Power supply device, power supply control device and control method thereof

Abstract

The invention provides a power supply device, a power supply control device and a control method thereof, the power supply control device is electrically connected to a power supply, and the power supply is used for supplying power to a post-stage circuit of the power supply control device. The power supply control device comprises a current limiting module and a control unit. The current-limiting module is electrically connected to the power supply and the post-stage circuit and comprises a first current-limiting unit and a second current-limiting unit which are connected in parallel, the first current-limiting unit is configured to limit a surge current generated when the post-stage circuit is started, and the second current-limiting unit is configured to limit a surge current generated when the power supply is abnormal. The control unit is electrically connected to the current limiting module and is configured to control the first current limiting unit and the second current limiting unit.

Description

Technical Field

[0001] The present case relates to a power supply device, a power supply control device and a control method thereof, and in particular to a power supply device, a power supply control device and a control method thereof that can realize soft start and current limiting. Background Art

[0002] In a centralized power supply architecture, compared with a single input power supply or redundant structure, a power supply with an automatic ATS (autotransfer switch) function can significantly reduce the cost and size of the power supply, while improving the reliability of the power supply. In high-power power supply products such as switching power supplies, there are usually large electrolytic capacitors. When the power is turned on or the input power is interrupted and then restored (also known as ride-through), the current charging the subsequent electrolytic capacitor is large, resulting in a large peak current.

[0003] Considering that in the process of switching between multiple input power sources, a surge current will be generated to charge the subsequent electrolytic capacitor. The traditional method of surge current suppression is to connect a thermistor (i.e., a current limiting resistor) in series in the loop to limit the surge current generated during the switching process. However, since the transient power of the current limiting resistor is large (depending on the capacity of the electrolytic capacitor and the output power of the power supply device), a sufficiently large volume is required for heat dissipation, which will occupy a large amount of space in the power supply device, and the current limiting resistor is greatly affected by temperature.

[0004] Therefore, it is an urgent need to provide a power supply device, a power supply control device and a control method thereof that can improve the above-mentioned prior art. Summary of the invention

[0005] The purpose of this case is to provide a power supply device, a power supply control device and a control method thereof, which can limit the surge current generated at startup to achieve soft start. Furthermore, the power supply device, the power supply control device and the control method thereof can also limit the surge current generated when the received power source changes.

[0006] In order to achieve the above-mentioned purpose, the present case provides a power supply control device, which is electrically connected to a power supply, wherein the power supply is used to supply power to a subsequent circuit of the power supply control device. The power supply control device includes a current limiting module and a control unit. The current limiting module is electrically connected to the power supply and the subsequent circuit, and includes a first current limiting unit and a second current limiting unit connected in parallel to each other, wherein the first current limiting unit is configured to limit the surge current generated when the subsequent circuit is started, and the second current limiting unit is configured to limit the surge current generated when the power supply changes. The control unit is electrically connected to the current limiting module, and is configured to control the first current limiting unit and the second current limiting unit.

[0007] In order to achieve the above-mentioned purpose, the present case further provides a control method of a power supply control device, wherein the power supply control device is electrically connected to a power supply, the power supply is used to supply power to a subsequent circuit of the power supply control device, and the power supply control device includes a current limiting module. The current limiting module is electrically connected to the power supply and the subsequent circuit, and includes a first current limiting unit and a second current limiting unit connected in parallel to each other. The control method includes: controlling the first current limiting unit to limit the surge current generated when the subsequent circuit is started; and controlling the second current limiting unit to limit the surge current generated when the power supply changes.

[0008] In order to achieve the above-mentioned purpose, the present case further provides a power supply device, which is electrically connected to the power supply and includes a post-stage circuit, a current limiting module and a control unit. The post-stage circuit includes a power factor correction circuit and a capacitor connected in parallel. The current limiting module is electrically connected between the power supply and the post-stage circuit or between the power factor correction circuit and the capacitor, and includes a first current limiting unit and a second current limiting unit connected in parallel to each other, wherein the first current limiting unit is configured to limit the surge current generated when the post-stage circuit is started, and the second current limiting unit is configured to limit the surge current generated when the power supply changes. The control unit is electrically connected to the current limiting module, and is configured to control the first current limiting unit and the second current limiting unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 FIG. 1 is a schematic diagram of the structure of a power supply control device according to an embodiment of the present invention.

[0010] Figure 2 FIG. 1 is a schematic diagram of a circuit structure of a power supply control device according to an embodiment of the present invention.

[0011] Figure 3 for Figure 2 Schematic diagram of waveform when the power supply control device is started when the first power supply is normal.

[0012] Figure 4 for Figure 2 Schematic diagram of waveforms of a power supply control device starting when the first power supply fails and the second power supply is normal.

[0013] Figure 5 for Figure 2 A waveform diagram of a power supply control device switching to a second power supply due to a first power supply failure during operation.

[0014] Figure 6 for Figure 2 A waveform diagram of a power supply control device that switches to a second power supply due to a first power supply failure during operation, and then switches back to the first power supply when the first power supply returns to normal.

[0015] Figure 7 FIG. 4 is a schematic diagram of the circuit structure of a power supply control device according to another embodiment of the present invention.

[0016] Figure 8 for Figure 7 Schematic diagram of waveform when the power supply control device is started when the first power supply is normal.

[0017] Fig. 9 for Figure 7 A waveform diagram of a power supply control device switching to a second power supply due to a first power supply failure during operation.

[0018] Fig.10 for Figure 7 A waveform diagram of a power supply control device that switches to a second power supply due to a first power supply failure during operation, and then switches back to the first power supply when the first power supply returns to normal.

[0019] Fig.11 FIG. 4 is a schematic diagram of the circuit structure of a power supply control device according to another embodiment of the present invention.

[0020] Fig.12 FIG. 1 is a schematic diagram of a circuit structure of a power supply device according to an embodiment of the present invention.

[0021] Fig.13 FIG. 4 is a schematic diagram of a circuit structure of a power supply device according to another embodiment of the present invention.

[0022] Fig.14 FIG. 4 is a schematic diagram of a circuit structure of a power supply device according to another embodiment of the present invention.

[0023] Fig.15 for Fig.14 A schematic diagram of the circuit structure of a variation of the power supply device shown.

