Flexible alternating-current energy consumption device and method for new energy flexible direct delivery system and control equipment of flexible alternating-current energy consumption device

Abstract

The invention discloses a flexible alternating current energy consumption device and method for a new energy flexible direct output system and control equipment of the flexible alternating current energy consumption device and method, and relates to the technical field of power system protection. According to the invention, the three-phase arrangement of the energy consumption switch is converted into the single-phase arrangement by using the scheme of AC-DC circuit conversion, so that the number and occupied area of required devices can be reduced. According to the alternating current energy consumption device, frequency conversion control is adopted, the energy consumption switch composed of the thyristor and the LC circuit and the buffer inductor are used, flexible controllability and flexible switching of energy consumption power are achieved, and the performance of the alternating current energy consumption device can be effectively improved.

Description

TECHNICAL FIELD

[0001] The application discloses a flexible AC power consumption device for a new energy flexible AC transmission system, a method and a control device thereof, and relates to the technical field of power system protection. BACKGROUND

[0002] For a new energy flexible AC transmission system, when faults such as converter station blocking and short circuit on the AC side of the receiving end occur, the new energy unit cannot be immediately withdrawn, the system transmission power rapidly decreases, the surplus power continuously charges the system, the DC side voltage continuously rises, and the voltage will exceed the equipment tolerance capacity in tens of milliseconds. Therefore, efficient consumption of the surplus power has become a core problem restricting the development of large-scale new energy systems. Among various fault ride-through modes, the power consumption device can quickly and reliably consume the surplus power, so that the non-permanent fault does not affect the normal operation of the overall power transmission system, and is a key to the further development of the new energy transmission system, and has been widely applied in engineering.

[0003] The power consumption device essentially uses power electronic switches to control resistors to consume power and maintain the stability of the DC voltage. According to the arrangement position of the power consumption device, the power consumption device is mainly divided into a DC power consumption device and an AC power consumption device. The DC power consumption device is arranged on the DC side of the system, and full-controlled power electronic switches (IGBT, IGCT, etc.) are used to control the input and removal of the power consumption resistor. This scheme realizes precise control of power dissipation by chopping and modulating the DC current on the power consumption resistor, but a high-voltage and large-capacity DC power consumption device is often composed of hundreds of expensive full-controlled power electronic switches, and the construction cost is huge, and the fault ride-through under the converter station blocking condition cannot be realized. At present, the DC power consumption device is only applied in special scenarios of offshore wind power, and the application range is limited. The AC power consumption device is arranged on the AC side of the system, as shown in FIG. 1, and uses half-controlled power electronic switches (thyristors) to control resistors to realize consumption of the surplus power. Compared with the DC power consumption device, the thyristor technology in the AC power consumption device is mature, and the economy and reliability are better than those of the full-controlled power electronic switches. In addition, the AC power consumption device can also be combined with mechanical switches and flexibly arranged at the sending end or the receiving end to meet the needs of efficient consumption of the surplus power under different new energy transmission scenarios (onshore and offshore) and different fault conditions, and has a broad application prospect. Figure 4

[0004] ​In the process of fault ride-through in seconds, DC voltage fluctuation is a key technical index to measure the performance of energy-consuming devices. However, in the process of operation of AC energy-consuming devices, due to the fact that thyristors do not have the ability to actively modulate the current of energy-consuming resistors, it is difficult to achieve accurate matching of the power absorbed by the energy-consuming resistors and the system surplus power. In the process of exiting of AC energy-consuming devices, thyristors rely on the zero-crossing of AC current to turn off, and after the system issues an exit instruction, it takes tens of milliseconds for AC energy-consuming devices to stop absorbing power. Therefore, AC energy-consuming devices have a large impact on system power and voltage during fault ride-through, resulting in a DC voltage fluctuation range that is difficult to meet the system requirements.

