An energy storage control method, system, storage medium, and processor based on instability mode recognition for automatic switching between grid-based control and grid-following control.

Abstract

This invention relates to the field of energy storage device control technology, and particularly to an energy storage control method, system, storage medium, and processor that automatically switches between grid-based control and grid-following control based on instability mode recognition. The method includes: acquiring three-phase voltage and current signals; calculating active and reactive power; performing Park transform on the three-phase voltage and current signals; calculating the output signal of the synchronization control loop; calculating the output signals of the power control and voltage outer loops; determining the switching conditions between grid-based and grid-following control modes, obtaining the synchronization phase, d-axis current reference value, and q-axis current reference value; calculating the d-axis and q-axis electromotive force of the current control loop, and obtaining the three-phase reference wave signal based on the synchronization phase through an inverse Park transform, and controlling the converter of the energy storage device. This invention automatically switches between grid-based and grid-following control modes, effectively reducing the risk of erroneous switching and improving the stability of grid connection for energy storage devices.

Description

Technical Field

[0001] This invention relates to the field of energy storage equipment control technology, and in particular to an energy storage control method, system, storage medium and processor that automatically switches between grid-based control and grid-following control based on instability mode recognition. Background Technology

[0002] In the new power system, new energy sources will become the main power source. The high penetration rate of new energy sources will profoundly change the form, characteristics, and mechanisms of the traditional power system. The new power system will exhibit characteristics such as power electronics, strong volatility, and uncertainty, posing new challenges to reliable power supply, safe and stable operation, and economical operation. Energy storage, as the central hub and link for multi-type energy complementarity, can enhance the flexibility and stability of the power system and is an important support for the new power system dominated by new energy sources. Configuring energy storage at new energy power plants can suppress fluctuations in new energy generation power, improve the ability of new energy sources to track planned power output, and reduce wind and solar curtailment. Configuring energy storage on the grid side can delay investment in transmission equipment and network upgrades and expansions, alleviate transmission channel congestion, and improve grid stability. Configuring energy storage on the load side can reduce peak-to-valley differences, improve power quality, and also serve as an emergency backup power source.

[0003] Energy storage controllers can be broadly classified into two categories: grid following (GFL) energy storage controllers and grid forming (GFM) energy storage controllers. GFL energy storage controllers synchronize with the grid via a phase-locked loop (PLL), while GFM energy storage controllers synchronize with the grid through power synchronization loops and other mechanisms. Existing research indicates that GFL control mode carries an instability risk under weak grid conditions, while GFM control mode carries an instability risk under strong grid conditions. Both control modes have their applicable operating conditions, and selecting the appropriate control mode under corresponding conditions is beneficial for improving grid stability.

[0004] In existing technologies, some inventions use real-time calculated grid strength or short-circuit ratio as criteria to automatically perform follow-type control and grid-based control. However, since grid strength is a system-level indicator, it cannot be accurately calculated from the perspective of the energy storage control device itself. Therefore, there is a problem of inappropriate switching timing, which may even lead to system instability. Summary of the Invention

[0005] To address the problems in existing technologies, this invention provides an energy storage control method, system, storage medium, and processor for automatic switching between grid-based and follow-grid control based on instability mode identification. Starting from monitoring the output variables of the control loop, it identifies the instability modes of the energy storage control device when using follow-grid or grid-based control. When instability is detected in the energy storage control device, it switches to the other control mode. The specific technical solution is as follows:

[0006] An energy storage control method based on instability mode recognition that automatically switches between grid-based control and grid-following control includes the following steps:

[0007] Step S1: Collect the three-phase voltage signal and three-phase current signal at the grid connection point of the energy storage device;

[0008] Step S2: Calculate the active power P and reactive power Q output by the energy storage device based on the three-phase voltage and current signals; Step S3: Perform Park transform on the three-phase voltage and current signals respectively to obtain the d-axis voltage component u. td q-axis voltage component u tq and the d-axis current component i d q-axis current component i q ;

[0009] Step S4, based on the active power P and the q-axis voltage component u tq And the reference value P of active power ref The output signal of the synchronization control loop is calculated. The synchronization control loop includes a phase-locked loop with follower control and a power synchronization loop with grid-type control. The output signal of the synchronization control loop includes the dq-axis phase θ output by the power synchronization loop with grid-type control. dq-GFM The dq-axis phase θ of the output of the follower-type control phase-locked loop dq-GFL ;

