DE102022201330A1 - Inverter device and method for operating an inverter device for a vehicle - Google Patents

Abstract

An inverter device (102) for a vehicle (100) comprises a supply interface (110) for applying a supply voltage and a consumer interface (112) for providing an operating voltage for operating an electrical consumer (106) and a power electronics device (120) for converting the supply voltage into the operating voltage and a heating device (130) which is designed to cause the coolant to be heated using the supply voltage and/or the operating voltage.

Description

The present invention relates to an inverter device and a method for operating an inverter device for a vehicle

In an electric vehicle, for example a battery electric vehicle (BEV), a plug-in hybrid (PHEV) or a fuel cell vehicle (FCEV), the internal combustion engine is no longer used as a heat source. Therefore, electrical energy must be used for heating. This reduces the range of the vehicle and should therefore be carried out as efficiently as possible.

Against this background, the present invention provides an improved inverter device and an improved method for operating an inverter device for a vehicle according to the independent claims. Advantageous configurations result from the dependent claims and the following description.

Advantageously, an inverter that is required in any case in an electric vehicle can be used in order to provide a cost-effective electric heater for electric and hybrid vehicles.

• eine Versorgungsschnittstelle zum Anlegen einer Versorgungsspannung und eine Verbraucherschnittstelle zum Bereitstellen einer Betriebsspannung zum Betreiben eines elektrischen Verbrauchers;
• eine Leistungselektronikeinrichtung zum Wandeln der Versorgungsspannung in die Betriebsspannung;
• einen Kühlmitteleinlass und einen Kühlmittelauslass zum Einbinden der Invertervorrichtung in einen ein Kühlmittel führenden Heizkreislauf des Fahrzeugs; und
• eine Heizeinrichtung mit einem ersten Kühlmittelanschluss, der mit dem Kühlmitteleinlass verbunden ist und einem zweiten Kühlmittelanschluss, der mit dem Kühlmittelauslass verbunden ist, wobei die Heizeinrichtung ausgebildet ist, um unter Verwendung der Versorgungsspannung und/oder der Betriebsspannung eine Erwärmung des Kühlmittels zu bewirken.

An inverter device for a vehicle has the following features:

• a supply interface for applying a supply voltage and a consumer interface for providing an operating voltage for operating an electrical consumer;
• a power electronics device for converting the supply voltage into the operating voltage;
• a coolant inlet and a coolant outlet for incorporating the inverter device into a coolant-carrying heating circuit of the vehicle; and
• a heating device with a first coolant connection which is connected to the coolant inlet and a second coolant connection which is connected to the coolant outlet, wherein the heating device is designed to heat up the coolant using the supply voltage and/or the operating voltage.

The vehicle can be implemented, for example, as an electric car with a battery, a plug-in hybrid, or a fuel cell vehicle. The inverter device can be suitable for converting a supply voltage provided by a battery of the vehicle, for example, into an operating voltage that can be used, for example, to operate an electric motor. Such an electric motor can be used, for example, to drive the vehicle. In order to convert the supply voltage, the power electronics device can include power electronics such as are used in known inverters. The power electronics device can thus provide the actual function of an inverter, ie voltage conversion. The power electronics device can be designed, for example, to convert a DC voltage provided at the supply interface into an AC voltage. The heating circuit can be used, for example, to provide heat for tempering an interior of the vehicle or an energy storage device of the vehicle. For this purpose, the coolant, for example cooling water, can be heated using the heating device and conveyed via the heating circuit to a component of the vehicle that is to be heated. To heat the coolant, the coolant can be passed through the heater. The heating device can be designed to convert electrical energy into thermal energy and to transfer it to the coolant. The electrical energy can be electrical energy provided via the supply interface or energy stored in the electronic power device. If electrical energy is fed in via the load interface, for example because the electrical load is temporarily operated as a generator, the electrical energy can also be electrical energy provided via the supply interface.

Advantageously, the use of the heating device makes it possible to dispense with the additional installation of electric high-voltage heaters, for example based on the heating rod principle, or heat pumps which are connected to a cooling circuit of the vehicle, which means that costs and additional components in the vehicle can be saved. According to one specific embodiment, the heating device can also be used for discharging the power electronics device, which means that an additional use of discharging networks can be dispensed with. This can also save costs. Advantageously, the heating device can be implemented without significant wear and tear, which ensures a long service life and thus makes it possible to dispense with monitoring and diagnosis and avoid the need for a replacement. This also ensures a very high level of availability.

If the consumer is an electric drive, the heating device can tion can advantageously be integrated into the inverter of the electric drive, for example by integrating a high-voltage heater or a high-voltage heater.

