DE102019001138A1 - Method for charging a battery of a vehicle electrical system and on-board charger for this purpose - Google Patents

Abstract

The invention relates to a method for charging a battery (2) of an electrical system (3), wherein a three-phase AC voltage is provided, and the three-phase AC voltage by means of a rectifier (6) is converted into a DC voltage, and the DC voltage by means of a first DC voltage converter (4 ) and a second DC voltage converter (5) for the battery (2), wherein the first DC voltage converter (4) with the first bridge circuit (B1) with the DC voltage and the second DC voltage converter (5) with the second bridge circuit (B2) with the DC voltage is supplied, and wherein the first DC voltage converter (4) and the second DC voltage energy converter (5) provide the DC voltage to the electrical system (3) without a functionality of a power factor correction filter. Furthermore, the invention relates to a on-board charger (1) for charging a battery (2) of a vehicle electrical system (3).

Description

The invention relates to a method for charging a battery of a vehicle electrical system, wherein a single-phase AC voltage is provided and the single-phase AC voltage is converted by means of a rectifier into a DC voltage and wherein the DC voltage is provided by means of a first DC voltage converter and / or a second DC voltage converter for the battery. Furthermore, the invention relates to a method for charging a battery of a vehicle electrical system, wherein a three-phase AC voltage is provided and the three-phase AC voltage is converted by means of a rectifier into a DC voltage and wherein the DC voltage provided by a first DC voltage converter and / or a second DC voltage converter for the battery becomes. Furthermore, the invention relates to an on-board charger for charging a battery of a vehicle electrical system with a rectifier, with at least two DC voltage converters, with two switches, with a capacitor and with a PFC throttle. Furthermore, the invention relates to an on-board charger for charging a battery of a vehicle electrical system with a rectifier and with at least two DC voltage converters.

The US 2015/0054469 A1 describes a charging control method and a charging control system for an environmentally friendly vehicle, whereby the charging control method and system can improve the charging efficiency thereby. In particular, an improvement of a power control method of a power factor correction converter is achieved while charging a battery through an on-board charger. The method detects a battery voltage during charging by a voltage detector and calculates a target value by a controller to maintain an output voltage of the PFC converter. The setpoint is calculated from the detected battery voltage and the maximum available load value of the DC / DC converter. The output voltage of the PFC converter is maintained based on the calculated target value.

The JP 2013034349 describes a charger. A vehicle may convert electrical energy from an external power source and charge an on-board power storage device using a charger. The charger includes a power factor correction circuit with switching elements. The PFC circuit converts AC power from the external power source into DC power and corrects a power factor. An electronic control unit changes a current frequency of the switching elements in the PFC circuit according to a fluctuation range of an input voltage from the external power source, thereby preventing the occurrence of an overcurrent condition in the charger.

This results in a disadvantage that on-board loaders consist of several Gleichrichtrichterzweigen, each DC converter branch has its own capacitor and its own PFC circuit. As a result, only a low power density can be achieved and, in particular, a multiplicity of electronic components is required for the on-board charger.

The object of the present invention is to provide a method and an on-board charger with which the efficiency can be improved in a three-phase or single-phase charging of a memory unit, since the losses of an active power factor correction can be reduced.

This object is achieved by a method and an on-board loader according to the independent claims. Meaningful developments emerge from the dependent claims.

One aspect of the invention relates to a method for charging a battery of a vehicle electrical system, wherein a single-phase AC voltage is provided and the single-phase AC voltage is converted by means of a rectifier into a DC voltage, wherein the DC voltage provided by a first DC voltage converter and / or a second DC voltage converter for the battery becomes. With the DC voltage, a capacitor is charged, wherein the first DC voltage converter and / or the second DC voltage converter can be supplied with the DC voltage with the capacitor, and wherein with a PFC inductor, which is connected with a first switch or with a second switch, the absorbed current is brought into phase with the single-phase AC voltage. With a second bridge circuit of the second DC voltage converter, a power factor correction filter can be formed and applied. By using the first DC voltage converter, the battery or a vehicle electrical system of a vehicle is supplied with the DC voltage and thus the charging of the battery can be carried out in particular only with one of the two DC voltage converter. As a result, in particular space can be saved, since even with existing three phases of the input conductor, which provides the AC voltage, only two DC voltage converters are needed. Since the second bridge circuit of the second DC-DC converter or the first bridge circuit of the first DC voltage converter together with the PFC choke and one of the diode bridges D1 . D2 or D3 can be applied as a power factor correction filter, can be dispensed with additional PFC interconnections and other semiconductor switches. As a result, costs and in particular space in the production of on-board loaders can be saved. Switching on the PFC choke through the switch eliminates the need for multiple PFC chokes as it allows switching between single-phase charging with power correction function and three-phase charging without power correction function. Thus only one PFC choke is needed.

