Auxiliary power supply system and auxiliary power supply control method

Abstract

The invention discloses an auxiliary power supply system which comprises a main auxiliary power supply and an auxiliary auxiliary power supply, the same output voltage of the main auxiliary power supply and the auxiliary auxiliary power supply is used as the input of respective auxiliary source voltage feedback loops, and the output voltage value of a main auxiliary power supply voltage loop is set as V1; the output voltage value of the auxiliary auxiliary power supply voltage loop is set to be V2, so that V1 is larger than V2, and an additional quick start power supply unit is arranged in the auxiliary auxiliary power supply to supply power to the PWM control unit; when the input power supply of the main and auxiliary power supplies is normal or only the input power supply of the main auxiliary power supply is normal, the main auxiliary power supply works, the auxiliary auxiliary power supply does not work, and the main auxiliary power supply supplies power to the to-be-supplied power supply system; when the input power supply of the auxiliary auxiliary power supply is normal and the input power of the main auxiliary power supply is suddenly down, the main auxiliary power supply does not work, the auxiliary auxiliary power supply is quickly started to work, the power supply system does not power down and works normally, and the auxiliary power supply system is low in cost, low in system loss and good in EMC (Electro Magnetic Compatibility) characteristic.

Description

Technical Field

[0001] The present invention belongs to the technical fields of wind power converters, large-scale grid-side energy storage, industrial and commercial energy storage, household energy storage, frequency converters, UPS, air conditioning drives, servo drives, etc., and specifically relates to an auxiliary power supply system and an auxiliary power supply control method. Background Art

[0002] In industrial applications, it is often required that when the DC side or AC side of the system loses power, the system must be able to communicate normally, that is, the auxiliary power supply in the system must work normally and short-term power failure is not allowed. There are requirements for isolation between the AC side and the DC side in the safety standards and specifications. Usually, the power electronic system is equipped with two sets of auxiliary power supplies for DC side power supply and AC side power supply, which meets the isolation requirements in the safety standards and specifications. When the DC side or the AC side loses power, the two sets of auxiliary power supplies are switched, and the switching completion time is in the order of 20 to 500ms. The system will be temporarily powered off during the switching process. In order to solve the problem of short-term power failure, the traditional technical solution is to set the main output voltage of two sets of auxiliary power supplies for feedback control respectively, and finally use the diode common cathode to take the high power to power the system. When the system is operating normally, the two sets of auxiliary power supplies work at the same time, the system loss is relatively high, the EMC characteristics are poor, and the cost is high for occasions with large auxiliary power sources.

[0003] Therefore, it is necessary to design an auxiliary power supply system and an auxiliary power supply control method, which can achieve the technical effect of only a single power supply working at any time for the system, and the system loss caused by the auxiliary power supply is low; reducing a switching power supply interference source, having good EMC characteristics, and low circuit cost. Summary of the invention

[0004] In view of the defects in the prior art, the purpose of the present invention is to provide an auxiliary power supply system, including a main auxiliary power supply and a secondary auxiliary power supply, wherein the same output voltage of the main auxiliary power supply and the secondary auxiliary power supply is used as the input of their respective auxiliary source voltage feedback loops, wherein the output voltage value of the main auxiliary power supply voltage loop is set to V1, and the output voltage value of the secondary auxiliary power supply voltage loop is set to V2, so that V1>V2, and an additional fast start power supply unit is set in the secondary auxiliary power supply to power the PWM control unit; when the main and secondary auxiliary power supply inputs are powered normally, or only the main auxiliary power supply input is powered normally, the main auxiliary power supply works, the secondary auxiliary power supply does not work, and the main auxiliary power supply is in standby mode. The power supply system supplies power; when the auxiliary auxiliary power input is normally powered and the main auxiliary power input suddenly loses power, the main auxiliary power does not work, and the auxiliary auxiliary power starts working quickly, and the power supply system does not lose power and works normally. This auxiliary power supply system has low cost, low system loss, and good EMC characteristics; it solves the problem of short-term power failure in the prior art. The traditional technical solution is to feedback control the main output voltages of the two sets of auxiliary power supplies respectively, and finally use the diode common cathode to take the high power to power the system. When the system is operating normally, the two sets of auxiliary sources work at the same time, the system loss is relatively high, the EMC characteristics are poor, and for occasions where the auxiliary source power is large, the cost is high. Technical problems.

