System for providing soft-stop dc / dc converter

Abstract

A system for providing a soft stop DC / DC converter. In at least one embodiment, a system is provided that includes a first circuit, a passive circuit, and at least one controller. The first circuit includes a plurality of switches, each of the plurality of switches being selectively activated, wherein a first voltage signal is generated in response to one or more second voltage signals in accordance with the selective activation of the switches of the plurality of switches. The passive circuit includes one or more passive components. The passive circuit generates a third voltage signal based on the first voltage signal. The at least one controller is programmed to receive an input indicative of the system being in an overload condition and, in response to the input, select a first group of switches of the plurality of switches. With the selection of the first group of switches, the one or more passive components of the passive circuit are enabled to discharge the third voltage signal.

Description

Technical Field

[0001] The aspects disclosed herein generally relate to a system for providing a soft-stop DC / DC converter. These and other aspects will be discussed in more detail herein. Attached Figure Description

[0002] Figure 1 An example of a system for providing a soft-stop DC-DC converter according to one embodiment is depicted;

[0003] Figure 2 A detailed implementation of a DC / DC converter according to one embodiment is described;

[0004] Figure 3 A description of an embodiment Figure 2 A DC / DC converter in which one or more switches close during overload conditions; and

[0005] Figure 4 Various waveforms associated with a DC / DC converter during overload conditions are depicted according to one embodiment. Detailed Implementation

[0006] Detailed embodiments of the invention are disclosed herein as needed; however, it should be understood that the disclosed embodiments are merely exemplary embodiments of the invention that can be embodied in various forms and alternative forms. The drawings are not necessarily drawn to scale; some features may be enlarged or minimized to show details of specific components. Therefore, the specific structural and functional details disclosed herein should not be construed as limiting, but merely as representative bases for teaching those skilled in the art to employ the invention in various ways.

[0007] Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings. Numerous specific details are set forth in the following detailed description to provide a thorough understanding of the various described embodiments. However, it will be apparent to those skilled in the art that the various described embodiments can be practiced without these specific details. In other instances, well-known methods, procedures, components, circuits, and networks have not been described in detail so as not to unnecessarily obscure aspects of the embodiments.

[0008] It should be understood that the disclosed embodiments are merely exemplary, and various forms and alternative forms are possible. The drawings are not necessarily drawn to scale; some features may be enlarged or minimized to show details of specific components. Therefore, the specific structural and functional details disclosed herein should not be construed as limiting, but merely as a representative basis for teaching those skilled in the art to adopt the embodiments according to this disclosure in various ways.

[0009] It should be understood that the disclosed embodiments are merely exemplary, and various forms and alternative forms are possible. The drawings are not necessarily drawn to scale; some features may be enlarged or minimized to show details of specific components. Therefore, the specific structural and functional details disclosed herein should not be construed as limiting, but merely as a representative basis for teaching those skilled in the art to adopt the embodiments according to this disclosure in various ways.

[0010] "One or more" and / or "at least one" includes functions performed by one element, functions performed by more than one element (e.g., in a distributed manner), several functions performed by one element, several functions performed by several elements, or any combination of the foregoing.

[0011] It should also be understood that although the terms first, second, etc., are used in some instances herein to describe various elements, these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, a first contact may be referred to as a second contact, and similarly, a second contact may be referred to as a first contact, without departing from the scope of the various described embodiments. Both the first contact and the second contact are contacts, but they are not the same contact.

[0012] The terminology used in the description of the various described embodiments herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used in the description of the various described embodiments and the appended claims, the singular forms “a”, “an”, and “described” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and covers any and all possible combinations of one or more of the associated listed items. It should be further understood that the terms “includes,” “including,” “comprises,” and / or “comprising”, when used in this specification, specify the presence of the stated features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or groups thereof.

[0013] As used herein, depending on the context, the term "if" may optionally be interpreted as meaning "when," "at," "in response to determination," or "in response to detection." Similarly, depending on the context, the phrase "if determination" or "if [the stated condition or event] is detected" may optionally be interpreted as meaning "when determination," "in response to determination," "when [the stated condition or event] is detected," or "in response to detection of [the stated condition or event]."

[0014] In a resonant circuit (e.g., LLC type) – DC / DC converter used in an on-board charger (OBC) for a vehicle, when an overload current (or overload condition) is detected, the charging system activates, for example, a pair of controlled switches in the DC / DC converter to close (or remain on) until the energy in the resonant circuit is minimized. Once the current in the resonant circuit decreases to a negligible value, the pair of controlled switches in the DC / DC converter can be disabled (or turned off) after a certain period of time has passed during the overload condition.

