Method and device for inhibiting magnetic bias during control switching process of through-phase traction power supply system

Abstract

The application discloses a through-phase traction power supply system control switching process magnetic bias suppression method and device, electronic equipment and storage medium, through analyzing the output transformer magnetic bias problem in the through-type flexible traction power supply system, including three main DC magnetic bias generation scenarios. A method for controlling the output transformer magnetic bias in the through-type flexible traction power supply system is proposed, including magnetic bias suppression control in normal operation, slow start control, voltage ± 90° phase control and phase splicing control when establishing voltage. The application implements the specific reasons and characteristics of the output transformer magnetic bias in the through-type flexible traction power supply system, deeply analyzes and describes the magnetic bias problem and the principle and implementation method of the magnetic bias control method, the control method is targeted, and the magnetic bias control method is detailed and effective, which can be applied to similar scenes.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of transformer magnetic bias suppression, and in particular relates to a method and device for suppressing magnetic bias during control switching process of a through-phase traction power supply system, an electronic device and a storage medium. BACKGROUND

[0002] The through-type flexible traction power supply system uses a static power converter (SPC) to replace the traditional traction transformer to perform three-phase to single-phase power conversion, realize the through connection of the traction network, cancel the electric phase separation, reduce the power quality problem, and can perform bilateral power supply and wide-area energy regulation, thus having a good development prospect.

[0003] After the structure of the traction power supply system is changed, the protection mechanism also has higher requirements: on the one hand, attention should be paid to the influence of voltage and current under fault on the SPC, and on the other hand, attention should be paid to limiting the spread of the fault along the through traction network to cause large-area parking. For the short-circuit fault of the traction network, in order to meet the above requirements, the related technology controls the fault current by making the SPC run uninterruptedly. The SPC is in a voltage frequency control (VFC) mode and a fault current control (FCC) mode during normal operation and short-circuit fault, respectively.

[0004] However, the mode switching in the process of starting to establish voltage of the SPC device and the short-circuit fault of the traction network and the clearing process brings about a sudden change in voltage amplitude, which may cause the output transformer of the SPC to have serious magnetic bias in a short time. At present, the related technology is mostly to solve the problem of small-amplitude accumulation of direct current magnetic bias, and lacks specific research on the transformer magnetic bias problem in the scene of the through-type flexible traction power supply system, which needs to be solved urgently. SUMMARY

[0005] The present application provides a method and device for suppressing magnetic bias during control switching process of a through-phase traction power supply system, an electronic device and a storage medium to solve the problem of SPC output transformer magnetic bias in the scene of the through-type flexible traction power supply system.

[0006] The first aspect embodiment of the application provides a method for inhibiting magnetic bias during switching process of a through-phase traction power supply system, comprising the following steps: identifying an actual working condition of the through-phase traction power supply system; when the actual working condition is a first switching working condition between system static and system start-up, the through-phase traction power supply system executes a preset voltage slow start control scheme or a preset voltage ±90° phase control scheme to inhibit magnetic bias generated when voltage of the through-phase traction power supply system is established; when the actual working condition is a steady voltage running working condition, the through-phase traction power supply system executes a preset magnetic bias inhibition control scheme to inhibit or correct magnetic bias generated in the through-phase traction power supply system; when the actual working condition is a second switching working condition between fault steady flow running and the steady voltage running, the through-phase traction power supply system executes the preset voltage slow start control scheme or the preset voltage phase splicing control scheme to inhibit magnetic bias generated in the through-phase traction power supply system during transient process.

[0007] Optionally, in one embodiment of the application, in the first switching working condition and the second switching working condition, the through-phase traction power supply system executes a preset voltage slow start control scheme or a preset voltage ±90° phase control scheme, so that after the through-phase traction power supply system enters the steady voltage running working condition, the through-phase traction power supply system executes the preset magnetic bias inhibition control scheme to correct magnetic bias in the through-phase traction power supply system.

[0008] Optionally, in one embodiment of the application, the through-phase traction power supply system executing the preset magnetic bias inhibition control scheme comprises: collecting a primary side current value of a primary side of a transformer and a secondary side current value of a secondary side of the transformer; calculating the primary side current value by a first proportion, and then subtracting the secondary side current value to obtain a difference value; calculating the difference value by a second proportion to obtain a transformer compensation voltage signal; and adding the transformer compensation voltage signal to a modulation voltage reference value of a converter after taking inversion, and performing closed-loop negative feedback adjustment.

[0009] Optionally, in one embodiment of the application, in the first switching working condition and the second switching working condition, the through-phase traction power supply system executes the preset voltage slow start control scheme, comprising: determining a slow start duration according to converter main loop parameters and control protection parameters; and controlling the amplitude of a modulation reference voltage signal of the converter to increase in a monotonically increasing manner to a required amplitude within the slow start duration when voltage is established.

[0010] Optionally, in one embodiment of the present application, in the first switching condition, the through-phase traction power supply system executes a preset voltage ±90° phase control scheme, including: when the through-phase traction power supply system starts, the voltage initial phase is controlled to be ±90° of cosine, and the voltage amplitude is stepped from 0 to a given value.

