UPFC-based moving die system, high-speed communication architecture and control method

Abstract

The invention discloses a UPFC moving mode system, a high-speed communication architecture and a control method. The UPFC moving mode system comprises a UPFC physical entity system, a UPFC digital twin system, a high-speed communication architecture and an interconnection interface. The UPFC digital twin system comprises a simulation model, a control system, a visual interface and an application service module. The high-speed communication architecture comprises a plurality of hosts and a communication network, the hosts are used for realizing a converter flow and control thereof in a UPFC physical entity system and realizing various functions of a UPFC digital twin system, and the communication network is used for communication among the hosts; the control method comprises an STATCOM mode, a UPFC mode and a fault protection mode. According to the method, virtual mapping can be carried out on a UPFC physical entity system, higher network throughput capacity is provided, the data transmission speed is effectively improved, the requirements of actual engineering for UPFC operation, protection and the like can be effectively met, and the method has the advantages of being multiple in function, high in communication efficiency, high in intelligent degree and the like.

Description

Technical Field

[0001] The present invention belongs to the field of electrical engineering technology, and in particular relates to a dynamic model system based on UPFC, a high-speed communication architecture and a control method. Background Art

[0002] The Unified Power Flow Controller (UPFC) combines the series compensation technology with the Static Synchronous Compensator (STATCOM), which can realize the precise control of the power system flow, significantly improving the transmission capacity and the safe and stable operation level of the power grid. However, in daily operation and maintenance, it is found that the "black module" problem caused by optical module failure, uplink communication fiber failure, board failure and module power failure seriously affects the reliable operation of the system, and its complex inducement also greatly increases the difficulty and workload of operation and maintenance. Among them, single-channel uplink communication is one of the main sources of increasing the hidden dangers of "black module" failure. In addition, the main functions of the UPFC monitoring system in the current project are status information visualization, equipment-side system control protection and typical fault handling, etc., but the status monitoring of key parameters that cannot be obtained by sensors, or the potential fault assessment based on historical working conditions, etc. are all lacking. The intelligent and digital operation and maintenance capabilities of the UPFC monitoring system still need to be improved.

[0003] The existing technologies for UPFC simulation, control or protection are: The patent with publication number CN111026078A proposes a hardware-in-the-loop test system for a hybrid UPFC control and protection algorithm, including: a simulation system, a switching device and a hybrid UPFC control and protection device, the simulation system is used to generate simulation operating parameters of UPFC according to the operating environment of UPFC; the switching device is used to receive the simulation operating parameters obtained by simulation of the simulation system, and send the simulation operating parameters to the hybrid UPFC control and protection device after protocol conversion; the hybrid UPFC control and protection device is used to receive the simulation operating parameters after protocol conversion, calculate the simulation operating parameters according to the hybrid UPFC control and protection algorithm, and generate a command signal; the switching device receives the command signal and sends it to the simulation system; the simulation system is used to execute the command signal, generate simulation operating data, and generate test results according to the simulation operating data.

[0004] The patent with the publication number CN108574282A proposes a power flow control method of UPFC in microgrid based on nonlinear control, including the following steps: analyzing the power flow control mode of microgrid; analyzing the working principle of UPFC; analyzing the power flow control characteristics of UPFC in microgrid; establishing the nonlinear mathematical model and control target of UPFC; adopting the series side backstepping sliding mode control strategy to make the control system stable at the equilibrium point; adopting the parallel side decoupling control strategy to compensate the reactive power regulation capability of the series side; determining the example and its necessary characteristics, and using Matlab / Simulink software to simulate and analyze the example. The method of the present invention lays the foundation for the design of power flow controller; establishing the nonlinear mathematical model of UPFC; adopting the decoupling control strategy based on the reactive power control mode for the parallel side controller; enhancing the anti-interference ability of the system nonlinearity and external disturbance, effectively realizing the control of the line power flow, determining the power regulation range, and realizing the power balance distribution of the system.

