A converter control system and a control method thereof

Abstract

An embodiment of the present application provides a converter control system and a control method thereof, wherein the system includes: at least one converter, a communication module and a controller; the controller is connected to each of the converters through the communication module; the converter is used to rectify and invert the electric energy of the power supply system, and obtain corresponding rectification parameters and inversion parameters; the controller is used to obtain the rectification parameters and inversion parameters of each of the converters through the communication module, and control the rectification processing process of the at least one converter according to the rectification parameters, or control the inversion processing process of the at least one converter according to the inversion parameters.

Description

Technical Field

[0001] The present application relates to the field of rail transportation, and is related to, but not limited to, a converter control system and a control method thereof. Background Art

[0002] Regenerative braking energy feedback devices primarily consist of insulated gate bipolar transistors (IGBTs), providing bidirectional power conversion capabilities for both inverter and rectifier outputs. However, currently, each function within these devices is implemented independently by a single converter within each traction station. There is no system-level information exchange between each converter and the power supply system, preventing rapid adjustments based on real-time system-level needs. This makes it difficult to achieve accurate reactive power compensation and meet system-level functional requirements. Summary of the Invention

[0003] In view of this, an embodiment of the present application provides a converter control system and a control method thereof.

[0004] The technical solution of this application is achieved as follows:

[0005] In a first aspect, an embodiment of the present application provides a converter control system, which is applied to a power supply system. The converter control system includes: at least one converter, a communication module, and a controller;

[0006] The controller is connected to each of the converters via the communication module;

[0007] The converter is used to perform rectification and inversion processing on the electric energy of the power supply system, and obtain rectification parameters and inversion parameters accordingly;

[0008] The controller is used to obtain the rectification parameters and the inversion parameters of each converter through the communication module, and control the rectification processing process of at least one converter according to the rectification parameters, or control the inversion processing process of at least one converter according to the inversion parameters.

[0009] In some embodiments, the converter control system further comprises: a monitoring device; the monitoring device is connected to the controller via the communication module;

[0010] The monitoring device is used to collect the rectification parameters and the inversion parameters acquired by the controller, and output the rectification parameters and the inversion parameters in real time.

[0011] In some embodiments, the converter control system further comprises: a monitoring device; the controller is integrated into the monitoring device;

[0012] The monitoring device controls the rectification process of the at least one converter according to the rectification parameters, or controls the inversion process of the at least one converter according to the inversion parameters.

[0013] In some embodiments, the monitoring device includes an alarm; the alarm is configured to issue an alarm signal when the rectification parameter is greater than a first preset threshold value and / or when the inversion parameter is greater than a second preset threshold value.

[0014] In some embodiments, the power supply system includes a power supply device and at least one power-consuming device; and one of the converters is connected between each power-consuming device and the power supply device.

[0015] In some embodiments, the communication module communicates using any one of the Goose communication mechanism, the Profibus communication protocol, the Modbus communication protocol, or the IEC60870-5-103 communication protocol.

[0016] In some embodiments, the communication module includes at least one network channel.

[0017] In some embodiments, each of the converters is interconnected with at least one other converter to achieve power distribution between the two interconnected converters.

[0018] In a second aspect, an embodiment of the present application provides a converter control method, which is applied to a converter control system. The converter control system includes: at least one converter, a communication module, and a controller; the method includes:

[0019] The controller obtains the rectification parameters and the inversion parameters of each converter in the converter control system through the communication module;

[0020] The rectification process of the at least one converter is controlled according to the rectification parameter, or the inversion process of the at least one converter is controlled according to the inversion parameter.

[0021] In some embodiments, the rectification parameters include: rectified output power and rectified output voltage; correspondingly, controlling the rectification process of the at least one converter according to the rectification parameters includes:

[0022] When the rectified output power of any of the converters is greater than or equal to a first threshold, determining the converter as a first target converter;

[0023] The rectifier output voltage of the first target converter is reduced, and the rectification process of the first target converter is controlled by at least one other converter adjacent to the first target converter.

[0024] In some embodiments, the inverter parameters include: inverter feedback power and inverter feedback starting voltage; correspondingly, controlling the inverter processing of the at least one converter according to the inverter parameters includes:

[0025] When the inverter feedback power of any of the converters is greater than or equal to a second threshold, determining the converter as a second target converter;

[0026] The inverter feedback starting voltage of at least one other converter adjacent to the second target converter in the converter control system is reduced, and the inverter processing process of the second target converter is controlled through the other converter.

[0027] In some embodiments, the rectification parameters include: rectification output power and rectification output voltage; the inversion parameters include: inversion feedback power; the method further includes:

[0028] When a change value of the rectifier output power of any of the converters within a first preset time period is less than or equal to a third threshold, determining the converter as a third target converter;

[0029] When the rectifier output power of the third target converter and the inverter feedback power of other converters except the third target converter meet a preset condition, the rectifier output voltage of the other converters is adjusted.

[0030] In some embodiments, the rectification parameters include: rectification output power; the inversion parameters include: inverter feedback power and inverter feedback starting voltage; the method further includes:

[0031] When a change value of the inverter feedback power of any of the converters within the second preset time period is less than or equal to a fourth threshold, determining the converter as a fourth target converter;

[0032] When the inverter feedback power of the fourth target converter and the rectifier output power of other converters except the fourth target converter meet a preset condition, the inverter feedback starting voltage of the fourth target converter is adjusted.

[0033] In some embodiments, the converter control system is applied to a power supply system, the power supply system including at least: a power supply device and at least one power-consuming device; the inverter parameter includes: an inverter feedback starting voltage; the method further includes:

[0034] Determining the transmission direction of electric energy in the converter corresponding to each electric device in the power supply system;

[0035] When the electric energy is transmitted to the electric device, the inverter feedback starting voltage of the corresponding current transformer is reduced according to a first preset gradient value, and the reduced inverter feedback starting voltage is greater than or equal to the first preset value;

[0036] When the electric energy is returned to the power supply device, the inverter feedback starting voltage of the corresponding current transformer is increased according to a second preset gradient value, and the increased inverter feedback starting voltage is less than or equal to the second preset value; wherein, the inverter feedback starting voltage is adjusted once within a third preset time period.

