A converter auxiliary source circuit with power-on and power-off timing sequence

Abstract

The present application discloses a converter auxiliary source circuit with power-on and power-off timing, 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 AC power of the AC power grid into DC power 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 power is turned on, the controller power supply is powered on first, and when power is turned off, the controller power supply is powered off later, and the drive power supply is always under the control of the controller.

Description

Technical Field

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

[0002] As a crucial component of power electronics, converters rely on auxiliary power circuits to provide the necessary power. However, existing auxiliary power circuits can only provide varying output voltages. Under extreme operating conditions, such as AC input power-up and power-down, the converter's switching transistors may become uncontrolled, leading to a complete converter failure.

[0003] In existing technologies, auxiliary power circuit design primarily focuses on providing a stable power supply to the main circuit and other auxiliary devices, meeting the basic requirements for normal inverter operation. However, when the inverter operates under extreme conditions of AC input power-up and power-down, the auxiliary power circuit cannot effectively control the switching mode, resulting in unstable inverter operation and increasing the risk of failure.

[0004] This problem arises primarily because existing auxiliary power circuits fail to adequately consider the converter's operational stability under various extreme operating conditions during design. When the AC input experiences drastic changes, the auxiliary power circuit is unable to adjust the output voltage in a timely manner, causing abnormalities in the control signals of the switching transistors, which in turn affects the normal operation of the entire converter.

[0005] Therefore, the prior art lacks an auxiliary source circuit that can effectively control the converter switch mode under extreme operating conditions such as AC input power-up and power-down, so as to ensure the stable operation of the converter and avoid out-of-control failures. Summary of the Invention

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

[0007] To achieve the above-mentioned purpose, according to the first aspect of the present invention, a converter auxiliary source circuit with power-on and power-off timing is provided, including an external auxiliary source board, a relay board and a main power module, the main power module including 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 AC power of the AC power grid into DC power 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 power is turned on, the controller power supply is powered on first, and when power is turned off, the controller power supply is turned off later, and 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 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 source circuit passes through the differential mode inductor L1 and is converted into power for the controller through the power module U1.

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

[0010] In an exemplary embodiment, the built-in auxiliary source circuit also 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.

[0011] In an exemplary embodiment, the built-in auxiliary power circuit uses a voltage reference chip ZD1 and an external resistor to set the supply voltage threshold of the controller power supply, and the supply voltage threshold is set to (1+R1 / R2)*Vref, where Vref is a 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 circuit, when the controller power supply reaches the power supply voltage threshold, the voltage reference chip ZD1 is turned on, and the optocoupler U3 of the circuit where the voltage reference chip ZD1 is located is turned on; using the resistor R5 and the resistor R7 to divide the voltage, the POMS tube Q1 is turned on, and the driving power supply is started.

[0013] In an exemplary embodiment, during the power-off process of the built-in auxiliary source circuit, the capacitor C5 is formed by multiple large-capacitance capacitors connected in parallel, and the power-off retention time of the controller power supply is much longer than the power-off retention time 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 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 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, the external auxiliary power board 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.

[0017] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art:

[0018] (1) The present invention provides a converter auxiliary source circuit with power-on and power-off timing. During the power-on process, the external auxiliary source board ensures that the main power module has auxiliary source power before the AC input. During the power-off process, it ensures that the auxiliary source power can be maintained for a period of time when the AC input is cut off, so that the entire main power module power-on and power-off process can be controlled.

[0019] (2) The built-in auxiliary power circuit has a controllable power-on process, which enables the controller to control the driver power supply. The threshold voltage of the controller power supply to control the driver power supply is set by the voltage reference chip and the external resistor. This avoids the startup condition of the controller power supply and uses a stable control power supply to control the driver power supply, thereby improving the reliability of the power-on process.

[0020] (3) The power-off process of the built-in auxiliary source circuit is controllable, which greatly increases the controller power supply capacitance, ensuring that when the input power is cut off, the controller power supply is kept off for the longest time, thereby improving the reliability of the power-off process. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0022] Figure 1 A schematic structural diagram of an optional converter auxiliary source circuit with power-on and power-off timing provided in an embodiment of the present application;

[0023] Figure 2 A structural block diagram of an optional auxiliary source board and relay board provided in an embodiment of the present application;

[0024] Figure 3 A structural block diagram of an optional built-in auxiliary source circuit provided in an embodiment of the present application;

[0025] Figure 4 A schematic diagram of the overall power-on and power-off effects of an optional auxiliary source circuit provided in an embodiment of the present application; DETAILED DESCRIPTION

[0026] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0027] The terms "first," "second," "third," and the like in the specification and claims of this application and the accompanying drawings are used to distinguish between different objects, not to describe a particular order. Furthermore, the terms "including," "having," and any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or elements is not limited to the listed steps or elements, but may optionally include steps or elements not listed, or may optionally include other steps or elements inherent to the process, method, product, or apparatus.

