Primary frequency modulation method for hybrid energy storage thermal power generating unit based on flywheel energy storage

Abstract

The application provides a primary frequency modulation method of a hybrid energy storage thermal power generating unit based on a flywheel energy storage device, and the method comprises the following steps: calculating a target power increment required for primary frequency modulation of the thermal power generating unit according to a frequency value of a power grid bus; collecting a real-time rotating speed of the flywheel energy storage device, and calculating a maximum power increment that can be output by the flywheel energy storage device in real time according to the real-time rotating speed; calculating a maximum power increment that can be output by a lithium battery energy storage device in real time according to a rated power value and a real-time power value of the lithium battery energy storage device; and dynamically allocating the power increments provided by the flywheel energy storage device, the lithium battery energy storage device and the generating unit in the primary frequency modulation in combination with the actual power regulation capabilities of the flywheel energy storage device and the lithium battery energy storage device and the rotating speed of the generator. The method involves the energy storage resources in the automatic power generation control of the generator unit, improves the frequency modulation effect and increases the frequency modulation response speed.

Description

Primary frequency regulation method for hybrid energy storage thermal power generating units based on flywheel energy storage Technical Field

[0001] This invention relates to the field of power system technology, and in particular to a primary frequency regulation method for a hybrid energy storage thermal power generator unit based on flywheel energy storage. Background Technology

[0002] With the continuous increase in electricity demand, the rational management of equipment such as thermal power generating units in the power system has become increasingly important. In the power grid, users' electricity demand needs to be matched with the electrical energy generated by the generating units; when an imbalance occurs, adjustments to the generating units are necessary. The main adjustment methods include primary frequency regulation and secondary frequency regulation.

[0003] In related technologies, primary frequency regulation of thermal power generating units typically relies on the unit's inherent frequency regulation function for automatic power generation control. For example, generator units with pure hydraulic speed regulation systems adjust the unit's valves according to oil pressure signals to regulate the unit's output. However, the above-mentioned frequency regulation method, based solely on the unit's automatic power generation control mode, may fail to meet the power increment required for primary frequency regulation in certain situations, resulting in poor frequency regulation performance, failure to achieve the expected frequency regulation effect, and slow frequency regulation response speed. Summary of the Invention

[0004] The present invention aims to at least partially solve one of the technical problems in the related art.

[0005] Therefore, the first objective of this invention is to propose a primary frequency regulation method for a hybrid energy storage thermal power generator unit based on flywheel energy storage.

[0006] The second objective of this invention is to propose a primary frequency regulation system for a hybrid energy storage thermal power generator unit based on flywheel energy storage.

[0007] A third objective of this invention is to provide a non-transitory computer-readable storage medium.

[0008] To achieve the above objectives, a first aspect of the present invention proposes a primary frequency regulation method for a hybrid energy storage thermal power generator unit based on flywheel energy storage, comprising:

[0009] Collect the frequency value of the power grid bus, and calculate the target power increment ΔP required for primary frequency regulation of the thermal power generating unit based on the frequency value;

[0010] The real-time rotational speed of the flywheel energy storage device is collected, and the maximum power increment ΔP that the flywheel energy storage device can output in real time is calculated based on the real-time rotational speed. F ;

[0011] The state of charge (SOC), rated power, and real-time power of the lithium battery energy storage device are collected. Based on the rated power and real-time power, the maximum power increment ΔP that the lithium battery energy storage device can output in real time is calculated. B ;

[0012] Based on the actual power regulation capabilities of the flywheel energy storage device and the lithium battery energy storage device, as well as the generator speed, the power increment provided by the flywheel energy storage device, the lithium battery energy storage device, and the generator set in the primary frequency regulation is dynamically allocated.

[0013] Optionally, in one embodiment of the present invention, the dynamic allocation of the power increment provided by the flywheel energy storage device, the lithium battery energy storage device, and the generator set in the primary frequency regulation includes:

[0014] If the target power increment ΔP is greater than zero, the real-time rotational speed is greater than the minimum rotational speed but less than the maximum rotational speed, and the state of charge is greater than 0.2 and less than 0.8, then the target power increment ΔP and the real-time rotational speed are determined. F and the ΔP B The relationship between them

[0015] If the ΔP F If the value is greater than ΔP, the turbine control valve and power of the unit are kept constant, and the flywheel energy storage device provides the target power increment ΔP required for the primary frequency regulation.

[0016] If the ΔP is greater than the ΔP F And the ΔP F With the ΔP B If the sum of the values ​​is greater than ΔP, then the flywheel energy storage device is subjected to virtual droop control and inertial control, and the lithium battery energy storage device supplements the power deficit.

[0017] Optionally, in one embodiment of the present invention, the dynamic allocation of the power increment provided by the flywheel energy storage device, the lithium battery energy storage device, and the generator set in the primary frequency regulation includes:

[0018] If the target power increment ΔP is greater than zero, the real-time rotational speed is greater than the minimum rotational speed, and the state of charge is greater than 0.8, then determine the target power increment ΔP and the ΔP... F The relationship between them

[0019] If the ΔP F If the value is greater than ΔP, the turbine control valve and power of the unit are kept constant, and the flywheel energy storage device provides the target power increment ΔP required for the primary frequency regulation.

[0020] If the ΔP is greater than the ΔPF And the ΔP F If the value is greater than zero, then the flywheel energy storage device is subjected to virtual droop control and inertial control, and the unit provides the deficit power.

