Intrinsically safe phase-shift resonant full-bridge circuit, charging device and system

Abstract

The invention provides an intrinsically safe phase-shift resonant full-bridge circuit, charging equipment and a system. The intrinsically safe phase-shift resonant full-bridge circuit comprises a phase-shift resonant control module, two isolation driving modules, two protection mechanism driving modules, a full-bridge module, a high-frequency transformer, a resonant inductor and an output rectification module. When each target positive pulse signal reaches to enable the second power switch tube to be switched on, a protection mechanism driving module connected with the second power switch tube controls the second power switch tube to be continuously switched on until the target positive pulse signal disappears or to be rapidly switched off according to the actual switch-on voltage drop of the second power switch tube; therefore, when a fault occurs, the second power switch tube is rapidly turned off, so that the intrinsic safety of the phase-shift resonant full-bridge circuit is realized, and the charging safety is ensured.

Description

Technical Field

[0001] The present application relates to the technical field of electric vehicle charging, and in particular to an intrinsically safe phase-shift resonant full-bridge circuit, charging equipment, and system. Background Art

[0002] As a safe, low-pollution, and low-cost new transportation option, electric vehicles have experienced rapid growth in recent years and are now widely used in household, freight, logistics, and passenger transport applications. Currently, electric vehicle charging equipment is typically based on a phase-shifted resonant full-bridge circuit structure to achieve ZVS (zero voltage switching), or soft switching.

[0003] Among them, the phase-shift resonant full-bridge circuit has common-mode conduction, transformer saturation, power tube overcurrent, transformer output overcurrent, short circuit and other faults. Therefore, if the above faults occur during charging, it will lead to device overheating, heat explosion, secondary breakdown, or even permanent damage, thereby causing safety accidents.

[0004] Therefore, in order to improve charging safety, it is necessary to stop charging in time when a fault occurs in the charging line to ensure charging safety. Summary of the Invention

[0005] The present application provides an intrinsically safe phase-shift resonant full-bridge circuit, a charging device, and a system to solve the problem in the prior art that it is difficult to stop charging in time when a charging circuit fails.

[0006] In a first aspect, the present application provides an intrinsically safe phase-shift resonant full-bridge circuit, characterized in that it includes: a phase-shift resonant control module, two isolation drive modules, two protection mechanism drive modules, a full-bridge module, a high-frequency transformer, a resonant inductor, and an output rectifier module; Each bridge arm of the full-bridge module includes a first power switch tube and a second power switch tube, the first power switch tube is connected to a power input module, the second power switch tube is grounded, the high-frequency transformer and the resonant inductor are connected between the first power switch tube and the second switch tube on the other bridge arm, and the power input module is used to provide a first direct current; The phase-shift resonance control module is connected to the two isolation drive modules. The two isolation drive modules, the two bridge arms, and the two protection mechanism drive modules correspond one-to-one. The isolation drive module is connected to the first power switch tube and is connected to the second power switch tube through the protection mechanism drive module. The protection mechanism drive module is also connected between the first power switch tube and the second power switch tube on the same bridge arm. The output rectifier module is connected to the load. The phase-shift resonance control module is configured to output two initial pulse signals with opposite pulses to the two isolation driving modules, and send the two initial pulse signals to the two isolation driving modules respectively; Each of the isolation driving modules is configured to obtain two driving pulse signals with opposite pulses according to the initial pulse signal, transmit one of the driving pulse signals to the first power switch tube, and transmit the other driving pulse signal to the second power switch tube through the corresponding protection mechanism driving module; The protection mechanism driving module is configured to obtain a target positive pulse signal according to the driving pulse signal, and in a normal state, drive the second power switch tube to conduct until the target positive pulse signal reaches a falling edge each time the target positive pulse signal is obtained; in an abnormal state, drive the second power switch tube each time the target positive pulse signal is obtained, and make the actual conduction voltage drop of the second power switch tube greater than a preset voltage drop after the second power switch tube is conducted, and drive the second power switch tube to be turned off within a preset time period according to the actual conduction voltage drop; The full-bridge module, high-frequency transformer, resonant inductor, and output rectifier module are configured to, in the normal state, generate a second DC power from the first DC power, where the second DC power is used to charge a load; and, in the abnormal state, provide an abnormal signal to the second power switch tube, where the abnormal signal is configured to cause the actual conduction voltage drop of the second power switch tube to be greater than a preset voltage drop; The initial pulse signal and the driving pulse signal are both bidirectional pulses.

