Power grid control method and system based on network construction type energy storage power station

Abstract

The invention provides a power grid control method and system based on a network construction type energy storage power station, and the method comprises the steps: enabling the network construction type energy storage power station to be connected in parallel with a target power grid at a common coupling point of a network type grid-connected converter, and generating the angular frequency of three-phase coordinate transformation in a grid-connected process based on the obtained voltage of the common coupling point; in the operation process of the power grid, a first control signal is sent to the grid-forming type energy storage power station, so that first-order low-pass filtering processing is carried out on the active power of the active droop control link and the reactive power of the reactive droop control link; the second control signal is used for adaptively adjusting the active droop coefficient of the active droop control link; the third control signal is fed into a forward path of an active droop control link after being subjected to high-pass filtering processing at the diagonal frequency; and executing a power grid control strategy generated by the first control signal, the second control signal and the third control signal. According to the method provided by the invention, the potential broadband oscillation of the following grid-connected converter can be effectively suppressed.

Description

Technical Field

[0001] The present application relates to the field of power electronics technology, and in particular to a power grid control method and system based on a grid-based energy storage power station. Background Art

[0002] The new power system is gradually becoming the future development trend due to its clean and pollution-free characteristics. However, the characteristics of a high proportion of new energy and a high proportion of power electronic equipment in the new power system have posed unprecedented challenges to the stability of the power system.

[0003] The large-scale replacement of traditional power generation equipment dominated by synchronous generators by power electronic equipment has profoundly affected the dynamic characteristics of the power system. The weak inertia support of renewable energy power generation, the volatility and uncertainty of output, the regional coupling of converters and AC / DC interconnection, and the negative damping characteristics generated by phase-locked loops have triggered a series of risks of wide-band oscillations. At present, renewable energy grid-connected converters in power systems mainly operate in grid-following mode, and are connected to the power grid by adjusting the grid-connected current. However, grid-following converters are difficult to provide synchronous inertia for power systems, have weak voltage / frequency regulation capabilities, and are highly dependent on synchronization links such as phase-locked loops. They are prone to instability under weak grid conditions. Therefore, grid-following converters based on phase-locked synchronization usually cause the power grid system to have a risk of wide-band oscillations due to the incorrect selection of the structure of the phase-locked loop and control parameters, which affects the stability of the power grid operation.

[0004] It can be seen that how to suppress the broadband oscillation of the power grid system caused by the grid-connected converter and ensure the stable operation of the power grid has become a technical problem that needs to be solved urgently by those skilled in the art. Summary of the invention

[0005] The purpose of this application is to provide a grid control method and system based on a grid-type energy storage power station, to solve the technical problem of how to suppress the wide-band oscillation of the grid system caused by the grid-connected converter and ensure the stable operation of the grid, to achieve the effect of suppressing the wide-band oscillation of the grid-connected converter due to phase-locked loop synchronization and improve the stability of the grid operation.

[0006] In a first aspect, an embodiment of the present application provides a grid control method based on a grid-connected energy storage power station, wherein the grid-connected energy storage power station is connected in parallel to a target grid at a common coupling point of a grid-connected converter, and the method comprises: Acquire a common coupling point voltage of a grid-connected converter in the target power grid, and generate an angular frequency of a three-phase coordinate transformation in a grid-connected process based on the common coupling point voltage; During the operation of the power grid, a first control signal is sent to the grid-type energy storage power station, wherein the first control signal is designed to perform first-order low-pass filtering on the active power of the active droop control link and the reactive power of the reactive droop control link respectively; Sending a second control signal to the grid-type energy storage power station, wherein the second control signal is designed to adaptively adjust the active power droop coefficient of the active power droop control link; Sending a third control signal to the grid-type energy storage power station, wherein the third control signal is designed to perform high-pass filtering on the angular frequency and then feed into the forward path of the active droop control link; A power grid control strategy generated by the first control signal, the second control signal, and the third control signal is executed.

[0007] Preferably, the active power of the active power droop control link and the reactive power of the reactive power droop control link of the grid-type energy storage power station are respectively subjected to first-order low-pass filtering, including: The output voltage of the grid-type energy storage power station, the grid voltage and the reactance of the transmission line are used to express the active power relationship and the reactive power relationship of the grid-type energy storage power station; Extracting active loop gain and active closed-loop transfer function from the active power disturbance amount obtained by the active power relational expression processed by the small signal component, and extracting reactive loop gain and reactive closed-loop transfer function from the reactive power disturbance amount obtained by the reactive power relational expression processed by the small signal component; Solving the active step response function extracted from the active closed-loop transfer function to obtain the active cut-off frequency lower limit value, and solving the reactive step response function extracted from the reactive closed-loop transfer function to obtain the reactive cut-off frequency lower limit value; Solving the active amplitude function of the loop gain of the first-order low-pass filtering process extracted from the active loop gain at twice the power frequency to obtain an active cutoff frequency upper limit value, and solving the reactive amplitude function of the loop gain of the first-order low-pass filtering process extracted from the reactive loop gain at twice the power frequency to obtain a reactive cutoff frequency upper limit value; According to the lower limit value of the active power cutoff frequency and the upper limit value of the active power cutoff frequency, the active power of the active power droop control link of the grid-type energy storage power station is subjected to first-order low-pass filtering, and according to the lower limit value of the reactive power cutoff frequency and the upper limit value of the reactive power cutoff frequency, the reactive power of the reactive power droop control link of the grid-type energy storage power station is subjected to first-order low-pass filtering.

[0008] Preferably, the adaptively adjusting the active power droop coefficient of the active power droop control link comprises: According to the active frequency droop curve, an active droop coefficient equation of the grid-type energy storage power station is obtained; According to the active power expression, the maximum active power is obtained; According to the active power maximum value and the angular frequency variation range limitation, the active power droop coefficient equation is optimized, and the active power droop coefficient of the active power droop control link is adaptively adjusted according to the optimized active power droop coefficient equation.

[0009] Preferably, the optimized active droop coefficient equation is: Among them, ω 0 is the rated angular frequency of the power grid, X gs is the reactance of the transmission line, V gf is the amplitude of the output voltage phasor of the grid-connected energy storage power station, V s is the grid voltage, δ g is the phase difference between the output voltage of the grid-connected energy storage power station and the grid voltage, i.e. the power angle, p g_ref It is the active power reference value of the grid-connected energy storage power station.