[0015] For example, after detecting an overcurrent (or overload condition), a controller operatively coupled to the DC / DC converter can continue to activate, for example, at least two switches located within the DC / DC converter, to maintain or preserve the connection between the DC / DC converter, the DC link, and the resonant circuit. In this case, by activating two switches during the overload condition, energy within the resonant circuit is dissipated to a low level. Once the energy in the resonant circuit is dissipated to a low or negligible level, the controller can disable the switches to ensure soft-stop operation with respect to the switches. If the controller disables all switches during the overload condition, energy within the resonant circuit is released, thereby forcing an undesirable overvoltage onto the switches, which could potentially damage such switches. The disclosed system is robust to overcurrent conditions caused by faulty loads (e.g., battery or high-voltage (HV) conditions) and prevents damage to various aspects related to the charging system.

[0016] Figure 1 An example of a system 100 (e.g., a charging system 100) according to one embodiment is depicted. System 100 includes an on-board charger (OBC) 102 located in a vehicle 104 and one or more batteries 108 (e.g., battery 108). The OBC 102 can be operatively coupled to an alternating current (AC) grid 110 for receiving AC energy to charge one or more batteries 108. The OBC 102 is typically configured to rectify AC energy into direct current (DC) energy for storage on the batteries 108. In another example, the OBC can invert DC energy, such as that provided by the batteries 108, into AC energy to transfer the AC energy back to the AC grid 110.

[0017] OBC 102 can be operatively coupled to AC grid 110 via charging station 112 (or Electric Vehicle Power Supply Equipment (EVSE)). Charging station 112 transfers energy between AC grid 110 and vehicle 104. Charging station 112 can be operatively coupled to various outputs of AC grid 110, such as lines (L1, L2, L3, and neutral (N) lines), to facilitate such energy transfer. OBC 102 includes a plurality of modular converters 140a-140c (or “140”). It should be appreciated that the number of modular converters 140a-140c located within OBC 102 can vary based on desired standards for a particular implementation. System 100 also includes at least one controller 103 (“Controller 103”) and a plurality of switch blocks 105a-105b. Similarly, the number of switch blocks 105a-105b utilized within OBC 102 can vary based on desired standards for a particular implementation.

[0018] Generally, controller 103 can selectively activate or deactivate one or more of the switching blocks 105a-105b to control the individual modular converters 140a-140c to facilitate the transfer of energy from AC grid 110 to battery 108. Similarly, controller 103 can selectively activate or deactivate one or more of the switching blocks 105a-105b to control the individual modular converters 140a-140c to facilitate the transfer of energy from battery 108 to AC grid 110. Each modular converter 140 includes a power factor corrector (PFC) 150, a DC link capacitor 152, and a DC / DC converter 154. Controller 103 also controls PFC 150 to perform AC / DC conversion to ensure a high power factor at the input of DC / DC converter 154. PFC 150 and DC / DC converter 154 are electrically coupled to each other via a capacitive energy buffer (or DC link capacitor 152). Controller 103 controls DC / DC converter 154 to convert a high-voltage stable input provided by DC link capacitor 152 into a DC voltage level suitable for storage on battery 108. Generally, DC / DC converter 154 converts a high-voltage input (e.g., a high-voltage DC input) provided by PFC 150 into a low-voltage output for storage on battery 108.

[0019] Figure 2A detailed implementation of a DC / DC converter 154 according to one embodiment is depicted. Each DC / DC converter 154 includes a first circuit 180, a passive circuit 182, a transformer 184, an output rectifier 186, and an output filter 188. A controller 103 selectively controls one or more switches 202a-202d of the first circuit 180 to generate a first voltage signal V1 in response to an input voltage signal (e.g., Vin + / -). For example, the controller 103 selectively activates and deactivates one or more switches 202a-202D at corresponding switching frequencies to generate the first voltage signal V1 based on the input voltage signal.

[0020] Passive circuit 182 can be implemented as a resonant circuit and includes one or more passive components, such as one or more capacitors Cr (“capacitor Cr”) and one or more inductors Lr (“inductor Lr”). Passive circuit 182 provides selective gain response to transformer 184 based on the switching frequency of controller 103 for selectively activating and deactivating one or more switches 202a-202d. For example, switches 202a-202d provide passive circuit 182 with an AC-based voltage (or a first voltage signal V1) having a varying frequency. Passive circuit 182 attenuates or amplifies the AC-based voltage based on the frequency of the AC-based voltage to generate an AC-based voltage output Vac. This aspect enables DC / DC converter 154 to increase or decrease the voltage (e.g., V2) provided by passive circuit 182.

