A locomotive high voltage input power release and reverse connection prevention circuit

Abstract

The present application relates to a kind of locomotive high voltage input power release and anti-reverse connection circuit, it includes input filter circuit, input detection circuit, high pipe control circuit, low pipe control circuit, positive and negative terminal switch tube TR12, TR1.Voltage input is rectified and filtered, comparator is compared in detection circuit, give normal or abnormal signal, feedback to the drive chip in two control circuits, to control the on-off of switch tube respectively correspondingly.When input overvoltage, comparator output abnormal signal to two control circuits to disconnect switch tube TR12, TR1;When input reverse, comparator provides signal to low pipe capacitor isolation drive chip to make switch tube TR1 cut off, realize reverse cut-off and prevent reverse connection.The circuit control is simple and fast, circuit structure responds fast, stable and reliable, low cost, can be widely used in high voltage product dc transmission ac system and other fields, its loss and heat quantity are lower, suitable for long distance, large capacity power transmission.

Description

Technical Field

[0001] The present invention relates to the technical field of high-voltage direct current power supplies, and in particular to a locomotive high-voltage input power supply release and reverse connection prevention circuit. Background Art

[0002] With the updating and iteration of semiconductor devices, the application voltage and power density of products are getting higher and higher. All fields are changing with each passing day, the requirements for products are getting higher and higher, and the reliable and safe application of products is becoming more and more urgent.

[0003] High-voltage DC transmission eliminates the inductive and capacitive reactance issues of AC systems. Furthermore, high-voltage DC transmits less current at the same power level, resulting in lower losses and heat generation, making it suitable for long-distance, high-capacity power transmission. This also allows for higher power applications. DC transmission eliminates the phase synchronization issues of AC systems, thus avoiding stability risks caused by frequency differences in cross-regional grid interconnections. In the event of a single-pole ground fault on a DC line, the rectifier and inverter stations can quickly lock out the thyristors, shutting off the current. This reduces fault recovery time compared to AC systems and allows for more rapid protection. Summary of the Invention

[0004] In view of this, a locomotive high-voltage input power release and reverse connection prevention circuit is provided, which has simple and fast circuit control, fast circuit structure response, stability and reliability, and low cost.

[0005] A locomotive high-voltage input power supply release and reverse connection prevention circuit includes an input filter circuit, an input detection circuit, a high-voltage control circuit, a low-voltage control circuit, a positive terminal switch tube TR12, and a negative terminal switch tube TR1;

[0006] The input detection circuit is connected to the input voltage through the diode D5. The input detection circuit includes at least one access resistor, a filter circuit, and a comparator U3-B. One end of the access resistor is connected to the diode D5 and the other end is connected to the first end of the filter circuit. The second end of the filter circuit is connected to the inverting input end of the comparator U3-B.

[0007] The high-voltage control circuit includes a high-voltage capacitor isolation driver chip U47 and a voltage stabilization circuit. The high-voltage capacitor isolation driver chip U47 is connected to the non-inverting input terminal of the comparator U3-B. The high-voltage capacitor isolation driver chip U47 receives a comparison signal from the comparator U3-B to control the on / off of the positive terminal switch TR12 based on the comparison signal. The voltage stabilization circuit is connected to the input voltage and provides a stable voltage to the high-voltage capacitor isolation driver chip U47. The cathode of the voltage stabilization circuit is connected to a first auxiliary power supply, and the anode is connected to the positive output terminal VBUS+ of the entire circuit.

[0008] The low-voltage transistor control circuit includes a low-voltage transistor capacitance isolation driver chip U2, which is connected to the non-inverting input terminal of the comparator U3-B. The low-voltage transistor capacitance isolation driver chip U2 receives a comparison signal from the comparator U3-B to control the on / off of the negative terminal switch TR1 based on the comparison signal.

[0009] The source of the positive terminal switch transistor TR12 is connected to the positive output terminal VBUS+ of the entire circuit, the drain is connected to the positive terminal of the input power supply, and the gate is connected to the high-voltage capacitor isolation driver chip U47; the source of the negative terminal switch transistor TR1 is grounded, the drain is connected to the negative terminal of the input power supply, and the gate is connected to the low-voltage capacitor isolation driver chip U2;

[0010] When the input is overvoltage, the comparator U3-B outputs an abnormal comparison signal to the high-voltage capacitor isolation driver chip U47 and the low-voltage capacitor isolation driver chip U2 to disconnect the switch tubes TR12 and TR1 respectively; when the input is reverse, the comparator U3-B provides a signal to the low-voltage capacitor isolation driver chip U2 to cut off the negative terminal switch tube TR1, thereby achieving reverse cutoff and preventing reverse connection.

[0011] Furthermore, the above-mentioned locomotive high-voltage input power release and anti-reverse connection circuit also includes an auxiliary power supply circuit, which includes a primary coil circuit, a first secondary coil circuit and a second secondary coil circuit. The primary coil circuit includes a switch tube Q9 and a primary coil T1-A. The gate of the switch tube Q9 is connected to a separate drive controller. One end of the primary coil T1-A is connected to the positive output terminal VBUS+ to import the output voltage of the positive output terminal VBUS+; the first secondary coil circuit and the second secondary coil circuit respectively have secondary coils to respond to the primary coil to obtain voltage, and after filtering, power is supplied to the high-voltage capacitor isolation driver chip U47 and the low-voltage capacitor isolation driver chip U2.