[0010] Preferably, the method of feeding the angular frequency into the forward path of the active droop control link after high-pass filtering includes: Determining a high-pass filter cutoff frequency according to the active cutoff frequency upper limit value; Based on the per-unit representation of the parameters of the active droop control link and the reactive droop control link of the grid-type energy storage power station, the equivalent relationship under small signals is extracted to obtain the first small signal representation of the angular frequency equation and the second small signal representation of the active power relationship equation; Simulating a small signal structure block diagram obtained according to the first small signal representation and the second small signal representation to obtain a forward gain of the high-pass filtering processing link; According to the high-pass filter cutoff frequency, the angular frequency is subjected to high-pass filtering, and according to the forward gain, the angular frequency subjected to high-pass filtering is amplified to obtain a compensation angular frequency deviation value; amplifying the second angular frequency according to the compensation angular frequency deviation value to obtain a third angular frequency; The third angular frequency is fed into the forward path of the active power droop control link.

[0011] In a second aspect, an embodiment of the present application provides a power grid control system based on a grid-type energy storage power station, wherein the grid-type energy storage power station is connected in parallel to a target power grid at a common coupling point of a grid-connected converter, and the system includes: an angular frequency generating unit, a first-order low-pass filter signal generating unit, an active droop coefficient adaptive adjustment signal generating unit, a high-pass filter signal generating unit, and an execution unit; The angular frequency generating unit is used to obtain the common coupling point voltage of the grid-connected converter in the target power grid, and generate the angular frequency of the three-phase coordinate transformation in the grid connection process based on the common coupling point voltage; The first-order low-pass filter signal generating unit is used to send a first control signal to the grid-type energy storage power station during the operation of the power grid, wherein the first control signal is designed to perform first-order low-pass filtering on the active power of the active droop control link and the reactive power of the reactive droop control link respectively; The active droop coefficient adaptive adjustment signal generating unit is used to send a second control signal to the grid-type energy storage power station, wherein the second control signal is designed to adaptively adjust the active droop coefficient of the active droop control link; The high-pass filter processing signal generating unit is used to send a third control signal to the grid-type energy storage power station, wherein the third control signal is designed to perform high-pass filtering on the angular frequency and then feed into the forward path of the active droop control link; The execution unit is used to execute the power grid control strategy generated by the first control signal, the second control signal and the third control signal.

[0012] Preferably, the active power of the active power droop control link and the reactive power of the reactive power droop control link of the grid-type energy storage power station are respectively subjected to first-order low-pass filtering, including: The output voltage of the grid-type energy storage power station, the grid voltage and the reactance of the transmission line are used to express the active power relationship and the reactive power relationship of the grid-type energy storage power station; Extracting active loop gain and active closed-loop transfer function from the active power disturbance amount obtained by the active power relational expression processed by the small signal component, and extracting reactive loop gain and reactive closed-loop transfer function from the reactive power disturbance amount obtained by the reactive power relational expression processed by the small signal component; Solving the active step response function extracted from the active closed-loop transfer function to obtain the active cut-off frequency lower limit value, and solving the reactive step response function extracted from the reactive closed-loop transfer function to obtain the reactive cut-off frequency lower limit value; Solving the active amplitude function of the loop gain of the first-order low-pass filtering process extracted from the active loop gain at twice the power frequency to obtain an active cutoff frequency upper limit value, and solving the reactive amplitude function of the loop gain of the first-order low-pass filtering process extracted from the reactive loop gain at twice the power frequency to obtain a reactive cutoff frequency upper limit value; According to the lower limit value of the active power cutoff frequency and the upper limit value of the active power cutoff frequency, the active power of the active power droop control link of the grid-type energy storage power station is subjected to first-order low-pass filtering, and according to the lower limit value of the reactive power cutoff frequency and the upper limit value of the reactive power cutoff frequency, the reactive power of the reactive power droop control link of the grid-type energy storage power station is subjected to first-order low-pass filtering.

[0013] Preferably, the adaptively adjusting the active power droop coefficient of the active power droop control link comprises: According to the active frequency droop curve, an active droop coefficient equation of the grid-type energy storage power station is obtained; According to the active power expression, the maximum active power is obtained; According to the active power maximum value and the angular frequency variation range limitation, the active power droop coefficient equation is optimized, and the active power droop coefficient of the active power droop control link is adaptively adjusted according to the optimized active power droop coefficient equation.

[0014] Preferably, the optimized active droop coefficient equation is: Among them, ω 0 is the rated angular frequency of the power grid, X gs is the reactance of the transmission line, V gf is the amplitude of the output voltage phasor of the grid-connected energy storage power station, V s is the grid voltage, δ g is the phase difference between the output voltage of the grid-connected energy storage power station and the grid voltage, i.e. the power angle, p g_ref It is the active power reference value of the grid-connected energy storage power station.

[0015] Preferably, the method of feeding the angular frequency into the forward path of the active droop control link after high-pass filtering includes: Determining a high-pass filter cutoff frequency according to the active cutoff frequency upper limit value; Based on the per-unit representation of the parameters of the active droop control link and the reactive droop control link of the grid-type energy storage power station, the equivalent relationship under small signals is extracted to obtain the first small signal representation of the angular frequency equation and the second small signal representation of the active power relationship equation; Simulating a small signal structure block diagram obtained according to the first small signal representation and the second small signal representation to obtain a forward gain of the high-pass filtering processing link; According to the high-pass filter cutoff frequency, the angular frequency is subjected to high-pass filtering, and according to the forward gain, the angular frequency subjected to high-pass filtering is amplified to obtain a compensation angular frequency deviation value; The compensation angular frequency deviation value is fed into the forward path of the active power droop control link.