[0005] To solve the above problems, existing solutions can be divided into two categories. One is to directly replace thyristors with fully controlled power electronic switches to actively modulate the current of energy-consuming resistors and achieve accurate control of the absorbed power. However, due to the high-current and multi-pulse operating conditions of AC energy-consuming devices, this solution requires a large number of fully controlled power electronic switches in series and parallel, which is expensive. The other is to increase the number of groups of AC energy-consuming devices, change the number of groups to be put into operation according to the required absorbed surplus power, and achieve smooth switching of energy-consuming devices through control strategies such as step switching during operation, thereby reducing the impact on the system. However, the main problem brought by increasing the number of groups is that AC energy-consuming devices are arranged in three phases, and too many groups will increase the number of devices and the occupied area. Taking the Zhangbei ± 500 kV / 3000 MW four-terminal flexible DC project as an example, the AC energy-consuming devices arranged at the Zhangbei station are divided into 8 groups, each group absorbs 375 MW of power, and a total of 720 thyristors are needed, occupying an area of 300 m 2 Based on the above analysis, it can be seen that the existing AC energy-consuming device solution still has some shortcomings and is difficult to balance high operating performance and high economy, which is not conducive to further popularization and application.

[0006] According to the foregoing description, the existing AC energy-consuming device solution can already achieve the basic function of system fault ride-through, but due to the limitations of the semi-controlled characteristics of thyristors and the topology of the device itself, the technical and economic performance of the current AC energy-consuming device is not good, which is specifically manifested in:

[0007] The power absorbed by the AC energy-consuming device needs to be matched with the system surplus power as much as possible, but under the existing topology, the power absorbed by a single energy-consuming branch is fixed, which leads to the need to increase the number of groups to smoothly absorb power, and the three-phase arrangement of energy-consuming switches further increases the cost and occupied area; the AC energy-consuming device needs to reduce the impact on the system as much as possible during switching, but due to the semi-controlled characteristics of thyristors, the energy-consuming resistors often delay exit, resulting in a DC voltage fluctuation range exceeding 10% during fault ride-through, which is not conducive to the stable operation of the system. Therefore, the contradiction between system operation requirements and low construction cost has become the main bottleneck restricting the technical progress and large-scale application of AC energy-consuming devices. SUMMARY

[0008] The present application provides a flexible AC energy consumption device, method and control equipment for a new energy flexible AC transmission and delivery system to solve the problems in the prior art.

[0009] In a first aspect, the present application provides a flexible AC energy consumption device for a new energy flexible AC transmission and delivery system, which is installed on an AC bus between a wind turbine generator and a sending-end converter station, and includes a three-phase diode rectifier bridge, a buffer inductor 8 and a sub-module 9.

[0010] The AC bus is connected to the buffer inductor 8 and the energy consumption resistor 14 in parallel through the three-phase diode rectifier bridge,

[0011] The buffer inductor 8 and the energy consumption resistor 14 are connected in series through a plurality of sub-modules 9.

[0012] In some implementations, the three-phase diode rectifier bridge includes diodes 1, 2, 3, 4, 5, 6 and a DC capacitor 7,

[0013] The anode of the diode 1 is connected to the cathode of the diode 4, the anode of the diode 2 is connected to the cathode of the diode 5, and the anode of the diode 3 is connected to the cathode of the diode 6; the cathode of the diode 1, the cathode of the diode 2 and the cathode of the diode 3 are connected to one end of the DC capacitor 7; the anode of the diode 4, the anode of the diode 5 and the anode of the diode 6 are connected to the other end of the DC capacitor 7.

[0014] One end of the buffer inductor 8 is connected to the cathode of the diode 3.

[0015] In some implementations, the sub-module 9 includes a voltage stabilizing resistor 10, a thyristor 11, an oscillation capacitor 12 and an oscillation inductor 13.

[0016] One end of the buffer inductor 8 is connected to one end of the voltage stabilizing resistor 10 through the input of the sub-module 9, the other end of the voltage stabilizing resistor 10 is connected to the output of the sub-module; the anode of the thyristor 11 is connected to the input of the sub-module, the cathode of the thyristor 11 is connected to the output of the sub-module; one end of the oscillation capacitor 12 is connected to the input of the sub-module, the other end of the oscillation capacitor 12 is connected to one end of the oscillation inductor 13, and the other end of the oscillation inductor 13 is connected to the output of the sub-module.