[0021] Optionally, in one embodiment of the present invention, the dynamic allocation of the power increment provided by the flywheel energy storage device, the lithium battery energy storage device, and the generator set in the primary frequency regulation includes:

[0022] If the target power increment ΔP is greater than zero, the real-time rotational speed is equal to the minimum rotational speed, and the state of charge is greater than 0.2 and less than 0.8, then determine the target power increment ΔP and the ΔP... B The relationship between them

[0023] If the ΔP B If the value is greater than ΔP, the turbine control valve and power of the unit are kept constant, and the target power increment ΔP required for the primary frequency regulation is provided by the lithium battery energy storage device.

[0024] If the ΔP is greater than the ΔP B And the ΔP B If the value is greater than zero, the unit will provide the shortfall power.

[0025] Optionally, in one embodiment of the present invention, the dynamic allocation of the power increment provided by the flywheel energy storage device, the lithium battery energy storage device, and the generator set in the primary frequency regulation includes:

[0026] If the target power increment ΔP is less than zero, the real-time rotational speed is less than the maximum rotational speed, and the state of charge is greater than 0.2 and less than 0.8, then the target power increment ΔP and the ΔP are determined. F and the ΔP B The relationship between them

[0027] If the ΔP F If the absolute value of ΔP is greater than the absolute value of ΔP, and the absolute value of ΔP is greater than zero, then the turbine control valve and power of the unit are kept constant, and the flywheel energy storage device provides the target power increment ΔP required for the primary frequency regulation.

[0028] If the absolute value of ΔP is greater than ΔP F The absolute value of ΔP F The absolute value of is greater than zero, and the ΔP F The absolute value of ΔP B If the sum of the absolute values ​​of the values ​​is greater than the absolute value of ΔP, then the flywheel energy storage device is subjected to virtual droop control and inertial control, and the lithium battery energy storage device supplements the power deficit.

[0029] Optionally, in one embodiment of the present invention, the dynamic allocation of the power increment provided by the flywheel energy storage device, the lithium battery energy storage device, and the generator set in the primary frequency regulation includes:

[0030] If the target power increment ΔP is less than zero, the real-time rotational speed is less than the maximum rotational speed, and the state of charge is greater than 0.8, then determine the target power increment ΔP and the ΔP... F The relationship between them

[0031] If the ΔP F If the absolute value of ΔP is greater than the absolute value of ΔP, and the absolute value of ΔP is greater than zero, then the turbine control valve and power of the unit are kept constant, and the flywheel energy storage device provides the target power increment ΔP required for the primary frequency regulation.

[0032] If the absolute value of ΔP is greater than ΔP F The absolute value of ΔP, and the ΔP F If the absolute value is greater than zero, then the flywheel energy storage device is subjected to virtual droop control and inertial control, and the unit supplements the power deficit.

[0033] Optionally, in one embodiment of the present invention, the dynamic allocation of the power increment provided by the flywheel energy storage device, the lithium battery energy storage device, and the generator set in the primary frequency regulation includes:

[0034] The target power increment ΔP is greater than zero, the real-time rotational speed is greater than the minimum rotational speed, the state of charge is greater than 0.2 and less than 0.8, and ΔP F With the ΔP B When the sum is greater than zero and less than ΔP, the power increment provided by the flywheel energy storage device, the lithium battery energy storage device, and the generator set is determined based on the generator's rotational speed.

[0035] If the absolute value of the generator's rotational speed is less than a preset speed threshold, then virtual droop control and inertial control are applied to the flywheel energy storage device to control the lithium battery energy storage device to output the maximum power increment ΔP. B The power shortage will be supplemented by the aforementioned units;

[0036] If the absolute value of the generator's rotational speed is greater than a preset speed threshold, then the flywheel energy storage device is subjected to virtual droop control and inertial control, and the lithium battery energy storage device supplements the missing power.

[0037] Optionally, in one embodiment of the present invention, the flywheel energy storage device is subjected to virtual droop control and inertial control using the following formula:

[0038]

[0039] Among them, P F (t) represents the output power of the flywheel's energy storage at time t, M. E K represents the virtual inertial control coefficient. d It is the droop coefficient.

[0040] To achieve the above objectives, a second aspect of the present invention provides a primary frequency regulation system for a hybrid energy storage thermal power generator unit based on flywheel energy storage, comprising:

[0041] The first calculation module is used to collect the frequency value of the power grid bus and calculate the target power increment ΔP required for the thermal power generating unit to perform a primary frequency regulation based on the frequency value.

[0042] The second calculation module is used to collect the real-time rotational speed of the flywheel energy storage device and calculate the maximum power increment ΔP that the flywheel energy storage device can output in real time based on the real-time rotational speed. F ;

[0043] The third calculation module is used to collect the state of charge, rated power value, and real-time power value of the lithium battery energy storage device, and calculate the maximum power increment ΔP that the lithium battery energy storage device can output in real time based on the rated power value and the real-time power value. B ;

[0044] The frequency regulation module is used to dynamically allocate the power increments provided by the flywheel energy storage device, the lithium battery energy storage device, and the generator set in the primary frequency regulation, based on the actual power regulation capabilities of the flywheel energy storage device and the lithium battery energy storage device, as well as the generator speed.

[0045] To achieve the above objectives, a third aspect of the present invention provides a non-transitory computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the primary frequency regulation method for a hybrid energy storage thermal power generator unit based on flywheel energy storage as described in the first aspect of the present invention.

