Grid-connected hybrid control method for direct-driven compressed air energy storage expansion power generation system

Abstract

The invention relates to the technical field of novel energy, in particular to a direct-drive type compressed air energy storage expansion power generation system grid-connected hybrid control method which comprises the following steps: acquiring operation parameters of a compressed air energy storage expansion power generation system at the current moment; adjusting the rotating speed of an expansion machine in the compressed air energy storage expansion power generation system based on the operating parameters at the current moment and the operating parameters at the previous moment, and detecting the output power of the compressed air energy storage expansion power generation system; if the output power of the compressed air energy storage expansion power generation system reaches the target power, the target expansion ratio and the target mass flow rate of an expansion machine are calculated according to the target demand power of the compressed air energy storage expansion power generation system, and the expansion machine is controlled through the target parameter expansion ratio and the target mass flow rate; the compressed air energy storage expansion power generation system is controlled to be connected to the grid through the expansion machine. Therefore, the problems that in the prior art, it is difficult to achieve higher efficiency while the system power is met, and the system energy efficiency is limited are solved.

Description

Technical Field

[0001] The present application relates to the field of new energy technologies, and in particular to a grid-connected hybrid control method for a direct-drive compressed air energy storage expansion power generation system. Background Art

[0002] As an advanced energy storage technology, CAES (Compressed Air Energy Storage) has the advantages of high efficiency and long cycle. It can provide reliable peak load regulation, voltage regulation, frequency regulation and other auxiliary service support for the power system, promote the development of clean energy, and open up a promising road for sustainable energy development. It plays an important role in the field of energy storage. However, there are still few related studies on the power generation mode of compressed air energy storage expansion power generation system and its interface with the power system. There is also a lack of literature on the power generation mode and control strategy of compressed air energy storage expansion power generation system.

[0003] At present, the grid-connected control strategy of compressed air energy storage expansion power generation system is limited to single maximum power or maximum efficiency control. It is difficult to achieve higher efficiency while meeting the system power, and the system energy efficiency needs to be further improved. Summary of the invention

[0004] The present application provides a direct-drive compressed air energy storage expansion power generation system grid-connected hybrid control method to solve the problems in related technologies such as difficulty in achieving higher efficiency while meeting system power and limitations on system energy efficiency.

[0005] The first aspect of the present application provides a direct-drive compressed air energy storage expansion power generation system grid-connected hybrid control method, including the following steps: obtaining the operating parameters of the compressed air energy storage expansion power generation system at the current moment; adjusting the speed of the expander in the compressed air energy storage expansion power generation system based on the operating parameters at the current moment and the operating parameters at the previous moment, and detecting the output power of the compressed air energy storage expansion power generation system; if the output power of the compressed air energy storage expansion power generation system reaches the target power, calculating the target expansion ratio and target mass flow rate of the expander according to the target demand power of the compressed air energy storage expansion power generation system, using the target expansion ratio and target mass flow rate to control the expander, and controlling the compressed air energy storage expansion power generation system to be connected to the grid through the expander.

[0006] Optionally, the operating parameters include at least one of DC bus voltage and current, a rotational speed of the expander, an expansion ratio and a mass flow rate.

[0007] Optionally, based on the operating parameters at the current moment and the operating parameters at the previous moment, the speed of the expander in the compressed air energy storage expansion power generation system is adjusted, including: calculating the power at the previous moment based on the DC bus voltage and current at the previous moment; after increasing the speed of the expander at the previous moment by a target step size, calculating the power at the current moment based on the DC bus voltage and current at the current moment; respectively calculating the speed difference and power difference between the current moment and the previous moment; and adjusting the speed of the expander in the compressed air energy storage expansion power generation system based on the speed difference and power difference.

[0008] Optionally, the speed of the expander in the compressed air energy storage expansion and power generation system is adjusted based on the speed difference and the power difference, including: if the speed difference and the power difference are both less than the target value, the speed of the expander is increased by the target step size, otherwise the speed of the expander is reduced by the target step size.

[0009] Optionally, before calculating the target expansion ratio and target mass flow rate of the expander according to the target required power of the compressed air energy storage expansion power generation system, it also includes: obtaining the design parameters of the expander; calculating the target expansion ratio and target mass flow rate ratio of the expander according to the design parameters and the target required power.

[0010] Optionally, calculating a target expansion ratio and a target mass flow rate of the expander according to the design parameters and the target required power includes: calculating a target speed of the expander according to the design parameters and the target required power; calculating a target expansion ratio and a target mass flow rate of the expander according to the design parameters and the target speed.

