A Chopping Control Method, Device, Equipment and Medium for a Traction System during Energy Feed

Abstract

The present application discloses a chopper control method, device, electronic device and computer-readable storage medium during the energy feedback of a traction system. The method includes: updating and sampling to obtain the initial value of the intermediate voltage at the starting moment of chopper turn-on; calculating the corresponding set value of the intermediate voltage based on the DC current set value; determining the end value of the intermediate voltage at the chopper turn-off moment based on the initial value of the intermediate voltage and the set value of the intermediate voltage, and the initial value of the intermediate voltage, the set value of the intermediate voltage, and the end value of the intermediate voltage are arranged in an arithmetic progression; determining the chopper duration required for the intermediate voltage to decrease from the initial value of the intermediate voltage to the end value of the intermediate voltage; calculating the duty cycle corresponding to the chopper duration, so as to generate a chopper pulse signal corresponding to the duty cycle for chopper regulation. The present application calculates and controls the duty cycle of the chopper pulse signal based on the intermediate voltage, reasonably discharges the energy of the intermediate circuit, avoids overcurrent of the DC current, and effectively ensures the safety and reliability of the entire traction system and power supply system.

Description

Technical Field

[0001] The present application relates to the technical field of power conversion, and particularly relates to a chopping control method, device, electronic device and computer-readable storage medium during energy feedback of a traction system. Background Art

[0002] For energy conservation, part of the kinetic energy during the braking process of a train can be converted into electrical energy by generating electricity through a traction motor, and then fed to the power grid through an intermediate DC link. The part of the energy exceeding the absorption capacity of the power grid can be dissipated on a braking resistor by chopping.

[0003] Generally, the power of an urban rail train under braking conditions is often greater than the traction power. Therefore, the DC current during high-speed and high-power electric braking of the train is often large. If the energy of the intermediate DC link is not controlled, it may cause the DC current in the intermediate DC link to be too high or even overcurrent, which will cause serious harm to the entire traction system and power supply system. Specifically, a relatively high DC current will cause the reactor at the front end of the inverter to overheat and be easily damaged when passing through the reactor. At the same time, a relatively high DC current flowing through the reactor will also generate a strong magnetic field radiation, interfering with the stable operation of devices such as sensors and control boards. In addition, when a relatively high DC current is fed back to the power grid, in severe cases, it will cause the power supply equipment to trip and burn out, causing serious harm to the entire traction system and power supply system.

[0004] In view of this, providing a solution to solve the above technical problems has been an urgent concern for those skilled in the art. Summary of the Invention

[0005] The purpose of the present application is to provide a chopping control method, device, electronic device and computer-readable storage medium during energy feedback of a traction system, so as to effectively solve the problem of too high DC current during energy feedback and ensure the safe operation of the traction system.

[0006] To solve the above technical problems, on the one hand, the present application discloses a chopping control method during energy feedback of a traction system, including:

[0007] Update the sampling to obtain the initial value of the intermediate voltage at the starting moment of chopping turn-on;

[0008] Calculate the corresponding set value of the intermediate voltage based on the DC current set value;

[0009] Determine the end value of the intermediate voltage at the chopping turn-off moment based on the initial value of the intermediate voltage and the set value of the intermediate voltage, and the initial value of the intermediate voltage, the set value of the intermediate voltage, and the end value of the intermediate voltage are arranged in an arithmetic progression;

[0010] Determine the chopping duration required to reduce the intermediate voltage from the initial value of the intermediate voltage to the end value of the intermediate voltage;

[0011] Calculate a duty cycle corresponding to the chopping duration, so as to generate a chopping pulse signal corresponding to the duty cycle for chopping control.

[0012] Optionally, calculating the corresponding intermediate voltage set value based on the DC current set value includes:

[0013] Update the sampling to obtain the initial DC current value at the starting moment of chopping turn-on;

[0014] Calculate the line impedance based on the initial DC current value and the initial intermediate voltage value;

[0015] Calculate the intermediate voltage set value based on the line impedance and the DC current set value;

[0016] Wherein, the intermediate voltage U d , the DC current I d , the line impedance R L and the grid voltage U net satisfy the relationship:

[0017] U d - U net = I d · R L .

