AC-dc power conversion module and driving method thereof

Abstract

The present application relates to an AC / DC power conversion module and its driving method. When the AC / DC converter is electrically coupled to an external power source, the microprocessor is powered by a step-down auxiliary circuit. After the microprocessor controls the start of the DC / DC converter for a specific time, the microprocessor controls the start of the AC / DC converter. Thereafter, the output voltage of the AC / DC converter is boosted, and the output voltage of the DC / DC converter is boosted accordingly. In this way, the power elements in the back-end DC / DC converter are started first, and then the power elements in the front-end AC / DC converter are started, thereby suppressing the inrush current. Moreover, once the external power source is connected, the step-down auxiliary circuit will automatically step down and supply power, allowing the module to automatically start operation. This achieves autonomous operation after power is supplied, without the need for additional circuits for power supply or control.

Description

Technical Field

[0001] This invention relates to an AC / DC power conversion module and its driving method, particularly a modular power conversion module with rectification and transformation functions and its driving method, which is especially suitable for power supply or electronic load and other power-related instruments and equipment. Background Technology

[0002] As technology continues to evolve, although the functions of power supply and electronic load instruments and equipment are becoming more and more diverse and powerful, the progress of AC / DC power converter circuits attached to them is quite limited. They have always maintained the old model, that is, each manufacturer's machine is designed independently for the characteristics and special needs of each machine, and the whole is embedded and mixed in the main circuit, making it impossible to separate individual functions of the converter and share the design.

[0003] Furthermore, in traditional power supply-related instruments and equipment, the actual power input and the intended power output require an auxiliary power supply for judgment and control, making it impossible to achieve a single power input operation mode. To elaborate further, taking a power supply as an example, the entire startup mechanism requires an auxiliary circuit driven by another power supply for detection, processing, and output control after the main power supply is connected to the power supply, making it impossible to achieve single circuit, single power supply processing and output.

[0004] Furthermore, existing AC / DC power converter circuits within power supply-related instruments lack abnormal situation notification and protection mechanisms. In the event of an abnormality, the AC / DC power converter circuit itself cannot immediately stop operating and report the issue; the main controller only takes appropriate action after the terminal power output conversion module detects the anomaly. However, this existing protection and notification mechanism cannot immediately notify the output module to stop operating, often resulting in significant damage to the instrument.

[0005] Therefore, it is evident that an AC / DC power converter module and its driving method that can modularize the AC / DC power converter circuit, requires no auxiliary circuit driven by an additional power source to assist in processing and control, and has protection and notification mechanisms is something that the relevant industries and the general public eagerly anticipate. Summary of the Invention

[0006] One of the main objectives of this invention is to achieve modularization of AC / DC power conversion. It can function as a power converter connected in parallel with mains power, and its downstream end can be arbitrarily paired with output power conversion modules that accept DC current input, such as power supply modules or electronic load modules. This allows various bidirectional power supply instruments to share the benefits of modularity. Accordingly, the modular design of this invention is highly beneficial for instrument maintenance during malfunctions and also greatly facilitates the development and design of various power supply products.

[0007] Another major objective of this invention is to achieve automatic startup and operation after power is supplied, without the need for additional circuitry driven by another external power source to assist in processing or judgment. In detail, when an external power source is connected, the module itself will automatically start the startup program and establish the input voltage required by the output power converter. Once the input voltage is established, it will automatically notify the output power converter that it can start operating, realizing a unified processing flow of single power input, direct processing, and direct output.

[0008] To achieve the aforementioned objectives, the present invention provides an AC / DC power conversion module, which mainly includes an AC / DC converter, a DC / DC converter, a buck converter auxiliary circuit, and a microprocessor. The AC / DC converter includes a first power element electrically coupled to an external power supply. The DC / DC converter includes a second power element and a third power element, which are electrically coupled to each other. The second power element is electrically coupled to the AC / DC converter, and the third power element is electrically coupled to the output power conversion module. The buck converter auxiliary circuit is electrically coupled between the AC / DC converter and the DC / DC converter. The microprocessor is electrically coupled to the AC / DC converter, the DC / DC converter, and the buck converter auxiliary circuit. When the AC / DC converter is electrically coupled to an external power supply, the buck converter auxiliary circuit supplies power to the microprocessor. After the microprocessor controls the activation of the second and third power elements for a specific time, the microprocessor controls the activation of the first power element. The output voltage of the AC / DC converter is boosted, and the output voltage of the DC / DC converter is boosted accordingly.

