Apparatus for single stage on-board charger with integrated ripple buffer control

Abstract

This application relates to an apparatus for a single-stage on-board charger with integrated pulsation buffer control. In at least one embodiment, a vehicle battery charger is provided. The charger includes at least one transformer, a first active bridge, a second active bridge, and at least one controller. The first active bridge includes a first plurality of switching devices positioned with a primary winding. The second active bridge includes a second plurality of switching devices positioned with a secondary winding. The controller is configured to activate the first plurality of switching devices based on a primary control signal and to activate the second plurality of switching devices based on a secondary control signal. The controller is configured to generate a secondary control signal according to a first control variable. The controller is also configured to generate a second control variable corresponding to a phase shift between the primary control signal and the secondary control signal.

Description

Technical Field

[0001] The aspects disclosed herein generally relate to devices for single-stage on-board chargers (OBCs) with integrated pulse buffer (PB) control. In one example, a device for a single-stage OBC with integrated PB can be implemented for vehicle applications. These and other aspects will be discussed in more detail herein. background

[0002] An onboard charger (OBC) for electric vehicles is used to charge the vehicle's traction battery. The OBC converts electrical power drawn from AC power into DC power and uses this DC power to charge the battery.

[0003] Overview

[0004] In at least one embodiment, a vehicle battery charger is provided. The charger includes at least one transformer, a first active bridge, a second active bridge, a ripple buffer (PB) converter, and at least one controller. The at least one transformer includes one or more primary windings and one or more secondary windings. The first active bridge includes a first plurality of switching devices positioned together with one or more primary windings on the primary side of the charger to generate a first voltage signal in response to an input voltage signal from a mains power source. The second active bridge includes a second plurality of switching devices positioned together with the secondary windings on the secondary side of the charger to generate a second voltage signal with current ripple in response to the first voltage signal. The ripple buffer (PB) converter is interfaced with the second active bridge and configured to reduce or eliminate current ripple from the second voltage signal, producing a smooth output signal suitable for one or more batteries stored in a vehicle. At least one controller is configured to selectively activate a first plurality of switching devices based on a single primary control signal to generate a first voltage signal in response to an input voltage signal, and to selectively activate a second plurality of switching devices based on a single secondary control signal to generate a second voltage signal in response to the first voltage signal. The at least one controller is also configured to generate a single secondary control signal according to a first control variable corresponding to a duty cycle. The at least one controller is further configured to generate a second control variable corresponding to a phase shift between the single primary control signal and the single secondary control signal. The second control variable enables the at least one controller to transfer power between a first active bridge and a second active bridge.

[0005] In at least one embodiment, a vehicle battery charger is provided. The charger includes at least one transformer, a first active bridge, a second active bridge, a ripple buffer (PB) converter, and at least one controller. The at least one transformer includes a primary and a secondary. The first active bridge includes a first plurality of switching devices positioned with the primary to generate a first voltage signal in response to an input voltage signal from a mains power source. The second active bridge includes a second plurality of switching devices positioned with the secondary to generate a second voltage signal with current ripple in response to the first voltage signal. The ripple buffer (PB) converter is docked to the second active bridge and configured to eliminate current ripple from the second voltage signal, generating a smooth output signal suitable for storage on one or more batteries in a vehicle. The at least one controller is configured to selectively activate the first plurality of switching devices based on a single primary control signal to generate the first voltage signal in response to the input voltage signal, and to selectively activate the second plurality of switching devices based on a single secondary control signal to generate the second voltage signal in response to the first voltage signal. The at least one controller is configured to generate a single secondary control signal according to a first control variable corresponding to a duty cycle. At least one controller is also configured to generate a second control variable corresponding to a phase shift between a single primary control signal and a single secondary control signal. The second control variable enables the at least one controller to transfer power between the first active bridge and the second active bridge.

[0006] In at least one embodiment, a vehicle battery charger is provided. The charger includes at least one transformer, a first active bridge, a second active bridge, and at least one controller. The at least one transformer includes a primary and a secondary. The first active bridge includes a first plurality of switching devices positioned with the primary to generate a first voltage signal in response to an input voltage signal from a mains power source. The second active bridge includes a second plurality of switching devices positioned with the secondary to generate a second voltage signal with current ripple in response to the first voltage signal. The at least one controller is configured to selectively activate the first plurality of switching devices based on a single primary control signal to generate the first voltage signal in response to the input voltage signal, and to selectively activate the second plurality of switching devices based on a single secondary control signal to generate the second voltage signal in response to the first voltage signal. The at least one controller is configured to generate a single secondary control signal according to a first control variable corresponding to a duty cycle. The at least one controller is also configured to generate a second control variable corresponding to a phase shift between the single primary control signal and the single secondary control signal. The second control variable enables the at least one controller to transfer power between the first and second active bridges. Brief description of the attached diagram

[0007] Embodiments of this disclosure are particularly pointed out in the appended claims. However, other features of various embodiments will become more apparent and will be best understood by taking into account the accompanying drawings and the following detailed description, wherein:

[0008] Figure 1 A block diagram of an electrical system with an on-board charger (OBC) is depicted;

[0009] Figure 2 A block diagram of the OBC is shown, where the OBC is a three-phase OBC;

[0010] Figure 3 An electrical schematic diagram of an OBC is depicted according to an embodiment, wherein the OBC is a single-phase OBC;

[0011] Figure 4 According to one embodiment, a description is provided. Figure 3 A more detailed example of the pulsation buffer (PB) converter shown;

[0012] Figure 5 Another PB converter is described according to one embodiment;

[0013] Figure 6A and 6B Each depicts a bridgeless structure according to one embodiment and a dual active bridge (DAB) stage coupled to a transformer for integrated docking with a rectifier;

[0014] Figure 7 According to one embodiment, an apparatus for a single-stage OBC (e.g., 11kW 400V volt variant) with an integrated PB is described;

[0015] Figure 8 According to another embodiment, another device is described for a single-stage OBC (e.g., 11kW 800V volt variant) with an integrated PB;

[0016] Figure 9 According to one embodiment, multiple control blocks implemented within the controller of the OBC are described;

[0017] Figure 10 According to one embodiment, a plurality of additional control blocks implemented within the controller are described;

[0018] Figure 11 An example of an OBC representing bidirectional current flow is depicted according to one embodiment;

[0019] Figure 12 According to one embodiment, the voltage output (V) across the primary side of the OBC is shown. o,p ) and the voltage output (V) across the secondary side of OCB o,s );

[0020] Figure 13 According to one embodiment, the normalized input current i is described. ac,n ;

[0021] Figure 14 According to one embodiment, various waveforms of battery current, mains current, PB voltage, PB peak voltage, FI control parameters, and D control parameters of energy flow from mains power to battery are shown; and

[0022] Figure 15 According to one embodiment, various battery currents, mains currents, PB voltages, PB peak voltages, FI control parameters, and D control parameters for the energy flow from the battery to the mains power supply are shown. Detailed description

[0023] As requested, detailed embodiments of the invention are disclosed herein; however, it should be understood that these disclosed embodiments are merely examples of how the invention can be implemented in different and alternative forms. The drawings are not necessarily to scale; some features may be exaggerated or minimized to show details of specific components. Therefore, the specific structural and functional details disclosed herein should not be construed as limiting, but rather serve only as a representative basis for teaching those skilled in the art to employ the invention in different ways.

