Energy consumption coordination control system, method and device of direct current energy consumption device

Abstract

The present application relates to offshore wind power DC transmission technology field, disclose a kind of energy consumption coordination control system, method and device of DC energy consumption device.The system of the present application includes DC energy consumption device and energy consumption coordination control device, when carrying out energy consumption coordination control, according to the allowable power module voltage fluctuation value DC capacitor of DC energy consumption device main loop is set, based on energy consumption coordination control device obtains the voltage at both ends of DC energy consumption device, and when the voltage at both ends of the DC energy consumption device is greater than the first voltage threshold, gradually cut off all power modules in preset time, when the voltage at both ends of DC energy consumption device is less than the second voltage threshold, gradually put in all power modules in preset time.The present application reduces the impact on DC bus by optimizing the setting of DC energy consumption device main loop parameters and combining the strategy of stepwise switching power modules, can reduce the fluctuation of DC bus voltage during energy consumption, with the advantages of high performance, high reliability and low cost.

Description

Technical Field

[0001] This invention relates to the field of offshore wind power DC transmission technology, and in particular to an energy consumption coordination control system, method and apparatus for a DC energy consumption device. Background Technology

[0002] When a fault occurs at the receiving end of an offshore wind power DC transmission system, causing a drop in AC grid voltage, the wind farm's power output cannot respond quickly. If the surplus power remains, the DC voltage will continue to rise until the system trips, endangering the safety of equipment such as flexible DC converter valves. To avoid system tripping, DC energy dissipation devices need to be configured.

[0003] Currently proposed DC power dissipation devices can be mainly divided into the following categories based on their main circuit structure: schemes using series valve power dissipation circuits with switching devices, schemes using modular distributed power dissipation resistor circuits, and semi-centralized schemes that combine the characteristics of series valve power dissipation circuits with switching devices and modular distributed power dissipation resistor circuits. The DC power dissipation device corresponding to the semi-centralized scheme typically consists of a series-connected power dissipation resistor and a power module. This DC power dissipation device is directly connected to the corresponding DC transmission system. The power module generally adopts the following topology: it includes a first power semiconductor switch, a second power semiconductor switch, a first anti-parallel diode, a second anti-parallel diode, and a DC capacitor. The anode of the first anti-parallel diode is connected to the emitter of the first power semiconductor switch, and the cathode of the first anti-parallel diode is connected to the collector of the first power semiconductor switch. The anode of the second anti-parallel diode is connected to the emitter of the second power semiconductor switch, and the cathode of the second anti-parallel diode is connected to the collector of the second power semiconductor switch. The first and second power semiconductor switches are connected in series and then in parallel with the DC capacitor.

[0004] Currently, when using a semi-centralized DC power dissipation device to balance and regulate the discharge power and surplus power, the process of putting the power module into and taking it out can easily cause an impact on the DC bus of the system, resulting in large fluctuations in the DC bus voltage. Summary of the Invention

[0005] This invention provides an energy consumption coordination control system, method, and apparatus for DC energy-consuming devices. It solves the technical problem that existing semi-centralized DC energy-consuming devices are prone to impacting the DC bus during the power module switching process, resulting in large fluctuations in the DC bus voltage. By optimizing the main circuit parameters of the DC energy-consuming device and combining a step-by-step power module switching strategy, the impact on the DC bus is reduced, and the fluctuation of the DC bus voltage during energy consumption is reduced. It has the advantages of high performance, high reliability, and low cost.

[0006] The first aspect of this invention provides an energy consumption coordination control system for a DC energy-consuming device, comprising a DC energy-consuming device and an energy consumption coordination control device. The DC energy-consuming device includes an energy-consuming resistor and a power module connected in series. The value of the DC capacitor in the power module satisfies the following:

[0007]

[0008] In the formula, C is the value of the DC capacitor in the power module, and I... dc ΔT is the rated current of the offshore wind power DC transmission system to which the DC energy-consuming device is connected, ΔU is the cycle of the primary power module commissioning and decommissioning project, and ΔU is the rated current of the offshore wind power DC transmission system to which the DC energy-consuming device is connected. dc The allowable voltage fluctuation value for the power module;

[0009] The energy consumption coordination control device includes an acquisition module and a control module; the acquisition module is used to acquire the voltage across the DC energy-consuming device; the control module is used to gradually disconnect all power modules within a time interval ΔT / 2 when the voltage across the DC energy-consuming device is greater than a first voltage threshold, and gradually connect all power modules within a time interval ΔT / 2 when the voltage across the DC energy-consuming device is less than a second voltage threshold; the second voltage threshold is greater than the first voltage threshold.