[0016] The present application provides a grid control method and system based on a grid-type energy storage power station. Compared with the prior art, the beneficial effects of the embodiments of the present application are as follows: The grid control method based on the grid-type energy storage power station provided in the present application slows down the changes in frequency and voltage through first-order low-pass filtering, suppresses potential medium and high frequency resonant frequency bands, suppresses low-frequency oscillation frequency bands through angular frequency high-pass filtering, and enhances the oscillation suppression capability of the entire frequency band through adaptive adjustment of the adaptive active power droop coefficient, thereby improving the stability of the grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a flow chart of a power grid control method based on a grid-type energy storage power station provided in an embodiment of the present application; Figure 2 It is a structural schematic diagram of a heterogeneous system in which a grid-connected converter and a grid-connected energy storage power station are connected in parallel, provided in an embodiment of the present application; Figure 3 is a schematic diagram of the control structure of a grid-connected converter provided in an embodiment of the present application; Figure 4 It is a schematic diagram of the control structure of a grid-type energy storage power station provided in an embodiment of the present application; Figure 5 It is a simplified structural schematic diagram of a grid-connected energy storage power station in a heterogeneous system in which a grid-connected converter and a grid-connected energy storage power station are connected in parallel, provided in an embodiment of the present application; Figure 6 It is a structural schematic diagram of a traditional active power droop controller and a reactive power droop controller provided in an embodiment of the present application; Figure 7 It is a structural schematic diagram of an improved active power droop controller and a reactive power droop controller provided in an embodiment of the present application; Figure 8 It is a simplified schematic diagram of a single-machine infinite system of a grid-type energy storage power station and a target power grid provided in an embodiment of the present application; Fig. 9 It is a small signal structure block diagram provided in the embodiment of the present application; Fig.10It is a power grid control system based on a grid-type energy storage power station provided in an embodiment of the present application. DETAILED DESCRIPTION

[0018] The following is a detailed description of the implementation mode of the present application in conjunction with the accompanying drawings. The embodiments are provided only for illustrative purposes and cannot be understood as limiting the present application. The accompanying drawings are only for reference and illustration purposes and do not constitute a limitation on the scope of patent protection of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present application. In the description of the present application, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first", "second", "third", etc. may explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise specified, the meaning of "multiple" is two or more.

[0019] In the description of the present application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be a connection between the two elements. The terms "vertical", "horizontal", "left", "right", "upper", "lower" and similar expressions used in this article are only for illustrative purposes, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application. The term "and / or" used in this article includes any and all combinations of one or more related listed items. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0020] In the description of this application, it should be noted that, unless otherwise defined, all technical and scientific terms used in this application have the same meaning as those commonly understood by those skilled in the art. The terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood by specific circumstances.

[0021] In the grid-following mode operation of the power grid, the grid-connected control strategy based on the phase-locked loop will reshape the impedance characteristics of the q-axis based on the dq-axis coordinate system control, causing a negative impedance region in the low-frequency band, which is the main reason for the phase-locked loop to cause the instability of the power system. The grid-connected energy storage power station can provide flexible frequency and voltage regulation, and can also provide inertia and wide-band damping for the power system. In addition, the grid-connected energy storage power station is equivalent to a controllable voltage source, which enables the grid-connected energy storage power station to improve the short-circuit ratio of the heterogeneous system connected in parallel with the grid-connected converter, enhance the stability of the heterogeneous system, and thus suppress the risk of wide-band oscillation caused by the phase-locked loop in the control strategy of the grid-connected converter, and improve the stability of the power grid.

[0022] In view of this, in one embodiment, Figure 1 As shown, a grid control based on a grid-connected energy storage power station is provided, wherein the grid-connected energy storage power station is connected in parallel to a target grid at a common coupling point of a grid-connected converter, and the method comprises the following steps: S1, obtaining the common coupling point voltage of the grid-connected converter in the target power grid; Figure 2 The figure shows a schematic diagram of the structure of a heterogeneous system in which a grid-connected converter and a grid-connected energy storage power station are connected in parallel according to the embodiment of the present invention. In the heterogeneous system in which a grid-connected converter and a grid-connected energy storage power station are connected in parallel, the grid-connected converter is connected to the grid through a first LCL filter and a first three-phase AC relay S r1 Connected to the grid, the connection point is the common coupling point, the voltage of the common coupling point is the common coupling point voltage, using v gabc The weak current environment of the power grid is represented by the grid voltage V s and inductor L s The first LCL filter consists of the first inverter side inductor L gi1 , the first filter capacitor C gf1 and the first grid-side inductor L gg1 The grid-type energy storage power station is connected in parallel to the common coupling point grid (represented by PCC in the figure) as an auxiliary to suppress the broadband oscillation of the grid-connected converter. The grid-type energy storage power station is connected to the grid through the second LCL filter and the second three-phase AC relay S r2 The second LCL filter is composed of a second inverter side inductor L gi2 , the second filter capacitor C gf2 and the second grid-side inductor L gg2 In addition, in Figure 2, v gdc1 is the DC side voltage of the grid-type converter, v gdc2 is the DC side voltage of the grid-connected energy storage power station, i ggabc1 is the first grid-connected voltage of the grid-connected converter, i ggabc2 is the second grid-connected voltage of the grid-connected energy storage power station, igiabc1 is the first inverter side current of the grid-connected converter, i giabc2 is the second inverter side current of the grid-connected energy storage power station, v gfabc1 is the first filter capacitor C gf1 The first capacitor voltage, v gfabc2 is the second filter capacitor C gf2 The second capacitor voltage.

[0023] S2. Based on the first voltage, generate an angular frequency of three-phase coordinate transformation during the grid connection process; Figure 3 The control structure of the grid-connected converter according to the embodiment of the present application is shown as a schematic diagram. The control structure of the grid-connected converter includes an inner current control loop and an outer power control loop. The outer power control loop is controlled by a first active power controller and a first reactive power controller. The first active power p output by the grid-connected converter is g1 and the first reactive power q g1 The first grid-connected current i ggabc1 and the first capacitor voltage v gfabc1 It is calculated based on the instantaneous power theory. Among them, the first active controller generates the d-axis reference current i of the current loop gi_ref_d , the first reactive power controller generates the q-axis reference current i of the current loop gi_ref_q The phase-locked loop locks the grid voltage at the PCC and generates the phase θ of the coordinate transformation during the grid connection process. g_ref1 and angular frequency ω. The inner current control loop is controlled by the first current loop, which is controlled according to the phase θ g_ref1 and dq axis reference current i gi_ref_dq , adjust the first inverter side current i giabc1 In addition, in Figure 3, p g_ref1 is the first active power reference value, q g1_ref1 is the first reactive power reference value, and PLL means phase-locked loop.

