Control method and system for multi-property-right concentrated sea wind sending-out connection transformer
By dynamically reducing the control method of the wind turbine's power and forced resection of the wind turbine set line, solve the fairness and fairness of the multi -property owner's access to the same maritime stations, the maximum power after the fault, the rapid and automatic demand, and the realization The safe and reliable operation of the connection and the maximum power of the power is delivered.
Patent Information
- Application Number
- CN202411462546.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-18
- Publication Date
- 2025-01-21
AI Technical Summary
The existing technology cannot effectively solve the engineering situation where multi-property owners access the same offshore converter station and send it out in a centralized manner, especially in meeting the needs of fair and just, maximum power delivery after failure, and rapid and automatic.
This paper proposes a multi-property sea breeze centralized transmission connection transformer control method. By judging whether a single connection transformer fails and whether the other connection transformers are overloaded, the active power of the wind turbine is dynamically reduced, and when the set safety value is not reached, the force is forced through a delay. Cut off the wind turbine power collection circuit corresponding to the property owner to ensure power delivery.
This method can effectively ensure the safe and reliable operation of the wind farm connection, maximize the effort of the effective power of the wind power after the connection is changed, and ensure the fairness and fairness of the effective power of various property units. Development.
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Figure CN119341133A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a control method and system for a multi-property sea wind centralized transmission connection transformer, belonging to the technical field of offshore wind power. Background Art
[0002] According to the requirements of the specification "NB_T 11403-2023 Design Code for Offshore Flexible DC Converter Stations", "the capacity of the interconnection transformer should be determined in combination with the DC system transmission capacity requirements; the capacity of the interconnection transformer should take redundancy into account. When one interconnection transformer fails and is out of operation, the capacity of the remaining interconnection transformer should not be less than 70% of the rated DC transmission power of the offshore converter station". If the load of the entire station is greater than 70% before the interconnection transformer N-1 occurs, it is necessary to reduce the output power of the wind turbine to avoid transformer losses.
[0003] At present, most offshore wind power plants do not implement this specification. To meet the 70% power delivery requirement, there are several simple technical solutions:
[0004] The connection transformers of the entire station are designed to deliver 100% power after N-1, but the equipment investment cost of this solution is too high.
[0005] When the number of connecting transformers is greater than 4, and the wind turbines are evenly distributed on the AC side of each connecting transformer, when N-1 occurs, even if the wind turbine power corresponding to the failed connecting transformer is not considered, the remaining 3 connecting transformers can deliver 75% of the power. However, this solution not only requires large initial equipment investment, but also occupies a large area.
[0006] When the N-1 fault occurs in the connecting transformer and the connecting transformer is overloaded, the collector line is cut off in turns until the connecting transformer power is lower than the rated value. This solution is simple, but if multiple property owners send power in a centralized manner, it is impossible to fairly select the collector line to be cut off.
[0007] Existing technology cannot solve the problem of multiple property owners accessing the same offshore converter station and sending power in a centralized manner. This type of project needs to meet the requirements of fairness, maximum power transmission after a fault, and rapidity and automation. Summary of the invention
[0008] In order to solve the above problems existing in the prior art, the present invention proposes a multi-property sea wind centralized transmission connection transformer control method and system.
[0009] The technical solution of the present invention is as follows:
[0010] On the one hand, the present invention provides a multi-property sea wind centralized transmission connection transformer control method, comprising the following steps:
[0011] Determine whether a single connected transformer has a fault and whether the remaining connected transformers are overloaded after a single fault occurs;
[0012] Dynamically reduce the active power of wind turbines according to the overload ratio of the remaining connected transformers;
[0013] Within a fixed time, if the active power of the wind turbine is reduced to the set safety value, the power reduction will be stopped. If the active power of the wind turbine is not reduced to the set safety value, the wind turbine collection line of the corresponding property owner will be forcibly cut off after a delay until the active power of the wind turbine is lower than the set safety value.
[0014] As a preferred embodiment of the present invention, the connection transformer is divided into an onshore connection transformer and an offshore connection transformer.
[0015] As a preferred embodiment of the present invention, when a single failure occurs in the onshore connection transformer, the control strategy of the active power of the wind turbine generator set is:
[0016] Assume that the onshore connecting transformer has N L Taiwan, and N L ≥2; the rated active power of the converter valve side of each onshore connection transformer is P TLe ; The real-time active power on the converter valve side of the nth onshore connection transformer is P TLn2 ; The circuit breaker status on the converter valve side of the nth onshore transformer is D TLn2 = {0,1}, the circuit breaker status of the grid side of the nth onshore transformer is D TLn1 ={0,1}, where 0 represents that the circuit breaker is in the open state, and 1 represents that the circuit breaker is in the closed state;
[0017] Assume that the wind farm has a total of M L The total rated power generation of wind turbines of the mth property unit is P Wme Each property unit passes X m The return fan collector line is connected to the offshore converter station. The real-time active power of the xth return fan collector line of the mth property unit is P Wmx , the status of the circuit breaker of the x-th return fan collector of the m-th property right unit is D Wmx ={0,1}, where 0 represents that the circuit breaker is in the open state, and 1 represents that the circuit breaker is in the closed state;
[0018] Collection D TLn1 and D TLn2 state, when D TLn1 or D TLn2 When the state changes from 1 to 0, it enters the judgment start state;
[0019] When entering the judgment start state, if the real-time active power P TLn2 >KL *P TLe , then the real-time active power of the wind turbine collection line of each property unit in the wind farm before control is recorded, among which the real-time active power of the wind turbine collection line of the mth property unit before control is P WBm , and after a delay of t L Then enter the startup state, where K L Indicates the reliability factor of overload safety and stability control of the onshore connection transformer;
[0020] When entering the startup state, the percentage of active power reduction of the wind turbine is calculated, as shown in the following formula:
[0021]
[0022] Where: P WD％ is the percentage of active power reduction of wind turbines;
[0023] Calculate M in sequence L The total active power limit value of the wind turbines of the mth property unit is calculated as follows:
[0024] P WDm =P WD％ *P WBm ;
[0025] Where: P WDm is the total active power limit of the wind turbines of the mth property right unit;
[0026] The total active power limit of each wind turbine of each property right unit is sent to the corresponding energy management system, requiring the total active power of the wind turbine of the property right unit to be reduced to below its total active power limit. LW Afterwards, it is determined whether the real-time total active power of the wind turbines of each property unit is reduced to below its total active power limit value, and the wind turbine collector circuit breaker of the property unit whose real-time total active power is still greater than its total active power limit value is disconnected.
