Totem-pole power factor correction circuit and related power conversion apparatus
Patent Information
- Application Number
- CN202510452878.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-11
- Publication Date
- 2026-10-20
AI Technical Summary
[0003]当交流输入电压于零交越区间(例如：交流输入电压信号在0V附近的电压区间、由负电压经过0V变为正电压的区间、或者由正电压经过0V变为负电压的区间)，图腾柱功率因数校正电路会有较高的漏电流尖峰(leakage current spike)伴随慢速臂电路的导通而出现，造成使用图腾柱功率因数校正电路的电源转换装置的漏电流超出规范，而可能造成其外部机壳因漏电流而使使用者触电、装置毁损甚至火灾等危害，也会使得图腾柱功率因数校正电路的电路设计存在较多限制
[0006]为达前述目的，本案另提供一种电源转换装置，包含:至少一图腾柱功率因数校正电路，用以接收输入电压及输入电流，而对应地提供输出电压及输出电流，且包含：快速臂电路，包含串联连接的快速上开关与快速下开关；慢速臂电路，包含串联连接的慢速上开关与慢速下开关，其中慢速上开关与慢速下开关电连接于中点，且中点到参考电位点之间存在端点电压；电容滤波电路，与快速臂电路及慢速臂电路电连接，且具有等效电容值；以及控制器，电连接于快速臂电路与慢速臂电路，用以输出第一控制信号、第二控制信号、第三控制信号及第四控制信号来分别控制快速上开关、快速下开关、慢速上开关与慢速下开关的运作；其中当输入电压大于第一门槛值且小于第二门槛值，且输入电压由负值往零的方向变化，控制器设置第一控制信号、第三控制信号及第四控制信号使快速上开关、慢速上开关与慢速下开关不导通，且控制器逐渐调升参考电压命令及参考电流命令的至少其中之一，使得第二控制信号的责任周期逐渐增加而使快速下开关间歇性的导通，以让端点电压变化斜率依据设定电压斜率进行调整；其中当输入电压大于第一门槛值且小于第二门槛值，且输入电压由正值往零的方向变化，控制器设置第二控制信号、第三控制信号及第四控制信号使快速下开关、慢速上开关与慢速下开关不导通，且该控制器逐渐调升参考电压命令及参考电流命令的至少其中之一，使得第一控制信号的责任周期逐渐增加而使该快速上开关间歇性的导通，以让端点电压变化斜率依据设定电压斜率进行调整。
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Abstract
Description
Technical Field
[0001] This case pertains to a totem pole power factor correction circuit, particularly a totem pole power factor correction circuit that can improve leakage current and related power conversion devices. Background Technology
[0002] Research on power factor correction technology is developing towards higher efficiency and higher power density in order to reduce energy loss and improve the overall system performance.
[0003] When the AC input voltage is in the zero-crossing range (e.g., the AC input voltage signal is in the voltage range near 0V, the range where the negative voltage changes from 0V to positive voltage, or the range where the positive voltage changes from 0V to negative voltage), the totem pole power factor correction circuit will have a high leakage current spike along with the conduction of the slow arm circuit. This will cause the leakage current of the power conversion device using the totem pole power factor correction circuit to exceed the specification, which may cause electric shock to the user, damage to the device, or even fire due to leakage current in the external casing. It will also impose more restrictions on the circuit design of the totem pole power factor correction circuit. Summary of the Invention
[0004] The purpose of this invention is to provide a totem pole power factor correction circuit and related power conversion device to effectively suppress defects such as leakage current.