[0010] Step S5, based on active power P, reactive power Q, and d-axis voltage component u td q-axis voltage component u tq And the reference value P of active power ref Reference value of reactive power Q ref The output signal of the power control and voltage outer loop is calculated. The power control and voltage outer loop includes an active power control loop for follower-type control, a reactive power control loop for follower-type control, and a reactive power and voltage control loop for grid-type control. The output signal of the power control and voltage outer loop includes the d-axis current component reference value i output by the power control loop in follower-type control. dref-GFL Reference value i of the q-axis current component output of the power control loop in follower-type control. qref-GFL Reference value i of the d-axis current component output of the power control loop in a network-type control system. dref-GFM Reference value i of the q-axis current component output of the power control loop in a network-type control system. qref-GFM ;

[0011] Step S6: Based on the output signal of the synchronization control loop and the output signal of the power control and voltage outer loop, determine the switching conditions between the network control mode and the follower control mode, and output the synchronization phase θ according to the switching flag variable F. dq d-axis current reference value idref and q-axis current reference value i qref ;

[0012] Step S7, based on the d-axis voltage component u td q-axis voltage component u tq d-axis current component i d q-axis current component i q d-axis current reference value i dref and q-axis current reference value i qref The d-axis internal electromotive force e of the current control loop is calculated. d and the electromotive force e on the q-axis q ;

[0013] Step S8, the electromotive force e in the d-axis of the current control loop is... d and the electromotive force e on the q-axis q Based on synchronous phase θ dq The three-phase reference wave signal e is obtained after inverse Parker transform. abc ;

[0014] Step S9, the three-phase reference wave signal e abc The signal is transmitted to the PMW modulation controller to generate a trigger signal, which in turn controls the converter of the energy storage device.

[0015] Preferably, the output signal of the synchronization control loop in step S4 is calculated as follows:

[0016]

[0017] Where, ω GFM For the angular velocity of the network-type control power synchronization loop, ω GFL For the angular velocity of the follow-type control phase-locked loop, k pPLL and k iPLL These are respectively follower-type control phase-locked synchronous loop PI PLL The proportional and integral coefficients; M and D are the inertia and damping parameters in the network-type control power synchronization loop, respectively; ω0 is the fundamental angular frequency.

[0018] Preferably, the calculation method for the output signal of the power control and voltage outer loop in step S5 is as follows:

[0019]

[0020] Where, k pAPC and k iAPC These are PI controllers in active power control with follow-type control. APC The proportionality coefficient and integral coefficient, k pTVC1 and k iTVC1 These are PI controllers in reactive power control with follower control.TVC1 The proportional coefficient and integral coefficient, U t To obtain the measured terminal voltage amplitude, K Q k is the reactive power regulation coefficient. pTVC2 and k iTVC2 These are PI controllers in network-type voltage control. TVC2 The proportional coefficient and integral coefficient.

[0021] Preferably, the switching conditions between network-type control and follower-type control in step S6 are as follows:

[0022] If the equipment is operating in follower control mode, the angular velocity ω of the follower control phase-locked loop is monitored in real time. GFL The value of ω is determined when the angular velocity ω of the follower-type control phase-locked loop is... GFL The following conditions are met when the follower-type control mode is considered unstable and can be switched to the network-type control mode, with the switching flag variable F set to 1:

[0023] (1)|ω0–ω GFL |≥Δω max-GFL And it continues to exceed t us1-GFL time;

[0024] (2) At t us2-GFL Within the time window, from |ω0–ω GFL |<Δω max-GFL Change to |ω0–ω GFL |≥Δω max-GFL The number of times is greater than n; where Δω max-GFL The maximum angular frequency deviation for determining the unstable state in a follower-type control phase-locked loop is generally Δω. max-GFL It must be less than the amplitude limit value in the phase-locked loop; t us1-GFL and t us2-GFL Parameters for determining instability in follower-type control mode; if the equipment is operating in grid-type control mode, the angular velocity ω of the grid-type control power synchronization loop is monitored in real time. GFM The value of ω when the angular velocity ω of the grid-type control power synchronization loop is... GFM The following conditions are met when the network-based control mode is considered unstable and can be switched to the following network-based control mode, with the switching flag variable F set to 0:

[0025] (1)|ω0–ω GFM |≥Δω max-GFM And it continues to exceed t us1-GFM time;

[0026] (2) At t us2-GFM Within the time window, from |ω0–ω GFM |<Δω max-GFM Change to |ω0–ωGFM |≥Δω max-GFM The number of times is greater than n; where Δω max-GFM The maximum angular frequency deviation for determining the instability state in a grid-type control power synchronization loop is t. us1-GFM and t us2-GFM Parameters used to determine the instability state of a network-type control mode.

