Energy storage control method and system capable of automatically switching network construction type control and network following type control based on instability mode recognition, storage medium and processor

Abstract

The invention relates to the technical field of energy storage equipment control, in particular to an energy storage control method and system capable of automatically switching between network construction type control and network following type control based on instability mode recognition, a storage medium and a processor, and the method comprises the steps: collecting three-phase voltage and current signals; calculating active power and reactive power; park transformation is carried out on the three-phase voltage and current signals; calculating an output signal of the synchronous control loop; calculating an output signal of the power control and voltage outer loop; judging a switching condition of the network construction type control mode and the following type control mode to obtain a synchronous phase, a d-axis current reference value and a q-axis current reference value; d-axis internal electromotive force and q-axis internal electromotive force of the current control loop are obtained through calculation, a three-phase reference wave signal is obtained through anti-Park transformation based on the synchronous phase, and a converter of the energy storage equipment is controlled. According to the invention, the network construction type control mode and the network following type control mode are automatically switched, the risk of wrong switching is effectively reduced, and the grid connection stability of the energy storage equipment is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage device control, and in particular to an energy storage control method, system, storage medium and processor for automatic switching between grid-building control and grid-following control based on instability mode recognition. Background Art

[0002] In the new power system, new energy will become the main power source. The new energy with high penetration rate will profoundly change the form, characteristics and mechanism of the traditional power system. The new power system will show the characteristics of power electronics, strong volatility and uncertainty, which will bring new challenges to reliable power supply, safe and stable and economic operation. As the hub and link of multi-type energy complementarity, energy storage can enhance the flexibility and stability of the power system and is an important support for the new power system with new energy as the main body. Configuring energy storage on the new energy station side can suppress the fluctuation of new energy power generation, improve the ability of new energy to track the output of power generation plan, and reduce the abandonment of wind and light; configuring energy storage on the grid side can delay the investment in transmission equipment and network upgrade and expansion, alleviate the congestion of transmission channels, and improve the stability of the grid; configuring energy storage on the load side can reduce the peak-to-valley difference, improve the quality of electricity, and play the role of emergency power supply.

[0003] Energy storage controllers can be roughly divided into two categories: Grid Following (GFL) energy storage controllers and Grid Forming (GFM) energy storage controllers. The Grid Following energy storage control device is synchronized with the grid through a phase-locked loop (PLL), while the Grid Forming energy storage control device is synchronized with the grid through a power synchronization loop and other links. Existing research shows that the Grid Following control mode has the risk of instability in weak grid conditions, and the Grid Forming control mode has the risk of instability in strong grid conditions. Both control modes have their applicable operating conditions. Selecting the appropriate control mode in the corresponding situation is conducive to improving the stability of the grid.

[0004] In the prior art, there are inventions that automatically perform follow-up control and network-building control based on the real-time calculation of grid strength or short-circuit ratio as a criterion. However, since grid strength is a system-level indicator, it cannot be accurately calculated from the perspective of the energy storage control device itself, so there is a problem of inappropriate switching time, and even system instability. Summary of the invention

[0005] In view of the problems in the prior art, the present invention provides an energy storage control method, system, storage medium and processor for automatic switching between grid-forming control and grid-following control based on instability mode recognition. Starting from the monitoring of the output variable of the control loop, the instability mode of the energy storage control device when the following control or grid-forming control is adopted is identified. When the energy storage control device is found to be instability, it is switched to another control mode. The specific technical scheme is as follows:

[0006] A method for automatically switching between grid-building control and grid-following control based on instability mode recognition is provided, comprising the following steps:

[0007] Step S1, collecting three-phase voltage signals and three-phase current signals of the energy storage device grid connection point;

[0008] Step S2, calculating the active power P and reactive power Q output by the energy storage device according to the three-phase voltage signal and the three-phase current signal; Step S3, performing Park transformation 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 ;

[0009] Step S4: according to the active power P and the q-axis voltage component u tq And the reference value of active power P ref , calculate and obtain the output signal of the synchronous control loop, the synchronous control loop includes a phase-locked synchronous loop of follower control and a power synchronous loop of network control; the output signal of the synchronous control loop includes a dq axis phase θ output by the network control power synchronous loop dq-GFM The dq axis phase θ of the output of the phase-locked synchronous loop is controlled by the follower type dq-GFL ;

