Circuit topology integrating auxiliary high / low voltage DC / DC converter with on-board charger

Abstract

The present disclosure provides a circuit topology integrating an auxiliary high / low voltage DC / DC converter with an on-board charger. An automotive power system has an isolated DC / DC converter that includes a transformer, first and second buses, and a circuit arrangement. The circuit arrangement comprises: a coil magnetically coupled to the transformer; a non-isolated DC / DC converter connected between the first bus line and the second bus line; and a no-load rectifier connected between the coil and the non-isolated DC / DC converter.

Description

Technical Field

[0001] The present disclosure relates to automotive power systems. Background Art

[0002] Cars can use electrical energy to power electric motors. The electric motors can convert this electrical energy into mechanical energy to propel the vehicle. Cars can include various power electronics to regulate and store the electrical energy. Summary of the invention

[0003] An automotive power system includes: a bidirectional totem pole power factor correction circuit; an isolated DC / DC converter, which includes a transformer, the transformer is connected to the bidirectional totem pole power factor correction circuit; a circuit arrangement, which includes a coil magnetically coupled to the transformer, a non-isolated DC / DC converter and a no-load rectifier, the no-load rectifier is connected between the coil and the non-isolated DC / DC converter; and a first bus, which is directly connected to the non-isolated DC / DC converter.

[0004] A vehicle includes: a bidirectional totem pole power factor correction circuit; a traction battery; an isolated DC / DC converter including a transformer connected between the bidirectional totem pole power factor correction circuit and the traction battery so that power from an AC source supplying the bidirectional totem pole power factor correction circuit charges the traction battery; and a circuit arrangement including a coil magnetically coupled to the transformer, a non-isolated DC / DC converter, and a no-load rectifier connected between the coil and the non-isolated DC / DC converter.

[0005] An automotive power system includes: an isolated DC / DC converter including a transformer; a first bus and a second bus; and a circuit arrangement including: a coil magnetically coupled to the transformer; a non-isolated DC / DC converter connected between the first bus and the second bus; and an off-load rectifier connected between the coil and the non-isolated DC / DC converter. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 is a schematic diagram of a system including a battery current control module.

[0007] Figure 2 is a schematic diagram of a system including an inverter system controller.

[0008] Figure 3 is a schematic diagram of an isolated AC / DC on-board charger.

[0009] Figure 4 is a schematic diagram of an isolated high voltage / low voltage DC / DC converter.

[0010] Figure 5 is a schematic diagram of a circuit topology for integrating an auxiliary high-voltage / low-voltage DC / DC converter with an on-board charger. DETAILED DESCRIPTION

[0011] Embodiments are described herein. However, it should be understood that the disclosed embodiments are merely examples and that other embodiments may take various and alternative forms. The drawings are not necessarily drawn to scale. Some features may be enlarged or minimized to show details of particular components. Therefore, the specific structural details and functional details disclosed herein should not be interpreted as limiting, but merely as a representative basis for teaching those skilled in the art.

[0012] The various features shown and described with reference to any one of the accompanying drawings may be combined with features shown in one or more other drawings to produce embodiments not explicitly shown or described. The combinations of features shown provide representative embodiments for typical applications. However, for specific applications or implementations, various combinations and modifications of features consistent with the teachings of the present disclosure may be desired.

[0013] Battery Current Control Modules (BCCMs) are components in automobiles, particularly those with electric or hybrid powertrains. These modules play a role in managing the flow of current into and out of the battery.

[0014] BCCMs act as control units that interface between the battery, charging system, and electrical loads. They monitor and control various parameters, such as battery state of charge, voltage, and temperature, and based on this information, they manage the current to the battery.

[0015] The BCCM can facilitate charge control by overseeing the battery's charging process and managing the voltage and current supplied by the charging system. By monitoring the battery's state of charge and adjusting charging parameters accordingly, the BCCM attempts to ensure that the battery receives the appropriate charge level to maintain performance.

[0016] Similarly, BCCMs can be responsible for discharge control. They can manage the current output from the battery to the electrical loads in the vehicle. By controlling the current, the BCCM can ensure a controlled power supply to the various electrical components and systems.

[0017] BCCMs can also implement various actions for the battery. For example, they can monitor battery temperature to prevent overheating. They can also detect overvoltage or undervoltage conditions and implement actions to prevent short circuits or excessive current draw.