[0027] Preferably, in step S6, the synchronization phase θ is output according to the switching flag variable F. dq d-axis current reference value i dref and q-axis current reference value i qref Specifically as follows:

[0028]

[0029] Preferably, in step S7, the electromotive force e within the d-axis of the current control loop... d and the electromotive force e on the q-axis q The calculation method is as follows:

[0030]

[0031] Where, k pACC and k iACC These are the proportional-integral controllers (PI) in the current control loop. ACC The proportionality coefficient and integral coefficient, L f ω0 is the filter inductance value, and ω0 is the fundamental angular frequency.

[0032] An energy storage control system based on instability mode recognition, which automatically switches between grid-based control and grid-following control, is applied to the method described above, comprising:

[0033] The acquisition module is used to acquire the three-phase voltage and three-phase current signals at the grid connection point of the energy storage device;

[0034] The active and reactive power calculation module is used to calculate the active power P and reactive power Q output by the energy storage device based on the three-phase voltage signal and the three-phase current signal.

[0035] The Parker transform module is used to perform Parker transforms on the three-phase voltage signal and the three-phase current signal to obtain the d-axis voltage component u. td q-axis voltage component u tq and the d-axis current component i d q-axis current component i q ;

[0036] The synchronous control loop module is used to control the active power P and the q-axis voltage components u. tq And the reference value P of active power refThe output signal of the synchronization control loop is calculated. The synchronization control loop includes a phase-locked loop with follower control and a power synchronization loop with grid-type control. The output signal of the synchronization control loop includes the dq-axis phase θ output by the power synchronization loop with grid-type control. dq-GFM The dq-axis phase θ of the output of the follower-type control phase-locked loop dq-GFL ;

[0037] The power control and voltage outer loop module is used to control the active power P, reactive power Q, and d-axis voltage component u. td q-axis voltage component u tq And the reference value P of active power ref Reference value of reactive power Q ref The output signal of the power control and voltage outer loop is calculated. The power control and voltage outer loop includes an active power control loop for follower-type control, a reactive power control loop for follower-type control, and a reactive power and voltage control loop for grid-type control. The output signal of the power control and voltage outer loop includes the d-axis current component reference value i output by the power control loop in follower-type control. dref-GFL Reference value i of the q-axis current component output of the power control loop in follower-type control. qref-GFL Reference value i of the d-axis current component output of the power control loop in a network-type control system. dref-GFM Reference value i of the q-axis current component output of the power control loop in a network-type control system. qref-GFM ;

[0038] The switching control module is used to determine the switching conditions between the network-type control mode and the follower-type control mode based on the output signals of the synchronization control loop and the power control and voltage outer loop, and outputs the synchronization phase θ according to the switching flag variable F. dq d-axis current reference value i dref and q-axis current reference value i qref ;

[0039] The current control loop module is used to control the current based on the d-axis voltage component u. td q-axis voltage component u tq d-axis current component i d q-axis current component i q d-axis current reference value i dref and q-axis current reference value i qref The d-axis internal electromotive force e of the current control loop is calculated. d and the electromotive force e on the q-axis q ;

[0040] The inverse Parker transformation module is used to convert the d-axis internal electromotive force e of the current control loop. d and the electromotive force e on the q-axis q Based on synchronous phase θ dqThe three-phase reference wave signal e is obtained after inverse Parker transform. abc ;

[0041] The trigger control module is used to trigger the three-phase reference wave signal e abc The signal is transmitted to the PMW modulation controller to generate a trigger signal, which in turn controls the converter of the energy storage device.

[0042] A computer-readable storage medium includes a stored program, wherein, when the program is executed, it controls the device where the computer-readable storage medium is located to perform the energy storage control method based on instability mode recognition, which automatically switches between grid-based control and grid-following control.

[0043] A processor for running a program, wherein the program executes the energy storage control method based on instability mode recognition that automatically switches between grid-based control and grid-following control.

[0044] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0045] This invention relates to an energy storage control method based on instability mode recognition, which automatically switches between grid-based and grid-following control modes. The method includes: acquiring three-phase voltage and current signals; calculating active and reactive power; performing Parker transform on the three-phase voltage and current signals; calculating the output signal of the synchronization control loop; calculating the output signals of the power control and voltage outer loops; determining the switching conditions between grid-based and follower control modes, obtaining the synchronization phase, d-axis current reference value, and q-axis current reference value; calculating the d-axis and q-axis internal electromotive force of the current control loop, and obtaining a three-phase reference wave signal based on the synchronization phase through an inverse Parker transform; and controlling the converter of the energy storage device using the three-phase reference wave signal. This invention starts from the key characteristics of energy storage device instability, detects the angular frequency output of the phase-locked loop and power synchronization loop in real time, and automatically switches between grid-based and grid-following control modes, effectively reducing the risk of erroneous switching and improving the grid-connected stability of the energy storage device. Attached Figure Description

[0046] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0047] Figure 1 This is a schematic diagram illustrating the principle of the method of the present invention;

[0048] Figure 2 This is a schematic diagram of the synchronous control loop.