[0017] In a second aspect, the present application provides a control method for a flexible AC energy consumption device for a new energy flexible AC transmission and delivery system, according to the device of the first aspect, including:

[0018] S1, according to the voltage Ud of the DC capacitor 7 and the rated power Prate of the new energy flexible AC transmission and delivery system, the resistance value of the energy consumption resistor 14 is obtained;

[0019] S2, according to the oscillation frequency fo of the LC branch, the requirement of reverse current provided by the LC branch through the thyristor 11 when it is turned off, the value Co of the oscillation capacitor 12 and the value Lo of the oscillation inductor 13 are obtained;

[0020] S3, according to 3 / 4 of the oscillation period of the LC branch, as the conduction time of the thyristor 11;

[0021] S4, according to the reverse recovery time tq of the thyristor 14, the maximum operating frequency fs_max of the thyristor is obtained;

[0022] S5, according to the surplus power of the new energy flexible direct current transmission system, the surplus power Psurplus of the new energy flexible direct current transmission system is consumed by keeping the conduction time of the thyristor 11 and adjusting the operating frequency;

[0023] S6, according to the rated voltage U rate of the thyristor 11 and the steady-state voltage U C_max of the DC capacitor 7, the number of series of the sub-modules 9 is set by reserving voltage margin.

[0024] In some implementations, the S5 includes:

[0025] S51, when the surplus power Psurplus of the new energy flexible direct current transmission system is the rated power Prate, the power coefficient k is equal to 1, and the operating frequency of the thyristor 11 is the maximum operating frequency fs_max;

[0026] S52, when the surplus power Psurplus of the new energy flexible direct current transmission system changes, the multiple relationship between the operating frequency fs of the thyristor 11 and the maximum operating frequency fs_max is expressed by k times relationship.

[0027] In some implementations, the S6 includes:

[0028] When the flexible alternating current energy consumption device works normally, the maximum voltage on the thyristor is 0.6U rate , and the number N of the sub-modules 9 is expressed as follows:

[0029]

[0030] Wherein, roundup means rounding up.

[0031] In a third aspect, an embodiment of the present application provides a control device for a flexible alternating current energy consumption device of a new energy flexible direct current transmission system, comprising:

[0032] A value obtaining unit 1 is configured to obtain the resistance value of the energy consumption resistor 14 according to the voltage Ud of the DC capacitor 7 and the rated power Prate of the new energy flexible direct current transmission system;

[0033] A value obtaining unit 2 is configured to obtain the value Co of the oscillation capacitor 12 and the value Lo of the oscillation inductor 13 according to the oscillation frequency fo of the LC branch and the requirement of providing reverse current by the LC branch when the thyristor 11 is off;

[0034] A value obtaining unit 3 is configured to obtain the conduction time of the thyristor 11 according to 3 / 4 of the oscillation period of the LC branch;

[0035] A value obtaining unit 4 is configured to obtain the maximum working frequency fs_max of the thyristor according to the reverse recovery time tq of the thyristor 14;

[0036] An adjusting unit is configured to adjust the surplus power Psurplus of the new energy flexible direct current transmission system by keeping the conduction time of the thyristor 11 and adjusting the working frequency of the thyristor 11 according to the surplus power Psurplus of the new energy flexible direct current transmission system;

[0037] for consumption treatment;

[0038] In some implementations, the adjusting unit comprises:

[0039] A parsing subunit 1 is configured to make the power coefficient k equal to 1 when the surplus power Psurplus of the new energy flexible direct current transmission system is equal to the rated power Prate, and the working frequency of the thyristor 11 is equal to the maximum working frequency fs_max;

[0040] A parsing subunit 2 is configured to express the multiple relationship between the working frequency fs of the thyristor 11 and the maximum working frequency fs_max by k times relationship when the surplus power Psurplus of the new energy flexible direct current transmission system changes.

[0041] In some implementations, the reserving unit comprises:

[0042] for reserving 40% voltage margin when the flexible alternating current energy consumption device works normally, so that the maximum voltage on the thyristor is 0.6U rate , the number N of the sub-modules 9 is expressed as follows:

[0043]

[0044] wherein, roundup represents rounding up.

