Charger arrangement and method for controlling a charger arrangement

Abstract

Charger arrangement (23) which has a control unit (28), a charger (30) and a housing (231), which charger (30) has first connections (321), an AC / DC converter (32), a DC intermediate circuit (34), a first DC / DC converter (36) and second connections (363, 364), which housing (231) contains the control unit (28) and the charger (30), which control unit (28) is designed to control the AC / DC converter (32) and the battery contactor arrangement (40), and on which DC intermediate circuit (34) DC consumer connections (51, 52, 53, 54) for connecting DC consumers (55, 56, 57, 58) are provided, characterized in that a battery contactor arrangement (40) is provided in the housing (231), which has third connections (401, 402) and fourth terminals (403, 404) and can be controlled by the control unit (28), wherein the first DC / DC converter (36) is designed as a bidirectional DC / DC converter (36),in a charging mode, to enable a conversion of a first DC voltage at the DC intermediate circuit (34) into a second DC voltage at the second terminals (363, 364), and in a consumption mode, to enable a conversion of a third DC voltage at the second terminals (363, 364) into a fourth voltage at the DC intermediate circuit (34), and which control unit (28) is designed to enable a corresponding control of the first DC / DC converter (36), wherein the control unit (28) has a voltage regulator (282), which voltage regulator (282) is designed to regulate the voltage at the DC intermediate circuit (34) to a voltage target value in the consumption mode, in order to thereby enable a determination / setting of the fourth voltage by the voltage regulator (282).

Description

The invention relates to a charger arrangement according to the preamble of claim 1.EP 3 183 795 B1, CN 104 494 535 A, CN 209 617 055 U, CN 209 972 203 U, US 2009 / 0 103 341 A1 and US 2016 / 0 016 479 A1 each show AC chargers for electric vehicles. Furthermore, a charging device arrangement of the generic type is known from US 2019 / 0 115 848 A1. Furthermore, DE 10 2018 104 914 A1 discloses a power arrangement in which a contactor arrangement is integrated. In addition, a charging device arrangement is known from DE 10 2016 007 948 A1, in which a first DC / DC converter is designed as a bi-directional DC / DC converter.It is therefore an object of the invention to provide a novel charger arrangement.This object is achieved by the subject matter of claim 1.A charger arrangement has a control unit, a charger, a battery contactor arrangement and a housing, which charger has first connections, an AC / DC converter, a DC link, a first DC / DC converter and second connections, which battery contactor arrangement has third connections and fourth connections, and which housing contains the control unit, the charger and the battery contactor arrangement, which control unit is designed to actuate the AC / DC converter, the first DC / DC converter and the battery contactor arrangement, and on which DC link DC load connections for connecting DC loads are provided.The provision of the charger, the battery contactor arrangement and the control unit in a housing has produced great synergy effects. The required volume, weight and technical outlay for the cabling, for plugs and pin strips, for interfaces and for the interconnection have been greatly reduced by the integration. In addition, the control unit can actuate a plurality of the components, and hardware is thereby saved. The provision of DC load connections on the DC intermediate circuit enables multiple use of the DC intermediate circuit and thus additional circuit simplification.The first DC / DC converter is designed as a bidirectional DC / DC converter to enable a first DC voltage at the DC link to be converted into a second DC voltage at the second connections in a charging mode and to enable a third DC voltage at the second connections to be converted into a fourth voltage at the DC link in a consuming mode, and the control unit is designed to enable a corresponding actuation of the first DC / DC converter. This allows the use of the DC intermediate circuit for supplying voltage to DC loads when the vehicle is not being charged. Since the power electronics are concerned, the multiple use of the first DC / DC converter leads to a marked reduction in the weight of the vehicle. In addition, the voltage range at the DC link can be reduced compared to the voltage range of the battery, and as a result, the DC loads can be designed with less circuit complexity than DC loads with a large input voltage range, as are required for the direct connection to the battery.The control