[0007] In one embodiment, the protection mechanism driving module includes: a positive pulse driving submodule and a pulse-by-pulse driving protection submodule; The pulse-by-pulse driving protection submodule includes: a first capacitor, a first resistor, a third power switch tube, a fourth power switch tube, a fifth power switch tube, a first diode, a second resistor, a third resistor, a second capacitor, a second diode, a fourth resistor, and a fifth resistor; The positive pulse driving submodule is connected to the isolation driving module. The first capacitor and the first resistor are connected in parallel between the control end of the second power switch tube and the control end of the third power switch tube. The control end of the third power switch tube and the control end of the fourth power switch tube are commonly connected to the first end of the fifth power switch tube. The first end of the fourth power switch tube is commonly connected to the control end of the second power switch tube, and the second end is commonly connected to the second end of the second power switch tube, the first end of the fourth power switch tube, and the second end of the fifth power switch tube. The first diode is connected between the first end of the second power switch tube and the second resistor. The second diode, the fourth resistor, and the fifth resistor are connected in series between the first diode and the second end of the fifth power switch tube. The third resistor and the second capacitor are connected in parallel between the first diode and the second end of the fifth power switch tube. The control end of the fifth power switch tube is connected between the fourth resistor and the fifth resistor.

[0008] In one embodiment, the positive pulse driving submodule includes: a sixth resistor, a sixth power switch tube and a third diode; The sixth resistor is connected between one end of the isolation driving module and the first end of the sixth power switch tube, the second end of the sixth power switch tube is connected to the anode of the third diode, and the control end of the sixth power switch tube and the cathode of the third diode are both connected to the other end of the isolation driving module.

[0009] In one embodiment, the third power switch tube, the fifth power switch tube, and the sixth power switch tube are all NMOS tubes; The fourth power switch tube is a PMOS tube.

[0010] In one embodiment, the third diode is a Schottky diode.

[0011] In one embodiment, the isolation driving module includes: a current driver and a pulse transformer, wherein the pulse transformer includes a primary winding and two secondary windings; The input end of the current driver is connected to the phase-shift resonance control module, the output end of the current driver is connected to the primary winding of the pulse transformer, one of the secondary windings of the pulse transformer is connected to the first power switch tube, and the other secondary winding of the pulse transformer is connected to the protection mechanism drive module.

[0012] In one embodiment, the first power switch tube and the second power switch tube are NMOS tubes or IGBTs.

[0013] In a second aspect, the present application provides a DC-DC charging device, comprising: an intrinsically safe phase-shift resonant full-bridge circuit, a power input circuit, and an output circuit as described in any one of the first aspects; The power input circuit is connected to the first power switch tube, and the output circuit is connected to the output rectifier module.

[0014] In a third aspect, the present application provides a charging system, comprising: the DC-DC charging device and the AC-DC charging device as described in the second aspect; The AC-DC charging device is connected to the power input circuit in the DC-DC charging device; The AC-DC charging device is used to obtain AC power and convert the AC power into a first DC power and transmit it to the power input circuit; The DC-DC charging device is configured to receive the first DC power, obtain second DC power based on the first DC power, and charge the load through the output circuit.

[0015] The intrinsically safe phase-shift resonant full-bridge circuit, charging device, and system provided by the present application, when each target positive pulse signal arrives to turn on the second power switch tube, the protection mechanism driving module connected to the second power switch tube controls the second power switch tube to continue to turn on until the target positive pulse signal disappears, or to quickly turn off, according to the actual conduction voltage drop of the second power switch tube, so that when a fault occurs, the second power switch tube can be quickly turned off, thereby achieving the intrinsic safety of the phase-shift resonant full-bridge circuit and ensuring charging safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0017] Figure 1 A structural frame of an intrinsically safe phase-shift resonant full-bridge circuit provided in one embodiment of the present application; Figure 2 A circuit diagram of an intrinsically safe phase-shift resonant full-bridge circuit provided in one embodiment of the present application; Figure 3 A timing diagram provided for an embodiment of the present application; Figure 4 A schematic diagram of the structure of a DC-DC charging device provided in one embodiment of the present application; Figure 5 A schematic diagram of the structure of a charging system provided in one embodiment of the present application. DETAILED DESCRIPTION

[0018] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application are clearly and completely described below. Obviously, the described embodiments are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts also fall within the scope of protection of this application.

[0019] In conventional phase-shift resonant full-bridge circuits, under the control of a phase-shift resonant control module, one of the two power switches in one bridge arm is turned on and the other is turned off at the same time. Correspondingly, one of the two power switches in the other bridge arm is turned on and the other is turned off. Therefore, in normal operation, input DC power is delivered to the load via the two turned-on power switches, the high-frequency transformer, the resonant inductor, and the output rectifier module.

