Networking converter, oscillation energy dissipation controller, system, method, equipment and medium

Abstract

The invention provides a network construction type converter, an oscillation energy dissipation controller, a system, a method, equipment and a medium, and relates to the field of power conversion, and the oscillation energy dissipation controller comprises an oscillation energy calculation module, a parameter adaptive adjustment module, an oscillation energy dissipation controller switching module and an oscillation energy dissipation module. The oscillation energy calculation module is used for calculating the oscillation energy of the port of the network-forming converter to obtain an oscillation energy calculation result; the oscillation energy dissipation controller switching module is used for generating a controller switching signal according to the oscillation energy calculation result; the parameter adaptive adjustment module is used for generating key control parameters according to the oscillation energy calculation result; and the oscillation energy dissipation module is used for calculating an additional control signal based on the controller switching signal and the key control parameter, so that the current loop controller regulates and controls the oscillation energy dissipation characteristic of the port of the network-forming converter according to the additional control signal. The scheme has good oscillation energy dissipation capability and oscillation damping capability.

Description

Technical Field

[0001] This application relates to the field of power electronic conversion technology, specifically to a grid-type converter and an oscillation energy dissipation controller, system, method, device, and medium. Background Technology

[0002] With the rapid development of power electronics technology, distributed power sources, electric vehicle loads, and energy storage systems have entered a new stage of large-scale and widespread integration, forming a complex operational pattern of coordinated interaction between power sources, grids, loads, and energy storage. Power electronic converters, as key components for grid connection of these devices, tend to exhibit capacitive impedance and negative resistance near system harmonic frequencies due to their rapid control characteristics. This, coupled with the intermittency and volatility of renewable energy generation and electric vehicle loads, leads to high system risk and multi-dimensional stability challenges. Therefore, the concept of grid-forming (GFM) converter control has emerged. Based on AC-DC conversion, grid-forming converters can establish a stable AC bus voltage using the DC bus, possessing the external characteristics of a voltage source and simulating the external characteristics of a synchronous machine, providing crucial voltage and frequency support for weak power systems.

[0003] Currently, although grid-type converters in related technologies can provide voltage and frequency support for distribution networks, their inherent oscillation characteristics may cause problems such as deterioration of oscillation characteristics and expansion of oscillation propagation range, leading to a decline in power quality in the distribution network. Summary of the Invention

[0004] This application provides a grid-type converter and an oscillation energy dissipation controller, system, method, device, and medium.

[0005] A first aspect of this application provides an oscillation energy dissipation controller for a grid-type converter, comprising: The oscillation energy calculation module is used to calculate the oscillation energy at the port of the grid-type converter, obtain the oscillation energy calculation results, and transmit them to the oscillation energy dissipation controller switching module and the parameter adaptive module. The oscillation energy dissipation controller switching module is used to determine the damping performance of the grid-type converter based on the oscillation energy calculation result, generate a controller switching signal, and transmit it to the oscillation energy dissipation module. The parameter adaptive adjustment module is used to generate key control parameters based on the oscillation energy calculation results and transmit them to the oscillation energy dissipation module. The oscillation energy dissipation module is used to calculate additional control signals based on the controller switching signal and the key control parameters, and transmit them to the current loop controller so that the current loop controller can adjust the oscillation energy dissipation characteristics of the grid-type converter port according to the additional control signals.

[0006] In one embodiment, the oscillation energy calculation module is specifically used for: Obtain the d-axis voltage component and q-axis voltage component of the AC side bus of the grid-type converter, as well as the d-axis current component and q-axis current component and phase θ of the output of the grid-type converter port; The oscillation energy is calculated based on the d-axis voltage component, q-axis voltage component, phase θ, d-axis current component, and q-axis current component.

[0007] In one embodiment, the key control parameters include the gain parameter of the oscillation energy dissipation module; the parameter adaptive adjustment module is specifically used for: When the calculated oscillation energy result is greater than 0, the maximum gain of the oscillation energy dissipation module is obtained, and the gain parameter is calculated based on the maximum gain and the calculated oscillation energy result. When the calculated oscillation energy is not greater than 0, the gain parameter is 1.