For example, the rectifier may be a diode rectifier with which the input voltage of the on-board charger can be converted into a DC voltage. Since the bridge circuits of the first DC voltage converter or the second DC voltage converter can be used as a power factor correction filter, charging losses occurring by dispensing with an additional PFC circuit can be reduced.

For example, a first and / or the second DC voltage converter may be an insulating DC / DC converter.

By way of example, the first bridge circuit or the second bridge circuit can be half-bridge switches or, in particular, semiconductor switches.

Another aspect of the invention relates to a method for charging a battery of a vehicle electrical system, wherein a three-phase AC voltage is provided and the three-phase AC voltage is converted by means of a rectifier into a DC voltage. The DC voltage is provided by means of a first DC voltage converter and / or a second DC voltage converter for the battery. In this case, the first DC voltage converter with the first bridge circuit is supplied with the DC voltage and the second DC voltage converter with the second bridge circuit with the DC voltage. In particular, the first DC voltage converter and the second DC voltage converter function as insulating DC / DC converters with which the battery and / or a vehicle electrical system of a vehicle can thus be supplied with the DC voltage.

Another aspect of the invention relates to an on-board charger for charging a battery of a vehicle electrical system with a rectifier, with at least two DC voltage converters, with a first switch, with a second switch, with a capacitor and with a PFC throttle. With the rectifier, a single-phase AC voltage can be converted into a DC voltage. In particular, the method can be carried out with the on-board loader for one of the preceding aspects. The rectifier can be, for example, a diode rectifier. The at least two DC voltage energy converters can be designed, for example, as insulating DC / DC converters. The capacitor may be, for example, a bulk capacitor, with which the two DC voltage converters can be supplied with DC voltage.

Another aspect of the invention relates to an on-board charger for charging a battery of a vehicle electrical system with a rectifier and with at least two DC voltage converters, wherein the rectifier converts a three-phase AC voltage into a DC voltage.

Further advantages, features and details of the invention will become apparent from the following description of preferred embodiments and from the drawings. The features and feature combinations mentioned above in the description as well as the features and feature combinations mentioned below in the description of the figures and / or in the figures alone can be used not only in the respectively specified combination but also in other combinations or in isolation, without the scope of To leave invention.

• 1 eine schematische Schaltung eines Bordladers zum Laden einer Batterie; und
• 2 einen beispielhaften Spannungsverlauf am Ausgang der Diodenbrücke beim dreiphasigen Laden der Batterie.

The following figures show in:

• 1 a schematic circuit of a on-board charger for charging a battery; and
• 2 an exemplary voltage waveform at the output of the diode bridge during three-phase charging of the battery.

The 1 shows a schematic circuit of a on-board charger 1 to charge a battery 2 of a vehicle electrical system 3 of a vehicle. The on-board loader 1 includes, for example, a first DC voltage converter 4 and a second DC voltage converter 5 , In particular, the on-board loader 1 on one input side a rectifier 6 on, with which an AC voltage of a power source can be rectified. For example, on the input side of the rectifier 6 a phase L1 . L2 or L3 be connected. At the rectifier 6 it may be, for example, a diode rectifier. The rectifier 6 in particular comprises a first diode bridge D1 and a second diode bridge D2 and a third diode bridge D3 , With the diode bridge D1 . D2 or D3 can be a single-phase AC voltage of the power source in a DC voltage being transformed. In particular, a three-phase AC voltage of the power source with all diode bridges D1 . D2 . D3 of the rectifier are converted into a DC voltage.