[0020] However, when a short circuit, common-state conduction, transformer saturation, power tube overcurrent, or transformer output overcurrent occurs in the charging circuit, for example, when common-state conduction occurs, two power switches on the same bridge arm are simultaneously turned on, causing the two power switches on the same bridge arm to short to ground, resulting in an instantaneous excessive current, device overheating and damage, or even system paralysis. Another example is when the transformer is saturated, resulting in excessive current in the charging circuit, causing overheating and damage to the device. Therefore, it is necessary to shut down and stop charging in the event of a fault.

[0021] Therefore, the present application provides an intrinsically safe phase-shift resonant full-bridge circuit, charging equipment, and system. For the power switch tube on any bridge arm, under the action of each positive pulse signal, the power switch tube on the bridge arm is turned on, and current flows through it. When in a normal state, the current flowing through is small; when a fault occurs, the current flowing through the power switch tube is large. Therefore, the present application uses the characteristic that when a fault occurs, the current is large after the power switch tube on the bridge arm is turned on, and the actual conduction voltage drop obtained by the large current on the power switch tube is large, so that the actual conduction voltage drop is processed according to the protection mechanism driving module, so that the power switch tube turned on on the bridge arm is quickly turned off and charging is stopped. It is achieved that after the power switch tube on the bridge arm is turned on at each positive pulse signal, if the charging power supply circuit is in a normal state, charging can be carried out normally. If the charging circuit is in a fault state, the phase-shift resonant full-bridge circuit can be turned off in time to stop charging, thereby improving the safety factor during charging.

[0022] Figure 1 The structural frame of the intrinsically safe phase-shift resonant full-bridge circuit provided in one embodiment of the present application is Figure 2This is a circuit diagram of an intrinsically safe phase-shift resonant full-bridge circuit provided in one embodiment of the present application. Figure 1 and Figure 2 As shown, the intrinsically safe phase-shift resonant full-bridge circuit 100 includes: a phase-shift resonant control module 101, two isolation drive modules 102, two protection mechanism drive modules 103, a full-bridge module 104, a high-frequency transformer 105, a resonant inductor 106 and an output rectifier module 107; Each bridge arm of the full-bridge module 104 includes a first power switch tube and a second power switch tube. The first power switch tube is connected to the power input module, and the second power switch tube is grounded. A high-frequency transformer 105 and a resonant inductor 106 are connected between the first power switch tube and the second switch tube on the other bridge arm. The power input module is used to provide a first direct current. The phase-shift resonance control module 101 is connected to two isolation drive modules 102. The two isolation drive modules 102, the two bridge arms, and the two protection mechanism drive modules 103 correspond one-to-one. The isolation drive module 102 is connected to the first power switch tube and is connected to the second power switch tube through the protection mechanism drive module 103. The protection mechanism drive module 103 is also connected between the first power switch tube and the second power switch tube on the same bridge arm. The output rectifier module 107 is connected to the load. The phase-shift resonance control module 101 is configured to output two initial pulse signals with opposite pulses to the two isolation driving modules 102 and send the two initial pulse signals to the two isolation driving modules 102 respectively; Each isolation driving module 102 is used to obtain two driving pulse signals with opposite pulses according to the initial pulse signal, and transmit one of the driving pulse signals to the first power switch tube, and transmit the other driving pulse signal to the second power switch tube through the corresponding protection mechanism driving module 103; The protection mechanism driving module 103 is configured to obtain a positive pulse signal based on the driving pulse signal. In a normal state, after each positive pulse signal is obtained, the second power switch tube is driven to conduct until the positive pulse signal reaches a falling edge. In an abnormal state, after each positive pulse signal is obtained, the second power switch tube is driven to conduct, and after the second power switch tube is turned on, the actual conduction voltage drop of the second power switch tube is greater than a preset voltage drop. The second power switch tube is driven to turn off within a preset time period based on the actual conduction voltage drop. The full-bridge module 104, the high-frequency transformer 105, the resonant inductor 106, and the output rectifier module 107 are configured to generate a second DC power from the first DC power in a normal state, and the second DC power is used to charge the load; in an abnormal state, an abnormal signal is provided to the second power switch tube, and the abnormal signal is used to make the actual conduction voltage drop of the second power switch tube greater than a preset voltage drop; Both the initial pulse signal and the driving pulse signal are bidirectional pulses.