[0011] The second aspect of the present application provides a direct-drive compressed air energy storage expansion power generation system grid-connected hybrid control device, including: an acquisition module, used to obtain the operating parameters of the compressed air energy storage expansion power generation system at the current moment; an adjustment module, used to adjust the speed of the expander in the compressed air energy storage expansion power generation system based on the operating parameters at the current moment and the operating parameters at the previous moment, and detect the output power of the compressed air energy storage expansion power generation system; a control module, used to calculate the target expansion ratio and target mass flow rate of the expander according to the target demand power of the compressed air energy storage expansion power generation system if the output power of the compressed air energy storage expansion power generation system reaches the target power, use the target expansion ratio and target mass flow rate to control the expander, and control the compressed air energy storage expansion power generation system to be connected to the grid through the expander.

[0012] Optionally, the operating parameters include at least one of DC bus voltage and current, a rotational speed of the expander, an expansion ratio and a mass flow rate.

[0013] Optionally, the adjustment module is further used to: calculate the power at the previous moment based on the DC bus voltage and current at the previous moment; after increasing the speed of the expander at the previous moment by a target step size, calculate the power at the current moment based on the DC bus voltage and current at the current moment; respectively calculate the speed difference and power difference between the current moment and the previous moment; and adjust the speed of the expander in the compressed air energy storage expansion power generation system based on the speed difference and power difference.

[0014] Optionally, the adjustment module is further used to: if the speed difference and the power difference are both smaller than the target values, increase the speed of the expander by the target step length; otherwise, reduce the speed of the expander by the target step length.

[0015] Optionally, it also includes: a first acquisition module, which is used to obtain the design parameters of the expander before calculating the target expansion ratio and target mass flow rate of the expander according to the target required power of the compressed air energy storage expansion power generation system; and calculate the target expansion ratio and target mass flow rate of the expander according to the design parameters and the target required power.

[0016] Optionally, the first acquisition module is further used to: calculate a target speed of the expander according to the design parameters and the target required power; calculate a target expansion ratio and a target mass flow rate of the expander according to the design parameters and the target speed.

[0017] The third aspect of the present application provides an electronic device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to execute a grid-connected hybrid control method for a direct-drive compressed air energy storage expansion power generation system as in the above-mentioned embodiment.

[0018] The fourth aspect of the present application provides a computer-readable storage medium on which a computer program or instruction is stored. The computer program or instruction is executed by a processor to perform a grid-connected hybrid control method for a direct-drive compressed air energy storage expansion power generation system as in the above-mentioned embodiment.

[0019] The fifth aspect of the present application provides a computer program product, including a computer program or instructions. When the computer program or instructions are executed, a grid-connected hybrid control method for a direct-drive compressed air energy storage expansion power generation system as in the above-mentioned embodiment is implemented.

[0020] Therefore, this application has at least the following beneficial effects:

[0021] The embodiment of the present application can adjust the speed of the expander in the compressed air energy storage power generation system according to the operating parameters of the compressed air energy storage expansion power generation system at the current moment and the previous moment until the output power reaches the target power, and calculate the target mass flow and target expansion ratio of the expander according to the target demand power. The target mass flow and target expansion ratio are related to the maximum efficiency. The expander is controlled by using the target mass flow and target expansion ratio to further optimize the energy efficiency of the compressed air energy storage power generation system, and can achieve higher efficiency while meeting the demand power, ensuring that the compressed air energy storage power generation system can efficiently and stably output electrical energy when connected to the grid, and ensuring that the compressed air energy storage power generation system can reach the optimal state under different operating conditions. As a result, the technical problems in the related technology such as it is difficult to achieve higher efficiency while meeting the system power and the system energy efficiency is limited are solved.

[0022] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0024] Figure 1 A schematic diagram of a grid-connected model of a direct-drive compressed air energy storage expansion power generation system provided according to an embodiment of the present application;

[0025] Figure 2 A flowchart of a direct-drive compressed air energy storage expansion power generation system grid-connected hybrid control and a compressed air energy storage expansion power generation system grid-connected hybrid control method provided according to an embodiment of the present application;

[0026] Figure 3 A flow chart of a grid-connected hybrid control strategy for a direct-drive compressed air energy storage expansion power generation system provided according to an embodiment of the present application;

[0027] Figure 4 This is an example diagram of a grid-connected hybrid control device for a direct-drive compressed air energy storage expansion power generation system provided according to an embodiment of the present application;

