Apparatus and method for compensating for leakage current

Abstract

The invention relates to an apparatus 1 for compensating for leakage current, having at least one first active HV cell 3 and having at least one second active HV cell 4, wherein the at least one first

Description

Apparatus and method for compensating for leakage current The invention relates to an apparatus and a method for compensating for leakage current, in particular for a battery charging circuit, in particular for a battery of a motor vehicle. Compensating for or reducing leakage currents is a relevant topic for battery charging circuits in the prior art, see for example EP 3 616 972 B1 and EP 3 599 690 B11. In the prior art relating to the topic of compensating for leakage current according to DE 10 2020 131 512 A1, the VPE potential is a relevant element in this case. The VPE potential is a voltage potential which is near to the protective conductor PE and typically has a maximum voltage difference of + / - 15 V from the protective conductor PE. The present invention seeks to provide an improved apparatus and an improved method for compensating for leakage current. An apparatus for compensating for leakage current is achieved by the features of claim 1. One exemplary embodiment of the invention relates to an apparatus for compensating for leakage current, having at least one first active HV cell and at least one second active HV cell, wherein the at least one first active HV cell is connected to a first potential and the at least one second active HV cell is connected to a second potential, wherein the at least one first active HV cell and the at least one second active HV cell supply a VPE potential via a respectively provided connection, wherein the leakage current is measured by a measuring circuit and added to an output of a provided pilot controller and supplied to the active HV cells as a current setpoint. The apparatus ensures that the pilot controller only has to correct deviations in the leakage current, meaning that the demands on the dynamics of the control circuit decrease and an improved result is achieved with less complexity and lower costs. Advantageously, there is provision in each case for a plurality of first active HV cells and a plurality of second active HV cells. In one exemplary embodiment, it is expedient if the measuring circuit, in particular ICOMP, provided controls a current source for generating a compensation current. In this case, the measuring circuit can be integrated with or connected to a transformer and connected to the first potential AC1 and to the second potential AC2. In a further exemplary embodiment, it is also expedient if the compensation current is delivered to a VPE controller before the output signal of the VPE controller is added to the signal from the output of the pilot controller. As a result, it is possible to generate a more stable signal. It is also advantageous if it is possible for the at least one first active HV cell or the first active HV cells and the at least one second active HV cell or the second active HV cells to be supplied with power from a high-voltage battery, for example in a voltage range of about 200 V or more, in particular of about 400 V or more, in particular of about 800 V or more, and / or supplied with power from an AC grid in the voltage range from 110 V to 277 V. In one exemplary embodiment, it is expedient if the first active HV cells and the second active HV cells have a first connection for connecting to the first potential or a second connection for connecting to the second potential, a third connection for connecting to the VPE potential and a fourth connection for feeding in the current setpoint. As a result, the current for compensating for the leakage current can be fed into the respective first active HV cell or into the first active HV cells and / or second active HV cell or into the second active HV cells. It is also advantageous if the VPE controller and / or the pilot controller are / is in the form of a P controller, a PI controller or a PID controller. This allows suitable control to be performed. It is also advantageous if the VPE potential is a potential near the protective conductor PE and in particular deviates from the protective conductor PE by about + / -30V A method for compensating for leakage current is achieved by the features of claim 8. One exemplary embodiment of the invention relates to a method for compensating for leakage current, in particular by way of an apparatus for compensating for leakage current according to the invention, wherein there is provision for at least one first active HV cell or first HV cells and at least one second active HV cell or second active HV cells, wherein the at least one first active HV cell or the first active HV cells is / are connected to a first potential and the at least one second active HV cell or the second active HV cells is / are connected to a second potential, wherein the at least one first active HV cell or the first active HV cells and at least one second active HV cell or the second active HV cells supply a VPE potential via a respectively provided connection, wherein the leakage current is measured and added to an output of a provided pilot controller and supplied to the active HV cells as a current setpoint. As a result, it is possible to compensate for the leakage current in a reliable and uncomplicated manner. It is also expedient if the measuring circuit is provided in such a way that it controls a current source for generating a compensation current which is controlled on the basis of the measured leakage current. The current used for compensation can thus be adjusted in line with the leakage current and added to the output value of the pilot controller in an appropriate magnitude. It is also advantageous if the compensation current is delivered to a VPE controller before the output signal of the VPE controller is added to the output of the pilot controller. This allows appropriate smoothing and adaptation. The invention will be explained in detail below on the basis of an exemplary embodiment with reference to the drawing. In the drawing: Figure 1 shows a schematic illustration of a circuit of an apparatus for compensating for leakage current according to an embodiment of the invention. Figure 1 shows a schematic illustration of a circuit of an apparatus 1 for compensating for leakage current. The apparatus has a first potential L / AC1 and a second potential N / AC2 and is for example in the form of a transformer and measuring circuit on a device 2. There is provision for at least one first active HV cell 3 or a plurality of first active HV cells 3. In the case of a plurality of first active HV cells 3, these first active HV cells 3 are for example electrically connected to one another, for example connected in parallel or connected in parallel in groups, the groups being connected in series. There is provision for at least one second active HV cell 4 or a plurality of second active HV cells 4. In the case of a plurality of second active HV cells 4, these second active HV cells 4 are for example electrically connected to one another, for example connected in parallel or connected in parallel in groups, the groups being connected in series. The at least one first active HV cell 3 or the first active HV cells 3 is / are connected to the first potential L / AC1 via a first connection 5. The at least one second active HV cell 4 or the second active HV cells 4 is / are connected to the second potential NJAC2 via a second connection 6. Furthermore, it is possible to connect the at least one first active HV cell 3 or the first active HV cells 3 and the at least one second active HV cell 4 or the second active HV cells 4 via a respectively provided third connection 7, 8 which supplies a VPE potential. In this case, the leakage current 9 is measured by a measuring resistor 18 and connected to the input of the VPE controller 14. In the exemplary embodiment shown, the measuring circuit 2 controls a current source 13 for generating a compensation current 19. At the same time, there is provision for a measuring circuit 2 which connects a signal 20 to an input of a pilot controller 10 and an adder 17 is used to add the output 11 of the pilot controller 10 to the output of the VPE controller 14 and supply the result to the active HV cells 3, 4 as a current setpoint 12. In one exemplary embodiment, it is expedient if the VPE controller 14 and / or the pilot controller 10 are / is optionally in the form of a P controller, a Pl controller or a PID controller. Figure 1 also shows that the at least one first active HV cell 3 or the first active HV cells 3 and the at least one second active HV cell 4 or the second active HV cells 4 have a first connection 5 or a second connection 6 for connecting to the first potential L / IAC1 or to the second potential N / AC2, respectively, a third connection 7, 8 for connecting to the VPE potential and a fourth connection 15, 16 for feeding in the current setpoint 12. According to one exemplary embodiment, it is possible for the at least one first active HV cell 3 or the first active HV cells 3 and / or the at least one second active HV cell 4 or the second active HV cells 4 to be supplied with power from a high-voltage battery, for example in a voltage range of about 200 V or more, in particular of about 400 V or more, in particular of about 800 V or more. Alternatively or in addition, power can also be supplied from an AC grid in the range from 110 V to 277 V. The VPE potential is a potential near the protective conductor PE and in particular deviates from PE by about + / - 30 V. The method according to the invention for compensating for leakage current by way of an apparatus 1 for compensating for leakage current ensures that there is provision for at least one first active HV cell 3 or first active HV cells 3 and at least one second active HV cell 4 or second active HV cells 4, wherein the at least one first active HV cell 3 or the first active HV cells 3 is / are connected to a first potential L / AC1 and the at least one second active HV cell 4 or the second active HV cells 4 is / are connected to a second potential N / AC2, wherein the at least one first active HV cell 3 or the first active HV cells 3 and the at least one second active HV cell 4 or the second active HV cells 4 supply a VPE potential via a respectively provided connection 7, 8, wherein the leakage current 9 is measured and, after being regulated by a VPE controller 14, is added using the adder 17 to an output 11 of a provided pilot controller 10 and supplied to the active HV cells 3, 4 as a current setpoint 12.