[0023] In this embodiment, in terms of circuit structure, each bridge arm of the full-bridge module 104 includes a first power switch tube and a second power switch tube, wherein, for each bridge arm, the first power switch tube and the second power switch tube are connected between the power input module and the ground. In this way, when common-state conduction occurs, the power input module and the ground are connected between the first power switch tube and the second power switch tube. Therefore, the current on the second power switch tube is relatively large, that is, an abnormal signal is provided to the second power switch tube, resulting in a large actual conduction voltage drop of the second power switch tube.

[0024] In normal state, such as Figure 2 As shown, at the same time point, the first power switch tube, the high-frequency transformer 105, the resonant inductor 106 on one bridge arm and the second power switch tube on the other bridge arm form a loop. When a fault occurs, for example, transformer saturation, power tube overcurrent, transformer output overcurrent, or short circuit, the current on the second power switch tube will also be large, that is, an abnormal signal is provided to the second power switch tube, resulting in a large actual conduction voltage drop of the second power switch tube.

[0025] Therefore, the working principle of the intrinsically safe phase-shift resonant full-bridge circuit is: The phase-shift resonance control module 101 outputs two initial pulse signals with opposite pulses to the two isolation driving modules 102 , wherein the initial pulse signals are bidirectional pulses. That is, when the initial pulse signal corresponding to one of the isolation driving modules 102 is a positive pulse, the initial pulse signal corresponding to the other isolation driving module 102 is a negative pulse.

[0026] Therefore, any isolation driver module 102 obtains two drive pulse signals with opposite pulses based on the initial pulse signal, wherein the drive pulse signals are bidirectional pulses. One of the drive pulse signals is transmitted to the control terminal of the first power switch tube on the corresponding bridge arm, and the other drive pulse signal is converted into a single-phase pulse signal, i.e., a target positive pulse signal, under the action of the protection mechanism driver module 103. That is, when the drive pulse signal is a positive pulse, the target positive pulse signal is a positive pulse, and when the drive pulse signal is a negative pulse, the target positive pulse signal is 0. Therefore, for the first power switch and the second power switch on the same bridge arm, at the same time point, the first power switch is turned off and the second power switch is turned on, or the first power switch is turned on and the second power switch is turned off.

[0027] Therefore, in a normal state, the first direct current provided by the power input module passes through the first power switch on one bridge arm, the primary winding of the high-frequency transformer 105, the resonant inductor 106, and the second power switch on the other bridge arm, and then is grounded. The output rectifier module 107 rectifies the alternating current on the secondary winding of the high-frequency transformer 105 to charge the load. At this time, because the current flowing through the second power switch is relatively small, the actual forward voltage drop of the second power switch is relatively small. The protection mechanism driving module 103 cannot short-circuit the control terminal and the second terminal of the second power switch based on the actual forward voltage drop of the second power switch. Therefore, the second power switch remains in the on state.

[0028] If it is a fault state at this time, for the second power switch tube on the other bridge arm, when its control end receives the target positive pulse signal and turns on, the current flowing through the second power switch tube on the first bridge arm is large. Therefore, at this time, the actual conduction voltage drop of the second power switch tube is large. The protection mechanism driving module 103 short-circuits the control end and the second end of the second power switch tube according to the actual conduction voltage drop of the second power switch tube, so that the second power switch tube is quickly turned off and charging stops.

[0029] When the second power switch tube is turned on by the next target positive pulse signal, if the fault is not resolved, the second power switch tube will still be quickly turned off, and this cycle will be repeated. Therefore, when each target positive pulse signal arrives to turn on the second power switch tube, the protection mechanism driving module 103 connected to the second power switch tube controls the second power switch tube to continue to be turned on until the target positive pulse signal disappears, or to be quickly turned off according to the actual conduction voltage drop of the second power switch tube, so that when a fault occurs, the second power switch tube can be quickly turned off, thereby achieving the intrinsic safety of the phase-shift resonant full-bridge circuit and ensuring charging safety.

[0030] Optional, such as Figure 2 As shown, the protection mechanism driving module 103 includes: a positive pulse driving submodule and a pulse-by-pulse driving protection submodule; The pulse-by-pulse drive protection submodule includes: a first capacitor C1, a first resistor R1, a third power switch tube M3, a fourth power switch tube M4, a fifth power switch tube M5, a first diode D1, a second resistor R2, a third resistor R3, a second capacitor C2, a second diode D2, a fourth resistor R4, and a fifth resistor R5; The positive pulse driving submodule is connected to the isolation driving module 102. The first capacitor C1 and the first resistor R1 are connected in parallel between the control end of the second power switch tube and the control end of the third power switch tube M3. The control end of the third power switch tube M3, the control end of the fourth power switch tube M4, and the first end of the fifth power switch tube are commonly connected. The first end of the fourth power switch tube M4 is commonly connected with the control end of the second power switch tube, and the second end is commonly connected with the second end of the second power switch tube, the first end of the fourth power switch tube M4, and the second end of the fifth power switch tube. The first diode D1 is connected between the first end of the second power switch tube and the second resistor R2. The second diode D2, the fourth resistor R4, and the fifth resistor R5 are connected in series between the first diode D1 and the second end of the fifth power switch tube M5. The third resistor R3 and the second capacitor C2 are connected in parallel between the first diode D1 and the second end of the fifth power switch tube. The control end of the fifth power switch tube is connected between the fourth resistor R4 and the fifth resistor R5.