[0011] Optionally, in one embodiment of the present application, in the second switching condition, the through-phase traction power supply system executes the preset voltage phase splicing control scheme, including: collecting the system voltage instantaneous value at the moment when the catenary short-circuit fault occurs; calculating the voltage phase θ according to the voltage instantaneous value r ; at the moment when the fault current stabilization operation is switched to the voltage stabilization operation, the phase of the converter modulation voltage is switched to the voltage phase, and the voltage amplitude is stepped from 0 to a given value.

[0012] The second aspect embodiment of the present application provides a through-phase traction power supply system control switching process magnetic bias suppression device, including: an identification module for identifying the actual working condition of the through-phase traction power supply system; a first suppression module for, when the actual working condition is a first switching condition between system static and system start, the through-phase traction power supply system executes a preset voltage slow start control scheme or a preset voltage ±90° phase control scheme, and the magnetic bias generated when the voltage of the through-phase traction power supply system is established is suppressed; a second suppression module for, when the actual working condition is a voltage stabilization operation condition, the through-phase traction power supply system executes a preset magnetic bias suppression control scheme, and the magnetic bias generated in the through-phase traction power supply system is suppressed or corrected; a third suppression module for, when the actual working condition is a second switching condition between a fault current stabilization operation and the voltage stabilization operation, the through-phase traction power supply system executes the preset voltage slow start control scheme or the preset voltage phase splicing control scheme, and the magnetic bias generated in the transient process of the through-phase traction power supply system is suppressed.

[0013] Optionally, in one embodiment of the present application, in the first switching condition and the second switching condition, the through-phase traction power supply system executes a preset voltage slow start control scheme or a preset voltage ±90° phase control scheme, so that after the through-phase traction power supply system enters the voltage stabilization operation condition, the through-phase traction power supply system executes the preset magnetic bias suppression control scheme to correct the magnetic bias in the through-phase traction power supply system.

[0014] Optionally, in an embodiment of the present application, the second inhibiting module comprises: a collecting unit configured to collect a primary side current value of the primary side of the transformer and a secondary side current value of the secondary side of the transformer; a calculating unit configured to calculate the primary side current value by a first proportion, and then subtract the secondary side current value to obtain a transformer compensation voltage signal; and an adjusting unit configured to add the transformer compensation voltage signal to a modulation voltage reference value of the converter after taking the opposite of the transformer compensation voltage signal, and perform closed-loop negative feedback adjustment.

[0015] Optionally, in an embodiment of the present application, in the first switching working condition and the second switching working condition, the through-phase traction power supply system performs the preset voltage slow-start control scheme, comprising: determining a slow-start duration according to converter main circuit parameters and control protection parameters; and increasing the amplitude of the modulation reference voltage signal of the converter to a required amplitude in a monotonically increasing manner within the slow-start duration when the voltage is established.

[0016] Optionally, in an embodiment of the present application, in the first switching working condition, the through-phase traction power supply system performs a preset voltage ±90° phase control scheme, comprising: when the through-phase traction power supply system is started, controlling the converter to make the voltage initial phase be ±90° of the cosine, and simultaneously the voltage amplitude is stepped from 0 to a given value.

[0017] Optionally, in an embodiment of the present application, in the second switching working condition, the through-phase traction power supply system performs the preset voltage phase splicing control scheme, comprising: collecting a system voltage instantaneous value at the moment when the catenary short-circuit fault occurs; calculating a voltage phase according to the voltage instantaneous value; and switching the phase of the converter modulation voltage to the voltage phase at the moment when the fault current stabilization operation is changed to the voltage stabilization operation, and simultaneously the voltage amplitude is stepped from 0 to a given value.

[0018] The third aspect embodiment of the present application 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 perform the through-phase traction power supply system control switching process magnetic bias suppression method as described in the above embodiments.

[0019] The fourth aspect embodiment of the present application provides a computer readable storage medium having a computer program stored thereon, wherein the program is executed by a processor to perform the through-phase traction power supply system control switching process magnetic bias suppression method as described in the above embodiments.

[0020] Therefore, the present application has at least the following beneficial effects:

[0021] The actual working condition of the through-phase traction power supply system is identified; when the actual working condition is a first switching working condition between system static and system start-up, the through-phase traction power supply system executes a preset voltage slow start control scheme or a preset voltage ±90° phase control scheme to suppress the magnetic bias generated when the through-phase traction power supply system is established; when the actual working condition is a steady voltage running working condition, the through-phase traction power supply system executes a preset magnetic bias suppression control scheme to suppress or correct the magnetic bias generated in the through-phase traction power supply system; when the actual working condition is a second switching working condition between fault steady flow running and steady voltage running, the through-phase traction power supply system executes a preset voltage slow start control scheme or a preset voltage phase splicing control scheme to suppress the magnetic bias generated in the transient process of the through-phase traction power supply system, so that the system can suppress the SPC output transformer DC magnetic bias during static to start-up and during the contact net short circuit fault handling process, avoid the transformer entering one-way magnetic saturation, avoid the excitation current surging to trigger the related protection to make the SPC lock, the control speed of the DC magnetic bias is fast, and the implementation method is simple, without the need to increase additional hardware devices. Therefore, the problems of SPC output transformer magnetic bias and the like in the through-type flexible traction power supply system are solved.