[0005] Specifically, in the first aspect of the present invention, the technical problem to be solved by the present invention is that in view of the deficiencies in the above-mentioned prior art, the present invention provides an auxiliary power supply system in the first aspect, including a main auxiliary power supply and a secondary auxiliary power supply, and using the same output voltage of the main auxiliary power supply and the secondary auxiliary power supply as the input of their respective auxiliary source voltage feedback loops, wherein the output voltage value of the main auxiliary power supply voltage loop is set to V1, and the output voltage value of the secondary auxiliary power supply voltage loop is set to V2, so that V1>V2, wherein V1 and V2 can both meet the power supply requirements of the system to be powered.

[0006] Preferably, an additional quick-start power supply unit is provided in the secondary auxiliary power supply to supply power to the PWM control unit.

[0007] In a second aspect, the present invention provides an auxiliary power supply system, the auxiliary power supply system comprising a power taking module and a power supply module connected in series;

[0008] The power taking modules are respectively connected to at least one DC power supply device and at least one AC power supply device;

[0009] The power supply module includes a first power supply module and a second power supply module connected in parallel, the first power supply module includes a first diode; the second power supply module includes a second diode;

[0010] The power taking module includes: a main auxiliary power module, the input end of the main auxiliary power module is connected to the DC power supply device, and one output end of the main auxiliary power module is connected to the positive electrode of the first diode; a secondary auxiliary power module, the input end of the secondary auxiliary power module is connected to the AC power supply device, and one output end of the secondary auxiliary power module is connected to the positive electrode of the second diode;

[0011] The power supply module further includes a DC auxiliary source module, the input end of the DC auxiliary source module is respectively connected to the first power supply module and the second power supply module, and the output end of the DC auxiliary source module is connected to the system to be powered;

[0012] The cathode of the first diode and the cathode of the second diode are both connected in series to one end of the same capacitor, and the other end of the capacitor is grounded.

[0013] Preferably, the first power supply module also includes a first resistor R01 and a second resistor R02, and the first diode, the first resistor R01, and the second resistor R02 are connected in series; the second power supply module also includes a third resistor R03 and a fourth resistor R04, and the second diode, the third resistor R03, and the fourth resistor R04 are connected in series.

[0014] Preferably, one input end of the main-auxiliary power module is connected to the positive electrode of the DC power supply device, the other input end of the main-auxiliary power module is connected to the first switch module, the first switch module is connected to the negative electrode of the DC power supply device, the input end of the first PWM control unit is connected between the first resistor R01 and the second resistor R02, and the output end of the first PWM control unit is connected to the first switch module.

[0015] Preferably, the AC power supply device is rectified by a rectifier, one input end of the auxiliary power module is connected to the positive output end of the rectifier, the other input end of the auxiliary power module is connected to the second switch module, the second switch module is connected to the negative output end of the rectifier, the input end of the second PWM control unit is connected between the third resistor R03 and the fourth resistor R04, and the output end of the second PWM control unit is connected to the second switch module.

[0016] Preferably, one input end of the DC auxiliary source module is connected between the first resistor R01 and the second resistor R02, and the other input end is connected between the third resistor R03 and the fourth resistor R04.

[0017] Preferably, another output terminal of the main auxiliary power module is grounded, another output terminal of the auxiliary auxiliary power module is grounded, and the second resistor R02 and the fourth resistor R04 are grounded.

[0018] Preferably, an additional fast-start power supply unit is provided in the secondary auxiliary power module to supply power to the second PWM control unit.