[0005] The patent with publication number CN110768268A provides a method and system for adjusting the HVDC power control strategy considering the commissioning of UPFC. The method and system collect historical data of the power grid, establish a time domain simulation analysis model on the simulation software, and when a disturbance occurs locally in the power grid, under the active power control strategy of the HVDC active power modulation model of the power grid, determine whether there is power oscillation in the interconnection section monitored by the active power modulation model. When there is power oscillation, determine whether the power delivery branches sampled by the UPFC fixed active power control model and the HVDC transmission section active power modulation model overlap. When there is overlap, remove the reference branch in the UPFC fixed power control branch. When there is no overlap, prevent power oscillation by correcting the HVDC power modulation control parameters.

[0006] However, the above solutions have failed to effectively combine physical entities and virtual space and explore the interconnection relationship, and have few functions, limited communication performance, and low intelligence. Summary of the invention

[0007] In view of this, the present invention provides a dynamic model system, a high-speed communication architecture and a control method of a UPFC, and realizes system construction through digital twin technology, which is used to solve the problems of the existing UPFC monitoring system with few functions, limited communication performance, and low intelligence level, and provides important technical support for the construction of digital intelligent power grid equipment, and has broad application prospects.

[0008] In order to solve the above technical problems, the present invention adopts the following technical solutions: The present invention provides a UPFC dynamic model system, including a UPFC physical entity system, a UPFC digital twin system, a high-speed communication architecture and an interconnection interface. The UPFC physical entity system includes a sending end AC source , AC source at receiving end , upper DC bus U dc +, lower DC bus U dc -, sending end line impedance X S , receiving end line impedance X R , parallel transformer T sh , Series transformer T se , a parallel side converter, a series side converter, a first circuit breaker QF1, a second circuit breaker QF2, a third circuit breaker QF3, a fourth circuit breaker QF4, a first disconnector DS1, a second disconnector DS2, a third disconnector DS3, a fourth disconnector DS4, a fifth disconnector DS5, a sixth disconnector DS6, a seventh disconnector DS7, an eighth disconnector DS8, a fuse FU and a thyristor bypass switch TBS; characterized in that: The UPFC digital twin system is used to simulate, control and provide application services to the UPFC physical entity system. The UPFC digital twin system includes a simulation model, a control system, a visualization interface and an application service module; The interconnection interface is used to realize data information interaction between the UPFC physical entity system and the UPFC digital twin system; The simulation model simulates each physical element in the UPFC circuit under the conditions of electric field, thermal field and stress field, and the simulation model is used for calling by the control system and the application service module; the control system is used to control the UPFC physical entity system and the simulation model in the UPFC digital twin system, and simultaneously obtain the actual operation data and the simulation operation data; the visualization interface is used to monitor and record the sequential control process of each converter, the real-time operation waveform of the UPFC physical entity system and the UPFC digital twin system, and the system status of the UPFC physical entity system and the UPFC digital twin system; The application service module is used for abnormal state diagnosis analysis, fault location and early warning analysis, historical data replay and health status assessment.

[0009] Preferably, the simulation model is divided into a basic model, an average model and a dynamic model according to the time scale. The basic model simulates the static parameters of each physical element, the average model simulates the physical quantities of each physical element at long time scale intervals; the dynamic model adds additional dynamic characteristics on the basis of the average model, including the transient process of switching on and off of the switch tube.

[0010] Preferably, the high-speed communication architecture includes several hosts and communication networks, the hosts are used to implement the converter process and its control in the UPFC physical entity system and to implement various functions of the UPFC digital twin system, and the communication network is used for communication between hosts; The hosts in the high-speed communication architecture include a parallel side converter host, a series side converter host, a protection service host, an intelligent auxiliary host, a first server, a second server and an operable host computer; the parallel side converter host is used to implement the parallel side converter sequential control process and its control, the series side converter host is used to implement the series side converter sequential control process and its control, the protection service host is used to implement converter protection, transformer protection and AC line protection, the intelligent auxiliary host is used to provide all functions of the UPFC digital twin system, the first server and the second server cooperate to realize the communication function, provide centralized computing, information publishing and data management services, and the operable host computer provides a friendly human-computer interaction interface.