The power electronics device may have a first coolant port connected to the coolant inlet and a second coolant port connected to the coolant outlet. In this case, the power electronics device can be designed to deliver thermal energy to the coolant during operation of the power electronics device. This makes it possible to exploit the fact that a coolant connection of an inverter can also be used advantageously for cooling the power electronics. For this reason too, it can be advantageous to implement an inverter as part of the heating circuit.

The inverter device may include a controller. The control device can be designed to provide a first control signal for controlling operation of the heating device and a second control signal for controlling operation of the power electronics device. The control device can include a microcontroller (μC) or be designed as a microcontroller. Thus, a control device that is required in any case to control the function of the inverter can also be used to control the heating device. This enables costs to be reduced by eliminating the need for a separate control device for the heating in the form of the heating device. It is therefore not necessary to integrate a separate control device into the heating device in order to control and monitor the heating device.

The control device can be designed to provide the first control signal for activating the heating device in response to a request signal which represents a heat request from the heating circuit. This takes place in particular to discharge the intermediate circuit capacitor. In this way, the heating device can only be activated when the temperature of the coolant is not sufficient to enable a desired heating function. This can save energy.

Additionally or alternatively, the control device can be designed to provide the first control signal for activating the heating device in response to an error signal. The error signal can represent, for example, an error state of the inverter device or an error in an electrical network of the vehicle that is electrically coupled to the inverter device. As a result, when a fault is detected, reliable discharge of the inverter device, in particular the intermediate circuit and/or the power electronics device, can be ensured via the heating device. Thus, a high-voltage heater integrated into an inverter can be used for active discharge. For example, a heating resistor of the heating device can be used to actively discharge an intermediate circuit in the event of a fault. This leads to a cost reduction due to the elimination of an additional network for active discharge in the inverter by using a heating element of the heating device. This is advantageous because high-voltage components in vehicles, such as the inverter of an electric vehicle drive, typically require active discharge, which ensures that the high voltage within the component is reduced to a harmless level within a defined time when the HV supply is disconnected, for example to less than 60V.

The combination of heating device and inverter means that a separate control unit for the heating device and a separate device in the form of a discharge network for actively discharging the inverter can be dispensed with.

The inverter device may include an intermediate circuit capacitor. In this case, the heating device can be connected in parallel with the intermediate circuit capacitor. The intermediate circuit capacitor can thus be used on the one hand to smooth out voltage fluctuations when the heating device is activated and deactivated, and on the other hand can be quickly discharged via the heating device if required.

For example, the heating device can comprise at least one electrically operable heating element. In this way, electrical energy can easily be converted into thermal energy. For example, the heating element can comprise a transistor, a power semiconductor, a resistor or a combination, for example a series connection of such elements. An active discharge network can be formed via such heating elements. Such a discharge network can be controlled in such a way that electrical power loss can be delivered to the heating circuit in a targeted manner. As a result, the discharge network can assume the function of a high-voltage heater. As a result, the vehicle no longer requires a separate and therefore more expensive high-voltage heater. Alternatively, instead of such a classic active discharge network, a heating element can be used, for example in the form of a PTC thermistor, a heating element or a layer heating element.

Advantageously, the heating device can be a heat exchanger, for example a plate heat exchanger, include. In this way, good thermal coupling can be created between the coolant and the heating element. As a result, the inflowing cooling water can be heated by means of the heating element, for example a high-voltage heating element.

The inverter device can be part of a supply device for a vehicle. In addition to the inverter device, such a supply device can include a battery which is connected to the supply interface of the inverter device in order to provide the supply voltage. This means that the energy stored in the battery can be used directly to heat the coolant.

Additionally or alternatively, the supply device can include the electrical consumer. The electrical consumer can be an electrical machine, for example an electric motor for driving the vehicle.

Additionally or alternatively, the supply device can include the heating circuit. Optionally, the heating circuit can include a pump for conveying the coolant through the heating circuit and a temperature control device for controlling the temperature of the vehicle or an element of the vehicle using the coolant.

A vehicle may be equipped with a named inverter device or a named supply device. The inverter device can advantageously be used as a replacement for known inverters and known heating devices.

• Einlesen eines Anforderungssignals, das eine Wärmeanforderung des Heizkreislaufs repräsentiert, und

A method for operating a said inverter device comprises the following steps:

• Reading in a request signal that represents a heat request from the heating circuit, and

activating the heater in response to the demand signal to cause heating of the coolant of the heating circuit using the supply voltage and/or the operating voltage.