[0024] It should be understood that the controllers disclosed herein may include various microprocessors, integrated circuits, memory devices (e.g., flash memory, random access memory (RAM), read-only memory (ROM), electrically programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or other suitable variations thereof), and software that cooperates with each other to perform the operations disclosed herein. Furthermore, these disclosed controllers use one or more microprocessors to execute a computer program contained in a non-transitory computer-readable medium, the computer program being programmed to perform any number of the disclosed functions. Additionally, the controllers provided herein include a housing and various numbers of microprocessors, integrated circuits, and memory devices (e.g., flash memory, random access memory (RAM), read-only memory (ROM), electrically programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM)) located within the housing. As described herein, the disclosed controllers also include hardware-based inputs and outputs for receiving data from and sending data to other hardware-based devices, respectively.

[0025] The aspects disclosed herein can provide a single-stage OBC that combines, for example, three rail secondarys with a single integrated PB (or integrated function), which is scaled down by a single switch in addition to a capacitor, without an inductor. The single-stage OBC can utilize an output filter inductor instead of an inductor. Typically, for a three-phase single-stage OBC, the secondary side of each of the three rails includes, for example, an H-bridge typically having, for example, 12 switches (e.g., 3 switches in parallel x 4) and a PB including, for example, a pair of switches (e.g., 2 switches in parallel), an inductor, and a capacitor. An output filter (e.g., one of two LC stages) is coupled to the PB. In one example, there can be 16 field-effect transistors (FETs) (e.g., with a 69 MΩ channel) and an operating voltage of 1200 V. The output filter can also provide an inductive effect in the PB stage.

[0026] Figure 1 A block diagram of an electrical system 10 having an on-board charger (OBC) 12 is shown in general. An example of an OBC is described in a pending U.S. application filed November 13, 2019, entitled “On-board Charger (OBC) Single-Stage Converter”, serial number 16 / 731,106 (“106 Application”), the disclosure of which is incorporated herein by reference in its entirety. The OBC 12 is generally located “on-board” on an electric vehicle 13. The term “electric vehicle” herein can include any type of vehicle that uses electrical power for vehicle propulsion and includes battery electric vehicles (BEVs), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and the like. The OBC 12 can be used to charge the traction battery 14 of the electric vehicle 13. The traction battery 14 can be a high-voltage (HV) direct current (DC) traction battery as specified according to the electrical energy requirements for propulsion of the electric vehicle.

[0027] Electrical system 10 also includes an alternating current (AC) power source (e.g., mains power source 16 from the power grid). OBC 12 uses electrical power from mains power source 16 to charge traction battery 14. OBC 12 includes an input terminal connected to mains power source 16 via external electric vehicle power supply device (EVSE) 18 to absorb electrical power from mains power source 16. OBC 12 includes an output terminal connected to traction battery 14. OBC 12 converts the electrical power absorbed from mains power source 16 into DC power and uses the DC power to charge traction battery 14.

[0028] Controller 20 is operatively coupled to OBC 12. Controller 20 may be an electronic device located on the electric vehicle 13 in an onboard manner, such as at least one processor, at least one microcontroller, etc. (e.g., a computer). Controller 20 may be defined as a vehicle controller. Controller 20 is operatively coupled to OBC 12 to control the operation of OBC 12. Controller 20 controls OBC 12 to convert electrical power from mains power supply 16 into DC power and to charge traction battery 14 with DC power. For example, controller 20 selectively controls the switching and switching duration of a power switch (not shown) located in OBC 12. The power switch can be used to convert electrical power received from mains power supply 16 into a predetermined amount of DC power. Controller 20 can communicate with and control other nodes in the electrical system 10 and electric vehicle 13, including nodes involved in charging applications.

[0029] Various OBCs may include a two-stage architecture comprising a power factor corrector (PFC) and a DC / DC converter (not shown). The PFC and DC / DC converter may be electrically coupled via a capacitive energy buffer (or “DC link capacitor”) (also not shown). The PFC may be connected to the mains power supply 16, and the DC / DC converter to the traction battery 14. The PFC performs AC / DC conversion and is controlled by controller 20 to ensure a high power factor at the input. Controller 20 controls the DC / DC converter to convert the high-voltage stable input at the DC link capacitor to the DC battery level for the traction battery 14. At this point, the DC / DC converter adapts the output voltage / current to the requirements of the traction battery 14. In summary, the PFC acts as a grid front-end, and the DC / DC converter adapts the output to the range of the traction battery 14.

[0030] Power FC typically includes one or more inductors, which can be bulky and expensive. The energy conversion scheme of a typical OBC inherently requires energy storage elements to store / provide the difference between the (electromagnetic compatibility (EMC) compliant) instantaneous input power and the (expectedly constant) output power. Currently, due to high power requirements, the energy storage elements utilized may involve the configuration of electrolytic capacitors (e.g., DC link capacitors). The potentially high capacitance requirements often result in bulky capacitors (i.e., DC link capacitors), which reduce power density (e.g., by approximately 30%) and have a significant impact on maximum operating temperature and estimated lifetime (e.g., mean time between failures (MTBF)).

[0031] Additionally, each rail of an OBC 12 can have one PFC and one DC / DC converter. Therefore, a typical three-phase OBC can include three sets of PFC and DC / DC converters. As mentioned above, each set includes multiple energy storage elements. That is, each rail includes one or more inductors in the PFC stage, and each rail includes electrolytic capacitors in the DC / DC converter stage. This aspect can lead to relatively poor power density and relatively poor MTBF, as well as increased cost.

[0032] Now for reference Figure 2 Continue to refer to Figure 1 The diagram shows a block diagram of OBC 12. OBC 12 can be an n-phase OBC, where n is an integer with a minimum value of 1. Figure 2 In the embodiment shown, OBC 12 may be a three-phase OBC having a first track 22a, a second track 22b, and a third track 22c.

[0033] Tracks 22a, 22b, and 22c may each include the same type of circuitry in the form of "modular converters," comprising AC / DC converters 24a, 24b, and 24c, respectively. Each AC / DC converter 24a, 24b, and 24c is a single-stage topology. Therefore, unlike a typical OBC with a two-stage architecture including one PFC, one DC link capacitor, and one DC / DC converter for each track, OBC 12 may include a single-stage architecture with one AC / DC converter for each track 22a, 22b, and 22c.

[0034] The OBC 12 also includes a pulse buffer (PB) converter 26. The PB converter 26 is shared by AC / DC converters 24a, 24b, and 24c. Specifically, as... Figure 2 As shown, AC / DC converters 24a, 24b, and 24c can be individually cascaded to PB converter 26. AC / DC converters 24a, 24b, and 24c can be connected to the mains power supply 16 at their respective inputs and to the inputs of PB converter 26 at their respective outputs. The output of PB converter 26 is connected to the traction battery 14. AC / DC converters 24a, 24b, and 24c, together with PB converter 26, are used to convert electrical power from the mains power supply 16 into DC power for charging the traction battery 14. More specifically, controller 20 controls the operation of AC / DC converters 24a, 24b, and 24c, as well as the operation of PB converter 26, according to a control strategy for OBC 12, to convert electrical power from the mains power supply 16 into DC power for charging the traction battery 14.

[0035] AC / DC converters 24a, 24b, and 24c comprise the same type of circuitry and function identically. Therefore, only AC / DC converter 24a will be described in more detail. Generally, AC / DC converter 24a includes a converter topology that ignores the use of a classic PFC and its associated inductor. AC / DC converter 24a can be combined with a ripple-buffered (PB) converter 26 to maximize the use of the energy storage capacitor for the traction battery 14 (e.g., the energy storage capacitor is connected in parallel with converter 26). This aspect can significantly reduce capacitor size requirements.

[0036] In operation, AC / DC converter 24a directly converts the input AC from trunk power supply 16 into DC voltage and a positive oscillating current (i.e., "current ripple"). As understood, the input AC from trunk power supply 16 is sinusoidal. The output of AC / DC converter 24a is DC voltage and current ripple. PB converter 26 post-processes the DC voltage and current ripple output of AC / DC converter 24a to preferably eliminate or substantially eliminate (or minimize or at least reduce) the current ripple and convert the output of AC / DC converter 24a into a battery-level DC output.

