Power conversion apparatus and control method therefor

Abstract

The invention provides a power conversion device. The power conversion device comprises a power transistor, a detection device, a signal converter and a controller. The detection device obtains a detection voltage by detecting an output voltage on an output terminal of the power conversion device and obtains a detection current by detecting an operation current of the power transistor. The signal converter converts the detection voltage from a first format to a second format, and converts the detection current from the first format to the second format. The controller receives the detection voltage and the detection current in the second format. The controller compares the detection voltage with a first voltage threshold value and a second voltage threshold value to adjust the control code, and generates a control signal transmitted to the control end of the power transistor according to the control code.

Description

Technical Field

[0001] The present invention relates to a power conversion device and a control method thereof, and more particularly, to a power conversion device capable of dynamically adjusting an output voltage according to a load state and a control method thereof. Background Art

[0002] In the prior art, power conversion devices often have fixed control signals so that the power conversion device generates an output voltage with a fixed value. When the load state changes, the output voltage may deviate from the target voltage specification and may not be adjusted to the target voltage in real time. In order to avoid the above problems, the target voltage is usually set directly to a higher value to ensure smooth operation of the system under different load states. In addition, the higher the value of the target voltage, the more power the system consumes. That is to say, in the prior art, the power conversion device cannot optimize the target voltage setting according to different load states. Summary of the invention

[0003] The invention provides a power conversion device capable of dynamically adjusting output voltage according to load status and a control method for the power conversion device.

[0004] According to an embodiment of the present invention, the power conversion device includes a power transistor, a detection device, a signal converter and a controller. The power transistor is coupled between the input end of the power conversion device and the output end of the power conversion device. The detection device is coupled to the output end of the power conversion device and the power transistor, and obtains the detection voltage by detecting the output voltage on the output end of the power conversion device and obtains the detection current by detecting the operating current of the power transistor. The signal converter is coupled to the detection device, converts the detection voltage from a first format to a second format, and converts the detection current from the first format to the second format. The controller is coupled to the control end of the power transistor and the signal converter, and receives the detection voltage and detection current in the second format. The controller compares the detection voltage with the first voltage threshold and the second voltage threshold to adjust the control code, and generates a control signal transmitted to the control end of the power transistor according to the control code.

[0005] According to an embodiment of the present invention, the control method for a power conversion device includes: a detection device obtains a detection voltage by detecting an output voltage at an output end of the power conversion device; the detection device obtains a detection current by detecting an operating current of a power transistor of the power conversion device; a signal converter converts the detection voltage from a first format to a second format and converts the detection current from the first format to the second format; a controller compares the detection voltage with a first voltage threshold and a second voltage threshold to adjust a control code; and the controller generates a control signal transmitted to the control end of the power transistor according to the control code.

[0006] In summary, the power conversion device disclosed in the present invention detects the detection output voltage on the output terminal to obtain the detection voltage, and detects the operating current of the power transistor in real time to obtain the detection current. By comparing the detection voltage with two voltage thresholds, the controller of the power conversion device can adjust the control code according to the comparison result, and the power conversion device can generate a control signal for controlling the power transistor of the power conversion device according to the control code. In this way, the output voltage generated by the power conversion device can be dynamically adjusted according to the load state of the power conversion device. The output voltage can be close to the target voltage, and the power consumption of the power conversion device can also be saved.

[0007] In order to make the above features and advantages of the present invention more easily understood, several embodiments accompanied by drawings are described in detail below. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The accompanying drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the invention and together with the description serve to explain the principles of the invention.

[0009] Figure 1 A block diagram of a power conversion device according to an embodiment of the present disclosure is shown.

[0010] Figure 2 A block diagram of a power conversion device according to another embodiment of the present disclosure is shown.

[0011] Figure 3 A flow chart showing the operation of the power conversion device according to an embodiment of the present disclosure.

[0012] Figure 4 A block diagram of a power conversion device according to another embodiment of the present disclosure is shown.

[0013] Figure 5 A flow chart showing a control method of a power conversion device according to an embodiment of the present disclosure is shown.