[0019] The present invention provides a method for controlling an auxiliary power supply in a third aspect, the method comprising the following steps:

[0020] (1) a main auxiliary power supply and a secondary auxiliary power supply are provided, wherein the main auxiliary power supply is a DC power supply and the secondary auxiliary power supply is an AC power supply;

[0021] (2) using the same output voltage of the main auxiliary power supply and the auxiliary auxiliary power supply as the input of their respective auxiliary source voltage feedback loops;

[0022] (3) The output voltage value of the main auxiliary power supply voltage loop is set to V1, and the output voltage value of the auxiliary auxiliary power supply voltage loop is set to V2, so that V1>V2, wherein both V1 and V2 can meet the power supply requirements of the system to be powered;

[0023] (4) an additional quick-start power supply unit is provided in the secondary auxiliary power supply to supply power to the PWM control unit;

[0024] (5) When only the main auxiliary power supply input is normal, the main auxiliary power supply works normally and supplies power to the system to be powered;

[0025] When the main auxiliary power supply and the auxiliary auxiliary power supply input power supply are normal, since V1>V2, the auxiliary auxiliary power supply is in a dormant state with no output voltage, and the main auxiliary power supply works normally to supply power to the system to be powered;

[0026] When the auxiliary power supply is normal and the main auxiliary power supply suddenly loses power, the main auxiliary power supply stops working.

[0027] The additional quick-start power supply unit provided in the auxiliary auxiliary power supply switches the auxiliary auxiliary power supply from a dormant state to a normal working state, and the auxiliary auxiliary power supply starts working quickly, and the power supply system does not lose power and works normally.

[0028] Compared with the prior art, the positive effect of the present invention is that the auxiliary power supply system in the present invention adopts auxiliary power supplies with different input power and adopts the same nominal voltage V0 as the feedback voltage point, and sets different output voltage values ​​through different auxiliary power supplies, and the voltage values ​​are all within the normal working range of the whole system, so that only one auxiliary power supply can supply power to the system to be powered at any time. At the same time, an additional fast-start power supply unit is set for the auxiliary power supply other than the highest output voltage value, so that when the DC or AC port of the system loses power, the auxiliary power supply can be switched smoothly, ensuring that the system to be powered will not experience a short-term power outage. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a circuit diagram of an auxiliary power supply system in the prior art;

[0030] Figure 2 A circuit diagram of the auxiliary power supply system in the present invention;

[0031] Figure 3 It is the DC power supply auxiliary power supply part in the auxiliary power supply system of the present invention;

[0032] Figure 4 It is the AC power supply auxiliary power supply part in the auxiliary power supply system of the present invention. DETAILED DESCRIPTION

[0033] Combine the following Figure 1-4 The present invention is further described with specific implementation modes.

[0034] See attached Figure 1 , Figure 1 It is a circuit diagram of an auxiliary power supply system in the prior art, wherein the auxiliary power supply system of the system to be powered is composed of two auxiliary power supplies, each of which has its own feedback and works independently, and supplies power to the system to be powered through a common cathode of a diode; when the auxiliary power supply system operates normally, the two sets of auxiliary power supplies need to work at the same time, the auxiliary power supply system has relatively high losses and poor EMC characteristics, and the cost is high for occasions where the auxiliary source power is large.

[0035] See attached Figure 2 , Figure 2 A circuit diagram of the auxiliary power supply system in the present invention;

[0036] Specifically, embodiment 1: an auxiliary power supply system, comprising a main auxiliary power supply and a secondary auxiliary power supply, wherein the same output voltage of the main auxiliary power supply and the secondary auxiliary power supply is used as the input of their respective auxiliary source voltage feedback loops, wherein the output voltage value of the main auxiliary power supply voltage loop is set to V1, and the output voltage value of the secondary auxiliary power supply voltage loop is set to V2, such that V1>V2, wherein both V1 and V2 can meet the power supply requirements of the system to be powered;

[0037] An additional quick-start power supply unit is provided in the secondary auxiliary power supply to supply power to the PWM control unit.

