Method and system and device for improving the accuracy of the frequency of an excitation control system

Abstract

The present disclosure provides a method, system and device for improving the accuracy of the frequency of an excitation control system, the method comprising: presetting an initial frequency maximum value and an initial duty cycle maximum value of the excitation control system; obtaining a maximum duty cycle output when the locomotive is under a self-load full load test; obtaining a temperature coefficient conversion value of the excitation winding in the excitation control system; determining a duty cycle maximum value in use according to the maximum duty cycle and the temperature coefficient conversion value; obtaining a duty cycle output in use of the excitation control system; and calculating a control frequency output by the excitation control system according to the duty cycle maximum value in use, the duty cycle output in use and the initial frequency maximum value. The method, system and device provided by the present disclosure optimize the duty cycle of the excitation system, ensure the output accuracy of the frequency, further improve the accuracy of the output voltage, and ensure the stability and reliability of the output signal.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of internal combustion engine generator excitation equipment, in particular to a method, system and device for improving the frequency accuracy of an excitation control system. BACKGROUND

[0002] Electric drive diesel locomotives generally provide the required power for transmission through diesel generator sets. The diesel engine is the power core of the entire power generation system and is the key equipment for converting chemical energy into mechanical energy. The synchronous generator is responsible for converting mechanical energy into electrical energy. In order to ensure that the synchronous generator outputs stable electrical energy, while limiting the power to ensure that the diesel engine is not overloaded, excitation control of the generator is required. The synchronous generator excitation control system is used to provide DC current to the magnetic field winding of the generator to establish a DC magnetic field, and can adjust the excitation current when the synchronous motor is running normally or an accident occurs to meet the needs of operation. The excitation system is an important part of the synchronous generator and has a direct impact on the reliability and economy of the generator operation.

[0003] The control device in the current excitation system is divided into centralized control mode and distributed control mode. In the centralized control mode, the acquisition and feedback control, current drive, and power module are integrated. The distributed control directly drives the IGBT chopper tube of the chopper by sending a PWM signal from the microcomputer control device, and the microcomputer device completes the generator voltage and current acquisition and PID control. The chopper directly controls the size of the generator excitation current as an execution structure. The control has the disadvantage that the PWM control signal line is too long, which may cause interference problems. In the related art, the microcomputer device sends a frequency signal, and the chopper receives the frequency signal and converts it into a pulse width signal. This method improves the anti-interference performance, but has the disadvantage that the frequency and the duty cycle are one-to-one corresponding. For example, when the frequency changes from 500Hz to 1000Hz, 500Hz corresponds to 0% duty cycle and 1000Hz corresponds to 100% duty cycle. When the input voltage range is close to the output voltage range, the one-to-one correspondence between the frequency and the duty cycle can meet the control accuracy, but if the input voltage is relatively high and the output voltage is relatively low, the accuracy will be lost, and in severe cases, the control will be unstable. In addition, the control device in the existing excitation system is not suitable for high-altitude applications and has a narrow application range. SUMMARY

[0004] Therefore, the purpose of the present disclosure is to provide a method, system and device for improving the frequency accuracy of an excitation control system to solve or partially solve the above technical problems.

[0005] To achieve the above purpose, the first aspect of the present disclosure provides a method for improving the frequency accuracy of an excitation control system, comprising:

[0006] preset an initial frequency maximum value and an initial duty cycle maximum value of the excitation control system;

[0007] obtain a maximum duty cycle outputted by the locomotive when performing a self-load full-load test;

[0008] obtain a temperature coefficient conversion value of the excitation winding in the excitation control system;

[0009] determine a duty cycle maximum value in use according to the maximum duty cycle and the temperature coefficient conversion value;

[0010] obtain a duty cycle outputted by the excitation control system in use;

[0011] calculate a control frequency outputted by the excitation control system according to the duty cycle maximum value in use, the duty cycle outputted in use and the initial frequency maximum value.

[0012] Further, the determination of the duty cycle maximum value in use according to the maximum duty cycle and the temperature coefficient conversion value comprises:

[0013] in response to determining that a product of the maximum duty cycle and the temperature coefficient conversion value is less than the initial duty cycle maximum value, determining the product as the duty cycle maximum value in use;

[0014] in response to determining that the product of the maximum duty cycle and the temperature coefficient conversion value is greater than or equal to the initial duty cycle maximum value, determining the initial duty cycle maximum value as the duty cycle maximum value in use.

[0015] Further, the control frequency outputted by the excitation control system in use is calculated according to the formula F=D / D max ×F max ,

[0016] wherein F represents the control frequency outputted by the excitation control system, D represents the duty cycle outputted in use, D max represents the duty cycle maximum value in use, and F max represents the initial frequency maximum value.

[0017] Based on the same inventive concept, a second aspect of the present disclosure provides an excitation control system, comprising:

[0018] an excitation chopper configured to output a current to an excitation coil of a generator to drive the generator to work;

[0019] The excitation control board is connected with the excitation chopper and the generator, is used for obtaining a first signal output by the generator, and receives a second signal sent by the vehicle controller; negative feedback compensation is performed according to a deviation value between the first signal and the second signal; the output frequency of the excitation control system is calculated by using the method for improving the frequency accuracy of the excitation control system in any one of the first aspects; and the output frequency is sent to the excitation chopper.