[0031] In this embodiment, the first power switch tube, the second power switch tube, the third power switch tube M3, and the fifth power switch tube M5 are all NMOS tubes. Figure 2 As shown, NMOS transistors M11, M12, M21, and M22 constitute a full-bridge module 104. NMOS transistors M11 and M12 are located on the same bridge arm, serving as the first and second power switches, respectively. NMOS transistors M21 and M22 are located on the same bridge arm, serving as the first and second power switches, respectively. Optionally, the first and second power switches may be IGBTs.

[0032] The fourth power switch tube M4 is a PMOS tube.

[0033] Reference Figure 2 and Figure 3 , the working principle of the intrinsically safe phase-shift resonant full-bridge circuit is explained: The driving process of the power switch tube on the bridge arm is explained by taking the driving of the NMOS tube M12 as an example: for Figure 2 The isolation driving module 102 located above receives the initial pulse signal of the bidirectional pulse sent by the phase-shift resonance control module 101, and outputs a driving pulse signal in phase with the initial pulse signal through A+ and A-, which is recorded as the first driving pulse signal; and inputs a driving pulse signal in phase with the initial pulse signal through B+ and B-, which is recorded as the second driving pulse signal.

[0034] Among them, when the first driving pulse signal is a negative pulse, the NMOS tube M11 is turned off. At this time, Figure 3 Medium B+ —B-corresponding timing diagram shows that the second driving pulse signal is a positive pulse, so if Figure 3 Medium B1 — It can be seen from the timing diagram corresponding to B2 that under the action of the positive pulse driving submodule, a positive pulse is obtained according to the second driving pulse signal, that is, the control end of the NMOS tube M12 is a positive pulse, and the NMOS tube M12 is turned on.

[0035] When the first driving pulse signal is a positive pulse, the NMOS tube M11 is turned on. Figure 3 Medium B+ — As can be seen from the timing diagram corresponding to B-, the second driving pulse signal switches from a positive pulse to a negative pulse. Under the action of the positive pulse driving submodule, that is, when the second driving pulse signal switches from a positive pulse to a negative pulse, the sixth power switch tube M6 is turned on. Figure 3 Medium B1 — It can be seen from the timing diagram corresponding to B2 that under the action of the positive pulse driving submodule, a 0 pulse is obtained according to the second driving pulse signal, that is, the control end of the NMOS tube M12 is a 0 pulse, and the NMOS tube M12 is turned off.

[0036] The above process converts the bidirectional second driving pulse signal into a unidirectional target positive pulse signal.

[0037] When the charging circuit is in normal state, when B1 — When B2 is a positive pulse, that is, when the target positive pulse signal arrives, the voltage at the control terminal B5 of the third power switch tube M3 increases rapidly under the action of the first capacitor C1 and the first resistor R1, that is, Figure 3 B5 — The timing diagram corresponding to B2 is a high level, the third power switch tube M3 is turned on, and the fourth power switch tube M4 is turned off.

[0038] After the third power switch tube M3 is turned on, Figure 2 It can be seen that the voltage at B6 is equal to the voltage at B2. At this time, B1 — B2 is a positive pulse, so the NMOS tube M12 is turned on.

[0039] After the NMOS transistor M12 is turned on, the 440V first DC power is transmitted through the NMOS transistor M22 to the primary winding of the high-frequency transformer 105. After passing through the secondary winding of the high-frequency transformer 105, it is rectified by the output rectifier module 107 to output the second DC power. At this point, the 440V first DC power passes through the NMOS transistor M22, the primary winding of the high-frequency transformer 105, the resonant inductor 106, and the NMOS transistor M12 before being grounded. At this point, the current flowing through the NMOS transistor M12 is relatively low. Therefore, the actual conduction voltage drop of the NMOS transistor M12 is less than 2.5V (VL). That is, the voltage at B8 is less than 2.5V.

