A static var generator controller based on multi-modal extended state observation

Abstract

The application provides a static reactive generator controller based on multi-mode extended state observation, comprising a coordinate transformation unit, an active current controller, a DC voltage controller, a reactive current controller and an SVPWM unit; the active current controller comprises a first multi-mode extended state observation unit, a first monitor unit and a first controller unit; the DC voltage controller comprises a second multi-mode extended state observation unit, a second monitor unit and a second controller unit; the reactive current controller comprises a third multi-mode extended state observation unit, a third monitor unit and a third controller unit. The application designs a group of extended state observers based on nominal control gain, and on-line evaluates the estimation performance of the extended state observers based on state estimation error, selects the extended state observer matched with the optimal model, and realizes the accurate estimation of disturbance and model parameter matching of the static reactive generator when performing reactive compensation.

Description

Technical Field

[0001] This invention relates to the field of direct current control technology for static var generators, and more particularly to a static var generator controller based on multimodal extended state observation. Background Technology

[0002] The basic principle of a Static Var Generator (SVG) is to precisely control and regulate the reactive power in the power grid using power electronic devices, maintaining the phase difference between voltage and current within a suitable range, thereby achieving reactive power compensation. The control system of the SVG is its core component, primarily responsible for controlling and regulating the power electronic devices to achieve precise control of the reactive power in the power grid.

[0003] Existing control methods for Static Var Generators (SVG) can be broadly categorized into two types: voltage-based control and current-based control. Voltage-based SVGs work by changing the phase and amplitude of the SVG output current to make the reactive power output proportional to the grid voltage. They offer advantages such as fast control response, high control accuracy, and low harmonic response to system current. However, their disadvantages include a relatively high control voltage requirement, greater susceptibility to system voltage fluctuations, and weaker response to grid imbalances. Current-based SVG control works by controlling the phase and amplitude of the SVG output current to make the reactive power output proportional to the current error. Their advantages include strong response to grid imbalances, a relatively low control voltage requirement, and less susceptibility to system voltage fluctuations. However, their disadvantages include slower control response, lower control accuracy, and stronger harmonic response to system current.

[0004] Commonly used control algorithms include PI control, fuzzy control, and neural network control. Among these, PI control is the most frequently used, offering advantages such as simplicity and good regulation performance. Fuzzy control, compared to traditional precise control methods, is adaptable to different power systems, exhibiting good adaptability and robustness. It can handle uncertainties and nonlinearities in the system, improving its scalability and stability. Static var generators (SVG) using neural network control, compared to traditional PI and fuzzy control, offer strong adaptability and robustness. Because it can simultaneously handle multiple input and output variables, it can comprehensively control and optimize the performance of the SVG. Furthermore, there are hybrid control methods, such as voltage-current control and voltage-power control, which combine the advantages of multiple control algorithms to achieve better control results. Different SVG control methods have their own advantages and disadvantages, and their selection and application should be based on the characteristics and requirements of the power system.

[0005] However, in the research on the control of static var generators, existing technologies have the following shortcomings in terms of controller design and control effect: First, the controller designs of existing static var generators all rely on some accurate model parameters, while the model parameters may change in actual systems, making it difficult to obtain their accurate values. Second, most existing static var generator controllers adopt passive anti-interference methods, which have a certain degree of lag and cannot achieve active anti-interference. Summary of the Invention

[0006] In view of the shortcomings of the prior art, this invention provides a static var generator (SVM) controller based on multimodal extended state observation. This invention designs a set of extended state observers based on nominal control gain, and performs online evaluation of the estimation performance of the extended state observers based on state estimation error. An evaluation and selection mechanism is established to select the extended state observer with the optimal model match, thereby achieving accurate estimation of disturbances and matching of model parameters when the static var generator performs reactive power compensation.

[0007] The technical means employed in this invention are as follows:

[0008] A static var generator controller based on multimodal extended state observation includes: a coordinate transformation unit, an active current controller, a DC voltage controller, a reactive current controller, and an SVPWM unit;

[0009] The active current controller includes a first multimode expansion state observation unit, a first monitoring unit, and a first controller unit; the DC voltage controller includes a second multimode expansion state observation unit, a second monitoring unit, and a second controller unit; the reactive current controller includes a third multimode expansion state observation unit, a third monitoring unit, and a third controller unit.

