Traction system optimization control method and device

Abstract

The invention provides a traction system optimization control method and device. The method comprises the steps of obtaining an intermediate link voltage of a traction system, an output voltage of an auxiliary inverter, an alternating current side voltage of a four-quadrant rectifier and a working mode of the four-quadrant rectifier; when the working mode is a controllable rectification mode, iteratively adjusting the intermediate link voltage according to the output voltage, a preset intermediate voltage step value and a preset upper limit value and a preset lower limit value of the modulation ratio of the auxiliary inverter until the modulation ratio of the auxiliary inverter is between the upper limit value and the lower limit value of the modulation ratio of the auxiliary inverter; generating a four-quadrant rectifier modulation ratio according to the adjusted intermediate link voltage and the AC side voltage; and when the modulation ratio of the four-quadrant rectifier is greater than the preset upper limit value of the modulation ratio of the four-quadrant rectifier, switching the working mode from a controllable rectification mode to an uncontrolled rectification mode. According to the invention, the self-adaptive switching of the working modes of the four-quadrant rectifier is realized, so that the four-quadrant uncontrolled rectification mode is fully utilized to supply power to the auxiliary inverter.

Description

Technical Field

[0001] The present application relates to the field of rail transit technology, and in particular to a traction system optimization control method and device. Background Art

[0002] EMU and locomotive traction systems based on overhead line power supply such as Fig.10 As shown in the figure, it mainly includes pantograph, main circuit breaker VCB, traction transformer, traction converter, traction motor and auxiliary converter. Each traction converter includes a four-quadrant rectifier, an intermediate link and a traction inverter. Among them, the four-quadrant rectifier converts the AC power on the overhead line side into DC power in the intermediate link, and the energy can flow bidirectionally between the AC power on the overhead line side and the DC power in the intermediate link; the traction inverter converts the DC power in the intermediate link into AC power to power the traction motor; the auxiliary inverter converts the DC power in the intermediate link into AC power to power the auxiliary inverter load.

[0003] The working modes of the four-quadrant rectifier include: uncontrolled rectification mode and controlled rectification mode. In the controlled rectification mode, the four-quadrant rectifier controls the driving pulses of the power switching devices to maintain the stability of the DC voltage in the intermediate link of the traction converter. However, in the controlled rectification mode, the AC side current of the four-quadrant rectifier has high-frequency harmonics, which stimulate the traction transformer to produce high-frequency magnetostriction and cause noise pollution. When the train is stationary (parked in the depot or on the platform), the negative impact of noise on the comfort of the passengers is more prominent, so the time that the four-quadrant rectifier works in the controlled rectification mode should be reduced as much as possible.

[0004] In the uncontrolled rectification mode, the pulses of the four-quadrant rectifier power switch devices are blocked, and the secondary voltage of the traction transformer charges the intermediate link through the four-quadrant rectifier diode circuit. If the intermediate link voltage in the uncontrolled rectification mode is higher than the auxiliary inverter input voltage requirement, the auxiliary inverter can theoretically be powered by the uncontrolled rectification mode. When the auxiliary inverter load changes, the intermediate voltage will change accordingly: the smaller the auxiliary inverter load, the higher the intermediate link voltage; the larger the auxiliary inverter load, the lower the intermediate link voltage.

[0005] Generally speaking, in order to limit the short-circuit current and suppress the grid-side harmonic current, the short-circuit impedance value of the on-board traction transformer is designed to be relatively large. Therefore, in the uncontrolled rectification mode of the four-quadrant rectifier, the auxiliary inverter load has a significant impact on the intermediate voltage. When the train is stationary, in order to ensure that the intermediate link voltage meets the full-load power supply requirements of the auxiliary inverter, the traditional control method of the traction converter for the intermediate link voltage is as follows: According to the traction system parameters (mainly including traction transformer parameters, traction converter parameters and auxiliary inverter parameters, etc.), with the help of theoretical calculation and simulation tools, the lower threshold of the contact network voltage under the full-load condition of the auxiliary inverter is obtained. When the actual value of the contact network voltage is higher than the minimum threshold, the four-quadrant rectifier is set to the uncontrolled rectification mode; when the actual value of the contact network voltage is lower than the lower threshold, the four-quadrant rectifier is set to the controlled rectification mode. The above control method has the following shortcomings:

[0006] (1) The minimum threshold of the overhead line voltage needs to be calculated based on the traction system parameters, which requires a lot of design work. When the traction system parameters change, the threshold needs to be recalculated, which has poor universality.

[0007] (2) The lower limit of the overhead line voltage threshold is designed to meet the full load condition of the auxiliary inverter. When the train is stationary, the auxiliary inverter load is generally small. The traditional control method may cause the four-quadrant rectifier to continue to work in the controlled rectification mode unnecessarily, and fail to fully utilize the uncontrolled rectification mode, generating noise and electromagnetic pollution. This disadvantage is particularly prominent when the traction transformer is relatively large and the lower limit of the overhead line voltage threshold is higher than the rated value of the overhead line voltage.

[0008] (3) Traditional control methods require real-time monitoring of contact network voltage, etc., and are highly dependent on related hardware acquisition equipment. Summary of the invention

[0009] In response to the problems in the prior art, the embodiments of the present application provide a traction system optimization control method and device, which can at least partially solve the problems in the prior art.

[0010] In a first aspect, the present application provides a traction system optimization control method, comprising:

[0011] Obtain the intermediate link voltage of the traction system, the output voltage of the auxiliary inverter, the AC side voltage of the four-quadrant rectifier, and the working mode of the four-quadrant rectifier;

[0012] When the working mode is the controllable rectification mode, iteratively adjusting the intermediate link voltage according to the output voltage, the preset intermediate voltage step value and the preset upper limit value and lower limit value of the auxiliary inverter modulation ratio until the auxiliary inverter modulation ratio is between the upper limit value and the lower limit value of the auxiliary inverter modulation ratio;

[0013] generating a four-quadrant rectifier modulation ratio according to the adjusted intermediate link voltage and the AC side voltage;

[0014] When the modulation ratio of the four-quadrant rectifier is greater than a preset upper limit value of the modulation ratio of the four-quadrant rectifier, the working mode is switched from the controlled rectification mode to the uncontrolled rectification mode.

[0015] Further, the iterative adjustment of the intermediate link voltage according to the output voltage, the preset intermediate voltage step value and the preset upper limit and lower limit of the auxiliary inverter modulation ratio until the auxiliary inverter modulation ratio is between the upper limit and lower limit of the auxiliary inverter modulation ratio includes:

[0016] generating an auxiliary inverter modulation ratio according to the intermediate link voltage and the output voltage;

[0017] Adjusting the intermediate link voltage according to the auxiliary inverter modulation ratio, the intermediate voltage step value, and the upper limit value and the lower limit value of the auxiliary inverter modulation ratio;

[0018] The above steps are iteratively performed until the auxiliary inverter modulation ratio is between an upper limit value and a lower limit value of the auxiliary inverter modulation ratio.