[0005] To achieve the aforementioned objective, this application provides a totem pole power factor correction circuit for receiving input voltage and input current, and correspondingly providing output voltage and output current, comprising: a fast arm circuit including a fast up switch and a fast down switch connected in series; a slow arm circuit including a slow up switch and a slow down switch connected in series, wherein the slow up switch and the slow down switch are electrically connected at a midpoint, and there is an endpoint voltage between the midpoint and a reference potential point; a capacitor filter circuit electrically connected to the fast arm circuit and the slow arm circuit, and having an equivalent capacitance value; and a controller electrically connected to the fast arm circuit and the slow arm circuit, for outputting a first control signal, a second control signal, a third control signal, and a fourth control signal to control the operation of the fast up switch, the fast down switch, the slow up switch, and the slow down switch, respectively; wherein when the input voltage is greater than a first threshold value and less than a second threshold value, and the input voltage changes from a negative value to zero... The controller sets a first control signal, a third control signal, and a fourth control signal to deactivate the fast-up switch, the slow-up switch, and the slow-down switch. The controller also gradually increases at least one of the reference voltage command and the reference current command, causing the duty cycle of the second control signal to gradually increase, thus intermittently turning on the fast-down switch. This allows the slope of the terminal voltage change to be adjusted according to a set voltage slope. Specifically, when the input voltage is greater than a first threshold value and less than a second threshold value, and the input voltage changes from a positive value to zero, the controller sets the second, third, and fourth control signals to deactivate the fast-down switch, the slow-up switch, and the slow-down switch. The controller also gradually increases at least one of the reference voltage command and the reference current command, causing the duty cycle of the first control signal to gradually increase, thus intermittently turning on the fast-up switch. This allows the slope of the terminal voltage change to be adjusted according to a set voltage slope.
[0006] To achieve the aforementioned objectives, this application further provides a power conversion device, comprising: at least one totem pole power factor correction circuit for receiving input voltage and input current, and correspondingly providing output voltage and output current, and comprising: a fast arm circuit including a fast up switch and a fast down switch connected in series; a slow arm circuit including a slow up switch and a slow down switch connected in series, wherein the slow up switch and the slow down switch are electrically connected at a midpoint, and there is an endpoint voltage between the midpoint and a reference potential point; a capacitor filter circuit electrically connected to the fast arm circuit and the slow arm circuit, and having an equivalent capacitance value; and a controller electrically connected to the fast arm circuit and the slow arm circuit, for outputting a first control signal, a second control signal, a third control signal, and a fourth control signal to control the operation of the fast up switch, the fast down switch, the slow up switch, and the slow down switch, respectively; wherein when the input voltage is greater than a first threshold value and less than a second threshold value, and the input voltage changes from a negative value... When the input voltage changes from positive to zero, the controller sets a first control signal, a third control signal, and a fourth control signal to deactivate the fast-up switch, the slow-up switch, and the slow-down switch. The controller also gradually increases at least one of the reference voltage command and the reference current command, causing the duty cycle of the second control signal to gradually increase, thus intermittently turning on the fast-down switch. This allows the slope of the terminal voltage change to be adjusted according to the set voltage slope. Specifically, when the input voltage is greater than a first threshold value and less than a second threshold value, and the input voltage changes from positive to zero, the controller sets a second control signal, a third control signal, and a fourth control signal to deactivate the fast-down switch, the slow-up switch, and the slow-down switch. The controller also gradually increases at least one of the reference voltage command and the reference current command, causing the duty cycle of the first control signal to gradually increase, thus intermittently turning on the fast-up switch. This allows the slope of the terminal voltage change to be adjusted according to the set voltage slope. Attached Figure Description
[0007] Figure 1 This is a schematic diagram of the circuit structure of one embodiment of the totem pole power factor correction circuit in this case;
[0008] Figure 2 for Figure 1 The diagram shows the waveform timing of the totem pole power factor correction circuit during operation.
[0009] Figure 3 for Figure 1 A schematic diagram of the circuit structure of one embodiment of the controller is shown.
[0010] Figure 4 This is a circuit diagram of one embodiment of the power conversion device in this case; and
[0011] Figure 5 for Figure 4 The diagram shows the waveform timing of the totem pole power factor correction circuit during operation.
