Multi-voltage vehicle electric system

• US 6,351,104 B1
• Filed: 04/24/2000
• Issued: 02/26/2002
• Est. Priority Date: 08/27/1998
• Status: Expired due to Fees

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Geiger, Albert, Koelle, Gerhard
• Primary Examiner(s): Mullins, Burton S.
• Assistant Examiner(s): GONZALEZ, JULIO CESAR
• Application Number:
  US09/530,088
• Time in Patent Office: 673 Days
• Field of Search: 322/90, 322/28, 322/33, 322/29, 322/46, 322/94, 320/17
• US Class Current: 322/22
• CPC Class Codes: B60R 16/03 for supply of electrical power to vehicle subsystems or for circuit arrangements for charging batteries H02J7/00
• CPC Class Codes: H02J 2310/46 for ICE-powered road vehicles
• CPC Class Codes: H02J 7/1438 in combination with power supplies for loads other than batteries
• CPC Class Codes: H02P 2101/45 for motor vehicles, e.g. car alternators
• CPC Class Codes: H02P 9/307 more than one voltage output
• CPC Class Codes: H02P 9/48 Arrangements for obtaining a constant output value at varying speed of the generator, e.g. on vehicle H02P9/04 - H02P9/46 take precedence

Abstract

A multi-voltage electrical system for a vehicle is described, which includes a generator and a voltage regulator; the voltage regulator regulates the output voltage of the generator to predeterminable values by varying the exciter current. Connected downstream of the generator are two rectifier arrangements, which lead to a terminal (B1) and a terminal (B2), respectively. At least the rectifier arrangement leading to the terminal having the lower voltage is designed as a controllable rectifier and is triggered by the voltage regulator in such a way that the desired voltage (UB1+) occurs. The other rectifier arrangement leads to the terminal (B2+), at which a higher voltage occurs, by suitable regulation of the exciter current. The controllable rectifier arrangement preferably includes six MOS field effect transistors.

Claims

1. A multi-voltage electrical system for a vehicle, having a generator and a voltage regulator that regulates the output voltage of the generator to predeterminable values by varying the current flowing through the exciter winding, having at least two rectifier arrangements downstream of the generator, in which the first rectifier arrangement leads to a first terminal (B1+), at which a first direct voltage (UB1+) occurs, and the second rectifier arrangement leads to a second terminal (B2+), at which a second, higher direct voltage (UB2+) is located, the first direct voltage (UB1+) and the second direct voltage (UB2+) being regulatable independently from a rotary speed, and said first rectifier arrangement is constructed as a controllable rectifier with at least six controllable rectifier elements, and two at a time of these are in series with one another and are each connected between one phase winding and the terminal (B1+), and that the voltage regulator (13) triggers the regulating transistor (12) in such a way that an exciter current (IE) flows, which causes a higher voltage (of 36 or 42 V) to occur at the terminal (B2+), and that the regulator (13) simultaneously triggers the controllable rectifiers (14) in such a way that a lower voltage (of 12 V or 14 V) occurs at the terminal (B1+) the first direct voltage (UB1+) and the second direct voltage (UB2+) being regulatable independently from a rotary speed.

2. The multi-voltage electrical system of claim 1, characterized in that the controllable rectifier elements are MOS field effect transistors, which are each triggered by the voltage regulator (13).

3. The multi-voltage electrical system of claim 1, characterized in that the voltage regulator (13) triggers the regulating transistor (12) in such a way that an exciter current (IE) flows, which causes a voltage of 36 or 42 V to occur at the terminal (B2+), and that the regulator (13) simultaneously triggers the controllable rectifiers (14) in such a way that a voltage of 12 V or 14 V occurs at the terminal (B1+).

4. The multi-voltage electrical system of claim 1, characterized in that the rectifier elements of group (G3) each have one diode per phase winding of the generator, whose anode is connected to the respective phase winding and whose cathodes jointly cooperate with a field effect transistor, as a controllable actuator, connected in series with them.

5. The multi-voltage electrical system of claim 1, characterized in that the generator (10) is an electrical machine (10a), which can be operated as a motor or as a generator, and the motor operating mode is used to start an internal combustion engine and the generator operating mode occurs after starting of the engine, and both the motor operating mode and the generator operating mode are performed using controllable rectifier elements.

6. The multi-voltage electrical system of claim 5, characterized in that the rectifier elements (G3) each have one field effect transistor per phase winding;

that the anode of the parasitic diode of the field effect transistor is connected to the respective phase winding, and the cathodes of the parasitic diode cooperate jointly with a field effect transistor, as a controllable actuator, connected in series with them.

7. The multi-voltage electrical system of claim 1, characterized in that the supply to the voltage network (N1) and to the voltage network (N2) is adjustable independently of one another.