[0019] Further, the adjusting the intermediate link voltage according to the auxiliary inverter modulation ratio, the intermediate voltage step value, and the upper limit value and the lower limit value of the auxiliary inverter modulation ratio includes:

[0020] When the auxiliary inverter modulation ratio is less than the lower limit value of the auxiliary inverter modulation ratio, reducing the intermediate link voltage by the intermediate voltage step value;

[0021] When the auxiliary inverter modulation ratio is greater than the upper limit value of the auxiliary inverter modulation ratio, increasing the intermediate link voltage by the intermediate voltage step value;

[0022] When the auxiliary inverter modulation ratio is not less than the lower limit value of the auxiliary inverter modulation ratio and not greater than the upper limit value of the auxiliary inverter modulation ratio, the intermediate link voltage is kept unchanged.

[0023] Furthermore, it also includes:

[0024] When the working mode is the uncontrolled rectification mode, the auxiliary inverter modulation ratio is calculated at every preset time interval according to the intermediate link voltage and the output voltage of the auxiliary inverter acquired in real time;

[0025] When the auxiliary inverter modulation ratio is greater than an upper limit value of the auxiliary inverter modulation ratio, the operating mode is switched from an uncontrolled rectification mode to a controlled rectification mode.

[0026] In a second aspect, the present application provides a traction system optimization control device, comprising:

[0027] A data acquisition unit, used to acquire the intermediate link voltage of the traction system, the output voltage of the auxiliary inverter, the AC side voltage of the four-quadrant rectifier and the working mode of the four-quadrant rectifier;

[0028] An intermediate link voltage adjustment unit, used for iteratively adjusting the intermediate link voltage according to the output voltage, a preset intermediate voltage step value, and a preset upper limit value and lower limit value of the auxiliary inverter modulation ratio when the working mode is a controllable rectification mode, until the auxiliary inverter modulation ratio is between the upper limit value and the lower limit value of the auxiliary inverter modulation ratio;

[0029] A four-quadrant rectifier modulation ratio generating unit, used for generating a four-quadrant rectifier modulation ratio according to the adjusted intermediate link voltage and the AC side voltage;

[0030] The first working mode switching unit is used to switch the working mode from the controlled rectification mode to the uncontrolled rectification mode when the modulation ratio of the four-quadrant rectifier is greater than a preset upper limit value of the modulation ratio of the four-quadrant rectifier.

[0031] Furthermore, the intermediate link voltage adjustment unit includes:

[0032] An auxiliary inverter modulation ratio generating module, used for generating an auxiliary inverter modulation ratio according to the intermediate link voltage and the output voltage;

[0033] An intermediate link voltage adjustment module, used for adjusting the intermediate link voltage according to the auxiliary inverter modulation ratio, the intermediate voltage step value, and the upper limit value and the lower limit value of the auxiliary inverter modulation ratio;

[0034] The iterative operation module is used to iteratively execute the above steps until the auxiliary inverter modulation ratio is between the upper limit value and the lower limit value of the auxiliary inverter modulation ratio.

[0035] Furthermore, the intermediate link voltage adjustment module includes:

[0036] An intermediate voltage reduction submodule, configured to reduce the intermediate link voltage by the intermediate voltage step value when the auxiliary inverter modulation ratio is less than the lower limit value of the auxiliary inverter modulation ratio;

[0037] An intermediate voltage increasing submodule, used for increasing the intermediate link voltage by the intermediate voltage step value when the auxiliary inverter modulation ratio is greater than the upper limit value of the auxiliary inverter modulation ratio;

[0038] The intermediate voltage maintaining submodule is used to keep the intermediate link voltage unchanged when the auxiliary inverter modulation ratio is not less than the lower limit value of the auxiliary inverter modulation ratio and not greater than the upper limit value of the auxiliary inverter modulation ratio.

[0039] Furthermore, it also includes:

[0040] An auxiliary inverter modulation ratio monitoring unit, used for calculating the auxiliary inverter modulation ratio according to the intermediate link voltage and the output voltage of the auxiliary inverter acquired in real time at every preset time interval when the working mode is the uncontrolled rectification mode;

[0041] The second working mode switching unit is used to switch the working mode from the uncontrolled rectification mode to the controlled rectification mode when the auxiliary inverter modulation ratio is greater than the upper limit value of the auxiliary inverter modulation ratio.

[0042] In a third aspect, the present application provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the method described in any one of the above embodiments when executing the computer program.

[0043] In a fourth aspect, the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method described in any of the above embodiments is implemented.

[0044] In a fifth aspect, the present application provides a computer program product, wherein the computer program product includes a computer program, and when the computer program is executed by a processor, the method described in any of the above embodiments is implemented.

[0045] The traction system optimization control method and device provided in the present application obtain the intermediate link voltage of the traction system, the output voltage of the auxiliary inverter, the AC side voltage of the four-quadrant rectifier and the working mode of the four-quadrant rectifier; when the working mode is the controllable rectification mode, the intermediate link voltage is iteratively adjusted according to the output voltage, the preset intermediate voltage step value and the preset upper limit and lower limit of the auxiliary inverter modulation ratio, until the auxiliary inverter modulation ratio is between the upper limit and lower limit of the auxiliary inverter modulation ratio; the four-quadrant rectifier modulation ratio is generated according to the adjusted intermediate link voltage and the AC side voltage; when the four-quadrant rectifier modulation ratio is greater than the preset upper limit of the four-quadrant rectifier modulation ratio, the working mode is switched from the controllable rectification mode to the uncontrolled rectification mode, thereby realizing the adaptive switching of the four-quadrant rectifier working mode, thereby making full use of the four-quadrant uncontrolled rectification mode to power the auxiliary inverter.