[0008] In one embodiment, the oscillation energy dissipation controller switching module is specifically used for: When the calculated oscillation energy is greater than a preset threshold, the value of the controller switching signal is 1. When the calculated oscillation energy is less than or equal to 0, the value of the controller switching signal is 0.

[0009] In one embodiment, the additional control signals include: a d-axis additional control signal and a q-axis additional control signal; The aforementioned oscillation energy dissipation module is specifically used for: Obtain the measured and rated values ​​of the target frequency on the AC side of the grid-type converter; The additional control signal for the d-axis is obtained based on the controller switching signal, gain parameter, d-axis current component, measured value, and rated value; and the additional control signal for the q-axis is generated based on the controller switching signal, gain parameter, q-axis current component, measured value, and rated value.

[0010] A second aspect of this application provides a grid-type converter, including the oscillation energy dissipation controller and current loop controller provided in the above embodiments; The oscillation energy dissipation controller is used to: calculate the oscillation energy at the port of the grid-type converter, generate additional control signals, and transmit them to the current loop controller; The current loop controller is used to: regulate the oscillation energy dissipation characteristics of the grid-type converter port according to the additional control signal; the additional control signal includes: d-axis additional control signal and q-axis additional control signal.

[0011] In one embodiment, the current loop controller is specifically used for: Obtain the proportional and integral gain of the current control loop, the d-axis current reference value, the q-axis current reference value, and the grid-connected line inductance of the converter; Based on the proportional and integral gain of the current control loop, the d-axis current reference value, the q-axis current reference value, the grid-connected line inductance of the converter, the additional control signal on the d-axis, and the additional control signal on the q-axis, a control command is generated. Based on the control commands, the oscillation energy dissipation characteristics of the ports of the grid converter are improved to effectively dampen the oscillation.

[0012] In one embodiment, the control commands include: d-axis control commands and q-axis control commands; The current loop controller is specifically used for: Based on the proportional and integral gain of the current control loop, the d-axis current component, the d-axis current reference value, the d-axis additional control signal, the measured value, and the grid-connected line inductance of the converter, a d-axis control command is generated; and based on the proportional and integral gain of the current control loop, the q-axis current component, the q-axis current reference value, the q-axis additional control signal, the measured value, and the grid-connected line inductance of the converter, a q-axis control command is generated.

[0013] In one embodiment, when the grid-type converter is applied to the distribution network test system and induces system oscillation, the oscillation energy dissipation controller is activated at a first preset time to suppress different oscillation types; the oscillation types include weakly damped type and oscillation instability type.

[0014] In one embodiment, when the grid-type converter is applied to a multi-node system and oscillation is generated, the grid-type converter is connected at a preset bus in the multi-node system. When the oscillation type is weakly damped, the controller is activated at the first preset time to suppress the oscillation. When the oscillation type is an oscillation instability type, the oscillation energy dissipation controller is activated at a first preset time to suppress the oscillation.

[0015] A third aspect of this application provides an energy dissipation control method, comprising: The oscillation energy emitted or absorbed at the port of the grid-type converter is calculated to obtain the oscillation energy calculation result. Based on the oscillation energy calculation results, the damping performance of the grid-type converter is determined to generate the controller switching signal, and key control parameters are generated based on the oscillation energy calculation results. Based on the controller switching signal and the key control parameters, an additional control signal is calculated to regulate the oscillation energy dissipation characteristics of the grid-type converter port through the current loop controller according to the additional control signal.

[0016] A fourth aspect of this application provides a control system for a grid-type converter, including the grid-type converter provided in the above embodiments.

[0017] A fifth aspect of this application provides an electronic 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 any of the above methods.

[0018] A sixth aspect of the present application provides a computer-readable storage medium having a computer program stored thereon, characterized in that the computer program, when executed by a processor, implements the steps of the method as described in any of the above.