[0027] As a preferred embodiment of the present invention, the delay t LW After that, the wind power collection line circuit breaker of the property right unit whose real-time total active power is still greater than its total active power limit value is disconnected in the following steps:
[0028] Assuming that the real-time total active power of the wind turbine of the mth property unit is still greater than its total active power limit, the collector circuit breaker of the wind turbine with the smallest power of the property unit is disconnected, that is, min{P Wmx}, at this time, the real-time total active power P of the wind turbine of the property right unit is determined again Wm Is it greater than P WDmIf it is still greater than , continue to disconnect the circuit breaker of the fan collector circuit with the smallest power in the remaining fan collector circuit until P Wm Is it greater than P WDm .
[0029] As a preferred embodiment of the present invention, when a single fault occurs in the offshore connection transformer, the first control strategy of the active power of the wind turbine generator set is:
[0030] Assume that the rated active power of the converter valve side of each offshore connection transformer is P TH1e ; The real-time active power on the converter valve side of the nth offshore connection transformer is P THn1 ; Each offshore transformer connected to the wind turbine side branch has a rated active power of P TH2e ; The real-time active power of the wind turbine side branch of the nth offshore connection transformer is P THn2 ; The rated active power of the second branch of the wind turbine side of each offshore connection transformer is P TH3e ; The real-time active power of the second branch of the wind turbine side of the nth offshore connection transformer is P THn3 ; The status of the circuit breaker on the converter valve side of the nth offshore connection transformer is D TLn1 = {0,1}; the state of the wind turbine branch circuit breaker of the nth offshore transformer is D TLn2 ={0,1}; the status of the second circuit breaker on the wind turbine side of the nth offshore transformer is D TLn3 ={0,1}; 0 represents that the circuit breaker is in the open state, and 1 represents that the circuit breaker is in the closed state;
[0031] Assume that the wind farm has a total of M L The total rated active power of the mth property unit connected to the wind turbine side branch 1 of the nth offshore connection transformer is P Wnm1e The total rated active power of the mth property unit connected to the wind turbine side branch 2 of the nth offshore connection transformer is P Wnm2e Each property unit passes X m The return fan collector line is connected to the offshore converter station. The real-time active power of the xth return fan collector line of the mth property unit is P Wmx , the status of the circuit breaker of the x-th return fan collector of the m-th property right unit is D Wmx ={0,1}, where 0 represents that the circuit breaker is in the open state, and 1 represents that the circuit breaker is in the closed state;
[0032] Collection D THn1 , D THn2 and D THn3 state, if any D THn1 , D THn2 or D THn3When the state changes from 1 to 0, it enters the judgment start state;
[0033] When entering the judgment start state, if the real-time active power P THn1 >K H *P TH1e , then the total real-time active power of the wind turbine collection line of each property unit in the wind farm before control is recorded, among which the total real-time active power of the wind turbine collection line of the mth property unit before control is P WBm , and after a delay of t H Then enter the startup state, where K H Indicates the reliability factor of overload safety and stability control of offshore connection transformer;
[0034] Calculate the percentage of active power reduction of the wind turbine when entering the startup state, as shown in the following formula:
[0035]
[0036] Where: P WD％ Indicates the percentage of active power reduction of wind turbines;
[0037] Calculate M in sequence L The total active power limit value of the wind turbines of the mth property unit is calculated as follows:
[0038] P WDm =P WD％ *P WBm ;
[0039] Where: P WDm is the total active power limit of the wind turbines of the mth property right unit;
[0040] The total active power limit of each wind turbine of each property right unit is sent to the corresponding energy management system, requiring the total active power of the wind turbine of the property right unit to be reduced to below its total active power limit. HW Afterwards, it is determined whether the real-time total active power of the wind turbines of each property unit is reduced to below its total active power limit value, and the wind turbine collector circuit breaker of the property unit whose real-time total active power is still greater than its total active power limit value is disconnected.
[0041] As a preferred embodiment of the present invention, the delay t HW After that, the wind power collection line circuit breaker of the property right unit whose real-time total active power is still greater than its total active power limit value is disconnected in the following steps:
[0042] Assuming that the real-time total active power of the wind turbine of the mth property unit is still greater than its total active power limit, the collector circuit breaker of the wind turbine with the smallest power of the property unit is disconnected, that is, min{P Wmx}, at this time, the real-time total active power P of the wind turbine of the property right unit is determined again Wm Is it greater than P WDm If it is still greater than , continue to disconnect the circuit breaker of the fan collector circuit with the smallest power in the remaining fan collector circuit until P Wm Is it greater than P WDm .
