High voltage auxiliary power supply and high voltage auxiliary power supply control system

Abstract

The present application provides a high-voltage auxiliary power supply and a high-voltage auxiliary power supply control system, and relates to the technical field of power supply equipment. In the high-voltage auxiliary power supply provided in the embodiment of the present application, there are few resistive elements, and the power consumption of the resistive elements is very low. There are no resistive elements with large power consumption in the high-voltage auxiliary power supply, so that the circuit has high working efficiency and is suitable for a wider range of input voltages. When such a high-voltage auxiliary power supply is applied to a high-voltage power supply, the existing voltage-equalizing terminal of the high-voltage power supply can be used as the input of the clamping circuit. Only a small number of components need to be added to the high-voltage power supply to realize the high-voltage auxiliary power supply in the present application. The circuit modification is simple and the circuit modification cost is low. The voltage borne by the first power device and the second power device is relatively low, and it can be realized by selecting devices with lower voltage levels, which further reduces the implementation cost of the high-voltage auxiliary power supply.

Description

Technical Field

[0001] The present application relates to the field of power supply equipment, and in particular, to a high-voltage auxiliary power supply and a high-voltage auxiliary power supply control system. Background Art

[0002] In power supply equipment with medium and large power levels, the role of the auxiliary power supply is to provide stable power to the control, sampling, protection, logic and drive auxiliary circuits in the system. After the equipment is powered on, the auxiliary power supply will work immediately to prepare for auxiliary power supply for the system. The auxiliary power supply is characterized by a small power level, generally with an output of several watts to tens of watts. The flyback topology is widely used in auxiliary power supplies because of its isolation characteristics, fewer components and simple circuits. In the field of high-voltage power conversion, such as the 550V high-voltage DC input voltage after uncontrolled rectification of three-phase AC power, the traditional flyback topology has a high primary emission voltage and peak voltage, and the voltage stress of its switching devices can reach more than 1000V. Such a high voltage level makes it difficult to select power devices, the cost is high and the performance of the auxiliary power supply is poor. Summary of the invention

[0003] In view of this, the present application provides a high-voltage auxiliary power supply and a high-voltage auxiliary power supply control system.

[0004] The technical solutions provided by this application are as follows:

[0005] A high-voltage auxiliary power supply, comprising: a transformer and a clamping circuit, wherein the clamping circuit is used to clamp the voltage on one side of the primary winding of the transformer, wherein the primary winding of the transformer is connected to an external power supply via a first positive input terminal, and the clamping circuit comprises a second positive input terminal, a clamping diode, a driving input terminal, a first diode, a second diode, a first voltage regulator tube, a first power device, a second voltage regulator tube, a third voltage regulator tube, a second power device, a first resistor, a negative input terminal, and a fourth voltage regulator tube, wherein:

[0006] The anode of the clamping diode is connected to the second positive input terminal, and the cathode of the clamping diode is connected to the primary winding of the transformer;

[0007] The driving input terminal is used to receive a driving signal to turn on or off the first power device or the second power device;

[0008] The anode of the first diode is connected to the driving input terminal, the cathode of the first diode is connected to the anode of the first voltage regulator tube, and the cathode of the first voltage regulator tube is connected to the control terminal of the first power device;

[0009] The control end of the first power device is also connected to the anode of the second diode and the cathode of the second voltage regulator tube, the cathode of the second diode is connected to the cathode of the third voltage regulator tube, the anode of the second voltage regulator tube is connected to the first potential end of the second power device, and the anode of the third voltage regulator tube is connected to the second positive input end;

[0010] The control end of the second power device is connected to the driving input end through the first resistor, the second potential end of the second power device is connected to the negative input end, the anode of the fourth voltage regulator is connected to the first potential end of the second power device, and the cathode of the fourth voltage regulator is connected to the cathode of the first diode;

[0011] The first potential end of the first power device is connected to the primary winding of the transformer, and the second potential end of the first power device is connected to the first potential end of the second power device.

[0012] Furthermore, the clamping circuit further includes a first capacitor, and the first capacitor is connected in parallel with the third voltage regulator tube.