[0019] This application provides a grid-type converter and an oscillation energy dissipation controller, system, method, device, and medium. The oscillation energy dissipation controller includes: an oscillation energy calculation module, a parameter adaptive adjustment module, an oscillation energy dissipation controller switching module, and an oscillation energy dissipation module. The oscillation energy calculation module calculates the oscillation energy emitted or absorbed by the grid-type converter port, obtains the oscillation energy calculation result, and transmits it to the oscillation energy dissipation controller switching module. The oscillation energy dissipation controller switching module determines the damping performance of the grid-type converter based on the oscillation energy calculation result, generates a controller switching signal, and transmits it to the oscillation energy dissipation module. The parameter adaptive adjustment module generates key control parameters based on the oscillation energy calculation result and transmits them to the oscillation energy dissipation module. The oscillation energy dissipation module calculates an additional control signal based on the controller switching signal and the key control parameters and transmits it to the current loop controller, so that the current loop controller adjusts the oscillation energy dissipation characteristics of the grid-type converter port according to the additional control signal.

[0020] Compared with existing technologies, the oscillation energy dissipation controller for grid-type converters in this application accurately calculates the oscillation energy at the converter ports through an oscillation energy calculation module, providing a data foundation for subsequent control. The parameter adaptive adjustment module dynamically generates key control parameters based on the energy calculation results, ensuring control adaptability to different oscillation conditions and possessing parameter adaptive capability, capable of changing controller parameters in real time according to changes in the system oscillation state. The oscillation energy dissipation controller switching module judges the system damping performance based on the energy calculation results and intelligently generates switching signals to avoid ineffective control or delayed intervention. The oscillation energy dissipation module, based on the switching signals and key parameters... An additional control signal is output to the current loop controller, which ultimately uses this additional signal to optimize the oscillation energy dissipation characteristics of the converter port. This ensures that the grid-type converter has good oscillation energy dissipation and oscillation damping capabilities, thus preserving the grid-type converter's ability to support the voltage and frequency of the distribution network. At the same time, the hierarchical collaborative control module completely suppresses the oscillation risk, significantly improving the power quality of the distribution network. Through the collaborative design of the oscillation energy dissipation controller and the current loop controller, the problems of distribution network oscillation deterioration, expanded propagation range, and power quality degradation caused by the inherent oscillation characteristics of traditional grid-type converters are effectively solved, enhancing the stability of the entire system. Attached Figure Description

[0021] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 A schematic diagram of the control structure of an existing grid-type converter provided in one embodiment of this application; Figure 2 This is a schematic diagram of the structure of a grid-type converter provided in one embodiment of this application; Figure 3 This is a schematic diagram illustrating the adaptive adjustment of the gain parameters of an oscillation energy dissipation module as energy changes, provided in one embodiment of this application. Figure 4 A schematic diagram of a current control loop including an oscillation capability dissipation module provided in one embodiment of this application; Figure 5 A schematic diagram of a test system including a grid-type converter provided in one embodiment of this application; Figure 6 A schematic diagram of the active power output of the converter after the oscillation energy dissipation controller is put into operation in a weakly damped scenario according to one embodiment of this application; Figure 7 A schematic diagram of the d-axis voltage after the oscillation energy dissipation controller is activated in a weakly damped scenario according to one embodiment of this application; Figure 8This is a schematic diagram of the active power output of the converter after the oscillation energy dissipation controller is put into operation in an oscillation instability scenario according to one embodiment of this application. Figure 9 This is a schematic diagram of the d-axis voltage after the oscillation energy dissipation controller is activated in an oscillation instability scenario according to one embodiment of this application. Figure 10 A schematic diagram showing the comparison of active power at different input times under weak damping conditions, provided as an embodiment of this application; Figure 11 A schematic diagram showing the comparison of active power at different input times under oscillation instability conditions according to one embodiment of this application; Figure 12 This is a schematic diagram of a 10-machine 39-bus system including a grid-type converter provided in one embodiment of the present application; Figure 13 A schematic diagram of the active power output of the converter after the oscillation energy dissipation controller is put into operation in a weakly damped scenario according to one embodiment of this application; Figure 14 A schematic diagram of the d-axis voltage after the oscillation energy dissipation controller is activated in a weakly damped scenario according to one embodiment of this application; Figure 15 This is a schematic diagram of the active power output of the converter after the oscillation energy dissipation controller is put into operation in an oscillation instability scenario according to one embodiment of this application. Figure 16 This is a schematic diagram of the d-axis voltage after the oscillation energy dissipation controller is activated in an oscillation instability scenario according to one embodiment of this application. Figure 17 A flowchart illustrating an energy dissipation control method provided in one embodiment of this application; Figure 18 This is a schematic diagram of the structure of an electronic device provided in one embodiment of this application.