unit also has a voltage regulator, which voltage regulator is designed to regulate the voltage at the DC intermediate circuit to a voltage setpoint value in the consumption mode, in order to enable a determination / determination of the fourth voltage by the voltage regulator in this way. The use of a voltage control is also possible, but a voltage regulator has proven to be very advantageous with regard to the DC loads connected to the DC intermediate circuit, since the circuit outlay in the case of the DC loads for the voltage adaptation is reduced.According to a preferred embodiment, the control unit has an interface, which interface is designed to receive a first item of information from at least one DC current consumer, which first item of information characterizes the energy requirement of the DC current consumer, and which control unit is designed to determine the magnitude of the fourth voltage at the DC link in the consumption mode as a function of the first item of information from the at least one DC current consumer and to actuate the first DC / DC converter accordingly.According to a preferred embodiment, the control unit is designed to receive a first item of information from at least two DC loads via the interface. By receiving such information, the control unit can preferably advantageously define the level of the fourth voltage.According to a preferred embodiment, the control unit has a microcontroller or microprocessor which is designed to actuate the AC / DC converter, the first DC / DC converter and the battery contactor arrangement. The multiple use of a microcontroller or microprocessor simplifies communication and allows good optimization.According to a preferred embodiment, a direct current consumer is provided in the housing, which direct current consumer is connected to the direct current intermediate circuit and is designed as a heating device for heating a fluid. Such a heating device can be used for heating the high-voltage battery or the passenger interior. The arrangement of such a direct current consumer in the housing has proven to be highly advantageous since the waste heat of the charging arrangement can also be used to heat the fluid, and at the same time cooling of the charging arrangement is possible. The weight saving and efficiency increase as a result are great.According to a preferred embodiment, at least one first direct current consumer is connected to the direct current consumer connections from the direct current consumer group consisting of:second DC / DC converter,heating apparatus for a fluid,an electric air conditioning compressor,roll stabilization arrangement, andinterior heaters.In these consumers, large increases in efficiency are possible due to the connection to the DC link and a corresponding actuation of the first DC / DC converter of the charging arrangement.According to a preferred embodiment, a second DC / DC converter is connected to the DC load connections, and the control unit is designed to actuate the second DC / DC converter. As a result, the control unit can directly influence the second DC / DC converter and actuate the latter in an optimized manner with regard to the charger arrangement.According to a preferred embodiment, a heating device for a fluid is connected to the direct current consumer connections, and the control unit is configured to actuate the heating device for the fluid. As a result, the control unit can directly influence the heating device and actuate it in an optimized manner with regard to the charging device arrangement.According to a preferred embodiment, a second DC / DC converter is connected to the DC load connections in order to enable a conversion of the voltage at the DC intermediate circuit. This conversion may include an increase or a decrease in voltage as required. For example, a voltage suitable for the low-voltage on-board power supply can be generated.The object is likewise achieved by a method for controlling a charger arrangement, in which the control unit, when determining the fourth voltage, weights the direct current consumer which has the highest energy requirement more strongly than the respective other direct current consumers. The direct current consumer with the highest energy requirement frequently also has the highest power loss, and since the power loss is dependent on the voltage at the direct current intermediate circuit, the stronger weighting of this direct current consumer makes it possible to advantageously define the fourth voltage.According to a preferred embodiment, the control unit calculates the fourth voltage by an optimization method, which optimization method is designed to reduce the total power loss of the