Primary frequency modulation control method and system for energy storage enhanced full-power pumped storage unit

Abstract

The invention discloses a primary frequency modulation control method and system for an energy storage enhanced full-power pumped storage unit. The primary frequency modulation control method comprises the following steps: constructing a first hybrid control loop containing voltage control and frequency control; determining an output parameter of voltage control and an input parameter of frequency control in the first hybrid control loop; establishing a first voltage control strategy and a first frequency control strategy based on the output parameters of voltage control and the input parameters of frequency control; and performing primary frequency modulation control according to the first voltage control strategy and the first frequency control strategy. Under the power distribution, the power fluctuation and the change rate of pumped storage can be greatly reduced, the advantages of the super capacitor and pumped storage can be fully played to improve the operation efficiency and prolong the service life of the full-power pumped storage unit, and the system cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of full-power pumped storage unit network construction, and in particular to a primary frequency regulation control method and system for an energy storage enhanced full-power pumped storage unit. Background Art

[0002] The increasing popularity of renewable energy has redefined the operation of modern power systems. In traditional power systems, synchronous generators are responsible for frequency regulation. When frequency events occur, they exhibit inertial response, which slows down frequency dynamics by absorbing or releasing the kinetic energy stored in the rotor of the synchronous generator. In a power system with full-power pumped storage units under grid control, frequency regulation will be taken over by the converter. One concept of frequency regulation in grid control is called virtual synchronous generator (VSG), and the basic idea of ​​this concept is to simulate the synchronous generator by properly controlling the power converter. However, in previous research works on VSG, VSG is usually realized by connecting an ideal DC voltage source to an inverter, and all control loops in VSG, such as inertia and speed regulator, are realized by the ideal DC voltage source, which is obviously not the actual situation. In fact, the participation of energy storage system in VSG is necessary to achieve frequency regulation, but the implementation and coordinated control of energy storage system in full-power pumped storage units under grid control have not been studied.

[0003] When selecting energy storage units in energy storage systems, high energy density units are preferably used together with high power density units to improve system operating efficiency and service life and reduce system costs. Among them, pumped storage is recognized by the world as a storage method with a long service life, large capacity, the most economical, most reliable, high commercial value, the most mature technology, and environmentally friendly. Therefore, one solution is a pumped storage / supercapacitor hybrid energy storage system, in which pumped storage is used to compensate for low-frequency power fluctuations and supercapacitors are used to compensate for high-frequency power fluctuations. In order to give full play to the advantages of different energy storage devices, low-pass / high-pass filters are usually used to extract low-frequency / high-frequency power fluctuations in the system. However, there is no guiding principle on how to design the cutoff frequency of such filters, which is usually determined by trial and error.

[0004] Based on the above problems, it is necessary to equip the full-power pumped storage unit with a suitable energy storage system to achieve power management, so that different energy storage units can cope with different types of power fluctuations to improve the system's operating efficiency and service life, and achieve practical full-power pumped storage unit frequency regulation control. At the same time, a direct design method for each control parameter in the energy storage system is needed to avoid the problem of improper design of the low-pass / high-pass filter cutoff frequency. Summary of the invention

[0005] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0006] In view of the above existing problems, the present invention is proposed.

[0007] Therefore, the present invention provides a primary frequency regulation control method and system for an energy storage enhanced full-power pumped storage unit, which can solve the problems mentioned in the background technology.

[0008] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0009] In a first aspect, the present invention provides a primary frequency regulation control method for an energy storage enhanced full-power pumped storage unit, comprising:

[0010] constructing a first hybrid control loop including voltage control and frequency control;

[0011] determining an output parameter of a voltage control and an input parameter of a frequency control in a first hybrid control loop;

[0012] Establishing a first voltage control strategy and a first frequency control strategy based on output parameters of voltage control and input parameters of frequency control;

[0013] A frequency modulation control is performed according to the first voltage control strategy and the first frequency control strategy.

[0014] As a preferred solution of the primary frequency regulation control method of the energy storage enhanced full-power pumped storage unit of the present invention, wherein: the construction of the first hybrid control loop including voltage control and frequency control includes:

[0015] The voltage control includes AC voltage control and DC voltage control;

[0016] The AC voltage control and the DC voltage control are independently controlled;

[0017] A first AC voltage control strategy is preset to perform AC voltage control, and a first DC voltage control strategy is preset to perform DC voltage control.

