Flywheel energy storage system defense method, device, equipment and medium

Abstract

The invention discloses a defense method and device for a flywheel energy storage system, equipment and a medium, and is applied to the field of flywheel energy storage systems. Wherein if the energy storage flywheel is in an abnormal operation state and the flywheel energy storage system is in an out-of-control state, the AC side defense device performs AC passive defense on the flywheel energy storage system; if the energy storage flywheel is in an abnormal operation state, the flywheel energy storage system is in a non-out-of-control state, and the machine side inverter is in an allowed operation state, the direct current side defense device performs direct current active defense; and if the energy storage flywheel is in an abnormal operation state, the flywheel energy storage system is in a non-out-of-control state, and the machine side inverter is in a non-allowed operation state, the AC side defense device performs AC active defense. The defense mode combining active defense and passive defense is adopted, the active defense provides the optimal braking capacity, the passive defense enables the energy storage flywheel to decelerate and brake according to the design process under the condition that the system is in the out-of-control state, and the stability is improved.

Description

Technical Field

[0001] The present application relates to the field of flywheel energy storage systems, and in particular, to a defense method, device, equipment and medium for a flywheel energy storage system. Background Art

[0002] At present, due to its characteristics of high discharge response speed, high discharge power, long life cycle, non-degradation, high environmental adaptability and high reliability, the flywheel energy storage system has received more and more attention in the fields of rail transit, power grid active support and hybrid energy storage. Therefore, the requirements for the single-machine power and energy storage capacity of the flywheel energy storage system are also getting higher and higher, with the power ranging from more than a dozen kW to the current MW level, and the energy storage capacity ranging from a few degrees of electricity to the current dozens of degrees of electricity. Since the energy storage flywheel in the flywheel energy storage system accounts for more than 50% of the value in the system, ensuring the normal operation of the energy storage flywheel is the primary goal of maintaining the normal operation of the flywheel energy storage system.

[0003] During the operation of the flywheel energy storage system, when the high-speed rotating energy storage flywheel experiences a failure similar to a drop due to unstable operation, in order to reduce the losses caused by the failure, it is often desired to reduce the speed of the flywheel from high speed to nearly 0 speed in the shortest possible time. Currently, the braking methods used are mostly single direct current (DC) side energy consumption mode and alternating current (AC) side energy consumption mode. For the DC side energy consumption mode, this mode requires the participation of the flywheel motor inverter, and when the flywheel experiences a drop failure, the sudden change in the load often causes overcurrent or overload failures in the flywheel converter, thereby losing control of the flywheel motor. Therefore, the reliability of the active defense method corresponding to the DC side energy consumption mode is relatively low. For the AC side energy consumption mode, the overall consumption process involves multiple time-varying quantities coupled with the rotational speed, such as back electromotive force, power, and energy storage, and the impedance in the discharge circuit is coupled with the frequency, resulting in relatively difficult calculations for determining the resistance value of the AC defense resistor.

[0004] In view of the above technologies, seeking a defense method for a flywheel energy storage system is an urgent problem for those skilled in the art. Summary of the Invention

[0005] The purpose of the present application is to provide a defense method, device, equipment and medium for a flywheel energy storage system, which can solve the problems of poor stability caused by the single DC side energy consumption mode and difficult calculation of the resistance value of the AC defense resistor in the existing technology.

[0006] To solve the above technical problems, the present application provides a defense method for a flywheel energy storage system, which is applied to a flywheel energy storage system including a DC-side defense device, a machine-side inverter, a machine-side switch, an AC-side defense device, a permanent magnet motor, and an energy storage flywheel. The DC-side defense device, the machine-side inverter, the machine-side switch, the permanent magnet motor, and the energy storage flywheel are connected in sequence, and the AC-side defense device is connected to the energy storage flywheel through the permanent magnet motor. The method includes:

[0007] If the energy storage flywheel is in an abnormal operating state and the flywheel energy storage system is in an out-of-control state, disconnect the machine-side switch and close the AC defense switch in the AC-side defense device, so that the AC-side defense device performs AC passive defense on the flywheel energy storage system;

[0008] If the energy storage flywheel is in an abnormal operating state, the flywheel energy storage system is in a non-out-of-control state, and the machine-side inverter is in an allowed operating state, close the machine-side switch and the DC defense switch in the DC-side defense device, and disconnect the AC defense switch, so that the DC-side defense device performs DC active defense;

[0009] If the energy storage flywheel is in an abnormal operating state, the flywheel energy storage system is in a non-out-of-control state, and the machine-side inverter is in a non-allowed operating state, disconnect the machine-side switch and the DC defense switch in the DC-side defense device, and close the AC defense switch, so that the AC-side defense device performs AC active defense.

[0010] Preferably, it further includes:

[0011] If the energy storage flywheel is in a normal operating state, close the machine-side switch and disconnect the AC defense switch and the DC defense switch.