[0012] In some specific embodiments, the first secondary coil circuit includes a first secondary coil T1-B, a diode D12 and a capacitor C13. The first secondary coil T1-B and one end of the anode of the diode D12 are connected in series and then connected in parallel with the capacitor C13. The negative electrode of the diode D12 is connected to the high-voltage capacitor isolation driver chip U47 to serve as the first auxiliary power supply. The other ends of the first secondary coil T1-B and the capacitor C13 are connected to the positive output terminal VBUS+; the second secondary coil circuit includes a second secondary coil T1-C, a diode D13 and a capacitor C14. The second secondary coil T1-C and one end of the anode of the diode D13 are connected in series and then connected in parallel with the capacitor C14. The negative electrode of the diode D13 is connected to the low-voltage capacitor isolation driver chip U2. The other ends of the second secondary coil T1-C and the capacitor C14 are grounded.

[0013] Furthermore, the voltage stabilizing circuit includes a voltage stabilizing diode U1 and a first current limiting resistor, wherein the anode and cathode of the voltage stabilizing diode U1 are respectively connected to two pins of the high-voltage capacitor isolation driver chip U47; the voltage stabilizing diode U1 is also connected in parallel with a capacitor C11, and the anode of the voltage stabilizing diode U1 is connected to the positive output terminal VBUS+ of the entire circuit; the first auxiliary power supply is connected to the cathode of the voltage stabilizing diode U1 through a diode D8.

[0014] Preferably, the non-inverting input terminal of the comparator U3-B is connected to a pin of the low-tube capacitor isolation driver chip U2, and a second auxiliary power supply is connected to the pin of the low-tube capacitor isolation driver chip U2 through a forward diode D9. The second auxiliary power supply is also grounded through a capacitor C12. One end of the capacitor C12 shares a reference supply voltage with the comparator U3-B and the other end is grounded. Another pin of the low-tube capacitor isolation driver chip U2 is connected to one end of the grounded capacitor C12.

[0015] Preferably, the access resistor includes a first seventy-nine resistor R179, a second zero-three resistor R203, and a second fifty-three resistor R253 connected in sequence, the filter circuit includes a second zero-six resistor R206 and a capacitor C164, and the filter circuit is connected between the second fifty-three resistor R253 and the inverting input terminal of the comparator.

[0016] Preferably, the high-voltage capacitor isolation driver chip U47 and / or the low-voltage capacitor isolation driver chip U2 are each connected to a comparison signal via an amplifier circuit.

[0017] Furthermore, the amplification circuit includes a transistor and a second current-limiting resistor, the first end of the second current-limiting resistor is connected to the comparison signal, the second end is connected to the base of the transistor, the emitter of the transistor is grounded, and the collector of the transistor is connected to the high-voltage capacitor isolation driver chip U47 or the low-voltage capacitor isolation driver chip U2; the second end of the second current-limiting resistor is also grounded through a resistor, the positive pole of a diode is connected between the resistor and the second current-limiting resistor, and the negative pole of the diode is connected to the first end of the second current-limiting resistor.

[0018] Furthermore, the high-voltage capacitor isolation driver chip U47 and / or the low-voltage capacitor isolation driver chip U2 are respectively connected to and control the switch tube TR12 or TR1 through a switching circuit. The switching circuit includes a voltage stabilizing unit, and the voltage stabilizing unit includes a voltage stabilizing current limiting resistor, a voltage stabilizing filter capacitor, and a switching voltage stabilizing tube. The switching voltage stabilizing current limiting resistor is connected to the reverse input end of the switching voltage stabilizing tube, the voltage stabilizing filter capacitor and the switching voltage stabilizing tube are connected in parallel, and the forward output end of the switching voltage stabilizing tube is connected to the gate of the switching tube TR1 or TR12 and is connected to the source of the switching tube through a resistor; the voltage stabilizing current limiting resistor is connected in parallel with a feedback resistor and a feedback diode, one end of the feedback resistor is connected to the reverse input end of the switching voltage stabilizing tube and the other end is connected to the positive electrode of the feedback diode, and the negative electrode of the voltage stabilizing current limiting resistor and the feedback diode are connected in parallel to a pin of the high-voltage capacitor isolation driver chip U47 and / or the low-voltage capacitor isolation driver chip U2.