[0028] Figure 5 It is a schematic diagram of the structure of an electronic device provided according to an embodiment of the present application. DETAILED DESCRIPTION

[0029] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0030] The following describes a direct-drive compressed air energy storage expansion power generation system grid-connected hybrid control method of an embodiment of the present application with reference to the accompanying drawings. In view of the problem mentioned in the background technology center that the current grid-connected control strategy of the compressed air energy storage expansion power generation system is limited to a single maximum power or maximum efficiency control, it is difficult to achieve higher efficiency while meeting the system power, and the system energy efficiency needs to be further improved, the present application provides a direct-drive compressed air energy storage expansion power generation system grid-connected hybrid control method, in which the speed of the expander in the compressed air energy storage power generation system can be adjusted according to the operating parameters of the compressed air energy storage expansion power generation system at the current moment and the previous moment until the output power reaches the target power, and the target mass flow rate and target expansion ratio of the expander are calculated according to the target demand power, the target mass flow rate, the target expansion ratio and the maximum efficiency are related, and the expander is controlled by using the target mass flow rate and the target expansion ratio to further optimize the energy efficiency of the compressed air energy storage power generation system, and can achieve higher efficiency while meeting the demand power, ensuring that the compressed air energy storage power generation system can efficiently and stably output electrical energy when connected to the grid, and ensuring that the compressed air energy storage power generation system can reach the optimal state under different operating conditions. As a result, the problems in related technologies such as difficulty in achieving higher efficiency while meeting system power and limitation of system energy efficiency are solved.

[0031] Before implementing the solution of the present application, it should be noted that the present application starts from an ideal state and, under adiabatic conditions, focuses on the expansion power generation part, simplifies the compressed air energy storage expansion power generation system, studies the principles and characteristics of the main components, and constructs a mathematical model to establish a direct-drive compressed air energy storage expansion power generation system grid-connected model. The solutions of the present application are all implemented by laying out the model.

[0032] like Figure 1 As shown, the direct-drive compressed air energy storage expansion power generation system grid-connected model includes a compressed air energy storage gas storage device, a throttle valve, an expander, a synchronous generator, a rectifier, and an inverter.

[0033] 1. Gas storage device

[0034] The gas storage device plays the role of storing compressed air in the compressed air energy storage expansion power generation system, which is equivalent to an energy transfer station for the entire system. The gas storage device can be an underground salt mine, cave, etc., or a gas tank can be used instead. According to the conservation of energy and momentum, the entire operation process of the gas storage device is considered at the same time, and the state equation of its internal pressure and temperature change is obtained:

[0035]

[0036] in, represents the intake air mass flow rate, Indicates the gas mass flow rate, m is the mass of the gas in the gas storage unit, h ac is the heat transfer efficiency between the gas and the wall of the gas storage unit, A c is the wall area of ​​the gas storage unit, T is the air temperature in the gas storage unit, T ac is the wall temperature of the gas storage unit, c p is the constant pressure specific heat capacity of air, c v is the constant volume specific heat capacity of air, R g is the gas constant, T in is the inlet temperature, T out is the outlet temperature.

[0037] 2. Throttle valve

[0038] The turbine inlet throttling control can adjust the air flow. By adjusting the valve opening, the pipeline resistance can be changed, so that the flow rate on both sides of the throttle valve reaches the preset value. According to the Bernoulli equation and the fluid continuity equation, the throttle valve flow equation under ideal conditions is derived as follows:

[0039]

[0040] In the formula, m TV A is the valve flow rate; TV Represents the flow area, which is a design parameter; is the throttle valve inlet pressure

[0041] 3. Expander

[0042] The expander is a core component in the compressed air energy storage expansion power generation system. It converts the compressed air energy stored in the high-pressure gas tank into mechanical energy. When the system needs to generate electricity, the high-pressure air in the gas tank is released to drive the expander to operate. The output power of the expander is related to the inlet air pressure, temperature, and flow rate. The output power and output torque are as follows:

[0043]

[0044] Among them, C pis the constant pressure specific heat capacity, k is the heat capacity ratio, k of air is 1.4, T is the total temperature at the inlet of the centripetal turbine, π, G, n are the centripetal turbine expansion ratio, flow rate, and speed respectively, and η is the centripetal turbine efficiency; T m is the output torque.