[0045] In a fourth aspect, an electronic device is provided, and the electronic device includes a memory and a processor, the memory is configured to store one or more computer instructions, and when the one or more computer instructions are executed by the processor, the method according to the first aspect is implemented.

[0046] In a fifth aspect, a computer storage medium is provided, and the computer storage medium stores a computer program, and when the computer program is executed by a processor, the method according to the first aspect is implemented.

[0047] One or more embodiments of the present application can bring at least the following beneficial effects:

[0048] The present application can reduce the number of required devices and the floor area by converting the three-phase arrangement of energy-consuming switches into a single-phase arrangement through the scheme of AC-DC conversion. Moreover, the energy-consuming switch composed of a thyristor and an LC circuit and the buffer inductor are used to achieve flexible and controllable energy consumption power and flexible switching, which can effectively improve the performance of the AC energy consumption device.

[0049] Compared with the traditional AC energy consumption device scheme with multiple three-phase arrangements, the flexible AC energy consumption device scheme provided by the present application can achieve flexible and adjustable energy consumption power. The precise frequency control is used, which can make the dissipated power more accurately match the surplus power during system failure, and the DC voltage ripple of the system is within 5%, which is 50% of the traditional AC energy consumption device. At the same time, compared with the traditional AC energy consumption device, the present application can save 40% of the device cost and 60% of the floor area through the single-phase arrangement of the energy consumption branch, which has higher technical and economic efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0050] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0051] Figure 1 is a structural topology diagram of a flexible AC energy consumption device for a new energy flexible DC transmission system provided by an embodiment of the present application;

[0052] Figure 2 is a runtime sequence diagram of a flexible AC energy consumption device for a new energy flexible DC transmission system provided by an embodiment of the present application;

[0053] Figure 3is a parameter design reference diagram of a flexible AC energy consumption device for a new energy flexible direct current transmission system provided by the embodiment;

[0054] Figure 4 is a traditional AC energy consumption device structure topology involved in the background art;

[0055] Figure 5 is an installation schematic diagram of a flexible AC energy consumption device for a new energy flexible direct current transmission system provided by the embodiment. DETAILED DESCRIPTION

[0056] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only a part of the embodiments of the application, rather than all the embodiments of the application. The components of the embodiments of the application described and shown in the drawings can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the application provided in the drawings is not intended to limit the scope of the claimed application, but only represents selected embodiments of the application. Based on the embodiments of the application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of the application.

[0057] Embodiment one:

[0058] Figure 1 shows a structure topology of a flexible AC energy consumption device for a new energy flexible direct current transmission system, as shown in Figure 1 the flexible AC energy consumption device for a new energy flexible direct current transmission system provided by the embodiment is installed on an AC bus between a wind turbine generator and a sending end converter station, and includes a three-phase diode rectifier bridge, a buffer inductor 8 and sub-modules 9. Figure 5

[0059] The AC bus is connected to the buffer inductor 8 and the energy consumption resistor 14 through the three-phase diode rectifier bridge in parallel,

[0060] The buffer inductor 8 and the energy consumption resistor 14 are connected in series through a plurality of sub-modules 9.

[0061] In some implementations, the three-phase diode rectifier bridge includes diodes 1, 2, 3, 4, 5, 6 and a DC capacitor 7,

[0062] The anode of the diode 1 is connected to the cathode of the diode 4, the anode of the diode 2 is connected to the cathode of the diode 5, and the anode of the diode 3 is connected to the cathode of the diode 6; the cathode of the diode 1, the cathode of the diode 2 and the cathode of the diode 3 are connected to one end of the DC capacitor 7; the anode of the diode 4, the anode of the diode 5 and the anode of the diode 6 are connected to the other end of the DC capacitor 7.​

[0063] One end of the buffer inductor 8 is connected to the cathode of the diode 3.

[0064] Specifically, the sub-module 9 includes a voltage stabilizing resistor 10, a thyristor 11, an oscillation capacitor 12 and an oscillation inductor 13.