[0022] Explanation of reference numerals in the attached figures: Oscillation energy dissipation controller-10; Oscillation energy calculation module-11; Parameter adaptive adjustment module-12; Oscillation energy dissipation controller switching module-13; Oscillation energy dissipation module-14; Current loop controller-20. Detailed Implementation

[0023] In the process of realizing this application, the inventors discovered that traditional solutions cause problems such as deterioration of the oscillation characteristics and expansion of the oscillation propagation range in the distribution network, which in turn leads to a decline in the power quality of the distribution network.

[0024] To make the technical solutions and advantages of the embodiments of this application clearer, the exemplary embodiments of this application will be described in further detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not an exhaustive list of all embodiments. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other.

[0025] Please see Figure 1 As shown, the grid-connected converter control technology in related technologies focuses on simulating the characteristics of synchronous generators to achieve grid inertia support and frequency regulation. This control technology introduces the rotor motion equations of the synchronous generator into the active power control loop, thereby simulating the inertial response characteristics of synchronous units. This can suppress grid frequency changes caused by load variations, sudden generator shutdowns, and random fluctuations in renewable energy output. The converter acquisition module outputs voltage Voabc and current Ioabc, which are transformed by the abc / dq module to obtain Vodq and Iodq. Then, the power calculation module calculates the real-time active power P and reactive power Q. P is introduced into the active power reference Pref as the control target through the virtual synchronous control module, and Q is introduced into the reactive power reference value Qref as the control target through the reactive power droop control module. The active power deviation is converted into a virtual inertial response, which is then used to generate a PWM signal through inverse coordinate transformation to drive the converter. This suppresses grid frequency changes caused by load, generator, or renewable energy fluctuations, simulating the inertia of synchronous units.

[0026] To enhance frequency regulation capabilities, frequency-active power droop control is superimposed on the active power control stage. This stage mimics the synchronous machine's characteristic of "frequency decrease leading to increased generation, frequency increase leading to decreased generation," introducing grid frequency feedback to establish a relationship and actively adjusting active power output. The voltage and current control loops target Vtclqref and Itclq respectively, maintaining output voltage and limiting fault current, allowing the converter to participate in frequency regulation like a synchronous machine. This compensates for the continuous adjustment needs after virtual inertia buffering, adapts to grid dynamics, and strengthens active support for grid frequency.

[0027] While the aforementioned grid-connected converters possess excellent voltage generation and inertia support capabilities, their control-grid coupling characteristics are prone to broadband oscillation risks. Due to the virtual synchronization and droop control resulting in equivalent impedance bias inductance and limited damping, low-frequency and medium-frequency oscillations are easily induced in multi-machine parallel systems. Multi-loop nested fast voltage and current control may create control resonance in the high-frequency band. Mismatch between virtual inertia and grid dynamic characteristics can lead to frequency-power coupled oscillations. When operating in conjunction with synchronous generators, voltage-excitation interactive oscillations may also occur. Their oscillation modes are highly sensitive to control parameters, especially under weak grid conditions and varying operating conditions.

[0028] To address the aforementioned deficiencies, this application provides an oscillation energy dissipation controller for grid-type converters. Compared with related technologies, the oscillation energy dissipation controller for grid-type converters in this application accurately calculates the oscillation energy at the converter ports through an oscillation energy calculation module, providing a data foundation for subsequent control. The parameter adaptive adjustment module dynamically generates key control parameters based on the energy calculation results, ensuring control adaptability to different oscillation conditions and possessing parameter adaptive capability, capable of changing controller parameters in real time according to changes in the system oscillation state. The oscillation energy dissipation controller switching module determines the system damping performance based on the energy calculation results and intelligently generates switching signals, avoiding ineffective control or delayed intervention. The energy dissipation module outputs additional control signals to the current loop controller based on the switching signal and key parameters. The current loop controller then uses these additional signals to optimize the oscillation energy dissipation characteristics of the converter port, ensuring that the grid-type converter has good oscillation energy dissipation and oscillation damping capabilities. This not only preserves the grid-type converter's ability to support the voltage and frequency of the distribution network, but also completely suppresses oscillation risks through hierarchical collaborative control modules, significantly improving the power quality of the distribution network. Through the collaborative design of the oscillation energy dissipation controller and the current loop controller, the problems of distribution network oscillation deterioration, expanded propagation range, and power quality degradation caused by the inherent oscillation characteristics of traditional grid-type converters are effectively solved, enhancing the stability of the entire system.