[0018] Optionally, determining the chopping duration required for the intermediate voltage to decrease from the initial intermediate voltage value to the final intermediate voltage value includes:

[0019] Calculate the energy change amount of the support capacitor during the period when the intermediate voltage decreases from the initial intermediate voltage value to the final intermediate voltage value;

[0020] Calculate the power difference between the chopping power of the chopping resistor in the traction system and the electric braking power of the motor;

[0021] Calculate the ratio of the energy change amount to the power difference to obtain the chopping duration.

[0022] Optionally, calculating the energy change amount of the support capacitor during the period when the intermediate voltage decreases from the initial intermediate voltage value to the final intermediate voltage value includes:

[0023] According to △E d = 0.5 · C · (U 2 d_stud - U 2 d_end ) calculate the energy change amount;

[0024] Wherein, △E d is the energy change amount; C is the capacitance value of the support capacitor; U d_studis the initial value of the intermediate voltage; U d_end is the end value of the intermediate voltage.

[0025] Optionally, calculating the power difference between the chopping power of the chopping resistor and the electric braking power of the motor in the traction system includes:

[0026] According to calculate the power difference between the chopping power of the chopping resistor and the electric braking power of the motor in the traction system;

[0027] where, P chop is the chopping power; P m is the electric braking power of a single motor; N is the total number of motors; U d_ref is the set value of the intermediate voltage; R chop is the resistance value of the chopping resistor; T e is the torque during train operation; n is the motor speed.

[0028] On the other hand, the present application discloses a chopping control device during the energy feedback of a traction system, including:

[0029] An update module, configured to update and sample to obtain the initial value of the intermediate voltage at the starting moment of chopping conduction;

[0030] A calculation module, configured to calculate the corresponding set value of the intermediate voltage based on the DC current set value; determine the end value of the intermediate voltage at the chopping turn-off moment based on the initial value of the intermediate voltage and the set value of the intermediate voltage, and the initial value of the intermediate voltage, the set value of the intermediate voltage, and the end value of the intermediate voltage are arranged in an arithmetic progression;

[0031] A determination module, configured to determine the chopping duration required for the intermediate voltage to decrease from the initial value of the intermediate voltage to the end value of the intermediate voltage; calculate the duty cycle corresponding to the chopping duration;

[0032] A control module, configured to generate a chopping pulse signal corresponding to the duty cycle for chopping regulation.

[0033] Optionally, when the calculation module calculates the corresponding set value of the intermediate voltage based on the DC current set value, it specifically is used for:

[0034] Update and sample to obtain the initial value of the DC current at the starting moment of chopping conduction; calculate the line impedance based on the initial value of the DC current and the initial value of the intermediate voltage; calculate the set value of the intermediate voltage based on the line impedance and the DC current set value;

[0035] where, the intermediate voltage U d 、DC current I d 、line impedance R L and grid voltage U netsatisfy the relational expression:

[0036] U d -U net = I d ·R L .

[0037] Optionally, when determining the chopping duration required for the intermediate voltage to decrease from the initial value of the intermediate voltage to the end value of the intermediate voltage, the determining module is specifically configured to:

[0038] Calculate the energy change of the support capacitor during the period when the intermediate voltage decreases from the initial value of the intermediate voltage to the end value of the intermediate voltage; calculate the power difference between the chopping power of the chopping resistor in the traction system and the electric braking power of the motor; calculate the ratio of the energy change to the power difference to obtain the chopping duration.

[0039] Optionally, when calculating the energy change of the support capacitor during the period when the intermediate voltage decreases from the initial value of the intermediate voltage to the end value of the intermediate voltage, the determining module is specifically configured to:

[0040] According to △E d = 0.5·C·(U 2 d_stud -U 2 d_end ) calculate the energy change;

[0041] wherein, △E d is the energy change; C is the capacitance value of the support capacitor; U d_stud is the initial value of the intermediate voltage; U d_end is the end value of the intermediate voltage.