[0018] Communication interfaces are often incorporated into the BCCM. These interfaces, such as the Controller Area Network (CAN) or LIN (Local Interconnect Network), allow the BCCM to exchange information with other vehicle systems, including the Engine Control Unit (ECU) or Body Control Module (BCM). This enables coordinated operation and integrated control across various vehicle functions. The BCCM can receive commands or instructions from other control units and adjust current accordingly.

[0019] BCCMs can have diagnostic capabilities. These modules monitor the health and performance of the battery system. They can log codes and provide diagnostic information to facilitate maintenance.

[0020] Inverter system controllers (ISCs) are also components in cars with electric powertrains. They play a role in managing and controlling the flow of power between the battery and the electric motor. The function of the inverter system controller is to convert direct current (DC) from the battery into alternating current (AC) to power the electric motor.

[0021] The ISC can act as a decision maker for the power electronics system. It can monitor various parameters (such as motor speed, torque and temperature) to ensure operation.

[0022] The task of the ISC is to convert the DC power from the battery into three-phase AC power suitable for the electric motor. It can control the switching of current and voltage using high-power semiconductor devices such as insulated gate bipolar transistors (IGBTs). By modulating the pulse width and frequency of the AC waveform, the inverter system controller manages the speed and torque output of the electric motor.

[0023] ISCs provide control of electric motors. They can use algorithms and control strategies to manage motor speed, torque, and direction of rotation. By adjusting the switching pattern of the IGBTs, the controller can change the frequency and amplitude of the AC waveform, thereby changing the motor operation.

[0024] ISC facilitates regenerative braking. During deceleration or braking, the electric motor acts as a generator, converting the vehicle's kinetic energy into electrical energy. The inverter system controller controls the flow of energy, directing it back to the battery for storage.

[0025] ISCs can be responsible for managing the thermal conditions of power electronics systems. They can monitor the temperature of inverters and electric motors and employ cooling systems (such as fans, liquid cooling, or radiators) to dissipate excess heat and maintain operating temperatures.

[0026] ISCs can incorporate diagnostic capabilities to detect and prevent faults in power electronic systems. They can monitor various parameters that can indicate potential faults, such as voltage, current, and temperature values. If a fault is detected, the controller can take corrective action, such as shutting down the system, activating other measures, or providing a fault code for diagnostic purposes.

[0027] ISCs typically have a communication interface, such as CAN or Ethernet, to enable integration with other vehicle systems. They can exchange information with the main control unit, enabling coordinated operation and facilitating diagnostics and troubleshooting. The communication interface also allows the controller to receive commands or instructions from the electronic control unit (ECU) and adjust the power output accordingly.

[0028] ISCs can incorporate features such as overvoltage and undervoltage monitoring, overcurrent monitoring, and isolation monitoring.

[0029] Integration of BCCM with ISC is often considered a challenge due to the disconnected circuits. Schematics of typical separate systems 10, 12 are shown in Figure 1 and Figure 2 Shown in.

[0030] refer to Figure 1 , the system 10 includes a BCCM 14, a traction battery 16, an auxiliary battery 18, and an onboard charging controller 20. The BCCM includes an AC / DC power factor correction circuit 22, an isolated high voltage DC / DC circuit 24, a link capacitor 26, and an isolated high voltage to low voltage DC / DC circuit 28. The isolated high voltage DC / DC circuit 24 is connected between the AC / DC power factor correction circuit 22 and the link capacitor 26. The link capacitor 26 is connected between the isolated high voltage DC / DC circuit 24 and the isolated high voltage to low voltage DC / DC circuit 28. The traction battery 16 and the auxiliary battery 18 are connected to the isolated high voltage to low voltage DC / DC circuit 28.

[0031] The AC / DC power factor correction circuit 22 includes an electromagnetic interference filter 30, a switch group 32, and an AC / DC power converter circuit 34. The switch group 32 is connected between the electromagnetic interference filter 30 and the AC / DC power converter circuit 34.

[0032] The isolated high-voltage DC / DC circuit 24 includes a first switch bridge 36, a transformer 38, and a second switch bridge 40. The first switch bridge 36 is directly connected to the power converter circuit 34. The transformer 38 is connected between the first switch bridge 36 and the second switch bridge 40.

[0033] The isolated high-voltage to low-voltage DC / DC circuit 28 includes an electromagnetic interference filter 42, a capacitor 44, and a high-voltage to low-voltage power converter circuit 46. The electromagnetic interference filter 42 is connected across the capacitor 44 and directly connected to the traction battery 16. The capacitor 44 is connected between the link capacitor 26 and the high-voltage to low-voltage power converter circuit 46. The high-voltage to low-voltage power converter circuit 46 is directly connected to the auxiliary battery 18.