[0014] [Explanation of Symbols]

[0015] 100: Power conversion device

[0016] 110, 210, 410: Power transistors

[0017] 120, 220, 420: Detection device

[0018] 130, 230, 430: Signal converter

[0019] 140, 240, 440: Controller

[0020] 150, 250, 450: Transistors

[0021] 160, 260, 460: Inductors

[0022] 200, 400: Power conversion device

[0023] 421, 422: Detection circuit

[0024] 470: Storage device

[0025] 471: Operational Circuit

[0026] 480: Interface

[0027] CS: Control signal

[0028] D1, DVo: detection voltage

[0029] D2, IS: detection current

[0030] D3: Power ratio information

[0031] D_max: first voltage threshold

[0032] D_min: Second voltage threshold

[0033] IOP: Operating Current

[0034] S310, S320, S330, S331, S332, S340, S341, S342, S510, S520, S530, S540, S550: Steps

[0035] TC: Object Code

[0036] VIN: Input voltage

[0037] Vo: output voltage DETAILED DESCRIPTION

[0038] The term "coupled (or connected)" in the specification of the present application (including the claims) is used in a broad sense and includes direct connection or coupling mode and indirect connection or coupling mode. For example, if the present disclosure describes that a first device is coupled (or connected) to a second device, this should be interpreted as the first device being directly connected to the second device, or the first device being indirectly connected to the second device by other devices or by a specific coupling mode. In addition, the terms such as "first" and "second" mentioned in the specification of the present application (including the claims) are only used to name the name of the element or distinguish different embodiments or scopes rather than to limit the upper or lower limit of the number of elements, nor to limit the order of the elements. In addition, in the drawings and embodiments, elements / components / steps with the same reference number represent the same or similar parts. Elements / components / symbols with the same reference number in different embodiments can refer to the relevant description.

[0039] Please refer to Figure 1 , Figure 1 FIG. 1 is a block diagram of a power conversion device according to an embodiment of the present disclosure. Figure 1 In the embodiment, the power conversion device 100 includes a power transistor 110, a detection device 120, a signal converter 130, a controller 140, a transistor 150 and an inductor 160. In this embodiment, the power conversion device 100 can be a direct current (DC) to DC buck converter. The first end of the power transistor 110 is coupled to the input end of the power conversion device 100 for receiving an input voltage VIN. The control end of the power transistor 110 is coupled to the controller 140 to receive a control signal CS. The second end of the power transistor 110 is coupled to the inductor 160, the first end of the transistor 150 and the detection device 120. On the other hand, the second end of the transistor 150 is coupled to the output end of the power conversion device 100, wherein the output end of the power conversion device 100 generates an output voltage Vo. The second end of the inductor 160 and the detection device 120 are also coupled to the output end of the power conversion device 100.

[0040] The power conversion device 100 is configured to perform a power conversion operation on an input voltage VIN by switching a power transistor 110 and a transistor 150. Both the input voltage VIN and the output voltage Vo may be direct current (DC) voltages.

[0041] In this embodiment, the detection device 120 is configured to detect the operating current IOP of the power transistor 110 to obtain the detection current IS, and the detection device 120 is further configured to detect the output voltage Vo of the power conversion device 100 to obtain the detection voltage DVo.

[0042] In this embodiment, the detection device 120 can sense the operating current IOP flowing through the power transistor 110 to obtain the detection current IS. Here, the detection current IS obtained by the detection device 120 can be in an analog format. In addition, the detection device 120 can obtain the detection voltage DVo by dividing the output voltage Vo at the output end of the power conversion device 100. The detection voltage DVo obtained by the detection device 120 can also be in an analog format.

[0043] Please note that the detection device 120 can simultaneously detect the operating current IOP of the power transistor 110 and the output voltage Vo of the power conversion device 100. The detection operation for detecting the operating current IOP of the power transistor 110 and the detection operation for detecting the output voltage Vo of the power conversion device 100 can be performed in real time.

