Full-duty-ratio magnetic isolation driving leakage protection circuit for space navigation and test method of full-duty-ratio magnetic isolation driving leakage protection circuit

Abstract

The invention discloses a full-duty-ratio magnetic isolation driving leakage protection circuit for aerospace and a test method, a test circuit structure comprising a driving isolation circuit, a leakage protection circuit, a primary side driving circuit and a secondary side driving circuit is built, a primary side driving signal is preset, when the primary side driving signal is turned off, the leakage protection circuit can quickly discharge the voltage at the two ends of a secondary side capacitor, and the voltage at the two ends of the secondary side capacitor can be quickly discharged. Therefore, the effect of quickly turning off the secondary side driving signal is achieved, and the influence on a main power circuit and rear-end electric equipment due to the fact that the secondary side switching tube is not turned off in time is greatly reduced while the secondary side driving signal is quickly turned off.

Description

Technical Field

[0001] The invention relates to a full-duty-cycle magnetic isolation drive discharge protection circuit for aerospace and a test method, belonging to the technical field of switching power supplies in the aerospace field. Background Art

[0002] With the development of aerospace technology, higher requirements are placed on the size and weight of spacecraft power controllers. Increasing the switching frequency can reduce the weight of the magnetic components of the power controller. Due to the high reliability requirements of spacecraft power controllers, MOS tube failure in the control device is not allowed during abnormal power failure, and the high-voltage and low-voltage systems, power and control circuits must not interfere with each other. Therefore, isolation and high reliability requirements are put forward for MOS tube driving. However, the currently commonly used isolation drive circuit has the disadvantage that when the primary side drive is turned off, the secondary side drive is not turned off in time. At this time, the secondary side switch tube will be in the open state for a long time, the heat consumption of the switch tube increases, and it is easy to damage the switch tube, and even cause failure. Summary of the invention

[0003] The technical problem solved by the present invention is: in view of the problem in the current prior art that the secondary drive signal cannot be turned off in time when the primary drive signal is turned off, a full-duty-cycle magnetic isolation drive discharge protection circuit and a test method for aerospace are proposed.

[0004] The present invention solves the above technical problems by the following technical solutions:

[0005] A full-duty-cycle magnetic isolation drive discharge protection circuit for aerospace use, comprising a drive isolation circuit, a discharge protection circuit, a primary drive circuit and a secondary drive circuit, wherein:

[0006] The primary side driving circuit, the positive terminal and the negative terminal are both connected to one end of the driving isolation circuit, generates and outputs the primary side PWM signal to the driving isolation circuit;

[0007] The secondary side driving circuit has a positive end connected to the other end of the driving isolation circuit and a negative end connected to one end of the discharge protection circuit, receives the secondary side PWM signal sent by the driving isolation circuit, and drives the external electrical equipment together with the primary side driving circuit;

[0008] A driving isolation circuit, one end of which is connected to the primary driving circuit, and the other end of which is connected to the discharge protection circuit and the secondary driving circuit at the same time, receives the primary PWM signal sent by the primary driving circuit, converts it into a secondary PWM signal and sends it to the secondary driving circuit, and stores energy in the process of converting the primary PWM signal;

[0009] The discharge protection circuit has one end connected to the drive isolation circuit and the other end connected to the secondary drive circuit; the primary PWM signal and the secondary PWM signal received by the drive isolation circuit are monitored, and when the primary PWM signal is disconnected, the internal conduction control discharges the energy stored in the drive isolation circuit and reduces the voltage at the connection position between the drive isolation circuit and the secondary drive circuit, and turns off the secondary PWM signal.

[0010] The driving isolation circuit includes a driving transformer T 1 , capacitor C 1 and C 2 ,in:

[0011] Drive transformer T 1 The same-name terminals on both sides are connected to capacitors C 1 And capacitor C 2 , capacitor C 1 Receive the primary PWM signal input by the primary drive circuit and convert it into an AC signal to drive the transformer T 1 After receiving the AC signal, the drive signal is obtained after voltage conversion and sent to the capacitor C 2 , capacitor C 2 The driving signal is converted into a secondary side driving PWM signal and sent to the secondary side driving circuit.