[0043] As a preferred embodiment of the present invention, when a single fault occurs in the offshore connection transformer, the second active power control strategy of the wind turbine generator set is:
[0044] Collection D THn1 , D THn2 and D THn3 state, if any D THn1 , D THn2 or D THn3 When the state changes from 1 to 0, it enters the judgment start state;
[0045] When entering the judgment start state, when the wind turbine side branch of the nth offshore connection transformer has a real-time active power P THn2 >K H *P TH2e Or the real-time active power P of the second branch of the wind turbine side of the nth offshore connection transformer THn3 >K H *P TH3e When the real-time active power before control of each property unit connected to the wind turbine side branch 1 of the nth offshore connection transformer or the real-time active power before control of each property unit connected to the wind turbine side branch 2 of the nth offshore connection transformer is recorded, among which the real-time active power before control of the mth property unit connected to the wind turbine side branch 1 of the nth offshore connection transformer is P WBnm2 The total real-time active power before control of the mth property unit connected to the wind turbine side branch 2 of the nth offshore connection transformer is P WBnm3 , after a delay of t H Then enter the startup state;
[0046] When entering the startup state, calculate the percentage of active power reduction of the wind turbine connected to the wind turbine side branch 1 of the nth offshore connection transformer
[0047] Calculate the percentage of active power reduction of the wind turbine connected to the wind turbine side branch 2 of the nth offshore connection transformer
[0048] Calculate the active power limit of each wind turbine of each property unit connected to the wind turbine side branch 1 of the nth offshore connection transformer, where the active power limit of the wind turbine of the mth property unit of the wind turbine side branch 1 of the nth offshore connection transformer is P WDn2m =P WDn2％ *P WBn2m The active power limit value of the wind turbine set of the wind turbine side branch 1 connected to the nth offshore connection transformer of each property unit is sent to the corresponding energy management system, requiring the property unit to reduce the active power of the wind turbine set of the wind turbine side branch 1 connected to the nth offshore connection transformer to below its active power limit value;
[0049] Calculate the active power limit of each wind turbine of each property unit connected to the wind turbine side branch 2 of the nth offshore connection transformer, where the active power limit of the wind turbine of the mth property unit of the wind turbine side branch 2 of the nth offshore connection transformer is P WDn3m =P WDn3％ *P WBn3m The active power limit value of the wind turbine set of the wind turbine side branch 2 connected to the nth offshore connection transformer of each property unit is sent to the corresponding energy management system, requiring the active power of the wind turbine set of the wind turbine side branch 2 connected to the nth offshore connection transformer of the property unit to be reduced to below its active power limit value;
[0050] After delay t HW After that, it is determined whether the real-time active power of the wind turbines connected to the wind turbine side branch 1 of the nth offshore connection transformer of each property unit is reduced to below its active power limit value, and the wind turbine collector circuit breaker of the wind turbine side branch 1 of the property unit connected to the nth offshore connection transformer whose real-time active power of the wind turbine is still greater than its active power limit value is disconnected;
[0051] After delay t HW Afterwards, determine whether the real-time active power of the wind turbine units on the wind turbine side branch two of the nth offshore connection transformer connected to each property unit is reduced to below its active power limit value, and control the wind turbine collector line circuit breaker of the wind turbine side branch two of the nth offshore connection transformer connected to the property unit whose real-time active power of the wind turbine unit is still greater than its active power limit value to be disconnected.
[0052] On the other hand, the present invention also provides a multi-property sea wind centralized transmission connection transformer control system, including a connection transformer diagnosis module, a wind turbine control module and a wind turbine collection line control module;
[0053] The connecting transformer diagnosis module is used to determine whether a single connecting transformer has a fault and whether the remaining connecting transformers are overloaded after a single fault occurs;
[0054] The wind turbine control module is used to dynamically reduce the active power of the wind turbine according to the overload ratio of the remaining connected transformers;
[0055] The wind turbine collection line control module is used to stop reducing power if the active power of the wind turbine group is reduced to a set safety value within a fixed time. If the active power of the wind turbine group is not reduced to the set safety value, the wind turbine collection line of the corresponding property owner is forcibly cut off after a delay until the active power of the wind turbine group is lower than the set safety value.
[0056] On the other hand, the present invention further provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the method described in any embodiment of the present invention is implemented.
[0057] In yet another aspect, the present invention further provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method described in any embodiment of the present invention.
[0058] The present invention has the following beneficial effects:
[0059] 1. The present invention is suitable for the safe and stable onshore or offshore connection transformer N-1 of multi-property sea wind centralized transmission projects. The strategy is simple and practical, and can effectively ensure the safe and reliable operation of wind farm connection transformers. At the same time, it can maximize the guarantee of the active power transmission of wind power after the onshore or offshore connection transformer N-1, and can ensure the fairness and justice of the active power transmission of each property unit, effectively supporting the development of multi-property sea wind centralized transmission projects. BRIEF DESCRIPTION OF THE DRAWINGS
[0060] Figure 1 is a flow chart of the method of the present invention;
[0061] Figure 2 This is the topology diagram of the large-scale offshore wind power flexible DC transmission system. DETAILED DESCRIPTION
[0062] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0063] It should be understood that the step numbers used in this document are only for convenience of description and are not intended to limit the order in which the steps are executed.
[0064] It should be understood that the terms used in the present specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.
[0065] The terms “include” and “comprising” indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.
[0066] The term "and / or" means and includes any and all possible combinations of one or more of the associated listed items.