[0046] Among them, when the four-quadrant pulse is activated under static conditions, the intermediate link DC voltage can be adaptively adjusted according to the modulation ratio of the auxiliary inverter to ensure that the modulation ratio of the auxiliary inverter works within the expected range under various working conditions such as light load or heavy load of the auxiliary inverter, avoiding the auxiliary inverter modulation ratio being too large or too small; the four-quadrant rectifier can realize the adaptive switching of the four-quadrant rectifier between the controlled rectification mode and the uncontrolled rectification mode according to the internal control variables such as the modulation ratio of the auxiliary inverter and the modulation ratio of the four-quadrant rectifier. When the contact network voltage changes dynamically or the output power of the auxiliary inverter changes dynamically, it can adaptively change accordingly and automatically switch the working mode of the four-quadrant rectifier; there is no need to collect the output power of the auxiliary inverter and the contact network voltage, and there is no need to pre-calculate the contact network voltage threshold for switching between the controlled rectification and uncontrolled rectification modes. The design workload is small, and the versatility to changes in traction system parameters is high, and the dependence on related hardware acquisition equipment is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0048] Figure 1 is a flow chart of a traction system optimization control method provided by an embodiment of the present application;

[0049] Figure 2 is a flow chart of a traction system optimization control method provided by an embodiment of the present application;

[0050] Figure 3 is a flow chart of a traction system optimization control method provided by an embodiment of the present application;

[0051] Figure 4 is a flow chart of a traction system optimization control method provided by an embodiment of the present application;

[0052] Figure 5 is a structural schematic diagram of a traction system optimization control device provided by an embodiment of the present application;

[0053] Figure 6 is a structural schematic diagram of a traction system optimization control device provided by an embodiment of the present application;

[0054] Figure 7 is a structural schematic diagram of a traction system optimization control device provided by an embodiment of the present application;

[0055] Figure 8is a structural schematic diagram of a traction system optimization control device provided by an embodiment of the present application;

[0056] Fig. 9 is a schematic diagram of the physical structure of an electronic device provided in one embodiment of the present application;

[0057] Fig.10 It is a structural schematic diagram of an EMU and locomotive traction system based on contact network power supply provided by an embodiment of the present application;

[0058] Fig.11 It is a schematic diagram of a switching state machine between a controlled rectification mode and an uncontrolled rectification mode provided in an embodiment of the present application. DETAILED DESCRIPTION

[0059] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the embodiments of the present application are further described in detail below in conjunction with the accompanying drawings. Here, the illustrative embodiments of the present application and their descriptions are used to explain the present application, but are not intended to limit the present application. It should be noted that, in the absence of conflict, the embodiments in the present application and the features in the embodiments can be combined arbitrarily with each other.

[0060] The following uses the server as an example of the execution subject to illustrate the specific implementation process of the traction system optimization control method provided in the embodiment of the present application.

[0061] Figure 1 is a flow chart of a traction system optimization control method provided by an embodiment of the present application, such as Figure 1 As shown, the traction system optimization control method provided by the present application includes:

[0062] S101: Acquire the intermediate link voltage of the traction system, the output voltage of the auxiliary inverter, the AC side voltage of the four-quadrant rectifier, and the working mode of the four-quadrant rectifier;

[0063] S102: When the working mode is the controllable rectification mode, iteratively adjusting the intermediate link voltage according to the output voltage, the preset intermediate voltage step value, and the preset upper limit and lower limit of the auxiliary inverter modulation ratio, until the auxiliary inverter modulation ratio is between the upper limit and lower limit of the auxiliary inverter modulation ratio;

[0064] S103: generating a four-quadrant rectifier modulation ratio according to the adjusted intermediate link voltage and the AC side voltage;

[0065] S104: When the modulation ratio of the four-quadrant rectifier is greater than a preset upper limit of the modulation ratio of the four-quadrant rectifier, switching the working mode from the controlled rectification mode to the uncontrolled rectification mode.

[0066] from Figure 1As can be seen from the shown process, the traction system optimization control method provided by the present application obtains the intermediate link voltage of the traction system, the output voltage of the auxiliary inverter, the AC side voltage of the four-quadrant rectifier and the working mode of the four-quadrant rectifier; when the working mode is the controllable rectification mode, the intermediate link voltage is iteratively adjusted according to the output voltage, the preset intermediate voltage step value and the preset upper limit and lower limit of the auxiliary inverter modulation ratio, until the auxiliary inverter modulation ratio is between the upper limit and lower limit of the auxiliary inverter modulation ratio; the four-quadrant rectifier modulation ratio is generated according to the adjusted intermediate link voltage and the AC side voltage; when the four-quadrant rectifier modulation ratio is greater than the preset upper limit of the four-quadrant rectifier modulation ratio, the working mode is switched from the controllable rectification mode to the uncontrolled rectification mode, thereby realizing the adaptive switching of the four-quadrant rectifier working mode, thereby making full use of the four-quadrant uncontrolled rectification mode to power the auxiliary inverter.

[0067] Each step is explained in detail below.

[0068] S101: Acquire the intermediate link voltage of the traction system, the output voltage of the auxiliary inverter, the AC side voltage of the four-quadrant rectifier, and the working mode of the four-quadrant rectifier;

[0069] Specifically, the EMU and locomotive traction systems based on overhead line power supply are Fig.10 As shown, it includes pantograph, main circuit breaker, traction transformer, four-quadrant rectifier, intermediate link, traction inverter, traction motor and auxiliary inverter. The starting process of the traction system is as follows: after the pantograph is raised and the main circuit breaker is closed, the traction transformer is energized, the four-quadrant rectifier converts the AC power of the traction transformer into DC power in the intermediate link, and the auxiliary inverter pulse is activated to supply power to the auxiliary load. After the train pushes the traction handle, the traction inverter pulse is activated to supply power to the traction motor and the EMU obtains traction.

[0070] The server first determines the intermediate link voltage of the traction system, the output voltage of the auxiliary inverter, the AC side voltage of the four-quadrant rectifier, and the current working mode of the four-quadrant rectifier. The intermediate link voltage is acquired in real time, the output voltage of the auxiliary inverter is the effective value of the AC voltage output by the auxiliary inverter at the load end, and the AC side voltage of the four-quadrant rectifier is calculated by the software control algorithm. The four-quadrant rectifier has multiple working modes, including controlled rectification mode and uncontrolled rectification mode. The server reads the current working mode of the four-quadrant rectifier to confirm whether it is operating in controlled rectification mode or uncontrolled rectification mode.

[0071] S102: When the working mode is the controllable rectification mode, iteratively adjusting the intermediate link voltage according to the output voltage, the preset intermediate voltage step value, and the preset upper limit and lower limit of the auxiliary inverter modulation ratio, until the auxiliary inverter modulation ratio is between the upper limit and lower limit of the auxiliary inverter modulation ratio;

[0072] Specifically, if the working mode is the controlled rectification mode, the server iteratively adjusts the intermediate link voltage according to the output voltage, the preset intermediate voltage step value, and the preset upper and lower limits of the auxiliary inverter modulation ratio. The intermediate voltage step value represents the increase or decrease amount of the intermediate link voltage, which is a preset value used to control the amplitude of each adjustment to ensure that the adjustment process is smooth and does not fluctuate excessively. According to the current DC side voltage and step value, the server gradually increases or decreases the target value of the intermediate link voltage to gradually approach the ideal state.

[0073] After each iteration, the server will compare the current auxiliary inverter modulation ratio with the preset upper limit and lower limit of the auxiliary inverter modulation ratio. If the current auxiliary inverter modulation ratio is not between the upper limit and lower limit of the auxiliary inverter modulation ratio, the server will continue to iteratively adjust the intermediate link voltage. If the current auxiliary inverter modulation ratio is between the upper limit and lower limit of the auxiliary inverter modulation ratio, the server executes the next step S103.

