Distributed series compensator control mode switching method and device

Abstract

The invention provides a distributed series compensator control mode switching method and device. And outputting an active power target value of a line where the distributed series compensator is located and a first voltage target value of the distributed series compensator according to the control mode of the distributed series compensator. And outputting an enable signal and a second voltage target value of the distributed series compensator according to the control mode. And switching the control mode of the distributed series compensator according to the active power target value, the first voltage target value, the second voltage target value and the enable signal of the line. According to the invention, smooth change of the power flow is realized when the distributed series compensator is switched among different control modes, impact on the power grid caused by sudden change of the power flow of the power grid due to switching of the control modes is effectively avoided, and stable operation of the power grid is ensured.

Description

Technical Field

[0001] This application relates to the field of power electronics technology, specifically to a method and apparatus for switching control modes of a distributed series compensator. Background Technology

[0002] Due to limitations in reliability and high cost of Unified Power Flow Controllers (UPFCs), distributed series compensators (DSCs) have emerged as a solution. DSCs offer a simple topology, are connected in series within the lines, are inexpensive, and are easier to operate and maintain. They possess powerful power flow regulation capabilities and can significantly improve the power quality of the grid, thereby dynamically optimizing the power flow distribution, effectively alleviating overload pressure on some heavily loaded lines, and enhancing the overall carrying capacity and security of the regional power grid.

[0003] In practical engineering applications, the control modes of distributed series compensators typically include constant power flow control mode, cross-sectional limit control mode, constant voltage control mode, and constant impedance control mode. Since different control modes of distributed series compensators correspond to different control objectives, switching between control modes is necessary.

[0004] Among the switching methods provided by related technologies, distributed series compensators can suppress sudden increases in line load or power grid power flow fluctuations caused by sudden line overload or adjacent line faults. However, when the distributed series compensator switches control modes, the output voltage will change sharply (drop or rise), causing large short-term fluctuations in power grid power flow, which will impact the power grid and affect its stable operation. Summary of the Invention

[0005] To address the problems affecting the stable operation of the power grid in the prior art, this application provides a method and apparatus for switching control modes of a distributed series compensator.

[0006] Firstly, this application provides a method for switching control modes of a distributed series compensator, which may include: The active power target value of the line where the distributed series compensator is located and the first voltage target value of the distributed series compensator are output according to the control mode of the distributed series compensator.

[0007] The control mode outputs an enable signal and the second voltage target value of the distributed series compensator.

[0008] The control mode of the distributed series compensator is switched according to the active power target value, the first voltage target value, the second voltage target value and the enable signal of the line.

[0009] In some possible implementations, the active power target value of the line where the distributed series compensator is located and the first voltage target value of the distributed series compensator are output according to the control mode of the distributed series compensator, including: When the control mode is either steady-flow control mode or section-limit control mode, ramp control is performed on the first and second active power reference values ​​of the line based on the control signal and the first step length signal to obtain the target active power value of the line. The first active power reference value indicates the active power reference value of the line when the distributed series compensator is operating in steady-flow control mode, and the second active power reference value indicates the active power reference value of the line when the distributed series compensator is operating in section-limit control mode.

[0010] When the control mode is constant voltage control mode or constant impedance control mode, ramp control is performed on the first voltage reference value and the second voltage reference value of the distributed series compensator according to the control signal and the second step size signal to obtain the first voltage target value. The first voltage reference value indicates the voltage reference value when the distributed series compensator is operating in constant voltage control mode, and the second voltage reference value indicates the voltage reference value when the distributed series compensator is operating in constant impedance control mode.

[0011] In other possible implementations, the output enable signal and the second target voltage value of the distributed series compensator are determined according to the control mode, including: The control mode is enabled based on the first active power reference value, the second active power reference value, the third voltage reference value, and the fourth voltage reference value to obtain an enable signal.

[0012] The first target voltage value is controlled by intermediate parameters based on the control mode and the state of the distributed series compensator to obtain the second target voltage value of the distributed series compensator. The state of the distributed series compensator includes both running and stopped states.

[0013] In some other possible implementations, the control mode of the distributed series compensator is switched based on the target active power value of the line, the first target voltage value, the second target voltage value, and the enable signal, including: Based on the enable signal and the second voltage target value, proportional-integral control is performed on the difference between the active power target value and the actual active power value of the line to obtain the third voltage target value of the distributed series compensator.

[0014] Depending on the control mode, select either the first voltage target value or the third voltage target value for output.