[0037] Now for reference Figure 3 Continue to refer to Figure 1 and Figure 2 The diagram shows the electrical schematic of OBC 12, where OBC 12 is a single-phase OBC. Figure 3 The description of OBC 12 in the text indicates a single-phase direct OBC implementation (unidirectional). For example... Figure 3 As shown, OBC 12 includes an AC / DC converter 24 and a pulsation buffer (PB) converter 26. The AC / DC converter 24 is connected to the mains power supply 16. The PB converter 26 is connected to the traction battery 14.

[0038] For example, in Figure 3 As shown, the AC / DC converter 24 includes a set of four diodes forming a full diode bridge rectifier 28 at the front end of the AC / DC converter 24. The rectifier 28 is connected to the mains power supply 16 to rectify the AC input of the AC / DC converter 24. The AC / DC converter 24 also includes a first set of four power switches forming a primary-side power switch bridge 30 on the primary side of the transformer Tx. The AC / DC converter 24 also includes a second set of four power switches forming a secondary-side power switch bridge 32 on the secondary side of the transformer Tx. In an improved version, multiple secondary-side power switch bridges 32 (each preferably having a separate secondary coil of Tx) may be provided on the secondary side of the transformer Tx.

[0039] The AC / DC converter 24, which has a primary-side power switch bridge 30 and a secondary-side power switch bridge 32 on the corresponding sides of the transformer Tx, comprises a structure based on a dual active bridge (DAB) topology. The controller 20 controls the power switch bridges 30 and 32 to convert the rectified voltage input from the rectifier 28 into a DC voltage and current ripple output. The DC voltage and current ripple output is output from the AC / DC converter 24 to the PB converter 26.

[0040] For example, in Figure 3 As shown, the PB converter 26 includes a pair of power switches 34 and an inductor L. r and energy storage capacitor C b Therefore, the PB converter 26 has current ripple processing based on a pulsating buffer topology. The PB converter 26 receives the current ripple from the output of the AC / DC converter 24. The controller 20 controls a pair of power switches 34 to eliminate the current ripple and convert the output of the AC / DC converter 24 into a battery-level DC output for charging the traction battery 14.

[0041] like Figure 3 As shown, the power switches of the primary-side power switch bridge 30 and the secondary-side power switch bridge 32 of the AC / DC converter 24 and the power switch pair 34 of the PB converter 26 are MOSFETs.

[0042] In OBC 12, only a single magnetic component (i.e., transformer Tx) is located in the DC / DC block of AC / DC converter 24. PB converter 26 replaces the DC link capacitor compensation function of a typical OBC. PB converter 26 compensates for the current ripple from the output of AC / DC converter 24 to PB converter 26 to provide a smooth DC output voltage, thereby significantly reducing the energy storage capacitor C of PB converter 26. b The size.

[0043] As shown, Figure 3 The OBC 12 shown is unidirectional because power flows from the mains power supply 16 to the AC / DC converter 24, then to the PB converter 26, and finally to the traction battery 14. However, the OBC 12 can be bidirectional. For example, the OBC 12 can be made bidirectional by replacing the diodes of the rectifier 28 of the AC / DC converter 24 with active switches (e.g., MOSFET switches), thus preparing it for a bidirectional rectifier. Therefore, the topology of the OBC 12 can be implemented using a synchronous rectifier (bidirectional), thereby enabling bidirectional power flow: grid to vehicle (G2V) and vehicle to grid (V2G).

[0044] Figure 4A more detailed example of the PB converter, shown as 26, is depicted. In one example, the PB converter 26 can be implemented as a step-down PB converter 26. In this case, the PB converter 26 can reduce the DC voltage supplied to the traction battery 14 by one or more of the AC / DC converters 24a, 24b, 24c.

[0045] As mentioned above, the PB converter 26 includes multiple power switches 34a and 34b, and an inductor L. r and energy storage capacitor C b Therefore, the PB converter 26 has current ripple processing based on a pulsating buffer topology. The PB converter 26 receives the current ripple from the output of the AC / DC converter 24. The controller 20 controls the power switches 34a, 34b to eliminate the current ripple and convert the output of the AC / DC converter 24 into a battery-level DC output for charging the traction battery 14. The buck PB converter 26 typically includes an inductor L r The capacitor C is connected in series to form the first branch 40. b Branch 40 is connected in parallel with power switch 34b to form second branch 42. First switch 34a is connected in series with first branch 40 and second branch 42. The layout or arrangement of PB converter 26, as directly mentioned above, results in an overall reduction in current from approximately 61A to approximately 31A at 400 volts.

[0046] Capacitor C b A parallel connection is made between the secondary-side power switch bridges (not shown) and included in the PB converter 26. The first terminal of the first switch 34a is connected to a node. In this node, Kirchoff's law applies, where I(power bridge) + I(PB) + ios = 0. The same applies to the power switches 34a, 34b and the inductor L. r The node formed between them. Flow to capacitor C. b The current flows through the inductor L r Vos is shared between the output of the power switch bridge (not shown), the PB converter 26, and the output battery.

[0047] PB converter 26 from capacitor C b A pair of power switches 34a, 34b of the PB converter 26 are operated to draw a buffer current associated with the buffer voltage and control the operation of the PB converter 26 to draw the necessary amount of buffer current associated with the buffer voltage and generate the target battery voltage / current from it. The target battery voltage / current is output from the PB converter 26 to charge the traction battery 14. Generally, the PB converter 26 is arranged to operate in the 800V range 142 (e.g., 450V-850V), but at the same time utilizes a reduced current. For example, the OBC 12 can operate in the 800V range.

[0048] Figure 5 Another PB converter 26 is described according to one embodiment. In one example, the PB converter 26 can be implemented as a boost PB converter 26. The PB converter 26 includes multiple power switches 34a and 34b, an inductor L r and energy storage capacitor C b The boost converter 26 includes an inductor L connected in series with power switches 34a and 34b. r Switch 34a and capacitor C b They are connected in series to form the first branch 46 (or the first node). Branch 46 is connected in parallel with the power switch 34b. The layout or arrangement of the PB converter 26, as directly mentioned above, results in an overall reduction of approximately 15A of current at 400 volts.

[0049] In capacitor C b The voltage at the point can be higher at a higher voltage and then the same energy flow at a lower current (see directly above). This lower current minimizes losses, thus improving efficiency. For example, stored in inductor L... r The energy in the capacitor is used to boost the voltage from battery 14 to that in capacitor C. b The higher voltage in the circuit. Therefore, due to the boost operation of the PB converter 26, capacitor C b The voltage can be higher than that of battery 14. This high-voltage operation ensures low current flow through PB converter 26, and thus ensures high-efficiency operation. PB converter 26 can be used to reduce the current levels of the 400V OBC variant. Generally, in boost mode, PB converter 26 requires capacitor C. b This is suitable for applications involving high voltages, such as those used in power devices. The PB converter 26 may be better suited for 400V batteries than 800V batteries.

[0050] Figure 6AAccording to one embodiment, a system 100 formed by modular converters 102 (or modular converters 102a-102c) is depicted, each modular converter 102 having dual active bridge (DAB) stages 104a, 104b. The modular converter 102 includes: a transformer 106 having a primary transformer 106a (e.g., the primary side of transformer 106), a secondary transformer 106b (e.g., the secondary side of transformer 106); and a rectifier 108. The rectifier 108 is formed by a full-bridge diode network 109, or the rectifier 108 is formed by a full-bridge switching circuit formed by switches 110a-110d. A controller 118 can control the switching states of the switches 110a-110d of the rectifier 108. For example, in the case where the converter 102 includes a rectifier 108 formed by a diode network 109, such a diode network 109 is not part of the DAB stage 104a, and the rectifier 108 enables unidirectional power transfer. Conversely, when the converter 102 includes a rectifier 108 formed by switches 110a-110d, such switches 110a-110d enable bidirectional power transfer. Figure 6A A first PB converter 126 and a second PB converter 126' are also shown. It should be understood that system 100 may include either the first PB converter 126 or the second PB converter 126'.