The steps of the method can be carried out, for example, using a control device, which can be an electrical device that processes electrical signals, for example sensor signals, and outputs control signals as a function thereof. The control device can have one or more suitable interfaces, which can be designed in terms of hardware and/or software. In the case of a hardware design, the interfaces can be part of an integrated circuit, for example, in which the functions of the control device are implemented. The interfaces can also be separate integrated circuits or at least partially consist of discrete components. In the case of a software design, the interfaces can be software modules which are present, for example, on a microcontroller alongside other software modules.

• 1 ein Fahrzeug mit einer Invertervorrichtung gemäß einem Ausführungsbeispiel; und
• 2 ein Ablaufdiagramm eines Ausführungsbeispiels eines Verfahrens zum Betreiben einer Invertervorrichtung.

The invention is explained in more detail by way of example with reference to the attached drawings. Show it:

• 1 a vehicle including an inverter device according to an embodiment; and
• 2 a flowchart of an embodiment of a method for operating an inverter device.

In the following description of preferred exemplary embodiments of the present invention, the same or similar reference symbols are used for the elements which are shown in the various figures and have a similar effect, with a repeated description of these elements being dispensed with.

1 12 shows a vehicle 100 with an inverter device 102 according to an embodiment. The inverter device 102, which can also be referred to as an inverter, is designed according to this exemplary embodiment in order to convert a supply voltage provided by an energy supply device, here by way of example a battery 104, into an operating voltage for operating an electrical load 106. Furthermore, the inverter device 102 is designed to heat a coolant of a heating circuit 108 .

The inverter device 102 has a supply interface 110 for applying the supply voltage and a load interface 112 for providing the operating voltage to the electrical load 106 . According to one exemplary embodiment, the supply interface 110 is connected to the battery 104, for example a high-voltage battery, via a switch 114, for example a battery contactor. According to one exemplary embodiment, load interface 112 is connected to electrical load 106 . Depending on the type of electrical load 106, the load interface 112 has two or more phases. According to one exemplary embodiment, the electrical load 106 is an electrical machine, for example an electrical drive for the vehicle 100. Such an electrical machine can optionally be operated in generator mode and electrical energy generated in the process can be used be fed back to consumer interface 112.

The inverter device 102 also has a coolant inlet 116 and a coolant outlet 118 for incorporating the inverter device 102 into the heating circuit 108 carrying the coolant.

The inverter device 102 has a power electronics device 120 for converting the supply voltage into the operating voltage. According to this exemplary embodiment, the power electronics device 120 includes power electronics 122 and optionally a cooling device 124 which, according to one exemplary embodiment, is connected to the heating circuit 108 . In this case, the cooling device 124 is implemented as a heat exchanger, for example. Heat generated by the power electronics 122 can be dissipated to the coolant using the cooling device 124 . For this purpose, the power electronics device 120 has a first coolant connection for fluidly connecting the cooling device 124 to the coolant inlet 116 and a second coolant connection for fluidly connecting the cooling device 124 to the coolant outlet 118 . According to one exemplary embodiment, one power electronics unit 122 corresponds to a transistor circuit for voltage conversion that is known from known inverters.

Optionally, the inverter device 102 has an intermediate circuit capacitor 126 which, according to one exemplary embodiment, is connected between electrical contacts of the supply interface 110 .

The inverter device 102 has a heating device 130 which enables the coolant to be heated. For this purpose, according to one exemplary embodiment, the heating device 130 has a first coolant connection which is fluidically connected to the coolant inlet 116 and a second coolant connection which is fluidically connected to the coolant outlet 118 . In this way, the coolant of the heating circuit 108 can be guided through the heating device 130 and heated by it. In this case, the heating device 130 is designed to generate heat using the supply voltage and/or the operating voltage and to transfer it to the coolant. For example, heating device 130 is designed to generate heat using electrical energy that is fed into inverter device 102 via supply interface 110 or consumer interface 112, or using electrical energy that is stored in power electronics device 120 or in intermediate circuit capacitor 126 .

According to one embodiment, electrical contacts of the heating device 130 are connected to the electrical contacts of the supply interface 110 . For example, heating device 130 is connected in parallel with intermediate circuit capacitor 126 .