[0037] In some embodiments, the converter control system further includes: a monitoring device; the converter control system is applied to a power supply system, and the power supply system at least includes: a power supply device; the method further includes:

[0038] Collecting the power factor of each of the power supply devices through the monitoring device;

[0039] According to the power factor, the phase between the current and the voltage of at least one shunt connected in the power supply system is adjusted to compensate for the capacitive reactive power or inductive reactive power of the power supply system.

[0040] In some embodiments, the rectification parameters include: rectified output power and rectified output voltage; the method further includes:

[0041] Obtaining the rectified output power of any of the converters and a change value of the rectified output power within a fourth preset time period;

[0042] When the change value is less than or equal to a fifth threshold, determining the converter with the maximum rectified output power as the fifth target converter;

[0043] The fifth target converter is controlled to stop operating.

[0044] The embodiments of the present application provide a converter control system and a control method thereof, wherein the converter control system includes: at least one converter, a controller and a communication module. Since the controller is connected to each converter through the communication module, the controller can obtain the rectification parameters and inversion parameters of each converter through the communication module, and control the rectification processing process of at least one converter according to the rectification parameters, or control the inversion processing process of at least one converter according to the inversion parameters. In this way, through the controller and communication module in the converter control system, information interaction between the converter equipment and the power supply system can be realized, thereby realizing the function of quickly adjusting the converter according to the real-time needs of the system level, and realizing accurate reactive power compensation of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In the accompanying drawings (which are not necessarily drawn to scale), like reference numerals may describe similar components in different views. Like reference numerals with different letter suffixes may represent different examples of similar components. The accompanying drawings generally illustrate various embodiments discussed herein by way of example and not limitation.

[0046] Figure 1 An optional structural diagram of a converter control system provided in an embodiment of the present application;

[0047] Figure 2 An optional structural diagram of a power supply system provided in an embodiment of the present application;

[0048] Figure 3 An optional structural diagram of a converter control system provided in an embodiment of the present application;

[0049] Figure 4 A schematic diagram of an optional flow chart of a converter control method provided in an embodiment of the present application;

[0050] Figure 5A A schematic diagram of an optional flow chart of a converter control method provided in an embodiment of the present application;

[0051] Figure 5B A schematic diagram of an optional flow chart of a converter control method provided in an embodiment of the present application;

[0052] Figure 5C A schematic diagram of an optional flow chart of a converter control method provided in an embodiment of the present application;

[0053] Figure 6 A schematic diagram of an optional flow chart of a converter control method provided in an embodiment of the present application;

[0054] Figure 7 This is a schematic diagram of an optional structure of the converter control system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0055] To make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the specific technical solutions of the invention will be further described in detail below in conjunction with the drawings in the embodiments of the present application. The following embodiments are used to illustrate the present application but are not intended to limit the scope of the present application.

[0056] In the following description, the suffixes such as "module" or "unit" used to represent elements are only used to facilitate the description of the present application and have no specific meaning. Therefore, "module" or "unit" can be used interchangeably.

[0057] In the following description, the terms "first\second" involved are merely used to distinguish similar objects and do not represent a specific ordering of the objects. It can be understood that "first\second\third" can be interchanged with a specific order or sequence where permitted, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein.

[0058] Before further describing the embodiments of the present application in detail, the following description of the related background technology is given:

[0059] Regenerative braking energy feedback devices are widely used in subway power supply systems. They convert the DC power generated by the train's regenerative braking into AC power and feed it back to the 10 / 35kV medium-voltage power grid for redistribution and utilization, thus converting kinetic energy consumed in the form of heat into reusable electrical energy.

[0060] Currently, all functions involved in regenerative braking energy feedback are implemented independently, using a single converter within each traction station as the operating unit. There is no system-level information exchange between each converter and the power supply system, preventing rapid adjustments based on real-time system-level needs. This makes it difficult to achieve accurate reactive power compensation and meet system-level functional requirements. There is also no information exchange between converters, preventing them from coordinating with each other. This limits their ability to dynamically adjust various thresholds to achieve energy savings and prevent circulating currents between converters.

[0061] In response to the problems existing in the related technologies, this application aims to solve the following key problems:

[0062] 1. Establish a full-line control system to implement information exchange and automatic control of converters in each traction substation (corresponding to the above-mentioned traction station) between devices and between devices and systems.

[0063] 2. The control system needs to meet the requirements of reliability, real-time and fast response. Among them, the device response time of IGBT in the converter is in microseconds. The control system needs to meet the real-time requirements of fast transmission to better play the advantages of system-level fast response.

[0064] 3. Use the control system to optimize and expand the functions of existing converters, so that the converters can play better and more roles.

[0065] The embodiments of the present application propose a converter control system and method based on Generic Object-Oriented Substation Event (Goose) communication. By utilizing the strong interoperability and real-time application characteristics of Goose communication, a control system is established to uniformly manage and control multiple converters on a subway line dynamically in real time, optimize the functions of the converters, and accurately control the output characteristics of the converters to achieve more accurate, intelligent and reasonable performance of the converters.

[0066] Figure 1 This is an optional structural diagram of the converter control system provided in the embodiment of the present application, such as Figure 1 As shown, the converter control system 10 includes: at least one converter (for example, Figure 1 , the converter 111 , the converter 112 . . . , the converter 11n ), the controller 12 and the communication module 13 are shown in the figure, and the converter control system is applied to a power supply system.

[0067] The controller 12 is connected to each of the converters via the communication module 13 .

[0068] Here, the communication module 13 refers to a communication module between each converter and the controller. There is at least one communication module, and there is one communication module between each converter and the controller.

[0069] In some embodiments, the communication module 13 communicates using any one of the Goose communication mechanism, the Profibus communication protocol, the Modbus communication protocol (Modbus protocol) or the IEC60870-5-103 communication protocol.

