Converter auxiliary source circuit with power-on and power-off time sequence

Abstract

The converter auxiliary source circuit comprises an external auxiliary source board, a relay board and a main power module, the main power module comprises a built-in auxiliary source circuit, the input end of the external auxiliary source board is connected to an alternating current power grid, and the output end of the external auxiliary source board is connected with a control winding of the relay board. The control module is used for converting three-phase alternating current of the alternating-current power grid into direct current and controlling the alternating-current power grid to enter the main power module; the relay board is connected between the alternating current power grid and the main power module and is used for controlling the alternating current input on-off state of the main power module; the output of the built-in auxiliary source circuit in the main power module is divided into two paths including controller power supply and driving power supply, the controller power supply is powered on firstly during power on, the controller power supply is powered off after power off during power off, and the driving power supply is always controlled by the controller.

Description

Technical Field

[0001] This application relates to the technical field of electrical equipment, and more specifically, to a converter auxiliary power source circuit with power-on and power-off time sequences. Background Art

[0002] As an important part of power electronic equipment, the auxiliary power source circuit of a converter provides necessary power supply for it. However, the existing auxiliary power source circuit can only provide different output voltages for the converter. In the extreme condition of AC input power-on and power-off, there may be a situation where the switching tube mode of the converter is out of control, resulting in an out-of-control fault of the entire converter.

[0003] In the prior art, the design of the auxiliary power source circuit mainly focuses on how to provide stable power supply for the main circuit and other auxiliary devices to meet the basic requirements for the normal operation of the converter. However, when the converter operates in the extreme condition of AC input power-on and power-off, the auxiliary power source circuit cannot effectively control the mode of the switching tube, thus making the operating state of the converter unstable and increasing the risk of faults.

[0004] The occurrence of this problem is mainly because when designing the existing auxiliary power source circuit, the operation stability of the converter under various extreme conditions is not fully considered. When the AC input changes violently, the auxiliary power source circuit cannot adjust the output voltage in time, resulting in abnormal control signals of the switching tube, which in turn affects the normal operation of the entire converter.

[0005] Therefore, in the prior art, there is a lack of an auxiliary power source circuit that can effectively control the switching tube mode of the converter under extreme conditions such as AC input power-on and power-off to ensure the stable operation of the converter and avoid out-of-control faults. Summary of the Invention

[0006] In view of at least one defect or improvement requirement of the prior art, the present invention provides a converter auxiliary power source circuit with power-on and power-off time sequences, which solves the problem that the existing auxiliary power source can only provide normal output voltage and cannot ensure that multiple auxiliary power sources are powered on and off in sequence, and ensures that the auxiliary power exists longer than the AC input power during the entire power-on and power-off process inside the main power module, realizing the controllable power-on and power-off of the entire main power module.

[0007] To achieve the above object, according to the first aspect of the present invention, a converter auxiliary source circuit with power-on and power-off time sequence is provided, including an external auxiliary source board, a relay board and a main power module. The main power module includes a built-in auxiliary source circuit. The input end of the external auxiliary source board is connected to the AC power grid, and the output end is connected to the control winding of the relay board, which is used to convert the three-phase alternating current of the AC power grid into direct current and control the AC power grid to enter the main power module. The relay board is connected between the AC power grid and the main power module and is used to control the on-off state of the AC input of the main power module. The output of the built-in auxiliary source circuit in the main power module is divided into two paths, including controller power supply and drive power supply. When powering on, the controller power supply is powered on first, and when powering off, the controller power supply is powered off later. The drive power supply is always under the control of the controller.

[0008] In an exemplary embodiment, the built-in auxiliary source circuit includes a power module U1, a differential-mode inductor L1, a capacitor C7, a capacitor C6, and a capacitor C5. The input end of the power module U1 is connected to one end of the capacitor C6, and the other end of the capacitor C6 is connected to the GND terminal of the power module U1 to be grounded. The differential-mode inductor L1 is connected between the capacitor C7 and the capacitor C6. One end of the capacitor C5 is connected to the output end of the power module U1, and the other end of the capacitor C5 is connected to the GND terminal of the power module U1 to be grounded. The input of the built-in auxiliary source circuit passes through the differential-mode inductor L1 and is then converted into controller power supply by the power module U1.

