CN116073427A - Additional circuit for a voltage-regulating circuit arrangement, voltage regulator and method for operating a generator unit - Google Patents

Abstract

The invention relates to an additional circuit (26) for use with a voltage regulation circuit arrangement (22) provided for operating a generator unit, the generator unit having an electrical machine with a rotor winding (16) and a stator winding (12) and a rectifier (14) connected to the machine, the electrical machine being connectable to a vehicle electrical system (10) via the rectifier, wherein the additional circuit (26) has a first connection, a second connection and a third connection, wherein the first connection is to be connected to a control connection (22 d) of the voltage regulation circuit arrangement (22), wherein the second connection serves as a new control connection, and wherein the third connection is to be connected to a positive supply voltage connection (20 e, 22e, b+), wherein the control connection (22 d) inside the voltage regulation circuit arrangement (22) is connectable to and separable from the positive supply voltage connection (20 e, 22e, b+), and wherein the additional circuit (26) is provided for limiting the electrical potential at the first connection (26 a) to a maximum value at a maximum limit value, which is smaller than a preset threshold value at the third connection (26 c+). The invention also relates to a voltage regulator (20), a method for operating a generator unit, a device having a generator unit, and an on-board electrical system.

Description

Additional circuit for a voltage-regulating circuit arrangement, voltage regulator and method for operating a generator unit

Technical Field

The invention relates to an additional circuit for use with a voltage regulation circuit arrangement, to a voltage regulator having a voltage regulation circuit arrangement and having such an additional circuit, to a device having a generator unit and having such a voltage regulator, to an on-board electrical system having such a device, in particular of a vehicle, and to a method for operating a generator unit, wherein the voltage regulation circuit arrangement is provided for operating the generator unit.

Background

Electrical machines, in particular generators, can be used in motor vehicles to convert mechanical energy into electrical energy. For this purpose, claw pole generators are generally used, which are mostly equipped with an electrical excitation device. Since such generators produce alternating current, which is mostly three-phase, rectification is required for the usual direct-current on-board electrical system of the motor vehicle. For this purpose, rectifiers based on semiconductor diodes or semiconductor switches may be used.

In addition, for regulating the on-board voltage, the excitation current flowing through the rotor winding of the generator can be controlled or regulated, i.e. the adjustment parameter for voltage regulation in a motor vehicle generator is the excitation current, i.e. the current flowing through the rotor winding of the generator and generating the excitation field. This is usually achieved by means of a switching unit of the voltage regulator (field regulator), which may comprise, for example, at least one switching transistor. The switching unit may switch on and off the exciting current. Further, the exciting current or exciting current/beat ratio may be changed so that the output voltage of the generator is adjusted to a desired value.

Disclosure of Invention

According to the invention, an additional circuit for use with a voltage regulation circuit arrangement provided for operating a generator unit, a voltage regulator having a voltage regulation circuit arrangement and such an additional circuit, a device having a generator unit and such a voltage regulator, an on-board electrical system, in particular a vehicle on-board electrical system, having such a device, and a method for operating a generator unit are proposed with the features of the independent claims. Advantageous embodiments are the subject matter of the dependent claims and the following description.

The present invention relates generally to the operation of a generator unit having an electrical machine with a rotor winding and a stator winding and a rectifier connected to the machine, by means of which the electrical machine is connectable to a (direct current) on-board electrical network. The voltage regulator (or generator regulator) regulates the voltage by the excitation current flowing through the rotor windings, thereby operating the generator unit. For this purpose, voltage regulators generally have a regulating circuit arrangement, which may be implemented, for example, as an application specific integrated circuit ASIC (english: application Specific Integrated Circuit), for example as a chip. There are provided semiconductor switches, such as MOSFETs or transistors, or other switching elements which can switch the excitation current on and off.