[0009] To achieve the aforementioned objectives, the present invention provides a driving method for an AC / DC power conversion module, wherein the AC / DC power conversion module mainly includes an AC / DC converter, a DC / DC converter, a buck converter auxiliary circuit, and a microprocessor, and the buck converter auxiliary circuit is electrically coupled between the AC / DC converter and the DC / DC converter; the driving method includes the following steps: first, providing an external power supply to the AC / DC converter and the buck converter auxiliary circuit; second, the buck converter auxiliary circuit modulates the received external power supply and supplies power to the microprocessor; third, the microprocessor activates the power components in the DC / DC converter for a specific time before activating the power components in the AC / DC converter; finally, the AC / DC converter modulates the voltage of the external power supply, and the output voltage of the DC / DC converter modulates accordingly.

[0010] Accordingly, the present invention provides the driving power for each major component (e.g., microprocessor) through a step-down auxiliary circuit, allowing each major component to start operating first. Moreover, the step-down auxiliary circuit is electrically coupled to an external power source, which means that once an external power source is connected, the step-down auxiliary circuit will automatically step down and supply power, allowing the module to start operating automatically. This achieves autonomous operation after being powered on, without the need for additional circuitry for power supply or control.

[0011] Furthermore, this invention configures the power components in the back-end DC / DC converter to start first, followed by the power components in the front-end AC / DC converter. This effectively suppresses inrush current, thereby preventing damage to electronic components on the primary side of the transformer due to inrush current. In addition, the AC / DC power conversion module of this invention shares the same microprocessor, which not only reduces costs but also results in smoother overall operation and higher efficiency.

[0012] In addition, the AC / DC power conversion module and its driving method of the present invention adopt digital control, so the protection value can be easily adjusted according to the needs of different output stages. Furthermore, the AC / DC power conversion module of the present invention has a protection notification mechanism. When the device malfunctions, it will actively notify the downstream output power conversion module and stop working to avoid a chain reaction that could lead to irreparable consequences. Attached Figure Description

[0013] Figure 1 This is a block diagram illustrating the usage scenario of a preferred embodiment of the present invention.

[0014] Figure 2 This is a system architecture diagram of a preferred embodiment of the present invention.

[0015] Figure 3 This is a flowchart of the driving method of the first embodiment of the present invention.

[0016] Figure 4 This is a schematic diagram of a microprocessor generating a power control signal according to a preferred embodiment of the present invention. Detailed Implementation

[0017] Before the AC / DC power conversion module and its driving method of the present invention are described in detail in this embodiment, it should be noted that similar components will be represented by the same component symbols in the following description. Furthermore, the accompanying drawings of the present invention are for illustrative purposes only and are not necessarily drawn to scale, and not all details may be shown in the drawings.

[0018] Please refer to the following first. Figure 1 The figure shows a block diagram illustrating the preferred embodiment of the present invention. As shown, the first terminal 11 of the AC / DC power conversion module 1 in this embodiment is coupled to an external power supply Po, meaning it can be connected in parallel with the mains power. Its second terminal 12 can be arbitrarily paired with an output power conversion module Pc that receives DC current input. This combination of the AC / DC power conversion module 1 and the output power conversion module Pc can form, for example, a power supply module or an electronic load module. In other words, this embodiment fully realizes modularity, allowing various bidirectional power supply instruments to share the advantages and benefits of modularity.

[0019] Please refer to the following: Figure 2 The figure shows a system architecture diagram of a preferred embodiment of the present invention. As shown in the figure, the AC / DC power conversion module 1 of this embodiment mainly includes an AC / DC converter 2, a DC / DC converter 3, a step-down auxiliary circuit 4, and a microprocessor 5. Furthermore, the AC / DC converter 2 of this embodiment mainly includes a first power element 21, a first drive circuit 211, an input voltage sensing circuit 22, an input current sensing circuit 23, an output voltage sensing circuit 24, and multiple passive elements 25.