[0024] S3. During the operation of the power grid, a first control signal is sent to the grid-type energy storage power station, wherein the first control signal is designed to perform first-order low-pass filtering on the active power of the active droop control link and the reactive power of the reactive droop control link respectively; Figure 4 The control structure of the grid-type energy storage power station of the embodiment of the present application is shown as a schematic diagram. The control structure of the grid-type energy storage power station includes a voltage and current double closed loop and a power control outer loop. The power control outer loop is controlled by a second active controller and a second reactive controller. The voltage and current double closed loop is controlled by a voltage loop and a second current loop. The second active power p output by the grid-type energy storage power station g2 and the second rated reactive power q g2 The second grid-connected current i ggabc2and the second capacitor voltage v gfabc2 It is calculated based on instantaneous power theory. Among them, the second active power controller is based on the second active power p g2 , the second active power reference value p g_ref2 The angular frequency ω determines the output frequency and phase θ g_ref , the second reactive power controller generates the d-axis reference voltage v of the voltage loop gf_ref_d , q-axis reference voltage v gf_ref_q Generally, it is set to 0. The voltage loop regulates the second output voltage v of the grid-type energy storage power station. gfabc2 The second current loop adjusts the second output current i giabc2 , suppressing the passive filter resonance and enhancing system stability. Figure 4 in,i gi_dq is i giabc2 The result after abc / dq coordinate transformation, v gf_dq Yes gfabc2 The result after abc / dq coordinate transformation, v gi_ref_dq is the dq axis reference voltage.

[0025] like Figure 5 The simplified structural diagram of the grid-connected energy storage power station in the heterogeneous system in which the grid-connected converter and the grid-connected energy storage power station are connected in parallel is shown in the figure. The grid-connected energy storage power station is connected to the grid by controlling the voltage of the second filter capacitor, and can be simplified to a controllable AC voltage source. Looking from the PCC point to the right, the grid-connected voltage v at this time is gabc The grid voltage v sabc and controllable voltage source, v gabc It is less affected by the dynamic process, so it can suppress the broadband oscillation caused by phase-locked synchronization of the grid-connected converter. On the other hand, the grid-connected converter based on phase-locked synchronization is very easy to become unstable under weak power grids, and the strength of the power grid is usually measured by the short-circuit ratio. Usually, the equivalent inductance L of the power grid is s The larger it is, the worse the stability of the system. Figure 5 After the controllable voltage source is connected to the PCC, the equivalent inductance of the power grid is greatly reduced and the short-circuit ratio of the system is greatly improved. Therefore, the heterogeneous system connected in parallel with the grid-connected converter and the grid-connected energy storage power station is more stable and the ability to suppress wide-band oscillations is significantly improved.

[0026] In a preferred embodiment of the present application, the active power controller adopts an active power droop controller, and the reactive power controller adopts a reactive power droop controller.

[0027] like Figure 6The figure shows the structure diagram of the traditional active power droop controller and reactive power droop controller. The active power output of the grid-type energy storage power station generates the phase of the coordinate transformation according to the active frequency droop curve; the reactive power generates the dq axis reference voltage v of the second voltage loop according to the reactive voltage droop curve. gi_ref_dq Among them, V gf_ref is the rated voltage of the power grid, k pf is the active frequency droop curve coefficient, k qv is the reactive frequency droop curve coefficient, ω 0 is the rated angular frequency of the grid, is the angular frequency deviation generated by active droop control, ω g is the angular frequency finally generated by active droop control, It is the voltage reference deviation generated by reactive power droop control.

[0028] In the preferred embodiment of the present application, Figure 7 The structure diagram of the improved active droop controller and reactive droop controller of the present application is shown. In the figure, HPF represents a high-pass filter. A first-order low-pass filtering process (represented by LPF in the figure) is introduced into the second active droop controller of the active droop control link and the second reactive droop controller of the reactive droop control link of the grid-type energy storage power station respectively. The first-order low-pass filtering process is implemented by a first-order low-pass filter. The first-order low-pass filtering process is represented as follows: Among them, ω pc is the cut-off frequency of the first-order low-pass filter of the active droop control link; ω qc is the cut-off frequency of the first-order low-pass filter of the reactive droop control link, s is the Laplace operator, T LPF(P) is the first-order low-pass filtering result of the second active power, T LPF(Q) It is the first-order low-pass filtering result of the second reactive output power.

[0029] Among them, the cutoff frequency of the first-order low-pass filter needs to be determined according to the power response speed and ripple suppression requirements, such as Figure 8 The figure shows a simplified schematic diagram of a single infinite system of a grid-type energy storage power station and a target grid. The grid-type energy storage power station can be simulated as a controllable AC voltage source. In a weak grid environment, the impedance of the transmission line is inductive, and the dynamic characteristics of the transmission line can be simulated by a pure inductor, whose reactance is X gs The amplitude of the output voltage phasor of the grid-type energy storage power station is expressed as , the grid voltage is expressed as , where δ g It is the phase difference between the output voltage of the grid-type energy storage power station and the grid voltage, that is, the power angle.

[0030] In view of this, the second active power relation and the second reactive power relation transmitted from the grid-building energy storage power station to the target grid are expressed as: The small signal components of the second active power and the second reactive power are extracted to obtain the active power disturbance and the reactive power disturbance respectively: in, Represents the disturbance amount.

[0031] The active loop gain and active closed-loop transfer function are extracted from the active power disturbance, and the reactive loop gain and reactive closed-loop transfer function are extracted from the reactive power disturbance. The active loop gain is expressed as: The active closed-loop transfer function is expressed as: The reactive loop gain is expressed as: The reactive closed-loop transfer function is expressed as: Among them, k pf is the active frequency droop curve coefficient, k qv is the reactive frequency droop curve coefficient.

[0032] The active step response function is extracted from the active closed-loop transfer function, and the reactive step response function is extracted from the reactive closed-loop transfer function. The expression of the active step response function is: The reactive step response function expression is: Among them, p g_steady and q g_steady represent the steady-state values ​​of the second active power and the second reactive power respectively, Indicates the response time.