[0018] As a preferred solution of the primary frequency regulation control method of the energy storage enhanced full-power pumped storage unit of the present invention, wherein: the first voltage control strategy and the first frequency control strategy based on the output parameters of the voltage control and the input parameters of the frequency control are established, including:

[0019] The first frequency control strategy is an arbitrary control strategy for obtaining a first output parameter by frequency controlling current and voltage;

[0020] The first voltage control strategy is any control strategy for performing voltage control on the first output parameter to obtain an AC voltage modulation signal and a DC voltage modulation signal.

[0021] As a preferred solution of the primary frequency regulation control method of the energy storage enhanced full-power pumped storage unit described in the present invention, wherein: the first voltage control strategy includes a first AC voltage control strategy and a first DC voltage control strategy;

[0022] The first AC voltage control strategy is any control strategy whose input is some parameters of the first output parameter and whose output is an AC voltage modulation signal;

[0023] The first DC voltage control strategy is an arbitrary control strategy whose input is some parameters of the first output parameter and whose output is a DC voltage modulation signal.

[0024] As a preferred scheme of the primary frequency regulation control method of the energy storage enhanced full-power pumped storage unit described in the present invention, wherein: the first hybrid control loop includes using an LC filtered three-phase inverter as an interface between the supercapacitor and the AC load, and the frequency control is achieved by pumped storage / supercapacitor, and the pumped storage is connected to the supercapacitor through a DC / DC converter.

[0025] As a preferred solution of the primary frequency regulation control method of the energy storage enhanced full-power pumped storage unit of the present invention, wherein: the primary frequency regulation control according to the first voltage control strategy and the first frequency control strategy includes:

[0026] Calculating a frequency-voltage proportionality coefficient based on power distribution between pumped storage and supercapacitors according to the first voltage control strategy and the first frequency control strategy;

[0027] A frequency modulation control is performed according to the frequency-voltage proportionality coefficient.

[0028] As a preferred solution of the primary frequency regulation control method of the energy storage enhanced full-power pumped storage unit of the present invention, wherein: the frequency-voltage proportional coefficient based on the power distribution between the pumped storage and the supercapacitor is calculated according to the first voltage control strategy and the first frequency control strategy, including:

[0029] Calculate the total power change of the energy storage system including pumped storage and supercapacitors;

[0030] Split the total power change into slow-changing power and fast-changing power:

[0031] The slow-changing power and the fast-changing power in the total power change are allocated to the pumped storage and the supercapacitor respectively;

[0032] The power change of the supercapacitor is expressed by differentiating the energy stored in the supercapacitor;

[0033] Let the power change of the supercapacitor be equal to the fast power change to obtain the relationship between frequency and voltage;

[0034] The frequency-voltage proportionality coefficient based on the power distribution between pumped storage and supercapacitors is calculated.

[0035] In a second aspect, the present invention provides a primary frequency regulation control system of an energy storage enhanced full-power pumped storage unit, comprising:

[0036] A loop building module, used for building a first hybrid control loop including voltage control and frequency control;

[0037] A parameter determination module, used to determine an output parameter of voltage control and an input parameter of frequency control in the first hybrid control loop;

[0038] A strategy establishing module, used to establish a first voltage control strategy and a first frequency control strategy based on an output parameter of voltage control and an input parameter of frequency control;

[0039] A control module is used to perform a frequency modulation control according to the first voltage control strategy and the first frequency control strategy.

[0040] In a third aspect, the present invention provides a computer device, comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the above-mentioned method when executing the computer program.

[0041] In a fourth aspect, the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program implements the steps of the method described above when executed by a processor.

[0042] Compared with the prior art, the invention has the following beneficial effects: the invention proposes a primary frequency regulation control method and system for energy storage enhanced full-power pumped storage units, constructs a first hybrid control loop including voltage control and frequency control; determines the output parameters of voltage control and the input parameters of frequency control in the first hybrid control loop; establishes a first voltage control strategy and a first frequency control strategy based on the output parameters of voltage control and the input parameters of frequency control; and performs primary frequency regulation control according to the first voltage control strategy and the first frequency control strategy. The method can realize the power management of the full-power pumped storage unit, so that the supercapacitor in the hybrid energy storage system can cope with high-frequency power fluctuations and the pumped storage can compensate for relatively long-term and dynamic slow power fluctuations. Under such power distribution, the power fluctuation and its change rate of pumped storage can be greatly reduced, and the advantages of supercapacitor and pumped storage can be fully utilized to improve the operating efficiency and service life of the full-power pumped storage unit, and reduce the system cost. Moreover, the frequency regulation control method does not rely on the traditional low-pass / high-pass filter design, and each control parameter and the power reference of the supercapacitor and pumped storage can be easily obtained by simulating the traditional virtual synchronous generator control. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0044] Figure 1 A method flow chart of a primary frequency regulation control method and system for an energy storage enhanced full-power pumped storage unit provided by an embodiment of the present invention;