[0028] According to one aspect of the embodiment of the present application, a converter auxiliary source circuit with power-on and power-off timing is provided. Figure 1The present invention describes a converter auxiliary source circuit with power-on and power-off timing sequences provided in an embodiment of the present application.

[0029] Figure 1 This is a schematic diagram of the structure of an optional converter auxiliary source circuit with power-on and power-off timing provided in an embodiment of the present application, such as Figure 1 As shown, the converter auxiliary source circuit with power-on and power-off timing may include: an external auxiliary source board, a relay board and a main power module, wherein the main power module includes a built-in auxiliary source circuit,

[0030] 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 AC power of the AC power grid into DC power and control the AC power grid to enter the main power module;

[0031] 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;

[0032] 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 power is turned on, the controller power supply is powered on first, and when power is turned off, the controller power supply is powered off later. The drive power supply is always under the control of the controller.

[0033] See Figure 1 Specifically, the auxiliary source circuit with power-on and power-off timing in this application is divided into two parts, one of which is the external auxiliary source board ( Figure 1 The auxiliary power board shown in the figure converts the 380V AC power output from the three-phase AC grid into 24V DC power. The other part is the built-in auxiliary power circuit in the main power module, which converts the 24V DC power 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 circuit ( Figure 1 The built-in auxiliary power supply circuit includes a 12V drive power supply module ( Figure 1 12V power supply module) and 5V controller power supply module ( Figure 1 5V power module shown in Figure 1).

[0034] In addition, the external auxiliary power board can control the AC input on / off status of the main power module through the relay board, ensuring that the main power module receives power from the auxiliary power supply before the AC input. The main power module's built-in auxiliary power circuit ensures that the controller is powered on first during power-up and powered off after the controller during power-down, ensuring that the drive power supply is under the control of the controller.

[0035] For example, Figure 2 A structural block diagram of an optional auxiliary source board and relay board provided in an embodiment of the present application, such as Figure 2As shown, the external auxiliary source board ( Figure 2 The auxiliary source board shown in the figure 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 auxiliary source board is connected to the relay board control winding, which is used to control the AC power grid to enter 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 source board, and the second path enters the main power module through the relay board. During the power-on process, the external auxiliary source board 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. When the AC input is powered off, the external auxiliary source board can maintain the auxiliary source power for a period of time due to the presence of the output capacitor, ensuring that the auxiliary source power inside the main power module exists longer than the AC input power during the entire power-on and power-off process, thereby realizing the controllable power on and off of the entire main power module.

[0036] An external auxiliary power board and relay board control the AC input to the main power module. During power-up, the AC input first passes through the external auxiliary power board. Once the external auxiliary power board has output, the relay board is activated, thereby controlling the AC input to the main power module. During power-down, due to the capacitor on the output side of the external auxiliary power board, the 24V output of the external auxiliary power board can be maintained for a period of time, ensuring that control power is maintained for a period of time after the main power module AC input is disconnected.

[0037] To address the situation where existing auxiliary sources can only provide normal output voltages and cannot ensure that multiple auxiliary sources are powered on and off in sequence, this application provides an optional auxiliary source circuit with power-on and power-off sequencing: the first part is an external auxiliary source board. During power-on, it ensures that the main power module is powered by the auxiliary source first and then by the AC input. During power-off, the auxiliary source powers off later than the AC input because it has output capacitors to store energy. The other part is a built-in auxiliary source circuit in the main power module. During power-on, when the controller power supply reaches a specific voltage value (the value at which the controller can operate stably), the driver power supply is started. During power-off, due to the large capacitor connected to the back end of the controller power supply, its power-off time is longer than that of the driver, ensuring that the driver operates under the control of the controller.

[0038] Optionally, Figure 3 This is a structural block diagram of an optional built-in auxiliary source circuit provided in an embodiment of the present application, such as Figure 3As shown, 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 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 source circuit passes through the differential mode inductor L1 and is converted into power for the controller through the power module U1.

[0039] It should be noted that Vin of the power module U1 is the input terminal, GND is the ground terminal, CTRL is the control pin, NC is the normally closed contact, +Vo is the output terminal, and OV is the overvoltage protection.

[0040] Furthermore, the built-in auxiliary power circuit also includes a power module U2, a capacitor C3, a capacitor C4, a PMOS tube 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 end of the power module U2 and is grounded. The source of the PMOS tube Q1 is connected to the input end of the power module U2, the drain of the PMOS tube Q1 is connected to the resistor R5 and the resistor R6 respectively, the resistor R7 is connected in series with the resistor R6, and the gate of the PMOS tube Q1 is connected to the resistor R4.

