Converter control method and device based on energy storage state change of physical element

Abstract

The invention belongs to the technical field of power system control, and particularly discloses a converter control method and device based on physical element energy storage state change. According to the invention, the active current of the internal potential node is directly used as an adjustment target, and the active current instruction value and the reactive current instruction value of the internal potential node are adjusted. An internal potential three-phase alternating current instruction value is generated according to the change of the active current instruction value and the reactive current instruction value of the internal potential node, and then the internal potential is adjusted, so that the control target and means are matched with the state of a physical energy storage element (namely a direct current capacitor and a filter inductor) of the converter; the control parameters can be selected in a targeted manner according to the dynamic response characteristics of the actual physical energy storage element of the converter, so that better dynamic performance is obtained, and the stability of the converter is maintained.

Description

Technical Field

[0001] The present application belongs to the technical field of power system control, and more specifically, to a converter control method and device based on changes in the energy storage state of a physical element. Background Art

[0002] The existing converter control mostly adopts cascade control, including dual-loop control of the DC voltage outer loop and the current inner loop. The DC voltage outer loop control adjusts the dq axis (where the d axis is the direct axis and the q axis is the quadrature axis) filter inductor current command value in the phase-locked coordinate system, and then drives the current inner loop to adjust the dq axis inner potential command value in the phase-locked coordinate system. However, from the perspective that the DC voltage outer loop control is to stabilize the DC capacitor voltage, the d axis filter inductor current in the phase-locked coordinate system that is adjusted is not the actual active current value of the inner potential node output by the DC capacitor to the grid side. The adjusted d axis filter inductor current will include two influencing factors. One is the dynamic influence of the filter inductor between the inner potential node and the terminal voltage node, and the other is that the outer loop output command is actually the command value formed by the voltage at the detection terminal of the phase-locked loop, which will be affected by the dynamic influence of the phase-locked loop. That is, the above-mentioned DC voltage outer loop control and current inner loop control cannot cooperate well with each other.

[0003] However, the inherent physical properties of the converter's physical energy storage elements, namely the DC capacitor and the filter inductor, cannot be changed. Therefore, when the adopted control strategy does not match the properties of the physical energy storage elements, the DC capacitor and the filter inductor may produce power oscillations under the control of the inner and outer loops, resulting in poor dynamic performance and stability of the converter. Summary of the invention

[0004] In view of the defects of the prior art, the purpose of this application is to provide a converter control method and device based on the change of the energy storage state of the physical element, aiming to solve the problem that when the control strategy adopted in the prior art does not match the properties of the physical energy storage elements in the converter, the dynamic performance and stability of the converter will deteriorate.

[0005] To achieve the above objectives, in a first aspect, the present application provides a converter control method based on the change of energy storage state of a physical element, comprising:

[0006] Obtaining an active current command value of an internal potential node and a reactive current command value of an internal potential node in the converter;

[0007] Generate an internal potential three-phase AC command value according to the internal potential node active current command value and the internal potential node reactive current command value;

[0008] According to the internal potential three-phase AC command value, a switching signal is generated to control the converter.

[0009] In some embodiments, obtaining an internal potential node active current command value and an internal potential node reactive current command value in the converter includes:

[0010] Obtaining an active current command value of an internal potential node according to an error between a DC capacitor voltage command value and a DC capacitor voltage detection value in the converter;

[0011] Obtaining an internal potential node reactive current command value according to an error between a terminal voltage command value and a terminal voltage detection value in the converter;

[0012] Or, the internal potential node reactive current command value is obtained according to the error between the grid-connected node reactive power command value and the grid-connected node reactive power detection value in the converter.

[0013] In some embodiments, generating an internal potential three-phase AC command value according to an internal potential node active current command value and an internal potential node reactive current command value includes:

[0014] Performing a first coordinate transformation on the active current command value of the inner potential node and the reactive current command value of the inner potential node to obtain a direct-axis current command value and a quadrature-axis current command value in a grid-connected node reference coordinate system;

[0015] Obtaining a direct-axis internal potential command value according to an error between a direct-axis current command value and a direct-axis current detection value;

[0016] Obtaining a quadrature-axis internal potential command value according to an error between a quadrature-axis current command value and a quadrature-axis current detection value;

[0017] The internal potential three-phase AC command value is generated based on the direct-axis internal potential command value and the quadrature-axis internal potential command value.