[0034] On-board charging controller 20 and Figure 1 The components shown communicate with and / or exert control over the components described.

[0035] refer to Figure 2 , the system 12 includes an electric machine 48, an ISC 50, and a traction battery 52. ​​The ISC 50 is connected between the electric machine 48 and the traction battery 52.

[0036] The ISC 50 has a three-phase inverter designed to drive the electric motor 48 and operates at a much higher power than the BCCM 14. The BCCM 14 also has three circuits configured as a three-phase inverter / rectifier. Two disconnect circuits are required to charge / discharge the traction battery 16 using the three-phase inverter of the ISC. The first disconnect circuit is used to disconnect the electric motor 48 from the ISC 50, and the second disconnect circuit is used to disconnect the ISC 50 from the traction battery 52. ​​The contactors used in these disconnect circuits must carry the entire current of the ISC. Adding these contactors increases the bill of materials count, which is not conducive to level integration. However, package-level integration can provide advantages because it reduces the overall package size and / or weight and the number of connectors and wires. For example, package-level integration of high-voltage / low-voltage DC / DC converters and AC / DC chargers can increase the power density of the system. It can save costs via shared coolant channels and by eliminating connectors.

[0037] refer to Figure 3 and Figure 4 , it can be shown that the high voltage circuit consumes almost half of the total footprint. Here, a new circuit topology is proposed that eliminates the high voltage circuit and reduces the space allocated to the high voltage to low voltage DC / DC converter board by integrating the high voltage / low voltage DC / DC converter. The topology can control the power flow between the high voltage DC / DC converter and the high voltage to low voltage DC / DC converter, overcome the high current circulation in the three-port transformer, and allow the control of the low voltage circuit to be decoupled from the high voltage DC / DC controller.

[0038] The high-voltage DC / DC switching frequency does not determine the switching frequency of the low-voltage circuit. For example, the low-voltage circuit can be designed using gallium nitride high electron mobility transistors, while the high-voltage DC / DC circuit can be designed using silicon carbide metal oxide semiconductor field effect transistors. Such implementations allow the low-voltage circuit to switch at a much higher frequency than the high-voltage DC / DC circuit, and thus increase its power density. The system does not need to integrate the resonant inductor with the transformer to achieve the optimal transformer implementation. And without increasing the low-voltage circuit, the proposed topology allows the elimination of the high-voltage circuit, which may include a transformer, a primary H-bridge, a gate driver, and a resonant inductor.

[0039] The on-board charger circuit can be modified so that additional circuitry is used to output two isolated low voltage levels. A single transformer isolates the high voltage AC domain, the high voltage DC domain, and the low voltage DC domain. The first low voltage output can be referred to as low voltage bus #1, and the second low voltage output can be referred to as low voltage bus #2.

[0040] Additional circuitry may include: a third coil of a transformer magnetically coupled to the on-board charger, a no-load rectifier, two coupled or uncoupled filter inductors, a filter capacitor for filtering the voltage after the inductor and providing a DC output to Bus #2, and a non-isolated DC / DC converter for reducing or increasing the input voltage from Bus #2 and providing a constant DC voltage to Bus #1.

[0041] The topology of the isolated high-voltage DC / DC converter as part of the on-board charger can be LLC, LCC, CLLC, DAB, etc.

[0042] The high voltage DC / DC converter may include the following: i) a switching bridge referenced to the high voltage AC domain and a switching bridge referenced to the high voltage DC domain; ii) a transformer having a primary winding referenced to the high voltage AC domain and a secondary winding referenced to the high voltage DC domain; iii) an optional impedance matching network of inductors and / or capacitors to match impedance and minimize reactive power in the transformer; the impedance matching network may also tune the impedance seen by the inverter / rectifier bridge to achieve soft switching (i.e., zero voltage switching or zero current switching); iv) a third coil magnetically coupled to the secondary winding and / or its primary winding of the transformer so that the voltage induced across the third coil depends on the voltage across the secondary winding; v) an unloaded rectifier for rectifying the voltage across the third winding to provide a constant DC voltage (V A); Under steady-state conditions, an unloaded rectifier may consume approximately 0A, and therefore the rectifier only needs to be rated to handle transient currents; the power consumed by the unloaded rectifier consists of pure losses in its components; vi) two inductors and capacitors forming a low-pass filter; two coupled or uncoupled inductors may be connected to the third coil terminal, and their other terminals may be tied together and connected to a capacitor referenced to low voltage ground; the voltage across the capacitor (V B ) is approximately the voltage at the output of the uncontrolled rectifier (V A ) half; voltage V B is the source voltage of low voltage bus #2; this voltage is expected to have a range that depends on the state of charge of the high voltage traction battery (e.g., the voltage supplied to bus #2 may have a nominal value of 48V and a range between 36V and 52V, depending on the state of charge of the high voltage traction battery); vii) a non-isolated DC / DC converter that accepts a voltage V B takes as input and steps it up or down to provide a controlled voltage V C ; V C Used as the power supply voltage of bus #1; when a low-voltage battery is connected to bus #1, the non-isolated DC / DC converter operates in current mode control or voltage mode control according to the charge state of the low-voltage battery; the non-isolated DC / DC charges the low-voltage battery and provides power to the load connected across bus #1.