[0019] Preferably, the input filter circuit is an LC filter circuit, which includes two capacitors connected in parallel between the positive and negative terminals of the input power supply or between the positive and ground terminals of the input power supply, and a positive terminal inductor LX1-B and a negative terminal inductor LX1-A connected between the two capacitors. A back-end capacitor C10 is connected in parallel between the positive output terminal VBUS+ and the ground terminal; the comparator U3-B provides a reference voltage through a reference power supply circuit, and the reference power supply circuit includes a power supply stabilizing unit, which is connected to the input power supply and then connected to the reverse Zener diode U4 through two current limiting resistors R17 and R56. The cathode of the Zener diode U4 is connected to the resistor R56 and to the non-inverting input terminal of the comparator U3-B to provide a reference voltage; the anode of the Zener diode U4 is grounded, and a filter capacitor C40 is connected in parallel, and two resistors R188 and R199 are also connected in parallel; the reference power supply circuit also supplies power to the high-voltage capacitor isolation driver chip U47 and the low-voltage capacitor isolation driver chip U2 at the same time.

[0020] In the locomotive's high-voltage input power release and reverse polarity protection circuit, a comparator circuit within the input detection circuit compares the input voltage to determine if it's overvoltage. If the input voltage is overvoltage, an abnormality signal is generated, and the chip disconnects the switching transistors, preventing damage to subsequent circuitry. Under normal input conditions, comparator U3-B generates a normal signal and sends it to the chip, turning on switching transistors TR1 and TR12 for proper operation. Simultaneously, the voltage regulator circuit provides a stable voltage to the chip. In the event of a reverse polarity input, TR1 is reverse-biased and cutoff, and TR12 lacks the startup voltage to activate. Therefore, the input detection circuit fails to detect a normal input voltage signal, preventing the entire input power current from circulating, effectively protecting subsequent circuitry. The entire circuit features simple and fast control, a fast response structure, and stable operation. It addresses safety concerns associated with reverse polarity and high-voltage input, providing increased safety, reliability, and cost-effectiveness. It is widely applicable to high-voltage products, such as DC transmission systems without AC, and offers reduced losses and heat generation, making it suitable for long-distance, high-capacity power transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a structural block diagram of a locomotive high-voltage input power release and reverse connection prevention circuit provided by an embodiment of the present invention.

[0022] Figure 2 It is a schematic diagram of the main circuit structure of a locomotive high-voltage input power release and reverse connection prevention circuit according to an embodiment of the present invention.

[0023] Figure 3 1 is a schematic structural diagram of an input detection circuit and a comparator thereof in an embodiment of the present invention.

[0024] Figure 4 Schematic diagram of the circuit structure of the high-voltage capacitor isolation driver chip in an embodiment of the present invention.

[0025] Figure 5 Schematic diagram of the circuit structure of the low-capacitance isolation driver chip in an embodiment of the present invention.

[0026] Figure 6 2 is a schematic structural diagram of a reference power supply circuit in an embodiment of the present invention.

[0027] Figure 7 It is a schematic diagram of the auxiliary power supply circuit structure provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0029] See also Figures 1 to 7 , showing the main circuit structure and component circuit of a locomotive high-voltage input power release and anti-reverse connection circuit provided by an embodiment of the present invention. The overall circuit includes an input filter circuit, an input detection circuit, a high-voltage control circuit, a low-voltage control circuit, a positive terminal switch tube TR12 and a negative terminal switch tube TR1; the input detection circuit is connected to the input voltage through a diode D5, and the input detection circuit includes at least one access resistor, a filter circuit, and a comparator U3-B. One end of the access resistor is connected to the diode D5, that is, connected Figure 2 The voltage access terminal HV in the filter circuit is connected; the other end is connected to the first end of the filter circuit, and the second end of the filter circuit is connected to the inverting input terminal of the comparator U3-B; the high-voltage control circuit includes a high-voltage capacitor isolation driver chip U47 and a voltage stabilization circuit. The high-voltage capacitor isolation driver chip U47 is connected to the non-inverting input terminal of the comparator U3-B, and the high-voltage capacitor isolation driver chip U47 receives the comparison signal of the comparator U3-B to control the on and off of the positive terminal switch tube TR12 based on the comparison signal. The voltage stabilization circuit is connected to the input voltage and provides a stable voltage to the high-voltage capacitor isolation driver chip U47. The cathode of the voltage stabilization circuit is connected to a first auxiliary power supply, and the anode is connected to the positive output terminal VBUS+ of the entire circuit; the low-voltage control circuit includes a low-voltage capacitor isolation driver chip U2, and the low-voltage capacitor isolation driver chip U2 is connected to the non-inverting input terminal of the comparator U3-B. The low-voltage capacitor isolation driver chip U2 receives the comparison signal of the comparator U3-B to control the on and off of the negative terminal switch tube TR1 based on the comparison signal. Therefore, the high-voltage capacitor isolation driver chip U47 and the low-voltage capacitor isolation driver chip U2 both receive the comparison signal from the comparator U3-B, that is, the comparison signal from Figure 3 The signal output terminal PG of the comparator U3-B shown corresponds to Figure 4 and Figure 5 The access terminal PG in the circuit. The source of the positive-side switching transistor TR12 is connected to the positive output terminal VBUS+ of the entire circuit, the drain is connected to the positive terminal of the input power supply, and the gate is connected to the high-side capacitor isolation driver chip U47. The source of the negative-side switching transistor TR1 is grounded, the drain is connected to the negative terminal of the input power supply, and the gate is connected to the low-side capacitor isolation driver chip U2. When the input is overvoltage, the comparator U3-B outputs an abnormal comparison signal to the high-side capacitor isolation driver chip U47 and the low-side capacitor isolation driver chip U2 to disconnect the switching transistors TR12 and TR1, respectively. When the input is reversed, the comparator U3-B provides a signal to the low-side capacitor isolation driver chip U2 to disconnect the negative-side switching transistor TR1, achieving reverse cutoff and preventing reverse connection. Diode D5 acts as an input rectifier.

