Offshore wind power generation output optimization connection system and use method

Abstract

The invention discloses an offshore wind power generation output optimization connection system and method. The invention relates to the technical field of offshore wind power generation. The rectifier modules are respectively connected with the windings through different transformer modules; the rectifiers are connected through different phasors; the rectifier module comprises four rectifiers, and the rectifiers are connected through different phasors A-B-C, A-C-B and B-C-A to realize balance and stability of three-phase power; the transformer module adjusts the voltage through different transformation ratios; the transformer module comprises a plurality of transformers (WGamp; ), the transformation ratio comprises 1: 1 and 1.73: 1; different transformation ratios can realize graded adjustment of the voltage, so that sudden change of the voltage is avoided; the rectifier modules are connected with the windings through different transformer modules, the rectifiers are connected through different phasors (A-B-C, A-C-B and B-C-A), and balance and stability of three-phase power are achieved. According to the design, voltage fluctuation caused by phase imbalance is avoided, and the stability of power output is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of offshore wind power generation, in particular to an optimization technology of an electrical connection system of offshore wind power generation, and in particular to an offshore wind power generation output optimization connection system and method. Background Art

[0002] As an emerging form of power generation, the technical background of offshore wind power generation mainly revolves around how to efficiently and stably transmit the electricity generated at sea to the onshore power grid. Traditionally, the grid access technology of offshore wind farms mainly relies on AC access technology and DC access technology, among which AC access technology is more common. In AC access technology, the AC power generated by offshore wind turbines is transmitted to the AC busbar of the AC assembly system of the offshore wind farm. After assembly, it is boosted by a transformer and connected to the onshore main power grid by an AC submarine cable. This connection method has the advantages of simple system structure and low cost, so it has been widely used in the early construction of offshore wind farms.

[0003] Wind energy is an unstable energy source that is greatly affected by wind speed. The output of offshore wind turbines varies with wind speed, and this instability can cause fluctuations in grid voltage. When the wind speed suddenly increases, the output of the wind turbine will also suddenly increase, which may cause a sudden increase in grid voltage (increase in voltage); conversely, when the wind speed suddenly decreases, the voltage may suddenly decrease (decrease in voltage). At the same time, there are large charging capacitors in AC submarine cables. When the cables transmit electrical energy, these capacitors will emit reactive power, causing the outlet voltage of the wind farm to become higher. If effective reactive power compensation measures are not taken in time, a sudden increase in voltage may occur.

[0004] Sudden changes in voltage can have a serious impact on the safe and stable operation of the power grid. Excessive voltage may damage the insulation of power grid equipment and even cause safety accidents such as fires; while too low voltage may cause power grid equipment to malfunction and even cause accidents such as power outages.

[0005] To this end, an offshore wind power generation output optimization connection system and method are proposed. Summary of the invention

[0006] In view of this, the embodiment of the present invention hopes to provide an offshore wind power generation output optimization connection system and method to solve or alleviate the technical problems existing in the prior art, that is, how to avoid sudden pressure increase or pressure decrease, and at least provide a beneficial option for this; the technical solution of the present invention is implemented as follows:

[0007] In the first aspect, an offshore wind power generation output optimization connection system is provided:

[0008] (1) Rectifier module, connected through different transformer modules and windings; each rectifier is connected through different phase quantities; the rectifier module includes four rectifiers, each rectifier is connected through different phase quantities ABC, ACB and BCA to achieve balance and stability of three-phase electricity;

[0009] (2) The transformer module adjusts the voltage through different transformation ratios. The transformer module includes multiple transformers (WG&) connected to the rectifier, and the transformation ratios include 1:1 and 1.73:1. Different transformation ratios can achieve graded voltage regulation, thereby avoiding sudden voltage changes.

[0010] (3) A phase adjustment module for ensuring the output three-phase voltage balance and avoiding voltage fluctuation of a certain phase. The phase relationship and phase adjustment relationship controlled by the phase adjustment module include:

[0011] (3.1) The phase relationship of the first rectifier group (Rectfier#1) is ABC, and the phase adjustment relationship is 1:1 and 1.73:1;

[0012] (3.2) The phase relationship ABC of the second rectifier group (Rectfier#2), the phase adjustment relationship is 1:1 and 1.73:1; wherein 1 and 1.73:1 are an additional or alternative adjustment relationship;

[0013] (3.3) The phase relationship of the third rectifier (Rectfier#3) is BCA, and the phase adjustment relationship is 1.73:1;

[0014] (3.4) The phase relationship of the fourth rectifier (Rectfier#4) is ACB, and the phase adjustment relationship is 1.73:1.