[0020] In this embodiment, the first power element 21 is a power switching device consisting of an insulated gate bipolar transistor (IGBT) and a silicon carbide (SIC) in parallel. This power element can effectively reduce switching losses. One end of the first drive circuit 211 is electrically connected to the first power element 21, and the other end is electrically connected to the microprocessor 5. Therefore, the first drive circuit 211 can be driven by the microprocessor 5 to control the operation of the first power element 21.

[0021] Furthermore, the input voltage sensing circuit 22 and the input current sensing circuit 23 of this embodiment are mainly used to detect the input voltage value V22 and the input current value V23 of the external power supply Po, respectively, and report them to the microprocessor 5. Moreover, the passive components 25 in the AC / DC converter 2 include electronic components such as inductors, capacitors, and resistors. As for the output voltage sensing circuit 24, it is mainly used to measure the output voltage of the AC / DC converter 2, and also to detect the voltage of the DC bus (DC BUS, not shown in the figure). In addition, the AC / DC converter 2 of this embodiment also has a power factor correction (PFC) circuit, which allows the power supply to transfer energy to downstream modules with the most efficient efficiency.

[0022] Furthermore, the DC / DC converter 3 of this embodiment mainly includes a second power element 31, a third power element 32, a second drive circuit 311, a third drive circuit 321, an isolation transformer 6, and a passive element 26. The second power element 31 and the third power element 32 are both silicon carbide semiconductor power elements; one end of the second drive circuit 311 and the third drive circuit 321 are electrically connected to the second power element 31 and the third power element 32, respectively, and the other end is electrically connected to the microprocessor 5. Therefore, the second drive circuit 311 and the third drive circuit 321 can be driven by the microprocessor 5 to control their respective operations. In addition, the passive element 26 in this embodiment is a resonator, whose main purpose is to transfer energy from the primary side to the secondary side. Overall, the DC / DC converter 3 of this embodiment is a bidirectional LLC resonant DC power converter with buck-boost isolation.

[0023] On the other hand, the buck converter 4 is electrically coupled between the AC / DC converter 2 and the DC / DC converter 3, and is also electrically connected to the microprocessor 5, the input voltage sensing circuit 22, the input current sensing circuit 23, the first drive circuit 211, the second drive circuit 311, and the third drive circuit 321. Essentially, the buck converter 4 in this embodiment has a high buck conversion rate, directly converting the input power from the external power supply Po into the operating voltage of the microprocessor 5, each drive circuit, and each sensing circuit, such as 12V or 5V, and directly supplying power to these components.

[0024] Please refer to the following: Figure 3 This is a flowchart of the driving method of the first embodiment of the present invention; the following describes the driving method and flow of the AC / DC power conversion module 1 in this embodiment: First, when the AC / DC power conversion module 1 is electrically coupled to an external power supply Po, that is, the external power supply Po supplies power to the AC / DC converter 2 and the step-down auxiliary circuit 4, please see... Figure 3 Step S100. At this time, the buck auxiliary circuit 4 modulates the received external power supply Po and supplies power to the microprocessor 5, the second drive circuit 311, the third drive circuit 321, the input voltage sensing circuit 22, the input current sensing circuit 23, and the output voltage sensing circuit 24. Figure 3 Step S110 in the process.

[0025] Furthermore, after the microprocessor 5 and the related sensing circuits receive the signal, the microprocessor 5 first outputs a control signal to the second drive circuit 311 and the third drive circuit 321 to activate the second power element 31 and the third power element 32. Figure 3 Step S120. That is, DC / DC converter 3 is started before AC / DC converter 2 supplies power to DC / DC converter 3. However, the purpose of this is to suppress inrush current. If AC / DC converter 2 directly supplies power to DC / DC converter 3 before the second power element 31 and the third power element 32 of DC / DC converter 3 are started, the peak current generated when the power supply starts may directly impact the electronic components in the circuit, especially the primary circuit of the transformer. This may affect the service life of the electronic components or even cause circuit failure or burnout.

[0026] Furthermore, after step S120 in this embodiment, that is, after the microprocessor 5 controls the startup of the second power element 31 and the third power element 32, the system will maintain a specific time, approximately tens of milliseconds, to ensure that the DC / DC converter 3 has been fully started before proceeding to step S130, that is, the microprocessor 5 outputs a power control signal to the first drive circuit 211 to control the startup of the first power element 21. The generation method of the power control signal will be described in detail below.