[0067] Embodiment 1:
[0068] This embodiment takes a large-scale offshore wind power flexible DC transmission project as an example. The project includes an onshore connection transformer, a flexible DC transmission system, an offshore connection transformer and a wind turbine. The number of onshore connection transformers or offshore connection transformers is greater than or equal to 2. The offshore connection transformer can adopt a two-winding transformer or a three-winding transformer wiring method (except for the converter valve side, there are 1 to 2 AC side windings connected to the wind turbine). The wiring form is shown in Figure 2 , the onshore connection transformer and the offshore connection transformer converter valve side are connected to the same bus section and connected to the converter valve, and the offshore connection transformer wind turbine side is provided with an independent AC bus according to the connection transformer winding, and the AC busbars on the wind turbine sides of different connection transformers are connected through a section circuit breaker. The connection method is determined according to different engineering requirements, and this embodiment only illustrates one connection method;
[0069] See also Figure 1 , a multi-property sea wind centralized transmission connection transformer control method, comprising the following steps:
[0070] Determine whether a single connected transformer has a fault and whether the remaining connected transformers are overloaded after a single fault occurs;
[0071] Dynamically reduce the active power of wind turbines according to the overload ratio of the remaining connected transformers;
[0072] Within a fixed time, if the active power of the wind turbine is reduced to the set safety value, the power reduction will be stopped. If the active power of the wind turbine is not reduced to the set safety value, the wind turbine collection line of the corresponding property owner will be forcibly cut off after a delay until the active power of the wind turbine is lower than the set safety value.
[0073] As a preferred implementation of this embodiment, the connection transformer is divided into an onshore connection transformer and an offshore connection transformer.
[0074] As a preferred implementation of this embodiment, when a single onshore connection transformer fails, the control strategy for the active power of the wind turbine generator set is:
[0075] Assume that the onshore connecting transformer has N L Taiwan, and N L ≥2; the rated active power of the converter valve side of each onshore connection transformer is P TLe ; The real-time active power on the converter valve side of the nth onshore connection transformer is P TLn2 ; The circuit breaker status on the converter valve side of the nth onshore transformer is D TLn2 = {0,1}, the circuit breaker status of the grid side of the nth onshore transformer is D TLn1 ={0,1}, where 0 represents that the circuit breaker is in the open state, and 1 represents that the circuit breaker is in the closed state;
[0076] Assume that the wind farm has a total of M L The total rated power generation of wind turbines of the mth property unit is P Wme Each property unit passes X m The return fan collector line is connected to the offshore converter station. The real-time active power of the xth return fan collector line of the mth property unit is P Wmx , the status of the circuit breaker of the x-th return fan collector of the m-th property right unit is D Wmx ={0,1}, where 0 represents that the circuit breaker is in the open state, and 1 represents that the circuit breaker is in the closed state;
[0077] Collection D TLn1 and D TLn2 state, when D TLn1 or D TLn2 When the state changes from 1 to 0 (or when receiving an external start command, such as the onshore connection transformer protection action, pole protection action signal), it enters the judgment start state;
[0078] When entering the judgment start state, if the real-time active power P TLn2 >K L *P TLe (K L It represents the overload safety and stability control reliability factor of the onshore connection transformer, which is divided into three categories in this embodiment: LⅠ , K LⅡ , K LⅢ, respectively represent the reliability coefficients of the overload safety and stability control of the onshore connection transformer in stages I, II, and III. The corresponding reliability coefficients are selected based on experience to participate in the judgment). The real-time active power of the wind turbine collection line before control of each property unit in the wind farm is recorded. Among them, the real-time active power of the wind turbine collection line before control of the mth property unit is P WBm , and select t according to the reliability coefficient LⅠ ,t LⅡ ,t LⅢ The corresponding delay in the program will enter the startup state after the corresponding delay.
[0079] When entering the startup state, the percentage of active power reduction of the wind turbine is calculated, as shown in the following formula:
[0080]
[0081] Where: P WD％ is the percentage of active power reduction of the wind turbine; only the non-faulty onshore connecting transformers are calculated here, and the formula represents the minimum value of the ratio of the rated active power to the real-time active power of all operating onshore connecting transformers;
[0082] Calculate M in sequence L The total active power limit value of the wind turbines of the mth property unit is calculated as follows:
[0083] P WDm =P WD％ *P WBm ;
[0084] Where: P WDm is the total active power limit of the wind turbines of the mth property right unit;
[0085] The total active power limit value of the wind turbines of each property right unit is sent to the corresponding energy management system, requiring the total active power of the wind turbines of the property right unit to be reduced to below its total active power limit value (at the same time, a locking command is sent to the corresponding AGC (Automatic Generation Control) system). After a delay of t LWⅠ ,t LWⅡ ,t LWⅢ (where t LWⅠ ,t LWⅡ ,t LWⅢ After respectively corresponding to the reliability coefficients of stage I, stage II and stage III of the onshore connection transformer overload safety and stability control, it is determined whether the real-time total active power of the wind turbines of each property unit is reduced to below its total active power limit value, and the wind turbine collector circuit breakers of the property units whose real-time total active power is still greater than their total active power limit value are controlled to be disconnected.
[0086] As a preferred implementation of this embodiment, after the delay t LW After that, the wind power collection line circuit breaker of the property right unit whose real-time total active power is still greater than its total active power limit value is disconnected in the following steps:
[0087] Assuming that the real-time total active power of the wind turbine of the mth property unit is still greater than its total active power limit, the collector circuit breaker of the wind turbine with the smallest power of the property unit is disconnected, that is, min{P Wmx}, at this time, the real-time total active power P of the wind turbine of the property right unit is determined again Wm Is it greater than P WDm If it is still greater than , continue to disconnect the circuit breaker of the fan collector circuit with the smallest power in the remaining fan collector circuit until P Wm Is it greater than P WDm .
[0088] As a preferred implementation of this embodiment, when a single fault occurs in the offshore connection transformer, the first control strategy of the active power of the wind turbine generator set is:
[0089] This embodiment takes the offshore connection transformer as an example with three coils. If the offshore connection transformer is a two-coil transformer, the judgment criterion of one branch can be reduced.