For example, it may be at the battery 2 to act a high-voltage battery of an electrically powered vehicle and the electrical system 3 can be designed as a high-voltage vehicle electrical system. The first DC voltage converter 4 and the second DC voltage converter 5 For example, insulating DC / DC converters can be formed.

In a first case, for example, with the on-board loader 1 the battery 2 of the electrical system 3 be charged by means of the DC voltage. This is the single-phase AC voltage with one of the diode bridges D1 . D2 or D3 of the rectifier 6 converted into DC voltage. The DC voltage can by means of the first DC voltage converter 4 or a second DC-DC converter 5 the battery 2 to be provided.

For example, the terminal N of the power source via a PFC choke 7 and by means of a closed first switch S1 with the on-board loader 1 get connected. To start the single-phase charging process, the first switch S1 closed and a second switch S2 it is open. The through the rectifier 6 rectified DC voltage is via a resistor R used a capacitor C subpoena. At the condenser C For example, it may be a bulk capacitor. The resistor serves as inrush current limit, with which the current can be monitored. In particular, to the resistance R a semiconductor switch 8th connected in parallel. With the semiconductor switch open 8th becomes the capacitor C about the resistance R pre-charged with DC voltage. After completion of the charging process of the capacitor C becomes the semiconductor switch 8th closed. For example, the diode bridge function D3 and a first bridge circuit B1 of the first DC voltage converter 4 as a totem pole circuit. As a result, in particular by means of the PFC throttle 7 Phase N is an alternating current component with the AC voltage component at the mains connection side of the input side of the on-board charger 1 brought into phase. For example, this is done via a current control. The current control, for example, with the totem pole circuit and the PFC throttle 7 reached. As a result, in particular a constant input DC voltage for the second DC voltage converter 5 to be provided. In particular, the current control is superimposed on a voltage control. As a result, for example, a defined voltage can be set at the output of the totem pole circuit. For example, this voltage may be greater than the maximum AC input voltage. For example, with this controlled output voltage, the capacitor C be provided and thus the second bridge circuit B2 to provide. As a result, in particular the second DC voltage converter 5 can be supplied with a constant voltage and thus in particular the battery 2 and / or the electrical system 3 be supplied with the voltage, in particular with the DC voltage.

In another application example, the battery 2 over the first DC voltage converter 4 be supplied with the DC voltage. In this case, the second bridge circuit B2 of the second DC voltage converter 5 as a totem pole circuit with the PFC choke 7 and the first diode bridge D1 or the second diode bridge D2 or the third diode bridge D3 educated. In particular, here is the first switch S1 opened and the second switch S2 closed. In this example, as previously described, the capacitor C about the resistance R preloaded, the semiconductor switch 8th is open and after completion of the charging process, the semiconductor switch is closed. The provided voltage of the capacitor C can via the first bridge circuit B1 to the first DC voltage converter 4 be delivered, so with the first DC voltage converter 4 the battery 2 can be loaded. In particular, the second bridge circuit functions in this example B2 in interaction with the PFC throttle 7 as a totem pole circuit. The totem pole circuit may in particular be a power factor correction filter. For example, with such a power factor correction filter, a power factor can be increased.

In another example, with the on-board loader 1 the battery 2 of the electrical system 3 with the rectified DC voltage of the rectifier 6 be charged, the rectifier 6 the three-phase AC voltage of the power source is provided. For example, in three-phase charging, the input power is less volatile with time than with single-phase charging, and thus the capacitor is turned on C not necessary in this case. Here is the semiconductor switch 8th opened in this case. In this case, the first diode bridge D1 and the second diode bridge D2 and the third diode bridge D3 of the rectifier 6 active and thus no parasitic capacitances occur after rectification. This will not distort the input current relative to the input voltage. This eliminates the need for an active PFC circuit. The first switch S1 and the second switch S2 are open in this case. For example, the input voltage via the first bridge circuit B1 of the first DC power converter 4 and the second bridge circuit B2 of the second DC voltage converter 5 vary between 480 volts and 560 volts. In this case, a DC voltage frequency for comparison to an AC voltage frequency, for example, be twice as large. In this case, the battery will 2 and / or the electrical system 3 each with two DC voltage converters 4 . 5 supplied with the DC voltage. In particular, the two DC voltage energy converters function 4 . 5 as insulating DC / DC converter. In this case, the AC component of the DC voltage can be reduced by controlling the two insulating DC / DC converter.