first DC / DC converter and the DC loads. Particularly in the case of battery-operated vehicles, a reduction in the total power loss makes it possible to increase the range of the vehicle.According to a preferred embodiment, the control unit is configured to carry out a change in the fourth voltage in the consumption mode and to check whether or not the electrical power at the DC link or at the second connections is reduced by this change, in order thereby to enable a reduction in the power loss. Such a configuration enables optimization of the power loss by maintaining a positive change and reversing a negative change. By making only small changes at all times, the DC loads can operate with the new voltage without any major adjustment, and this enables a comparatively fast optimization of the fourth voltage.Further details and advantageous developments of the invention are evident from the exemplary embodiments described below and illustrated in the drawings, which are in no way to be understood as limiting the invention, and from the dependent claims. The following are shown: FIG. 1 shows a vehicle having a charger arrangement at a charging station, and FIG. 2 shows a possible optimization of the voltage across a DC intermediate circuit.In the following, identical or identically acting parts are provided with the same reference symbols and are usually described only once. The description is based on one another across the figures in order to avoid unnecessary repetitions.FIG. 1 shows a schematic illustration of an exemplary embodiment with a vehicle 10 which is connected to a charging station 12. The vehicle 10 has a charging device arrangement 23, which can be connected to the charging station 12 via a charging connection 24, and which can be connected to a battery 26, in particular to a high-voltage battery, via a battery connection 25. The charger assembly 23 includes a control unit 28, a charger 30, a battery contactor assembly 40, and a housing 231. The charger 30 has first terminals 321 for connection to the charging terminal 24, an AC / DC converter 32, a DC link 34, a DC / DC converter 36 which is connected to the AC / DC converter via the DC link 34, and second terminals 363, 364 for connecting the DC / DC converter 36 to the battery contactor arrangement 40. The battery contactor arrangement 40 has third terminals 401, 402 for connection to the DC / DC converter 36 and fourth terminals 403, 404 for connection to the battery terminal 25. The housing 231 preferably contains at least the control unit 28, the charger 30 and the battery contactor arrangement 40. The control unit 28 is for driving the AC / DC converter 32, DC / DC converter 36 and battery contactor arrangement 40, and DC load connections 51, 52, 53, 54 for connecting DC loads 55, 56, 57, 58 are provided on DC link 34 via lines 49, 50.The battery contactor arrangement 40 enables a disconnection between the battery 26 and the charger 30.The direct current consumer 57 is preferably a heating device, in particular a heating device for a fluid such as water. Warmed water is advantageous, for example, for preconditioning the battery 26. the DC power consumer 58 is, for example, a further DC / DC converter which can convert the DC voltage at the DC link 34 into a higher or lower voltage and provide it at a terminal 64. The direct current consumers 55, 56 are, for example, an electric air conditioning compressor, a roll stabilization arrangement, an interior heater or another device which is operated with a direct voltage.The charging device 30 can be galvanically separated from the charging station 12 (e.g. via transformer) or galvanically connected.The control unit 28 preferably has a microcontroller or microprocessor 281, and it enables the microcontroller or microprocessor 281 to actuate various devices, in particular the AC / DC converter 32, the DC / DC converter 36 and the battery contactor arrangement 40.The control unit 28 preferably has a voltage regulator 282 which is designed to regulate the voltage at the DC intermediate circuit 34 to a voltage setpoint value in a consumption mode.The control unit 28 has an interface 61 which is connected to the DC loads 55, 56, 57, 58 via data lines 60. Wireless transmission is also possible. The interface 61 enables input and / or output.The DC / DC converter 36 is preferably designed as a bidirectional DC / DC converter 36. In a charging mode, it enables the conversion of a first DC voltage at the DC intermediate circuit 34 into a second DC voltage at the second terminals 363, 364. This allows, for example, a charging process in which an alternating current is supplied to the AC / DC converter 32 via the charging station 12, the