[0010] The coordinate transformation unit consists of a 3s / 2r coordinate transformation unit and a 2r / 2s coordinate transformation unit. The 3s / 2r coordinate transformation unit is used to realize the transformation between the three-phase stationary coordinate system ABC and the two-phase rotating coordinate system dq. The input of the 3s / 2r coordinate transformation unit is the current i in the power grid. a i b and i c The output is the current signal i that needs to be transformed to a two-phase rotating coordinate system. d and i q Current signal i d Connected to the input terminals of the first multimodal extended state observation unit and the second monitor unit, i qIt is connected to the third multimodal extended state observation unit and the third monitor unit 3; the 2r / 2s coordinate transformation unit is used to realize the transformation between the two-phase rotating coordinate system dq and the two-phase stationary coordinate system α-β, and the input of the 2r / 2s coordinate transformation unit is the u output by the second controller unit. d and the output u of the third controller unit q ;

[0011] The output of the first multimodal extended state observation unit is connected to the first monitoring unit, and the output of the first monitoring unit is connected to the input of the first controller unit.

[0012] The output of the second multimodal extended state observation unit is connected to the second monitoring unit, and the output of the second monitoring unit is connected to the input of the second controller unit. The second controller unit outputs u. q After a 2r / 2s coordinate transformation, it is connected to the input terminal of the SVPWM unit;

[0013] The output of the third multimodal extended state observation unit is connected to the input of the third monitor unit, and the output of the third monitor unit is connected to the third controller unit. The third controller unit outputs u. q After a 2r / 2s transformation, it is connected to the input terminal of the SVPWM unit;

[0014] The SVPWM unit generates a modulation signal to control the state of the switching transistors in the main circuit of the static var generator. The SVPWM unit is a space voltage vector modulation unit.

[0015] Compared with the prior art, the present invention has the following advantages:

[0016] First, the static var generator controller design method based on a multimodal extended state observer proposed in this invention does not require any precisely known model parameter information, but only the nominal value of the control gain. This relaxes the dependence on model parameters and makes the controller design universal.

[0017] Second, unlike the existing reactive power generator controllers that passively compensate for disturbances, the proposed method can accurately estimate the uncertainty of system model parameters and external disturbances, and actively estimate and compensate for disturbances, thereby improving the robustness of the system.

[0018] Third, the system equations of the active current controller and the DC voltage controller are second-order systems. When designing the control scheme, this invention adopts the backstepping method to design the control scheme step by step, thus structuring the controller design process. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of a static var generator controller based on multimodal extended state observation according to the present invention.

[0021] Figure 2 This is a simulation diagram of the DC-side voltage waveform of the static var generator in an embodiment of the present invention.

[0022] Figure 3 This is a simulation diagram of the power factor of the static var generator in an embodiment of the present invention.

[0023] Figure 4 This is a simulation diagram of the grid voltage and current waveforms of the static var generator in an embodiment of the present invention.

[0024] Figure 5 This is a simulation diagram showing the results of the first multimodal extended state observation unit estimating state variables in an embodiment of the present invention.

[0025] Figure 6 This is a simulation diagram showing the results of the second multimodal extended state observation unit estimating state variables in an embodiment of the present invention.

[0026] Figure 7 This is a simulation diagram showing the results of the third multimodal extended state observation unit estimating state variables in an embodiment of the present invention.

[0027] Figure 8 This is a simulation diagram of the estimation system uncertainty term by the first multimodal extended state observation unit in an embodiment of the present invention.

[0028] Figure 9 This is a simulation diagram of the second multimodal extended state observation unit estimating the system uncertainty in an embodiment of the present invention.