[0040] The voltage at B8 is clamped by the first diode D1, so that the voltage at B7 is less than 3.2V. After being divided by the second resistor R2 and the third resistor R3, the second capacitor C2 is charged. The voltage at B3 (which is consistent with the voltage at B7) is divided by the second diode D2, the fourth resistor R4, and the fifth resistor R5 to obtain the voltage at the control terminal B4 of the fifth power switch tube M5, corresponding to Figure 3 The timing diagram corresponding to B4_B2 is Figure 3 It can be seen that the voltage of B4_B2 is less than 2V, and the fifth power switch tube M5 is turned off, thereby ensuring that the NMOS tube M12 is B1 — The target positive pulse signal of B2 controls conduction.

[0041] When B1 — When the target positive pulse signal of B2 switches to a falling edge, the voltage at the control terminal B5 of the third power switch tube M3 drops, causing the third power switch tube M3 to be turned off and the fourth power switch tube M4 to be turned on. Figure 3 As can be seen from the timing diagram of B1_B6, the voltage drop between B1 and B6 quickly becomes 0, causing the NMOS tube M12 to be quickly turned off, thereby improving the turn-off speed of the NMOS tube M12.

[0042] When the charging circuit is faulty and the target positive pulse signal corresponding to B1-B2 arrives, the NMOS transistor M12 is turned on, as can be seen from the above process. At this time, due to the fault in the charging circuit, the current flowing through NMOS transistor M12 is large. Therefore, the actual conduction voltage drop of NMOS transistor M12 is greater than 2.5V (VL), that is, the voltage at B8 is greater than 2.5V.

[0043] The voltage at B8 is clamped by the first diode D1, so that the voltage at B7 is greater than 3.2V, and is divided by the second resistor R2 and the third resistor R3 to charge the second capacitor C2. The voltage at B3 is divided by the second diode D2, the fourth resistor R4, and the fifth resistor R5 to obtain the voltage at the control terminal B4 of the fifth power switch tube M5, corresponding to Figure 3 The timing diagram corresponding to B4_B2 is Figure 3 It can be seen that the voltage of B4_B2 is greater than 2V and remains greater than 2V within a target positive pulse signal, so that the fifth power switch tube M5 is turned on. Figure 3 From the timing diagram corresponding to B5_B2, it can be seen that the voltage drop between B5 and B2 is 0.

[0044] Therefore, the third power switch tube M3 is turned off, and the fourth power switch tube M4 is turned on. Figure 3As can be seen from the timing diagram of B1_B6, the voltage drop between B1 and B6 quickly becomes 0, so that the NMOS tube M12 is quickly turned off under the target positive pulse signal, thereby achieving fault detection for each target positive pulse signal. When a fault occurs, the NMOS tube M12 is quickly turned off, ensuring the intrinsic safety of the phase-shift resonant full-bridge circuit.

[0045] Optional, such as Figure 2 As shown, the positive pulse driving submodule includes: a sixth resistor R6, a sixth power switch tube M6 and a third diode D3; The sixth resistor R6 is connected between one end of the isolation driving module 102 and the first end of the sixth power switch tube M6. The second end of the sixth power switch tube M6 is connected to the anode of the third diode D3. The control end of the sixth power switch tube M6 and the cathode of the third diode D3 are both connected to the other end of the isolation driving module 102.

[0046] In this embodiment, the sixth power switch tube M6 is an NMOS tube, and the third diode D3 can be a Schottky diode. Then, when the first driving pulse signal is a negative pulse, the NMOS tube M11 is turned off. At this time, Figure 3 Medium B+ — B-corresponding timing diagram shows that the second driving pulse signal is a positive pulse, the third diode D3 is turned on, the conduction voltage drop is 0.25V, and the sixth power switch tube M6 is turned off. Then, if Figure 3 Medium B1 — The timing diagram corresponding to B2 shows that B1 — B2 is a positive pulse.

[0047] like Figure 3 Medium B+ — As can be seen from the timing diagram corresponding to B-, when the second driving pulse signal switches from a positive pulse to a negative pulse, the third diode D3 is reversely turned off, and the reverse voltage of the third diode D3 is applied to the sixth power switch tube M6, and is a positive voltage, so that the sixth power switch tube M6 is quickly turned on. Then, if Figure 3 Medium B1 — The timing diagram corresponding to B2 shows that B1 — B2 is 0 pulse, which realizes B+ — B- has the function of quickly converting the bidirectional driving pulse signal output into a single-phase target positive pulse signal.

