Main power source type new energy station cluster control and damping oscillation system and control method thereof

Abstract

The application provides a main power supply type new energy station cluster control and damping oscillation system and a control method thereof, and comprises the following steps: S1, identifying grid-connected inverter grid frequency and voltage variation amplitude, and based on the identified grid-connected inverter grid frequency and voltage variation amplitude, actively performing primary frequency regulation and actively supporting grid-connected point voltage by a grid-connected power generation unit; S2, on the basis of active primary frequency regulation of the grid-connected power generation unit, dynamically selecting an adjustment step size according to a difference between target power and actual power; and S3, on the basis of active support of the grid-connected power generation unit on the grid-connected point voltage, dynamically selecting a voltage adjustment step size according to a difference between target reactive power and actual reactive power.

Description

Technical Field

[0001] This invention relates to the field of grid-connected inverter technology, specifically to a main power source type new energy power plant cluster control and damping oscillation system and its control method. Background Technology

[0002] With the transformation of the energy structure, renewable energy power plants, characterized by their cleanliness and renewability, have become an important part of the power system, mainly including wind farms and photovoltaic power plants. In the event of a grid emergency, renewable energy power plants must not only quickly adjust their active power to respond to frequency changes, but also be able to provide reactive power to the maximum extent to maintain voltage stability.

[0003] Traditional renewable energy power plants typically use grid-connected inverters and converters. Since grid-connected technology does not have the ability to actively support grid frequency and voltage, traditional energy management systems can only adjust power and voltage according to the active and reactive power commands issued by the dispatch center. They cannot cooperate with the inverters and have poor ability to suppress grid frequency and voltage fluctuations.

[0004] The inverters and converters used in main power generation renewable energy power plants are generally grid-connected technologies that actively support grid frequency and voltage. The system proposed in this invention can coordinate with grid-connected inverters and converters to actively support grid frequency and voltage while dynamically absorbing active and reactive power tasks allocated by the grid, thus ensuring the stability of grid frequency and voltage. It also supports the complete grid mode parameter distribution and display functions of the inverter, and can effectively suppress or attenuate oscillations through parameter adjustment.

[0005] Patent document CN119231560A (application number: 202310796472.1) discloses a new energy power generation cluster and its oscillation suppression method and apparatus. The oscillation suppression method includes: determining whether the overall oscillation of the transmission aggregation point of the new energy power generation cluster meets a preset oscillation condition based on the electrical quantity of the transmission aggregation point; in response to meeting the preset oscillation condition, determining the active power compensation value of each new energy generator unit based on the equivalent electrical distance of each new energy generator unit in the new energy power generation cluster from the transmission aggregation point and the current active power value; distributing the respective active power compensation value to each new energy generator unit to control each new energy generator unit to achieve optimal damping compensation for single-unit active power output; wherein, the transmission aggregation point is connected to the AC side of a nearby flexible DC transmission device, and the DC side of the flexible DC transmission device is used to transmit flexible DC power. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the purpose of this invention is to provide a main power source type new energy power station cluster control and damping oscillation system and its control method.

[0007] A control method for a main power source type new energy power station cluster control and damping oscillation system provided by the present invention includes:

[0008] Step S1: Identify the grid frequency and voltage variation amplitude of the grid inverter, and based on the identified grid frequency and voltage variation amplitude of the grid inverter, actively perform primary frequency regulation and actively support the grid connection point voltage through the grid generation unit;

[0009] Step S2: Based on the active primary frequency regulation of the grid-connected power generation unit, dynamically select the adjustment step size according to the difference between the target power and the actual power;

[0010] Step S3: Based on the active support of the grid connection point voltage by the grid-connected power generation unit, dynamically select the voltage adjustment step size according to the difference between the target reactive power and the actual reactive power.

[0011] Preferably, step S2 includes:

[0012] When the difference between the target power and the actual power approaches zero, the proportional gain tends to the minimum proportional gain. The adjustment step size decreases; when the difference between the target power and the actual power approaches the maximum allowable difference... At this time, the proportionality coefficient tends to the maximum proportionality coefficient. Adjust the stride to become larger.

[0013] Preferably, ;

[0014] in, Indicates the minimum proportionality coefficient; Indicates the maximum proportionality coefficient; This represents the absolute value of the current power difference; Indicates the maximum permissible difference;

[0015] The adjustment instructions include:

[0016]

[0017] Where, when the target power > the actual power, >0, then >0 indicates according to Increase the proportion;

[0018] When the target power is less than the actual power <0, then <0 indicates according to Reduce proportionally.