[0009] In an exemplary embodiment, the built-in auxiliary source circuit further includes a power module U2, a capacitor C3, a capacitor C4, a PMOS transistor Q1, a resistor R5, a resistor R6, a resistor R7, and a resistor R4. One end of the capacitor C3 is connected to the output end of the power module U2, and the other end of the capacitor C3 is grounded. One end of the capacitor C4 is connected to the input end of the power module U2, and the other end of the capacitor C4 is connected to the GND terminal of the power module U2 to be grounded. The source electrode of the PMOS transistor Q1 is connected to the input end of the power module U2. The gate electrode of the PMOS transistor Q1 is respectively connected to the resistor R5 and the resistor R6. The resistor R7 is connected in series with the resistor R6. The drain electrode of the PMOS transistor Q1 is connected to the resistor R4.

[0010] In an exemplary embodiment, the built-in auxiliary source circuit further includes an optocoupler U3, a capacitor C2, a voltage reference chip ZD1, a capacitor C1 and a diode D1 connected in series, with the other end of the capacitor C1 grounded, and resistors R3, R1 and R2 connected in series in sequence. The other end of the resistor R3 is connected to the light-emitting diode in the optocoupler U3, the other end of the resistor R2 is grounded, one end of the voltage reference chip ZD1 is connected to the light-emitting diode, and the other end is connected to the resistor R2.

[0011] In an exemplary embodiment, the built-in auxiliary power source circuit uses a voltage reference chip ZD1 and an external resistor to set the power supply voltage threshold for the controller power supply. The power supply voltage threshold is set to (1 + R1 / R2)*Vref, where Vref is the reference voltage determined according to the selected voltage reference chip ZD1.

[0012] In an exemplary embodiment, during the power-on process of the built-in auxiliary power source circuit, when the controller power supply reaches the power supply voltage threshold, the voltage reference chip ZD1 conducts, and the optocoupler U3 in the loop where the voltage reference chip ZD1 is located is turned on; by using resistors R5 and R7 for voltage division, the POMS transistor Q1 conducts, and the drive power supply is turned on.

[0013] In an exemplary embodiment, during the power-off process of the built-in auxiliary power source circuit, the capacitor C5 is formed by connecting multiple capacitors with large capacitance values in parallel. The power-off hold time of the controller power supply is much longer than that of the drive power supply, and the drive power supply is always under the control of the controller.

[0014] In an exemplary embodiment, the external auxiliary power source board includes a rectifier circuit, a surge suppression circuit, a DC / DC isolation conversion circuit, and an output filter circuit.

[0015] In an exemplary embodiment, after the AC input enters the converter, it includes a first path and a second path. The first path enters the external auxiliary power source board, and the second path enters the main power module through the relay board.

[0016] In an exemplary embodiment, during the power-on process of the external auxiliary power source board, it is first powered by the AC input, and then the relay board is turned on. The on-off state of the AC input of the main power module is controlled through the relay board.

[0017] Generally speaking, compared with the prior art through the above technical solutions conceived by the present invention, the following beneficial effects can be achieved: (1) The present invention provides a converter auxiliary power source circuit with power-on and power-off timing. During the power-on process, the external auxiliary power source board ensures that the main power module has auxiliary power first and then AC input. During the power-off process, it ensures that the auxiliary power can still be maintained for a period of time when the AC input of the main power module is powered off, realizing controllability of the entire power-on and power-off process of the main power module.

[0018] (2) The power-on process of the built-in auxiliary power source circuit is controllable, realizing the function of controlling the drive power supply by the controller power supply, and setting the threshold voltage for controlling the drive power supply by the controller power supply through the voltage reference chip and the external resistor. The purpose is to avoid the start-up condition of the controller power supply and use a stable control power supply to control the drive power supply, thereby improving the reliability of the power-on process.

[0019] (3) The power-down process of the built-in auxiliary source circuit is controllable, significantly increasing the power supply capacitor of the controller. Ensure that when the input power is cut off, the power supply of the controller has the longest power-down hold time, improving the reliability of the power-down process. Description of the Drawings

[0020] To more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0021] Figure 1 FIG. is a schematic structural diagram of an optional converter auxiliary source circuit with power-on and power-off time sequences provided by an embodiment of the present application; Figure 2 FIG. is a structural block diagram of an optional auxiliary source board and relay board provided by an embodiment of the present application; Figure 3 FIG. is a structural block diagram of an optional built-in auxiliary source circuit provided by an embodiment of the present application; Figure 4 FIG. is a schematic diagram of the overall power-on and power-off effect of an optional auxiliary source circuit provided by an embodiment of the present application; Detailed Embodiments In order to make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0022] The terms "first", "second", "third", etc. in the specification and claims of the present application and the above drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but optionally further includes steps or units not listed, or optionally further includes other steps or units inherent to these processes, methods, products, or devices.