[0020] Further, the excitation control board comprises an analog conversion module, a control system module and a frequency signal pulse output module.

[0021] The analog conversion module is connected with the generator, is used for obtaining a first signal output by the generator, and sends the first signal to the control system module.

[0022] The control system module is used for receiving a second signal sent by the vehicle controller and receiving a first signal sent by the analog conversion module; negative feedback compensation is performed according to a deviation value between the first signal and the second signal; a control frequency is calculated by using the method for improving the frequency accuracy of the excitation control system in any one of the first aspects; and the control frequency is output to the frequency signal pulse output module.

[0023] The frequency signal pulse output module is used for receiving the control frequency and converting the control frequency into a pulse signal; and the pulse signal is output to the excitation chopper.

[0024] Further, the excitation chopper comprises:

[0025] A water-cooled radiator;

[0026] A support capacitor arranged on the top of the water-cooled radiator;

[0027] Circuit elements arranged on the top of the water-cooled radiator and spaced apart from the support capacitor;

[0028] A low-inductance bus arranged above the support capacitor and the circuit elements;

[0029] A control box arranged above the low-inductance bus and fixed with the water-cooled radiator.

[0030] Further, the circuit elements comprise an absorption resistor, a control switch tube, a temperature relay, an input anti-reverse diode and a connector arranged in a spaced-apart manner, the absorption resistor and the control switch tube are arranged close to the support capacitor, and the input anti-reverse diode and the temperature relay are both arranged between the control switch tube and the connector.

[0031] Further, the control box is provided with a control board, a drive control board, a voltage detection board and a power module at intervals, the drive control board is located between the control board and the voltage detection board, and the control box is further provided with an external control connector on the outer wall close to the control board.

[0032] Based on the same inventive concept, a third aspect of the present disclosure provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the method of any one of the first aspect.

[0033] Based on the same inventive concept, a fourth aspect of the present disclosure provides a non-transitory computer readable storage medium, which stores computer instructions for causing a computer to execute the method of any one of the first aspect.

[0034] From the above, it can be seen that the method, system and device for improving the frequency accuracy of the excitation control system provided by the present disclosure optimize the duty cycle of the excitation system, so that the frequency and the duty cycle are no longer in a fixed proportional relationship, when the input voltage is relatively high and the output voltage is relatively low, the accuracy of the frequency is not lost, and the oscillation is not caused, the output accuracy of the frequency is ensured, and the accuracy of the output voltage is improved, and the output signal is stable and reliable. BRIEF DESCRIPTION OF DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the present disclosure or the related art, the drawings needed to be used in the embodiments or the related art description will be briefly introduced. Obviously, the drawings in the following description are only embodiments of the present disclosure, and other drawings can be obtained by those skilled in the art without creative labor.

[0036] Figure 1 Flowchart of the method for improving the frequency accuracy of the excitation control system according to the embodiment of the present disclosure;

[0037] Figure 2 Detailed flowchart of the method for improving the frequency accuracy of the excitation control system according to the embodiment of the present disclosure;

[0038] Figure 3 Structure diagram of the excitation control system according to the embodiment of the present disclosure;

[0039] Figure 4 Electrical diagram of the excitation control system according to the embodiment of the present disclosure;

[0040] Figure 5 Structure diagram of the excitation chopper according to the embodiment of the present disclosure;

[0041] Figure 6 Front view of the excitation chopper of the embodiment of the present disclosure;

[0042] Figure 7 Top view of the excitation chopper of the embodiment of the present disclosure without the control box;

[0043] Figure 8 Internal schematic view of the control box of the embodiment of the present disclosure;

[0044] Figure 9 Structural schematic view of the electronic device of the embodiment of the present disclosure.

[0045] Wherein, 100, excitation chopper; 101, handle; 102, fastener; 103, low inductance busbar; 104, circuit element; 104-1, connector; 105, control box; 105-1, external control connector; 105-2, control board; 105-3, drive control board; 105-4, voltage detection board; 105-5, power module; 106, water-cooled radiator;

[0046] 200, excitation control board; 300, generator;

[0047] C1, support capacitor; R1, absorption resistor; IGBT1, first control switch tube; IGBT2, second control switch tube; KTE1, temperature relay; VD1, input anti-reverse diode. DETAILED DESCRIPTION

[0048] In order to make the objectives, technical solutions and advantages of the present disclosure clearer, the present disclosure is further described in detail below with reference to the embodiments and the accompanying drawings.

[0049] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present disclosure should be understood as the general meaning understood by those skilled in the art to which the present disclosure belongs. The terms "first", "second", and similar terms used in the embodiments of the present disclosure do not represent any order, number, or importance, but are only used to distinguish different components. The terms "include", "contain", and similar terms mean that the elements or objects before the terms cover the elements or objects listed after the terms and their equivalents, and do not exclude other elements or objects. The terms "connect" or "connected" and similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The terms "up", "down", "left", "right", and the like only represent relative positional relationships, and when the absolute positions of the described objects change, the relative positional relationships may also change accordingly.