[0019] Preferably, step S3 includes:

[0020] When the target reactive power is greater than the actual reactive power, the step size is dynamically adjusted by increasing the ratio.

[0021] When the target reactive power is less than the actual reactive power, the dynamic adjustment step size is reduced by the proportional adjustment step size.

[0022] When the difference between the target reactive power and the actual reactive power approaches 0, the proportional gain approaches the minimum proportional gain. The adjustment step size decreases; when the difference between the target reactive power and the actual reactive power approaches the maximum allowable difference... At this time, the proportionality coefficient tends to the maximum proportionality coefficient. Adjust the stride length to increase;

[0023] ;

[0024] in, Indicates the minimum proportionality coefficient; Indicates the maximum proportionality coefficient; This represents the absolute value of the current power difference; Indicates the maximum permissible difference;

[0025] The adjustment instructions include:

[0026]

[0027] Where, when the target power > the actual power, >0, then >0 indicates according to Increase the proportion;

[0028] When the target power is less than the actual power <0, then <0 indicates according to Reduce proportionally.

[0029] Preferably, the control method further includes: suppressing or attenuating the oscillation phenomenon by adjusting the parameters of the grid-connected inverter;

[0030] Initialize the parameters of the grid-type inverter to enable it to suppress oscillations.

[0031] When the grid-connected inverter experiences oscillation, the parameters of the current grid-connected inverter are adjusted so that the grid frequency and voltage can be regulated based on active oscillation damping, thereby restoring the grid frequency and voltage to a stable state.

[0032] According to the present invention, a main power source type new energy power station cluster control and damping oscillation system is provided, comprising:

[0033] Module M1: Identifies the grid frequency and voltage variation amplitude of the grid inverter, and actively performs primary frequency regulation and actively supports the grid connection point voltage through the grid generation unit based on the identified grid frequency and voltage variation amplitude of the grid inverter.

[0034] Module M2: Based on the active primary frequency regulation of the grid-connected power generation unit, the adjustment step is dynamically selected according to the difference between the target power and the actual power.

[0035] Module M3: Based on the active support of the grid connection point voltage by the grid-connected power generation unit, the voltage adjustment step is dynamically selected according to the difference between the target reactive power and the actual reactive power.

[0036] Preferably, the module M2 includes:

[0037] When the difference between the target power and the actual power approaches zero, the proportional gain tends to the minimum proportional gain. The adjustment step size decreases; when the difference approaches the maximum allowable difference... At this time, the proportionality coefficient tends to the maximum proportionality coefficient. Adjust the stride to become larger.

[0038] Preferably,

[0039] ;

[0040] in, Indicates the minimum proportionality coefficient; Indicates the maximum proportionality coefficient; This represents the absolute value of the current power difference; Indicates the maximum permissible difference;

[0041] The adjustment instructions include:

[0042]

[0043] Where, when the target power > the actual power, >0, then >0 indicates according to Increase the proportion;

[0044] When the target power is less than the actual power <0, then <0 indicates according to Reduce proportionally.

[0045] Preferably, the module M3 includes:

[0046] When the target reactive power is greater than the actual reactive power, the step size is dynamically adjusted by increasing the ratio.

[0047] When the target reactive power is less than the actual reactive power, the dynamic adjustment step size is reduced by the proportional adjustment step size.

[0048] When the difference between the target reactive power and the actual reactive power approaches 0, the proportional gain approaches the minimum proportional gain. The adjustment step size decreases; when the difference between the target reactive power and the actual reactive power approaches the maximum allowable difference... At this time, the proportionality coefficient tends to the maximum proportionality coefficient. Adjust the stride length to increase;

[0049] ;

[0050] in, Indicates the minimum proportionality coefficient; Indicates the maximum proportionality coefficient; This represents the absolute value of the current power difference; Indicates the maximum permissible difference;

[0051] The adjustment instructions include:

[0052]

[0053] Where, when the target power > the actual power, >0, then >0 indicates according to Increase the proportion;

[0054] When the target power is less than the actual power <0, then <0 indicates according to Reduce proportionally.

[0055] Preferably, the system further includes: suppressing or attenuating the oscillation phenomenon by adjusting the parameters of the grid-connected inverter;

[0056] Initialize the parameters of the grid-type inverter to enable it to suppress oscillations.