[0051] The first PB converter 126 includes a capacitor 120, switches 114e-114f, and an inductor L. r The second PB converter 126' includes capacitors, switches 114e-114f, and inductor L. r The first PB converter 126 or the second PB converter 126' cooperates with the DAB stage 104b to convert energy for storage. The choice of whether the first PB converter 126 or the second PB converter 126' is implemented depends on the output voltage that is desired to be stored on the battery 14. The DAB stage 104a includes switches 110e–110h operably coupled to the primary transformer 106a. The DAB stage 104b includes switches 114a–114d operably coupled to the secondary transformer 106b.

[0052] Figure 6B According to one embodiment, a system 100' is depicted consisting of a modular converter 102 (or 102a-120c) having dual active bridge (DAB) stages 104a, 104b. System 100' is generally similar to... Figure 6ASystem 100. However, some differences exist. For example, the diode network 109 in system 100' is implemented as a half-bridge diode network (while in system 100, the diode network 109 is implemented as a full-bridge diode network). As mentioned above, when system 100' includes a rectifier 108 formed by the diode network 109, such a diode network 109 is not part of the DAB stage 104a and achieves unidirectional power transfer. Conversely, when system 100' includes a rectifier 108 formed by switches 110a-110b, such switches 110a-110b (i.e., rectifier 108) achieve bidirectional power transfer. It should be recognized that system 100' may include a first PB converter 126 or a second PB converter 126'.

[0053] DAB stage 104a includes switches 110c–110f operably coupled to the apex of primary transformer 106a. The midpoint 136 of transformer 106 is coupled to the mains power supply. As mentioned above, either the first PB converter 126 or the second PB converter 126' is functionally combined with DAB stage 104b. The choice of whether to implement the first PB converter 126 or the second PB converter 126' depends on the output voltage desired to be stored in battery 14. DAB stage 104a includes switches 110c–110f operably coupled to primary transformer 106a. DAB stage 104b includes switches 114a–114d operably coupled to secondary transformer 106b.

[0054] As shown, combined with Figure 6A Compared to the total of 8 switches shown, system 100' provides a reduced number of switches overall (e.g., 6 switches in total), resulting in higher efficiency. Furthermore, system 100' provides bidirectional characteristics by replacing diodes with various switching devices 110a-110b. Figure 6B The illustrated system 100' provides an input rectifier 108 or 109 combined with a primary full-bridge (e.g., DAB stage 104a) and a transformer primary 106a (e.g., having two windings and a neutral point 136). A PB converter 126 (or 126') is decoupled from the secondary full-bridge (e.g., DAB stage 104b). Aspects disclosed herein generally provide for integrating the PB converter 126 onto the secondary side 107 of the configuration 102.

[0055] Figure 7According to one embodiment, an apparatus 200 for a single-stage OBC (e.g., an 11kW 400V variant) having an integrated PB converter 226 is depicted. The apparatus 200 generally includes a plurality of modular converters 101a-101n (or “101”). Each corresponding modular converter 101 includes a rectifier half-bridge structure 108 and DAB stages 104a, 104b. Each modular converter 101 also includes a transformer 106 (e.g., a single transformer 106 having two primary windings 106a (or primary-side transformer 106a) on the primary side 105 and two or more secondary windings (or secondary-side transformer 106b) on the secondary side 107) and the PB converter 226. Typically, each modular converter 101 has a transformer 106, and each transformer 106 includes a primary winding with two coils or windings 106a (with a midpoint 136a) (or two primary windings 106a) and a secondary winding with two coils or windings 106b (with a midpoint 136b) (or two secondary windings 106b). Figure 7 Details of the modular converter 101a are shown, which includes a primary transformer 106a and a secondary transformer 106b, as well as many other features. Although Figure 7 Additional modular converters 101b–101n are shown; however, it should be understood that each of these modular converters 101b–101n includes features similar to those depicted in modular converter 101a. It should be recognized that the primary winding 106a is shown only for modular converter 101a, and not for the remaining modular converters 101b–101n. Similarly, it should be recognized that the secondary winding 106b… Figure 7 The diagram shows all modular converters 101a-101n.

[0056] The device 200 includes a first filter 202, a second filter 204, and a plurality of switching devices 206. The first filter 202 is operatively coupled to the primary side 105 of each converter 101. The second filter 204 is operatively coupled to the secondary side 107 shared by all converters 101. The first filter 202 may be an AC electromagnetic interference (EMI) filter compliant with EMC (electromagnetic compatibility) standards. The second filter 204 may be a DC EMI filter used to ensure smooth output current is supplied to the battery 215. The second filter 204 can be implemented in many OBC designs in the automotive market. It should be understood that the number of modular converters 101 implemented in the disclosed device 200 may vary based on desired standards for a particular implementation.

[0057] Each converter 101 includes multiple switches 210a-210f (“210”) and capacitor 212. A rectifier 108 is formed via switches 210a-210b. For each modular converter 101, the multiple switches 210 and capacitor 212 are operatively coupled to a primary-side transformer 106. The operation of the device 200 is similar to that described above. For example, the rectifier 108, including switches 210a and 210b, provides a rectified output voltage or current in response to the output provided by the first filter 202. The rectifier 108 provides a rectified output voltage to the primary side 105. At least one controller 218 (hereinafter referred to as “controller 218”) controls the switches 210 to provide a necessary amount of rectified output current associated with the rectified output voltage from the rectifier 108, thereby generating a primary-side output voltage or current on the primary-side transformer 106a.

[0058] Switches 210c–210f on the primary side 105 receive the rectified output voltage / current from rectifier 108. As will be described in more detail below, controller 218 controls the operation of the primary-side power switch bridge (or switches 210c–210f) to draw the necessary amount of rectified output current associated with the rectified output voltage from rectifier 108, thereby generating a primary-side output voltage on primary-side transformer 106a. Controller 218 controls switches 214a–214d to generate a secondary-side input voltage / current on secondary side 107 (or secondary-side transformer 106b).

[0059] PB converter 226 includes switches 214e, capacitors 220 and 222, and an inductor 227. Capacitor 222 is a bus capacitor used for decoupling electrical components on PB converter 226. Inductor 227 and capacitor 220 form a resonant circuit that ensures soft switching and stores energy. Capacitor 220 is charged with a secondary-side input voltage or current, and thus provides the secondary-side input voltage or current. PB converter 226 draws a buffer current associated with the buffer voltage from capacitor 220, which is supplied to battery 215 via a second filter 204. Controller 218 controls the operation of power switches 214a-214d. Power switches 214a-214d, along with switch 214e and capacitor 220, are located on secondary side 107. Therefore, in this respect, a portion of the PB converter 226 (e.g., switch 214e and capacitor 220) is combined with switches 214a-214d (or DAB stage 104b) on the secondary side 107. The PB converter 226 draws the necessary amount of buffer current associated with the buffer voltage, thereby generating the target battery voltage / current. The PB converter 226 generates the required current to eliminate current ripple that may have a frequency of, for example, 100 kHz (or intermediate frequency) and provides a smooth DC current to the battery 215. The PB converter 226 generates the target battery voltage / current to charge the traction battery 215. As described above, the PB converter 226 is combined with the secondary side 107 (e.g., switches 214a-214d). The controller 218 employs a control strategy (and control block) that enables the control of the PB converter 226 to be integrated with the control of the secondary side 104b. It should be understood that the secondary side 107 includes the DAB stage 104b, the transformer secondary 106b, and the PB converter 226.