[0029] Figure 10 This is a simulation diagram of the estimation of system uncertainties by the multi-third-mode extended state observation unit in an embodiment of the present invention. Detailed Implementation

[0030] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0031] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0032] like Figure 1 As shown, this invention provides a static var generator (SVM) controller based on multimodal extended state observation, comprising a coordinate transformation unit, an active current controller, a DC voltage controller, a reactive current controller, and an SVPWM unit. The active current controller consists of a first multimodal extended state observation unit (shown as multimodal extended state observation unit 1 in the figure), a first monitoring unit (shown as monitoring unit 1 in the figure), and a first controller unit (shown as controller unit 1 in the figure). The DC voltage controller consists of a second multimodal extended state observation unit (shown as multimodal extended state observation unit 2 in the figure), a second monitoring unit (shown as monitoring unit 2 in the figure), and a second controller unit (shown as controller unit 2 in the figure). The reactive current controller consists of a third multimodal extended state observation unit (shown as multimodal extended state observation unit 3 in the figure), a third monitoring unit (shown as monitoring unit 3 in the figure), and (shown as controller unit 3 in the figure). The coordinate transformation unit consists of 3s / 2r and 2r / 2s coordinate transformation units. The 3s / 2r unit realizes the three-phase to two-phase transformation, that is, the transformation between the three-phase stationary coordinate system ABC and the two-phase rotating coordinate system dq. Its input is the current i in the power grid. a i b and i c The output is the current signal i that needs to be transformed to a two-phase rotating coordinate system. d and i q i dConnected to the input terminals of the multimodal extended state observation unit 1 and the monitor unit 2, i q Connected to the multimodal extended state observation unit 3 and the monitor unit 3; the 2r / 2s coordinate transformation unit realizes the transformation between the two-phase rotating coordinate system dq and the two-phase stationary coordinate system α-β, and its input is the u output by the second controller unit. d and the output u of the third controller unit q .

[0033] like Figure 1 As shown, the output of the multimodal expansion state observation unit 1 is connected to the monitor unit 1, the output of the multimodal expansion state observation unit 2 is connected to the monitor unit 2, the output of the monitor unit 1 is connected to the input of the controller unit 1, and the output of the monitor unit 2 is connected to the input of the controller unit 2. The output of the controller unit 2 is connected to the input of the SVPWM unit after a 2r / 2s coordinate transformation; the output of the multimodal expansion state observation unit 3 is connected to the input of the monitor unit 3, and the output of the monitor unit 3 is connected to the controller unit 3. The u output by the controller unit 2... d and the u output of controller unit 3 q After a 2r / 2s transformation, it is connected to the input terminal of the SVPWM unit. The SVPWM unit generates a modulation signal to control the state of the switching transistors in the main circuit of the static var generator. The SVPWM unit is a space vector modulation unit.

[0034] Furthermore, the mathematical model of the static var generator is as follows:

[0035]

[0036] Where e a ,e b ,e c Let i be the phase voltage of phases A, B, and C of the power grid. a i b i c Let u be the phase current of phases A, B, and C of the power grid. dc The DC side voltage of the static var generator is s. a ,s b ,s c The switching function of the three-phase bridge is linearized by equivalent coordinate transformation, resulting in the mathematical model of the static var generator in a two-phase rotating coordinate system:

[0037]

[0038] Wherein: e d e represents the d-axis component of the grid voltage. qLet i be the q-axis component of the grid voltage. d i is the d-axis component of the AC side current of the static var generator. q Let s be the q-axis component of the AC side current of the static var generator. d Let s be the d-axis component of the three-phase bridge switching function. q Let u be the q-axis component of the three-phase bridge switching function. d =u dc s d u is the d-axis component of the AC side voltage of the static var generator. q =u dc s q Let L be the q-axis component of the AC side voltage of the static var generator, L be the inductance of the reactor connected to the AC side of the static var generator, C be the energy storage capacitor on the DC side of the static var generator, R be the equivalent resistance of the reactor and switching elements, and u be the q-axis component of the AC side voltage of the static var generator. dc Let ω be the DC side voltage of the SVG, ω be the angular velocity and ω = 2πf, f be the grid frequency and f = 50Hz.

[0039] The following section provides further details on the specific content of each functional unit.