[0018] In some embodiments, generating a switch signal according to the internal potential three-phase AC command value to control the converter includes:

[0019] Performing a second coordinate transformation on the direct-axis internal potential command value and the quadrature-axis internal potential command value to obtain the internal potential three-phase AC command value;

[0020] The internal potential three-phase AC command value is pulse-width modulated to generate a switching signal to control the converter.

[0021] In some embodiments, performing a first coordinate transformation on the active current command value of the internal potential node and the reactive current command value of the internal potential node to obtain the direct axis current command value and the quadrature axis current command value in the grid-connected node reference coordinate system includes:

[0022] According to the phase difference between the internal potential AC signal and the grid-connected node AC voltage, the internal potential node active current command value and the internal potential node reactive current command value are subjected to a rotating coordinate transformation to obtain the direct-axis current command value and the quadrature-axis current command value. The first coordinate transformation is determined according to the rotating coordinate transformation.

[0023] In some embodiments, performing a second coordinate transformation on the direct-axis internal potential command value and the quadrature-axis internal potential command value to obtain a three-phase AC command value includes:

[0024] According to the phase of the AC voltage of the grid-connected node, the direct-axis internal potential command value and the quadrature-axis internal potential command value are transformed from the rotating coordinate system to the three-phase stationary coordinate system to obtain the internal potential three-phase AC command value, and the second coordinate transformation is determined based on the transformation from the rotating coordinate system to the three-phase stationary coordinate system.

[0025] In some embodiments, the phase of the internal potential AC signal and the phase of the grid-connected node AC voltage are obtained by:

[0026] Convert the three-phase AC signal to the target coordinate system;

[0027] The signal corresponding to the first coordinate axis of the target coordinate system is used as the real part of the three-phase AC signal, and the signal corresponding to the second coordinate axis is used as the imaginary part of the three-phase AC signal to construct a complex number;

[0028] Based on the argument function, obtain the phase corresponding to the complex number;

[0029] Alternatively, based on a phase-locked loop detection method, the phase of the three-phase AC signal is obtained;

[0030] The three-phase AC signal is an internal potential AC signal or a grid-connected node AC voltage.

[0031] In a second aspect, the present application provides a converter control device based on a change in energy storage state of a physical element, comprising:

[0032] An acquisition module, used to acquire an active current command value of an internal potential node and a reactive current command value of an internal potential node in the converter;

[0033] A generating module, used for generating an internal potential three-phase AC command value according to an internal potential node active current command value and an internal potential node reactive current command value;

[0034] The control module is used to generate a switch signal according to the internal potential three-phase AC command value to control the converter.

[0035] In a third aspect, the present application provides an electronic device comprising: at least one memory for storing programs; and at least one processor for executing the programs stored in the memory. When the programs stored in the memory are executed, the processor is used to execute the converter control method based on the change of energy storage state of a physical element described in the first aspect or any embodiments of the first aspect.

[0036] In a fourth aspect, the present application provides a computer-readable storage medium, which stores a computer program. When the computer program runs on a processor, the processor executes the converter control method based on the change of the energy storage state of a physical element described in the first aspect or any embodiments of the first aspect.

[0037] In a fifth aspect, the present application provides a computer program product, which, when executed on a processor, enables the processor to execute the converter control method based on the change of energy storage state of a physical element as described in the first aspect or any embodiments of the first aspect.

[0038] In general, the above technical solutions conceived by this application have the following beneficial effects compared with the prior art:

[0039] The converter control method and device based on the change of energy storage state of physical elements provided in the present application directly take the active current of the internal potential node as the adjustment target, and adjust the active current command value and reactive current command value of the internal potential node. And generate the internal potential three-phase AC command value according to the change of the active current command value and reactive current command value of the internal potential node, and then adjust the internal potential, so that the control target and means match the state of the physical energy storage element (i.e., DC capacitor and filter inductor) of the converter, and can select the control parameters according to the dynamic response characteristics of the actual physical energy storage element of the converter in a targeted manner, so as to obtain better dynamic performance and maintain its own stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a schematic diagram of the original structure of the inner and outer loop control of the converter provided by the prior art;

[0041] Figure 2 It is a flow chart of a converter control method based on a change in energy storage state of a physical element provided in an embodiment of the present application;

[0042] Figure 3 It is a schematic diagram of a two-level control structure provided in an embodiment of the present application;

[0043] Figure 4 It is a structural diagram of an implementation method of the error control module provided in an embodiment of the present application;

[0044] Figure 5It is a structural diagram of an implementation method of the current error control module provided in an embodiment of the present application;

[0045] Figure 6 It is a structural schematic diagram of an implementation method of the first coordinate transformation provided in an embodiment of the present application;