[0012] Preferably, it further includes:

[0013] Obtain the first set of operating data and the second set of operating data in the flywheel energy storage system;

[0014] Determine the resistance value of the DC defense resistor and the duty cycle of the DC defense switch in the DC-side defense device according to the first set of operating data;

[0015] Determine the resistance value of the AC defense resistor in the AC-side defense device according to the second set of operating data.

[0016] Preferably, determining the resistance value of the DC defense resistor and the duty cycle of the DC defense switch in the DC-side defense device according to the first set of operating data includes:

[0017] Obtain the DC active defense constant power corresponding to the DC-side defense device, the bus voltage, and the maximum duty cycle corresponding to the DC defense switch in the first set of operating data;

[0018] Obtain the maximum torque corresponding to the permanent magnet motor in the first set of operating data;

[0019] Obtain the flywheel speed corresponding to the energy storage flywheel in the first set of operating data;

[0020] Determine the resistance value of the DC defense resistor based on the DC active defense constant power, bus voltage, and maximum duty cycle;

[0021] Determine the duty cycle of the DC defense switch based on the resistance value of the DC defense resistor, maximum torque, flywheel speed, and bus voltage.

[0022] Preferably, it further includes:

[0023] Obtain the moment of inertia and maximum stored energy corresponding to the energy storage flywheel in the first set of operating data

[0024] Determine the lowest speed in the constant power region of the DC active defense according to the DC active defense constant power and maximum torque;

[0025] Determine the variation characteristic of the speed with time in the constant power region of the DC active defense according to the moment of inertia, maximum stored energy, flywheel speed, DC active defense constant power, and time;

[0026] If the flywheel speed is lower than the lowest speed in the constant power region, obtain the initial stored energy corresponding to the variable power region in the DC active defense;

[0027] Determine the variation characteristic of the speed with time in the operating region based on the variation characteristic of the speed with time in the constant power region and the initial stored energy.

[0028] Preferably, determining the resistance value of the AC defense resistor in the AC side defense device according to the second set of operating data includes:

[0029] Obtain the moment of inertia, maximum stored energy, and corresponding flywheel speed of the energy storage flywheel in the second set of operating data;

[0030] Obtain the permanent magnet flux linkage, number of motor poles, number of motor phases, motor phase resistance, phase inductance, and braking phase resistance of the permanent magnet motor in the second set of operating data;

[0031] Determine the resistance value of the corresponding AC defense resistor according to the moment of inertia, maximum stored energy, corresponding flywheel speed, permanent magnet flux linkage, number of motor poles, number of motor phases, motor phase resistance, phase inductance, and braking phase resistance.

[0032] Preferably, determining the resistance value of the corresponding AC defense resistor according to the moment of inertia, maximum stored energy, corresponding flywheel speed, permanent magnet flux linkage, number of motor poles, number of motor phases, motor phase resistance, phase inductance, and braking phase resistance includes:

[0033] Determine the transformation characteristics of the flywheel energy storage over time based on the moment of inertia, maximum stored energy, and the corresponding flywheel speed, permanent magnet magnetic flux, number of motor pole pairs, number of motor phases, motor phase resistance, phase inductance, and braking phase resistance;

[0034] Determine the variation characteristics of the flywheel speed over time, the variation characteristics of the active defense power on the AC side over time, and the variation characteristics of the AC side current over time based on the transformation characteristics of the flywheel energy storage over time;

[0035] Determine the resistance value of the AC defense resistor based on the transformation characteristics of the flywheel energy storage over time, the variation characteristics of the flywheel speed over time, the variation characteristics of the active defense power on the AC side over time, and the variation characteristics of the AC side current over time.

[0036] On the other hand, the present application also provides a defense device for a flywheel energy storage system, which is applied to a flywheel energy storage system including a DC side defense device, a machine side inverter, a machine side switch, an AC side defense device, a permanent magnet motor, and an energy storage flywheel. Among them, the DC side defense device, the machine side inverter, the machine side switch, the permanent magnet motor, and the energy storage flywheel are connected in sequence, and the AC side defense device is connected to the energy storage flywheel through the permanent magnet motor. The device includes:

[0037] An AC passive defense module, which is used to disconnect the machine side switch and close the AC defense switch in the AC side defense device when the energy storage flywheel is in an abnormal operating state and the flywheel energy storage system is in an out-of-control state, so that the AC side defense device can perform AC passive defense on the flywheel energy storage system;

[0038] A DC active defense module, which is used to close the machine side switch and the DC defense switch in the DC side defense device and disconnect the AC defense switch when the energy storage flywheel is in an abnormal operating state, the flywheel energy storage system is in a non-out-of-control state, and the machine side inverter is in an allowed operating state, so that the DC side defense device can perform DC active defense;

[0039] An AC active defense module, which is used to disconnect the machine side switch and the DC defense switch in the DC side defense device and close the AC defense switch when the energy storage flywheel is in an abnormal operating state, the flywheel energy storage system is in a non-out-of-control state, and the machine side inverter is in a non-allowed operating state, so that the AC side defense device can perform AC active defense.