Such voltage regulators or regulating circuit arrangements generally have a connection for a light source or lamp (load indicator lamp). In the simplest case, this may be a positive generator output (e.g., referred to as b+ or d+). However, for providing further functions, a control connection (in particular a connection) can also be provided, which is connectable to and disconnectable from a positive supply voltage in the regulator, in particular via a semiconductor switch, and/or is connectable to and disconnectable from a ground, in particular via a semiconductor switch. In an advantageous embodiment, the control connection can be connected alternately to the positive supply voltage or to ground (for example, referred to by the applicant as connection "L") via a corresponding semiconductor switch. Depending on the operating state of the regulator or the generator and the on-board electrical system, such a control connection "L" controls the display element via a so-called lamp output stage (ground direction) when a fault is found, or controls the switching on of the load via a so-called relay output stage (b+ direction) during fault-free generator operation. Depending on the manner of operation, current flows into or out of the regulator through the control connection "L". However, excessive currents can damage or even destroy the associated output stage and thus lead to damage or even destroy the regulator.

This potentially damaging current occurs in particular when the potential applied at the control connection is greater than the potential applied at the positive supply voltage connection (i.e. b+) of the voltage regulator or regulation circuit arrangement. This situation arises, for example, when a significantly lower voltage is applied at the positive supply voltage connection of the voltage regulator than at the control connection by a starting procedure, for example when the starter is arranged in the vicinity of the generator and the electrical leads between the relevant positive supply connections are short.

Against this background, an additional circuit for protecting control connections is proposed with three connections, which in particular limits (also) the potential at a first one of the three connections to be connected to the control connection to a maximum limit value when a potential above a limit value is applied at a second one of the three connections serving as a new control connection. In this case, the limit value is smaller than the potential at the third connection to be connected to the positive supply voltage connection of the voltage regulation circuit or the generator unit by a predetermined threshold value (which may be very small, for example, also 0V or approximately 0V, or may also be, for example, 0.5V, 1V or 2V). In this case, too high a current is therefore prevented from flowing from the outside into the control connection of the regulating circuit (as will be explained further below, in the opposite direction, if necessary, current is still possible to flow). However, in any event, a conductive connection may still exist between the second connection terminal and the first connection terminal.

In particular, voltage regulators having a regulating circuit arrangement always have a further or external control connection, which is connected inside the voltage regulator to a control connection (for example, referred to as pin L) of the regulating circuit arrangement (i.e., for example, ASIC). The second connection may then be connected to this additional or external control connection (e.g., referred to as terminal L-terminal) of the voltage regulator (i.e., the entire component). In other words, the additional circuit is then connected with the first connection and the second connection between the two terminal L connections of the regulating circuit arrangement and the voltage regulator (otherwise these terminal L connections are for example only simply electrically conductively connected).

The third connection of the additional circuit is connected to the positive supply voltage connection, more precisely in particular to the positive supply voltage connection of the voltage regulator or the regulating circuit arrangement. Here, two connection terminals can also be present, but are usually connected electrically conductively inside, so that they do not depend on the exact location of the connection of the third connection terminal. In any case, it is important that the supply voltage applied at the voltage regulator is applied at the third connection.

Voltage regulators typically include a circuit board or the like upon which regulating circuitry and other components are built. The additional circuit can also be simply supplemented there; the second connection of the additional circuit then forms a "new" control connection of the voltage regulator.

The additional circuit preferably has a current control element which is provided to limit the potential at the first connection to a limit value, in particular (also) when the potential at the second connection is higher than the limit value or higher than the potential at the third connection. As the current control element, in particular, a semiconductor element such as a MOSFET is considered. Particularly suitable are n-channel MOSFETs, preferably self-closing (or normally-closed). In principle, however, other semiconductors (in particular so-called quadrupoles) such as FETs, IGBTs or other transistors are also possible, provided that a potential-dependent current control function is achieved. The current control element controls the current between the first current connection and the second current connection in particular in dependence on the potential at the control connection of the current control element. For better readability, the mentioned connections are described below by means of MOSFETs and are referred to as gate, source and drain.

