Internal combustion locomotive main generator excitation chopper control unit

Abstract

This invention discloses a control unit for an excitation chopper of a main generator in an internal combustion locomotive. It includes a voltage acquisition module and a frequency acquisition module for acquiring the output voltage and frequency of an AC auxiliary generator, respectively; an analog input module for rectifying, amplifying, and filtering the main generator excitation current signal before transmitting it to the control module; and a drive module for driving the excitation chopper with drive signals and protection start signals output from the control module. This invention acquires the output voltage and frequency of the AC auxiliary generator through the power acquisition module and the frequency acquisition module, transmits them to the main control unit, and then sends them to the control module of the chopper control unit through the frequency input module. The fast signal acquisition and processing speed accelerates the response speed of the entire chopper control unit, resulting in high real-time performance of the main generator excitation current regulation. Furthermore, the structure is simple and easy to implement.

Description

Technical Field

[0001] This invention relates to the field of hardware circuit design, and in particular to a control unit for an excitation chopper of a main generator in an internal combustion engine vehicle. Background Technology

[0002] In modern diesel locomotives, the main generator is a crucial component of the locomotive's traction system. The diesel engine drives the main generator to produce three-phase alternating current, which in turn drives the traction motors. The chopper is a device that controls the excitation regulation of the main generator. Based on the diesel engine speed, the main generator's operating status, and the traction power set by the locomotive controller, it adjusts the main generator's excitation current to meet the locomotive's traction power requirements.

[0003] Existing chopper control units mostly use 8-bit microcontrollers and lack ADC peripheral functions. The slow signal acquisition and processing speed limits the response speed of the entire closed-loop system of the chopper control unit, resulting in lag and affecting the real-time regulation of the main generator excitation current. Summary of the Invention

[0004] This invention provides a control unit for the excitation chopper of the main generator of an internal combustion locomotive to overcome the above-mentioned technical problems.

[0005] To achieve the above objectives, the technical solution of the present invention is as follows:

[0006] A control unit for an excitation chopper of a main generator in an internal combustion locomotive includes a locomotive main control unit, an AC auxiliary generator, and also includes a power supply module, a voltage acquisition module, a frequency acquisition module, a frequency input module, a digital input module, a digital output module, an analog input module, a drive module, and a control module.

[0007] The power supply module is connected to the control module and is used to supply power to the excitation chopper control unit.

[0008] The voltage acquisition module is connected to the locomotive main control unit and the AC auxiliary generator respectively, and is used to acquire the output voltage of the AC auxiliary generator and transmit it to the locomotive main control unit.

[0009] The frequency acquisition module is connected to the locomotive main control unit and the AC auxiliary generator respectively, and is used to acquire the output voltage frequency of the AC auxiliary generator and transmit it to the locomotive main control unit.

[0010] The frequency input module is connected to the locomotive main control unit and the control module respectively, and is used to transmit the gate drive signal of the locomotive main control unit to the control module to control the excitation chopper.

[0011] The digital input module is connected to the control module and the locomotive main control unit respectively, and is used to transmit the digital signal of the locomotive main control unit to the control module to control the chopper to shut off the excitation current of the main generator.

[0012] The digital output module is connected to the control module and the locomotive main control unit respectively, and is used to transmit the digital level signal of the chopper to the locomotive main control unit so that the locomotive main control unit can output a fault reset signal to the chopper.

[0013] The analog input module is connected to the control module and is used to rectify, amplify and filter the main generator excitation current signal before transmitting it to the control module.

[0014] The drive module is connected to the control module and the excitation chopper respectively, so as to drive the excitation chopper through the drive module outputting the drive signal and protection start signal of the control module.

[0015] The control module is used to receive input signals from the power acquisition module, frequency acquisition module, analog input module, digital input module, and frequency input module, and to control the chopper through the drive module.

[0016] Furthermore, the circuit structure of the voltage acquisition module includes: a precision rectifier circuit and an amplification and shaping circuit;

[0017] The precision rectifier circuit includes resistors R34 (third and fourth), R37 (third and seventh), R38 (third and eighth), R39 (third and ninth), diode D16 (first and sixth), diode D17 (first and seventh), and operational amplifier U10A. One end of resistor R37 is connected to the AC auxiliary generator, and the other end is connected to one end of resistor R38. The other end of resistor R38 is connected to one end of resistor R39. The other end of resistor R39 is connected to one end of resistor R34. The terminal is connected to the AC auxiliary generator; the inverting input terminal of the operational amplifier U10A is connected to the connection of the third seven resistor R37 and the third eight resistor R38; the non-inverting input terminal of the operational amplifier U10A is grounded; one end of the first six diode D16 is connected to the connection of the third eight resistor R38 and the third nine resistor R39, and the other end is connected to the output terminal of the operational amplifier U10A; one end of the first seven diode D17 is connected to the output terminal of the operational amplifier U10A, and the other end is connected to the inverting input terminal of the operational amplifier U10A.

[0018] The amplification and shaping circuit includes a third five-resistor R35, a fourth three-resistor R43, a fourth zero-capacitor C40, a fourth two-capacitor C42, a fourth three-capacitor C43, and an operational amplifier U10B. The inverting input of the operational amplifier U10B is connected to the junction of the third four-resistor R34 and the third nine-resistor R39. The non-inverting input of the operational amplifier U10B is grounded. The output of the operational amplifier U10B is connected to one end of the fourth zero-capacitor C40, and the other end of the fourth zero-capacitor C40 is connected to the inverting input of the operational amplifier U10B. The circuit is connected to the input terminal; one end of the third resistor R35 is connected to the inverting input terminal of the operational amplifier U10B, and the other end is connected to one end of the fourth capacitor C42; the other end of the fourth capacitor C42 is grounded; the fourth capacitor C43 is connected in parallel with the fourth capacitor C42; the two ends of the fourth capacitor C43 are respectively connected to the locomotive main control unit; one end of the fourth resistor R43 is connected to the output terminal of the operational amplifier U10B, and the other end is connected to the connection point of the third resistor R35 and the fourth capacitor C42.