[0044] The signal converter 130 receives the detection current IS and the detection voltage DVo. The signal converter 130 converts the detection current IS and the detection voltage DVo from a first format to a second format. In this embodiment, the signal converter 130 may be an analog to digital converter (ADC), and the signal converter 130 may convert the detection current IS in an analog format into a detection current D2 in a digital mode. In addition, the signal converter 130 may also convert the detection voltage DVo in an analog format into a detection voltage D1 in a digital mode. The signal converter 130 transmits the detection voltage D1 and the detection current D2 in a digital format to the controller 140.

[0045] In this embodiment, the controller 140 may pre-set a first voltage threshold and a second voltage threshold, wherein the first voltage threshold may be greater than the second voltage threshold. The controller 140 may compare the detection voltage D1 with the first voltage threshold and the second voltage threshold to generate a comparison result, and adjust the control code according to the comparison result. In this embodiment, the detection voltage D1, the first voltage threshold, the second voltage threshold and the control code may all be codes.

[0046] The control code may be set to an initial value in an initial state by the controller 140. The initial value may be determined according to a normal load state of the power conversion device 100.

[0047] In the detailed operation of the power conversion device 100, when the detection voltage D1 is greater than the first voltage threshold, the controller 140 may reduce the control code by the first step value. In this embodiment, when the detection voltage D1 is greater than the first threshold, the output voltage Vo of the power conversion device 100 may be too high and greater than the target voltage. The increase in the output voltage Vo of the power conversion device 100 may be caused by the reduction of the load of the power conversion device 100. In this way, the controller 140 can reduce the control code by the first step value.

[0048] On the other hand, when the detection voltage D1 is less than the second threshold value, the output voltage Vo of the power conversion device 100 may be too low and less than the target voltage. The reduction in the output voltage Vo of the power conversion device 100 may be caused by an increase in the load of the power conversion device 100. In this way, the controller 140 may increase the control code by the second step value.

[0049] In this embodiment, the first step size value may be equal to the second step size value or may be different from the second step size value. In some embodiments, the first step size value and the second step size value may be 1.

[0050] On the other hand, the controller 140 further converts the control code into a control signal CS. In this embodiment, the control signal CS may be a pulse-width-modulation (PWM) signal. The controller 140 may control the duty ratio of the control signal CS according to the value of the digital code. In detail, the controller 140 may adjust the duty ratio of the control signal CS according to the change of the control code. For example, if the control code increases, the duty ratio may be increased by the controller 140, and if the control code decreases, the duty ratio may be reduced by the controller 140.

[0051] By adjusting the duty cycle of the control signal CS, the operating current IOP flowing through the power transistor 110 can be adjusted accordingly. In detail, if the duty cycle of the control signal increases, the operating current IOP flowing through the power transistor 110 can be increased accordingly. If the duty cycle of the control signal decreases, the operating current IOP flowing through the power transistor 110 can be reduced accordingly. It can be seen that by adjusting the operating current IOP flowing through the power transistor 110 corresponding to the load change of the power conversion device 100, the output voltage Vo of the power conversion device 100 can be maintained at the target voltage in real time. In this way, the output voltage Vo of the power conversion device 100 will not be too high or too low, the working efficiency of the load circuit can be maintained, and the power consumption of the power conversion device 100 can also be saved.

[0052] Please refer to Figure 2 , Figure 2FIG. 1 is a block diagram of a power conversion device according to another embodiment of the present disclosure. Figure 2 In the embodiment, the power conversion device 200 includes a power transistor 210, a detection device 220, a signal converter 230, a controller 240, a transistor 250 and an inductor 260. In this embodiment, the power conversion device 100 can be a DC to DC boost converter. The first end of the power transistor 210 receives the input voltage VIN through the inductor 260. The control end of the power transistor 210 is coupled to the controller 240 to receive the control signal CS. The second end of the power transistor 210 is coupled to the detection device 220 and the reference ground end. On the other hand, the first end of the transistor 250 is coupled to the coupling end of the inductor 260 and the power transistor 210; the second end of the transistor 250 is coupled to the output end of the power conversion device 200, wherein the output end of the power conversion device 200 generates the output voltage Vo.

[0053] The power conversion device 200 is configured to perform a power conversion operation on an input voltage VIN by switching a power transistor 210 and a transistor 250. Both the input voltage VIN and the output voltage Vo may be direct current (DC) voltages.