[0012] Explanation of reference numerals in the attached figures
[0013] 1, 1a, 1b: Totem Pole Power Factor Correction Circuit
[0014] 2: Fast Arm Circuit
[0015] 3: Slow-speed arm circuit
[0016] 4: Capacitor Filtering Circuit
[0017] 5: Controller
[0018] 6: Feedback circuit
[0019] 7: Transformer
[0020] 8: Rectifier circuit
[0021] 9: Load
[0022] 10: Power conversion device
[0023] 40: Reference signal generation circuit
[0024] 41: First comparator
[0025] 42: Pulse Width Modulation Signal Generation Circuit
[0026] 43: Second comparator
[0027] Vin: Input voltage
[0028] Iin: Input current
[0029] Vout: Output voltage
[0030] Iout: Output current
[0031] Qh: Quick-start switch
[0032] Ql: Quick-release switch
[0033] Sh: Slowly turn on the switch
[0034] Sl: Slow-speed switch
[0035] Nc: Midpoint
[0036] Vn: Terminal voltage
[0037] G: Grounding point
[0038] H: High-voltage terminal
[0039] Tf: Low-voltage endpoint
[0040] C1: First Y capacitor
[0041] C2: Second Y capacitor
[0042] C3: Third Y capacitor
[0043] t1, t2, t3, t4, t5, T1, T2, T3, T4, T5, T6, T7, T8: Time
[0044] VQh: First control signal
[0045] VQl: Second control signal
[0046] VSh: Third control signal
[0047] VSl: Fourth control signal
[0048] Vfb: Voltage feedback signal
[0049] Ifb: Current feedback signal
[0050] Vref: Reference voltage command
[0051] Iref: Reference Current Command
[0052] Ilim: Leakage inductance current tolerance
[0053] Ilk: Leakage current
[0054] L, N: Input terminals Detailed Implementation
[0055] Some typical embodiments embodying the features and advantages of this invention will be described in detail in the following description. It should be understood that this invention can have various variations in different implementations, all of which do not depart from the scope of this invention, and the descriptions and drawings herein are for illustrative purposes only and not for limiting the invention.
[0056] Please see Figure 1 , Figure 2 and Figure 3 ,in Figure 1 This is a circuit diagram illustrating one embodiment of the totem pole power factor correction circuit in this case. Figure 2 for Figure 1 The diagram shows the waveform timing of the totem pole power factor correction circuit during operation. Figure 3 for Figure 1The diagram shows a detailed circuit structure of the controller. The input terminal of the totem pole power factor correction circuit 1 is electrically connected to the input power supply 8, and the output terminal of the totem pole power factor correction circuit 1 is electrically connected to the load 9. The totem pole power factor correction circuit 1 receives the input voltage Vin and input current Iin provided by the AC input power supply 8 at its input terminal (L,N), and performs power factor correction to provide a DC output voltage Vout and output current Iout at its output terminal. The totem pole power factor correction circuit 1 includes a fast arm circuit 2, a slow arm circuit 3, a capacitor filter circuit 4, a controller 5, a feedback circuit 6, a transformer 7, and a rectifier circuit 8. The fast arm circuit 2 is electrically connected to the input power supply 8 and includes at least one bridge arm circuit. Each bridge arm circuit includes a fast upper switch Qh and a fast lower switch Ql connected in series. The slow arm circuit 3 and the fast arm circuit 2 are connected in parallel. The slow arm circuit 3 includes a slow upper switch Sh and a slow lower switch Sl connected in series. The slow upper switch Sh and the slow lower switch Sl are electrically connected at the midpoint Nc, and there is an endpoint voltage Vn between the midpoint Nc and the reference potential point. The reference potential point can be set as the ground point G, the high-voltage endpoint H at the electrical connection between the fast arm circuit 2 and the slow arm circuit 3, or the low-voltage endpoint Tf at the electrical connection between the fast arm circuit 2 and the slow arm circuit 3.
[0057] The capacitor filter circuit 4 is electrically connected to the fast arm circuit 2 and the slow arm circuit 3. In some embodiments, the capacitor filter circuit 4 includes a first Y capacitor C1 and a second Y capacitor C2. The two ends of the first Y capacitor C1 and the second Y capacitor C2 are respectively electrically connected between the input terminal (L, N) and the ground point G, and the mutually coupled ends of the first Y capacitor C1 and the second Y capacitor C2 are electrically connected to the ground point G. In some embodiments, the totem pole power factor correction circuit 1 includes a third Y capacitor C3. The two ends of the third Y capacitor C3 are electrically connected between the low-voltage terminal Tf at the electrical connection point of the fast arm circuit 2 and the slow arm circuit 3 and the ground point G.