[0043] Bidirectional power between the AC source and the high voltage battery is controlled by controlling the high voltage DC / DC switching frequency, controlling the phase shift between the primary bridge and the secondary bridge, and controlling the phase shift between the arms of the primary bridge.

[0044] The algorithm, method or process disclosed herein can be delivered to or implemented by a computer, a controller or a processing device, which may include any dedicated electronic control unit or a programmable electronic control unit. Similarly, the algorithm, method or process can be stored in various forms as data and instructions that can be executed by a computer or a controller, including but not limited to information permanently stored on a non-writable storage medium such as a read-only memory device and information that can be modified and stored on a writable storage medium such as an optical disk, a random access memory device or other magnetic and optical media. The algorithm, method or process can also be implemented by a software executable object. Alternatively, a suitable hardware component (such as an application-specific integrated circuit, a field programmable gate array, a state machine or other hardware component or device) or a combination of firmware, hardware and software components can be used to embody the algorithm, method or process in whole or in part.

[0045] While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms encompassed by the claims.

[0046] The words used in the specification are descriptive rather than limiting, and it should be understood that various changes may be made without departing from the spirit and scope of these disclosed materials. For example, the terms "controller" and "controllers" may be used interchangeably herein because the functionality of a controller may be distributed across several controllers / modules that may all communicate via standard techniques.

[0047] As previously mentioned, the features of the various embodiments may be combined to form additional embodiments of the invention that may not be explicitly described or shown. Although various embodiments may have been described as providing advantages or being preferred over other embodiments or prior art implementations with respect to one or more desired characteristics, it will be appreciated by those of ordinary skill in the art that one or more features or characteristics may be compromised to achieve desired overall system properties, depending on the specific application and implementation. These properties may include, but are not limited to, strength, durability, marketability, appearance, packaging, size, serviceability, weight, manufacturability, ease of assembly, and the like. For this reason, embodiments described as being less desirable than other embodiments or prior art implementations with respect to one or more characteristics are not outside the scope of this disclosure and may be desirable for specific applications.

[0048] According to the present invention, there is provided an automotive power system having: a bidirectional totem pole power factor correction circuit; an isolated DC / DC converter comprising a transformer connected to the bidirectional totem pole power factor correction circuit; a circuit arrangement comprising a coil magnetically coupled to the transformer, a non-isolated DC / DC converter and a no-load rectifier connected between the coil and the non-isolated DC / DC converter; and a first bus directly connected to the non-isolated DC / DC converter.

[0049] According to an embodiment, the circuit arrangement further comprises a pair of inductors connected between the coil and the non-isolated DC / DC converter.

[0050] According to an embodiment, the inductors are coupled.

[0051] According to an embodiment, the invention is also characterized by a second bus connected between the non-isolated DC / DC converter and the inductor.

[0052] According to an embodiment, the voltage on the first bus and the voltage on the second bus are different.

[0053] According to an embodiment, the invention also features a capacitor configured to filter the voltage after the inductor.

[0054] According to an embodiment, the isolated DC / DC converter comprises an impedance matching network configured to match an impedance in the transformer.

[0055] According to the present invention, a vehicle is provided having: a bidirectional totem pole power factor correction circuit; a traction battery; an isolated DC / DC converter including a transformer connected between the bidirectional totem pole power factor correction circuit and the traction battery so that power from an AC source supplying the bidirectional totem pole power factor correction circuit charges the traction battery; and a circuit arrangement including a coil magnetically coupled to the transformer, a non-isolated DC / DC converter, and a no-load rectifier connected between the coil and the non-isolated DC / DC converter.