[0057] When the grid-connected inverter experiences oscillation, the parameters of the current grid-connected inverter are adjusted so that the grid frequency and voltage can be regulated based on active oscillation damping, thereby restoring the grid frequency and voltage to a stable state.

[0058] Compared with the prior art, the present invention has the following beneficial effects:

[0059] 1. This invention solves the problem that the power generation of main power source type new energy power plants depends on natural conditions, and the output of the power plants has strong randomness and uncontrollability, which leads to fluctuations in grid frequency and grid voltage.

[0060] 2. The present invention suppresses fluctuations in grid frequency and grid voltage in two steps. First, the grid inverter actively identifies the magnitude of grid frequency and voltage changes and actively generates active and reactive power for rapid primary support. Then, the main power source type new energy power plant cluster control and damping oscillation system will, according to the active and reactive power regulation target values ​​given by the dispatch, perform a secondary allocation of active and reactive power of the inverter / converter after the inverter has autonomously responded, and perform dynamic fine control until the regulation is in place.

[0061] 3. This invention includes methods for adjusting grid frequency and voltage. One method is to dynamically fine-tune the angle of reactive power target value based on the autonomous response of the grid-connected inverter / converter. The other method is to support the complete grid-connected mode parameter distribution and display function of the inverter, which can effectively suppress or attenuate the oscillation phenomenon through parameter adjustment.

[0062] 4. This invention solves the problem of periodic attenuation fluctuations in voltage or frequency caused by insufficient system damping or control parameter mismatch when new energy power generation equipment (such as wind turbines, photovoltaic inverters, energy storage converters, etc.) interacts with the power grid, by adopting a damped oscillation control method applicable to main power source type new energy power plants.

[0063] 5. This invention relates to the system architecture and control method of the energy management system for main power source type new energy power plants, including cluster active power coordination control, cluster reactive voltage control and damped oscillation control functions. Attached Figure Description

[0064] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0065] Figure 1 This is a schematic diagram of the control and damping oscillation system for a main power source type new energy power station cluster.

[0066] Figure 2 Flowchart of the control method for the main power source type new energy power station cluster control and damped oscillation system. Detailed Implementation

[0067] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0068] Example 1

[0069] According to the present invention, a main power source type new energy power station cluster control and damping oscillation system is provided, such as Figure 1 As shown, it includes:

[0070] Cluster active power coordination control: It can coordinate the active power distribution of new energy power generation unit clusters. Based on the active primary frequency regulation of grid-connected power generation units, it selects a proportional increase or proportional decrease control strategy according to the difference between the target power and the actual power. During the adjustment process, it dynamically selects the adjustment step size according to the size of the difference between the target power and the actual power. The principle is that the smaller the difference, the smaller the step size, so as to ensure that the over-generation or under-generation is not achieved while adjusting quickly and accurately to the target.

[0071] When the actual power is lower than the target power (target power - actual power > 0), it indicates that the output of the power generation unit is insufficient, and power needs to be increased to meet the demand. When the actual power is higher than the target power (target power - actual power < 0), it indicates that the output of the power generation unit is too high, and output needs to be reduced to avoid over-generation.

[0072] Target power > Actual power: Select proportional increase (increase output);

[0073] Target power < actual power: Select proportional reduction (reduce output);

[0074] Based on the difference between the target power and the actual power:

[0075] ΔP=Pref Pact

[0076] Where Pref represents the target power and Pact represents the actual power.

[0077] Specific calculation formula:

[0078] Dynamic adjustment of control gain (proportional coefficient adjustment)

[0079] ;

[0080] Where: Kp,min: minimum proportional coefficient (used when the difference is very small); Kp,max: maximum proportional coefficient (used when the difference is very large); ΔPmax: maximum allowable difference (sets the maximum deviation range); |ΔP|: the absolute value of the current power difference;

[0081] When the difference |ΔP| approaches 0, the proportional coefficient approaches Kp,min, and the adjustment step size becomes smaller;

[0082] When the difference reaches its maximum value ΔPmax, the proportional coefficient tends to Kp,max, and the adjustment step size becomes larger;

[0083] Adjustment command (output change)

[0084]

[0085] If ΔP>0 (target is greater than actual), then ΔPcontrol>0 indicates that a proportional increase (increase in output) is needed.

[0086] If ΔP < 0 (the target is less than the actual value), then ΔPcontrol < 0 indicates that the output needs to be reduced proportionally.