[0033] According to the active step response function, the lower limit value of the active cutoff frequency of the first-order low-pass filter is expressed as: in, It is the calculation result of the active step response function under a specific limit time. The specific time substituted is determined by the power grid standard or the IEEE standard.

[0034] According to the reactive step response function, the reactive cutoff frequency lower limit expression of the first-order low-pass filter is: in, It is the calculation result of the reactive step response function under a specific limit time. The specific time is determined by the power grid standard or IEEE standard.

[0035] According to the requirements of IEEE Std.2800-2022, the response time of active power is within 2s and the response time of reactive power is within 1s. g_step / p g_steady =0.9 and the response time of active power are substituted into the expression of the lower limit of active power cutoff frequency of the first-order low-pass filter to solve the lower limit of active power cutoff frequency of the first-order low-pass filter. g_step / q g_steady =0.9 and the reactive power response time are substituted into the reactive cutoff frequency lower limit value expression of the first-order low-pass filter to solve the reactive cutoff frequency lower limit value of the first-order low-pass filter. It can be seen from the active cutoff frequency lower limit value expression and the reactive cutoff frequency lower limit value expression that the reactive cutoff frequency lower limit value of the first-order low-pass filter with reactive droop control is greater than the active cutoff frequency lower limit value of the first-order low-pass filter with active droop control. Therefore, the reactive cutoff frequency lower limit value of the first-order low-pass filter with reactive droop control can be used as the cutoff frequency lower limit value of the first-order low-pass filter.

[0036] In addition, the first-order low-pass filter needs to suppress the active and reactive ripples at twice the power frequency caused by the unbalanced load and the grid voltage. The active amplitude function of the loop gain at twice the power frequency is extracted from the active loop gain. The active amplitude function expression is: in, Indicates the rated frequency of the power grid, Represents the imaginary part.

[0037] The reactive amplitude function of the loop gain at twice the power frequency is extracted from the reactive loop gain. The expression of the reactive amplitude function is: In order to achieve sufficient ripple attenuation, the right side of the active and reactive amplitude function expressions should be less than , the expression of the upper limit of active cut-off frequency can be obtained as: The expression of reactive power cut-off frequency upper limit is: Thus, the upper and lower limits of the cutoff frequency of the first-order low-pass filter of the active droop control link and the upper and lower limits of the cutoff frequency of the first-order low-pass filter of the reactive droop control link can be obtained. For convenience, a unified upper and lower limits of the cutoff frequency can be selected.

[0038] S3, sending a second control signal to the grid-type energy storage power station, wherein the second control signal is designed to adaptively adjust the active power droop coefficient of the active power droop control link; Figure 7 As shown in the figure, the active power droop coefficient of the active power droop control link of the grid-type energy storage power station is adaptively adjusted, and the droop relationship between active power and frequency is expressed as: Among them, p g_ref is the second active power reference value, p g It is the second active power output by the energy storage power station.

[0039] From the second active power expression, we can see that when V gf and V s When stable, p g The maximum value of is expressed as: The expression of active power droop coefficient obtained from active power frequency droop curve is: Among them, ω 0 is the rated angular frequency of the grid, is the minimum angular frequency of the power grid.

[0040] According to the maximum active power, the active power droop coefficient equation is transformed, and the transformed active power droop coefficient equation is obtained as follows: In actual power systems, there are certain requirements for power quality. The angular frequency variation range does not exceed ±1%, which needs to be taken into account when designing the droop coefficient. Therefore, based on the angular frequency variation range limitation, the transformed active power droop coefficient equation is optimized to obtain the optimized active power droop coefficient equation, which is expressed as: Where V gf and V s It can be updated in real time through sampling, so k pf It will also be adjusted in real time.

[0041] According to the optimized active power droop coefficient equation, the active power droop coefficient of the active power droop control link of the grid-type energy storage power station is adaptively adjusted to reduce the frequency fluctuation range and suppress the full-band oscillation of the power grid.

[0042] S4, sending a third control signal to the grid-type energy storage power station, wherein the third control signal is designed to perform high-pass filtering on the angular frequency and then feed into the forward path of the active droop control link; Figure 7 As shown in the figure, the angular frequency of the phase-locked loop output of the grid-connected converter is fed into the forward path of the active droop control link of the grid-connected energy storage power station after high-pass filtering and gain link adjustment. Figure 7 In Represents the compensation angular frequency deviation value generated by the high-pass filter branch, In order to more conveniently demonstrate the high-pass filter processing link, Figure 7 The parameters of active and reactive droop control in are expressed in the form of per-unit values, and the equivalent relationship under small signals is extracted to obtain the first small signal expression of the angular frequency equation and the second small signal expression of the second active power relationship, where the second small signal expression of the second active power equation is: in, It represents the per unit value of the output voltage of the grid-type energy storage power station in the steady state. Indicates the per unit value of the grid voltage in steady state. Indicates the output phase of the grid-type energy storage power station in steady state, Indicates the per-unit value of the rated phase. The phase small signal generated by the active droop control represents the per-unit value, Indicates the per-unit value of the grid rated phase small signal representation, k s It represents the steady-state value of active power after all per-unit parameters are calculated.

[0043] The first small signal of the angular frequency equation is expressed as: According to the above first small signal representation and the second small signal representation, a small signal structure block diagram of the active droop control of the improved grid-type energy storage power station of the present application can be drawn, see Fig. 9 For the sake of convenience, the small signal structure diagram does not include a first-order low-pass filter. Fig. 9 ,when For positive time, There is a decreasing trend. decreases, the forward power deviation increases, making To regain the increasing trend and make the system reach a stable equilibrium point, we can select a suitable k ω value, so that the active droop control link can suppress low-frequency oscillation and have the ability to quickly stabilize. The same is true when it is negative. Generally speaking, the low frequency range that needs to be compensated is between 0.1Hz and 2Hz, and the time constant of the high-pass filter is more suitable between 0.1s and 20s, that is, the cut-off frequency can be selected between 0.05Hz and 10Hz. The forward gain of the high-pass filter processing link can be calculated in the simulation software according to Fig. 9 The small signal structure block diagram constructed is debugged to observe the effect of damped oscillation. For the selection of the cutoff frequency of the high-pass filter, according to the upper limit of the active cutoff frequency of the first-order low-pass filter link, an optional value close to the upper limit of the active cutoff frequency of the low-pass filter is selected, thereby increasing the range of broadband oscillation suppression.

