Power distribution network control method and device, computer device, readable storage medium and program product

Abstract

The application relates to a power distribution network control method and device, computer equipment, a computer readable storage medium and a computer program product. The method comprises the following steps: obtaining a DC bus voltage, an AC side voltage, an AC side current and an AC bus current corresponding to an interface converter; establishing a dynamic power balance relationship between the AC side and the DC side based on the DC bus voltage, the AC side voltage and the AC side current, and calculating a target frequency, a target phase angle and a target voltage amplitude corresponding to an AC voltage output by the interface converter; decomposing the AC bus current to obtain a target harmonic component; and calculating an interface converter control quantity based on the target frequency, the target phase angle, the target voltage amplitude and the target harmonic component. The method can improve the operation stability and power quality of the power distribution network.

Description

Technical Field

[0001] This application relates to the field of power distribution network technology, and in particular to a power distribution network control method, device, computer equipment, computer-readable storage medium, and computer program product. Background Technology

[0002] With China's rapid economic development and accelerated urbanization, urban villages have emerged during urban expansion. Due to their high population density and continuously increasing electricity load, these villages are placing significant pressure on the power supply capacity and operational stability of existing power distribution networks. Simultaneously, with the large-scale integration of distributed photovoltaic power, energy storage, electric vehicle charging facilities, and various DC loads, the power distribution networks in urban villages are gradually exhibiting a hybrid AC / DC configuration and a multi-source, multi-load operation. Therefore, multi-port flexible DC capacity adjustment technology has emerged to achieve energy exchange and power coordination between the AC and DC sides.

[0003] In related technologies, droop control, improved droop control, or virtual synchronous motor control are commonly used to regulate AC and DC power, and active filtering and other methods are used to mitigate AC harmonics in order to improve the stability of the distribution network and power quality.

[0004] However, most existing control methods only optimize for a single problem and cannot simultaneously address the requirements of bidirectional power flow, power quality management, and system dynamic stability. Furthermore, in scenarios with large-scale distributed equipment integration and rapid load fluctuations, issues such as insufficient inertial support, lag in dynamic response, and low harmonic compensation accuracy still exist, which can easily affect the stable operation of AC / DC hybrid distribution networks. Summary of the Invention

[0005] Therefore, it is necessary to provide a distribution network control method, device, computer equipment, computer-readable storage medium, and computer program product that can improve the operational stability of the distribution network in response to the above-mentioned technical problems.

[0006] Firstly, this application provides a power distribution network control method, including:

[0007] The method, applied to an interface converter connected to both a DC power grid and an AC power grid, includes:

[0008] Obtain the operating data corresponding to the interface converter, including DC bus voltage, AC side voltage, AC side current and AC bus current;

[0009] Based on the DC bus voltage, the AC side voltage, and the AC side current, a dynamic power balance relationship between the AC side and the DC side is established, and the target frequency and target phase angle corresponding to the output AC voltage of the interface converter are calculated based on the dynamic power balance relationship.

[0010] Obtain the target reactive power value and the actual reactive power, and calculate the target voltage amplitude corresponding to the output AC voltage of the interface converter based on the deviation between the target reactive power value and the actual reactive power.

[0011] Based on the AC side voltage, the AC side current, and the AC bus current, the AC bus current is decomposed to obtain the target harmonic component corresponding to the AC bus current; the target harmonic component is the harmonic current component in the AC bus current.

[0012] Based on the target frequency, the target phase angle, the target voltage amplitude, and the target harmonic components, the control quantity of the interface converter is calculated; the control quantity is used to control the interface converter to perform AC / DC side power regulation and harmonic compensation.

[0013] In one embodiment, establishing a dynamic power balance relationship between the AC side and the DC side based on the DC bus voltage, the AC side voltage, and the AC side current includes:

[0014] Calculate the actual angular frequency of the AC side based on the AC side voltage and the AC side current;

[0015] Calculate the DC-side voltage deviation based on the DC bus voltage;

[0016] The dynamic power balance relationship is established based on the AC frequency inertia term corresponding to the actual angular frequency on the AC side, the AC droop control term corresponding to the AC frequency deviation, the DC voltage inertia term corresponding to the DC voltage deviation on the DC side, and the DC droop control term.

[0017] In one embodiment, calculating the target frequency and target phase angle corresponding to the output AC voltage of the interface converter based on the dynamic power balance relationship includes:

[0018] The target frequency corresponding to the output AC voltage of the interface converter is calculated based on the dynamic power balance relationship.

[0019] The target phase angle is obtained by integrating the angular frequency change process corresponding to the target frequency.

[0020] In one embodiment, the step of decomposing the AC bus current based on the AC side voltage, the AC side current, and the AC bus current to obtain the target harmonic component corresponding to the AC bus current includes:

[0021] Based on the AC side voltage and the AC side current, calculate the instantaneous active power and instantaneous reactive power on the AC side;

[0022] Based on the instantaneous active power, instantaneous reactive power, AC voltage, and AC current on the AC side, a power component mapping relationship is established, and the fundamental active current component and fundamental reactive current component in the AC bus current are calculated based on the power component mapping relationship; the power component mapping relationship is used to characterize the correspondence between AC voltage, AC current, and AC power.

