A control method, device and equipment for comprehensive regulation of voltage and current of a substation and a storage medium

Abstract

The application discloses a substation voltage and current comprehensive regulation control method and device, equipment and storage medium, relates to the power grid technical field, and the method comprises the following steps: obtaining the real-time current signal of the transformer side and the output voltage signal of the rear-end inverter; obtaining the transformer side fundamental frequency current signal according to the real-time current signal; obtaining the reference current according to the difference between the transformer side fundamental frequency current signal and the real-time current signal; generating the first modulation signal of the front-end rectifier according to the reference current and the predictive control coefficient; generating the corresponding reverse harmonic compensation signal according to the output voltage signal; generating the second modulation signal of the rear-end inverter according to the reverse harmonic compensation signal; and controlling the front-end rectifier and the rear-end inverter to work cooperatively according to the first modulation signal and the second modulation signal. The method can cooperatively regulate the voltage amplitude or current harmonic of the substation output.

Description

Technical Field

[0001] This application relates to the field of power grid technology, and in particular to a control method, device, equipment and storage medium for integrated voltage and current regulation of substations. Background Technology

[0002] With the continuous expansion of my country's power grid and the increasing complexity of its load structure, substations at all voltage levels face severe power quality problems. The power grid contains a large number of industrial inductive loads, distributed single-phase loads, and power electronic nonlinear loads. These loads not only lead to a decrease in the system power factor and reduced power supply efficiency, but also inject a large amount of harmonics and negative sequence currents into the grid, seriously threatening the safe, stable, and high-quality operation of the power grid. Therefore, effective comprehensive power quality control of substations, especially on the 10kV side, has become a key technical requirement for improving the operational level of the power grid.

[0003] Existing technical solutions all adopt a parallel structure, which only adjusts a specific power quality parameter (such as voltage amplitude or current harmonics) output by the substation, and lacks a mechanism to coordinate and control the two in a unified manner. Summary of the Invention

[0004] This application provides a control method, device, equipment, and storage medium for integrated voltage and current regulation of a substation, which can coordinately regulate the voltage amplitude or current harmonics output by the substation.

[0005] To achieve the above objectives, this application adopts the following technical solution: Firstly, this application provides a control method for integrated voltage and current regulation in a substation, including: Acquire the real-time current signal on the transformer side and the output voltage signal of the downstream inverter; Based on the real-time current signal, the transformer-side fundamental frequency current signal is obtained; The reference current is obtained based on the difference between the transformer-side fundamental frequency current signal and the real-time current signal; Based on the reference current and the predicted control coefficient, a first modulation signal for the front-end rectifier is generated; Based on the output voltage signal, a corresponding reverse harmonic compensation signal is generated; Based on the reverse harmonic compensation signal, a second modulation signal for the back-end inverter is generated; Based on the first modulation signal and the second modulation signal, the front-end rectifier and the back-end inverter are controlled to work together.

[0006] Optionally, the predictive control coefficients are obtained in the following manner: The predictive control coefficients are obtained based on the filter inductance value of the front-end rectifier and the sampling period of the controller.

[0007] Optionally, obtaining the transformer-side fundamental frequency current signal based on the real-time current signal includes: Discrete sampling is performed on the real-time current signal; In the discrete domain, a high-frequency equivalent method is used, and the fundamental frequency current signal on the transformer side is separated by low-pass filtering or fundamental frequency extraction algorithm.

[0008] Optionally, generating a corresponding reverse harmonic compensation signal based on the output voltage signal includes: Harmonic analysis is performed on the output voltage signal to extract harmonic voltage components; The harmonic voltage components are inverted to generate the reverse harmonic compensation signal.

[0009] Optionally, the method further includes: Calculate the required reactive power compensation capacity of the front-end rectifier in real time; The upper limit of the amplitude of the second modulation signal of the back-end inverter is adjusted according to the reactive power compensation capacity and the preset rated capacity of the device.

[0010] Optionally, adjusting the upper limit of the amplitude of the second modulation signal of the back-end inverter based on the reactive power compensation capacity and the preset rated capacity of the device includes: The upper limit of the amplitude of the second modulation signal of the back-end inverter is adjusted according to the ratio of the reactive power compensation capacity to the preset rated capacity of the device.

[0011] Optionally, the front-end rectifier and the back-end inverter belong to multiple sets of parallel AC-DC-AC conversion units.