[0045] Figure 2 A hybrid energy storage system topology and control block diagram of a primary frequency regulation control method and system for an energy storage enhanced full-power pumped storage unit provided by one embodiment of the present invention;

[0046] Figure 3 A frequency control block diagram of a primary frequency regulation control method and system for an energy storage enhanced full-power pumped storage unit provided by an embodiment of the present invention;

[0047] Figure 4 A voltage control block diagram of a primary frequency regulation control method and system for an energy storage enhanced full-power pumped storage unit provided by an embodiment of the present invention;

[0048] Figure 5 A response schematic diagram of a primary frequency regulation control method and system for an energy storage enhanced full-power pumped storage unit provided by an embodiment of the present invention;

[0049] Figure 6 A schematic diagram of power distribution of a primary frequency regulation control method and system for an energy storage enhanced full-power pumped storage unit provided in one embodiment of the present invention;

[0050] Figure 7 An internal structural diagram of a computer device for a primary frequency regulation control method and system for an energy storage-enhanced full-power pumped storage unit provided in accordance with an embodiment of the present invention. DETAILED DESCRIPTION

[0051] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0052] Example 1

[0053] Reference Figure 1-Figure 7 , which is the first embodiment of the present invention, provides a primary frequency regulation control method and system for an energy storage enhanced full-power pumped storage unit, comprising:

[0054] There are some problems in the existing related technologies. For example, during the frequency modulation process, the traditional pumped storage unit cannot respond to the rapid changes of the grid frequency in time due to its slow response speed, resulting in poor frequency modulation effect. In addition, when dealing with power fluctuations, traditional units often cannot take into account both rapidity and stability, which affects the operating efficiency and life of the unit.

[0055] The present application provides a method that can effectively solve the above-mentioned problems. Next, multiple embodiments will be combined to explain in detail how to implement the primary frequency regulation control method of the energy storage enhanced full-power pumped storage unit;

[0056] Figure 1 A method flow chart of a primary frequency regulation control method and system of an energy storage enhanced full-power pumped storage unit is shown, comprising:

[0057] S101, constructing a first hybrid control loop including voltage control and frequency control;

[0058] In an embodiment of the present application, constructing a first hybrid control loop including voltage control and frequency control includes:

[0059] Voltage control includes AC voltage control and DC voltage control;

[0060] AC voltage control and DC voltage control are independent controls;

[0061] A first AC voltage control strategy is preset to perform AC voltage control, and a first DC voltage control strategy is preset to perform DC voltage control.

[0062] In an optional embodiment, voltage control realizes accurate power management of full-power pumped storage units. Through the constructed hybrid control loop, the output parameters of voltage control can be flexibly adjusted to adapt to the rapid changes in grid frequency, thereby improving the response speed and accuracy of primary frequency regulation. At the same time, the input parameters of frequency control can be dynamically adjusted according to the actual needs of the grid to ensure the stable operation of the unit under different working conditions.

[0063] In an optional embodiment, voltage control includes AC voltage control and DC voltage control, which can be achieved by designing various different control block diagrams. The control processes of AC and DC are different, so at least two control block diagrams for voltage need to be designed, and the designed block diagrams can be adjusted according to actual grid conditions. For example, AC voltage control can use a proportional integral differential (PID) controller, while DC voltage control can use a fuzzy logic controller to adapt to different control requirements and grid characteristics.

[0064] In an optional embodiment, the control strategy can be further optimized, for example, by introducing an adaptive control algorithm so that the voltage control strategy can automatically adjust parameters according to the real-time state of the power grid, thereby achieving more accurate and efficient power management. In addition, the frequency control strategy can be combined with a prediction algorithm to predict the changing trend of the power grid frequency in advance, so as to respond in advance and further improve the performance of frequency modulation control.

[0065] It should be noted that the underlying logic of the control block diagram of voltage control and power control can be used as both the first voltage control strategy and the first frequency control strategy.

[0066] In an embodiment of the present application, the first hybrid control loop includes using an LC filtered three-phase inverter as an interface between the supercapacitor and the AC load, and frequency control is achieved by pumped storage / supercapacitor, and the pumped storage is connected to the supercapacitor via a DC / DC converter.

[0067] In the embodiment of the present application, frequency control is implemented by pumped storage / supercapacitor, pumped storage is connected to supercapacitor through DC / DC converter, and LC filter three-phase inverter is used as the interface between supercapacitor and AC load. Voltage control is controlled by the voltage reference value provided by the frequency controller, and consists of two independent parts, AC voltage control and DC voltage control, both of which adopt a standard cascade control structure, including a current inner loop and a voltage outer loop.