[0048] Optional, such as Figure 2 As shown, the isolated driving module 102 includes: a current driver U and a pulse transformer T, the pulse transformer T includes a primary winding and two secondary windings; The input end of the current driver U is connected to the phase shift resonance control module 101, the output end of the current driver U is connected to the primary winding of the pulse transformer T, one of the secondary windings of the pulse transformer T is connected to the first power switch tube, and the other secondary winding of the pulse transformer T is connected to the protection mechanism driving module 103.

[0049] In this embodiment, the structures of the two isolation driving modules 102 are the same, and any one of the isolation driving modules 102 is taken as an example for description: The phase shift resonance control module 101 includes, for example, a control chip such as UCC28950, UCC28951, or NCP1399, wherein the core algorithm inside the control module 101 is used to implement phase shift control logic and soft switch management, and reference may be made to the prior art for details.

[0050] The phase-shift resonance control module 101 outputs two initial pulse signals with opposite pulses, one of which is sent to the current driver U of one isolation driving module 102 , and the other is sent to the current driver U of the other isolation driving module 102 .

[0051] For any isolated driver module 102, after receiving the initial pulse signal, the current driver U amplifies the initial pulse signal and transmits it to the primary winding of the pulse transformer T. According to the operating principle of the pulse transformer T, after the pulse transformer T passes the amplified initial pulse signal through the two secondary windings, a bidirectional drive pulse signal is obtained on each secondary winding, wherein the drive pulse signals obtained on the two secondary windings are in opposite directions. That is, when the drive pulse signals corresponding to the output terminals A+ and A- of the secondary winding are positive pulses, the drive pulse signals corresponding to the output terminals B+ and B- are negative pulses.

[0052] Among them, for two isolated driving modules 102, when the driving pulse signal corresponding to the output terminals A+ and A- of one of the secondary windings corresponding to one isolated driving module 102 is a positive pulse, and the driving pulse signal corresponding to B+ and B- is a negative pulse, the driving pulse signal corresponding to the output terminals C+ and C- of one of the secondary windings corresponding to the other isolated driving module 102 is a negative pulse, and the driving pulse signal corresponding to D+ and D- is a positive pulse.

[0053] Figure 4 This is a schematic diagram of the structure of a DC-DC charging device provided in one embodiment of the present application. Figure 4 As shown, the DC-DC charging device 1000 includes: an intrinsically safe phase-shift resonant full-bridge circuit 100 , a power input circuit 200 and an output circuit 300 .

[0054] The power input circuit 200 is connected to the first power switch tube, and the output circuit 300 is connected to the output rectifier module 107 .

[0055] In this embodiment, the structure and working principle of the intrinsically safe phase-shift resonant full-bridge circuit 100 may refer to any of the above embodiments and will not be described in detail here.

[0056] The power input circuit 200 is used to provide a first direct current, for example, a 440V direct current.

[0057] Figure 5 This is a schematic diagram of the structure of a charging system provided in one embodiment of the present application. Figure 5 As shown, the charging system includes: a DC-DC charging device 1000 and an AC-DC charging device 2000; The AC-DC charging device 2000 is connected to the power input circuit 200 in the DC-DC charging device 1000; AC-DC charging device 2000, used to obtain AC power and convert the AC power into a first DC power and transmit it to the power input circuit 200; The DC-DC charging device 1000 is configured to receive a first DC power, obtain a second DC power based on the first DC power, and charge a load through an output circuit 300 .

[0058] It should be noted that the AC-DC charging device 2000 may be a charging device having multiple household power connection terminals.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some or all of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. An intrinsically safe phase-shift resonant full-bridge circuit, characterized in that: include: Phase-shift resonant control module, two isolation drive modules, two protection mechanism drive modules, full-bridge module, high-frequency transformer, resonant inductor and output rectifier module; Each bridge arm of the full-bridge module includes a first power switch tube and a second power switch tube, the first power switch tube is connected to a power input module, the second power switch tube is grounded, the high-frequency transformer and the resonant inductor are connected between the first power switch tube and the second switch tube on the other bridge arm, and the power input module is used to provide a first direct current; The phase-shift resonance control module is connected to the two isolation drive modules. The two isolation drive modules, the two bridge arms, and the two protection mechanism drive modules correspond one-to-one. The isolation drive module is connected to the first power switch tube and is connected to the second power switch tube through the protection mechanism drive module. The protection mechanism drive module is also connected between the first power switch tube and the second power switch tube on the same bridge arm. The output rectifier module is connected to the load. The phase-shift resonance control module is configured to output two initial pulse signals with opposite pulses to the two isolation driving modules, and send the two initial pulse signals to the two isolation driving modules respectively; Each of the isolation driving modules is configured to obtain two driving pulse signals with opposite pulses according to the initial pulse signal, transmit one of the driving pulse signals to the first power switch tube, and transmit the other driving pulse signal to the second power switch tube through the corresponding protection mechanism driving module; The protection mechanism driving module is configured to obtain a target positive pulse signal according to the driving pulse signal, and in a normal state, drive the second power switch tube to conduct until the target positive pulse signal reaches a falling edge each time the target positive pulse signal is obtained; in an abnormal state, drive the second power switch tube each time the target positive pulse signal is obtained, and make the actual conduction voltage drop of the second power switch tube greater than a preset voltage drop after the second power switch tube is conducted, and drive the second power switch tube to be turned off within a preset time period according to the actual conduction voltage drop; The full-bridge module, high-frequency transformer, resonant inductor, and output rectifier module are configured to, in the normal state, generate a second DC power from the first DC power, where the second DC power is used to charge a load; and, in the abnormal state, provide an abnormal signal to the second power switch tube, where the abnormal signal is configured to cause the actual conduction voltage drop of the second power switch tube to be greater than a preset voltage drop; The initial pulse signal and the driving pulse signal are both bidirectional pulses.