[0090] Assume that the rated active power of the converter valve side of each offshore connection transformer is P TH1e ; The real-time active power on the converter valve side of the nth offshore connection transformer is P THn1 ; Each offshore transformer connected to the wind turbine side branch has a rated active power of P TH2e ; The real-time active power of the wind turbine side branch of the nth offshore connection transformer is P THn2 ; The rated active power of the second branch of the wind turbine side of each offshore connection transformer is P TH3e ; The real-time active power of the second branch of the wind turbine side of the nth offshore connection transformer is P THn3 ; The status of the circuit breaker on the converter valve side of the nth offshore connection transformer is D TLn1 = {0,1}; the state of the wind turbine branch circuit breaker of the nth offshore transformer is D TLn2 ={0,1}; the status of the second circuit breaker on the wind turbine side of the nth offshore transformer is D TLn3 ={0,1}; 0 represents that the circuit breaker is in the open state, and 1 represents that the circuit breaker is in the closed state;
[0091] Assume that the wind farm has a total of M L The total rated active power of the mth property unit connected to the wind turbine side branch 1 of the nth offshore connection transformer is P Wnm1eThe total rated active power of the mth property unit connected to the wind turbine side branch 2 of the nth offshore connection transformer is P Wnm2e Each property unit passes X m The return fan collector line is connected to the offshore converter station. The real-time active power of the xth return fan collector line of the mth property unit is P Wmx , the status of the circuit breaker of the x-th return fan collector of the m-th property right unit is D Wmx ={0,1}, where 0 represents that the circuit breaker is in the open state, and 1 represents that the circuit breaker is in the closed state;
[0092] Collection D THn1 , D THn2 and D THn3 state, if any D THn1 , D THn2 or D THn3 The state changes from 1 to 0 (or when receiving an external start command, such as the onshore connection transformer protection action, the pole protection action signal), then it enters the judgment start state;
[0093] When entering the judgment start state, if the real-time active power P THn1 >K H *P TH1e (K H It represents the overload safety and stability control reliability factor of the offshore connection transformer, which is divided into three categories in this embodiment. HⅠ , K HⅡ , K HⅢ , respectively represent the reliability coefficients of overload safety and stability control of offshore transformers in stages I, II and III. The corresponding reliability coefficients are selected based on experience to participate in the judgment). The total real-time active power of the wind turbine collection line before control of each property unit in the wind farm is recorded. Among them, the total real-time active power of the wind turbine collection line before control of the mth property unit is P WBm , and select t according to the reliability coefficient HⅠ ,t HⅡ ,t HⅢ The corresponding delay in the program will enter the startup state after the corresponding delay.
[0094] Calculate the percentage of active power reduction of the wind turbine when entering the startup state, as shown in the following formula:
[0095]
[0096] Where: P WD％ Indicates the percentage of active power reduction of the wind turbine; only the non-faulty offshore connecting transformers are calculated here, and the formula represents the minimum value of the ratio of the rated active power to the real-time active power of all operating offshore connecting transformers;
[0097] Calculate M in sequence L The total active power limit value of the wind turbines of the mth property unit is calculated as follows:
[0098] P WDm =P WD％ *P WBm ;
[0099] Where: P WDm is the total active power limit of the wind turbines of the mth property right unit;
[0100] The total active power limit value of the wind turbines of each property right unit is sent to the corresponding energy management system (and the locking command is sent to the corresponding AGC (Automatic Generation Control) system), requiring the total active power of the wind turbines of the property right unit to be reduced to below its total active power limit value. After a delay of t HWⅠ ,t HWⅡ ,t HWⅢ After (where t HWⅠ ,t HWⅡ ,t HWⅢ Corresponding to the reliability coefficients of offshore connection variable overload safety and stability control section I, section II, and section III respectively), it is determined whether the real-time total active power of the wind turbines of each property unit is reduced to below its total active power limit value, and the wind turbine collector circuit breaker of the property unit whose real-time total active power is still greater than its total active power limit value is disconnected.
[0101] As a preferred implementation of this embodiment, after the delay t HW After that, the wind power collection line circuit breaker of the property right unit whose real-time total active power is still greater than its total active power limit value is disconnected in the following steps:
[0102] Assuming that the real-time total active power of the wind turbine of the mth property unit is still greater than its total active power limit, the collector circuit breaker of the wind turbine with the smallest power of the property unit is disconnected, that is, min{p Wmx}, at this time, the real-time total active power P of the wind turbine of the property right unit is determined again Wm Is it greater than P WDm If it is still greater than , continue to disconnect the circuit breaker of the fan collector circuit with the smallest power in the remaining fan collector circuit until P Wm Is it greater than P WDm .
[0103] As a preferred implementation of this embodiment, when a single fault occurs in the offshore connection transformer, the second active power control strategy of the wind turbine generator set is:
[0104] Collection DTHn1 , D THn2 and D THn3 state, if any D THn1 , D THn2 or D THn3 When the state changes from 1 to 0, it enters the judgment start state;
[0105] When entering the judgment start state, when the wind turbine side branch of the nth offshore connection transformer has a real-time active power P THn2 >K H *P TH2e Or the real-time active power P of the second branch of the wind turbine side of the nth offshore connection transformer THn3 >K H *P TH3e Time (K H It represents the overload safety and stability control reliability factor of the offshore connection transformer, which is divided into three categories in this embodiment. HⅠ , K HⅡ , K HⅢ , respectively represent the reliability coefficients of overload safety and stability control of offshore connection transformers in stages I, II and III. The corresponding reliability coefficients are selected according to experience to participate in the judgment). The sum of the real-time active power before control of each property unit connected to branch 1 of the wind turbine side of the nth offshore connection transformer or the sum of the real-time active power before control of each property unit connected to branch 2 of the wind turbine side of the nth offshore connection transformer is recorded. Among them, the sum of the real-time active power before control of the mth property unit connected to branch 1 of the wind turbine side of the nth offshore connection transformer is P WBnm2 The total real-time active power before control of the mth property unit connected to the wind turbine side branch 2 of the nth offshore connection transformer is P WBnm3 , and select t according to the reliability coefficient HⅠ ,t HⅡ ,t HⅢ The corresponding delay in the program will enter the startup state after the corresponding delay.