[0012] Secondly, this application provides a control device for integrated voltage and current regulation in a substation, comprising: The acquisition module is used to acquire the real-time current signal on the transformer side and the output voltage signal of the downstream inverter; The data processing module is used to obtain the transformer-side fundamental frequency current signal based on the real-time current signal; obtain the reference current based on the difference between the transformer-side fundamental frequency current signal and the real-time current signal; generate the first modulation signal of the front-end rectifier based on the reference current and the predictive control coefficient; generate the corresponding reverse harmonic compensation signal based on the output voltage signal; and generate the second modulation signal of the back-end inverter based on the reverse harmonic compensation signal. The control module is used to control the front-end rectifier and the back-end inverter to work together according to the first modulation signal and the second modulation signal, respectively.

[0013] Thirdly, this application provides a computing device, including a memory and a processor; The memory stores one or more computer programs, the one or more computer programs including instructions; when the instructions are executed by the processor, the computing device performs the method as described in any one of the first aspects.

[0014] Fourthly, this application provides a computer-readable storage medium for storing a computer program for performing the method as described in any one of the first aspects.

[0015] As can be seen from the above technical solution, this application has at least the following beneficial effects: In this application, by real-time acquisition of transformer-side current and inverter output voltage signals, on the one hand, a reference current is generated based on the difference between the base frequency current and the real-time current. Combined with predictive control coefficients, the front-end rectifier is regulated to achieve dynamic reactive power compensation and effective suppression of harmonics and negative sequence currents, solving the problems of low system power factor and current distortion. On the other hand, through harmonic analysis and reverse compensation signal generation, inverter output voltage distortion is specifically addressed, ensuring voltage sinusoidality and stability. This breaks through the limitations of existing technologies that can only adjust voltage or current parameters individually, achieving coordinated management of voltage and current and multi-dimensional improvement of power quality.

[0016] Furthermore, by employing discrete sampling, high-frequency equivalent, and fundamental frequency extraction algorithms, the fundamental frequency current signal can be quickly separated and harmonic components extracted, providing reliable data support for the generation of control commands. The predictive control coefficient is scientifically set based on the rectifier filter inductance and sampling period, and the reverse harmonic compensation signal directly cancels out the root cause of voltage distortion. Combined with the redundant execution capability of multiple parallel AC-DC-AC conversion units, the control commands are quickly implemented, effectively improving the response speed to dynamic load changes and ensuring that voltage and current parameters remain stable within a reasonable range.

[0017] Furthermore, by calculating the reactive power compensation capacity in real time and dynamically adjusting the upper limit of the inverter modulation signal amplitude, the rated capacity of the device is reasonably allocated, avoiding the risk of overload operation and extending the service life of the equipment. The structure of multiple parallel conversion units has redundancy capabilities, which can effectively cope with single unit failure scenarios and ensure the continuous effectiveness of the control function. At the same time, this method does not require changing the existing substation main wiring structure, is suitable for complex power grid environments with a large number of inductive, single-phase and nonlinear loads, and has a wide range of applications and high deployment flexibility.

[0018] It should be understood that the descriptions of technical features, technical solutions, beneficial effects, or similar language in this application do not imply that all features and advantages can be achieved in any single embodiment. Rather, it is understood that the description of a feature or beneficial effect means that a specific technical feature, technical solution, or beneficial effect is included in at least one embodiment. Therefore, the descriptions of technical features, technical solutions, or beneficial effects in this specification do not necessarily refer to the same embodiment. Furthermore, the technical features, technical solutions, and beneficial effects described in this embodiment can be combined in any suitable manner. Those skilled in the art will understand that embodiments can be implemented without one or more specific technical features, technical solutions, or beneficial effects of a particular embodiment. In other embodiments, additional technical features and beneficial effects may be identified in specific embodiments that do not embody all embodiments. Attached Figure Description

[0019] Figure 1 A flowchart of a control method for integrated voltage and current regulation in a substation, provided as an embodiment of this application; Figure 2 Schematic diagram of a 10kV voltage and current integrated control device; Figure 3 A schematic diagram of a control device for integrated voltage and current regulation in a substation, provided in an embodiment of this application; Figure 4 This is a schematic diagram of a computing device provided in an embodiment of this application. Detailed Implementation

[0020] The terms "first," "second," and "third," etc., used in this application specification and accompanying drawings are used to distinguish different objects, not to limit a specific order.

[0021] In the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design that is described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design. Specifically, the use of the terms "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0022] With the continuous expansion of my country's power grid and the increasing complexity of its electricity load structure, the 10kV side of substations faces the prominent problem of comprehensive deterioration of power quality. Specifically, this manifests as low system power factor leading to insufficient power supply efficiency, excessive grid harmonic content causing power quality distortion, the presence of negative sequence current causing three-phase operation imbalance, and frequent voltage fluctuations and distortions affecting the stability of power supply to the load side. Existing technologies, lacking a unified and coordinated control mechanism for voltage and current parameters, can only address certain types of problems individually and cannot achieve comprehensive and effective power quality optimization.