[0068] In the embodiment of the present application, the following is designed: Figure 2The topology and control block diagram of the hybrid energy storage system shown in Figure 1 shows the topology of the entire system. The pumped storage is connected to the supercapacitor through a DC / DC converter, and the supercapacitor is connected to the AC load through an LC filter three-phase inverter. The system also includes frequency control and voltage control modules to adjust the working state of the system. The pumped storage unit is connected to the grid and converts energy through water flow. The DC / DC converter is used to connect the pumped storage and the supercapacitor to achieve energy conversion between the two. The LC filter three-phase inverter serves as an interface between the supercapacitor and the AC load to ensure power quality. The supercapacitor is used to respond quickly to frequency changes. The frequency control and voltage control modules are responsible for adjusting the output of the system to maintain stability.

[0069] S102, determining an output parameter of voltage control and an input parameter of frequency control in a first hybrid control loop;

[0070] In an optional embodiment, according to the designed first hybrid control circuit, the control relationship between different controls in the hybrid control circuit is obtained, and the output parameter of one control can be used to control the output parameter of another control, and the comprehensive control of the entire system can also be achieved through the combination of several control parameters. For example, by adjusting the output parameter of the frequency control, the response of the voltage control can be directly affected, and the output parameter of the voltage control can also be adjusted to achieve a rapid response to the change of the grid frequency. In addition, by setting the output parameter of the voltage control, it can be ensured that the unit can operate stably when the grid frequency fluctuates, avoiding system instability or failure caused by excessive frequency fluctuations.

[0071] In an optional embodiment, the output parameters of the voltage control may include at least set values ​​of the AC voltage and the DC voltage, and their response times, etc.

[0072] In an optional embodiment, the input parameters of the frequency control may include the real-time measurement value of the grid frequency and the preset frequency adjustment range, etc. By accurately setting these parameters, it can be ensured that when the grid frequency fluctuates, the system can respond quickly while maintaining stable operation of the unit.

[0073] In the embodiment of the present application, the output parameter of the voltage control is set to obtain the voltage modulation signal m in the AC current loop. d With m q And the DC current loop obtains the voltage modulation signal m b , the input parameter of frequency control is set to the inverter three-phase output AC voltage V gabc With current I gabc .

[0074] It should be noted that all designed block diagrams must ensure that the target voltage control output is obtained through the power control input, then the designed block diagrams meet the requirements of this application and are within the protection scope of this application.

[0075] S103, establishing a first voltage control strategy and a first frequency control strategy based on output parameters of voltage control and input parameters of frequency control;

[0076] In the embodiment of the present application, establishing a first voltage control strategy and a first frequency control strategy based on output parameters of voltage control and input parameters of frequency control includes:

[0077] The first frequency control strategy is an arbitrary control strategy for obtaining a first output parameter by frequency controlling the current and the voltage;

[0078] The first voltage control strategy is any control strategy for performing voltage control on the first output parameter to obtain an AC voltage modulation signal and a DC voltage modulation signal.

[0079] In an optional embodiment, the first output parameter may be various parameters that can be obtained according to the current and voltage, such as the phase difference and amplitude of the current and voltage, etc. The specific design may be designed according to the actual needs of relevant technical personnel.

[0080] In the embodiment of the present application, the current and voltage are the three-phase output AC voltage and current of the inverter in the hybrid energy storage system;

[0081] In the embodiment of the present application, the first output parameter selects the output voltage reference value, the output voltage phase angle, and the adjustment amount of the DC voltage reference value, and the output voltage reference value, the output voltage phase angle, and the adjustment amount of the DC voltage reference value are calculated by combining the three-phase output AC voltage and current of the inverter in the hybrid energy storage system with the first frequency control strategy;

[0082] In an optional embodiment, various control strategies for calculating the output voltage reference value, the output voltage phase angle, and the adjustment amount of the DC voltage reference value through the three-phase output AC voltage and current of the inverter in the hybrid energy storage system should be within the protection scope of this application;

[0083] In an optional embodiment, various control strategies for performing voltage control on the output voltage reference value, the output voltage phase angle and the adjustment amount of the DC voltage reference value to obtain an AC voltage modulation signal and a DC voltage modulation signal should be within the protection scope of the present application.

[0084] In the embodiment of the present application, the first voltage control strategy includes a first AC voltage control strategy and a first DC voltage control strategy;

[0085] The first AC voltage control strategy is any control strategy whose input is some parameters of the first output parameter and whose output is an AC voltage modulation signal;

[0086] The first DC voltage control strategy is an arbitrary control strategy whose input is some parameters of the first output parameter and whose output is a DC voltage modulation signal.