[0013] Furthermore, the high-voltage auxiliary power supply also includes: a rectifier output circuit, which is connected to the secondary winding of the transformer and is used to output the rectified current to an external device.

[0014] Furthermore, the rectifier output circuit includes: an output diode, an output capacitor and an output resistor, wherein:

[0015] The anode of the output diode is connected to the secondary winding of the transformer, the cathode of the output diode is connected to one end of the output resistor, the other end of the output resistor is connected to the secondary winding of the transformer, the output capacitor is connected in parallel with the output resistor, and the anode of the output diode serves as the output end of the rectifier output circuit.

[0016] Furthermore, the high-voltage auxiliary power supply further includes a voltage balancing circuit, and the voltage balancing circuit includes a second resistor, a third resistor, a second capacitor and a third capacitor; wherein:

[0017] One end of the second resistor is connected to the first positive input terminal, and the other end is connected to the second positive input terminal, and the second capacitor is connected in parallel with the second resistor;

[0018] One end of the third resistor is connected to the second positive input terminal, and the other end is connected to the negative input terminal. The third capacitor is connected in parallel with the third resistor.

[0019] Furthermore, the resistance of the second resistor is equal to the resistance of the third resistor, and the capacitance of the second capacitor is equal to the capacitance of the third capacitor, so that the voltage value of the second positive input terminal is equal to half of the voltage value of the first positive input terminal.

[0020] The present application also provides a high-voltage auxiliary power supply control system, comprising the high-voltage auxiliary power supply described above, and a control chip connected to the drive input end, wherein the control chip is used to generate a drive signal to control the first power device or the second power device to be turned on or off.

[0021] Furthermore, the clamping circuit further includes a first capacitor, and the first capacitor is connected in parallel with the third voltage regulator tube.

[0022] Furthermore, the high-voltage auxiliary power supply also includes: a rectifier output circuit, which is connected to the secondary winding of the transformer and is used to output the rectified current to an external device.

[0023] Furthermore, the rectifier output circuit includes: an output diode, an output capacitor and an output resistor, wherein:

[0024] The anode of the output diode is connected to the secondary winding of the transformer, the cathode of the output diode is connected to one end of the output resistor, the other end of the output resistor is connected to the secondary winding of the transformer, the output capacitor is connected in parallel with the output resistor, and the anode of the output diode serves as the output end of the rectifier output circuit.

[0025] In the high-voltage auxiliary power supply provided in the embodiment of the present application, there are very few resistive elements, and the power consumption of the resistive elements is very low. There are no resistive elements with large power consumption in the high-voltage auxiliary power supply, so that the circuit has high working efficiency and is suitable for a wider range of input voltages. When such a high-voltage auxiliary power supply is used in a high-voltage power supply, the existing voltage-equalizing terminal of the high-voltage power supply can be used as the input of the clamping circuit. Only a small number of elements need to be added to the high-voltage power supply to realize the high-voltage auxiliary power supply in the present application. The circuit modification is simple and the circuit modification cost is low. The voltage borne by the first power device and the second power device is relatively low, and it can be realized by selecting devices with lower voltage levels, which further reduces the implementation cost of the high-voltage auxiliary power supply.

[0026] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 A circuit diagram of an existing high-voltage auxiliary power supply provided in an embodiment of the present application.

[0029] Figure 2 A circuit diagram of a high-voltage auxiliary power supply provided in an embodiment of the present application.

[0030] Figure 3 Another circuit diagram of a high-voltage auxiliary power supply provided in an embodiment of the present application.

[0031] Figure 4 A circuit diagram of a high-voltage auxiliary power supply control system provided in an embodiment of the present application.

[0032] Icon: 10-high voltage auxiliary power supply; 100-transformer; 200-clamping circuit; 300-output circuit; 400-voltage equalizing circuit; 20-control chip. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application.