[0012] The positive terminal of the primary drive circuit is connected to the capacitor C 1 One end of the capacitor C 1 The other end is connected to the driving transformer T 1 At the primary side, the negative end of the primary drive circuit is connected to the drive transformer T 1 At the secondary side, drive transformer T 1 One end of the secondary side is also connected to the capacitor C 2 One end of the capacitor C 2 The other end is connected to the positive end of the secondary drive circuit, and the negative end of the secondary drive circuit is connected to the drive transformer T 1 Secondary side end.

[0013] The discharge protection circuit includes a resistor R 1 , resistor R 2 , resistor R 3 、PNP transistor Q 1 、NPN transistor Q 2 、NPN transistor Q 3 、Diode D 1 And capacitor C 3 ,in:

[0014] PNP transistor Q 1 The collector of the drive transformer T 1 Secondary side same name terminal and resistor R 1 Connected, PNP transistor Q1 The emitter and capacitor C 2 , capacitor C 3 And the resistor R 2 Connected, PNP transistor Q 1 The base of the NPN transistor Q 3 The collector of diode D 1 Anode and drive transformer T 1 Secondary side non-same name terminal, NPN transistor Q 2 Emitter, NPN transistor Q 3 The emitter is connected to the diode D 1 Cathode and resistor R 1 And NPN transistor Q 2 The base of NPN transistor Q 2 The base and resistor R 2 , capacitor C 3 Connected, NPN transistor Q 2 The collector and resistor R 3 And NPN transistor Q 3 The base is connected.

[0015] When the primary PWM signal voltage increases, the discharge protection circuit turns on the NPN transistor Q according to the monitoring result. 2 The primary PWM signal passes through the primary PWM signal NPN transistor Q 2 The base of the converted secondary PWM drive signal voltage increases;

[0016] When the primary PWM signal voltage drops to a specified range, the drive transformer T 1 No energy coupling is performed, capacitor C 2 The energy is stored by the NPN transistor Q 2 Release energy.

[0017] When the primary PWM signal is suddenly turned off, the driving transformer T 1 No energy coupling is performed, capacitor C 2 The energy is stored through the resistor R 3 Flows to NPN transistor Q 3 The base of the NPN transistor Q 3 Conducting, collector voltage decreases; NPN transistor Q 3 Collector and PNP transistor Q 1 The base of the PNP transistor Q 1 -be end generates voltage difference, PNP transistor Q 1 conduction, capacitor C 2 The voltage reduction at both ends causes the secondary PWM signal to be turned off synchronously with the primary PWM signal.

[0018] A test method implemented according to an isolated drive discharge protection circuit includes:

[0019] Connect the drive isolation circuit, the discharge protection circuit, the primary drive circuit and the secondary drive circuit to build an isolation drive discharge protection circuit;

[0020] Preset the primary PWM signal frequency and drive duty cycle corresponding to each group of tests required for the circuit test;

[0021] Start circuit testing, set the primary PWM signal with the first set of primary PWM signal frequency and driving duty cycle, output the primary PWM signal from the primary driving circuit to the driving isolation circuit, monitor the voltage of the primary PWM signal and the secondary PWM signal through the discharge protection circuit, and complete the first set of circuit testing;

[0022] Adjust the primary PWM signal frequency and the driving duty cycle, set the primary PWM signal with the second set of primary PWM signal frequency and driving duty cycle, and repeat the circuit test until all sets of primary PWM signal frequencies and driving duty cycles are traversed;

[0023] Record the voltage peaks of the primary PWM signal and the secondary PWM signal under each set of primary PWM signal frequencies and driving duty cycles.

[0024] There are 6 preset circuit test groups, which are circuit tests corresponding to three signal duty cycles under two signal frequencies. The two signal frequencies and three signal duty cycles are selected according to the power usage of external electrical equipment corresponding to the primary drive circuit and the secondary drive circuit.

[0025] The specific method of circuit testing is:

[0026] The primary side driving circuit sets the primary side PWM signal according to the current group primary side PWM signal frequency and driving duty cycle, and outputs the primary side PWM signal to the driving isolation circuit; the driving isolation circuit receives the primary side PWM signal sent by the primary side driving circuit, converts it into a secondary side PWM signal and sends it to the secondary side driving circuit, and stores energy in the primary side PWM signal conversion process;

[0027] The secondary side driving circuit receives the secondary side PWM signal sent by the driving isolation circuit, and drives the external electrical equipment together with the primary side driving circuit.