[0058] Transformer 7 includes a primary winding and a secondary winding (not shown). The primary winding is electrically connected to the slow-speed arm circuit 3, and transformer 7 uses electromagnetic coupling to transfer the electrical energy received by the primary winding to the secondary winding. Rectifier circuit 8 is electrically connected to the secondary winding of transformer 7 to rectify the electrical energy provided by the secondary winding of transformer 7, thereby providing output voltage Vout and output current Iout.
[0059] Controller 5 is electrically connected to the input terminal, reference potential point, fast arm circuit 2, and slow arm circuit 3 of totem pole power factor correction circuit 1. It is used to detect the input voltage Vin and determine whether the input voltage Vin is within the zero-crossing range based on the detection result (e.g., whether the controller 5 determines whether the input voltage Vin is in the voltage range near 0V, the range where the input voltage Vin changes from negative to positive after passing through 0V, or the range where the input voltage Vin changes from positive to negative after passing through 0V). For example... Figure 2 During the time intervals t1 to t2 or t3 to t4, the AC input voltage Vin is located between the voltage ranges (first threshold value Vth1, second threshold value Vth2). The controller 5 outputs a first control signal VQh, a second control signal VQl, a third control signal VSh, and a fourth control signal VSl based on the input voltage Vin and the terminal voltage Vn to control the operation of the fast-up switch Qh, the fast-down switch Ql, the slow-up switch Sh, and the slow-down switch Sl, respectively.
[0060] In some embodiments, the totem pole power factor correction circuit 1 further includes a feedback circuit 6 electrically connected between the rectifier circuit 8 and the output terminal of the totem pole power factor correction circuit 1, for detecting the output voltage Vout and the output current Iout, and generating a voltage feedback signal Vfb and a current feedback signal Ifb accordingly based on the detection results.
[0061] In some embodiments, the controller 5 includes a reference signal generation circuit 40, a first comparator 41, and a pulse width modulation signal generation circuit 42. The reference signal generation circuit 40 is electrically connected to the input of the totem-pole power factor correction circuit 1 and to a reference potential point. It detects the input voltage Vin and the endpoint voltage Vn, and generates a reference voltage command Vref based on a set voltage slope and the endpoint voltage Vn when the input voltage Vin is in the zero-crossing range. The first comparator 41 is electrically connected to the reference signal generation circuit 40 and the feedback circuit 6. The first comparator 41 compares the reference voltage command Vref with the voltage feedback signal Vfb and outputs a first comparison signal. The pulse width modulation signal generation circuit 42 is electrically connected to the first comparator 41, the fast up switch Qh, the fast down switch Ql, the slow up switch Sh, and the slow down switch Sl. It outputs a first control signal VQh, a second control signal VQl, a third control signal VSh, and a fourth control signal VSl to control the operation of the fast up switch Qh, the fast down switch Ql, the slow up switch Sh, and the slow down switch Sl, respectively. The pulse width modulation signal generation circuit 42 further adjusts the first control signal VQh and the second control signal VQl according to the first comparator signal to control the operation of the fast up switch Qh and the fast down switch Ql, so that the slope of the terminal voltage Vn change is adjusted according to the set voltage slope.
[0062] In some embodiments, the reference signal generation circuit 40 further detects the input current Iin to generate a reference current command Iref based on a set voltage slope and the endpoint voltage Vn within the zero-crossing point range of the input voltage Vin. Furthermore, the controller 5 includes a second comparator 43 electrically connected to the reference signal generation circuit 40 and the feedback circuit 6. The second comparator 43 compares the reference current command Iref with the current feedback signal Ifb and outputs a second comparison signal, causing the pulse width modulation signal generation circuit 42 to output a first control signal VQh, a second control signal VQl, a third control signal VSh, and a fourth control signal VSl to control the operation of the fast up switch Qh, the fast down switch Ql, the slow up switch Sh, and the slow down switch Sl, respectively. The pulse width modulation signal generation circuit 42 further adjusts the first control signal VQh and the second control signal VQl based on the second comparison signal to control the operation of the fast up switch Qh and the fast down switch Ql, so that the slope of the endpoint voltage Vn change is adjusted according to the set voltage slope.