[0042] Optionally, when calculating the power difference between the chopping power of the chopping resistor in the traction system and the electric braking power of the motor, the determining module is specifically configured to:

[0043] According to calculate the power difference between the chopping power of the chopping resistor in the traction system and the electric braking power of the motor;

[0044] wherein, P chop is the chopping power; P m is the electric braking power of a single motor; N is the total number of motors; U d_ref is the set value of the intermediate voltage; R chop is the resistance value of the chopping resistor; T e is the torque during train operation; n is the motor speed.

[0045] On the other hand, the present application also discloses an electronic device, including:

[0046] A memory for storing a computer program;

[0047] A processor for executing the computer program to implement the steps of any of the chopping control methods during the energy feedback of the traction system as described above.

[0048] On the other hand, the present application also discloses a computer-readable storage medium, in which a computer program is stored, and when the computer program is executed by a processor, it is used to implement the steps of any of the chopping control methods during the energy feedback of the traction system as described above.

[0049] The chopping control method during the energy feedback of the traction system provided by the present application includes: updating the sampling to obtain the initial value of the intermediate voltage at the starting moment of chopping conduction; calculating the corresponding set value of the intermediate voltage based on the DC current set value; determining the ending value of the intermediate voltage at the chopping turn-off moment based on the initial value of the intermediate voltage and the set value of the intermediate voltage, and the initial value of the intermediate voltage, the set value of the intermediate voltage, and the ending value of the intermediate voltage are arranged in an arithmetic progression; determining the chopping duration required for the intermediate voltage to decrease from the initial value of the intermediate voltage to the ending value of the intermediate voltage; calculating the duty cycle corresponding to the chopping duration, so as to generate a chopping pulse signal corresponding to the duty cycle for chopping regulation.

[0050] The beneficial effects of the chopping control method, device, electronic device, and computer-readable storage medium during the energy feedback of the traction system provided by the present application are: the present application calculates and controls the duty cycle of the chopping pulse signal based on the intermediate voltage, so as to discharge the energy of the intermediate circuit regularly and orderly, make the current of the intermediate DC circuit stable within a certain range and avoid overcurrent, and effectively ensure the safety and reliability of the entire traction system and power supply system. Description of the Drawings

[0051] In order to more clearly illustrate the technical solutions in the prior art and the embodiments of the present application, the following will briefly introduce the drawings required for the description of the prior art and the embodiments of the present application. Of course, the following drawings related to the embodiments of the present application only show a part of the embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to the provided drawings, and the other obtained drawings also fall within the protection scope of the present application.

[0052] Figure 1 It is a flowchart of a chopping control method during the energy feedback of a traction system disclosed in an embodiment of the present application;

[0053] Figure 2 It is a schematic diagram of the main circuit structure of a traction system disclosed in an embodiment of the present application;

[0054] Figure 3Schematic diagram of the topology structure of a traction inverter disclosed in an embodiment of the present application;

[0055] Figure 4 Chopping schematic diagram when the traction system feeds energy back, disclosed in an embodiment of the present application;

[0056] Figure 5 Control block diagram of a chopping control method when the traction system feeds energy back, disclosed in an embodiment of the present application;

[0057] Figure 6 Structural block diagram of a chopping control device when the traction system feeds energy back, disclosed in an embodiment of the present application;

[0058] Figure 7 Structural block diagram of an electronic device disclosed in an embodiment of the present application. Detailed implementation manners

[0059] The core of the present application is to provide a chopping control method, device, electronic device and computer-readable storage medium when the traction system feeds energy back, so as to effectively solve the problem of excessive DC current during energy feedback and ensure the safe operation of the traction system.

[0060] In order to describe the technical solutions in the embodiments of the present application more clearly and completely, the following will introduce the technical solutions in the embodiments of the present application in conjunction with the accompanying drawings in the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0061] When urban rail trains are in operation, due to the large number of stations, they often frequently switch between traction and braking conditions. In the high-speed braking condition, in order to reduce brake shoe wear and at the same time reduce energy consumption, the electric braking of the traction system is usually used to brake the train and recover energy. The electric braking converts the kinetic energy of the train into electrical energy, and the electrical energy is fed back to the power grid through the DC side of the traction system. The energy that cannot be absorbed by the power grid is then converted into heat energy through the braking resistor for energy dissipation.