[0024] Fig.16 for Fig.15 Schematic diagram of the waveform of the power supply device returning to normal after a brief power failure.

[0025] The reference numerals are described as follows:

[0026] 1: Power supply control device

[0027] 11: First input terminal

[0028] 12: Second input terminal

[0029] 13: Input switching unit

[0030] 14: Current limiting module

[0031] 15: The first current limiting unit

[0032] 16: Second current limiting unit

[0033] 17: Control unit

[0034] 21: First Power Source

[0035] 22: Second power supply

[0036] 3: Post-stage circuit

[0037] Vin: input voltage

[0038] Vo: output voltage

[0039] 11a: First input positive terminal (positive pole)

[0040] 11b: First input negative terminal (negative pole)

[0041] 12a: Second input positive terminal (positive pole)

[0042] 12b: Second input negative terminal (negative pole)

[0043] R1: Current limiting resistor

[0044] Q1: The first switch

[0045] R2: The first voltage divider resistor

[0046] R3: The second voltage divider resistor

[0047] R4: sampling resistor

[0048] Q2: The second switch tube

[0049] D1: The first diode

[0050] D2: Second diode

[0051] D3: The third diode

[0052] D4: The fourth diode

[0053] V1: preset voltage

[0054] t: time

[0055] T0, T1: time

[0056] SW: Switching state of input switching unit

[0057] T2, T3, T4, T5, T6: time

[0058] V21: Electric energy provided by the first power source

[0059] V22: Power provided by the second power supply

[0060] DR1: Input switching unit control signal

[0061] T7, T8, T9, T10, T11, T12, T13, T14, T15, T16: Time

[0062] T17, T18, T19, T20, T21, T22: Time

[0063] 1a: Power supply control device

[0064] 14a: Current limiting module

[0065] 18: Main relay

[0066] DR2: Control signal of main relay

[0067] 100: Power supply device

[0068] C: Output capacitance

[0069] L: Inductance

[0070] Q3: The third switch tube

[0071] Q4: The fourth switch

[0072] D5: The fifth diode

[0073] D6: The sixth diode

[0074] D7: The seventh diode

[0075] D8: The eighth diode

[0076] 100a, 100b: power supply device

[0077] 14b: Current limiting module

[0078] 100c: Power supply device

[0079] 23: Power supply

[0080] V23: The power provided by the power supply

[0081] T23, T24, T25, T26, T27, T28: Time DETAILED DESCRIPTION

[0082] Some typical embodiments that embody the features and advantages of the present invention will be described in detail in the following description. It should be understood that the present invention can have various variations in different implementations without departing from the scope of the present invention, and the descriptions and illustrations therein are essentially only for illustration, not for limiting the present invention.

[0083] See also Figure 1 , Figure 1 FIG. 1 is a schematic diagram of the structure of a power supply control device according to an embodiment of the present invention. Figure 1As shown, the power supply control device 1 includes a first input terminal 11, a second input terminal 12, an input switching unit 13, a current limiting module 14 and a control unit 17. The first input terminal 11 is electrically connected to the first power supply 21, and the second input terminal 12 is electrically connected to the second power supply 22. The input switching unit 13 is used to switch between connecting the first input terminal 11 and connecting the second input terminal 12, so that one of the first power supply 21 and the second power supply 22 is used as a power supply for supplying power to the subsequent circuit 3. The current limiting module 14 is electrically connected to the input switching unit 13 and the subsequent circuit 3, and includes a first current limiting unit 15 and a second current limiting unit 16 connected in parallel to each other, wherein the first current limiting unit 15 is configured to limit the surge current generated when the subsequent circuit 3 is started, and the second current limiting unit 16 is configured to limit the surge current generated when the input switching unit 13 is switched. The control unit 17 is electrically connected to the input switching unit 13 and the current limiting module 14, and is configured to control the input switching unit 13, the first current limiting unit 15 and the second current limiting unit 16. The control method of the power supply control device 1 is described in detail as follows.

[0084] Before the subsequent circuit 3 of the power supply control device 1 is started, the first current limiting unit 15 and the second current limiting unit 16 are disconnected. When the subsequent circuit 3 of the power supply control device 1 is started, the first current limiting unit 15 is controlled to be turned on to limit the current flowing through the first current limiting unit 15, and the output voltage Vo of the subsequent circuit 3 gradually rises. When the difference between the maximum value of the input voltage Vin and the output voltage Vo is less than the first threshold value (for example but not limited to 20V), the control unit 17 controls the second current limiting unit 16 to be turned on, and the setting of the first threshold value is used to ensure that the current flowing through the second current limiting unit 16 is not too large. Therefore, a soft start function can be achieved. In addition, after the second current limiting unit 16 is turned on, the control unit 17 can control the first current limiting unit 15 to remain turned on, and can also control the first current limiting unit 15 to be disconnected.

[0085] In the case where the second current limiting unit 16 is turned on and normally supplies power to the subsequent circuit 3, when any of the first power supply 21 and the second power supply 22 fails, the control unit 17 is configured to control the first current limiting unit 15 and the second current limiting unit 16 to be disconnected. After the first current limiting unit 15 and the second current limiting unit 16 are disconnected, the input switching unit 13 can be switched. It should be noted that when the input switching unit 13 is switched, it is necessary to ensure that the first input terminal 11 and the second input terminal 12 of the power supply control device 1 and the subsequent circuit 3 of the power supply control device 1 are completely disconnected. When switching to another power supply, that is, when the input switching unit 13 is switched from one of the first input terminal 11 and the second input terminal 12 to the other of the first input terminal 11 and the second input terminal 12, the control unit 17 controls the second current limiting unit 16 to be in a current limiting state or a fully turned-on state according to the comparison of the input voltage Vin received by the power supply control device 1 and the output voltage Vo of the subsequent circuit 3. Specifically, when the difference between the absolute value of the input voltage Vin and the output voltage Vo is greater than the second threshold, in order to avoid the generation of impact current, the control unit 17 controls the second current limiting unit 16 to be in a current limiting state to limit the current flowing through the second current limiting unit 16 to be equal to the preset current. Conversely, when the difference between the absolute value of the input voltage Vin and the output voltage Vo is less than or equal to the second threshold, it means that the input voltage Vin and the output voltage Vo are relatively close, so the control unit 17 controls the second current limiting unit 16 to be in a fully conductive state, and a large current will not be generated due to the large voltage difference. It should be understood that the second threshold may be equal to the first threshold or may not be equal.