The 2 shows a schematic course of the voltage curve U at the output of the diode bridge D1 . D2 . D3 of the rectifier 6 during three-phase charging of the battery 2 by means of the on-board loader 1 , The rectified voltage is in this example as a wavy voltage curve U shown. Here is also the period of the voltage curve U in the three-phase case after rectification one-sixth smaller and the ripple now has a sixfold frequency in relation to the input voltage of one phase. The voltage curve U thus shows a rectified DC voltage. With the DC voltage, in particular, the battery 2 Loading.

LIST OF REFERENCE NUMBERS

1

board charger

2

battery

3

board network

4

First DC voltage converter

5

Second DC voltage converter

6

rectifier

7

PFC reactor

8th

Semiconductor switches

B1

First bridge circuit

B2

Second bridge circuit

C

capacitor

D1

First diode bridge

D2

Second diode bridge

D3

Third diode bridge

R

resistance

S1

first switch

S2

second switch

U

voltage curve

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 2015/0054469 A1 [0002]
• JP 2013034349 [0003]

Claims (7)

A method for charging a battery (2) of a vehicle electrical system (3), wherein - a single-phase AC voltage is provided, and - the single-phase AC voltage is converted by means of a rectifier (6) into a DC voltage, and - the DC voltage by means of a first DC voltage converter (4) and / or a second DC voltage converter (5) for the battery (2) is provided, characterized in that - a capacitor (C) is charged with the DC voltage, with which the first DC voltage converter (4) or the second DC voltage converter (5) with the DC voltage is supplied, and wherein - with a PFC choke (7) which is connected to a first switch (S1) or a second switch (S2), the single-phase AC voltage is brought into phase, wherein - a second bridge circuit (B2 ) of the second DC voltage converter (5) or a first bridge circuit (B1) of the first DC voltage energy (4) is provided for functionality as a power factor correction filter. Method according to Claim 1 , characterized in that a totem pole circuit is formed with a diode bridge (D1, D2, D3) of the rectifier (6) and with the first bridge circuit (B1) or with the second bridge circuit (B2). Method according to Claim 2 , characterized in that with the totem pole circuit and the PFC inductor (7), a current control is formed, with which a constant input DC voltage for the first DC voltage converter (4) or the second DC voltage converter (5) is provided. A method for charging a battery (2) of a vehicle electrical system (3), wherein - a three-phase AC voltage is provided, and - the three-phase AC voltage is converted by means of a rectifier (6) into a DC voltage, and - the DC voltage by means of a first DC voltage converter (4) and a second DC voltage converter (5) for the battery (2), characterized in that - the first DC voltage converter (4) with the first bridge circuit (B1) with the DC voltage and the second DC voltage converter (5) with the second bridge circuit (B2 ) is supplied with the DC voltage, and wherein - the first DC voltage converter (4) and the second DC voltage converter (5) without a functionality as power factor correction filter, the on-board network (3) with the DC voltage supply. Method according to Claim 4 , characterized in that with a control of the first DC voltage converter (4) and the second DC voltage converter (5) an AC voltage component of the DC voltage is reduced. On-board charger (1) for charging a battery (2) of a vehicle electrical system (3) with a rectifier (6), with at least two DC voltage converters (4, 5), with a switch (S1), with a switch (S2), with a capacitor (C) and with a PFC throttle (7), wherein the on-board loader (1) for carrying out a method according to one of Claims 1 to 3 is trained. On-board charger (1) for charging a battery (2) of a vehicle electrical system (3) with a rectifier (6) and with at least two DC voltage converters (4, 5), wherein the on-board loader (1) for carrying out a method according to one of Claims 4 to 5 is trained.

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