[0044] like Figure 8 As shown, according to the high-pass filter cutoff frequency, the angular frequency is high-pass filtered, and the angular frequency after high-pass filtering is amplified according to the forward gain to obtain the compensated angular frequency deviation value, and the compensated angular frequency deviation value and the angular frequency deviation generated by the active droop control are combined. The addition process is performed to feed into the forward path of the active droop control link, and the high-pass filtering process of the angular frequency is used to suppress the low-frequency oscillation frequency band.

[0045] In the grid control method based on the grid-type energy storage power station disclosed in the present application, the grid-type energy storage power station is connected in parallel to the target grid at the common coupling point of the grid-connected converter, and the common coupling point voltage of the grid-connected converter in the target grid is obtained; based on the common coupling point voltage, the angular frequency of the three-phase coordinate transformation in the grid connection process is generated; during the operation of the grid, a first control signal is sent to the grid-type energy storage power station to perform first-order low-pass filtering on the active power of the active droop control link and the reactive power of the reactive droop control link respectively; a second control signal is sent to the grid-type energy storage power station to adaptively adjust the active droop coefficient of the active droop control link; a third control signal is sent to the grid-type energy storage power station to perform high-pass filtering on the angular frequency and then feed it into the forward path of the active droop control link; and a grid control strategy generated by the first control signal, the second control signal and the third control signal is executed. The grid control method based on the grid-type energy storage power station provided in the present application slows down the changes in frequency and voltage through first-order low-pass filtering, suppresses potential medium and high frequency resonant frequency bands, suppresses low-frequency oscillation frequency bands through angular frequency high-pass filtering, and enhances the oscillation suppression capability of the entire frequency band through adaptive adjustment of the active power droop coefficient, thereby improving the stability of the grid.

[0046] It should be noted that although the steps in the above flowchart are shown in sequence according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order restriction for the execution of these steps, and these steps can be executed in other orders.

[0047] In one embodiment, based on the grid control method based on the grid-type energy storage power station disclosed in the embodiment of the present application, Fig.10 As shown, a power grid control system based on a grid-type energy storage power station is provided. The grid-type energy storage power station is connected in parallel to the target power grid at the common coupling point of the grid-type grid-connected converter. The system includes: an angular frequency generating unit, a first-order low-pass filter signal generating unit, an active droop coefficient adaptive adjustment signal generating unit, a high-pass filter signal generating unit and an execution unit; The angular frequency generating unit is used to obtain the common coupling point voltage of the grid-connected converter in the target power grid, and generate the angular frequency of the three-phase coordinate transformation in the grid connection process based on the common coupling point voltage; The first-order low-pass filter signal generating unit is used to send a first control signal to the grid-type energy storage power station during the operation of the power grid, wherein the first control signal is designed to perform first-order low-pass filtering on the active power of the active droop control link and the reactive power of the reactive droop control link respectively; The active droop coefficient adaptive adjustment signal generating unit is used to send a second control signal to the grid-type energy storage power station, wherein the second control signal is designed to adaptively adjust the active droop coefficient of the active droop control link; The high-pass filter processing signal generating unit is used to send a third control signal to the grid-type energy storage power station, wherein the third control signal is designed to perform high-pass filtering on the angular frequency and then feed into the forward path of the active droop control link; The execution unit is used to execute the power grid control strategy generated by the first control signal, the second control signal and the third control signal.

[0048] The active power of the active power droop control link and the reactive power of the reactive power droop control link of the grid-type energy storage power station are respectively subjected to first-order low-pass filtering, including: The output voltage of the grid-type energy storage power station, the grid voltage and the reactance of the transmission line are used to express the active power relationship and the reactive power relationship of the grid-type energy storage power station; Extracting active loop gain and active closed-loop transfer function from the active power disturbance amount obtained by the active power relational expression processed by the small signal component, and extracting reactive loop gain and reactive closed-loop transfer function from the reactive power disturbance amount obtained by the reactive power relational expression processed by the small signal component; Solving the active step response function extracted from the active closed-loop transfer function to obtain the active cut-off frequency lower limit value, and solving the reactive step response function extracted from the reactive closed-loop transfer function to obtain the reactive cut-off frequency lower limit value; Solving the active amplitude function of the loop gain of the first-order low-pass filtering process extracted from the active loop gain at twice the power frequency to obtain an active cutoff frequency upper limit value, and solving the reactive amplitude function of the loop gain of the first-order low-pass filtering process extracted from the reactive loop gain at twice the power frequency to obtain a reactive cutoff frequency upper limit value; According to the lower limit value of the active power cutoff frequency and the upper limit value of the active power cutoff frequency, the active power of the active power droop control link of the grid-type energy storage power station is subjected to first-order low-pass filtering, and according to the lower limit value of the reactive power cutoff frequency and the upper limit value of the reactive power cutoff frequency, the reactive power of the reactive power droop control link of the grid-type energy storage power station is subjected to first-order low-pass filtering.

[0049] Wherein, the adaptive adjustment of the active power droop coefficient of the active power droop control link includes: According to the active frequency droop curve, an active droop coefficient equation of the grid-type energy storage power station is obtained; According to the active power expression, the maximum active power is obtained; According to the active power maximum value and the angular frequency variation range limitation, the active power droop coefficient equation is optimized, and the active power droop coefficient of the active power droop control link is adaptively adjusted according to the optimized active power droop coefficient equation.

[0050] Among them, the optimized active droop coefficient equation is: Among them, ω 0 is the rated angular frequency of the power grid, X gs is the reactance of the transmission line, V gf is the amplitude of the output voltage phasor of the grid-connected energy storage power station, V s is the grid voltage, δ g is the phase difference between the output voltage of the grid-connected energy storage power station and the grid voltage, i.e. the power angle, p g_ref It is the active power reference value of the grid-connected energy storage power station.

