阅读说明：本技术 具有用于使电容器放电的电流消耗电路的电气系统、相关的机动车辆和方法 (Electrical system having a current-consuming circuit for discharging a capacitor, associated motor vehicle and method ) 是由 P.洛伊-拉方德 于 2018-03-08 设计创作，主要内容包括：电气系统(100)包括：-电容器(C)；-电力供应设备(102)；-电力接收设备(104)；-电流消耗电气电路(108),其被设计为消耗经由第一接口端子(B<Sub>A</Sub>)进入并经由第二接口端子(B<Sub>B</Sub>)离开的电流(i)。电气系统(100)被设计为使得当电力供应设备(102)连接到电容器(C)的端子时,电流消耗电气电路(108)消耗放电电流(i)。电流消耗电气电路(108)包括晶体管(Q1),晶体管(Q1)被布置为使得所消耗的电流(i)经由晶体管(Q1)的电流输入端子(C1)进入并经由晶体管(Q1)的电流输出端子(E1)离开,并且电流输出端子(E1)连接到晶体管(Q1)的控制端子(B1)以使晶体管(Q1)稳定。(An electrical system (100) comprises: -a capacitor (C); -a power supply device (102); -a power receiving device (104); -a current consuming electrical circuit (108) designed to consume current via the first interface terminal (B) A ) Into and through the second interface terminal (B) B ) The leaving current (i). The electrical system (100) is designed such that the current consuming electrical circuit (108) consumes the discharge current (i) when the power supply device (102) is connected to the terminals of the capacitor (C). The current consuming electrical circuit (108) comprises a transistor (Q1), the transistor (Q1) being arranged such that the consumed current (i) enters via a current input terminal (C1) of the transistor (Q1) and passes via the transistor (Q1)The current output terminal (E1) of (Q1) is off, and the current output terminal (E1) is connected to the control terminal (B1) of the transistor (Q1) to stabilize the transistor (Q1).)

1. An electrical system (100) comprising:

-a capacitor (C) having two terminals (B)_E，B_F)；

-a power supply device (102) connected to a terminal (B) of the capacitor (C)_E，B_F)；

-a power receiving device (104) connected to a terminal (B) of the capacitor (C)_E，B_F) To receive power supplied by the power supply device (102);

-a current consuming electrical circuit (108) havingHaving terminals (B) respectively connected to said capacitors (C)_E，B_F) Two interface terminals (B)_A，B_B) And is designed to consume via the first interface terminal (B)_A) Into and through the second interface terminal (B)_B) The current (i) leaving the reactor,

the electrical system (100) being designed such that the current-consuming electrical circuit (108) consumes the current (i) when the power supply device (102) is connected to the terminals of the capacitor (C),

the electrical system (100) is characterized in that: the current consuming electrical circuit (108) comprises a transistor (Q1), the transistor (Q1) being arranged such that the consumed current (i) enters via a current input terminal (C1) of the transistor (Q1) and exits via a current output terminal (E1) of the transistor (Q1), and the current output terminal (E1) is connected to a control terminal (B) of the transistor (Q1) to stabilize the transistor (Q1).

2. The electrical system (100) of claim 1, wherein the current consuming electrical circuit (108) includes a zener diode (D1) connected between the current output terminal (E1) of the transistor (Q1) and the control terminal (B1) of the transistor (Q1) to stabilize the transistor (Q1).

3. The electrical system (100) of claim 1 or 2, wherein the current consuming electrical circuit (108) comprises a control terminal (B1) connected to the transistor (Q1) and the first interface terminal (B)_A) With a resistor (R4) in between.

4. The electrical system (100) of any of claims 1 to 3, wherein the current consuming electrical circuit (108) comprises a current input terminal (C1) connected to the transistor (Q1) and the first interface terminal (B)_A) With a resistor (R1) in between.

5. The electrical system (100) of any of claims 1-4, wherein the electrical current consumes an electrical powerThe circuit (108) comprises a first interface terminal (B) connected between the current output terminal (E1) and the second interface terminal (B)_B) With a resistor (R2) in between.

6. The electrical system (100) according to any one of claims 1 to 5, wherein the power supply device (102) is designed to apply a DC supply voltage (E).

7. The electrical system (100) according to claim 6, wherein the DC supply voltage (E) is higher than 60V, preferably higher than 300V.

8. The electrical system (100) according to any one of claims 1 to 7, wherein the power supply device (102) comprises one of: a battery charger (302) and a battery (304).

9. The electrical system (100) of any of claims 1 to 8, wherein the power receiving device (104) comprises one of: a battery (304), an inverter (306), and a DC to DC converter (310).

10. The electrical system (100) of any one of claims 1 to 9, wherein the current consuming electrical circuit (108) is a passive circuit.