[0062] If the energy dissipated by chopping is not controlled under high-power braking conditions, it may cause the DC current flowing back to the grid side to be too large or even overcurrent, which will cause great harm to the reliable operation of the traction power supply system equipment. Aiming at the problem of overcurrent of the DC current during energy feedback caused by too high braking power of the train under the braking condition, the present application provides a chopping control scheme when the traction system feeds energy back, which can effectively solve this problem.

[0063] See Figure 1 As shown, an embodiment of the present application discloses a chopping control method when the traction system feeds energy back, which mainly includes:

[0064] S101: Update the sampling to obtain the initial value of the intermediate voltage at the starting moment of chopper turn-on.

[0065] S102: Calculate the corresponding set value of the intermediate voltage based on the DC current set value.

[0066] S103: Determine the end value of the intermediate voltage at the chopper turn-off moment based on the initial value of the intermediate voltage and the set value of the intermediate voltage. The initial value of the intermediate voltage, the set value of the intermediate voltage, and the end value of the intermediate voltage are arranged in an arithmetic progression.

[0067] S104: Determine the chopping duration required for the intermediate voltage to decrease from the initial value of the intermediate voltage to the end value of the intermediate voltage.

[0068] S105: Calculate the duty cycle corresponding to the chopping duration, so as to generate a chopping pulse signal corresponding to the duty cycle for chopping control.

[0069] Specifically, refer to Figure 2 , Figure 2 which is a schematic diagram of the main circuit structure of a traction system disclosed in an embodiment of the present application. Among them, the topological structure of the traction inverter can be specifically referred to Figure 3 . In addition, C is a support capacitor, and the voltage across its two ends is the intermediate voltage U d ; the DC current flowing to the pantograph during chopping is I d ; R chop is a chopping resistor, and the current flowing through it is the chopping current I chop .

[0070] The present application is controlled from the perspective of the DC side reflux energy, and the energy of the intermediate DC link is effectively controlled based on the chopping control technology to ensure that the intermediate DC current in the loop is relatively stable and does not overcurrent. Specifically, the present application pre-sets a set value for the DC current, that is, the DC current set value I d_ref , and through relevant chopping control, the DC current is controlled within a small variation range centered on the DC current set value.

[0071] Combined with Figure 2 it can be known that according to the intermediate voltage U d , the DC current I d , the line impedance R L and the grid voltage U net the relationship between them is:

[0072] U d -U net =I d ·R L ;

[0073] It can be known that the DC current I d and the intermediate voltage U dis directly related. Therefore, by controlling the chopping to stabilize the intermediate voltage U d , the DC current I can be effectively stabilized d .

[0074] See Figure 4 , Figure 4 which is a chopping schematic diagram of a traction system during energy feedback disclosed in an embodiment of the present application. Among them, U d_stud is the initial value of the intermediate voltage; U d_ref is the set value of the intermediate voltage; U d_end is the end value of the intermediate voltage. U d_stud is specifically obtained by sampling at the initial moment of chopping, and U d_ref can be specifically calculated and obtained according to the DC current set value I d_ref in combination with the above relational expression.

[0075] As Figure 4 shown in the chopping control method of the present application, in each control cycle, after the chopping is turned on, when the value of the intermediate voltage U d decreases from U d_stud to U d_end , the chopping is turned off. During the off period, the intermediate voltage rises again due to the continuous braking of the train; until the next control cycle when the chopping is turned on again.

[0076] Among them, it should be emphasized that for the moment when the chopping is turned off, that is, the moment when the value of the intermediate voltage U d decreases to U d_end , the present application specifically limits the value of U d_end : Let U d_stud , U d_ref , U d_end be arranged in an arithmetic progression, that is:

[0077] △U = U d_stud - U d_ref = U d_ref - U d_end ;

[0078] In this way, based on U d_stud , U d_ref , the value of U d_end can be determined. Further, during the chopping turn-on process of each control cycle, the energy change amount stored in the support capacitor can be calculated as:

[0079] △E d = 0.5·C·(U 2 d_stud - U 2 d_end );

[0080] Among them, △Ed is the energy change; C is the capacitance value of the support capacitor; U d_stud is the initial value of the intermediate voltage; U d_end is the end value of the intermediate voltage.