[0029] Please see Figure 2 As shown, Figure 2 The diagram below shows the structure of a grid-type converter provided in this application embodiment. The grid-type converter includes an oscillation energy dissipation controller 10 and a current loop controller 20. The oscillation energy dissipation controller 10 includes an oscillation energy calculation module 11, a parameter adaptive adjustment module 12, an oscillation energy dissipation controller switching module 13, and an oscillation energy dissipation module 14.

[0030] The oscillation energy calculation module 11 is used to calculate the oscillation energy emitted or absorbed by the grid-type converter port, obtain the oscillation energy calculation result, and transmit it to the oscillation energy dissipation controller switching module 12; the oscillation energy dissipation controller switching module 13 is used to determine the damping performance of the grid-type converter based on the oscillation energy calculation result, generate a controller switching signal, and transmit it to the oscillation energy dissipation module 14 and the parameter adaptive module 12; the parameter adaptive adjustment module 12 is used to generate key control parameters based on the oscillation energy calculation result and transmit them to the oscillation energy dissipation module 14; the oscillation energy dissipation module 14 is used to calculate additional control signals based on the controller switching signal and key control parameters and transmit them to the current loop controller 20, so that the current loop controller 20 adjusts the oscillation energy dissipation characteristics of the grid-type converter port according to the additional control signals.

[0031] It should be noted that the above-mentioned oscillation energy dissipation controller and current loop controller are connected, the oscillation energy calculation module is connected to the parameter adaptive adjustment module and the oscillation energy dissipation controller switching module respectively, and the oscillation energy dissipation module is connected to the parameter adaptive adjustment module, the oscillation energy dissipation controller switching module and the current loop controller respectively.

[0032] Specifically, the aforementioned grid-type converter includes an AC-side bus and an output port. It can acquire the d-axis voltage component and q-axis voltage component of the AC-side bus, as well as the d-axis current component and q-axis current component and phase θ of the output port of the grid-type converter. Based on these parameters, the oscillation energy emitted or absorbed by the port of the grid-type converter is calculated by the oscillation energy calculation module. The oscillation energy calculation result is then transmitted to the oscillation energy dissipation controller switching module and the parameter adaptive module.

[0033] The oscillation energy dissipation controller switching module determines the damping performance of the grid-type converter based on the positive or negative value of the oscillation energy calculation result. When it exceeds a preset threshold, it indicates that the system oscillation has reached a level requiring intervention, and generates a controller switching signal for the oscillation energy dissipation module, which is then transmitted to the oscillation energy dissipation module. Simultaneously, the parameter adaptive adjustment module adjusts the key control parameters in the oscillation energy dissipation module based on the magnitude of the oscillation energy calculation result at the current grid-type converter port and transmits this adjustment to the oscillation energy dissipation module. These key control parameters can be gain parameters. Finally, the oscillation energy dissipation module calculates the additional control signal to be generated based on the gain parameters and the controller switching signal, and superimposes this additional control signal onto the current control loop of the grid-type converter. This current control loop can be controlled by a current loop controller, thereby improving the oscillation energy dissipation characteristics of the grid-type converter port, effectively damping the oscillation, and ensuring the safety and stability of the distribution network.