According to one exemplary embodiment, the heating device 130 comprises an electrically operable heating element 132 and a heat exchanger 134, for example a plate heat exchanger. According to one exemplary embodiment, the heat generated by the heating element 132 is given off to the coolant via the heat exchanger 134 . For this purpose, according to one exemplary embodiment, the heat exchanger 134 is integrated into the heating circuit 118 via the coolant connections of the heating device 130 and the coolant inlet 116 as well as the coolant outlet 118 . According to one exemplary embodiment, the heating device 130 has a switch 136 via which a current flow through the heating element 132 can be controlled, for example permitted or interrupted. According to one embodiment, the switch 136 and the heating element 132 are connected in series and in parallel with the intermediate circuit capacitor 126 . Alternatively, the switch 136 is integrated into the heating element 132, for example. When the switch 136 is closed, heat can be generated by the heating element 132 , for example using energy fed into the inverter device 102 via the supply interface 110 , and transferred to the coolant using the heat exchanger 134 . As a result, for example, a required temperature of the coolant conveyed through the heating circuit 108 can be achieved and maintained. According to one embodiment, when the switch 136 is open, no further heat is generated by the heater 130 to heat the coolant.

Known electrical heating devices can be used as the heating element 132, for example a high-voltage heater, a PTC thermistor, a heating element or a layer heating element. According to one exemplary embodiment, at least a section of the heating element 132 is in direct contact with the coolant when the heating device 130 is in operation, so that the heat exchanger 134 can be dispensed with.

Heating device 130 optionally includes at least one temperature sensor, for example for detecting a temperature of the coolant flowing into heating device 130, of the coolant flowing out of heating device 130 and/or a temperature of heating element 132. Using corresponding temperature sensor signals from the temperature sensor or sensors, operation can be carried out , for example a heating output of the heating element 132 can be controlled. Protection against overheating can also be implemented by opening the switch 136, for example, when a temperature within the heating device 130 exceeds a limit value.

According to one exemplary embodiment, heating circuit 108, which can also be referred to as a cooling circuit, includes a temperature control device 140, which is designed, for example, to heat a region or an element of vehicle 100 using thermal energy provided via the coolant. For example, the temperature control device 140 can be used to heat an interior of the vehicle 100 or to control the temperature of an electrical energy supply device of the vehicle 100 .

Thermal energy removed from the cooling circuit 108 via the temperature control device 140 can be compensated for again by the heating device 130 . The heating circuit 108 optionally includes a temperature sensor 142 which is designed to detect a temperature of the coolant flowing in the heating circuit 108 and to provide a temperature signal 144 representing the temperature. The temperature sensor 142 can be arranged at a suitable position on the heating circuit 108 .

Optionally, the heating circuit 108 includes a pump 146 for pumping the coolant through the heating circuit 108.

According to one embodiment, the inverter device 102 has a controller 150 . The control device 150 is designed to provide a first control signal 152 for controlling an operation of the heating device 130 . For example, control signal 152 is used to activate and deactivate heater 130 . For example, control signal 152 is used to control a switching state of switch 136 .

For example, the control device 150 is designed to provide the first control signal 152 for activating the heating device 130 when a heat request from the heating circuit 130 is indicated via a request signal. Such a request signal can, for example, correspond to temperature signal 144 or be determined from temperature signal 144 . A corresponding request signal can also be provided, for example, by temperature control device 140 or a heating control unit of vehicle 100 .

Additionally or alternatively, the control device 150 is designed to provide the first control signal 152 for activating the heating device 130 in order to activate a discharge function for discharging electrical energy stored within the inverter device 102 . Thus, the heater 130 can be used as a discharge circuit. In this case, a further discharge circuit within the inverter device 102 can be dispensed with. For example, control device 150 is designed to provide first control signal 152 for activating heating device 130 when an error signal 154 indicates a detected error in a supply device, for example in an electrical network of vehicle 100 into which inverter device 102 is integrated.

According to one embodiment, this is a fault condition that requires an electrical discharge of the inverter device. According to one exemplary embodiment, error signal 154 is provided by a monitoring device 156 , which is designed to monitor operation of inverter device 102 .

According to one exemplary embodiment, the control device 150 is designed to provide a second control signal 158 for controlling an operation of the power electronics device 120 . For example, the second control signal 158 is suitable for activating the power electronics 122 and optionally setting a conversion characteristic of the power electronics 122 for converting the supply voltage into the operating voltage.

In this case, the control device 150 is designed, for example, as a control device that is used both to control an operation of the heating device 130 and an operation of the power electronics device 120 .

Alternatively, the inverter device 102 is designed, for example, with two separate control devices for controlling the operation of the heating device 130 and the operation of the power electronics device 120 .