[0022] Additional aspects and advantages of the present application will be in part apparent and in part pointed out hereinafter. BRIEF DESCRIPTION OF DRAWINGS

[0023] The above and / or additional aspects and advantages of the present application will become apparent and be readily appreciated from the following description, including the accompanying drawings, wherein:

[0024] Figure 1 A flowchart of a through-phase traction power supply system control switching process magnetic bias suppression method according to an embodiment of the present application is provided;

[0025] Figure 2 A principle diagram of a through-phase traction power supply system control switching process magnetic bias suppression method according to an embodiment of the present application is provided;

[0026] Figure 3 An execution logic schematic diagram of a magnetic bias suppression control method according to an embodiment of the present application is provided;

[0027] Figure 4 A specific implementation flow of a magnetic bias suppression control method with a magnetic flux observer according to an embodiment of the present application is provided;

[0028] Figure 5 An execution logic schematic diagram of a transformer magnetic bias control performed by a voltage slow start scheme according to an embodiment of the present application is provided;

[0029] Figure 6 An execution logic diagram for transformer magnetic bias control provided by a phase continuous control scheme according to an embodiment of the present application;

[0030] Figure 7 An example diagram of a magnetic bias suppression device for a through-type in-phase traction power supply system control switching process according to an embodiment of the present application;

[0031] Figure 8 A structural diagram of an electronic device provided by an embodiment of the present application.

[0032] Legend: identification module - 100, first suppression module - 200, second suppression module - 300, third suppression module - 400, memory - 801, processor - 802, communication interface - 803. DETAILED DESCRIPTION

[0033] Embodiments of the present application are described in detail below with reference to the accompanying drawings, examples of which are shown in the drawings, in which the same or similar notations are used to denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by reference to the accompanying drawings are exemplary and are intended to explain the present application, and cannot be understood as limiting the present application.

[0034] A through-type in-phase traction power supply system control switching process magnetic bias suppression method, device, electronic device and storage medium of an embodiment of the present application are described below with reference to the accompanying drawings. In view of the problems mentioned in the above background art, the present application provides a through-type in-phase traction power supply system control switching process magnetic bias suppression method, in which the actual working condition of the through-type in-phase traction power supply system is identified; when the actual working condition is a first switching working condition between system static and system start-up, the through-type in-phase traction power supply system executes a preset voltage slow start control scheme or a preset voltage ±90° phase control scheme to suppress the magnetic bias generated when the voltage of the through-type in-phase traction power supply system is established; when the actual working condition is a steady voltage running working condition, the through-type in-phase traction power supply system executes a preset magnetic bias suppression control scheme to suppress or correct the magnetic bias generated in the through-type in-phase traction power supply system; and when the actual working condition is a second switching working condition between a transient process and steady voltage control, the through-type in-phase traction power supply system executes a preset voltage slow start control scheme or a preset voltage phase splicing control scheme to suppress the magnetic bias generated in the transient process of the through-type in-phase traction power supply system, so that the system can suppress the SPC output transformer DC magnetic bias during static to start-up and during the catenary short circuit fault handling process, avoid the transformer entering one-way magnetic saturation, avoid the excitation current surging to trigger related protection to make the SPC lock, the control speed of the DC magnetic bias is fast, and the implementation method is simple and does not need to increase additional hardware devices. Thus, the problems of SPC output transformer magnetic bias in the through-type flexible traction power supply system are solved.

[0035] In order to introduce the magnetic bias suppression method of the embodiments of the present application, first introduce the scene of magnetic bias generation in the through-phase traction power supply system, specifically, the output transformer magnetic bias problem in the through-type flexible traction power supply system, which is mainly divided into the following three categories:

[0036] The first category, the system is started by static, enters the VFC mode to establish the voltage, and the magnetic bias related to the initial phase of the voltage;

[0037] The second category, when the system has established voltage and is stably running, that is, in the VFC mode, due to the non-ideal symmetry of the converter output voltage, the direct current magnetic bias may also be accumulated under long-term integration;

[0038] The third category, when the traction network occurs a short circuit fault, the system enters the fault current control FCC mode, and the system voltage transient process after re-entering the VFC mode after the fault is removed may cause transformer magnetic bias.

[0039] The embodiments of the present application propose three starting control methods for the magnetic bias problem caused by the short-time process of normal starting or mode switching:

[0040] Method 1, voltage slow starting control, the voltage amplitude is slowly raised from 0 to a given value, and the phase can be preset to a fixed value;

[0041] Method 2, voltage ±90° phase control, the voltage amplitude is stepped to a given value, and the phase is set to 90 degrees or -90 degrees;

[0042] Method 3, voltage phase splicing control, the voltage amplitude is stepped to a given value, and the phase is set to the phase record value at the initial time when the VFC mode is switched to the FCC mode, that is, the voltage phase of the VFC mode is basically consistent before and after the fault by ignoring the series of changes of the voltage phase in the FCC mode.

[0043] The above magnetic bias suppression method of the embodiments of the present application will be introduced in detail for the above magnetic bias.

[0044] Specifically, Figure 1 A flowchart of a through-phase traction power supply system control switching process magnetic bias suppression method provided by the embodiments of the present application.

[0045] As Figure 1 shown, the through-phase traction power supply system control switching process magnetic bias suppression method includes the following steps:

[0046] In step S101, the actual working condition of the through-phase traction power supply system is identified.