[0023] According to one aspect of the embodiments of the present application, a converter auxiliary source circuit with power-on and power-off time sequences is provided. The following combines Figure 1 Describe the converter auxiliary source circuit with power-on and power-off time sequences provided by the embodiments of the present application.

[0024] Figure 1This is a schematic diagram of an optional converter auxiliary power source circuit with power-on and power-off timing provided by an embodiment of the present application. As Figure 1 shown, the converter auxiliary power source circuit with power-on and power-off timing may include: an external auxiliary power source board, a relay board, and a main power module. The main power module includes a built-in auxiliary power source circuit. The input end of the external auxiliary power source board is connected to the AC power grid, and the output end is connected to the control winding of the relay board, which is used to convert the three-phase alternating current of the AC power grid into direct current and control the AC power grid to enter the main power module. The relay board is connected between the AC power grid and the main power module, and is used to control the on-off state of the AC input of the main power module. The output of the built-in auxiliary power source circuit in the main power module is divided into two paths, including controller power supply and drive power supply. When powering on, the controller power supply is powered on first, and when powering off, the controller power supply is powered off later. The drive power supply is always under the control of the controller.

[0025] Please refer to Figure 1 . Specifically, the auxiliary power source circuit with power-on and power-off timing in the present application is divided into two parts. One part is the external auxiliary power source board ( Figure 1 the auxiliary power source board shown in), which converts the 380V alternating current output by the three-phase AC power grid into 24V direct current. The other part is the built-in auxiliary power source circuit in the main power module, which converts the 24V direct current into 12V drive power supply and 5V controller power supply. The main power module includes a power conversion circuit connected to the relay board and a built-in auxiliary power source circuit ( Figure 1 the auxiliary power source circuit shown in). The built-in auxiliary power source circuit includes a 12V drive power supply module ( Figure 1 the 12V power supply module shown in) and a 5V controller power supply module ( Figure 1 the 5V power supply module shown in).

[0026] In addition, the external auxiliary power source board can control the on-off state of the AC input of the main power module through the relay board to ensure that the main power module has auxiliary power supply first and then AC input power supply. The built-in auxiliary power source circuit of the main power module ensures that the controller power supply is powered on first when powering on and powered off later when powering off, ensuring that the drive power supply is always under the control of the controller.

[0027] Exemplarily, Figure 2 This is a schematic block diagram of an optional auxiliary power source board and relay board provided by an embodiment of the present application. As Figure 2 shown, the external auxiliary power source board ( Figure 2The external auxiliary power board shown in [description] includes a rectifier circuit, a surge suppression circuit, a DC / DC isolation conversion circuit, and an output filter circuit, with an output of DC24V / 160W. The output of the external auxiliary power board is connected to the control winding of the relay board, which is used to control the entry of the AC power grid into the main power module. After the AC input enters the converter, it includes a first path and a second path. The first path enters the external auxiliary power board, and the second path enters the main power module through the relay board. During the power-on process of the external auxiliary power board, it is first powered by the AC input, then the relay board is turned on, and the on-off state of the AC input of the main power module is controlled through the relay board. When the AC input is powered off, the external auxiliary power board can maintain auxiliary power for a period of time due to the existence of the output capacitor, ensuring that the auxiliary power exists inside the main power module for a longer time than the AC input power during the entire power-on and power-off process, and realizing the controllability of the power-on and power-off of the entire main power module.

[0028] An external auxiliary power board and a relay board are used to control the AC input of the main power module. During the power-on process, the AC input first passes through the external auxiliary power board. After the external auxiliary power board has an output, the relay board is controlled to turn on to achieve the purpose of controlling the AC input of the main power module. During the power-off process, since there is a capacitor on the output side of the external auxiliary power board, the 24V output of the external auxiliary power can be maintained for a period of time, ensuring that the control power can be maintained for a period of time after the AC input of the main power module is powered off.

[0029] In view of the situation that the existing auxiliary power source can only provide a normal output voltage and cannot ensure the sequential power-on and power-off of multiple auxiliary power sources, an optional auxiliary power source circuit with power-on and power-off timing sequences provided in this application: The first part is the external auxiliary power board. During the power-on process, it ensures that the main power module is first powered by the auxiliary power source and then by the AC input. During the power-off process, due to the output capacitor storing energy, the auxiliary power source loses power later than the AC input. The other part is the built-in auxiliary power source circuit of the main power module. During the power-on process, when the power supply to the controller reaches a specific voltage value (the value at which the controller can operate stably), the drive power supply is started. During the power-off process, since a large capacitor is connected to the back end of the controller power supply, its power-off time is longer than that of the drive, ensuring that the drive operates under the control of the controller.

