Circuit arrangement for supplying a rotor winding of a separately excited synchronous machine and circuit arrangement

Abstract

The invention relates to a circuit arrangement (1) for powering a rotor winding (2) of a separately excited synchronous machine, comprising a bridge circuit having at least two active semiconductor switches (T1 to T4), wherein the rotor winding (2) and at least one inductance (4) connected in series with the rotor winding (2) are arranged in a bridge branch (3), wherein the inductance (4) is a primary inductance (5) of a transformer (6), wherein a secondary inductance (7) of the transformer (6) is connected to an input of a DC / DC converter (8), wherein a storage element (9) for a direct voltage is arranged at an output of the DC / DC converter (8).

Description

Technical Field

[0001] The present invention relates to a circuit device for supplying power to the rotor winding of a separately excited synchronous motor and a higher-level circuit device. Background Technology

[0002] A separately excited synchronous motor is used, for example, as a motor in the traction system of an electric vehicle. Here, the rotor windings are energized with direct current (DC). This DC current is generated by the voltage of a high-voltage battery using a bridge circuit. This bridge circuit can have four active semiconductor switches, which are controlled diagonally in a pulsed manner according to the desired current direction, thereby averaging the desired current intensity. If the current direction cannot be reversed through the rotor windings, two diagonally opposite semiconductor switches are sufficient; other components in the half-bridge can be diodes. Due to the clock control of the semiconductor switches, ripples are formed, which generate interference radiation. Here, the inductance of the rotor windings is frequency-dependent, and thus almost zero within a specific frequency range, so current variations can be very large. Therefore, it is known to connect an additional inductor in series with the rotor windings, which suppresses current variations. Such an additional inductor is relatively large and expensive. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to realize a circuit device for supplying power to the rotor windings of a separately excited synchronous motor, in which interference radiation is reduced. Another technical problem to be solved is to realize a higher-level circuit device having circuit devices for separately excited synchronous motors and circuit devices for low-voltage vehicle-mounted networks.

[0004] The solution to the above-mentioned technical problem is obtained through circuit devices having the features of the present invention. Other advantageous designs are obtained by the present invention.

[0005] The circuit arrangement for powering the rotor windings of a separately excited synchronous motor includes a bridge circuit with at least two active semiconductor switches, wherein the rotor windings and at least one inductor connected in series with the rotor windings are arranged in the bridge branch. Here, the inductor is configured as the primary inductance of a transformer, wherein the secondary inductance of the transformer is connected to the input of a DC / DC converter, wherein a storage element for DC voltage is arranged at the output of the DC / DC converter. This significantly attenuates ripple and stores the energy of the ripple as DC voltage, which can then be used to power electrical equipment. For example, this voltage can be used to power the DC / DC converter and / or as a redundant power source for other electrical equipment, as will be explained in more detail later. Another advantage is that the primary inductor can be configured to be smaller. Here, the transformer functions as an EMC (electromagnetic compatibility) filter. The storage element is, for example, a battery or a capacitor (e.g., configured as a supercapacitor). The DC / DC converter is, for example, a boost converter, a buck converter, a buck-boost converter, or a Sepic converter.

[0006] In another embodiment, a series circuit of at least one capacitor and at least one resistor is arranged at a center tap between the rotor winding and the inductor, wherein the center tap between the capacitor and the resistor is connected to the control input of the DC / DC converter. This series circuit is used to measure the AC voltage applied due to ripple. Thus, the DC / DC converter can be selectively switched on when the voltage is sufficiently high. Alternatively, a diode can be used, which then reaches its turn-on voltage due to the AC voltage. The aim is to switch the DC / DC converter only when the voltage at its input is sufficiently high, thereby reducing converter losses.

[0007] In another embodiment, the rotor winding is the primary inductance of a second transformer, and the secondary inductance of the second transformer is connected in series or parallel with the secondary inductance of the first transformer. Therefore, additional interference energy can be coupled out, increasing the current at the DC / DC converter in the parallel connection and increasing the voltage at the DC / DC converter in the series connection.

[0008] In another implementation, the secondary inductor is an unused stator winding of the synchronous motor, so no additional components are required.

[0009] Furthermore, a circuit arrangement including a circuit arrangement for a separately excited synchronous motor and a circuit arrangement for a low-voltage vehicle network is disclosed. The circuit arrangement for the separately excited synchronous motor has a circuit arrangement for the stator winding, a circuit arrangement for the rotor winding, and at least one control circuit. The circuit arrangement for the low-voltage vehicle network has at least one DC / DC converter and a control circuit. Here, the circuit arrangement for the rotor winding is constructed as described above, i.e., it has at least one transformer, a DC / DC converter, and a storage element.