[0074] Figure 2 is a flow chart of a traction system optimization control method provided by an embodiment of the present application, such as Figure 2 As shown, S102 includes:

[0075] S201: generating an auxiliary inverter modulation ratio according to the intermediate link voltage and the output voltage;

[0076] Specifically, the server uses the current intermediate link voltage and the output voltage of the auxiliary inverter to calculate the modulation ratio of the auxiliary inverter. The server collects real-time data of the intermediate link voltage, which reflects the current load demand and operating status of the system and has a direct impact on the output of the auxiliary inverter. By accurately obtaining the intermediate link voltage, the server can ensure that the subsequent auxiliary inverter modulation ratio calculation is based on the current real system status.

[0077] In one embodiment, the server calculates the auxiliary inverter modulation ratio k according to the intermediate link voltage and the output voltage of the auxiliary inverter. aux (n) is represented as follows:

[0078]

[0079] Where U out (n) represents the output voltage of the auxiliary inverter, U dc(n) represents the intermediate link voltage, and n is a natural number.

[0080] S202: adjusting the intermediate link voltage according to the auxiliary inverter modulation ratio, the intermediate voltage step value, and the upper limit value and the lower limit value of the auxiliary inverter modulation ratio;

[0081] Specifically, the server uses the modulation ratio of the auxiliary inverter and the preset intermediate voltage step value to dynamically adjust the intermediate link voltage. The modulation ratio of the auxiliary inverter indicates whether the current intermediate link voltage meets the actual operation requirements. The intermediate voltage step value represents the increment or decrement of each adjustment of the intermediate voltage. The server gradually increases or decreases the intermediate link voltage according to the current auxiliary inverter modulation ratio and the intermediate voltage step value to ensure that the auxiliary inverter modulation ratio is between the upper limit and the lower limit of the auxiliary inverter modulation ratio.

[0082] Figure 3 is a flow chart of a traction system optimization control method provided by an embodiment of the present application, such as Figure 3 As shown, S202 includes:

[0083] S301: When the modulation ratio of the auxiliary inverter is less than a preset lower limit, reducing the intermediate link voltage by the step value;

[0084] Specifically, the server detects the modulation ratio k of the auxiliary inverter aux (n) is lower than the preset lower limit value k of the auxiliary inverter modulation ratio auxL After that, k aux (n) <k auxL , automatically reduce the intermediate link voltage by a step value, and the adjusted intermediate link voltage is U dc (n+1)=U dc (n)-δ. The lower limit of the modulation ratio of the auxiliary inverter is selected independently according to the needs.

[0085] S302: When the modulation ratio of the auxiliary inverter is greater than a preset second upper limit value, increasing the intermediate link voltage by the step value;

[0086] Specifically, the server detects the modulation ratio k of the auxiliary inverter aux (n) is higher than the preset upper limit value k of the auxiliary inverter modulation ratio auxH After that, k aux (n)>k auxL , automatically increase the intermediate link voltage by a step value, and the adjusted intermediate link voltage is U dc (n+1)=U dc (n)+δ. The upper limit of the modulation ratio of the auxiliary inverter is selected independently according to the needs.

[0087] S303: When the modulation ratio of the auxiliary inverter is not less than the lower limit value and not greater than the second upper limit value, the intermediate link voltage is kept unchanged.

[0088] Specifically, when the modulation ratio of the auxiliary inverter is within the set upper and lower limits, that is, k auxL <k aux (n) <k auxH , the server keeps the intermediate link voltage unchanged, that is, U dc (n+1)=U dc (n). The server confirms that the value of the modulation ratio of the auxiliary inverter is between the upper limit and the lower limit of the modulation ratio of the auxiliary inverter, indicating that the current intermediate link voltage meets the auxiliary inverter modulation ratio requirement and the traction system is in a balanced state.

[0089] S203: Iteratively execute the above steps until the auxiliary inverter modulation ratio is between the upper limit value and the lower limit value of the auxiliary inverter modulation ratio.

[0090] Specifically, if the current auxiliary inverter modulation ratio is not between the upper limit and the lower limit of the auxiliary inverter modulation ratio, the server continues to perform the iteration process of the previous steps to continuously optimize the intermediate link voltage and the auxiliary inverter modulation ratio. In each iteration, the server calculates a new auxiliary inverter modulation ratio. Through repeated iterations, the auxiliary inverter modulation ratio is ensured to be between the upper limit and the lower limit of the auxiliary inverter modulation ratio, at which point the iteration stops.

[0091] S103: generating a four-quadrant rectifier modulation ratio according to the adjusted intermediate link voltage and the AC side voltage;

[0092] Specifically, the server uses the adjusted intermediate link voltage and the AC side voltage of the four-quadrant rectifier to calculate the modulation ratio of the four-quadrant rectifier. The adjusted intermediate link voltage is obtained by the server in the previous step according to the auxiliary inverter modulation ratio optimization.

[0093] In one embodiment, the server calculates the modulation ratio k of the four-quadrant rectifier according to the adjusted intermediate link voltage and the AC side voltage of the four-quadrant rectifier. rec (n+1) is represented as follows:

[0094]

[0095] Where U ac (n+1) represents the AC side voltage of the four-quadrant rectifier, U dc (n+1) represents the adjusted intermediate link voltage, and n is a natural number.

[0096] S104: When the modulation ratio of the four-quadrant rectifier is greater than a preset upper limit of the modulation ratio of the four-quadrant rectifier, switching the working mode from the controlled rectification mode to the uncontrolled rectification mode.

[0097] Specifically, the server compares the current four-quadrant rectifier modulation ratio with the preset upper limit of the four-quadrant rectifier modulation ratio. If the four-quadrant rectifier modulation ratio is lower than the upper limit of the four-quadrant rectifier modulation ratio, the current working state is maintained; if the four-quadrant rectifier modulation ratio exceeds the upper limit of the four-quadrant rectifier modulation ratio, the server triggers a mode switch and switches the working mode of the four-quadrant rectifier from a controlled rectification mode to an uncontrolled rectification mode. Among them, the upper limit of the four-quadrant rectifier modulation ratio is selected autonomously according to needs. After the working mode is switched, the server continues to monitor the traction system in real time to ensure that it remains stable in the uncontrolled rectification mode. If new voltage fluctuations or other abnormal conditions occur, it may trigger the process of switching to the controlled rectification mode again.

[0098] In one embodiment, the switching state machine between the controlled rectification mode and the uncontrolled rectification mode is as follows: Fig.11 shown.