[0023] The fundamental active current component and the fundamental reactive current component are separated from the AC bus current to obtain the target harmonic component corresponding to the AC bus current.

[0024] In one embodiment, calculating the control quantity of the interface converter based on the target frequency, the target phase angle, the target voltage amplitude, and the target harmonic components includes:

[0025] Based on the target frequency, the target phase angle, and the target voltage amplitude, a target voltage vector corresponding to the output AC voltage of the interface converter is generated, and the target voltage vector is converted into a target voltage reference value in a rotating coordinate system.

[0026] Calculate the target current reference value based on the target voltage reference value and the actual output voltage corresponding to the interface converter;

[0027] Calculate the control voltage corresponding to the interface converter based on the target current reference value, the target harmonic component, and the actual output current of the interface converter.

[0028] The control quantity is generated based on the control voltage.

[0029] In one embodiment, the method further includes:

[0030] Generate a corresponding pulse width modulation control signal based on the control quantity;

[0031] The power switching devices in the interface converter are turned on or off based on the pulse width modulation control signal, so as to adjust the corresponding AC output voltage and AC output current of the interface converter.

[0032] Secondly, this application provides a power distribution network control device applied to an interface converter; the device includes:

[0033] The acquisition module is used to acquire the operating data corresponding to the interface converter, including DC bus voltage, AC side voltage, AC side current and AC bus current.

[0034] The first calculation module is used to establish a dynamic power balance relationship between the AC side and the DC side based on the DC bus voltage, the AC side voltage and the AC side current, and to calculate the target frequency and target phase angle corresponding to the output AC voltage of the interface converter based on the dynamic power balance relationship.

[0035] The second calculation module is used to obtain the target value of reactive power and the actual reactive power, and to calculate the target voltage amplitude corresponding to the output AC voltage of the interface converter based on the deviation between the target value of reactive power and the actual reactive power.

[0036] The harmonic determination module is used to decompose the AC bus current based on the AC side voltage, the AC side current, and the AC bus current to obtain the target harmonic component corresponding to the AC bus current; the target harmonic component is the harmonic current component in the AC bus current;

[0037] The control module is used to calculate the control quantity of the interface converter based on the target frequency, the target phase angle, the target voltage amplitude, and the target harmonic components; the control quantity is used to control the interface converter to perform AC / DC side power regulation and harmonic compensation. Step C.

[0038] Thirdly, this application also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps of the method in any of the above embodiments.

[0039] Fourthly, this application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method in any of the above embodiments.

[0040] Fifthly, this application also provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the methods in any of the above embodiments.

[0041] The aforementioned power distribution network control method, device, computer equipment, computer-readable storage medium, and computer program product acquire DC bus voltage, AC side voltage, AC side current, and AC bus current. Then, based on the DC bus voltage, AC side voltage, and AC side current, a dynamic power balance relationship is established between the AC and DC sides, and the target frequency and target phase angle corresponding to the AC voltage output by the interface converter are calculated accordingly. Simultaneously, the target voltage amplitude is calculated based on the deviation between the target reactive power value and the actual reactive power. By coordinating the adjustment of the frequency, phase angle, and voltage amplitude corresponding to the AC voltage output by the interface converter, the interface converter can dynamically adjust the power transmission process between the AC and DC sides according to changes in AC and DC power, thereby improving the stability of the AC side voltage and the overall system stability. Furthermore, by decomposing the AC bus current to obtain the target harmonic components, and combining the target frequency, target phase angle, target voltage amplitude, and target harmonic components, the control quantity of the interface converter is calculated, enabling the interface converter to compensate for AC side harmonic currents while regulating AC and DC side power. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments of this application or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0043] Figure 1 This is an application environment diagram of the power distribution network control method in one embodiment;

[0044] Figure 2 This is a flowchart illustrating a power distribution network control method in one embodiment;

[0045] Figure 3 This is a block diagram of a virtual synchronous motor control in one embodiment;

[0046] Figure 4 This is a control block diagram of a power distribution network control method in an exemplary embodiment;

[0047] Figure 5 This is a schematic diagram of the interface converter in one embodiment.

[0048] Figure 6 This is a structural block diagram of a power distribution network control device in one embodiment;

[0049] Figure 7 This is an internal structural diagram of a computer device in one embodiment. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0051] The power distribution network control method provided in this application can be applied to, for example... Figure 1 The application environment includes a DC power grid 102, an interface converter 104, and an AC power grid 106, with the interface converter connected to both the DC power grid 102 and the AC power grid 106.

[0052] Because DC and AC power grids operate differently—DC power is transmitted in DC form, while AC power is transmitted in AC form—an interface converter 104 is needed to achieve power conversion and exchange between the DC and AC sides. Furthermore, with the integration of distributed power sources, energy storage devices, and nonlinear loads, the AC side is prone to problems such as harmonics, voltage fluctuations, and power fluctuations. Therefore, in addition to enabling bidirectional power flow between the AC and DC sides, the interface converter 104 is also used to regulate the output state of the AC side to achieve AC / DC power balance control and AC harmonic compensation.