[0034] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. At the same time, in the description of this application, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0035] In order to obtain a high voltage auxiliary power supply in the prior art, the following methods are generally used: Figure 1The circuit shown in the figure, wherein VIN is the positive electrode of the input voltage and GND is the negative electrode of the input voltage. The power devices Q10 and Q20 and the control signal DRIVE form a StackFET structure. In such a structure, the power device can select a MOSFET with a withstand voltage of 600V. In such a circuit structure, when a driving signal is generated at the DRIVE end, the drain of Q20 drives the source of Q10, and at the same time, the drain of Q10 drives the primary of the transformer. When a shutdown signal is generated at the DRIVE end, the drain of Q10 is limited to a certain voltage by the Zener diodes D40, D50, and D60. D40, D50, and D60 can use Zener diodes with a voltage regulation value of 150V, so Q10 can be clamped at 450V, and the maximum combined peak drain voltage of Q10 and Q20 can be extended to 1050V. Resistors R10, R20, and R30 can provide start-up charging for the gate of Q10, and R40 damps high-frequency oscillations. Figure 1 During operation of the circuit shown, the gate of the power device is mainly driven by the charges stored in the capacitors of D40, D50, and D60, and the voltage regulator D30 limits the driving voltage amplitude from the gate to the source of Q10.

[0036] In the above auxiliary power supply circuit, there are multiple resistance elements such as R10, R20, R30, R40, and R70, and during the operation of the circuit, a large current will flow through these resistance elements, resulting in large resistive losses. When such a circuit is used in a scenario with a higher input voltage, the resistive loss will increase sharply, making the circuit practical.

[0037] In view of this, the embodiment of the present application provides a high voltage auxiliary power supply 10, such as Figure 2 As shown, it includes: a transformer 100 and a clamping circuit 200 .

[0038] The clamping circuit 200 is used to clamp the voltage on one side of the primary winding of the transformer 100, and the primary winding of the transformer 100 is connected to an external power source via the first positive input terminal. The embodiment of the present application does not limit the specific parameters of the transformer 100.

[0039] The clamping circuit 200 includes a second positive input terminal, a clamping diode 8, a driving input terminal, a first diode 6, a second diode 9, a first voltage regulator 11, a first power device, a second voltage regulator 10, a third voltage regulator 2, a second power device, a first resistor, a negative input terminal and a fourth voltage regulator 12.

[0040] The anode of the clamping diode 8 is connected to the second positive input terminal, and the cathode of the clamping diode is connected to the primary winding of the transformer 100. The driving input terminal is used to receive a driving signal to turn on or off the first power device or the second power device. The anode of the first diode 6 is connected to the driving input terminal, the cathode of the first diode 6 is connected to the anode of the first voltage regulator tube 11, and the cathode of the first voltage regulator tube 11 is connected to the control terminal of the first power device 1.

[0041] The control end of the first power device 1 is also connected to the anode of the second diode 9 and the cathode of the second voltage-stabilizing tube 10, the cathode of the second diode 9 is connected to the cathode of the third voltage-stabilizing tube 2, the anode of the second voltage-stabilizing tube 10 is connected to the first potential end of the second power device 2, and the anode of the third voltage-stabilizing tube 2 is connected to the second positive input end.

[0042] The control end of the second power device is connected to the driving input end through the first resistor, the second potential end of the second power device is connected to the negative input end, the anode of the fourth voltage regulator is connected to the first potential end of the second power device, and the cathode of the fourth voltage regulator is connected to the cathode of the first diode.

[0043] The first potential end of the first power device is connected to the primary winding of the transformer 100 , and the second potential end of the first power device is connected to the first potential end of the second power device.

[0044] In an embodiment of the present application, the second positive input terminal can be connected to the first positive input terminal through the voltage balancing circuit 400, and the voltage value of the second positive input terminal can be half of the voltage value of the first positive input terminal. It can be understood that in actual use, the high-voltage power supply circuit where the high-voltage auxiliary power supply 10 is located generally adopts a topological structure such as a full-bridge circuit or a half-bridge circuit in series with the primary side, so that the high-voltage power supply circuit itself has a voltage balancing terminal, and the voltage of the voltage balancing terminal is half of the voltage value of the first positive input terminal. The second positive input terminal can be directly connected to the voltage balancing terminal instead of being connected to the first positive input terminal through the voltage balancing circuit 400, so as to realize the input of the second positive input terminal.