[0010] According to one aspect of the invention, the first voltage threshold is the product of the rated voltage of the offshore wind power DC transmission system and a first voltage coefficient, and the second voltage threshold is the product of the rated voltage of the offshore wind power DC transmission system and a second voltage coefficient, wherein the second voltage coefficient is greater than the first voltage coefficient.

[0011] According to one achievable method of the first aspect of the present invention, the value of the DC capacitor in the power module is set to...

[0012] According to one achievable method of the first aspect of the present invention, when the DC power dissipation device employs a centralized power dissipation resistor, the resistance value of the centralized power dissipation resistor satisfies:

[0013]

[0014] In the formula, R1 represents the resistance value of the centralized energy-consuming resistor, U N Let k be the rated voltage of the offshore wind power DC transmission system, and k be the margin factor, satisfying k≤1, P N The rated power of the offshore wind power DC transmission system is given.

[0015] According to one achievable method of the first aspect of the present invention, when the DC power dissipation device employs a distributed power dissipation resistor, the resistance value of the distributed power dissipation resistor is:

[0016]

[0017] In the formula, R2 represents the resistance value of the distributed energy-consuming resistor, and N2 is the number of distributed energy-consuming resistors in the DC energy-consuming device.

[0018] According to one achievable method based on the first aspect of the invention, the number of power modules satisfies:

[0019]

[0020] In the formula, N represents the number of power modules in the DC power consumption device, and U N U is the rated voltage of the offshore wind power DC transmission system. ave U is the long-term average voltage of the power module. ave The value is determined by the voltage level of the switching device.

[0021] According to one achievable method based on the first aspect of the invention, the number of power modules is set as follows:

[0022]

[0023] In the formula, Indicates to The value is rounded up.

[0024] A second aspect of the present invention provides an energy consumption coordination control method for a DC energy-consuming device, characterized in that the method is based on the energy consumption coordination control system of the DC energy-consuming device as described in any one of the preceding claims, and the method includes:

[0025] Obtain the voltage across the DC power-consuming device;

[0026] When the voltage across the DC power consuming device is greater than the first voltage threshold, all power modules are gradually disconnected within a time interval of ΔT / 2; when the voltage across the DC power consuming device is less than the second voltage threshold, all power modules are gradually connected within a time interval of ΔT / 2.

[0027] A third aspect of the present invention provides an energy consumption coordination control device for a DC energy-consuming device, comprising:

[0028] A memory for storing instructions; wherein the instructions are used to implement the energy consumption coordination control method for the DC energy-consuming device as described above.

[0029] A processor for executing instructions in the memory.

[0030] The fourth aspect of the present invention provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the energy consumption coordination control method for a DC energy-consuming device as described above.

[0031] As can be seen from the above technical solutions, the present invention has the following advantages:

[0032] The system of this invention includes a DC energy-consuming device and an energy consumption coordination control device. The DC capacitors in the power modules of the DC energy-consuming device are set according to the allowable voltage fluctuation value of the power modules. Based on the voltage across the DC energy-consuming device obtained by the energy consumption coordination control device, when the voltage across the DC energy-consuming device is greater than a first voltage threshold, all power modules are gradually disconnected within a time interval ΔT / 2. When the voltage across the DC energy-consuming device is less than a second voltage threshold, all power modules are gradually connected within a time interval ΔT / 2. The second voltage threshold is greater than the first voltage threshold, where ΔT is the cycle of one power module connection / disconnection process. This invention reduces the impact on the DC bus by optimizing the main circuit parameters of the DC energy-consuming device and combining a step-by-step power module switching strategy, thereby reducing the fluctuation of the DC bus voltage during energy consumption. It has the advantages of high performance, high reliability, and low cost. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention 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 only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 A structural connection block diagram of an energy consumption coordination control system for a DC energy consumption device is provided as an optional embodiment of the present invention;

[0035] Figure 2 This is a schematic diagram of the coordinated control process of a DC energy-consuming device by an energy consumption coordination control device according to an optional embodiment of the present invention;

[0036] Figure 3 This is a wiring diagram of a DC power consumption device connected to a symmetrical unipolar DC transmission system according to an optional embodiment of the present invention;

[0037] Figure 4 This is a wiring diagram of a DC energy-consuming device connected to a bipolar DC transmission system according to an optional embodiment of the present invention.

[0038] Figure 5This is a wiring diagram of a DC power consumption device connected to a dual-valve-group series DC transmission system according to an optional embodiment of the present invention;

[0039] Figure 6 The flowchart illustrates an energy consumption coordination control method for a DC energy-consuming device, provided as an optional embodiment of the present invention.