[0045] 4. Permanent magnet synchronous generator

[0046] The permanent magnet synchronous generator converts the mechanical energy stored in compressed air into electrical energy; when the system needs to release the stored energy, the permanent magnet synchronous generator starts to rotate and converts its kinetic energy into electrical energy. The permanent magnet synchronous generator eliminates the complex excitation winding and has the advantages of simple structure, low cost, reliable operation, and no excitation loss, which is conducive to improving the power density and efficiency of the system. In addition, the permanent magnet synchronous generator can adjust the speed and frequency, which is conducive to the optimization design of the compressed air energy storage expansion power generation system. Its voltage and current equation is:

[0047]

[0048] The mechanical motion equation is:

[0049]

[0050] Among them, T e =3 / 2p[(L d -L q )i sd i sq +ψ f i sq ]; (1g)

[0051] Considering that the proportion of stator copper loss and iron loss relative to output power is very small and can be ignored, it is assumed that the generator output active power P s and electromagnetic power P e equal:

[0052] P s =P e =ω r T e ; (1h)

[0053] In the formula, u d 、u q 、i sd 、i sq are the components of the stator voltage and stator current on the d-axis and q-axis respectively, is the rotor flux, R s is the stator resistance; L d , L q is the stator direct-axis and quadrature-axis inductance, ω s ,ω rare the electrical angular velocity and the rotor mechanical angular velocity respectively, p is the number of generator pole pairs, J is the rotor moment of inertia, T e 、T m They are electromagnetic torque and mechanical torque respectively.

[0054] 5. Rectifier and inverter

[0055] Rectifiers are used to convert AC to DC, and inverters are used to convert DC to AC. These two devices play a key role in the power system, allowing different types of power supplies and electronic devices to be compatible and work together.

[0056] The power output of the magnetic synchronous motor is transmitted to the load through the rectifier and inverter. The converter adopts a dual pulse width modulation structure. The use of a suitable coordinated control strategy for the dual PWM converter can achieve a real-time balance between the expander output and demand, so that the output of the expansion power generation system changes with the power demand rate command. The model of the rectifier under the d and q axes is:

[0057]

[0058] The inverter model under the d and q axes is:

[0059]

[0060] In the formula, e d 、e q 、i gd 、i gq are the d-axis and q-axis components of the load-side voltage and current, respectively, v dc is the DC side voltage, C is the DC side capacitance, R g , L g is the equivalent resistance and inductance on the load side, i s is the current flowing out of the rectifier, i g is the inverter current.

[0061] Specifically, Figure 2 A flow chart of a grid-connected hybrid control method for a direct-drive compressed air energy storage expansion power generation system provided in an embodiment of the present application.

[0062] like Figure 1 As shown, the grid-connected control method of the compressed air energy storage expansion power generation system includes the following steps:

[0063] In step S101, the operating parameters of the compressed air energy storage expansion power generation system at the current moment are obtained.

[0064] The operating parameters include at least one of the DC bus voltage and current, the speed of the expander, the expansion ratio and the mass flow rate.

[0065] In step S102, based on the operating parameters at the current moment and the operating parameters at the previous moment, the speed of the expander in the compressed air energy storage expansion power generation system is adjusted, and the output power of the compressed air energy storage expansion power generation system is detected.

[0066] It can be understood that the embodiment of the present application can adjust the speed of the expander in the compressed air energy storage power generation system based on the operating parameters at the current moment and the operating parameters at the previous moment, and detect the output power of the compressed air energy storage expansion power generation system to achieve the maximum output of the output power of the compressed air energy storage expansion power generation system. The specific adjustment method is as follows.

[0067] In an embodiment of the present application, the speed of the expander in the compressed air energy storage expansion power generation system is adjusted based on the operating parameters at the current moment and the operating parameters at the previous moment, including: calculating the power at the previous moment based on the DC bus voltage and current at the previous moment; after increasing the speed of the expander at the previous moment by a target step size, calculating the power at the current moment based on the DC bus voltage and current at the current moment; respectively calculating the speed difference and power difference between the current moment and the previous moment; and adjusting the speed of the expander in the compressed air energy storage expansion power generation system based on the speed difference and the power difference.

[0068] It can be understood that the embodiment of the present application can calculate the power at the current moment and the power at the previous moment based on the DC bus voltage and current at the previous moment, respectively, and adjust the speed of the expander based on the power difference and the speed difference.

[0069] In an embodiment of the present application, the speed of the expander in the compressed air energy storage expansion and power generation system is adjusted based on the speed difference and the power difference, including: if the speed difference and the power difference are both less than the target value, the speed of the expander is increased by the target step size, otherwise the speed of the expander is reduced by the target step size.

[0070] The target value and the target step length may be pre-set according to specific circumstances, for example, the target value is 0 and the target step length is 10 rpm.