[0070] Here, the Goose communication mechanism is a mechanism in the global standard (IEC61850) in the field of power system automation that is used to meet the fast messaging requirements of substation automation systems. It is mainly used to realize information transmission between multiple intelligent electronic devices and can transmit data quickly and reliably. Goose communication can transmit data quickly and reliably, and has the characteristics of strong interoperability and real-time application. The Profibus communication protocol is a fieldbus standard used in automation technology. The Modbus communication protocol is a serial communication protocol. Currently, Modbus has become the industry standard for communication protocols in the industrial field and has become a commonly used connection method between industrial electronic devices.

[0071] In some embodiments, the converter has a port supporting Goose communication, Profibus communication, Modbus communication, and IEC60870-5-103 communication.

[0072] In some embodiments, the communication module 13 includes at least one network channel, that is, the communication network used in the communication module can be a single network structure or a dual network structure.

[0073] The converter is used to rectify and invert the electric energy of the power supply system, and obtain corresponding rectification parameters and inversion parameters. The converter is an electrical device that changes the voltage, frequency, number of phases and other electrical quantities or characteristics of the power supply system. The converter in the embodiment of the present application has two functions: rectification and inversion. Rectification refers to the conversion of AC power into DC power, and the power flow of this conversion is from the power supply to the load; inversion refers to the conversion of DC power into AC power, and the functional flow of this conversion is from the load to the power supply. In some embodiments, the main component of the converter is IGBT, which can realize both rectification and inversion functions.

[0074] The controller 12 is used to obtain the rectification parameters and the inversion parameters of each converter through the communication module, and control the rectification processing process of the at least one converter according to the rectification parameters, or control the inversion processing process of the at least one converter according to the inversion parameters.

[0075] In some embodiments, the rectification parameters are parameters related to the rectification process of the converter; in the embodiment of the present application, the rectification parameters may include: rectification output power and rectification output voltage. Rectification output voltage refers to the output voltage output to the power-consuming device after the alternating current provided by the power supply device is rectified; rectification output power refers to: the product of the rectification output voltage and the rectification output current within a preset time period. The inversion parameters are parameters related to the inversion process of the converter; in the embodiment of the present application, the inversion parameters may include: inversion feedback power and inversion feedback starting voltage. The inversion feedback power refers to: the product of the inversion output voltage and the inversion output current within a preset time period; the inversion feedback starting voltage refers to: the lowest voltage at which the converter starts inversion operation.

[0076] Figure 2 An optional structural diagram of the power supply system provided in the embodiment of the present application is as follows: Figure 2 As shown, the power supply system 20 includes: a power supply device 21 and at least one power-consuming device (for example, Figure 2 , the electric devices 221, 222, ..., 22n shown in FIG.

[0077] In the embodiment of the present application, one converter is connected between each of the electrical devices and the power supply device 21 .

[0078] In some embodiments, the power supply device 21 may be a power grid, and the power-consuming device may be a subway, a vehicle, or other equipment.

[0079] In some embodiments, a converter is connected between the power supply device 21 and each of the power-consuming devices, and the converter is used to rectify the electric energy output from the power supply device to the power-consuming device, or to invert the electric energy fed back from the power-consuming device to the power supply device.

[0080] The converter control system provided in the embodiment of the present application includes: at least one converter, a controller and a communication module. Since the controller is connected to each converter through the communication module, the controller can obtain the rectification parameters and inversion parameters of each converter through the communication module, and control the rectification processing process of at least one converter according to the rectification parameters, or control the inversion processing process of at least one converter according to the inversion parameters. In this way, through the controller and communication module in the converter control system, information interaction between the converter equipment and the power supply system can be realized, thereby realizing the function of quickly adjusting the converter according to the real-time needs of the system level, and realizing accurate reactive power compensation of the system.

[0081] Figure 3 This is an optional structural diagram of the converter control system provided in the embodiment of the present application, such as Figure 3 As shown, the converter control system 30 includes at least: at least one converter (for example, Figure 3 , the converter 311 , the converter 312 . . . , the converter 31n ), the communication module 32 , the monitoring device 33 , the controller 331 and the alarm 332 are shown.

[0082] In some embodiments, the monitoring device 33 is connected to the at least one converter via the communication module 32 .

[0083] Here, the monitoring device 33 is used to collect the rectification parameters and the inversion parameters acquired by the controller 331, and output the rectification parameters and the inversion parameters in real time.

[0084] In some embodiments, the controller 331 can be independent of the monitoring device 33, or the controller can be integrated into the monitoring device 33. When the controller is integrated into the monitoring device 33, the monitoring device controls the rectification process of the at least one converter according to the rectification parameters, or controls the inversion process of the at least one converter according to the inversion parameters. When the controller is integrated into the monitoring device 33, control of multiple converters in the power supply system can be achieved without adding additional hardware devices.

[0085] In some embodiments, the monitoring device 33 further includes an alarm 332 .

[0086] The alarm is used to send out an alarm signal when the rectification parameter is greater than a first preset threshold value and / or when the inversion parameter is greater than a second preset threshold value.

[0087] In some embodiments, each of the converters is interconnected with at least one other converter to achieve power distribution between the two interconnected converters.

[0088] In some embodiments, the converters are connected to each other via a communication module 32 to achieve information exchange and mutual coordination between the converter devices, and to avoid functions such as circulating current between the converter devices.

[0089] An embodiment of the present application provides a converter control system, comprising: a monitoring device, a communication module and at least one converter. Since a controller is integrated in the monitoring device, and the monitoring device is connected to each converter through the communication module, the rectification processing process of at least one converter can be controlled by the monitoring device, or the inversion processing process of at least one converter can be controlled. In this way, information interaction between the converter device and the power supply system can be realized, thereby realizing the function of quickly adjusting the converter according to the real-time requirements of the system level; further, by integrating the controller inside the monitoring device, it is possible to control multiple converters in the power supply system without adding hardware equipment, thereby saving engineering costs.