[0021] Transformer 184 typically includes a primary side 185a and a secondary side 185b. Transformer 184 includes a predetermined number of windings (or turns) on each of the primary side 185a and the secondary side 185b. In one example, transformer 184 may be a near-1:1 component. For example, for an 11kW production OBC unit, transformer 184 may include or have a 14:15 turns ratio. Transformer 184 is typically used to isolate an AC-based voltage (or waveform) provided by passive circuitry 182. Output rectifier 186 typically includes a plurality of diodes 187a-187d that act as rectifiers to provide a low DC-based voltage Vdc in response to the voltage Vac provided by transformer 184. Output filter 188 includes a capacitor Cout to filter the low DC-based voltage Vdc to provide a final output voltage Vout. The final output voltage Vout is suitable for storage on battery 108.

[0022] System 100 includes one or more current (or voltage) sensors 192 (e.g., sensor 192) that can be positioned around DC / DC converter 154. Sensor 192 provides controller 103 with an output indicating a low DC-based voltage Vdc provided by DC / DC converter 154. Controller 103 compares the measured voltage or current to a predetermined value to determine if DC / DC converter 154 (or system 100) is in an overload condition. In an overload condition, DC / DC converter 154 may be generating excessive current or voltage, and it is desirable to deactivate DC / DC converter 154 to avoid damage to various components. If the measured voltage or current exceeds the predetermined value, controller 103 determines that system 100 is in an overload condition.

[0023] When an overload condition is detected, the controller 103 continues to selectively activate at least two of the switches, such as switches 202a-202d, while the passive circuit (or resonant circuit) 182 releases voltage across its capacitor and inductor before all switches 202a-202d are completely deactivated. Figure 3 The previous embodiment utilizes a controller that completely deactivates switches 202a-202d upon detecting an overload condition. This could force unwanted overvoltages to transfer to switches 202a-202d, potentially damaging them. By allowing at least two switches 202a-202d to remain activated during an overload condition via a soft-stop operation, passive circuit 182 is allowed to fully release current and prevent unwanted voltages from reaching switches 202a-202d. For example, energy stored in capacitor Cr and inductor Ir in passive circuit 182 should be released to avoid damaging switches 202a-202d.

[0024] Figure 3 The energy in passive circuit 182 is depicted being released via loop 210. Given that DC link capacitor 152 is positioned in series with DC / DC converter 154 (e.g., in series with capacitor Cr of DC / DC converter 154), energy from DC link capacitor 152 will not flow into DC / DC converter 154. When controller 103 determines, based on measurements provided by sensor 192, that the current across passive circuit 182 has decreased to a negligible value, controller 103 can then deactivate the remaining switches 202a-202d, causing DC / DC converter 154 to stop providing a DC-based voltage Vdc. For example, as... Figure 3As shown, in response to controller 103 determining that DC / DC converter 154 is in an overload condition, controller 103 can selectively activate two switches 202b and 202c to release energy from passive circuit 182. Controller 103 can employ a soft-stop operation during the overload condition by activating at least two switches 202a-202d for, for example, two switching cycles (or, for example, 16µs) to allow sufficient time for capacitor Cr and / or inductor Ir to fully discharge. In this case, a soft-stop operation can be more advantageous than a hard-stop operation (e.g., all switches 202a-202d are turned off) to prevent or minimize the possibility of damage to switches 202a-202d by excessive energy released by passive circuit 182.

[0025] Figure 4 Various waveforms associated with the DC / DC converter 154 during an overload condition according to one embodiment are depicted. Waveform 300 generally corresponds to the amount of energy (or current) flowing in the passive circuit 182. Waveform 302 generally corresponds to the switching current applied to switches 202a-202d to activate / deactivate the switches. Specifically, waveform 304 generally corresponds to the switching current applied to switches 202b, 202c. Waveform 306 generally corresponds to the switching current applied to switches 202a, 202d. At 310, this condition generally indicates the moment when the DC / DC converter 154 begins to experience an overload condition. At 312, this condition generally corresponds to the moment when the controller 103 deactivates switches 202b, 202c in response to detecting an overload condition. As shown at 314, during the overload condition, the controller 103 continues to selectively activate switches 202a, 202d while deactivating switches 202b, 202c. At position 316, it can be seen that the passive circuit 182 is fully discharged.