[0019] Furthermore, the circuit structure of the frequency acquisition module includes: a bandpass filter circuit and a comparator circuit;

[0020] The bandpass filter circuit includes a fourth and fifth resistor R45, a fourth and sixth resistor R46, a fifth zero resistor R50, a fifth and first resistor R51, a fourth and fifth capacitor C45, a fourth and ninth capacitor C49, and an operational amplifier U12A. One end of the fourth and fifth resistor R45 is connected to the AC auxiliary generator, and the other end is connected to one end of the fourth and sixth resistor R46. The other end of the fourth and sixth resistor R46 is connected to the non-inverting input terminal of the operational amplifier U12A. One end of the fourth and fifth capacitor C45 is connected at the junction of the fourth and fifth resistors R45 and R46, and the other end is connected to the output terminal of the operational amplifier U12A. One end of the fifth zero resistor R50 is connected to the output terminal of the operational amplifier U12A, and the other end is connected to the inverting input terminal of the operational amplifier U12A. One end of the fifth and first resistor R51 is connected to the inverting input terminal of the operational amplifier U12A, and the other end is grounded. One end of the fourth and ninth capacitor C49 is connected to the non-inverting input terminal of the operational amplifier U12A, and the other end is grounded.

[0021] The comparator circuit includes resistors R47 (47th), R48 (48th), R49 (49th), R52 (52nd), C51 (51st), and operational amplifier U12B. One end of resistor R48 is connected to the output of operational amplifier U12A, and the other end is connected to the non-inverting input of operational amplifier U12B. The inverting input of operational amplifier U12B is connected to one end of capacitor C51, and the other end of capacitor C51 is grounded. One end of resistor R52 is connected to the inverting input of operational amplifier U12B, and the other end is connected to the power supply module. One end of resistor R47 is connected to the inverting input of operational amplifier U12B, and the other end is connected to the power supply module. One end of resistor R49 is connected to the output of operational amplifier U12B, and the other end is connected to the locomotive main control unit.

[0022] Furthermore, the circuit structure of the analog input module includes: a full-wave rectifier circuit, an amplification and filtering circuit, and an output circuit; one end of the full-wave rectifier circuit is connected to the main generator, and the other end is connected to the amplification and filtering circuit; the other end of the amplification and filtering circuit is connected to one end of the output circuit, and the other end of the output circuit is connected to the control module.

[0023] The amplification and filtering circuit includes a third capacitor C32, a third capacitor C35, a seventeenth resistor R17, a second resistor R23, a fourteenth resistor R14, a second resistor R24, a nineteenth resistor R19, operational amplifiers U7A and U7B, a second resistor R26, a second resistor R29, and a third capacitor C37. One end of the third capacitor C32 is connected to one end of the full-wave rectifier circuit, and the other end is grounded. The seventeenth resistor R17 is connected at the connection point between the third capacitor C32 and the full-wave rectifier circuit, and the other end is connected to the inverting input terminal of operational amplifier U7A. One end of the fourteenth resistor R14 is connected to the inverting input terminal of operational amplifier U7A, and the other end is connected to the output terminal of operational amplifier U7A. One end of the nineteenth resistor R19 is connected to the operational amplifier U7A. The output terminal of A is connected, and the other end is connected to the non-inverting input terminal of the operational amplifier U7B; the inverting input terminal of the operational amplifier U7B is connected to one end of the second nine-resistor R29; the other end of the second nine-resistor R29 is grounded; the third seven-capacitor C37 is connected in parallel with the second nine-resistor R29; one end of the second six-resistor R26 is connected to the inverting input terminal of the operational amplifier U7B, and the other end is connected to the output terminal of the operational amplifier U7B; one end of the third five-capacitor C35 is connected to the other end of the full-wave rectifier circuit, and the other end is grounded; the second three-resistor R23 is connected at the connection point between the third five-capacitor C35 and the full-wave rectifier circuit, and the other end is connected to the non-inverting input terminal of the operational amplifier U7A; one end of the second four-resistor R24 ​​is connected to the non-inverting input terminal of the operational amplifier U7A, and the other end is grounded;

[0024] The output circuit includes a second resistor R21, an eighth diode D8, a third capacitor C36, and a second resistor R25; one end of the third capacitor C36 is connected to the control module, and the other end is grounded; one end of the second resistor R21 is connected to the output terminal of the operational amplifier U7B, and the other end is connected to the control module; the eighth diode D8 and the second resistor R25 are both connected in parallel with the third capacitor C36.

[0025] Furthermore, the circuit structure of the driving module includes: a logic protection circuit, an optocoupler isolation circuit, a power amplifier circuit, and an output voltage adjustment circuit;

[0026] The logic protection circuit includes a first gate circuit U5A and a second gate circuit U5B; the first input terminal of the second gate circuit U5B is connected to the drive signal output terminal of the control module, the second input terminal of the second gate circuit U5B is grounded, and the output terminal of the second gate circuit U5B is connected to the second input terminal of the first gate circuit U5A; the first input terminal of the first gate circuit U5A is connected to the protection start signal output terminal of the control module.

[0027] The optocoupler isolation circuit includes a fifth resistor R57, an optocoupler U17, a sixth capacitor C63, a second diode D21, a fifth eighth resistor R58, and a fifth fifth resistor R55. One end of the fifth seventh resistor R57 is connected to the output terminal of the first gate circuit U5A, and the other end is connected to pin 1 of the optocoupler U17. Pin 2 of the optocoupler U17 is grounded. Pin 3 of the optocoupler U17 is connected to the power supply module. Pin 4 of the optocoupler U17 is connected to one end of the fifth fifth resistor R55. The other end of the fifth fifth resistor R55 is connected to one end of the fifth eighth resistor R58, and the other end of the fifth eighth resistor R58 is connected to the power supply module. The sixth third capacitor C63 and the second first diode D21 are both connected in parallel with the fifth eighth resistor R58.