[0087] Fast response: Large step size can quickly reduce deviation, but may cause oscillation or overshoot;

[0088] Smooth adjustment: Small steps can avoid over-adjustment and ensure system stability, but the response may be slower;

[0089] This embodiment dynamically adjusts the step size by the difference value, achieving the effect of "fast adjustment and slow convergence", balancing response speed and system stability.

[0090] Cluster reactive power coordination control: This system can coordinate the reactive power distribution of new energy power generation unit clusters. Based on the active support of grid-connected voltage by the grid-connected power generation unit, it selects a proportional increase or proportional decrease control strategy according to the difference between the target power and the actual power. During the adjustment process, the voltage adjustment step is dynamically selected according to the size of the difference between the target reactive power and the actual reactive power. The principle is that the smaller the difference, the smaller the step, so as to quickly and accurately adjust to the position while ensuring that there is no over-generation or under-generation.

[0091] Real-time data acquisition and monitoring: The system collects operational data from each power generation unit in real time to ensure that the operation status of the new energy power station is monitorable and traceable.

[0092] Oscillation Damping Function: The software supports comprehensive grid mode parameter distribution and display functions, enabling effective suppression or attenuation of oscillation phenomena through parameter adjustment. Specifically, when oscillation occurs in the grid-connected inverter, the parameters of the current inverter are adjusted to allow it to regulate the grid frequency and voltage based on active oscillation damping, thereby restoring the grid frequency and voltage to a stable state.

[0093] The autonomous frequency and voltage support capability of the grid-type inverter is controlled by the internal algorithm of the inverter. All input parameters involved in the algorithm can be remotely monitored and adjusted by the main power source type new energy power station cluster control and damping oscillation system when oscillation occurs in the power station, thereby quickly suppressing the oscillation.

[0094] Equipment start / stop control: The start and stop of group control equipment.

[0095] Data recording and querying: Supports historical data querying.

[0096] Energy storage control: Supports active and reactive power control of energy storage systems.

[0097] Energy storage data monitoring: Supports monitoring of energy storage system data.

[0098] According to the present invention, a control method for a main power source type new energy power station cluster control and damped oscillation system is provided, such as... Figure 2 As shown, it includes:

[0099] The program starts, initializes the last execution time, and checks whether the time interval is greater than 1 second. If it is greater than 1 second, it updates the last execution time and obtains all field data, including the active and reactive power setpoints, matrix status, and other data, and calculates various power and statistical information for the entire field.

[0100] The target active power is calculated based on the active power control mode (remote / local) and the set value. The proportional increase or proportional decrease control strategy is selected based on the relationship between the target power and the actual power.

[0101] The target reactive power is calculated based on the reactive power control mode (remote / local) and the set value, and reactive power is distributed within the control dead zone.

[0102] The calculated active and reactive power commands are sent to each array, and the system statistics are updated. The program ends.

[0103] Those skilled in the art will understand that, in addition to implementing the system, apparatus, and their modules provided by this invention in purely computer-readable program code, the same program can be implemented in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers by logically programming the method steps. Therefore, the system, apparatus, and their modules provided by this invention can be considered a hardware component, and the modules included therein for implementing various programs can also be considered structures within the hardware component; alternatively, modules for implementing various functions can be considered both software programs implementing the method and structures within the hardware component.