[0081] Since during the chopper turn-on process in each control period, the energy generated by the electric machine braking and the change in the energy stored in the support capacitor are both consumed by the chopper resistor, the following can be obtained:

[0082] E chop = P chop ·t chop = ΔE d + N·P m ·t chop ;

[0083] Among them, E chop is the energy consumed by the chopper resistor; P chop is the chopping power; t chop is the chopper turn-on duration within a single control period; P m is the electric braking power of a single motor; N is the number of motors; △E d is the energy change of the support capacitor during the chopper turn-on process; N·P m ·t chop is the energy generated by the braking of the motor during the chopper turn-on process.

[0084] Thus, after determining the value of △E d_stud based on U d_ref and U d , and determining the value of N·P m ·t chop , E chop can be calculated. Combining with P chop , the corresponding value of t chop can be obtained, and the duty cycle can be further calculated as follows:

[0085]

[0086] α = t chop / T c ;

[0087] Among them, T c is the control period. In this way, the corresponding chopping pulse signal can be generated according to the calculated duty cycle to achieve the chopping regulation of the traction system, so as to stabilize the DC current within a certain range and avoid overcurrent.

[0088] The chopping control method during energy feedback of the traction system provided by the embodiments of the present application includes: updating the sampling to obtain the initial value of the intermediate voltage at the starting moment of chopping turn-on; calculating the corresponding set value of the intermediate voltage based on the DC current set value; determining the end value of the intermediate voltage at the moment of chopping turn-off based on the initial value of the intermediate voltage and the set value of the intermediate voltage, and the initial value of the intermediate voltage, the set value of the intermediate voltage, and the end value of the intermediate voltage are arranged in an arithmetic progression; determining the chopping duration required for the intermediate voltage to decrease from the initial value of the intermediate voltage to the end value of the intermediate voltage; calculating the duty cycle corresponding to the chopping duration, so as to generate a chopping pulse signal corresponding to the duty cycle for chopping control.

[0089] It can be seen that the chopping control method during energy feedback of the traction system provided by the present application calculates and controls the duty cycle of the chopping pulse signal based on the intermediate voltage, regularly discharges the energy of the intermediate circuit in an orderly manner, and stabilizes the current in the intermediate DC circuit within a certain range to avoid overcurrent. And the present application does not need to additionally increase hardware equipment, and can control the DC current flowing back to the grid side through the reactor by software method, reduce the temperature rise and magnetic field radiation of the reactor, and effectively ensure the safety and reliability of the entire traction system and power supply system.

[0090] See Figure 5 , Figure 5 is the control block diagram of a chopping control method during energy feedback of a traction system disclosed in an embodiment of the present application.

[0091] As Figure 5 shown, as a specific embodiment, on the basis of the above content, the chopping control method during energy feedback of the traction system provided by the embodiments of the present application calculates the corresponding set value of the intermediate voltage based on the DC current set value, including:

[0092] Updating the sampling to obtain the initial value of the DC current at the starting moment of chopping turn-on;

[0093] Calculating the line impedance based on the initial value of the DC current and the initial value of the intermediate voltage;

[0094] Calculating the set value of the intermediate voltage based on the line impedance and the DC current set value;

[0095] Wherein, the intermediate voltage U d , the DC current I d , the line impedance R L and the grid voltage U net satisfy the relational expression:

[0096] U d -U net =I d ·R L .

[0097] Specifically, according to this relational expression, when the initial value I of the DC current at the starting moment of chopper turn-on is obtained by sampling d_stud and the initial value U of the intermediate voltage d_stud , the line impedance can be calculated correspondingly according to the relational expression. Furthermore, substituting the set value I of the DC current d_ref into this relational expression again, the set value U of the intermediate voltage can be calculated d_ref .

[0098] R L =(U d_stud -U net ) / I d_stud ;

[0099] U d_ref =U net +I d_ref ·R L .