[0051] The step of feeding the angular frequency into the forward path of the active droop control link after high-pass filtering includes: Determining a high-pass filter cutoff frequency according to the active cutoff frequency upper limit value; Based on the per-unit representation of the parameters of the active droop control link and the reactive droop control link of the grid-type energy storage power station, the equivalent relationship under small signals is extracted to obtain the first small signal representation of the angular frequency equation and the second small signal representation of the active power relationship equation; Simulating a small signal structure block diagram obtained according to the first small signal representation and the second small signal representation to obtain a forward gain of the high-pass filtering processing link; According to the high-pass filter cutoff frequency, the angular frequency is subjected to high-pass filtering, and according to the forward gain, the angular frequency subjected to high-pass filtering is amplified to obtain a compensation angular frequency deviation value; The compensation angular frequency deviation value is fed into the forward path of the active power droop control link.

[0052] For the specific limitations of the power grid control system based on the grid-type energy storage power station, please refer to the limitations of the power grid control method based on the grid-type energy storage power station mentioned above. The corresponding technical effects can also be equivalently obtained, which will not be repeated here. Each module in the above-mentioned power grid control system based on the grid-type energy storage power station can be implemented in whole or in part through software, hardware and a combination thereof. The above-mentioned modules can be embedded in or independent of the processor in the computer device in the form of hardware, or can be stored in the memory of the computer device in the form of software, so that the processor can call and execute the operations corresponding to the above modules.

[0053] In summary, the embodiments of the present application provide a grid control method and system based on a grid-type energy storage power station, which solves the technical problem of how to suppress the wide-band oscillation of the grid system caused by the grid-type grid-connected converter and ensure the stable operation of the grid. The method connects the grid-type energy storage power station in parallel to the target grid at the common coupling point of the grid-type grid-connected converter, and obtains the common coupling point voltage of the grid-type grid-connected converter in the target grid; based on the common coupling point voltage, generates the angular frequency of the three-phase coordinate transformation in the grid connection process; during the operation of the grid, sends a first control signal to the grid-type energy storage power station to perform first-order low-pass filtering on the active power of the active droop control link and the reactive power of the reactive droop control link respectively; sends a second control signal to the grid-type energy storage power station to adaptively adjust the active droop coefficient of the active droop control link; sends a third control signal to the grid-type energy storage power station to feed the angular frequency into the forward path of the active droop control link after high-pass filtering; executes the grid control strategy generated by the first control signal, the second control signal and the third control signal. The grid control method based on the grid-type energy storage power station provided in the present application slows down the changes in frequency and voltage through first-order low-pass filtering, suppresses potential medium and high frequency resonant frequency bands, suppresses low-frequency oscillation frequency bands through angular frequency high-pass filtering, and enhances the oscillation suppression capability of the entire frequency band through adaptive adjustment of the adaptive active power droop coefficient, thereby improving the stability of the grid.

[0054] Each embodiment in this specification is described in a progressive manner, and the same or similar parts of each embodiment can be directly referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment. It should be noted that the technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, all possible combinations of the technical features in the above-mentioned embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0055] The above-described embodiments only express several preferred implementations of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several improvements and substitutions can be made without departing from the technical principles of the present application, and these improvements and substitutions should also be regarded as the protection scope of the present application. Therefore, the protection scope of the patent application shall be based on the protection scope of the claims.

Claims

1. A power grid control method based on a grid-type energy storage power station, characterized in that: The grid-connected energy storage power station is connected in parallel to the target power grid at the common coupling point of the grid-connected converter, and the method comprises: Acquire a common coupling point voltage of a grid-connected converter in the target power grid, and generate an angular frequency of a three-phase coordinate transformation in a grid-connected process based on the common coupling point voltage; During the operation of the power grid, a first control signal is sent to the grid-type energy storage power station, wherein the first control signal is designed to perform first-order low-pass filtering on the active power of the active droop control link and the reactive power of the reactive droop control link respectively; Sending a second control signal to the grid-type energy storage power station, wherein the second control signal is designed to adaptively adjust the active power droop coefficient of the active power droop control link; Sending a third control signal to the grid-type energy storage power station, wherein the third control signal is designed to perform high-pass filtering on the angular frequency and then feed into the forward path of the active droop control link; A power grid control strategy generated by the first control signal, the second control signal, and the third control signal is executed.

2. The grid control method based on the grid-type energy storage power station according to claim 1, characterized in that: The first-order low-pass filtering is performed on the active power of the active power droop control link and the reactive power of the reactive power droop control link of the grid-type energy storage power station, respectively, including: The output voltage of the grid-type energy storage power station, the grid voltage and the reactance of the transmission line are used to express the active power relationship and the reactive power relationship of the grid-type energy storage power station; Extracting active loop gain and active closed-loop transfer function from the active power disturbance amount obtained by the active power relational expression processed by the small signal component, and extracting reactive loop gain and reactive closed-loop transfer function from the reactive power disturbance amount obtained by the reactive power relational expression processed by the small signal component; Solving the active step response function extracted from the active closed-loop transfer function to obtain the active cut-off frequency lower limit value, and solving the reactive step response function extracted from the reactive closed-loop transfer function to obtain the reactive cut-off frequency lower limit value; Solving the active amplitude function of the loop gain of the first-order low-pass filtering process extracted from the active loop gain at twice the power frequency to obtain an active cutoff frequency upper limit value, and solving the reactive amplitude function of the loop gain of the first-order low-pass filtering process extracted from the reactive loop gain at twice the power frequency to obtain a reactive cutoff frequency upper limit value; According to the lower limit value of the active power cutoff frequency and the upper limit value of the active power cutoff frequency, the active power of the active power droop control link of the grid-type energy storage power station is subjected to first-order low-pass filtering, and according to the lower limit value of the reactive power cutoff frequency and the upper limit value of the reactive power cutoff frequency, the reactive power of the reactive power droop control link of the grid-type energy storage power station is subjected to first-order low-pass filtering.

3. The grid control method based on the grid-type energy storage power station according to claim 2 is characterized in that: The adaptively adjusting the active power droop coefficient of the active power droop control link includes: According to the active frequency droop curve, an active droop coefficient equation of the grid-type energy storage power station is obtained; According to the active power expression, the maximum active power is obtained; According to the active power maximum value and the angular frequency variation range limitation, the active power droop coefficient equation is optimized, and the active power droop coefficient of the active power droop control link is adaptively adjusted according to the optimized active power droop coefficient equation.

