A wind-solar hybrid fast frequency modulation control method and system

Abstract

The present invention provides a wind-solar complementary fast frequency modulation control method, comprising the following steps: setting a system fast frequency modulation dead zone, and starting an energy storage device when the system frequency enters the fast frequency modulation dead zone; collecting the CT signal and PT signal of the power station to obtain the power station operation parameters including frequency, voltage, and active power; receiving the active power adjustment instruction forwarded by the AGC in real time, and combining the real-time frequency of the power system to perform frequency modulation according to a preset frequency modulation strategy. The present invention can perform high-frequency and high-precision measurement of the power station system operation parameters by adding a high-speed frequency measuring device, and analyze the real-time frequency value of the power system and the future output trend corresponding to the current state in combination with the active power adjustment instruction forwarded by the AGC, and adjust the system frequency. The present invention can enable the wind-solar system to have a frequency response characteristic, effectively and quickly participate in the system frequency modulation, reduce or avoid negative impacts on the system frequency modulation, and avoid sacrificing wind energy utilization and solar energy utilization.

Description

Technical Field

[0001] The present invention relates to the field of power system frequency regulation, and in particular to a wind-solar hybrid fast frequency regulation control method and system. Background Art

[0002] At present, wind energy and solar energy have been effectively applied to the power system as new energy sources, and wind energy and solar energy are complementary in time and region. For example, the sun is strong and the wind is weak during the day, while the wind is stronger at night. In theory, they can provide relatively stable and continuous power output.

[0003] However, in actual applications, wind-solar complementary power generation needs to be improved urgently in supporting the stability of the power system due to its unstable output and great influence from the environment. Summary of the invention

[0004] The purpose of the present invention is to provide a wind-solar hybrid fast frequency modulation control method and system, which adds a high-speed frequency measuring device to measure the operating parameters of the power station system with high frequency and high precision, combines the active power adjustment instructions forwarded by the AGC, analyzes the real-time frequency value of the power system and the future output trend corresponding to the current state, and adjusts the system frequency. The present invention can make the wind-solar system have frequency response characteristics, effectively and quickly participate in system frequency modulation, reduce or avoid negative impacts on system frequency modulation, and avoid sacrificing wind energy utilization and solar energy utilization.

[0005] To achieve the above objectives, combined Figure 1 The present invention proposes a wind-solar hybrid fast frequency modulation control method, the fast frequency modulation control method comprising the following steps:

[0006] S1, set the system fast frequency regulation dead zone, when the system frequency enters the fast frequency regulation dead zone, start the energy storage device;

[0007] S2, collect the CT signal and PT signal of the power station to obtain the power station operation parameters including frequency, voltage and active power;

[0008] S3, receiving the active power adjustment command forwarded by the AGC in real time, combining the real-time frequency of the power system, and adjusting the frequency according to the preset frequency adjustment strategy;

[0009] The preset frequency modulation strategy includes:

[0010] The real-time frequency value of the power system and the future output trend corresponding to the current state are analyzed, and the value of the system frequency and the working state of the energy storage equipment are adjusted according to the active power-frequency characteristic curve function.

[0011] As a preferred example, in step S1, the fast frequency modulation dead zone is ±0.1 Hz.

[0012] As a preferred example, in step S3, the process of analyzing and obtaining the real-time frequency value of the power system and the future output trend corresponding to the current state includes the following steps:

[0013] Combined with the active power adjustment instructions forwarded by the AGC and the external environment change trend, the future output trend and frequency change trend corresponding to the current state are determined.

[0014] As a preferred example, the external environment change trend includes a wind change trend and a solar energy change trend.

[0015] As a preferred example, the active power-frequency characteristic curve function is:

[0016]

[0017] Among them, P0 is the initial value of active power, in MW; P N is the starting capacity, in MW; f N System rated frequency, in Hz; f d System frequency dead zone, in Hz; δ% is the new energy fast frequency response adjustment rate.

[0018] As a preferred example, the method further includes: adjusting the frequency by adopting a segmented frequency modulation method.