[0010] In another embodiment, the storage element is a redundant power supply for the DC / DC converter and / or control circuitry of the circuitry used in the low-voltage vehicle network. Typically, the circuitry for the low-voltage vehicle network and the control circuitry for the separately excited synchronous motor are located on separate circuit boards, thereby providing redundant voltage supply across the circuit boards.

[0011] In another embodiment, the storage element also serves as a redundant power supply for the control circuitry of a separately excited synchronous motor.

[0012] In another embodiment, the circuit devices are arranged in a common housing, thereby enabling very short connection paths and, in particular, reducing the risk of disconnection between different circuit devices.

[0013] In another embodiment, the DC / DC converter of the circuitry for a low-voltage vehicle network has an output connector for a low-voltage storage unit, which serves as a power source for the control circuitry. Here, the low-voltage storage unit can be, for example, a 12V, 24V, 36V, or 48V battery or capacitor. The low-voltage storage unit can be mounted externally to shorten the connection path.

[0014] This invention is preferably used in the traction network of electric vehicles. Attached Figure Description

[0015] The present invention will now be described in more detail with reference to preferred embodiments. In the accompanying drawings:

[0016] Figure 1 A schematic circuit arrangement for supplying power to the rotor windings of a separately excited synchronous motor is shown, and

[0017] Figure 2 The diagram illustrates schematic circuitry including circuitry for separately excited synchronous motors and circuitry for low-voltage on-board networks. Detailed Implementation

[0018] exist Figure 1The diagram shows a circuit arrangement 1 for supplying power to the rotor winding 2 of a separately excited synchronous motor (not shown). This circuit arrangement 1 has a bridge circuit with four active semiconductor switches T1 to T4, wherein the rotor winding 2 and at least one inductor 4 connected in series with the rotor winding 2 are arranged in a bridge branch 3. In the example shown, the semiconductor switches T1 to T4 are configured as bipolar transistors, which has advantages in terms of cutoff characteristics. However, other semiconductor switches, such as GaN HEMTs, MOSFETs, or IGBTs, can also be used in principle, as long as the cutoff capability is guaranteed. The bridge circuit is connected to the positive potential HV+ and the negative potential HV- of the traction voltage. To energize the rotor winding 2 with a desired magnitude of DC current, the diagonally opposite semiconductor switches (e.g., T1 and T4 or T2 and T3) are controlled in a pulsed manner, wherein the other semiconductor switches are turned off. By selecting the semiconductor switches T1, T4 or T2, T3 controlled in a pulsed manner, the direction of the current in the rotor winding 2 can be changed. If this is not necessary, passive diodes can be used instead of two diagonally opposite semiconductor switches (e.g., T2, T3). Here, inductor 4 is used to dampen ripple caused by pulses. Inductor 4 is the primary inductor 5 of transformer 6, where the secondary inductor 7 of transformer 6 is connected to the input of DC / DC converter 8. A storage element 9 for DC voltage is arranged at the output of DC / DC converter 8. A series circuit of at least one capacitor C and at least one resistor R is arranged at the center tap 10 between rotor winding 2 and inductor 4, where the center tap 11 between capacitor C and resistor R is connected to the control input 12 of DC / DC converter 8. This capacitively couples the AC voltage generated by ripple to the output. DC / DC converter 8 can be turned on when the voltage is sufficiently high (e.g., greater than 1 V). This avoids the high conversion losses that would occur when DC / DC converter 8 must boost a very small voltage to, for example, 12 V. Here, storage element 9 can also provide the supply voltage for DC / DC converter 8 and serves as a redundant voltage source for other electrical devices. By coupling the interference energy in the ripple to the output in an inductive manner, the DC current is largely smoothed, thus transformer 6 functions as an EMC filter, converting the interference energy into a DC voltage and utilizing it effectively. If the circuit arrangement 1 also has a separate EMC filter, the size of that separate EMC filter can be designed to be smaller (or, in extreme cases, omitted entirely). The rotor winding 2 is also shown as the primary inductor 13 of another transformer 14, whose secondary inductor 15 is connected in parallel with the secondary inductor 7 of the first transformer 6. This second transformer 14 further couples more interference energy from the ripple to the output. Secondary inductors 7 and 15 can also be connected in series.