[0040] On the other hand, the present application also provides an electronic device, including a memory for storing a computer program;

[0041] A processor, which is used to implement the steps of the above-mentioned defense method for the flywheel energy storage system when executing the computer program.

[0042] On the other hand, the present application also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the above-mentioned defense method for the flywheel energy storage system are implemented.

[0043] It can be seen that the present application adopts a defense method combining active defense and passive defense. Its active defense coordinates with the machine-side inverter to provide the optimal braking ability and shorten the active kinetic energy defense process while protecting the system from overvoltage. The passive defense enables the energy storage flywheel to decelerate and brake according to the designed process when the flywheel energy storage system is in an out-of-control state, thereby ensuring the operation of the energy storage flywheel. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the embodiments of the present application, the following will briefly introduce the drawings required in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0045] Figure 1 It is a flowchart of a defense method for a flywheel energy storage system provided by an embodiment of the present application;

[0046] Figure 2 It is a structural diagram of a flywheel energy storage system provided by an embodiment of the present application;

[0047] Figure 3 It is a design flowchart of a DC defense resistor provided by an embodiment of the present application;

[0048] Figure 4 It is an equivalent circuit diagram of an AC defense resistor provided by an embodiment of the present application;

[0049] Figure 5 It is a design flowchart of an AC defense resistor provided by an embodiment of the present application;

[0050] Figure 6 It is a structural diagram of a defense device for a flywheel energy storage system provided by another embodiment of the present application;

[0051] Figure 7 It is a structural diagram of an electronic device provided by another embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0052] The following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, rather than all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present application.

[0053] The core of the present application is to provide a defense method, device, equipment and medium for a flywheel energy storage system.

[0054] In order to enable those skilled in the art to better understand the solution of the present application, the present application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0055] Figure 1 It is a flowchart of a defense method for a flywheel energy storage system provided by an embodiment of the present application. As Figure 1 shown, it includes the following steps:

[0056] S10: When the energy storage flywheel is in an abnormal operating state and the flywheel energy storage system is in an out-of-control state, disconnect the machine-side switch and close the AC defense switch in the AC-side defense device, so that the AC-side defense device can perform AC passive defense on the flywheel energy storage system.

[0057] S11: When the energy storage flywheel is in an abnormal operating state, the flywheel energy storage system is in a non-out-of-control state, and the machine-side inverter is in an allowed operating state, close the machine-side switch and the DC defense switch in the DC-side defense device, and disconnect the AC defense switch, so that the DC-side defense device can perform DC active defense.

[0058] S12: When the energy storage flywheel is in an abnormal operating state, the flywheel energy storage system is in a non-out-of-control state, and the machine-side inverter is in a non-allowed operating state, disconnect the machine-side switch and the DC defense switch in the DC-side defense device, and close the AC defense switch, so that the AC-side defense device can perform AC active defense.

[0059] In a specific embodiment, the defense method for the flywheel energy storage system provided by the present application is applied to a flywheel energy storage system as Figure 2 shown, which includes: a DC-side defense device 1, a machine-side inverter 2, a machine-side switch 3, an AC-side defense device 4, a permanent magnet motor 5 and an energy storage flywheel 6. And the DC-side defense device 1 includes a DC defense switch (T1-T4), DC defense resistors R1 and R2; the AC-side device 4 includes an AC defense switch K and AC defense resistors R3, R4, R5. In addition, it further includes: a machine-side converter controller 7, a magnetic bearing controller 8 and a magnetic bearing 9. The connection relationship of the flywheel energy storage system is: the DC-side defense device 1, the machine-side inverter 2, the machine-side switch 3, the permanent magnet motor 5 and the energy storage flywheel 6 are connected in sequence; the AC-side defense device 4 is connected to the energy storage flywheel 6 through the permanent magnet motor 5; the machine-side converter controller 7 is connected to the magnetic bearing 9 through the magnetic bearing controller 8; and the machine-side converter controller 7 is also connected to the machine-side inverter 2, the DC-side defense device 1 and the machine-side switch 3.

[0060] In a specific embodiment, the flywheel energy storage system is divided into four cases. The first case: the energy storage flywheel 6 is normal; the second case: the energy storage flywheel 6 is in an abnormal operating state (abnormal state), and the flywheel energy storage system is in an out-of-control state; the third case: the energy storage flywheel 6 is in an abnormal operating state, the flywheel energy storage system is in a non-out-of-control state, and the machine-side inverter 2 is in an allowed operating state; the fourth case: the energy storage flywheel 6 is in an abnormal operating state, the flywheel energy storage system is in a non-out-of-control state, and the machine-side inverter 2 is in a non-allowed operating state.

[0061] For the first state: when the energy storage flywheel 6 is in a normal state, close the machine-side switch 3, and disconnect the AC protection switch K and the DC protection switch (T1 - T4), that is, the DC-side protection device 1 and the AC-side protection device 4 are not connected to the system.