[0028] The power amplifier circuit includes a driver chip U15, a fifth and sixth capacitor C56, and a seventh and sixth capacitor C76.

[0029] The IN pin of the driver chip U15 is connected to the connection point of the fifth resistor R55 and the fifth resistor R58; the GND pin of the driver chip U15 is connected to the connection point of the fifth resistor R58 and the power supply module; the VCC pin of the driver chip U15 is connected to one end of the seventh capacitor C76, and the other end of the seventh capacitor C76 is connected to the GND pin of the driver chip U15; the fifth capacitor C56 and the seventh capacitor C76 are connected in parallel;

[0030] The output voltage adjustment circuit includes a linear regulator U16, a capacitor filter circuit, a fifth resistor R53, a second zero-diode D20, and a fifth resistor R54. The IN pin of the linear regulator U16 is connected to the VCC pin of the driver chip U15; the GND pin of the linear regulator U16 is connected to the GND pin of the driver chip U15; one end of the fifth resistor R53 is connected to the OUT pin of the driver chip U15, and the other end is connected to the main generator excitation chopper interface J4; the two ends of one end of the second zero-diode D20 are respectively connected to the main generator excitation chopper interface J4 and the main generator excitation chopper interface J5; the fifth resistor R54 is connected in parallel with the second zero-diode D20; the IN pin, GND pin, and OUT pin of the linear regulator U16 are all connected to the capacitor filter circuit; the capacitor filter circuit is connected to the main generator excitation chopper interface J5.

[0031] Furthermore, it also includes a protection module;

[0032] The protection module is connected to the control module to shut down the excitation chopper when the main rectifier of the excitation chopper control unit fails.

[0033] Beneficial effects: The main generator excitation chopper control unit of the present invention collects the output voltage and output voltage frequency of the AC auxiliary generator through the power acquisition module and the frequency acquisition module, and transmits them to the main control unit. After that, they are sent to the control module of the chopper control unit through the frequency input module. The signal acquisition and processing speed is fast, which speeds up the response speed of the entire chopper control unit, making the real-time adjustment of the main generator excitation current highly effective. Moreover, the structure is simple and easy to implement. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This is a structural diagram of the hardware circuit platform of the chopper control unit of the present invention;

[0036] Figure 2 This is a functional block diagram of the voltage acquisition module circuit in an embodiment of the present invention;

[0037] Figure 3 This is a circuit schematic diagram of the voltage acquisition module in an embodiment of the present invention;

[0038] Figure 4 This is a functional block diagram of the frequency acquisition module circuit in an embodiment of the present invention;

[0039] Figure 5 This is a schematic diagram of the frequency acquisition module circuit in an embodiment of the present invention;

[0040] Figure 6 This is a functional block diagram of the analog input module circuit in an embodiment of the present invention;

[0041] Figure 7 This is a schematic diagram of the analog input module circuit in an embodiment of the present invention;

[0042] Figure 8 This is a functional block diagram of the driving module circuit in an embodiment of the present invention;

[0043] Figure 9 Schematic diagram of the logic protection circuit of the driving module in the embodiments of the present invention;

[0044] Figure 10 The schematic diagram of the optocoupler isolation and power amplifier circuit of the driving module in the embodiment of the present invention. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0046] This embodiment provides a control unit for the excitation chopper of the main generator in an internal combustion locomotive, such as... Figure 1 As shown, it includes the locomotive main control unit, AC auxiliary generator, power supply module, voltage acquisition module, frequency acquisition module, frequency input module, digital input module, digital output module, analog input module, drive module, and control module;

[0047] The power supply module is connected to the control module and is used to supply power to the entire excitation chopper control unit; the power supply module in this embodiment can convert the ±15V power input from the connector into ±5V, ±12V and +8V.

[0048] The voltage acquisition module is connected to both the locomotive main control unit and the AC auxiliary generator, and is used to acquire the output voltage of the AC auxiliary generator and send it to the locomotive main control unit. The voltage acquisition module receives the output voltage of the AC auxiliary generator through a precision rectifier circuit composed of resistors R34, R37, R38, R39, diode D16, diode D17, and operational amplifier U10A. Then, it passes through an amplification and shaping circuit composed of resistor R35, R43, capacitor C40, C42, C43, and operational amplifier U10B before being sent to the locomotive main control unit. The ratio between the output voltage of the voltage acquisition module and the voltage of the AC auxiliary generator is a constant. The specific functional block diagram is shown below. Figure 2 As shown, the circuit schematic is as follows: Figure 3 As shown.

[0049] Preferably, the circuit structure of the voltage acquisition module includes: a precision rectifier circuit and an amplification and shaping circuit; one side of the precision rectifier circuit is connected to the AC auxiliary generator, and the other side is connected to the amplification and shaping circuit; the other side of the amplification and shaping circuit is connected to the locomotive main control unit.

[0050] The precision rectifier circuit includes resistors R34 (third and fourth), R37 (third and seventh), R38 (third and eighth), R39 (third and ninth), diode D16 (first and sixth), diode D17 (first and seventh), and operational amplifier U10A. One end of resistor R37 is connected to the AC auxiliary generator, and the other end is connected to one end of resistor R38. The other end of resistor R38 is connected to one end of resistor R39. The other end of resistor R39 is connected to one end of resistor R34. The terminal is connected to the AC auxiliary generator; the inverting input terminal of the operational amplifier U10A is connected to the connection of the third seven resistor R37 and the third eight resistor R38; the non-inverting input terminal of the operational amplifier U10A is grounded; one end of the first six diode D16 is connected to the connection of the third eight resistor R38 and the third nine resistor R39, and the other end is connected to the output terminal of the operational amplifier U10A; one end of the first seven diode D17 is connected to the output terminal of the operational amplifier U10A, and the other end is connected to the inverting input terminal of the operational amplifier U10A.