[0041] It should be noted that Vin+ of the power module U2 is the input terminal, Vout+ is the output terminal, GND is the ground terminal, and OV is the overvoltage protection.

[0042] Furthermore, the built-in auxiliary source circuit also 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, and resistors R3, R1 and R2 are 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.

[0043] Optionally, combined Figure 1-Figure 3 As shown, the built-in auxiliary power circuit is divided into two outputs, one is the controller power supply 5V, and the other is the driver power supply 12V. The external auxiliary power circuit inputs 24V and is converted into controller power supply 5V through the differential mode inductor L1 through the power module U1.

[0044] In an exemplary embodiment, the built-in auxiliary power circuit uses a voltage reference chip ZD1 and an external resistor to set the supply voltage threshold of the controller power supply, and the supply voltage threshold is set to (1+R1 / R2)*Vref, where Vref is a reference voltage determined according to the selected voltage reference chip ZD1.

[0045] In an exemplary embodiment, during the power-on process of the built-in auxiliary power circuit, when the controller power supply reaches the power supply voltage threshold, the voltage reference chip ZD1 is turned on, and the optocoupler U3 of the circuit where the voltage reference chip ZD1 is located is turned on; using the resistor R5 and the resistor R7 to divide the voltage, the POMS tube Q1 is turned on, and the driving power supply is started.

[0046] Specifically, if Figure 3 As shown, the built-in auxiliary power supply circuit uses a voltage reference chip and external resistors to set the controller supply voltage threshold. During power-up, when the controller supply voltage reaches the threshold voltage (1 + R1 / R2) * Vref, the reference voltage Vref varies depending on the selected voltage reference chip. Voltage reference chip ZD1 turns on, and the optocoupler U3 in its circuit turns on, causing R5, R4, and R7 to divide the voltage. Generally, R4 is much smaller than R5 and R7, but in practice, R5 and R7 divide the voltage. At this point, the G-pole (gate) voltage of PMOS transistor Q1 is 24V * R7 / (R5 + R7). The drive signal is applied to PMOS transistor Q1 in the power supply circuit, turning on PMOS transistor Q1, and the power supply module begins operating, outputting a normal 12V output.

[0047] The built-in auxiliary power circuit has a controllable power-up process, enabling the controller to control the driver power supply. A voltage reference chip and external resistors are used to set the threshold voltage for the controller to control the driver power supply. This avoids the controller power supply startup condition and uses a stable control power supply to control the driver power supply, improving the reliability of the power-up process.

[0048] In an exemplary embodiment, during the power-off process of the built-in auxiliary source circuit, the capacitor C5 is formed by multiple large-capacitance capacitors connected in parallel, and the power-off retention time of the controller power supply is much longer than the power-off retention time of the drive power supply, and the drive power supply is always under the control of the controller.

[0049] During power-off of the built-in auxiliary power circuit, the 5V power supply capacitor C5 in this application is actually composed of multiple large-capacity capacitors connected in parallel. This ensures that the 5V controller power supply's power-off hold-up time is significantly longer than that of the 12V driver power supply, ensuring that the driver power supply remains under controller control during power-off. The built-in auxiliary power circuit's power-off process is controllable. By significantly increasing the controller power supply capacitor, the controller power supply's power-off hold-up time is maximized when the input power is lost, improving the reliability of the power-off process.

[0050] Preferably, Figure 4 This is a schematic diagram of the overall power-on and power-off effect of an optional auxiliary source circuit provided in an embodiment of the present application, combined with Figure 1 and Figure 4 It can be seen that after the AC power grid has supplied power for dozens of cycles, at time t0, the auxiliary source board starts to work, and the power-on time lasts for several cycles.

[0051] At time t1, the auxiliary source board output rises to the starting voltage Vth of the 5V power module, and the 5V output begins to rise.

[0052] At time t2, the 5V power module rises to the supply voltage threshold (1+R1 / R2)*Vref, and the 12V power module starts.

[0053] At time t3, the 12V power supply module completes the startup process and outputs 12V steadily.

[0054] At time t4, the relay reaches the starting voltage Vrelay, the relay board is turned on, and the main power module has AC input.

[0055] At time t5, the auxiliary source board completes the startup process and outputs 24V steadily.

[0056] At time t6, the AC power grid is disconnected and the auxiliary power board slowly powers down.

[0057] At time t7, since the capacitor at the back end of the 12V power module is small, it starts to power off a short time after 24V drops to Vref.