[0019] As a preferred example, the value of the frequency of the regulating system and the working state of the energy storage device include the following:

[0020] (1) When the power system frequency is higher than the preset system frequency, has not reached the dead zone, and the future output trend decreases or remains unchanged, no frequency regulation is performed;

[0021] (2) When the power system frequency is higher than the preset system frequency and has not reached the dead zone but the future output trend increases, the control system frequency is maintained below the current frequency value and the additional electric energy is stored in the energy storage device for charging;

[0022] (3) When the power system frequency is higher than the preset system frequency and reaches the dead zone, all electric energy is controlled to be stored in the energy storage device;

[0023] (4) When the power system frequency is lower than the preset system frequency, has not reached the dead zone, and the future output trend increases or remains unchanged, no frequency regulation is performed;

[0024] (5) When the power system frequency is lower than the preset system frequency and has not reached the dead zone but the future output trend is decreasing, the control system frequency is maintained above the current frequency value and shows an upward trend;

[0025] (6) When the power system frequency is lower than the preset system frequency and reaches the dead zone, the control system frequency is maintained at the maximum frequency and the energy storage device is switched to a discharge state.

[0026] As a preferred example, the preset system frequency is 50 Hz.

[0027] Based on the above method, the present invention also mentions a wind-solar hybrid fast frequency modulation control system, which includes an integrated intelligent terminal, a fast frequency response system, a high-speed frequency measurement device and an energy storage device;

[0028] The high-speed frequency measuring device is connected to the power station CT and PT, collects the power station CT signal and PT signal, obtains the power station operation parameters including frequency, voltage and active power, and sends them to the fast frequency response system;

[0029] The fast frequency response system includes a setting unit for setting a fast frequency modulation dead zone of the system;

[0030] The fast frequency response system is connected to the integrated intelligent terminal and the energy storage device respectively, receives the active power adjustment instruction forwarded by the AGC in real time, and performs frequency adjustment according to the preset frequency adjustment strategy in combination with the real-time frequency of the power system;

[0031] The preset frequency modulation strategy includes:

[0032] The real-time frequency value of the power system and the future output trend corresponding to the current state are analyzed, and the value of the system frequency and the working state of the energy storage equipment are adjusted according to the active power-frequency characteristic curve function.

[0033] Compared with the prior art, the technical solution of the present invention has the following significant beneficial effects:

[0034] (1) By adding a high-speed frequency measuring device, the power station system operating parameters can be measured at high frequency and high precision to achieve fast and precise frequency regulation.

[0035] (2) The present invention enables the wind-solar system to have frequency response characteristics, effectively and quickly participate in system frequency modulation, and reduce or avoid negative impacts on system frequency modulation.

[0036] (3) Enable the power system to stabilize power output and avoid sacrificing wind and solar energy utilization.

[0037] (4) Comprehensively consider the frequency regulation strategy from the perspectives of current frequency value and future output trend to achieve more accurate and timely frequency regulation.

[0038] It should be understood that all combinations of the aforementioned concepts and the additional concepts described in more detail below can be considered as part of the inventive subject matter of the present disclosure as long as such concepts are not mutually inconsistent. In addition, all combinations of the claimed subject matter are considered as part of the inventive subject matter of the present disclosure.

[0039] The foregoing and other aspects, embodiments and features of the present invention can be more fully understood from the following description in conjunction with the accompanying drawings. Other additional aspects of the present invention, such as the features and / or beneficial effects of the exemplary embodiments, will be apparent from the following description or learned from the practice of the specific embodiments according to the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component shown in various figures may be represented by the same reference numeral. For clarity, not every component is labeled in every figure. Embodiments of various aspects of the present invention will now be described by way of example and with reference to the accompanying drawings, in which:

[0041] Figure 1 It is a flow chart of the wind-solar hybrid fast frequency modulation control method of the present invention.

[0042] Figure 2 It is a schematic diagram of the active power-frequency droop characteristics of the new energy of the present invention. DETAILED DESCRIPTION

[0043] In order to better understand the technical content of the present invention, specific embodiments are given and described as follows in conjunction with the accompanying drawings.

[0044] Various aspects of the present invention are described in this disclosure with reference to the accompanying drawings, in which many illustrative embodiments are shown. The embodiments of the present disclosure are not necessarily defined to include all aspects of the present invention. It should be understood that the various concepts and embodiments introduced above, as well as those described in more detail below, can be implemented in any of many ways, because the concepts and embodiments disclosed by the present invention are not limited to any implementation. In addition, some aspects disclosed by the present invention can be used alone, or in any appropriate combination with other aspects disclosed by the present invention.

[0045] Combination Figure 1 The present invention proposes a wind-solar hybrid fast frequency modulation control method, the fast frequency modulation control method comprising the following steps:

[0046] S1, set the system fast frequency regulation dead zone, when the system frequency enters the fast frequency regulation dead zone, start the energy storage device.

[0047] S2, collects the CT signal and PT signal of the power station to obtain the power station operation parameters including frequency, voltage and active power.

