Discriminating electronic device for detecting an overvoltage or an overcurrent in a control circuit of an electrical machine

Abstract

The invention relates to an electronic device (10) suitable for detecting at least one overvoltage or one overcurrent on at least one control line of an electrical machine, the device comprising at least two sensors (1000, 1100, 1200) each respectively coupled to at least two separate control lines, a microcontroller (100) suitable for receiving an electrical signal through a first input terminal (110), each sensor (1000, 1100, 1200) being suitable for detecting the occurrence of an overvoltage or an overcurrent on the control line to which it is coupled, and for generating an electrical signal through a sensor output (1001, 1101, 1201) representative of the overvoltage, the electronic device (10) being respectively coupled to each sensor (1000, 1100, 1200), on the one hand, and to the input terminal (110) on the other.

Description

Discriminatory electronic device for detecting overvoltage or overcurrent in a control circuit of an electrical machine. DESCRIPTION [Technical field]

[0001] The present invention relates to a discriminating electronic device for detecting an overvoltage or an overcurrent in a control circuit of an electrical machine.

[0002] The present invention finds preferential but non-limiting applications in the automotive field.

[0003] The present invention can be implemented, for example, in an electronic circuit integrating a control structure of an electrical machine such as a three-phase asynchronous motor. [State of the prior art]

[0004] It is common for an electric vehicle to use at least one electric machine, such as, for example, a three-phase asynchronous motor. Such a motor is supplied with electrical energy by an electrical network coupled to at least one battery of the vehicle and is controlled by an electronic device comprising, for example, at least one microcontroller.

[0005] To control the motor torque of the electric machine, sensors are placed on control lines coupling the electric motor to the battery. These sensors are suitable for measuring a voltage or current flowing in each phase of the electric motor and allow the motor torque of the electric machine to be managed in real time.

[0006] In addition, each sensor is also adapted to detect overvoltage or overcurrent on the said control line to which it is connected. Thus, a voltage or current sensor has at least two separate pins to generate the said two signals.

[0007] In order to process this information, the microcontroller must have as many input pins as there are signals generated by the sensor(s). So, for example, to manage a single current sensor, the microcontroller must allocate two pins in order to manage the signal representing the current flowing in the control line and the signal representing the presence of an overcurrent on said control line.

[0008] Thus, the microcontroller must have a large number of pins to manage the said signals coming from the sensors, generating additional costs and connection problems when designing the printed circuit.

[0009] There is therefore a need to optimize the allocation of pins of a microcontroller while ensuring the safety rules for controlling said electrical machine. [Statement of the invention] The invention relates to an electronic device suitable for detecting at least one overvoltage or overcurrent on at least one control line of an electrical machine comprising at least two sensors coupled respectively to at least two separate control lines, a microcontroller suitable for receiving an electrical signal on a first input terminal, each sensor being suitable for detecting the occurrence of an overvoltage or overcurrent on the control line where it is coupled, and for generating an electrical signal on a sensor output representative of said overvoltage or overcurrent.The electronic device is on the one hand coupled respectively to each sensor and on the other hand coupled to the input terminal, and the electronic device is adapted to couple respectively to each sensor a resistive means having a different resistance value so as to generate on the input terminal a multi-level electrical signal representative of the control line(s) where the overvoltage or overcurrent is detected by at least one of the sensors. For example, the multi-level electrical signal representative of the control line(s) where the overvoltage or overcurrent is detected by at least one of the sensors has voltage levels between 0 and 5 Volts. In another exemplary embodiment, the two consecutive levels of the multilevel signal are spaced at least 0.5 Volt apart. In an advantageous embodiment, said device comprises three sensors. For example, the first resistive means has a resistance value that is half the resistance value of the second resistive means, and the resistance value of the second resistive means has a value that is 1.5 times lower than the resistance value of the third resistive means. [Description of the drawings]

[0010] Other characteristics and advantages of the invention will become apparent from reading the description which follows. This is purely illustrative and must be read in conjunction with the appended drawings in which:

[0011] [Fig 1] Figure 1 is a structural diagram of an electronic device for detecting an overvoltage or an overcurrent in a control circuit of an electrical machine according to an exemplary embodiment of the invention, [Description of embodiments]

[0012] The invention will be described in an exemplary embodiment in which three current sensors are coupled to an electrical machine (not shown). Of course, this example is not limiting and the number of coupled sensors can vary from 2 sensors to n sensors. Furthermore, the invention can operate with current sensors or voltage sensors or position sensors. It will also be possible to combine different sensor technologies. It will also be possible to indifferently combine current sensors with voltage sensors with position sensors. Preferably, the sensor output is an open collector output.

[0013] Figure 1 schematically illustrates an electronic device 10, a microcontroller 100 and a first current sensor 1000, a second current sensor 1100 and a third current sensor 1200. To simplify the description and understanding of the invention, the connection associated with the sensors and / or the input of the microcontroller 100 is not shown in Figure 1. Those skilled in the art know that, in such an example of coupling, it is necessary to connect for example a “pull up” resistor Rp connected to a power supply Vp and also connected to a capacitor Cp.

[0014] The microcontroller 100 is adapted to control at least one electrical machine and comprises an input pin 110 adapted to receive an electrical signal coming from the electronic device 10. Only the components and pins useful for understanding the invention are shown in the drawing so as not to complicate the description.