[0086] In some embodiments, the input switching unit 13 is connected to one of the first input terminal 11 and the second input terminal 12 by default. For example, the input switching unit 13 is connected to the first input terminal 11 by default, so that the first power supply 21 is used as the power supply by default. Specifically, the input switching unit 13 includes an input relay. When the first power supply 21 is normal, the input relay is connected to the first input terminal 11 without additional control; when the first power supply 21 fails, the input relay switches to connect to the second input terminal 12, and once the first power supply 21 returns to normal, the input relay switches back to connect to the first input terminal 11. In other embodiments, the input switching unit 13 is equivalent to the first power supply 21 and the second power supply 22.

[0087] See also Figure 2 , Figure 2 FIG. 1 is a schematic diagram of the circuit structure of a power supply control device 1 according to an embodiment of the present invention. Figure 2 In, with Figure 1 Components with similar functions are denoted by the same reference numerals and will not be described in detail herein. Figure 2In the illustrated embodiment, the first input terminal 11 includes a first input positive terminal 11a and a first input negative terminal 11b, wherein the first input positive terminal 11a and the first input negative terminal 11b are respectively electrically connected to the positive terminal and the negative terminal of the first power source 21. The second input terminal 12 includes a second input positive terminal 12a and a second input negative terminal 12b, wherein the second input positive terminal 12a and the second input negative terminal 12b are respectively electrically connected to the positive terminal and the negative terminal of the second power source 22. The input relay of the input switching unit 13 may be, for example but not limited to, a double-pole double-throw switch as illustrated in the figure. The first current limiting unit 15 includes a current limiting resistor R1 and a first switch tube Q1 connected in series between a first node and a second node, wherein the first switch tube Q1 is configured to be turned on by the difference between the input voltage Vin received by the power supply control device 1 and the output voltage Vo of the post-stage circuit 3 when the post-stage circuit 3 of the power supply control device 1 is started, so as to limit the current flowing through the post-stage circuit 3 by using the current limiting resistor R1; in this embodiment, the input current received by the power supply control device 1 is transmitted to the post-stage circuit 3 via the current limiting resistor R1 and the first switch tube Q1. In some embodiments, the first current limiting unit 15 further includes a first voltage dividing resistor R2 and a second voltage dividing resistor R3, wherein the first end and the second end of the first voltage dividing resistor R2 are electrically connected to the first node and the control end of the first switch tube Q1, respectively, and the first end and the second end of the second voltage dividing resistor R3 are electrically connected to the control end of the first switch tube Q1 and the second node, respectively. When the subsequent circuit 3 is started, since the output voltage Vo is zero, the difference between the input voltage Vin and the output voltage Vo is large, so the voltage drop on the second voltage-dividing resistor R3 can turn on the first switch tube Q1. Therefore, when the first voltage-dividing resistor R2 and the second voltage-dividing resistor R3 are used, there is no need to use a separate power supply to drive the first switch tube Q1. Of course, in some embodiments, the first voltage-dividing resistor R2 and the second voltage-dividing resistor R3 may not be provided.

[0088] The second current limiting unit 16 includes a sampling resistor R4 and a second switch tube Q2 connected in series, wherein the sampling resistor R4 and the second switch tube Q2 are electrically connected to the first node and the second node, respectively. The control unit 17 can selectively control the second switch tube Q2 to operate in the linear region or the saturation region, so as to correspondingly make the second current limiting unit 16 in a current limiting state or a fully conductive state. Furthermore, the control unit 17 can generate a driving signal for controlling the second switch tube Q2 according to the current flowing through the sampling resistor R4. In addition, the first switch tube Q1 and the second switch tube Q2 are not limited to the embodiments shown in the figure, and can be, for example, but not limited to, a metal oxide semiconductor field effect transistor or an insulated gate bipolar transistor.

[0089] In some embodiments, the power supply control device 1 further includes a rectifier circuit, wherein the rectifier circuit architecture is configured to rectify the current flowing into the first current limiting unit 15 and the second current limiting unit 16 into a direct current. The rectifier circuit includes a first rectifier bridge arm and a second rectifier bridge arm connected in parallel with the first current limiting unit 15 and the second current limiting unit 16, wherein the first rectifier bridge arm includes a first diode D1 and a second diode D2, and a common connection point of the first diode D1 and the second diode D2 is connected to the input switching unit 13, and the second rectifier bridge arm includes a third diode D3 and a fourth diode D4, and a common connection point of the third diode D3 and the fourth diode D4 is connected to the subsequent circuit 3.

[0090] The following is based on Figure 2 The circuit topology shown is used, and the operation of the power supply control device 1 is described in detail by taking the input switching unit 13 connected to the first input terminal 11 by default and the first power supply 21 as the power supply as an example.

[0091] Figure 3 FIG. 1 is a waveform diagram of the subsequent circuit 3 of the power supply control device 1 when the first power supply 21 is normal. Figure 3 In the figure, the horizontal axis is time t. Figure 3 And with Figure 2 . At time T0, the power supply control device 1 receives the input voltage Vin. At this time, the first switch tube Q1 and the second switch tube Q2 are both in the off state, and the output voltage Vo has not yet been established. Then, the first switch tube Q1 is automatically turned on by the difference between the input voltage Vin and the output voltage Vo. Specifically, the difference between the input voltage Vin and the output voltage Vo is large, so the first voltage-dividing resistor R2 and the second voltage-dividing resistor R3 generate a driving signal by dividing the voltage to establish a voltage on the control end of the first switch tube Q1, so that the first switch tube Q1 is turned on. After the first switch tube Q1 is turned on, the input current received by the power supply control device 1 flows to the subsequent circuit 3 through the first current-limiting unit 15, wherein the first current-limiting unit 15 limits the current flowing therethrough, so that the output voltage Vo gradually increases. At time T1, the output voltage Vo rises to the preset voltage V1. At this time, the difference between the maximum value of the input voltage Vin and the output voltage Vo is correspondingly less than the first threshold value, so the second switch tube Q2 is turned on. In this embodiment, after the second switch Q2 is turned on, after time T1, the first switch Q1 remains turned on, waiting for a subsequent turn-off instruction, and is turned off at the latest before the input switching unit 13 switches. Of course, the first switch Q1 can also be turned off after a delay of a period of time after the second switch Q2 is turned on.