[0062] For the second state, when the energy storage flywheel 6 is in an abnormal operating state and the flywheel energy storage system is in an out-of-control state, disconnect the machine-side switch 2, and close the AC protection switch K in the AC-side protection device 4, so that the AC-side protection device 4 performs passive AC protection on the flywheel energy storage system, that is, the current flywheel kinetic energy is consumed on the AC-side protection device 4.

[0063] For the third state, when the energy storage flywheel 6 is in an abnormal operating state, the flywheel energy storage system is in a non-out-of-control state, and the machine-side inverter 2 is in an allowed operating state, close the machine-side switch 3 and the DC protection switch (T1 - T4) in the DC-side protection device 1, and disconnect the AC protection switch K, so that the DC-side protection device 1 performs active DC protection. The process of the active DC protection is as follows: the machine-side inverter 2 controls the permanent magnet motor 5 according to the operation mode of constant power + variable power; at the same time, controls the duty ratios of T1 and T3 according to the voltage stabilization mode to stabilize the bus voltage, and consumes the kinetic energy on the DC-side active protection device 1.

[0064] For the fourth state, when the energy storage flywheel 6 is in an abnormal operating state, the flywheel energy storage system is in a non-out-of-control state, and the machine-side inverter 2 is in a non-allowed operating state, disconnect the machine-side switch 3 and the DC protection switch (T1 - T4) in the DC-side protection device 1, and close the AC protection switch K, so that the AC-side protection device 4 performs active AC protection. The kinetic energy of the energy storage flywheel 6 is consumed on the AC-side protection device 4.

[0065] A defense method for a flywheel energy storage system provided by the present application is applied to a flywheel energy storage system including a DC-side defense device, a machine-side inverter, a machine-side switch, an AC-side defense device, a permanent magnet motor, and a storage flywheel. Among them, the DC-side defense device, the machine-side inverter, the machine-side switch, the permanent magnet motor, and the storage flywheel are connected in sequence, and the AC-side defense device is connected to the storage flywheel through the permanent magnet motor. The method includes: if the storage flywheel is in an abnormal operating state and the flywheel energy storage system is in an out-of-control state, disconnect the machine-side switch and close the AC defense switch in the AC-side defense device, so that the AC-side defense device performs AC passive defense on the flywheel energy storage system; if the storage flywheel is in an abnormal operating state, the flywheel energy storage system is in a non-out-of-control state, and the machine-side inverter is in an allowed operating state, close the machine-side switch and the DC defense switch in the DC-side defense device, and disconnect the AC defense switch, so that the DC-side defense device performs DC active defense; if the storage flywheel is in an abnormal operating state, the flywheel energy storage system is in a non-out-of-control state, and the machine-side inverter is in a non-allowed operating state, disconnect the machine-side switch and the DC defense switch in the DC-side defense device, and close the AC defense switch, so that the AC-side defense device performs AC active defense. Thus, it can be seen that the present application adopts a defense method combining active defense and passive defense. Its active defense coordinates with the machine-side inverter to provide the optimal braking ability and shorten the kinetic energy active defense process while protecting the system from overvoltage. The passive defense enables the storage flywheel to decelerate and brake according to the designed process when the flywheel energy storage system is in an out-of-control state, thereby ensuring the operation of the storage flywheel.

[0066] In a specific embodiment, since the DC-side defense device 1 performs DC active defense on the flywheel energy storage system through the internal DC defense switch (T1 - T4) and DC defense resistors (R1 and R2), and the AC-side defense device 4 performs AC passive defense and AC active defense on the flywheel energy storage system through the internal AC defense switch K and AC defense resistors (R3, R4, R5), therefore, before implementing the defense method for the flywheel energy storage system provided by the present application, a flywheel energy storage system that meets the requirements needs to be constructed.

[0067] For the DC-side defense device 1, it is necessary to determine the duty cycle of the internal DC defense switch and the resistance value of the DC defense resistor. The specific implementation method is as follows:

[0068] Step 1: Obtain the DC active defense constant power corresponding to the DC-side defense device , the bus voltage , the maximum energy storage , and the maximum duty cycle corresponding to the DC defense switch , the maximum torque corresponding to the permanent magnet motor , the flywheel speed corresponding to the storage flywheel and the moment of inertia Among them, the DC active defense constant power , the bus voltage , the maximum duty cycle , the maximum torque , the flywheel speed , the maximum energy storage and the moment of inertia constitute the first set of operating data.

[0069] Step 2: Construct the following relational expressions based on the data in Step 1:

[0070] ;

[0071] ;

[0072] In the above two formulas, is the time. According to the above two relational expressions, determine the variation characteristics of the speed in the constant power region with time, which can be understood as a function of the flywheel speed with respect to time: ; At the same time, according to the above formula, the lowest speed in the constant power region in DC active defense can also be obtained .