[0011] Preferably, the communication network of the high-speed communication architecture adopts dual LAN networking, including LAN1, a first LAN2, an RJ45 Ethernet interface, a second RJ45 Ethernet interface, a first Ethernet signal transformer, a second Ethernet signal transformer, a first MAC / PHY transceiver, a second MAC / PHY transceiver and a CPU, one end of the first RJ45 Ethernet interface is connected to LAN1, and the other end is connected to one end of the first Ethernet transformer, the other end of the first Ethernet transformer is connected to one end of the first MAC / PHY transceiver, and the other end of the first MAC / PHY transceiver is connected to the CPU; one end of the second RJ45 Ethernet interface is connected to LAN2, and the other end is connected to one end of the second Ethernet transformer 2, the other end of the second Ethernet transformer is connected to one end of the second MAC / PHY transceiver, and the other end of the second MAC / PHY transceiver is connected to the CPU.

[0012] The second aspect of the present invention provides a high-speed communication architecture using the dynamic model system described in the first aspect of the present invention; The high-speed communication architecture includes several hosts and a communication network. The hosts are used to implement the converter process and its control in the UPFC physical entity system and to implement various functions of the UPFC digital twin system. The communication network is used for communication between hosts. Preferably, the communication network of the high-speed communication architecture adopts dual LAN networking, including LAN1, a first LAN2, an RJ45 Ethernet interface, a second RJ45 Ethernet interface, a first Ethernet signal transformer, a second Ethernet signal transformer, a first MAC / PHY transceiver, a second MAC / PHY transceiver and a CPU, one end of the first RJ45 Ethernet interface is connected to LAN1, and the other end is connected to one end of the first Ethernet transformer, the other end of the first Ethernet transformer is connected to one end of the first MAC / PHY transceiver, and the other end of the first MAC / PHY transceiver is connected to the CPU; one end of the second RJ45 Ethernet interface is connected to LAN2, and the other end is connected to one end of the second Ethernet transformer 2, the other end of the second Ethernet transformer is connected to one end of the second MAC / PHY transceiver, and the other end of the second MAC / PHY transceiver is connected to the CPU.

[0013] The second aspect of the present invention provides a control method for the UPFC dynamic model system according to the first aspect of the present invention. When the system only needs fast reactive power compensation, the series side does not work and the parallel side works and runs in STATCOM mode. When the system needs to control the power flow and voltage distribution and take into account dynamic reactive power compensation, the series side is connected and the parallel side runs in UPFC mode. When a system failure occurs, operation fault protection is performed. When in the STATCOM mode, the parallel side works under the grid-side AC voltage control; when in the UPFC mode, the parallel side works under reactive power control; the series side works under line active power control and line reactive power control, and the series side performs line fault restart control; before the series side is connected, the series side performs smooth start control; the operation fault protection includes line protection, transformer protection and UPFC body protection; Preferably, the smooth start control is specifically: S1. Before starting, the states of the circuit breakers and disconnectors are as follows: the first circuit breaker QF1 is disconnected, the second circuit breaker QF2 is closed, the third circuit breaker QF3 is disconnected, the fourth circuit breaker QF4 is closed, the first disconnector DS1 is disconnected, the second disconnector DS2 is disconnected, the third disconnector DS3 is disconnected, the fourth disconnector DS4 is disconnected, the fifth disconnector DS5 is disconnected, the sixth disconnector DS6 is disconnected, the seventh disconnector DS7 is disconnected, and the eighth disconnector DS8 is disconnected. Set the startup parameters of the series side converter according to system requirements; S2. Sequentially close the second isolating switch DS2, the third isolating switch DS3, the seventh isolating switch DS7, the eighth isolating switch DS8, the fifth isolating switch DS5, the sixth isolating switch DS6, the fourth isolating switch DS4; S3. Close the third circuit breaker QF3 to complete the series connection of transformer T seCharging of the primary winding; disconnecting the fourth circuit breaker QF4 to complete the series connection of the transformer T se Connection between the secondary winding and the series side converter; S4. Close the first circuit breaker QF1. At the same time, the parallel side converter and the series side converter receive the start signal and charge. At this time, the current loop of the series side converter transmits current in the circuit. i 1 is used as a reference value to control the output current of the series side converter i se Close to the circuit transfer current converted to the secondary side i 1. When the amplitude difference between the two is less than the set series side smooth access current threshold, it means that charging is completed, the first isolating switch DS1 is closed, and then the second circuit breaker QF2 is disconnected. At the same time, its current loop reference value is converted to the output of the series side converter voltage loop. At this time, the series side converter is smoothly connected to the main circuit.