11. A motor vehicle (300) comprising an electrical system (100) according to any one of claims 1 to 10.

12. One kind is provided with two terminals (B)_E，B_F) The method of discharging a capacitor (C) of (1), comprising:

-when connecting the power supply device (102) to the terminal (B) of the capacitor (C)_E，B_F) To have terminals (B) respectively connected to the capacitors (C) when a supply voltage (E) is applied across the terminals of the capacitors (C)_E，B_F) Two interface terminals (B)_A，B_B) The current consumption electric circuit (108) consumes the current via the first interface terminal (B)_A) Enters and exits via the second interface terminal (B)_B) Current (i) of (a);

-when the power supply device (102) is no longer operating to no longer limit the capacitor voltage (u) present across the terminals of the capacitor (C)_C) Said current consuming electrical circuit (108) consumes said current (i) to discharge said capacitor (C),

the method is characterized in that: the current consuming electrical circuit (108) used in the preceding step comprises a transistor (Q1), the transistor (Q1) being arranged such that the consumed current (i) enters via a current input terminal (C1) of the transistor (Q1) and exits via a current output terminal (E1) of the transistor (Q1), and a current output terminal (E1) of the transistor (Q1) is connected to a control terminal (B1) of the transistor (Q1) to stabilize the transistor (Q1).

Technical Field

The present invention relates to the discharge of capacitors, particularly in the field of electric motor vehicles (electric vehicles).

Background

US patent publication US 6204612B1 describes a capacitor to the terminals of which an electrical power module is intended to be connected. In addition, it describes a current-consuming electrical circuit comprising a stabilizing transistor connected to a terminal of a capacitor. In this publication, the current consuming electrical circuit is designed to be activated so as to consume a substantially constant discharge current when the power module is mechanically and electrically disconnected from the capacitor. Thus, the consumption of current discharges the capacitor, thereby preventing an electric shock that may occur if the operator touches the capacitor. More specifically, the power module comprises a conductor arranged to short-circuit the controlled switch in order to deactivate the current consuming circuitry. Thus, when the power module is disconnected, the conductor is disconnected from the controlled switch, causing the current consuming electrical circuit to be activated. This solution has the disadvantage of requiring the presence of mechanical elements (conductors) on the power module side. Moreover, this solution does not allow discharging the capacitor while the power module is still mechanically in place but electrically disconnected from the capacitor, for example in case of electrical connection failure.

In addition, it is known to connect a resistor to the terminals of a capacitor supplied by the high voltage source to discharge the capacitor in the event of disconnection of the high voltage source. A disadvantage of this solution is that the resistor continues to consume a large amount of current even when not needed, i.e. when the high voltage source is connected to the capacitor.

It is an object of the present invention to at least partly overcome the above problems.

Disclosure of Invention

To this end, an electrical system is proposed, comprising:

-a capacitor having two terminals;

-a power supply device connected to terminals of the capacitor;

-a power receiving device connected to a terminal of the capacitor to receive power supplied by the power supply device;

a current-consuming electrical circuit having two interface terminals connected respectively to the terminals of the capacitor and designed to consume a current entering via the first interface terminal and exiting via the second interface terminal,

the electrical system is designed such that, when the power supply device is connected to the terminals of the capacitor, the current consuming electrical circuit consumes current,

the electrical system is characterized in that: the current consuming electrical circuit comprises a transistor arranged such that the consumed current enters via a current input terminal of the transistor and exits via a current output terminal of the transistor, and the current output terminal is connected to a control terminal of the transistor to stabilize the transistor.

Optionally, the current consuming electrical circuit comprises a zener diode connected between the current output terminal of the transistor and the control terminal of the transistor to stabilize the transistor.

Also optionally, the current consuming electrical circuit comprises a resistor connected between the control terminal of the transistor and the first interface terminal.

Also optionally, the current consuming electrical circuit comprises a resistor connected between the current input terminal of the transistor and the first interface terminal.

Also optionally, the current consuming electrical circuit comprises a resistor connected between the current output terminal and the second interface terminal.

Also optionally, the power supply device is designed to apply a DC supply voltage.

Also optionally, the DC supply voltage is higher than 60V, preferably higher than 300V.

Also optionally, the power supply device comprises one of: a battery charger and a battery.

Also optionally, the power receiving device includes one of: a battery, an inverter, and a DC-to-DC converter.

An electrical system according to the invention is also presented.

Throughout the foregoing text, the current consuming electrical circuit may be a passive circuit. The current-consuming electrical circuit may be supplied with electrical power exclusively via the two interface terminals, in particular by the capacitor to be discharged, when the power supply device is not operating. Furthermore, the electrical discharge circuit may be devoid of any computational component, that is to say of any component designed to run a computer program, such as a microcontroller or microprocessor.