[0010] Step S5: According to the active power P, reactive power Q, d-axis voltage component u td , q-axis voltage component u tq And the reference value of active power P ref , the reference value of reactive power Q ref , calculate and obtain the output signal of the power control and voltage outer loop, the power control and voltage outer loop includes the active power control loop of the follower control, the reactive power control loop of the follower control and the reactive and voltage control loop of the network 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 the follower control dref-GFL , the q-axis current component reference value i output by the power control loop in the follower control qref-GFL , the d-axis current component reference value i output by the power control loop in the grid control dref-GFM , the q-axis current component reference value i output by the power control loop in the grid control qref-GFM ;

[0011] Step S6, judging the switching condition between the meshing control mode and the following control mode according to the output signal of the synchronous control loop and the output signal of the power control and voltage outer loop, and outputting the synchronous 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, according to 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 Calculate the d-axis internal electromotive force e of the current control loop d and the electromotive force e in the q axis q ;

[0013] Step S8: The d-axis internal electromotive force e of the current control loop is d and the electromotive force e in the q axis q Based on the synchronization phase θ dq After the reverse Pike transformation, the three-phase reference wave signal e is obtained. abc ;

[0014] Step S9: convert the three-phase reference wave signal e abc The trigger signal is transmitted to the PMW modulation controller to control the converter of the energy storage device.

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

[0016]

[0017] Among them, ω GFM is the angular velocity of the network-type control power synchronization ring, ω GFL is the angular velocity of the follower type control phase-locked synchronous loop, k pPLL and k iPLL They are follower type control phase-locked synchronous loop PI PLL The proportional coefficient and integral coefficient of M and D are the inertia parameter and damping parameter in the network-type control power synchronization loop respectively; ω 0 is the fundamental angular frequency.

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

[0019]

[0020] Among them, k pAPC and k iAPC They are PI controller PI in follow-up control and active control respectively. APC The proportionality coefficient and integration coefficient, k pTVC1 and k iTVC1They are PI controller PI in follow-up control reactive control TVC1 The proportional coefficient and integral coefficient, U t is the measured terminal voltage amplitude, K Q is the reactive power regulation coefficient, k pTVC2 and k iTVC2 They are PI controller PI in network control voltage control TVC2 The proportional coefficient and integral coefficient.

[0021] Preferably, the switching conditions between the networking control and the following control in step S6 are as follows:

[0022] If the device is running in the follower control mode, the angular velocity ω of the follower control phase-locked synchronization loop is monitored in real time. GFL When the angular velocity ω of the phase-locked synchronous loop is controlled by the follower type GFL When the following conditions are met, the following control mode is considered to be unstable and can be switched to the networking control mode, with the switching flag variable F set to 1:

[0023] (1)|ω 0 –ω GFL |≥Δω max-GFL , and lasts for more than t us1-GFL time;

[0024] (2) At t us2-GFL In the time window, from |ω 0 –ω GFL |<Δω max-GFL Change to |ω 0 –ω GFL |≥Δω max-GFL The number of times is greater than n; among them, Δω max-GFL It is the maximum angular frequency deviation of the follower control phase-locked synchronous loop to judge the instability state, generally Δω max-GFL must be smaller than the limit value in the phase-locked synchronization loop; t us1-GFL and t us2-GFL Parameters for judging the instability of the following control mode; if the device is running in the networking control mode, the angular velocity ω of the networking control power synchronization ring is monitored in real time GFM When the grid-type control power synchronization ring angular velocity ω GFM When the following conditions are met, the network-building control mode is considered to be unstable and can be switched to the network-following control mode, with the switching flag variable F set to 0:

[0025] (1)|ω 0 –ω GFM |≥Δω max-GFM , and lasts for more than t us1-GFM time;

[0026] (2) At t us2-GFM In the time window, from |ω 0 –ω GFM |<Δω max-GFM Change to |ω 0 –ω GFM |≥Δω max-GFM The number of times is greater than n; among them, Δω max-GFM is the maximum angular frequency deviation of the grid-type control power synchronization loop to determine the instability state, t us1-GFM and t us2-GFM It is a parameter for judging the instability state of the network control mode.

[0027] Preferably, in step S6, the synchronous 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 The details are as follows:

[0028]

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

[0030]

[0031] Among them, k pACC and k iACC They are the proportional integral controller PI in the current control loop ACC The proportional coefficient and integral coefficient, L f is the filter inductance value, ω 0 is the fundamental angular frequency.