[0040] Figure label:

[0041] 1-DC power consumption device; 2-Energy consumption coordination and control device; 3-High-end valve group; 4-Low-end valve group; 11-Power consumption resistor; 12-Power module; 21-Acquisition module; 22-Control module; 111-Centralized power consumption resistor; 112-Distributed power consumption resistor. Detailed Implementation

[0042] This invention provides an energy consumption coordination control system, method, and apparatus for DC energy-consuming devices, which addresses the technical problem that existing semi-centralized DC energy-consuming devices are prone to impacting the DC bus during the power module input and output processes, resulting in significant fluctuations in the DC bus voltage.

[0043] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0044] This invention provides an energy consumption coordination control system for a DC power consumption device.

[0045] Please see Figure 1 , Figure 1 The diagram shows a structural connection block diagram of an energy consumption coordination control system for a DC energy-consuming device provided in an embodiment of the present invention.

[0046] This invention provides an energy consumption coordination control system for a DC energy-consuming device, comprising a DC energy-consuming device 1 and an energy consumption coordination control device 2. The DC energy-consuming device 1 includes an energy-consuming resistor 11 and a power module 12 connected in series. The value of the DC capacitor in the power module 12 satisfies the following:

[0047]

[0048] In the formula, C is the value of the DC capacitor in the power module 12, and I dcΔT is the rated current of the offshore wind power DC transmission system to which DC energy dissipation device 1 is connected, ΔU is the cycle of the primary power module commissioning and decommissioning project, and ΔU is the rated current of the offshore wind power DC transmission system to which DC energy dissipation device 1 is connected. dc The allowable voltage fluctuation value for the power module;

[0049] The energy consumption coordination control device 2 includes an acquisition module 21 and a control module 22; the acquisition module 21 is used to acquire the voltage across the DC energy consumption device 1; the control module 22 is used to gradually disconnect all power modules 12 within a time ΔT / 2 when the voltage across the DC energy consumption device 1 is greater than a first voltage threshold, and gradually connect all power modules 12 within a time ΔT / 2 when the voltage across the DC energy consumption device 1 is less than a second voltage threshold; the second voltage threshold is greater than the first voltage threshold.

[0050] Considering the voltage rise of the power module during a single power module commissioning / decommissioning process:

[0051]

[0052] In the formula, ΔU SM For the module voltage rise during a power module commissioning / decommissioning project, I chopper The current flowing through DC power consumption device 1 is the current.

[0053] Based on ΔU SM In this embodiment, the value of the DC capacitor in the power module 12 is set to satisfy the calculation formula. This ensures that the set DC capacitor parameters can provide sufficient capacitance when the module voltage rises, and combined with the strategy of step-switching power modules 12, it can reduce the impact on the DC bus and reduce the fluctuation of DC bus voltage during energy consumption.

[0054] In one feasible manner, the first voltage threshold is the product of the rated voltage of the offshore wind power DC transmission system and a first voltage coefficient, and the second voltage threshold is the product of the rated voltage of the offshore wind power DC transmission system and a second voltage coefficient, wherein the second voltage coefficient is greater than the first voltage coefficient.

[0055] The first voltage coefficient and the second voltage coefficient are set according to the actual situation.

[0056] Wherein, when the offshore wind power DC transmission system adopts a symmetrical single-pole connection, the voltage between the corresponding poles is used as the rated voltage; when the offshore wind power DC transmission system adopts a symmetrical double-pole connection, the voltage between the corresponding pole and ground is used as the rated voltage; when the offshore wind power DC transmission system adopts a high-low valve group connection, the DC voltage of the corresponding single valve group is used as the rated voltage.

[0057] According to this embodiment, the coordination control process of the energy consumption coordination control device 2 on the DC energy consumption device 1 is as follows: Figure 2 As shown. Figure 2 Middle,U dc This represents the voltage across DC power consumption device 1, where k1 is the first voltage coefficient, k2 is the second voltage coefficient, and U... N The rated voltage of the offshore wind power DC transmission system to which the DC energy dissipation device 1 is connected.

[0058] In one feasible manner, the value of the DC capacitor in the power module 12 is set to...

[0059]

[0060] In another possible way, for The value is rounded up, and the resulting value is used as the value of the DC capacitor in the power module 12.

[0061] In one feasible implementation, when the DC power dissipation device 1 employs a centralized power dissipation resistor 111, the resistance value of the centralized power dissipation resistor 111 satisfies:

[0062]

[0063] In the formula, R1 represents the resistance value of the centralized energy-dissipating resistor 111, U N Let k be the rated voltage of the offshore wind power DC transmission system, and k be the margin factor, satisfying k≤1, P N The rated power of the offshore wind power DC transmission system is given.