[0040] A. Coordinate Transformation Unit

[0041] The coordinate transformation unit uses phase-locked loop (PLL) technology to obtain the required phase signal and complete the coordinate transformation. The coordinate transformation unit consists of 3s / 2r and 2r / 2s coordinate transformation units. The 3s / 2r unit performs a three-phase to two-phase transformation, i.e., the transformation between the three-phase stationary coordinate system ABC and the two-phase rotating coordinate system dq. Its input is the current i in the power grid. a i b and i c The output is the current signal i that needs to be transformed to a two-phase rotating coordinate system. d and i q i d Connected to the input terminals of the multimodal extended state observation unit 1 and the monitor unit 2, i q Connected to the multimodal extended state observation unit 3 and the monitor unit 3; the 2r / 2s coordinate transformation unit realizes the transformation between the two-phase rotating coordinate system dq and the two-phase stationary coordinate system α-β, and its input is the u output by the second controller unit. d and the output u of the third controller unit q .

[0042] Taking the coordinate transformation of current as an example, the coordinate transformation from the three-phase stationary coordinate system to the α-β coordinate system is as follows:

[0043]

[0044] Then transform the α-β coordinate system to the dq coordinate system. The transformation equation is:

[0045]

[0046] Substituting formula (3) into formula (4) yields:

[0047]

[0048] B. Active current controller

[0049] The active current controller consists of a multi-mode extended state observer unit 1, a monitor unit 1, and a controller unit 1.

[0050] B1, Multimodal Extended State Observation Unit 1

[0051] The input to the multimodal extended state observation unit 1 is the d-axis component e of the grid voltage. d d-axis component of AC side current of static var generator i d and DC side voltage u dc The output is a list of state items. The estimated value Estimated value of external disturbance To simplify the calculation, let

[0052]

[0053] in, This is an estimate of the state term u. Let b be the estimate of external disturbances, i∈{1,...N}, where N is the number of observers. 1i The control gain is defined as the control gain within a given error range, and k1 and k2 are the control parameters of the first extended state observation unit.

[0054] B2, Monitoring Unit 1

[0055] The input to monitor unit 1 is the output of multimodal extended state observer 1. and state quantity u i The actual value, the output is the selected control gain b1 and disturbance.

[0056] The monitor signal is an exponentially weighted sum of the output errors of the monitor signals associated with each observer. Norms can be implemented as linear filters:

[0057]

[0058] Where i∈{1,...N}, λ1>0 are design parameters, and μ 1i(t) is the weighted norm of the monitoring signal generated for each observer. Here, u represents the deviation value of the state variable, and u represents the actual value of the state variable. The selected signal input is the output of the multimodal extended state observer 1. The difference between the actual value of the state variable and the different control gains b 1i The signal σ1 is used to select an observer from N observers at each time step to minimize its bias. The formula is:

[0059]

[0060] B3, Controller Unit 1

[0061] The input to controller unit 1 is the DC side reference voltage u of the static var generator. re f and the optimal disturbance estimate and optimal gain output from monitor unit 1. The output is current i. d Reference current value i dref Its control law is as follows:

[0062]

[0063] in, b1 is the optimal disturbance estimate selected by the first monitoring unit, and ω is the selected first optimal gain. c1 U is the first controller coefficient. dc u is the DC side voltage of the SVG. dcref The given DC-side reference voltage for the SVG.

[0064] C. DC voltage controller

[0065] The DC voltage controller consists of a multi-mode extended state observer unit 2, a monitor unit 2, and a controller unit 2.

[0066] C1, Multimodal Extended State Observation Unit 2

[0067] The input to the multimodal extended state observation unit 2 is the d-axis component e of the AC side voltage of the static var generator. d and the d-axis component of the current i d The output is a statement about state item i. di The estimated value Estimated value of external disturbance As shown in the following formula:

[0068]

[0069] Where i = 1, ..., N, b 2i K is the control gain within a given error range, and k3 and k4 are the control parameters of the first extended state observation unit.