[0056] According to an embodiment, the invention is also characterized by a bus directly connected to the non-isolated DC / DC converter.

[0057] According to an embodiment, the circuit arrangement further comprises a pair of inductors connected between the coil and the non-isolated DC / DC converter.

[0058] According to an embodiment, the inductors are coupled.

[0059] According to an embodiment, the circuit arrangement further comprises a capacitor, and wherein the inductor and the capacitor form a low-pass filter.

[0060] According to an embodiment, the present invention is also characterized by a bus connected between the non-isolated DC / DC converter and the capacitor.

[0061] According to an embodiment, the circuit arrangement is configured such that, during operation, the voltage across the capacitor is smaller than the voltage across the capacitor of the no-load rectifier.

[0062] According to an embodiment, the isolated DC / DC converter and the circuit arrangement are configured such that during operation, a voltage range across the capacitor depends on a state of charge of the traction battery.

[0063] According to the present invention, an automotive power system is provided, which has: an isolated DC / DC converter, which includes a transformer; a first bus and a second bus; and a circuit arrangement, which includes: a coil magnetically coupled to the transformer; a non-isolated DC / DC converter, which is connected between the first bus and the second bus; and an unloaded rectifier, which is connected between the coil and the non-isolated DC / DC converter.

[0064] According to an embodiment, the invention also features a bidirectional totem pole power factor correction circuit connected to the isolated DC / DC converter.

[0065] According to an embodiment, the circuit arrangement is configured such that the voltages of the buses are different during operation.

[0066] According to an embodiment, the circuit arrangement further comprises a pair of inductors connected between the coil and the non-isolated DC / DC converter.

[0067] According to an embodiment, the inductors are coupled.

Claims

1. An automotive power system, comprising: Bidirectional totem pole power factor correction circuit; an isolated DC / DC converter including a transformer connected to the bidirectional totem pole power factor correction circuit; a circuit arrangement comprising a coil magnetically coupled to the transformer, a non-isolated DC / DC converter, and an off-load rectifier connected between the coil and the non-isolated DC / DC converter; as well as A first bus is directly connected to the non-isolated DC / DC converter.

2. The automotive power system of claim 1, wherein the circuit arrangement further comprises a pair of inductors connected between the coil and the non-isolated DC / DC converter.

3. The automotive power system of claim 2, wherein the inductor is coupled. 4 . The automotive power system of claim 2 , further comprising a second bus connected between the non-isolated DC / DC converter and the inductor.

5. The automotive power system of claim 4, wherein a voltage on the first bus and a voltage on the second bus are different. 6 . The automotive power system of claim 4 , further comprising a capacitor configured to filter the voltage after the inductor. 7 . The automotive power system of claim 1 , wherein the isolated DC / DC converter includes an impedance matching network configured to match an impedance in the transformer.

8. A vehicle comprising: Bidirectional totem pole power factor correction circuit; Traction batteries; an isolated DC / DC converter including a transformer connected between the bidirectional totem pole power factor correction circuit and the traction battery so that power from an AC source supplying the bidirectional totem pole power factor correction circuit charges the traction battery; and A circuit arrangement includes a coil magnetically coupled to the transformer, a non-isolated DC / DC converter, and a no-load rectifier connected between the coil and the non-isolated DC / DC converter.

9. The vehicle of claim 8, further comprising a bus directly connected to the non-isolated DC / DC converter.

10. The vehicle of claim 8, wherein the circuit arrangement further comprises a pair of inductors connected between the coil and the non-isolated DC / DC converter.

11. The vehicle of claim 10, wherein the circuit arrangement further comprises a capacitor, and wherein the inductor and the capacitor form a low pass filter.

12. The vehicle of claim 11 further comprising a bus connected between the non-isolated DC / DC converter and the capacitor.

13. The vehicle of claim 11, wherein the circuit arrangement is configured such that during operation, a voltage across the capacitor is less than a voltage across a capacitor of the no-load rectifier.

14. The vehicle of claim 11, wherein the isolated DC / DC converter and the circuit arrangement are configured such that during operation, a voltage range across the capacitor depends on a state of charge of the traction battery.

15. An automotive power system, comprising: An isolated DC / DC converter, the isolated DC / DC converter comprising a transformer; a first bus and a second bus; as well as A circuit arrangement includes: a coil magnetically coupled to the transformer; a non-isolated DC / DC converter connected between the first bus and the second bus; and an off-load rectifier connected between the coil and the non-isolated DC / DC converter.

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