[0032] An energy storage control system for automatic switching between grid-building control and grid-following control based on instability mode recognition, applied to the method described, comprising:

[0033] An acquisition module, used to acquire three-phase voltage signals and three-phase current signals of 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 according to the three-phase voltage signal and the three-phase current signal;

[0035] The Parker transformation module is used to perform Parker transformation 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] Synchronous control loop module, used to calculate the active power P and q-axis voltage component u tq And the reference value of active power P ref , calculate and obtain the output signal of the synchronous control loop, the synchronous control loop includes a phase-locked synchronous loop of follower control and a power synchronous loop of network control; the output signal of the synchronous control loop includes a dq axis phase θ output by the network control power synchronous loop dq-GFM The dq axis phase θ of the output of the phase-locked synchronous loop is controlled by the follower type dq-GFL ;

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

[0038] The switching control module is used to determine the switching conditions between the network control mode and the follower control mode according to the output signal of the synchronous control loop and the output signal of the power control and voltage outer loop, and output the synchronous 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 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 Calculate the d-axis internal electromotive force e of the current control loop d and the electromotive force e in the q axis q ;

[0040] The anti-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 in the q axis q Based on the synchronization phase θ dq After the reverse Pike transformation, the three-phase reference wave signal e is obtained. abc ;

[0041] The trigger control module is used to convert the three-phase reference wave signal e abc The trigger signal is transmitted to the PMW modulation controller to control the converter of the energy storage device.

[0042] A computer-readable storage medium includes a stored program, wherein when the program is run, the device where the computer-readable storage medium is located is controlled to execute the energy storage control method for automatic switching between networking type control and grid-following type control based on instability mode recognition.

[0043] A processor is used to run a program, wherein when the program is running, the energy storage control method for automatically switching between grid-building control and grid-following control based on instability pattern recognition is executed.

[0044] Compared with the prior art, the present invention has the following beneficial effects:

[0045] The present invention provides an energy storage control method for automatic switching between a grid-forming control and a grid-following control based on instability mode recognition, the method comprising: collecting three-phase voltage and current signals; calculating active power and reactive power; performing Parker transformation on the three-phase voltage and current signals; calculating the output signal of the synchronization control loop; calculating the output signal of the power control and voltage outer loop; judging the switching conditions between the grid-forming control mode and the following control mode, obtaining the synchronization phase, the d-axis current reference value, and the q-axis current reference value; calculating the d-axis internal electromotive force and the q-axis internal electromotive force of the current control loop, and obtaining the three-phase reference wave signal based on the synchronization phase through reverse Parker transformation; and controlling the converter of the energy storage device through the three-phase reference wave signal. Starting from the key characterization of the instability of the energy storage device, the present invention detects the angular frequency output by the phase-locked loop and the power synchronization loop in real time, automatically switches between the grid-forming control mode and the grid-following control mode, effectively reducing the risk of mis-switching and improving the stability of the energy storage device in grid connection. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for the specific embodiments or the description of the prior art. 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 according to the actual scale.

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

[0048] Figure 2 It is the principle schematic diagram of the synchronous control loop;

[0049] Figure 3 It is the principle diagram of power control and voltage outer loop;

[0050] Figure 4 This is the principle diagram of the current control loop. DETAILED DESCRIPTION

[0051] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work 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 "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

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

[0054] It should be further understood that the term "and / or" used in the present description and the appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0055] Embodiment 1:

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

[0057] Step S1, collecting three-phase voltage signals and three-phase current signals of the grid-connected point of the energy storage device.

[0058] Step S2, calculate the active power P and reactive power Q output by the energy storage device according to the three-phase voltage signal and the three-phase current signal. Step S3, perform Park transformation on the three-phase voltage signal and the three-phase current signal to obtain the d-axis voltage component utd , q-axis voltage component u tq , and the d-axis current component i d , q-axis current component i q .

[0059] Step S4: according to the active power P and the q-axis voltage component u tq And the reference value of active power P ref , calculate and obtain the output signal of the synchronous control loop, the synchronous control loop includes a phase-locked synchronous loop of follower control and a power synchronous loop of network control; the output signal of the synchronous control loop includes a dq axis phase θ output by the network control power synchronous loop dq-GFM The dq axis phase θ of the output of the phase-locked synchronous loop is controlled by the follower type dq-GFL .