[0104] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A control method for a main power source type new energy power station cluster control and damped oscillation system, characterized in that, include: Step S1: Identify the grid frequency and voltage variation amplitude of the grid inverter, and based on the identified grid frequency and voltage variation amplitude of the grid inverter, actively perform primary frequency regulation and actively support the grid connection point voltage through the grid generation unit; Step S2: Based on the active primary frequency regulation of the grid-connected power generation unit, dynamically select the frequency adjustment step size according to the difference between the target power and the actual power; Step S3: Based on the active support of the grid connection point voltage by the grid-connected power generation unit, dynamically select the voltage adjustment step size according to the difference between the target reactive power and the actual reactive power; Step S2 includes: When the target power is greater than the actual power, the proportional increase dynamic adjustment step size is selected; When the target power is less than the actual power, select the proportional minus the dynamic adjustment step size; When the difference between the target power and the actual power approaches zero, the proportional gain tends to the minimum proportional gain. The adjustment step size decreases; when the difference between the target power and the actual power approaches the maximum allowable difference... At this time, the proportionality coefficient tends to the maximum proportionality coefficient. Adjust the stride length to be larger; in, Indicates the minimum proportionality coefficient; Indicates the maximum proportionality coefficient; This represents the absolute value of the current power difference; Indicates the maximum permissible difference; The adjustment instructions include: Where, when the target power > the actual power, >0, then >0 indicates according to Increase the proportion; When the target power is less than the actual power <0, then <0 indicates according to Reduce proportionally; Step S3 includes: When the target reactive power is greater than the actual reactive power, the step size is dynamically adjusted by increasing the ratio. When the target reactive power is less than the actual reactive power, the dynamic adjustment step size is reduced by the proportional adjustment step size. When the difference between the target reactive power and the actual reactive power approaches 0, the proportional gain approaches the minimum proportional gain. The adjustment step size decreases; when the difference between the target reactive power and the actual reactive power approaches the maximum allowable difference... At this time, the proportionality coefficient tends to the maximum proportionality coefficient. Adjust the stride length to be larger; ； in, Indicates the minimum proportionality coefficient; Indicates the maximum proportionality coefficient; This represents the absolute value of the current power difference; Indicates the maximum permissible difference; The adjustment instructions include: Where, when the target power > the actual power, >0, then >0 indicates according to Increase the proportion; When the target power is less than the actual power <0, then <0 indicates according to Reduce proportionally; The control method further includes: suppressing or attenuating the oscillation phenomenon by adjusting the parameters of the grid-type inverter; Initialize the parameters of the grid-type inverter to enable it to suppress oscillations. When the grid-connected inverter experiences oscillation, the parameters of the current grid-connected inverter are adjusted so that the grid frequency and voltage can be regulated based on active oscillation damping, thereby restoring the grid frequency and voltage to a stable state.

2. A main power source type new energy power station cluster control and damping oscillation system, characterized in that, include: Module M1: Identifies the grid frequency and voltage variation amplitude of the grid inverter, and actively performs primary frequency regulation and actively supports the grid connection point voltage through the grid generation unit based on the identified grid frequency and voltage variation amplitude of the grid inverter. Module M2: Based on the active primary frequency regulation of the grid-connected power generation unit, the adjustment step is dynamically selected according to the difference between the target power and the actual power. Module M3: Based on the active support of the grid connection point voltage by the grid-connected power generation unit, the voltage adjustment step is dynamically selected according to the difference between the target reactive power and the actual reactive power. The module M2 includes: When the target power is greater than the actual power, the proportional increase dynamic adjustment step size is selected; When the target power is less than the actual power, select the proportional minus the dynamic adjustment step size; When the difference between the target power and the actual power approaches zero, the proportional gain tends to the minimum proportional gain. The adjustment step size decreases; when the difference between the target power and the actual power approaches the maximum allowable difference... At this time, the proportionality coefficient tends to the maximum proportionality coefficient. Adjust the stride length to be larger; ； in, Indicates the minimum proportionality coefficient; Indicates the maximum proportionality coefficient; This represents the absolute value of the current power difference; Indicates the maximum permissible difference; The adjustment instructions include: Where, when the target power > the actual power, >0, then >0 indicates according to Increase the proportion; When the target power is less than the actual power <0, then <0 indicates according to Reduce proportionally; The module M3 includes: When the target reactive power is greater than the actual reactive power, the step size is dynamically adjusted by increasing the ratio. When the target reactive power is less than the actual reactive power, the dynamic adjustment step size is reduced by the proportional adjustment step size. When the difference between the target reactive power and the actual reactive power approaches 0, the proportional gain approaches the minimum proportional gain. The adjustment step size decreases; when the difference between the target reactive power and the actual reactive power approaches the maximum allowable difference... At this time, the proportionality coefficient tends to the maximum proportionality coefficient. Adjust the stride length to be larger; ； in, Indicates the minimum proportionality coefficient; Indicates the maximum proportionality coefficient; This represents the absolute value of the current power difference; Indicates the maximum permissible difference; The adjustment instructions include: Where, when the target power > the actual power, >0, then >0 indicates according to Increase the proportion; When the target power is less than the actual power <0, then <0 indicates according to Reduce proportionally; The system also includes: suppressing or attenuating the oscillation phenomenon by adjusting the parameters of the grid-type inverter; Initialize the parameters of the grid-type inverter to enable it to suppress oscillations. When the grid-connected inverter experiences oscillation, the parameters of the current grid-connected inverter are adjusted so that the grid frequency and voltage can be regulated based on active oscillation damping, thereby restoring the grid frequency and voltage to a stable state.

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