[0030] Furthermore, the locomotive high-voltage input power release and reverse connection protection circuit also includes an auxiliary power supply circuit, comprising a primary coil circuit, a first secondary coil circuit, and a second secondary coil circuit. The primary coil circuit includes a switch Q9 and a primary coil T1-A. The gate of the switch Q9 is connected to a separate drive controller. One end of the primary coil T1-A is connected to the positive output terminal VBUS+ to receive the output voltage of the positive output terminal VBUS+. The first and second secondary coil circuits each have a secondary coil that responds to the primary coil to obtain a voltage. After filtering, the voltage is supplied to the high-voltage capacitor isolation driver chip U47 and the low-voltage capacitor isolation driver chip U2. The auxiliary power supply circuit discharges when the input is overvoltage and is powered by two auxiliary power supplies when the input is normal. The auxiliary power supply primarily powers the high-voltage capacitor isolation driver chip U47 and the low-voltage capacitor isolation driver chip U2.

[0031] Specifically, if Figure 7 As shown, the auxiliary power supply circuit is a transformer structure, wherein one end of the primary coil T1-A is connected to the positive output terminal of the input power supply, providing initial power, and the other end is connected to the drain of the switching tube Q9, and the source of the switching tube Q9 is grounded. The first secondary coil circuit includes a first secondary coil T1-B, a diode D12, and a capacitor C13. The first secondary coil T1-B and the anode end of the diode D12 are connected in series, then connected in parallel with the capacitor C13. The cathode of the diode D12 is connected to the powered circuit. The other ends of the first secondary coil T1-B and the capacitor C13 are each connected to the positive output terminal VBUS+. The second secondary coil circuit has a similar structure to the first secondary coil circuit. Specifically, the second secondary coil circuit includes a second secondary coil T1-C, a diode D13, and a capacitor C14. The second secondary coil T1-C and the anode end of the diode D13 are connected in series, then connected in parallel with the capacitor C14. The cathode of the diode D13 is connected to the powered circuit. The other ends of the second secondary coil T1-C and the capacitor C14 are each grounded.

[0032] When the input is normal, the high-capacitance isolation driver chip U47 and the low-capacitance isolation driver chip U2, based on the comparison signal, respectively turn on the switch tubes TR12 and TR1, and the positive output terminal VBUS+ provides power normally. At this time, the DRIVER in the auxiliary power supply turns on the switch tube Q9 as needed, and the positive output terminal VBUS+ simultaneously starts the power supply to the auxiliary power supply circuit. In this way, when the DRIVER controls the opening of the switch tube Q9, power is provided to AUX and AUX1 through the primary coil T1-A and the two secondary coils T1-B and T1-C. In this way, AUX, the first auxiliary power supply, is connected to the voltage stabilization circuit, and AUX1, the second auxiliary power supply, directly supplies power to U2. When the input is overvoltage, the high-capacitance isolation driver chip U47 and the low-capacitance isolation driver chip U2 respectively control the switch tubes TR12 and TR1 to turn off. At this time, the AUX auxiliary power supply provides power to the positive output terminal VBUS+ until the two auxiliary sources are discharged.

[0033] like Figure 4 As shown, in a specific embodiment, the voltage stabilizing circuit connected to the high-voltage capacitor isolation driver chip U47 includes a voltage stabilizing diode U1 and a first current limiting resistor. The anode and cathode of the voltage stabilizing diode U1 are respectively connected to two pins of the high-voltage capacitor isolation driver chip U47; the voltage stabilizing diode U1 is also connected in parallel with a capacitor C11, and the anode of the voltage stabilizing diode U1 is connected to the positive output terminal VBUS+ of the entire circuit; a first auxiliary power supply such as AUX is connected to the positive electrode of the voltage stabilizing diode U1 through a diode D8. Specifically, the cathode of the voltage stabilizing diode U1, i.e., the reflection input terminal, is connected to the power input, i.e. Figure 2 and Figure 4 The voltage access terminal HV shown is connected. There are two first current limiting resistors, namely R23 and R19. Since it is a high voltage input, the two resistors R23 and R19 also play a role in voltage division. Furthermore, the voltage zener diode U1 also has an intermediate node, and a third current limiting resistor R20 is connected in parallel between the intermediate node of the voltage zener diode U1 and the cathode, and a fourth current limiting resistor R21 is connected in parallel between the intermediate node of the voltage zener diode U1 and the anode. The first auxiliary power supply AUX is preferably connected to the cathode of the voltage zener diode U1 through a forward diode D8. The anode and cathode of the voltage zener diode U1 are respectively connected to two pins of the high-voltage capacitor isolation driver chip U47 to provide a stable voltage to the chip.