[0090] Figure 4 An optional flow chart of a converter control method provided in an embodiment of the present application, wherein the control method is applied to a converter control system, wherein the converter control system includes: at least one converter, a communication module, a controller, and a monitoring device; Figure 4 As shown, the method includes the following steps:

[0091] Step S401: The controller obtains rectification parameters and inversion parameters of each converter in the converter control system through the communication module.

[0092] In some embodiments, the controller may be an independent part or integrated into a monitoring device in a converter control system.

[0093] In some embodiments, the rectification parameter is a parameter related to the rectification process of the converter.

[0094] In some embodiments, the inversion parameter is a parameter related to an inversion process of the converter.

[0095] Step S402: Control the rectification process of the at least one converter according to the rectification parameters, or control the inversion process of the at least one converter according to the inversion parameters.

[0096] The converter control method provided in the embodiment of the present application can control the rectification process of the converter according to the rectification parameters obtained by the controller, or control the inversion processing process of the converter according to the inversion parameters obtained by the controller. In this way, the working status of each converter can be monitored and adjusted in real time.

[0097] Figure 5A An optional flow chart of a converter control method provided in an embodiment of the present application is provided. The control method is applied to a converter control system, wherein the converter control system includes: at least one converter, a communication module, and a controller; Figure 5A As shown, the method includes the following steps:

[0098] Step S501: The controller obtains rectification parameters and inversion parameters of each converter in the converter control system through the communication module.

[0099] The implementation process and function of step S501 are the same as those of step S401 in the above embodiment.

[0100] Step S502: Control the rectification process of the at least one converter according to the rectification parameters, or control the inversion process of the at least one converter according to the inversion parameters.

[0101] In some embodiments, the rectification parameters include rectified output power and rectified output voltage. The rectified output power refers to the product of the rectified output voltage and the rectified output current within a preset time period. The rectified output voltage refers to the output voltage of the AC power provided by the power supply device after rectification and output to the power-consuming device.

[0102] In some embodiments, the inverter parameters include: inverter feedback power and inverter feedback start-up voltage. The inverter feedback power refers to the product of the inverter output voltage and the inverter output current within a preset time period. The inverter feedback start-up voltage refers to the minimum voltage at which the converter begins inverter operation.

[0103] In some embodiments, controlling the rectification process of the at least one converter according to the rectification parameters in step S502 may also be achieved by the following steps:

[0104] Step S5021: When the rectifier output power of any of the converters is greater than or equal to a first threshold, the converter is determined as a first target converter.

[0105] Step S5022: reduce the rectifier output voltage of the first target converter, and control the rectification process of the first target converter through at least one other converter adjacent to the first target converter.

[0106] In the embodiment of the present application, the term "adjacent" refers to being adjacent to the first target converter in terms of position. The first threshold value may be any reasonable value, and the embodiment of the present application does not impose any limitation on the value of the first threshold value.

[0107] In an embodiment of the present application, the controller monitors the rectifier output power of each converter in real time through a communication module. When the rectifier output power of any converter reaches a set value P1, and the rectifier output power P1 of the converter is greater than or equal to a first threshold value, the rectifier output voltage of the converter is reduced to form a voltage difference with an adjacent converter, and the adjacent converter provides partial support power supply capability for the converter.

[0108] In the embodiment of the present application, the above-mentioned control method can reduce the maximum output power of a single converter, thereby reducing the installation capacity of a single converter by 30% to 40%, greatly reducing project investment, and saving limited equipment installation space.

[0109] In some embodiments, the process of controlling the inversion process of the at least one converter according to the inversion parameter in step S502 may also be implemented by the following steps:

[0110] Step S5023: When the inverter feedback power of any of the converters is greater than or equal to a second threshold, the converter is determined as a second target converter.

[0111] Step S5024: reducing the inverter feedback starting voltage of at least one other converter adjacent to the second target converter in the converter control system, and controlling the inverter process of the second target converter through the other converter.

[0112] In the embodiment of the present application, the term "adjacent" refers to being adjacent to the second target converter in terms of position. The second threshold value may be any reasonable value, and the embodiment of the present application does not impose any limitation on the value of the second threshold value.

[0113] In an embodiment of the present application, the controller monitors the inverter feedback power of each converter in real time through a communication module. When the inverter feedback power of any converter reaches a set value P2, and the inverter feedback power P2 of the converter is greater than or equal to a second threshold value, the inverter feedback starting voltage of other converters adjacent to the second target converter is reduced so that a voltage difference is formed between the converter and the adjacent converter, and the adjacent converter provides more support feedback capability to the converter. Through the above control method, the inverter feedback power of a single converter can be reduced.

[0114] Figure 5B An optional flow chart of the converter control method provided in the embodiment of the present application is shown as follows: Figure 5B As shown, in some embodiments, the control method further includes the following steps:

[0115] Step S503: The controller obtains the rectifier output power of any of the converters and the inverter feedback power of other converters.

[0116] Step S504: Determine whether a change value of the rectifier output power of any of the converters within a first preset time period is less than or equal to a third threshold.

[0117] In some embodiments, the first preset time period can be 30 seconds, 1 minute, or 5 minutes. The embodiment of the present application does not impose any restrictions on the length of the first preset time period. The third threshold can be any reasonable value. The embodiment of the present application does not impose any restrictions on the size of the third threshold.

[0118] In some embodiments, when the change value of the rectifier output power of the first target converter within the first preset time period is greater than a first threshold, step S505 is executed; when the change value of the rectifier output power of the first target converter within the first preset time period is less than or equal to the first threshold, step S506 is executed.

[0119] Step S505: Do not adjust the rectifier output voltage of any converter.

[0120] Step S506: Determine the converter as the third target converter.

[0121] Step S507 : determining whether the rectifier output power of the third target converter and the inverter feedback power of other converters except the third target converter meet a preset condition.

[0122] In some embodiments, the preset condition is: the rectifier feedback power of the third target converter is equal to the rectifier output power of other converters except the third target converter, or the rectifier feedback power of the third target converter is equal to the rectifier output power of other converters except the third target converter within a smaller threshold range.