[0063] In some embodiments, when the input voltage Vin is greater than a first threshold value Vth1 and less than a second threshold value Vth2, the controller 5 determines that the input voltage Vin is in the zero-crossing interval. The first threshold value Vth1 and the second threshold value Vth2 can also be set to appropriate voltage values to determine whether the input voltage Vin is in the zero-crossing interval.
[0064] In some embodiments, when the input voltage Vin changes from negative to zero, and the input voltage Vin is greater than the first threshold value Vth1 and less than the second threshold value Vth2, the controller 5 determines that the input voltage Vin is in the zero crossing range. The reference signal generation circuit 40 gradually increases the reference voltage command Vref and / or the reference current command Iref, so that the duty cycle of the second control signal VQl gradually increases, so that the slope of the endpoint voltage Vn change is adjusted according to the set voltage slope. For example, when the reference potential point is the ground point G, the endpoint voltage Vn is the voltage difference between the input terminal N and the ground point G. The controller 5 sets the first control signal VQh, the third control signal VSh, and the fourth control signal VSl to deactivate the fast up switch Qh, the slow up switch Sh, and the slow down switch Sl, and gradually increases the duty cycle of the second control signal VQl to intermittently activate the fast down switch Ql, so as to reduce the endpoint voltage Vn to 0 according to the set voltage slope (i.e., make the voltage level of the input terminal N equal to that of the ground point G). In another embodiment, when the reference potential point is the high-voltage endpoint H, the endpoint voltage Vn is the voltage difference between the input terminal N and the high-voltage endpoint H. The controller 5 sets the first control signal VQh, the third control signal VSh, and the fourth control signal VSl to deactivate the fast-up switch Qh, the slow-up switch Sh, and the slow-down switch Sl, and gradually increases the duty cycle of the second control signal VQl to intermittently activate the fast-down switch Ql, thereby raising the endpoint voltage Vn to the output voltage Vout according to the set voltage slope (i.e., making the voltage levels of the input terminal N and the ground point G equal). When the input voltage Vin changes from a positive value to zero, and the input voltage Vin is less than the second threshold value Vth2 and greater than the first threshold value Vth1, the controller 5 determines that the input voltage Vin is in the zero crossing range. The reference signal generation circuit 40 gradually increases the reference voltage command Vref and / or the reference current command Iref, causing the duty cycle of the first control signal VQh to gradually increase, so that the slope of the endpoint voltage Vn change is adjusted according to the set voltage slope. For example, when the reference potential point is ground point G, the endpoint voltage Vn is the voltage difference between the input terminal N and the ground point G. The controller 5 sets the second control signal VQl, the third control signal VSh, and the fourth control signal VSl to deactivate the fast down switch Ql, the slow up switch Sh, and the slow down switch Sl, and gradually increases the duty cycle of the first control signal VQh to intermittently activate the fast up switch Qh, so as to reduce the endpoint voltage Vn to 0 according to the set voltage slope (i.e., to make the voltage levels of the input terminal N and the ground point G equal).In another embodiment, when the reference potential point is the high-voltage endpoint H, the endpoint voltage Vn is the voltage difference between the input terminal N and the high-voltage endpoint H. The controller 5 sets the second control signal VQl, the third control signal VSh, and the fourth control signal VSl to deactivate the fast down switch Ql, the slow up switch Sh, and the slow down switch Sl, and gradually increases the duty cycle of the first control signal VQh to intermittently activate the fast up switch Qh, so as to raise the endpoint voltage Vn to the output voltage Vout according to the set voltage slope (i.e., to make the voltage level of the input terminal N equal to that of the ground point G).
[0065] In some embodiments, when the absolute value of the input voltage Vin is less than a first voltage threshold (e.g., the first voltage threshold is equal to the absolute value of a first threshold value Vth1 or a second threshold value Vth2), the controller 5 sets a third control signal VSh and a fourth control signal VSl to prevent the slow-speed up switch Sh and the slow-speed down switch Sl from conducting. The controller controls the operation of the fast-speed up switch Qh, the fast-speed down switch Ql, the slow-speed up switch Sh, and the slow-speed down switch Sl through the first control signal VQh, the second control signal VQl, the third control signal VSh, and the fourth control signal VSl, so as to change the terminal voltage Vn to the required voltage value according to the set voltage slope.