[0034] like Figure 5As shown, in another specific embodiment, the non-inverting input terminal of the comparator U3-B is connected to a pin of the low-tube capacitor isolation driver chip U2, and a second auxiliary power supply AUX1 is connected to the pin of the low-tube capacitor isolation driver chip U2 through a forward diode D9. The second auxiliary power supply AUX1 is also grounded through a capacitor C12. One end of the capacitor C12 shares a reference supply voltage with the comparator U3-B and the other end is grounded. Another pin of the low-tube capacitor isolation driver chip U2 is connected to one grounded end of the capacitor C12 to power the chip.

[0035] Preferably, in the input detection circuit, the access resistor includes a first seventy-nine resistor R179, a second zero-three resistor R203, and a second fifty-three resistor R253 connected in sequence, the filter circuit includes a second zero-six resistor R206 and a capacitor C164, and the filter circuit is connected between the second fifty-three resistor R253 and the inverting input terminal of the comparator. In addition, as shown in the figure, the same-direction input terminal of the comparator U3-B is connected to the power supply terminal through the second fifty-one resistor R251, and the same-direction input terminal of the comparator U3-B is also grounded through a second fifty-four resistor R254 and connected to the comparison signal output terminal through a second fifty-five resistor R255. The power supply circuit of the comparator U3-B is mainly Figure 6 The reference power supply circuit is shown. Figure 6 The reference power supply circuit shown has a second part of the comparator U3-C, which matches the comparator U3-B and is part of the entire comparison module. Figure 6 As shown, the reference power supply circuit includes a power supply stabilizing unit, which is connected to a DC+ DC power supply as an input power supply, that is, Figure 2 and Figure 6 The voltage input terminal HV is connected, and then connected to the reverse voltage stabilizing diode U4 through two current limiting resistors R17 and R56. The cathode of the voltage stabilizing diode U4 is connected to the resistor R56 and the power supply terminal of the comparator U3-B, that is, Figure 6The VDD terminal in the circuit is connected to the non-inverting input of comparator U3-B as the reference voltage. The anode of Zener diode U4 is grounded, and a filter capacitor C40 is connected in parallel. Two resistors, R188 and R199, are also connected in parallel. The two resistors R188 and R199 are connected in series, with the node between them connected to the middle reference electrode of Zener diode U4. Therefore, regardless of whether the DC power supply input is normal voltage, high voltage, or overvoltage, the reference power supply circuit can provide a stable reference voltage to the comparator. R17, R56, R188, and R189 form a voltage divider network. A high-voltage signal is introduced from the HV terminal. After multi-stage resistor division, a lower voltage signal proportional to HV is obtained at the junction of R188 and R189. One input terminal, VCC, of ​​the second part of comparator U3-C is connected to the supply voltage, such as that from U40 or C40. The other terminal, GND, of the second part of comparator U3-C is grounded. At the same time, the reference voltage is also supplied to the high-voltage capacitor isolation driver chip U47 and the low-voltage capacitor isolation driver chip U2. Figure 4 and 5 As shown, Figure 6 The output voltage is connected to the voltage output terminal VDD. Figure 4 The voltage access terminal VDD and the voltage access terminal VDD of the high-voltage capacitor isolation driver chip U47 are shown as follows: Figure 5 The voltage access terminal VDD of the low-transistor capacitor isolation driver chip U2 is shown, and the stable voltage is also provided to another pin of the low-transistor capacitor isolation driver chip U2, which is also connected to the second auxiliary power supply AUX1. In addition, when the normal voltage input and the output of the entire circuit are normal, the comparator U3-B outputs a normal signal, and the reference voltage is also directly provided to the high-transistor capacitor isolation driver chip U47 and the low-transistor capacitor isolation driver chip U2, for example. Figure 4 and 5 As shown, the reference supply voltage VDD is also supplied to the high-voltage capacitor isolation driver chip U47 through a resistor R549. At the same time, a capacitor C151 is connected in parallel between the VDD input terminal and the resistor R549 for filtering, and the capacitor C151 is grounded. Similarly, the reference supply voltage VDD is also supplied to the low-voltage capacitor isolation driver chip U2 through a resistor R24. At the same time, a capacitor C9 is connected in parallel between the VDD input terminal and the resistor R549 for filtering, and the capacitor C9 is grounded.