[0028] The circuit test is implemented by means of a simulation device; after the simulation test is completed, the circuit is actually measured, and the voltage peak values ​​of the signals obtained from the actual circuit measurement and simulation test of all groups are recorded for analysis and comparison.

[0029] The advantages of the present invention compared with the prior art are:

[0030] (1) The present invention provides a full-duty-cycle magnetic isolation drive discharge protection circuit and test method for aerospace use, which overcomes the disadvantage of the traditional isolation drive method that the secondary drive cannot be turned off in time when the primary drive is turned off, and achieves rapid shutdown of the secondary drive signal while greatly reducing the impact of the untimely shutdown of the secondary switch tube on the main power circuit and the back-end electrical equipment;

[0031] (2) When the isolation drive circuit proposed in the present invention works normally, the rising and falling time of the secondary drive signal are consistent with the prior art, and the components selected in the circuit are all passive devices, including resistors, capacitors, and low-power transistors, which have low power consumption and are easy to implement;

[0032] (3) The isolated drive discharge protection circuit proposed in the present invention can adapt to the main power circuit with full duty cycle and high operating frequency, ensure the isolation design of the primary and secondary side drive signals, and improve the reliability of the power supply operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 A block diagram of a circuit for quickly shutting down an isolated secondary-side drive signal provided by the present invention;

[0034] Figure 2 A circuit block diagram of a traditional isolation driving method provided by the present invention;

[0035] Figure 3 A first set of driving simulation waveform diagrams provided by the present invention;

[0036] Figure 4 A second set of driving simulation waveform diagrams provided by the present invention;

[0037] Figure 5 A third group of driving simulation waveform diagrams provided by the present invention;

[0038] Figure 6 A fourth set of driving simulation waveform diagrams provided by the present invention;

[0039] Figure 7 The fifth group of driving simulation waveform diagrams provided by the present invention;

[0040] Figure 8 The sixth group of driving simulation waveform diagrams provided by the present invention;

[0041] Fig. 9 The following are measured waveform diagrams of two driving modes with different duty cycles provided by the present invention. DETAILED DESCRIPTION

[0042] A full-duty-cycle magnetic isolation drive discharge protection circuit and test method for aerospace use, which construct a test circuit structure including a drive isolation circuit, a discharge protection circuit, a primary drive circuit and a secondary drive circuit, and preset a primary drive signal. When the primary drive signal is turned off, the discharge protection circuit can quickly discharge the voltage across the secondary capacitor to achieve the effect of quickly turning off the secondary drive signal. While quickly turning off the secondary drive signal, the impact of the untimely shutdown of the secondary switch tube on the main power circuit and the back-end electrical equipment is greatly reduced.

[0043] The full duty cycle magnetic isolation drive discharge protection circuit for aerospace use includes a drive isolation circuit, a discharge protection circuit, a primary drive circuit and a secondary drive circuit, wherein:

[0044] The primary side driving circuit, the positive terminal and the negative terminal are both connected to one end of the driving isolation circuit, generates and outputs the primary side PWM signal to the driving isolation circuit;

[0045] The secondary side driving circuit has a positive end connected to the other end of the driving isolation circuit and a negative end connected to one end of the discharge protection circuit; it receives the secondary side PWM signal sent by the driving isolation circuit and drives the external electrical equipment together with the primary side driving circuit;

[0046] A driving isolation circuit, one end of which is connected to the primary driving circuit, and the other end of which is connected to the discharge protection circuit and the secondary driving circuit at the same time, receives the primary PWM signal sent by the primary driving circuit, converts it into a secondary PWM signal and sends it to the secondary driving circuit, and stores energy in the process of converting the primary PWM signal;

[0047] The discharge protection circuit has one end connected to the drive isolation circuit and the other end connected to the secondary drive circuit; the primary PWM signal and the secondary PWM signal received by the drive isolation circuit are monitored, and when the primary PWM signal is disconnected, the internal conduction control discharges the energy stored in the drive isolation circuit and reduces the voltage at the connection position between the drive isolation circuit and the secondary drive circuit, and turns off the secondary PWM signal.