[0015] (4) Capacitor bank, including:

[0016] (4.1) Capacitor at the input end (at the power line): used to filter out high-frequency noise and harmonics in the power supply, providing purer power to the inverter and other equipment.

[0017] (4.2) DC bus capacitors (DC link of inverter): used to smooth the DC voltage, store energy and keep the output voltage stable when the AC input voltage fluctuates. These capacitors ensure that the inverter can provide a stable DC voltage to the inverter bridge.

[0018] Capacitors at the output (on the motor connection line): Used to filter out high-frequency harmonic currents that may be generated by the inverter, which may interfere with the normal operation of the motor or generate additional heat.

[0019] (5) The output of all rectifiers is aggregated to the load. The load is synchronously regulated by a 12-phase SC. The use of SC can ensure the stability and synchronization of the output, thereby avoiding sudden changes in voltage.

[0020] (6) Under normal circumstances, the phase relationship is generally selected as abc: suitable for sea areas with stable wind and small wind direction changes. This phase relationship is simple and stable, suitable for operation in an environment with relatively constant wind conditions. At the same time, the deformation mode of the phase relationship is based on the characteristics of different sea areas, and the deformation includes the following types:

[0021] (6.1) bac: Applicable to sea areas where wind speed and direction change frequently but the change amplitude is not large. By adjusting the phase sequence, it can better adapt to small changes in wind direction and reduce the fluctuation of power output caused by wind direction changes;

[0022] (6.2) cab: Applicable to sea areas where wind force and direction vary dramatically and there is a clear wind direction preference; this phase relationship may help improve power output efficiency under certain specific wind direction conditions;

[0023] (6.3) acb: Applicable to sea areas where wind force and direction vary in a complex manner and require a more flexible phase relationship to adapt; by adjusting the phase relationship, it can better adapt to changing wind conditions and improve the stability and efficiency of the system;

[0024] (6.4) Phase difference adjustment (such as abc, but with a small phase difference between each phase): Applicable to sea areas where wind direction changes slowly but the phase relationship needs to be fine-tuned to improve the quality of power output; by adjusting the phase difference, the waveform of power output can be optimized and harmonics and voltage fluctuations can be reduced;

[0025] (6.5) Phase interleaving (abc, bac are used alternately): It is suitable for sea areas where wind speed and direction change irregularly and are difficult to predict. Through phase interleaving, the phase relationship can be switched under different wind conditions to find the optimal power output solution;

[0026] (6.6) Composite phase relationship (composite of abc and bca): Applicable to sea areas with complex wind force and direction changes and multiple wind direction preferences. Through the composite phase relationship, it can better adapt to the changing wind conditions and improve the adaptability and stability of the system.

[0027] In general, the system contains four rectifiers, each connected through different phase quantities (ABC, ACB, BCA). This design allows the three-phase power to remain balanced and stable during the rectification process, avoiding voltage fluctuations caused by phase imbalance. Different phase quantity connection methods provide the system with higher flexibility and adaptability, allowing the system to adjust the phase relationship according to changes in wind conditions, thereby maintaining the stability of power output.

[0028] The transformer module adjusts the voltage through different ratios (1:1 and 1.73:1). This hierarchical regulation mechanism enables the system to adjust the voltage level according to actual needs and avoids sudden changes in voltage. When wind conditions change, the system can adapt to the new power output requirements by adjusting the transformer ratio, thereby maintaining voltage stability.

[0029] At the same time, the phase adjustment module is used to ensure the balance of the output three-phase voltage and avoid voltage fluctuations in one phase. By accurately controlling the phase relationship, the system can further optimize the power output and reduce voltage fluctuations and harmonics. Different phase adjustment relationships (such as 1:1 and 1.73:1) provide the system with additional adjustment means, allowing the system to maintain voltage stability over a wider range.

[0030] The output of all rectifiers is aggregated to the load and synchronized by 12-phase synchronous condensers. The use of condensers ensures the stability and synchronization of the output and avoids sudden voltage changes caused by load changes. Synchronous condensers can respond to load changes in real time and adjust power output, thereby maintaining voltage stability and efficient power transmission.

[0031] At the same time, the system provides a variety of phase relationship deformation modes to adapt to wind conditions in different sea areas. By adjusting the phase relationship, the system can better adapt to wind changes and reduce fluctuations in power output; different phase relationship deformation modes (such as bac, cab, etc.) provide the system with higher flexibility and adaptability, allowing the system to maintain stable power output under various wind conditions.