4. The grid control method based on the grid-type energy storage power station according to claim 3 is characterized in that: The optimized active droop coefficient equation is: Where, ω0 is the rated angular frequency of the power grid, X gs is the reactance of the transmission line, V gf is the amplitude of the output voltage phasor of the grid-connected energy storage power station, V s is the grid voltage, δ g is the phase difference between the output voltage of the grid-connected energy storage power station and the grid voltage, i.e. the power angle, p g_ref It is the active power reference value of the grid-connected energy storage power station.

5. The grid control method based on the grid-type energy storage power station according to claim 2, characterized in that: The method of feeding the angular frequency into the forward path of the active droop control link after high-pass filtering includes: Determining a high-pass filter cutoff frequency according to the active cutoff frequency upper limit value; Based on the per-unit representation of the parameters of the active droop control link and the reactive droop control link of the grid-type energy storage power station, the equivalent relationship under small signals is extracted to obtain the first small signal representation of the angular frequency equation and the second small signal representation of the active power relationship equation; Simulating a small signal structure block diagram obtained according to the first small signal representation and the second small signal representation to obtain a forward gain of the high-pass filtering processing link; According to the high-pass filter cutoff frequency, the angular frequency is subjected to high-pass filtering, and according to the forward gain, the angular frequency subjected to high-pass filtering is amplified to obtain a compensation angular frequency deviation value; The compensation angular frequency deviation value is fed into the forward path of the active power droop control link.

6. A power grid control system based on a grid-type energy storage power station, characterized in that: The grid-type energy storage power station is connected in parallel to the target power grid at the common coupling point of the grid-type grid-connected converter, and the system includes: an angular frequency generation unit, a first-order low-pass filter signal generation unit, an active droop coefficient adaptive adjustment signal generation unit, a high-pass filter signal generation unit and an execution unit; The angular frequency generating unit is used to obtain the common coupling point voltage of the grid-connected converter in the target power grid, and generate the angular frequency of the three-phase coordinate transformation in the grid connection process based on the common coupling point voltage; The first-order low-pass filter signal generating unit is used to send a first control signal to the grid-type energy storage power station during the operation of the power grid, wherein the first control signal is designed to perform first-order low-pass filtering on the active power of the active droop control link and the reactive power of the reactive droop control link respectively; The active droop coefficient adaptive adjustment signal generating unit is used to send a second control signal to the grid-type energy storage power station, wherein the second control signal is designed to adaptively adjust the active droop coefficient of the active droop control link; The high-pass filter processing signal generating unit is used to send a third control signal to the grid-type energy storage power station, wherein the third control signal is designed to perform high-pass filtering on the angular frequency and then feed into the forward path of the active droop control link; The execution unit is used to execute the power grid control strategy generated by the first control signal, the second control signal and the third control signal.

7. The power grid control system based on the grid-type energy storage power station according to claim 6, characterized in that: The first-order low-pass filtering is performed on the active power of the active power droop control link and the reactive power of the reactive power droop control link of the grid-type energy storage power station, respectively, including: The output voltage of the grid-type energy storage power station, the grid voltage and the reactance of the transmission line are used to express the active power relationship and the reactive power relationship of the grid-type energy storage power station; Extracting active loop gain and active closed-loop transfer function from the active power disturbance amount obtained by the active power relational expression processed by the small signal component, and extracting reactive loop gain and reactive closed-loop transfer function from the reactive power disturbance amount obtained by the reactive power relational expression processed by the small signal component; Solving the active step response function extracted from the active closed-loop transfer function to obtain the active cut-off frequency lower limit value, and solving the reactive step response function extracted from the reactive closed-loop transfer function to obtain the reactive cut-off frequency lower limit value; Solving the active amplitude function of the loop gain of the first-order low-pass filtering process extracted from the active loop gain at twice the power frequency to obtain an active cutoff frequency upper limit value, and solving the reactive amplitude function of the loop gain of the first-order low-pass filtering process extracted from the reactive loop gain at twice the power frequency to obtain a reactive cutoff frequency upper limit value; According to the lower limit value of the active power cutoff frequency and the upper limit value of the active power cutoff frequency, the active power of the active power droop control link of the grid-type energy storage power station is subjected to first-order low-pass filtering, and according to the lower limit value of the reactive power cutoff frequency and the upper limit value of the reactive power cutoff frequency, the reactive power of the reactive power droop control link of the grid-type energy storage power station is subjected to first-order low-pass filtering.

8. The power grid control system based on the grid-type energy storage power station according to claim 7, characterized in that: The adaptively adjusting the active power droop coefficient of the active power droop control link includes: According to the active frequency droop curve, an active droop coefficient equation of the grid-type energy storage power station is obtained; According to the active power expression, the maximum active power is obtained; According to the active power maximum value and the angular frequency variation range limitation, the active power droop coefficient equation is optimized, and the active power droop coefficient of the active power droop control link is adaptively adjusted according to the optimized active power droop coefficient equation.

9. The power grid control system based on the grid-type energy storage power station according to claim 8, characterized in that: The optimized active droop coefficient equation is: Where, ω0 is the rated angular frequency of the power grid, X gs is the reactance of the transmission line, V gf is the amplitude of the output voltage phasor of the grid-connected energy storage power station, V s is the grid voltage, δ g is the phase difference between the output voltage of the grid-connected energy storage power station and the grid voltage, i.e. the power angle, p g_ref It is the active power reference value of the grid-connected energy storage power station.

10. The power grid control system based on the grid-type energy storage power station according to claim 7, characterized in that: The method of feeding the angular frequency into the forward path of the active droop control link after high-pass filtering includes: Determining a high-pass filter cutoff frequency according to the active cutoff frequency upper limit value; Based on the per-unit representation of the parameters of the active droop control link and the reactive droop control link of the grid-type energy storage power station, the equivalent relationship under small signals is extracted to obtain the first small signal representation of the angular frequency equation and the second small signal representation of the active power relationship equation; Simulating a small signal structure block diagram obtained according to the first small signal representation and the second small signal representation to obtain a forward gain of the high-pass filtering processing link; According to the high-pass filter cutoff frequency, the angular frequency is subjected to high-pass filtering, and according to the forward gain, the angular frequency subjected to high-pass filtering is amplified to obtain a compensation angular frequency deviation value; The compensation angular frequency deviation value is fed into the forward path of the active power droop control link.

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