The gate connection (or generally the control connection) of the current control element is then preferably connected to the third connection via a resistor. In addition, the source terminal (or generally the first current terminal) of the current control element is preferably connected to the first terminal, and the drain terminal (or generally the second current terminal) is connected to the second terminal.

In this way, no higher voltage occurs at the control connection of the regulating circuit arrangement than at the positive power connection of the regulating circuit arrangement, and thus no current can flow from the control connection into the regulating circuit arrangement and to the positive power connection of the regulating circuit arrangement.

When the potential at the gate connection is higher than at the source connection (to be precise, usually higher than the settable threshold voltage U if necessary) _GS(th) In particular, the threshold value mentioned is referred to here, by which the boundary value is defined), i.e. U _GS >U _GS(th) The current control element is normally on. However, when the potential at the positive supply connection of the voltage regulator or voltage regulating circuit drops or falls, but the potential at the second connection or at the new control connection does not drop (or when the potential at the second connection goes high but the potential at the positive supply connection does not), then the current control element changes to a voltage following mode. The current control element adjusts (in the ohmic range) the difference between the source connection and the gate connection (just the threshold voltage U _GS(th) ) The method comprises the steps of carrying out a first treatment on the surface of the If the voltage at the source connection drops, the difference from the gate connection increases and the gate opens more; the source voltage thus rises again and the gate is then closed again more. These states then alternate continuously. However, the current control element is never fully closed or blocked, and the voltage at the source connection is maintained. Thus, the control of the voltage regulating circuit mechanism is not performedOvercurrent occurs in the system connection terminal (first connection terminal, source electrode).

Furthermore, the gate connection may be connected to the third connection via a zener diode (in addition to the resistances already mentioned); this causes a reduction in the quiescent current requirement. Furthermore, the gate connection may be connected to ground (or ground connection) by a (further) zener diode. This protects the gate connection of the current control element from excessive voltages.

A diode, in particular a schottky diode, is preferably arranged in the conducting direction between the first connection and the second connection and in parallel with the current control element. The function of the relay output stage described above can thus be supported, i.e. the control connection within the voltage regulation circuit arrangement is connectable to and disconnectable from the positive supply voltage connection, i.e. current flows from the control connection. Depending on the type of current control element or semiconductor element, its body diode may also be sufficient to generate a sufficiently high current (e.g. for activating a relay).

Other advantages and design aspects of the invention will be apparent from the description and drawings.

The invention is schematically illustrated by means of embodiments in the drawings and is described below with reference to the drawings.

Drawings

Fig. 1 shows a circuit diagram of an on-board electrical system with a voltage regulator according to a preferred embodiment of the invention.

Fig. 2 shows an additional circuit according to a preferred embodiment of the invention.

Fig. 3 shows an additional circuit according to another preferred embodiment of the invention.

Detailed Description

Fig. 1 shows a circuit diagram of an on-board electrical system 10, in particular of a (motor) vehicle, having a voltage source 11 and a load or battery 1.

The voltage source 11 has an electrical machine or generator with a stator with stator windings 12, a rectifier 14 connected downstream of the stator, a rotor with rotor windings 16, which in particular can be driven by a motor or an internal combustion engine of the vehicle, and a voltage regulator 20 (also referred to as a field regulator) according to the invention, which serves for presetting the excitation current through the rotor windings 16 or for regulating the generator voltage. The voltage regulator 20 is used to regulate the generator voltage between the connection b+ and the ground GND to a set value, for example to approximately 14V-15V in the case of a so-called 12V on-board electrical system having a nominal voltage of 12V. The generator voltage is thus the rectified output voltage of the generator or the vehicle electrical system voltage.

The voltage regulator 20 has a preferred embodiment of the actual regulating circuit arrangement 22, which can be embodied, for example, as an application-specific integrated circuit ASIC (english Application Specific Integrated Circuit), in particular as a chip (for example also programmable), and of an additional circuit 26 according to the invention, which is described in more detail with reference to fig. 2 and 3. The voltage regulator 20 and the regulating circuit means 22 are each indicated by a surrounding dashed line. The additional circuit 26 can be formed, for example, on an additional circuit board, the connection ends of the control chip and the additional circuit being electrically connected, for example, by means of a stamped grid. Additional circuit boards or additional circuits may also provide additional functions, such as protecting the regulator chip from external overvoltages.