[0046] Figure 7 It is a structural schematic diagram of an implementation method of the second coordinate transformation provided in an embodiment of the present application;

[0047] Figure 8 This is one of the structural schematic diagrams of the implementation method of phase detection provided in the embodiment of the present application;

[0048] Fig. 9 This is a second structural diagram of a method for implementing phase detection provided in an embodiment of the present application;

[0049] Fig.10 It is a structural schematic diagram of a converter control device based on a change in energy storage state of a physical element provided in an embodiment of the present application;

[0050] Fig.11 It is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0051] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0052] The term "and / or" in this article is a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. The symbol " / " in this article indicates that the associated objects are in an or relationship, for example, A / B means A or B.

[0053] The terms "first" and "second" in the specification and claims herein are used to distinguish different objects rather than to describe a specific order of objects. For example, the first coordinate transformation and the second coordinate transformation are used to distinguish different coordinate transformations rather than to describe a specific order of coordinate transformations.

[0054] In the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0055] In the description of the embodiments of the present application, unless otherwise specified, “plurality” means two or more than two.

[0056] See also Figure 1 , DC capacitor voltage command value U dcref and DC capacitor voltage detection value U dc The error between them is formed into the d-axis current command value in the terminal voltage phase-locked coordinate system through the proportional integral (PI) controller. Terminal voltage command value V tref The terminal voltage detection value V t The error between them is used to form the q-axis current command value in the terminal voltage phase-locked coordinate system through the integral controller Then the dq axis current command value (including and Respectively with the dq axis current detection value (including the d axis current detection value and q-axis current detection value The error is formed by the PI controller into the dq axis potential command value (including the d axis potential command value) in the terminal voltage phase-locked coordinate system. and the q-axis potential command value Finally, the dq axis internal potential command value forms the internal potential three-phase AC command value E according to the phase-locked phase of the terminal voltage. abc , and then the switching signal is formed by pulse width modulation (PWM) to drive the insulated-gate bipolar transistor (IGBT) switching device.

[0057] Therefore, for the original control of the converter, it adjusts the dq axis current command value in the terminal voltage phase-locked coordinate system through the outer loop control, thereby realizing the control of the DC capacitor voltage, and changes the dq current value of the filter inductor current in the phase-locked coordinate system by adjusting the internal potential.

[0058] Based on this, the embodiment of the present application provides a converter control method and device based on the change of energy storage state of physical elements, so that the control means matches the demand for physical energy storage element state regulation. Because physically, on the one hand, the DC voltage is the state of energy storage of the DC capacitor, and the change of the DC voltage is directly determined by the current flowing into and out of the DC capacitor, that is, the active current of the internal potential node; on the other hand, the three-phase AC current output by the DC capacitor through the three-phase bridge arm of the converter directly reflects the state of energy storage of the filter inductor, which depends on the internal potential and the three-phase AC voltage at the grid connection point. Therefore, physically speaking, since the physical properties of the above-mentioned DC capacitor and filter inductor are inherent, what can be changed artificially is the control method and structure, so it is necessary to coordinate the relationship between the change of the DC capacitor state and the change of the filter inductor state in the control.

[0059] However, from the existing control method, the converter adopts the dual-loop control of the DC voltage outer loop and the current inner loop. The DC voltage outer loop control adjusts the d-axis filter inductor current in the phase-locked coordinate system, which is not the actual DC capacitor output to the grid side of the internal potential node active current value. The adjusted d-axis filter inductor current will include two influencing factors. One is the dynamic influence of the filter inductor between the internal potential node and the terminal voltage node, and the other is that the outer loop output command is actually the command value formed by the phase-locked loop detection terminal voltage, that is, it will be affected by the dynamics of the phase-locked loop. That is, the above-mentioned DC voltage outer loop control and current inner loop control cannot cooperate well with each other. In the case of fluctuations in the DC capacitor voltage, the active current of the internal potential node should be directly adjusted to stabilize the DC capacitor voltage. However, since the current inner loop control does not directly target the active current of the internal potential node as the adjustment target, it may cause resonance between the DC capacitor and the filter inductor. Therefore, the two-stage control structure adopted in this application directly corresponds to the state changes of the two physical energy storage elements, the DC capacitor and the filter inductor, and can better coordinate the interaction relationship between the elements in the actual physical system, as well as the transmission process of power and energy.

[0060] The embodiments of the present application are described below in conjunction with the drawings in the embodiments of the present application.