[0030] Optionally, Figure 3 is a structural block diagram of an optional built-in auxiliary power source circuit provided by an embodiment of this application, as Figure 3As shown, the built-in auxiliary power source circuit includes a power module U1, a differential-mode inductor L1, a capacitor C7, a capacitor C6, and a capacitor C5. The input end of the power module U1 is connected to one end of the capacitor C6, the other end of the capacitor C6 is connected to the GND end of the power module U1 and grounded. The differential-mode inductor L1 is connected between the capacitor C7 and the capacitor C6. One end of the capacitor C5 is connected to the output end of the power module U1, and the other end of the capacitor C5 is connected to the GND end of the power module U1 and grounded. The input of the built-in auxiliary power source circuit passes through the differential-mode inductor L1 and is converted by the power module U1 to supply power to the controller.

[0031] It should be noted that Vin of the power module U1 is the input end, GND is the grounding end, CTRL is the control pin, NC is the normally closed contact, +Vo is the output end, and OV is the overvoltage protection.

[0032] Further, the built-in auxiliary power source circuit further includes a power module U2, a capacitor C3, a capacitor C4, a PMOS transistor Q1, a resistor R5, a resistor R6, a resistor R7, and a resistor R4. One end of the capacitor C3 is connected to the output end of the power module U2, the other end of the capacitor C3 is grounded. One end of the capacitor C4 is connected to the input end of the power module U2, and the other end of the capacitor C4 is connected to the GND end of the power module U2 and grounded. The source electrode of the PMOS transistor Q1 is connected to the input end of the power module U2. The gate electrode of the PMOS transistor Q1 is respectively connected to the resistor R5 and the resistor R6. The resistor R7 is connected in series with the resistor R6. The drain electrode of the PMOS transistor Q1 is connected to the resistor R4.

[0033] It should be noted that Vin+ of the power module U2 is the input end, Vout+ is the output end, GND is the grounding end, and OV is the overvoltage protection.

[0034] Even further, the built-in auxiliary power source circuit further includes an optocoupler U3, a capacitor C2, a voltage reference chip ZD1, a capacitor C1 and a diode D1 connected in series, the other end of the capacitor C1 is grounded, a resistor R3, a resistor R1 and a resistor R2 connected in series in sequence. The other end of the resistor R3 is connected to the light-emitting diode in the optocoupler U3. The other end of the resistor R2 is grounded. One end of the voltage reference chip ZD1 is connected to the light-emitting diode and the other end is connected to the resistor R2.

[0035] Optionally, in combination with Figures 1 - 3 As shown, the built-in auxiliary power source circuit is divided into two output paths. One path is 5V for supplying power to the controller, and the other path is 12V for supplying power to the driver. The input of the external auxiliary power source circuit is 24V. After passing through the differential-mode inductor L1, it is converted by the power module U1 to supply 5V power to the controller.

[0036] In an exemplary embodiment, the built-in auxiliary power source circuit uses a voltage reference chip ZD1 and an external resistor to set the power supply voltage threshold for the controller power supply. The power supply voltage threshold is set to (1 + R1 / R2) * Vref, where Vref is the reference voltage determined according to the selected voltage reference chip ZD1.

[0037] In an exemplary embodiment, during the power-on process of the built-in auxiliary power source circuit, when the controller power supply reaches the power supply voltage threshold, the voltage reference chip ZD1 conducts, and the optocoupler U3 in the loop where the voltage reference chip ZD1 is located turns on; by using resistors R5 and R7 for voltage division, the POMS transistor Q1 conducts, and the drive power supply is turned on.

[0038] Specifically, as Figure 3 shown, the built-in auxiliary power source circuit uses a voltage reference chip and an external resistor to set the power supply voltage threshold for the controller. During the power-on process, when the controller power supply voltage reaches the threshold voltage (1 + R1 / R2) * Vref, the reference voltage Vref has different voltage values according to the selection of the voltage reference chip. The voltage reference chip ZD1 conducts, and the optocoupler U3 in its loop turns on, and R5, R4, and R7 are used for voltage division. Generally, R4 is much smaller than R5 and R7. In fact, it is R5 and R7 that are used for voltage division. At this time, the voltage at the G (gate) pole of the POMS transistor Q1 is 24V * R7 / (R5 + R7). There is a drive signal for the PMOS transistor Q1 in the drive power supply loop, the POMS transistor Q1 conducts, and the drive power supply module starts to work and normally outputs 12V.