[0066] In addition, the totem pole power factor correction circuit 1 can perform normal power factor correction operation, for example... Figure 2 The data is shown for times t2 to t3 and t4 to t5. When the input voltage Vin is in the positive half-cycle, the slow up switch Sh remains on, the slow down switch Sl remains off, and the fast up switch Qh and fast down switch Ql alternately conduct. When the input voltage Vin is in the negative half-cycle, the slow up switch Sh remains off, the slow down switch Sl remains on, and the fast up switch Qh and fast down switch Ql alternately conduct.
[0067] When measuring the leakage current of the totem pole power factor correction circuit 1, the measuring instrument can be connected to Nc and G to measure the leakage current, and the following relationship can be obtained:
[0068] Ilk = Cy*(dVn / dt);
[0069] Where Ilk is the leakage current measured at points Nc and G, Cy is the equivalent capacitance between points Nc and G, and dVn / dt is the rate of change of the terminal voltage Vn over time (the slope of the terminal voltage Vn change). From the above formula, it can be seen that since the equivalent capacitance Cy of the capacitor filter circuit 4 is a known value, as long as the rate of change of the terminal voltage Vn over time is controlled so that the slope of the terminal voltage Vn at the charging and discharging times of the capacitor filter circuit 4 multiplied by the equivalent capacitance Cy is lower than the allowable leakage current value Ilim (for example, making the absolute value of the slope dVn / dt multiplied by the equivalent capacitance Cy lower than the allowable leakage current value Ilim), the leakage current Ilk can be controlled within the allowable leakage inductance current value Ilim to comply with safety regulations. Therefore, in this case, the controller 5 detects the input voltage Vin and the terminal voltage Vn. When the absolute value of the input voltage Vin is less than the first voltage threshold (the first voltage threshold is equal to the absolute value of the first threshold value Vth1 or the second threshold value Vth2), the controller 5 adjusts the first control signal VQh and the second control signal VQl according to the set voltage slope and the terminal voltage Vn to control the operation of the fast up switch Qh and the fast down switch Ql, so that the slope of the terminal voltage Vn change is adjusted according to the set voltage slope. In this way, the totem pole power factor correction circuit 1 can suppress the leakage current within the allowable value Ilim of the leakage inductance current. Furthermore, by suppressing the leakage current of the totem pole power factor correction circuit 1, the capacitance value of the capacitor filter circuit 4 of the totem pole power factor correction circuit 1 can be avoided from having a high limitation.
[0070] Please see Figure 4 and Figure 5 ,in Figure 4 This is a circuit diagram of the power conversion device in an embodiment of this case. Figure 5 for Figure 4 The diagram shows the waveform timing of the totem pole power factor correction circuit during operation. As shown, the power conversion device 10 of this embodiment includes at least two such circuits. Figure 1 The totem pole power factor correction circuit 1 is shown. Figure 4 The power conversion device 10 of the embodiment includes three totem pole power factor correction circuits (1, 1a, 1b) (hereinafter referred to as...). Figure 4 The circuits, from top to bottom, are called the first totem pole power factor correction circuit 1, the second totem pole power factor correction circuit 1a, and the third totem pole power factor correction circuit 1b. The first totem pole power factor correction circuit 1, the second totem pole power factor correction circuit 1a, and the third totem pole power factor correction circuit 1b are connected in parallel and electrically connected to the input power supply 8. As mentioned above, each totem pole power factor correction circuit 1, 1a, and 1b can suppress the leakage current Ilk to within the allowable value Ilim of the leakage inductance current, so it will not be described again here.