[0099] Figure 4 is a flow chart of a traction system optimization control method provided by an embodiment of the present application, such as Figure 4 As shown, the traction system optimization control method provided by the present application also includes:

[0100] S401: When the working mode is an uncontrolled rectification mode, calculating the auxiliary inverter modulation ratio according to the intermediate link voltage and the output voltage of the auxiliary inverter acquired in real time at every preset time interval;

[0101] Specifically, when the train is stationary, after the main circuit breaker and the incoming contactor are closed, the four-quadrant rectifier is connected to the overhead line. At this time, the four-quadrant rectifier first works in the uncontrolled rectification mode to maintain the intermediate link voltage, and the auxiliary inverter is activated to supply power to the auxiliary load.

[0102] When the four-quadrant rectifier is in the uncontrolled rectification mode, the modulation ratio of the auxiliary inverter is calculated at every preset time interval to monitor the modulation ratio of the auxiliary inverter. The server calculates the modulation ratio of the auxiliary inverter based on the intermediate link voltage and the output voltage of the auxiliary inverter obtained in real time.

[0103] In one embodiment, the server calculates the auxiliary inverter modulation ratio k according to the intermediate link voltage and the output voltage of the auxiliary inverter. aux (n) is represented as follows:

[0104]

[0105] Where U out(n) represents the output voltage of the auxiliary inverter, U dc (n) represents the intermediate link voltage, and n is a natural number.

[0106] S402: When the auxiliary inverter modulation ratio is greater than an upper limit value of the auxiliary inverter modulation ratio, switching the operating mode from an uncontrolled rectification mode to a controlled rectification mode.

[0107] Specifically, the server compares the calculated auxiliary inverter modulation ratio with the upper limit of the auxiliary inverter modulation ratio, wherein the upper limit of the auxiliary inverter modulation ratio is selected autonomously according to the needs. If the auxiliary inverter modulation ratio is less than the upper limit of the auxiliary inverter modulation ratio, the server will continue to monitor the auxiliary inverter modulation ratio; once the auxiliary inverter modulation ratio k aux (n) Exceeds the preset upper limit value k of the auxiliary inverter modulation ratio auxH After that, k aux (n)>k auxH , the server will switch the working mode, the uncontrolled rectification mode is no longer applicable, triggering the mode switch, and the server will switch the working mode of the four-quadrant rectifier from the uncontrolled rectification mode back to the controlled rectification mode. After switching to the controlled rectification mode, the server will execute S102.

[0108] In one embodiment, in the uncontrolled rectification mode, when the contact network voltage increases, the intermediate link DC voltage increases accordingly, and the four-quadrant rectifier maintains the uncontrolled rectification mode; when the contact network voltage decreases, the intermediate link DC voltage decreases accordingly. If the server detects that the modulation ratio of the auxiliary inverter is higher than the upper threshold value, the four-quadrant rectifier switches from the uncontrolled rectification mode to the controlled rectification mode.

[0109] In one embodiment, in the controlled rectification mode, when the contact network voltage changes and causes the four-quadrant modulation ratio to be higher than the upper threshold value, the four-quadrant rectifier switches from the controlled rectification mode to the uncontrolled rectification mode. Thus, during the change of the contact network voltage, the four-quadrant uncontrolled rectification mode is fully utilized to supply power to the auxiliary inverter.

[0110] In one embodiment, in the uncontrolled rectification mode, when the auxiliary inverter load decreases, resulting in a decrease in the auxiliary inverter modulation ratio, the four-quadrant rectifier maintains the uncontrolled rectification mode; when the auxiliary inverter load increases, resulting in an increase in the auxiliary inverter modulation ratio and exceeding an upper threshold value, the four-quadrant rectifier switches from the uncontrolled rectification mode to the controlled rectification mode.

[0111] In one embodiment, in the controlled rectification mode, when the auxiliary inverter load decreases, resulting in a decrease in the auxiliary inverter modulation ratio and a decrease below the lower threshold, the intermediate voltage target value of the four-quadrant rectifier is automatically adjusted down accordingly; when the four-quadrant modulation ratio is higher than the upper threshold, the four-quadrant rectifier switches from the controlled rectification mode to the uncontrolled rectification mode; when the auxiliary inverter load increases, resulting in an increase in the auxiliary inverter modulation ratio and a increase above the upper threshold, the intermediate voltage target value of the four-quadrant rectifier is automatically increased accordingly. Thus, in the process of the auxiliary inverter load changing, the uncontrolled rectification mode is fully utilized to power the auxiliary inverter.

[0112] The present application provides a traction system optimization control method, which obtains the intermediate link voltage of the traction system, the output voltage of the auxiliary inverter, the AC side voltage of the four-quadrant rectifier and the working mode of the four-quadrant rectifier; when the working mode is the controllable rectification mode, iteratively adjusts the intermediate link voltage according to the output voltage, the preset intermediate voltage step value and the preset upper limit and lower limit of the auxiliary inverter modulation ratio, until the auxiliary inverter modulation ratio is between the upper limit and lower limit of the auxiliary inverter modulation ratio; generates the four-quadrant rectifier modulation ratio according to the adjusted intermediate link voltage and the AC side voltage; when the four-quadrant rectifier modulation ratio is greater than the preset upper limit of the four-quadrant rectifier modulation ratio, switches the working mode from the controllable rectification mode to the uncontrolled rectification mode, thereby realizing adaptive switching of the four-quadrant rectifier working mode, thereby making full use of the four-quadrant uncontrolled rectification mode to power the auxiliary inverter.

[0113] Among them, when the four-quadrant pulse is activated under static conditions, the intermediate link DC voltage can be adaptively adjusted according to the modulation ratio of the auxiliary inverter to ensure that the modulation ratio of the auxiliary inverter works within the expected range under various working conditions such as light load or heavy load of the auxiliary inverter, avoiding the auxiliary inverter modulation ratio being too large or too small; the four-quadrant rectifier can realize the adaptive switching of the four-quadrant rectifier between the controlled rectification mode and the uncontrolled rectification mode according to the internal control variables such as the modulation ratio of the auxiliary inverter and the modulation ratio of the four-quadrant rectifier. When the contact network voltage changes dynamically or the output power of the auxiliary inverter changes dynamically, it can adaptively change accordingly and automatically switch the working mode of the four-quadrant rectifier; there is no need to collect the output power of the auxiliary inverter and the contact network voltage, and there is no need to pre-calculate the contact network voltage threshold for switching between the controlled rectification and uncontrolled rectification modes. The design workload is small, and the versatility to changes in traction system parameters is high, and the dependence on related hardware acquisition equipment is low.