[0092] Figure 4 FIG. 1 is a waveform diagram of the start-up of the rear circuit 3 of the power supply control device 1 when the first power supply 21 fails and the second power supply 22 is normal. Figure 4, SW reflects the switching state of the input switching unit 13. SW at a low level represents that the input switching unit 13 is connected to the first input terminal 11, and SW at a high level represents that the input switching unit 13 is connected to the second input terminal 12. Figure 4 And with Figure 2 . At time T2, the power supply control device 1 receives the input voltage Vin, and at this time, the first switch tube Q1 and the second switch tube Q2 are both in the off state. At time T3, the first power supply 21 fails and cannot supply power normally, so the input switching unit 13 switches from connecting to the first input terminal 11 to connecting to the second input terminal 12. At time T4, the first switch tube Q1 is automatically turned on by the difference between the input voltage Vin and the output voltage Vo. After the first switch tube Q1 is turned on, the input current received by the power supply control device 1 flows to the subsequent circuit 3 through the first current limiting unit 15, wherein the first current limiting unit 15 limits the current flowing therethrough, so that the output voltage Vo gradually increases. At time T5, the output voltage Vo rises to the preset voltage V1, and at this time, the difference between the maximum value of the input voltage Vin and the output voltage Vo is correspondingly less than the first threshold value, so the second switch tube Q2 is turned on. In this embodiment, after the second switch tube Q2 is turned on, the first switch tube Q1 is turned off at time T6. In other embodiments, the first switch tube Q1 may remain turned on after time T5 to wait for a subsequent turn-off instruction.

[0093] Figure 5 FIG. 1 is a waveform diagram of the power supply control device 1 switching to the second power supply 22 due to a failure of the first power supply 21 during operation. Figure 5 In FIG. 1 , V21 represents the power provided by the first power source 21 , V22 represents the power provided by the second power source 22 , and DR1 represents the control signal input to the switching unit 13 . Figure 5 And with Figure 2. Before time T7, the input switching unit 13 is connected to the first input terminal 11, and the first power supply 21 is used as the power supply. At time T7, the first power supply 21 fails and loses power, and then the output voltage Vo gradually decreases. After a certain delay (to avoid misoperation), at time T8, the control unit 17 controls the first switch tube Q1 to turn off. It should be understood that the first switch tube Q1 is turned off at this time only as an example, and the first switch tube Q1 only needs to be turned off before time T9 (that is, before the control unit 17 controls the input switching unit 13 to switch). At time T9, the control unit 17 controls the second switch tube Q2 to turn off, and sends a control signal DR1 to control the input switching unit 13 to switch to connect to the second input terminal 12. After a delay, at time T10, the input switching unit 13 switches to connect to the second input terminal 12, and the second power supply 22 is used as the power supply. At this time, the control unit 17 controls the second switch tube Q2 to turn on so that the output voltage Vo rises, wherein the control method for the second switch tube Q2 depends on the magnitude relationship between the output voltage Vo and the input voltage Vin, so as to limit the surge current generated by the switching of the input switching unit 13. At time T10, the difference between the absolute value of the input voltage Vin and the output voltage Vo is greater than the second threshold value, and the control unit 17 controls the second switch tube Q2 to work in the linear region, and adjusts the driving voltage of the second switch tube Q2 to limit the current flowing through the second switch tube Q2 to be equal to the preset current. At this time, the second current limiting unit 16 is in the current limiting state, wherein the second threshold value can be, for example, but not limited to, zero. At time T11, the difference between the absolute value of the input voltage Vin and the output voltage Vo begins to be less than or equal to the second threshold value, and the control unit 17 controls the second switch tube Q2 to work in the saturation region, and thereafter the second current limiting unit 16 is in the fully turned-on state. After the second switch tube Q2 operates in the saturation region, at time T12, the output voltage Vo reaches the reference value.

[0094] Figure 6 The waveform diagram of the power supply control device 1 is that the first power supply 21 fails and switches to the second power supply 22 during operation, and then switches back to the first power supply 21 when the first power supply 21 returns to normal. Figure 6 The waveform and operation before time T13 are similar to Figure 5 The same as shown, no further description is given here. Figure 6 And with Figure 2. After the power supply control device 1 switches to the second power supply 22 as the power supply due to the failure of the first power supply 21, the first power supply 21 returns to normal at time T13. Within a certain period of time, the voltage of the first power supply 21 is detected. After confirming that the first power supply 21 is normal, at time T15, the control unit 17 controls the second switch tube Q2 to turn off, and sends a control signal DR1 to control the input switching unit 13 to switch to connect to the first input terminal 11. After a delay, at time T16, the input switching unit 13 switches to connect to the second input terminal 12, and the first power supply 21 begins to be used as the power supply. At this time, the control unit 17 controls the second switch tube Q2 to turn on to increase the output voltage Vo, wherein the control method for the second switch tube Q2 depends on the relationship between the output voltage Vo and the input voltage Vin, so as to limit the surge current generated by the switching of the input switching unit 13. Similarly, at time T16, the difference between the absolute value of the input voltage Vin and the output voltage Vo is greater than the second threshold value, and the control unit 17 controls the second switch tube Q2 to operate in the linear region, and adjusts the driving voltage of the second switch tube Q2 to limit the current flowing through the second switch tube Q2 to be equal to the preset current. At this time, the second current limiting unit 16 is in the current limiting state; at time T17, the difference between the absolute value of the input voltage Vin and the output voltage Vo begins to be less than or equal to the second threshold value. At this time, the control unit 17 controls the second switch tube Q2 to operate in the saturation region, and thereafter the second current limiting unit 16 is in a fully conductive state. After the second switch tube Q2 operates in the saturation region, at time T18, the output voltage Vo reaches the reference value.

[0095] In addition, in some embodiments, Figure 7 As shown, the current limiting module 14a of the power supply control device 1a further includes a main relay 18 connected in parallel to the first current limiting unit 15 and the second current limiting unit 16. The influence of the main relay 18 on the operation process of the power supply control device 1a is described as follows.