[0087] In an optional embodiment, the first output parameter calculated by combining the three-phase output AC voltage and current of the inverter in the hybrid energy storage system with the first frequency control strategy is used as the input of the voltage control. The voltage control in this application is to obtain the final AC voltage modulation signal and the DC voltage modulation signal. Therefore, any type of control strategy that can obtain the AC voltage modulation signal or the DC voltage modulation signal through any number of parameters in the first output parameter should be within the protection scope of this application;

[0088] In the embodiment of the present application, the first AC voltage control strategy is as follows: Figure 4 As shown in the AC voltage control part, several parameters selected in the first output parameter are specifically output voltage reference values, and the input selected by the first DC voltage control strategy is the adjustment amount of the DC voltage reference value in the first output parameter.

[0089] In the embodiment of the present application, the active power P is obtained by the power calculation module. e and reactive power Q e , the specific formula is:

[0090]

[0091] Among them, P e is the output active power, Q e is the output reactive power, V d With V q , I d with I q The inverter three-phase output AC voltage V gabc With current I gabc The voltage and current dq components generated after Park transformation.

[0092] In the embodiment of the present application, the output reactive power Q e The output voltage reference value is generated by reactive power droop control:

[0093]

[0094] Among them, v gref is the output voltage reference value, v* is the output voltage given value, v* pu is the per unit value of the output voltage given value, Q ref is the reactive power reference value, Qrefpu is the per unit value of reactive power reference value, k q is the reactive voltage droop coefficient.

[0095] In the embodiment of the present application, the per-unit value of the frequency deviation is generated by the output voltage and the frequency reference value:

[0096]

[0097] Among them, f gpu is the per-unit value of the output frequency, Δf gpu is the per-unit value of frequency deviation, K ppll , K ipll are the proportional and integral coefficients of the phase-locked loop, s is the Laplace operator, and f ref is the output frequency reference value, f refpu It is the per-unit value of the output frequency reference value.

[0098] In the embodiment of the present application, the per-unit value of the power deviation is generated by the frequency deviation and the output power reference value:

[0099]

[0100] Among them, ΔP pu is the per-unit value of power deviation, P ref is the output power reference value, P refpu is the per-unit value of the output power reference value, R d is the power frequency droop coefficient, k p (s) is the transfer function simulating the dynamics of the governor and the intermediate reheat turbine, T G is the speed governor coefficient, F HP is the turbine HP coefficient, T RH is the time constant of the reheating device, T CH is the main inlet flow time constant.

[0101] In the embodiment of the present application, the output angular frequency and the voltage phase angle are obtained by virtual synchronous control based on frequency regulation, and the specific formula is:

[0102]

[0103] Among them, θ0 is the output voltage phase angle, ω0 is the output angular frequency, H and D are the inertia time constant and damping coefficient of VSG control respectively.

[0104] In the embodiment of the present application, the adjustment amount of the DC voltage reference value is generated by the frequency deviation:

[0105]

[0106] Where Δv cdcrefis the adjustment value of the DC voltage reference value, K fv is the frequency-voltage proportionality coefficient, v* cdc is the given value of DC voltage.

[0107] In the embodiment of the present application, the initial AC current reference value is obtained from the AC voltage loop, and the specific formula is:

[0108]

[0109] Among them, i cidref with i ciqref is the d and q axis current reference value generated by the AC voltage loop, k pv With k iv They are the proportional coefficient and integral coefficient of the AC voltage loop respectively.

[0110] In the embodiment of the present application, the voltage modulation signal m is obtained by the AC current loop. d With m q , the specific formula is:

[0111]

[0112] Among them, m d With m q is the voltage modulation signal generated by the AC current loop, I d with I q is the output current dq component, k pc With k ic are the proportional coefficient and integral coefficient of the AC current loop, v cdc is the DC voltage value. d With m q Send it to the Park inverse transform module to obtain the modulation wave m abc , and the modulation wave m abc The signal is sent to the pulse width modulation module to generate a drive signal to control the on and off of the IGBT in the inverter.

[0113] In the embodiment of the present application, the initial DC current reference value is obtained by the DC voltage loop, and the specific formula is:

[0114]

[0115] Among them, i bref k is the DC current reference value generated by the DC voltage loop, pvb With k ivb They are the proportional coefficient and integral coefficient of the DC voltage loop respectively.