[0015] Secondly, this application provides a distributed series compensator control mode switching device, which may include: The first output module is used to output the target active power value of the line where the distributed series compensator is located and the first target voltage value of the distributed series compensator according to the control mode of the distributed series compensator.

[0016] The second output module is used to output an enable signal and the second voltage target value of the distributed series compensator according to the control mode.

[0017] The switching module is used to switch the control mode of the distributed series compensator according to the active power target value, the first voltage target value, the second voltage target value and the enable signal of the line.

[0018] In some possible implementations, the first output module is specifically used for: When the control mode is either steady-flow control mode or section-limit control mode, ramp control is performed on the first and second active power reference values ​​of the line based on the control signal and the first step length signal to obtain the target active power value of the line. The first active power reference value indicates the active power reference value of the line when the distributed series compensator is operating in steady-flow control mode, and the second active power reference value indicates the active power reference value of the line when the distributed series compensator is operating in section-limit control mode.

[0019] When the control mode is constant voltage control mode or constant impedance control mode, ramp control is performed on the first voltage reference value and the second voltage reference value of the distributed series compensator according to the control signal and the second step size signal to obtain the first voltage target value. The first voltage reference value indicates the voltage reference value when the distributed series compensator is operating in constant voltage control mode, and the second voltage reference value indicates the voltage reference value when the distributed series compensator is operating in constant impedance control mode.

[0020] In some other possible implementations, the second output module is specifically used for: The control mode is enabled based on the first active power reference value, the second active power reference value, the first voltage reference value, and the second voltage reference value to obtain an enable signal.

[0021] The first target voltage value is controlled by intermediate parameters based on the control mode and the state of the distributed series compensator to obtain the second target voltage value of the distributed series compensator. The state of the distributed series compensator includes both running and stopped states.

[0022] In some other possible implementations, the switching module is specifically used for: Based on the enable signal and the second voltage target value, proportional-integral control is performed on the difference between the active power target value and the actual active power value of the line to obtain the third voltage target value of the distributed series compensator.

[0023] Depending on the control mode, select either the first voltage target value or the third voltage target value for output.

[0024] In another aspect, this application also provides a computer device, including: one or more processors.

[0025] A processor is used to execute one or more programs.

[0026] When one or more programs are executed by one or more processors, the switching method described above is implemented.

[0027] Furthermore, this application also provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed, it implements the switching method described above.

[0028] Compared with the prior art, the beneficial effects of this application are as follows: The distributed series compensator (DSC) control mode switching method provided in this application outputs the active power target value of the line where the DSC is located and the first voltage target value of the DSC based on the control mode of the DSC. It also outputs an enable signal and a second voltage target value of the DSC based on the control mode. Finally, it switches the control mode of the DSC based on the line's active power target value, the first voltage target value, the second voltage target value, and the enable signal. This application achieves smooth power flow changes when the DSC switches between different control modes, effectively avoiding sudden power flow changes in the power grid caused by control mode switching, thus preventing impacts on the power grid and ensuring stable grid operation.

[0029] In this application, under open-loop control mode, when the target voltage value changes, the output voltage of the distributed series compensator can smoothly transition without causing disturbance to the power grid.

[0030] In this application, under closed-loop control mode, the active power output of the distributed series compensator can be smoothly adjusted when the grid control target value changes, without causing disturbance to the grid.

[0031] In the technical solution provided in this application, when a sudden change occurs in the power grid, the distributed series compensator can still respond quickly and achieve reliable switching of control modes. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a schematic flowchart of a distributed series compensator control mode switching method in an embodiment of this application; Figure 2 This is a schematic flowchart of a distributed series compensator control mode switching method in an embodiment of this application; Figure 3 This is a schematic structural diagram of a distributed series compensator control mode switching device in an embodiment of this application. Detailed Implementation

[0034] The technical solutions in this application will now be described with reference to the accompanying drawings.

[0035] The terms "first," "second," etc., used in the specification, embodiments, claims, and drawings of this application are for distinguishing purposes only and should not be construed as indicating or implying relative importance or order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion, such as including a series of steps or units. A method, system, product, or apparatus is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to these processes, methods, products, or apparatuses.

[0036] It should be understood that in this application, "at least one (item)" means one or more, and "more than" means two or more. "And / or" is used to describe the relationship between related objects, indicating that three relationships can exist. For example, "A and / or B" can represent three cases: only A exists, only B exists, and both A and B exist simultaneously, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one (item) of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one (item) of a, b, or c can represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be single or multiple.

[0037] Example 1: This application provides a method for switching control modes of a distributed series compensator. The control modes include closed-loop control mode and open-loop control mode. The closed-loop control modes include constant power flow control mode and cross-sectional limit control mode. The open-loop control modes include constant voltage control mode and constant impedance control mode.