[0036] Furthermore, the high-voltage capacitor isolation driver chip U47 and / or the low-voltage capacitor isolation driver chip U2 are respectively connected to the comparison signal through an amplifier circuit. Preferably, the amplifier circuit includes a transistor and a second current-limiting resistor, the first end of the second current-limiting resistor is connected to the comparison signal, the second end is connected to the base of the transistor, the emitter of the transistor is grounded, and the collector of the transistor is connected to the high-voltage capacitor isolation driver chip U47 or the low-voltage capacitor isolation driver chip U2; the second end of the second current-limiting resistor is also grounded through a resistor, the positive pole of a diode is connected between the resistor and the second current-limiting resistor, and the negative pole of the diode is connected to the first end of the second current-limiting resistor. Figure 4 As shown, specifically, in terms of high-voltage driving, the amplifier circuit includes a transistor Q90 and a second current-limiting resistor R550. The first end of the second current-limiting resistor R550 is connected to the comparison signal, and the second end is connected to the base of the transistor Q90. The emitter of the transistor Q90 is grounded, and the collector of the transistor Q90 is connected to the high-voltage capacitor isolation driver chip U47. The second end of the second current-limiting resistor R550 is also grounded through a fifth resistor R551, or the base of the transistor Q90 is grounded through the fifth resistor R551, and the input voltage of the transistor Q90 is always positive. The positive pole of a diode D156 is connected between the fifth resistor R551 and the second current-limiting resistor R550, and the negative pole of the diode D156 is connected to the first end of the second current-limiting resistor R550. As shown Figure 5 As shown, in terms of low-power tube driving, the amplifier circuit includes a transistor Q8 and a second current limiting resistor. The second current limiting resistor in the low-power tube is Figure 5 Resistor R30 is connected to the comparison signal at its first end and to the base of transistor Q8 at its second end. The emitter of transistor Q8 is grounded, and the collector of transistor Q8 is connected to the high-voltage capacitor isolation driver chip U47. The second end of resistor R30 is also connected to ground via a second resistor R25, or in other words, the base of transistor Q8 is grounded via the second resistor R25. The anode of a diode D11 is connected between the second resistor R25 and resistor R30, and the cathode of diode D11 is connected to the first end of resistor R30.

[0037] Preferably, the high-capacitance isolation driver chip U47 and / or the low-capacitance isolation driver chip U2 are respectively connected to and control the switch tube TR12 or TR1 through a switch circuit. Figure 2 and 4 As shown, one pin of the high-voltage capacitor isolation driver chip U47 is connected to the high-voltage control terminal, that is, Figure 2 and 4 The high-level control terminal PUT_H shown is connected; Figure 2 and 5As shown, one pin of the low-voltage transistor capacitor isolation driver chip U2 is connected to the low-voltage transistor control terminal, that is, Figure 2 and 5 The low-side control terminal PUT_L is connected to the switch as shown. This switching circuit helps to quickly supply power and quickly turn off the switch. Figure 1 As shown, the switching circuit includes a voltage stabilizing unit, which includes a voltage stabilizing current limiting resistor, a voltage stabilizing filter capacitor, and a switching voltage stabilizing tube. The voltage stabilizing current limiting resistor is connected to the reverse input end of the switching voltage stabilizing tube. The specific connection circuit distinguishes between high-voltage and low-voltage tubes entering the circuit part. Specifically, as Figure 1 As shown, in the switching circuit connected to the switching tube TR12, the voltage stabilizing unit includes a high-voltage stabilizing current limiting resistor R88, a high-voltage stabilizing filter capacitor C57, and a high-voltage stabilizing tube D86. The high-voltage stabilizing current limiting resistor R88 is connected to the reverse input terminal of the high-voltage stabilizing tube D86. The high-voltage stabilizing filter capacitor C57 and the high-voltage stabilizing tube D86 are connected in parallel. The forward output terminal of the high-voltage stabilizing tube D86 is connected to the gate of the switching tube TR12 and is connected to the source of the switching tube TR12 through a resistor R148. The high-voltage stabilizing current limiting resistor R88 is connected in parallel with a feedback resistor R81 and a feedback diode D99. One end of the feedback resistor R81 is connected to the reverse input terminal of the high-voltage stabilizing tube D86 and the other end is connected to the positive electrode of the feedback diode D99. The negative electrodes of the high-voltage stabilizing current limiting resistor R88 and the feedback diode D99 are connected in parallel to a pin of the high-voltage capacitor isolation driver chip U47. The switch circuit structure of the low-tube capacitance isolation driver chip U2 connected to the switch tube TR1 is basically the same, as shown in the figure, and will not be repeated in this embodiment.

[0038] In addition, preferably, the input filter circuit is an LC filter circuit, comprising two capacitors C7 and C6 connected in parallel between the positive and negative terminals of the input power supply or between the positive and ground terminals of the input power supply, and a positive terminal inductor LX1-B and a negative terminal inductor LX1-A connected between the two capacitors. A back-end capacitor C10 is connected in parallel between the positive output terminal VBUS+ and the ground terminal. The input detection circuit is connected to the line from the LC filter circuit to the switch transistor TR12, that is, a diode D5 is connected between the positive terminal inductor LX1-B and the drain of the switch transistor TR12, and then to the filter circuit and comparator circuit.