[0053] In one exemplary embodiment, such as Figure 2 As shown, a power distribution network control method is provided, which is applied to... Figure 1 Taking the interface converter 104 as an example, the explanation includes the following steps 202 to 210. Wherein:

[0054] Step 202: Obtain the operating data corresponding to the interface converter. The operating data includes DC bus voltage, AC side voltage, AC side current and AC bus current.

[0055] Among them, the operation data refers to the status monitoring data during the operation of the power grid, which is used to characterize the current operation status of the AC and DC sides. The operation data includes DC bus voltage, AC side voltage, AC side current and AC bus current.

[0056] Optionally, voltage and current data during the operation of the interface converter are collected in real time by voltage sampling units and current sampling units located on the AC and DC sides of the interface converter, and corresponding operating data are generated based on the collected voltage and current data. Specifically, the voltage sampling unit is used to collect the DC bus voltage and AC side voltage, and the current sampling unit is used to collect the AC side current and AC bus current.

[0057] Step 204: Based on the DC bus voltage, AC side voltage and AC side current, establish a dynamic power balance relationship between the AC side and the DC side, and calculate the target frequency and target phase angle corresponding to the output AC voltage of the interface converter based on the dynamic power balance relationship.

[0058] Here, the target frequency refers to the frequency reference value corresponding to the AC voltage output by the interface converter; the target phase angle refers to the phase angle reference value corresponding to the AC voltage output by the interface converter.

[0059] Since the interface converter needs to achieve bidirectional power regulation between the AC side and the DC side during operation, and there is a dynamic coupling relationship between the power change process of the AC side and the DC side, it is necessary to establish a dynamic power balance relationship between the AC side and the DC side to dynamically constrain the power regulation process of the interface converter, thereby reducing power fluctuations and improving the system's operational stability.

[0060] Optionally, the AC power change state is calculated based on the AC side voltage and AC side current, and the DC power change state is calculated based on the DC bus voltage. Then, according to the correspondence between the AC power change state and the DC power change state, the power transmission process of the interface converter between the AC side and the DC side is balanced and constrained so that the AC side and the DC side maintain dynamic power balance when exchanging power, thereby establishing the corresponding dynamic power balance relationship.

[0061] Optionally, after obtaining the dynamic power balance relationship, the AC side operating data and the DC side operating data are input into the dynamic power balance relationship, and based on the power balance state between the AC side and the DC side, the target frequency and target phase angle corresponding to the output AC voltage of the interface converter are calculated to control the interface converter to perform power regulation between the AC side and the DC side.

[0062] Step 206: Obtain the target reactive power value and the actual reactive power, and calculate the target voltage amplitude corresponding to the output AC voltage of the interface converter based on the deviation between the target reactive power value and the actual reactive power.

[0063] Among them, the reactive power target value refers to the expected reactive power reference value of the interface converter output or absorbed; the actual reactive power refers to the reactive power that the interface converter currently outputs or absorbs.

[0064] Since there is a correlation between reactive power and AC voltage, changes in the reactive power output of the interface converter will affect the AC voltage state. When there is a deviation between the actual reactive power output of the interface converter and the system's expected reactive power, it indicates a difference between the current AC voltage support state and the target state. Therefore, it is necessary to adjust the voltage amplitude corresponding to the AC voltage output of the interface converter according to the reactive power deviation to achieve stable AC voltage control.

[0065] Optionally, the deviation between the target reactive power value and the actual reactive power is calculated, the adjustment relationship between reactive power and output AC voltage amplitude is established, and the target voltage amplitude corresponding to the output AC voltage of the interface converter is dynamically adjusted based on the reactive power deviation, thereby realizing AC side reactive power regulation and AC voltage stability control.

[0066] Specifically, firstly, a preset voltage amplitude is used as the base output voltage of the interface converter; then, by calculating the deviation between the target reactive power value and the actual reactive power, the difference between the current AC side reactive power support state and the target reactive power support state is obtained; finally, the base output voltage is corrected according to the difference, thereby obtaining the target voltage amplitude corresponding to the AC output voltage of the interface converter.

[0067] For example, the adjustment relationship between reactive power and output AC voltage amplitude is shown in formula (1):

[0068] Formula (1)

[0069] in, This is the effective value of the virtual potential. This is the effective value of the no-load potential. This is the reactive power-voltage droop factor. This is the target value for reactive power. This represents the actual reactive power value. This control simulates the excitation regulation function of a synchronous motor, achieving precise reactive power control by adjusting the effective value of the virtual electromotive force, thereby further improving the stability of the AC side voltage.

[0070] Step 208: Based on the AC side voltage, AC side current and AC bus current, decompose the AC bus current to obtain the target harmonic component corresponding to the AC bus current; the target harmonic component is the harmonic current component in the AC bus current.

[0071] The target harmonic component refers to the distorted current component in the AC bus current, excluding the fundamental active current component and the fundamental reactive current component.

[0072] Since the AC bus current includes fundamental active current component, fundamental reactive current component and harmonic current component, and the AC side voltage and AC side current can characterize the current power state of the AC side, the different power components in the AC bus current can be separated based on the correspondence between the AC side voltage, AC side current and AC bus current, so as to obtain the corresponding target harmonic components.