[0038] like Figure 1 As shown, the switching method 100 includes the following steps: Step S1: Based on the control mode Mode of the distributed series compensator, output the active power target value Pout of the line where the distributed series compensator is located and the first voltage target value Uout1 of the distributed series compensator.

[0039] Step S2: Output the enable signal EN and the second voltage target value Uout2 of the distributed series compensator according to the control mode Mode.

[0040] Step S3: Switch the control mode of the distributed series compensator according to the active power target value Pout, the first voltage target value Uout1, the second voltage target value Uout2 and the enable signal EN.

[0041] In some possible implementations, step S1 outputs the target active power value of the line where the distributed series compensator is located and the first target voltage value of the distributed series compensator according to the control mode of the distributed series compensator, including: When the control mode is set to constant power flow control mode or cross-sectional limit control mode, refer to Figure 2 Based on the control signal CTRL and the first-step long signal STEP1, ramp control is performed on the first active power reference value Pref1 and the second active power reference value Pref2 of the line to obtain the target active power value Pout of the line. The first active power reference value Pref1 indicates the active power reference value of the line when the distributed series compensator is operating in steady flow control mode, and the second active power reference value Pref2 indicates the active power reference value of the line when the distributed series compensator is operating in section limit control mode.

[0042] Specifically, when the control signal CTRL is valid, ramp control is enabled, and the active power target value of the line transitions smoothly. When the control signal CTRL is invalid, ramp control is disabled, and the active power target value of the line can directly and quickly respond to changes, meeting the fast response characteristic requirements of the distributed series compensator.

[0043] When the control mode is constant voltage control mode or constant impedance control mode, ramp control is performed on the first voltage reference value Uref1 and the second voltage reference value Uref2 of the distributed series compensator according to the control signal CTRL and the second step signal STEP2 to obtain the first voltage target value Uout1. The first voltage reference value Uref1 indicates the voltage reference value when the distributed series compensator is operating in constant voltage control mode, and the second voltage reference value Uref2 indicates the voltage reference value when the distributed series compensator is operating in constant impedance control mode.

[0044] Specifically, when the control signal CTRL is valid, ramp control is enabled, and the voltage reference value transitions smoothly; when the control signal CTRL is invalid, ramp control is disabled, and the voltage reference value can directly and quickly respond to changes, meeting the fast response characteristic requirements of the distributed series compensator.

[0045] In some other possible implementations, step S2 outputs an enable signal and a second target voltage value for the distributed series compensator according to the control mode, including: refer to Figure 2 The control mode Mode is enabled based on the first active power reference value Pref1, the second active power reference value Pref2, the first voltage reference value Uref1, and the second voltage reference value Uref2, resulting in the enable signal EN.

[0046] For example, when the control mode is switched to steady current control mode, the output enable signal can be high when only Pref1 changes. Otherwise, the output enable signal can be low.

[0047] Based on the control mode (Mode) and the state (State) of the distributed series compensator, intermediate control is applied to the first voltage target value Uout1 to obtain the second voltage target value Uout2 of the distributed series compensator. The state of the distributed series compensator includes both running and stopped states.

[0048] In some other possible implementations, the control mode of the distributed series compensator is switched based on the target active power value of the line, the first target voltage value, the second target voltage value, and the enable signal, including: refer to Figure 2 Based on the enable signal EN and the second voltage target value Uout2, proportional-integral control (i.e., PI control) is performed on the difference between the active power target value Pout and the actual active power value P of the line to obtain the third voltage target value Uout3 of the distributed series compensator.

[0049] Based on the control mode, select either the first voltage target value Uout1 or the third voltage target value Uout3 for output.

[0050] Example 2: Based on the same inventive concept, embodiments of this application also provide a distributed series compensator control mode switching device. For example... Figure 3 As shown, the switching device 200 may include: The first output module 201 is used to output the active power target value Pout of the line where the distributed series compensator is located and the first voltage target value Uout1 of the distributed series compensator according to the control mode Mode of the distributed series compensator.

[0051] The second output module 202 is used to output the enable signal EN and the second voltage target value Uout2 of the distributed series compensator according to the control mode Mode.

[0052] The switching module 203 is used to switch the control mode of the distributed series compensator according to the active power target value Pout of the line, the first voltage target value Uout1, the second voltage target value Uout2 and the enable signal EN.