[0096] When the rear stage circuit 3 of the power supply control device 1a is in normal operation at the first power supply 21, the corresponding waveform is as follows: Figure 8 As shown. After the input current received by the power supply control device 1a flows to the subsequent circuit 3 via the first current limiting unit 15, so that the output voltage Vo gradually rises, at time T1, the output voltage Vo rises to the preset voltage V1, so that the difference between the maximum value of the input voltage Vin and the output voltage Vo is correspondingly less than the first threshold value, at which time the main relay 18 is turned on, and the second switch tube Q2 remains off.

[0097] When the power supply control device 1a switches to the second power supply 22 due to a failure of the first power supply 21 during operation, the corresponding waveform is as follows: Fig. 9 As shown. Fig. 9In the figure, DR2 represents the control signal of the main relay 18. After the first power supply 21 fails and loses power, at time T8, the control unit 17 sends a control signal DR2 to control the main relay 18 to turn off, and at the same time controls the first switch tube Q1 to turn off. Furthermore, in order to avoid arcing when the main relay 18 is turned off, the control unit 17 also controls the second switch tube Q2 to be in a fully conductive state at time T8. After a delay, at time T9, the main relay 18 is turned off, and at this time, the second switch tube Q2 is also turned off, and the control unit 17 sends a control signal DR1 to control the input switching unit 13 to switch to connect to the second input terminal 12. Then, at time T12, the output voltage Vo reaches the reference value, and at this time the control unit 17 sends a control signal DR2 to control the main relay 18 to turn on. Then, at time T19, the main relay 18 is turned on. Then, at time T20, the control unit 17 controls the second switch tube Q2 to turn off.

[0098] When the power supply control device 1a switches to the second power supply 22 due to a failure of the first power supply 21 during operation, and then switches back to the first power supply 21 when the first power supply 21 returns to normal, the corresponding waveform is as follows: Fig.10 As shown. Fig.10 The waveform and operation before time T13 are similar to Fig. 9 The same as shown, no further description is given here. After time T13 and when it is confirmed that the first power supply 21 has returned to normal, at time T14, the control unit 17 sends a control signal DR2 to control the main relay 18 to turn off, and in order to avoid arcing when the main relay 18 is turned off, the control unit 17 also controls the second switch tube Q2 to be in a fully conductive state. After a delay, at time T15, the main relay 18 is turned off, and at this time, the second switch tube Q2 is also turned off, and the control unit 17 sends a control signal DR1 to control the input switching unit 13 to switch to connect to the first input terminal 11. Then, at time T18, the output voltage Vo reaches the reference value, and at this time the control unit 17 sends a control signal DR2 to control the main relay 18 to turn on. Then, at time T21, the main relay 18 is turned on. Then, at time T22, the control unit 17 controls the second switch tube Q2 to turn off.

[0099] In addition, in the aforementioned embodiment, the current limiting module (14, 14a) is connected in series between the first output terminal of the input switching unit 13 and the first input terminal of the subsequent circuit 3. However, the present invention is not limited thereto. In other embodiments, the current limiting module (14, 14a) may also be connected in series between the second output terminal of the input switching unit 13 and the second input terminal of the subsequent circuit 3. Fig.11 exemplified.

[0100] Fig.12 is a schematic diagram of the circuit structure of a power supply device according to an embodiment of the present invention, wherein Figure 2Elements with similar structures and functions are denoted by the same reference numerals and will not be described in detail herein. Fig.12 As shown, in this embodiment, the rear stage circuit 3 of the power supply device 100 includes a power factor correction circuit and an output capacitor C. The power factor correction circuit includes an inductor L and a switch bridge arm and a diode bridge arm connected in parallel to the output capacitor C, the switch bridge arm includes a third switch tube Q3 and a fourth switch tube Q4 connected in series, the diode bridge arm includes a fifth diode D5 and a sixth diode D6 connected in series, and the first end and the second end of the inductor L are respectively electrically connected to the current limiting module 14 and the common connection point of the third switch tube Q3 and the fourth switch tube Q4. The power factor correction circuit also includes a bypass branch, which includes a diode bridge arm connected in parallel to the output capacitor C, the diode bridge arm includes a seventh diode D7 and an eighth diode D8, wherein the common connection point of the seventh diode D7 and the eighth diode D8 is electrically connected to the first end of the inductor L. In the startup or fault switching stage, the input current charges the output capacitor C through the seventh diode D7 and the eighth diode D8.

[0101] It should be noted that Fig.12 Only one implementation of the subsequent stage circuit is illustrated, but possible implementations of the subsequent stage circuit of the present invention are not limited thereto.

[0102] In addition, in the aforementioned embodiments, the current limiting modules (14, 14a) are both connected between the input switching unit 13 and the subsequent circuit 3. However, the present invention is not limited thereto. In some embodiments, when the subsequent circuit 3 includes a power factor correction circuit and an output capacitor C, the current limiting module can also be connected between the power factor correction circuit and the output capacitor C. In this case, there is no need to additionally set up a rectifier circuit connected to the current limiting module 14b. In some embodiments, such as Fig.13 As shown, in the power supply device 100a, the current limiting module 14b is connected between the second output terminal of the power factor correction circuit and the negative terminal of the output capacitor C. In other embodiments, Fig.14 As shown, in the power supply device 100b, the current limiting module 14b can also be connected between the first output terminal of the power factor correction circuit and the positive terminal of the output capacitor C. Fig.13 or Fig.14 When the connection mode is used, the subsequent load such as the LLC circuit can be electrically connected to the first output terminal and the second output terminal of the power factor correction circuit to obtain electrical energy, or directly electrically connected to the positive terminal and the negative terminal of the output capacitor C to obtain electrical energy. Fig.13 and Fig.14 In the embodiment shown, the operation mode of the input switching unit 13, the first current limiting unit 15 and the second current limiting unit 16 is the same as Figures 3 to 6 It should be understood that Fig.13 and Fig.14The current limiting module may also include first and second voltage dividing resistors for driving the first switch tube Q1.