[0047] It can be understood that the embodiments of the present application execute different magnetic bias suppression control schemes according to different actual working conditions of the through-phase traction power supply system. In the embodiments of the present application, the actual working conditions can include the through-phase traction power supply system at rest, starting, transient process, VFC and switching process between them. In order to better describe the scheme of the present application, the embodiments of the present application limit the actual working conditions, wherein the working condition switching between the through-phase traction power supply system at rest and starting is referred to as the first switching working condition, and the working condition switching between the through-phase traction power supply system fault current stabilization operation and voltage stabilization operation is referred to as the second switching working condition, wherein the fault current stabilization operation is the response mode of the through-phase traction power supply system when the overhead contact line short circuit fault occurs. After identifying the actual working condition of the through-phase traction power supply system, the through-phase traction power supply system executes the corresponding magnetic bias suppression method, which will be described in detail below.

[0048] In step S102, when the actual working condition is the first switching working condition between the system at rest and the system starting, the through-phase traction power supply system executes the preset voltage slow starting control scheme or the preset voltage ±90° phase control scheme to suppress the magnetic bias generated when the voltage of the through-phase traction power supply system is established.

[0049] It should be noted that the magnetic bias control method proposed in the present application mainly consists of two parts, which are represented by the dashed box ① and the dashed box ② in the following. Figure 2 The box ① represents the above-mentioned magnetic bias suppression control, which works throughout the VFC to correct the magnetic bias or suppress the generation of the magnetic bias. The box ② represents the starting scheme of the VFC, which only works when the voltage is established in the VFC mode. The present application provides two VFC starting schemes, VFC starting scheme one: voltage slow starting control; and VFC starting scheme two: voltage ±90° phase control, one of which can be selected as appropriate.

[0050] The scope of the embodiments of the present application is applicable to all small systems with consistent traction substation model switching behavior, that is, after the overhead contact line short circuit fault occurs, all traction substations will be switched from the VFC to the FCC control, and after the fault is cleared, all traction substations will be switched back to the VFC synchronously, and the same VFC starting scheme is used. Specifically, the specific implementation process of the above-mentioned magnetic bias suppression control scheme and the two VFC starting schemes will be described in detail below.

[0051] Alternatively, in an embodiment of the present application, in the first switching working condition, the through-phase traction power supply system executes the preset voltage slow starting control scheme, which includes: determining the slow starting time length according to the converter main circuit parameters and the control and protection parameters; when the voltage is established, the amplitude of the modulation reference voltage signal of the converter is increased to the required amplitude in a monotonically increasing manner within the slow starting time length, including but not limited to linearly increasing, and the initial phase can be preset to a fixed value.

[0052] Optionally, in an embodiment of the present application, in the first switching working condition, the through-phase traction power supply system executes a preset voltage slow-start control scheme or a preset voltage ±90° phase control scheme, so that after the through-phase traction power supply system enters a steady voltage running working condition, the through-phase traction power supply system executes a preset magnetic bias suppression control scheme to correct the magnetic bias in the through-phase traction power supply system.

[0053] The above-mentioned voltage slow-start scheme, i.e., VFC start-up scheme I, specifically, in an embodiment of the present application, a suitable slow-start time t_m is first set according to the system start-up speed requirement and the consideration of alleviating the magnetic bias, and a typical value is, for example, 100 ms to 1 s; the amplitude of the modulation reference voltage signal of the converter is linearly increased from 0 to the rated amplitude within the slow-start time when establishing the voltage, and taking linear growth as an example:

[0054]

[0055] The voltage slow-start scheme of entering the VFC mode is characterized in that the magnetic bias is basically not generated in the process of establishing the voltage, and this method can directly solve the magnetic bias problem of the first type; for the third type of magnetic bias problem, the voltage slow-start when re-entering the VFC mode also plays a role of not bringing new DC magnetic bias, but cannot eliminate the residual magnetic bias left when the short-circuit fault occurs, and the control effect on the third type of magnetic bias problem is limited.

[0056] Optionally, in an embodiment of the present application, in the first switching working condition, the through-phase traction power supply system executes a preset voltage ±90° phase control scheme, which includes: when the through-phase traction power supply system starts, the voltage initial phase is controlled to be ±90° below the cosine by the converter, and at the same time, the voltage amplitude is stepped to a given value from 0.

[0057] Specifically, in an embodiment of the present application, the voltage ±90° phase control scheme, i.e., VFC start-up scheme II, for the case that the system enters the VFC mode from static, the voltage initial phase is controlled to be ±90° below the cosine by the converter at the start-up, which can solve the problem of the above-mentioned first type of magnetic bias; similarly, for the third type of magnetic bias problem, the voltage ±90° phase control plays a role of not bringing new DC magnetic bias, but cannot eliminate the residual magnetic bias left when the short-circuit fault occurs, and the control effect on the third type of magnetic bias problem is limited.

[0058] In step S103, when the actual working condition is the steady voltage running working condition, the through-phase traction power supply system executes a preset magnetic bias suppression control scheme to suppress or correct the magnetic bias generated in the through-phase traction power supply system.

[0059] Optionally, in one embodiment of the present application, the through-phase traction power supply system executes a preset magnetic bias suppression control scheme, which comprises: collecting the primary current value of the primary side of the transformer and the secondary current value of the secondary side of the transformer; calculating the primary current value by a first proportion, and then subtracting the secondary current value, and then calculating the difference value by a second proportion to obtain a transformer compensation voltage signal; and adding the transformer compensation voltage signal to the modulation voltage reference value of the converter after taking the opposite, and performing closed-loop negative feedback adjustment.