[0071] It can be understood that in the embodiment of the present application, when the speed difference and the power difference are both smaller than the target value, the speed of the expander can be increased by the target step size, otherwise the speed of the expander can be reduced by the target step size, until the output power of the compressed air energy storage expansion power generation system reaches the target power, wherein the target power is the maximum output power.

[0072] Specifically, the embodiment of the present application can use the perturbation observation method in the self-optimization algorithm to construct a maximum power tracking control strategy for the compressed air energy storage expansion power generation system. By increasing or decreasing the speed of the expander and the synchronous generator in the compressed air energy storage expansion power generation system, the direction of change of the generator output power is analyzed, so that the speed at the next moment is always in the direction of increasing power, for example:

[0073] Use the fixed-step perturbation observation method to set the step size of the speed change, read the DC bus voltage and current to calculate the power at the current moment. Then the speed increases by one step, and the DC bus voltage and current are obtained to calculate the power at this time, and the current speed and power are subtracted from the previous moment to determine the direction of speed and power change. If the power difference is less than zero and the speed difference is less than zero, the speed increases by one step; if the power difference is less than zero and the speed difference is greater than zero, the speed decreases by one step; if the power difference is greater than zero and the speed difference is greater than zero, the speed decreases by one step; if the power difference is greater than zero and the speed difference is less than zero, the speed decreases by one step, so that the speed of the generator and expander is consistent with the preset speed, where the preset speed is the speed corresponding to the maximum power.

[0074] In step S103, if the output power of the compressed air energy storage expansion power generation system reaches the target power, the target expansion ratio and target mass flow rate of the expander are calculated according to the target demand power of the compressed air energy storage expansion power generation system, and the expander is controlled by the target expansion ratio and target mass flow rate, and the compressed air energy storage expansion power generation system is connected to the grid through the expander.

[0075] It can be understood that in the embodiment of the present application, when the output power of the compressed air energy storage expansion power generation system reaches the target power, the target mass flow rate and target expansion ratio of the expander are calculated according to the target demand power of the compressed air energy storage expansion power generation system, and the expander is controlled by using the target mass flow rate and target expansion ratio. The compressed air energy storage expansion power generation system is connected to the grid through the expander, so that the compressed air energy storage expansion power generation system can work at the maximum efficiency as much as possible, so as to improve the energy efficiency of the compressed air energy storage expansion power generation system and ensure that the compressed air energy storage expansion power generation system can output electricity efficiently and stably when connected to the grid.

[0076] In an embodiment of the present application, before calculating the target expansion ratio and target mass flow rate of the expander according to the target demand power of the compressed air energy storage expansion power generation system, it also includes: obtaining the design parameters of the expander; calculating the target expansion ratio and target mass flow rate of the expander based on the design parameters and the target demand power.

[0077] Among them, the design parameters include design flow, design expansion ratio, design speed, specific heat capacity, temperature, polytropic index, design efficiency, etc.

[0078] It can be understood that the embodiment of the present application can calculate the target expansion ratio and target mass flow rate of the expander according to the design parameters of the expander and the target required power. The specific calculation method is as follows.

[0079] In an embodiment of the present application, a target expansion ratio and a target mass flow rate of the expander are calculated according to a target required power of a compressed air energy storage expansion power generation system, including: calculating a target speed of the expander based on design parameters and target required power; calculating a target expansion ratio and a target mass flow rate of the expander according to design parameters and target speed.

[0080] It can be understood that the embodiment of the present application can calculate the target speed of the expander according to the design parameters and the target required power, and calculate the target expansion ratio and the target mass flow rate based on the target speed and the design parameters. The specific calculation method is as follows.

[0081] Specifically, the maximum efficiency tracking is controlled as follows: according to the target demand power, the optimized expansion ratio (target expansion ratio) and the optimized mass flow rate (target mass flow rate) of the expander under the demand power are calculated according to formula (2c) and formula (2d), so that the compressed air energy storage expansion power generation system can track its efficiency curve as much as possible when the power demand changes, thereby improving the efficiency of the expander and achieving the purpose of reducing energy waste.