[0045] In the above circuit, when the driving input terminal inputs a driving signal into the circuit, the second power device Q2 is turned on, and at the same time, the driving signal generates a source driving signal after passing through the first diode D6 and the first voltage regulator D11, driving the first power device Q1 to turn on, and the primary side of the transformer 100 starts to store energy. When the driving input terminal inputs a shutdown signal, the second power device Q2 is turned off, and the shutdown voltage of the second power device Q2 is forward-conducted through the second voltage regulator D10 and the second diode D9, which can clamp the voltage of the transformer 100 to the sum of the third voltage regulator D2 and the second positive input terminal voltage. The remaining peak voltage and reflected voltage when the second power device Q2 is turned off can be borne by the first power device Q1. The first diode D6, the first voltage regulator D11 and the fourth voltage regulator D12 can prevent the first power device and the second power device from reverse overvoltage breakdown.

[0046] The clamping circuit 200 further includes a first capacitor, which is connected in parallel with the third voltage regulator tube.

[0047] The high-voltage auxiliary power supply 10 further includes: a rectifier output circuit 300 , which is connected to the secondary winding of the transformer 100 and is used to output rectified current to an external device.

[0048] The rectifier output circuit 300 includes: an output diode, an output capacitor and an output resistor, wherein:

[0049] The anode of the output diode is connected to the secondary winding of the transformer 100, the cathode of the output diode is connected to one end of the output resistor, the other end of the output resistor is connected to the secondary winding of the transformer 100, the output capacitor is connected in parallel with the output resistor, and the anode of the output diode serves as the output end of the rectifier output circuit 300.

[0050] like Figure 3 As shown, the high-voltage auxiliary power supply 10 further includes a voltage balancing circuit 400, and the voltage balancing circuit 400 includes a second resistor, a third resistor, a second capacitor and a third capacitor; wherein:

[0051] One end of the second resistor is connected to the first positive input terminal, and the other end is connected to the second positive input terminal, and the second capacitor is connected in parallel with the second resistor;

[0052] One end of the third resistor is connected to the second positive input terminal, and the other end is connected to the negative input terminal. The third capacitor is connected in parallel with the third resistor.

[0053] The resistance of the second resistor is equal to the resistance of the third resistor, and the capacitance of the second capacitor is equal to the capacitance of the third capacitor, so that the voltage value of the second positive input terminal is equal to half of the voltage value of the first positive input terminal.

[0054] like Figure 4 As shown, the present application also provides a high-voltage auxiliary power supply control system, including the high-voltage auxiliary power supply 10 described above, and a control chip 20 connected to the drive input end, wherein the control chip 20 is used to generate a drive signal to control the first power device or the second power device to be turned on or off.

[0055] Furthermore, the clamping circuit 200 further includes a first capacitor, and the first capacitor is connected in parallel with the third voltage regulator tube.

[0056] Furthermore, the high-voltage auxiliary power supply 10 further includes: a rectifier output circuit 300 , wherein the rectifier output circuit 300 is connected to the secondary winding of the transformer 100 and is used to output the rectified current to an external device.

[0057] Furthermore, the rectifier output circuit 300 includes: an output diode, an output capacitor and an output resistor, wherein:

[0058] The anode of the output diode is connected to the secondary winding of the transformer 100, the cathode of the output diode is connected to one end of the output resistor, the other end of the output resistor is connected to the secondary winding of the transformer 100, the output capacitor is connected in parallel with the output resistor, and the anode of the output diode serves as the output end of the rectifier output circuit 300.