[0065] One end of the buffer inductor 8 is connected to one end of the voltage stabilizing resistor 10 through the input of the sub-module 9, the other end of the voltage stabilizing resistor 10 is connected to the output of the sub-module; the anode of the thyristor 11 is connected to the input of the sub-module, the cathode of the thyristor 11 is connected to the output of the sub-module; one end of the oscillation capacitor 12 is connected to the input of the sub-module, the other end of the oscillation capacitor 12 is connected to one end of the oscillation inductor 13, the other end of the oscillation inductor 13 is connected to the output of the sub-module.

[0066] As shown in Figure 1 , a flexible AC energy consumption device includes: a three-phase diode rectifier bridge, a buffer inductor, and a plurality of sub-modules connected in series and connected to an energy consumption resistor.

[0067] The three-phase diode rectifier bridge includes: six diodes and one DC capacitor; characterized in that: the anode of diode 1 is connected to the cathode of diode 4, the anode of diode 2 is connected to the cathode of diode 5, and the anode of diode 3 is connected to the cathode of diode 6; the cathode of diode 1, the cathode of diode 2, and the cathode of diode 3 are connected to one end of the DC capacitor 7; the anode of diode 4, the anode of diode 5, and the anode of diode 6 are connected to the other end of the DC capacitor 7; the DC capacitor 7 functions to maintain the stability of the output voltage of the diode rectifier bridge on the DC side; one end of the buffer inductor 8 is connected to the cathode of diode 3, and the other end of the buffer inductor 8 is connected to the input of the sub-module; the buffer inductor 8 functions to reduce the impact on the system voltage when the energy consumption device is switched;

[0068] The sub-module 9 includes: a voltage stabilizing resistor, a thyristor, an oscillation capacitor, and an oscillation inductor; characterized in that: one end of the voltage stabilizing resistor 10 is connected to the input of the sub-module, the other end of the voltage stabilizing resistor 10 is connected to the output of the sub-module; the anode of the thyristor 11 is connected to the input of the sub-module, the cathode of the thyristor 11 is connected to the output of the sub-module; one end of the oscillation capacitor 12 is connected to the input of the sub-module, the other end of the oscillation capacitor 12 is connected to one end of the oscillation inductor 13, the other end of the oscillation inductor 13 is connected to the output of the sub-module; the LC branch composed of the oscillation capacitor 12 and the oscillation inductor 13 generates an oscillation current, which can provide a reverse turn-off current for the thyristor 11;

[0069] As shown in Figure 2 , the working process will be described in detail in time sequence;

[0070] Before t0, the new energy flexible direct current transmission system is in normal operation, the system charges the direct current capacitor 7 and the oscillation capacitor 12; the flexible alternating current energy consumption device monitors the direct current voltage in real time, and when the monitoring value is lower than the set value, the energy consumption device does not work;

[0071] At t0, a low-voltage fault occurs at the receiving end of the new energy flexible direct current transmission system, the system has surplus power, and the direct current voltage continues to rise;

[0072] At t1, the flexible alternating current energy consumption device monitors that the direct current voltage exceeds the set value, controls the flexible alternating current energy consumption device to enter the energy consumption state, starts to apply a trigger pulse to the thyristor 11, the LC branch starts to oscillate, and the energy consumption is performed by the energy consumption resistor 14;

[0073] At t2, the LC branch current Io reaches the maximum positive value, the LC branch current Io is greater than the energy consumption resistor current IR, at this time, the reverse current flows into the cathode of the thyristor 11, and the thyristor 11 is turned off;

[0074] At t3, the LC branch oscillation ends, and thereafter the system charges the direct current capacitor 7 and the oscillation capacitor 12 to restore the energy to the level before t1; after t3, the above process is repeated to maintain the stability of the direct current voltage;

[0075] At t4, the low-voltage fault at the receiving end of the new energy flexible direct current transmission system ends, the flexible alternating current energy consumption device monitors that the system alternating current voltage is restored, and when the direct current voltage drops to the set value, the flexible alternating current energy consumption device is controlled to be locked, and the flexible alternating current energy consumption device exits.