[0038] Specifically, embodiment 2: an auxiliary power supply system, the auxiliary power supply system comprising a power taking module and a power supply module connected in series;

[0039] The power taking modules are respectively connected to at least one DC power supply device and at least one AC power supply device;

[0040] The power supply module includes a first power supply module and a second power supply module connected in parallel, the first power supply module includes a first diode; the second power supply module includes a second diode;

[0041] The power taking module includes: a main auxiliary power module, the input end of the main auxiliary power module is connected to the DC power supply device, and one output end of the main auxiliary power module is connected to the positive electrode of the first diode; a secondary auxiliary power module, the input end of the secondary auxiliary power module is connected to the AC power supply device, and one output end of the secondary auxiliary power module is connected to the positive electrode of the second diode;

[0042] The power supply module further includes a DC auxiliary source module, the input end of the DC auxiliary source module is respectively connected to the first power supply module and the second power supply module, and the output end of the DC auxiliary source module is connected to the system to be powered;

[0043] The cathode of the first diode and the cathode of the second diode are both connected in series to one end of the same capacitor, and the other end of the capacitor is grounded;

[0044] The first power supply module further includes a first resistor R01 and a second resistor R02, and the first diode, the first resistor R01, and the second resistor R02 are connected in series; the second power supply module further includes a third resistor R03 and a fourth resistor R04, and the second diode, the third resistor R03, and the fourth resistor R04 are connected in series;

[0045] One input end of the main and auxiliary power modules is connected to the positive electrode of the DC power supply device, the other input end of the main and auxiliary power modules is connected to the first switch module, the first switch module is connected to the negative electrode of the DC power supply device, the input end of the first PWM control unit is connected between the first resistor R01 and the second resistor R02, and the output end of the first PWM control unit is connected to the first switch module;

[0046] The AC power supply device is rectified by a rectifier, one input end of the auxiliary power module is connected to the positive output end of the rectifier, the other input end of the auxiliary power module is connected to the second switch module, the second switch module is connected to the negative output end of the rectifier, the input end of the second PWM control unit is connected between the third resistor R03 and the fourth resistor R04, and the output end of the second PWM control unit is connected to the second switch module;

[0047] One input end of the DC auxiliary source module is connected between the first resistor R01 and the second resistor R02, and the other input end is connected between the third resistor R03 and the fourth resistor R04;

[0048] Another output terminal of the main auxiliary power module is grounded, another output terminal of the auxiliary auxiliary power module is grounded, and the second resistor R02 and the fourth resistor R04 are grounded;

[0049] An additional fast-start power supply unit is provided in the secondary auxiliary power module to supply power to the second PWM control unit.

[0050] Specifically, embodiment 3: a method for controlling power supply of an auxiliary power supply, the control method comprising the following steps:

[0051] (1) a main auxiliary power supply and a secondary auxiliary power supply are provided, wherein the main auxiliary power supply is a DC power supply and the secondary auxiliary power supply is an AC power supply;

[0052] (2) using the same output voltage of the main auxiliary power supply and the auxiliary auxiliary power supply as the input of their respective auxiliary source voltage feedback loops;

[0053] (3) The output voltage value of the main auxiliary power supply voltage loop is set to V1, and the output voltage value of the auxiliary auxiliary power supply voltage loop is set to V2, so that V1>V2, wherein both V1 and V2 can meet the power supply requirements of the system to be powered;

[0054] (4) an additional quick-start power supply unit is provided in the secondary auxiliary power supply to supply power to the PWM control unit;

[0055] (5) When only the main auxiliary power supply input is normal, the main auxiliary power supply works normally and supplies power to the system to be powered;

[0056] When the main auxiliary power supply and the auxiliary auxiliary power supply input power supply are normal, since V1>V2, the auxiliary auxiliary power supply is in a dormant state with no output voltage, and the main auxiliary power supply works normally to supply power to the system to be powered;

[0057] When the auxiliary power supply is normal and the main auxiliary power supply suddenly loses power, the main auxiliary power supply stops working.