[0023] These problems mainly stem from the dual limitations of load characteristics and existing technologies: on the one hand, a large number of industrial inductive loads in the power grid consume reactive power, unbalanced access of distributed single-phase loads generates negative sequence currents, and nonlinear loads such as power electronic loads inject harmonics. The superposition of these three types of loads exacerbates the complexity of power quality problems. On the other hand, the parallel structure control scheme currently used in substations has inherent defects. Parallel capacitors cannot be continuously adjusted and have limited functions. Parallel static var generators (SVG) and static synchronous compensators (STATCOM) have limited ability to suppress harmonics and negative sequence currents. Various devices lack a coordinated control mechanism, making it difficult to fundamentally solve the problem of comprehensive deterioration of power quality.

[0024] In view of this, embodiments of this application provide a control method for comprehensive voltage and current regulation in substations, which can be executed by a processing device. This processing device can be a terminal or a server. Terminals include, but are not limited to, smartphones, tablets, laptops, personal digital assistants, or smart wearable devices. Servers can be cloud servers, such as central servers in a central cloud computing cluster or edge servers in an edge cloud computing cluster. Alternatively, servers can be located in a local data center. A local data center refers to a data center directly controlled by the user.

[0025] To address the limitations of existing parallel control schemes (such as parallel capacitors, parallel static var generators (SVG), and static synchronous compensators (STATCOM)) which are functionally singular and lack a coordinated voltage and current control mechanism, thus failing to comprehensively solve the comprehensive power quality problems of low power factor, excessive harmonics, negative sequence current, and voltage distortion on the 10kV side of substations, this application adopts a different approach. It acquires two key signals in real time: transformer-side current and inverter output voltage. Specifically, it designs control logic to address reactive power, harmonics, and negative sequence issues at the current level, and voltage distortion issues at the voltage level. At the front-end rectifier side, a reference current is constructed based on the difference between the base frequency current and the real-time current, and precise current control is achieved by combining predictive control coefficients. At the back-end inverter side, a reverse compensation signal is generated through harmonic analysis to specifically suppress voltage distortion. Simultaneously, relying on multiple sets of parallel AC-DC-AC conversion units, a coordinated control mechanism and capacity adaptation logic are established for both sides, ultimately achieving unified and comprehensive management of voltage and current. This fills the functional limitations of existing technologies and comprehensively improves the power quality and operational stability of substations.

[0026] To make the technical solution of this application clearer and easier to understand, the control method for integrated voltage and current regulation of a substation provided in the embodiments of this application will be described below with reference to the accompanying drawings. Figure 1 As shown, this figure is a flowchart of a control method for integrated voltage and current regulation in a substation, provided in an embodiment of this application. The method includes: S201, The processing equipment acquires the real-time current signal on the transformer side and the output voltage signal of the downstream inverter.

[0027] The transformer side specifically refers to the output terminal of the 10kV transformer in a substation (the side connected to the control device). The current and voltage signals on this side directly reflect the power quality status of the power grid and are the data source for the design of control strategies.

[0028] Real-time current signals are dynamic change data of the three-phase current on the transformer side (including components such as fundamental frequency current, harmonic current, and negative sequence current) collected in real time by current sensors, which can truly reflect the current operating status of the power grid.

[0029] The back-end inverter is the inverter stage in a multi-group parallel AC-DC-AC conversion unit. It is responsible for converting the stable DC power output from the rectifier into AC power with adjustable frequency and amplitude. Its output voltage directly affects the power supply quality on the load side and is the execution unit for voltage regulation.

[0030] The output voltage signal is the dynamic voltage data of the inverter output terminal collected in real time by a voltage sensor (which may contain harmonic voltage components and pose a risk of voltage distortion). It serves as the basis for assessing voltage quality and formulating control strategies.

[0031] Specifically, the processing equipment initiates a data acquisition command and simultaneously acquires two types of real-time signals through current sensors deployed at the transformer output end and voltage sensors deployed at the back-end inverter output end: one is the dynamic current data (real-time current signal) on the transformer side, which includes interference information such as reactive current, harmonic current, and negative sequence current generated by inductive loads and nonlinear loads in the power grid; the other is the dynamic voltage data (output voltage signal) of the back-end inverter, which reflects the actual state of the power supply voltage on the load side and may have voltage distortion problems caused by current distortion or load fluctuations.