[0051] The amplification and shaping circuit includes a third five-resistor R35, a fourth three-resistor R43, a fourth zero-capacitor C40, a fourth two-capacitor C42, a fourth three-capacitor C43, and an operational amplifier U10B. The inverting input of the operational amplifier U10B is connected to the junction of the third four-resistor R34 and the third nine-resistor R39. The non-inverting input of the operational amplifier U10B is grounded. The output of the operational amplifier U10B is connected to one end of the fourth zero-capacitor C40, and the other end of the fourth zero-capacitor C40 is connected to the inverting input of the operational amplifier U10B. The circuit is connected to the input terminal; one end of the third resistor R35 is connected to the inverting input terminal of the operational amplifier U10B, and the other end is connected to one end of the fourth capacitor C42; the other end of the fourth capacitor C42 is grounded; the fourth capacitor C43 is connected in parallel with the fourth capacitor C42; the two ends of the fourth capacitor C43 are respectively connected to the locomotive main control unit; one end of the fourth resistor R43 is connected to the output terminal of the operational amplifier U10B, and the other end is connected to the connection point of the third resistor R35 and the fourth capacitor C42.

[0052] The frequency acquisition module is connected to the locomotive main control unit and the AC auxiliary generator respectively, and is used to acquire the output voltage frequency of the AC auxiliary generator and send it to the locomotive main control unit.

[0053] In this embodiment, the frequency acquisition module converts the output voltage of the AC auxiliary generator into a ±15V square wave signal. This signal is achieved by passing the output voltage through a bandpass filter circuit composed of resistors R45, R46, R50, R51, C45, C49, and operational amplifier U12A. The comparator circuit, composed of resistors R47, R48, R49, R52, C51, and operational amplifier U12B, then converts the sine wave into a square wave signal. The output frequency of the frequency acquisition module is proportional to the rotational speed of the AC auxiliary generator; this is a constant. The specific functional block diagram is shown below. Figure 4 As shown, the circuit schematic is as follows: Figure 5 As shown.

[0054] Preferably, the circuit structure of the frequency acquisition module includes: a bandpass filter circuit and a comparator circuit;

[0055] The bandpass filter circuit includes a fourth and fifth resistor R45, a fourth and sixth resistor R46, a fifth zero resistor R50, a fifth and first resistor R51, a fourth and fifth capacitor C45, a fourth and ninth capacitor C49, and an operational amplifier U12A. One end of the fourth and fifth resistor R45 is connected to the AC auxiliary generator, and the other end is connected to one end of the fourth and sixth resistor R46. The other end of the fourth and sixth resistor R46 is connected to the non-inverting input terminal of the operational amplifier U12A. One end of the fourth and fifth capacitor C45 is connected at the junction of the fourth and fifth resistors R45 and R46, and the other end is connected to the output terminal of the operational amplifier U12A. One end of the fifth zero resistor R50 is connected to the output terminal of the operational amplifier U12A, and the other end is connected to the inverting input terminal of the operational amplifier U12A. One end of the fifth and first resistor R51 is connected to the inverting input terminal of the operational amplifier U12A, and the other end is grounded. One end of the fourth and ninth capacitor C49 is connected to the non-inverting input terminal of the operational amplifier U12A, and the other end is grounded.

[0056] The comparator circuit includes resistor R47 (fourth seven), resistor R48 (fourth eight), resistor R49 (fourth nine), resistor R52 (fifth two), capacitor C51 (fifth one), and operational amplifier U12B.

[0057] One end of the fourth resistor R48 is connected to the output terminal of the operational amplifier U12A, and the other end is connected to the non-inverting input terminal of the operational amplifier U12B; the inverting input terminal of the operational amplifier U12B is connected to one end of the fifth capacitor C51, and the other end of the fifth capacitor is grounded; one end of the fifth resistor R52 is connected to the inverting input terminal of the operational amplifier U12B, and the other end is connected to one -15V connector of the power supply module; one end of the fourth resistor R47 is connected to the inverting input terminal of the operational amplifier U12B, and the other end is connected to one +15V connector of the power supply module; one end of the fourth resistor R49 is connected to the output terminal of the operational amplifier U12B, and the other end is connected to the locomotive main control unit;

[0058] The frequency input module is connected to both the locomotive main control unit and the control module, and is used to transmit the gate drive signal of the locomotive main control unit to the control module to control the excitation chopper; the frequency input module is connected to the control module, the gate drive signal of the locomotive main control unit is sent to the control module, the control module obtains the duty cycle of the chopper drive pulse according to the gate drive signal, and drives the chopper IGBT through the drive module to control the chopper;

[0059] Specifically, in this embodiment, the duty cycle of the chopper drive pulse obtained from the gate drive signal is accomplished by a proportional-integral algorithm, which is existing technology and will not be described in detail here.

[0060] The frequency input module transmits the gate drive signal from the locomotive main control unit to the MCU of the chopper control unit after isolation and level conversion. The excitation current is the current controlled by the IGBT driven by the excitation chopper; the chopper control unit controls the magnitude of the excitation current based on the drive information.

[0061] The digital input module is connected to the control module and the locomotive main control unit respectively, and is used to transmit the digital signals of the locomotive main control unit to the control module to control the chopper to shut off the excitation current of the main generator, and to control the chopper to reset according to the fault reset signal output by the locomotive main control unit to the chopper.

[0062] The digital input module receives a digital signal with a high level of +74V and a low level of 0V. The digital input module has two inputs: one signal is responsible for shutting off the main generator excitation current, and the other is responsible for providing fault reset. Both input signals are isolated from the entire chopper control unit.

[0063] The digital output module is connected to the locomotive main control unit and is used to provide the locomotive main control unit with the digital level signal of the chopper (the operating status of the chopper), that is, to provide the locomotive main control unit with the digital level signal of the chopper, including the high bit of the fault status word of the status feedback, the low bit of the fault status word of the status feedback, and the drive signal of the GFD contactor.