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

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

[0062]

[0063] Among them, ω GFM is the angular velocity of the network-type control power synchronization ring, ω GFL is the angular velocity of the follower type control phase-locked synchronous loop, k pPLL and k iPLL They are follower type control phase-locked synchronous loop PI PLL The proportional coefficient and integral coefficient of M and D are the inertia parameter and damping parameter in the network-type control power synchronization loop respectively; ω 0 is the fundamental angular frequency.

[0064] Step S5: According to the active power P, reactive power Q, d-axis voltage component u td , q-axis voltage component u tq And the reference value of active power P ref , the reference value of reactive power Q ref , calculate and obtain the output signal of the power control and voltage outer loop, the power control and voltage outer loop includes the active power control loop of the follower control, the reactive power control loop of the follower control and the reactive and voltage control loop of the network 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 the follower control dref-GFL, the q-axis current component reference value i output by the power control loop in the follower control qref-GFL , the d-axis current component reference value i output by the power control loop in the grid control dref-GFM , the q-axis current component reference value i output by the power control loop in the grid control qref-GFM .

[0065] Figure 3 This is the schematic diagram of the power control and voltage outer loop. Figure 3 From top to bottom, they are active power control of following type control, reactive power control of following type control, and reactive power and voltage control of network type control. APC Indicates the PI controller in the active power control of the following control, PI TVC1 It represents the PI controller in the reactive power control of the following control. TVC2 Represents the PI controller in the network control voltage control.

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

[0067]

[0068] Among them, k pAPC and k iAPC They are PI controller PI in follow-up control and active control respectively. APC The proportionality coefficient and integration coefficient, k pTVC1 and k iTVC1 They are PI controller PI in follow-up control reactive control TVC1 The proportional coefficient and integral coefficient, U t is the measured terminal voltage amplitude, K Q is the reactive power regulation coefficient, k pTVC2 and k iTVC2 They are PI controller PI in network control voltage control TVC2 The proportional coefficient and integral coefficient.

[0069] Step S6, judging the switching condition between the meshing control mode and the following control mode according to the output signal of the synchronous control loop and the output signal of the power control and voltage outer loop, and outputting the synchronous 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 switching conditions between networking control and following control are as follows:

[0071] If the device is running in the follower control mode, the angular velocity ω of the follower control phase-locked synchronization loop is monitored in real time. GFLWhen the angular velocity ω of the phase-locked synchronous loop is controlled by the follower type GFL When the following conditions are met, the following control mode is considered to be unstable and can be switched to the networking control mode, with the switching flag variable F set to 1:

[0072] (1)|ω 0 –ω GFL |≥Δω max-GFL , and lasts for more than t us1-GFL time;

[0073] (2) At t us2-GFL In the time window, from |ω 0 –ω GFL |<Δω max-GFL Change to |ω 0 –ω GFL |≥Δω max-GFL The number of times is greater than n;

[0074] Among them, Δω max-GFL It is the maximum angular frequency deviation of the follower control phase-locked synchronous loop to judge the instability state, generally Δω max-GFL must be smaller than the limit value in the phase-locked synchronization loop; t us1-GFL and t us2-GFL It is a parameter for judging the instability of the following control mode. max-GFL It should be smaller than the limit value in the follower control phase-locked synchronous loop. us1-GFL 500ms is acceptable, t us2-GFL It can be 1s, and n can be 3 times, which should be set according to the equipment conditions. us1-GFL and t us2-GFL It should not be less than 50ms, should not be greater than 3s, and n should not be greater than 10 times.