The regulating circuit 22 has a switch 22b, for example a semiconductor switch, such as a MOSFET, an IGBT or a thyristor, by means of which switch 22b the current flowing through the rotor winding 16 can be switched on, and the regulating circuit 22 also has a diode 22a for free flow of the excitation current. The diode 22a may also be configured as a semiconductor switch. The voltage regulator 20 is connected to the rotor winding 16 via a connection 16 a. Instead of being directly connected to the ground GND as described above, the rotor winding 16 may also be connected to the voltage regulator 20 via a further connection and be grounded there. It is emphasized that the rotor windings are arranged on the rotor of the electrical machine and not inside the voltage regulator 20.

The regulator circuit 22 further has a phase input connection 22c and a control connection 22d.

Furthermore, a control circuit 24 (logic circuit) is provided for the switch 22b, by means of which, for example, a gate voltage can be applied in order to close the switch 22b or to switch it on and to open it or to switch it off. Further, the control circuit 24 is (indirectly) connected to the connection terminals b+ and GND. The connection to connection b+ is effected via positive supply voltage connection 22e of regulation circuit 22 or positive supply voltage connection 20e of voltage regulator 20. The two connection terminals 22c, 22d are likewise led to the control circuit 24.

The control circuit 24 itself may in turn comprise the necessary switching elements, for example switching elements (e.g. MOSFETs or other transistors) 24a, 24b for providing the function of the control connection 22d, which switching elements are shown in an enlarged view of the control circuit 24. These switching elements may be controlled by a logic circuit 24c (with a driver), and the logic circuit 24c may also control the switch 22b. The switching element 24a serves as a so-called relay output stage for connecting the control connection 22d inside the voltage regulating circuit 22 to the positive supply voltage connection 22 or for separating it from it. The switching element 24b serves as a so-called lamp output stage for connecting the control connection 22d inside the voltage regulating circuit 22 to or separating it from the negative supply voltage connection (ground GND). The switching elements are normally always on in opposite directions, i.e. one switching element is open and the other switching element is closed.

Furthermore, a phase or phase winding V (here one of the three phases of the stator winding) is connected to the connection 20c of the voltage regulator 20 and then to the phase input connection 22c of the regulating circuit means 22; thereby, the phase voltage signal of the phase V can be supplied to the control circuit 24.

The control connection 22d is connected via an additional circuit 26 and a control connection 20d at the voltage regulator to the lamp 3 (load indicator lamp) and to the ignition switch 2 (so-called terminal 15) or to the relay 4. The function of which is known and not described here.

Furthermore, a starter 18 is provided, which serves to start the internal combustion engine. The starter 18 and its connection (not mentioned here) to the on-board electrical system or to the connection b+ are thus located, for example, in the vicinity of a supply voltage connection 20e of the voltage regulator 20. During start-up, a large current is typically required in the starter 18; this can lead to a drop or drop in the voltage or potential at the starter 18 and thus in particular also at the supply voltage connection 20e of the voltage regulator 20. This results in a higher voltage or higher potential being applied at the control connection ( connection 22d or 20 d) than at the supply voltage connection 20e (or 22 e). This may, for example, result in a high current flowing through the switch 24a (or its body diode) and damage the switch.

In fig. 2, an additional circuit 26 according to a preferred embodiment of the invention is shown, more precisely with specific (electronic) components and their interconnections. The additional circuit 26 may in particular be of the type in fig. 1, which is only shown here as block 26.