[0116] In the embodiment of the present application, the voltage modulation signal m is obtained by the DC current loop. b , the specific formula is:

[0117]

[0118] Among them, m b is the voltage modulation signal generated by the DC current loop, i b is the DC current value, k pcb With k icb are the proportional coefficient and integral coefficient of the DC current loop, v b is the energy storage voltage value. b The signal is sent to the pulse width modulation module to generate a drive signal to control the on and off of the IGBT in the inverter.

[0119] It should be noted that establishing a first voltage control strategy based on output parameters of voltage control and input parameters of frequency control and a first frequency control strategy can achieve rapid and accurate control of grid frequency and voltage, thereby improving the stability and response speed of the entire power system. Through this control strategy, the system can dynamically adjust the output according to the real-time needs of the power grid to ensure the continuity and reliability of power supply. In addition, the strategy can also optimize the charging and discharging process of energy storage equipment, extend the service life of the equipment, and reduce energy loss. In practical applications, this control method can effectively cope with fluctuations in grid load, especially during peak hours or in emergency situations, to ensure the stable operation of the power system.

[0120] S104, performing a frequency modulation control according to the first voltage control strategy and the first frequency control strategy.

[0121] In the embodiment of the present application, performing a frequency modulation control according to the first voltage control strategy and the first frequency control strategy includes:

[0122] Calculating a frequency-voltage proportionality coefficient based on power distribution between pumped storage and supercapacitors according to a first voltage control strategy and a first frequency control strategy;

[0123] A frequency modulation control is performed according to the frequency-voltage proportional coefficient.

[0124] In the embodiment of the present application, the frequency-voltage proportional coefficient based on the power distribution between the pumped storage and the supercapacitor is calculated according to the first voltage control strategy and the first frequency control strategy, including:

[0125] Calculate the total power change of the energy storage system including pumped storage and supercapacitors;

[0126] Split the total power change into slow-changing power and fast-changing power:

[0127] The slow-changing power and the fast-changing power in the total power change are allocated to the pumped storage and the supercapacitor respectively;

[0128] The power change of the supercapacitor is expressed by differentiating the energy stored in the supercapacitor;

[0129] Let the power change of the supercapacitor be equal to the fast power change to obtain the relationship between frequency and voltage;

[0130] The frequency-voltage proportionality coefficient based on the power distribution between pumped storage and supercapacitors is calculated.

[0131] Specifically, the total power change of the hybrid energy storage system is calculated:

[0132]

[0133] Among them, ΔP tpu is the total power change of the hybrid energy storage system, ΔP e is the power variation caused by load and new energy.

[0134] In the embodiment of the present application, the total power change is divided into p (s) and the slow-changing power including Δf gpu Fast changing power with respect to the time derivative:

[0135]

[0136] In the embodiment of the present application, the slow-changing power and the fast-changing power in the total power change are respectively allocated to the pumped storage and the supercapacitor:

[0137]

[0138] Among them, ΔP bpu Indicates the per-unit value of the power change of pumped storage, ΔP cpu Indicates the per-unit value of the supercapacitor power change.

[0139] In the embodiment of the present application, the power change of the supercapacitor is represented by differentiating the energy stored in the supercapacitor:

[0140]

[0141] Where Δv cdcpu Indicates the per unit value of DC voltage regulation, C dc Indicates the size of the supercapacitor.

[0142] In the embodiment of the present application, the power change of the supercapacitor is equal to the fast power change to obtain the relationship between frequency and voltage:

[0143]

[0144] In the embodiment of the present application, the frequency-voltage proportionality coefficient based on the power distribution between the pumped storage and the supercapacitor is calculated:

[0145]

[0146] It should be noted that this application proposes a primary frequency regulation control method for an energy storage enhanced full-power pumped storage unit, which equips the full-power pumped storage unit with a hybrid energy storage system with frequency regulation capability, so that the supercapacitor can cope with high-frequency power fluctuations and the pumped storage can compensate for long-term slow power fluctuations, giving full play to the advantages of supercapacitors and pumped storage to improve the operating efficiency and service life of the full-power pumped storage unit and reduce system costs. In addition, the frequency regulation control method does not rely on the traditional low-pass / high-pass filter design, and can directly obtain the various control parameters of the hybrid energy storage system and the power benchmarks of the supercapacitor and pumped storage based on the traditional virtual synchronous generator control parameters.

[0147] This embodiment also provides an energy storage enhanced full-power pumped storage unit primary frequency regulation control system, including:

[0148] A loop building module, used for building a first hybrid control loop including voltage control and frequency control;

[0149] A parameter determination module, used to determine an output parameter of voltage control and an input parameter of frequency control in the first hybrid control loop;

[0150] A strategy establishing module, used to establish a first voltage control strategy and a first frequency control strategy based on an output parameter of voltage control and an input parameter of frequency control;

[0151] The control module is used to perform a frequency modulation control according to a first voltage control strategy and a first frequency control strategy.