[0060] It should be recognized that, assuming the various values ​​of the electrical equipment shown on device 200 are utilized, device 200 can be used in conjunction with a 22kW, 400V variant. In this regard, battery 215 is coupled to the midpoint of primary-side transformer 106a via inductor 227, and capacitor 222 is coupled to the secondary bus (e.g., coupled to switch 214), which can be charged to 800V or approximately 800V.

[0061] Figure 8 According to one embodiment, a device 300 for a single-stage OBC (e.g., an 11kW 800V variant) having an integrated PB converter 226 is depicted. The device 300 is generally similar to the combination described above. Figure 7 The device 200 is shown. Battery 215 is coupled to a different... Figure 7 The secondary bus (e.g., coupled to switch 214). Figure 7 The device 200 typically provides an output voltage of 400V, while Figure 8The device 300 typically provides an output voltage of 800V. Capacitor 222 is coupled to the midpoint of the secondary-side transformer 106a on the secondary side 107 via inductor 227, and capacitor 222 can be charged to 800V. Figure 8 These aspects and Figure 7 The differences are shown. It should be recognized that, assuming the various values ​​of the electrical equipment shown on device 200 are utilized, device 300 can be used in conjunction with a 22kW, 800V variant.

[0062] Figure 9 According to one embodiment, a first control block 400 located within a controller 218 is depicted. The controller 218 utilizes the first control block 400 to control various aspects of devices 200 and 300. These aspects will be discussed in more detail below. The first control block 400 includes a first portion 401 and a second portion 403. The first portion 401 includes an adder 402 and a proportional-integral-derivative (PID) controller 404. The controller 218 determines the maximum peak voltage (e.g., V_PB_MAX) of the PB converter 226 and provides it to the adder 402. The maximum peak voltage of the PB converter 226 typically corresponds to the maximum voltage at capacitor 220. It should be appreciated that one or more voltage sensors (not shown) may be located around the PB converter 226 to provide the maximum peak voltage of the PB converter 226 (e.g., the voltage across capacitor 220). The controller 218 is operatively coupled to one or more voltage sensors to provide the maximum peak voltage of the PB converter 226. Controller 218 also supplies adder 402 with the maximum voltage (e.g., 800V for devices 200 and 300) allowed to be stored on capacitor 220 of PB converter 226 (e.g., V_PB_OBJ). V_PB_OBJ is based on the design parameters of the selected pulsating buffer capacitor 220. For example, V_PB_OBJ is the maximum voltage that the secondary side 107 can operate at according to the design (e.g., 950V; e.g., depending on the design, V_PB_OBJ is the maximum voltage at which the secondary side 107 can operate in the range of, for example, 220–1100 volts, however, in one example, 950V may be preferred). V_PB_MAX is variable, ranging from the maximum peak voltage of capacitor 220 (e.g., see...). Figure 14The peak voltage of PB (708) is obtained. Considering the technology and maximum voltage of capacitor 220, V_PB_OBJ is selected to optimize the operating conditions of devices 200 and 300 to optimize the cost of capacitor 220. Typically, the value of V_PB_OBJ is pre-stored in controller 218. Adder 402 subtracts V_PB_MAX from V_PB_OBJ and provides the difference between V_PB_MAX and V_PB_OBJ to PID controller 404. PID controller 404 generates the desired root mean square value of the current input (e.g., Iac_rms), which corresponds to the desired input current request for driving switches 210 and 214 after subsequent execution on the second part 403 and the first control part 451 (see below), which provides control parameters FI on the primary side 105 and secondary side 107 of devices 200 and 300 (e.g., a power plant).

[0063] The second part 403 of the first control block 400 includes a gain circuit 406 and a multiplier circuit 408. An oscillating waveform (e.g., a sine wave) is provided to the gain circuit 406 and the multiplier circuit 408. The multiplier circuit 408 multiplies the oscillating waveform by a desired Rms current input (e.g., Iac_rms) generated by the PID controller 404 to produce a transformed Iac_rms current (or Iac_Obj_PH1, where PH1 corresponds to line 1). This is performed for each of the converters 101a-101n in the system 700 or 800. It should be appreciated that, in combination Figure 9-10 The operations described and executed are performed for each converter 101. The first control block 400 provides AC current to the power plant when the device 200 or 300 discharges current (i.e., the battery 14 provides power back to the grid (or the mains power 16)) and provides Iac_Obj_PH1 to the power plant when the device 200 or 300 charges the battery 14.

[0064] Figure 10 According to one embodiment, a second control block 450 located within a controller 218 is depicted. The controller 218 also utilizes the second control block 450 to control various aspects of the device 200 or 300. The second control block 450 includes a first portion 451 and a second portion 453. The first portion 451 includes a first gain circuit 452, a second gain circuit 454, a first multiplexer circuit 456, a second multiplexer circuit 458, a first comparator 460, and a first PID controller 462. The first multiplexer 456 includes inputs 457a–457c, and the second multiplexer includes inputs 459a–459c. The first gain circuit 452 receives Iac_PH1 corresponding to the AC current measured in line 1 (see [link to relevant documentation]). Figure 7 and Figure 8 , Figure 7 and Figure 8 The lines 1, 2, and 3 from the mains power supply and the neutral input are depicted (see the output of the AC EMI filter 202).

[0065] When Iac_PH1 is positive, the signal is passed to the first input 457a of the first multiplexer circuit 456. When Iac_PH1 is negative, the signal is passed to the first gain circuit 452, where the signal is multiplied by a negative unit value. Vac_PH1 typically represents the voltage indicating when to select input 457a or 459a (e.g., when Vac_PH1 is positive) or input 457c or 459c (e.g., when Vac_PH1 is negative). The output of the first gain circuit 452 (e.g., positive Iac_PH1) is then sent to the third input 457c of the first multiplexer 456. The first comparator 460 compares the outputs from the first multiplexer 456 and the second multiplexer 458 (e.g., Iac_PH1 and Iac_Obj_PH1) with each other. If comparator 406 provides the difference between the outputs of multiplexers 456 and 458, the first PID controller 462 applies a compensation factor and generates a signal or parameter FI corresponding to the power plant operating variable. The variable FI corresponds to the phase shift between the control signal used to activate / deactivate switch 210 on the primary side 105 and the control signal used to activate / deactivate switch 214 on the secondary side 107.

[0066] For example, refer to Figure 7 and Figure 8The controller 218 provides a single primary control signal to switches 210c, 210d, 210e, and 210f of DAB stage 104a on the primary side 105, and a single secondary control signal to switches 214a, 214b, 214c, and 214d of DAB stage 104b on the secondary side 107. Therefore, at this point, the variable FI corresponds to the phase shift between the single primary control signal and the single secondary control signal. It should be understood that the controller 218 generates a single primary control signal for each modular converter 101a-101n (or track) and sends a single primary control signal to switches 210c, 210d, 210e, and 210f, and also generates a single secondary control signal for each modular converter 101a-101n (or track) and sends a single secondary control signal to switches 214a, 214b, 214c, and 214d. It should also be recognized that a single primary control signal selectively activates any one or more of switches 210c, 210d, 210e, and 210f, and / or selectively deactivates any one or more of switches 210c, 210d, 210e, and 210f. Similarly, it should be recognized that a single secondary control signal selectively deactivates any one or more of switches 214a, 214b, 214c, and 214d, and / or selectively deactivates any one or more of switches 214a, 214b, 214c, and 214d.