The additional circuit 26 has a first connection 26a, a second connection 26b, and a third connection 26c. The possible ground-connection terminals are not explicitly mentioned. The first connection 26a is connected to the control connection 22d of the regulator circuit mechanism 22, the second connection 26b is connected to the control connection 20d of the voltage regulator 20, and the third connection 26c is connected to the positive power supply connection 22e of the regulator circuit mechanism 22 or the positive power supply connection 20e of the voltage regulator 20 (as can be seen in fig. 1, both positive power supply connections are identical).

The additional circuit 26 also has a current control element 30 in the form of a self-closing n-channel MOSFET, which in turn has a gate connection 31, a source connection 32 and a drain connection 33. The gate connection 31 is connected via a resistor 40 and a zener diode 37 to the third connection 26b and thus to the positive supply voltage connection 22e of the regulating circuit arrangement, the source connection 32 to the first connection 26a and thus to the control connection 22d of the regulating circuit arrangement, and the drain connection 33 to the second connection 26b and thus to the control connection 20d of the voltage regulator (the lamp or relay is in turn connected to this control connection 20 d). In addition, the gate connection 31 is grounded via a (further) zener diode 38.

In normal operation, the potential at the positive power supply connection 22e and the control connection 20d of the voltage regulator (and thus at the second connection 26b and the third connection 26 c) is typically at least substantially the same. A certain voltage drop of, for example, approximately 1V to 2V occurs by the control circuit 22 or the control circuit 24 there, so that the potential at the control connection 22d of the control circuit 22 and thus at the first connection 26b is correspondingly smaller. Also, there will be some voltage drop across the current control element 30. Accordingly, a corresponding voltage or potential difference exists between the third connection terminal 26c and the first connection terminal 26a and thus between the gate connection terminal 31 and the source connection terminal 32, which voltage or potential difference causes the current control element 30 to conduct.

If the potential at the positive supply connection 22e (and at the third connection 26c and the gate connection 31) is now reduced, for example by a high current consumption in the starter, but the potential at the control connection 20d (and at the second connection 26b and the drain connection 33) of the voltage regulator 20 is not or does not drop drastically, the gate-source-voltage U _GS Down to the threshold value U _GS(th) The following and the current control element 30 is turned off. Then, the gate-source-voltage rises slightly again, so that the current control element 30 is closed; the above-described regulation mode of alternating opening and closing is achieved. Thereby, the adjusting circuit mechanism 22 is protected.

Furthermore, a diode 35, which is configured as a schottky diode, is arranged in the conducting direction between the first connection terminal 26a (and the source connection terminal 32) and the second connection terminal 26b (and the drain connection terminal 33) and in parallel to the current control element 30. This supports the function of the relay output stage 24a and allows, for example, the relay 4 to be activated via the control connection 22d, even if the current control element 30 should not allow a high current.

The proposed additional circuit 26 thus protects the control connection of the regulating circuit arrangement 22 from a relative overvoltage between the control connection itself of the regulating circuit arrangement 22 and the positive supply voltage connection. Thus, no higher voltage occurs at the control connection of the regulating circuit arrangement than at the positive supply voltage connection of the regulating circuit arrangement. Overload of the regulating circuit means (which may be configured as a chip, for example) due to undesired reverse currents is avoided.

Fig. 3 shows an additional circuit 26 according to a further preferred embodiment of the invention, which is to be precise also with specific (electronic) components and their interconnection. The additional circuit 26 may be in particular those of fig. 1 or 2, but is supplemented by further electronic components, such as diodes (zener diodes), capacitors, resistors and fuses, which are not explicitly labeled here and are used for EMV purposes (EMV stands for electromagnetic compatibility).

These further electronic components have no significant influence on the operation of the remaining circuits, so that for their description reference can be made to fig. 2 and the description thereof, which correspondingly apply here.