[0152] The above-mentioned unit modules may be embedded in or independent of a processor in a computer device in the form of hardware, or may be stored in a memory in a computer device in the form of software, so that the processor can call and execute operations corresponding to the above-mentioned modules.

[0153] This embodiment also provides a computer device, which may be a terminal, and its internal structure diagram may be as shown in FIG. Figure 7As shown. The computer device includes a processor, a memory, a communication interface, a display screen and an input device connected through a system bus. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be achieved through WIFI, an operator network, NFC (near field communication) or other technologies. When the computer program is executed by the processor, a primary frequency modulation control method of a full-power pumped storage unit with energy storage enhancement is implemented. The display screen of the computer device can be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device can be a touch layer covered on the display screen, or a key, trackball or touchpad set on the computer device shell, or an external keyboard, touchpad or mouse.

[0154] This embodiment further provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the following steps are implemented:

[0155] constructing a first hybrid control loop including voltage control and frequency control;

[0156] determining an output parameter of a voltage control and an input parameter of a frequency control in a first hybrid control loop;

[0157] Establishing a first voltage control strategy and a first frequency control strategy based on output parameters of voltage control and input parameters of frequency control;

[0158] A frequency modulation control is performed according to the first voltage control strategy and the first frequency control strategy.

[0159] Example 2

[0160] Reference Figure 2-Figure 6 , which is an embodiment of the present invention, provides a primary frequency regulation control method and system for a full-power pumped storage unit with energy storage enhancement. In order to verify the beneficial effects of the present invention, scientific demonstration is carried out through experiments.

[0161] The specific parameters of the example are shown in Table 1.

[0162] Table 1 Pumped storage unit and controller parameters

[0163]

[0164] Figure 2It is a topology and control block diagram of a hybrid energy storage system based on frequency regulation proposed in the present invention, wherein frequency regulation is achieved by pumped storage / supercapacitor, pumped storage is connected to supercapacitor through DC / DC converter, and LC filter three-phase inverter is used as the interface between supercapacitor and AC load. The voltage controller is controlled by the voltage reference value provided by the frequency controller, and consists of two independent parts, AC voltage control and DC voltage control, both of which adopt a standard cascade control structure, including a current inner loop and a voltage outer loop.

[0165] like Figure 3 The frequency control block diagram is shown in Figure 1. The entire system adjusts input signals (such as frequency and voltage) and maintains the stability of the output frequency through various control loops (such as PLL and PID controller).

[0166] like Figure 4 Voltage control block diagram, AC voltage control part: The AC voltage loop generates d and q axis current reference values, which are then used to generate voltage modulation signals through the AC current loop, and finally sent to the Park inverse transformation module to generate modulation waves to control the IGBT in the inverter. DC voltage control part: The DC voltage loop generates a DC current reference value, which is then used to generate voltage modulation signals through the DC current loop, and then sent to the pulse width modulation module to generate drive signals to control the IGBT in the inverter.

[0167] Figure 5 The DC voltage response and frequency change rate response of the system when the load increases by 50%. It can be seen that the full-power pumped storage unit exhibits an inertial frequency response similar to that of a traditional synchronous generator. While the DC voltage tracks its reference value, its change is consistent with the change in the system frequency change rate. The change in DC voltage compensates for high-frequency power fluctuations, so pumped storage only needs to compensate for slowly changing power.

[0168] Figure 6 The power response of the system when the load increases by 50%, that is, the power distribution between the supercapacitor and the pumped storage. It can be seen that the supercapacitor can respond quickly to frequency events and provide rapid power changes, so that the pumped storage can slowly compensate for low-frequency power fluctuations. The hybrid energy storage system exhibits good power management capabilities and frequency response characteristics.

[0169] In summary, the present invention proposes a primary frequency regulation control method for a full-power pumped storage unit with energy storage enhancement, constructing a first hybrid control loop including voltage control and frequency control; determining the output parameters of the voltage control and the input parameters of the frequency control in the first hybrid control loop; establishing a first voltage control strategy and a first frequency control strategy based on the output parameters of the voltage control and the input parameters of the frequency control; and performing a primary frequency regulation control according to the first voltage control strategy and the first frequency control strategy. The method can realize the power management of the full-power pumped storage unit, so that the supercapacitor in the hybrid energy storage system can cope with high-frequency power fluctuations, and the pumped storage can compensate for relatively long-term and dynamic slow power fluctuations. Under such power distribution, the power fluctuation and its change rate of the pumped storage can be greatly reduced, and the advantages of the supercapacitor and pumped storage can be fully utilized to improve the operating efficiency and service life of the full-power pumped storage unit, and reduce the system cost. Moreover, the frequency regulation control method does not rely on the traditional low-pass / high-pass filter design, and each control parameter and the power reference of the supercapacitor and pumped storage can be easily obtained by simulating the traditional virtual synchronous generator control.