[0075] If the device is running in the meshing control mode, the angular velocity ω of the meshing control power synchronization ring is monitored in real time. GFM When the grid-type control power synchronization ring angular velocity ω GFM When the following conditions are met, the network-building control mode is considered to be unstable and can be switched to the network-following control mode, with the switching flag variable F set to 0:

[0076] (1)|ω 0 –ω GFM |≥Δω max-GFM , and lasts for more than t us1-GFM time;

[0077] (2) At t us2-GFM In the time window, from |ω 0 –ω GFM |<Δω max-GFM Change to |ω 0 –ωGFM |≥Δω max-GFM The number of times is greater than n;

[0078] Among them, Δω max-GFM is the maximum angular frequency deviation of the grid-type control power synchronization loop to determine the instability state, t us1-GFM and t us2-GFM It is a parameter for judging the instability state of the network control mode. Considering that the network control equipment has a certain ability of primary frequency modulation, its normal operation may deviate from the rated angular frequency (i.e. ω 0 ), so Δω max-GFM Generally greater than Δω max-GFL .t us1-GFM 500ms is acceptable, t us2-GFM It can be 1s, and n can be 3 times, which should be set according to the equipment conditions. us1-GFM and t us2-GFM It should not be less than 50ms, should not be greater than 3s, and n should not be greater than 10 times.

[0079] Output 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 The details are as follows:

[0080]

[0081] Step S7, according to 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 Calculate the d-axis internal electromotive force e of the current control loop d and the electromotive force e in the q axis q .

[0082] Figure 4 The schematic diagram of the current control loop, where PI ACC represents the proportional-integral controller in the current control loop, ω 0 is the fundamental angular frequency. For a 50Hz system, ω 0 =100πrad / s.

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

[0084]

[0085] Among them, k pACC and k iACC They are the proportional integral controller PI in the current control loop ACC The proportional coefficient and integral coefficient, L f is the filter inductance value, ω 0 is the fundamental angular frequency.

[0086] Step S8: The d-axis internal electromotive force e of the current control loop is d and the electromotive force e in the q axis q Based on the synchronization phase θ dq After the reverse Pike transformation, the three-phase reference wave signal e is obtained. abc .

[0087] Step S9: convert the three-phase reference wave signal e abc The trigger signal is transmitted to the PMW modulation controller to control the converter of the energy storage device.

[0088] Embodiment 2:

[0089] Based on the same inventive concept as that of Example 1, this embodiment provides an energy storage control system for automatic switching between grid-building control and grid-following control based on instability mode recognition, which is applied to the method described, including:

[0090] An acquisition module, used to acquire three-phase voltage signals and three-phase current signals of 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 according to the three-phase voltage signal and the three-phase current signal;

[0092] The Parker transformation module is used to perform Parker transformation 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] Synchronous control loop module, used to calculate the active power P and q-axis voltage component u tq And the reference value of active power P ref , calculate and obtain the output signal of the synchronous control loop, the synchronous control loop includes a phase-locked synchronous loop of follower control and a power synchronous loop of network control; the output signal of the synchronous control loop includes a dq axis phase θ output by the network control power synchronous loop dq-GFM The dq axis phase θ of the output of the phase-locked synchronous loop is controlled by the follower type dq-GFL ;

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

[0095] The switching control module is used to determine the switching conditions between the network control mode and the follower control mode according to the output signal of the synchronous control loop and the output signal of the power control and voltage outer loop, and output the synchronous 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 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 Calculate the d-axis internal electromotive force e of the current control loop d and the electromotive force e in the q axis q ;

[0097] The anti-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 in the q axis q Based on the synchronization phase θ dq After the reverse Pike transformation, the three-phase reference wave signal e is obtained. abc ;

[0098] The trigger control module is used to convert the three-phase reference wave signal e abc The trigger signal is transmitted to the PMW modulation controller to control the converter of the energy storage device.

[0099] Embodiment 3:

[0100] Based on the same inventive concept as Example 1, this embodiment provides a computer-readable storage medium, which includes a stored program, wherein when the program is running, the device where the computer-readable storage medium is located is controlled to execute the energy storage control method for automatic switching between networking type control and grid-following type control based on instability mode recognition.

[0101] Embodiment 4:

[0102] Based on the same inventive concept as Example 1, this embodiment provides a processor, which is used to run a program, wherein when the program is running, the energy storage control method of automatically switching between grid-building type control and grid-following type control based on instability mode recognition is executed.

[0103] Those of ordinary skill in the art will appreciate that the modules of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition of each example has been generally described in terms of function in the above description. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0104] In the embodiments provided by the present invention, it should be understood that the division of modules is only a logical function division, and there may be other division methods in actual implementation, for example, multiple modules can be combined into one module, one module can be split into multiple modules, or some features can be ignored, etc.

[0105] In addition, each functional module in each embodiment of the present invention may be integrated into one processing module, or each module may exist physically separately, or two or more modules may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of software functional modules.