[0082] When the speed changes, in order to achieve the highest expander efficiency, the relationship between the expander speed, flow rate and expansion ratio should satisfy:

[0083]

[0084]

[0085] Where G is the flow rate of the expander when it is working, π is the expansion ratio of the expander when it is working, n is the speed of the expander, and n d , G d , π d are the design flow rate, design speed and design expansion ratio respectively. From formula (2a) and formula (2b), it can be seen that there is a coupling relationship between the flow rate and the expansion ratio, which is shown in formula (2c) after sorting:

[0086]

[0087] Substituting formula (2c) into formula (1c) yields:

[0088]

[0089] Wherein, P is the power given value (target required power), and m is the number of stages of the multi-stage expansion system. When the power given value is constant, the expansion ratio when the expander efficiency is maximum can be calculated by formula (2d).

[0090] In summary, the grid-connected control method of the compressed air energy storage expansion power generation system of the embodiment of the present application is mainly divided into two parts: a maximum power tracking control method (controlling the rotation speed of the expander to enable the system to quickly output the maximum power) and a maximum efficiency tracking control method (controlling the expansion ratio of the expander and the throttle valve opening to control the intake mass flow rate so that the system can operate at optimal efficiency under different required power conditions).

[0091] Combining the two, with demand power as the coupling condition, the maximum power control is used in the initial operation of the compressed air energy storage expansion power generation system to quickly maximize the output power, and then switch to maximum efficiency tracking control to adjust the system expansion ratio and air mass flow rate to make it track the maximum efficiency curve as much as possible, further improving the system energy efficiency, and thus ensuring that the compressed air energy storage expansion power generation system can output electricity efficiently and stably when connected to the grid.

[0092] Specifically, the grid-connected hybrid control strategy process of the compressed air energy storage expansion power generation system is as follows: Figure 3 As shown, including:

[0093] 1. Maximum Power Tracking

[0094] 1. Use the fixed-step perturbation observation method to set the step size of the speed change.

[0095] 2. Read the DC bus voltage and current to calculate the power at the current moment.

[0096] 3. The speed increases by one step, and the DC bus voltage and current are obtained to calculate the power at this time. The current speed and power are subtracted from the previous moment to determine the direction of speed and power change.

[0097] 4. Determine the power difference. If the power difference is less than zero and the speed difference is less than zero, the speed will increase by one step; if the power difference is less than zero and the speed difference is greater than zero, the speed will decrease by one step; if the power difference is greater than zero and the speed difference is greater than zero, the speed will decrease by one step; if the power difference is greater than zero and the speed difference is less than zero, the speed will decrease by one step, so that the speed of the generator and expander is consistent with the preset speed.

[0098] 2. Maximum efficiency tracking

[0099] 1. Obtain target power, required power, mass flow rate, speed, expansion ratio design value, etc.

[0100] 2. The required power and the expansion ratio and mass flow rate at the corresponding target speed are calculated according to formulas (2d) and (2c), which have been described in the above embodiments and will not be repeated here.

[0101] According to the grid-connected hybrid control method for a direct-drive compressed air energy storage expansion power generation system proposed in the embodiment of the present application, the rotation speed of the expander in the compressed air energy storage expansion power generation system can be adjusted according to the operating parameters of the compressed air energy storage expansion power generation system at the current moment and the previous moment until the output power reaches the target power, and the target expansion ratio and target mass flow rate of the expander are calculated according to the target demand power. The target expansion ratio and target mass flow rate are related to the maximum efficiency. The expander is controlled by using the target mass flow rate and the target expansion ratio to further optimize the energy efficiency of the compressed air energy storage power generation system, and higher efficiency can be achieved while meeting the demand power, ensuring that the compressed air energy storage power generation system can output electric energy efficiently and stably when connected to the grid, and ensuring that the compressed air energy storage power generation system can reach the optimal state under different operating conditions.

[0102] Next, a grid-connected hybrid control device for a direct-drive compressed air energy storage expansion power generation system proposed in accordance with an embodiment of the present application will be described with reference to the accompanying drawings.

[0103] Figure 4 It is a block diagram of a grid-connected hybrid control device for a direct-drive compressed air energy storage expansion power generation system according to an embodiment of the present application.

[0104] like Figure 4 As shown, the direct-drive compressed air energy storage expansion power generation system grid-connected hybrid control device 10 includes: an acquisition module 100, an adjustment module 200 and a control module 300.

[0105] Among them, the acquisition module 100 is used to obtain the operating parameters of the compressed air energy storage expansion power generation system at the current moment; the adjustment module 200 is used to adjust the speed of the expander in the compressed air energy storage expansion power generation system based on the operating parameters at the current moment and the operating parameters at the previous moment, and detect the output power of the compressed air energy storage expansion power generation system; the control module 300 is used to calculate the target expansion ratio and target mass flow rate of the expander according to the target demand power of the compressed air energy storage expansion power generation system if the output power of the compressed air energy storage expansion power generation system reaches the target power, and use the target expansion ratio and target mass flow rate to control the expander, and control the compressed air energy storage expansion power generation system to be connected to the grid through the expander.