[0073] Optionally, the current power transmission state of the AC side is determined based on the AC side voltage and AC side current, and the stable power transmission component and the unstable distortion component in the AC bus current are separated according to the correspondence between the AC bus current and the AC side power transmission state; wherein, the stable power transmission component includes the fundamental active current component and the fundamental reactive current component, and the unstable distortion component includes the corresponding harmonic current component; then, the unstable distortion component is taken as the corresponding target harmonic component.

[0074] Step 210: Calculate the control quantity of the interface converter based on the target frequency, target phase angle, target voltage amplitude, and target harmonic components; the control quantity is used to control the interface converter to perform AC / DC side power regulation and harmonic compensation.

[0075] Optionally, the target output state of the interface converter is first determined based on the target frequency, target phase angle, target voltage amplitude, and target harmonic components; then, the current actual output state of the interface converter is obtained; finally, the state deviation between the target output state and the actual output state is calculated, and the output adjustment amount of the interface converter is determined based on the state deviation to generate the corresponding control quantity.

[0076] Optionally, the interface converter generates a corresponding pulse width modulation control signal based on the control quantity, and controls the power switching devices in the interface converter to turn on or off based on the pulse width modulation control signal, so as to adjust the corresponding AC output state and output compensation current of the interface converter.

[0077] Since the target frequency, target phase angle, and target voltage amplitude are used to characterize the target AC output state of the interface converter when it transmits power between the AC and DC sides, and the target harmonic components are used to characterize the harmonic compensation requirements on the AC side, the interface converter can dynamically adjust the AC output state and output compensation current based on the control quantity, thereby realizing AC / DC side power regulation and AC side harmonic compensation.

[0078] In the aforementioned power distribution network control method, the DC bus voltage, AC side voltage, AC side current, and AC bus current are acquired. Then, a dynamic power balance relationship between the AC and DC sides is established based on these parameters, and the target frequency and target phase angle corresponding to the AC output voltage of the interface converter are calculated accordingly. Simultaneously, the target voltage amplitude is calculated based on the deviation between the target reactive power value and the actual reactive power. By coordinating the adjustment of the frequency, phase angle, and voltage amplitude corresponding to the AC output voltage of the interface converter, the interface converter can dynamically adjust the power transmission process between the AC and DC sides according to changes in AC and DC power, thereby improving the stability of the AC side voltage and the overall system stability. Furthermore, the target harmonic components are obtained by decomposing the AC bus current, and the control quantities of the interface converter are calculated by combining the target frequency, target phase angle, target voltage amplitude, and target harmonic components. This allows the interface converter to compensate for AC side harmonic currents while regulating AC and DC side power.

[0079] In one embodiment, the above-mentioned establishment of a dynamic power balance relationship between the AC side and the DC side based on the DC bus voltage, AC side voltage, and AC side current includes: calculating the actual angular frequency of the AC side based on the AC side voltage and AC side current; calculating the DC side voltage deviation based on the DC bus voltage; and establishing a dynamic power balance relationship based on the AC frequency inertia term corresponding to the actual angular frequency of the AC side, the AC droop control term corresponding to the AC frequency deviation, the DC voltage inertia term corresponding to the DC side voltage deviation, and the DC droop control term.

[0080] Among them, the AC frequency inertia term is used to characterize the inertial response characteristics during the AC side frequency change process; the AC droop control term is used to characterize the power regulation relationship corresponding to the AC frequency deviation; the DC voltage inertia term is used to characterize the inertial response characteristics during the DC bus voltage change process; and the DC droop control term is used to characterize the power regulation relationship corresponding to the DC bus voltage deviation.

[0081] In this embodiment, by associating the AC side frequency change process with the DC side voltage change process, the interface converter can simultaneously consider the AC side power change state and the DC side power change state when adjusting power between the AC and DC sides, thereby maintaining a dynamic balance between the AC and DC sides during power exchange.

[0082] Optionally, an AC-side dynamic power response model is established based on the AC frequency inertia term and AC droop control term corresponding to the actual angular frequency on the AC side; simultaneously, a DC-side dynamic power response model is established based on the DC voltage inertia term and DC droop control term corresponding to the DC voltage deviation; then, the AC-side dynamic power response model and the DC-side dynamic power response model are coupled to obtain the corresponding dynamic power balance relationship. For example, the dynamic power balance relationship is shown in formula (2):

[0083] Formula (2)

[0084] in, For rotational inertia, For AC rated angular frequency, To exchange actual angular frequencies, For AC droop coefficient, This is the actual voltage of the DC bus. This is the rated voltage of the DC bus. This is the DC droop factor. It is a DC capacitor. This represents the phase angle difference between the virtual potential and the AC bus voltage.

[0085] Among them, the AC frequency inertia term Used to characterize the instantaneous power change corresponding to an alternating current frequency change; DC voltage inertia term. This is used to characterize the instantaneous power change corresponding to a change in DC bus voltage. By introducing AC frequency inertia terms and DC voltage inertia terms into the dynamic power balance relationship, the power throughput characteristics of the power sources, energy storage devices, and loads in the AC / DC subgrid can be utilized to provide inertial support for the AC frequency and DC bus voltage, thereby reducing power fluctuations when the interface converter adjusts power between the AC and DC sides and improving system operational stability.