[0019] exist Figure 2 The diagram schematically illustrates a circuit device 20, which includes a circuit device 21 for a separately excited synchronous motor and a circuit device 22 for a low-voltage on-board network. Circuit devices 21 and 22 are respectively arranged on circuit boards 23 and 24 and housed in a common housing 25. The circuit device 21 for the separately excited synchronous motor includes a circuit device 26 for the stator winding and a circuit device 1 for the rotor winding 2 (see [reference]). Figure 1 The circuit device 22 for a low-voltage vehicle network includes at least one galvanically isolated DC / DC converter 29, an auxiliary DC / DC converter 30, and a control circuit 31. The auxiliary DC / DC converter 30 can also be integrated into the DC / DC converter 29, allowing voltage to be directly extracted from the output of the DC / DC converter 29 to power the electrical equipment. Here, the output terminal 32 of the DC / DC converter 29 is connected to a storage unit 33, which provides the voltage. The auxiliary DC / DC converter 30 provides voltage. And the storage element 9 of circuit device 1 provides voltage (See) Figure 1 The main power supply for control circuits 27 and 31 is voltage. Among them, voltage This is a redundant power supply for control circuit 31 and auxiliary DC / DC converter 30. The redundant power supply for control circuit 27 is a voltage... This is so that circuit device 21 can be activated in the event of a failure in storage unit 33. In principle... It can also be used as an additional redundant power supply for control circuit 27.

[0020] List of reference numerals

[0021] 1) Circuit device

[0022] 2) Rotor winding

[0023] 3) Bridge Branch Road

[0024] 4) Inductance

[0025] 5) Primary inductor

[0026] 6) Transformer

[0027] 7) Secondary inductor

[0028] 8) DC / DC converter

[0029] 9) Storage elements

[0030] 10) Center tap

[0031] 11) Center tap

[0032] 12) Control input terminal

[0033] 13) Primary inductor

[0034] 14) Transformer

[0035] 15) Secondary inductor

[0036] 20) Circuit device

[0037] 21) Circuit device

[0038] 22) Circuit device

[0039] 23) Circuit board

[0040] 24) Circuit board

[0041] 25) Common shell

[0042] 26) Circuit device

[0043] 27) Control circuit

[0044] 29) DC / DC converter

[0045] 30) Auxiliary DC / DC converter

[0046] 31) Control circuit

[0047] 32) Output connector

[0048] 33) Storage unit

[0049] C) Capacitors

[0050] HV+) positive potential

[0051] HV-) negative potential

[0052] R) Resistance

[0053] T1 to T4) Semiconductor switches

[0054] )Voltage

[0055] )Voltage

[0056] )Voltage

Claims

1. A circuit arrangement (1) for supplying power to the rotor winding (2) of a separately excited synchronous motor, the circuit arrangement comprising a bridge circuit having at least two active semiconductor switches (T1 to T4), wherein, The rotor winding (2) and at least one inductor (4) connected in series with the rotor winding (2) are arranged in the bridge branch (3), characterized in that, The inductor (4) is the primary inductor (5) of the transformer (6), wherein the secondary inductor (7) of the transformer (6) is connected to the input terminal of the DC / DC converter (8), wherein a storage element (9) for DC voltage is arranged at the output terminal of the DC / DC converter (8).

2. The circuit device according to claim 1, characterized in that, A series circuit of at least one capacitor (C) and at least one resistor (R) is arranged at the intermediate tap (10) between the rotor winding (2) and the inductor (4), wherein the intermediate tap (11) between the capacitor (C) and the resistor (R) is connected to the control input terminal (12) of the DC / DC converter (8).

3. The circuit device according to any one of the preceding claims, characterized in that, The rotor winding (2) is the primary inductance (13) of the second transformer (14), and the secondary inductance (15) of the second transformer is connected in series or in parallel with the secondary inductance (7).

4. The circuit device according to claim 3, characterized in that, The second-stage inductor (15) is an unused stator winding of the synchronous motor.

5. A circuit device (20) comprising a circuit arrangement (21) for a separately excited synchronous motor and a circuit arrangement (22) for a low-voltage vehicle network, wherein, The circuit arrangement (21) for the separately excited synchronous motor has a circuit arrangement (26) for the stator winding, a circuit arrangement (1) for the rotor winding (2), and at least one control circuit (27), and the circuit arrangement (22) for the low-voltage vehicle network has at least one DC / DC converter (29) and a control circuit (31), characterized in that, The circuit device (1) for the rotor winding (2) is constructed according to any one of claims 1 to 4.

6. The circuit device according to claim 5, characterized in that, The storage element (9) is a redundant power supply for the DC / DC converter (29) and / or control circuit (31) used in low-voltage vehicle networks.

7. The circuit device according to claim 5 or 6, characterized in that, The storage element (9) is a redundant power supply for the control circuit (2) of the separately excited synchronous motor.

8. The circuit device according to any one of claims 5 to 7, characterized in that, The circuit device (20) is arranged in the housing (25).

9. The circuit device according to any one of claims 5 to 8, characterized in that, The DC / DC converter (29) has an output connector (32) for a low-voltage storage unit (33), wherein the low-voltage storage unit (33) is a power supply for the control circuits (27, 31).

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