alternating current is converted by the AC / DC converter 32 into a direct current at the direct current intermediate circuit 34 and subsequently the voltage at the direct current intermediate circuit 34 is converted by the DC / DC converter into a voltage at the terminals 363, 364 suitable for the battery 26.The DC link 34 includes a first line 341 (positive line) and a second line 342 (negative line) connected to terminals 323, 324 of the AC / DC converter 32 and to terminals 361, 362 of the DC / DC converter 36. The lines 341, 342 are interconnected by a capacitor assembly 343. The capacitor arrangement 343 is exemplary. Usually, more complex filter circuits are additionally provided for smoothing the current and the voltage and for improving the EMC (electromagnetic compatibility) in the DC intermediate circuit.In a consumption mode, in which energy from the battery 26 is used for operating the DC loads 55, 56, 57, 58 and the vehicle 10 is not connected to a charging station 12 for charging, on the other hand, a third DC voltage at the second connections 363, 364, which can be generated by the battery 26, is converted at least temporarily into a fourth voltage at the DC link 34.The control unit 28 is preferably designed to receive a first item of information from at least one of the DC loads 55, 56, 57, 58 via the interface 61, which first item of information characterizes the energy requirement of the DC load 55, 56, 57, 58. This first information item can be, for example, a value for the required electrical power of the DC power consumer, or else, for example, a value between zero and one, with zero corresponding to a switched-off DC power consumer and one corresponding to a DC power consumer operated under full power. The first information item can also comprise, for example, the current power loss of the DC power consumer, which is dependent, inter alia, on the energy requirement.The control unit 28 is preferably designed to receive such first information from at least two DC consumers 55, 56, 57, 58 via the interface 61.In practice, the different DC loads operate with different efficiency at different input voltages, i.e. a climate compressor can operate most efficiently at a voltage of 700 volts at the DC intermediate circuit 34, for example, while a roll stabilization arrangement operates most efficiently at a voltage of 400 volts, for example.The control unit 28 preferably contains data about the power loss of the individual direct current consumers as a function of the first information.Preferably, the control unit 28 determines the fourth voltage as a function of that direct current consumer 55, 56, 57, 58 which has the highest energy requirement. For this purpose, a stronger weighting of that direct current consumer which has the highest energy requirement can preferably take place, and the remaining direct current consumers can be taken into account to a lesser extent.FIG. 2 shows, by way of example, a plot of the power loss P_V in watts over the fourth voltage U at the DC intermediate circuit 34 in volts for a first load V 1 and a second load V 2 with respectively predefined energy requirements. The first load V 1 overall has a higher power loss P_V than the second load V 2. The first load V 1 has a low point at a voltage U of approximately 570 volts, and at lower and higher voltages U, the power loss P_V increases sharply. This is an approximately parabolic curve.The second direct current consumer V 2, on the other hand, has a comparatively flat increasing power loss P_V with a slightly positive curvature.The curve V 1+V 2 shows the sum of the power losses P_V of the consumers V 1 and V 2. The low point is at a slightly lower voltage of approximately 550 volts than the low point of the curve of the first DC current consumer V 1. Preferably, an optimization method takes place in the control unit 28, via which the fourth voltage is calculated. The optimization method is preferably designed to reduce the total power loss of the DC / DC converter and of the DC loads 55, 56, 57, 58. In the exemplary embodiment, the voltage at the low point of the curve V 1+V 2 can be selected as the optimized fourth voltage. Of course, more complicated methods are also possible, for example the use of a Lagrange optimization method in which secondary conditions are taken into account as Lagrange multipliers.It is also possible to measure the current flowing on the battery side of the DC / DC converter or the current flowing on the DC link 34, and to find a minimum or at least an improvement by varying the fourth DC voltage on the DC link 34. Such an optimization method can take place at the beginning of the consumption mode or else continuously.