[0058] The additional quick-start power supply unit provided in the auxiliary auxiliary power supply switches the auxiliary auxiliary power supply from a dormant state to a normal working state, and the auxiliary auxiliary power supply starts working quickly, and the power supply system does not lose power and works normally.

[0059] Specifically, the auxiliary power supply system of the fourth embodiment is composed of a DC auxiliary power supply and an AC auxiliary power supply. Figure 2As shown, the output of the DC auxiliary power supply is set by designing the values ​​of R01 and R02, which is recorded as V1; the output of the AC auxiliary power supply is set by designing the values ​​of R03 and R04, which is recorded as V2. If V1>V2, the DC auxiliary power supply is the main auxiliary power supply of the system, that is, as long as the DC power supply is normal, only the DC auxiliary power supply works normally and supplies power to the system to be powered, and the AC auxiliary power supply is in a dormant state and does not work; if the AC auxiliary power supply does not set an additional fast-start power supply unit to supply power to the AC auxiliary power PWM control unit; the AC side input power supply is normal, and during the process of DC side input power failure, the AC power auxiliary power supply will be temporarily powered off (20ms to 500ms level), and the auxiliary power supply of the system to be powered will be temporarily powered off. In order to achieve that the system to be powered does not lose power when the AC side input power supply is normal and the DC side input is powered off, an additional fast-start power supply unit needs to be set to supply power to the PWM control unit of the AC power auxiliary source.

[0060] This embodiment has two improvements: Figure 2 The parts A and B are marked in the figure.

[0061] like Figure 2 As shown in A: Both the DC input power supply auxiliary power supply and the AC input power supply auxiliary power supply use V0 as the voltage loop feedback voltage point, and set the values ​​of R01, R02 and R03, R04 respectively. Under the premise of meeting the power supply requirements of the system to be powered, the output target voltages of the two auxiliary power supplies are different. Then, due to the natural adjustment of the voltage feedback loop, when the auxiliary power input power supply is normal, only the auxiliary power supply with a higher output feedback voltage setting will work to supply power to the system to be powered. For example, by setting the target output voltage of the DC power supply auxiliary power supply to be higher than the target output voltage of the AC power supply auxiliary power supply, when the auxiliary power supply system is powered by DC and AC normally, only the DC power supply auxiliary power supply will work, and the AC power supply auxiliary power supply will be in a dormant and non-working state.

[0062] When the DC and AC input power supplies are normal, and the output voltage set by R03 and R04 is lower than the output voltage set by R01 and R02, the AC input auxiliary power supply is in a dormant state, and the PWM control unit power supply VCC is always in a UVLO cycle. In this way, when the AC auxiliary source goes from dormant to started, the PWM control unit needs to go through the process of jumping out of the UVLO cycle and emitting waves. The whole time is in the order of 10 to 500ms, which will cause the system to lose power temporarily. In order to solve this problem, it is necessary to Figure 2 As shown in B, an additional D fast-start power supply unit is set to power the PWM control unit, so that the PWM control unit will never enter the UVLO cycle. The AC auxiliary source startup only directly transmits the PWM control unit, which is completed instantly (<1ms), and the system will not be temporarily powered off.

[0063] Figure 2 Improved points A and B are applicable to situations where there are more than or equal to two auxiliary power sources for the system. For A, the common output voltage is used as the voltage loop feedback point. Different output voltages are set on the premise that the power supply range of the system to be powered is met. In this way, only one auxiliary power supply is working at any time. For all auxiliary power supplies except the auxiliary power supply with the highest output voltage setting, an additional fast-start power supply unit shown in part B is added to ensure that the system to be powered does not lose power when the auxiliary power supply is switched.