[0032] In the second aspect, a method for using an offshore wind power generation output optimization connection system

[0033] S1, rectifier module configuration: according to the initial wind conditions and sea characteristics, select the corresponding rectifier phase relationship, generally selected as abc;

[0034] S2. Transformer module setting: The transformer module includes multiple transformers connected to the rectifier, and the ratios include 1:1 and 1.73:1; according to the power output requirements, the transformer ratio is initially set to ensure that the voltage level meets the system requirements.

[0035] S3, capacitor bank configuration: ensure that the capacitors at the input, DC bus, and output are correctly connected to filter out high-frequency noise and harmonics, smooth the DC voltage, and protect the motor from harmonic current interference;

[0036] S4, Synchronous condenser settings: The outputs of all rectifiers are aggregated to the load and synchronously adjusted through the 12-phase synchronous condensers; the condensers are initialized to ensure that they can respond to load changes in real time, adjust power output, and maintain voltage stability;

[0037] S5. Adjust the phase relationship of the rectifier according to the change of wind conditions in the sea area;

[0038] If the wind force and direction change frequently but not much, you can choose the bac phase relationship; if the wind force and direction change violently and there is an obvious wind direction preference, you can choose the cab phase relationship, etc. By adjusting the phase relationship, you can optimize the power output and reduce voltage fluctuations.

[0039] S6. Transformer ratio adjustment: When wind conditions change, adjust the transformer ratio according to power output requirements; if you need to increase the voltage level, select a ratio of 1.73:1; if you need to keep the voltage stable, select a ratio of 1:1; avoid voltage mutations through a graded adjustment mechanism to ensure stable system operation.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] 1. Balancing and stabilizing effect of rectifier modules: The rectifier modules are connected through different transformer modules and windings, and each rectifier is connected through different phase quantities (ABC, ACB, BCA), achieving balance and stability of three-phase electricity. This design avoids voltage fluctuations caused by phase imbalance and ensures the stability of power output.

[0042] 2. Voltage grading regulation of transformer module: The transformer module adjusts the voltage through different transformation ratios (1:1 and 1.73:1), realizing voltage grading regulation. This mechanism avoids sudden changes in voltage and enables the system to adjust the voltage level according to actual power demand, thereby maintaining voltage stability.

[0043] 3. Precise control of the phase adjustment module: The phase adjustment module ensures the balance of the output three-phase voltage and avoids the fluctuation of a certain phase voltage. By accurately controlling the phase relationship, the system can further optimize the power output and reduce voltage fluctuations and harmonics. Different phase adjustment relationships (such as 1:1 and 1.73:1) provide the system with additional adjustment means, allowing the system to maintain voltage stability over a wider range.

[0044] 4. Flexible adaptation of multiple phase relationships: The system provides multiple phase relationship deformation modes to adapt to wind conditions in different sea areas:

[0045] (1) abc: suitable for sea areas with stable wind force and small wind direction changes, simple and stable;

[0046] (2) bac: suitable for sea areas where wind force and direction change frequently but the change amplitude is not large, and better adapts to small changes in wind direction;

[0047] (3) Cab: Applicable to sea areas where wind speed and direction change dramatically and there is a clear wind direction preference, to improve power output efficiency;

[0048] (4) acb: Applicable to sea areas where wind speed and direction change in a complex manner and require flexible phase relationships to adapt, improving system stability and efficiency;

[0049] (5) Phase difference adjustment: Applicable to sea areas where wind speed and direction change slowly but the phase relationship needs to be fine-tuned to improve the quality of power output and optimize the power output waveform;

[0050] (6) Phase interleaving: Applicable to sea areas where wind speed and direction change irregularly and are difficult to predict. Phase interleaving is used to switch to the optimal solution.

[0051] (7) Composite phase relationship: Applicable to sea areas where wind speed and direction vary complexly and there are multiple wind direction preferences, improving system adaptability and stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or technical descriptions will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0053] Figure 1 It is a schematic diagram of the system composition of the present invention;

[0054] Figure 2 for Figure 1 Schematic diagram after removing the identification lines;

[0055] Figure 3 It is a schematic diagram of the method for using the system of the present invention. DETAILED DESCRIPTION

[0056] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below;

[0057] It should be noted that the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same or similar parts between the various embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part description.