[0053] In some possible implementations, the first output module 201 is specifically used for: When the control mode is set to constant power flow control mode or cross-sectional limit control mode, refer to Figure 2 Based on the control signal CTRL and the first-step long signal STEP1, ramp control is performed on the first active power reference value Pref1 and the second active power reference value Pref2 of the line to obtain the target active power value Pout of the line. The first active power reference value Pref1 indicates the active power reference value of the line when the distributed series compensator is operating in steady flow control mode, and the second active power reference value Pref2 indicates the active power reference value of the line when the distributed series compensator is operating in section limit control mode.

[0054] Specifically, when the control signal CTRL is valid, ramp control is enabled, and the active power target value of the line transitions smoothly. When the control signal CTRL is invalid, ramp control is disabled, and the active power target value of the line can directly and quickly respond to changes, meeting the fast response characteristic requirements of the distributed series compensator.

[0055] When the control mode is constant voltage control mode or constant impedance control mode, ramp control is performed on the first voltage reference value Uref1 and the second voltage reference value Uref2 of the distributed series compensator according to the control signal CTRL and the second step signal STEP2 to obtain the first voltage target value Uout1. The first voltage reference value Uref1 indicates the voltage reference value when the distributed series compensator is operating in constant voltage control mode, and the second voltage reference value Uref2 indicates the voltage reference value when the distributed series compensator is operating in constant impedance control mode.

[0056] Specifically, when the control signal CTRL is valid, ramp control is enabled, and the voltage reference value transitions smoothly; when the control signal CTRL is invalid, ramp control is disabled, and the voltage reference value can directly and quickly respond to changes, meeting the fast response characteristic requirements of the distributed series compensator.

[0057] In some other possible implementations, the second output module 202 is specifically used for: refer to Figure 2The control mode Mode is enabled based on the first active power reference value Pref1, the second active power reference value Pref2, the first voltage reference value Uref1, and the second voltage reference value Uref2, resulting in the enable signal EN.

[0058] For example, when the control mode is switched to steady current control mode, the output enable signal can be high when only Pref1 changes. Otherwise, the output enable signal can be low.

[0059] Based on the control mode (Mode) and the state (State) of the distributed series compensator, intermediate control is applied to the first voltage target value Uout1 to obtain the second voltage target value Uout2 of the distributed series compensator. The state of the distributed series compensator includes both running and stopped states.

[0060] In some possible implementations, the switching module 203 is specifically used for: refer to Figure 2 Based on the enable signal EN and the second voltage target value Uout2, proportional-integral control (i.e., PI control) is performed on the difference between the active power target value Pout and the actual active power value P of the line to obtain the third voltage target value Uout3 of the distributed series compensator.

[0061] Based on the control mode, select either the first voltage target value Uout1 or the third voltage target value Uout3 for output.

[0062] Example 3: Based on the same inventive concept, this application also provides a computer device, which includes a processor and a memory. The memory stores a computer program, which includes program instructions. The processor executes the program instructions stored in the computer storage medium. The processor may be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. It is the computing and control core of the terminal, and is suitable for implementing one or more instructions. Specifically, it is suitable for loading and executing one or more instructions in the computer storage medium to implement the corresponding method flow or corresponding function, so as to implement the steps of the switching method provided in the above embodiments.

[0063] Example 4: Based on the same inventive concept, this application also provides a computer-readable storage medium, specifically a computer-readable storage medium (Memory). A computer-readable storage medium is a memory device in a computer device used to store programs and data. It is understood that the computer-readable storage medium here can include both the built-in storage medium in the computer device and extended storage media supported by the computer device. The computer-readable storage medium provides storage space that stores the terminal's operating system. Furthermore, the storage space also stores one or more instructions suitable for loading and execution by a processor. These instructions can be one or more computer programs (including program code). It should be noted that the computer-readable storage medium here can be high-speed RAM or non-volatile memory, such as at least one disk storage device. The processor can load and execute one or more instructions stored in the computer-readable storage medium to implement the steps of the switching method provided in the above embodiments.

[0064] Those skilled in the art will understand that the embodiments of the application can be provided as a method, system, or computer program product. Therefore, the application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the application can take the form of a computer program product implemented on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0065] The application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0066] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0067] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0068] The above are merely examples of the application and are not intended to limit the application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the application shall be included within the scope of the claims of the pending application.

Claims

1. A method for switching control modes of a distributed series compensator, characterized by, include: The active power target value of the line where the distributed series compensator is located and the first voltage target value of the distributed series compensator are output according to the control mode of the distributed series compensator. According to the control mode, an enable signal and the second voltage target value of the distributed series compensator are output; The control mode of the distributed series compensator is switched according to the active power target value of the line, the first voltage target value, the second voltage target value and the enable signal.