[0050] Generally, when the control frequency signal output by the excitation control system is in the operating range of 480-1000 Hz, the signal is stable and reliable; when in the range of 480-500 Hz, the excitation is directly blocked; when in the range of 501-1000 Hz, the duty cycle is calculated according to the formula D"=(F"-500) / (1000-500), wherein F" is the control frequency, and D" is the duty cycle.

[0051] In the related art, the setting method of the driving signal of the control frequency is: when the signal of the control frequency is in the range of 0-1000 Hz, the calculation formula of the control frequency and the duty cycle is D"=(F"-500) / (1000-500)×100%, that is, when the control frequency is 1000 Hz, the corresponding duty cycle is 100%.

[0052] The adoption of this direct proportional relationship makes the entire calculation process simple, but the disadvantage is that when the input voltage is relatively high and the actual output voltage is relatively low, the adoption of this fixed proportional relationship will lead to poor voltage regulation accuracy, and in severe cases, even cause oscillation.

[0053] Based on the above situation, the present disclosure proposes a method and device and equipment for improving the frequency accuracy of an excitation control system.

[0054] The detailed content of the present disclosure will be described below in combination with the drawings.

[0055] Reference Figure 1 A method for improving the frequency accuracy of an excitation control system, comprising:

[0056] Step S101, presetting the initial frequency maximum value and the initial duty cycle maximum value of the excitation control system.

[0057] Specifically, referring to the frequency maximum value and the duty cycle maximum value of the excitation control system in the related art, in this embodiment, the initial frequency maximum value F max of the control system is preset to 1000 Hz, and the corresponding initial duty cycle maximum value D max is 100%.

[0058] Step S102, obtaining the maximum duty cycle output when the locomotive is subjected to self-load full-load test.

[0059] Specifically, the locomotive is subjected to self-load full load test, the excitation control system connected with the locomotive receives the second signal sent by the vehicle controller, and receives the first signal output by the generator connected with the excitation control system, and the deviation value between the first signal and the second signal is subjected to negative feedback compensation (i.e. proportion-integral-differential coefficient regulating, PID regulating); then the output frequency of the excitation control system is output; according to the output frequency, the duty cycle corresponding to the output frequency is calculated according to the formula D" = (F"-500) / (1000-500) x 100%, which is the maximum duty cycle D1 output by the locomotive during self-load full load test.

[0060] The first signal refers to the voltage value and current value output by the generator, and the second signal refers to the target voltage value and current limit value sent by the vehicle controller. The excitation control board calculates the first deviation value and the second deviation value (the first deviation value refers to the deviation value between the voltage value and the target voltage value, and the second deviation value refers to the deviation value between the current value and the current limit value) according to the received first signal and second signal, and then the excitation control board performs negative feedback compensation according to the first deviation value and the second deviation value.

[0061] Step S103, obtaining the temperature coefficient conversion value of the excitation winding in the excitation control system.

[0062] Specifically, in the embodiment, the temperature coefficient conversion value of the excitation winding in the excitation control system is represented by K. The temperature coefficient conversion value is closely related to the temperature coefficient of the excitation winding, and fully considers the different performances of the excitation winding at different temperatures, so the value of K is as follows:

[0063] In the embodiment, the value of the temperature coefficient conversion value K is described in detail by taking the copper material used in the generator excitation winding of the excitation control system as an example. The temperature coefficient of copper is p = 0.0043, and the environmental temperature is generally in the range of -40-60℃. Assuming that the temperature is -40℃ during the self-load full load test of the diesel engine, considering that the environmental temperature may rise to 60℃ in summer, the K value can be estimated according to the following formula:

[0064] p = [(R-R0) / (t-t0)] / R0

[0065] Where R0 is the resistance value of the excitation winding at -40℃ (t0), and R is the resistance value of the excitation winding at 60℃ (t). Then [(R-R0) / (60-(-40))] / R0 = p = 0.0043, and R = 1.43R0.

[0066] Therefore, the accurate value of the temperature coefficient conversion value K is 1.43.

[0067] It should be noted that, in actual use or calculation, K can be 1.5 for a little margin or for convenience of calculation.

[0068] Step S104, determining the maximum duty cycle in use according to the maximum duty cycle and the temperature coefficient conversion value.

[0069] Specifically, when the product of the maximum duty cycle and the temperature coefficient conversion value is less than the initial maximum duty cycle, the product is determined as the maximum duty cycle in use; when the product of the maximum duty cycle and the temperature coefficient conversion value is greater than or equal to the initial maximum duty cycle, the initial maximum duty cycle is determined as the maximum duty cycle in use.

[0070] In the embodiment, the value of KxD1 is compared with the current D max If KxD1 max , the value of KxD1 is determined as the maximum duty cycle in use; if KxD1 max , the preset initial maximum duty cycle D max is determined as the maximum duty cycle in use.

[0071] Step S105, obtaining the duty cycle output by the excitation control system in use.

[0072] Specifically, in actual use, the maximum duty cycle in use is re-determined through the above steps S101-S104 on the basis of the environmental temperature and the temperature sensitivity of the excitation winding, and after the maximum duty cycle in use is determined, the maximum duty cycle in use is used for calculation in all subsequent calculation processes.

[0073] Step S106, calculating the control frequency output by the excitation control system according to the maximum duty cycle in use, the duty cycle output in use and the initial maximum frequency.