It is also presented a method of discharging a capacitor having two terminals, comprising:

when connecting a power supply device to the terminals of the capacitor to apply a supply voltage across the terminals of the capacitor, a current consuming electrical circuit having two interface terminals respectively connected to the terminals of the capacitor consumes a current entering via the first interface terminal and exiting via the second interface terminal.

When the power supply device is no longer operating to no longer limit the capacitor voltage present across the terminals of the capacitor, the current-consuming electrical circuit consumes current to discharge the capacitor,

the method is characterized in that: the current consuming electrical circuit used in the previous step comprises a transistor arranged such that the consumed current enters via a current input terminal of the transistor and exits via a current output terminal of the transistor, and the current output terminal of the transistor is connected to a control terminal of the transistor to stabilize the transistor.

In a particular embodiment of the invention, the current consuming electrical circuit used in the steps of the above-mentioned discharging method further comprises a zener diode connected between the current output terminal of the transistor and the control terminal of the transistor to stabilize the transistor.

In another particular embodiment of the invention, the current consuming electrical circuit used in the steps of the above-mentioned discharging method further comprises a resistor connected between the current input terminal of the transistor and the first interface terminal.

Drawings

Fig. 1 is a circuit diagram of an electrical system including a current consuming electrical circuit for discharging a capacitor according to the present invention.

Fig. 2 is a timing chart showing changes over time in the capacitor voltage and the current into the current-consuming electrical circuit.

FIG. 3 is a diagram illustrating a motor vehicle including at least one electrical system such as that shown in FIG. 1.

Detailed Description

An electrical system 100 embodying the present invention will now be described with reference to fig. 1.

The electrical system 100 first comprises a circuit having two power supply terminals B_C、B_DIs designed to supply a supply voltage E across the two power supply terminals. For example, the supply voltage E is substantially constant. Further, in the described example, the power supply terminal B_DIs connected to the electrical ground of the electrical system 100 and is intended to have the power supply terminal B_CAt a positive potential of + E V.

The electrical system 100 further includes a power receiving device 104, and the power receiving device 104 is connected to the power supply terminal B_C、B_DAnd is designed to receive power supplied by the power supply apparatus 102.

The electrical system 100 further comprises a capacitor C having respective connection terminals B to the power supply terminals B_C、B_DTwo terminals B_E、B_FAnd is designed, for example, to smooth the supply voltage E. The capacitor C has across its terminals B equal to the supply voltage E of the power supply device 102 when in operation_E、B_FVoltage u of capacitor_C。

The electrical system 100 further comprises a current consuming electrical circuit 108, the current consuming electrical circuit 108 having terminals B connected to the capacitors C, respectively_E、B_FTwo interface terminals B_A、B_BTo receive the capacitor voltage u_C. The current consuming electrical circuit 108 is designed to consume current via the first interface terminal B_AInto and through the second interface terminal B_BThe exiting current.

When the power supply apparatus 102 is not operating, e.g. when it is disconnected, electricityThe current consuming electrical circuit 108 is particularly intended to discharge the capacitor C. For example, in FIG. 1, when the power is supplied to terminal B_C、B_DIs connected to the interface terminal B_A、B_BThis occurs when one of the connections of (1) is broken.

The current consuming electrical circuit 108 includes a transistor Q1, the transistor Q1 having a current input terminal C1, a current output terminal E1, and a control terminal B1. In the depicted example, the transistor Q1 is a bipolar transistor having a collector, an emitter, and a base corresponding to the current input terminal C1, the current output terminal E1, and the control terminal B1, respectively. The open or closed state of the transistor Q1 is defined by a control voltage V1 present between the control terminal B1 and the current output terminal E1. In addition, the current i flows through the transistor Q1 by entering through the current input terminal C1 and exiting through the current output terminal E1.

In the depicted example, the current consuming electrical circuit 108 further includes a current input terminal C1 and an interface terminal B connected thereto_AResistor R1 in between.

In the depicted example, the current consuming electrical circuit 108 further includes a current output terminal E1 connected to the interface terminal B_BResistor R2 in between.

In the depicted example, the current consuming electrical circuit 108 further includes a second terminal connected between the control terminal B1 and the interface terminal B_AResistor R4 in between.

In the depicted example, the current consuming electrical circuit 108 further includes a second terminal connected between the control terminal B1 and the interface terminal B_BZener diode D1 in between.

Therefore, the current output terminal E1 of the transistor Q1 is connected to the control terminal B1 of the transistor Q1 through the resistor R2 and the zener diode D1 to stabilize the transistor Q1.

The operation of the electrical system 100 will now be described with reference to fig. 2.

Initially, the power supply device 102 is operational and supplies a supply voltage E, which in the depicted example has a value of 500V. Usually, the supply voltage E is a "high voltage", which means that in the automotive field it has a value of more than 60V, preferably more than 300V.

Thus, the capacitor C is charged with the supply voltage E, so that the capacitor voltage u_CEqual to the supply voltage E.