[0067] For example, regarding a controller 218 that provides a single primary control signal to switches 210c, 210d, 210e, and 210f, the single primary control signal is provided by controller 218 to drive all switches 210c, 210d, 210e, and 210f with, for example, a fixed duty cycle of 50%. Generally, each half-bridge of the switches can be commanded by a driver (not shown) with the same pulse width modulation (PWM) signal, activating the gates of the high sides of switches 210c, 210d, 210e, and 210f when the low side of switches 210c, 210d, 210e, and 210f is low.

[0068] For a single secondary control signal, controller 218 has information corresponding to the operating frequency (e.g., duty cycle (control variable D)) of switches 210c, 201d, 210e, and 210f, and control variable FI for a single primary control signal. This aspect defines the single secondary control signal. Generally, any half-bridge or each full-bridge (or DAB stages 104a and 104b) is driven via a single chip to ensure switching dead times. The dead time can be very short compared to the duty cycle in which both switches in a half-bridge (or bridge branch) are off (e.g., one switch just turned on and then off, and the other switch is off and will switch on). This is to ensure that, in any case (e.g., due to delays caused by capacitance), both switches will not be on simultaneously, and this situation could lead to a short circuit and potentially burn out both components. On the other hand, this operation causes the high switch of the first bridge branch to be activated simultaneously with the low switch of the second bridge branch, and vice versa. The low switch of the first bridge branch is activated simultaneously with the high switch of the second bridge branch. Knowing all this, (according to the chip manufacturer's definition) the driver chip control input, controller 218 converts a single primary control signal and a single secondary control signal into driver chip control inputs.

[0069] Return to reference Figure 10 Similarly, Iac_Obj_PH1 is sent to the first input 459a of the second multiplexer 458. (As in combination...) Figure 9 As mentioned, Iac_Obj_PH1 is provided (or generated) by the second part 403 of the first control block 400. When Iac_Obj_PH1 is positive, this signal or parameter is passed to the first input 459a of the second multiplexer circuit 458. When Iac_Obj_PH1 is negative, this signal or parameter is passed to the second gain circuit 454, where Iac_Obj_PH1 is multiplied by a negative unit value. The output of the second gain circuit 454 (e.g., a positive Iac_PH1) is then transmitted to the third input 459c of the second multiplexer 458.

[0070] The second part 453 includes an averaging block 470, a second comparator 472, and a third PID controller 474. The sensed or measured high-voltage (HV) battery current (Ibatt_m) is provided to the averaging block 470. The averaging block 470 is a moving averaging block that acquires a predetermined number of samples Ibatt_m, obtains the average value of the predetermined number of samples, and provides the corresponding output to the second comparator 472. The second comparator 472 receives the target charging current (Ibatt) of the battery 215. The second comparator 472 obtains the difference between Ibatt_m and Ibatt and provides the output to the third PID controller 474. The third PID controller 474 adjusts the difference between the current values ​​and generates a corresponding compensation D value. The third PID controller 474 generates an output signal (or control variable) D corresponding to the control signal, controlling the switch 214 on the secondary side 107 with a corresponding duty cycle, thereby providing the required amount of current to the battery 215. The controller 218 dynamically adjusts the control variable D, which allows the PB converter 226 to be integrated with the secondary side 107. For example, previous implementations provided a fixed D, which required additional electronics. Given that the embodiments disclosed herein provide a variable or dynamically controlled D (e.g., a variable duty cycle), a separate PB converter and DAB secondary side 104b are no longer necessary.

[0071] Figure 11 An example of an OBC 500 exhibiting bidirectional current flow is depicted according to one embodiment. Figure 11The diagram corresponds to a single track (or converter 101). The OBC 500 includes a DAB primary side 505, a DAB secondary side 507, a rectifier 528, and a PB converter 526 located on and integrated with the DAB secondary side 507. The rectifier 528 includes switches 502a-502b. The primary side 505 includes switches 510a-510d (“500”) and the primary side 503 of transformer 506. The secondary side 507 includes switches 514a-514e and the secondary side 507 of transformer 506. The PB converter 526 includes switches 514e, capacitors 520 and 522, and an inductor 527. Battery 515 receives power from the PB converter 526, while the OBC 500 converts AC power from the mains power supply 516. It should be recognized that OBC500 is bidirectional. In one direction (or when OBC500 is releasing energy or in a releasing state), OBC500 enables battery 515 to supply voltage to secondary side 507, and energy is fed back through primary side 505 to provide AC output on the grid. In the other direction (or when OBC500 is in a charging phase (AC-DC conversion to store DC energy in battery 515), OBC500 supplies AC energy from mains power supply 516 to primary side 505, whereby AC output is thus supplied to secondary side 507 (and PB converter 526) to generate DC output for storage in battery 515. The variable i is depicted on primary side 505. ac Corresponding to the AC current generated by the mains power supply 516, V o,p V corresponds to the voltage generated on the primary side 505 when switch 510 is controlled by controller 218. o,s Corresponding to the voltage generated on the secondary side 507, i 电池 This corresponds to the charging current supplied to battery 515 by the secondary side during the charging state. When OBC 500 is in the discharging state, the current i ac The value is negative. Similarly, when OBC 500 is in a discharged state, as shown in the example... Figure 10 The parameter FI determined by the second control block 450 of the controller 210 shown is also negative.

[0072] Figure 12 According to one embodiment, the voltage output (V) across the primary side of OBC 500 (or device 200 and / or 300) is shown. o,p The voltage output (V) across the secondary side of the 600 and OCB 500 (or devices 200 and / or 300) o,s )602. The article mentions... Figure 11 All references to the components or features also apply. Figure 7 and Figure 8 Features or components. For example... Figure 12As shown, controller 218 controls switch 510 (or 210) at a corresponding switching frequency to generate voltage V across primary side 505 (or 105). o,p .like Figure 10 As shown, controller 218 controls switch 514 (or 214) to generate voltage V across secondary side 507 (or 107). o,s Its duty cycle is based on D, determined by the second part 453 of the second control block 450. The duty cycle D generated by the controller 218 for controlling the switch 514 (or 214) can compensate for the battery current i. 电池 The 50 / 60Hz ripple is controlled by controller 218. The duty cycle of control switch 510 (or 210) can be fixed at, for example, 0.5.

[0073] The parameter FI generated by the second control block 450 of controller 218 typically corresponds to a power correction factor and can be used to ensure proper mains power supply 516 and power transfer from primary side 105 (or 505) to secondary side 107 (or 507). As described above, parameter FI corresponds to the phase shift between the control signal for activating / deactivating switch 210 on primary side 105 and the control signal for activating / deactivating switch 214 on secondary side 107. Figure 12 As shown, parameter FI provides the voltage V. o,p and V o,s The movement between them. If the parameter FI of any of the multiple modular converters 101a-101n (or "101") of device 200 or 300 is equal to 0, then Iac,obj becomes zero, and the corresponding converter 101 exhibiting FI equal to zero does not provide power. It should be recognized that the modular converters 101 can operate independently of each other.

[0074] According to one embodiment, Figure 13 The normalized input current i corresponds to the parameters D and FI. ac,nThe graph 600 is typically divided into a first part 602 and a second part 604. When the OBC 500 (including devices 200 and / or 300) is in a discharging state (e.g., the vehicle battery 515 is supplying voltage energy from the secondary 507 to the primary 505 or OBC 500, and / or devices 200 and / or 300 are converting DC voltage to AC voltage), the first part 602 represents the normalized values ​​for D and FI. In the discharging state, the graph 600 depicts a negative value for parameter FI. When the OBC 500 (e.g., OBC 500 and / or devices 200 and 300) inverts the input AC energy from the mains power supply 516 into DC energy for storage in the battery 515, the second part 604 represents the normalized values ​​for D and FI. In the charging state, the graph 600 depicts a positive value for FI. It is worth noting that the values ​​shown for D and FI are normalized values.