[0048] The drive isolation circuit includes a drive transformer T 1 , capacitor C 1 and C 2 ,in:

[0049] Drive transformer T 1 The same-name terminals on both sides are connected to capacitors C 1 And capacitor C 2 , capacitor C 1 Receive the primary PWM signal input by the primary drive circuit and convert it into an AC signal to drive the transformer T 1 After receiving the AC signal, the drive signal is obtained after voltage conversion and sent to the capacitor C 2 , capacitor C 2The driving signal is converted into a secondary side driving PWM signal and sent to the secondary side driving circuit.

[0050] The positive terminal of the primary drive circuit is connected to the capacitor C 1 One end of the capacitor C 1 The other end is connected to the driving transformer T 1 At the primary side, the negative end of the primary drive circuit is connected to the drive transformer T 1 At the secondary side, drive transformer T 1 One end of the secondary side is also connected to the capacitor C 2 One end of the capacitor C 2 The other end is connected to the positive end of the secondary drive circuit, and the negative end of the secondary drive circuit is connected to the drive transformer T 1 Secondary side end.

[0051] The discharge protection circuit includes a resistor R 1 , resistor R 2 , resistor R 3 、PNP transistor Q 1 、NPN transistor Q 2 、NPN transistor Q 3 、Diode D 1 and capacitor C 3 ,in:

[0052] PNP transistor Q 1 The collector of the drive transformer T 1 Secondary side same name terminal and resistor R 1 Connected, PNP transistor Q 1 The emitter and capacitor C 2 , capacitor C 3 And the resistor R 2 Connected, PNP transistor Q 1 The base of the NPN transistor Q 3 The collector of diode D 1 Anode and drive transformer T 1 Secondary side non-same name terminal, NPN transistor Q 2 Emitter, NPN transistor Q 3 The emitter is connected to the diode D 1 Cathode and resistor R 1 And NPN transistor Q 2 The base of NPN transistor Q 2 The base and resistor R 2 , capacitor C 3 Connected, NPN transistor Q 2 The collector and resistor R 3 And NPN transistor Q 3 The base is connected.

[0053] When the primary PWM signal voltage increases, the discharge protection circuit turns on the NPN transistor Q according to the monitoring result. 2 The primary PWM signal passes through the primary PWM signal NPN transistor Q 2 The base of the converted secondary PWM drive signal voltage increases;

[0054] When the primary PWM signal voltage drops to a specified range, the drive transformer T 1 No energy coupling is performed, capacitor C 2 The energy is stored by the NPN transistor Q 2 Release energy.

[0055] When the primary PWM signal is suddenly turned off, the driving transformer T 1 No energy coupling is performed, capacitor C 2 The energy is stored through the resistor R 3 Flows to NPN transistor Q 3 The base of the NPN transistor Q 3 Conducting, collector voltage decreases; NPN transistor Q 3 Collector and PNP transistor Q 1 The base of the PNP transistor Q 1 -be end generates voltage difference, PNP transistor Q 1 conduction, capacitor C 2 The voltage reduction at both ends causes the secondary PWM signal to be turned off synchronously with the primary PWM signal.

[0056] The test method for implementing the isolated drive discharge protection circuit includes the following steps:

[0057] Connect the drive isolation circuit, the discharge protection circuit, the primary drive circuit and the secondary drive circuit to build an isolation drive discharge protection circuit;

[0058] Preset the primary PWM signal frequency and drive duty cycle corresponding to each group of tests required for the circuit test;

[0059] Start circuit testing, set the primary PWM signal with the first set of primary PWM signal frequency and driving duty cycle, output the primary PWM signal from the primary driving circuit to the driving isolation circuit, monitor the voltage of the primary PWM signal and the secondary PWM signal through the discharge protection circuit, and complete the first set of circuit testing;

[0060] Adjust the primary PWM signal frequency and the driving duty cycle, set the primary PWM signal with the second set of primary PWM signal frequency and driving duty cycle, and repeat the circuit test until all sets of primary PWM signal frequencies and driving duty cycles are traversed;

[0061] Record the voltage peaks of the primary PWM signal and the secondary PWM signal under each set of primary PWM signal frequencies and driving duty cycles.

[0062] There are 6 preset circuit test groups, which are circuit tests corresponding to three signal duty cycles under two signal frequencies. The two signal frequencies and three signal duty cycles are selected according to the power usage of external electrical equipment corresponding to the primary drive circuit and the secondary drive circuit.