[0076] Embodiment two:

[0077] In a second aspect, as Figure 3 shown, the embodiment of the present application provides a control method of a flexible alternating current energy consumption device for a new energy flexible direct current transmission system, according to the device of embodiment one, comprising:

[0078] S1, according to the voltage Ud of the direct current capacitor 7 and the rated power Prate of the new energy flexible direct current transmission system, the resistance value of the energy consumption resistor 14 is obtained; represented as formula (1):

[0079]

[0080] S2, according to the oscillation frequency fo of the LC branch, the value Co of the oscillation capacitor 12 and the value Lo of the oscillation inductor 13 are obtained by the requirement of the reverse current provided by the LC branch when the thyristor 11 is turned off; represented as formula (2), formula (3);

[0081]

[0082] S3, according to the LC branch oscillation period 3 / 4, as the thyristor 11 conduction time, expressed as formula (4);

[0083]

[0084] S4, according to the thyristor 14 reverse recovery time tq, get the maximum operating frequency fs_max of the thyristor, expressed as formula (5):

[0085]

[0086] S5, according to the surplus power of the new energy flexible direct current transmission system, by keeping the conduction time of the thyristor 11, by adjusting the operating frequency to the new energy flexible direct current transmission system surplus power Psurplus for disposal.

[0087] Specifically, S5, comprising:

[0088] S51, when the new energy flexible direct current transmission system surplus power Psurplus is rated power Prate, the power coefficient k is equal to 1, the operating frequency of the thyristor 11 is the maximum operating frequency fs_max;

[0089] S52, when the new energy flexible direct current transmission system surplus power Psurplus changes, the working frequency fs of the thyristor 11 and the maximum working frequency fs_max are expressed by the multiple relationship through the k times relationship;

[0090] Expressed as formula (6), formula (7);

[0091] P surplus =kP rate (6)

[0092] f s =kf s_max (7)

[0093] In the formula, I o LC branch current, I R is the current on the energy dissipation resistor 14;

[0094] In determining the number of submodules N, in order to ensure the reliable operation of the thyristor 11, it is necessary to reserve sufficient voltage margin, at this time, the thyristor 11 rated voltage is U rate , the voltage of the DC capacitor 7 at steady state is U C_max .

[0095] Reserve 40% voltage margin, then in the normal work of the flexible alternating current energy dissipation device, the maximum voltage on the thyristor is 0.6U rate Therefore, the number of submodules N can be determined by (8):

[0096]

[0097] Here, roundup means rounding up.

[0098] Example 3:

[0099] Thirdly, embodiments of the present invention provide a control device for a flexible AC energy dissipation device in a new energy flexible direct transmission system, comprising:

[0100] Value acquisition unit 1 is used to determine the voltage Ud of DC capacitor 7 and the rated power of the new energy flexible direct transmission system.

[0101] Prate, get the resistance value of power-consuming resistor 14;

[0102] Value acquisition unit 2 is used to determine the value of the LC branch when the thyristor 11 is turned off, based on the oscillation frequency fo of the LC branch.

[0103] The branch provides the reverse current requirement, so obtain the value Co of the oscillating capacitor 12 and the value Lo of the oscillating inductor 13;

[0104] The value acquisition unit 3 is used to take 3 / 4 of the oscillation period of the LC branch as the conduction time of the thyristor 11;

[0105] The value acquisition unit 4 is used to obtain the maximum operating frequency fs_max of the thyristor based on the reverse recovery time tq of the thyristor 14.

[0106] The adjustment unit is used to adjust the operating frequency of the new energy flexible direct transmission system based on the surplus power of the system by maintaining the conduction time of the thyristor 11.

[0107] Psurplus handles the disposal.

[0108] Specifically, the adjustment unit includes:

[0109] Analysis subunit 1 is used to determine the power coefficient k equals 1 when the surplus power Psurplus of the new energy flexible direct transmission system is the rated power Prate, and the operating frequency of the thyristor 11 is the maximum operating frequency fs_max.

[0110] Analysis subunit 2 is used to represent the multiple relationship between the operating frequency fs and the maximum operating frequency fs_max of the thyristor 11 through a k-fold relationship when the surplus power Psurplus of the new energy flexible direct transmission system changes.