[0103] In addition, in the aforementioned embodiment, the power supply device and the power supply control device are both connected to two power supplies (i.e., the first power supply 21 and the second power supply 22), and one of the two power supplies is used as the power supply for supplying power to the subsequent circuit by switching. However, in fact, the present case is not limited to this. Specifically, the power supply device and the power supply control device of the present case may also be connected to only one power supply, and the power supply is used as the power supply for supplying power to the subsequent circuit. In other words, the power supply device and the power supply control device in the aforementioned embodiment may be connected to only one power supply, and in this case, the input switching unit may not be included.

[0104] by Fig.14 Taking the power supply device 100b as an example, Fig.15 exemplify Fig.14 A variation of the power supply device. Fig.15 In, with Fig.14 Elements with similar structures and functions are denoted by the same reference numerals and will not be described in detail herein. Fig.15 As shown, in this embodiment, the power supply device 100c is only connected to one power source 23 and does not include an input switching unit. The location of the current limiting module 14b is not limited to Fig.15 For details, please refer to Figures 11 to 14 The position adjustment shown is not described here in detail. The corresponding operation process is described as follows.

[0105] When the rear stage circuit 3 is started when the power supply 23 is normal, the specific operation mode and waveform changes are Figure 3 The same is shown, so it will not be repeated here.

[0106] If the power supply 23 fails during operation, the subsequent circuit 3 will naturally be unable to continue to operate. However, if the power supply 23 returns to normal after a short failure, the corresponding waveform is as follows: Fig.16 As shown. Fig.16 In the figure, V23 represents the power provided by power source 23. Fig.16 And with Fig.15. Before time T23, the power supply 23 serves as a power supply and supplies power normally. At time T23, the power supply 23 fails and loses power, and then the output voltage Vo gradually decreases. After a certain delay (to avoid misoperation), at time T24, the control unit 17 controls the first switch tube Q1 to turn off. It should be understood that the first switch tube Q1 is turned off at this time only as an example, and the first switch tube Q1 only needs to be turned off before time T25 (that is, before the control unit 17 controls the second switch tube Q2 to turn off). At time T25, the control unit 17 controls the second switch tube Q2 to turn off. After the first time, at time T26, the power supply 23 returns to normal and supplies power. It should be understood that the first time is a short time interval, which does not exceed the maximum waiting time specified by the power supply system. When the power failure exceeds the maximum waiting time, the power supply device stops running. Furthermore, at time T26, the control unit 17 controls the second switch tube Q2 to be turned on so that the output voltage Vo rises, wherein the control method for the second switch tube Q2 depends on the magnitude relationship between the output voltage Vo and the input voltage Vin, so as to limit the surge current. At time T26, the difference between the absolute value of the input voltage Vin and the output voltage Vo is greater than the second threshold value, and the control unit 17 controls the second switch tube Q2 to operate in the linear region, and adjusts the driving voltage of the second switch tube Q2 to limit the current flowing through the second switch tube Q2 to be equal to the preset current, at which time the second current limiting unit 16 is in the current limiting state. At time T27, the difference between the absolute value of the input voltage Vin and the output voltage Vo begins to be less than or equal to the second threshold value, at which time the control unit 17 controls the second switch tube Q2 to operate in the saturation region, and thereafter the second current limiting unit 16 is in a fully turned-on state. After the second switch tube Q2 operates in the saturation region, at time T28, the output voltage Vo reaches the reference value.

[0107] In addition, if the circuit architecture in the aforementioned other embodiments is adjusted to be connected to only one power source and not include an input switching unit, the corresponding operation method is also similar, so it will not be described in detail here.

[0108] In summary, the present invention provides a power supply device, a power supply control device and a control method thereof, which can switch the received power supply and limit the surge current generated at startup to achieve soft start. Furthermore, the power supply device, the power supply control device and the control method thereof can also limit the surge current generated when the power supply changes, that is, when the power supply is restored after a short failure or when switching occurs between sub-power supplies within the power supply.

[0109] It should be noted that the above are only preferred embodiments for illustrating the present invention, and the present invention is not limited to the embodiments described. The scope of the present invention is determined by the claims. Moreover, the present invention may be modified in various ways by those skilled in the art, but all of them are within the scope of the claims.

Claims

1. A power supply control device, electrically connected to a power supply, wherein the power supply is used to supply power to a subsequent circuit of the power supply control device, the power supply control device comprising: a current limiting module, electrically connected to the power supply and the subsequent circuit, and comprising a first current limiting unit and a second current limiting unit connected in parallel to each other, wherein the first current limiting unit is configured to limit the surge current generated when the subsequent circuit is started, and the second current limiting unit is configured to limit the surge current generated when the power supply is abnormal; and A control unit is electrically connected to the current limiting module and is configured to control the first current limiting unit and the second current limiting unit.

2. The power supply control device as described in claim 1, wherein when the subsequent circuit is started, the first current limiting unit is turned on, and when the difference between the maximum value of the input voltage received by the power supply control device and the output voltage of the subsequent circuit is less than a first threshold value, the control unit is configured to control the second current limiting unit to be turned on.

3. The power supply control device as described in claim 1, wherein the power supply abnormality is manifested as the power supply failing and restoring normal power supply after a first time, and when the power supply restoring normal power supply after the first time, the control unit is structured to control the second current limiting unit to be in a current limiting state or a fully conductive state based on a comparison of the input voltage received by the power supply control device and the output voltage of the subsequent circuit.

4. The power supply control device according to claim 3, wherein: When the power supply resumes normal power supply after the first time of the fault, when the difference between the absolute value of the input voltage and the output voltage is greater than a second threshold value, the control unit controls the second current limiting unit to be in the current limiting state to limit the current flowing through the second current limiting unit to be equal to the preset current; when the difference is less than or equal to the second threshold value, the control unit controls the second current limiting unit to be in the fully on state.

5. A power supply control device as described in claim 1, wherein the power supply includes a first power supply and a second power supply, and the power supply control device also includes a first input terminal, a second input terminal and an input switching unit, the first input terminal is electrically connected to the first power supply, the second input terminal is electrically connected to the second power supply, and the input switching unit is configured to switch between connecting to the first input terminal and connecting to the second input terminal so that one of the first power supply and the second power supply is used as the power supply for supplying power to the subsequent circuit, and the power supply change is manifested as switching between the first power supply and the second power supply; the current limiting module is electrically connected to the input switching unit, and the second current limiting unit is also configured to limit the surge current generated when the input switching unit is switched; the control unit is also electrically connected to the input switching unit to control the input switching unit.