[0064] The digital output module sends the status feedback signal to the locomotive main control unit by using relays to isolate and convert the signal level, based on the status feedback signal provided to the locomotive main control unit.

[0065] The analog input module is connected to the control module and is used to process the voltage signal input by the sensor, which is fed back by the excitation current of the main generator, after passing through a full-wave rectifier circuit, and then through an amplification and filtering circuit composed of capacitors C32, C35, and C37; resistors R17, R23, R14, R24, R19, R26, and R29; and operational amplifiers U7A and U7B. The signal is then sent to the MCU of the chopper control unit for processing. The specific circuit functional block diagram is shown below. Figure 6 As shown, the circuit schematic is as follows: Figure 7 As shown.

[0066] Preferably, the circuit structure of the analog input module includes: a full-wave rectifier circuit, an amplification and filtering circuit, and an output circuit; one end of the full-wave rectifier circuit is connected to the main generator, and the other end is connected to the amplification and filtering circuit; the other end of the amplification and filtering circuit is connected to one end of the output circuit, and the other end of the output circuit is connected to the control module.

[0067] Specifically, the full-wave rectifier circuit in this embodiment is a conventional rectifier circuit. In this embodiment, the AC power from the main generator via the sensor is converted into DC power through the full rectifier circuit, which consists of a sixteenth resistor R16, a second resistor R22, and a rectifier bridge. The sixteenth resistor R16 and the second resistor R22 are respectively connected to the positive and negative terminals of the main generator. One end of the rectifier bridge is connected to the other end of the sixteenth resistor R16, and the other end is connected to the other end of the second resistor R22, together forming a full-wave rectifier circuit.

[0068] The amplification and filtering circuit includes a third capacitor C32, a third capacitor C35, a seventeenth resistor R17, a second resistor R23, a fourteenth resistor R14, a second resistor R24, a nineteenth resistor R19, operational amplifiers U7A and U7B, a second resistor R26, a second resistor R29, and a third capacitor C37. One end of the third capacitor C32 is connected to one end of the full-wave rectifier circuit, and the other end is grounded. The seventeenth resistor R17 is connected at the connection point between the third capacitor C32 and the full-wave rectifier circuit, and the other end is connected to the inverting input terminal of operational amplifier U7A. One end of the fourteenth resistor R14 is connected to the inverting input terminal of operational amplifier U7A, and the other end is connected to the output terminal of operational amplifier U7A. One end of the nineteenth resistor R19 is connected to the operational amplifier U7A. The output terminal of A is connected, and the other end is connected to the non-inverting input terminal of the operational amplifier U7B; the inverting input terminal of the operational amplifier U7B is connected to one end of the second nine-resistor R29; the other end of the second nine-resistor R29 is grounded; the third seven-capacitor C37 is connected in parallel with the second nine-resistor R29; one end of the second six-resistor R26 is connected to the inverting input terminal of the operational amplifier U7B, and the other end is connected to the output terminal of the operational amplifier U7B; one end of the third five-capacitor C35 is connected to the other end of the full-wave rectifier circuit, and the other end is grounded; the second three-resistor R23 is connected at the connection point between the third five-capacitor C35 and the full-wave rectifier circuit, and the other end is connected to the non-inverting input terminal of the operational amplifier U7A; one end of the second four-resistor R24 ​​is connected to the non-inverting input terminal of the operational amplifier U7A, and the other end is grounded;

[0069] The output circuit includes a second resistor R21, an eighth diode D8, a third capacitor C36, and a second resistor R25.

[0070] One end of the third capacitor C36 is connected to the control module, and the other end is grounded; one end of the second resistor R21 is connected to the output terminal of the operational amplifier U7B, and the other end is connected to the control module; the eighth diode D8 and the second resistor R25 are both connected in parallel with the third capacitor C36.

[0071] The drive module takes the drive signal and protection start signal output by the control module (MCU), passes them through the logic protection circuits of the first gate circuit U5A and the second gate circuit U5B, then through the optocoupler U17 for opto-isolation, and finally sends them to the drive chip U15 for power amplification. After passing through the output voltage adjustment circuit composed of the linear regulator U16, the fifth resistor R53, and the fifth resistor R54, the output is sent to the IGBT via the main generator excitation chopper interface J4 and the main generator excitation chopper interface J5 (connectors J4 and J5), enabling the chopper's IGBT to operate according to the drive signal output by the control module's MCU. The specific circuit functional block diagram is shown below. Figure 8 As shown, the circuit schematic is as follows: Figure 9 and Figure 10 As shown.

[0072] Preferably, the circuit structure of the driving module includes: a logic protection circuit, an optocoupler isolation circuit, a power amplifier circuit, and an output voltage adjustment circuit;

[0073] The logic protection circuit includes a first gate circuit U5A and a second gate circuit U5B; the first input terminal of the second gate circuit U5B is connected to the drive signal output terminal of the control module, the second input terminal of the second gate circuit U5B is grounded, and the output terminal of the second gate circuit U5B is connected to the second input terminal of the first gate circuit U5A; the first input terminal of the first gate circuit U5A is connected to the protection start signal output terminal of the control module.

[0074] The optocoupler isolation circuit includes a fifth resistor R57, an optocoupler U17, a sixth capacitor C63, a second diode D21, a fifth eighth resistor R58, and a fifth fifth resistor R55. One end of the fifth seventh resistor R57 is connected to the output terminal of the first gate circuit U5A, and the other end is connected to pin 1 of the optocoupler U17. Pin 2 of the optocoupler U17 is grounded. Pin 3 of the optocoupler U17 is connected to one 12V connector of the power supply module. Pin 4 of the optocoupler U17 is connected to one end of the fifth fifth resistor R55. The other end of the fifth fifth resistor R55 is connected to one end of the fifth eighth resistor R58, and the other end of the fifth eighth resistor R58 is connected to one 12V connector of the power supply module. The sixth third capacitor C63 and the second first diode D21 are both connected in parallel with the fifth eighth resistor R58.