[0063] The specific method of circuit testing is:

[0064] The primary side driving circuit sets the primary side PWM signal according to the current group primary side PWM signal frequency and driving duty cycle, and outputs the primary side PWM signal to the driving isolation circuit; the driving isolation circuit receives the primary side PWM signal sent by the primary side driving circuit, converts it into a secondary side PWM signal and sends it to the secondary side driving circuit, and stores energy in the primary side PWM signal conversion process;

[0065] The secondary side driving circuit receives the secondary side PWM signal sent by the driving isolation circuit, and drives the external electrical equipment together with the primary side driving circuit.

[0066] The circuit test is implemented through simulation equipment; after the simulation test, the circuit is actually measured, and the voltage peak values ​​of the signals obtained from the actual circuit measurement and simulation test of all groups of circuits are recorded for analysis and comparison.

[0067] The following is further described in conjunction with the accompanying drawings and preferred embodiments of the specification:

[0068] In the current embodiment, the conventional circuit such as Figure 2 As shown, there is no discharge part; aerospace full duty cycle magnetic isolation drive discharge protection circuit, such as Figure 1 As shown;

[0069] The key test circuit is composed of a drive isolation circuit and a discharge protection circuit. When the primary drive signal is turned off, the discharge protection circuit can quickly discharge the voltage across the secondary capacitor to achieve the effect of quickly shutting off the secondary drive signal.

[0070] When the primary side drive PWM signal is working normally, it passes through the DC blocking capacitor C 1 Converted into AC quantity, through the driving transformer T 1 Energy is converted and sent to the secondary side to achieve the effect of primary side controlling isolation and driving the secondary side. 2 The drive signal is converted into a secondary side drive PWM signal to drive the secondary side switch. When the primary side drive PWM signal is high, the secondary side PWM drive signal is high, and the secondary side PWM drive signal is high. 2 , capacitor C 3 Sent to transistor Q 2 Base, Q 2When the primary side drives the PWM signal to low, the primary side no longer has energy coupled to the secondary side through the drive transformer, and the secondary side energy is coupled to the secondary side through Q 2 The resistance R of the collector terminal 3 Fast discharge, the secondary side PWM drive signal is quickly turned off to prepare for the next cycle of PWM signal cycle.

[0071] When the primary side drive PWM signal is suddenly turned off, the drive transformer no longer performs primary and secondary energy exchange, and the secondary side capacitor C 2 The stored energy can only be released through the secondary drive circuit. 2 The energy stored in the resistor R 3 Flow to transistor Q 3 Base, Q 3 is turned on, the collector voltage is low; due to Q 3 Collector and Q 1 The base is connected, Q 1 There is a voltage difference at the -be end, and the transistor Q 1 conduction, quickly turns the capacitor C 2 The voltage at both ends is pulled low and the secondary side driving PWM signal is turned off.

[0072] In this embodiment, the amplitude of the primary drive signal is 12V, the switching frequency is 100kHz to 200kHz, and the duty cycles are designed to be 0.15, 0.45, and 0.75 respectively for simulation.

[0073] like Figure 3 As shown in the figure, the first set of test contents are Saber simulation waveforms of two driving modes when the driving signal frequency is 100kHz and the duty cycle D=0.15; Figure 4 As shown in FIG. 1 , the Saber simulation waveforms of the two driving modes are shown when the driving signal frequency is 100kHz and the duty cycle D=0.45; Figure 5 As shown in FIG. 1 , the Saber simulation waveforms of the two driving modes are shown when the driving signal frequency is 100kHz and the duty cycle D=0.75; Figure 6 As shown in FIG. 1 , the Saber simulation waveforms of the two driving modes are shown when the driving signal frequency is 200kHz and the duty cycle D=0.15; Figure 7 As shown in FIG. 1 , the Saber simulation waveforms of the two driving modes are shown when the driving signal frequency is 200kHz and the duty cycle D=0.45; Figure 8 As shown in FIG. 1 , the Saber simulation waveforms of the two driving modes are shown when the driving signal frequency is 200kHz and the duty cycle D=0.75; Fig. 9 As shown in FIG. 1 , there are two driving modes with different duty cycles. Fig. 9 (a) is the measured comparison diagram of the traditional technology (D = 0.15), Fig. 9 (b) is a comparison diagram of the actual measurement of the embodiment technology (D = 0.15), Fig. 9 (c) is the measured comparison chart of the traditional technology (D = 0.45), Fig. 9 (d) is a comparison diagram of the actual measurement of the embodiment technology (D = 0.45), Fig. 9 (e) is the measured comparison diagram of the traditional technology (D = 0.75), Fig. 9 (f) is a comparison diagram of the actual measurement of the embodiment technology (D = 0.75).