[0070] C2, Monitoring Unit 2

[0071] The input to monitor unit 2 is the output of multimodal extended state observer 2. and state quantity i di The actual value, the output is the selected control gain b2 and disturbance.

[0072] The monitor signal is an exponentially weighted sum of the output errors of the monitor signals associated with each observer. Norms can be implemented as linear filters:

[0073]

[0074] Where i∈{1,...N}, λ2>0 are design parameters, and μ 2i (t) represents the weighted norm of the monitoring signal generated for each observer. Let i be the deviation value of the state variable. d b is the actual value of the state variable. 2i This is the second control gain. The selected signal input is the output of the multimodal extended state observer 2. and state quantity i di The difference between the actual values ​​and the different control gains b 2i The signal σ2 is used to select an observer from N observers at each time step to minimize its bias. The formula is:

[0075]

[0076] C3, Controller Unit 2

[0077] The input to controller unit 2 is the output i of controller unit 1. dref The optimal disturbance estimate and optimal gain are output from monitoring unit 2. The output is the reference value of the d-axis component of the AC side voltage of the static var generator. Its control law is as follows:

[0078]

[0079] in, b2 is the optimal disturbance estimate selected by the monitor, and ω is the optimal gain selected. c2 For controller coefficients.

[0080] D. Reactive current controller

[0081] The reactive current controller consists of a multi-mode extended state observer unit 3, a monitor unit 3, and a controller unit 3.

[0082] D1, Multimodal Extended State Observation Unit 3

[0083] The input to the mode expansion state observation unit 3 is the q-axis component e of the AC side voltage of the static var generator. q and the q-axis component of the current i q Output the state item i qi The estimated value Estimated value of external disturbance As shown in the following formula:

[0084]

[0085] Where i = 1, ..., N, b 3i K is the control gain within a given error range, and k5 and k6 are the control parameters of the first extended state observation unit.

[0086] D2, Monitoring Unit 3

[0087] The input to monitor unit 3 is the output of the multimodal extended state observer. and state quantity i qi The actual value, the output is the selected control gain b3 and disturbance.

[0088] The monitor signal is an exponentially weighted sum of the output errors of the monitor signals associated with each observer. Norms can be implemented as linear filters:

[0089]

[0090] Where i∈{1,...N}, λ3>0 are design parameters, and μ 3i (t) represents the weighted norm of the monitoring signal generated for each observer. The deviation value of the state variable. For the output of the third multimodal extended state observer, i q b is the actual value of the state variable. 3i This is the third control gain. The selected signal input is the output of the multimodal extended state observer 3. and state quantity i qi The difference between the actual values ​​and the different control gains b 3i The signal σ3 is used to select one observer from N observers at each time step to minimize its bias. Its formula is:

[0091]

[0092] D3, Controller Unit 3

[0093] The input to controller unit 3 is the q-axis reference component i of the static var generator AC side current. qrefThe optimal disturbance estimate and optimal gain are output from monitoring unit 3. The output is a reference value for the q-axis component of the AC side voltage of the static var generator. The design control law is as follows:

[0094]

[0095] Among them, u q For the q-axis voltage control law, i qref For current i q The reference current value, b3 is the optimal disturbance estimate selected by the monitor, and ω is the optimal gain selected. c3 For controller coefficients.

[0096] E, SVPWM unit

[0097] The SVPWM unit input is the output u from the DC voltage control module. d and the output u of the reactive current control module q u after 2r / 2s transformation bet and u alf The output is a signal that drives the switching elements to turn on and off. The SVPWM unit uses space vector modulation technology to modulate the reference value of the AC side voltage of the static var generator into a signal that drives the switching elements to turn on and off, and sends this signal to the three-phase bridge circuit to control the switching elements to turn on and off.