[0027] Please refer to the following: Figure 4 This is a schematic diagram of a microprocessor generating a power control signal according to a preferred embodiment of the present invention. The microprocessor 5 in this embodiment mainly includes a voltage compensator Gc, a current compensator Gi, and a computing unit MCU. The voltage compensator Gc generates a current control command Iac based on a predetermined voltage value Vset and the output voltage value V24 detected by the output voltage sensing circuit 24. Further explanation: the predetermined voltage value Vset is a voltage value set by the user through a human-machine interface and a DC bus (DCBus, not shown in the figure). This predetermined voltage value Vset is compared with the output voltage value V24 (e.g., added or subtracted) and then fed into the voltage compensator Gc. The voltage compensator Gc then compensates for this voltage through function calculations and steady-state error compensation, thereby generating the current control command Iac, which is a voltage-type AC control signal.

[0028] Next, the current control command Iac is compared with the input current value V23 detected by the input current sensing circuit 23, for example, by addition or subtraction. The current value after comparison enters the current compensator Gi, which compensates for the current through function calculation and steady-state error compensation, thereby generating the output control command Sout. In addition, the arithmetic unit MCU obtains the voltage phase of the input voltage value V22 detected by the input voltage sensing circuit 22 through phase-locked loop calculation, and the arithmetic unit MCU generates the power control signal Vpwm based on the aforementioned output control command Sout and the input voltage phase. In other words, the arithmetic unit MCU calculates the conduction of the first power element 21, that is, the duty ratio of the semiconductor switching element, based on the aforementioned output control command Sout and the input voltage phase, and outputs the PWM (Pulse Width Modulation) type power control signal Vpwm to the first drive circuit 211, thereby driving the first power element 21 to operate.

[0029] Please continue reading. Figure 3When the power components within AC / DC converter 2 are activated, AC / DC converter 2 can immediately modulate the voltage of the external power supply Po, typically boosting it. On the other hand, because the AC / DC power conversion module 1 in this embodiment employs an open-loop design, once the power supply from AC / DC converter 2 boosts the voltage, the voltage within DC / DC converter 3 will also be modulated and boosted accordingly. Figure 3 Step S140. Finally, the DC / DC converter 3 outputs the modulated current to the output power conversion module Pc for subsequent power supply or electronic load processing, which is... Figure 3 Step S150 in the process.

[0030] Therefore, the AC / DC power conversion module and its driving method in this embodiment have at least the following advantages:

[0031] This embodiment realizes the modularization of AC / DC power conversion, which can be used as a power converter connected in parallel with the mains power. Its back end can be arbitrarily matched with an output power conversion module Pc with DC current input, such as a power supply module or an electronic load module, so that various bidirectional power supply instruments can share the results of modularization.

[0032] The AC / DC power conversion module 1 in this embodiment combines the requirements of various power supply instruments for AC / DC power conversion modules, including universal input, overall efficiency and power isolation, and adopts active power factor correction and bidirectional LLC resonant power module.

[0033] In this embodiment, the AC / DC power conversion module 1 uses a digital signal processor (DSP) as the microprocessor 5 and employs digital signal control, thus allowing for easy adjustment of protection values ​​to meet the needs of different output stages. Furthermore, the AC / DC converter 2 and DC / DC converter 3 share the DSP 5, which not only reduces costs but also ensures smoother overall operation and higher efficiency.

[0034] In this embodiment, the power components in the AC / DC converter 2 are insulated gate bipolar transistors (IGBTs) connected in parallel with silicon carbide (SiC) power switching devices, which can effectively reduce switching losses. Moreover, the power components in the DC / DC converter 3 use silicon carbide components as the main switching elements, which can improve the overall module efficiency.

[0035] In this embodiment, the DC / DC converter 3 is a transformer of a bidirectional LLC resonant DC power converter LLC module with step-up / step-down isolation. The number of turns can be adjusted to meet the output high and low voltage requirements.

[0036] In this embodiment, the AC / DC power conversion module 1 achieves "single power input, autonomous startup". It first provides the driving power to the microprocessor, various sensing circuits and power component drive circuits through the step-down auxiliary circuit 4, allowing the main components to start operating in advance. That is, after the external power supply Po supplies power, the step-down auxiliary circuit 4 will automatically step down and supply power, allowing the module to start operating automatically. It achieves autonomous operation after being powered on, without the need for additional circuits to supply power or control it. Moreover, once the voltage is established, it will automatically notify the output power converter Pc to start operation.