[0074] According to the simulation data statistics in Table 1 and the measured data statistics in Table 2, the larger the duty cycle of the primary drive signal, the larger the amplitude of the secondary drive signal of the existing isolation drive method after the primary drive is turned off, and the slower the shutdown; the isolation drive circuit proposed in the present invention can respond quickly after the primary drive is turned off, and pull down the secondary drive signal to achieve the purpose of quickly turning off the secondary switch tube.

[0075] Table 1

[0076]

[0077] Table 2

[0078]

[0079]

[0080] The circuit design and testing method proposed in the current embodiment overcome the shortcomings of the traditional isolation driving method that the secondary side drive cannot be shut down in time when the primary side drive is shut down, and achieves rapid shutdown of the secondary side drive signal while greatly reducing the impact of the untimely shutdown of the secondary side switch tube on the main power circuit and back-end electrical equipment.

[0081] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

[0082] The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

Claims

1. A full duty cycle magnetic isolation drive discharge protection circuit for aerospace use, characterized by: It includes a drive isolation circuit, a discharge protection circuit, a primary drive circuit and a secondary drive circuit, wherein: The primary side driving circuit, the positive terminal and the negative terminal are both connected to one end of the driving isolation circuit, generates and outputs the primary side PWM signal to the driving isolation circuit; The secondary side driving circuit has a positive end connected to the other end of the driving isolation circuit and a negative end connected to one end of the discharge protection circuit, receives the secondary side PWM signal sent by the driving isolation circuit, and drives the external electrical equipment together with the primary side driving circuit; A driving isolation circuit, one end of which is connected to the primary driving circuit, and the other end of which is connected to the discharge protection circuit and the secondary driving circuit at the same time, receives the primary PWM signal sent by the primary driving circuit, converts it into a secondary PWM signal and sends it to the secondary driving circuit, and stores energy in the process of converting the primary PWM signal; The discharge protection circuit has one end connected to the drive isolation circuit and the other end connected to the secondary drive circuit; the primary PWM signal and the secondary PWM signal received by the drive isolation circuit are monitored, and when the primary PWM signal is disconnected, the internal conduction control discharges the energy stored in the drive isolation circuit and reduces the voltage at the connection position between the drive isolation circuit and the secondary drive circuit, and turns off the secondary PWM signal.

2. The full duty cycle magnetic isolation drive discharge protection circuit for aerospace use according to claim 1, characterized in that: The drive isolation circuit includes a drive transformer T1, capacitors C1 and C2, wherein: The same-named ends on both sides of the driving transformer T1 are connected to capacitors C1 and C2 respectively. Capacitor C1 receives the primary PWM signal input by the primary driving circuit and converts it into an AC signal. The driving transformer T1 receives the AC signal and obtains the driving signal after voltage transformation and sends it to capacitor C2. Capacitor C2 converts the driving signal into a secondary driving PWM signal and sends it to the secondary driving circuit.

3. The full duty cycle magnetic isolation drive discharge protection circuit for aerospace use according to claim 2, characterized in that: The positive end of the primary drive circuit is connected to one end of the capacitor C1, the other end of the capacitor C1 is connected to one end of the primary side of the driving transformer T1, the negative end of the primary drive circuit is connected to one end of the secondary side of the driving transformer T1, the secondary side of the driving transformer T1 is also connected to one end of the capacitor C2, the other end of the capacitor C2 is connected to the positive end of the secondary drive circuit, and the negative end of the secondary drive circuit is also connected to one end of the secondary side of the driving transformer T1.