[0100] As a specific embodiment, based on the above content, the chopper control method during the energy feedback of the traction system provided by the embodiment of the present application determines the chopping duration required for the intermediate voltage to decrease from the initial value of the intermediate voltage to the end value of the intermediate voltage, including:

[0101] Calculating the energy change amount of the support capacitor during the period when the intermediate voltage decreases from the initial value of the intermediate voltage to the end value of the intermediate voltage;

[0102] Calculating the power difference between the chopping power of the chopping resistor in the traction system and the electric braking power of the motor;

[0103] Calculating the ratio of the energy change amount to the power difference to obtain the chopping duration.

[0104] Among them, the energy change amount of the support capacitor during the period when the intermediate voltage decreases from the initial value of the intermediate voltage to the end value of the intermediate voltage can be specifically calculated according to the following formula:

[0105] △E d =0.5·C·(U 2 d_stud -U 2 d_end );

[0106] Among them, △E d is the energy change amount; C is the capacitance value of the support capacitor; U d_stud is the initial value of the intermediate voltage; U d_end is the end value of the intermediate voltage.

[0107] In addition, the power difference between the chopping power of the chopping resistor in the traction system and the electric braking power of the motor can be specifically calculated according to the following formula:

[0108]

[0109] Among them, P chop is the chopping power; P m is the electric braking power of a single motor; N is the total number of motors; U d_ref is the intermediate voltage set value; R chop is the resistance value of the chopping resistor; T e is the torque during train operation; n is the motor speed.

[0110] See Figure 6 As shown, the embodiment of the present application discloses a chopping control device during the energy feedback of a traction system, mainly including:

[0111] An update module 201, configured to update and sample the initial value of the intermediate voltage at the starting moment of chopping conduction;

[0112] A calculation module 202, configured to calculate the corresponding intermediate voltage set value based on the DC current set value; determine the end value of the intermediate voltage at the chopping turn-off moment based on the initial value of the intermediate voltage and the intermediate voltage set value, and the initial value of the intermediate voltage, the intermediate voltage set value, and the end value of the intermediate voltage are arranged in an arithmetic progression;

[0113] A determination module 203, configured to determine the chopping duration required for the intermediate voltage to decrease from the initial value of the intermediate voltage to the end value of the intermediate voltage; calculate the duty cycle corresponding to the chopping duration;

[0114] A control module 204, configured to generate a chopping pulse signal corresponding to the duty cycle for chopping regulation.

[0115] It can be seen that the chopping control device during the energy feedback of the traction system disclosed in the embodiment of the present application calculates and controls the duty cycle of the chopping pulse signal based on the intermediate voltage, so as to regularly and orderly discharge the energy of the intermediate circuit, keep the current in the intermediate DC circuit stable within a certain range and avoid overcurrent, effectively ensuring the safety and reliability of the entire traction system and power supply system.

[0116] Regarding the specific content of the above-mentioned chopping control device during the energy feedback of the traction system, reference can be made to the detailed introduction of the chopping control method during the energy feedback of the traction system described above, and details will not be repeated here.

[0117] As a specific embodiment, on the basis of the above content, when calculating the corresponding intermediate voltage set value based on the DC current set value, the calculation module 202 of the chopping control device during the energy feedback of the traction system disclosed in the embodiment of the present application is specifically configured to:

[0118] Update and sample the initial value of the DC current at the starting moment of chopping conduction; calculate the line impedance based on the initial value of the DC current and the initial value of the intermediate voltage; calculate the intermediate voltage set value based on the line impedance and the DC current set value;

[0119] Among them, the intermediate voltage U d , the DC current I d , the line impedance R L and the grid voltage U net satisfy the relational expression:

[0120] U d - U net = I d · R L .

[0121] As a specific embodiment, on the basis of the above content, the chopper control device during the energy feedback of the traction system disclosed in the embodiments of the present application, when the determination module 203 determines the chopping duration required for the intermediate voltage to decrease from the initial intermediate voltage value to the final intermediate voltage value, specifically is used for:

[0122] Calculate the energy change amount of the support capacitor during the period when the intermediate voltage decreases from the initial intermediate voltage value to the final intermediate voltage value; calculate the power difference between the chopping power of the chopping resistor in the traction system and the electric braking power of the motor; calculate the ratio of the energy change amount to the power difference to obtain the chopping duration.