[0114] Based on the same inventive concept, the embodiments of the present application also provide a traction system optimization control device, which can be used to implement the method described in the above embodiments, as described in the following embodiments. Since the principle of solving the problem by the traction system optimization control device is similar to that of the traction system optimization control method, the implementation of the traction system optimization control device can refer to the implementation of the method based on software performance benchmark determination, and the repeated parts will not be repeated. As used below, the terms "unit" or "module" can be a combination of software and / or hardware that implements predetermined functions. Although the system described in the following embodiments is preferably implemented in software, the implementation of hardware, or a combination of software and hardware, is also possible and conceivable.

[0115] Figure 5 is a schematic diagram of the structure of a traction system optimization control device provided in an embodiment of the present application, such as Figure 5 As shown, the device comprises:

[0116] The data acquisition unit 501 is used to acquire the intermediate link voltage of the traction system, the output voltage of the auxiliary inverter, the AC side voltage of the four-quadrant rectifier and the working mode of the four-quadrant rectifier;

[0117] Specifically, the EMU and locomotive traction systems based on overhead line power supply are Fig.10 As shown, it includes pantograph, main circuit breaker, traction transformer, four-quadrant rectifier, intermediate link, traction inverter, traction motor and auxiliary inverter. The starting process of the traction system is as follows: after the pantograph is raised and the main circuit breaker is closed, the traction transformer is energized, the four-quadrant rectifier converts the AC power of the traction transformer into DC power in the intermediate link, and the auxiliary inverter pulse is activated to supply power to the auxiliary load. After the train pushes the traction handle, the traction inverter pulse is activated to supply power to the traction motor and the EMU obtains traction.

[0118] The data acquisition unit 501 first determines the intermediate link voltage of the traction system, the output voltage of the auxiliary inverter, the AC side voltage of the four-quadrant rectifier, and the current working mode of the four-quadrant rectifier. The intermediate link voltage is acquired in real time, the output voltage of the auxiliary inverter is the effective value of the AC voltage output by the auxiliary inverter at the load end, and the AC side voltage of the four-quadrant rectifier is calculated by the software control algorithm. The four-quadrant rectifier has multiple working modes, including a controlled rectification mode and an uncontrolled rectification mode. The data acquisition unit 501 reads the current working mode of the four-quadrant rectifier to confirm whether it is operating in a controlled rectification mode or an uncontrolled rectification mode.

[0119] An intermediate link voltage adjustment unit 502, configured to iteratively adjust the intermediate link voltage according to the output voltage, a preset intermediate voltage step value, and a preset upper limit value and lower limit value of the auxiliary inverter modulation ratio when the working mode is a controllable rectification mode, until the auxiliary inverter modulation ratio is between the upper limit value and the lower limit value of the auxiliary inverter modulation ratio;

[0120] Specifically, if the working mode is the controlled rectification mode, the intermediate link voltage adjustment unit 502 iteratively adjusts the intermediate link voltage according to the output voltage, the preset intermediate voltage step value, and the preset upper limit and lower limit of the auxiliary inverter modulation ratio. The intermediate voltage step value represents the increase or decrease amount of the intermediate link voltage, which is a preset value used to control the amplitude of each adjustment to ensure that the adjustment process is smooth and does not fluctuate excessively. According to the current DC side voltage and the step value, the intermediate link voltage adjustment unit 502 gradually increases or decreases the target value of the intermediate link voltage to gradually approach the ideal state.

[0121] After each iteration, the intermediate link voltage adjustment unit 502 will compare the current auxiliary inverter modulation ratio with the preset upper limit and lower limit of the auxiliary inverter modulation ratio. If the current auxiliary inverter modulation ratio is not between the upper limit and lower limit of the auxiliary inverter modulation ratio, the server will continue to iteratively adjust the intermediate link voltage. If the current auxiliary inverter modulation ratio is between the upper limit and lower limit of the auxiliary inverter modulation ratio, the server will execute the next step.

[0122] A four-quadrant rectifier modulation ratio generating unit 503, used to generate a four-quadrant rectifier modulation ratio according to the adjusted intermediate link voltage and the AC side voltage;

[0123] Specifically, the four-quadrant rectifier modulation ratio generating unit 503 uses the adjusted intermediate link voltage and the AC side voltage of the four-quadrant rectifier to calculate the modulation ratio of the four-quadrant rectifier. The adjusted intermediate link voltage is obtained by the intermediate link voltage adjusting unit 502 in the preceding step according to the auxiliary inverter modulation ratio optimization.

[0124] In one embodiment, the four-quadrant rectifier modulation ratio generating unit 503 calculates the four-quadrant rectifier modulation ratio k according to the adjusted intermediate link voltage and the AC side voltage of the four-quadrant rectifier. rec (n+1) is represented as follows:

[0125]

[0126] Where U dc (n+1) represents the AC side voltage of the four-quadrant rectifier, U dc (n+1) represents the adjusted intermediate link voltage, and n is a natural number.

[0127] The first working mode switching unit 504 is used to switch the working mode from the controlled rectification mode to the uncontrolled rectification mode when the modulation ratio of the four-quadrant rectifier is greater than a preset upper limit of the modulation ratio of the four-quadrant rectifier.

[0128] Specifically, the first working mode switching unit 504 compares the current four-quadrant rectifier modulation ratio with the preset upper limit value of the four-quadrant rectifier modulation ratio. If the four-quadrant rectifier modulation ratio is lower than the upper limit value of the four-quadrant rectifier modulation ratio, the current working state is maintained; if the four-quadrant rectifier modulation ratio exceeds the upper limit value of the four-quadrant rectifier modulation ratio, the first working mode switching unit 504 triggers the mode switching and switches the working mode of the four-quadrant rectifier from the controlled rectification mode to the uncontrolled rectification mode. Among them, the upper limit value of the four-quadrant rectifier modulation ratio is selected autonomously according to needs. After the working mode is switched, the server continues to monitor the traction system in real time to ensure that it remains stable in the uncontrolled rectification mode. If new voltage fluctuations or other abnormal conditions occur, it may trigger the process of switching to the controlled rectification mode again.

[0129] Figure 6 is a schematic diagram of the structure of a traction system optimization control device provided in an embodiment of the present application. Figure 5 Based on the embodiment, further, Figure 6 As shown, the traction system optimization control device provided by the present application also includes:

[0130] An auxiliary inverter modulation ratio generating module 601, configured to generate an auxiliary inverter modulation ratio according to the intermediate link voltage and the output voltage;

[0131] An intermediate link voltage adjustment module 602, configured to adjust the intermediate link voltage according to the auxiliary inverter modulation ratio, the intermediate voltage step value, and the upper limit value and the lower limit value of the auxiliary inverter modulation ratio;

[0132] The iterative operation module 603 is used to iteratively execute the above steps until the auxiliary inverter modulation ratio is between the upper limit value and the lower limit value of the auxiliary inverter modulation ratio.