[0106] When entering the startup state, calculate the percentage of active power reduction of the wind turbine connected to the wind turbine side branch 1 of the nth offshore connection transformer (Only calculate P THn2 >K H *P TH2e The wind turbine side branch of the nth offshore connected transformer (1);
[0107] Calculate the percentage of active power reduction of the wind turbine connected to the wind turbine side branch 2 of the nth offshore connection transformer (Only calculate P THn3 >K3*P TH3e The nth offshore connection transformer fan side branch 2);
[0108] Calculate the active power limit value of the wind turbine set of each property unit connected to the wind turbine side branch 1 of the nth offshore connection transformer, where the active power limit value of the wind turbine set of the mth property unit of the wind turbine side branch 1 of the nth offshore connection transformer is O WDn2m =O WDn2％ *P WBn2m The active power limit value of the wind turbine set of the wind turbine side branch 1 connected to the nth offshore connection transformer of each property unit is sent to the corresponding energy management system, requiring the property unit to reduce the active power of the wind turbine set of the wind turbine side branch 1 connected to the nth offshore connection transformer to below its active power limit value;
[0109] Calculate the active power limit of each wind turbine of each property unit connected to the wind turbine side branch 2 of the nth offshore connection transformer, where the active power limit of the wind turbine of the mth property unit of the wind turbine side branch 2 of the nth offshore connection transformer is P WDn3m =P WDn3％ *P WBn3m The active power limit value of the wind turbine set of the wind turbine side branch 2 connected to the nth offshore connection transformer of each property unit is sent to the corresponding energy management system, requiring the active power of the wind turbine set of the wind turbine side branch 2 connected to the nth offshore connection transformer of the property unit to be reduced to below its active power limit value;
[0110] After delay t HWⅠ ,t HWⅡ ,t HWⅢ After (where t HWⅠ ,t HWⅡ ,t HWⅢ Corresponding to the reliability coefficients of the overload safety and stability control of offshore connection transformers in stages I, II and III respectively), it is determined whether the real-time active power of the wind turbines connected to the wind turbine side branch 1 of the nth offshore connection transformer of each property unit is reduced to below its active power limit value, and the wind turbine collector circuit breaker of the wind turbine side branch 1 of the wind turbine side connected to the property unit whose real-time active power of the wind turbines is still greater than its active power limit value is disconnected;
[0111] After delay t HWⅠ ,t HWⅡ ,t HWⅢ After (where t HWⅠ ,t HWⅡ ,t HWⅢCorresponding to the reliability coefficients of the overload safety and stability control of offshore connection transformers in sections I, II and III respectively), it is determined whether the real-time active power of the wind turbine units connected to the wind turbine side branch 2 of the nth offshore connection transformer of each property unit is reduced to below its active power limit value, and the wind turbine collector circuit breaker of the wind turbine side branch 2 of the wind turbine unit connected to the nth offshore connection transformer of the property unit whose real-time active power is still greater than its active power limit value is disconnected;
[0112] In this embodiment, the disconnection logic of the wind turbine collector circuit breaker of branch one and branch two on the wind turbine side of the nth offshore connection transformer connected by the property unit is the same as the first control strategy, and the first control strategy and the second control strategy are respectively suitable for different application scenarios.
[0113] Embodiment 2:
[0114] A multi-property sea wind centralized transmission connection transformer control system, including a connection transformer diagnosis module, a wind turbine control module and a wind turbine collection line control module;
[0115] The connecting transformer diagnosis module is used to determine whether a single connecting transformer has a fault and whether the remaining connecting transformers are overloaded after a single fault occurs;
[0116] The wind turbine control module is used to dynamically reduce the active power of the wind turbine according to the overload ratio of the remaining connected transformers;
[0117] The wind turbine collection line control module is used to stop reducing power if the active power of the wind turbine group is reduced to a set safety value within a fixed time. If the active power of the wind turbine group is not reduced to the set safety value, the wind turbine collection line of the corresponding property owner is forcibly cut off after a delay until the active power of the wind turbine group is lower than the set safety value.
[0118] The system is used to implement the method in Example 1, which will not be described in detail here.
[0119] Embodiment three:
[0120] This embodiment provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the method described in any embodiment of the present invention when executing the program.
[0121] Embodiment 4:
[0122] This embodiment provides a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the method described in any embodiment of the present invention is implemented.
[0123] In the embodiments of the present application, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent the existence of A alone, the existence of A and B at the same time, and the existence of B alone. Among them, A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following" and similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b and c can be represented by: a, b, c, a and b, a and c, b and c, or a and b and c, where a, b, c can be single or multiple.
[0124] Those of ordinary skill in the art will appreciate that the various units and algorithm steps described in the embodiments disclosed herein can be implemented in a combination of electronic hardware, computer software, and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.
[0125] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.
[0126] In several embodiments provided in the present application, if any function is implemented in the form of a software functional unit 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 application, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (Read-Only Memory; hereinafter referred to as: ROM), random access memory (Random Access Memory; hereinafter referred to as: RAM), disk or optical disk, and other media that can store program codes.
[0127] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.
Claims
1. A multi-property sea wind centralized transmission connection transformer control method, characterized in that: The following steps are involved: Determine whether a single connected transformer has a fault and whether the remaining connected transformers are overloaded after a single fault occurs; Dynamically reduce the active power of wind turbines according to the overload ratio of the remaining connected transformers; Within a fixed time, if the active power of the wind turbine is reduced to the set safety value, the power reduction will be stopped. If the active power of the wind turbine is not reduced to the set safety value, the wind turbine collection line of the corresponding property owner will be forcibly cut off after a delay until the active power of the wind turbine is lower than the set safety value.