[0039] As can be seen, in the locomotive's high-voltage input power supply release and reverse polarity protection circuit, the comparator circuit in the input detection circuit compares the input voltage to determine if it is overvoltage. When the input voltage is overvoltage, an abnormality signal is generated. High-voltage capacitor isolation driver chip U47 and low-voltage capacitor isolation driver chip U2, respectively, disconnect switches TR12 and TR1, preventing damage to subsequent circuits and thus effectively protecting them. Under normal input conditions, comparator U3-B generates a normal signal and sends it to high-voltage capacitor isolation driver chip U47 and low-voltage capacitor isolation driver chip U2, turning on switches TR1 and TR12, ensuring normal operation of the power supply. Simultaneously, the voltage regulator circuit provides a stable voltage to high-voltage capacitor isolation driver chip U47 and low-voltage capacitor isolation driver chip U2. When the input is reverse polarity, comparator U3-B generates an abnormality signal, causing switch TR1 to be reverse biased and cut off. Simultaneously, TR12 is also turned off, preventing the startup voltage from being generated. Consequently, the input detection circuit fails to detect a normal input voltage signal, preventing the entire input power current from forming a loop, effectively protecting subsequent circuits and preventing reverse polarity.

[0040] It should be noted that the present invention is not limited to the above-mentioned embodiments. Based on the creative spirit of the present invention, those skilled in the art can also make other changes. These changes made based on the creative spirit of the present invention should be included in the scope of protection required by the present invention.

Claims

1. A locomotive high-voltage input power release and reverse connection protection circuit, comprising an input filter circuit and an input detection circuit, characterized in that: It also includes a high-voltage control circuit, a low-voltage control circuit, a positive terminal switch tube TR12, and a negative terminal switch tube TR1; The input detection circuit is connected to the input voltage through the diode D5. The input detection circuit includes at least one access resistor, a filter circuit, and a comparator U3-B. One end of the access resistor is connected to the cathode of the diode D5, and the other end of the access resistor is connected to the first end of the filter circuit. The anode of the diode D5 is connected to the input filter circuit; the second end of the filter circuit is connected to the inverting input end of the comparator U3-B. The high-voltage control circuit includes a high-voltage capacitor isolation driver chip U47 and a voltage stabilization circuit. The high-voltage capacitor isolation driver chip U47 is connected to the non-inverting input terminal of the comparator U3-B. The high-voltage capacitor isolation driver chip U47 receives a comparison signal from the comparator U3-B to control the on / off of the positive terminal switch TR12 based on the comparison signal. The voltage stabilization circuit is connected to the input voltage and provides a stable voltage to the high-voltage capacitor isolation driver chip U47. The cathode of the voltage stabilization circuit is connected to a first auxiliary power supply, and the anode is connected to the positive output terminal VBUS+ of the entire circuit. The low-voltage transistor control circuit includes a low-voltage transistor capacitance isolation driver chip U2, which is connected to the non-inverting input terminal of the comparator U3-B. The low-voltage transistor capacitance isolation driver chip U2 receives a comparison signal from the comparator U3-B to control the on / off of the negative terminal switch TR1 based on the comparison signal. The source of the positive terminal switch transistor TR12 is connected to the positive output terminal VBUS+ of the entire circuit, the drain is connected to the positive terminal of the input power supply, and the gate is connected to the high-voltage capacitor isolation driver chip U47; the source of the negative terminal switch transistor TR1 is grounded, the drain is connected to the negative terminal of the input power supply, and the gate is connected to the low-voltage capacitor isolation driver chip U2; When the input is overvoltage, the comparator U3-B outputs an abnormal comparison signal to the high-voltage capacitor isolation driver chip U47 and the low-voltage capacitor isolation driver chip U2 to disconnect the switch tubes TR12 and TR1; when the input is reverse, the comparator U3-B provides a signal to the low-voltage capacitor isolation driver chip U2 to cut off the negative terminal switch tube TR1, thereby achieving reverse cutoff and preventing reverse connection.

2. The locomotive high-voltage input power release and reverse connection prevention circuit according to claim 1, characterized in that: It also includes an auxiliary power supply circuit, which includes a primary coil circuit, a first secondary coil circuit and a second secondary coil circuit. The primary coil circuit includes a switch tube Q9 and a primary coil T1-A. The gate of the switch tube Q9 is connected to a separate drive controller. One end of the primary coil T1-A is connected to the positive output terminal VBUS+ to import the output voltage of the positive output terminal VBUS+; the first secondary coil circuit and the second secondary coil circuit respectively have secondary coils to respond to the primary coil to obtain voltage, and after filtering, power is supplied to the high-voltage capacitor isolation driver chip U47 and the low-voltage capacitor isolation driver chip U2.

3. The locomotive high-voltage input power release and reverse connection prevention circuit according to claim 2, characterized in that: The first secondary coil circuit includes a first secondary coil T1-B, a diode D12 and a capacitor C13. The first secondary coil T1-B and one end of the anode of the diode D12 are connected in series and then connected in parallel with the capacitor C13. The cathode of the diode D12 is connected to the high-voltage capacitor isolation driver chip U47 to serve as the first auxiliary power supply. The other ends of the first secondary coil T1-B and the capacitor C13 are connected to the positive output terminal VBUS+. The second secondary coil circuit includes a second secondary coil T1-C, a diode D13 and a capacitor C14. The second secondary coil T1-C and one end of the anode of the diode D13 are connected in series and then connected in parallel with the capacitor C14. The cathode of the diode D13 is connected to the low-voltage capacitor isolation driver chip U2. The other ends of the second secondary coil T1-C and the capacitor C14 are grounded.