4. The full duty cycle magnetic isolation drive discharge protection circuit for aerospace use according to claim 2, characterized in that: The discharge protection circuit includes a resistor R1, a resistor R2, a resistor R3, a PNP transistor Q1, an NPN transistor Q2, an NPN transistor Q3, a diode D1 and a capacitor C3, wherein: The collector of the PNP transistor Q1 is connected to the same-name terminal of the secondary side of the driving transformer T1 and the resistor R1, the emitter of the PNP transistor Q1 is connected to the capacitor C2, the capacitor C3 and the resistor R2, the base of the PNP transistor Q1 is connected to the collector of the NPN transistor Q3, the anode of the diode D1 is connected to the non-same-name terminal of the secondary side of the driving transformer T1, the emitter of the NPN transistor Q2, and the emitter of the NPN transistor Q3, the cathode of the diode D1 is connected to the resistor R1 and the base of the NPN transistor Q2, the base of the NPN transistor Q2 is connected to the resistor R2 and the capacitor C3, and the collector of the NPN transistor Q2 is connected to the resistor R3 and the base of the NPN transistor Q3.

5. The full duty cycle magnetic isolation drive discharge protection circuit for aerospace use according to claim 4, characterized in that: When the voltage of the primary PWM signal increases, the discharge protection circuit turns on the NPN transistor Q2 according to the monitoring result, and the primary PWM signal passes through the base of the primary PWM signal NPN transistor Q2, and the converted secondary PWM drive signal voltage increases; When the primary PWM signal voltage drops to a specified range, the driving transformer T1 stops coupling energy, and the energy stored in the capacitor C2 is discharged by the NPN transistor Q2.

6. The full duty cycle magnetic isolation drive discharge protection circuit for aerospace use according to claim 4, characterized in that: When the primary PWM signal is suddenly turned off, the driving transformer T1 does not couple energy, the energy stored in capacitor C2 flows to the base of NPN transistor Q3 through resistor R3, NPN transistor Q3 is turned on, and the collector voltage decreases; the collector of NPN transistor Q3 is connected to the base of PNP transistor Q1, a voltage difference is generated at the-be end of PNP transistor Q1, PNP transistor Q1 is turned on, and the voltage across capacitor C2 decreases, causing the secondary PWM signal to be turned off synchronously with the primary PWM signal.

7. A test method for implementing the isolated drive discharge protection circuit according to claim 6, characterized in that include: Connect the drive isolation circuit, the discharge protection circuit, the primary drive circuit and the secondary drive circuit to build an isolation drive discharge protection circuit; Preset the primary PWM signal frequency and drive duty cycle corresponding to each group of tests required for the circuit test; Start circuit testing, set the primary PWM signal with the first set of primary PWM signal frequency and driving duty cycle, output the primary PWM signal from the primary driving circuit to the driving isolation circuit, monitor the voltage of the primary PWM signal and the secondary PWM signal through the discharge protection circuit, and complete the first set of circuit testing; Adjust the primary PWM signal frequency and the driving duty cycle, set the primary PWM signal with the second set of primary PWM signal frequency and driving duty cycle, and repeat the circuit test until all sets of primary PWM signal frequencies and driving duty cycles are traversed; Record the voltage peaks of the primary PWM signal and the secondary PWM signal under each set of primary PWM signal frequencies and driving duty cycles.

8. The method for testing a full duty cycle magnetic isolation drive discharge protection circuit for aerospace use according to claim 7, characterized in that: There are 6 preset circuit test groups, which are circuit tests corresponding to three signal duty cycles under two signal frequencies. The two signal frequencies and three signal duty cycles are selected according to the power usage of external electrical equipment corresponding to the primary drive circuit and the secondary drive circuit.

9. The method for testing a full duty cycle magnetic isolation drive discharge protection circuit for aerospace use according to claim 7, characterized in that: The specific method of circuit testing is: The primary side driving circuit sets the primary side PWM signal according to the current group primary side PWM signal frequency and driving duty cycle, and outputs the primary side PWM signal to the driving isolation circuit; the driving isolation circuit receives the primary side PWM signal sent by the primary side driving circuit, converts it into a secondary side PWM signal and sends it to the secondary side driving circuit, and stores energy in the primary side PWM signal conversion process; The secondary side driving circuit receives the secondary side PWM signal sent by the driving isolation circuit, and drives the external electrical equipment together with the primary side driving circuit.

10. The method for testing a full duty cycle magnetic isolation drive discharge protection circuit for aerospace use according to claim 7, characterized in that: The circuit test is implemented by means of a simulation device; after the simulation test is completed, the circuit is actually measured, and the voltage peak values ​​of the signals obtained from the actual circuit measurement and simulation test of all groups are recorded for analysis and comparison.

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