8. A multi-voltage electrical system for a vehicle, having a generator and a voltage regulator that regulates the output voltage of the generator to predeterminable values by varying the current flowing through the exciter winding, having at least two rectifier arrangements downstream of the generator, in which the first rectifier arrangement leads to a first terminal (B1+), at which a first direct voltage (UB1+) occurs, and the second rectifier arrangement leads to a second terminal (B2+), at which a second, higher direct voltage (UB2+) is located, characterized in that the first rectifier arrangement is constructed as a controllable rectifier with at least six controllable rectifier elements, and two at a time of these are in series with one another and are each connected between one phase winding and the terminal (B1+), a battery (37) can be connected to the terminal (B1+), and at least one 12 V electrical system consumer (36) can be incorporated via at one switch (35), and that at the terminal (B2+) via at least one switch (32), consumers (33) that have a power consumption can be incorporated, and optionally a further battery (34) can be connected to the terminal (B2+).

9. A multi-voltage electrical system for a vehicle, having a generator and a voltage regulator that regulates the output voltage of the generator to predeterminable values by varying the current flowing through the exciter winding, having at least two rectifier arrangements downstream of the generator, in which the first rectifier arrangement leads to a first terminal (B1+), at which a first direct voltage (UB1+) occurs, and the second rectifier arrangement leads to a second terminal (B2+), at which a second, higher direct voltage (UB2+) is located, characterized in that the first rectifier arrangement is constructed as a controllable rectifier with at least six controllable rectifier elements, and two at a time of these are in series with one another and are each connected between one phase winding and the terminal (B1+), the generator (10) is an electrical machine (10a), which can be operated as a motor or as a generator, and the motor operating mode is used to start an internal combustion engine and the generator operating mode occurs after starting of the engine, and both the motor operating mode and the generator operating mode are performed using controllable rectifier elements, and in the motor operating mode, the electrical machine (10a) operates as a synchronous or an asynchronous motor, and the group (G1) and the group (G2) of controllable rectifiers act as controllable inverters and supply the electrical machine with voltage from the battery (34).

10. A multi-voltage electrical system for a vehicle, having a generator and a voltage regulator that regulates the output voltage of the generator to predeterminable values by varying the current flowing through the exciter winding, having at least two rectifier arrangements downstream of the generator, in which the first rectifier arrangement leads to a first terminal (B1+), at which a first direct voltage (UB1+) occurs, and the second rectifier arrangement leads to a second terminal (B2+), at which a second, higher direct voltage (UB2+) is located, characterized in that the first rectifier arrangement is constructed as a controllable rectifier with at least six controllable rectifier elements, and two at a time of these are in series with one another and are each connected between one phase winding and the terminal (B1+), the generator (10) is an electrical machine (10a), which can be operated as a motor or as a generator, and the motor operating mode is used to start an internal combustion engine and the generator operating mode occurs after starting of the engine, and both the motor operating mode and the generator operating mode are performed using controllable rectifier elements, and in the mode of operation as a generator, the controllable rectifiers of groups (G1 and G2) are used for charging the network (N1), and the groups (G1 and G3) are used for charging the network (N2).

11. A multi-voltage electrical system for a vehicle, having a generator and a voltage regulator that regulates the output voltage of the generator to predeterminable values by varying the current flowing through the exciter winding, having at least two rectifier arrangements downstream of the generator, in which the first rectifier arrangement leads to a first terminal (B1+), at which a first direct voltage (UB1+) occurs, and the second rectifier arrangement leads to a second terminal (B2+), at which a second, higher direct voltage (UB2+) is located, characterized in that the first rectifier arrangement is constructed as a controllable rectifier with at least six controllable rectifier elements, and two at a time of these are in series with one another and are each connected between one phase winding and the terminal (B1+), and the regulator switches the controllable rectifiers of the group (G1, G2, G3) and the regulating transistor (12) for the excitation control of the generator in phase synchronism in such a way that the predetermined voltage values are established at the network (N1) and the network (N2) regardless of the applicable network load and the generator rpm.

12. A multi-voltage electrical system for a vehicle, having a generator and a voltage regulator that regulates the output voltage of the generator to predeterminable values by varying the current flowing through the exciter winding, having at least two rectifier arrangements downstream of the generator, in which the first rectifier arrangement leads to a first terminal (B1+), at which a first direct voltage (UB1+) occurs, and the second rectifier arrangement leads to a second terminal (B2+), at which a second, higher direct voltage (UB2+) is located, characterized in that the first rectifier arrangement is constructed as a controllable rectifier with at least six controllable rectifier elements, and two at a time of these are in series with one another and are each connected between one phase winding and the terminal (B1+), if the voltage network (1) is inadequately supplied despite maximum excitation of the generator, a clocked triggering of the rectifier elements acting on the network (N2) is done, and the energy stored as a result in the starter winding of the generator is fed into the network (N1).