[0032] The processing equipment collects these two types of signals to provide complete and real-time raw data support for subsequent control steps such as separating the fundamental frequency current, calculating the reference current, extracting harmonic components, and generating modulation signals. This ensures that the control strategy can accurately match the current power quality status of the power grid and achieve the goal of dynamic control based on actual operating conditions.

[0033] S202. The processing equipment obtains the transformer-side fundamental frequency current signal based on the real-time current signal.

[0034] The fundamental frequency current signal refers to the current component in the real-time current signal whose frequency is consistent with the fundamental frequency of the power grid. It is the current component that ensures the normal power supply of the power grid and maintains the stability of the power factor. It is also the target reference signal for subsequent calculation of reference current and realization of current regulation.

[0035] Specifically, the processing equipment performs discrete sampling of the real-time current signal; in the discrete domain, a high-frequency equivalent method is used to separate the transformer-side fundamental frequency current signal through low-pass filtering or fundamental frequency extraction algorithm.

[0036] The specific process is as follows: First, the processing equipment performs periodic discrete sampling on the continuously changing real-time current signal, converting the originally continuously changing analog signal into a discrete digital signal. This adapts to the operational logic of the digital controller, laying the foundation for subsequent data processing. Then, in the discrete domain, the high-frequency equivalence assumption is applied. Since the controller's sampling frequency is much higher than the grid's fundamental frequency, the minute fluctuations in the fundamental frequency current over a short period can be ignored. This assumption effectively simplifies the computational process. Based on this, a low-pass filtering algorithm is used to filter out harmonic components with frequencies higher than the fundamental frequency, or a fundamental frequency extraction algorithm is used to directly separate the 50Hz fundamental frequency component. Both algorithms can eliminate interference components such as harmonic currents and negative sequence currents contained in the real-time current signal, ultimately obtaining a clean transformer-side fundamental frequency current signal. This provides an accurate target benchmark for subsequent reference current calculations and rectifier-side control operations.

[0037] S203. The processing equipment obtains the reference current based on the difference between the transformer-side fundamental frequency current signal and the real-time current signal.

[0038] The reference current is the target compensation current set by the processing equipment to achieve current regulation. Its value corresponds to the interference components (such as harmonics, negative sequence current, etc.) that need to be canceled in the real-time current, and it is the basis for generating the rectifier regulation signal.

[0039] The processing equipment first separates the pure fundamental frequency current from the real-time current using an algorithm, and then calculates the difference between the fundamental frequency current and the real-time current containing interference. This difference is the reference current, which physically represents the interference current component that needs to be offset by rectifier adjustment. This step transforms the power quality problem into a quantifiable control target, providing a clear compensation direction for subsequent rectifier-side control.

[0040] The formula for calculating the reference current is:

[0041] in, Indicates the first Reference current at time [time] Indicates the first The transformer-side fundamental frequency current signal at a given time (the pure fundamental frequency component that has been separated). Indicates the first The real-time current signal at any given time (the original sampled current including interference components).

[0042] S204. The processing equipment generates the first modulation signal for the front-end rectifier based on the reference current and the predicted control coefficient.

[0043] The predictive control coefficients are obtained based on the filter inductance value of the front-end rectifier and the sampling period of the controller. These predictive control coefficients determine the response speed and stability of the current regulation and are parameters of the predictive current control strategy. The expression for calculating the predictive control coefficients is:

[0044] in, Represents the predictive control coefficient. This indicates the filter inductance value of the front-end rectifier. This indicates the sampling period of the controller.

[0045] The first modulation signal is the control command signal output by the processing equipment to the front-end rectifier. It is a PWM modulation wave signal. The rectifier can adjust its own switching state according to this signal, thereby changing the output voltage / current and realizing the regulation of the transformer side current.

[0046] The processing equipment uses the reference current requiring compensation as the control target, and combines it with the predictive control coefficients determined by hardware parameters to calculate the control signal (first modulation signal) of the front-end rectifier through a predictive current control algorithm. This step transforms the reference current, the control target, into an executable switching control command for the rectifier, enabling the rectifier to accurately adjust the current and cancel out interference components (harmonics, negative sequence, etc.) in the real-time current.

[0047] The voltage expression corresponding to the generation of the first modulation signal is:

[0048] in, Indicates the first At the sampling time, the port voltage of the current on the front-end rectifier is adjusted (this voltage corresponds to the parameters of the first modulation signal and is used to drive the rectifier switching action). Indicates the first Real-time voltage signal on the transformer side at the sampling time; Indicates the first Reference current at any given time.