[0073] Step 3: When the flywheel speed is lower than the lowest speed in the constant power region of DC active defense, determine the variation characteristics of the speed in the power reduction region with time, and its expression is as follows:

[0074] ;

[0075] Among them, and are the upper and lower limits of the integration time, is the integration time, is the initial energy storage, and the expression is:

[0076] ;

[0077] Step 4: Determine the variation characteristics of the speed in the entire operating region with time based on the variation characteristics of the speed in the constant power region with time and the variation characteristics of the speed in the power reduction region with time, and further determine the variation characteristics of the DC active defense power with time.

[0078] Step 5: Based on the DC active defense constant power , the bus voltage and the maximum duty cycle determine the resistance value of the DC defense resistor, and its expression is:

[0079] ;

[0080] Step 6: Determine the function of the duty cycle of the DC defense switch based on the above parameters and formulas and further determine the duty cycle whose expression is:

[0081] ;

[0082] As can be seen from the above, in the design of the DC defense resistors (R1 and R2) of the present application, they are braked at a constant power during the high-speed operation stage of the energy storage flywheel 6. As the rotational speed of the energy storage flywheel 6 decreases, the current of the permanent magnet motor 5 gradually increases. When the constant power discharge reaches the maximum current of the permanent magnet motor 5, the braking process enters the reduced-power braking, and the permanent magnet motor 5 maintains the maximum current for braking.

[0083] Therefore, based on the above steps, the design process of the DC defense resistors (R1 and R2) is as Figure 3 shown:

[0084] S20: Start

[0085] S21: Obtain the DC active defense constant power, bus voltage, maximum duty cycle, maximum torque, flywheel speed, maximum energy storage, and moment of inertia.

[0086] S22: Determine the lowest speed in the constant power region of the DC active defense.

[0087] S23: Determine the variation characteristics of the rotational speed in the constant power region with time.

[0088] S24: Determine whether the flywheel speed is lower than the lowest speed in the constant power region.

[0089] S25: If so, determine the variation characteristics of the rotational speed in the reduced-power region with time; if not, return to the steps of S23.

[0090] S26: Determine whether the constant power rotational speed is less than the rated speed.

[0091] S27: If so, determine the resistance value of the DC defense resistor and the duty cycle of the DC defense switch; if not, return to the steps of S25.

[0092] S28: End.

[0093] The above steps S20 - S28 are the summary of steps 1 - 6 in the design of the above DC side defense device, so the present application will not elaborate here.

[0094] For the AC side defense device 4, when the energy storage flywheel 6 fails and is braked by the machine-side braking resistor, the internal resistance, inductance of the motor, and the external braking device form a closed loop, and its equivalent circuit is as follows Figure 4As shown, it includes a resistor (RS + RB), an inductor LS, and a back electromotive force Em.

[0095] Based on Figure 4 the circuit shown, it is necessary to determine the resistance value of the AC defense resistor inside it. The specific implementation method is as follows:

[0096] Step 1: Obtain the moment of inertia corresponding to the energy storage flywheel, the maximum energy storage, and the corresponding flywheel speed in the second set of operating data; the permanent magnet flux linkage of the permanent magnet motor, the number of motor pole pairs, the number of motor phases, the phase resistance RS of the motor (with a resistance value of ), the phase inductance LS (with an inductance value of ), and the braking phase resistance RB (with a resistance value of ). Among them, the moment of inertia, the maximum energy storage, and the corresponding flywheel speed, the permanent magnet flux linkage, the number of motor pole pairs, the number of motor phases, the phase resistance of the motor, the phase inductance, and the braking phase resistance constitute the second set of operating data.

[0097] Step 2: Establish the following dynamic balance between electrical energy and kinetic energy, and its expression is as follows:

[0098] ;

[0099] Among them, is the energy storage function, i is the current, t is the time, is the integration time.

[0100] Step 3: Obtain the dynamic characteristics of the energy storage varying with time through the relationship between the current i and the back electromotive force Em in the circuit diagram, the relationship between the back electromotive force Em and the energy storage, the relationship between the flywheel speed and the energy storage, and its expression is as follows:

[0101] ;

[0102] Step 4: Determine the variation characteristics of the flywheel speed with time, the variation characteristics of the active defense power on the AC side with time, and the variation characteristics of the AC side current with time according to the variation characteristics of the flywheel energy storage with time.

[0103] Step 5: According to the above change characteristics, adjust the resistance value of the AC side defense resistor to obtain different flywheel deceleration curves, and finally select the maximum resistance value that meets the braking time requirement as the resistance value of the AC side defense resistor in the AC side defense device.

[0104] As can be seen from the above, the design of its AC side defense resistor uses the back electromotive force as the bridge for the conversion between mechanical energy and electrical energy, establishes the energy dynamic relationship between the flywheel kinetic energy and the AC side defense electrical energy, and solves the variation characteristics of the rotational speed with the discharge time. Further obtain the variation characteristics of the flywheel energy storage with time, the variation characteristics of the flywheel rotational speed with time, the variation characteristics of the AC side active defense power with time, and the variation characteristics of the AC side current with time. By adjusting the AC defense resistor value, different AC side active defense processes are obtained.