[0086] Thus, by establishing a dynamic power balance relationship between the AC and DC sides, and introducing AC frequency inertia and DC voltage inertia terms into the dynamic power balance relationship, the interface converter can simultaneously consider the dynamic power change process of the AC and DC sides when adjusting power between the AC and DC sides. This reduces frequency fluctuations and DC voltage fluctuations caused by power surges, and improves the system's inertial support capability and operational stability.

[0087] Furthermore, in one embodiment, the above-mentioned calculation of the target frequency and target phase angle corresponding to the output AC voltage of the interface converter based on the dynamic power balance relationship includes: calculating the target frequency corresponding to the output AC voltage of the interface converter based on the dynamic power balance relationship; and performing integral calculation on the angular frequency change process corresponding to the target frequency to obtain the target phase angle.

[0088] Optionally, after obtaining the dynamic power balance relationship, the AC side operating data and DC side operating data are input into the dynamic power balance relationship, and the target frequency corresponding to the AC voltage output by the interface converter is solved based on the dynamic power balance relationship; then, the target phase angle is solved based on the change process corresponding to the target frequency. For example, the solution relationship for the target phase angle is shown in formula (3):

[0089] Formula (3)

[0090] in, The target phase angle corresponding to the AC output voltage of the interface converter. This is the angular frequency corresponding to the target frequency.

[0091] Thus, by solving for the target frequency and target phase angle corresponding to the AC output voltage of the interface converter based on the dynamic power balance relationship, the frequency and phase corresponding to the AC output voltage of the interface converter can be dynamically adjusted according to the power change status of the AC and DC sides, thereby realizing stable power transmission between the AC and DC sides.

[0092] In one embodiment, the above-mentioned decomposition of the AC bus current based on the AC side voltage, AC side current, and AC bus current to obtain the target harmonic component corresponding to the AC bus current includes: calculating the instantaneous active power and instantaneous reactive power of the AC side based on the AC side voltage and AC side current; establishing a power component mapping relationship based on the instantaneous active power, instantaneous reactive power, AC side voltage, and AC side current, and calculating the fundamental active current component and fundamental reactive current component in the AC bus current based on the power component mapping relationship; the power component mapping relationship is used to characterize the correspondence between the AC side voltage, AC side current, and AC side power; and separating the fundamental active current component and fundamental reactive current component from the AC bus current to obtain the target harmonic component corresponding to the AC bus current.

[0093] The AC bus current can generally be understood as consisting of normal power transmission current and distortion current. Normal power transmission current mainly includes the fundamental active current component and the fundamental reactive current component, while distortion current mainly includes harmonic current components generated by nonlinear loads. Therefore, this embodiment obtains the target harmonic component that needs compensation by first determining the fundamental current component used for normal power transmission in the AC bus current, and then separating this fundamental current component from the AC bus current.

[0094] Optionally, instantaneous active power and instantaneous reactive power are calculated based on AC-side voltage and AC-side current. Then, the equivalent conductance and equivalent susceptance corresponding to the AC bus current are determined based on the relationship between instantaneous active power, instantaneous reactive power, and AC-side voltage. The equivalent conductance characterizes the current component in the AC bus current corresponding to active power, and the equivalent susceptance characterizes the current component in the AC bus current corresponding to reactive power. Subsequently, the fundamental conductance and fundamental susceptance are extracted from the equivalent conductance and equivalent susceptance through filtering. Based on the fundamental conductance, fundamental susceptance, and AC-side voltage, the fundamental active current component and fundamental reactive current component are calculated.

[0095] Furthermore, after obtaining the fundamental active current component and the fundamental reactive current component, the fundamental active current component and the fundamental reactive current component are taken as the fundamental current component in the AC bus current, and the difference between the AC bus current and the fundamental current component is taken as the target harmonic component. That is to say, the target harmonic component can be expressed as the remaining current component in the total AC bus current after removing the fundamental active current component and the fundamental reactive current component.

[0096] By using the above method, harmonic current components can be identified from the AC bus current when there is distortion in the AC bus voltage or nonlinear change in the load. This provides a basis for the subsequent harmonic compensation current output by the interface converter, thereby improving the accuracy of harmonic detection and the effect of power quality management.

[0097] In one embodiment, the above-mentioned calculation of the control quantity of the interface converter based on the target frequency, target phase angle, target voltage amplitude, and target harmonic component includes: generating a target voltage vector corresponding to the output AC voltage of the interface converter based on the target frequency, target phase angle, and target voltage amplitude, and converting the target voltage vector into a target voltage reference value in a rotating coordinate system; calculating a target current reference value based on the target voltage reference value and the actual output voltage of the interface converter; calculating the control voltage corresponding to the interface converter based on the target current reference value, target harmonic component, and the actual output current of the interface converter; and generating the control quantity based on the control voltage.

[0098] The target voltage vector refers to the voltage vector information used to characterize the target state of the output AC voltage of the interface converter, including the target frequency, target phase angle, and target voltage amplitude corresponding to the output AC voltage.

[0099] Optionally, firstly, based on the target frequency, target phase angle, and target voltage amplitude, the target AC output state corresponding to the interface converter is determined. The target AC output state is used to characterize the target output voltage state of the interface converter on the AC side. Then, the current actual output state of the interface converter is obtained, and the difference between the target output state and the actual output state is compared to determine the output adjustment amount corresponding to the interface converter. Subsequently, the output state of the interface converter is dynamically adjusted according to the output adjustment amount so that the actual output state of the interface converter gradually approaches the target output state.