[0059] In summary, in the high-voltage auxiliary power supply 10 provided in the embodiment of the present application, there are very few resistive elements, and the power consumption of the resistive elements is very low. There are no resistive elements with large power consumption in the high-voltage auxiliary power supply 10, so that the circuit has high working efficiency and is suitable for a wider range of input voltages. When such a high-voltage auxiliary power supply 10 is used in a high-voltage power supply, the existing voltage-equalizing terminal of the high-voltage power supply can be used as the input of the clamping circuit 200. Only a small number of components need to be added to the high-voltage power supply to realize the high-voltage auxiliary power supply 10 in the present application. The circuit modification is simple and the circuit modification cost is low. The voltage borne by the first power device and the second power device is relatively low, and it can be realized by selecting devices with a lower voltage level, which further reduces the implementation cost of the high-voltage auxiliary power supply 10.

[0060] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application. It should be noted that similar numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

[0061] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A high voltage auxiliary power supply, characterized in that: include: A transformer, a clamping circuit and a voltage equalizing circuit, wherein the clamping circuit is used to clamp the voltage on one side of the primary winding of the transformer, the primary winding of the transformer is connected to an external power supply through a first positive input terminal, and the clamping circuit includes a second positive input terminal, a clamping diode, a driving input terminal, a first diode, a second diode, a first voltage regulator, a first power device, a second voltage regulator, a third voltage regulator, a second power device, a first resistor, a negative input terminal and a fourth voltage regulator, wherein: The anode of the clamping diode is connected to the second positive input terminal, and the cathode of the clamping diode is connected to the primary winding of the transformer; The driving input terminal is used to receive a driving signal to turn on or off the first power device or the second power device; The anode of the first diode is connected to the driving input terminal, the cathode of the first diode is connected to the anode of the first voltage regulator tube, and the cathode of the first voltage regulator tube is connected to the control terminal of the first power device; The control end of the first power device is also connected to the anode of the second diode and the cathode of the second voltage regulator tube, the cathode of the second diode is connected to the cathode of the third voltage regulator tube, the anode of the second voltage regulator tube is connected to the first potential end of the second power device, and the anode of the third voltage regulator tube is connected to the second positive input end; The control end of the second power device is connected to the driving input end through the first resistor, the second potential end of the second power device is connected to the negative input end, the anode of the fourth voltage regulator is connected to the first potential end of the second power device, and the cathode of the fourth voltage regulator is connected to the cathode of the first diode; The first potential end of the first power device is connected to the primary winding of the transformer, and the second potential end of the first power device is connected to the first potential end of the second power device; The clamping circuit further includes a first capacitor, and the first capacitor is connected in parallel with the third voltage regulator tube; The voltage balancing circuit includes a second resistor, a third resistor, a second capacitor and a third capacitor; wherein: One end of the second resistor is connected to the first positive input terminal, and the other end is connected to the second positive input terminal, and the second capacitor is connected in parallel with the second resistor; One end of the third resistor is connected to the second positive input terminal, and the other end is connected to the negative input terminal. The third capacitor is connected in parallel with the third resistor.

2. The high voltage auxiliary power supply according to claim 1, characterized in that: The high-voltage auxiliary power supply further includes: a rectifier output circuit, which is connected to the secondary winding of the transformer and is used to output rectified current to an external device.

3. The high voltage auxiliary power supply according to claim 2, characterized in that: The rectifier output circuit includes: an output diode, an output capacitor and an output resistor, wherein: The anode of the output diode is connected to the secondary winding of the transformer, the cathode of the output diode is connected to one end of the output resistor, the other end of the output resistor is connected to the secondary winding of the transformer, the output capacitor is connected in parallel with the output resistor, and the anode of the output diode serves as the output end of the rectifier output circuit.

4. The high voltage auxiliary power supply according to claim 1, characterized in that: The resistance of the second resistor is equal to the resistance of the third resistor, and the capacitance of the second capacitor is equal to the capacitance of the third capacitor, so that the voltage value of the second positive input terminal is equal to half of the voltage value of the first positive input terminal.

5. A high voltage auxiliary power supply control system, characterized in that: It comprises the high-voltage auxiliary power supply as described in any one of claims 1 to 4, and a control chip connected to the drive input terminal, wherein the control chip is used to generate a drive signal to control the first power device or the second power device to be turned on or off.

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