[0106] If the integrated module is implemented in the form of a software function 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, which is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a server or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, read-only memory (ROM, Read-0nlyMemory), random access memory (RAM, RandomAccessMemory), mobile hard disk, magnetic disk or optical disk, etc., various media that can store program codes.

[0107] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention.

Claims

1. A method for automatically switching between grid-building control and grid-following control based on instability mode recognition, characterized in that: The following steps are involved: Step S1, collecting three-phase voltage signals and three-phase current signals of the energy storage device grid connection point; Step S2, calculating the active power P and reactive power Q output by the energy storage device according to the three-phase voltage signal and the three-phase current signal; Step S3: Perform Park transformation 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 ; Step S4: according to the active power P and the q-axis voltage component u tq And the reference value of active power P ref , calculate and obtain the output signal of the synchronous control loop, the synchronous control loop includes a phase-locked synchronous loop of follower control and a power synchronous loop of network control; the output signal of the synchronous control loop includes a dq axis phase θ output by the network control power synchronous loop dq-GFM The dq axis phase θ of the output of the phase-locked synchronous loop is controlled by the follower type dq-GFL ; Step S5: According to the active power P, reactive power Q, d-axis voltage component u td , q-axis voltage component u tq And the reference value of active power P ref , the reference value of reactive power Q ref , calculate and obtain the output signal of the power control and voltage outer loop, the power control and voltage outer loop includes the active power control loop of the follower control, the reactive power control loop of the follower control and the reactive and voltage control loop of the network 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 the follower control dref-GFL , the q-axis current component reference value i output by the power control loop in the follower control qref-GFL , the d-axis current component reference value i output by the power control loop in the grid control dref-GFM , the q-axis current component reference value i output by the power control loop in the grid control qref-GFM ; Step S6, judging the switching condition between the meshing control mode and the following control mode according to the output signal of the synchronous control loop and the output signal of the power control and voltage outer loop, and outputting the synchronous 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 ; Step S7, according to 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 Calculate the d-axis internal electromotive force e of the current control loop d and the electromotive force e in the q axis q ; Step S8: The d-axis internal electromotive force e of the current control loop is d and the electromotive force e in the q axis q Based on the synchronization phase θ dq After the reverse Pike transformation, the three-phase reference wave signal e is obtained. abc ; Step S9: convert the three-phase reference wave signal e abc The trigger signal is transmitted to the PMW modulation controller to control the converter of the energy storage device.

2. According to claim 1, a method for automatically switching between grid-building control and grid-following control based on instability mode recognition, characterized in that: The output signal of the synchronous control loop in step S4 is calculated as follows: Among them, ω GFM is the angular velocity of the network-type control power synchronization ring, ω GFL is the angular velocity of the follower type control phase-locked synchronous loop, k pPLL and k iPLL They are follower type control phase-locked synchronous loop PI PLL are the proportional coefficient and integral coefficient; M and D are the inertia parameter and damping parameter in the network-type control power synchronization loop respectively; ω0 is the fundamental angular frequency.

3. The energy storage control method for automatic switching between grid-building control and grid-following control based on instability mode recognition according to claim 1 is characterized in that: The calculation method of the output signal of the power control and voltage outer loop in step S5 is as follows: Among them, k pAPC and k iAPC They are PI controller PI in follow-up control and active control respectively. APC The proportionality coefficient and integration coefficient, k pTVC1 and k iTVC1 They are PI controller PI in follow-up control reactive control TVC1 The proportional coefficient and integral coefficient, U t is the measured terminal voltage amplitude, K Q is the reactive power regulation coefficient, k pTVC2 and k iTVC2 They are PI controller PI in network control voltage control TVC2 The proportional coefficient and integral coefficient.