[0058] Embodiment 1: Figures 1-2 As shown, this embodiment discloses an offshore wind power generation output optimization connection system:

[0059] (1) Rectifier module, connected through different transformer modules and windings; each rectifier is connected through different phase quantities; the rectifier module includes four rectifiers, each rectifier is connected through different phase quantities ABC, ACB and BCA to achieve balance and stability of three-phase electricity;

[0060] It can be understood that this design allows the system to maintain stability and efficiency of power output under different wind conditions by adjusting the phase connection of the rectifier.

[0061] (2) The transformer module adjusts the voltage through different transformation ratios. The transformer module includes multiple transformers (WG&) connected to the rectifier, and the transformation ratios include 1:1 and 1.73:1. Different transformation ratios can achieve graded voltage regulation, thereby avoiding sudden voltage changes.

[0062] It can be understood that different transformation ratios can achieve graded voltage regulation, thereby avoiding sudden voltage changes and ensuring the stability and adaptability of power output.

[0063] (3) A phase adjustment module for ensuring the output three-phase voltage balance and avoiding voltage fluctuation of a certain phase. The phase relationship and phase adjustment relationship controlled by the phase adjustment module include:

[0064] (3.1) The phase relationship of the first rectifier group (Rectfier#1) is ABC, and the phase adjustment relationship is 1:1 and 1.73:1;

[0065] (3.2) The phase relationship ABC of the second rectifier group (Rectfier#2), the phase adjustment relationship is 1:1 and 1.73:1; wherein 1 and 1.73:1 are an additional or alternative adjustment relationship;

[0066] (3.3) The phase relationship of the third rectifier (Rectfier#3) is BCA, and the phase adjustment relationship is 1.73:1;

[0067] (3.4) The phase relationship of the fourth rectifier (Rectfier#4) is ACB, and the phase adjustment relationship is 1.73:1.

[0068] (4) Capacitor bank, including:

[0069] (4.1) Capacitor at the input end (at the power line): used to filter out high-frequency noise and harmonics in the power supply, providing purer power to the inverter and other equipment.

[0070] (4.2) DC bus capacitors (DC link of inverter): used to smooth the DC voltage, store energy and keep the output voltage stable when the AC input voltage fluctuates. These capacitors ensure that the inverter can provide a stable DC voltage to the inverter bridge.

[0071] It can be understood that the selection and adjustment of this phase relationship helps the system to better adapt to wind conditions in different sea areas.

[0072] Capacitors at the output (on the motor connection line): Used to filter out high-frequency harmonic currents that may be generated by the inverter, which may interfere with the normal operation of the motor or generate additional heat.

[0073] (5) The output of all rectifiers is aggregated to the load. The load is synchronously regulated by a 12-phase SC. The use of SC can ensure the stability and synchronization of the output, thereby avoiding sudden changes in voltage.

[0074] (6) Under normal circumstances, the phase relationship is generally selected as abc: suitable for sea areas with stable wind and small wind direction changes. This phase relationship is simple and stable, suitable for operation in an environment with relatively constant wind conditions. At the same time, the deformation mode of the phase relationship is based on the characteristics of different sea areas, and the deformation includes the following types:

[0075] (6.1) bac: Applicable to sea areas where wind speed and direction change frequently but the change amplitude is not large. By adjusting the phase sequence, it can better adapt to small changes in wind direction and reduce the fluctuation of power output caused by wind direction changes;

[0076] (6.2) cab: Applicable to sea areas where wind force and direction vary dramatically and there is a clear wind direction preference; this phase relationship may help improve power output efficiency under certain specific wind direction conditions;

[0077] (6.3) acb: Applicable to sea areas where wind force and direction vary in a complex manner and require a more flexible phase relationship to adapt; by adjusting the phase relationship, it can better adapt to changing wind conditions and improve the stability and efficiency of the system;

[0078] (6.4) Phase difference adjustment (such as abc, but with a small phase difference between each phase): Applicable to sea areas where wind direction changes slowly but the phase relationship needs to be fine-tuned to improve the quality of power output; by adjusting the phase difference, the waveform of power output can be optimized and harmonics and voltage fluctuations can be reduced;

[0079] (6.5) Phase interleaving (abc, bac are used alternately): It is suitable for sea areas where wind speed and direction change irregularly and are difficult to predict. Through phase interleaving, the phase relationship can be switched under different wind conditions to find the optimal power output solution;

[0080] (6.6) Composite phase relationship (composite of abc and bca): Applicable to sea areas with complex wind force and direction changes and multiple wind direction preferences. Through the composite phase relationship, it can better adapt to the changing wind conditions and improve the adaptability and stability of the system.