[0046] The technical solution provided by the embodiments of the present invention brings at least the following beneficial effects: This application first determines the power deficit for primary frequency regulation of the power grid, then compares the power deficit with the output power of the energy storage unit to determine the operation of the energy storage unit and the generator unit. Thus, based on the different operating conditions of the generator unit, the energy storage unit and the generator unit are controlled to perform different actions. Specifically, virtual droop control and inertial control are used for the flywheel energy storage unit, with the lithium battery energy storage unit absorbing the power deficit, and the generator unit serving as a backup for frequency regulation. Therefore, this application incorporates energy storage resources into automatic generation control, prioritizing the use of flywheel energy storage units, extending the service life of lithium battery energy storage technology. When flywheel energy storage cannot regulate frequency independently, a hybrid energy storage method combining lithium battery energy storage and flywheel energy storage is used to extend the service life of the generator, serving as a backup for frequency regulation, ensuring power quality, improving frequency regulation effect, and increasing response speed. Furthermore, the use of virtual droop control and inertial control for the flywheel energy storage device gives the flywheel energy storage virtual inertial characteristics, improving the stability of the power system.

[0047] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0048] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0049] Figure 1 is a flowchart of a primary frequency regulation method for a thermal power generating unit based on flywheel energy storage and hybrid energy storage provided by the present invention.

[0050] Figure 2 is a flowchart illustrating a method for dynamically allocating power increments provided by a flywheel energy storage device, a lithium battery energy storage device, and a generator unit in a primary frequency regulation process, as provided by the present invention.

[0051] Figure 3 is a schematic diagram of the primary frequency regulation system of a thermal power generator set based on flywheel energy storage, provided by the present invention. Detailed Implementation

[0052] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0053] It should be noted that, with the continuous development of energy storage technology, in the embodiments of this invention, energy storage resources are incorporated into the automatic power generation control of the generator set, thereby effectively improving automatic power generation efficiency, compensating for the shortcomings of traditional automatic power generation control, improving frequency regulation, and increasing response speed. The energy storage devices used in the embodiments of the invention include flywheel energy storage devices and lithium battery energy storage devices.

[0054] Flywheel energy storage, partly a power-type energy storage technology, boasts high energy density, fast response, high cycle life, long service life, high efficiency, and pollution-free recovery. It can play a significant role in renewable energy consumption and power plant frequency regulation. Lithium-ion battery energy storage, on the other hand, is an energy-type energy storage technology, characterized by high energy density, long cycle life, low self-discharge rate, no memory effect, and environmental friendliness. Therefore, this application pre-installs both types of energy storage devices in the generator set, and combines them with the unit's own functions to achieve a hybrid energy storage solution that integrates the advantages of both.

[0055] The following description, with reference to the accompanying drawings, illustrates a primary frequency regulation method and system for a hybrid energy storage thermal power generator unit based on flywheel energy storage, according to embodiments of the present invention.

[0056] Figure 1 is a flowchart of a primary frequency regulation method for a thermal power generating unit based on flywheel energy storage, provided by the present invention.

[0057] As shown in Figure 1, the primary frequency regulation method for a thermal power generating unit based on flywheel energy storage and hybrid energy storage includes the following steps:

[0058] Step S10: Collect the frequency value of the power grid bus and calculate the target power increment ΔP required for the thermal power generating unit to perform a primary frequency regulation based on the frequency value.

[0059] Primary frequency regulation refers to the automatic control process by which the control system of generating units in the power grid automatically controls the increase or decrease of active power of the units when the grid frequency deviates from the rated value, thereby limiting the change in grid frequency and maintaining a stable grid frequency. When the grid frequency decreases, the primary frequency regulation function requires the generating units to quickly increase the load using their heat storage; conversely, the generating units quickly decrease the load.

[0060] Specifically, this application first determines the target power increment ΔP required for primary frequency regulation, which facilitates the subsequent determination of the operation status of each energy storage device and unit based on this power increment ΔP, in order to meet the power increment required for primary frequency regulation. Since primary frequency regulation is performed when the grid frequency deviates, the target power increment ΔP is calculated based on the frequency value of the grid bus.

[0061] In one embodiment of the present invention, the target power increment ΔP required to calculate based on the frequency value can be obtained by multiplying the collected frequency value of the power grid bus by the negative of the power-frequency standby coefficient of the thermal power generating unit. For example, in this embodiment, the collected frequency value of the power grid bus is Δf, and the power-frequency standby coefficient of the thermal power generating unit is K. g Then the target power increment ΔP = -K g Δf.

[0062] Step S20: Collect the real-time rotational speed of the flywheel energy storage device, and calculate the maximum power increment ΔP that the flywheel energy storage device can output in real time based on the real-time rotational speed. F .

[0063] Flywheel energy storage refers to an energy storage method that uses an electric motor to drive a flywheel to rotate at high speed, and then uses the flywheel to drive a generator to generate electricity when needed. Therefore, when the flywheel energy storage device provides power increments, in one embodiment of the invention, the power value that the flywheel energy storage device can release and absorb can be calculated based on the flywheel's rotational speed, thereby determining the maximum power increment ΔP that the flywheel energy storage device can output in real time. F .

[0064] In one embodiment of the present invention, the flywheel energy storage device can output the maximum power increment ΔP in real time. F It can be calculated by multiplying the flywheel output torque by the rotational speed.

[0065] For example, in this embodiment, the flywheel output torque is Tem, and the rotational speed is Δn. The flywheel energy storage device can then output a maximum power increment ΔP in real time. F =Tem*Δn.

[0066] Step S30: Collect the state of charge, rated power value, and real-time power value of the lithium battery energy storage device, and calculate the maximum power increment ΔP that the lithium battery energy storage device can output in real time based on the rated power value and real-time power value. B .

[0067] The state of charge (SOC) of a lithium battery is the ratio of its remaining capacity to its capacity when fully charged. This invention first collects the SOC data of the lithium battery energy storage device, using this SOC as a criterion for subsequently determining how the flywheel energy storage device, the lithium battery energy storage device, and the generator set provide the power increment.