[0106] In an embodiment of the present application, the operating parameters include at least one of the DC bus voltage and current, the speed of the expander, the expansion ratio and the mass flow rate.

[0107] In an embodiment of the present application, the adjustment module 200 is further used to: calculate the power at the previous moment based on the DC bus voltage and current at the previous moment; after increasing the speed of the expander at the previous moment by the target step size, calculate the power at the current moment based on the DC bus voltage and current at the current moment; respectively calculate the speed difference and power difference between the current moment and the previous moment; adjust the speed of the expander in the compressed air energy storage expansion power generation system based on the speed difference and the power difference.

[0108] In the embodiment of the present application, the adjustment module 200 is further used to: if the speed difference and the power difference are both smaller than the target value, increase the speed of the expander by the target step length; otherwise, reduce the speed of the expander by the target step length.

[0109] In the embodiment of the present application, the device 10 of the embodiment of the present application further includes: a first acquisition module.

[0110] Among them, the first acquisition module is used to obtain the design parameters of the expander before calculating the target expansion ratio and target mass flow rate of the expander according to the target required power of the compressed air energy storage expansion power generation system; and calculate the target expansion ratio and target mass flow rate of the expander according to the design parameters and the target required power.

[0111] In an embodiment of the present application, the first acquisition module is further used to: calculate the target speed of the expander according to the design parameters and the target required power; calculate the target expansion ratio and target mass flow rate of the expander according to the design parameters and the target speed.

[0112] It should be noted that the aforementioned explanation of the embodiment of the grid-connected hybrid control method of the direct-drive compressed air energy storage expansion power generation system is also applicable to the grid-connected hybrid control device of the direct-drive compressed air energy storage expansion power generation system of this embodiment, and will not be repeated here.

[0113] According to the grid-connected hybrid control device of the direct-drive compressed air energy storage expansion power generation system proposed in the embodiment of the present application, the rotation speed of the expander in the compressed air energy storage expansion power generation system can be adjusted according to the operating parameters of the compressed air energy storage expansion power generation system at the current moment and the previous moment until the output power reaches the target power, and the target mass flow rate and target expansion ratio of the expander are calculated according to the target demand power. The target mass flow rate and target expansion ratio are related to the maximum efficiency. The expander is controlled by using the target mass flow rate and target expansion ratio to further optimize the energy efficiency of the compressed air energy storage power generation system, and can achieve higher efficiency while meeting the demand power, thereby ensuring that the compressed air energy storage power generation system can output electric energy efficiently and stably when connected to the grid, and ensuring that the compressed air energy storage power generation system can reach the optimal state under different operating conditions.

[0114] Figure 5A schematic diagram of the structure of an electronic device provided in an embodiment of the present application. The electronic device may include:

[0115] A memory 501 , a processor 502 , and a computer program stored in the memory 501 and executable on the processor 502 .

[0116] When the processor 502 executes the program, the grid-connected hybrid control method of the direct-drive compressed air energy storage expansion power generation system provided in the above embodiment is implemented.

[0117] Furthermore, the electronic device further comprises:

[0118] The communication interface 503 is used for communication between the memory 501 and the processor 502 .

[0119] The memory 501 is used to store computer programs that can be executed on the processor 502 .

[0120] The memory 501 may include a high-speed RAM memory, and may also include a non-volatile memory (non-volatile memory), such as at least one disk memory.

[0121] If the memory 501, the processor 502 and the communication interface 503 are implemented independently, the communication interface 503, the memory 501 and the processor 502 can be connected to each other through a bus and communicate with each other. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 5 Only one thick line is used in the diagram, but this does not mean that there is only one bus or only one type of bus.

[0122] Optionally, in a specific implementation, if the memory 501, the processor 502 and the communication interface 503 are integrated on a chip, the memory 501, the processor 502 and the communication interface 503 can communicate with each other through an internal interface.

[0123] The processor 502 may be a central processing unit (CPU), or an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present application.

[0124] An embodiment of the present application also provides a computer-readable storage medium having a computer program or instruction stored thereon. When the computer program or instruction is executed by a processor, the above-mentioned direct-drive compressed air energy storage expansion power generation system grid-connected hybrid control method is implemented.

[0125] An embodiment of the present application also provides a computer program product, including a computer program or instructions, which, when executed, implements the above-mentioned direct-drive compressed air energy storage expansion power generation system grid-connected hybrid control method.