[0133] Figure 7 is a schematic diagram of the structure of a traction system optimization control device provided in an embodiment of the present application. Figure 6 Based on the embodiment, further, Figure 7 As shown, the traction system optimization control device provided by the present application also includes:

[0134] The intermediate voltage reduction submodule 701 is used to reduce the intermediate link voltage by the intermediate voltage step value when the auxiliary inverter modulation ratio is less than the lower limit value of the auxiliary inverter modulation ratio;

[0135] The intermediate voltage increasing submodule 702 is used to increase the intermediate link voltage by the intermediate voltage step value when the auxiliary inverter modulation ratio is greater than the upper limit value of the auxiliary inverter modulation ratio;

[0136] The intermediate voltage maintaining submodule 703 is used to maintain the intermediate link voltage unchanged when the auxiliary inverter modulation ratio is not less than the lower limit value of the auxiliary inverter modulation ratio and not greater than the upper limit value of the auxiliary inverter modulation ratio.

[0137] Figure 8 is a schematic diagram of the structure of a traction system optimization control device provided in an embodiment of the present application. Figure 5 Based on the embodiment, further, Figure 8 As shown, the traction system optimization control device provided by the present application also includes:

[0138] The auxiliary inverter modulation ratio monitoring unit 801 is used to calculate the auxiliary inverter modulation ratio according to the intermediate link voltage and the output voltage of the auxiliary inverter obtained in real time at every preset time interval when the working mode is the uncontrolled rectification mode;

[0139] The second working mode switching unit 802 is used to switch the working mode from the uncontrolled rectification mode to the controlled rectification mode when the auxiliary inverter modulation ratio is greater than the upper limit value of the auxiliary inverter modulation ratio.

[0140] The present application provides a traction system optimization control method and device, which obtains the intermediate link voltage of the traction system, the output voltage of the auxiliary inverter, the AC side voltage of the four-quadrant rectifier and the working mode of the four-quadrant rectifier; when the working mode is the controllable rectification mode, iteratively adjusts the intermediate link voltage according to the output voltage, the preset intermediate voltage step value and the preset upper limit and lower limit of the auxiliary inverter modulation ratio until the auxiliary inverter modulation ratio is between the upper limit and lower limit of the auxiliary inverter modulation ratio; generates the four-quadrant rectifier modulation ratio according to the adjusted intermediate link voltage and the AC side voltage; when the four-quadrant rectifier modulation ratio is greater than the preset upper limit of the four-quadrant rectifier modulation ratio, switches the working mode from the controllable rectification mode to the uncontrolled rectification mode, thereby realizing the adaptive switching of the four-quadrant rectifier working mode, thereby making full use of the four-quadrant uncontrolled rectification mode to power the auxiliary inverter.

[0141] Among them, when the four-quadrant pulse is activated under static conditions, the intermediate link DC voltage can be adaptively adjusted according to the modulation ratio of the auxiliary inverter to ensure that the modulation ratio of the auxiliary inverter works within the expected range under various working conditions such as light load or heavy load of the auxiliary inverter, avoiding the auxiliary inverter modulation ratio being too large or too small; the four-quadrant rectifier can realize the adaptive switching of the four-quadrant rectifier between the controlled rectification mode and the uncontrolled rectification mode according to the internal control variables such as the modulation ratio of the auxiliary inverter and the modulation ratio of the four-quadrant rectifier. When the contact network voltage changes dynamically or the output power of the auxiliary inverter changes dynamically, it can adaptively change accordingly and automatically switch the working mode of the four-quadrant rectifier; there is no need to collect the output power of the auxiliary inverter and the contact network voltage, and there is no need to pre-calculate the contact network voltage threshold for switching between the controlled rectification and uncontrolled rectification modes. The design workload is small, and the versatility to changes in traction system parameters is high, and the dependence on related hardware acquisition equipment is low.

[0142] Fig. 9 is a schematic diagram of the physical structure of an electronic device provided in an embodiment of the present application, such as Fig. 9 As shown, the electronic device may include: a processor (processor) 901, a communication interface (Communications Interface) 902, a memory (memory) 903 and a communication bus 904, wherein the processor 901, the communication interface 902, and the memory 903 communicate with each other through the communication bus 904. The processor 901 can call the logic instructions in the memory 903 to execute the following method: obtain the intermediate link voltage of the traction system, the output voltage of the auxiliary inverter, the AC side voltage of the four-quadrant rectifier and the working mode of the four-quadrant rectifier; when the working mode is the controllable rectification mode, iteratively adjust the intermediate link voltage according to the output voltage, the preset intermediate voltage step value and the preset upper limit and lower limit of the auxiliary inverter modulation ratio until the auxiliary inverter modulation ratio is between the upper limit and lower limit of the auxiliary inverter modulation ratio; generate the four-quadrant rectifier modulation ratio according to the adjusted intermediate link voltage and the AC side voltage; when the four-quadrant rectifier modulation ratio is greater than the preset upper limit of the four-quadrant rectifier modulation ratio, switch the working mode from the controlled rectification mode to the uncontrolled rectification mode.

[0143] In addition, the logic instructions in the above-mentioned memory 903 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on such an understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or the part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a disk or an optical disk.

[0144] The present embodiment discloses a computer program product, which includes a computer program stored on a computer-readable storage medium, and the computer program includes program instructions. When the program instructions are executed by a computer, the computer can execute the methods provided by the above-mentioned method embodiments, for example, including: obtaining an intermediate link voltage of a traction system, an output voltage of an auxiliary inverter, an AC side voltage of a four-quadrant rectifier, and an operating mode of the four-quadrant rectifier; when the operating mode is a controllable rectification mode, iteratively adjusting the intermediate link voltage according to the output voltage, a preset intermediate voltage step value, and a preset upper limit value and lower limit value of a modulation ratio of the auxiliary inverter, until the modulation ratio of the auxiliary inverter is between the upper limit value and the lower limit value of the modulation ratio of the auxiliary inverter; generating a modulation ratio of the four-quadrant rectifier according to the adjusted intermediate link voltage and the AC side voltage; when the modulation ratio of the four-quadrant rectifier is greater than the preset upper limit value of the modulation ratio of the four-quadrant rectifier, switching the operating mode from the controlled rectification mode to the uncontrolled rectification mode.

[0145] The present embodiment provides a computer-readable storage medium, which stores a computer program, and the computer program enables the computer to execute the methods provided by the above-mentioned method embodiments, for example, including: obtaining the intermediate link voltage of the traction system, the output voltage of the auxiliary inverter, the AC side voltage of the four-quadrant rectifier and the working mode of the four-quadrant rectifier; when the working mode is the controllable rectification mode, iteratively adjusting the intermediate link voltage according to the output voltage, the preset intermediate voltage step value and the preset upper limit and lower limit of the auxiliary inverter modulation ratio until the auxiliary inverter modulation ratio is between the upper limit and lower limit of the auxiliary inverter modulation ratio; generating the four-quadrant rectifier modulation ratio according to the adjusted intermediate link voltage and the AC side voltage; when the four-quadrant rectifier modulation ratio is greater than the preset upper limit of the four-quadrant rectifier modulation ratio, switching the working mode from the controlled rectification mode to the uncontrolled rectification mode.