[0049] Figure 3 This is a schematic diagram illustrating the principle of power control and voltage outer loop.

[0050] Figure 4 This is a schematic diagram of the current control loop. Detailed Implementation

[0051] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0052] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0053] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0054] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0055] Example 1:

[0056] like Figure 1 As shown, this embodiment provides an energy storage control method for automatic switching between grid-based control and grid-following control based on instability mode recognition, including the following steps:

[0057] Step S1: Collect the three-phase voltage signal and three-phase current signal at the grid connection point of the energy storage device.

[0058] Step S2: Calculate the active power P and reactive power Q output by the energy storage device based on the three-phase voltage and current signals. Step S3: Perform Park transform on the three-phase voltage and current signals respectively to obtain the d-axis voltage component u. td q-axis voltage component u tq and the d-axis current component i d q-axis current component i q .

[0059] Step S4, based on the active power P and the q-axis voltage component u tq And the reference value P of active power ref The output signal of the synchronization control loop is calculated. The synchronization control loop includes a phase-locked loop with follower control and a power synchronization loop with grid-type control. The output signal of the synchronization control loop includes the dq-axis phase θ output by the power synchronization loop with grid-type control. dq-GFM The dq-axis phase θ of the output of the follower-type control phase-locked loop dq-GFL .

[0060] Figure 2 This is a schematic diagram of the synchronous control loop. Figure 2 In the diagram, from top to bottom, are the power synchronization loop for network-type control and the phase-locked loop for follower-type control, where s represents the complex variable in the Laplace transform. PI PLL This refers to the PI controller in a follower-type phase-locked loop synchronization loop.

[0061] The output signal of the synchronization control loop is calculated as follows:

[0062]

[0063] Where, ω GFM For the angular velocity of the network-type control power synchronization loop, ω GFL For the angular velocity of the follow-type control phase-locked loop, k pPLL and k iPLL These are respectively follower-type control phase-locked synchronous loop PI PLL The proportional and integral coefficients; M and D are the inertia and damping parameters in the network-type control power synchronization loop, respectively; ω0 is the fundamental angular frequency.

[0064] Step S5, based on active power P, reactive power Q, and d-axis voltage component u td q-axis voltage component u tq And the reference value P of active power ref Reference value of reactive power Q ref The output signal of the power control and voltage outer loop is calculated. The power control and voltage outer loop includes an active power control loop for follower-type control, a reactive power control loop for follower-type control, and a reactive power and voltage control loop for grid-type control. The output signal of the power control and voltage outer loop includes the d-axis current component reference value i output by the power control loop in follower-type control. dref-GFL Reference value i of the q-axis current component output of the power control loop in follower-type control. qref-GFL Reference value i of the d-axis current component output of the power control loop in a network-type control system. dref-GFM Reference value i of the q-axis current component output of the power control loop in a network-type control system. qref-GFM.

[0065] Figure 3 This is a schematic diagram of the power control and voltage outer loop. Figure 3 From top to bottom, the diagrams represent active power control using a follower-type control system, reactive power control using a follower-type control system, and reactive power and voltage control using a grid-based control system. Among these, PI... APC This refers to the PI controller in active power control with a follower-type control mechanism. TVC1 This refers to the PI controller in reactive power control with follow-type control. TVC2 This refers to the PI controller in a grid-type voltage control system.

[0066] The calculation method for the output signal of the power control and voltage outer loop is as follows:

[0067]

[0068] Where, k pAPC and k iAPC These are PI controllers in active power control with follow-type control. APC The proportionality coefficient and integral coefficient, k pTVC1 and k iTVC1 These are PI controllers in reactive power control with follower control. TVC1 The proportional coefficient and integral coefficient, U t To obtain the measured terminal voltage amplitude, K Q k is the reactive power regulation coefficient. pTVC2 and k iTVC2 These are PI controllers in network-type voltage control. TVC2 The proportional coefficient and integral coefficient.

[0069] Step S6: Based on the output signal of the synchronization control loop and the output signal of the power control and voltage outer loop, determine the switching conditions between the network control mode and the follower control mode, and output the synchronization phase θ according to the switching flag variable F. dq d-axis current reference value i dref and q-axis current reference value i qref .