Claims

Patent claims 1. An apparatus for compensating for leakage current, having at least one first active HV cell and having at least one second active HV cell, wherein the at least one first active HV cell is connected to a first potential and the at least one second active HV cell is connected to a second potential, wherein the at least one first active HV cell or the first active HV cells and the at least one second active HV cellor the second active HV cells supply a VPE potential via a respectively provided connection, wherein the leakage current is measured by a measuring circuit and added to an output of a provided pilot controller and supplied to the active HV cells as a current setpoint.

2. The apparatus for compensating for leakage current as claimed in claim 1, wherein the measuring circuit provided controls a current source for generating a compensation current.

3. The apparatus for compensating for leakage current as claimed in claim 1 or 2, wherein the compensation current is delivered to a VPE controller before the output signal of the VPE controller is added to the output of the pilot controller.

4. The apparatus for compensating for leakage current as claimed in claim 1, 2 or 3, wherin it is possible for the at least one first active HV cell or the first active HV cells and / or the at least one second active HV cell or the second active HV cells to be supplied with power from a high-voltage battery, for example in a voltage range of about 200 V or more, in particular of about 400 V or more, in particular of about 800 V or more, and / or supplied with power from an AC grid in the voltage range from 110 V to 277 V.

5. The apparatus for compensating for leakage current as claimed in claim 1, 2, 3 or 4, wherein the first active HV cells and the second active HV cells have a first connection for connecting to the first potential or a second connection for connecting to the second potential, a third connection for connecting to the VPE potential and a fourth connection for feeding in the current setpoint.

6. The apparatus for compensating for leakage current as claimed in claim 1, 2, 3, 4 or 5, wherein the VPE controller and / or the pilot controller are / is in the form of a P controller, a Pl controller or a PID controller. (. The apparatus for compensating for leakage current as claimed in any one of the preceding claims, wherein the VPE potential is a potential near the protective conductor PE and in particular deviates from PE by about + / - 30 V.

8. A method for compensating for leakage current, in particular by way of an apparatus for compensating for leakage current according to one of the preceding claims, wherein there is provision for at least one first active HV cell or first active HV cells and at least one second active HV cell or second active HV cells, wherein the at least one first active HV cell or the first active HV cells is / are connected to a first potential and the at least one second active HV cell or the second active HV cells is / are connected to a second potential, wherein the at least one first active HV cell or the first active HV cells and at least one second active HV cell or the second active HV cells supply a VPE potential via a respectively provided connection, wherein the leakage current is measured and added to an output of a provided pilot controller and supplied to the battery cells as a current setpoint.

9. The method for compensating for leakage current as claimed in claim 8, wherein the measuring circuit is provided in such a way that it controls a current source for generating a compensation current which is controlled on the basis of the measured leakage current.

10. The method for compensating for leakage current as claimed in clam 8 or 9, wherein the compensation current is delivered to a VPE controller before the output signal of the VPE controller is added to the output of the pilot controller.