[0014] Preferably, the startup parameters of the series side converter are set according to the system requirements, including the active power reference of the series side converter. , Series Side Converter Reactive Power Benchmark and the series side smooth access current threshold, the setting values ​​of both are consistent with those when operating under rated conditions.

[0015] Preferably, the line fault restart control is specifically as follows: when a fault occurs, it is determined whether the fault is a line fault or an equipment fault. When it is determined to be a line fault, the thyristor bypass switch TBS is closed, the series side converter is locked, and the series side converter is isolated from the main circuit and exits operation; After the reclosing setting time has passed, which is the time from when the device senses that the circuit breaker is disconnected to when the device allows the closing command to be issued; by detecting the line voltage, current and switch position, it is determined whether the line is operating normally. If normal, the thyristor bypass switch TBS is disconnected to restart the series side converter.

[0016] Preferably, the reclosing setting time is set between 0.8-2.0s.

[0017] Preferably, the line protection, transformer protection and UPFC body protection of the operation fault protection are specifically: the line protection includes overvoltage protection and circuit breaker protection; the transformer protection includes transformer electric quantity protection and transformer non-electric quantity protection; the UPFC body protection specifically includes parallel side action and series side action; Parallel side actions: alarm, switch control system, lock parallel side converter, trip parallel transformer converter side switch, trip parallel transformer grid side switch in case of failure; Series side actions: alarm, switch control system, lock series side converter, trigger thyristor bypass switch TBS to turn on, close series transformer line side bypass switch, close series transformer converter side bypass switch; A fault on the parallel side will trip the series side: a fault in the AC area on the series side will only exit the converter on the corresponding side; a fault in the converter area on the series side will trip the other sides.

[0018] The beneficial effects of the present invention compared with the prior art are: The present invention provides a UPFC dynamic model system, a high-speed communication architecture and a control method. The digital twin technology is used to establish the connection between the UPFC physical entity and the virtual mapping space, and a dual LAN networking method is used to establish a reliable and efficient information communication network. A control strategy that matches the actual engineering situation is proposed to cope with different on-site requirements, and a variety of application services supporting the digital twin are provided, thereby effectively solving the deficiencies of the original UPFC monitoring system in terms of function and communication, and providing an important reference for realizing the digital and intelligent upgrade of UPFC equipment operation and maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the structure of a UPFC dynamic model system disclosed in an embodiment of the present application; Figure 2 It is a schematic diagram of the dual LAN communication network connection disclosed in the embodiment of the present application; Figure 3 A schematic diagram of the control system parallel-side converter control disclosed in an embodiment of the present application; Figure 4 A control schematic diagram of a series-side converter control system disclosed in an embodiment of the present application; Figure 5 It is a flow chart of smooth start control implementation disclosed in the embodiment of the present application. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the present invention more clear, the technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0021] The embodiments described in the present invention are only some embodiments of the present invention, not all embodiments. Based on the spirit of the present invention, other embodiments obtained by ordinary technicians in this field without creative work are all within the protection scope of the present invention.

[0022] like Figure 1 As shown, embodiment 1 of the present invention proposes a UPFC dynamic model system, including a UPFC physical entity system, a UPFC digital twin system, a high-speed communication architecture and an interconnection interface, wherein the UPFC physical entity system includes a sending end AC source , AC source at receiving end , upper DC bus U dc +, lower DC bus U dc -, sending end line impedance X S , receiving end line impedance X R , parallel transformer T sh , Series transformer T se , parallel side converter, series side converter, first circuit breaker QF1, second circuit breaker QF2, third circuit breaker QF3, fourth circuit breaker QF4, first disconnector DS1, second disconnector DS2, third disconnector DS3, fourth disconnector DS4, fifth disconnector DS5, sixth disconnector DS6, seventh disconnector DS7, eighth disconnector DS8, fuse FU and thyristor bypass switch TBS; The UPFC digital twin system is used to simulate, control and provide application services to the UPFC physical entity system. The UPFC digital twin system includes a simulation model, a control system, a visualization interface and an application service module; The interconnection interface is used to realize data information interaction between the UPFC physical entity system and the UPFC digital twin system; The simulation model simulates each physical element in the UPFC circuit under the conditions of electric field, thermal field and stress field, and the simulation model is used for calling by the control system and the application service module; the control system is used to control the UPFC physical entity system and the simulation model in the UPFC digital twin system, and simultaneously obtain the actual operation data and the simulation operation data; the visualization interface is used to monitor and record the sequential control process of each converter, the real-time operation waveform of the UPFC physical entity system and the UPFC digital twin system, and the system status of the UPFC physical entity system and the UPFC digital twin system; The application service module is used for abnormal state diagnosis analysis, fault location and early warning analysis, historical data replay and health status assessment.