[0060] Specifically, in the embodiments of the present application, Figure 3 The execution logic of the magnetic bias suppression control method of the present application is shown. As Figure 3 shown, the magnetic bias suppression control method first needs to install current sensors on the primary side and the secondary side of the transformer, and collect the currents i1 and i2 of the primary side and the secondary side in real time; then signal processing is needed, and the primary side current i1 is converted to the secondary side by the transformation ratio K inv , and then subtracted from the secondary side current i2 to obtain a magnetic bias signal Then i_bias is multiplied by a proper proportion coefficient to obtain a compensation voltage signal u_compensation for the magnetic bias; and the compensation voltage signal u_compensation is taken as the opposite number and added to the modulation voltage reference value of the converter, which essentially realizes a closed-loop negative feedback of the magnetic bias amount.

[0061] It can be understood that the magnetic bias suppression control method is characterized in that the collected current signal and the feedback voltage compensation signal are instantaneous values, and therefore has the advantage of fast magnetic bias control speed.

[0062] In addition, the magnetic bias suppression control method is a method without a direct magnetic flux observer. If there is a related transformer magnetic flux observer, the corresponding magnetic bias signal φ_bias can be directly observed for feedback control, and the principle is the same as the above method. Figure 4 The specific implementation process of the magnetic bias suppression control method with a magnetic flux observer is shown.

[0063] In step S104, when the actual working condition is the second switching working condition between the fault steady flow operation and the steady voltage operation, the through-phase traction power supply system executes a preset voltage slow start control scheme or a preset voltage phase splicing control scheme to suppress the magnetic bias generated by the transient process of the through-phase traction power supply system.

[0064] Optionally, in an embodiment of the present application, in the first switching working condition and the second switching working condition, the through-phase traction power supply system performs a preset voltage slow-start control scheme, which comprises: determining a slow-start duration according to the main circuit parameters and the control and protection parameters of the converter; when the rated voltage is established, controlling the amplitude of the modulation reference voltage signal of the converter to monotonously increase to a required amplitude in the slow-start duration in a linear manner, for example, but not limited to, and the initial phase can be preset as a fixed value.

[0065] Specifically, in the second switching working condition, the through-phase traction power supply system performs a preset voltage slow-start control scheme which is the same as that in the first switching working condition, and no detailed description is given. It should be noted that the above-mentioned second switching working condition corresponds to the third type of magnetic bias problem, and the slow-start can only suppress part of the DC magnetic bias, and the remaining part needs to rely on the DC magnetic bias suppression control to eliminate.

[0066] Optionally, in an embodiment of the present application, in the second switching working condition, the through-phase traction power supply system performs a preset voltage phase splicing control scheme, which comprises: collecting the instantaneous value of the system voltage at the moment when the catenary short-circuit fault occurs; calculating the voltage phase θ r at the moment when the fault current stabilization control is switched to the voltage stabilization control, switching the phase of the modulation voltage of the converter to the voltage phase θ r , and simultaneously the voltage amplitude is stepped from 0 to a given value.

[0067] Specifically, in an embodiment of the present application, in the voltage phase splicing control scheme, for the case that the system enters the VFC mode again after passing through the short-circuit fault and clearing the fault, a phase storage variable needs to be added in the control logic first, and the system voltage phase θ at the moment when the fault occurs is recorded at the moment. Then, at the moment when the system enters the VFC mode again after clearing the fault, the phase of the modulation voltage of the converter is instantaneously switched to θ , and simultaneously the voltage amplitude is stepped from 0 to a given value.

[0068] Optionally, in an embodiment of the present application, in the second switching working condition, the through-phase traction power supply system performs a preset voltage slow-start control scheme or a preset voltage phase splicing control scheme, so that after the through-phase traction power supply system enters the voltage stabilization running working condition, the through-phase traction power supply system performs a preset magnetic bias suppression control scheme to correct the magnetic bias in the through-phase traction power supply system.

[0069] It can be understood that the phase continuous control scheme entering the VFC mode is characterized in that the voltage phase of the whole system needs to be switched by the control of the converter, which can be realized for the current small-scale through-type flexible traction power supply system; in the process of the transient state such as fault occurrence and removal in the actual engineering, the actual output of the converter voltage may not be completely equal to the control reference value due to the constraint of the external conditions of the system, so there is still a certain DC magnetic bias, which also needs to be corrected by the above magnetic bias suppression control.

[0070] The through-type in-phase traction power supply system control switching process magnetic bias suppression method will be described below by specific examples in combination with the accompanying drawings. The implementation of the transformer magnetic bias control method proposed in the present application mainly includes two schemes of voltage slow start and voltage phase control.

[0071] Figure 5 The execution logic of the voltage slow start scheme for transformer magnetic bias control is shown. As shown in Figure 5

[0072] State 1: The system is started by static, the magnetic bias suppression control starts to work, and the voltage is established by selecting the voltage slow start scheme.

[0073] State 2: Enter the stable VFC mode, monitor the traction network current, if it is greater than or equal to the set threshold value, it is judged that the traction network has a short circuit fault, enter the next state, otherwise maintain in this state, and the traction network voltage is kept by the converter control.

