METHOD FOR PROTECTING AN ELECTRICAL CIRCUIT INCLUDING AN ELECTRICAL POWER CONVERTER

Abstract

The invention relates to a method for protecting an electrical circuit comprising a power converter, a switch configured to open and close, and a battery. The method comprises the following steps when the switch opens: The method comprises the following steps: - Measurement steps (E1, E2) of the current and voltage in the circuit; - A voltage regulation step (E3) where the voltage is regulated to a setpoint value when the current is below a predetermined threshold value; - A current regulation step (E4) where the current is regulated to a setpoint value when the current exceeds the predetermined threshold value; - A current increase step (E5) of the setpoint value by a predetermined increment under certain conditions. Figure 2

Description

Title of the invention: METHOD FOR PROTECTING AN ELECTRICAL CIRCUIT COMPRISING AN ELECTRICAL POWER CONVERTER

[0001] The present invention relates to the field of power electronics, more particularly to means of protection, especially against short circuits, of electrical power converters in electrical circuits.

[0002] Such electrical power converters are used, for example, in the electrical circuits of electric vehicles, that is, those equipped with at least one battery for storing electrical energy intended for their propulsion by a motor. This includes vehicles with a single means of electric propulsion, as well as hybrid vehicles incorporating at least one mode of electric propulsion.

[0003] Patent application DE102021108698 describes a method implementing an electrical circuit comprising an electrical power converter including a switch and a coil. A predetermined algorithm calculates a switching time of the switch from an electrical current intensity profile in the coil, actuating the switch according to the calculated switching time.

[0004] That said, particularly in the event of a short circuit in the electrical circuit, the electric current intensity profile contains abnormal electric current intensity values ​​that can distort the calculations of such an algorithm, or even stop the operation of the electrical power converter.

[0005] The objective of the invention is to overcome this drawback by proposing a method offering increased safety.

[0006] Thus, the invention proposes a method for protecting an electrical circuit comprising an electrical power converter, a switch, configured to be in a closed state or an open state, and a battery, the method comprising the following steps when the switch changes from the closed state to the open state: - a step of measuring a value of electric current intensity in the electrical circuit; - a step of measuring a voltage value of the electrical power converter; - a step of regulating the voltage value of the electrical power converter to a first predetermined setpoint voltage value when the measured electrical current intensity value is less than a first predetermined electrical current intensity value; - a step of regulating the value of the electric current in the electrical circuit to a setpoint electric current intensity value when the measured electric current intensity value is greater than the first predetermined electric current intensity value, - a step of increasing the setpoint electric current intensity value by incrementing it by a predetermined electric current intensity increment value when the measured voltage value is less than a second predetermined setpoint voltage value and when the measured electric current intensity value is less than a second predetermined electric current intensity value.

[0007] Such a method allows the power converter to continue operating in the event of a short circuit in the electrical circuit, thereby improving the reliability of the electrical circuit, particularly during the transient time of the switch transitioning from the closed to the open state. Furthermore, the increment is chosen so that the power converter continues to supply power to the electrical components connected to the circuit during this transient time, preventing a sudden increase in the electrical current that would lead to the power converter shutting down.

[0008] Advantageously, the method further includes, after the step of increasing the setpoint value of electric current intensity, a step of regulating the value of electric current intensity in the electrical circuit to the first predetermined intensity value when the measured voltage value is greater than the second predetermined setpoint voltage value.

[0009] Advantageously, the first predetermined electric current intensity value is between 150A and 250A.

[0010] Advantageously, the second predetermined electric current intensity value is between 350A and 450A.

[0011] Advantageously, the first predetermined setpoint voltage value is between 13.9V and 14.1V.

[0012] Advantageously, the predetermined electric current intensity increment value is between IA and 20A.

[0013] Advantageously, the second predetermined setpoint voltage value is between 11V and 13V.

[0014] The invention also relates to a computer program comprising program code instructions for executing the steps of the process defined above, when said program is running on a computer.

[0015] The invention further relates to an assembly comprising an electronic control unit including acquisition means and processing means, by software instructions stored in memory, as well as control means required for the implementation of the computer program defined as previously.

[0016] The invention will be further detailed by the non-limiting embodiment and the accompanying figures in which: - [Fig.1] schematically illustrates an electrical circuit according to an embodiment of the present invention; - [Fig.2] illustrates a flowchart representing, according to one embodiment, the steps of a process for protecting an electrical circuit illustrated in [Fig.1].

[0017] As illustrated in [Fig.1], an electrical circuit 10 comprises an electrical power converter 11, a switch 12, configured to be in a closed state or an open state, and a battery 13, according to an embodiment of the present invention.

[0018] An electrical power converter 11 is a device configured to transform one form of energy into another form of energy.

[0019] The electrical power converter 11 is also configured to regulate the voltage and current intensity in the electrical circuit 10.

[0020] Electrical power converters include types such as AC-DC, DC-DC, AC-AC, and DC-AC converters; typically in this case, the electrical power converter 11 is a DC-DC converter.

[0021] In [Fig.1], the electrical circuit 10 is electrically connected to a first electronic component 14A by point 10A. Similarly, the electrical circuit 10 is electrically connected to a second electronic component 14B by point 10B.

[0022] For example, the first electronic circuit is configured to secure the braking of a vehicle, while the second electronic circuit is configured to secure the trajectory of the vehicle.