[0023] Specifically, the application service module combines big data technology to analyze the data obtained from the operation of the UPFC physical entity system and the data obtained from calling the simulation model to perform system dynamic simulation, and uses statistical methods such as regression analysis and time series analysis or machine learning methods such as artificial neural networks and deep learning to build prediction models, decision models or evaluation models, output the prediction, decision and evaluation results of the application service, reveal the future trend of the data, improve the reliability of decision-making and enhance the multi-dimensional evaluation capabilities; This embodiment evaluates the aging and life of the submodules of the UPFC physical entity system. The main component that restricts the service life of the UPFC submodule is the submodule capacitor, and its key aging parameters are the submodule capacitor value and the submodule capacitor equivalent series resistance. The operation of the UPFC physical entity system and the UPFC digital twin system can obtain information such as the DC bus voltage, AC side voltage / current, submodule voltage and submodule current, and establish a data set in units of year-month-day-hour-minute. The BP neural network is used in combination with the circuit principle to establish a prediction model for the submodule capacitor aging parameters, and the prediction model is trained with the UPFC physical entity system data as input to obtain the current submodule capacitor value and submodule equivalent series resistance, and update the component parameters of the UPFC digital twin system simulation model to obtain the submodule life evaluation result at this time. Based on this, the future working conditions of the UPFC physical entity system are simulated in the UPFC digital twin system, and the submodule life prediction trend can be further obtained.

[0024] Preferably, the simulation model is divided into a basic model, an average model and a dynamic model according to the time scale. The basic model simulates the static parameters of each physical element, the average model simulates the physical quantities of each physical element at long time scale intervals; the dynamic model adds additional dynamic characteristics on the basis of the average model, including the transient process of switching on and off of the switch tube.

[0025] The high-speed communication architecture includes several hosts and communication networks. The hosts are used to implement the converter process and its control in the UPFC physical entity system and to realize the various functions of the UPFC digital twin system. The communication network is used for communication between hosts.

[0026] Preferably, the hosts in the high-speed communication architecture include a parallel side converter host, a series side converter host, a protection service host, an intelligent auxiliary host, a first server, a second server and an operable host computer; the parallel side converter host is used to implement the parallel side converter sequential control process and its control, the series side converter host is used to implement the series side converter sequential control process and its control, the protection service host is used to implement converter protection, transformer protection and AC line protection, the intelligent auxiliary host is used to provide all functions of the UPFC digital twin system, the first server and the second server cooperate to implement communication functions, provide centralized computing, information publishing and data management services, and the operable host computer provides a friendly human-computer interaction interface.

[0027] Preferably, if Figure 2As shown, the communication network of the high-speed communication architecture adopts dual LAN networking, including LAN1, a first LAN2, an RJ45 Ethernet interface, a second RJ45 Ethernet interface, a first Ethernet signal transformer, a second Ethernet signal transformer, a first MAC / PHY transceiver, a second MAC / PHY transceiver and a CPU, one end of the first RJ45 Ethernet interface is connected to LAN1, and the other end is connected to one end of the first Ethernet transformer, the other end of the first Ethernet transformer is connected to one end of the first MAC / PHY transceiver, and the other end of the first MAC / PHY transceiver is connected to the CPU; one end of the second RJ45 Ethernet interface is connected to LAN2, and the other end is connected to one end of the second Ethernet transformer 2, the other end of the second Ethernet transformer is connected to one end of the second MAC / PHY transceiver, and the other end of the second MAC / PHY transceiver is connected to the CPU.