[0054] The detection device 220 detects the operating current IOP of the power transistor 210 through the second terminal of the power transistor 210, and the detection device 220 accordingly obtains the detection current IS. The detection device 220 further detects the output voltage Vo of the power conversion device 200 to obtain the detection voltage DVo.

[0055] The detection voltage DVo and the detection current IS are transmitted to the signal converter 230 , and the signal converter 230 may perform an analog-to-digital conversion operation on the detection voltage DVo and the detection current IS to obtain the detection voltage D1 and the detection current D2 as digital codes, respectively.

[0056] The controller 240 receives the detection voltage D1 and the detection current D2, performs a comparison operation on the detection voltage D1 to generate a digital code, and converts the digital code to generate a control signal CS. Figure 1 The operation of the controller 140 in the embodiment is the same and will not be repeated here.

[0057] Please refer to Figure 3 , Figure 3 A flow chart showing the operation of a power conversion device according to an embodiment of the present disclosure is shown. In step S310, a controller of the power conversion device sets a first voltage threshold (e.g., D_max) and a second voltage threshold (e.g., D_min). The first voltage threshold may correspond to the maximum value of the output voltage of the power conversion device, and the second voltage threshold may correspond to the minimum value of the output voltage of the power conversion device.

[0058] In step S320, the output voltage of the power conversion device can be detected in real time, and the signal converter can convert the detection voltage in analog format into a detection voltage in digital format (e.g., D1). In addition, the power conversion device compares the detection voltage (e.g., D1) with a first voltage threshold (e.g., D_max) and a second voltage threshold (e.g., D_min) in real time. If the detection voltage D1 is greater than the first voltage threshold D_max (step S330), step S331 can be implemented, and the control code generated by the controller of the power conversion device is reduced by 1. Then, in step S332, the controller can generate a control signal with a lower duty cycle transmitted to the power transistor of the power conversion device corresponding to the control code, and the target voltage of the power conversion device can be reduced.

[0059] On the other hand, if the detection voltage D1 is less than the second voltage threshold D_min (step S340), step S341 may be implemented, and the control code generated by the controller of the power conversion device may be increased by 1. Then, in step S342, the controller may generate a control signal with a higher duty cycle transmitted to the power transistor of the power conversion device corresponding to the control code, and the target voltage of the power conversion device may be increased.

[0060] Steps S320 to S332 and S342 may be repeated several times. In this way, the output voltage of the power conversion device may be dynamically adjusted and maintained at a target value regardless of changes in the load state.

[0061] Please refer to Figure 4 , Figure 4 1 is a block diagram of a power conversion device according to another embodiment of the present disclosure. The power conversion device 400 includes a power transistor 410, a detection device 420, a signal converter 430, a controller 440, a transistor 450, an inductor 460, and a storage device 470. In this embodiment, the power conversion device 400 can be a DC to DC buck converter, and in other embodiments, the power conversion device 400 can be reconfigured into a DC to DC boost converter by replacing the position of the inductor 460.

[0062] The power transistor 410 receives an input voltage VIN, is coupled to the controller 440 through a control terminal, and is coupled to an inductor 460, a transistor 450, and a detection device 420. The inductor 460 is coupled to the transistor 450 and the detection device 420 through the output terminal of the power conversion device 400. The detection device 420 includes detection circuits 421 and 422. The detection circuit 421 is coupled to the power transistor 410, and can detect the operating current flowing through the power transistor 410 to obtain a detection current IS in an analog format. The detection circuit 422 is coupled to the output terminal of the power conversion device 400, and divides the output voltage Vo at the output terminal of the power conversion device 400 to obtain a detection voltage DVo in an analog format.

[0063] The signal converter 430 is coupled to the detection device 420. The signal converter 430 receives the detection current IS and the detection voltage DVo, and converts the detection current IS and the detection voltage DVo in analog format into the detection current D2 and the detection voltage D1 in digital format, respectively. The signal converter 430 transmits the detection current D2 and the detection voltage D1 to the controller 440. The signal converter 430 is further coupled to the storage device 470, and further transmits the detection current D2 and the detection voltage D1 to the storage device 470. The storage device 470 may store the detection current D2 and the detection voltage D1 in a memory array or a plurality of registers. Here, the memory array may be any type of memory array, such as a static random access memory (SRAM) array, a dynamic random access memory (DRAM) array, a flash memory array, a resistive random access memory (ReRAM) or any type of memory array known to those skilled in the art.