[0081] Embodiment 2: Figure 3 As shown, this embodiment further discloses a method for using the connection system based on the first embodiment, including the following steps:

[0082] S1, rectifier module configuration: according to the initial wind conditions and sea characteristics, select the corresponding rectifier phase relationship, generally selected as abc;

[0083] S2. Transformer module setting: The transformer module includes multiple transformers connected to the rectifier, and the ratios include 1:1 and 1.73:1; according to the power output requirements, the transformer ratio is initially set to ensure that the voltage level meets the system requirements.

[0084] S3, capacitor bank configuration: ensure that the capacitors at the input, DC bus, and output are correctly connected to filter out high-frequency noise and harmonics, smooth the DC voltage, and protect the motor from harmonic current interference;

[0085] S4, Synchronous condenser settings: The outputs of all rectifiers are aggregated to the load and synchronously adjusted through the 12-phase synchronous condensers; the condensers are initialized to ensure that they can respond to load changes in real time, adjust power output, and maintain voltage stability;

[0086] S5. Adjust the phase relationship of the rectifier according to the change of wind conditions in the sea area;

[0087] If the wind force and direction change frequently but not much, you can choose the bac phase relationship; if the wind force and direction change violently and there is an obvious wind direction preference, you can choose the cab phase relationship, etc. By adjusting the phase relationship, you can optimize the power output and reduce voltage fluctuations.

[0088] S6. Transformer ratio adjustment: When wind conditions change, adjust the transformer ratio according to power output requirements; if you need to increase the voltage level, select a ratio of 1.73:1; if you need to keep the voltage stable, select a ratio of 1:1; avoid voltage mutations through a graded adjustment mechanism to ensure stable system operation.

[0089] For those skilled in the art, it can be further appreciated that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in the above description according to function. 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 the present invention.

[0090] The above embodiments only express the implementation methods of the relevant practical applications of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. An offshore wind power generation output optimization connection system, characterized in that: include: The rectifier modules are connected through different transformer modules and windings respectively; each rectifier is connected through different phase quantities; The transformer module adjusts the voltage through different transformation ratios; Phase adjustment module used to ensure the output three-phase voltage balance and avoid voltage fluctuation of one phase; The outputs of all rectifiers are summed to the load.

2. The connection system according to claim 1, characterized in that: The rectifier module includes four rectifiers, each of which is connected through different phase quantities ABC, ACB and BCA to achieve balance and stability of three-phase electricity.

3. The connection system according to claim 2, characterized in that: The transformer module includes a plurality of transformers connected to the rectifier, and the transformation ratios include 1:1 and 1.73:

1.

4. The connection system according to any one of claims 1 to 3, characterized in that: The phase relationship and phase adjustment relationship controlled by the phase adjustment module include: The phase relationship ABC of the first group of rectifiers, the phase adjustment relationship 1:1 and 1.73:1; The phase relationship ABC of the second group of rectifiers, the phase adjustment relationship 1:1 and 1.73:1; The phase relationship BCA of the third group of rectifiers, the phase adjustment relationship is 1.73:1; The phase relationship of the fourth group of rectifiers is ACB, and the phase adjustment relationship is 1.73:

1.

5. The connection system according to claim 4, characterized in that: In the phase adjustment relationship of the second group of rectifiers, the 1 and the 1.73:1 are an additional or alternative adjustment relationship.

6. The connection system according to claims 1 to 3, characterized in that: The deformation modes of the phase relationship include: abc, bac, cab, acb, phase difference adjustment, and phase interleaving.

7. The connection system according to claim 6, characterized in that: The deformation mode of the phase relationship also includes a complex phase relationship.

8. The connection system according to claim 1, characterized in that: The load is synchronously regulated by a 12-phase phase modulator.

9. A method for using the connection system according to claims 1 to 8, characterized in that: S1, rectifier module configuration; S2. Initially set the transformer ratio according to the power output requirements; S3, filter out high-frequency noise and harmonics, smooth the DC voltage, and protect the motor from harmonic current interference; S4: The outputs of all rectifiers are aggregated to the load and regulated synchronously by the 12-phase synchronous condensers; the condensers are initialized, the power output is adjusted, and the voltage is kept stable; S5. Adjust the phase relationship of the rectifier according to the change of wind conditions in the sea area; S6. Transformer ratio adjustment: When wind conditions change, adjust the transformer ratio according to power output requirements.

10. The method of use according to claim 9, characterized in that: In S6, if the voltage level needs to be increased, a transformation ratio of 1.73:1 is selected; if the voltage needs to be kept stable, a transformation ratio of 1:1 is selected.

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