[0100] Furthermore, during the adjustment of the output state of the interface converter, the harmonic compensation current corresponding to the target harmonic component is controlled to be output by the interface converter in combination with the harmonic compensation requirements, thereby realizing AC side harmonic compensation.

[0101] Optionally, when adjusting the output state of the interface converter, the corresponding AC output quantity of the interface converter is converted to a synchronous rotating coordinate system (direct-quadrature coordinate system, dq coordinate system) for control. The synchronous rotating coordinate system converts periodically changing AC quantities into relatively stable control quantities, thereby reducing the coupling effect between AC variables and improving the stability and control accuracy of the interface converter output adjustment process.

[0102] like Figure 3 As shown, in this embodiment, the AC frequency-DC voltage control simulates the mechanical motion equations of the synchronous motor to regulate active power. It exhibits a droop characteristic in steady state, and this control loop outputs the frequency and phase of the virtual electromotive force (EMF) E. The virtual excitation control simulates the excitation regulation of the synchronous motor to control reactive power and outputs the effective value of the virtual EMF E. The AC frequency-DC voltage control and virtual excitation control ultimately output the virtual EMF phasor E, and the virtual synchronous motor terminal voltage reference phasor U is obtained according to the electromagnetic equations. After voltage-current dual closed-loop tracking control and pulse width modulation, the switching control signal of the interface converter is finally obtained.

[0103] in, , , , , , Modulated wave ,Voltage and current The d-axis and q-axis components; both voltage and current loops use proportional-integral (PI) control, with transfer functions respectively. , .

[0104] In the above embodiments, by generating the target voltage vector corresponding to the interface converter based on the target frequency, target phase angle and target voltage amplitude, and by generating the control quantity corresponding to the interface converter step by step based on the target voltage reference value, target current reference value and control voltage, the interface converter can dynamically adjust the AC output voltage and output current according to the target output state, thereby improving the output control accuracy of the interface converter and the stability of system operation.

[0105] In one embodiment, the method further includes: generating a corresponding pulse width modulation control signal based on the control quantity; and controlling the power switching device in the interface converter to turn on or off based on the pulse width modulation control signal, so as to adjust the AC output voltage and AC output current of the interface converter.

[0106] In this embodiment, the control quantity is essentially used to characterize the current required output regulation state of the interface converter. Then, the interface converter generates a corresponding pulse width modulation (PWM) control signal based on the control quantity, and controls the power switching devices in the interface converter to turn on or off based on the PWM control signal, thereby changing the corresponding output voltage and output current state of the interface converter, so that the actual output state of the interface converter gradually approaches the target output state.

[0107] In the above manner, the control requirements corresponding to the target frequency, target phase angle, target voltage amplitude, and target harmonic components obtained above can be converted into a switching control process that can be executed by the interface converter, thereby realizing AC / DC side power regulation and AC side harmonic compensation.

[0108] In one exemplary embodiment, combined with Figure 4 as well as Figure 5 , Figure 4 This is a control block diagram of a power distribution network control method in an exemplary embodiment; Figure 5 This is a schematic diagram of the interface converter in one embodiment.

[0109] like Figure 4 As shown, firstly, the DC bus voltage, the AC side voltage of the interface converter, and the AC side current of the interface converter are obtained. Then, based on the interface converter VSG (Virtual Synchronous Generator) control algorithm, the target frequency, target phase angle, and target voltage amplitude corresponding to the output AC voltage of the interface converter are calculated. The specific calculation process can be referred to the relevant steps in the above embodiment, and will not be repeated here. Afterwards, the corresponding target voltage vector is generated based on the target frequency, target phase angle, and target voltage amplitude, and the target voltage vector is input into the voltage and current dual closed-loop control module.

[0110] Simultaneously, a harmonic current detection module based on FBD (Fryze-Buchholz-Depenbrock, FBD power theory) power theory acquires the AC bus current and calculates the corresponding target harmonic components based on the AC bus current. The process of calculating the target harmonic components can refer to the process in the above embodiment, and will not be repeated here. Then, the target harmonic components are input to the voltage-current dual closed-loop control module to adjust the output state of the interface converter in accordance with the harmonic compensation requirements corresponding to the target harmonic components.

[0111] Subsequently, the voltage and current dual closed-loop control module calculates the control quantity corresponding to the interface converter based on the target voltage vector and the target harmonic component, and generates the corresponding pulse width modulation control signal according to the control quantity through the pulse width modulation module to control the power switching device in the interface converter to turn on or off, thereby adjusting the AC output voltage and AC output current of the interface converter to achieve AC / DC side power regulation and AC side harmonic compensation.

[0112] In the above embodiments, the target voltage vector corresponding to the AC output voltage of the interface converter is generated by the VSG control algorithm of the interface converter, and the voltage and current are controlled by dual closed-loop control based on the target harmonic component obtained by FBD power theory. This enables the interface converter to dynamically adjust the AC output voltage and AC output current according to the AC and DC side operating status, thereby improving the stability of AC and DC side power regulation. At the same time, by combining the target harmonic component for output regulation, the AC side harmonic current can be compensated, thereby improving the AC side power quality.