[0064] On the other hand, the storage device 470 may be coupled to the interface 480 and receive the target code through the interface 480. The storage device 470 may store the target code TC and transmit the target code TC to the controller 440. In the present embodiment, the controller 440 may determine the first voltage threshold and the second voltage threshold according to the target code TC. That is, the user of the power conversion device 400 may dynamically adjust the target voltage of the power conversion device 400 by inputting the target code TC into the storage device 470 using the interface 480. In addition, the interface 480 may be a serial transmission interface or a parallel transmission interface. The interface 480 may be implemented by any transmission interface known to those skilled in the art, and is not particularly limited here.

[0065] In the present embodiment, the storage device 470 includes an operation circuit 471. The operation circuit 471 can perform operation on the detection voltage D1 and the detection current D2 to obtain power ratio information D3. The operation circuit 471 can store the power ratio information D3 in a memory array or a register of the storage device 470, and provide the power ratio information D3 to the controller 440. In detail, the operation circuit 471 can multiply the detection voltage D1 by the detection current D2 to obtain the power ratio information D3. Here, the detection voltage D1, the detection current D2, and the power ratio information D3 are all digital codes.

[0066] On the other hand, the controller 440 may further set a power ratio threshold. The controller 440 may compare the power ratio information D3 with the power ratio threshold to adjust the control code. For example, if the power ratio information D3 is greater than the power ratio threshold, the controller 440 may reduce the control code to reduce the duty cycle of the control signal CS. In this way, the operating current flowing through the power transistor 410 may be reduced.

[0067] It should be noted here that the controller 440 can monitor the operating current flowing through the power transistor 410 according to the detection current D2.

[0068] The controller 440 may be a processor with computing capabilities. Alternatively, the controller 440 may be designed by a hardware description language (HDL) or any other design method for digital circuits familiar to those skilled in the art, and may be a hardware circuit implemented by a field programmable gate array (FPGA), a complex programmable logic device (CPLD), or an application-specific integrated circuit (ASIC).

[0069] Please refer to Figure 5 , Figure 5A flow chart of a control method for a power conversion device according to an embodiment of the present disclosure is shown. In step S510, a detection device of the power conversion device obtains a detection voltage by detecting an output voltage at an output terminal of the power conversion device. In step S520, the detection device obtains a detection current by detecting an operating current of a power transistor of the power conversion device. In step S530, a signal converter of the power conversion device converts the detection voltage from a first format to a second format and converts the detection current from a first format to a second format. In step S540, a controller of the power conversion device compares the detection voltage with a first voltage threshold and a second voltage threshold to adjust a control code. In step S550, the controller generates a control signal transmitted to a control terminal of the power transistor according to the control code.

[0070] The detailed operations of step S510 to step S550 may refer to the above embodiment and will not be described in detail here.

[0071] In summary, the power conversion device of the present disclosure detects the operating current and output voltage of the power transistor to generate the detection current and detection voltage respectively. By converting the detection current and detection voltage into digital format. The power conversion device compares the detection voltage with two voltage thresholds to adjust the control code, and converts the control code into a control signal for controlling the operating current flowing through the power transistor. That is, when the load state of the power conversion device changes, the output voltage of the power conversion device can be dynamically adjusted to match the target voltage.

[0072] It will be apparent to those skilled in the art that various modifications and variations may be made to the structure of the disclosed embodiments without departing from the scope or spirit of the present disclosure. In summary, the present disclosure is intended to cover modifications and variations of the present disclosure as long as they fall within the scope of the appended claims and their equivalents.