[0064] In one feasible implementation, when the DC power dissipation device 1 employs a distributed power dissipation resistor 112, the resistance value of the distributed power dissipation resistor 112 is:

[0065]

[0066] In the formula, R2 represents the resistance value of the distributed energy dissipation resistor 112, and N2 is the number of distributed energy dissipation resistors 112 in the DC energy dissipation device 1.

[0067] In a specific implementation, the resistance of the centralized energy-consuming resistor 111 is set to the upper limit of the first resistance value. In other possible implementations, for... The value is rounded down to the nearest integer, and the resulting value is used as the upper limit of the first resistor.

[0068] Specifically, depending on the type of offshore wind power DC transmission system to which the DC energy dissipation device 1 is connected, it is determined whether the DC energy dissipation device 1 uses a distributed energy dissipation resistor 112 or a centralized energy dissipation resistor 111. Specifically, when the offshore wind power DC transmission system is a symmetrical single-pole connected DC transmission system, the energy dissipation resistor 1 in the DC energy dissipation device 1 uses a distributed energy dissipation resistor 112. For example... Figure 3 As shown, the DC power consumption device 1 has two power modules 12, and the power consumption resistor 11 is divided into two distributed power consumption resistors 112.

[0069] When the offshore wind power DC transmission system is a bipolar DC transmission system, a centralized energy-consuming resistor 111 is used in the DC energy-consuming device 1. For example... Figure 4 As shown, a DC energy dissipation device 1 is installed between the positive line and the neutral line of the bipolar DC transmission system, and another DC energy dissipation device 1 is installed between the negative line and the neutral line of the bipolar DC transmission system. Each DC energy dissipation device 1 uses a centralized energy dissipation resistor 111 and a centralized inductor 32.

[0070] When the offshore wind power DC transmission system is a dual-valve series DC transmission system, the DC energy consumption device 1 uses a centralized energy consumption resistor 111 and a centralized inductor 32. For example... Figure 5 As shown, a DC energy dissipation device 1 is installed at the high-end valve group 3 of the dual-valve group series DC transmission system, and another DC energy dissipation device 1 is installed at the low-end valve group 4. Each DC energy dissipation device 1 uses a centralized energy dissipation resistor 111.

[0071] In one feasible manner, the number of power modules 12 satisfies:

[0072]

[0073] In the formula, N represents the number of power modules 12 in the DC power consumption device 1, and U N U is the rated voltage of the offshore wind power DC transmission system. ave U is the long-term average voltage of power module 12. ave The value is determined by the voltage level of the switching device.

[0074] In one feasible implementation, the number of power modules 12 is set as follows:

[0075]

[0076] In the formula, Indicates to The value is rounded up.

[0077] In this embodiment, to The value is rounded up to be used as the number of power modules 2 in the DC energy-consuming device, which can minimize the cost of energy consumption coordination and control.

[0078] The present invention also provides an energy consumption coordination control method for a DC energy-consuming device, which is based on the energy consumption coordination control system of the DC energy-consuming device as described in any of the above embodiments.

[0079] Please see Figure 6 , Figure 6 A flowchart of an energy consumption coordination control method for a DC energy-consuming device provided by an embodiment of the present invention is shown.

[0080] An embodiment of the present invention provides an energy consumption coordination control method for a DC energy-consuming device, comprising:

[0081] Obtain the voltage across DC power consumption device 1;

[0082] When the voltage across the DC power consuming device 1 is greater than the first voltage threshold, all power modules 12 are gradually disconnected within a time interval of ΔT / 2; when the voltage across the DC power consuming device 1 is less than the second voltage threshold, all power modules 12 are gradually connected within a time interval of ΔT / 2.

[0083] The present invention also provides an energy consumption coordination control device for a DC power consumption device, comprising:

[0084] A memory is used to store instructions; wherein the instructions are used to implement the energy consumption coordination control method of the DC energy-consuming device as described in the above embodiment;

[0085] A processor for executing instructions in the memory.

[0086] The present invention also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the energy consumption coordination control method for the DC energy-consuming device as described in the above embodiments.

[0087] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the methods and apparatus described above can be referred to the corresponding process in the foregoing system embodiments, and the specific beneficial effects of the methods and apparatus described above can be referred to the corresponding beneficial effects in the foregoing system embodiments, and will not be repeated here.