[0049] This voltage value will be converted into a corresponding PWM modulation signal, namely the first modulation signal, which is used to control the switching action of the front-end rectifier.

[0050] The discrete-domain expression is discretized from the voltage continuous-domain equation. The voltage continuous-domain equation is:

[0051] in, This indicates the port voltage of the rectifier at which the regulating current is applied; Indicates the voltage on the transformer side; Indicates the transformer-side regulating current. Indicates the rectifier filter inductance. This indicates the rate of change of the regulating current.

[0052] The derivation process is as follows: In digital control, the sampling period is used. Discrete sampling is performed on a continuous signal, and the difference between adjacent sampling times is used to approximate the continuous rate of change: Take time (No. (Sampling time), corresponding to continuous signal , , ; Take time (No. (Sampling time), corresponding to continuous signal ; Continuous rate of change Approximation using discrete differences: .

[0053] Substituting the above approximation into the continuous domain equation, we obtain the discrete domain expression:

[0054] Combined with predictive control coefficients and the high-frequency equivalence assumption ( (Since the sampling frequency is much higher than the power grid base frequency, the current change is negligible in a short time), further simplified to:

[0055] S205. The processing equipment generates a corresponding reverse harmonic compensation signal based on the output voltage signal.

[0056] Specifically, the processing equipment performs harmonic analysis on the output voltage signal and extracts the harmonic voltage components; it then inverts the harmonic voltage components to generate a reverse harmonic compensation signal.

[0057] Harmonic analysis is a signal processing method used to identify and separate voltage components (i.e., harmonic voltages) whose frequencies are integer multiples of the grid fundamental frequency (50Hz) from the output voltage signal. Algorithms include Fast Fourier Transform (FFT).

[0058] Harmonic voltage components are voltage components in the output voltage signal other than the fundamental frequency (50Hz) (such as the 3rd, 5th, and 7th harmonics). They are interference components that cause voltage distortion and affect power supply quality.

[0059] The reverse harmonic compensation signal is obtained by inverting the phase of the extracted harmonic voltage components. Its phase is opposite to that of the harmonic voltage components and its amplitude is matched. It is used to cancel the harmonics in the output voltage and restore the voltage to sinusoidal.

[0060] The processing equipment first performs harmonic analysis on the inverter's output voltage signal, separating out the harmonic voltage components that cause voltage distortion. Then, the harmonic voltage component The inverse signal is obtained by inverting the signal. This indicates the reverse harmonic compensation signal.

[0061] Through this operation, the reverse harmonic compensation signal can be superimposed and canceled by the original harmonic voltage component, ultimately eliminating the distortion component in the output voltage and ensuring a stable sinusoidal voltage on the load side.

[0062] S206. The processing equipment generates a second modulation signal for the back-end inverter based on the reverse harmonic compensation signal.

[0063] The second modulation signal is the control command (modulation wave signal) output by the processing equipment to the back-end inverter. The inverter can adjust the switching state according to this signal, thereby outputting a compensation voltage to eliminate harmonics and ensure the voltage quality on the load side.

[0064] The processing equipment uses the reverse harmonic compensation signal, which is used to cancel harmonics, as its core. It combines this signal with the original modulation signal of the inverter to generate control commands (i.e., the second modulation signal) for the back-end inverter. This step transforms the need to eliminate voltage distortion into switching operation commands that the inverter can execute, enabling the inverter to output the corresponding compensation voltage and ultimately cancel the harmonic components in the output voltage.

[0065] The reverse harmonic compensation signal is combined with the original modulating wave to obtain the modulating wave corresponding to the second modulating signal:

[0066] in, This indicates the modulated wave corresponding to the second modulating signal. This indicates the reverse harmonic compensation signal.

[0067] In the discrete domain, the first The modulated wave corresponding to the second modulated signal at the sampling time:

[0068] in, Indicates the first The modulated wave corresponding to the second modulated signal at the sampling time. Indicates the first The original modulation wave signal of the inverter at the sampling time. Indicates the first Harmonic voltage components in the inverter output voltage at the sampling time It represents the ratio coefficient between the inverter's modulated wave and the actual output voltage.

[0069] The second modulation signal is the inverter's control command, which is transmitted through... This is converted into the actual output voltage; at the same time, the second modulation signal incorporates the reverse harmonic compensation signal, so that the final output voltage eliminates harmonic distortion and retains only the stable fundamental frequency voltage.

[0070] S207. The processing equipment controls the front-end rectifier and the back-end inverter to work together according to the first modulation signal and the second modulation signal, respectively.