Claims

Charger arrangement (23) which has a control unit (28), a charger (30) and a housing (231), which charger (30) has first connections (321), an AC / DC converter (32), a DC link (34), a first DC / DC converter (36) and second connections (363, 364), which housing (231) contains the control unit (28) and the charger (30), which control unit (28) is designed to actuate the AC / DC converter (32) and the battery contactor arrangement (40), and on which DC link (34) DC load connections (51, 52, 53, 54) are provided to connect DC loads (55, 56, 57, 58), characterized in that a battery contactor arrangement (40) is provided in the housing (231), which third connections (401, 53, 54) are provided, 402) and fourth terminals (403, 404) and can be controlled by the control unit (28), wherein the first DC / DC converter (36) is designed as a bidirectional DC / DC converter (36) to enable a conversion of a first DC voltage at the DC link (34) into a second DC voltage at the second terminals (363, 364) in a charging mode and to enable a conversion of a third DC voltage at the second terminals (363, 364) into a fourth voltage at the DC link (34) in a consumption mode, and which control unit (28) is designed to enable a corresponding control of the first DC / DC converter (36), wherein the control unit (28) has a voltage regulator (282), which voltage regulator (282) is designed to enable a corresponding control of the first DC / DC converter (36), In the consumption mode, the voltage at the DC intermediate circuit ( 34) can be regulated to a voltage setpoint value, in order to thereby enable the voltage regulator ( 282) to determine / define the fourth voltage.Charging device arrangement (23) according to Claim 1, in which the control unit (28) has an interface (61), which interface (61) is designed to receive a first item of information from at least one direct-current consumer (55, 56, 57, 58), which first item of information characterizes the energy requirement of the direct-current consumer (55, 56, 57, 58), and which control unit (28) is designed to determine the magnitude of the fourth voltage at the direct-current intermediate circuit (34) in the consumption mode on the basis of the first item of information from the at least one direct-current consumer (55, 56, 57, 58) and to actuate the first DC / DC converter (36) accordingly.Charger arrangement (23) according to Claim 2, in which the control unit (28) is designed to receive a first item of information from at least two DC loads (55, 56, 57, 58) via the interface (61).Charging device arrangement (23) according to one of the preceding claims, in which the control unit (28) has a microcontroller or microprocessor (281), which is designed to actuate the AC / DC converter (32), the first DC / DC converter (36) and the battery contactor arrangement (40).Charger arrangement (23) according to one of the preceding claims, in which a direct current consumer (57) is provided in the housing (231), which direct current consumer (57) is connected to the direct current intermediate circuit (34) and is designed as a heating device (57) for heating a fluid.Charger arrangement (23) according to one of the preceding claims, in which at least one first direct current consumer (55, 56, 57, 58) is connected to the direct current consumer connections (51, 52, 53, 54) from the direct current consumer group consisting of: - second DC / DC converter (58), - heating device (57) for a fluid, - electric air conditioning compressor (55), - roll stabilization arrangement (56), and - interior heater.Charger arrangement (23) according to Claim 6, in which a second DC / DC converter (58) is connected to the DC consumer connections (51, 52, 53, 54), and in which the control unit (28) is designed to actuate the second DC / DC converter (58).Charger arrangement (23) according to Claim 6 or 7, in which a heating device (57) for a fluid is connected to the DC consumer connections (51, 52, 53, 54), and in which the control unit (28) is designed to actuate the heating device (57) for the fluid.Charger arrangement (23) according to one of the preceding claims, in which a second DC / DC converter (58) is connected to the DC consumer connections (51, 52, 53, 54) in order to enable conversion of the voltage from the DC intermediate circuit (34).Method for controlling a charger arrangement (23) according to Claim 3, in which, when determining the fourth voltage, the control unit (28) weights that direct current consumer (55, 56, 57, 58) which has the highest energy requirement more strongly than the respective other direct current consumers (55, 56, 57, 58).Method for controlling a charger arrangement (23) according to Claim 4, in which the control unit (28) calculates the fourth voltage by means of an optimization method, which optimization method is designed to reduce the total power loss of the first DC / DC converter (36) and of the DC loads (55, 56, 57, 58).Method for controlling a charging device arrangement (23) according to one of the preceding claims, in which the control unit (28) carries out a change in the fourth voltage in the consumption mode and checks whether or not the electrical power at the DC link (34) or at the second connections (363, 364) is reduced by this change, in order thereby to enable a reduction in the power loss.

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