[0098] The present invention will be further illustrated below with an example of the application of a specific static var generator in reactive power compensation. Figure 1 This is a schematic diagram of the structure of the present invention, wherein the static var generator model in a two-phase rotating coordinate system is as follows:

[0099]

[0100] The specific parameter selection is as follows: the DC side energy storage capacitor is 1100μF, the AC side connecting reactor inductance is 5mH, and the equivalent resistance of the connecting reactor and switching elements is 0.1Ω. Initially, the load is an inductive load with an active power of 1000W and a reactive power of 1000Var. To observe the compensation capability and dynamic compensation performance of the static var generator under different loads, the load is switched to a capacitive load with an active power of 1000W and a reactive power of 1000Var at 0.6s. The extended state observer used in the control system satisfies equations (6), (10), and (14), where the parameters of the extended state observer are: k1 = 250, k2 = 25000, k3 = 300, k4 = 13000, k5 = 300, k6 = 1000.

[0101] Simulation results are as follows Figure 2-4 As shown. Figure 2The waveform of the DC-side voltage of the static var generator is shown. The given DC-side voltage is 600V. Considering that in actual experiments, an uncontrolled rectification experiment will be performed first, during which the DC-side voltage is around 500V. Therefore, the DC-side voltage is set to 500V at the beginning of the simulation. Furthermore, at 0.6s, the load changes from an inductive load to a capacitive load, causing the DC voltage to fluctuate. Figure 3 The graph shows the power factor waveform of the static var generator. As can be seen, this invention can essentially improve the power factor to around 1, achieving the effect of reactive power compensation. After a load change in 0.6 seconds, the power factor recovers to around 1 after a short period of fluctuation. Figure 4 The waveform diagram shows the voltage and current of the power grid. The voltage and current are basically in phase. The static var generator can compensate for the reactive power generated by the load.

[0102] Simulation results show that the designed multimodal extended state observer can select the most suitable control algorithm and adjust the control gain in real time according to the actual operating state of the system. The monitor unit selects the parameters most suitable for the model and switches at the appropriate time, achieving an optimal combination of performance indicators reflecting system stability, accuracy, and speed. Increasing the number of observers is used to achieve the same optimal combination of performance indicators reflecting system stability, accuracy, and speed. Figure 5-10 As shown, the optimal value is selected and sent to the controller to complete the control task of the static var generator. This improves the system's anti-interference capability, simplifies the controller design, and meets the design objectives.

[0103] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A static var generator controller based on multimodal extended state observation, characterized in that, include: Coordinate transformation unit, active current controller, DC voltage controller, reactive current controller and SVPWM unit; The active current controller includes a first multimode expansion state observation unit, a first monitoring unit, and a first controller unit; the DC voltage controller includes a second multimode expansion state observation unit, a second monitoring unit, and a second controller unit; the reactive current controller includes a third multimode expansion state observation unit, a third monitoring unit, and a third controller unit. The coordinate transformation unit is composed of Coordinate transformation unit and The coordinate transformation unit consists of, the The coordinate transformation unit is used to realize the three-phase stationary coordinate system. and two-phase rotating coordinate system The transformation between them, the The input to the coordinate transformation unit is the current in the power grid. , and The output is the AC side current of the static var generator. Axial components and the AC side current of the static var generator Axial components Current signal It is connected to the input terminals of the first multimodal extended state observation unit and the second monitor unit. It is connected to the third multimodal extended state observation unit and the third monitoring unit; The coordinate transformation unit is used to implement a two-phase rotating coordinate system. and two-phase stationary coordinate system The transformation between them, the The input to the coordinate transformation unit is the output of the second controller unit. and the output of the third controller unit ; The output of the first multimodal extended state observation unit is connected to the first monitoring unit, and the output of the first monitoring unit is connected to the input of the first controller unit. The output of the second multimodal extended state observation unit is connected to the second monitoring unit, and the output of the second monitoring unit is connected to the input of the second controller unit. The output of the second controller unit is... through After coordinate transformation, it is connected to the input terminal of the SVPWM unit; The output of the third multimodal extended state observation unit is connected to the input of the third monitor unit, and the output of the third monitor unit is connected to the third controller unit. The output of the third controller unit is... through After coordinate transformation, it is connected to the input terminal of the SVPWM unit; The SVPWM unit generates a modulation signal to control the state of the switching transistors in the main circuit of the static var generator. The SVPWM unit is a space voltage vector modulation unit.