2. The intrinsically safe phase-shift resonant full-bridge circuit according to claim 1, characterized in that: The protection mechanism driving module includes: a positive pulse driving submodule and a pulse-by-pulse driving protection submodule; The pulse-by-pulse driving protection submodule includes: a first capacitor, a first resistor, a third power switch tube, a fourth power switch tube, a fifth power switch tube, a first diode, a second resistor, a third resistor, a second capacitor, a second diode, a fourth resistor, and a fifth resistor; The positive pulse driving submodule is connected to the isolation driving module. The first capacitor and the first resistor are connected in parallel between the control end of the second power switch tube and the control end of the third power switch tube. The control end of the third power switch tube and the control end of the fourth power switch tube are commonly connected to the first end of the fifth power switch tube. The first end of the fourth power switch tube is commonly connected to the control end of the second power switch tube, and the second end is commonly connected to the second end of the second power switch tube, the first end of the fourth power switch tube, and the second end of the fifth power switch tube. The first diode is connected between the first end of the second power switch tube and the second resistor. The second diode, the fourth resistor, and the fifth resistor are connected in series between the first diode and the second end of the fifth power switch tube. The third resistor and the second capacitor are connected in parallel between the first diode and the second end of the fifth power switch tube. The control end of the fifth power switch tube is connected between the fourth resistor and the fifth resistor.

3. The intrinsically safe phase-shift resonant full-bridge circuit according to claim 2, characterized in that: The positive pulse driving submodule includes: a sixth resistor, a sixth power switch tube and a third diode; The sixth resistor is connected between one end of the isolation driving module and the first end of the sixth power switch tube, the second end of the sixth power switch tube is connected to the anode of the third diode, and the control end of the sixth power switch tube and the cathode of the third diode are both connected to the other end of the isolation driving module.

4. The intrinsically safe phase-shift resonant full-bridge circuit according to claim 3, characterized in that: The third power switch tube, the fifth power switch tube and the sixth power switch tube are all NMOS tubes; The fourth power switch tube is a PMOS tube.

5. The intrinsically safe phase-shift resonant full-bridge circuit according to claim 3, characterized in that: The third diode is a Schottky diode.

6. The intrinsically safe phase-shift resonant full-bridge circuit according to any one of claims 1 to 5, characterized in that: The isolated driving module includes: a current driver and a pulse transformer, wherein the pulse transformer includes a primary winding and two secondary windings; The input end of the current driver is connected to the phase-shift resonance control module, the output end of the current driver is connected to the primary winding of the pulse transformer, one of the secondary windings of the pulse transformer is connected to the first power switch tube, and the other secondary winding of the pulse transformer is connected to the protection mechanism drive module.

7. The intrinsically safe phase-shift resonant full-bridge circuit according to any one of claims 1 to 5, characterized in that: The first power switch tube and the second power switch tube are NMOS tubes or IGBTs.

8. A DC-DC charging device, characterized in that: include: The intrinsically safe phase-shift resonant full-bridge circuit, power input circuit, and output circuit according to any one of claims 1 to 7; The power input circuit is connected to the first power switch tube, and the output circuit is connected to the output rectifier module.

9. A charging system, characterized in that: include: The DC-DC charging device and AC-DC charging device according to claim 8; The AC-DC charging device is connected to the power input circuit in the DC-DC charging device; The AC-DC charging device is used to obtain AC power and convert the AC power into a first DC power and transmit it to the power input circuit; The DC-DC charging device is configured to receive the first DC power, obtain second DC power based on the first DC power, and charge the load through the output circuit.

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