[0105] In summary, the design process of its AC side defense resistor is as Figure 5 shown, including the following process:

[0106] S30: Start.

[0107] S31: Obtain the moment of inertia, the maximum energy storage, and the corresponding flywheel rotational speed, permanent magnet magnetic flux, number of motor pole pairs, number of motor phases, motor phase resistance, phase inductance, and braking phase resistance.

[0108] S32: Set the AC side defense resistor.

[0109] S33: Establish a dynamic balance between electrical energy and kinetic energy.

[0110] S34: Determine the variation characteristics of the flywheel energy storage with time, the variation characteristics of the flywheel rotational speed with time, the variation characteristics of the AC side active defense power with time, and the variation characteristics of the AC side current with time.

[0111] S35: Judge whether the defense time at this time meets the defense requirements;

[0112] S36: If so, end; if not, return to the step of S32.

[0113] Among them, the above steps S30 - S36 are the summary of steps 1 - 5 in the above AC defense resistor design, so this application will not elaborate here.

[0114] It should be noted that the embodiments provided in this application are only one implementable way, but not limited to only this implementable way, and can be set by oneself according to the needs of the user.

[0115] Thus, it can be seen that the flywheel energy storage system provided by this application has the following advantages:

[0116] 1. This application adopts a combination of active defense (DC active defense and AC active defense) and passive defense (AC passive defense). When active defense is required, DC active defense is preferentially considered for activation.

[0117] 2. When active defense is engaged, the DC active defense function is enabled under the condition that the machine-side inverter allows operation. The DC-side defense consumes energy at a set constant power for a long time, and the energy storage flywheel decelerates to the safe speed range within a short time.

[0118] 3. When active defense is engaged, the AC active defense function is enabled under the condition that the machine-side inverter does not allow operation. The permanent magnet motor is connected to the AC defense resistor, and the kinetic energy of the flywheel is converted into electrical energy through the permanent magnet motor and consumed on the AC defense resistor, ultimately reducing the flywheel speed to the safe speed range.

[0119] 4. The DC defense resistor is designed according to the discharge processes of the constant power section and the variable power section; the AC defense resistor is designed according to the variable power discharge process.

[0120] In the above embodiments, the method of the flywheel energy storage system is described in detail. This application also provides corresponding embodiments of the flywheel energy storage system device. It should be noted that this application describes the embodiments of the device part from two perspectives, one is from the perspective of functional modules, and the other is from the perspective of hardware.

[0121] Figure 6 The following is a structural diagram of a defense device for a flywheel energy storage system provided in another embodiment of this application. The defense device of the flywheel energy storage system is applied to a flywheel energy storage system including: a DC-side defense device, a machine-side inverter, a machine-side switch, an AC-side defense device, a permanent magnet motor, and an energy storage flywheel. Among them, the DC-side defense device, the machine-side inverter, the machine-side switch, the permanent magnet motor, and the energy storage flywheel are connected in sequence, and the AC-side defense device is connected to the energy storage flywheel through the permanent magnet motor. This device includes:

[0122] An AC passive defense module 11, which is used to disconnect the machine-side switch and close the AC defense switch in the AC-side defense device when the energy storage flywheel is in an abnormal operating state and the flywheel energy storage system is in an out-of-control state, so that the AC-side defense device performs AC passive defense on the flywheel energy storage system;

[0123] A DC active defense module 12, which is used to close the machine-side switch and the DC defense switch in the DC-side defense device and disconnect the AC defense switch when the energy storage flywheel is in an abnormal operating state, the flywheel energy storage system is in a non-out-of-control state, and the machine-side inverter is in an allowable operating state, so that the DC-side defense device performs DC active defense;

[0124] The AC active defense module 13 is used to disconnect the machine-side switch and the DC defense switch in the DC-side defense device and close the AC defense switch when the energy storage flywheel is in an abnormal operating state, the flywheel energy storage system is in a non-out-of-control state, and the machine-side inverter is in a non-permitted operating state, so that the AC-side defense device can perform AC active defense.

[0125] Since the embodiments in the device part correspond to the embodiments in the method part, please refer to the description of the embodiments in the method part for the embodiments in the device part, and will not be elaborated here.

[0126] Figure 7 The structural diagram of the electronic device provided by another embodiment of the present application is as Figure 7 shown. The electronic device includes: a memory 20 for storing computer programs;

[0127] a processor 21 for implementing the steps of the defense method of the flywheel energy storage system as mentioned in the above embodiments when executing the computer program.

[0128] The electronic device provided in this embodiment may include but is not limited to a smart phone, a tablet computer, a notebook computer, a desktop computer, etc.