4. The energy storage control method for automatic switching between grid-building control and grid-following control based on instability mode recognition according to claim 1 is characterized in that: The switching conditions between the networking control and the following control in step S6 are as follows: if the device is running in the following control mode, the angular velocity ω of the following control phase-locked synchronization loop is monitored in real time. GFL When the angular velocity ω of the phase-locked synchronous loop is controlled by the follower type GFL When the following conditions are met, the following control mode is considered to be unstable and can be switched to the networking control mode, with the switching flag variable F set to 1: (1)|ω0–ω GFL |≥Δω max-GFL , and lasts for more than t us1-GFL time; (2) At t us2-GFL In 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; Among them, Δω max-GFL It is the maximum angular frequency deviation of the follower control phase-locked synchronous loop to judge the instability state, generally Δω max-GFL must be smaller than the limit value in the phase-locked synchronization loop; t us1-GFL and t us2-GFL Parameters for judging the instability of the following control mode; if the device is running in the networking control mode, the angular velocity ω of the networking control power synchronization ring is monitored in real time GFM When the grid-type control power synchronization ring angular velocity ω GFM When the following conditions are met, the network-building control mode is considered to be unstable and can be switched to the network-following control mode, with the switching flag variable F set to 0: (1)|ω0–ω GFM |≥Δω max-GFM , and lasts for more than t us1-GFM time; (2) At t us2-GFM In 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; among them, Δω max-GFM is the maximum angular frequency deviation of the grid-type control power synchronization loop to determine the instability state, t us1-GFM and t us2-GFM It is a parameter for judging the instability state of the network control mode.

5. The energy storage control method for automatic switching between grid-building control and grid-following control based on instability mode recognition according to claim 1 or 4, characterized in that: In step S6, the synchronous 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 The details are as follows:

6. The energy storage control method for automatic switching between grid-building control and grid-following control based on instability mode recognition according to claim 1 is characterized in that: The d-axis internal electromotive force e of the current control loop in step S7 d and the electromotive force e in the q axis q The calculation method is as follows: Among them, k pACC and k iACC They are the proportional integral controller PI in the current control loop ACC The proportional coefficient and integral coefficient, L f is the filter inductance value, ω0 is the fundamental angular frequency.

7. An energy storage control system with automatic switching between grid-building control and grid-following control based on instability mode recognition, characterized in that: The method applied to any one of claims 1 to 6 comprises: An acquisition module, used to acquire three-phase voltage signals and three-phase current signals of the grid connection point of the energy storage device; 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 according to the three-phase voltage signal and the three-phase current signal; The Parker transformation module is used to perform Parker transformation 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 ; Synchronous control loop module, used to calculate the active power P and q-axis voltage component u tq And the reference value of active power P ref , calculate and obtain the output signal of the synchronous control loop, the synchronous control loop includes a phase-locked synchronous loop of follower control and a power synchronous loop of network control; the output signal of the synchronous control loop includes a dq axis phase θ output by the network control power synchronous loop dq-GFM The dq axis phase θ of the output of the phase-locked synchronous loop is controlled by the follower type dq-GFL ; The power control and voltage outer loop module is used to calculate the active power P, reactive power Q, and d-axis voltage component u td , q-axis voltage component u tq And the reference value of active power P ref , the reference value of reactive power Q ref , calculate and obtain the output signal of the power control and voltage outer loop, the power control and voltage outer loop includes the active power control loop of the follower control, the reactive power control loop of the follower control and the reactive and voltage control loop of the network 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 the follower control dref-GFL , the q-axis current component reference value i output by the power control loop in the follower control qref-GFL , the d-axis current component reference value i output by the power control loop in the grid control dref-GFM , the q-axis current component reference value i output by the power control loop in the grid control qref-GFM ; The switching control module is used to determine the switching conditions between the network control mode and the follower control mode according to the output signal of the synchronous control loop and the output signal of the power control and voltage outer loop, and output the synchronous 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 ; The current control loop module is used to control 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 Calculate the d-axis internal electromotive force e of the current control loop d and the electromotive force e in the q axis q ; The anti-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 in the q axis q Based on the synchronization phase θ dq After the reverse Pike transformation, the three-phase reference wave signal e is obtained. abc ; The trigger control module is used to convert the three-phase reference wave signal e abc The trigger signal is transmitted to the PMW modulation controller to control the converter of the energy storage device.

8. A computer-readable storage medium, characterized in that: The computer-readable storage medium includes a stored program, wherein when the program is running, the device where the computer-readable storage medium is located is controlled to execute the energy storage control method for automatic switching between grid-forming control and grid-following control based on instability mode recognition as described in any one of claims 1 to 6.

9. A processor, characterized in that: The processor is used to run a program, wherein when the program is run, the energy storage control method for automatic switching between grid-building control and grid-following control based on instability mode recognition as described in any one of claims 1 to 6 is executed.

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