[0039] The power-on process of the built-in auxiliary power source circuit is controllable, realizing the function of controlling the drive power supply by the controller power supply, and setting the threshold voltage for controlling the drive power supply by the controller power supply through the voltage reference chip and the external resistor. The purpose is to avoid the start-up condition of the controller power supply and use a stable control power supply to control the drive power supply, improving the reliability of the power-on process.

[0040] In an exemplary embodiment, during the power-off process of the built-in auxiliary power source circuit, the capacitor C5 is formed by connecting multiple large-capacitance capacitors in parallel. The power-off holding time of the controller power supply is much longer than that of the drive power supply, and the drive power supply is always under the control of the controller.

[0041] During the power-off process of the built-in auxiliary power source circuit, in this application, the 5V power supply capacitor C5 is actually formed by connecting multiple large-capacitance capacitors in parallel, ensuring that the power-off holding time of the 5V controller power supply is much longer than that of the 12V drive power supply, so that the drive power supply is always in the control process of the controller during the power-off process. The power-off process of the built-in auxiliary power source circuit is controllable. By significantly increasing the controller power supply capacitor, it is ensured that when the input power is cut off, the power-off holding time of the controller power supply is the longest, improving the reliability of the power-off process.

[0042] Preferably,Figure 4 It is a schematic diagram of the overall power-on and power-off effect of an optional auxiliary power source circuit provided by an embodiment of the present application. Combining Figure 1 and Figure 4 it can be seen that after the AC power grid supplies power for dozens of cycles, at time t0, the auxiliary power source board starts to work, and the power-on time lasts for several cycles.

[0043] At time t1, the output of the auxiliary power source board rises to the startup voltage Vth of the 5V power module, and the 5V output starts to rise.

[0044] At time t2, the 5V power module rises to the power supply voltage threshold (1 + R1 / R2)*Vref, and the 12V power module starts.

[0045] At time t3, the 12V power module completes the startup process and stably outputs 12V.

[0046] At time t4, the relay reaches the startup voltage Vrelay, the relay board is turned on, and the main power module has AC input.

[0047] At time t5, the auxiliary power source board completes the startup process and stably outputs 24V.

[0048] At time t6, the AC power grid is powered off, and the auxiliary power source board slowly loses power.

[0049] At time t7, since the capacitance at the back end of the 12V power module is small, it starts to lose power after the 24V drops to a short time lower than Vref.

[0050] At time t8, the 24V voltage drops to 0.

[0051] At time t9, the 12V voltage drops to 0.

[0052] At time t10, since a large capacitor C5 is connected to the back end of the 5V power module, it loses power last, and the voltage drops to 0 at time t11.

[0053] During the power-on process, the external auxiliary power source board ensures that the main power module has auxiliary power first and then AC input. During the power-off process, it ensures that the auxiliary power can still be maintained for a period of time when the AC input of the main power module is powered off, realizing the controllability of the entire power-on and power-off process of the main power module.

[0054] The above are only exemplary embodiments of the present disclosure, and the scope of the present disclosure cannot be limited thereby. That is, any equivalent changes and modifications made in accordance with the teachings of the present disclosure still fall within the scope covered by the present disclosure. After considering the specification and practicing the present disclosure herein, those skilled in the art will readily conceive of other embodiments of the present disclosure. This application is intended to cover any variations, uses, or adaptations of the present disclosure, which follow the general principles of the present disclosure and include common general knowledge or conventional technical means in the technical field not recorded in the present disclosure. The specification and examples are only regarded as exemplary, and the scope and spirit of the present disclosure are defined by the claims.

[0055] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0056] Those skilled in the art can easily understand that the above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A converter auxiliary power source circuit with power-on and power-off time sequences, characterized in that, It includes an external auxiliary power board, a relay board and a main power module. The main power module includes a built-in auxiliary power circuit. The input end of the external auxiliary power board is connected to the AC power grid, and the output end is connected to the control winding of the relay board, which is used to convert the three-phase alternating current of the AC power grid into direct current and control the AC power grid to enter the main power module. The relay board is connected between the AC power grid and the main power module and is used to control the on-off state of the AC input of the main power module. The output of the built-in auxiliary power circuit in the main power module is divided into two paths, including controller power supply and drive power supply. When powering on, the controller power supply is powered on first, and when powering off, the controller power supply is powered off later. The drive power supply is always under the control of the controller.