[0074] State 3: The system is switched to the FCC mode, since the output voltage amplitude of the converter is relatively small at this time, the influence on the magnetic flux is small, and there is no magnetic bias suppression control in this state. Monitor the traction network voltage, if it is greater than or equal to the set threshold value, it is judged that the traction network short circuit fault has been cleared, enter the next state, otherwise maintain in this state, and the traction network current is kept by the converter control.

[0075] State 4: The system reenters the VFC mode, the magnetic bias suppression control starts to work, and the voltage is established by selecting the voltage slow start, so that the voltage amplitude is linearly increased from 0 to the required voltage amplitude, and then enters state 2 again.

[0076] Figure 6 The execution logic of the phase continuous control scheme for transformer magnetic bias control is shown. As shown in Figure 6

[0077] State 1: The system is started by static, the magnetic bias suppression control starts to work, and the voltage is established by selecting the voltage ±90° phase control scheme, the initial phase of the voltage is set to ±90° of the cosine, and the voltage amplitude is stepped to the given value.

[0078] ​​State 2: Enter stable VFC mode, monitor traction network current, if greater than or equal to the set threshold, determine that the traction network has a short circuit fault, enter the next state, otherwise maintain in this state, control the traction network voltage to keep a certain value through the converter.

[0079] State 3: The system switches to FCC mode, and the voltage phase θ of the system at this time is recorded r .

[0080] State 4: Enter stable FCC, since the output voltage amplitude of the converter at this time is relatively small, the influence on the magnetic flux is small, there is no field suppression control in this state. Monitor the traction network voltage, if greater than or equal to the set threshold, determine that the traction network short circuit fault has been cleared, enter the next state, otherwise maintain in this state, control the traction network current to keep a certain value through the converter.

[0081] State 5: The system reenters VFC mode, the field suppression control starts to work, the voltage ±90° phase control scheme is selected to establish the voltage, and the system voltage phase is switched to the previously recorded θ through the converter control r , at the same time the voltage amplitude jumps from 0 to the given value and keeps the required value, and then enters state 2 again.

[0082] It should be noted that the criteria for system mode switching in the implementation process shown in the drawings of the present application are: when i2 exceeds the set threshold i set , it is determined that the system switches from the stable voltage operation condition to the fault stable current operation condition; when u2 exceeds the set threshold u set , it is determined that the system switches from the fault stable current operation condition to the stable voltage operation condition. The mode switching criteria include but are not limited to the above methods.

[0083] The embodiments of the present application have been simulated by PSCAD software, dynamic model test and Beijing Daxing Airport line through traction power supply actual engineering application, which confirms the feasibility and reliability of the proposed field control method.

[0084] According to the method for inhibiting magnetic bias in the switching process of the through-phase traction power supply system, the magnetic bias problem of the output transformer in the through-type flexible traction power supply system is completely analyzed, including three main DC magnetic bias generation scenarios, a method for controlling the magnetic bias of the output transformer in the through-type flexible traction power supply system is proposed, including the magnetic bias inhibition control acting in normal operation and the slow start control and voltage phase control acting in voltage establishment. The specific implementation method and implementation process of the magnetic bias control method are described in detail. The specific causes and characteristics of the magnetic bias of the output transformer in the through-type flexible traction power supply system are implemented, and the magnetic bias problem and the principle and implementation method of the magnetic bias control method are analyzed and described in depth. The control method is targeted and detailed and effective, and can be applied to similar scenarios.

[0085] Secondly, the through-phase traction power supply system control switching process magnetic bias inhibition device according to the embodiment of the application is described with reference to the accompanying drawings.

[0086] Figure 7 The through-phase traction power supply system control switching process magnetic bias inhibition device according to the embodiment of the application is a block diagram.

[0087] As shown in Figure 7 , the through-phase traction power supply system control switching process magnetic bias inhibition device 10 comprises an identification module 100, a first inhibition module 200, a second inhibition module 300 and a third inhibition module 400.

[0088] The identification module 100 is configured to identify the actual working condition of the through-phase traction power supply system. The first inhibition module 200 is configured to, when the actual working condition is a first switching working condition between system static and system start, execute a preset voltage slow start control scheme or a preset voltage ±90° phase control scheme on the through-phase traction power supply system to inhibit the magnetic bias generated when the voltage of the through-phase traction power supply system is established. The second inhibition module 300 is configured to, when the actual working condition is a voltage stabilization working condition, execute a preset magnetic bias inhibition control scheme on the through-phase traction power supply system to inhibit or correct the magnetic bias generated in the through-phase traction power supply system. The third inhibition module 400 is configured to, when the actual working condition is a second switching working condition between fault current stabilization operation and voltage stabilization operation, execute a preset voltage slow start control scheme or a preset voltage phase splicing control scheme on the through-phase traction power supply system to inhibit the magnetic bias generated in the transient process of the through-phase traction power supply system.

[0089] Optionally, in one embodiment of the present application, in the first switching mode and the second switching mode, the through-phase traction power supply system executes a preset voltage slow-start control scheme or a preset voltage ±90° phase control scheme, so that after the through-phase traction power supply system enters a steady voltage operation mode, the through-phase traction power supply system executes a preset magnetic bias suppression control scheme to correct the magnetic bias in the through-phase traction power supply system.