2. A method for controlling a transformer for centralized transmission of multi-property sea wind according to claim 1, characterized in that: The connection transformer is divided into an onshore connection transformer and an offshore connection transformer.
3. A method for controlling a transformer for centralized transmission of multi-property sea wind according to claim 2, characterized in that: When a single onshore connection transformer fails, the control strategy for the active power of the wind turbine is: Assume that the onshore connecting transformer has N L Taiwan, and N L ≥2; the rated active power of the converter valve side of each onshore connection transformer is P TLe ; The real-time active power on the converter valve side of the nth onshore connection transformer is P TLn2 ; The circuit breaker status on the converter valve side of the nth onshore transformer is D TLn2 = {0,1}, the circuit breaker status of the grid side of the nth onshore transformer is D TLn1 ={0,1}, where 0 represents that the circuit breaker is in the open state, and 1 represents that the circuit breaker is in the closed state; Assume that the wind farm has a total of M L The total rated power generation of wind turbines of the mth property unit is P Wme Each property right unit passes X m The return fan collector line is connected to the offshore converter station. The real-time active power of the xth return fan collector line of the mth property unit is P Wmx , the status of the circuit breaker of the x-th return fan collector of the m-th property right unit is D Wmx ={0,1}, where 0 represents that the circuit breaker is in the open state, and 1 represents that the circuit breaker is in the closed state; Collection D TLn1 and D TLn2 state, when D TLn1 or D TLn2 When the state changes from 1 to 0, it enters the judgment start state; When entering the judgment start state, if the real-time active power P TLn2 >K L *P TLe , then the real-time active power of the wind turbine collection line of each property unit in the wind farm before control is recorded, among which the real-time active power of the wind turbine collection line of the mth property unit before control is P WBm , and after a delay of t L Then enter the startup state, where K L Indicates the reliability factor of overload safety and stability control of the onshore connection transformer; When entering the startup state, the percentage of active power reduction of the wind turbine is calculated, as shown in the following formula: Where: P WD％ is the percentage of active power reduction of wind turbines; Calculate M in sequence L The total active power limit value of the wind turbines of the mth property unit is calculated as follows: P WDm =P WD％ *P WBm ; Where: P WDm is the total active power limit of the wind turbines of the mth property right unit; The total active power limit of each wind turbine of each property right unit is sent to the corresponding energy management system, requiring the total active power of the wind turbine of the property right unit to be reduced to below its total active power limit. LW Afterwards, it is determined whether the real-time total active power of the wind turbines of each property unit is reduced to below its total active power limit value, and the wind turbine collector circuit breaker of the property unit whose real-time total active power is still greater than its total active power limit value is disconnected.
4. A method for controlling a transformer for centralized transmission of multi-property sea wind according to claim 3, characterized in that: The delay t LW After that, the wind power collection line circuit breaker of the property right unit whose real-time total active power is still greater than its total active power limit value is disconnected in the following steps: Assuming that the real-time total active power of the wind turbine of the mth property unit is still greater than its total active power limit, the collector circuit breaker of the wind turbine with the smallest power of the property unit is disconnected, that is, min{P Wmx }, at this time, the real-time total active power P of the wind turbine of the property right unit is determined again Wm Is it greater than P WDm If it is still greater than , continue to disconnect the circuit breaker of the fan collector circuit with the smallest power in the remaining fan collector circuit until P Wm Is it greater than P WDm .
5. A multi-property sea wind centralized transmission connection transformer control method according to claim 2, characterized in that: When a single fault occurs in the offshore connection transformer, the first control strategy of the active power of the wind turbine generator set is: Assume that the rated active power of the converter valve side of each offshore connection transformer is P TH1e ; The real-time active power on the converter valve side of the nth offshore connection transformer is P THn1 ; Each offshore transformer connected to the wind turbine side branch has a rated active power of P TH2e ; The real-time active power of the wind turbine side branch of the nth offshore connection transformer is P THn2 ; The rated active power of the second branch of the wind turbine side of each offshore connection transformer is P TH3e ; The real-time active power of the second branch of the wind turbine side of the nth offshore connection transformer is P THn3 ; The status of the circuit breaker on the converter valve side of the nth offshore connection transformer is D TLn1 = {0,1}; the state of the wind turbine branch circuit breaker of the nth offshore transformer is D TLn2 ={0,1}; the status of the second circuit breaker on the wind turbine side of the nth offshore transformer is D TLn3 ={0,1}; 0 represents that the circuit breaker is in the open state, and 1 represents that the circuit breaker is in the closed state; Assume that the wind farm has a total of M L The total rated active power of the mth property unit connected to the wind turbine side branch 1 of the nth offshore connection transformer is P Wnm1e The total rated active power of the mth property unit connected to the wind turbine side branch 2 of the nth offshore connection transformer is P Wnm2e Each property unit passes X m The return fan collector line is connected to the offshore converter station. The real-time active power of the xth return fan collector line of the mth property unit is P Wmx , the status of the circuit breaker of the x-th return fan collector of the m-th property right unit is D Wmx ={0,1}, where 0 represents that the circuit breaker is in the open state and 1 represents that the circuit breaker is in the closed state; Collection D THn1 , D THn2 and D THn3 state, if any D THn1 , D THn2 or D THn3 When the state changes from 1 to 0, it enters the judgment start state; When entering the judgment start state, if the real-time active power P THn1 >K H *P TH1e , then the total real-time active power of the wind turbine collection line of each property unit in the wind farm before control is recorded, among which the total real-time active power of the wind turbine collection line of the mth property unit before control is P WBm , and after a delay of t H Then enter the startup state, where K H Indicates the reliability factor of overload safety and stability control of offshore connection transformer; Calculate the percentage of active power reduction of the wind turbine when entering the startup state, as shown in the following formula: Where: P WD％ Indicates the percentage of active power reduction of wind turbines; Calculate M in sequence L The total active power limit value of the wind turbines of the mth property unit is calculated as follows: P WDm =P WD％ *P WBm ; Where: P WDm is the total active power limit of the wind turbines of the mth property right unit; The total active power limit of each wind turbine of each property right unit is sent to the corresponding energy management system, requiring the total active power of the wind turbine of the property right unit to be reduced to below its total active power limit. HW Afterwards, it is determined whether the real-time total active power of the wind turbines of each property unit is reduced to below its total active power limit value, and the wind turbine collector circuit breaker of the property unit whose real-time total active power is still greater than its total active power limit value is disconnected.