[0061] Please see further Figure 2 , an embodiment of the present application provides a converter control method based on the change of energy storage state of a physical element, which may include: step 110, step 120 and step 130.

[0062] Step 110 obtains the internal potential node active current command value and the internal potential node reactive current command value in the converter;

[0063] Step 120 generates an internal potential three-phase AC command value according to the internal potential node active current command value and the internal potential node reactive current command value;

[0064] Step 130 generates a switch signal according to the internal potential three-phase AC command value to control the converter.

[0065] Please see further Figure 3 The embodiment of the present application adopts a two-stage control structure consisting of a DC capacitor state control structure and a filter inductor control structure.

[0066] The DC capacitor state control structure generates the internal potential node active current command value I required by the filter inductor control structure edref The reactive current command value I eqref , that is, the output of the DC capacitor state control structure is the internal potential node active current command I edref The value and the internal potential node reactive current command value I eqref , as the input signal of the next level filter inductor control structure. The filter inductor control structure is based on the active current command value I of the internal potential node. edref The reactive current command value I eqref Generate internal potential three-phase AC command value E abc .

[0067] According to the internal potential three-phase AC command value E abc , generating a switching signal to drive the IGBT switching device in the converter to form a three-phase AC voltage, i.e., the internal potential AC signal E a ' bc In the embodiment of the present application, the switch signal is a PWM signal.

[0068] The embodiment of the present application provides a converter control method based on the change of energy storage state of physical elements, which directly takes the active current of the internal potential node as the adjustment target, and adjusts the active current command value and reactive current command value of the internal potential node. And according to the change of the active current command value and reactive current command value of the internal potential node, the internal potential three-phase AC command value is generated, and then the internal potential is adjusted, so that the control target and means match the state of the physical energy storage element (i.e., DC capacitor and filter inductor) of the converter, and the control parameters can be selected according to the dynamic response characteristics of the actual physical energy storage element of the converter in a targeted manner, so as to obtain better dynamic performance and maintain its own stability.

[0069] Further, in some embodiments, in step 110, obtaining the internal potential node active current command value and the internal potential node reactive current command value in the converter may include:

[0070] Obtaining an active current command value of an internal potential node according to an error between a DC capacitor voltage command value and a DC capacitor voltage detection value in the converter;

[0071] Obtaining an internal potential node reactive current command value according to an error between a terminal voltage command value and a terminal voltage detection value in the converter;

[0072] Or, the internal potential node reactive current command value is obtained according to the error between the grid-connected node reactive power command value and the grid-connected node reactive power detection value in the converter.

[0073] In the specific implementation, the error between the DC capacitor voltage command value and the DC capacitor voltage detection value forms the active current command value of the internal potential node. Since the internal potential output current includes a reactive current component, the regulation of the internal potential reactive current component can be achieved in two ways. The first is to form the internal potential node reactive current command value through an error control module using the error between the terminal voltage command value and the detection value. The second is to give a grid-connected node reactive power command value, and the error between the given grid-connected node reactive power detection value and the grid-connected point reactive power command value is formed through an error control module.

[0074] Please continue to see Figure 3 The DC capacitor state control structure includes two levels of control. On the one hand, the DC capacitor voltage command value U dcref and DC capacitor voltage detection value U dc Input to adder 1 to obtain the error ΔU between the two dc , the error ΔU dc The error control module 2 forms the internal potential node active current command value I edref On the other hand, the reactive current command value I eqref There are two ways to do this. The first way is to use the terminal voltage amplitude command value V tref The terminal voltage detection value V t The error between t The error control module 2 forms the internal potential node reactive current command value I eqref The second method is to use the grid-connected node reactive power command value Q tref And the reactive power detection value Q of the grid-connected node t The error between t The error control module 2 forms the internal potential node reactive current command value I eqref .

[0075] Please see further Figure 4 , is an implementation of the error control module 2 in the DC capacitor state control structure. The error control module 2 is composed of a proportional amplifier, an integrator and an adder. The error signal (including ΔU dc , ΔV t and ΔQ t) one way through the proportional amplifier 21, the other way through the proportional amplifier 22 connected to the integrator 23, and then the adder 24 adds the two results to obtain the output signal (including U dcref and I eqref ).