[0126] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or N embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0127] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0128] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or N executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0129] It should be understood that the various parts of the present application can be implemented by hardware, software, firmware or a combination thereof. In the above embodiment, the N steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one or a combination of multiple of the following technologies known in the art: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0130] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

Claims

1. A direct-drive compressed air energy storage expansion power generation system grid-connected hybrid control method, characterized in that: The following steps are involved: Obtaining the operating parameters of the compressed air energy storage expansion power generation system at the current moment; Based on the operating parameters at the current moment and the operating parameters at the previous moment, adjusting the speed of the expander in the compressed air energy storage expansion power generation system, and detecting the output power of the compressed air energy storage expansion power generation system; If the output power of the compressed air energy storage expansion power generation system reaches the target power, the target expansion ratio and target mass flow rate of the expander are calculated according to the target demand power of the compressed air energy storage expansion power generation system, and the expander is controlled by using the target expansion ratio and target mass flow rate. The compressed air energy storage expansion power generation system is connected to the grid through the expander.

2. The direct-drive compressed air energy storage expansion power generation system grid-connected hybrid control method according to claim 1 is characterized in that: The operating parameters include at least one of the DC bus voltage and current, the speed of the expander, the expansion ratio and the mass flow rate.

3. The direct-drive compressed air energy storage expansion power generation system grid-connected hybrid control method according to claim 2 is characterized in that: The adjusting the speed of the expander in the compressed air energy storage expansion power generation system based on the operating parameters at the current moment and the operating parameters at the previous moment includes: Calculating the power at the last moment based on the DC bus voltage and current at the last moment; After increasing the speed of the expander at the previous moment by the target step length, the power at the current moment is calculated based on the DC bus voltage and current at the current moment; Calculating the speed difference and power difference between the current moment and the previous moment respectively; The speed of the expander in the compressed air energy storage expansion power generation system is adjusted based on the speed difference and the power difference.

4. The direct-drive compressed air energy storage expansion power generation system grid-connected hybrid control method according to claim 3 is characterized in that: The adjusting the speed of the expander in the compressed air energy storage expansion power generation system based on the speed difference and the power difference includes: If the speed difference and the power difference are both smaller than the target values, the speed of the expander is increased by a target step length; otherwise, the speed of the expander is reduced by a target step length.

5. The direct-drive compressed air energy storage expansion power generation system grid-connected hybrid control method according to claim 2, characterized in that: Before calculating the target expansion ratio and the target mass flow rate of the expander according to the target required power of the compressed air energy storage expansion power generation system, the method further includes: Obtaining design parameters of the expander; The target expansion ratio and the target mass flow rate of the expander are calculated according to the design parameters and the target required power.

6. The direct-drive compressed air energy storage expansion power generation system grid-connected hybrid control method according to claim 5, characterized in that: The calculating the target expansion ratio and the target mass flow rate of the expander according to the design parameters and the target required power includes: Calculating a target speed of the expander according to the design parameters and the target required power; A target expansion ratio and a target mass flow rate of the expander are calculated according to the design parameters and the target rotation speed.

7. A direct-drive compressed air energy storage expansion power generation system grid-connected hybrid control device, characterized in that: include: An acquisition module, used to acquire the operating parameters of the compressed air energy storage expansion power generation system at the current moment; An adjustment module, used to adjust the speed of the expander in the compressed air energy storage expansion power generation system based on the operating parameters at the current moment and the operating parameters at the previous moment, and detect the output power of the compressed air energy storage expansion power generation system; A control module is used to calculate the target expansion ratio and target mass flow rate of the expander according to the target demand power of the compressed air energy storage expansion power generation system if the output power of the compressed air energy storage expansion power generation system reaches the target power, and use the target expansion ratio and target mass flow rate to control the expander, so as to control the compressed air energy storage expansion power generation system to be connected to the grid through the expander.

8. An electronic device, characterized in that: include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the grid-connected hybrid control method for a direct-drive compressed air energy storage expansion power generation system as described in any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program or instruction stored thereon, characterized in that: The computer program or instruction is executed by a processor to implement the grid-connected hybrid control method for a direct-drive compressed air energy storage expansion power generation system as described in any one of claims 1-6.

10. A computer program product comprising a computer program or instructions, characterized in that When the computer program or instruction is executed, the grid-connected hybrid control method of the direct-drive compressed air energy storage expansion power generation system as described in any one of claims 1-6 is implemented.

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