[0123] In some embodiments, when the rectifier output power and the inverter feedback power of other converters except the third target converter meet the preset conditions, step S508 is executed; when the rectifier output power and the inverter feedback of other converters except the third target converter do not meet the preset conditions, return to execute step S505.

[0124] Step S508: Adjust the rectifier output voltage of the other converters.

[0125] In an embodiment of the present application, the controller monitors the output status of each converter in real time through a communication module. When any converter is in a certain constant working state for a long time (the time length can be set), for example, the rectifier output power (the size of the rectifier output power can be set) changes slightly for a long time, it should be calculated whether other converters except the converter have an inverter feedback power that is opposite to the direction of power transmission in the converter and equal to the size of the rectifier output power. If so, there is a circulating current phenomenon; the controller sends an alarm signal and adjusts the rectifier output voltage of other converters except the converter.

[0126] Figure 5C An optional flow chart of the converter control method provided in the embodiment of the present application is shown as follows: Figure 5C As shown, in some embodiments, the control method further includes the following steps:

[0127] Step S509: The controller obtains the inverter feedback output power of any converter and the rectifier output power of other converters.

[0128] Step S510: Determine whether a change value of the inverter feedback power of any of the converters within a second preset time period is less than or equal to a fourth threshold.

[0129] In some embodiments, the second preset time period can be 30 seconds, 1 minute, or 5 minutes. The embodiment of the present application does not limit the length of the second preset time period. The fourth threshold can be any reasonable value. The embodiment of the present application does not limit the size of the fourth threshold.

[0130] In some embodiments, when the change value of the inverter output power of any of the converters within the second preset time period is greater than a fourth threshold, step S511 is executed; when the change value of the rectifier output power of any of the converters within the second preset time period is less than or equal to the fourth threshold, step S512 is executed.

[0131] Step S511: Do not adjust the inverter feedback starting voltage of any converter.

[0132] Step S512: Determine the converter as the fourth target converter.

[0133] Step S513 : Determine whether the inverter feedback power of the fourth target converter and the rectifier output power of other converters except the fourth target converter meet preset conditions.

[0134] In some embodiments, the preset condition is: the inverter feedback power of the fourth target converter is equal to the rectifier output power of other converters except the fourth target converter, or the inverter feedback power of the fourth target converter is equal to the rectifier output power of other converters except the fourth target converter within a smaller threshold range.

[0135] In some embodiments, when the inverter feedback power of the fourth target converter and the rectifier output power of other converters except the fourth target converter meet the preset conditions, step S514 is executed; when the inverter feedback power of the fourth target converter and the rectifier output power of other converters except the fourth target converter do not meet the preset conditions, return to execute step S511.

[0136] Step S514: adjusting the inverter feedback starting voltage of the fourth target converter.

[0137] In an embodiment of the present application, the controller monitors the output status of each converter in real time through a communication module. When any converter is in a certain constant working state for a long time (the time length can be set), for example, the inverter feedback power has a small change for a long time (the size of the inverter feedback power can be set), it should be calculated whether other converters have a rectifier output power that is opposite to the direction of power transmission of the converter and equal to the size of the inverter feedback power. If so, there is a circulating current phenomenon; the controller sends an alarm signal and adjusts the inverter feedback starting voltage of the converter.

[0138] Figure 6 An optional flow chart of a converter control method provided in an embodiment of the present application, wherein the control method is applied to a converter control system, wherein the converter control system includes: at least one converter, a communication module, and a controller; wherein the converter control system is applied to a power supply system, wherein the power supply system includes at least: a power supply device and at least one power-consuming device; wherein the inverter parameters include: an inverter feedback starting voltage; and Figure 6 As shown, the method includes the following steps:

[0139] Step S601: Determine the transmission direction of electric energy in the converter corresponding to each electric device in the power supply system.

[0140] In some embodiments, a converter is connected between each of the power-consuming devices and the power supply device in the power supply system.

[0141] Step S602: When the electric energy is transmitted to the electric device, the inverter feedback starting voltage of the corresponding current transformer is reduced according to a first preset gradient value, and the reduced inverter feedback starting voltage is greater than or equal to the first preset value.

[0142] In some embodiments, the first preset gradient value can be any reasonable value or multiple values. In the embodiment of the present application, there is no limitation on the size and number of the first preset gradient values.

[0143] In some embodiments, the first preset value is the minimum voltage of the DC system when it is no-loaded. When the electric energy is returned to the power-consuming device, the inverter feedback startup voltage of the corresponding shunt is reduced, and the total amount of regenerative inverter feedback energy of the corresponding shunt is increased. However, the inverter feedback startup voltage of the corresponding shunt cannot be lower than the no-load voltage of the DC system.

[0144] Step S603: When the electric energy is returned to the power supply device, the inverter feedback starting voltage of the corresponding current transformer is increased according to a second preset gradient value, and the increased inverter feedback starting voltage is less than or equal to the second preset value; wherein, the inverter feedback starting voltage is adjusted once within a third preset time period.

[0145] In some embodiments, the second preset gradient value can be any reasonable value or multiple values. In the embodiment of the present application, there is no limitation on the size and number of the second preset gradient values.

[0146] In the embodiment of the present application, the third preset time period can be 30 seconds, 1 minute or 5 minutes. In the embodiment of the present application, there is no limit on the size of the third preset time period.

[0147] In some embodiments, the inverter feedback startup voltage is adjusted once within the third preset time period in order to avoid oscillation of the power supply system caused by frequent adjustments.

[0148] In some embodiments, the second preset value is the maximum voltage allowed in the DC system. When power is fed back to the power supply grid (i.e., the power supply device), the inverter feedback startup voltage of the corresponding shunt is increased, thereby reducing the total amount of regenerative inverter feedback energy of the corresponding shunt. However, the inverter feedback startup voltage of the corresponding shunt must not be so high as to cause the DC system voltage to exceed the allowed value.