[0076] Further, in some embodiments, in step 120, generating the internal potential three-phase AC command value according to the internal potential node active current command value and the internal potential node reactive current command value may include:

[0077] Performing a first coordinate transformation on the active current command value of the inner potential node and the reactive current command value of the inner potential node to obtain a direct-axis current command value and a quadrature-axis current command value in a grid-connected node reference coordinate system;

[0078] Obtaining a direct-axis internal potential command value according to an error between a direct-axis current command value and a direct-axis current detection value;

[0079] Obtaining a quadrature-axis internal potential command value according to an error between a quadrature-axis current command value and a quadrature-axis current detection value;

[0080] The internal potential three-phase AC command value is generated based on the direct-axis internal potential command value and the quadrature-axis internal potential command value.

[0081] Please see further Figure 3 In the filter inductor state control structure, firstly, the active current command value I of the internal potential node is edref The reactive current command value I eqref The dq axis current command values ​​(including the d axis current command value I tdref and q-axis current command value I tqref ). Then according to the d-axis current command value I tdref and the d-axis current detection value I td The error between td The current error control module 4 forms the d-axis potential command value E in the grid point reference coordinate system. td , according to the q-axis current command value I tqref and the q-axis current detection value I tq The error between tq The current error control module 4 forms the q-axis potential command value E in the grid-connected point reference coordinate system. tq Among them, the dq axis current detection value is obtained by converting the inductor three-phase AC detection value I abc It is obtained by converting the abc coordinate system to the dq coordinate system based on the phase of the three-phase AC signal.

[0082] According to E td and E tq, determine the internal potential three-phase AC command value E abc .

[0083] Please see further Figure 5 , is an implementation of the current error control module 4 in the filter inductor state control structure. The current error control module 4 is composed of a proportional amplifier, an integrator and an adder. The dq current error signal (including ΔI td and ΔI tq ) One path passes through the proportional amplifier 41, and the other path first passes through the proportional amplifier 42 and is connected to the integrator 43, and then the adder 44 adds the two results to obtain the dq axis internal potential command value E td and E tq .

[0084] Further, in some embodiments, in step 130, generating a switch signal according to the internal potential three-phase AC command value to control the converter may include:

[0085] Performing a second coordinate transformation on the direct-axis internal potential command value and the quadrature-axis internal potential command value to obtain the internal potential three-phase AC command value;

[0086] The internal potential three-phase AC command value is pulse-width modulated to generate a switching signal to control the converter.

[0087] Please continue to see Figure 3 In the embodiment of the present application, the d-axis potential command value E td and the q-axis potential command value E tq ) is converted into a three-phase AC signal E through the second coordinate transformation 5 abc , and then the obtained three-phase AC signal E abc The switching signal formed by pulse width modulation drives the IGBT switching device in the converter to form a three-phase AC voltage.

[0088] Further, in some embodiments, in the above steps, performing a first coordinate transformation on the active current command value of the inner potential node and the reactive current command value of the inner potential node to obtain the direct-axis current command value and the quadrature-axis current command value in the grid-connected node reference coordinate system may include:

[0089] According to the phase difference between the internal potential AC signal and the grid-connected node AC voltage, the internal potential node active current command value and the internal potential node reactive current command value are subjected to a rotating coordinate transformation to obtain the direct-axis current command value and the quadrature-axis current command value. The first coordinate transformation is determined according to the rotating coordinate transformation.

[0090] In the embodiment of the present application, the input of the first coordinate transformation 3 is the internal potential AC signal E a ' bc The AC voltage of the grid-connected node (i.e. the three-phase detection value of the terminal voltage Vtabc ) between the phase difference θ e -θ t (θ e is the internal potential AC signal E a ' bc The phase, θ t is the grid-connected node AC voltage V tabc Phase), internal potential node active current command value I eqref The reactive current command value I eqref Internal potential node active current command value I eqref The reactive current command value I eqref , according to the phase difference θ between the internal potential AC signal and the grid-connected node AC voltage e -θ t , after the first coordinate transformation 3, the dq axis current command values ​​are output.

[0091] Specifically, the input internal potential node active current command value I eqref The reactive current command value I eqref , based on the internal potential AC signal E a ' bc The AC voltage V tabc The phase difference θ e -θ t By rotating the coordinates, it is converted into the d-axis current command value I under the terminal voltage orientation. tdref and the q-axis current command value I tqref .

[0092] Please see further Figure 6 , is an implementation of the first coordinate transformation 3, which is composed of trigonometric functions (including cosine function 31 and sine function 32), multiplier 33 and adder 34, and its basic principle is based on rotation coordinate transformation, as shown in the following formula:

[0093]

[0094] Through this rotation coordinate transformation, the internal potential node active current command value I eqref The reactive current command value I eqref Convert to the dq axis current command value I under the terminal voltage reference tdref and I tqref .