[0113] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0114] Based on the same inventive concept, this application also provides a distribution network control device for implementing the distribution network control method described above. The solution provided by this device is similar to the implementation scheme described in the above method; therefore, the specific limitations in one or more distribution network control device embodiments provided below can be found in the limitations of the distribution network control method described above, and will not be repeated here.

[0115] In one exemplary embodiment, such as Figure 6 As shown, a power distribution network control device is provided, comprising: an acquisition module 100, a first calculation module 200, a second calculation module 300, a harmonic determination module 400, and a control module 500, wherein:

[0116] The acquisition module 100 is used to acquire the operating data corresponding to the interface converter. The operating data includes DC bus voltage, AC side voltage, AC side current and AC bus current.

[0117] The first calculation module 200 is used to establish a dynamic power balance relationship between the AC side and the DC side based on the DC bus voltage, AC side voltage and AC side current, and to calculate the target frequency and target phase angle corresponding to the output AC voltage of the interface converter based on the dynamic power balance relationship.

[0118] The second calculation module 300 is used to obtain the target value of reactive power and the actual reactive power, and to calculate the target voltage amplitude corresponding to the output AC voltage of the interface converter based on the deviation between the target value of reactive power and the actual reactive power.

[0119] The harmonic determination module 400 is used to decompose the AC bus current based on the AC side voltage, AC side current and AC bus current to obtain the target harmonic component corresponding to the AC bus current; the target harmonic component is the harmonic current component in the AC bus current.

[0120] The control module 500 is used to calculate the control quantity of the interface converter based on the target frequency, target phase angle, target voltage amplitude and target harmonic components; the control quantity is used to control the interface converter to perform AC / DC side power regulation and harmonic compensation.

[0121] In one embodiment, the first computing module 200 includes:

[0122] The angular frequency calculation unit is used to calculate the actual angular frequency of the AC side based on the AC side voltage and AC side current.

[0123] The deviation calculation unit is used to calculate the DC side voltage deviation based on the DC bus voltage.

[0124] The relationship establishment unit is used to establish a dynamic power balance relationship based on the AC frequency inertia term corresponding to the actual angular frequency of the AC side, the AC droop control term corresponding to the AC frequency deviation, the DC voltage inertia term corresponding to the DC voltage deviation, and the DC droop control term.

[0125] In one embodiment, the first computing module 200 includes:

[0126] The frequency calculation unit is used to calculate the target frequency corresponding to the output AC voltage of the interface converter based on the dynamic power balance relationship.

[0127] The phase angle calculation unit is used to perform integral calculations on the angular frequency change process corresponding to the target frequency to obtain the target phase angle.

[0128] In one embodiment, the harmonic determination module 400 includes:

[0129] The power calculation unit is used to calculate the instantaneous active power and instantaneous reactive power on the AC side based on the AC side voltage and AC side current.

[0130] The component mapping unit is used to establish a power component mapping relationship based on the instantaneous active power, instantaneous reactive power, AC voltage, and AC current on the AC side, and to calculate the fundamental active current component and fundamental reactive current component in the AC bus current based on the power component mapping relationship; the power component mapping relationship is used to characterize the correspondence between AC voltage, AC current, and AC power.

[0131] The harmonic separation unit is used to separate the fundamental active current component and the fundamental reactive current component from the AC bus current to obtain the target harmonic component corresponding to the AC bus current.

[0132] In one embodiment, the control module 500 includes:

[0133] The voltage calculation unit is used to generate a target voltage vector corresponding to the output AC voltage of the interface converter based on the target frequency, target phase angle and target voltage amplitude, and convert the target voltage vector into a target voltage reference value in a rotating coordinate system.

[0134] The current calculation unit is used to calculate the target current reference value based on the target voltage reference value and the actual output voltage of the interface converter.

[0135] The control voltage calculation unit is used to calculate the control voltage corresponding to the interface converter based on the target current reference value, the target harmonic component, and the actual output current of the interface converter.

[0136] The control quantity generation unit is used to generate control quantities based on the control voltage.

[0137] In one embodiment, the above-described apparatus further includes a signal control module, which comprises:

[0138] The signal generation unit is used to generate corresponding pulse width modulation control signals based on the control quantity.

[0139] The converter control unit is used to control the power switching devices in the interface converter to turn on or off based on the pulse width modulation control signal, so as to adjust the corresponding AC output voltage and AC output current of the interface converter.

[0140] Each module in the aforementioned power distribution network control device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of a computer device in hardware form or independent of it, or stored in the memory of a computer device in software form, so that the processor can call and execute the operations corresponding to each module.

[0141] In one exemplary embodiment, a computer device is provided, which may be a server, and its internal structure diagram may be as follows: Figure 7 As shown, this computer device includes a processor, memory, input / output interfaces (I / O), and a communication interface. The processor, memory, and I / O interfaces are connected via a system bus, and the communication interface is also connected to the system bus via the I / O interfaces. The processor provides computational and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and a database. The internal memory provides the environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The database stores runtime data. The I / O interfaces are used for exchanging information between the processor and external devices. The communication interface is used for communication with external terminals via a network connection. When the computer program is executed by the processor, it implements a power distribution network control method.