[0028] Embodiment 2 of the present invention provides a control method for the UPFC dynamic model system described in Embodiment 1 of the present invention: When the system only needs fast reactive power compensation, the series side does not work and the parallel side works in STATCOM mode; when the system needs to control power flow and voltage distribution and take into account dynamic reactive power compensation, the series side is connected and the parallel side runs in UPFC mode. When a system failure occurs, operational fault protection is performed; like Figure 3 As shown, when in the STATCOM mode, the parallel side works in the grid-side AC voltage control; when in the UPFC mode, the parallel side works in the reactive power control; Figure 4 As shown, the series side works under line active power control and line reactive power control, and the series side performs line fault restart control; before the series side is connected, the series side performs smooth start control; the operation fault protection includes line protection, transformer protection and UPFC body protection; Preferably, if Figure 5 As shown, the smooth start control is specifically as follows: S1. Before starting, the states of the circuit breakers and disconnectors are as follows: the first circuit breaker QF1 is disconnected, the second circuit breaker QF2 is closed, the third circuit breaker QF3 is disconnected, the fourth circuit breaker QF4 is closed, the first disconnector DS1 is disconnected, the second disconnector DS2 is disconnected, the third disconnector DS3 is disconnected, the fourth disconnector DS4 is disconnected, the fifth disconnector DS5 is disconnected, the sixth disconnector DS6 is disconnected, the seventh disconnector DS7 is disconnected, and the eighth disconnector DS8 is disconnected. Set the startup parameters of the series side converter according to system requirements; S2. Sequentially close the second isolating switch DS2, the third isolating switch DS3, the seventh isolating switch DS7, the eighth isolating switch DS8, the fifth isolating switch DS5, the sixth isolating switch DS6, the fourth isolating switch DS4; S3. Close the third circuit breaker QF3 to complete the series connection of transformer T se Charging of the primary winding; disconnecting the fourth circuit breaker QF4 to complete the series connection of the transformer T se Connection between the secondary winding and the series side converter; S4. Close the first circuit breaker QF1. At the same time, the parallel side converter and the series side converter receive the start signal and charge. At this time, the current loop of the series side converter transmits current in the circuit. i 1 is used as a reference value to control the output current of the series side converter i se Close to the circuit transfer current converted to the secondary side i 1. When the amplitude difference between the two is less than the set series side smooth access current threshold, it means that charging is completed, the first isolating switch DS1 is closed, and then the second circuit breaker QF2 is disconnected. At the same time, its current loop reference value is converted to the output of the series side converter voltage loop. At this time, the series side converter is smoothly connected to the main circuit.

[0029] Specifically, the series side smoothing access current threshold is set to 1%; Preferably, the startup parameters of the series side converter are set according to the system requirements, including the active power reference of the series side converter. , Series Side Converter Reactive Power Benchmark and the series side smooth access current threshold, both of which are set to the same value as when running under rated conditions. Preferably, the line fault restart control is specifically as follows: when a fault occurs, it is determined whether the fault is a line fault or an equipment fault. When it is determined to be a line fault, the thyristor bypass switch TBS is closed, the series side converter is locked, and the series side converter is isolated from the main circuit and exits operation; After the reclosing setting time has passed, which is the time from when the device senses that the circuit breaker is disconnected to when the device allows the closing command to be issued; by detecting the line voltage, current and switch position, it is determined whether the line is operating normally. If normal, the thyristor bypass switch TBS is disconnected to restart the series side converter.

[0030] Preferably, the reclosing setting time is set between 0.8-2.0s.

[0031] Preferably, the line protection, transformer protection and UPFC body protection of the operation fault protection are specifically: the line protection includes overvoltage protection and circuit breaker protection; the transformer protection includes transformer electric quantity protection and transformer non-electric quantity protection; the UPFC body protection specifically includes parallel side action and series side action; Parallel side actions: alarm, switch control system, lock parallel side converter, trip parallel transformer converter side switch, trip parallel transformer grid side switch in case of failure; Series side actions: alarm, switch control system, lock series side converter, trigger thyristor bypass switch TBS to turn on, close series transformer line side bypass switch, close series transformer converter side bypass switch; A fault on the parallel side will trip the series side: a fault in the AC area on the series side will only exit the converter on the corresponding side; a fault in the converter area on the series side will trip the other sides.

[0032] From the above description, it can be seen that in response to the shortcomings of the prior art, the present invention provides a UPFC dynamic model system, a high-speed communication architecture, and a control method, and constructs a twin model corresponding to the UPFC physical entity based on digital twin technology; the high-speed communication architecture using dual LAN networking can aggregate the bandwidth of two or more LAN interfaces, thereby providing higher network throughput and effectively improving the data transmission speed; the provided control method can meet the requirements for UPFC operation and protection in actual engineering, and has the advantages of multiple functions, high communication efficiency and high degree of intelligence.