[0048] S3, receiving the active power adjustment command forwarded by the AGC in real time, combining the real-time frequency of the power system, and adjusting the frequency according to the preset frequency adjustment strategy.

[0049] The preset frequency modulation strategy includes:

[0050] The real-time frequency value of the power system and the future output trend corresponding to the current state are analyzed, and the value of the system frequency and the working state of the energy storage equipment are adjusted according to the active power-frequency characteristic curve function.

[0051] The present invention first adds a high-speed frequency measuring device to measure the operating parameters of the power station system at a high frequency and with high precision to obtain the data basis for rapid frequency modulation. The higher the acquisition frequency, the higher the precision, and the better the final frequency modulation efficiency. The system rapid frequency modulation dead zone corresponds to the precision of the frequency modulation result. The smaller the dead zone range, the higher the precision, and the more stable the final system frequency. By setting the rapid frequency modulation dead zone, the controllable setting of the system frequency stability is achieved.

[0052] On this basis, the active power adjustment instructions forwarded by the AGC are received in real time, the current active power is identified, and the future output trend and frequency change trend corresponding to the current state are judged according to the active power adjustment instructions forwarded by the AGC and the trend of changes in the external environment. The frequency adjustment strategy is comprehensively considered from the two perspectives of the current frequency value and the future output trend to achieve more accurate and more timely frequency adjustment, thereby reducing or avoiding negative impacts on the system frequency regulation.

[0053] The external environment change trends here include wind power change trends and solar energy change trends, which correspond to the output trends of two new energy sources, wind power and photovoltaic power, respectively. The wind power change trends and solar energy change trends can be obtained from external systems (such as meteorological systems), or they can be measured and analyzed in combination with historical data.

[0054] Figure 2 This is a schematic diagram of the active power-frequency droop characteristics of new energy. Figure 2 It can be seen that the active power-frequency characteristic curve function is:

[0055]

[0056] Among them, P0 is the initial value of active power, in MW; P N is the starting capacity, in MW; f N System rated frequency, in Hz; f d System frequency dead zone, in Hz; δ% is the new energy fast frequency response adjustment rate.

[0057] As a preferred example, the preset system frequency is assumed to be 50 Hz, and the fast frequency modulation dead zone is ±0.1 Hz.

[0058] The value of the frequency of the regulating system and the working state of the energy storage device include the following:

[0059] (1) When the power system frequency is higher than 50 Hz, has not reached the dead zone, and the future output trend is decreasing or unchanged, no frequency regulation is performed.

[0060] (2) When the power system frequency is higher than 50 Hz and has not reached the dead zone but the future output trend is increasing, the control system frequency is maintained below the current frequency value and the extra electric energy is stored in the energy storage device for charging.

[0061] (3) When the power system frequency is higher than 50 Hz and reaches the dead zone, all electrical energy is controlled to be stored in the energy storage device.

[0062] (4) When the power system frequency is lower than 50 Hz, has not reached the dead zone, and the future output trend is increasing or unchanged, no frequency regulation is performed.

[0063] (5) When the power system frequency is lower than 50 Hz and has not reached the dead zone but the future output trend is decreasing, the control system frequency is maintained above the current frequency value and shows an upward trend.

[0064] (6) When the power system frequency is lower than 50 Hz and reaches the dead zone, the control system frequency is maintained at the maximum frequency and the energy storage device is switched to the discharge state.

[0065] Preferably, segmented frequency modulation is used to control the entire system so as to finely control the output.

[0066] Based on the aforementioned method, the present invention also mentions a wind-solar complementary fast frequency modulation control system, which includes an integrated intelligent terminal, a fast frequency response system, a high-speed frequency measurement device and an energy storage device.

[0067] The high-speed frequency measuring device is connected to the power station CT and PT, collects the power station CT signal and PT signal, obtains the power station operation parameters including frequency, voltage, and active power, and sends them to the fast frequency response system.

[0068] The fast frequency response system includes a setting unit for setting a fast frequency modulation dead zone of the system.

[0069] The fast frequency response system is connected to the integrated intelligent terminal and the energy storage device respectively, receives the active power adjustment instruction forwarded by the AGC in real time, and performs frequency adjustment according to the preset frequency adjustment strategy in combination with the real-time frequency of the power system.

[0070] The preset frequency modulation strategy includes:

[0071] The real-time frequency value of the power system and the future output trend corresponding to the current state are analyzed, and the value of the system frequency and the working state of the energy storage equipment are adjusted according to the active power-frequency characteristic curve function.