According to one exemplary embodiment, the power electronics device 120, the heating device 130, the control device 150 and optionally the intermediate circuit capacitor 126 are integrated into the inverter device 102 designed as an inverter. For example, the inverter device 102 has a housing within which the power electronics device 120, the heating device 130, the control device 150 and optionally the intermediate circuit capacitor 126 are arranged. Such a housing has the supply interface 110 and the consumer interface 112, for example in the form of connectors. In addition, such a housing has the coolant inlet 116 and the coolant outlet 118, for example in the form of flanges or threaded elements for the fluid-tight connection of hoses or pipes for conducting the coolant.

2 shows a flowchart of an embodiment of a method for operating an inverter device. This can be an inverter device, as shown in FIG 1 was described.

In a step 201, a request signal is read, which represents a heat request from the heating circuit. Additionally or alternatively, in a step 203, an error signal is read in, which indicates a detected error state, for example within the inverter device or within a supply device comprising the inverter device. According to one embodiment, this is a fault condition that requires an electrical discharge of the inverter device.

In a step 205, the heater is activated in response to the heat request and/or in response to the detected fault condition to cause heating of the coolant of the heating circuit by using the supply voltage, the operating voltage or electrical energy stored within the inverter device.

Reference List

100

vehicle

102

inverter device

104

battery

106

electrical consumer

108

heating circuit

110

supply interface

112

consumer interface

114

Switch

116

coolant inlet

118

coolant outlet

120

power electronics device

122

power electronics

124

cooling device

126

intermediate circuit capacitor

130

heating device

132

heating element

134

heat exchanger

136

Switch

140

temperature control device

142

temperature sensor

144

temperature signal

146

pump

150

control device

152

first control signal

154

error signal

156

monitoring device

158

second control signal

201

Reading in a request signal

203

Reading an error signal

205

Activation of the heating device

Claims (12)

Inverter device (102) for a vehicle (100) with the following features: a supply interface (110) for applying a supply voltage and a consumer interface (112) for providing an operating voltage for operating an electrical consumer (106); a power electronics device (120) for converting the supply voltage into the operating voltage; a coolant inlet (116) and a coolant outlet (118) for incorporating the inverter device (102) into a coolant-carrying heating circuit (108) of the vehicle (100); and a heating device (130) with a first coolant connection, which is connected to the coolant inlet (116) and a second coolant connection, which is connected to the coolant outlet (118), wherein the heating device (130) is designed to use the supply voltage and/or or the operating voltage to cause the coolant to heat up. Inverter device (102) according to claim 1 , in which the power electronics device (120) has a first coolant connection, which is connected to the coolant inlet (116), and has a second coolant connection, which is connected to the coolant outlet (118), wherein the power electronics device (120) is designed to during of operating the power electronics device (120) to deliver thermal energy to the coolant. Inverter device (102) according to any one of the preceding claims, with a control device (150) which is designed to a first Provide a control signal (152) for controlling an operation of the heating device (130) and a second control signal (158) for controlling an operation of the power electronics device (120). Inverter device (102) according to claim 3 , In which the control device (150) is designed to provide the first control signal (152) for activating the heating device (130) in response to a request signal representing a heat request from the heating circuit (108). Inverter device (102) according to claim 3 or 4 , wherein the control device (150) is designed to provide the first control signal (152) for activating the heating device (130) in response to an error signal (154). Inverter device (102) according to one of the preceding claims, with an intermediate circuit capacitor (126), the heating device (130) being connected in parallel with the intermediate circuit capacitor (126). Inverter device (102) according to one of the preceding claims, in which the heating device (130) comprises an electrically operable heating element (132). Inverter device (102) according to one of the preceding claims, in which the heating device (130) is a PTC thermistor, a heating element or a layer heating element. Inverter device (102) according to one of the preceding claims, in which the heating device (130) comprises a heat exchanger (134). Supply device for a vehicle (100), the supply device comprising the following features: an inverter device (102) according to any one of the preceding claims; and a battery (104), which is connected to the supply interface (110) of the inverter device (102) to provide the supply voltage, and/or to the electrical consumer (106) in the form of an electric motor for driving the vehicle (100) and/or to the heating circuit (108), the heating circuit (108) having a pump (142) for conveying the coolant through the heating circuit (108) and a temperature control device (140) for temperature control of the vehicle (100) or an element of the vehicle (100) using the coolant. Vehicle (100) with an inverter device (102) according to one of Claims 1 until 9 or according to a supply device claim 10 . Method for operating an inverter device (102) according to one of Claims 1 until 9 , wherein the method comprises the following steps: reading in (201) a request signal that represents a heat request from the heating circuit (108); and activating (205) the heater (130) in response to the request signal to cause heating of the coolant of the heating circuit (108) using the supply voltage and/or the operating voltage.

Images