[0033] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or terminal device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or terminal device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or terminal device including the elements.

[0034] As described above, the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A UPFC dynamic model system, comprising a UPFC physical entity system, a UPFC digital twin system, a high-speed communication architecture and an interconnection interface, wherein the UPFC physical entity system comprises a sending end AC source , AC source at receiving end , upper DC bus U dc +, lower DC bus U dc -, sending end line impedance X S , receiving end line impedance X R , parallel transformer T sh , Series transformer T se , a parallel side converter, a series side converter, a first circuit breaker QF1, a second circuit breaker QF2, a third circuit breaker QF3, a fourth circuit breaker QF4, a first disconnector DS1, a second disconnector DS2, a third disconnector DS3, a fourth disconnector DS4, a fifth disconnector DS5, a sixth disconnector DS6, a seventh disconnector DS7, an eighth disconnector DS8, a fuse FU and a thyristor bypass switch TBS; characterized in that: The UPFC digital twin system is used to simulate, control and provide application services to the UPFC physical entity system. The UPFC digital twin system includes a simulation model, a control system, a visualization interface and an application service module; The interconnection interface is used to realize data information interaction between the UPFC physical entity system and the UPFC digital twin system; The simulation model simulates each physical component in the UPFC circuit under electric field, thermal field and stress field, and the simulation model is used for calling by the control system and application service module; the control system is used to control the UPFC physical entity system and the simulation model in the UPFC digital twin system, and simultaneously obtain actual operation data and simulation operation data; the visualization interface is used to monitor and record the sequential control process of each converter, the real-time operation waveforms of the UPFC physical entity system and the UPFC digital twin system, and the system status of the UPFC physical entity system and the UPFC digital twin system.

2. A UPFC dynamic model system according to claim 1, characterized in that: The simulation model is divided into a basic model, an average model and a dynamic model according to the time scale. The basic model simulates the static parameters of each physical element, the average model simulates the physical quantities of each physical element at long time scale intervals; the dynamic model adds additional dynamic characteristics on the basis of the average model, including the transient process of switching on and off of the switch tube.

3. A UPFC dynamic mold system according to claim 1, characterized in that: The high-speed communication architecture includes several hosts and communication networks. The hosts are used to implement the converter process and its control in the UPFC physical entity system and to realize the various functions of the UPFC digital twin system. The communication network is used for communication between hosts. The hosts in the high-speed communication architecture include a parallel side converter host, a series side converter host, a protection service host, an intelligent auxiliary host, a first server, a second server and an operable host computer; the parallel side converter host is used to implement the parallel side converter sequential control process and its control, the series side converter host is used to implement the series side converter sequential control process and its control, the protection service host is used to implement converter protection, transformer protection and AC line protection, the intelligent auxiliary host is used to provide all functions of the UPFC digital twin system, the first server and the second server cooperate to realize the communication function, provide centralized computing, information publishing and data management services, and the operable host computer provides a friendly human-computer interaction interface.

4. A UPFC dynamic model system according to claim 3, characterized in that: The communication network of the high-speed communication architecture adopts dual LAN networking, including LAN1, a first LAN2, an RJ45 Ethernet interface, a second RJ45 Ethernet interface, a first Ethernet signal transformer, a second Ethernet signal transformer, a first MAC / PHY transceiver, a second MAC / PHY transceiver and a CPU, one end of the first RJ45 Ethernet interface is connected to LAN1, and the other end is connected to one end of the first Ethernet transformer, the other end of the first Ethernet transformer is connected to one end of the first MAC / PHY transceiver, and the other end of the first MAC / PHY transceiver is connected to the CPU; One end of the second RJ45 Ethernet interface is connected to LAN2, and the other end is connected to one end of the second Ethernet transformer, the other end of the second Ethernet transformer is connected to one end of the second MAC / PHY transceiver, and the other end of the second MAC / PHY transceiver is connected to the CPU.