[0068] Specifically, this application first determines the rated power value P of the lithium battery energy storage device. B-Rated and real-time power value P B-ActualBased on the rated power value and the real-time power value, the power value that the lithium battery energy storage device can release and absorb is calculated, and then the maximum power increment ΔP that the lithium battery energy storage device can output in real time is determined. B For example, subtracting the rated power value from the real-time power value determines the power that a lithium battery energy storage device can release.

[0069] Step S40: Based on the actual power regulation capabilities of the flywheel energy storage device and the lithium battery energy storage device, as well as the generator speed, dynamically allocate the power increment provided by the flywheel energy storage device, the lithium battery energy storage device, and the generator unit in the primary frequency regulation.

[0070] The actual power regulation capability of flywheel energy storage devices and lithium battery energy storage devices refers to the maximum power increment that each of these devices can output in real time.

[0071] Specifically, this invention compares the power deficit ΔP of primary frequency regulation with the actual output power of the energy storage device. First, the flywheel energy storage unit provides the required power increment. When the flywheel energy storage cannot regulate the frequency on its own, a hybrid energy storage method combining lithium battery energy storage and flywheel energy storage is adopted. If the hybrid energy storage unit also cannot achieve frequency regulation, then frequency regulation is achieved by combining the frequency regulation capability of the generator set itself.

[0072] To more clearly illustrate the specific implementation process of the method for dynamically allocating the power increment provided by the flywheel energy storage device, lithium battery energy storage device, and generator unit in primary frequency regulation according to the present invention, the following is an exemplary description of a dynamic allocation method for power increment provided in the invention.

[0073] Figure 2 is a flowchart illustrating a method for dynamically allocating the power increment provided by a flywheel energy storage device, a lithium battery energy storage device, and a generating unit in primary frequency regulation, as provided by this invention. As shown in Figure 2, the method first obtains the grid frequency f, rotational speed ω, load soc, and flywheel rotational speed n. Then, it calculates the primary frequency regulation power increment ΔP, the power value that the flywheel energy storage device can release, and the power value that it can absorb ΔP. F And calculate the maximum power increment ΔP that the lithium battery energy storage device can output in real time. B Then, based on ΔP, ΔP F and ΔP B This method dynamically allocates the power increments provided by flywheel energy storage devices, lithium battery energy storage devices, and generating units during primary frequency regulation, based on various quantitative relationships between them. It provides allocation methods for power changes under several different conditions.

[0074] As a first example, the dynamic allocation of power increments provided by the flywheel energy storage device, lithium battery energy storage device, and generator unit in primary frequency regulation includes:

[0075] Under the conditions that the target power increment ΔP is greater than zero, the real-time speed is greater than the minimum speed but less than the maximum speed, and the state of charge is greater than 0.2 and less than 0.8, determine the target power increment ΔP, ΔP F and ΔP B The relationship between them

[0076] If ΔP F Greater than ΔP, i.e., ΔP F If ΔP>0, the turbine control valve and power of the control unit remain unchanged, and the target power increment ΔP required for primary frequency regulation is provided by the flywheel energy storage device;

[0077] If ΔP is greater than ΔP F And ΔP F With ΔP B The sum of is greater than ΔP, that is, ΔP > ΔP F >0, ΔP F +ΔP B If ΔP>0, then virtual droop control and inertial control are applied to the flywheel energy storage device, and the missing power is supplemented by the lithium battery energy storage device.

[0078] Among them, lithium battery energy storage devices supplement the power deficit: P B (t)=ΔP-P F (t), P B (t) represents the output power command of the electrochemical energy storage at time t, P F (t) represents the output power command of the flywheel energy storage at time t, ΔP F The maximum power that the flywheel can output in real time for energy storage is ΔP. B The maximum power that can be output in real time for lithium battery energy storage.

[0079] Specifically, in one embodiment of the present invention, the method for virtual droop control and inertial control of the flywheel energy storage device includes:

[0080] Among them, P F (t) represents the output power of the flywheel energy storage at time t, K d It is the droop coefficient, M E For virtual inertial control coefficients.

[0081] As a second example, dynamically allocating the power increments provided by flywheel energy storage devices, lithium battery energy storage devices, and generator units in primary frequency regulation includes:

[0082] When the target power increment ΔP is greater than zero, the real-time speed is greater than the minimum speed, and the state of charge is greater than 0.8, determine the target power increment ΔP and ΔP. F The relationship between them

[0083] If ΔPF Greater than ΔP, i.e., ΔP F If ΔP>0, the turbine control valve and power of the control unit remain unchanged, and the target power increment ΔP required for primary frequency regulation is provided by the flywheel energy storage device;

[0084] If ΔP is greater than ΔP F And ΔP F Greater than zero, i.e., ΔP > ΔP F If the value is greater than 0, then virtual droop control and inertial control are applied to the flywheel energy storage device, and the unit provides the deficit power.

[0085] Among them, the power change ΔP required by the unit U＝ ΔP-P F (t), P F (t) represents the output power command of the flywheel energy storage at time t, ΔP F The maximum power that can be output in real time for flywheel energy storage.

[0086] Specifically, in one embodiment of the present invention, a method for virtual droop control and inertial control of flywheel energy storage is described:

[0087]

[0088] As a third example, dynamically allocating the power increments provided by flywheel energy storage devices, lithium battery energy storage devices, and generator units in primary frequency regulation includes:

[0089] Under the conditions that the target power increment ΔP is greater than zero, the real-time speed is equal to the minimum speed, and the state of charge is greater than 0.2 and less than 0.8, determine the target power increment ΔP and ΔP. B The relationship between them

[0090] If ΔP B Greater than ΔP, i.e., ΔP B If ΔP>0, the turbine control valve and power of the control unit remain unchanged, and the target power increment ΔP required for primary frequency regulation is provided by the lithium battery energy storage device;

[0091] If ΔP is greater than ΔP B And ΔP B Greater than zero, i.e., ΔP > ΔP B If the value is greater than 0, the generator set will provide the shortfall power.