[0149] In some embodiments, the converter control system further includes: a monitoring device; the converter control system is applied to a power supply system, and the power supply system at least includes: a power supply device; the method further includes the following steps:

[0150] Step S604: Collect the power factor of each power supply device through the monitoring device.

[0151] In some embodiments, the power factor of the converter refers to the power factor of the power supply line side of the substation / switch station that carries the converter.

[0152] Step S605: Adjust the phase between the current and the voltage of at least one converter in the power supply system according to the power factor to compensate for capacitive reactive power or inductive reactive power of the power supply system.

[0153] In some embodiments, the power supply system includes: a main substation or a switch station.

[0154] In an embodiment of the present application, the compensation characteristics of the converter put into operation within the power supply range of the substation are automatically calculated based on the power factor. If there is inductive reactive power in the power supply system, capacitive reactive power is compensated; if there is capacitive reactive power in the power supply system, inductive reactive power is compensated. The compensation target value is generally 1.

[0155] In some embodiments, the rectification parameters include: rectified output power and rectified output voltage; the method further includes:

[0156] Step S606: Obtain the rectified output power of any of the converters and a change value of the rectified output power within a fourth preset time period.

[0157] In the embodiment of the present application, the fourth preset time period may be 30 seconds, 1 minute or 5 minutes. In the embodiment of the present application, there is no restriction on the size of the fourth preset time period.

[0158] Step S607: Determine whether the change value of the rectified output power is less than or equal to a fifth threshold.

[0159] In some embodiments, when the change value of the rectified output power is less than or equal to the fifth threshold, step S608 is executed; when the change value of the rectified output power is greater than the fifth threshold, step S609 is executed.

[0160] Step S608: Determine the converter with the maximum rectified output power as the fifth target converter.

[0161] Step S609: Do not adjust the working state of the fifth target converter.

[0162] Step S610: Control the fifth target converter to stop working.

[0163] The converter control method provided in the embodiment of the present application can dynamically adjust the inverter feedback starting voltage of the converter according to the rectifier output power or inverter feedback power of the converter obtained by the controller, thereby realizing reasonable distribution of regenerative braking energy in the AC system and the DC system, avoiding the active power return phenomenon, and at the same time, by dynamically adjusting the output characteristics of each converter, realizing reasonable power support between adjacent converters, reducing the installation capacity of the converter by 30% to 50%, and significantly reducing project investment.

[0164] Figure 7 This is an optional structural diagram of the converter control system provided in the embodiment of the present application, such as Figure 7 As shown, the converter control system 70 includes: a plurality of converters (eg, Figure 7 The converter 71, converter 72 ... converter 74), controller 75, Supervisory Control And Data Acquisition (SCADA) 76, and Goose communication network 77 shown in the figure are used in a power supply system, which includes: a power supply device and at least one power-consuming device; in the embodiment of the present application, the Goose communication network refers to the communication network between each converter and the controller; in the embodiment of the present application, the power-consuming device is illustrated by taking a subway as an example.

[0165] In the embodiment of the present application, each converter needs to have a port that supports Goose communication.

[0166] In an embodiment of the present application, n sets of converters may be provided for one line. Generally, one set of converters is provided for each traction substation. In the present application, one set of controllers is provided for one line. The controller has control strategies for various controls and can realize various control functions.

[0167] In the embodiment of the present application, by building a Goose communication network, fast communication is achieved between each converter and the controller, and between converters, so as to realize real-time monitoring and control of each converter by the controller.

[0168] In the embodiment of the present application, the controller is connected to the SCADA system (corresponding to the monitoring equipment in the above embodiment) to exchange information.

[0169] In some embodiments, all functions of the controller can be integrated into the SCADA system.

[0170] In some embodiments, the control network (corresponding to the communication module in the above embodiment) can also be constructed using a converter that supports Profibus, Modbus and IEC60870-5-103 communication interfaces. Therefore, the control method proposed in this application is also applicable to communication processes such as Profibus, Modbus and IEC60870-5-103.

[0171] This application utilizes the strong interoperability and real-time application characteristics of Goose communication to establish a control system to uniformly manage, dynamically manage, monitor and control multiple converters on a subway line in real time, optimize converter functions, accurately control converter output characteristics, and achieve more accurate, intelligent and reasonable converter performance.

[0172] In the embodiment of the present application, the controller includes but is not limited to the following control processes:

[0173] (1) Dynamically adjust the starting voltage value of the converter to convert DC power into AC power (corresponding to the inverter feedback starting voltage in the above embodiment), optimize the power transmission path, improve the reuse rate of power and reduce the electricity cost expenditure of rail transit.

[0174] The controller reads the power transmission direction of the main substation (including: power substation and traction substation) / switch station through the SCADA system; when there is a situation where power is returned to the power supply side grid (corresponding to the power return from the power user to the power supply device in the above embodiment), the inverter feedback starting voltage of the converter is increased to reduce the total amount of regenerative inverter feedback energy of the converter, but the inverter feedback starting voltage value of the converter cannot be so high as to cause the DC system voltage to exceed the allowable value (corresponding to the second preset value in the above embodiment). Conversely, if there is no situation where power is returned to the power supply side grid (corresponding to the power transmission from the power supply device to the power user in the above embodiment), the inverter feedback starting voltage value of the converter is reduced to increase the total amount of regenerative inverter feedback energy of the converter, but the inverter feedback starting voltage value of the converter cannot be lower than the DC system no-load voltage value (corresponding to the first preset value in the above embodiment).

[0175] (2) Dynamically adjust the output characteristics of the converter in the rectifier working state, optimize the reasonable distribution of electric energy in the DC traction network, form a support relationship of power supply capacity between adjacent converters, reduce the installation capacity of a single converter by 30% to 50%, and thus significantly reduce project investment.

[0176] The controller monitors the rectifier output power of each converter in real time through the Goose communication network; when the rectifier output power of a converter reaches the set value P1 (P1≤P N , P N Refers to the rated output power of the converter), reducing the rectifier output voltage of the converter to form a voltage difference with the adjacent converter, and the adjacent converter provides partial support power supply capacity.