[0064] Specifically, Example 5: Figure 3 As shown: the DC power supply auxiliary power supply part in the auxiliary power supply system of the present invention; the auxiliary power supply input comes from the battery or the DC bus, and the output is used to supply power to the system to be powered, so as to ensure the normal control and operation of the system to be powered. The auxiliary power supply feedback voltage point is taken from the nominal voltage +12V CTRL, R254 and R709 set +12V CTRL to 11.87V, U22 and the peripheral circuits constitute the PWM control unit, which executes the driving control of the main MOS tube Q26, and finally completes the precise adjustment of +12V_CTRL=11.87V; the PWM control unit starts the power supply circuit composed of R1, R2, R7-R10, C51, and C229, which is a typical general setting. The PWM control unit needs to go through the process of charging and waving to start, and the time is on the order of 10 to 500ms.

[0065] Specifically, Example 6: Figure 4 The figure shows the AC power supply auxiliary power supply part in the auxiliary power supply system of the present invention. The auxiliary power supply input comes from the AC power grid and outputs power to the system to be powered to ensure the normal control and operation of the system to be powered. The auxiliary power supply feedback voltage point is taken from the nominal voltage +12V_CTRL. R296 and R295 set +12V_CTRL to 10.3V, which is lower than Figure 3 Therefore, when the DC input power supply is normal, Figure 4 The auxiliary power supply is in sleep mode, and U25 and its peripheral circuits constitute a PWM control unit. Figure 4 The marked C part is the stable power supply for the PWM control unit; in this way, the auxiliary power supply only needs the PWM control unit to start from sleep, and the startup is completed instantly (<1ms).

[0066] like Figure 4Figure C shows an additional fast-start power supply unit configured for the PWM control unit. The general requirement is to convert the auxiliary power input high voltage into the low voltage (usually 10-25VDC) required by the PWM control unit, with a small current capability requirement (10-30mA) and low output voltage accuracy requirement (<5V), which can be achieved at low cost. The specific design idea is to first roughly reduce the higher input voltage through TVS, and then use a suitable BUCK voltage reduction method to achieve this. Figure 4 Part C is the specific implementation.

[0067] Compared with the prior art, the positive effect of the present invention is that the auxiliary power supply system in the present invention adopts auxiliary power supplies with different input power and adopts the same nominal voltage V0 as the feedback voltage point, and sets different output voltage values ​​through different auxiliary power supplies, and the voltage values ​​are all within the normal working range of the whole system, so that only one auxiliary power supply can supply power to the system to be powered at any time. At the same time, an additional fast-start power supply unit is set for the auxiliary power supply other than the highest output voltage value, so that when the DC or AC port of the system loses power, the auxiliary power supply can be switched smoothly, ensuring that the system to be powered will not experience a short-term power outage.

[0068] In summary, the above only embodies the preferred technical solutions of the present invention. Any changes that may be made to certain parts thereof by those skilled in the art all embody the principles of the present invention and should all fall within the technical scope of the present invention.

Claims

1. An auxiliary power supply system, comprising a main auxiliary power supply and a secondary auxiliary power supply, Features: The same output voltage of the main auxiliary power supply and the auxiliary auxiliary power supply is used as the input of their respective auxiliary source voltage feedback loops, wherein the output voltage value of the main auxiliary power supply voltage loop is set to V1, and the output voltage value of the auxiliary auxiliary power supply voltage loop is set to V2, so that V1>V2, wherein V1 and V2 can both meet the power supply requirements of the system to be powered.

2. An auxiliary power supply system as claimed in claim 1, It is characterized in that An additional quick-start power supply unit is provided in the secondary auxiliary power supply to supply power to the PWM control unit.

3. An auxiliary power supply system, comprising a power supply module and a power supply module connected in series; The power taking modules are respectively connected to at least one DC power supply device and at least one AC power supply device; The power supply module includes a first power supply module and a second power supply module connected in parallel, the first power supply module includes a first diode; the second power supply module includes a second diode; The power taking module include: A main auxiliary power module, wherein the input end of the main auxiliary power module is connected to the DC power supply device, and one output end of the main auxiliary power module is connected to the positive electrode of the first diode; a secondary auxiliary power module, wherein the input end of the secondary auxiliary power module is connected to the AC power supply device, and one output end of the secondary auxiliary power module is connected to the positive electrode of the second diode; characterized in that: The power supply module further includes a DC auxiliary source module, the input end of the DC auxiliary source module is respectively connected to the first power supply module and the second power supply module, and the output end of the DC auxiliary source module is connected to the system to be powered; The cathode of the first diode and the cathode of the second diode are both connected in series to one end of the same capacitor, and the other end of the capacitor is grounded.