[0070] The specific switching conditions between network-based control and follower-based control are as follows:

[0071] If the equipment is operating in follower control mode, the angular velocity ω of the follower control phase-locked loop is monitored in real time. GFL The value of ω is determined when the angular velocity ω of the follower-type control phase-locked loop is... GFL The following conditions are met when the follower-type control mode is considered unstable and can be switched to the network-type control mode, with the switching flag variable F set to 1:

[0072] (1)|ω0–ωGFL |≥Δω max-GFL And it continues to exceed t us1-GFL time;

[0073] (2) At t us2-GFL Within the time window, from |ω0–ω GFL |<Δω max-GFL Change to |ω0–ω GFL |≥Δω max-GFL The number of times is greater than n;

[0074] Where, Δω max-GFL The maximum angular frequency deviation for determining the unstable state in a follower-type control phase-locked loop is generally Δω. max-GFL It must be less than the amplitude limit value in the phase-locked loop; t us1-GFL and t us2-GFL Parameters used to determine the instability state of a follower-type control mode. Generally, Δω max-GFL It must be less than the limiting value in the follower-type control phase-locked loop synchronization loop. t us1-GFL 500ms can be taken, t us2-GFL The value can be 1 second, and n can be taken 3 times; the specific settings should be determined based on the equipment specifications. us1-GFL and t us2-GFL The time should not be less than 50ms, not more than 3s, and n should not be more than 10 times.

[0075] If the equipment is operating in network-type control mode, the angular velocity ω of the network-type control power synchronization loop is monitored in real time. GFM The value of ω when the angular velocity ω of the grid-type control power synchronization loop is... GFM The following conditions are met when the network-based control mode is considered unstable and can be switched to the following network-based control mode, with the switching flag variable F set to 0:

[0076] (1)|ω0–ω GFM |≥Δω max-GFM And it continues to exceed t us1-GFM time;

[0077] (2) At t us2-GFM Within the time window, from |ω0–ω GFM |<Δω max-GFM Change to |ω0–ω GFM |≥Δω max-GFM The number of times is greater than n;

[0078] Where, Δω max-GFM The maximum angular frequency deviation for determining the instability state in a grid-type control power synchronization loop is t. us1-GFM and t us2-GFMParameters used to determine the instability state of a network-type control mode. Considering that network-type control equipment has a certain primary frequency regulation capability, its normal operation may deviate significantly from the rated angular frequency (i.e., ω0), therefore Δω max-GFM Generally greater than Δω max-GFL . t us1-GFM 500ms can be taken, t us2-GFM The value can be 1 second, and n can be taken 3 times; the specific settings should be determined based on the equipment specifications. us1-GFM and t us2-GFM The time should not be less than 50ms, not more than 3s, and n should not be more than 10 times.

[0079] Output synchronization phase θ based on switching flag variable F dq d-axis current reference value i dref and q-axis current reference value i qref Specifically as follows:

[0080]

[0081] Step S7, based on the d-axis voltage component u td q-axis voltage component u tq d-axis current component i d q-axis current component i q d-axis current reference value i dref and q-axis current reference value i qref The d-axis internal electromotive force e of the current control loop is calculated. d and the electromotive force e on the q-axis q .

[0082] Figure 4 This is a schematic diagram of a current control loop, where PI... ACC This represents the proportional-integral controller in the current control loop, where ω0 is the fundamental angular frequency. For a 50Hz system, ω0 = 100π rad / s.

[0083] The internal electromotive force e of the current control loop along the d-axis d and the electromotive force e on the q-axis q The calculation method is as follows:

[0084]

[0085] Where, k pACC and k iACC These are the proportional-integral controllers (PI) in the current control loop. ACC The proportional coefficient and integral coefficient, L f ω0 is the filter inductance value, and ω0 is the fundamental angular frequency.

[0086] Step S8, the electromotive force e in the d-axis of the current control loop is... dand the electromotive force e on the q-axis q Based on synchronous phase θ dq The three-phase reference wave signal e is obtained after inverse Parker transform. abc .

[0087] Step S9, the three-phase reference wave signal e abc The signal is transmitted to the PMW modulation controller to generate a trigger signal, which in turn controls the converter of the energy storage device.

[0088] Example 2:

[0089] Based on the same inventive concept as Embodiment 1, this embodiment provides an energy storage control system that automatically switches between grid-based control and grid-following control based on instability mode recognition, applied to the method described, including:

[0090] The acquisition module is used to acquire the three-phase voltage and three-phase current signals at the grid connection point of the energy storage device;

[0091] The active and reactive power calculation module is used to calculate the active power P and reactive power Q output by the energy storage device based on the three-phase voltage signal and the three-phase current signal.