4. The locomotive high-voltage input power release and reverse connection prevention circuit according to claim 1, characterized in that: The voltage stabilizing circuit includes a voltage stabilizing diode U1 and a first current limiting resistor. The anode and cathode of the voltage stabilizing diode U1 are respectively connected to two pins of the high-voltage capacitor isolation driver chip U47. The voltage stabilizing diode U1 is also connected in parallel with a capacitor C11. The anode of the voltage stabilizing diode U1 is connected to the positive output terminal VBUS+ of the entire circuit. The first auxiliary power supply is connected to the cathode of the voltage stabilizing diode U1 through a diode D8.

5. The locomotive high-voltage input power release and reverse connection prevention circuit according to claim 1, characterized in that: The signal output end of the comparator U3-B is connected to the comparison signal receiving pin of the low-tube capacitor isolation driver chip U2 through an amplification circuit, and a second auxiliary power supply AUX1 is connected to the power supply pin of the low-tube capacitor isolation driver chip U2 through a forward diode D9. The second auxiliary power supply is also grounded through a capacitor C12. One end of the capacitor C12 shares a reference supply voltage with the comparator U3-B and the other end is grounded. The ground pin of the low-tube capacitor isolation driver chip U2 is connected to one end of the grounded capacitor C12.

6. The locomotive high-voltage input power release and reverse connection prevention circuit according to claim 1, characterized in that: The access resistor includes a first seventy-nine resistor R179, a second zero-three resistor R203, and a second fifty-three resistor R253 connected in sequence. The filter circuit includes a second zero-six resistor R206 and a capacitor C164. The filter circuit is connected between the second fifty-three resistor R253 and the inverting input terminal of the comparator.

7. The locomotive high-voltage input power release and reverse connection prevention circuit according to claim 1, characterized in that: The high-voltage capacitor isolation driver chip U47 and / or the low-voltage capacitor isolation driver chip U2 are each connected to a comparison signal via an amplifier circuit.

8. The locomotive high-voltage input power release and reverse connection prevention circuit according to claim 7, characterized in that: The amplification circuit includes a transistor and a second current-limiting resistor. The first end of the second current-limiting resistor is connected to the comparison signal, and the second end is connected to the base of the transistor. The emitter of the transistor is grounded, and the collector of the transistor is connected to the high-voltage capacitor isolation driver chip U47 or the low-voltage capacitor isolation driver chip U2; the second end of the second current-limiting resistor is also grounded through a resistor, the positive pole of a diode is connected between the resistor and the second current-limiting resistor, and the negative pole of the diode is connected to the first end of the second current-limiting resistor.

9. The locomotive high-voltage input power release and reverse connection prevention circuit according to claim 1, characterized in that: The high-capacitor isolation driver chip U47 and / or the low-capacitor isolation driver chip U2 are respectively connected to and control the switch tube TR12 or TR1 through a switching circuit. The switching circuit includes a voltage stabilizing unit, which includes a voltage stabilizing current limiting resistor, a voltage stabilizing filter capacitor, and a switching voltage stabilizing tube. The voltage stabilizing current limiting resistor is connected to the reverse input end of the switching voltage stabilizing tube. The voltage stabilizing filter capacitor and the switching voltage stabilizing tube are connected in parallel. The forward output end of the switching voltage stabilizing tube is connected to the gate of the switching tube TR1 or TR12 and is connected to the source of the switching tube through a resistor. The voltage-stabilizing and current-limiting resistor is connected in parallel with a feedback resistor and a feedback diode. One end of the feedback resistor is connected to the reverse input end of the switching voltage-stabilizing tube, and the other end is connected to the positive electrode of the feedback diode. The negative electrode of the voltage-stabilizing and current-limiting resistor and the feedback diode are connected in parallel to a pin of the high-voltage capacitor isolation driver chip U47 and / or the low-voltage capacitor isolation driver chip U2.

10. The locomotive high-voltage input power release and reverse connection prevention circuit according to claim 1, characterized in that: The input filter circuit is an LC filter circuit, which includes two capacitors connected in parallel between the positive and negative terminals of the input power supply or between the positive and ground terminals of the input power supply, and a positive terminal inductor LX1-B and a negative terminal inductor LX1-A connected between the two capacitors. A back-end capacitor C10 is connected in parallel between the positive output terminal VBUS+ and the ground terminal. The comparator U3-B provides a reference voltage through a reference power supply circuit. The reference power supply circuit includes a power supply stabilization unit, which is connected to the input power supply and then connected to the cathode of the Zener diode U4 through two current-limiting resistors R17 and R56. The anode of the Zener diode U4 is grounded. The filter capacitor C40 and the two ends of the Zener diode U4 are connected in parallel, and the two resistors R188 and R199 are connected in series to form a series circuit, which is connected in parallel with the Zener diode U4. The connection node of the two resistors R188 and R199 is connected to the reference electrode of the Zener diode U4. The reference power supply circuit also supplies power to the high-voltage capacitor isolation driver chip U47 and the low-voltage capacitor isolation driver chip U2.

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