[0071] In this embodiment, when the controller 5 determines that the input voltage Vin is in the zero-crossing range, the first totem-pole power factor correction circuit 1 of the power conversion device 10 adjusts the first control signal VQh and the second control signal VQl according to the set voltage slope and the endpoint voltage Vn to control the operation of the fast up switch Qh and the fast down switch Ql, so that the slope of the endpoint voltage Vn change is adjusted according to the set voltage slope, for example... Figure 5 The times T1 to T2 and T5 to T6 are shown. Similarly, in the second totem pole power factor correction circuit 1a, when the controller 5 determines that the input voltage Vin is in the zero-crossing interval, the controller 5 adjusts the first control signal VQh and the second control signal VQl according to the set voltage slope and the endpoint voltage Vn to control the operation of the fast up switch Qh and the fast down switch Ql, so that the slope of the endpoint voltage Vn change is adjusted according to the set voltage slope, for example... Figure 5 The times T2 to T3 and T6 to T7 are shown. Similarly, in the third totem pole power factor correction circuit 1b, when the controller 5 determines that the input voltage Vin is in the zero-crossing range, the controller 5 adjusts the first control signal VQh and the second control signal VQl according to the set voltage slope and the endpoint voltage Vn to control the operation of the fast up switch Qh and the fast down switch Ql, so that the slope of the endpoint voltage Vn change is adjusted according to the set voltage slope, for example... Figure 5 The times T3 to T4 and T7 to T8 are shown. Furthermore, the time periods during which the first totem pole power factor correction circuit 1, the second totem pole power factor correction circuit 1a, and the third totem pole power factor correction circuit 1b adjust the slope of the terminal voltage Vn according to a set voltage slope are staggered. By staggering the time periods during which the multiple totem pole power factor correction circuits 1 reduce the terminal voltage Vn, leakage current spikes can be effectively reduced.
[0072] In summary, this invention provides a totem pole power factor correction circuit and a power conversion device applicable thereto. When the input voltage is in the zero crossing range, the controller of the totem pole power factor correction circuit adjusts the operation of the fast up switch and fast down switch according to the set voltage slope and the terminal voltage, so that the slope of the terminal voltage change is adjusted according to the set voltage slope. Thus, the totem pole power factor correction circuit can effectively suppress leakage current within the allowable value of leakage inductance current.
Claims
1. A totem pole power factor correction circuit for receiving input voltage and input current, and correspondingly providing output voltage and output current, comprising: A fast arm circuit, comprising a fast up switch and a fast down switch connected in series; A slow-speed arm circuit includes a slow-speed up switch and a slow-speed down switch connected in series, wherein the slow-speed up switch and the slow-speed down switch are electrically connected at a midpoint, and there is an endpoint voltage between the midpoint and a reference potential point. A capacitor filter circuit is electrically connected to the fast arm circuit and the slow arm circuit, and has an equivalent capacitance value. as well as The controller is electrically connected to the fast arm circuit and the slow arm circuit, and is used to output a first control signal, a second control signal, a third control signal and a fourth control signal to control the operation of the fast up switch, the fast down switch, the slow up switch and the slow down switch respectively. When the input voltage is greater than a first threshold value and less than a second threshold value, and the input voltage changes from negative to zero, the controller sets the first control signal, the third control signal, and the fourth control signal to prevent the fast up switch, the slow up switch, and the slow down switch from conducting. The controller gradually increases at least one of the reference voltage command and the reference current command, so that the duty cycle of the second control signal gradually increases, causing the fast down switch to conduct intermittently, so that the slope of the terminal voltage change is adjusted according to the set voltage slope. as well as When the input voltage is greater than the first threshold value and less than the second threshold value, and the input voltage changes from a positive value to zero, the controller sets the second control signal, the third control signal, and the fourth control signal to deactivate the fast down switch, the slow up switch, and the slow down switch. The controller also gradually increases at least one of the reference voltage command and the reference current command, causing the duty cycle of the first control signal to gradually increase and the fast up switch to conduct intermittently, so that the slope of the terminal voltage change is adjusted according to the set voltage slope.
2. The totem pole power factor correction circuit according to claim 1 further includes a feedback circuit electrically connected to the output terminal of the totem pole power factor correction circuit, for detecting the output voltage and the output current, and outputting a voltage feedback signal and a current feedback signal based on the detection result.