[0088] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the system embodiments described above are merely illustrative. For instance, the division of modules in the energy consumption coordination and control device 2 is only a logical functional division. In actual implementation, there may be other division methods. For example, multiple modules or components may be combined or integrated into another device, or some features may be ignored or not executed.

[0089] Furthermore, in the various embodiments of the present invention, the modules of the energy consumption coordination and control device 2 can be integrated into one processing module, or each module can exist physically separately, or two or more modules can be integrated into one module. The integrated modules can be implemented in hardware or as software functional modules.

[0090] If each module in the energy consumption coordination and control device 2 is implemented as a software functional module and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0091] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An energy consumption coordination control system for a DC energy-consuming device, comprising a DC energy-consuming device and an energy consumption coordination control device, wherein the DC energy-consuming device includes an energy-consuming resistor and a power module connected in series, characterized in that, The value of the DC capacitor in the power module satisfies the following: ； In the formula, The value of the DC capacitor in the power module is given. The rated current of the offshore wind power DC transmission system to which the DC energy-consuming device is connected. This refers to the cycle of a single power module commissioning / discontinuation project. The allowable voltage fluctuation value for the power module; The energy consumption coordination and control device includes an acquisition module and a control module; the acquisition module is used to acquire the voltage across the DC energy-consuming device; the control module is used to control the voltage across the DC energy-consuming device when the voltage is greater than a first voltage threshold. Gradually disconnect all power modules within a time period, and when the voltage across the DC power consumption device is less than the second voltage threshold, All power modules are gradually put into operation within a certain time period; the second voltage threshold is greater than the first voltage threshold. The This is determined based on the module voltage rise during the primary power module commissioning / decommissioning process, and is used to ensure that the DC capacitor provides sufficient capacitance when the module voltage rise is reached. The module voltage rise during the primary power module commissioning / decommissioning process is: ； In the formula, For the module voltage rise during a power module commissioning / decommissioning project, This refers to the current flowing through the DC power-consuming device.

2. The energy consumption coordination control system for the DC energy-consuming device according to claim 1, characterized in that, The first voltage threshold is the product of the rated voltage of the offshore wind power DC transmission system and the first voltage coefficient, and the second voltage threshold is the product of the rated voltage of the offshore wind power DC transmission system and the second voltage coefficient, wherein the second voltage coefficient is greater than the first voltage coefficient.

3. The energy consumption coordination control system for the DC energy-consuming device according to claim 1, characterized in that, The value of the DC capacitor in the power module is set to... .

4. The energy consumption coordination control system for the DC energy-consuming device according to claim 1, characterized in that, When the DC power dissipation device uses a centralized power dissipation resistor, the resistance value of the centralized power dissipation resistor satisfies: ； In the formula, This indicates the resistance value of the centralized energy-consuming resistor. The rated voltage of the offshore wind power DC transmission system is [not specified]. Let be the margin coefficient, satisfying , The rated power of the offshore wind power DC transmission system is given.

5. The energy consumption coordination control system for the DC energy-consuming device according to claim 4, characterized in that, When the DC power dissipation device uses distributed power dissipation resistors, the resistance value of the distributed power dissipation resistors is: ； In the formula, This indicates the resistance value of the distributed energy-consuming resistor. The number of distributed energy-consuming resistors in the DC energy-consuming device.

6. The energy consumption coordination control system for the DC energy-consuming device according to claim 1, characterized in that, The number of power modules satisfies: ； In the formula, This indicates the number of power modules in the DC power consumption device. The rated voltage of the offshore wind power DC transmission system is [not specified]. This is the long-term average voltage of the power module. The value is determined by the voltage level of the switching device.

7. The energy consumption coordination control system for the DC energy-consuming device according to claim 6, characterized in that, The number of power modules is set as follows: ； In the formula, Indicates to The value is rounded up.

8. A method for coordinated energy consumption control of a DC energy-consuming device, characterized in that, The method is based on the energy consumption coordination control system of the DC energy-consuming device as described in any one of claims 1-7, and the method includes: Obtain the voltage across the DC power-consuming device; When the voltage across the DC power consumption device is greater than the first voltage threshold, Gradually disconnect all power modules within a certain time; when the voltage across the DC power consumption device is less than the second voltage threshold, All power modules will be gradually put into operation within a certain timeframe.

9. An energy consumption coordination control device for a DC energy-consuming device, characterized in that, include: A memory for storing instructions; wherein the instructions are used to implement the energy consumption coordination control method for the DC energy-consuming device as described in claim 8; A processor for executing instructions in the memory.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, which, when executed by a processor, implements the energy consumption coordination control method for the DC energy-consuming device as described in claim 8.

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