6. A method for controlling a transformer for centralized transmission of multi-property sea wind according to claim 5, characterized in that: The delay t HW After that, the wind power collection line circuit breaker of the property right unit whose real-time total active power is still greater than its total active power limit value is disconnected in the following steps: Assuming that the real-time total active power of the wind turbine of the mth property unit is still greater than its total active power limit, the collector circuit breaker of the wind turbine with the smallest power of the property unit is disconnected, that is, min{P Wmx }, at this time, the real-time total active power P of the wind turbine of the property right unit is determined again Wm Is it greater than P WDm If it is still greater than , continue to disconnect the circuit breaker of the fan collector circuit with the smallest power in the remaining fan collector circuit until P Wm Is it greater than P WDm .
7. A method for controlling a transformer for centralized transmission of multi-property sea wind according to claim 5, characterized in that: When a single fault occurs in the offshore connection transformer, the second control strategy for the active power of the wind turbine generator set is: Collection D THn1 , D THn2 and D THn3 state, if any D THn1 , D THn2 or D THn3 When the state changes from 1 to 0, it enters the judgment start state; When entering the judgment start state, when the wind turbine side branch of the nth offshore connection transformer has a real-time active power P THn2 >K H *P TH2e Or the real-time active power P of the second branch of the wind turbine side of the nth offshore connection transformer THn3 >K H *P TH3e When the real-time active power before control of each property unit connected to the wind turbine side branch 1 of the nth offshore connection transformer or the real-time active power before control of each property unit connected to the wind turbine side branch 2 of the nth offshore connection transformer is recorded, among which the real-time active power before control of the mth property unit connected to the wind turbine side branch 1 of the nth offshore connection transformer is P WBnm2 The total real-time active power before control of the mth property unit connected to the wind turbine side branch 2 of the nth offshore connection transformer is P WBnm3 , after a delay of t H Then enter the startup state; When entering the startup state, calculate the percentage of active power reduction of the wind turbine connected to the wind turbine side branch 1 of the nth offshore connection transformer Calculate the percentage of active power reduction of the wind turbine connected to the wind turbine side branch 2 of the nth offshore connection transformer Calculate the active power limit of each wind turbine of each property unit connected to the wind turbine side branch 1 of the nth offshore connection transformer, where the active power limit of the wind turbine of the mth property unit of the wind turbine side branch 1 of the nth offshore connection transformer is P WDn2m =P WDn2％ *P WBn2m The active power limit value of the wind turbine set of the wind turbine side branch 1 connected to the nth offshore connection transformer of each property unit is sent to the corresponding energy management system, requiring the property unit to reduce the active power of the wind turbine set of the wind turbine side branch 1 connected to the nth offshore connection transformer to below its active power limit value; Calculate the active power limit of each wind turbine of each property unit connected to the wind turbine side branch 2 of the nth offshore connection transformer, where the active power limit of the wind turbine of the mth property unit of the wind turbine side branch 2 of the nth offshore connection transformer is P WDn3m =P WDn3％ *P WBn3m The active power limit value of the wind turbine set of the wind turbine side branch 2 connected to the nth offshore connection transformer of each property unit is sent to the corresponding energy management system, requiring the active power of the wind turbine set of the wind turbine side branch 2 connected to the nth offshore connection transformer of the property unit to be reduced to below its active power limit value; After delay t HW After that, it is determined whether the real-time active power of the wind turbines connected to the wind turbine side branch 1 of the nth offshore connection transformer of each property unit is reduced to below its active power limit value, and the wind turbine collector circuit breaker of the wind turbine side branch 1 of the property unit connected to the nth offshore connection transformer whose real-time active power of the wind turbine is still greater than its active power limit value is disconnected; After delay t HW Afterwards, determine whether the real-time active power of the wind turbine units on the wind turbine side branch two of the nth offshore connection transformer connected to each property unit is reduced to below its active power limit value, and control the wind turbine collector line circuit breaker of the wind turbine side branch two of the nth offshore connection transformer connected to the property unit whose real-time active power of the wind turbine unit is still greater than its active power limit value to be disconnected.
8. A multi-property sea wind centralized transmission connection transformer control system, characterized in that: It includes a connection transformer diagnosis module, a wind turbine control module and a wind turbine collector line control module; The connecting transformer diagnosis module is used to determine whether a single connecting transformer has a fault and whether the remaining connecting transformers are overloaded after a single fault occurs; The wind turbine control module is used to dynamically reduce the active power of the wind turbine according to the overload ratio of the remaining connected transformers; The wind turbine collection line control module is used to stop reducing power if the active power of the wind turbine group is reduced to a set safety value within a fixed time. If the active power of the wind turbine group is not reduced to the set safety value, the wind turbine collection line of the corresponding property owner is forcibly cut off after a delay until the active power of the wind turbine group is lower than the set safety value.
9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the method according to any one of claims 1 to 7 is implemented.
10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the method according to any one of claims 1 to 7 is implemented.