3. The totem pole power factor correction circuit according to claim 2, wherein the controller comprises: A reference signal generation circuit is electrically connected to the input terminal and the reference potential point to detect the input voltage and the terminal voltage. When the input voltage is in the zero crossing range, the circuit calculates the set voltage slope based on the allowable value of the leakage inductance current and the equivalent capacitance value, and generates a reference voltage command based on the set voltage slope. A first comparator is electrically connected to the reference signal generation circuit and the feedback circuit, used to compare the reference voltage command and the voltage feedback signal, and output a first comparison signal; as well as A pulse width modulation (PWM) signal generation circuit is electrically connected to the first comparator, the fast up switch, the fast down switch, the slow up switch, and the slow down switch, and outputs the first control signal, the second control signal, the third control signal, and the fourth control signal. The PWM signal generation circuit further adjusts the first control signal and the second control signal according to the first comparator signal to control the operation of the fast up switch and the fast down switch, so that the slope of the terminal voltage change is adjusted according to the set voltage slope.
4. The totem pole power factor correction circuit according to claim 3, wherein the reference signal generation circuit detects the input current to generate a reference current command based on the detection result of the input current and the set voltage slope when the input voltage is in the zero crossover interval.
5. The totem pole power factor correction circuit according to claim 4, wherein the controller includes a second comparator electrically connected to the reference signal generation circuit and the feedback circuit, the second comparator compares the reference current command and the current feedback signal, and outputs a second comparison signal, so that the pulse width modulation signal generation circuit adjusts the first control signal and the second control signal according to the second comparison signal to control the operation of the fast up switch and the fast down switch, so that the slope of the terminal voltage change is adjusted according to the set voltage slope.
6. The totem pole power factor correction circuit according to claim 1, wherein when the input voltage is greater than the first threshold value and less than the second threshold value, the controller determines that the input voltage is in the zero crossover interval.
7. A power conversion device, comprising: At least one totem-pole power factor correction circuit is used to receive input voltage and input current, and output output voltage and output current, and includes: A fast arm circuit, comprising a fast up switch and a fast down switch connected in series; A slow-speed arm circuit includes a slow-speed up switch and a slow-speed down switch connected in series, wherein the slow-speed up switch and the slow-speed down switch are electrically connected at a midpoint, and there is an endpoint voltage between the midpoint and a reference potential point. A capacitor filter circuit is electrically connected to the fast arm circuit and the slow arm circuit, and has an equivalent capacitance value. as well as The controller is electrically connected to the fast arm circuit and the slow arm circuit, and is used to output a first control signal, a second control signal, a third control signal and a fourth control signal to control the operation of the fast up switch, the fast down switch, the slow up switch and the slow down switch respectively. When the input voltage is greater than a first threshold value and less than a second threshold value, and the input voltage changes from negative to zero, the controller sets the first control signal, the third control signal, and the fourth control signal to deactivate the fast up switch, the slow up switch, and the slow down switch. The controller gradually increases at least one of the reference voltage command and the reference current command, so that the duty cycle of the second control signal gradually increases, causing the fast down switch to conduct intermittently, so that the slope of the terminal voltage change is adjusted according to the set voltage slope. as well as When the input voltage is greater than the first threshold value and less than the second threshold value, and the input voltage changes from a positive value to zero, the controller sets the second control signal, the third control signal, and the fourth control signal to deactivate the fast down switch, the slow up switch, and the slow down switch. The controller also gradually increases at least one of the reference voltage command and the reference current command, causing the duty cycle of the first control signal to gradually increase and the fast up switch to conduct intermittently, so that the slope of the terminal voltage change is adjusted according to the set voltage slope.
8. The power conversion device according to claim 7, wherein when the controller determines that the input voltage is in the zero-crossing range, the controller of each totem pole power factor correction circuit of the power conversion device adjusts the first control signal and the second control signal to control the operation of the fast-up switch and the fast-down switch, so that the time period during which the slope of the endpoint voltage change is adjusted according to the set voltage slope is different from the time period during which the controller of other totem pole power factor correction circuits adjusts the first control signal and the second control signal to control the operation of the fast-up switch and the fast-down switch, so that the slope of the endpoint voltage change is adjusted according to the set voltage slope.