[0074] Specifically, the control frequency output by the excitation control system in use is calculated according to the formula F=D / D max xF max .

[0075] Wherein, F represents the control frequency output by the excitation control system, D represents the duty cycle output in use, D max represents the maximum duty cycle in use, and F max represents the initial maximum frequency.

[0076] By the method of the present disclosure, the control accuracy of the excitation control system can be improved. For example, in the present embodiment, the input voltage of the excitation control system is 600V, the rated output voltage is 120V, and the initial duty cycle maximum value is 100%. The actual output duty cycle is 120V / 600V=0.2, i.e. the actual maximum duty cycle is 20%. According to the formula D"=(F"-500) / (1000-500)×100%, D"=20% is substituted into the formula, and the control frequency F"=200Hz is obtained. Therefore, the adjustable range of the actual frequency is 0-200Hz. Assuming that the actual output voltage of the generator is 2000V, then 2000V / 200Hz=10V / 1Hz, and the error accuracy is relatively high.

[0077] If the optimization method of the present disclosure is used, the value of K is 1.5, and then 1.5*0.2=0.3<the initial duty cycle maximum value of 100% is determined as the maximum duty cycle value during use, and the actual maximum duty cycle during use is 30%. At this time, the corresponding relationship between the frequency and the duty cycle is: the frequency corresponds to the duty cycle 0.3 when the frequency is 1000Hz, which is equivalent to the frequency adjustable range of 0-1000Hz. Assuming that the generator output voltage is 2000V, the control frequency is 1000Hz, and the frequency range is 0-1000Hz, assuming that the generator output voltage is 2000V, then 2000V / 1000Hz=2V / 1Hz. The error accuracy is obviously reduced. The method of the present disclosure obviously improves the control frequency accuracy of the excitation control system, and achieves the purpose of improving the output voltage accuracy.

[0078] The method for improving the frequency accuracy of the excitation control system provided by the present disclosure optimizes the duty cycle of the excitation system, so that the frequency and the duty cycle are no longer in a fixed proportional relationship. When the input voltage is relatively high and the output voltage is relatively low, the frequency accuracy will not be lost, and the oscillation will not be caused. The output accuracy of the frequency is ensured, and the accuracy of the output voltage is improved, so that the output signal is stable and reliable.

[0079] In the present disclosure, the excitation winding resistance parameter extraction and the maximum duty cycle setting value adaptive optimization are adopted to improve the control accuracy. At the same time, the temperature characteristics of the excitation winding are also considered to avoid that the current cannot work at full load at high temperature.

[0080] In some embodiments, with reference to Figure 2 , the method for improving the frequency accuracy of the excitation control system comprises:

[0081] (1) According to the initial D max =100% formula, the frequency maximum value F max =1000; and the duty cycle is converted to D=F / 1000×D max .

[0082] (2) When the locomotive is under self-load full load test, the maximum duty cycle D1 at this time is obtained through PID adjustment output.

[0083] (3) The KxD1 value is compared with the current D max , if KxD1 max (Initial value D max = 100%; K is converted according to the temperature coefficient of the field winding, and the current value can be 1.5), replace D max = KxD1 value; D = F / 1000xD max .

[0084] (4) If KxD1 value is greater than D max , keep D max = 1.

[0085] (5) End.

[0086] Based on the same inventive concept, the disclosure also provides a kind of excitation control system corresponding to the method of any of the above embodiments.

[0087] Referring to Figure 3 , One An excitation control system includes:

[0088] Excitation chopper 100, for outputting current to the field coil of generator 300, to drive the generator 300 to work;

[0089] Excitation control board 200, connected with excitation chopper 100 and generator 300, for obtaining first signal output by generator 300, and receiving second signal sent by whole vehicle controller;According to the deviation value between the first signal and the second signal, negative feedback compensation is carried out;The output frequency of the excitation control system is calculated using any one of the methods for improving the frequency accuracy of the excitation control system;The output frequency is sent to the excitation chopper 100.

[0090] Specifically, the excitation chopper 100 is used as the execution part of the excitation control system, for outputting current to the field coil of generator 300, to drive the generator 300 to work. The excitation control board 200 is used as the control part of the excitation control system, for sending the output frequency to the excitation chopper 100, as the control frequency of the excitation chopper 100.

[0091] The excitation control board 200 is used to obtain the first signal output by the generator 300, which refers to the voltage value and the current value output by the generator 300. At the same time, the excitation control board 200 receives the second signal sent by the vehicle controller, which refers to the target voltage value and the current limit value sent by the vehicle controller. After the excitation control board 200 receives the first signal and the second signal, the excitation control board 200 calculates the first deviation value and the second deviation value (the first deviation value refers to the deviation value between the voltage value and the target voltage value, and the second deviation value refers to the deviation value between the current value and the current limit value) according to the received first signal and second signal, and then the excitation control board 200 performs negative feedback compensation according to the first deviation value and the second deviation value. After negative feedback compensation, the control system in the excitation control board 200 calculates the output frequency of the excitation control system using the method for improving the frequency accuracy of the excitation control system, and sends the output frequency to the excitation chopper 100.