[0075] The power amplifier circuit includes a driver chip U15, a fifth and sixth capacitor C56, and a seventh and sixth capacitor C76. The IN pin of the driver chip U15 is connected to the connection point of the fifth and eighth resistors R55 and R58. The GND pin of the driver chip U15 is connected to the connection point of the fifth and eighth resistors R58 and the power supply module. The VCC pin of the driver chip U15 is connected to one end of the seventh and sixth capacitor C76, and the other end of the seventh and sixth capacitor C76 is connected to the GND pin of the driver chip U15. The fifth and sixth capacitors C56 and C76 are connected in parallel.

[0076] The output voltage adjustment circuit includes a linear regulator U16, a capacitor filter circuit, a fifth resistor R53, a second zero-diode D20, and a fifth resistor R54. The IN pin of the linear regulator U16 is connected to the VCC pin of the driver chip U15; the GND pin of the linear regulator U16 is connected to the GND pin of the driver chip U15; one end of the fifth resistor R53 is connected to the OUT pin of the driver chip U15, and the other end is connected to the main generator excitation chopper interface J4; the two ends of one end of the second zero-diode D20 are respectively connected to the main generator excitation chopper interface J4 and the main generator excitation chopper interface J5; the fifth resistor R54 is connected in parallel with the second zero-diode D20; the IN pin, GND pin, and OUT pin of the linear regulator U16 are all connected to the capacitor filter circuit; the capacitor filter circuit is connected to the main generator excitation chopper interface J5.

[0077] Specifically, the capacitor filter circuit in this embodiment includes a fifth capacitor C52, a fifth capacitor C53, a fifth capacitor C54, a sixth capacitor C60, a sixth capacitor C61, and a sixth capacitor C62; wherein, one end of the fifth capacitor C52 is connected to the IN pin of the linear regulator U16, and the other end is connected to the OUT pin of the linear regulator U16; one end of the sixth capacitor C60 is connected to the OUT pin of the linear regulator U16, and the other end is connected to the GND pin of the linear regulator U16; the fifth capacitors C53 and C54 are both connected in parallel with the fifth capacitor C52; the sixth capacitors C61 and C62 are both connected in parallel with the sixth capacitor C60; the OUT pin of the linear regulator U16 is connected to the main generator excitation chopper;

[0078] Specifically, the control module is the core module of the chopper. It uses a 32-bit microcontroller with a Cortex-M3 ARM core as the MCU, with a maximum clock frequency of 108MHz. It features a 12-bit on-chip ADC peripheral, offering several times the processing speed compared to an 8-bit microcontroller, and adds analog signal acquisition functionality while accelerating digital signal acquisition. The MCU, based on the acquired data and the chopper control algorithm, outputs drive signals and other feedback signals. Specifically, the drive signals are those that drive the chopper's IGBTs to switch; the other feedback signals are the output signals from the digital output module.

[0079] The control module is used to receive input signals from the power acquisition module, frequency acquisition module, analog input module, digital input module, and frequency input module, and to control the chopper through the drive module.

[0080] The internal combustion engine main generator excitation chopper control unit in this embodiment also includes a protection module, which is connected to the control module to shut down the excitation chopper when the main rectifier of the excitation chopper control unit fails.

[0081] Specifically, the protection module can shut off the excitation current when the main rectifier fails. That is, when a fault occurs in the chopper main circuit, the protection module will quickly turn on according to the protection start signal to provide a freewheeling circuit for the circuit.

[0082] The working principle of this embodiment is as follows:

[0083] When the entire locomotive main generator excitation chopper control unit starts working, the voltage acquisition module and frequency acquisition module collect the voltage and frequency information of the current three-phase auxiliary AC generator of the locomotive. To avoid delays, the collected voltage and frequency information is connected to the locomotive main control unit via hardwire. The locomotive main control unit calculates the output frequency information based on the collected voltage, frequency, and the locomotive's given power, and sends it to the control module of the chopper control unit through the frequency input module. The control module calculates the drive signal based on the input frequency, and the drive signal drives the chopper IGBT through the drive module to control the chopper output. The analog input module collects the signal from the locomotive main generator excitation current feedback sensor. When the chopper rectifier diode fails (short circuit), causing the main generator excitation current to reverse polarity and exceed the threshold voltage, it indicates a fault state. At this time, the control module will block the drive module and simultaneously send a start signal to the protection module. The protection start signal turns on the IGBT through the drive module, providing a freewheeling circuit for the excitation current and protecting the chopper.

[0084] The locomotive main control unit can also directly control the chopper's shutdown and fault reset. When the locomotive main control unit outputs a signal to shut down the main generator excitation chopper or to reset a fault, the signal is sent to the chopper control unit's control module via a digital input module. The control module then responds accordingly based on the input signal. When the chopper is operating, the chopper control unit sends a status signal back to the locomotive main control unit via a digital output module. Figure 1 This is a schematic diagram of the board-level hardware circuit platform structure for the chopper control unit.

[0085] In this embodiment, the chopper control unit exhibits fast signal acquisition and processing speed, resulting in a rapid response from the chopper control unit and impacting the real-time performance of the main generator excitation current regulation. Furthermore, the chopper control board in this embodiment is designed as a four-layer board, offering high electromagnetic compatibility.