[0075] The curve 600 can be interpreted as follows. The parameter FI controls the direction and magnitude of the input current, while D allows for variation in magnitude for a given input current direction. For example, assuming D equals 0.4 and FI equals -0.05 (see Part 1, 602), then the normalized input current (e.g., i...) ac,n The value is equal to 0.3 (e.g., 0.32). In this case, the current i ac 30% is transferred from OBC 500 (or device 200 or 300) back to the mains power supply 516 (or the grid). For example, assuming D equals 0.3 and FI equals 0.2 (see Part 2 604), the normalized input current (e.g., i ac,n The value is equal to 0.8. In this case, the current i supplied from the mains power supply 516 is... ac 80% is transferred back to battery 515 of OBC 500 (or device 200 or 300). Parameter FI corresponds to the phase shift between the primary full bridge (e.g., switches 510a-510d) and the second full bridge (e.g., switches 514a-514d).

[0076] Figure 14 According to one embodiment, a graph 700 is shown, which includes various waveforms relating to the energy flow from the mains power supply 516 to the battery 515: battery current 702, mains current 704, PB voltage 706, PB peak voltage 708, FI control parameter 710, and D control parameter 712. In this case, the OBC 500 (including device 200 or 300) is in a charging state because the FI control parameter 710 includes a positive value (e.g., the FI control parameter 710 is above a zero threshold). The controller 218 modulates parameters f1 and D to achieve a smooth DC output current during vehicle charging.

[0077] Figure 15 According to one embodiment, a graph 800 shows various waveforms of the energy flow from the mains power supply 516 to the battery 515, including battery current 802, mains current 804, PB voltage 806, PB peak voltage 808, FI control parameter 810, and D control parameter 812. In this case, the OBC 500 (including device 200 or 300) is in a discharging state because the FI control parameter 710 includes a negative value (e.g., the FI control parameter 710 is below the zero threshold of 1000 units (see the y-axis of graph 700)). FI and D are modulated according to a previously defined control scheme to achieve a sinusoidal mains current when the vehicle is discharging.

[0078] While exemplary embodiments have been described above, this does not mean that these embodiments describe all possible forms of the invention. Rather, the language used in this specification is illustrative rather than restrictive, and it should be understood that various changes can be made without departing from the spirit and scope of the invention. Furthermore, features of different implementation embodiments can be combined to form other embodiments of the invention.

[0079] Various aspects of this disclosure may be implemented in one or more of the following embodiments:

[0080] Project 1): A vehicle battery charger, comprising:

[0081] At least one transformer having one or more primary windings and one or more secondary windings;

[0082] A first active bridge includes a first plurality of switching devices, which are positioned together with one or more primary windings on the primary side of the charger to generate a first voltage signal in response to an input voltage signal from a mains power supply.

[0083] The second active bridge includes a second plurality of switching devices, which are positioned together with the one or more secondary windings on the secondary side of the charger to generate a second voltage signal with current ripple in response to the first voltage signal.

[0084] A ripple buffer (PB) converter, which interfaces with the second active bridge and is configured to reduce or eliminate current ripple from the second voltage signal, and produce a smooth output signal suitable for storage on one or more batteries in a vehicle; and

[0085] At least one controller is configured to:

[0086] The first plurality of switching devices are selectively activated based on a single primary control signal to generate the first voltage signal in response to the input voltage signal;

[0087] The second plurality of switching devices are selectively activated based on a single secondary control signal to generate the second voltage signal in response to the first voltage signal; the at least one controller is configured to generate the single secondary control signal according to a first control variable corresponding to the duty cycle; and

[0088] A second control variable is generated corresponding to the phase shift between the single primary control signal and the single secondary control signal, wherein the second control variable enables the at least one controller to transfer power between the first active bridge and the second active bridge.

[0089] Project 2): A vehicle battery charger according to Project 1), wherein the first control variable is further based on the measured current of the one or more batteries.

[0090] Project 3): A vehicle battery charger according to Project 2), wherein the first control variable varies with the target charging current and with the measured current of the one or more batteries.

[0091] Project 4): A vehicle battery charger according to Project 2), wherein the at least one controller includes a moving average block programmed to obtain a predetermined number of samples of the measured current of the one or more batteries to generate a final measured current of the one or more batteries.

[0092] Project 5): A vehicle battery charger according to Project 4), wherein the at least one controller includes a comparator for obtaining the difference between a target charging current and a final measured current of the one or more batteries to provide a first difference output.

[0093] Project 6): The vehicle battery charger according to Project 5), wherein the at least one controller includes a proportional-integral-derivative (PID) controller to generate a first control variable (D) based on the first difference output.

[0094] Item 7): A vehicle battery charger according to Item 1), wherein the at least one controller is further configured to generate the first control variable to compensate for current ripple in the current supplied to the one or more batteries on the vehicle.

[0095] Project 8): A vehicle battery charger according to Project 1), wherein the second control variable (FI) is based at least on the AC current measured from the input voltage signal of the mains power supply.

[0096] Project 9): A vehicle battery charger according to Project 8), wherein the second control variable (FI) is also based at least on the maximum peak voltage of the PB converter and the maximum voltage stored in the capacitor located in the PB converter.

[0097] Item 10): A vehicle battery charger, comprising:

[0098] At least one transformer having a primary and a secondary;

[0099] A first active bridge includes a first plurality of switching devices positioned together with the primary to generate a first voltage signal in response to an input voltage signal from a mains power supply.

[0100] The second active bridge includes a second plurality of switching devices positioned together with the secondary to generate a second voltage signal with current ripple in response to the first voltage signal.

[0101] A ripple buffer (PB) converter, which interfaces with the second active bridge and is configured to eliminate current ripple from the second voltage signal, and produce a smooth output signal suitable for storage on one or more batteries in a vehicle; and

[0102] At least one controller is configured to:

[0103] The first plurality of switching devices are selectively activated based on a single primary control signal to generate the first voltage signal in response to the input voltage signal;

[0104] The second plurality of switching devices are selectively activated based on a single secondary control signal to generate the second voltage signal in response to the first voltage signal; the at least one controller is configured to generate the single secondary control signal according to a first control variable corresponding to the duty cycle; and

[0105] A second control variable is generated corresponding to the phase shift between the single primary control signal and the single secondary control signal, wherein the second control variable enables the at least one controller to transfer power between the first active bridge and the second active bridge.

[0106] Item 11): A vehicle battery charger according to Item 10), wherein the first control variable is further based on the measured current of the one or more batteries.

[0107] Item 12): A vehicle battery charger according to Item 11), wherein the first control variable varies with the target charging current and with the measured current of the one or more batteries.

[0108] Item 13): A vehicle battery charger according to Item 11), wherein the at least one controller includes a moving average block programmed to obtain a predetermined number of samples of the measured current of the one or more batteries to generate a final measured current of the one or more batteries.

[0109] Item 14): A vehicle battery charger according to Item 13), wherein the at least one controller includes a comparator for obtaining the difference between a target charging current and a final measured current of the one or more batteries to provide a first difference output.

[0110] Item 15): The vehicle battery charger according to Item 14), wherein the at least one controller includes a proportional-integral-derivative (PID) controller to generate a first control variable (D) based on the first difference output.

[0111] Item 16): A vehicle battery charger according to Item 10), wherein the at least one controller is further configured to generate the first control variable to compensate for current ripple in the current for one or more batteries on the vehicle.