[0129] Among them, the processor 21 may include one or more processing cores, such as a 4-core processor, an 8-core processor, etc. The processor 21 may be implemented in at least one hardware form of a digital signal processor (DSP), a field-programmable gate array (FPGA), and a programmable logic array (PLA). The processor 21 may also include a main processor and a coprocessor. The main processor is a processor for processing data in the wake state, also known as a central processing unit (CPU); the coprocessor is a low-power processor for processing data in the standby state. In some embodiments, the processor 21 may be integrated with a graphics processing unit (GPU), and the GPU is responsible for rendering and drawing the content to be displayed on the display screen. In some embodiments, the processor 21 may also include an artificial intelligence (AI) processor, and the AI processor is used to process computational operations related to machine learning.

[0130] The memory 20 may include one or more computer-readable storage media, which may be non-transitory. The memory 20 may further include high-speed random access memory, as well as non-volatile memory, such as one or more disk storage devices and flash storage devices. In this embodiment, the memory 20 is at least used to store the following computer program 201. After the computer program is loaded and executed by the processor 21, it can implement the relevant steps of the defense method of the flywheel energy storage system disclosed in any of the foregoing embodiments. In addition, the resources stored in the memory 20 may further include an operating system 202, data 203, etc., and the storage method may be transient storage or permanent storage.

[0131] In some embodiments, the electronic device may further include a display screen 22, an input / output interface 23, a communication interface 24, a power supply 25, and a communication bus 26.

[0132] Those skilled in the art can understand that Figure 7 the structure shown in does not constitute a limitation on the electronic device, and it may include more or fewer components than those shown in the figure.

[0133] The electronic device provided by the embodiment of the present application includes a memory and a processor. When the processor executes the program stored in the memory, it can implement the above-mentioned defense method of the flywheel energy storage system and has the same beneficial effects.

[0134] Finally, the present application also provides an embodiment corresponding to a computer-readable storage medium. A computer program is stored on the computer-readable storage medium. When the computer program is executed by a processor, it implements the steps recorded in the above method embodiment.

[0135] It can be understood that if the method in the above embodiments is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and executes all or part of the steps of the methods described in the various embodiments of the present application. The foregoing storage media include: USB flash drives, mobile hard disks, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical discs and other various media that can store program codes.

[0136] The above has introduced in detail a defense method, device, equipment and medium for a flywheel energy storage system provided by this application. The various embodiments in the specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. For the same or similar parts among the various embodiments, reference can be made to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple. For related parts, reference can be made to the description in the method part. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the principle of this application, several improvements and modifications can be made to this application, and these improvements and modifications also fall within the protection scope of the claims of this application.

[0137] It should also be noted that in this specification, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including one..." does not exclude the existence of another identical element in the process, method, article or device including the said element.

Claims

1. A defense method for a flywheel energy storage system, characterized in that, Applied to a flywheel energy storage system including a DC side defense device, a machine side inverter, a machine side switch, an AC side defense device, a permanent magnet motor, and a energy storage flywheel, wherein the DC side defense device, the machine side inverter, the machine side switch, the permanent magnet motor, and the energy storage flywheel are connected in sequence, and the AC side defense device is connected to the energy storage flywheel through the permanent magnet motor. The method includes: If the energy storage flywheel is in an abnormal operating state and the flywheel energy storage system is in an out-of-control state, disconnect the machine side switch and close the AC defense switch in the AC side defense device, so that the AC side defense device performs AC passive defense on the flywheel energy storage system; If the energy storage flywheel is in an abnormal operating state, the flywheel energy storage system is in a non-out-of-control state, and the machine side inverter is in an allowed operating state, close the machine side switch and the DC defense switch in the DC side defense device, and disconnect the AC defense switch, so that the DC side defense device performs DC active defense; If the energy storage flywheel is in an abnormal operating state, the flywheel energy storage system is in a non-out-of-control state, and the machine side inverter is in a non-allowed operating state, disconnect the machine side switch and the DC defense switch in the DC side defense device, and close the AC defense switch, so that the AC side defense device performs AC active defense.

2. The defense method of the flywheel energy storage system according to claim 1, characterized in that, Further includes: If the energy storage flywheel is in a normal operating state, close the machine side switch and disconnect the AC defense switch and the DC defense switch.

3. The defense method of the flywheel energy storage system according to claim 1, characterized in that, Further includes: Obtain the first set of operation data and the second set of operation data in the flywheel energy storage system; Determine the resistance value of the DC defense resistor and the duty cycle of the DC defense switch in the DC side defense device according to the first set of operation data; Determine the resistance value of the AC defense resistor in the AC side defense device according to the second set of operation data.