[0072] The present invention uses the aforementioned control method and control system to enable the wind-solar hybrid system to have the ability to modulate the system frequency, and achieves rapid frequency modulation through a high-speed frequency measuring device and an energy storage system, thereby improving the stability of the power system.

[0073] Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. A person with ordinary knowledge in the technical field to which the present invention belongs may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be determined by the definition of the claims.

Claims

1. A wind-solar hybrid fast frequency modulation control method, characterized in that: The fast frequency modulation control method comprises the following steps: S1, set the system fast frequency regulation dead zone, when the system frequency enters the fast frequency regulation dead zone, start the energy storage device; S2, collect the CT signal and PT signal of the power station to obtain the power station operation parameters including frequency, voltage and active power; S3, receiving the active power adjustment command forwarded by the AGC in real time, combining the real-time frequency of the power system, and adjusting the frequency according to the preset frequency adjustment strategy; The preset frequency modulation strategy includes: Analyze and obtain the future output trend corresponding to the real-time frequency value of the power system and the current state, and adjust the value of the system frequency and the working state of the energy storage device according to the active power-frequency characteristic curve function; the process of analyzing and obtaining the future output trend corresponding to the real-time frequency value of the power system and the current state includes the following steps: combining the active power adjustment instruction forwarded by the AGC and the external environment change trend, judging the future output trend and frequency change trend corresponding to the current state; The value of the frequency of the regulating system and the working state of the energy storage device include the following: (1) When the power system frequency is higher than the preset system frequency, has not reached the dead zone, and the future output trend decreases or remains unchanged, no frequency regulation is performed; (2) When the power system frequency is higher than the preset system frequency and has not reached the dead zone but the future output trend increases, the control system frequency is maintained below the current frequency value and the additional electric energy is stored in the energy storage device for charging; (3) When the power system frequency is higher than the preset system frequency and reaches the dead zone, all electric energy is controlled to be stored in the energy storage device; (4) When the power system frequency is lower than the preset system frequency, has not reached the dead zone, and the future output trend increases or remains unchanged, no frequency regulation is performed; (5) When the power system frequency is lower than the preset system frequency and has not reached the dead zone but the future output trend is decreasing, the control system frequency is maintained above the current frequency value and shows an upward trend; (6) When the power system frequency is lower than the preset system frequency and reaches the dead zone, the control system frequency is maintained at the maximum frequency and the energy storage device is switched to a discharge state.

2. The wind-solar hybrid fast frequency modulation control method according to claim 1, characterized in that: In step S1, the fast frequency modulation dead zone is ±0.1 Hz.

3. The wind-solar hybrid fast frequency modulation control method according to claim 1, characterized in that: The external environment change trend includes the wind change trend and the solar energy change trend.

4. The wind-solar hybrid fast frequency modulation control method according to claim 1, characterized in that: The active power-frequency characteristic curve function is: Among them, P0 is the initial value of active power, in MW; P N is the starting capacity, in MW; f N System rated frequency, in Hz; f d System frequency dead zone, in Hz; δ% is the new energy fast frequency response adjustment rate.

5. The wind-solar hybrid fast frequency modulation control method according to claim 1, characterized in that: The preset system frequency is 50 Hz.

6. The wind-solar hybrid fast frequency modulation control method according to claim 1, characterized in that: The method further comprises: adjusting the frequency by adopting a segmented frequency modulation method.

7. A wind-solar hybrid fast frequency modulation control system, using any wind-solar hybrid fast frequency modulation control method according to any one of claims 1 to 6, characterized in that: The fast frequency modulation control system includes an integrated intelligent terminal, a fast frequency response system, a high-speed frequency measurement device and an energy storage device; The high-speed frequency measuring device is connected to the power station CT and PT, collects the power station CT signal and PT signal, obtains the power station operation parameters including frequency, voltage and active power, and sends them to the fast frequency response system; The fast frequency response system includes a setting unit for setting a fast frequency modulation dead zone of the system; The fast frequency response system is connected to the integrated intelligent terminal and the energy storage device respectively, receives the active power adjustment instruction forwarded by the AGC in real time, and performs frequency adjustment according to the preset frequency adjustment strategy in combination with the real-time frequency of the power system; The preset frequency modulation strategy includes: The real-time frequency value of the power system and the future output trend corresponding to the current state are analyzed, and the value of the system frequency and the working state of the energy storage equipment are adjusted according to the active power-frequency characteristic curve function.

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