[0037] In this embodiment, the step-down auxiliary circuit 4 is electrically coupled between the AC / DC converter 2 and the DC / DC converter 3. This configuration not only reduces the size but also greatly reduces the complexity of the circuit and improves efficiency and service life.

[0038] The AC / DC power conversion module 1 in this embodiment has a protection notification mechanism. When the device performs an abnormal operation, it will actively notify the output power conversion module Pc at the back end and stop working to avoid a chain reaction that could lead to irreparable consequences.

[0039] The above embodiments are merely illustrative examples for ease of explanation. The scope of the claims of this invention should be determined by the scope of the claims, and not limited to the above embodiments.

[0040] Explanation of reference numerals in the attached figures

[0041] 1: AC / DC power conversion module

[0042] 2: AC / DC converter

[0043] 3: DC / DC converter

[0044] 4: Step-down auxiliary circuit

[0045] 5: Microprocessor

[0046] 6: Isolation Transformer

[0047] 11: First end

[0048] 12: Second end

[0049] 21: First power element

[0050] 22: Input voltage sensing circuit

[0051] 23: Input current sensing circuit

[0052] 24: Output voltage sensing circuit

[0053] 25, 26: Passive components

[0054] 31: Second power element

[0055] 32: Third power element

[0056] 211: First driving circuit

[0057] 311: Second drive circuit

[0058] 321: Third drive circuit

[0059] Gc: Voltage compensator

[0060] Gi: Current Compensator

[0061] Iac: Current control command

[0062] MCU: Computational Unit

[0063] Pc: Output power conversion module

[0064] Po: External power supply

[0065] Sout: Output control commands

[0066] V22: Input voltage value

[0067] V23: Input current value

[0068] V24: Output voltage value.

Claims

1. An AC / DC power conversion module, comprising: An AC / DC converter, which includes a first power element; The first power element is electrically coupled to an external power source; A DC / DC converter includes a second power element and a third power element; the second power element and the third power element are electrically coupled to each other, and the second power element is electrically coupled to the AC / DC converter, and the third power element is electrically coupled to the output power conversion module; A step-down auxiliary circuit, electrically coupled between the AC / DC converter and the DC / DC converter; and The microprocessor is electrically coupled to the AC / DC converter, the DC / DC converter, and the step-down auxiliary circuit. Specifically, when the AC / DC converter is electrically coupled to the external power supply, the microprocessor is powered by the step-down auxiliary circuit. After the microprocessor controls the activation of the second and third power components for a specific time, the microprocessor then controls the activation of the first power component. The output voltage of the AC / DC converter increases, and the output voltage of the DC / DC converter increases accordingly. The AC / DC converter further includes a first drive circuit, an input voltage sensing circuit, and an input current sensing circuit. The first drive circuit is electrically coupled to the first power element, the microprocessor, and the buck converter auxiliary circuit. The input voltage sensing circuit and the input current sensing circuit are electrically coupled to the microprocessor and the buck converter auxiliary circuit. When the AC / DC converter is electrically coupled to an external power source, the buck converter auxiliary circuit supplies power to the first drive circuit, the input voltage sensing circuit, and the input current sensing circuit. The input voltage sensing circuit and the input current sensing circuit respectively provide input voltage and input current values ​​to the microprocessor. The AC / DC converter further includes an output voltage sensing circuit electrically coupled between the first power element and the DC / DC converter, and electrically coupled to the microprocessor and the buck converter auxiliary circuit. The output voltage sensing circuit provides the output voltage value to the microprocessor. The microprocessor includes a voltage compensator, a current compensator, and an arithmetic unit. The voltage compensator generates a current control command based on a predetermined voltage value and the output voltage value. The current compensator generates an output control command based on the current control command and the input current value. The arithmetic unit processes the input voltage value to obtain the input voltage phase, and generates a power control signal based on the output control command and the input voltage phase, and outputs it to the first drive circuit.