[0111] Furthermore, the reserved unit includes:

[0112] For when the flexible AC power consumption device is working normally, the maximum voltage on the thyristor is 0.6U by reserving 40% voltage margin rate The number N of the sub-modules 9 is expressed as follows:

[0113]

[0114] Wherein, roundup means rounding up.

[0115] Embodiment Four

[0116] The embodiment also provides an electronic device, comprising a memory and a processor, the memory is used for storing one or more computer instructions, wherein the one or more computer instructions are executed by the processor to realize the method of the embodiment two;

[0117] In actual application, the processor can be an Application Specific Integrated Circuit (ASIC), a Digital Signal Processor (DSP), a Digital Signal Processing Device (DSPD), a Programmable Logic Device (PLD), a Field Programmable Gate Array (FPGA), a controller, a microcontroller (MCU), a microprocessor or other electronic elements, which are used to execute the method in the above embodiments.

[0118] The method realized by the embodiment is as shown in the embodiment two.

[0119] Embodiment Five

[0120] The embodiment also provides a computer storage medium, the computer readable storage medium stores a computer program, and the computer program is executed by one or more processors to realize the method of the embodiment one;

[0121] The computer readable storage medium can be realized by any type of volatile or nonvolatile storage devices or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk or optical disk.

[0122] The method implemented by the embodiment is shown in Embodiment 2.

[0123] In several embodiments provided by the embodiments of the present application, it should be understood that the disclosed system and method can also be implemented by other ways. The system and method embodiments described above are only illustrative.

[0124] It should be noted that in this paper, the terms "first", "second" and the like in the description and claims of the application and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily describe a specific order or sequence. The terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or device. Without more limitations, the element defined by the statement "including a" does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0125] Although the embodiments of the present application are disclosed as above, the content described is only for the purpose of facilitating understanding of the embodiments adopted by the present application, and is not intended to limit the present application. Any person skilled in the art of the present application can make any modification and change in the form and details without departing from the spirit and scope of the present application, but the patent protection scope of the present application shall be subject to the scope defined by the appended claims.

Claims

1. A flexible AC power consumption device for a new energy flexible AC transmission and delivery system, which is installed on an AC bus between a wind turbine generator and a sending-end converter station, characterized in that, The three-phase diode rectifier bridge, the buffer inductor 8 and the sub-module 9 are connected in series. The AC bus is connected to the buffer inductor 8 and the energy consumption resistor 14 in parallel through the three-phase diode rectifier bridge, The buffer inductor 8 and the energy consumption resistor 14 are connected in series through the plurality of sub-modules 9.

2. The apparatus of claim 1, wherein, The three-phase diode rectifier bridge includes diodes 1, 2, 3, 4, 5, 6 and a DC capacitor 7, The anode of the diode 1 is connected to the cathode of the diode 4, the anode of the diode 2 is connected to the cathode of the diode 5, and the anode of the diode 3 is connected to the cathode of the diode 6; the cathode of the diode 1, the cathode of the diode 2 and the cathode of the diode 3 are connected to one end of the DC capacitor 7; the anode of the diode 4, the anode of the diode 5 and the anode of the diode 6 are connected to the other end of the DC capacitor 7; One end of the buffer inductor 8 is connected to the cathode of the diode 3.

3. The apparatus of claim 1, wherein, The sub-module 9 includes a voltage stabilizing resistor 10, a thyristor 11, an oscillation capacitor 12 and an oscillation inductor 13. One end of the buffer inductor 8 is connected to one end of the voltage stabilizing resistor 10 through the input of the sub-module 9, the other end of the voltage stabilizing resistor 10 is connected to the output of the sub-module; the anode of the thyristor 11 is connected to the input of the sub-module, the cathode of the thyristor 11 is connected to the output of the sub-module; one end of the oscillation capacitor 12 is connected to the input of the sub-module, the other end of the oscillation capacitor 12 is connected to one end of the oscillation inductor 13, the other end of the oscillation inductor 13 is connected to the output of the sub-module.