4. The defense method of the flywheel energy storage system according to claim 3, characterized in that, The determining the resistance value of the DC defense resistor and the duty cycle of the DC defense switch in the DC side defense device according to the first set of operation data includes: Obtain the DC active defense constant power corresponding to the DC side defense device, the bus voltage, and the maximum duty cycle corresponding to the DC defense switch in the first set of operation data; Obtain the maximum torque corresponding to the permanent magnet motor in the first set of operation data; Obtain the flywheel speed corresponding to the energy storage flywheel in the first set of operation data; Determine the resistance value of the DC defense resistor based on the DC active defense constant power, the bus voltage, and the maximum duty cycle; Determine the duty cycle of the DC defense switch based on the resistance value of the DC defense resistor, the maximum torque, the flywheel speed, and the bus voltage.

5. The defense method of the flywheel energy storage system according to claim 4, characterized in that, Further includes: Obtain the moment of inertia and the maximum stored energy corresponding to the energy storage flywheel in the first set of operation data; Determine the lowest speed in the constant power region of the DC active defense according to the DC active defense constant power and the maximum torque; Determine the change characteristic of the rotational speed with time in the constant power region of the DC active defense according to the moment of inertia, the maximum stored energy, the flywheel speed, the DC active defense constant power, and time. If the rotational speed of the flywheel is lower than the lowest speed in the constant power region, obtain the initial stored energy corresponding to the variable power region in the DC active defense. Based on the variation characteristics of the rotational speed in the constant power region with time and the initial stored energy, determine the variation characteristics of the rotational speed in the operating region with time.

6. The defense method of the flywheel energy storage system according to any one of claims 3-5, characterized in that, The determination of the resistance value of the AC defense resistor in the AC side defense device according to the second set of operating data includes: Obtain the moment of inertia, maximum stored energy, and corresponding flywheel rotational speed of the energy storage flywheel in the second set of operating data. Obtain the permanent magnet flux linkage, number of motor poles, number of motor phases, motor phase resistance, phase inductance, and braking phase resistance of the permanent magnet motor in the second set of operating data. Determine the resistance value of the corresponding AC defense resistor according to the moment of inertia, the maximum stored energy, the corresponding flywheel rotational speed, the permanent magnet flux linkage, the number of motor poles, the number of motor phases, the motor phase resistance, the phase inductance, and the braking phase resistance.

7. The defense method of the flywheel energy storage system according to claim 6, characterized in that, The determination of the resistance value of the corresponding AC defense resistor according to the moment of inertia, the maximum stored energy, the corresponding flywheel rotational speed, the permanent magnet flux linkage, the number of motor poles, the number of motor phases, the motor phase resistance, the phase inductance, and the braking phase resistance includes: Determine the variation characteristics of the flywheel stored energy with time according to the moment of inertia, the maximum stored energy, the corresponding flywheel rotational speed, the permanent magnet flux linkage, the number of motor poles, the number of motor phases, the motor phase resistance, the phase inductance, and the braking phase resistance. Determine the variation characteristics of the flywheel rotational speed with time, the variation characteristics of the active defense power on the AC side with time, and the variation characteristics of the AC side current with time according to the variation characteristics of the flywheel stored energy with time. Determine the resistance value of the AC defense resistor according to the variation characteristics of the flywheel stored energy with time, the variation characteristics of the flywheel rotational speed with time, the variation characteristics of the active defense power on the AC side with time, and the variation characteristics of the AC side current with time.

8. A defense device for a flywheel energy storage system, characterized in that, Applied to a flywheel energy storage system including a DC side defense device, a machine side inverter, a machine side switch, an AC side defense device, a permanent magnet motor, and an energy storage flywheel, where the DC side defense device, the machine side inverter, the machine side switch, the permanent magnet motor, and the energy storage flywheel are connected in sequence, and the AC side defense device is connected to the energy storage flywheel through the permanent magnet motor. This device includes: An AC passive defense module, used to disconnect the machine side switch and close the AC defense switch in the AC side defense device when the energy storage flywheel is in an abnormal operating state and the flywheel energy storage system is in an out-of-control state, so that the AC side defense device performs AC passive defense on the flywheel energy storage system. A DC active defense module, used to close the machine side switch and the DC defense switch in the DC side defense device and disconnect the AC defense switch when the energy storage flywheel is in an abnormal operating state, the flywheel energy storage system is not in an out-of-control state, and the machine side inverter is in an allowed operating state, so that the DC side defense device performs DC active defense. The AC active defense module is used to disconnect the machine-side switch and the DC defense switch in the DC-side defense device and close the AC defense switch when the energy storage flywheel is in an abnormal operating state, the flywheel energy storage system is in a non-out-of-control state, and the machine-side inverter is in a non-permissible operating state, so that the AC-side defense device can perform AC active defense.

9. An electronic device, characterized in that, It includes a memory for storing computer programs; A processor for implementing the steps of the defense method of the flywheel energy storage system according to any one of claims 1 to 7 when executing the computer program.

10. A computer-readable storage medium, characterized in that, A computer program is stored on the computer-readable storage medium, and when the computer program is executed by a processor, the steps of the defense method of the flywheel energy storage system according to any one of claims 1 to 7 are implemented.

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