[0092] Specifically, in one embodiment of the present invention, the deficit power that the unit needs to provide can be ΔP. U It can be achieved through the formula ΔP U＝ ΔP-P B (t), to calculate the power deficit, where P B(t) represents the output power command of the lithium battery energy storage at time t.

[0093] As a fourth example, dynamically allocating the power increments provided by flywheel energy storage devices, lithium battery energy storage devices, and generator units in primary frequency regulation includes:

[0094] When the target power increment ΔP is less than zero, the real-time speed is less than the maximum speed, and the state of charge is greater than 0.2 and less than 0.8, determine the target power increment ΔP and ΔP. F and ΔP B The relationship between them

[0095] If ΔP F The absolute value of is greater than the absolute value of ΔP, and the absolute value of ΔP is greater than zero, i.e., |ΔP| > 0. F If |>|ΔP|>0, the turbine control valve and power of the control unit remain unchanged, and the target power increment ΔP required for primary frequency regulation is provided by the flywheel energy storage device;

[0096] If the absolute value of ΔP is greater than ΔP F The absolute value of ΔP F The absolute value of is greater than zero, and ΔP F The absolute value of ΔP B The sum of the absolute values ​​of ΔP and ΔP is greater than the absolute value of ΔP, i.e., |ΔP| > |ΔP. F |>0,|ΔP F +ΔP B If |>|ΔP|>0, then virtual droop control and inertial control are applied to the flywheel energy storage device, and the missing power is supplemented by the lithium battery energy storage device.

[0097] Specifically, in one embodiment of the present invention, the method for performing virtual droop control and inertial control on the flywheel energy storage device, and supplementing the power deficit by the lithium battery energy storage device, is as follows:

[0098]

[0099] As a fifth example, dynamically allocating the power increments provided by flywheel energy storage devices, lithium battery energy storage devices, and generator units in primary frequency regulation includes:

[0100] When the target power increment ΔP is less than zero, the real-time speed is less than the maximum speed, and the state of charge is greater than 0.8, determine the target power increment ΔP and ΔP. F The relationship between them

[0101] If ΔP F The absolute value of is greater than the absolute value of ΔP, and the absolute value of ΔP is greater than zero, i.e., |ΔP| > 0. FIf |>|ΔP|>0, then the turbine control valve and power of the control unit remain unchanged, and the target power increment ΔP required for primary frequency regulation is provided by the flywheel energy storage device;

[0102] If the absolute value of ΔP is greater than ΔP F The absolute value of ΔP, and ΔP F The absolute value of |ΔP| is greater than zero, i.e., |ΔP|>|ΔP F If |>0, then virtual droop control and inertial control are applied to the flywheel energy storage device, and the generator unit supplements the power deficit. The power change ΔP required by the generator unit is... U＝ ΔP-P F (t).

[0103] As a sixth example, dynamically allocating the power increments provided by flywheel energy storage devices, lithium battery energy storage devices, and generator units in primary frequency regulation includes:

[0104] When the target power increment ΔP is greater than zero, the real-time speed is greater than the minimum speed, the state of charge is greater than 0.2 and less than 0.8, and ΔP F With ΔP B When the sum is greater than zero and less than ΔP, i.e., ΔP > ΔP F +ΔP B >0, the power increment provided by the flywheel energy storage device, lithium battery energy storage device, and generator set is determined based on the generator's rotational speed.

[0105] If the absolute value of the generator's speed is less than a preset speed threshold, then virtual droop control and inertia control are applied to the flywheel energy storage device to control the lithium battery energy storage device to output the maximum power increment ΔP. B The power shortage will be supplemented by the generating units;

[0106] If the absolute value of the generator's speed is greater than the preset speed threshold, virtual droop control and inertial control are applied to the flywheel energy storage device, and the lithium battery energy storage device supplements the power deficit.

[0107] For example, in one embodiment of this application, the preset speed threshold can be 50 rad / min, that is, if |Δn|≤50 rad / min, the power change ΔP that the unit needs to provide. U＝ ΔP-P F (t)-P B (t), virtual droop control and inertial control are applied to the flywheel energy storage to control the lithium battery energy storage device to supplement the power deficit, P B (t) represents the output power command of the electrochemical energy storage at time t, P F(t) represents the output power command of the flywheel energy storage at time t; if |Δn|>50rad / min, virtual droop control and inertial control are performed on the flywheel energy storage. Since the unit is in the dead zone due to inactivity, the lithium battery energy storage device supplements the power deficit, where the power deficit P supplemented by the lithium battery energy storage device is... B (t)=ΔP-P F (t), P B (t) represents the output power command of the electrochemical energy storage at time t, P F (t) represents the output power command of the flywheel energy storage at time t.

[0108] Furthermore, in one embodiment of this application, virtual droop control and inertial control of the flywheel energy storage device are performed using the following formula:

[0109]

[0110] Among them, P F (t) represents the output power of the flywheel's energy storage at time t, M. E K represents the virtual inertial control coefficient. d It is the droop coefficient.