[0177] In the embodiment of the present application, the above-mentioned control method can reduce the maximum output power of a single converter, thereby reducing the installation capacity of a single converter by 30% to 40%, greatly reducing project investment, and saving limited equipment installation space underground.

[0178] (3) Dynamically adjust the starting voltage value of the converter when it is in the inverter feedback working state (corresponding to the inverter feedback starting voltage in the above embodiment), optimize the reasonable distribution of electric energy in the DC traction network, form an inverter feedback support relationship between adjacent converters, and reduce the feedback capacity of a single converter.

[0179] The controller monitors the inverter feedback power of each converter in real time through the Goose communication network; when the rectifier output power of a converter reaches the set value P2 (P2≤P N , P N refers to the rated output power of the converter), reducing the inverter feedback starting voltage of the adjacent converter to form a voltage difference with the inverter feedback starting voltage of the adjacent converter, so that the adjacent converter can provide more support feedback capacity.

[0180] In the embodiment of the present application, the above control method can reduce the power of the inverter feedback of a single converter.

[0181] (4) Dynamically adjust the compensation strategy of the converter during reactive power compensation to improve the power factor of the power supply system injected into the point of common coupling (PCC).

[0182] The controller reads the power factor of the sampling point on the incoming line side of the main substation / switch station through the SCADA system. The controller automatically calculates the compensation characteristics of each converter in operation within the power supply range of the main substation / switch station, including adjusting whether to compensate inductive or capacitive reactive power and the compensation capacity. The controller makes the power factor of the sampling point close to 1, fully utilizes the capabilities of each converter, and improves the power factor injected into the PCC point of the power supply system.

[0183] (5) Dynamically adjust the compensation strategy of the converter during reactive power compensation to improve the power factor of the 10 / 35kV power supply line side of this substation and realize local dynamic compensation.

[0184] The controller reads the power factor of the sampling point on the 10 / 35kV power incoming side of the substation through the SCADA system or direct sampling. The controller automatically calculates the compensation characteristics of the converters put into operation within the power supply range of the substation, including adjusting whether to compensate inductive or capacitive reactive power and the size of the compensation capacity, so that the power factor of the sampling point is close to 1, giving full play to the capacity of the converter, improving the power factor of the substation, realizing on-site reactive power compensation, and saving the system's energy loss.

[0185] (6) Monitor the output status of each converter in real time to avoid circulating current between converters and cause unnecessary power loss.

[0186] The controller monitors the output status of each converter in real time through the Goose communication network. When a converter is in a certain constant working state for a long time (the time length can be set), such as the rectifier output power or inverter feedback power with small changes for a long time (the size of the rectifier output power and the inverter feedback power can be set), it should be calculated whether other converters have an inverter feedback power / rectifier output power that is opposite to the direction of power transmission of the converter and equal to the rectifier output power / inverter feedback power. If so, there is a circulation phenomenon, and the controller should issue an alarm signal and remind to adjust the starting threshold of the corresponding converter (corresponding to the inverter feedback starting voltage in the above embodiment).

[0187] (7) Monitor the output status of each converter in real time, select and analyze the fault point, and issue an alarm signal or issue an instruction to stop the converter.

[0188] The controller monitors the output status of each converter in real time through the Goose communication network. When some converters maintain a relatively stable rectifier output power (the rectifier output power level can be set) for a long period of time (the length of time can be set), a short circuit fault should have occurred on the DC side. The controller should compare the rectifier output power levels of each converter and find the converter with the maximum rectifier output power. If the short circuit fault point is closest to the converter, the controller will send an alarm signal to the substation SCADA or issue a command to stop the converter or trip the incoming circuit breaker.

[0189] (8) When the above controller is dynamically adjusted, in order to avoid system oscillation caused by frequent adjustments, a trigger gradient value for the adjustment can be set. For example, the adjustment is only made when the reverse power transmission reaches a certain power value, or a limit is added to allow only one adjustment within a certain time window.

[0190] (9) The Goose communication network between each converter and controller can be a single network structure or a redundant dual network structure.

[0191] Because each converter in the related art independently implements its preset functions, there is no information exchange between each device and the power supply system, or between each device, making it impossible to quickly adjust according to real-time needs, resulting in limited functionality. It is also difficult to properly distribute energy between the DC and AC sides. It is even more difficult to intelligently and proactively detect faults and avoid circulating currents between them. However, the converter control system and method based on Goose communication proposed in this application can monitor and adjust the operating status of each converter in real time with minimal additional investment or even no additional hardware equipment (the controller can be integrated into the SCADA system), so that regenerative braking energy is reasonably distributed between the AC and DC systems, avoiding active power feedback. At the same time, by dynamically adjusting the output characteristics of each converter, reasonable power support can be achieved between adjacent converters, reducing the installed capacity of the converter by 30% to 50%, significantly reducing project investment. It can also realize intelligent and proactive fault detection, fault location, fault alarm, and the issuance of shutdown instructions, and can also avoid circulating currents between converters. The converter control system and method provided by the embodiments of this application have high economic and technical value.

[0192] The control system and method provided in the embodiments of the present application can be implemented by adding a set of controllers, or integrated into a SCADA system. These control methods and strategies are implemented through programs preset in the controller or SCADA system.

[0193] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, such as: multiple units or components can be combined, or can be integrated into another system, or some features can be ignored or not executed. In addition, the coupling, direct coupling, or communication connection between the components shown or discussed can be through some interfaces, and the indirect coupling or communication connection of the devices or units can be electrical, mechanical or other forms.

[0194] In addition, the functional units in the embodiments of the present invention can all be integrated into one processing module, or each unit can be a separate unit, or two or more units can be integrated into one unit; the above-mentioned integrated unit can be implemented in the form of hardware or in the form of hardware plus software functional units. It can be understood by those skilled in the art that all or part of the steps of the above-mentioned method embodiments can be completed by hardware related to program instructions, and the above-mentioned program can be stored in a computer-readable storage medium. When the program is executed, it executes the steps of the above-mentioned method embodiments; and the above-mentioned storage medium includes various media that can store program codes, such as mobile storage devices, read-only memories (ROMs), random access memories (RAMs), magnetic disks or optical disks.