[0071] The front-end rectifier and the back-end inverter consist of multiple parallel AC-DC-AC conversion units. An AC-DC-AC conversion unit is a typical circuit structure in power electronics, with a flow of AC → DC → AC. First, the rectifier converts the input AC power into DC power, and then the inverter converts the DC power back into the required AC power. The "multiple parallel units" here refers to multiple AC-DC-AC conversion units operating simultaneously in parallel.

[0072] The advantage of this structure is that it can increase the overall power capacity of the device (multiple groups working together can handle more electrical energy) and improve the reliability of the system (if one group fails, the other groups can continue to operate), thereby better realizing the comprehensive control of voltage and current.

[0073] in, Figure 2 This is a schematic diagram of a 10kV voltage and current integrated control device.

[0074] The processing equipment will send the two previously generated control commands (first modulation signal and second modulation signal) to the front-end rectifier and the back-end inverter, respectively: The first modulation signal given to the front-end rectifier is used to control the rectifier to regulate the current on the transformer side, cancel out the interference components such as harmonics and negative sequence in the real-time current, and ensure the current quality on the grid side. The second modulation signal is given to the back-end inverter to control the inverter to adjust the output voltage, cancel the harmonic components in the voltage, and ensure the voltage quality on the load side.

[0075] The purpose of their collaborative operation is to optimize the current on the grid side by using the front-end rectifier and optimize the voltage on the load side by using the back-end inverter, thereby achieving comprehensive regulation of voltage and current by the entire device and ensuring power quality on both the grid and load sides.

[0076] The method also includes: The processing equipment calculates the reactive power compensation capacity required by the front-end rectifier in real time; based on the reactive power compensation capacity and the preset rated capacity of the device, it adjusts the upper limit of the amplitude of the second modulation signal of the back-end inverter.

[0077] Reactive power compensation capacity is the amount of additional reactive power that the front-end rectifier needs to output to optimize the power quality on the grid side (such as improving the power factor). This part of the power will occupy the total capacity of the device.

[0078] The rated capacity of the device is the maximum total power that the entire device (multiple AC-DC-AC units) can output, which is the upper limit of the device's hardware capabilities.

[0079] Specifically, the processing equipment adjusts the upper limit of the amplitude of the second modulation signal of the back-end inverter based on the ratio of the reactive power compensation capacity to the preset rated capacity of the device.

[0080] The processing equipment calculates the reactive power compensation capacity currently required by the front-end rectifier in real time, and then, in conjunction with the rated capacity of the device, dynamically adjusts the upper limit of the amplitude of the second modulation signal of the back-end inverter: The larger the ratio of reactive power compensation capacity to rated capacity, the more capacity the front-end rectifier occupies, and the less available capacity is left for the back-end inverter. Therefore, the upper limit of the amplitude of the second modulation signal should be reduced (to avoid the inverter output power exceeding the remaining capacity). The smaller this ratio, the less capacity is occupied by the front end, the more available capacity the back-end inverter has, and the upper limit of the amplitude of the second modulation signal can be appropriately increased, allowing the inverter to output more power to meet load demands.

[0081] Simply put, this achieves power balance between the front and back ends by dynamically allocating the total capacity of the device, ensuring the reactive power compensation needs of the front-end rectifier while preventing the back-end inverter from exceeding the device's power limit.

[0082] Based on the above description, this application has the following beneficial effects: In this application, by real-time acquisition of transformer-side current and inverter output voltage signals, on the one hand, a reference current is generated based on the difference between the base frequency current and the real-time current. Combined with predictive control coefficients, the front-end rectifier is regulated to achieve dynamic reactive power compensation and effective suppression of harmonics and negative sequence currents, solving the problems of low system power factor and current distortion. On the other hand, through harmonic analysis and reverse compensation signal generation, inverter output voltage distortion is specifically addressed, ensuring voltage sinusoidality and stability. This breaks through the limitations of existing technologies that can only adjust voltage or current parameters individually, achieving coordinated management of voltage and current and multi-dimensional improvement of power quality.

[0083] Furthermore, by employing discrete sampling, high-frequency equivalent, and fundamental frequency extraction algorithms, the fundamental frequency current signal can be quickly separated and harmonic components extracted, providing reliable data support for the generation of control commands. The predictive control coefficient is scientifically set based on the rectifier filter inductance and sampling period, and the reverse harmonic compensation signal directly cancels out the root cause of voltage distortion. Combined with the redundant execution capability of multiple parallel AC-DC-AC conversion units, the control commands are quickly implemented, effectively improving the response speed to dynamic load changes and ensuring that voltage and current parameters remain stable within a reasonable range.