[0111] In addition to the above-described method for dynamically allocating the power increments provided by the flywheel energy storage device, lithium battery energy storage device, and generator unit in primary frequency regulation, other allocation examples of the power increments provided by the flywheel energy storage device, lithium battery energy storage device, and generator unit in primary frequency regulation can be performed in the following embodiments of the present invention. These other allocation examples are described in detail below:

[0112] As a seventh example, dynamically allocating the power increments provided by flywheel energy storage devices, lithium battery energy storage devices, and generator units in primary frequency regulation includes:

[0113] When the target power increment ΔP is less than zero, the real-time speed is equal to the maximum speed, and the state of charge is greater than 0.2 and less than 0.8, determine the target power increment ΔP and ΔP. F and ΔP B The relationship between them

[0114] If ΔP B If the absolute value of ΔP is greater than the absolute value of ΔP, then the turbine control valve and power of the control unit remain unchanged, and the lithium battery energy storage device provides the power increment ΔP = P required for primary frequency regulation. B (t), where P B (t) represents the output power command of the lithium battery energy storage at time t;

[0115] If the absolute value of ΔP is greater than ΔP B The absolute value of the deficit is then provided by the generator set.

[0116] Specifically, in one embodiment of this application, when |ΔP|>|ΔP B |>0, the power change ΔP required by the unit U =ΔP-P B (t). P B (t) represents the output power command of the lithium battery energy storage at time t, ΔP B The maximum power that can be output in real time for lithium battery energy storage.

[0117] As an eighth example, dynamically allocating the power increments provided by flywheel energy storage devices, lithium battery energy storage devices, and generator units in primary frequency regulation includes:

[0118] When the target power increment ΔP is equal to 0, i.e. ΔP = 0, the turbine control valve of the control unit remains unchanged, and both the flywheel energy storage and lithium battery energy storage are in a holding state, neither discharging nor absorbing electricity.

[0119] As a ninth example, dynamically allocating the power increments provided by flywheel energy storage devices, lithium battery energy storage devices, and generator units in primary frequency regulation includes:

[0120] When the target power increment ΔP is less than zero, the real-time speed is less than the maximum speed, the state of charge is greater than 0.2 and less than 0.8, and the absolute value of ΔP is greater than ΔP B With ΔP F The sum, i.e., |ΔP|>|ΔP F +ΔP B |>0, the power increment provided by the flywheel energy storage device, lithium battery energy storage device, and generator unit is determined based on the generator's rotational speed.

[0121] If the absolute value of the generator's speed is less than a preset speed threshold, then virtual droop control and inertia control are applied to the flywheel energy storage device to control the lithium battery energy storage device to output the maximum power increment ΔP. B The power shortage will be supplemented by the generating units;

[0122] If the absolute value of the generator's speed is greater than the preset speed threshold, virtual droop control and inertial control are applied to the flywheel energy storage device, and the lithium battery energy storage device supplements the power deficit.

[0123] For example, the preset speed threshold can be 50 rad / min. If |Δn|≤50 rad / min, the power change ΔP that the unit needs to provide is... U＝ ΔP-P F (t)-P B (t), virtual droop control and inertial control are applied to the flywheel energy storage to control the lithium battery energy storage device to supplement the power deficit, P B (t) represents the output power command of the electrochemical energy storage at time t, P F(t) represents the output power command of the flywheel energy storage at time t; if |Δn|>50rad / min, virtual droop control and inertial control are performed on the flywheel energy storage. Since the unit is in the dead zone due to inactivity, the lithium battery energy storage device supplements the power deficit, where the power deficit P supplemented by the lithium battery energy storage device is... B (t)=ΔP-P F (t), P B (t) represents the output power command of the electrochemical energy storage at time t, P F (t) represents the output power command of the flywheel energy storage at time t.

[0124] In summary, this invention proposes a primary frequency regulation method for a hybrid energy storage thermal power generator unit based on flywheel energy storage. First, the power deficit for primary frequency regulation of the power grid is determined. Then, the power deficit is compared with the output power of the energy storage unit to determine the operation of the energy storage unit and the generator unit. Based on the different operating conditions of the generator unit, the energy storage unit and the generator unit are controlled to perform different actions. Specifically, virtual droop control and inertial control are used for the flywheel energy storage unit, with the lithium battery energy storage unit absorbing the power deficit, serving as a backup for frequency regulation. Thus, this method integrates energy storage resources into automatic generation control, prioritizing the use of flywheel energy storage units to extend the service life of lithium battery energy storage technology. When flywheel energy storage cannot regulate frequency independently, a hybrid energy storage approach combining lithium battery and flywheel energy storage is used to extend the generator's service life, serving as a backup for frequency regulation, ensuring power quality, improving frequency regulation effectiveness, and increasing response speed. Furthermore, virtual droop control and inertial control methods are used for flywheel energy storage devices to give flywheel energy storage virtual inertial characteristics, thereby improving the stability of the power system.

[0125] Figure 3 is a schematic diagram of the primary frequency regulation system of a hybrid energy storage thermal power generator unit based on flywheel energy storage provided in an embodiment of the present invention.

[0126] As shown in Figure 3, the primary frequency regulation system of the hybrid energy storage thermal power generator unit based on flywheel energy storage includes the following modules: first calculation module 100, second calculation module 200, third calculation module 300 and frequency regulation module 400.

[0127] The first calculation module 100 is used to collect the frequency value of the power grid bus and calculate the target power increment ΔP required for the thermal power generating unit to perform a primary frequency regulation based on the frequency value.

[0128] The second calculation module 200 is used to collect the real-time rotational speed of the flywheel energy storage device and calculate the maximum power increment ΔP that the flywheel energy storage device can output in real time based on the real-time rotational speed. F ;

[0129] The third calculation module 300 is used to collect the state of charge, rated power value, and real-time power value of the lithium battery energy storage device, and calculate the maximum power increment ΔP that the lithium battery energy storage device can output in real time based on the rated power value and real-time power value. B ;

[0130] The frequency regulation module 400 is used to dynamically allocate the power increment provided by the flywheel energy storage device, the lithium battery energy storage device, and the generator unit in primary frequency regulation, based on the actual power regulation capabilities of the flywheel energy storage device and the lithium battery energy storage device and the generator speed.