6. The power supply control device as claimed in claim 5, wherein the input switching unit comprises an input relay, and when the first power supply is normal, the input relay is connected to the first input terminal, and when the first power supply fails, the input relay is switched to be connected to the second input terminal.

7. The power supply control device as described in claim 5, wherein when the subsequent circuit is started, the first current limiting unit is turned on, and when the difference between the maximum value of the input voltage received by the power supply control device and the output voltage of the subsequent circuit is less than a first threshold value, the control unit is configured to control the second current limiting unit to be turned on. 8 . The power supply control device as claimed in claim 5 , wherein when the power supply fails, the control unit is configured to control the first current limiting unit and the second current limiting unit to be disconnected.

9. The power supply control device as described in claim 8, wherein the current limiting module further includes a main relay connected in parallel to the first current limiting unit and the second current limiting unit, and when the power supply fails, the control unit is configured to send a control signal to control the main relay to shut down, and control the first current limiting unit to disconnect, and control the second current limiting unit to be in a fully conductive state, until the main relay is turned off and then the second current limiting unit is controlled to disconnect.

10. The power supply control device as described in claim 5, wherein when the input switching unit switches from being connected to one of the first input terminal and the second input terminal to being connected to the other of the first input terminal and the second input terminal, the control unit is configured to control the second current limiting unit to be in a current limiting state or a fully conductive state based on comparing the input voltage received by the power supply control device with the output voltage of the subsequent circuit.

11. The power supply control device according to claim 10, wherein: When the input switching unit switches from one of the voltages connected to the first input terminal and the second input terminal to the other voltage connected to the first input terminal and the second input terminal, when the difference between the absolute value of the input voltage and the output voltage is greater than a second threshold value, the control unit controls the second current limiting unit to be in the current limiting state to limit the current flowing through the second current limiting unit to be equal to a preset current; when the difference is less than or equal to the second threshold value, the control unit controls the second current limiting unit to be in the fully on state.

12. A power supply control device as described in claim 11, wherein the current limiting module further includes a main relay connected in parallel to the first current limiting unit and the second current limiting unit, and when the input switching unit switches from one connected to the first input terminal and the second input terminal to the other connected to the first input terminal and the second input terminal, when the difference is less than or equal to the second threshold value, the control unit is configured to control the main relay to be turned on after the second current limiting unit is in the fully turned-on state.

13. The power supply control device as described in claim 5, wherein the first current limiting unit includes a current limiting resistor and a first switch tube connected in series between a first node and a second node; when the subsequent circuit is started, the first switch is turned on so that the current limiting resistor limits the current flowing through the subsequent circuit. 14 . The power supply control device as claimed in claim 13 , wherein the first switch transistor is turned on by being controlled by a difference between an input voltage received by the power supply control device and an output voltage of the subsequent circuit.

15. A power supply control device as described in claim 13, wherein the first current limiting unit further includes a first voltage-dividing resistor and a second voltage-dividing resistor, the first end and the second end of the first voltage-dividing resistor are electrically connected to the first node and the control end of the first switch tube, respectively, and the first end and the second end of the second voltage-dividing resistor are electrically connected to the control end of the first switch tube and the second node, respectively.

16. A power supply control device as described in claim 5, wherein the second current limiting unit includes a second switch tube, wherein when the input switching unit switches from one of the first input terminal and the second input terminal to the other of the first input terminal and the second input terminal, when the difference between the absolute value of the input voltage received by the power supply control device and the output voltage of the subsequent circuit is greater than a second threshold value, the control unit controls the second switch tube to operate in a linear region to limit the current flowing through the second switch tube to be equal to a preset current; when the difference is less than or equal to the second threshold value, the control unit controls the second switch tube to operate in a saturation region.

17. The power supply control device as described in claim 16, wherein the second current limiting unit further includes a sampling resistor connected in series to the second switch tube, and the control unit generates a driving signal for controlling the second switch tube according to the current flowing through the sampling resistor, so as to limit the current flowing through the second current limiting unit to a preset current through the driving signal. 18 . The power supply control device as claimed in claim 5 , wherein the current limiting module is connected in series between the input switching unit and the subsequent circuit. 19 . The power supply control device as claimed in claim 18 , further comprising a rectifier circuit, wherein the rectifier circuit is configured to rectify the current flowing into the second current limiting unit and the first current limiting unit into a direct current.

20. A power supply control device as described in claim 19, wherein the rectifier circuit includes a first rectifier bridge arm and a second rectifier bridge arm connected in parallel with the second current limiting unit and the first current limiting unit, the first rectifier bridge arm includes a first diode and a second diode, the second rectifier bridge arm includes a third diode and a fourth diode, the common connection point of the first diode and the second diode is connected to the input switching unit, and the common connection point of the third diode and the fourth diode is connected to the subsequent circuit.

21. The power supply control device as described in claim 1, wherein the post-stage circuit includes a power factor correction circuit and a capacitor connected to each other, and the current limiting module is connected in series between the output end of the power factor correction circuit and the capacitor.

22. A control method for a power supply control device, wherein the power supply control device is electrically connected to a power supply, the power supply is used to supply power to a subsequent circuit of the power supply control device, the power supply control device comprises a current limiting module, the current limiting module is electrically connected to the power supply and the subsequent circuit, and comprises a first current limiting unit and a second current limiting unit connected in parallel to each other; the control method comprises: Controlling the first current limiting unit to limit the surge current generated when the subsequent circuit is started; and The second current limiting unit is controlled to limit the surge current generated when the power source changes.

23. The control method as claimed in claim 22, further comprising: when the subsequent circuit is started, when the difference between the maximum value of the input voltage received by the power supply control device and the output voltage of the subsequent circuit is less than a first threshold, controlling the second current limiting unit to be turned on.

24. The control method as described in claim 22, wherein the power supply abnormality is manifested as a failure of the power supply and restoration of normal power supply after a first time after the failure, and further comprises: when the power supply restores normal power supply after the first time after the failure, based on comparing the input voltage received by the power supply control device with the output voltage of the subsequent circuit, controlling the second current limiting unit to be in a current limiting state or a fully conductive state.