[0195] The methods disclosed in the several method embodiments provided in this application can be arbitrarily combined without conflict to obtain new method embodiments.

[0196] The features disclosed in the several product embodiments provided in this application can be arbitrarily combined without conflict to obtain new product embodiments.

[0197] The features disclosed in the several method or device embodiments provided in this application can be arbitrarily combined without conflict to obtain new method embodiments or device embodiments.

[0198] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A converter control system, characterized in that: Applied to a power supply system, the converter control system comprises: at least one converter, a communication module and a controller; The controller is connected to each of the converters via the communication module; The converter is used to perform rectification and inversion processing on the electric energy of the power supply system, and obtain corresponding rectification parameters and inversion parameters; the rectification parameters include: rectification output power and rectification output voltage; the inversion parameters include: inverter feedback power and inverter feedback starting voltage; The controller is configured to obtain the rectification parameters and the inversion parameters of each of the converters through the communication module, and control the rectification process of the at least one converter according to the rectification parameters; or, when the inverter feedback power of any of the converters is greater than or equal to a second threshold, determine the converter as a second target converter, reduce the inverter feedback starting voltage of at least one other converter adjacent to the second target converter in the converter control system, and control the inversion process of the second target converter through the other converters; The controller is also used to determine the converter as the first target converter when the rectifier output power of any of the converters is greater than or equal to a first threshold; reduce the rectifier output voltage of the first target converter, and control the rectification processing process of the first target converter through at least one other converter adjacent to the first target converter.

2. The system according to claim 1, wherein: The converter control system further comprises: a monitoring device; The monitoring device is connected to the controller via the communication module; The monitoring device is used to collect the rectification parameters and the inversion parameters acquired by the controller, and output the rectification parameters and the inversion parameters in real time.

3. The system according to claim 1, wherein: The converter control system further comprises: a monitoring device; The controller is integrated into the monitoring device; The monitoring device controls the rectification process of the at least one converter according to the rectification parameters, or controls the inversion process of the at least one converter according to the inversion parameters.

4. The system according to claim 2 or 3, characterized in that The monitoring equipment includes an alarm; The alarm is used to send out an alarm signal when the rectification parameter is greater than a first preset threshold value and / or when the inversion parameter is greater than a second preset threshold value.

5. The system according to claim 1, wherein: The communication module uses any one of the Goose communication mechanism, Profibus communication protocol, Modbus communication protocol or IEC60870-5-103 communication protocol for communication.

6. A converter control method, characterized in that: Applied to a converter control system, the converter control system includes: at least one converter, a communication module and a controller; the method includes: The controller obtains the rectification parameters and the inversion parameters of each converter in the converter control system through the communication module; the rectification parameters include: rectification output power and rectification output voltage; the inversion parameters include: inverter feedback power and inverter feedback starting voltage; controlling a rectification process of the at least one converter according to the rectification parameter, or controlling an inversion process of the at least one converter according to the inversion parameter; Correspondingly, controlling the rectification process of the at least one converter according to the rectification parameter includes: When the rectified output power of any of the converters is greater than or equal to a first threshold, determining the converter as a first target converter; reducing a rectifier output voltage of the first target converter, and controlling a rectification process of the first target converter through at least one other converter adjacent to the first target converter; Correspondingly, controlling the inversion process of the at least one converter according to the inversion parameter includes: When the inverter feedback power of any of the converters is greater than or equal to a second threshold, determining the converter as a second target converter; The inverter feedback starting voltage of at least one other converter adjacent to the second target converter in the converter control system is reduced, and the inverter processing process of the second target converter is controlled through the other converter.

7. The method according to claim 6, characterized in that The inverter parameters include: inverter feedback power; the method further includes: When a change value of the rectifier output power of any of the converters within a first preset time period is less than or equal to a third threshold, determining the converter as a third target converter; When the rectifier output power of the third target converter and the inverter feedback power of other converters except the third target converter meet a preset condition, the rectifier output voltage of the other converters is adjusted.

8. The method according to claim 6, characterized in that The inverter parameters include: inverter feedback power and inverter feedback starting voltage; the method further includes: When a change value of the inverter feedback power of any of the converters within the second preset time period is less than or equal to a fourth threshold, determining the converter as a fourth target converter; When the inverter feedback power of the fourth target converter and the rectifier output power of other converters except the fourth target converter meet a preset condition, the inverter feedback starting voltage of the fourth target converter is adjusted.

9. The method according to claim 6, characterized in that The converter control system is applied to a power supply system, which includes at least: a power supply device and at least one power-consuming device; the inverter parameters include: an inverter feedback starting voltage; and the method further includes: Determining the transmission direction of electric energy in the converter corresponding to each electric device in the power supply system; When the electric energy is transmitted to the electric device, the inverter feedback starting voltage of the corresponding current transformer is reduced according to a first preset gradient value, and the reduced inverter feedback starting voltage is greater than or equal to the first preset value; When the electric energy is returned to the power supply device, the inverter feedback starting voltage of the corresponding current transformer is increased according to a second preset gradient value, and the increased inverter feedback starting voltage is less than or equal to the second preset value; wherein, the inverter feedback starting voltage is adjusted once within a third preset time period.

10. The method according to claim 6, characterized in that The converter control system further includes: a monitoring device; the converter control system is applied to a power supply system, the power supply system at least including: a power supply device; the method further includes: Collecting the power factor of each of the power supply devices through the monitoring device; According to the power factor, the phase between the current and the voltage of at least one converter in the power supply system is adjusted to compensate for the capacitive reactive power or the inductive reactive power of the power supply system.

11. The method according to claim 6, characterized in that The method further comprises: Obtaining the rectified output power of any of the converters and a change value of the rectified output power within a fourth preset time period; When the change value is less than or equal to a fifth threshold, determining the converter with the maximum rectified output power as the fifth target converter; The fifth target converter is controlled to stop operating.

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