[0090] Optionally, in one embodiment of the present application, the second suppression module 300 comprises: an acquisition unit configured to acquire a primary side current value of a primary side of a transformer and a secondary side current value of a secondary side of the transformer; a calculation unit configured to calculate the primary side current value by a first proportion, and then subtract the secondary side current value to obtain a transformer compensation voltage signal; and an adjustment unit configured to add the transformer compensation voltage signal to a modulation voltage reference value of a converter after taking the opposite, and perform closed-loop negative feedback adjustment.

[0091] Optionally, in one embodiment of the present application, in the first switching mode and the second switching mode, the through-phase traction power supply system executes a preset voltage slow-start control scheme, which comprises: determining a slow-start duration according to converter main circuit parameters and control protection parameters; and controlling the amplitude of a modulation reference voltage signal of the converter to monotonically increase to a required amplitude within the slow-start duration when establishing voltage.

[0092] Optionally, in one embodiment of the present application, in the first switching mode, the through-phase traction power supply system executes a preset voltage ±90° phase control scheme, which comprises: when the through-phase traction power supply system is started, controlling the converter to make the voltage initial phase be ±90° below the cosine, and at the same time, the voltage amplitude is stepped from 0 to a given value.

[0093] Optionally, in one embodiment of the present application, in the second switching mode, the through-phase traction power supply system executes a preset voltage phase splicing control scheme, which comprises: acquiring a system voltage instantaneous value at the moment when a catenary short-circuit fault occurs; calculating a voltage phase according to the voltage instantaneous value; and at the moment when the fault steady current control is switched to steady voltage control, switching the phase of the converter modulation voltage to the voltage phase, and at the same time, the voltage amplitude is stepped from 0 to a given value.

[0094] It should be noted that the foregoing explanation and description of the embodiment of the method for suppressing magnetic bias in the switching process of the through-phase traction power supply system also apply to the embodiment of the device for suppressing magnetic bias in the switching process of the through-phase traction power supply system, which will not be described here again.

[0095] The through-type same-phase traction power supply system control switching process magnetic bias suppression device provided by the embodiment of the application is obtained by analyzing the output transformer magnetic bias problem in the through-type flexible traction power supply system, including three main DC magnetic bias generation scenarios. A method for controlling the output transformer magnetic bias in the through-type flexible traction power supply system is proposed, including magnetic bias suppression control that works during normal operation and slow start control and voltage phase control that work when the voltage is established. The embodiment of the application implements the specific reasons and characteristics of the output transformer magnetic bias in the through-type flexible traction power supply system, and deeply analyzes and describes the magnetic bias problem and the principle and implementation method of the magnetic bias control method. The control method is targeted and detailed and effective, and can be applied to similar scenarios.

[0096] Figure 8 The structure schematic diagram of the electronic device provided by the embodiment of the application is provided. The electronic device can include:

[0097] The memory 801, the processor 802 and the computer program stored in the memory 801 and executable on the processor 802.

[0098] The processor 802 implements the through-type same-phase traction power supply system control switching process magnetic bias suppression method provided in the above embodiment when executing the program.

[0099] Further, the electronic device further includes:

[0100] The communication interface 803 is used for communication between the memory 801 and the processor 802.

[0101] The memory 801 is used to store the computer program executable on the processor 802.

[0102] The memory 801 can include a high-speed RAM memory, and can also include a non-volatile memory, for example, at least one disk memory.

[0103] If the memory 801, the processor 802 and the communication interface 803 are independently implemented, the communication interface 803, the memory 801 and the processor 802 can be connected to each other through a bus and complete the communication between each other. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. For the convenience of representation, Figure 8Only one bus or only one type of bus can exist, however.

[0104] Optionally, in a specific implementation, if the memory 801, the processor 802 and the communication interface 803 are integrated on a chip, the memory 801, the processor 802 and the communication interface 803 can complete the communication with each other through an internal interface.

[0105] The processor 802 can be a central processing unit (CPU) or an application specific integrated circuit (ASIC), or one or more integrated circuits configured to perform the methods described in the embodiments of the present application.

[0106] The embodiment further provides a computer readable storage medium, which stores a computer program, and the program is executed by a processor to implement the method for suppressing magnetic bias of a control switching process of a through-phase traction power supply system.

[0107] In the description of the specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in one or N embodiments or examples. In addition, the person skilled in the art can combine and combine the different embodiments or examples described in the specification and the features of the different embodiments or examples without contradiction.

[0108] In addition, the terms "first", "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "N" is at least two, for example, two, three, etc., unless otherwise specifically limited.

[0109] Any process or method described in a flowchart or otherwise described herein can be understood as representing a module, segment, or portion of code that includes one or more executable instructions for implementing the specified logical functions or steps, and the preferred embodiments of the application include additional or fewer steps, or combinations of steps, or the order of the steps can be different from those shown or discussed. It is intended that additional or fewer steps be performed between any two steps, and one of ordinary skill in the art would recognize many variations based on the functional description.