4. An auxiliary power supply system as claimed in claim 3, It is characterized in that The first power supply module also includes a first resistor R01 and a second resistor R02, and the first diode, the first resistor R01, and the second resistor R02 are connected in series; the second power supply module also includes a third resistor R03 and a fourth resistor R04, and the second diode, the third resistor R03, and the fourth resistor R04 are connected in series.

5. An auxiliary power supply system as claimed in claim 4, It is characterized in that One input end of the main-auxiliary power module is connected to the positive electrode of the DC power supply device, the other input end of the main-auxiliary power module is connected to the first switch module, the first switch module is connected to the negative electrode of the DC power supply device, the input end of the first PWM control unit is connected between the first resistor R01 and the second resistor R02, and the output end of the first PWM control unit is connected to the first switch module.

6. An auxiliary power supply system as claimed in claim 5, It is characterized in that The AC power supply device is rectified by a rectifier, one input end of the auxiliary power module is connected to the positive output end of the rectifier, the other input end of the auxiliary power module is connected to the second switch module, the second switch module is connected to the negative output end of the rectifier, the input end of the second PWM control unit is connected between the third resistor R03 and the fourth resistor R04, and the output end of the second PWM control unit is connected to the second switch module.

7. An auxiliary power supply system as claimed in claim 6, It is characterized in that One input end of the DC auxiliary source module is connected between the first resistor R01 and the second resistor R02 , and the other input end is connected between the third resistor R03 and the fourth resistor R04 .

8. An auxiliary power supply system as claimed in claim 7, It is characterized in that Another output terminal of the main auxiliary power module is grounded, another output terminal of the auxiliary auxiliary power module is grounded, and the second resistor R02 and the fourth resistor R04 are grounded.

9. An auxiliary power supply system according to any one of claims 3 to 8, It is characterized in that An additional fast-start power supply unit is provided in the secondary auxiliary power module to supply power to the second PWM control unit.

10. An auxiliary power supply control method, applied to an auxiliary power supply system as claimed in any one of claims 3 to 9, Features: The control method comprises the following steps: (1) a main auxiliary power supply and a secondary auxiliary power supply are provided, wherein the main auxiliary power supply is a DC power supply and the secondary auxiliary power supply is an AC power supply; (2) using the same output voltage of the main auxiliary power supply and the auxiliary auxiliary power supply as the input of their respective auxiliary source voltage feedback loops; (3) The output voltage value of the main auxiliary power supply voltage loop is set to V1, and the output voltage value of the auxiliary auxiliary power supply voltage loop is set to V2, so that V1>V2, wherein both V1 and V2 can meet the power supply requirements of the system to be powered; (4) an additional quick-start power supply unit is provided in the secondary auxiliary power supply to supply power to the PWM control unit; (5) When only the main auxiliary power supply input is normal, the main auxiliary power supply works normally and supplies power to the system to be powered; When the main auxiliary power supply and the auxiliary auxiliary power supply input power supply are normal, since V1>V2, the auxiliary auxiliary power supply is in a dormant state with no output voltage, and the main auxiliary power supply works normally to supply power to the system to be powered; When the auxiliary power supply is normal and the main auxiliary power supply suddenly loses power, the main auxiliary power supply stops working. The additional quick-start power supply unit provided in the auxiliary auxiliary power supply switches the auxiliary auxiliary power supply from a dormant state to a normal working state, and the auxiliary auxiliary power supply starts working quickly, and the power supply system does not lose power and works normally.

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