[0086] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An internal combustion engine locomotive main generator field chopper control unit comprising a locomotive main control unit, an alternating current auxiliary generator, characterized by, The power supply module, the voltage acquisition module, the frequency acquisition module, the frequency quantity input module, the digital quantity input module, the digital quantity output module, the analog quantity input module, the driving module and the control module are further included. The power supply module is connected with the control module, and is used for supplying power to the excitation chopper control unit. The voltage acquisition module is connected with the locomotive main control unit and the AC auxiliary generator respectively, and is used for acquiring the output voltage of the AC auxiliary generator and transmitting the output voltage to the locomotive main control unit; the circuit structure of the voltage acquisition module comprises a precision rectification circuit and an amplification shaping circuit; one side of the precision rectification circuit is connected with the AC auxiliary generator, and the other side is connected with the amplification shaping circuit; the other side of the amplification shaping circuit is connected with the locomotive main control unit; The frequency acquisition module is connected with the locomotive main control unit and the AC auxiliary generator respectively, and is used for acquiring the output voltage frequency of the AC auxiliary generator and transmitting the output voltage frequency to the locomotive main control unit; the circuit structure of the frequency acquisition module comprises a band-pass filter circuit and a comparator circuit; The frequency quantity input module is connected with the locomotive main control unit and the control module respectively, and is used for transmitting the gate drive signal of the locomotive main control unit to the control module, so as to control the excitation chopper. The digital quantity input module is connected with the control module and the locomotive main control unit respectively, and is used for transmitting the digital quantity signal of the locomotive main control unit to the control module, so as to control the chopper to close the main generator excitation current. The digital quantity output module is connected with the control module and the locomotive main control unit respectively, and is used for transmitting the digital quantity level signal of the chopper to the locomotive main control unit, so as to output a fault reset signal to the chopper through the locomotive main control unit. The analog quantity input module is connected with the control module, and is used for rectifying and amplifying and filtering the main generator excitation current signal and then transmitting the main generator excitation current signal to the control module; the circuit structure of the analog quantity input module comprises a full-wave rectification circuit, an amplification filter circuit and an output circuit; one end of the full-wave rectification circuit is connected with the main generator, and the other end is connected with the amplification filter circuit; the other end of the amplification filter circuit is connected with one end of the output circuit, and the other end of the output circuit is connected with the control module; The driving module is connected with the control module and the excitation chopper respectively, so as to drive the excitation chopper through the driving module by the driving signal and the protection start signal output by the control module; the circuit structure of the driving module comprises a logic protection circuit, an optical coupling isolation circuit, a power amplification circuit and an output voltage adjustment circuit. The control module is used for receiving the input signals of the voltage acquisition module, the frequency acquisition module, the analog quantity input module, the digital quantity input module and the frequency quantity input module, and controlling the chopper through the driving module. The protection module is further included; The protection module is connected with the control module, so as to turn off the excitation chopper when the main rectifier of the excitation chopper control unit fails.

2. The main generator excitation chopper control unit of the internal combustion locomotive according to claim 1, wherein The precision rectifier circuit comprises a third fourth resistor R34, a third seventh resistor R37, a third eighth resistor R38, a third ninth resistor R39, a first sixth diode D16, a first seventh diode D17 and an operational amplifier U10A; one end of the third seventh resistor R37 is connected with the auxiliary alternator, and the other end is connected with one end of the third eighth resistor R38; the other end of the third eighth resistor R38 is connected with one end of the third ninth resistor R39; the other end of the third ninth resistor R39 is connected with one end of the third fourth resistor R34, and the other end of the third fourth resistor R34 is connected with the auxiliary alternator; the reverse input end of the operational amplifier U10A is connected at the connection of the third seventh resistor R37 and the third eighth resistor R38; the same input end of the operational amplifier U10A is grounded; one end of the first sixth diode D16 is connected at the connection of the third eighth resistor R38 and the third ninth resistor R39, and the other end is connected with the output end of the operational amplifier U10A; one end of the first seventh diode D17 is connected with the output end of the operational amplifier U10A, and the other end is connected with the reverse input end of the operational amplifier U10A; The amplification shaping circuit comprises a third fifth resistor R35, a fourth third resistor R43, a fourth zero capacitor C40, a fourth second capacitor C42, a fourth third capacitor C43 and an operational amplifier U10B; the reverse input end of the operational amplifier U10B is connected at the connection of the third fourth resistor R34 and the third ninth resistor R39; the same input end of the operational amplifier U10B is grounded; the output end of the operational amplifier U10B is connected with one end of the fourth zero capacitor C40, and the other end of the fourth zero capacitor C40 is connected with the reverse input end of the operational amplifier U10B; one end of the third fifth resistor R35 is connected with the reverse input end of the operational amplifier U10B, and the other end is connected with one end of the fourth second capacitor C42; the other end of the fourth second capacitor C42 is grounded; the fourth third capacitor C43 is connected with the fourth second capacitor C42 in parallel; the fourth third capacitor C43 is connected with the locomotive main control unit respectively at two ends; one end of the fourth third resistor R43 is connected with the output end of the operational amplifier U10B, and the other end is connected at the connection of the third fifth resistor R35 and the fourth second capacitor C42.

3. The main generator excitation chopper control unit of the internal combustion locomotive according to claim 1, characterized in that, The band-pass filter circuit comprises a fourth fifth resistor R45, a fourth sixth resistor R46, a fifth zero resistor R50, a fifth first resistor R51, a fourth fifth capacitor C45, a fourth ninth capacitor C49 and an operational amplifier U12A; one end of the fourth fifth resistor R45 is connected with the auxiliary alternator, and the other end is connected with one end of the fourth sixth resistor R46; the other end of the fourth sixth resistor R46 is connected with the same direction input end of the operational amplifier U12A; one end of the fourth fifth capacitor C45 is connected at the connection of the fourth fifth resistor R45 and the fourth sixth resistor R46, and the other end is connected with the output end of the operational amplifier U12A; one end of the fifth zero resistor R50 is connected with the output end of the operational amplifier U12A, and the other end is connected with the reverse input end of the operational amplifier U12A; one end of the fifth first resistor R51 is connected with the reverse input end of the operational amplifier U12A, and the other end is grounded; one end of the fourth ninth capacitor C49 is connected with the same direction input end of the operational amplifier U12A, and the other end is grounded; The comparator circuit comprises a fourth seventh resistor R47, a fourth eighth resistor R48, a fourth ninth resistor R49, a fifth second resistor R52, a fifth first capacitor C51 and an operational amplifier U12B; one end of the fourth eighth resistor R48 is connected with the output end of the operational amplifier U12A, and the other end is connected with the same direction input end of the operational amplifier U12B; the reverse input end of the operational amplifier U12B is connected with one end of the fifth first capacitor C51, and the other end of the fifth first capacitor is grounded; one end of the fifth second resistor R52 is connected with the reverse input end of the operational amplifier U12B, and the other end is connected with the power supply module; one end of the fourth seventh resistor R47 is connected with the reverse input end of the operational amplifier U12B, and the other end is connected with the power supply module; one end of the fourth ninth resistor R49 is connected with the output end of the operational amplifier U12B, and the other end is connected with the locomotive main control unit.