[0110] It should be understood that aspects of the application can be implemented in hardware, software, firmware or combinations thereof. In the above embodiments, the steps or methods can be implemented in software or firmware that is stored in memory and executed by a suitable instruction execution system. As such, if desired, the functions can be implemented in hardware, using, for example, any or a combination of the following technologies, which are all well-known in the art: a discrete logic circuit having logic gates for implementing logic functions upon an application of data signals, an application specific integrated circuit having appropriate combinational logic gates, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0111] Those of skill in the art would understand that information and signals can be represented using any of a variety of technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that can be referenced throughout the above description can be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof. Those of skill would further appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the disclosure herein can be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality, rather than their specific arrangement of parts. Depending upon the implementation, those of skill in the art would recognize that an illustrative component, block, module, circuit, or step can be implemented in hardware, software, or a combination of both.

Claims

1. A method for controlling the magnetic bias suppression of a switching process in a through-phase traction power supply system, characterized in that The method comprises the following steps: identifying the actual working condition of the through-phase traction power supply system; when the actual working condition is a first switching working condition between system static and system start-up, the through-phase traction power supply system executes a preset voltage slow start control scheme or a preset voltage ±90° phase control scheme to suppress the magnetic bias generated when the through-phase traction power supply system is established voltage; when the actual working condition is a steady voltage running working condition, the through-phase traction power supply system executes a preset magnetic bias suppression control scheme to suppress or correct the magnetic bias generated in the through-phase traction power supply system; when the actual working condition is a second switching working condition between fault steady flow running and the steady voltage running, the through-phase traction power supply system executes the preset voltage slow start control scheme or the preset voltage phase splicing control scheme to suppress the magnetic bias generated in the transient process of the through-phase traction power supply system; wherein, in the second switching working condition, the through-phase traction power supply system executes the preset voltage phase splicing control scheme, comprising: collecting the system voltage instantaneous value at the moment when the catenary short circuit fault occurs; calculating the voltage phase according to the voltage instantaneous value; at the moment when the fault steady flow running is changed into the steady voltage running, the phase of the converter modulation voltage is switched to the voltage phase, and the voltage amplitude is stepped from 0 to a given value.

2. The method of claim 1, wherein, In the first switching working condition and the second switching working condition, the through-phase traction power supply system executes a preset voltage slow start control scheme or a preset voltage ±90° phase control scheme, so that after the through-phase traction power supply system enters the steady voltage running working condition, the through-phase traction power supply system executes the preset magnetic bias suppression control scheme to correct the magnetic bias in the through-phase traction power supply system.

3. The method of claim 1, wherein, The through-phase traction power supply system executes the preset magnetic bias suppression control scheme, comprising: collecting the primary side current value of the transformer primary side and the secondary side current value of the transformer secondary side; calculating the difference between the primary side current value after the first proportion calculation and the secondary side current value, and obtaining the transformer compensation voltage signal after the second proportion calculation of the difference value; after the transformer compensation voltage signal is inverted, it is added to the modulation voltage reference value of the converter for closed-loop negative feedback adjustment.

4. The method of claim 1, wherein, In the first switching working condition and the second switching working condition, the through-phase traction power supply system executes the preset voltage slow start control scheme, comprising: determining the slow start duration according to the converter main circuit parameters and control protection parameters; when the rated voltage is established, the amplitude of the modulation reference voltage signal of the converter is increased to the required amplitude in a monotonically increasing manner within the slow start duration.

5. The method of claim 1, wherein, In the first switching working condition, the through-phase traction power supply system executes a preset voltage ±90° phase control scheme, comprising: when the through-phase traction power supply system starts, the voltage initial phase is controlled to be ±90° of the cosine by the converter, and the voltage amplitude is stepped from 0 to a given value.

6. A device for suppressing magnetic bias during a control switching process in a through-phase traction power supply system, characterized in that comprising: an identification module for identifying the actual working condition of the through-phase traction power supply system; The first suppression module is configured to, when the actual working condition is a first switching working condition between system static and system start-up, execute a preset voltage slow start control scheme or a preset voltage ±90° phase control scheme on the through same-phase traction power supply system, and suppress the magnetic bias generated when the voltage of the through same-phase traction power supply system is established. The second suppression module is configured to, when the actual working condition is a voltage stabilization working condition, execute a preset magnetic bias suppression control scheme on the through same-phase traction power supply system, and suppress or correct the magnetic bias generated in the through same-phase traction power supply system. The third suppression module is configured to, when the actual working condition is a second switching working condition between a fault current stabilization working condition and the voltage stabilization working condition, execute the preset voltage slow start control scheme or the preset voltage phase splicing control scheme on the through same-phase traction power supply system, and suppress the magnetic bias generated in the through same-phase traction power supply system in a transient process. In the second switching working condition, the through same-phase traction power supply system executes the preset voltage phase splicing control scheme, which includes: collecting a system voltage instantaneous value at a moment when a catenary short-circuit fault occurs; calculating a voltage phase according to the voltage instantaneous value; and switching a phase of a converter modulation voltage to the voltage phase while the voltage amplitude is stepped from 0 to a given value at a moment when the fault current stabilization working condition is switched to the voltage stabilization working condition.

7. An electronic device, comprising: The computer program is stored in the memory and executable on the processor, and the processor executes the program to implement the method for suppressing magnetic bias in a switching process of a through same-phase traction power supply system control. The program is executed by the processor to implement the method for suppressing magnetic bias in a switching process of a through same-phase traction power supply system control.

8. A computer-readable storage medium having stored thereon a computer program, characterized in that, ​

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