[0092] The Parker transform module is used to perform Parker transforms on the three-phase voltage signal and the three-phase current signal to obtain the d-axis voltage component u. td q-axis voltage component u tq and the d-axis current component i d q-axis current component i q ;

[0093] The synchronous control loop module is used to control the active power P and the q-axis voltage components u. tq And the reference value P of active power ref The output signal of the synchronization control loop is calculated. The synchronization control loop includes a phase-locked loop with follower control and a power synchronization loop with grid-type control. The output signal of the synchronization control loop includes the dq-axis phase θ output by the power synchronization loop with grid-type control. dq-GFM The dq-axis phase θ of the output of the follower-type control phase-locked loop dq-GFL ;

[0094] The power control and voltage outer loop module is used to control the active power P, reactive power Q, and d-axis voltage component u. td q-axis voltage component u tq And the reference value P of active power ref Reference value of reactive power Q refThe output signal of the power control and voltage outer loop is calculated. The power control and voltage outer loop includes an active power control loop for follower-type control, a reactive power control loop for follower-type control, and a reactive power and voltage control loop for grid-type control. The output signal of the power control and voltage outer loop includes the d-axis current component reference value i output by the power control loop in follower-type control. dref-GFL Reference value i of the q-axis current component output of the power control loop in follower-type control. qref-GFL Reference value i of the d-axis current component output of the power control loop in a network-type control system. dref-GFM Reference value i of the q-axis current component output of the power control loop in a network-type control system. qref-GFM ;

[0095] The switching control module is used to determine the switching conditions between the network-type control mode and the follower-type control mode based on the output signals of the synchronization control loop and the power control and voltage outer loop, and outputs the synchronization phase θ according to the switching flag variable F. dq d-axis current reference value i dref and q-axis current reference value i qref ;

[0096] The current control loop module is used to control the current based on the d-axis voltage component u. td q-axis voltage component u tq d-axis current component i d q-axis current component i q d-axis current reference value i dref and q-axis current reference value i qref The d-axis internal electromotive force e of the current control loop is calculated. d and the electromotive force e on the q-axis q ;

[0097] The inverse Parker transformation module is used to convert the d-axis internal electromotive force e of the current control loop. d and the electromotive force e on the q-axis q Based on synchronous phase θ dq The three-phase reference wave signal e is obtained after inverse Parker transform. abc ;

[0098] The trigger control module is used to trigger the three-phase reference wave signal e abc The signal is transmitted to the PMW modulation controller to generate a trigger signal, which in turn controls the converter of the energy storage device.

[0099] Example 3:

[0100] Based on the same inventive concept as Embodiment 1, this embodiment provides a computer-readable storage medium, which includes a stored program, wherein, when the program is executed, it controls the device where the computer-readable storage medium is located to perform the energy storage control method of automatic switching between grid-based control and grid-following control based on instability mode recognition.

[0101] Example 4:

[0102] Based on the same inventive concept as Embodiment 1, this embodiment provides a processor for running a program, wherein the program executes the energy storage control method for automatic switching between grid-type control and grid-following control based on instability mode recognition.

[0103] Those skilled in the art will recognize that the modules of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components of the examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of the invention.

[0104] In the embodiments provided by this invention, it should be understood that the division of modules is only a logical functional division. In actual implementation, there may be other division methods, such as multiple modules can be combined into one module, one module can be split into multiple modules, or some features can be ignored.

[0105] Furthermore, the functional modules in the various embodiments of the present invention can be integrated into one processing module, or each module can exist physically separately, or two or more modules can be integrated into one module. The integrated modules described above can be implemented in hardware or as software functional modules.

[0106] If the integrated module is implemented as a software functional module and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, 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. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0107] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