[0092] In some embodiments, with reference to Figure 4 , the excitation control board 200 comprises an analog conversion module, a control system module, and a frequency signal pulse output module, wherein

[0093] The analog conversion module is connected with the generator 300, and is used to obtain the first signal output by the generator 300, and send the first signal to the control system module.

[0094] The control system module is used to receive the second signal sent by the vehicle controller, and receive the first signal sent by the analog conversion module; perform negative feedback compensation according to the deviation value between the first signal and the second signal; calculate the control frequency using any one of the methods for improving the frequency accuracy of the excitation control system, and then output the control frequency to the frequency signal pulse output module.

[0095] The frequency signal pulse output module is used to receive the control frequency and convert the control frequency into a pulse signal, and output the pulse signal to the excitation chopper 100.

[0096] Specifically, the first signal refers to the voltage value and the current value output by the generator 300. The second signal refers to the target voltage value and the current limit value sent by the vehicle controller. After the control system module receives the first signal and the second signal, the control system module calculates a first deviation value and a second deviation value (the first deviation value refers to the deviation value between the voltage value and the target voltage value, and the second deviation value refers to the deviation value between the current value and the current limit value) according to the received first signal and second signal, and then the control system module performs negative feedback compensation according to the first deviation value and the second deviation value, calculates the control frequency after negative feedback compensation using the method for improving the frequency accuracy of the excitation control system, and then outputs the control frequency to the frequency signal pulse output module.

[0097] The excitation control system provided by the present disclosure has a more reasonable arrangement that the control part and the chopper execution part are separately arranged. The excitation control board 200 as the control part can be inserted into a weak current cabinet, share the Ethernet and the multi-functional vehicle bus (MVB) communication of the cabinet, and simultaneously collect the voltage and current signals output by the generator 300.

[0098] The separate arrangement of the excitation control board 200 and the excitation chopper 100 makes the placement position of the excitation control board 200 not limited by the excitation chopper 100. The excitation control board 200 can be conveniently placed in various weak current control cabinets such as the vehicle controller, the transmission control unit (TCU) cabinet, and the like, share the Ethernet, the MVB bus and the voltage and current sensors, reduce the cost of detecting the voltage and current sensors on the locomotive, and improve the reliability.

[0099] In the embodiment, the excitation control board 200 is connected with the vehicle controller. The excitation control board 200 receives the target voltage value and the current limit value sent by the vehicle controller, performs PID adjustment according to the target voltage value and the current limit value, and outputs a frequency signal. The frequency signal is converted into a PWM pulse signal after being collected by the chopper. See Figure 1 .

[0100] Using the frequency signal as the driving signal is more convenient and reliable than directly using the pulse width signal or the direct pulse line driving. The signal is simple and reliable, and has strong anti-interference performance.

[0101] In the traditional centralized excitation control system, each module is arranged in the high-voltage area of the auxiliary transformer cabinet, which leads to inconvenience in on-site installation and debugging, and inconvenience in program modification and downloading. The distributed excitation control system adopted by the present disclosure can solve the above problems. In order to ensure safety, the control function is integrated into the upper computer, which can well solve the debugging problem.

[0102] In some embodiments, reference is made to Figure 5 , Figure 6The excitation chopper 100 comprises a water-cooled radiator 106, a support capacitor C1 located on the top of the water-cooled radiator 106, circuit elements 104 arranged at intervals with the support capacitor C1 on the top of the water-cooled radiator 106, a low-inductance bus 103 arranged at intervals above the support capacitor C1 and the circuit elements 104, and a control box 105 located above the low-inductance bus 103 and fixed with the water-cooled radiator 106.

[0103] Specifically, the low-inductance bus 103 is fixed above the support capacitor C1 and the circuit elements 104 by the fastener 102, and the low-inductance bus 103 is arranged at intervals with the support capacitor C1 and the circuit elements 104.

[0104] The control box 105 is fixed with the water-cooled radiator 106 by a support, and the control box 105 is located above the low-inductance bus 103.

[0105] Both ends of the top of the water-cooled radiator 106 are provided with mounting handrails, and positioning pins are arranged on both sides of the connector 104-1 to facilitate maintenance and installation personnel to fix the entire module.

[0106] The excitation chopper 100 integrates control, communication, IGBT driving and other functions, and the main circuit of the excitation chopper 100 adopts a DC-DC chopping circuit structure, two input anti-reverse diodes VD1 are used to isolate low-voltage 110V and high-voltage 600V respectively, and the excitation chopper 100 integrates a discharge resistor, current sampling, a water-cooled radiator 106, an intermediate DC support capacitor C1, two IGBT elements required for an IGBT bridge arm, a low-inductance bus 103, a temperature relay KTE1, etc. The control box 105 on the excitation chopper 100 comprises a power module 105-5, a control board 105-2, a driving board, and a voltage detection board 105-4.

[0107] The main circuit of the excitation chopper 100 adopts a step-down chopping, wherein the power supply is a DC 600V direct current input voltage; C1 is a support capacitor used to filter out ripples in the direct current voltage; R1 is an absorption resistor that reduces the voltage between the two ends of the capacitor to a safe voltage in a short time when the device is not working; when the chopper is working, the first control switch tube IGBT1 is always in an open state, and the reverse diode connected in parallel inside it acts as a freewheeling diode, and the second control switch tube GBT2 is periodically turned on and off to realize chopping control of the output voltage.