[0112] Item 17): A vehicle battery charger according to Item 10), wherein the second control variable (FI) is based at least on the AC current measured from the input voltage signal of the mains power supply.

[0113] Item 18): The vehicle battery charger according to Item 17), wherein the second control variable (FI) is also based at least on the maximum peak voltage of the PB converter and the maximum voltage stored in the capacitor located in the PB converter.

[0114] Item 19): A vehicle battery charger, comprising:

[0115] At least one transformer having a primary and a secondary;

[0116] A first active bridge includes a first plurality of switching devices positioned together with the primary to generate a first voltage signal in response to an input voltage signal;

[0117] A second active bridge includes a second plurality of switching devices positioned together with the secondary winding to generate a second voltage signal with current ripple in response to the first voltage signal; and

[0118] At least one controller is configured to:

[0119] The first plurality of switching devices are selectively activated based on a single primary control signal to generate the first voltage signal in response to the input voltage signal;

[0120] The second plurality of switching devices are selectively activated based on a single secondary control signal to generate the second voltage signal in response to the first voltage signal; the at least one controller is configured to generate the single secondary control signal according to a first control variable corresponding to the duty cycle; and

[0121] A second control variable is generated corresponding to the phase shift between the single primary control signal and the single secondary control signal, wherein the second control variable enables the at least one controller to transfer power between the first active bridge and the second active bridge.

[0122] Item 20): The vehicle battery charger according to Item 19) further includes a ripple buffer (PB) converter, which is connected to the second active bridge and configured to reduce or eliminate current ripple from the second voltage signal and generate a smooth output signal suitable for storage on one or more batteries in the vehicle.

Claims

1. A vehicle battery charger, comprising: At least one transformer having one or more primary windings and one or more secondary windings; A first active bridge includes a first plurality of switching devices, which are positioned together with one or more primary windings on the primary side of the vehicle battery charger to generate a first voltage signal in response to an input voltage signal from a mains power source. The second active bridge includes a second plurality of switching devices, which are positioned together with the one or more secondary windings on the secondary side of the vehicle battery charger to generate a second voltage signal with current ripple in response to the first voltage signal. A ripple buffer converter, which interfaces with the second active bridge and is configured to reduce or eliminate current ripple from the second voltage signal, and produce a smooth output signal suitable for storage on one or more batteries in a vehicle. as well as At least one controller is configured to: The first plurality of switching devices are selectively activated based on a single primary control signal to generate the first voltage signal in response to the input voltage signal; The second plurality of switching devices are selectively activated based on a single secondary control signal to generate the second voltage signal in response to the first voltage signal, and the at least one controller is configured to generate the single secondary control signal according to a first control variable corresponding to the duty cycle. as well as A second control variable is generated corresponding to the phase shift between the single primary control signal and the single secondary control signal, wherein the second control variable enables the at least one controller to transfer power between the first active bridge and the second active bridge; wherein the second control variable is based at least on the maximum peak voltage of the pulsating buffer converter and the maximum voltage stored on the capacitor located in the pulsating buffer converter.

2. The vehicle battery charger of claim 1, wherein, The first control variable is also based on the measured current of the one or more batteries.

3. The vehicle battery charger of claim 2, wherein, The first control variable changes with the target charging current and with the measured current of the one or more batteries.

4. The vehicle battery charger according to claim 2, wherein, The at least one controller includes a moving average block programmed to obtain a predetermined number of samples of the measured current of the one or more batteries to generate the final measured current of the one or more batteries.

5. The vehicle battery charger according to claim 4, wherein, The at least one controller includes a comparator for obtaining the difference between the target charging current and the final measured current of the one or more batteries to provide a first difference output.

6. The vehicle battery charger according to claim 5, wherein, The at least one controller includes a proportional-integral-derivative (PID) controller to generate a first control variable (D) based on the first difference output.

7. The vehicle battery charger according to claim 1, wherein, The at least one controller is also configured to generate the first control variable to compensate for current ripple in the current supplied to the one or more batteries on the vehicle.

8. The vehicle battery charger according to claim 1, wherein, The second control variable (FI) is based at least on the AC current measured from the input voltage signal of the main power supply.

9. A vehicle battery charger, comprising: At least one transformer having a primary and a secondary; A first active bridge includes a first plurality of switching devices positioned together with the primary to generate a first voltage signal in response to an input voltage signal from a mains power supply. The second active bridge includes a second plurality of switching devices positioned together with the secondary to generate a second voltage signal with current ripple in response to the first voltage signal. A ripple buffer converter, which interfaces with the second active bridge and is configured to eliminate current ripple from the second voltage signal and produce a smooth output signal suitable for storage on one or more batteries in a vehicle; as well as At least one controller is configured to: The first plurality of switching devices are selectively activated based on a single primary control signal to generate the first voltage signal in response to the input voltage signal; The second plurality of switching devices are selectively activated based on a single secondary control signal to generate the second voltage signal in response to the first voltage signal, and the at least one controller is configured to generate the single secondary control signal according to a first control variable corresponding to the duty cycle. as well as A second control variable is generated corresponding to the phase shift between the single primary control signal and the single secondary control signal, wherein the second control variable enables the at least one controller to transfer power between the first active bridge and the second active bridge; wherein the second control variable is based at least on the maximum peak voltage of the pulsating buffer converter and the maximum voltage stored on the capacitor located in the pulsating buffer converter.

10. The vehicle battery charger according to claim 9, wherein, The first control variable is also based on the measured current of the one or more batteries.

11. The vehicle battery charger according to claim 10, wherein, The first control variable changes with the target charging current and with the measured current of the one or more batteries.

12. The vehicle battery charger according to claim 10, wherein, The at least one controller includes a moving average block programmed to obtain a predetermined number of samples of the measured current of the one or more batteries to generate the final measured current of the one or more batteries.

13. The vehicle battery charger according to claim 12, wherein, The at least one controller includes a comparator for obtaining the difference between the target charging current and the final measured current of the one or more batteries to provide a first difference output.

14. The vehicle battery charger according to claim 13, wherein, The at least one controller includes a proportional-integral-derivative (PID) controller to generate a first control variable (D) based on the first difference output.

15. The vehicle battery charger according to claim 9, wherein, The at least one controller is also configured to generate the first control variable to compensate for current ripple in the current supplied to one or more batteries in the vehicle.

16. The vehicle battery charger according to claim 9, wherein, The second control variable (FI) is based at least on the AC current measured from the input voltage signal of the main power supply.

17. A vehicle battery charger, comprising: At least one transformer having a primary and a secondary; A first active bridge includes a first plurality of switching devices positioned together with the primary to generate a first voltage signal in response to an input voltage signal; The second active bridge includes a second plurality of switching devices positioned together with the secondary to generate a second voltage signal with current ripple in response to the first voltage signal. as well as At least one controller is configured to: The first plurality of switching devices are selectively activated based on a single primary control signal to generate the first voltage signal in response to the input voltage signal; The second plurality of switching devices are selectively activated based on a single secondary control signal to generate the second voltage signal in response to the first voltage signal, and the at least one controller is configured to generate the single secondary control signal according to a first control variable corresponding to the duty cycle. as well as A second control variable is generated corresponding to the phase shift between the single primary control signal and the single secondary control signal, wherein the second control variable enables the at least one controller to transfer power between the first active bridge and the second active bridge; wherein the second control variable is based at least on the maximum peak voltage of the pulsating buffer converter and the maximum voltage stored on the capacitor located in the pulsating buffer converter.

18. The vehicle battery charger of claim 17, further comprising the ripple buffer converter, the ripple buffer converter being interfaced with the second active bridge and configured to reduce or eliminate current ripple from the second voltage signal and generate a smooth output signal suitable for storage on one or more batteries in the vehicle.

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