[0170] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

[0171] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of complete hardware embodiments, complete software embodiments, or embodiments in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code. The scheme in the embodiments of the present application can be implemented in various computer languages, for example, object-oriented programming language Java and literal scripting language JavaScript, etc.

[0172] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0173] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0174] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0175] Although the preferred embodiments of the present application have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present application.

[0176] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A primary frequency regulation control method for an energy storage enhanced full-power pumped storage unit, characterized in that: include: constructing a first hybrid control loop including voltage control and frequency control; determining an output parameter of a voltage control and an input parameter of a frequency control in a first hybrid control loop; Establishing a first voltage control strategy and a first frequency control strategy based on output parameters of voltage control and input parameters of frequency control; A frequency modulation control is performed according to the first voltage control strategy and the first frequency control strategy.

2. The primary frequency regulation control method of the energy storage enhanced full-power pumped storage unit according to claim 1, characterized in that: The first hybrid control loop including voltage control and frequency control is constructed as follows: The voltage control includes AC voltage control and DC voltage control; The AC voltage control and the DC voltage control are independently controlled; A first AC voltage control strategy is preset to perform AC voltage control, and a first DC voltage control strategy is preset to perform DC voltage control.

3. The primary frequency regulation control method of the energy storage enhanced full-power pumped storage unit according to claim 2, characterized in that: The establishing of a first voltage control strategy and a first frequency control strategy based on output parameters of voltage control and input parameters of frequency control comprises: The first frequency control strategy is an arbitrary control strategy for obtaining a first output parameter by frequency controlling current and voltage; The first voltage control strategy is any control strategy for performing voltage control on the first output parameter to obtain an AC voltage modulation signal and a DC voltage modulation signal.

4. The primary frequency regulation control method of the energy storage enhanced full-power pumped storage unit according to claim 3, characterized in that: The first voltage control strategy includes a first AC voltage control strategy and a first DC voltage control strategy; The first AC voltage control strategy is any control strategy whose input is some parameters of the first output parameter and whose output is an AC voltage modulation signal; The first DC voltage control strategy is an arbitrary control strategy whose input is some parameters of the first output parameter and whose output is a DC voltage modulation signal.

5. The primary frequency regulation control method of the energy storage enhanced full-power pumped storage unit according to claim 4, characterized in that: The first hybrid control loop includes using an LC filtered three-phase inverter as an interface between the supercapacitor and the AC load, and frequency control is achieved by pumped storage / supercapacitor, and the pumped storage is connected to the supercapacitor through a DC / DC converter.

6. The primary frequency regulation control method of the energy storage enhanced full-power pumped storage unit according to claim 5, characterized in that: The performing frequency modulation control according to the first voltage control strategy and the first frequency control strategy includes: Calculating a frequency-voltage proportionality coefficient based on power distribution between pumped storage and supercapacitors according to the first voltage control strategy and the first frequency control strategy; A frequency modulation control is performed according to the frequency-voltage proportionality coefficient.

7. The primary frequency regulation control method of the energy storage enhanced full-power pumped storage unit according to claim 6, characterized in that: The calculation of the frequency-voltage proportionality coefficient based on the power distribution between the pumped storage and the supercapacitor according to the first voltage control strategy and the first frequency control strategy includes: Calculate the total power change of the energy storage system including pumped storage and supercapacitors; Split the total power change into slow-changing power and fast-changing power: The slow-changing power and the fast-changing power in the total power change are allocated to the pumped storage and the supercapacitor respectively; The power change of the supercapacitor is expressed by differentiating the energy stored in the supercapacitor; Let the power change of the supercapacitor be equal to the fast power change to obtain the relationship between frequency and voltage; The frequency-voltage proportionality coefficient based on the power distribution between pumped storage and supercapacitors is calculated.

8. A primary frequency regulation control system for a full-power pumped storage unit with enhanced energy storage, characterized in that: include: A loop building module, used for building a first hybrid control loop including voltage control and frequency control; A parameter determination module, used to determine an output parameter of voltage control and an input parameter of frequency control in the first hybrid control loop; A strategy establishing module, used to establish a first voltage control strategy and a first frequency control strategy based on output parameters of voltage control and input parameters of frequency control; A control module is used to perform a frequency modulation control according to the first voltage control strategy and the first frequency control strategy.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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