[0123] As a specific embodiment, on the basis of the above content, the chopper control device during the energy feedback of the traction system disclosed in the embodiments of the present application, when the determination module 203 calculates the energy change amount of the support capacitor during the period when the intermediate voltage decreases from the initial intermediate voltage value to the final intermediate voltage value, specifically is used for:

[0124] According to △E d = 0.5 · C · (U 2 d_stud - U 2 d_end ) to calculate the energy change amount;

[0125] Among them, △E d is the energy change amount; C is the capacitance value of the support capacitor; U d_stud is the initial intermediate voltage value; U d_end is the final intermediate voltage value.

[0126] As a specific embodiment, on the basis of the above content, the chopper control device during the energy feedback of the traction system disclosed in the embodiments of the present application, when the determination module 203 calculates the power difference between the chopping power of the chopping resistor in the traction system and the electric braking power of the motor, specifically is used for:

[0127] According to to calculate the power difference between the chopping power of the chopping resistor in the traction system and the electric braking power of the motor;

[0128] Among them, P chop is the chopping power; Pm is the electric braking power of a single motor; N is the total number of motors; U d_ref is the intermediate voltage set value; R chop is the resistance value of the chopping resistor; T e is the torque during train operation; n is the motor speed.

[0129] See Figure 7 As shown, an embodiment of the present application discloses an electronic device, including:

[0130] A memory 301 for storing a computer program;

[0131] A processor 302 for executing the computer program to implement the steps of any of the chopping control methods during the energy feedback of the traction system as described above.

[0132] Further, an embodiment of the present application also discloses a computer-readable storage medium, in which a computer program is stored, and when the computer program is executed by a processor, it is used to implement the steps of any of the chopping control methods during the energy feedback of the traction system as described above.

[0133] Regarding the specific content of the above-mentioned electronic device and computer-readable storage medium, reference can be made to the detailed introduction of the chopping control method during the energy feedback of the traction system described above, and details will not be repeated here.

[0134] In the embodiments of the present application, each embodiment is described in a progressive manner. The key point of each embodiment is the difference from other embodiments. The same or similar parts among the embodiments can be referred to each other. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the description of the method part.

[0135] It should also be noted that in the present application document, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. In addition, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including one..." does not exclude the existence of another identical element in the process, method, article or device including the element.

[0136] The above has introduced the technical solution provided by this application in detail. Specific examples are used herein to elaborate on the principle and implementation manner of this application. The description of the above embodiments is only used to help understand the method and its core idea of this application. It should be noted that for those of ordinary skill in the art, without departing from the principle of this application, several improvements and modifications can still be made to this application, and these improvements and modifications also fall within the protection scope of this application.

Claims

1. A chopper control method during the energy feedback of a traction system, characterized in that, Including: Updating and sampling to obtain the initial value of the intermediate voltage at the starting moment of chopper turn-on; Calculating the corresponding set value of the intermediate voltage based on the DC current set value; Determining the end value of the intermediate voltage at the chopper turn-off moment based on the initial value of the intermediate voltage and the set value of the intermediate voltage, and the initial value of the intermediate voltage, the set value of the intermediate voltage, and the end value of the intermediate voltage are arranged in an arithmetic progression; Determining the chopping duration required for the intermediate voltage to decrease from the initial value of the intermediate voltage to the end value of the intermediate voltage; Calculating the duty cycle corresponding to the chopping duration so as to generate a chopping pulse signal corresponding to the duty cycle for chopping control; The calculating the corresponding set value of the intermediate voltage based on the DC current set value includes: Updating and sampling to obtain the initial value of the DC current at the starting moment of chopper turn-on; Calculating the line impedance based on the initial value of the DC current and the initial value of the intermediate voltage; Calculating the set value of the intermediate voltage based on the line impedance and the DC current set value; Among them, the intermediate voltage U d , the DC current I d , the line impedance R L and the grid voltage U net satisfy the relationship: U d -U net = I d ·R L ; The determining the chopping duration required for the intermediate voltage to decrease from the initial value of the intermediate voltage to the end value of the intermediate voltage includes: Calculating the energy change amount of the support capacitor during the intermediate voltage decreasing from the initial value of the intermediate voltage to the end value of the intermediate voltage; Calculating the power difference between the chopping power of the chopping resistor in the traction system and the electric braking power of the motor; Calculating the ratio of the energy change amount to the power difference to obtain the chopping duration; The calculating the energy change amount of the support capacitor during the intermediate voltage decreasing from the initial value of the intermediate voltage to the end value of the intermediate voltage includes: According to △E d = 0.5·C·(U 2 d_stud - U 2 d_end ) calculate the amount of energy change; Among them, △E d is the energy change amount; C is the capacitance value of the support capacitor; U d_stud is the initial value of the intermediate voltage; U d_end is the end value of the intermediate voltage; The calculating the power difference between the chopping power of the chopping resistor in the traction system and the electric braking power of the motor includes: According to calculate the power difference between the chopping power of the chopping resistor in the traction system and the electric braking power of the motor; Among them, P chop is the chopping power; P m is the electric braking power of a single motor; N is the total number of motors; U d_ref is the set value of the intermediate voltage; R chop is the resistance value of the chopping resistor; T e is the torque during train operation; n is the motor speed.