2. The auxiliary power source circuit of the converter with power-on and power-off time sequences as claimed in claim 1, wherein The built-in auxiliary power circuit includes a power module U1, a differential-mode inductor L1, a capacitor C7, a capacitor C6, and a capacitor C5. The input end of the power module U1 is connected to one end of the capacitor C6, and the other end of the capacitor C6 is connected to the GND terminal of the power module U1 to be grounded. The differential-mode inductor L1 is connected between the capacitor C7 and the capacitor C6. One end of the capacitor C5 is connected to the output end of the power module U1, and the other end of the capacitor C5 is connected to the GND terminal of the power module U1 to be grounded. The input of the built-in auxiliary power circuit passes through the differential-mode inductor L1 and is then converted into controller power supply by the power module U1.

3. The auxiliary power source circuit of the converter with power-on and power-off time sequences as described in claim 1, characterized in that, The built-in auxiliary power circuit further includes a power module U2, a capacitor C3, a capacitor C4, a PMOS transistor Q1, a resistor R5, a resistor R6, a resistor R7, and a resistor R4. One end of the capacitor C3 is connected to the output end of the power module U2, and the other end of the capacitor C3 is grounded. One end of the capacitor C4 is connected to the input end of the power module U2, and the other end of the capacitor C4 is connected to the GND terminal of the power module U2 to be grounded. The source electrode of the PMOS transistor Q1 is connected to the input end of the power module U2. The gate electrode of the PMOS transistor Q1 is respectively connected to the resistor R5 and the resistor R6. The resistor R7 is connected in series with the resistor R6. The drain electrode of the PMOS transistor Q1 is connected to the resistor R4.

4. The auxiliary power source circuit of the converter with power-on and power-off time sequences as described in claim 1, wherein, The built-in auxiliary power circuit further includes an optocoupler U3, a capacitor C2, a voltage reference chip ZD1, a capacitor C1 and a diode D1 connected in series, the other end of the capacitor C1 is grounded, resistors R3, R1 and R2 connected in series in turn. The other end of the resistor R3 is connected to the light-emitting diode in the optocoupler U3. The other end of the resistor R2 is grounded. One end of the voltage reference chip ZD1 is connected to the light-emitting diode and the other end is connected to the resistor R2.

5. The auxiliary power source circuit of the converter with power-on and power-off time sequence as described in claim 4, characterized in that The built-in auxiliary power circuit uses the voltage reference chip ZD1 and an external resistor to set the power supply voltage threshold of the controller power supply. The power supply voltage threshold is set to (1 + R1 / R2)*Vref, where Vref is the reference voltage determined according to the selected voltage reference chip ZD1.

6. The auxiliary power source circuit of the converter with power-on and power-off time sequences according to any one of claims 2-5, characterized in that During the power-on process of the built-in auxiliary power source circuit, when the power supply of the controller reaches the power supply voltage threshold, the voltage reference chip ZD1 conducts, and the optocoupler U3 in the loop where the voltage reference chip ZD1 is located turns on; by using the voltage division of resistor R5 and resistor R7, the POMS transistor Q1 conducts, and the drive power supply is turned on.

7. The auxiliary power source circuit of the converter with power-on and power-off time sequences as described in claim 6, wherein During the power-off process of the built-in auxiliary power source circuit, the capacitor C5 is formed by connecting multiple large-capacitance capacitors in parallel. The power-off hold time of the controller power supply is much longer than that of the drive power supply, and the drive power supply is always under the control of the controller.

8. The converter auxiliary power source circuit with power-on and power-off time sequences according to claim 1, wherein The external auxiliary power source board includes a rectifier circuit, a surge suppression circuit, a DC / DC isolation conversion circuit, and an output filter circuit.

9. The converter auxiliary power source circuit with power-on and power-off time sequences according to claim 1, wherein After the AC input enters the converter, it includes a first path and a second path. The first path enters the external auxiliary power source board, and the second path enters the main power module through the relay board.

10. The converter auxiliary power source circuit with power-on and power-off time sequences according to claim 1, wherein During the power-on process of the external auxiliary power source board, it is first powered by the AC input, and then the relay board is turned on to control the on / off state of the AC input of the main power module through the relay board.

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