5. A control method for the UPFC dynamic model system according to any one of claims 1 to 3, characterized in that: When the system only needs fast reactive power compensation, the series side does not work and the parallel side works in STATCOM mode; when the system needs to control power flow and voltage distribution and take into account dynamic reactive power compensation, the series side is connected and the parallel side runs in UPFC mode. When a system failure occurs, operational fault protection is performed; When in the STATCOM mode, the parallel side works under grid-side AC voltage control; in the UPFC mode, the parallel side works under reactive power control; the series side works under line active power control and line reactive power control, and the series side performs line fault restart control; before the series side is connected, the series side performs smooth start control; operation fault protection includes line protection, transformer protection and UPFC body protection.

6. A control method for a UPFC dynamic model system according to claim 5, characterized in that : The smooth start control is specifically as follows: S1. Before starting, the states of the circuit breakers and disconnectors are as follows: the first circuit breaker QF1 is disconnected, the second circuit breaker QF2 is closed, the third circuit breaker QF3 is disconnected, the fourth circuit breaker QF4 is closed, the first disconnector DS1 is disconnected, the second disconnector DS2 is disconnected, the third disconnector DS3 is disconnected, the fourth disconnector DS4 is disconnected, the fifth disconnector DS5 is disconnected, the sixth disconnector DS6 is disconnected, the seventh disconnector DS7 is disconnected, and the eighth disconnector DS8 is disconnected. Set the startup parameters of the series side converter according to system requirements; S2. Sequentially close the second isolating switch DS2, the third isolating switch DS3, the seventh isolating switch DS7, the eighth isolating switch DS8, the fifth isolating switch DS5, the sixth isolating switch DS6, the fourth isolating switch DS4; S3. Close the third circuit breaker QF3 to complete the series connection of transformer T se Charging of the primary winding; disconnecting the fourth circuit breaker QF4 to complete the series connection of the transformer T se Connection between the secondary winding and the series side converter; S4. Close the first circuit breaker QF1. At the same time, the parallel side converter and the series side converter receive the start signal and charge. At this time, the current loop of the series side converter transmits current in the circuit. i 1 is used as a reference value to control the output current of the series side converter i se Close to the circuit transfer current converted to the secondary side i 1. When the amplitude difference between the two is less than the set series side smooth access current threshold, it means that charging is completed, the first isolating switch DS1 is closed, and then the second circuit breaker QF2 is disconnected. At the same time, its current loop reference value is converted to the output of the series side converter voltage loop. At this time, the series side converter is smoothly connected to the main circuit.

7. A control method for a UPFC dynamic model system according to claim 6, characterized in that : The startup parameters of the series side converter are set according to the system requirements, including the active power reference of the series side converter. , Series Side Converter Reactive Power Benchmark and the series side smooth access current threshold, the setting values ​​of both are consistent with those when operating under rated conditions.

8. The control method of a UPFC dynamic mold system according to claim 5, characterized in that: The line fault restart control is specifically as follows: when a fault occurs, it is determined whether the fault is a line fault or an equipment fault. When it is determined to be a line fault, the thyristor bypass switch TBS is closed, the series side converter is locked, and the series side converter is isolated from the main circuit and exits operation; After the reclosing setting time has passed, the reclosing setting time is set to the time from when the device senses the circuit breaker is disconnected to when the device allows the closing command to be issued; By detecting the line voltage, current and switch position, it is determined whether the line is operating normally. If normal, the thyristor bypass switch TBS is disconnected to restart the series side converter.

9. A control method for a UPFC dynamic model system according to claim 8, characterized in that: The reclosing setting time is set between 0.8-2.0s.

10. The control method of a UPFC dynamic model system according to claim 5, characterized in that: The line protection, transformer protection and UPFC body protection of the operation fault protection are specifically: line protection includes overvoltage protection and circuit breaker protection; transformer protection includes transformer power protection and transformer non-power protection; UPFC body protection specifically includes parallel side action and series side action; Parallel side actions: alarm, switch control system, lock parallel side converter, trip parallel transformer converter side switch, trip parallel transformer grid side switch in case of failure; Series side actions: alarm, switch control system, lock series side converter, trigger thyristor bypass switch TBS to turn on, close series transformer line side bypass switch, close series transformer converter side bypass switch; A fault on the parallel side will trip the series side: a fault in the AC area on the series side will only exit the converter on the corresponding side; a fault in the converter area on the series side will trip the other sides.

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