[0095] Furthermore, in some embodiments, in the above steps, performing a second coordinate transformation on the direct-axis internal potential command value and the quadrature-axis internal potential command value to obtain the three-phase AC command value may include:

[0096] According to the phase of the AC voltage of the grid-connected node, the direct-axis internal potential command value and the quadrature-axis internal potential command value are transformed from the rotating coordinate system to the three-phase stationary coordinate system to obtain the internal potential three-phase AC command value. The second coordinate transformation is determined according to the transformation from the rotating coordinate system to the three-phase stationary coordinate system.

[0097] In the specific implementation, the dq axis potential command value E td and E tq The three-phase AC signal is obtained by transforming the dq coordinates to the abc three-phase coordinates under the terminal voltage phase reference, and then the three-phase AC signal is input into the pulse width modulation module.

[0098] The input of the second coordinate transformation 5 is the phase θ of the AC voltage at the grid-connected node. t , dq axis internal potential command value E td and E tq . dq axis internal potential command value E td and E tq According to the transformation from dq coordinates to abc three-phase coordinates, the internal potential three-phase AC command value E is obtained. abc .

[0099] Please see further Figure 7 , is a method for realizing the second coordinate transformation 5, including trigonometric functions (including cosine function 51 and sine function 52), multiplier 53, adder 54 and amplifier 55, and its purpose is to realize the conversion of dq axis internal potential command value E td and E tq Converted into internal potential three-phase AC command value E abc The basic principle is to first convert the dq coordinate system to the target coordinate system, i.e., the αβ coordinate system, and then convert it to the three-phase stationary coordinate system, i.e., the three-phase AC instantaneous value (including E a 、E b and E c ), as shown in the following formula:

[0100]

[0101] Furthermore, in some embodiments, the phase of the internal potential AC signal and the phase of the grid-connected node AC voltage may be obtained by:

[0102] Convert the three-phase AC signal to the target coordinate system;

[0103] The signal corresponding to the first coordinate axis of the target coordinate system is used as the real part of the three-phase AC signal, and the signal corresponding to the second coordinate axis is used as the imaginary part of the three-phase AC signal to construct a complex number;

[0104] Based on the argument function, obtain the phase corresponding to the complex number;

[0105] Alternatively, based on a phase-locked loop detection method, the phase of the three-phase AC signal is obtained;

[0106] The three-phase AC signal is an internal potential AC signal or a grid-connected node AC voltage.

[0107] In the embodiment of the present application, the internal potential AC signal E a ' bc The phase θ e The three-phase AC voltage V tabc The phase θ t The detection can be performed through phase detection 6, which includes two methods: direct phase detection calculation and phase-locked loop-based detection.

[0108] The first direct phase detection calculation method first uses the first module 61 to convert the input three-phase AC signal X abc (including E a ' bc or V tabc ) are respectively converted from the abc coordinates to the target coordinate system, i.e., the αβ coordinate system, and the signal corresponding to the first coordinate axis (i.e., the α-axis signal X α ) as the real part of the three-phase AC signal, and the signal corresponding to the second coordinate axis (i.e., the β-axis signal X β ) as the imaginary part of the three-phase AC signal, thereby constructing a complex number, and then the third module 63 performs an amplitude function operation on the complex number to obtain the phase of the three-phase AC signal, as shown in detail Figure 8 shown.

[0109] The second method is based on a phase-locked loop detection method. First, the three-phase AC signal X is converted into abc The abc coordinates are converted to the dq coordinate system based on the phase of the three-phase AC signal, and the q-axis signal X q The angular frequency error is outputted by the PI controller 65, and then the angular frequency error is added to the angular frequency ω0 of the power frequency signal by the adder 66 to form the final angular frequency, and then the final angular frequency is integrated by the integrator 67 to generate the phase of the three-phase AC signal, as shown in detail. Fig. 9 shown.

[0110] The converter control method based on the change of energy storage state of physical elements provided in the embodiment of the present application includes a two-level control structure of DC capacitor state control and filter inductor state control. The DC capacitor state control adjusts the active current command value and reactive current command value of the internal potential node, and the filter inductor state control adjusts the internal potential according to the change of the active current command value and reactive current command value of the internal potential node. The two-level control structure designed in the embodiment of the present application directly corresponds to the state change of the two physical energy storage elements, the DC capacitor and the filter inductor, and can better coordinate the interaction relationship between the elements in the actual physical system, as well as the transmission process of power and energy.