[0084] Furthermore, by calculating the reactive power compensation capacity in real time and dynamically adjusting the upper limit of the inverter modulation signal amplitude, the rated capacity of the device is reasonably allocated, avoiding the risk of overload operation and extending the service life of the equipment. The structure of multiple parallel conversion units has redundancy capabilities, which can effectively cope with single unit failure scenarios and ensure the continuous effectiveness of the control function. At the same time, this method does not require changing the existing substation main wiring structure, is suitable for complex power grid environments with a large number of inductive, single-phase and nonlinear loads, and has a wide range of applications and high deployment flexibility.

[0085] The above text combined Figure 1 The control method for integrated regulation of substation voltage and current provided in the embodiments of this application has been described in detail. The apparatus and equipment provided in the embodiments of this application will be described below with reference to the accompanying drawings.

[0086] like Figure 3 As shown in the figure, this is a schematic diagram of a control device for integrated voltage and current regulation in a substation according to an embodiment of this application. The device includes: The acquisition module 301 is used to acquire the real-time current signal on the transformer side and the output voltage signal of the downstream inverter; The data processing module 302 is used to obtain the transformer-side fundamental frequency current signal based on the real-time current signal; obtain a reference current based on the difference between the transformer-side fundamental frequency current signal and the real-time current signal; generate a first modulation signal for the front-end rectifier based on the reference current and the predictive control coefficient; generate a corresponding reverse harmonic compensation signal based on the output voltage signal; and generate a second modulation signal for the back-end inverter based on the reverse harmonic compensation signal. The control module 303 is used to control the front-end rectifier and the back-end inverter to work together according to the first modulation signal and the second modulation signal, respectively.

[0087] Optionally, the data processing module 302 is specifically used to obtain the predictive control coefficients based on the filter inductance value of the front-end rectifier and the sampling period of the controller.

[0088] Optionally, the data processing module 302 is specifically used to perform discrete sampling on the real-time current signal; In the discrete domain, a high-frequency equivalent method is used, and the fundamental frequency current signal on the transformer side is separated by low-pass filtering or fundamental frequency extraction algorithm.

[0089] Optionally, the data processing module 302 is specifically used to perform harmonic analysis on the output voltage signal and extract harmonic voltage components; The harmonic voltage components are inverted to generate the reverse harmonic compensation signal.

[0090] Optionally, the data processing module 302 is also used to calculate the reactive power compensation capacity required by the front-end rectifier in real time; The upper limit of the amplitude of the second modulation signal of the back-end inverter is adjusted according to the reactive power compensation capacity and the preset rated capacity of the device.

[0091] Optionally, the data processing module 302 is specifically used to adjust the upper limit of the amplitude of the second modulation signal of the back-end inverter according to the ratio of the reactive power compensation capacity to the preset rated capacity of the device.

[0092] The substation voltage and current integrated regulation control device according to the embodiments of this application can correspondingly execute the method described in the embodiments of this application, and the other operations and / or functions of each module / unit of the substation voltage and current integrated regulation control device are respectively for realizing Figure 1 For the sake of brevity, the corresponding processes of each method in the illustrated embodiments will not be described in detail here.

[0093] This application also provides a computing device. For example... Figure 4 As shown in the figure, this is a schematic diagram of a computing device provided in an embodiment of this application. The computing device 700 includes a bus 701, a processor 702, a communication interface 703, and a memory 704. The processor 702, the memory 704, and the communication interface 703 communicate with each other via the bus 701.

[0094] The 701 bus can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. Buses can be categorized as address buses, data buses, control buses, etc. For ease of representation, Figure 4 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0095] The processor 702 can be any one or more of the following processors: central processing unit (CPU), graphics processing unit (GPU), microprocessor (MP), or digital signal processor (DSP).

[0096] The communication interface 703 is used for communication with external devices.

[0097] Memory 704 may include volatile memory, such as random access memory (RAM). Memory 704 may also include non-volatile memory, such as read-only memory (ROM), flash memory, hard disk drive (HDD), or solid state drive (SSD).

[0098] The memory 704 stores executable code, and the processor 702 executes the executable code to perform the aforementioned control method for integrated voltage and current regulation of the substation.

[0099] Specifically, in achieving Figure 3 In the case of the illustrated embodiment, and Figure 3 When the modules or units of the substation voltage and current integrated control device described in the embodiment are implemented through software, the execution... Figure 3 The software or program code required for the functions of each module / unit can be partially or entirely stored in the memory 704. The processor 702 executes the program code corresponding to each unit stored in the memory 704 to execute the aforementioned control method for integrated voltage and current regulation of the substation.