[0146] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0147] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0148] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0149] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0150] In the description of this specification, the description with reference to the terms "one embodiment", "a specific embodiment", "some embodiments", "for example", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0151] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present application. It should be understood that the above description is only a specific embodiment of the present application and is not intended to limit the scope of protection of the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A traction system optimization control method, characterized in that: include: Obtain the intermediate link voltage of the traction system, the output voltage of the auxiliary inverter, the AC side voltage of the four-quadrant rectifier, and the working mode of the four-quadrant rectifier; When the working mode is the controllable rectification mode, iteratively adjusting the intermediate link voltage according to the output voltage, the preset intermediate voltage step value and the preset upper limit value and lower limit value of the auxiliary inverter modulation ratio until the auxiliary inverter modulation ratio is between the upper limit value and the lower limit value of the auxiliary inverter modulation ratio; generating a four-quadrant rectifier modulation ratio according to the adjusted intermediate link voltage and the AC side voltage; When the modulation ratio of the four-quadrant rectifier is greater than a preset upper limit value of the modulation ratio of the four-quadrant rectifier, the working mode is switched from the controlled rectification mode to the uncontrolled rectification mode.

2. The traction system optimization control method according to claim 1, characterized in that: The iterative adjustment of the intermediate link voltage according to the output voltage, the preset intermediate voltage step value, and the preset upper limit and lower limit of the auxiliary inverter modulation ratio until the auxiliary inverter modulation ratio is between the upper limit and lower limit of the auxiliary inverter modulation ratio includes: generating an auxiliary inverter modulation ratio according to the intermediate link voltage and the output voltage; Adjusting the intermediate link voltage according to the auxiliary inverter modulation ratio, the intermediate voltage step value, and the upper limit value and the lower limit value of the auxiliary inverter modulation ratio; The above steps are iteratively performed until the auxiliary inverter modulation ratio is between an upper limit value and a lower limit value of the auxiliary inverter modulation ratio.

3. The traction system optimization control method according to claim 2, characterized in that: The step of adjusting the intermediate link voltage according to the auxiliary inverter modulation ratio, the intermediate voltage step value, and the upper limit value and the lower limit value of the auxiliary inverter modulation ratio includes: When the auxiliary inverter modulation ratio is less than the lower limit value of the auxiliary inverter modulation ratio, reducing the intermediate link voltage by the intermediate voltage step value; When the auxiliary inverter modulation ratio is greater than the upper limit value of the auxiliary inverter modulation ratio, increasing the intermediate link voltage by the intermediate voltage step value; When the auxiliary inverter modulation ratio is not less than the lower limit value of the auxiliary inverter modulation ratio and not greater than the upper limit value of the auxiliary inverter modulation ratio, the intermediate link voltage is kept unchanged.

4. The traction system optimization control method according to claim 1, characterized in that: Also includes: When the working mode is the uncontrolled rectification mode, the auxiliary inverter modulation ratio is calculated at every preset time interval according to the intermediate link voltage and the output voltage of the auxiliary inverter acquired in real time; When the auxiliary inverter modulation ratio is greater than an upper limit value of the auxiliary inverter modulation ratio, the operating mode is switched from an uncontrolled rectification mode to a controlled rectification mode.

5. A traction system optimization control device, characterized in that: include: A data acquisition unit, used to acquire the intermediate link voltage of the traction system, the output voltage of the auxiliary inverter, the AC side voltage of the four-quadrant rectifier and the working mode of the four-quadrant rectifier; An intermediate link voltage adjustment unit, used for iteratively adjusting the intermediate link voltage according to the output voltage, a preset intermediate voltage step value, and a preset upper limit value and lower limit value of the auxiliary inverter modulation ratio when the working mode is a controllable rectification mode, until the auxiliary inverter modulation ratio is between the upper limit value and the lower limit value of the auxiliary inverter modulation ratio; A four-quadrant rectifier modulation ratio generating unit, used for generating a four-quadrant rectifier modulation ratio according to the adjusted intermediate link voltage and the AC side voltage; The first working mode switching unit is used to switch the working mode from the controlled rectification mode to the uncontrolled rectification mode when the modulation ratio of the four-quadrant rectifier is greater than a preset upper limit value of the modulation ratio of the four-quadrant rectifier.

6. The traction system optimization control device according to claim 5, characterized in that: The intermediate link voltage adjustment unit comprises: An auxiliary inverter modulation ratio generating module, used for generating an auxiliary inverter modulation ratio according to the intermediate link voltage and the output voltage; An intermediate link voltage adjustment module, used for adjusting the intermediate link voltage according to the auxiliary inverter modulation ratio, the intermediate voltage step value, and the upper limit value and the lower limit value of the auxiliary inverter modulation ratio; The iterative operation module is used to iteratively execute the above steps until the auxiliary inverter modulation ratio is between the upper limit value and the lower limit value of the auxiliary inverter modulation ratio.

7. The traction system optimization control device according to claim 6, characterized in that: The intermediate link voltage adjustment module comprises: An intermediate voltage reduction submodule, configured to reduce the intermediate link voltage by the intermediate voltage step value when the auxiliary inverter modulation ratio is less than the lower limit value of the auxiliary inverter modulation ratio; An intermediate voltage increasing submodule, used for increasing the intermediate link voltage by the intermediate voltage step value when the auxiliary inverter modulation ratio is greater than the upper limit value of the auxiliary inverter modulation ratio; The intermediate voltage maintaining submodule is used to keep the intermediate link voltage unchanged when the auxiliary inverter modulation ratio is not less than the lower limit value of the auxiliary inverter modulation ratio and not greater than the upper limit value of the auxiliary inverter modulation ratio.

8. The traction system optimization control device according to claim 5, characterized in that: Also includes: An auxiliary inverter modulation ratio monitoring unit, used for calculating the auxiliary inverter modulation ratio according to the intermediate link voltage and the output voltage of the auxiliary inverter acquired in real time at every preset time interval when the working mode is the uncontrolled rectification mode; The second working mode switching unit is used to switch the working mode from the uncontrolled rectification mode to the controlled rectification mode when the auxiliary inverter modulation ratio is greater than the upper limit value of the auxiliary inverter modulation ratio.

9. A computer device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the method according to any one of claims 1 to 4 is implemented.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method according to any one of claims 1 to 4 is implemented.

11. A computer program product, characterized in that The computer program product comprises a computer program, and when the computer program is executed by a processor, the method according to any one of claims 1 to 4 is implemented.

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