a first measuring conductor 59, and the second terminal b and thus the second contact plate 23.2 is electrically connected to the third terminal c and thus the touch point 15 via a second measuring conductor 61. A fourth measuring resistor 62 is arranged in the first measuring conductor 59, and a fifth measuring resistor 65 is arranged in the second measuring conductor 61. In this case, the measuring device 25 comprises two voltage measuring devices, referred to as second voltage measuring device 67 and third voltage measuring device 69 in distinction to the single—first—voltage measuring device 37 of the preceding embodiments, wherein the second voltage measuring device 67 is adapted to measure an electrical voltage drop across the fourth measuring resistor 63, and wherein the third voltage measuring device 69 is adapted to measure a second electrical voltage drop across the fifth measuring resistor 65. Due to the electrical parallel connection of the fourth measuring resistor 63 and the fifth measuring resistor 65, they in turn have twice the resistance value 2R.sub.M compared to the single first measuring resistor 36. The decoupling of the impedance measurement with the impedance measuring device 41 takes place here directly via the measuring resistors 63, 65 themselves. In this way, too, a more precise measurement of the impedance is advantageously possible than in the first embodiment example according to FIG. 2. The double voltage measurement via the second voltage measuring device 67 and the third voltage measuring device 69 advantageously enables a plausibility check of the measured values against each other.