[0023] The first electronic component 14A and the second electronic component 14B are both powered by battery 13 and electrical power converter 11.

[0024] By default, switch 12 is in the closed state, so that electric current flows in the electrical circuit 10.

[0025] When a short circuit occurs in the second electronic component 14B, the switch 12 is flipped to the open state, the electrical circuit 10 comprising a first electrical sub-circuit and a second electrical sub-circuit.

[0026] The first electrical sub-circuit includes the electrical power converter 11 and the first electronic component 14A.

[0027] The second electrical sub-circuit comprising battery 13 and the second faulty electrical component.

[0028] In practice, in such a case of short circuit, the intensity of the electric current in the first electrical sub-circuit typically increases from 250A to 350A, i.e. an increase of about one hundred amperes in a few milliseconds.

[0029] A logic diagram of a method for protecting the electrical circuit 10 when the switch 12 changes from the closed state to the open state is illustrated [Fig.2], the steps of the method being described below according to an embodiment of the present invention.

[0030] In a measurement step El, an electric current intensity value is measured in the electrical circuit 10.

[0031] In a measurement step E2, a voltage value of the electrical power converter 11 is measured.

[0032] In a regulation step E3, the voltage value of the electrical power converter 11 is regulated to reach a first predetermined setpoint voltage value when the measured electric current intensity value is less than a first predetermined electric current intensity value.

[0033] For example, the first predetermined setpoint voltage value is 14V and the first predetermined electric current intensity value is equal to 250A.

[0034] In a regulation step E4, the value of the electric current in the electrical circuit 10 is regulated to reach a setpoint electric current intensity value when the measured electric current intensity value is greater than the first predetermined electric current intensity value.

[0035] For example, at this regulation step E4, the setpoint value of electric current intensity is equal to 250A.

[0036] In an increase step E5, the setpoint electric current intensity value is increased by incrementing it by a predetermined electric current intensity increment value when the measured voltage value is less than a second predetermined setpoint voltage value and when the measured electric current intensity value is less than a second predetermined electric current intensity value.

[0037] The condition on the second predetermined setpoint voltage value allows in particular to detect a short circuit in the electrical circuit 10 even without the switch 12 opening, indicating that a short circuit has occurred in the electrical circuit 10.

[0038] For example, for a second predetermined electric current intensity value of 350A and a predetermined electric current intensity increment value of 10A, the setpoint electric current intensity value, after this increase step E5, is equal to 260A.

[0039] In this way, the steps of the process are repeated until the measured electric current intensity value reaches the second predetermined electric current intensity value.

[0040] Thus, this allows the electrical power converter 11 to continue to supply the first electrical component in the first electrical sub-circuit when a short circuit occurs in the second electronic component 14B and when the switch 12 switches from the closed state to the open state.

[0041] Without this method, an increase of 250A to 350A in the electric current in the first sub-circuit risks causing the electrical power converter 11 to shut down. Thus, the method offers additional safety in the event of a short circuit in the electrical circuit 10.

[0042] The method advantageously includes a regulation step E6, the value of electric current intensity in the electrical circuit 10 is regulated to reach the first predetermined intensity value when the measured voltage value is greater than the second predetermined setpoint voltage value.

Claims

Demands

1. A method for protecting an electrical circuit (10) comprising an electrical power converter (11), a switch (12) configured to be in a closed or open state, and a battery (13), the method comprising the following steps when the switch (12) changes from the closed state to the open state: - a measurement step (E1) of an electric current intensity value in the electrical circuit (10); - a measurement step (E2) of a voltage value of the electrical power converter (11); - a regulation step (E3) of the voltage value of the electrical power converter (11) to a first predetermined setpoint voltage value when the measured electric current intensity value is less than a first predetermined electric current intensity value;- a regulation step (E4) of the value of the electric current in the electrical circuit (10) to a setpoint electric current intensity value when the measured electric current intensity value is greater than the first predetermined electric current intensity value, - an increase step (E5) of the setpoint electric current intensity value by incrementing it by a predetermined electric current intensity increment value when the measured voltage value is less than a second predetermined setpoint voltage value and when the measured electric current intensity value is less than a second predetermined electric current intensity value.;

2. A method according to claim 1, characterized in that the method further comprises, after the step of increasing (E5) the setpoint electric current intensity value, a step of regulating (E6) the electric current intensity value in the electrical circuit (10) to the first predetermined intensity value when the measured voltage value is greater than the second predetermined setpoint voltage value.

3. A method according to claim 1, characterized in that the first predetermined electric current intensity value is between 150A and 250A.

4. A method according to claim 1 or 2, characterized in that the second predetermined electric current intensity value is between 350A and 450A.

5. A method according to any one of claims 1 to 3, characterized in that the first predetermined setpoint voltage value is between 13.9V and 14.1V.

6. A method according to any one of claims 1 to 4, characterized in that the second predetermined setpoint voltage value is between 11V and 13V.

7. A method according to any one of claims 1 to 6, characterized in that the predetermined electric current intensity increment value is between IA and 20A.

8. Computer program comprising program code instructions for carrying out the steps of the process according to any one of claims 1 to 7, when said program is running on a computer.

9. Vehicle comprising an electronic control unit including acquisition means and processing means, by means of software instructions stored in memory, as well as control means required for the implementation of the computer program according to claim 8.

Images