Claims

1. A power conversion device, comprising: a power transistor coupled between an input terminal of the power conversion device and an output terminal of the power conversion device; A detection device, coupled to the output terminal of the power conversion device and the power transistor, obtains a detection voltage by detecting an output voltage on the output terminal of the power conversion device and obtains a detection current by detecting an operating current of the power transistor; a signal converter, coupled to the detection device, converting the detection voltage from a first format to a second format, and converting the detection current from the first format to the second format; as well as a controller, coupled to the control terminal of the power transistor and the signal converter, receiving the detection voltage and the detection current in the second format, The controller compares the detection voltage with a first voltage threshold and a second voltage threshold to adjust a control code, and generates a control signal transmitted to the control terminal of the power transistor according to the control code.

2. The power conversion device according to claim 1, wherein the first voltage threshold is greater than the second voltage threshold, and if the detection voltage is greater than the first voltage threshold, the controller reduces the control code by a first step value; if the detection voltage is less than the second voltage threshold, the controller increases the control code by a second step value. 3 . The power conversion device according to claim 2 , wherein the first step size is equal to or different from the second step size.

4. The power conversion device according to claim 1, wherein the detection device comprises: a first detection circuit, coupled to the output terminal of the power conversion device, for detecting the detection voltage; as well as The second detection circuit is coupled to the power transistor and is used for detecting the operating current to obtain the detection current. 5 . The power conversion device according to claim 4 , wherein the first detection circuit generates the detection voltage by dividing the output voltage of the power conversion device. 6 . The power conversion apparatus of claim 1 , wherein the signal converter is an analog-to-digital converter, the first format is an analog format and the second format is a digital format. 7 . The power conversion device according to claim 1 , wherein the controller adjusts the duty cycle of the control signal according to the change of the control code. 8 . The power conversion device according to claim 7 , wherein when the control code increases, the controller increases the duty cycle of the control signal; and when the control code decreases, the controller decreases the duty cycle of the control signal.

9. The power conversion device according to claim 1, further comprising: a storage device coupled to the controller and the signal converter, The storage device stores the detection voltage and the detection current. 10 . The power conversion device according to claim 9 , wherein the storage device provides the detection voltage and the detection current to the controller. 11 . The power conversion device according to claim 9 , wherein the storage device further receives a target code through an interface and provides the target code to the controller. 12 . The power conversion device according to claim 11 , wherein the controller sets the first voltage threshold and the second voltage threshold according to the target code.

13. The power conversion device according to claim 9, wherein the storage device further comprises: The operation circuit is configured to perform operation on the detection voltage and the detection current to obtain power ratio information, and the operation circuit provides the power ratio information to the controller. 14 . The power conversion device according to claim 13 , wherein the controller further sets a power ratio threshold, and compares the power ratio information with the power ratio threshold to adjust the control code. 15 . The power conversion device according to claim 1 , wherein the controller further sets a current threshold, and compares the detected current with the current threshold to adjust the control code.

16. The power conversion device according to claim 1, further comprising: an inductor coupled between the input terminal of the power conversion device and the first terminal of the power transistor, or coupled between the output terminal of the power conversion device and the second terminal of the power transistor; as well as A transistor is coupled between the output terminal of the power conversion device and the second terminal of the power transistor.

17. A control method for a power conversion device, comprising: The detection device detects the output voltage at the output end of the power conversion device to obtain a detection voltage; The detection device obtains a detection current by detecting an operating current of a power transistor of the power conversion device; converting the detection voltage from a first format to a second format and converting the detection current from the first format to the second format by a signal converter; The controller compares the detection voltage with a first voltage threshold and a second voltage threshold to adjust the control code; as well as The controller generates a control signal transmitted to the control terminal of the power transistor according to the control code.

18. The control method according to claim 17, wherein the first voltage threshold is greater than the second voltage threshold; If the detection voltage is greater than the first voltage threshold, the controller reduces the control code by a first step length value; and If the detection voltage is less than the second voltage threshold, the controller increases the control code by a second step value.

19. The control method according to claim 18, further comprising: When the control code increases, the controller increases the duty cycle of the control signal; as well as When the control code decreases, the duty cycle of the control signal is decreased by the controller.

20. The control method according to claim 17, further comprising: Performing calculation on the detection voltage and the detection current to obtain power ratio information; as well as A power ratio threshold is set, and the power ratio information is compared with the power ratio threshold to adjust the control code.

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