[0026] Project 1. A system comprising a first circuit, a passive circuit, and at least one controller. The first circuit includes a plurality of switches, each of which is selectively activated, wherein a first voltage signal is generated in response to one or more second voltage signals based on the selective activation of the switches among the plurality of switches. The passive circuit includes one or more passive components. The passive circuit generates a third voltage signal based on the first voltage signal. The at least one controller is programmed to receive an input indicating that the system is in an overload condition, and in response to the input, select a first group of switches among the plurality of switches. By utilizing the selection of the first group of switches, the one or more passive components of the passive circuit are able to release the third voltage signal.

[0027] Item 2. According to Item 1, the plurality of switches receive one or more first voltage signals at a switching frequency.

[0028] Project 3. According to Project 1, the passive circuit generates the third voltage signal by attenuating the first voltage signal based on the switching frequency used by the at least one controller to activate the switches among the plurality of switches.

[0029] Project 4. According to Project 1, the passive circuit generates the third voltage signal by increasing the first voltage signal based on the switching frequency of the switches used by the at least one controller to activate the switches among the plurality of switches.

[0030] Item 5. According to Item 1, the system includes a transformer operatively coupled to the passive circuit to provide an AC waveform based on the third voltage signal.

[0031] Item 6. According to Item 5, the system includes an output rectifier that generates a direct current (DC) voltage signal by rectifying the AC waveform.

[0032] Item 7. According to Item 6, the system includes an output filter that provides a filtered DC voltage signal based on the DC voltage signal.

[0033] Item 8. According to Item 7, the at least one controller is further programmed to compare the DC input value provided on the input with a predetermined value, and to selectively activate the first group of switches among the plurality of switches based on the comparison.

[0034] Item 9. According to Item 8, the at least one controller is further programmed to selectively activate the first group of switches among the plurality of switches in response to the DC input value being greater than the predetermined value.

[0035] Item 10. According to Item 1, the one or more passive components of the passive circuit include capacitors and inductors.

[0036] Item 11. According to Item 1, the at least one controller is further programmed to selectively deactivate a second set of switches among the plurality of switches when the system is in the overload condition.

[0037] Item 12. According to Item 11, when the at least one controller selectively deactivates the second group of switches among the plurality of switches, the at least one controller activates the first group of switches among the plurality of switches to release the third voltage signal from the one or more passive components.

[0038] Project 13. A system comprising a first circuit, a passive circuit, and at least one controller. The first circuit includes a plurality of switches, each of which is selectively activated, wherein a first voltage signal is generated in response to one or more second voltage signals based on the selective activation of the switches among the plurality of switches. The passive circuit generates a third voltage signal based on the first voltage signal. The at least one controller is programmed to receive an input indicating that the system is in an overload condition, and in response to the input, select a first group of switches among the plurality of switches. The selection of the first group of switches enables the passive circuit to release the third voltage signal.

[0039] Item 14. According to Item 13, the passive circuit generates the third voltage signal by attenuating the first voltage signal based on a first switching frequency used by the at least one controller to activate the switches among the plurality of switches.

[0040] Item 15. According to Item 14, the passive circuit generates the third voltage signal by increasing the first voltage signal based on a second switching frequency used by the at least one controller to activate the switches among the plurality of switches.

[0041] Item 16. According to Item 15, the first switching frequency is different from the second switching frequency.

[0042] Item 17. According to Item 13, the passive circuit includes a capacitor and an inductor, wherein the capacitor and the inductor are positioned in series with each other.

[0043] Item 18. According to Item 13, when the system is in the overload condition, the at least one controller selectively deactivates the second group of switches among the plurality of switches, while activating the first group of switches among the plurality of switches to release the third voltage signal from the passive circuit.

[0044] Item 19. According to Item 13, the first group of switches in the plurality of switches corresponds to at least two switches in the plurality of switches.

[0045] Item 20. A system comprising a first circuit, a passive circuit, and at least one controller. The first circuit includes a plurality of switches, each of which is selectively activated, wherein a first voltage signal is generated in response to one or more second voltage signals based on the selective activation of the switches among the plurality of switches. The passive circuit generates a third voltage signal based on the first voltage signal. The at least one controller is programmed to receive an input indicating that the system is in an overload condition, and in response to the input, to select a first group of switches among the plurality of switches. The selection of the first group of switches enables the passive circuit to release the third voltage signal.

[0046] It should be understood that the controllers disclosed herein may include various microprocessors, integrated circuits, memory devices (e.g., FLASH, 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 work together to perform the operations disclosed herein. Additionally, such controllers may utilize 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 functions disclosed. Furthermore, the controllers provided herein include a housing and various numbers of microprocessors, integrated circuits, and memory devices (e.g., FLASH, 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. The controllers disclosed herein also include hardware-based inputs and outputs for receiving data from and sending data to other hardware-based devices discussed herein.