2. A chopper control device during the energy feedback of a traction system, characterized in that, Including: An updating module for updating and sampling to obtain the initial value of the intermediate voltage at the starting moment of chopper turn-on; A calculating module for calculating the corresponding set value of the intermediate voltage based on the DC current set value; determining the end value of the intermediate voltage at the chopper turn-off moment based on the initial value of the intermediate voltage and the set value of the intermediate voltage, and the initial value of the intermediate voltage, the set value of the intermediate voltage, and the end value of the intermediate voltage are arranged in an arithmetic progression; A determining module for determining the chopping duration required for the intermediate voltage to decrease from the initial value of the intermediate voltage to the end value of the intermediate voltage; Calculating the duty cycle corresponding to the chopping duration; A control module for generating a chopping pulse signal corresponding to the duty cycle for chopping control; When the calculating module calculates the corresponding set value of the intermediate voltage based on the DC current set value, it is specifically used for: Updating and sampling to obtain the initial value of the DC current at the starting moment of chopper turn-on; calculating the line impedance based on the initial value of the DC current and the initial value of the intermediate voltage; calculating the set value of the intermediate voltage based on the line impedance and the DC current set value; Among them, the intermediate voltage U d , the DC current I d , the line impedance R L and the grid voltage U net satisfy the relationship: U d -U net = I d ·R L ; When the determining module determines the chopping duration required for the intermediate voltage to decrease from the initial value of the intermediate voltage to the end value of the intermediate voltage, it is specifically used for: Calculate the energy change of the support capacitor during the reduction of the intermediate voltage from the initial value of the intermediate voltage to the end value of the intermediate voltage; calculate the power difference between the chopping power of the chopping resistor in the traction system and the electric braking power of the motor; calculate the ratio of the energy change to the power difference to obtain the chopping duration; The calculation of the energy change of the support capacitor during the reduction of the intermediate voltage from the initial value of the intermediate voltage to the end value of the intermediate voltage includes: According to △E d = 0.5·C·(U 2 d_stud - U 2 d_end ) to calculate the amount of energy change; Among them, △E d is the energy change amount; C is the capacitance value of the support capacitor; U d_stud is the initial value of the intermediate voltage; U d_end is the end value of the intermediate voltage; The calculation of the power difference between the chopping power of the chopping resistor in the traction system and the electric braking power of the motor includes: According to calculate the power difference between the chopping power of the chopping resistor in the traction system and the electric braking power of the motor; Among them, P chop is the chopping power; P m is the electric braking power of a single motor; N is the total number of motors; U d_ref is the set value of the intermediate voltage; R chop is the resistance value of the chopping resistor; T e is the torque during train operation; n is the motor speed.

3. An electronic device, characterized in that, Includes: A memory for storing a computer program; A processor for executing the computer program to implement the steps of the chopping control method during the energy feedback of the traction system as claimed in claim 1.

4. A computer-readable storage medium, characterized in that, A computer program is stored in the computer-readable storage medium, and when the computer program is executed by a processor, it is used to implement the steps of the chopping control method during the energy feedback of the traction system as claimed in claim 1.

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