4. The main generator excitation chopper control unit of the internal combustion locomotive according to claim 1, characterized in that, The amplification filter circuit comprises a third capacitor C32, a third capacitor C35, a seventeenth resistor R17, a second capacitor R23, a fourteenth resistor R14, a second capacitor R24, a nineteenth resistor R19, an operational amplifier U7A, an operational amplifier U7B, a second capacitor R26, a second capacitor R29, a third capacitor C37; one end of the third capacitor C32 is connected with one end of the full-wave rectifier circuit, and the other end is grounded; the seventeenth resistor R17 is connected at the connection of the third capacitor C32 and the full-wave rectifier circuit, and the other end is connected with the reverse input end of the operational amplifier U7A; one end of the fourteenth resistor R14 is connected with the reverse input end of the operational amplifier U7A, and the other end is connected with the output end of the operational amplifier U7A; one end of the nineteenth resistor R19 is connected with the output end of the operational amplifier U7A, and the other end is connected with the same input end of the operational amplifier U7B; the reverse input end of the operational amplifier U7B is connected with one end of the second capacitor R29; the other end of the second capacitor R29 is grounded; the third capacitor C37 is connected with the second capacitor R29 in parallel; one end of the second capacitor R26 is connected with the reverse input end of the operational amplifier U7B, and the other end is connected with the output end of the operational amplifier U7B; one end of the third capacitor C35 is connected with the other end of the full-wave rectifier circuit, and the other end is grounded; the second capacitor R23 is connected at the connection of the third capacitor C35 and the full-wave rectifier circuit, and the other end is connected with the same input end of the operational amplifier U7A; one end of the second capacitor R24 is connected with the same input end of the operational amplifier U7A, and the other end is grounded; The output circuit comprises a second resistor R21, an eighth diode D8, a third capacitor C36 and a second resistor R25; one end of the third capacitor C36 is connected with the control module, and the other end is grounded; one end of the second resistor R21 is connected with the output end of the operational amplifier U7B, and the other end is connected with the control module; the eighth diode D8 and the second resistor R25 are both connected with the third capacitor C36 in parallel.

5. The main generator excitation chopper control unit of the internal combustion locomotive according to claim 1, characterized in that, The logic protection circuit comprises a first gate circuit U5A and a second gate circuit U5B; the first input end of the second gate circuit U5B is connected with the driving signal output end of the control module, the second input end of the second gate circuit U5B is grounded, and the output end of the second gate circuit U5B is connected with the second input end of the first gate circuit U5A; the first input end of the first gate circuit U5A is connected with the protection starting signal output end of the control module. The light coupling isolation circuit comprises a fifth seventh resistor R57, a photoelectric coupler U17, a sixth third capacitor C63, a second diode D21, a fifth eighth resistor R58, and a fifth fifth resistor R55; one end of the fifth seventh resistor R57 is connected with the output end of the first gate circuit U5A, and the other end is connected with the pin 1 of the photoelectric coupler U17; the pin 2 of the photoelectric coupler U17 is grounded; the pin 3 of the photoelectric coupler U17 is connected with the power supply module; the pin 4 of the photoelectric coupler U17 is connected with one end of the fifth fifth resistor R55, the other end of the fifth fifth resistor R55 is connected with one end of the fifth eighth resistor R58, and the other end of the fifth eighth resistor R58 is connected with the power supply module; the sixth third capacitor C63 and the second diode D21 are both connected in parallel with the fifth eighth resistor R58; The power amplification circuit comprises a driving chip U15, a fifth sixth capacitor C56, and a seventh sixth capacitor C76; The IN pin of the driving chip U15 is connected at the connection position of the fifth fifth resistor R55 and the fifth eighth resistor R58; the GND pin of the driving chip U15 is connected at the connection position of the fifth eighth resistor R58 and the power supply module; the VCC pin of the driving chip U15 is connected with one end of the seventh sixth capacitor C76, and the other end of the seventh sixth capacitor C76 is connected with the GND pin of the driving chip U15; the fifth sixth capacitor C56 is connected in parallel with the seventh sixth capacitor C76; The output voltage adjustment circuit comprises a linear voltage regulator U16, a capacitor filter circuit, a fifth third resistor R53, a second zero diode D20, and a fifth fourth resistor R54; the IN pin of the linear voltage regulator U16 is connected with the VCC pin of the driving chip U15; the GND pin of the linear voltage regulator U16 is connected with the GND pin of the driving chip U15; one end of the fifth third resistor R53 is connected with the OUT pin of the driving chip U15, and the other end is connected with the main generator excitation chopper interface J4; two ends of one end of the second zero diode D20 are respectively connected with the main generator excitation chopper interface J4 and the main generator excitation chopper interface J5; the fifth fourth resistor R54 is connected in parallel with the second zero diode D20; the IN pin of the linear voltage regulator U16, the GND pin of the linear voltage regulator U16, and the OUT pin of the linear voltage regulator U16 are all connected with the capacitor filter circuit; the capacitor filter circuit is connected with the main generator excitation chopper interface J5.

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