Claims

1. An energy storage control method based on instability mode recognition with automatic switching between grid-based control and grid-following control, characterized in that, Includes the following steps: Step S1: Collect the three-phase voltage signal and three-phase current signal at the grid connection point of the energy storage device; Step S2: Calculate the active power output of the energy storage device based on the three-phase voltage signal and the three-phase current signal. P and reactive power Q ; Step S3: Perform Parker transform on the three-phase voltage signal and the three-phase current signal respectively to obtain the d-axis voltage component. u td q-axis voltage component u tq and d-axis current components i d q-axis current component i q ; Step S4, based on active power P q-axis voltage component u tq and reference values ​​for active power P ref The output signal of the synchronization control loop is calculated. The synchronization control loop includes a phase-locked loop with follower-type control and a power synchronization loop with grid-type control. The output signal of the synchronization control loop includes the output signal of the power synchronization loop with grid-type control. dq Axial phase θ dq-GFM and the output of the follow-type control phase-locked synchronization loop dq Axial phase θ dq-GFL ; Step S5, based on active power P、 reactive power Q、 d-axis voltage component u td q-axis voltage component u tq and reference values ​​for active power P ref Reference values ​​for reactive power Q ref The output signal of the power control and voltage outer loop is calculated. The power control and voltage outer loop includes an active power control loop for follower-type control, a reactive power control loop for follower-type control, and a reactive power and voltage control loop for grid-type control. The output signal of the power control and voltage outer loop includes the reference value of the d-axis current component output by the power control loop in follower-type control. i dref-GFL 、 Reference value of q-axis current component output of power control loop in follower control i qref-GFL 、 Reference value of d-axis current component output of power control loop in network control i dref-GFM Reference value of q-axis current component output of power control loop in network control i qref-GFM ; Step S6: Based on the output signal of the synchronization control loop and the output signal of the power control and voltage outer loop, determine the switching conditions between the network control mode and the follower control mode, and determine the switching flag variable. F Output Synchronization Phase θ dq 、d Shaft current reference value i dref and q Shaft current reference value i qref ; Step S7, based on the d-axis voltage component u td q-axis voltage component u tq d-axis current component i d q-axis current component i q , d Shaft current reference value i dref and q Shaft current reference value i qref The current control loop was calculated. d Internal electromotive force e d and q Internal electromotive force e q ; Step S8, the current control loop... d Internal electromotive force e d and q Internal electromotive force e q Based on synchronization phase θ dq The three-phase reference wave signal is obtained after inverse Parker transformation. e abc ; Step S9, the three-phase reference wave signal e abc The signal is transmitted to the PWM modulation controller to generate a trigger signal, which in turn controls the converter of the energy storage device. The specific switching conditions between network-based control and follower control in step S6 are as follows: If the equipment is operating in follower control mode, the angular velocity ω of the follower control phase-locked loop is monitored in real time. GFL The value of ω is determined when the angular velocity ω of the follower-type control phase-locked loop is... GFL The following conditions are met when the follower-type control mode is considered unstable and can be switched to the network-type control mode, with the flag variable being switched. F Set to 1: (1)|ω0–ω GFL |≥Δω max-GFL And continued to exceed t us1-GFL time; ω 0 represents the fundamental angular frequency; (2) In t us2-GFL Within the time window, from |ω0–ω GFL |<Δω max-GFL Change to |ω0–ω GFL |≥Δω max-GFL The number of times is greater than n ; Where, Δω max-GFL The maximum angular frequency deviation, Δω, is used to determine the unstable state of the follower-type control phase-locked loop. max-GFL It must be smaller than the limiting value in the phase-locked loop; t us1-GFL and t us2-GFL Parameters used to determine the instability state of the follower control mode; If the equipment is operating in network-type control mode, the angular velocity ω of the network-type control power synchronization loop is monitored in real time. GFM The value of ω when the angular velocity ω of the grid-type control power synchronization loop is... GFM The following conditions are met when the network-based control mode is considered unstable and can be switched to the following network-based control mode, with the switching flag variable... F Set to 0: (1)|ω0–ω GFM |≥Δω max-GFM And continued to exceed t us1-GFM time; (2) In t us2-GFM Within the time window, from |ω0–ω GFM |<Δω max-GFM Change to |ω0–ω GFM |≥Δω max-GFM The number of times is greater than n ; Where, Δω max-GFM The maximum angular frequency deviation for determining the instability state in a grid-type control power synchronization loop. t us1-GFM and t us2-GFM Parameters used to determine the instability state of a network-type control mode.

2. The energy storage control method based on instability mode recognition and automatic switching between grid-based control and grid-following control according to claim 1, characterized in that, The calculation method for the output signal of the synchronization control loop in step S4 is as follows: ； in, ω GFM To construct the angular velocity of the grid-type control power synchronization loop, ω GFL To control the angular velocity of the phase-locked loop synchronization loop, k pPLL and k iPLL These are respectively follower-type control phase-locked synchronous loop PI PLL The proportional coefficient and integral coefficient; M and D These are the inertia and damping parameters in the grid-type control power synchronization loop, respectively.