2. The AC / DC power conversion module according to claim 1, wherein, The DC / DC converter also includes a second drive circuit and a third drive circuit; the second drive circuit is electrically coupled to the second power element, the microprocessor and the buck auxiliary circuit, and the third drive circuit is electrically coupled to the third power element, the microprocessor and the buck auxiliary circuit; when the AC / DC converter is electrically coupled to the external power supply, the buck auxiliary circuit supplies power to the second drive circuit and the third drive circuit.

3. The AC / DC power conversion module according to claim 1, wherein, The DC / DC converter also includes an isolation transformer electrically coupled between the second power element and the third power element.

4. The AC / DC power conversion module according to claim 3, wherein, The DC / DC converter also includes a resonator electrically coupled between the second power element and the isolation transformer.

5. A driving method for an AC / DC power conversion module, wherein, The AC / DC power conversion module includes an AC / DC converter, a DC / DC converter, a step-down auxiliary circuit, and a microprocessor. The step-down auxiliary circuit is electrically coupled between the AC / DC converter and the DC / DC converter. The microprocessor is electrically coupled to the AC / DC converter, the DC / DC converter, and the step-down auxiliary circuit. The driving method includes the following steps: (A) Provide external power to the AC / DC converter and the step-down auxiliary circuit; (B) The step-down auxiliary circuit modulates the received external power supply and supplies power to the microprocessor; (C) After the microprocessor activates the power components within the DC / DC converter for a specific period of time; (D) The microprocessor activates the power components within the AC / DC converter; and (E) The AC / DC converter modulates the voltage of the external power supply, and the output voltage of the DC / DC converter modulates accordingly. The AC / DC converter further includes a first drive circuit, an input voltage sensing circuit, and an input current sensing circuit. The first drive circuit is electrically coupled to the power components within the AC / DC converter, the microprocessor, and the buck converter auxiliary circuit. The input voltage sensing circuit and the input current sensing circuit are electrically coupled to the microprocessor and the buck converter auxiliary circuit. When the AC / DC converter is electrically coupled to an external power source, the buck converter auxiliary circuit supplies power to the first drive circuit, the input voltage sensing circuit, and the input current sensing circuit. The input voltage sensing circuit and the input current sensing circuit respectively provide input voltage and input current values ​​to the microprocessor. The AC / DC converter also includes an output voltage sensing circuit, which is electrically coupled between the power components within the AC / DC converter and the DC / DC converter, and electrically coupled to the microprocessor and the buck converter auxiliary circuit. The output voltage sensing circuit provides the output voltage value to the microprocessor. The microprocessor includes a voltage compensator, a current compensator, and an arithmetic unit. The voltage compensator generates a current control command based on a predetermined voltage value and the output voltage value. The current compensator generates an output control command based on the current control command and the input current value. The arithmetic unit processes the input voltage value to obtain the input voltage phase, and generates a power control signal based on the output control command and the input voltage phase, and outputs it to the first drive circuit.

6. The driving method for the AC / DC power conversion module according to claim 5, wherein, The DC / DC converter further includes a second driving circuit and a third driving circuit; the first driving circuit, the second driving circuit, the third driving circuit, the input voltage sensing circuit, the input current sensing circuit, and the output voltage sensing circuit are electrically coupled to the microprocessor and the buck auxiliary circuit. The first driving circuit is used to drive the power components in the AC / DC converter, and the second driving circuit and the third driving circuit are used to drive the power components in the DC / DC converter. In step (B), the buck auxiliary circuit also supplies power to the first driving circuit, the second driving circuit, the third driving circuit, the input voltage sensing circuit, the input current sensing circuit, and the output voltage sensing circuit.

7. The driving method for the AC / DC power conversion module according to claim 6, wherein, The microprocessor includes a voltage compensator, a current compensator, and an arithmetic unit; in step (D), the microprocessor outputs a power control signal to the first drive circuit to activate the power components within the AC / DC converter; the power control signal is generated through the following processing: The voltage compensator generates a current control command based on a predetermined voltage value and the output voltage value detected by the output voltage sensing circuit; The current compensator generates an output control command based on the current control command and the input current value detected by the input current sensing circuit. as well as The arithmetic unit calculates the input voltage value detected by the input voltage sensing circuit to obtain the input voltage phase, and generates the power control signal according to the output control command and the input voltage phase.

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