[0108] The main circuit excitation circuit is provided with 96V excitation power supply from the battery, the excitation contactor is first closed, then the charging relay is closed to charge the support capacitor C1 of the excitation chopper 100, and when the charging is completed, the excitation chopper 100 provides initial excitation power supply to the excitation winding of the generator 300. When the output voltage of the 600V DC / DC module reaches 500V, the excitation contactor is started to be disconnected, and after the excitation process is completed, the normal excitation state is entered.

[0109] The internal overvoltage and undervoltage protection, temperature protection, and excitation output overcurrent protection of the chopper are realized by detecting the input voltage, intermediate voltage, output current, and temperature relay KTE1.

[0110] The entire excitation chopper 100 adopts a multiple protection control mode, and the entire protection logic is rigorous and has high reliability. The chopper has perfect protection, such as overtemperature, input overvoltage, undervoltage, and output overcurrent. The control board 105-2 can also perform various overvoltage and undervoltage protection and excitation current protection by obtaining information through the network.

[0111] In some embodiments, referring to Figure 7 , the circuit element 104 includes the absorption resistor R1, the control switch tube IGBT, the temperature relay KTE1, the input anti-reverse diode VD1, and the connector 104-1, the absorption resistor R1 and the control switch tube IGBT are arranged close to the support capacitor C1, and the input anti-reverse diode VD1 and the temperature relay KTE1 are located between the control switch tube IGBT and the connector 104-1.

[0112] Specifically, in the embodiment, the input anti-reverse diode VD1 is provided with three, and the single input anti-reverse diode VD1 is arranged in parallel, and the temperature relay KTE1 is located between the adjacent two input anti-reverse diodes VD1. Through the three diodes, the automatic switching of the excitation excitation and the normal operation of the excitation is realized, and the separate excitation current limiting resistor is reduced, and the space and the cost are saved.

[0113] The water-cooled radiator 106 mainly undertakes the heat transfer and cooling of the input anti-reverse diode VD1 and the chopper tube, so that the working temperature rise of the tube does not exceed the specified range.

[0114] In addition, the water-cooled radiator 106 also plays a role in fixing and bearing other components. The power module (input anti-reverse diode VD1 and IGBT module) of the main circuit, the support capacitor C1, the discharge resistor, the current sensor, etc. are directly installed and fixed on the water-cooled radiator 106. The low-inductance bus bar 103 is connected with the power module and the support capacitor C1. Through the low-inductance bus bar 103, the stray inductance can be reduced, the voltage and current peak can be reduced, and the working efficiency and reliability of the chopper can be improved.

[0115] In some embodiments, the control box 105 is provided with a control board 105-2, a drive control board 105-3, a voltage detection board 105-4, and a power module 105-5, the drive control board 105-3 is located between the control board 105-2 and the voltage detection board 105-4, and the control box 105 is further provided with an external control connector 105-1 on the outer wall close to the control board 105-2.

[0116] Specifically, the control box 105 controls the working state of the excitation chopper 100 and detects the state of the generator 300.

[0117] The control board 105-2 is used to detect the input signal and output signal of the main circuit module and the output signal of the generator 300, and to send a control signal to the drive control board 105-3 according to the input signal and output signal of the main circuit module and the output signal of the generator 300, and the drive control board 105-3 controls the off-pulse frequency and pulse width of the switching element in the excitation chopper 100 according to the control signal to adjust the output current of the excitation chopper 100.

[0118] The power module 105-5 is used to receive the driving power of an external power source (such as a battery) and convert the driving voltage to provide working power for the control board 105-2, the drive control board 105-3, and the voltage detection board 105-4. Figure 4 The power module 105-5 is used to receive the driving power of an external power source (such as a battery) and convert the driving voltage to provide working power for the control board 105-2, the drive control board 105-3, and the voltage detection board 105-4.

[0119] It should be noted that the required working power of the control board 105-2, the drive control board 105-3, and the voltage detection board 105-4 is different, so the power module 105-5 is required to convert the driving power of the external power source to provide working power for the control board 105-2, the drive control board 105-3, and the voltage detection board 105-4.

[0120] In some embodiments, in order to make the excitation chopper system of the present disclosure suitable for high-altitude environments, the excitation chopper system of the present disclosure is designed according to different voltage levels from device selection to creepage distance, electrical clearance, etc., and the electrical insulation performance, creepage distance, and electrical clearance of the entire system are considered when designing, and the high-altitude correction coefficient is considered for the internal electrical components. The devices in the excitation chopper of the present disclosure all use 4000VAC devices with a withstand voltage that meets the requirements of high-altitude applications.

[0121] For example, the altitude coefficient of 5100m relative to 1400m is 1.575, when designing the system, all electrical clearances, creepage distances need to be multiplied by the altitude coefficient under the conventional (altitude 1400m) size to obtain the actual size at an altitude of 5100m. For example, an electrical clearance is 2m at an altitude of 1400m, then the electrical clearance at an altitude of 5100m is 2m x 1.575 = 3.15m. Designing the actual minimum electrical clearance required in the system according to the altitude coefficient can effectively prevent electrical breakdown and insulation withstand voltage test failure.