Claims (14)

1. An additional circuit (26) for use with a voltage regulating circuit arrangement (22), the voltage regulating circuit arrangement (22) being arranged for operating a generator unit having an electrical machine with a rotor winding (16) and a stator winding (12) and a rectifier (14) connected to the machine, the electrical machine being connectable to an on-board electrical network (10) through the rectifier,

wherein the additional circuit (26) has a first connection (26 a), a second connection (26B) and a third connection (26 c), wherein the first connection (26 a) is to be connected to a control connection (22 d) of the voltage regulation circuit (22), wherein the second connection (26B) serves as a new control connection, and wherein the third connection (26 c) is to be connected to a positive supply voltage connection (20 e, 22e, b+), and

wherein a control connection (22 d) inside the voltage regulation circuit (22) is connectable to and separable from the positive supply voltage connection (20 e, 22e, B+),

wherein the additional circuit (26) is arranged for limiting the potential at the first connection (26 a) to a maximum limit value, which is smaller than the potential at the third connection (26 c) by a preset threshold value.

2. Additional circuit (26) according to claim 1, comprising a current control element between the first connection (26 a) and the second connection (26 b), the current control element being arranged to limit the potential at the second connection (26 b) to a limit value, in particular when the potential applied at the second connection (26 b) is higher than the limit value or higher than the potential at the third connection (26 c).

3. Additional circuit (26) according to claim 2, wherein the current control element (30) is configured as a semiconductor element having a gate connection (31), wherein the gate connection (31) is connected to the third connection (26 c), in particular via a resistor (40).

4. An additional circuit (26) according to claim 3, wherein the source connection (32) of the current control element is connected to the first connection (26 a), and wherein the drain connection (33) of the current control element is connected to the second connection (26 b).

5. Additional circuit (26) according to claim 3 or 4, wherein the current control element (30) is configured as a self-closing, in particular as an n-channel MOSFET.

6. Additional circuit (26) according to any one of claims 3 to 5, wherein the gate connection (31) is connected to the third connection (26 c) by a zener diode (37), and/or wherein the gate connection (31) is connected to ground by a zener diode (38).

7. Additional circuit (26) according to any one of claims 2 to 6, comprising a diode (35), in particular a schottky diode, which is arranged in the conducting direction between the first connection (26 a) and the second connection (26 b) and in parallel with the current control element (30).

8. An additional circuit (26) according to any of the preceding claims, wherein the third connection (26 c) is to be connected to a positive power supply connection (20 e) of the voltage regulating circuit arrangement (22).

9. A voltage regulator (20) for operating a generator unit having an electrical machine with a rotor winding (16) and a stator winding (12) and a rectifier (14) connected to the machine, the electrical machine being connected to an on-board electrical system (10) via the rectifier,

the voltage regulator (20) comprising a voltage regulating circuit arrangement (22) having a control connection (22 d) and an additional circuit (26) according to any of the preceding claims,

wherein the control connection (22 d) inside the voltage regulating circuit (22) is connectable to and separable from the positive supply voltage connection (20 e, 22e, b+).

10. The voltage regulator (20) of claim 9, wherein the control connection (22 d) internal to the voltage regulating circuit means (22) is connectable to and separable from the negative supply voltage connection.

11. A method for operating a generator unit with an electrical machine having a rotor winding (16) and a stator winding (12) and a rectifier (14) connected to the machine, by means of which the electrical machine is connectable to an on-board electrical system (10), using a voltage regulator (20) having a voltage regulation circuit arrangement (22),

wherein the potential at the control connection (22 d) of the voltage regulating circuit (22) is limited to a maximum limit value, which is smaller than the potential at the positive supply connection (20 e) of the voltage regulator (20) by a predetermined threshold value, wherein the control connection (22 d) inside the voltage regulating circuit (22) is connectable to and separable from the positive supply voltage connection (20 e, 22e, b+).

12. The method according to claim 11, wherein a voltage regulator (20) according to claim 9 or 10 is used.

13. An arrangement with a generator unit and a voltage regulator (20) according to claim 9 or 10, the generator unit having an electrical machine with a rotor winding (16) and a stator winding (12) and a rectifier (14) connected to the machine, the electrical machine being connectable to an on-board electrical network (10) through the rectifier.

14. An on-board electrical system (10) having a voltage source (11) and at least one load (1), wherein the voltage source (11) has a device according to claim 13.

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