[0142] Those skilled in the art will understand that Figure 7 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0143] In one exemplary embodiment, a computer device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps of the method in any of the above embodiments.

[0144] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the steps of the method in any of the above embodiments.

[0145] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, represents the steps of the method in any of the above embodiments.

[0146] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, artificial intelligence (AI) processors, etc., and are not limited to these.

[0147] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0148] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A power distribution network control method, characterized in that, The method, applied to an interface converter connected to both a DC power grid and an AC power grid, includes: Obtain the operating data corresponding to the interface converter, including DC bus voltage, AC side voltage, AC side current and AC bus current; Based on the DC bus voltage, the AC side voltage, and the AC side current, a dynamic power balance relationship between the AC side and the DC side is established, and the target frequency and target phase angle corresponding to the output AC voltage of the interface converter are calculated based on the dynamic power balance relationship. Obtain the target reactive power value and the actual reactive power, and calculate the target voltage amplitude corresponding to the output AC voltage of the interface converter based on the deviation between the target reactive power value and the actual reactive power. Based on the AC side voltage, the AC side current, and the AC bus current, the AC bus current is decomposed to obtain the target harmonic component corresponding to the AC bus current; the target harmonic component is the harmonic current component in the AC bus current. Based on the target frequency, the target phase angle, the target voltage amplitude, and the target harmonic components, the control quantity of the interface converter is calculated; the control quantity is used to control the interface converter to perform AC / DC side power regulation and harmonic compensation.

2. The method according to claim 1, characterized in that, The process of establishing a dynamic power balance relationship between the AC side and the DC side based on the DC bus voltage, the AC side voltage, and the AC side current includes: Calculate the actual angular frequency of the AC side based on the AC side voltage and the AC side current; Calculate the DC-side voltage deviation based on the DC bus voltage; The dynamic power balance relationship is established based on the AC frequency inertia term corresponding to the actual angular frequency on the AC side, the AC droop control term corresponding to the AC frequency deviation, the DC voltage inertia term corresponding to the DC voltage deviation on the DC side, and the DC droop control term.

3. The method according to claim 1, characterized in that, The calculation of the target frequency and target phase angle corresponding to the output AC voltage of the interface converter based on the dynamic power balance relationship includes: The target frequency corresponding to the output AC voltage of the interface converter is calculated based on the dynamic power balance relationship. The target phase angle is obtained by integrating the angular frequency change process corresponding to the target frequency.

4. The method according to claim 1, characterized in that, The step of decomposing the AC bus current based on the AC side voltage, the AC side current, and the AC bus current to obtain the target harmonic component corresponding to the AC bus current includes: Based on the AC side voltage and the AC side current, calculate the instantaneous active power and instantaneous reactive power on the AC side; Based on the instantaneous active power, instantaneous reactive power, AC voltage, and AC current on the AC side, a power component mapping relationship is established, and the fundamental active current component and fundamental reactive current component in the AC bus current are calculated based on the power component mapping relationship; the power component mapping relationship is used to characterize the correspondence between AC voltage, AC current, and AC power. The fundamental active current component and the fundamental reactive current component are separated from the AC bus current to obtain the target harmonic component corresponding to the AC bus current.

5. The method according to claim 1, characterized in that, The calculation of the control quantity of the interface converter based on the target frequency, the target phase angle, the target voltage amplitude, and the target harmonic components includes: Based on the target frequency, the target phase angle, and the target voltage amplitude, a target voltage vector corresponding to the output AC voltage of the interface converter is generated, and the target voltage vector is converted into a target voltage reference value in a rotating coordinate system. Calculate the target current reference value based on the target voltage reference value and the actual output voltage corresponding to the interface converter; Calculate the control voltage corresponding to the interface converter based on the target current reference value, the target harmonic component, and the actual output current of the interface converter. The control quantity is generated based on the control voltage.

6. The method according to claim 1, characterized in that, The method further includes: Generate a corresponding pulse width modulation control signal based on the control quantity; The power switching devices in the interface converter are turned on or off based on the pulse width modulation control signal, so as to adjust the corresponding AC output voltage and AC output current of the interface converter.

7. A power distribution network control device, characterized in that, Applied to an interface converter; the device includes: The acquisition module is used to acquire the operating data corresponding to the interface converter, including DC bus voltage, AC side voltage, AC side current and AC bus current. The first calculation module is used to establish a dynamic power balance relationship between the AC side and the DC side based on the DC bus voltage, the AC side voltage and the AC side current, and to calculate the target frequency and target phase angle corresponding to the output AC voltage of the interface converter based on the dynamic power balance relationship. The second calculation module is used to obtain the target value of reactive power and the actual reactive power, and to calculate the target voltage amplitude corresponding to the output AC voltage of the interface converter based on the deviation between the target value of reactive power and the actual reactive power. The harmonic determination module is used to decompose the AC bus current based on the AC side voltage, the AC side current, and the AC bus current to obtain the target harmonic component corresponding to the AC bus current; the target harmonic component is the harmonic current component in the AC bus current; The control module is used to calculate the control quantity of the interface converter based on the target frequency, the target phase angle, the target voltage amplitude, and the target harmonic components; the control quantity is used to control the interface converter to perform AC / DC side power regulation and harmonic compensation.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 6.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 6.

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