[0122] In addition, the high and low voltage areas in the excitation chopper are designed separately, and the driving lines are as short as possible. Shielding, grounding and other methods are used during wiring to prevent electromagnetic interference.

[0123] It should be noted that the method of the embodiments of the present disclosure can be executed by a single device, such as a computer or a server. The method of the embodiments can also be applied to a distributed scenario, and completed by multiple devices cooperating with each other. In this distributed scenario, one of the multiple devices can only execute one or more steps in the method of the embodiments of the present disclosure, and the multiple devices can interact with each other to complete the method.

[0124] It should be noted that some embodiments of the present disclosure have been described above. Other embodiments are within the scope of the appended claims. In some cases, the acts or steps recited in the claims can be performed in an order different than that described above and still achieve desirable results. Additionally, the process depicted in the figures can not require the particular order shown, or sequential order, to achieve the desired results. In certain implementations, multitasking and parallel processing can be advantageous.

[0125] Based on the same inventive concept, the present disclosure also provides an electronic device corresponding to the method of any of the above embodiments, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the method of any of the embodiments for improving the accuracy of the frequency of the excitation control system.

[0126] Figure 9 A more specific hardware structure of an electronic device provided by the present embodiment is shown, which can include a processor 1010, a memory 1020, an input / output interface 1030, a communication interface 1040 and a bus 1050. The processor 1010, the memory 1020, the input / output interface 1030 and the communication interface 1040 are connected to each other through the bus 1050 for communication within the device.

[0127] The processor 1010 can be implemented by a general-purpose CPU (Central Processing Unit), a microprocessor, an ASIC (Application Specific Integrated Circuit), or one or more integrated circuits, etc., for executing relevant programs to implement the technical solutions provided by the embodiments of the present specification.

[0128] The memory 1020 can be implemented by a ROM (Read Only Memory), a RAM (Random Access Memory), a static storage device, a dynamic storage device, etc. The memory 1020 can store an operating system and other application programs, and when the technical solutions provided by the embodiments of the present specification are implemented by software or firmware, the relevant program codes are stored in the memory 1020 and called and executed by the processor 1010.

[0129] The input / output interface 1030 is configured to connect input / output modules to implement information input and output. The input / output modules can be configured as components in the device (not shown in the figure) or externally connected to the device to provide corresponding functions. The input devices can include a keyboard, a mouse, a touch screen, a microphone, various sensors, etc., and the output devices can include a display, a speaker, a vibrator, an indicator light, etc.

[0130] The communication interface 1040 is configured to connect a communication module (not shown in the figure) to implement the communication interaction between the device and other devices. The communication module can realize communication through a wired manner (such as USB, network cable, etc.) or through a wireless manner (such as mobile network, WIFI, Bluetooth, etc.).

[0131] The bus 1050 includes a channel for transmitting information between various components (such as the processor 1010, the memory 1020, the input / output interface 1030, and the communication interface 1040) of the device.

[0132] It should be noted that although the above device only shows the processor 1010, the memory 1020, the input / output interface 1030, the communication interface 1040, and the bus 1050, in the specific implementation process, the device can also include other components necessary for normal operation. In addition, those skilled in the art can understand that the above device can also only include the components necessary to implement the solutions of the embodiments of the present specification, and does not have to include all the components shown in the figure.

[0133] The electronic device of the above embodiment is used to implement the method of improving the accuracy of the frequency of the excitation control system in any of the preceding embodiments, and has the beneficial effects of the corresponding method embodiments, which are not described here again.

[0134] Based on the same inventive concept, the disclosure also provides a non-transitory computer-readable storage medium storing computer instructions for causing the computer to perform the method of improving the accuracy of the frequency of the excitation control system according to any of the above embodiments.

[0135] The computer-readable medium of the present embodiment includes permanent and non-permanent, removable and non-removable media, which can be implemented by any method or technology to store information. The information can be computer-readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassette, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transmission medium that can be used to store information accessible by a computing device.

[0136] The storage medium of the above embodiment stores computer instructions for causing the computer to perform the method of improving the accuracy of the frequency of the excitation control system according to any of the above embodiments, and has the beneficial effects of the corresponding method embodiments, which are not described here again.

[0137] Those skilled in the art should understand that the above discussion of any of the embodiments is only exemplary and is not intended to imply that the scope of the present disclosure (including claims) is limited to these examples; under the idea of the present disclosure, the above embodiments or technical features between different embodiments can also be combined, the steps can be implemented in any order, and there are many other changes of different aspects of the embodiments of the present disclosure as described above. In order to be brief, they are not provided in detail.

[0138] Additionally, to simplify the description and discussion, and so as not to obscure the embodiments of the disclosure with details that are well known to those skilled in the art, some conventional attributes of integrated circuit (IC) chips and other components can or can not be shown in the drawings or discussed below. Furthermore, devices can be shown in block diagram form in order to avoid obscuring the embodiments of the disclosure, and this also acknowledges the fact that the details in regard to how such block devices are implemented are highly dependent on the platform within which an embodiment of the disclosure is being implemented (i.e., such details should be completely evident to those skilled in the art). Where specific details are set forth in order to describe an illustrative embodiment of the disclosure, it will be apparent to one skilled in the art that the embodiment of the disclosure can be practiced without, or with variations of, these specific details. Thus, the description is to be considered as illustrative and not restrictive, and the scope of the disclosure is to be determined not with the assistance of the foregoing description alone.