The control terminal B1 of the transistor Q1 is charged through the resistor R4, so that the transistor Q1 is in a closed (conductive) state. Thus, a non-zero current i is from the interface terminal B_AFlows to interface terminal B through transistor Q1_B. Since the transistor Q1 is stable, the current i is substantially constant even in the event of fluctuations in the supply voltage E, and its value is 5mA in the example shown. In general, the current i preferably has a value greater than 1 mA.

At time t₀Here, the power supply device 102 is transitioned to the non-operating state, for example, by being disconnected from the rest of the electrical system 100.

Thus, the consumption of the current i causes the capacitor C to discharge and thus the capacitor voltage u_CAnd (4) descending. Since transistor Q1 is stable, the current i flowing through it is substantially constant (in practice, slightly decreasing), at a significantly higher level than if it were discharged into a simple resistor. In particular, in the latter case, the current will decrease exponentially, and therefore very quickly, at the first instant after the disconnection of the power supply device 102. Therefore, since the consumed current i is kept at a high level, close to at time t₀Previous level, capacitor voltage u_CAnd rapidly decreases.

Preferably, the components are selected so that the capacitor C is less than 60 seconds (time t in fig. 2)₁) Internal discharge to less than 60V.

Since the transistor Q1 is stable, the current consuming electrical circuit 108 can be calibrated to enable the current i (i.e., t when the power supply 102 is operating)₀Before) is smaller, no matter how smaller than when using a discharge resistor. Therefore, in the electrical system 100, the loss caused by the consumption of the current i when the power supply apparatus 102 operates is lower than when the resistor is used.

Furthermore, at time t₂When the capacitor voltage u is_CWhen it becomes too low to stabilize transistor Q1, current consuming device 108It will "collapse" (collapse), i.e. it is no longer able to keep the current i substantially constant, and the current will decrease very rapidly. Since the required discharge of the capacitor (u) has already been achieved_C<60V) so the collapse is insignificant.

Further, from the foregoing, it will be appreciated that the current consuming electrical circuit 108 is a passive circuit, meaning both: which is designed exclusively via two interface terminals B when the power supply device 102 is not operating_A、B_BSupplied power, specifically supplied through capacitor C; and it does not comprise any computing components, that is to say any components designed to run a computer program, such as a microcontroller or microprocessor.

An electric vehicle 300 will now be described with reference to fig. 3.

The electric vehicle 300 includes a charger 302, the charger 302 being designed to connect to a power grid and provide a DC voltage.

The electric vehicle 300 also includes a high-voltage battery 304 designed to be charged by a charger 302.

The electric vehicle 300 further includes a capacitor C1 interposed between the charger 302 and the high-voltage battery 304.

The electric vehicle 300 further includes an inverter 306, and the inverter 306 is designed to supply an AC voltage based on the DC voltage from the high-voltage battery 304.

The electric vehicle 300 further includes a capacitor C2 interposed between the high-voltage battery 304 and the inverter 306.

The electric vehicle 300 further includes an electric motor 308, and the electric motor 308 is designed to be supplied with electric power by the inverter 306 and to drive wheels of the electric vehicle 300.

The electric vehicle 300 further includes a DC-to-DC converter 310, the DC-to-DC converter 310 being designed to supply a low voltage based on a high voltage supplied by the high-voltage battery 304.

The electric vehicle 300 further includes a capacitor C3 interposed between the high voltage battery 304 and the DC-to-DC converter 310.

The electric vehicle 300 also includes a low-voltage battery 312 designed to be charged by the DC-to-DC converter 310. The low-voltage battery 312 is used, for example, to supply electric power to accessories of the electric vehicle 300.

The current consuming electrical circuit 108 described with reference to fig. 1 may be used for each of the capacitors C1, C2, C3. Thus, depending on the capacitors involved, the power supply device 102 therefore comprises one of the following: a charger 302 and a high voltage battery 304, and the power receiving device includes one of: a high voltage battery 304, an inverter 306, and a DC to DC converter 310.

The invention is not limited to the above-described embodiments but is defined by the appended claims. Indeed, it will be apparent to those skilled in the art that modifications may be made.

For example, one or the other of resistors R1 and R2 may be omitted.

In addition, the zener diode D1 may be replaced with a resistor.

Also, each of the one or more resistors R1, R2, and R4 is preferably a resistor having a resistance that changes little with temperature, for example 100 parts per million that changes by at most 1 ohm per degree celsius between 0 ℃ and 150 ℃.

Furthermore, the terms used in the claims should not be construed as being limited to the elements in the above-described embodiments, but should be construed to cover all equivalent elements that can be inferred from the common general knowledge of those skilled in the art.

Specifically, the term "electric vehicle" also covers the case of a hybrid vehicle that includes both an electric motor and an internal combustion engine for driving wheels.