2. The handover method of claim 1, wherein, The step of outputting the active power target value of the line where the distributed series compensator is located and the first voltage target value of the distributed series compensator according to the control mode of the distributed series compensator includes: When the control mode is either constant power flow control mode or cross-sectional limit control mode, ramp control is performed on the first active power reference value and the second active power reference value of the line according to the control signal and the first step length signal to obtain the active power target value of the line; wherein, the first active power reference value is used to indicate the active power reference value of the line when the distributed series compensator is operating in the constant power flow control mode, and the second active power reference value is used to indicate the active power reference value of the line when the distributed series compensator is operating in the cross-sectional limit control mode; When the control mode is a constant voltage control mode or a constant impedance control mode, the first voltage reference value and the second voltage reference value of the distributed series compensator are ramped according to the control signal and the second step size signal to obtain the first voltage target value; wherein, the first voltage reference value is used to indicate the voltage reference value of the distributed series compensator when operating in the constant voltage control mode, and the second voltage reference value is used to indicate the voltage reference value of the distributed series compensator when operating in the constant impedance control mode.

3. The handover method of claim 2, wherein, The step of outputting an enable signal and the second voltage target value of the distributed series compensator according to the control mode includes: The control mode is enabled based on the first active power reference value, the second active power reference value, the first voltage reference value, and the second voltage reference value to obtain the enable signal; The first voltage target value is controlled by an intermediate quantity according to the control mode and the state of the distributed series compensator to obtain the second voltage target value of the distributed series compensator; wherein, the state of the distributed series compensator includes a running state and a stopped state.

4. The handover method of claim 1, wherein, The step of switching the control mode of the distributed series compensator based on the active power target value of the line, the first voltage target value, the second voltage target value, and the enable signal includes: Based on the enable signal and the second voltage target value, proportional-integral control is performed on the difference between the active power target value and the actual active power value of the line to obtain the third voltage target value of the distributed series compensator. Based on the control mode, the first voltage target value or the third voltage target value is selected for output.

5. A distributed series compensator control mode switching apparatus characterized by comprising: include: The first output module is used to output the active power target value of the line where the distributed series compensator is located and the first voltage target value of the distributed series compensator according to the control mode of the distributed series compensator. The second output module is used to output an enable signal and the second voltage target value of the distributed series compensator according to the control mode. The switching module is used to switch the control mode of the distributed series compensator according to the active power target value of the line, the first voltage target value, the second voltage target value and the enable signal.

6. The switching device according to claim 5, characterized in that, The first output module is specifically used for: When the control mode is either constant power flow control mode or cross-sectional limit control mode, ramp control is performed on the first active power reference value and the second active power reference value of the line according to the control signal and the first step length signal to obtain the active power target value of the line; wherein, the first active power reference value is used to indicate the active power reference value of the line when the distributed series compensator is operating in the constant power flow control mode, and the second active power reference value is used to indicate the active power reference value of the line when the distributed series compensator is operating in the cross-sectional limit control mode; When the control mode is a constant voltage control mode or a constant impedance control mode, the first voltage reference value and the second voltage reference value of the distributed series compensator are ramped according to the control signal and the second step size signal to obtain the first voltage target value; wherein, the first voltage reference value is used to indicate the voltage reference value of the distributed series compensator when operating in the constant voltage control mode, and the second voltage reference value is used to indicate the voltage reference value of the distributed series compensator when operating in the constant impedance control mode.

7. The switching device according to claim 6, characterized in that, The second output module is specifically used for: The control mode is enabled based on the first active power reference value, the second active power reference value, the first voltage reference value, and the second voltage reference value to obtain the enable signal; The first voltage target value is controlled by an intermediate quantity according to the control mode and the state of the distributed series compensator to obtain the second voltage target value of the distributed series compensator; wherein, the state of the distributed series compensator includes a running state and a stopped state.

8. The switching device according to claim 5, characterized in that, The switching module is specifically used for: Based on the enable signal and the second voltage target value, proportional-integral control is performed on the difference between the active power target value and the actual active power value of the line to obtain the third voltage target value of the distributed series compensator. Based on the control mode, the first voltage target value or the third voltage target value is selected for output.

9. A computer device, characterized in that, include: One or more processors; The processor is used to store one or more programs; When the one or more programs are executed by the one or more processors, the switching method as described in any one of claims 1 to 4 is implemented.

10. A computer-readable storage medium, characterized in that, It contains a computer program, which, when executed, implements the switching method as described in any one of claims 1 to 4.

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