[0139] While the disclosure has been described in connection with specific embodiments thereof, many alternatives, modifications and variations will be apparent to those skilled in the art in light of the foregoing description. For example, other memory architectures (e.g., dynamic RAM (DRAM)) can use the embodiments discussed.

[0140] Embodiments of the disclosure are intended to cover all such alternatives, modifications and variations as falling within the scope of the appended claims. Accordingly, any omission, modification, equivalent replacement, improvement, etc. made within the spirit and principle of the embodiments of the disclosure should be included in the protection scope of the disclosure.

Claims

1. A method of improving the accuracy of the frequency of an excitation control system, characterized by, The method is executed by an excitation control system connected with a vehicle controller and a generator, and comprises the following steps: presetting an initial frequency maximum value and an initial duty cycle maximum value of the excitation control system; acquiring a maximum duty cycle output by the locomotive during a self-load full-load test, comprising: receiving a second signal sent by the vehicle controller and a first signal output by the generator, and performing negative feedback compensation according to a deviation value between the first signal and the second signal to obtain an output frequency of the locomotive during the self-load full-load test; and determining the maximum duty cycle output by the locomotive during the self-load full-load test according to the output frequency of the locomotive during the self-load full-load test; acquiring a temperature coefficient conversion value of an excitation winding in the excitation control system; determining a duty cycle maximum value in use according to the maximum duty cycle and the temperature coefficient conversion value; acquiring a duty cycle output by the excitation control system in use; calculating a control frequency output by the excitation control system according to the duty cycle maximum value in use, the duty cycle output in use and the initial frequency maximum value.

2. The method of claim 1, wherein, The method of determining the duty cycle maximum value in use according to the maximum duty cycle and the temperature coefficient conversion value comprises: in response to determining that a product of the maximum duty cycle and the temperature coefficient conversion value is less than the initial duty cycle maximum value, determining the product as the duty cycle maximum value in use; in response to determining that the product of the maximum duty cycle and the temperature coefficient conversion value is greater than or equal to the initial duty cycle maximum value, determining the initial duty cycle maximum value as the duty cycle maximum value in use.

3. The method of claim 1, wherein, According to the formula F = D / D max x F max The control frequency output by the excitation control system is calculated, wherein F represents a control frequency output from the excitation control system, D represents a duty ratio at the time of use, D max represents a maximum value of the duty ratio at the time of use, F max represents a maximum value of the initial frequency.

4. An excitation control system characterized by comprising: The method comprises: an excitation chopper for outputting current to an excitation coil of a generator to drive the generator to work; an excitation control board connected with the excitation chopper and the generator, for acquiring a first signal output by the generator and receiving a second signal sent by a vehicle controller; performing negative feedback compensation according to a deviation value between the first signal and the second signal; calculating an output frequency of the excitation control system by using the method of improving the frequency accuracy of the excitation control system according to any one of claims 1 to 3; and sending the output frequency to the excitation chopper.

5. The system of claim 4, wherein, The excitation control board comprises: an analog conversion module, a control system module and a frequency signal pulse output module, wherein the analog conversion module is connected with the generator, for acquiring the first signal output by the generator and sending the first signal to the control system module; the control system module is configured to receive the second signal sent by the vehicle controller and the first signal sent by the analog conversion module; perform negative feedback compensation according to a deviation value between the first signal and the second signal; calculate a control frequency by using the method of improving the frequency accuracy of the excitation control system according to any one of claims 1 to 3; and output the control frequency to the frequency signal pulse output module; the frequency signal pulse output module is configured to receive the control frequency and convert the control frequency into a pulse signal; and output the pulse signal to the excitation chopper.

6. The system of claim 4, wherein, The excitation chopper comprises: a water-cooled radiator; A support capacitor is arranged on the top of the water-cooled radiator. A circuit element is arranged on the top of the water-cooled radiator and spaced from the support capacitor. A low-inductance bus is arranged above the support capacitor and the circuit element. A control box is arranged above the low-inductance bus and fixed with the water-cooled radiator.

7. The system of claim 6, wherein, The circuit element comprises a plurality of components arranged in a spaced manner, including an absorption resistor, a control switch tube, a temperature relay, an input anti-reverse diode and a connector, the absorption resistor and the control switch tube are arranged close to the support capacitor, the input anti-reverse diode and the temperature relay are both arranged between the control switch tube and the connector.

8. The system of claim 6, wherein, The control box comprises a control board, a driving control board, a voltage detection board and a power module arranged in a spaced manner, the driving control board is arranged between the control board and the voltage detection board, and the control box is further provided with an external control connector on the outer wall close to the control board.

9. An electronic device, comprising: A computer program product comprising a memory, a processor and a computer program stored on the memory and executable on the processor, the processor executes the program to implement the method of any one of claims 1 to 3.

10. A non-transitory computer-readable storage medium, comprising: The non-transitory computer readable storage medium stores computer instructions for causing a computer to execute the method of any one of claims 1 to 3.

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