25. The control method of claim 24, wherein when the power source resumes normal power supply after the first time of failure, the control method further comprises: When the difference between the absolute value of the input voltage and the output voltage is greater than a second threshold, controlling the second current limiting unit to be in the current limiting state to limit the current flowing through the second current limiting unit to be equal to a preset current; and When the difference is less than or equal to the second threshold, the second current limiting unit is controlled to be in the fully-on state.

26. The control method as claimed in claim 22, wherein the power source comprises a first power source and a second power source, the power supply control device further comprises a first input terminal, a second input terminal and an input switching unit, the first input terminal is electrically connected to the first power source, the second input terminal is electrically connected to the second power source, and the control method further comprises: Controlling the input switching unit to switch between connecting to the first input terminal and connecting to the second input terminal, so that one of the first power supply and the second power supply is used as a power supply for supplying power to the subsequent circuit, and the power supply change is manifested as a switch between the first power supply and the second power supply; and The second current limiting unit is controlled to limit the surge current generated when the input switching unit is switched.

27. The control method as claimed in claim 26, wherein the input switching unit comprises an input relay, and the control method further comprises: When the first power supply is normal, the input relay is controlled to be connected to the first input terminal. When the first power supply fails, the input relay is controlled to switch to be connected to the second input terminal.

28. The control method as claimed in claim 26, further comprising: when the subsequent circuit is started, when the difference between the maximum value of the input voltage received by the power supply control device and the output voltage of the subsequent circuit is less than a first threshold, controlling the second current limiting unit to be turned on.

29. The control method according to claim 26, further comprising: When the power supply fails, the first current limiting unit and the second current limiting unit are controlled to be disconnected.

30. The control method as claimed in claim 29, wherein the current limiting module further comprises a main relay connected in parallel to the first current limiting unit and the second current limiting unit, and the control method further comprises: When the power supply fails, a control signal is sent to control the main relay to disconnect, and the first current limiting unit to disconnect, and the second current limiting unit to be in a fully conductive state until the main relay is disconnected and the second current limiting unit is controlled to disconnect.

31. The control method as described in claim 26 further comprises: when the input switching unit switches from one of the input terminals connected to the first input terminal and the second input terminal to the other of the input terminals connected to the first input terminal and the second input terminal, the second current limiting unit is controlled to be in a current limiting state or a fully conductive state according to a comparison between the input voltage received by the power supply control device and the output voltage of the subsequent circuit.

32. The control method as claimed in claim 31, wherein when the input switching unit switches from being connected to one of the first input terminal and the second input terminal to being connected to the other of the first input terminal and the second input terminal, the control method further comprises: When the difference between the absolute value of the input voltage and the output voltage is greater than a second threshold, controlling the second current limiting unit to be in the current limiting state to limit the current flowing through the second current limiting unit to be equal to a preset current; and When the difference is less than or equal to the second threshold, the second current limiting unit is controlled to be in the fully-on state.

33. The control method as claimed in claim 32, wherein the current limiting module further comprises a main relay connected in parallel to the first current limiting unit and the second current limiting unit, and when the input switching unit switches from one connected to the first input terminal and the second input terminal to the other connected to the first input terminal and the second input terminal, the control method further comprises: When the difference is less than or equal to the second threshold, the main relay is controlled to be turned on after the second current limiting unit is in the fully turned-on state.

34. The control method according to claim 26, wherein the first current limiting unit comprises a current limiting resistor and a first switch tube connected in series, and the current limiting resistor and the first switch tube are electrically connected to a first end and a second end of the main relay, respectively, and the control method further comprises: When the subsequent circuit of the power supply control device is started, the first switch tube is controlled to be turned on so that the current limiting resistor limits the current flowing through the subsequent circuit.

35. The control method as claimed in claim 34, further comprising: turning on the first switch tube by utilizing the difference between the input voltage received by the power supply control device and the output voltage of the subsequent circuit.

36. The control method as claimed in claim 26, wherein the second current limiting unit comprises a second switch tube, and the control method further comprises: When the input switching unit switches from one of the first input terminal and the second input terminal to the other of the first input terminal and the second input terminal, if the difference between the absolute value of the input voltage received by the power supply control device and the output voltage of the subsequent circuit is greater than a second threshold, the second switch tube is controlled to operate in a linear region to limit the current flowing through the second switch tube to be equal to a preset current; if the difference is less than or equal to the second threshold, the second switch tube is controlled to operate in a saturation region.

37. The control method as described in claim 36, wherein the second current limiting unit further includes a sampling resistor connected in series to the second switch tube, and the control method further includes: generating a driving signal for controlling the second switch tube according to the current flowing through the sampling resistor, so as to limit the current flowing through the second current limiting unit to a preset current through the driving signal.

38. The control method as described in claim 26, wherein the current limiting module is connected in series between the input switching unit and the subsequent circuit, the power supply control device further includes a rectifier circuit, and the control method further includes: using the rectifier circuit to rectify the current flowing into the second current limiting unit and the first current limiting unit into a direct current.

39. A power supply device, electrically connected to a power source, and comprising: a post-stage circuit, comprising a power factor correction circuit and a capacitor connected in parallel, wherein the post-stage circuit is powered by the power supply; a current limiting module, electrically connected between the power supply and the subsequent circuit or between the power factor correction circuit and the capacitor, and comprising a first current limiting unit and a second current limiting unit connected in parallel to each other, wherein the first current limiting unit is configured to limit the surge current generated when the subsequent circuit is started, and the second current limiting unit is configured to limit the surge current generated when the power supply is abnormal; and A control unit is electrically connected to the current limiting module and is configured to control the first current limiting unit and the second current limiting unit.

40. A power supply device as described in claim 39, wherein the power supply includes a first power supply and a second power supply, and the power supply device also includes a first input terminal, a second input terminal and an input switching unit, the first input terminal is electrically connected to the first power supply, the second input terminal is electrically connected to the second power supply, and the input switching unit is configured to switch between connecting to the first input terminal and connecting to the second input terminal so that one of the first power supply and the second power supply is used as the power supply for supplying power to the subsequent circuit, and the power supply change is manifested as switching between the first power supply and the second power supply; the current limiting module is electrically connected to the input switching unit, and the second current limiting unit is also configured to limit the surge current generated when the input switching unit is switched; the control unit is also electrically connected to the input switching unit to control the input switching unit.

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