[0015] The first current sensor 1000 comprises a first current sensor output pin 1001 adapted to generate a signal upon detection by said first current sensor 1000 of an overcurrent on the control line of the associated and not shown synchronous machine. In other words, when the first current sensor 1000 detects on the control line where it is coupled a current exceeding a predetermined threshold level, it generates a signal of the voltage level variation type on its first current sensor output pin 1001.

[0016] The first current sensor 1000 comprises, as mentioned above, another output pin adapted to generate a signal representative of the intensity of the current flowing in said control line which is not shown.

[0017] The second current sensor 1100 has a second current sensor output pin 1101 adapted to generate a signal upon detection by the second current sensor 1100 of an overcurrent on the control line of the associated asynchronous machine.

[0018] The third current sensor 1200 has a third current sensor output pin 1201 adapted to generate a signal upon detection by the third current sensor 1200 of an overcurrent on the control line of the associated synchronous machine.

[0019] The electronic device 10 comprises a first electronic device input 10_1, a second electronic device input 10_2, a third electronic device input 10_3. The electronic device 10 further comprises a first electronic device output 10_4, a second electronic device output 10_5, a third electronic device output 10_6.

[0020] The first electronic device input 10_1 is coupled to the first current sensor output pin 1001, the second electronic device input 10_2 is coupled to the second current sensor output pin 1101, and the third electronic device input 10_3 is coupled to the third electronic device input 1201. The first electronic device output 10_4, the second electronic device output 10_5, and the third electronic device output 10_6 are all coupled to the input pin 110 of the microcontroller 100.

[0021] Cleverly, the electronic device 10 comprises between the first electronic device input 10_1 and the first electronic device output 10_4 a first resistive means 20. The electronic device 10 comprises between the second electronic device input 10_2 and the second electronic device output 10_5 a second resistive means 30. The electronic device 10 comprises between the third electronic device input 10_3 and the third electronic device output 10_6 a third resistive means 40.

[0022] The first resistive means 20, the second resistive means 30 and the third resistive means 40 are for example one or more resistors coupled in parallel having different equivalent resistance values. In other words, the resistance value of the first resistive means 20 is different from the resistance value of the second resistive means 30, itself different from the resistance value of the third resistive means 40.

[0023] Cleverly, the respective values ​​of the resistances of the three resistive means 20, 30 and 40 are determined so that the value of the signal applied to the input pin 110 of the microcontroller 100, representative of an overvoltage detected by at least one current sensor, is different for each sensor and has different levels.

[0024] Cleverly, the first resistive means 20, the second resistive means 30 and the third resistive means 40 have resistance values ​​making it possible to detect on the single input pin 110 an overvoltage on at least one of the three control lines of the electrical machine on which the three current sensors 1000, 1100 and 1200 are respectively coupled.

[0025] Cleverly, the values ​​of the first resistive means 20, the second resistive means 30 and the third resistive means 40 are determined so that it is also possible to detect overcurrents on several of the control lines simultaneously.

[0026] Advantageously, it is also possible to identify which current sensor 1000, 1100, 1200 generated said signal representative of an overcurrent.

[0027] For example, the first resistive means 20 has a resistance value of 3kΩ, the second resistive means 30 has a resistance value of 6kΩ, and the third resistive means 40 has a resistance value of 10kΩ.

[0028] Thanks to the invention and thanks to the electronic device, it is possible to detect overcurrent problems on one or more control lines of an electrical machine using a single input pin of the microcontroller.

[0029] Cleverly, it is possible to couple N current or voltage sensors on a single input pin of the microcontroller.

Claims

Claims

1. Electronic device (10) adapted for detecting at least one overvoltage or overcurrent on at least one control line of an electrical machine comprising at least two sensors (1000, 1100, 1200) coupled respectively to at least two separate control lines, a microcontroller (100) adapted to receive an electrical signal on a first input terminal (110), each sensor (1000, 1100, 1200) being adapted to detect the occurrence of an overvoltage or overcurrent on the control line where it is coupled, and to generate an electrical signal on a sensor output (1001, 1101, 1201) representative of said overvoltage or overcurrent, characterized in that the electronic device (10) is on the one hand respectively coupled to each sensor (1000, 1100, 1200) and on the other hand coupled to the input terminal (110), and in that the electronic device (10) is adapted to couple respectively to each sensor (1000, 1100,1200) a resistive means (20, 30, 40) having a different resistance value so as to generate on the input terminal (110) a multi-level electrical signal representative of the control line(s) where the overvoltage or overcurrent is detected by at least one of the sensors (1000, 1100, 1200).,

2. Electronic device (10) according to claim 1, in which the multi-level electrical signal representative of the control line(s) where the overvoltage or overcurrent is detected by at least one of the sensors (1000, 1100, 1200) has voltage levels between 0 and 5 Volts.

3. An electronic device (10) according to claim 1 or claim 2, wherein two consecutive levels of the multi-level signal are spaced apart by at least 0.5 Volts.

4. An electronic device (10) according to any one of claims 1 to 3, wherein said device comprises three sensors (1000, 1100, 1200).

5. The electronic device (10) of claim 4, wherein the first resistive means (20) has a resistance value twice as low as the resistance value of the second resistive means (30), and the resistance value of the second resistive means (30) has a value 1.5 times as low as the resistance value of the third resistive means (40).

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