[0131] It should be noted that the explanation of the above-described embodiment of the primary frequency regulation method for a hybrid energy storage thermal power generator unit based on flywheel energy storage also applies to the system of this embodiment. Please refer to the relevant description of the above embodiment, which will not be repeated here.

[0132] In summary, this invention proposes a primary frequency regulation system for a hybrid energy storage thermal power generator based on flywheel energy storage. This system integrates energy storage resources into automatic power generation control, prioritizing the use of flywheel energy storage units to extend the lifespan of lithium battery energy storage technology. When flywheel energy storage cannot regulate frequency independently, a hybrid energy storage approach combining lithium battery and flywheel energy storage is employed to further extend the generator's lifespan. The generator set serves as a backup for frequency regulation, ensuring power quality, improving frequency regulation effectiveness, and increasing response speed. Furthermore, virtual droop control and inertial control methods are used on the flywheel energy storage device to endow it with virtual inertial characteristics, thereby enhancing the stability of the power system.

[0133] To implement the above embodiments, this application also proposes a non-transitory computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the primary frequency regulation method for a hybrid energy storage thermal power generator unit based on flywheel energy storage as described in any of the above embodiments.

[0134] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0135] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0136] Any process or method description in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing custom logic functions or processes, and the scope of preferred embodiments of the invention includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as should be understood by those skilled in the art to which embodiments of the invention pertain.

[0137] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Alternatively, the computer-readable medium may be paper or other suitable media on which the program can be printed, since the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in a computer memory.

[0138] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware as in another embodiment, it can be implemented using any of the following techniques known in the art, or a combination thereof: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0139] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

[0140] Furthermore, the functional units in the various embodiments of the present invention can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0141] The storage medium mentioned above can be a read-only memory, a disk, or an optical disk, etc. Although embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A primary frequency regulation method for a hybrid energy storage thermal power generating unit based on flywheel energy storage, characterized in that, Includes the following steps: Collect the frequency value of the power grid bus, and calculate the target power increment ΔP required for primary frequency regulation of the thermal power generating unit based on the frequency value; The real-time rotational speed of the flywheel energy storage device is collected, and the maximum power increment ΔP that the flywheel energy storage device can output in real time is calculated based on the real-time rotational speed. F Collect the state of charge, rated power, and real-time power of the lithium battery energy storage device; calculate the maximum power increment ΔP that the lithium battery energy storage device can output in real time based on the rated power and real-time power. B Based on the actual power regulation capabilities of the flywheel energy storage device and the lithium battery energy storage device, as well as the generator speed, the power increment provided by the flywheel energy storage device, the lithium battery energy storage device, and the generator set in the primary frequency regulation is dynamically allocated. The dynamic allocation of the power increment provided by the flywheel energy storage device, the lithium battery energy storage device, and the generator set in the primary frequency regulation includes: determining the target power increment ΔP when the target power increment ΔP is less than zero, the real-time speed is less than the maximum speed, and the state of charge is greater than 0.2 and less than 0.

8. F and the ΔP B The relationship between ΔP F If the absolute value of ΔP is greater than the absolute value of ΔP, and the absolute value of ΔP is greater than zero, then the turbine control valve and power of the unit are kept constant, and the flywheel energy storage device provides the target power increment ΔP required for the primary frequency regulation; if the absolute value of ΔP is greater than ΔP... F The absolute value of ΔP F The absolute value of is greater than zero, and the ΔP F The absolute value of ΔP B If the sum of the absolute values ​​of the values ​​is greater than the absolute value of ΔP, then virtual droop control and inertial control are applied to the flywheel energy storage device, and the lithium battery energy storage device supplements the power deficit. The dynamic allocation of the power increment provided by the flywheel energy storage device, the lithium battery energy storage device, and the generator set in the primary frequency regulation includes: determining the target power increment ΔP and the sum of the absolute values ​​of the ... F The relationship between ΔP F If the absolute value of ΔP is greater than the absolute value of ΔP, and the absolute value of ΔP is greater than zero, then the turbine control valve and power of the unit are kept constant, and the flywheel energy storage device provides the target power increment ΔP required for the primary frequency regulation; if the absolute value of ΔP is greater than ΔP... F The absolute value of ΔP, and the ΔP F If the absolute value is greater than zero, then the flywheel energy storage device is subjected to virtual droop control and inertial control, and the unit supplements the power deficit.

2. The frequency modulation method according to claim 1, characterized in that, The dynamic allocation of the power increment provided by the flywheel energy storage device, the lithium battery energy storage device, and the generator set in the primary frequency regulation includes: determining the target power increment ΔP, the real-time rotational speed greater than zero, the real-time rotational speed greater than the minimum rotational speed and less than the maximum rotational speed, and the state of charge greater than 0.2 and less than 0.8 when the target power increment ΔP is greater than zero, the real-time rotational speed is greater than the minimum rotational speed and less than the maximum rotational speed, and the state of charge is greater than 0.2 and less than 0.

8. F and the ΔP B The relationship between ΔP F If the value is greater than ΔP, the turbine control valve and power of the unit are kept constant, and the flywheel energy storage device provides the target power increment ΔP required for the primary frequency regulation; if the value of ΔP is greater than ΔP... F And the ΔP F With the aforementioned ΔP B If the sum of the values ​​is greater than ΔP, then the flywheel energy storage device is subjected to virtual droop control and inertial control, and the lithium battery energy storage device supplements the power deficit.