[0058] At time t8, the 24V voltage drops to 0.

[0059] At time t9, the 12V voltage drops to 0.

[0060] At time t10, since the large capacitor C5 is connected to the rear end of the 5V power supply module, it is powered off last, and the voltage drops to 0 at time t11.

[0061] During the power-on process, the external auxiliary power board ensures that the main power module receives auxiliary power before the AC input. During the power-off process, it ensures that the auxiliary power can be maintained for a period of time when the AC input is cut off, making the entire main power module power-on and power-off process controllable.

[0062] The above is only an exemplary embodiment of the present disclosure and cannot be used to limit the scope of the present disclosure. That is, any equivalent changes and modifications made according to the teachings of the present disclosure are still within the scope of the present disclosure. After considering the specification and practicing the disclosure herein, those skilled in the art will easily think of the implementation scheme of the present disclosure. This application is intended to cover any variation, use or adaptation of the present disclosure, which follows the general principles of the present disclosure and includes common knowledge or customary technical means in the art that are not recorded in the present disclosure. The description and examples are to be regarded as exemplary only, and the scope and spirit of the present disclosure are defined by the claims.

[0063] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, 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, they should be considered to be within the scope of this specification.

[0064] It will be easily understood by those skilled in the art that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A converter auxiliary source circuit with power-on and power-off timing sequence, characterized in that: It includes 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 and the main power module, and is used to convert the three-phase AC power of the AC power grid into DC power 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 powered on, the controller power supply is powered on first, and when powered off, the controller power supply is powered off later. The drive power supply is always under the control of the controller; 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 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 source circuit passes through the differential mode inductor L1 and is converted into power supply for the controller through the power module U1; The built-in auxiliary power circuit also includes a power module U2, a capacitor C3, a capacitor C4, a PMOS tube 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 end of the power module U2 and is grounded. The source of the PMOS tube Q1 is connected to the input end of the power module U2, and the drain of the PMOS tube Q1 is respectively connected to one end of the resistor R5, one end of the resistor R6, and the input end of the power module U1. One end of the resistor R7 is connected to the other end of the resistor R6 and the optocoupler U3, and the other end of the resistor R7 is grounded. The gate of the PMOS tube Q1 is connected to one end of the resistor R4 and the other end of the resistor R5. The other end of the resistor R4 is connected to the optocoupler U3, and the optocoupler U3 is connected to the output end of the power module U1.

2. The converter auxiliary power circuit with power-on and power-off timing sequence according to claim 1, characterized in that: The built-in auxiliary source circuit also 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, one end of the capacitor C2 is connected to the optocoupler U3, and the other end is connected to the resistor R3, the other end of the diode D1 is connected to the resistor R1, the resistors R3, R1 and R2 are 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, the resistors R3, R1 and R2 are connected in series in sequence and are connected to the output end of the power module U1.

3. The converter auxiliary power circuit with power-on and power-off timing sequence according to claim 2, characterized in that: The built-in auxiliary power circuit uses a voltage reference chip ZD1 and an external resistor to set the supply voltage threshold of the controller power supply. The supply voltage threshold is set to (1+R1 / R2)*Vref, where Vref is a reference voltage determined according to the selected voltage reference chip ZD1.

4. The converter auxiliary power circuit with power-on and power-off timing sequence according to claim 3, characterized in that: During the power-on process of the built-in auxiliary source circuit, when the controller power supply reaches the power supply voltage threshold, the voltage reference chip ZD1 is turned on, and the optocoupler U3 of the circuit where the voltage reference chip ZD1 is located is turned on; the resistors R5 and R7 are used to divide the voltage, and the POMS tube Q1 is turned on to start the driving power supply.

5. The converter auxiliary power circuit with power-on and power-off sequence according to claim 1, characterized in that: During the power-off process of the built-in auxiliary source circuit, the capacitor C5 is formed by multiple large-capacitance capacitors connected in parallel. The power-off holding time of the controller power supply is much longer than the power-off holding time of the drive power supply, and the drive power supply is always under the control of the controller.

6. The converter auxiliary power circuit with power-on and power-off sequence according to claim 1, characterized in that: The external auxiliary source board includes a rectifier circuit, a surge suppression circuit, a DC / DC isolation conversion circuit, and an output filter circuit which are connected in series in sequence.

7. The converter auxiliary power circuit with power-on and power-off timing sequence according to claim 1, characterized in that: After the AC input enters the converter, it includes a first path and a second path. The first path enters the external auxiliary source board, and the second path enters the main power module through the relay board.

8. The converter auxiliary power circuit with power-on and power-off sequence according to claim 1, characterized in that: During the power-on process, the external auxiliary source board 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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