[0047] Although exemplary embodiments have been described above, these embodiments are not intended to describe all possible forms of the invention. Rather, the language used in this specification is descriptive 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 various embodiments can be combined to form other embodiments of the invention.

Claims

1. A system comprising: A first circuit includes a plurality of switches, each of which is selectively activated, wherein a first voltage signal is generated in response to one or more second voltage signals based on the selective activation of the switches among the plurality of switches. A passive circuit, comprising one or more passive components, wherein the passive circuit generates a third voltage signal based on the first voltage signal; as well as At least one controller is programmed to receive an input indicating that the system is in an overload condition, and in response to the input, to select a first group of switches among the plurality of switches, wherein the selection of the first group of switches enables one or more passive components of the passive circuit to release the third voltage signal.

2. The system of claim 1, wherein the plurality of switches receive the one or more second voltage signals at a switching frequency.

3. The system of claim 1, wherein the passive circuit generates the third voltage signal by attenuating the first voltage signal based on the switching frequency of the switches used by the at least one controller to activate the switches among the plurality of switches.

4. The system of claim 1, wherein the passive circuit generates the third voltage signal by increasing the first voltage signal based on the switching frequency of the switches used by the at least one controller to activate the switches among the plurality of switches.

5. The system of claim 1 further includes a transformer operatively coupled to the passive circuit to provide an alternating current (AC) waveform based on the third voltage signal.

6. The system of claim 5 further includes an output rectifier that generates a direct current (DC) voltage signal by rectifying the AC waveform.

7. The system of claim 6 further includes an output filter, the output filter providing a filtered DC voltage signal based on the DC voltage signal.

8. The system of claim 7, wherein the at least one controller is further programmed to compare a DC input value provided on the input with a predetermined value, and to selectively activate the first group of switches among the plurality of switches based on the comparison.

9. The system of claim 8, wherein the at least one controller is further programmed to selectively activate the first group of switches among the plurality of switches in response to the DC input value being greater than the predetermined value.

10. The system of claim 1, wherein the one or more passive components of the passive circuit include capacitors and inductors.

11. The system of claim 1, wherein the at least one controller is further programmed to selectively deactivate a second set of switches among the plurality of switches when the system is in the overload condition.

12. The system of claim 11, wherein when the at least one controller selectively deactivates the second group of switches among the plurality of switches, the at least one controller activates the first group of switches among the plurality of switches to release the third voltage signal from the one or more passive components.

13. A system comprising: A first circuit includes a plurality of switches, each of which is selectively activated, wherein a first voltage signal is generated in response to one or more second voltage signals based on the selective activation of the switches among the plurality of switches. A passive circuit that generates a third voltage signal based on the first voltage signal; as well as At least one controller is programmed to receive an input indicating that the system is in an overload condition, and in response to the input, to select a first group of switches among the plurality of switches, wherein the selection of the first group of switches enables the passive circuit to release the third voltage signal.

14. The system of claim 13, wherein the passive circuit generates the third voltage signal by attenuating the first voltage signal based on a first switching frequency used by the at least one controller to activate the switches among the plurality of switches.

15. The system of claim 14, wherein the passive circuit generates the third voltage signal by increasing the first voltage signal based on a second switching frequency used by the at least one controller to activate the switches among the plurality of switches.

16. The system of claim 15, wherein the first switching frequency is different from the second switching frequency.

17. The system of claim 13, wherein the passive circuitry comprises a capacitor and an inductor, and wherein the capacitor and the inductor are positioned in series with each other.

18. The system of claim 13, wherein when the system is in the overload condition, the at least one controller selectively deactivates the second group of switches among the plurality of switches while activating the first group of switches among the plurality of switches to release the third voltage signal from the passive circuit.

19. The system of claim 13, wherein the first group of switches in the plurality of switches corresponds to at least two of the plurality of switches.

20. A system comprising: A plurality of switches, each of which is selectively activated, wherein a first voltage signal is generated in response to one or more second voltage signals based on the selective activation of the switches among the plurality of switches; A passive circuit that generates a third voltage signal based on the first voltage signal; as well as At least one controller is programmed to receive an input indicating that the system is in an overload condition, and in response to the input, selectively activate a first group of switches among the plurality of switches and selectively deactivate a second group of switches among the plurality of switches, wherein the passive circuit is able to release the third voltage signal based on the selective activation of the first group of switches among the plurality of switches and the selective deactivation of the second group of switches among the plurality of switches.

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