3. The frequency modulation method according to claim 1, characterized in that, The dynamic allocation of the power increment provided by the flywheel energy storage device, the lithium battery energy storage device, and the generator set in the primary frequency regulation includes: determining the target power increment ΔP and the real-time speed greater than the minimum speed and the state of charge greater than 0.8 when the target power increment ΔP is greater than zero, the real-time speed is greater than the minimum speed, and the state of charge is greater than 0.

8. F The relationship between ΔP F If the value is greater than ΔP, the turbine control valve and power of the unit are kept constant, and the flywheel energy storage device provides the target power increment ΔP required for the primary frequency regulation; if the value of ΔP is greater than ΔP... F And the ΔP F If the value is greater than zero, then the flywheel energy storage device is subjected to virtual droop control and inertial control, and the unit provides the deficit power.

4. The frequency modulation method according to claim 1, characterized in that, The dynamic allocation of the power increment provided by the flywheel energy storage device, the lithium battery energy storage device, and the generator set in the primary frequency regulation includes: determining the target power increment ΔP and the ΔP when the target power increment ΔP is greater than zero, the real-time speed is equal to the minimum speed, and the state of charge is greater than 0.2 and less than 0.

8. B The relationship between ΔP B If the value is greater than ΔP, the turbine control valve and power of the unit are kept constant, and the target power increment ΔP required for the primary frequency regulation is provided by the lithium battery energy storage device; if the value of ΔP is greater than ΔP... B And the ΔP B If the value is greater than zero, the unit will provide the shortfall power.

5. The frequency modulation method according to claim 1, characterized in that, The dynamic allocation of the power increment provided by the flywheel energy storage device, the lithium battery energy storage device, and the generator set in the primary frequency regulation includes: when the target power increment ΔP is greater than zero, the real-time speed is greater than the minimum speed, the state of charge is greater than 0.2 and less than 0.8, and ΔP F With the aforementioned ΔP B If the sum of the values ​​is greater than zero and less than ΔP, the power increment provided by the flywheel energy storage device, the lithium battery energy storage device, and the generator set is determined based on the generator's rotational speed. If the absolute value of the generator's rotational speed is less than a preset speed threshold, virtual droop control and inertial control are applied to the flywheel energy storage device, and the lithium battery energy storage device is controlled to output the maximum power increment ΔP. B The generator set will supplement the power deficit; if the absolute value of the generator speed is greater than a preset speed threshold, the flywheel energy storage device will be subject to virtual droop control and inertial control, and the lithium battery energy storage device will supplement the power deficit.

6. The frequency modulation method according to claim 2, characterized in that, The flywheel energy storage device is subjected to virtual droop control and inertial control using the following formulas: Among them, P F (t) represents the output power of the flywheel's energy storage at time t. K represents the virtual inertial control coefficient. d It is the droop coefficient.

7. A primary frequency regulation system for a hybrid energy storage thermal power generator unit based on flywheel energy storage, characterized in that, It includes the following modules: a first calculation module, used to collect the frequency value of the power grid bus and calculate the target power increment ΔP required for the thermal power generating unit to perform primary frequency regulation based on the frequency value; The second calculation module is used to collect the real-time rotational speed of the flywheel energy storage device and calculate the maximum power increment ΔP that the flywheel energy storage device can output in real time based on the real-time rotational speed. F ; The third calculation module is used to collect the state of charge, rated power value, and real-time power value of the lithium battery energy storage device, and calculate the maximum power increment ΔP that the lithium battery energy storage device can output in real time based on the rated power value and the real-time power value. B The frequency regulation module is used to dynamically allocate the power increment provided by the flywheel energy storage device, the lithium battery energy storage device, and the generator set in the primary frequency regulation, based on the actual power regulation capabilities of the flywheel energy storage device and the lithium battery energy storage device, as well as the generator speed. The dynamic allocation of the power increment provided by the flywheel energy storage device, the lithium battery energy storage device, and the generator set in the primary frequency regulation includes: determining the target power increment ΔP when the target power increment ΔP is less than zero, the real-time speed is less than the maximum speed, and the state of charge is greater than 0.2 and less than 0.

8. F and the ΔP B The relationship between ΔP F If the absolute value of ΔP is greater than the absolute value of ΔP, and the absolute value of ΔP is greater than zero, then the turbine control valve and power of the unit are kept constant, and the flywheel energy storage device provides the target power increment ΔP required for the primary frequency regulation; if the absolute value of ΔP is greater than ΔP... F The absolute value of ΔP F The absolute value of is greater than zero, and the ΔP F The absolute value of ΔP B If the sum of the absolute values ​​of the values ​​is greater than the absolute value of ΔP, then virtual droop control and inertial control are applied to the flywheel energy storage device, and the lithium battery energy storage device supplements the power deficit. The dynamic allocation of the power increment provided by the flywheel energy storage device, the lithium battery energy storage device, and the generator set in the primary frequency regulation includes: determining the target power increment ΔP and the sum of the absolute values ​​of the ... F The relationship between ΔP F If the absolute value of ΔP is greater than the absolute value of ΔP, and the absolute value of ΔP is greater than zero, then the turbine control valve and power of the unit are kept constant, and the flywheel energy storage device provides the target power increment ΔP required for the primary frequency regulation; if the absolute value of ΔP is greater than ΔP... F The absolute value of ΔP, and the ΔP F If the absolute value is greater than zero, then the flywheel energy storage device is subjected to virtual droop control and inertial control, and the unit supplements the power deficit.

8. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the primary frequency regulation method for a hybrid energy storage thermal power generator unit based on flywheel energy storage as described in any one of claims 1-6.

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