2. A static var generator controller based on multimodal extended state observation according to claim 1, characterized in that, The mathematical model of the static var generator in a two-phase rotating coordinate system is as follows: in, The d-axis component of the grid voltage. For the grid voltage Axial components, For the AC side current of the static var generator Axial components, For the AC side current of the static var generator Axial components, For the three-phase bridge switching function in Components of the axis, For the three-phase bridge switching function in Components of the axis, For the AC side voltage of the static var generator Axial components, For the AC side voltage of the static var generator Axial components, This refers to the inductance value of the reactor connected to the AC side of the static var generator. This refers to the value of the DC-side energy storage capacitor of the static var generator. This represents the equivalent resistance value of the reactor and switching elements. This is the DC-side voltage of the SVG. Angular velocity, , This refers to the power grid frequency.

3. A static var generator controller based on multimodal extended state observation according to claim 2, characterized in that, The first multimodal extended state observation unit is used to output the squared state quantity of the DC side voltage of the SVG according to the following calculation. The estimated value Estimated values ​​of external disturbances ,make : in, For the actual value of the square state quantity of the DC side voltage of the SVG The estimated value, This is an estimate of external disturbances. , For the number of observers, The first control gain, These are the control parameters for the first extended state observation unit; The first monitoring unit is configured to select an exponentially weighted average of the monitoring signal output error associated with each observer according to the following method: Norm, and determine the selected control gain by choosing the observer that minimizes the deviation: Among them, , For design parameters, Generate a weighted norm for the monitoring signal for each observer. The deviation value of the state variable. This is the output of the first multimodal extended state observer. This represents the actual value of the squared state quantity of the DC-side voltage of the SVG. The first control gain; The first controller unit is used to calculate the output current according to the following Reference current value : in, The optimal disturbance estimate selected for the first monitoring unit. The first optimal gain was selected. The first controller coefficient, This is the DC-side voltage of the SVG. The given DC-side reference voltage for the SVG.

4. A static var generator controller based on multimodal extended state observation according to claim 3, characterized in that, The second multimodal extended state observation unit is used to calculate and output the AC side current of the static var generator according to the following calculations. Axial components The estimated value and estimates of external disturbances : in, For the AC side current of the static var generator Axial components The estimated value, This is an estimate of the external disturbance. , For the second control gain, These are the control parameters for the second extended state observation unit; The second monitoring unit is used to select the exponentially weighted average of the monitoring signal output error associated with each observer according to the following method: Norm, and determine the selected control gain by choosing the observer that minimizes the deviation: in, , For design parameters, Generate a weighted norm for the monitoring signal for each observer. The deviation value of the state variable. This is the output of the second multimodal extended state observer. For the AC side current of the static var generator Axial components, This is the second control gain; The second controller unit is used to output the AC side voltage of the static var generator according to the following calculation. Reference values ​​for axis components: in, AC side voltage of static var generator Reference values ​​for axis components. The optimal disturbance estimate selected for the second monitoring unit. This represents the second optimal gain selected. This is the coefficient for the second controller.

5. A static var generator controller based on multimodal extended state observation according to claim 4, characterized in that, The third multimodal extended state observation unit is used to calculate and output the AC side current of the static var generator according to the following calculations. Axial components The estimated value and estimates of external disturbances : in, , For the third control gain, These are the control parameters for the third extended state observation unit; The third monitoring unit is used to select the exponentially weighted average of the monitoring signal output error associated with each observer according to the following method: Norm, and determine the selected control gain by choosing the observer that minimizes the deviation: in, , For design parameters, Generate a weighted norm for the monitoring signal for each observer. The deviation value of the state variable. This is the output of the third multimodal extended state observer. For the AC side current of the static var generator Axial components, This is the third control gain; The third controller unit is used to calculate and output a reference value for the q-axis component of the AC side voltage of the static var generator based on the following calculation: in, This is the reference value for the q-axis component of the AC side voltage of the static var generator. For current The reference current value, The optimal disturbance estimate selected for the third monitoring unit. The third optimal gain was selected. This is the coefficient for the third controller.

Images