4. A control method for a flexible AC power consumption device of a new energy flexible AC transmission and delivery system, according to any one of claims 1-3, characterized in that, Comprising: S1, according to the voltage Ud of the DC capacitor 7 and the rated power Prate of the new energy flexible direct current transmission system, the resistance value of the energy consumption resistor 14 is obtained; S2, according to the oscillation frequency fo of the LC branch, the value Co of the oscillation capacitor 12 and the value Lo of the oscillation inductor 13 are obtained through the requirement of the reverse current provided by the LC branch when the thyristor 11 is turned off; S3, according to 3 / 4 of the oscillation period of the LC branch, the conduction time of the thyristor 11 is obtained; S4, according to the reverse recovery time tq of the thyristor 14, the maximum working frequency fs_max of the thyristor is obtained; S5, according to the surplus power of the new energy flexible direct current transmission system, the surplus power Psurplus of the new energy flexible direct current transmission system is handled through the adjustment of the working frequency by keeping the conduction time of the thyristor 11; S6, setting the number of series of the sub-modules 9 by reserving a voltage margin in accordance with the rated voltage U of the thyristor 11 rate and the steady state voltage U of the DC capacitor 7 C_max , 5. The method of claim 4, wherein, S5, comprising: S51, when the surplus power Psurplus of the new energy flexible direct current transmission system is the rated power Prate, the power coefficient k is equal to 1, and the working frequency of the thyristor 11 is the maximum working frequency fs_max; S52, when the surplus power Psurplus of the new energy flexible direct current transmission system changes, the multiple relationship between the working frequency fs of the thyristor 11 and the maximum working frequency fs_max is represented through the k times relationship.

6. The method of claim 4, wherein, S6, comprising: When the flexible AC energy consumption device is working normally, the maximum voltage on the thyristor is 0.6U by reserving 40% voltage margin rate The number N of the sub-modules 9 is expressed as follows: Wherein, roundup represents rounding up.

7. A control device for a flexible AC power consumption device of a new energy flexible direct current transmission system, characterized in that, Comprising: The value obtaining unit 1 is used for obtaining the resistance value of the energy consumption resistor 14 according to the voltage Ud of the DC capacitor 7 and the rated power Prate of the new energy flexible direct current transmission system; A value obtaining unit 2 is configured to obtain a value Co of the oscillation capacitor 12 and a value Lo of the oscillation inductor 13 according to an oscillation frequency fo of the LC branch and a requirement of providing a reverse current by the LC branch when the thyristor 11 is turned off. A value obtaining unit 3 is configured to obtain a conduction time of the thyristor 11 according to 3 / 4 of an oscillation period of the LC branch. A value obtaining unit 4 is configured to obtain a maximum operating frequency fs_max of the thyristor according to a reverse recovery time tq of the thyristor 14. An adjusting unit is configured to absorb the surplus power Psurplus of the new energy flexible HVDC transmission system by keeping the conduction time of the thyristor 11 and adjusting the operating frequency according to the surplus power Psurplus of the new energy flexible HVDC transmission system. a reserve unit for setting the number of series of sub-modules 9 by a reserve voltage margin, in dependence of the rated voltage U rate and the steady state voltage U of the DC capacitor 7 C_max of the thyristor 11.

8. The apparatus of claim 7, wherein, The adjusting unit comprises: An analyzing sub-unit 1 is configured to make the power coefficient k equal to 1 and the operating frequency of the thyristor 11 equal to the maximum operating frequency fs_max when the surplus power Psurplus of the new energy flexible HVDC transmission system is equal to a rated power Prate. An analyzing sub-unit 2 is configured to express a multiple relationship between the operating frequency fs of the thyristor 11 and the maximum operating frequency fs_max by a k times relationship when the surplus power Psurplus of the new energy flexible HVDC transmission system changes.

9. An electronic device, comprising: A computer readable storage medium stores a computer program, and the computer program is executed by a processor to implement the method in any one of claims 4-6.

10. A computer-readable storage medium, characterized in that, The computer readable storage medium stores a computer program, and the computer program is executed by a processor to implement the method in any one of claims 4-6.

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