[0111] The converter control device based on the change of the energy storage state of the physical element provided by the present invention is described below. The converter control device based on the change of the energy storage state of the physical element described below and the converter control method based on the change of the energy storage state of the physical element described above can be referenced to each other.

[0112] See also Fig.10 , an embodiment of the present application provides a converter control device based on the change of energy storage state of a physical element, which may include: an acquisition module 1010 , a generation module 1020 and a control module 1030 .

[0113] An acquisition module 1010 is used to acquire an active current command value of an internal potential node and a reactive current command value of an internal potential node in the converter;

[0114] A generating module 1020, for generating an internal potential three-phase AC command value according to the internal potential node active current command value and the internal potential node reactive current command value;

[0115] The control module 1030 is used to generate a switch signal according to the internal potential three-phase AC command value to control the converter.

[0116] The embodiment of the present application provides a converter control device based on the change of energy storage state of physical elements, which directly takes the active current of the internal potential node as the adjustment target, and adjusts the active current command value and reactive current command value of the internal potential node. And according to the change of the active current command value and reactive current command value of the internal potential node, the internal potential three-phase AC command value is generated, and then the internal potential is adjusted, so that the control target and means match the state of the physical energy storage element (i.e., DC capacitor and filter inductor) of the converter, and the control parameters can be selected according to the dynamic response characteristics of the actual physical energy storage element of the converter in a targeted manner, so as to obtain better dynamic performance and maintain its own stability.

[0117] It can be understood that the detailed functional implementation of each of the above-mentioned units / modules can be found in the introduction of the aforementioned method embodiment, and will not be repeated here.

[0118] It should be understood that the above-mentioned device is used to execute the method in the above-mentioned embodiment. The implementation principle and technical effect of the corresponding program module in the device are similar to those described in the above-mentioned method. The working process of the device can refer to the corresponding process in the above-mentioned method, which will not be repeated here.

[0119] Based on the method in the above embodiment, the present application embodiment provides an electronic device, see Fig.11 The electronic device may include: a processor 1110, a communication interface 1120, a memory 1130 and a communication bus 1140, wherein the processor 1110, the communication interface 1120 and the memory 1130 communicate with each other via the communication bus 1140. The processor 1110 may call the logic instructions in the memory 1130 to execute the method in the above embodiment.

[0120] In addition, the logic instructions in the above-mentioned memory 1130 can be implemented in the form of software functional units and can be stored in a computer-readable storage medium when sold or used as an independent product. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product, which is stored in a storage medium and includes a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application.

[0121] Based on the method in the above embodiment, an embodiment of the present application provides a computer-readable storage medium, which stores a computer program. When the computer program runs on a processor, the processor executes the method in the above embodiment.

[0122] Based on the method in the above embodiment, an embodiment of the present application provides a computer program product. When the computer program product runs on a processor, the processor executes the method in the above embodiment.

[0123] It is understandable that the processor in the embodiment of the present application may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field programmable gate arrays (FPGA) or other programmable logic devices, transistor logic devices, hardware components or any combination thereof. The general-purpose processor may be a microprocessor or any conventional processor.

[0124] The method steps in the embodiments of the present application can be implemented by hardware or by a processor executing software instructions. The software instructions can be composed of corresponding software modules, and the software modules can be stored in random access memory (RAM), flash memory, read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), registers, hard disks, mobile hard disks, CD-ROMs, or any other form of storage medium known in the art. An exemplary storage medium is coupled to a processor so that the processor can read information from the storage medium and write information to the storage medium. Of course, the storage medium can also be a component of the processor. The processor and the storage medium can be located in an ASIC.

[0125] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium or transmitted through the computer-readable storage medium. The computer instructions may be transmitted from a website site, a computer, a server or a data center to another website site, a computer, a server or a data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium may be any available medium that a computer can access or a data storage device such as a server or a data center that includes one or more available media integrated. The available medium may be a magnetic medium (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid-state drive (SSD)), etc.

[0126] It should be understood that the various numerical numbers involved in the embodiments of the present application are only used for the convenience of description and are not used to limit the scope of the embodiments of the present application.

[0127] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A converter control method based on the change of energy storage state of physical components, It is characterized in that include: Obtaining an active current command value of an internal potential node and a reactive current command value of an internal potential node in the converter; Generate an internal potential three-phase AC command value according to the internal potential node active current command value and the internal potential node reactive current command value; A switching signal is generated according to the internal potential three-phase AC command value to control the converter.