3. The energy storage control method based on instability mode recognition and automatic switching between grid-based control and grid-following control according to claim 1, characterized in that, The calculation method for the output signal of the power control and voltage outer loop in step S5 is as follows: ； in, k pAPC and k iAPC These are PI controllers in active power control with follow-type control. APC proportionality coefficient and integral coefficient, k pTVC1 and k iTVC1 These are PI controllers in reactive power control with follower control. TVC1 proportionality coefficient and integral coefficient, U t To measure the amplitude of the terminal voltage, K Q This is the reactive power regulation coefficient. k pTVC2 and k iTVC2 These are PI controllers in network-type voltage control. TVC2 The proportional coefficient and integral coefficient.

4. The energy storage control method based on instability mode recognition and automatic switching between grid-based control and grid-following control according to claim 1, characterized in that, In step S6, the switching flag variable is used. F Output Synchronization Phase θ dq 、d Shaft current reference value i dref and q Shaft current reference value i qref Specifically as follows: ； ； 。 5. The energy storage control method based on instability mode recognition and automatic switching between grid-based control and grid-following control according to claim 1, characterized in that, The current control loop in step S7 d Internal electromotive force e d and q Internal electromotive force e q The calculation method is as follows: ； in, k pACC and k iACC These are the proportional-integral controllers (PI) in the current control loop. ACC proportionality coefficient and integral coefficient, L f This is the value of the filter inductance. ω 0 represents the fundamental angular frequency.

6. An energy storage control system based on instability mode recognition and automatic switching between grid-based control and grid-following control, characterized in that, The method applied to any one of claims 1 to 5 includes: The acquisition module is used to acquire the three-phase voltage and three-phase current signals at the grid connection point of the energy storage device; The active and reactive power calculation module is used to calculate the active power output of the energy storage device based on the three-phase voltage and current signals. P and reactive power Q ; The Parker transform module is used to perform Parker transforms on the three-phase voltage signals and three-phase current signals to obtain the d-axis voltage components. u td q-axis voltage component u tq and d-axis current components i d q-axis current component i q ; Synchronous control loop module, used to determine active power P q-axis voltage component u tq and reference values ​​for active power P ref The output signal of the synchronization control loop is calculated. The synchronization control loop includes a phase-locked loop with follower-type control and a power synchronization loop with grid-type control. The output signal of the synchronization control loop includes the output signal of the power synchronization loop with grid-type control. dq Axial phase θ dq-GFM and the output of the follow-type control phase-locked synchronization loop dq Axial phase θ dq-GFL ; The power control and voltage outer loop module is used to control the active power. P、 reactive power Q、 d-axis voltage component u td q-axis voltage component u tq and reference values ​​for active power P ref Reference values ​​for reactive power Q ref The output signal of the power control and voltage outer loop is calculated. The power control and voltage outer loop includes an active power control loop for follower-type control, a reactive power control loop for follower-type control, and a reactive power and voltage control loop for grid-type control. The output signal of the power control and voltage outer loop includes the reference value of the d-axis current component output by the power control loop in follower-type control. i dref-GFL 、 Reference value of q-axis current component output of power control loop in follower control i qref-GFL 、 Reference value of d-axis current component output of power control loop in network control i dref-GFM Reference value of q-axis current component output of power control loop in network control i qref-GFM ; The switching control module is used to determine the switching conditions between the network-type control mode and the follower-type control mode based on the output signals of the synchronous control loop and the power control and voltage outer loop, and to determine the switching conditions based on the switching flag variable. F Output Synchronization Phase θ dq 、 d Shaft current reference value i dref and q Shaft current reference value i qref ; The current control loop module is used to control the current based on the d-axis voltage component. u td q-axis voltage component u tq d-axis current component i d q-axis current component i q , d Shaft current reference value i dref and q Shaft current reference value i qref The current control loop was calculated. d Internal electromotive force e d and q Internal electromotive force e q ; The inverse Parker converter module is used to convert the current control loop... d Internal electromotive force e d and q Internal electromotive force e q Based on synchronization phase θ dq The three-phase reference wave signal is obtained after inverse Parker transformation. e abc ; The trigger control module is used to trigger the three-phase reference wave signal. e abc The signal is transmitted to the PMW modulation controller to generate a trigger signal, which in turn controls the converter of the energy storage device.

7. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored program, wherein, when the program is executed, it controls the device where the computer-readable storage medium is located to perform the energy storage control method of any one of claims 1 to 5, which automatically switches between grid-based control and grid-following control based on instability mode recognition.

8. A processor, characterized in that, The processor is used to run a program, wherein the program executes the energy storage control method based on instability mode recognition and automatic switching between grid-type control and grid-following control as described in any one of claims 1 to 5.

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