[0100] This application also provides a computer-readable storage medium. The computer-readable storage medium can be any available medium capable of being stored by a computing device, or a data storage device such as a data center containing one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid-state drive). The computer-readable storage medium includes instructions that instruct the computing device to execute the aforementioned control method for integrated voltage and current regulation in substations.

[0101] This application also provides a computer program product comprising one or more computer instructions. When the computer instructions are loaded and executed on a computing device, all or part of the processes or functions described in this application are generated.

[0102] The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions may be transmitted from one website, computer, or data center to another website, computer, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line) or wireless (e.g., infrared, wireless, microwave, etc.) means.

[0103] When the computer program product is executed by a computer, the computer executes any one of the aforementioned control methods for integrated voltage and current regulation of substations. The computer program product can be a software installation package; when any of the aforementioned control methods for integrated voltage and current regulation of substations is required, the computer program product can be downloaded and executed on the computer.

[0104] The descriptions of the processes or structures corresponding to the above figures each have their own emphasis. For parts of a process or structure that are not described in detail, please refer to the relevant descriptions of other processes or structures.

[0105] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions within the technical scope disclosed in this application should be covered within the scope of protection of this application.

Claims

1. A control method for integrated voltage and current regulation in a substation, characterized in that, The method includes: Acquire the real-time current signal on the transformer side and the output voltage signal of the downstream inverter; Based on the real-time current signal, the transformer-side fundamental frequency current signal is obtained; The reference current is obtained based on the difference between the transformer-side fundamental frequency current signal and the real-time current signal; Based on the reference current and the predicted control coefficient, a first modulation signal for the front-end rectifier is generated; Based on the output voltage signal, a corresponding reverse harmonic compensation signal is generated; Based on the reverse harmonic compensation signal, a second modulation signal for the back-end inverter is generated; Based on the first modulation signal and the second modulation signal, the front-end rectifier and the back-end inverter are controlled to work together.

2. The method according to claim 1, characterized in that, The predictive control coefficients are obtained in the following way: The predictive control coefficients are obtained based on the filter inductance value of the front-end rectifier and the sampling period of the controller.

3. The method according to claim 1, characterized in that, The step of obtaining the transformer-side fundamental frequency current signal based on the real-time current signal includes: Discrete sampling is performed on the real-time current signal; In the discrete domain, a high-frequency equivalent method is used, and the fundamental frequency current signal on the transformer side is separated by low-pass filtering or fundamental frequency extraction algorithm.

4. The method according to claim 1, characterized in that, The step of generating a corresponding reverse harmonic compensation signal based on the output voltage signal includes: Harmonic analysis is performed on the output voltage signal to extract harmonic voltage components; The harmonic voltage components are inverted to generate the reverse harmonic compensation signal.

5. The method according to claim 1, characterized in that, The method further includes: Calculate the required reactive power compensation capacity of the front-end rectifier in real time; The upper limit of the amplitude of the second modulation signal of the back-end inverter is adjusted according to the reactive power compensation capacity and the preset rated capacity of the device.

6. The method according to claim 5, characterized in that, The step of adjusting the upper limit of the amplitude of the second modulation signal of the back-end inverter according to the reactive power compensation capacity and the preset rated capacity of the device includes: The upper limit of the amplitude of the second modulation signal of the back-end inverter is adjusted according to the ratio of the reactive power compensation capacity to the preset rated capacity of the device.

7. The control method according to claim 1, characterized in that, The front-end rectifier and the back-end inverter belong to multiple sets of parallel AC-DC-AC conversion units.

8. A control device for integrated voltage and current regulation in a substation, characterized in that, The device includes: The acquisition module is used to acquire the real-time current signal on the transformer side and the output voltage signal of the downstream inverter; The data processing module is used to obtain the transformer-side fundamental frequency current signal based on the real-time current signal; obtain the reference current based on the difference between the transformer-side fundamental frequency current signal and the real-time current signal; generate the first modulation signal of the front-end rectifier based on the reference current and the predictive control coefficient; generate the corresponding reverse harmonic compensation signal based on the output voltage signal; and generate the second modulation signal of the back-end inverter based on the reverse harmonic compensation signal. The control module is used to control the front-end rectifier and the back-end inverter to work together according to the first modulation signal and the second modulation signal, respectively.

9. A computing device, characterized in that, Including memory and processor; The memory stores one or more computer programs, the one or more computer programs including instructions; when the instructions are executed by the processor, the computing device performs the method as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium is used to store a computer program for performing the method as described in any one of claims 1 to 7.

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