2. The converter control method based on the change of energy storage state of a physical element as claimed in claim 1, It is characterized in that The step of obtaining the active current command value of the internal potential node and the reactive current command value of the internal potential node in the converter comprises: Obtaining the active current command value of the internal potential node according to the error between the DC capacitor voltage command value and the DC capacitor voltage detection value in the converter; acquiring the reactive current command value of the inner potential node according to the error between the terminal voltage command value and the terminal voltage detection value in the converter; Or, the reactive current command value of the internal potential node is obtained according to the error between the reactive power command value of the grid-connected node and the reactive power detection value of the grid-connected node in the converter.

3. The converter control method based on the change of energy storage state of a physical element as claimed in claim 1, It is characterized in that The generating of the internal potential three-phase AC command value according to the internal potential node active current command value and the internal potential node reactive current command value comprises: Performing a first coordinate transformation on the active current command value of the inner potential node and the reactive current command value of the inner potential node to obtain a direct-axis current command value and a quadrature-axis current command value in a grid-connected node reference coordinate system; Obtaining a direct-axis internal potential command value according to an error between the direct-axis current command value and the direct-axis current detection value; Obtaining a quadrature-axis internal potential command value according to an error between the quadrature-axis current command value and the quadrature-axis current detection value; The internal potential three-phase AC command value is generated based on the direct-axis internal potential command value and the quadrature-axis internal potential command value.

4. The converter control method based on the change of energy storage state of a physical element as claimed in claim 3, It is characterized in that The step of generating a switch signal according to the internal potential three-phase AC command value to control the converter comprises: Performing a second coordinate transformation on the direct-axis internal potential command value and the quadrature-axis internal potential command value to obtain an internal potential three-phase AC command value; The internal potential three-phase AC command value is pulse-width modulated to generate the switching signal and control the converter.

5. The converter control method based on the change of energy storage state of a physical element as claimed in claim 3, It is characterized in that The performing a first coordinate transformation on the active current command value of the inner potential node and the reactive current command value of the inner potential node to obtain a direct-axis current command value and a quadrature-axis current command value in a grid-connected node reference coordinate system includes: According to the phase difference between the internal potential AC signal and the grid-connected node AC voltage, the internal potential node active current command value and the internal potential node reactive current command value are subjected to a rotating coordinate transformation to obtain the direct-axis current command value and the quadrature-axis current command value, and the first coordinate transformation is determined based on the rotating coordinate transformation.

6. The converter control method based on the change of energy storage state of a physical element as claimed in claim 4, It is characterized in that The step of performing a second coordinate transformation on the direct-axis internal potential command value and the quadrature-axis internal potential command value to obtain a three-phase AC command value includes: According to the phase of the AC voltage of the grid-connected node, the direct-axis internal potential command value and the quadrature-axis internal potential command value are transformed from a rotating coordinate system to a three-phase stationary coordinate system to obtain the internal potential three-phase AC command value, and the second coordinate transformation is determined according to the transformation from the rotating coordinate system to the three-phase stationary coordinate system.

7. The converter control method based on the change of energy storage state of a physical element as claimed in claim 5, It is characterized in that The method for acquiring the phase of the internal potential AC signal and the phase of the grid-connected node AC voltage includes: Convert the three-phase AC signal to the target coordinate system; A complex number is constructed by taking a signal corresponding to a first coordinate axis of a target coordinate system as a real part of the three-phase AC signal and a signal corresponding to a second coordinate axis as an imaginary part of the three-phase AC signal; Based on the argument function, obtaining the phase corresponding to the complex number; Alternatively, based on a phase-locked loop detection method, the phase of the three-phase AC signal is obtained; Wherein, the three-phase AC signal is the internal potential AC signal or the grid-connected node AC voltage.

8. A converter control device based on the change of energy storage state of physical elements, It is characterized in that include: An acquisition module, used to acquire an active current command value of an internal potential node and a reactive current command value of an internal potential node in the converter; A generating module, used for generating an internal potential three-phase AC command value according to the internal potential node active current command value and the internal potential node reactive current command value; The control module is used to generate a switch signal according to the internal potential three-phase AC command value to control the converter.

9. An electronic device, It is characterized in that include: at least one memory for storing a computer program; At least one processor is used to execute the program stored in the memory. When the program stored in the memory is executed, the processor is used to execute the converter control method based on the change of the energy storage state of the physical element as described in any one of claims 1-7.

10. A computer-readable storage medium storing a computer program. It is characterized in that When the computer program runs on a processor, the processor is enabled to execute the converter control method based on the change of energy storage state of a physical element as described in any one of claims 1 to 7.

Images