[0034] Optionally, to improve the damping performance of grid-connected converters, the core logic revolves around optimizing the converter's port impedance characteristics. Oscillations between grid-connected converters and the distribution network often originate from the coupled resonance between the converter's port impedance and the grid impedance at specific frequencies. This is especially true in weakly damped scenarios where a high proportion of inductive impedance can easily trigger wideband oscillations. Based on this, impedance reshaping technology can be employed by designing additional damping controllers to introduce impedance adjustment components into the converter's original voltage and current loops. First, the system's resonant frequency range is locked through impedance measurement or simulation. Then, notch filter controllers, proportional resonant controllers, etc., are designed specifically to superimpose their output signals onto the voltage or current commands. Ultimately, resistive damping components are added to the resonant frequency range to counteract the negative impact of inductive impedance, thereby reducing impedance coupling risks at their source and achieving oscillation suppression. Advanced algorithms such as model predictive control can also be used to establish a high-precision dynamic model of the grid-type converter (including topology, filtering links, and grid equivalent impedance) to predict current, voltage, frequency and other state variables in real time over multiple control cycles. Then, with the goal of minimizing frequency deviation and current fluctuation, combined with hardware constraints such as converter switching frequency and current limit, the optimal control variable is solved and the converter is driven to output electrical energy that adapts to the current oscillation state, quickly dissipating oscillation energy and thus improving the oscillation suppression capability of the grid-type converter.

[0035] This application provides an oscillation energy dissipation controller for a grid-type converter. The oscillation energy dissipation controller includes: an oscillation energy calculation module, a parameter adaptive adjustment module, an oscillation energy dissipation controller switching module, and an oscillation energy dissipation module. The oscillation energy calculation module calculates the oscillation energy emitted or absorbed at the grid-type converter port, obtains the oscillation energy calculation result, and transmits it to the oscillation energy dissipation controller switching module. The oscillation energy dissipation controller switching module determines the damping performance of the grid-type converter based on the oscillation energy calculation result, generates a controller switching signal, and transmits it to the oscillation energy dissipation module. The parameter adaptive adjustment module generates key control parameters based on the oscillation energy calculation result and transmits them to the oscillation energy dissipation module. The oscillation energy dissipation module calculates an additional control signal based on the controller switching signal and the key control parameters and transmits it to the current loop controller. The current loop controller adjusts the oscillation energy dissipation characteristics of the grid-type converter port according to the additional control signal. Compared with existing technologies, the oscillation energy dissipation controller for grid-type converters in this application accurately calculates the oscillation energy at the converter ports through an oscillation energy calculation module, providing a data foundation for subsequent control. The parameter adaptive adjustment module dynamically generates key control parameters based on the energy calculation results, ensuring control adaptability to different oscillation conditions and possessing parameter adaptive capability, capable of changing controller parameters in real time according to changes in the system oscillation state. The oscillation energy dissipation controller switching module judges the system damping performance based on the energy calculation results and intelligently generates switching signals to avoid ineffective control or delayed intervention. The oscillation energy dissipation module, based on the switching signals and key parameter inputs… An additional control signal is sent to the current loop controller, which then uses this signal to optimize the oscillation energy dissipation characteristics of the converter port. This ensures that the grid-type converter has good oscillation energy dissipation and oscillation damping capabilities, preserving the grid-type converter's ability to support the voltage and frequency of the distribution network. At the same time, the hierarchical collaborative control module completely suppresses oscillation risks, significantly improving the power quality of the distribution network. Through the collaborative design of the oscillation energy dissipation controller and the current loop controller, the problems of distribution network oscillation deterioration, expanded propagation range, and power quality degradation caused by the inherent oscillation characteristics of traditional grid-type converters are effectively solved, enhancing the stability of the entire system.

[0036] In one optional embodiment of this application, the oscillation energy calculation module is specifically used for: Obtain the d-axis voltage components and q-axis voltage components of the AC side bus of the grid-type converter, as well as the d-axis current components, q-axis current components, and phase θ of the output of the grid-type converter port; calculate the oscillation energy based on the d-axis voltage components, q-axis voltage components, phase θ, d-axis current components, and q-axis current components.

[0037] It should be noted that after constructing the oscillation energy calculation module of the grid converter port, the d-axis voltage component and q-axis voltage component of the AC side bus of the grid converter, as well as the d-axis current component and q-axis current component and phase θ of the grid converter port output, can be obtained to calculate the oscillation energy calculation result.

[0038] Optionally, voltage and current sensors can be used to first collect the three-phase voltage of the AC bus and the three-phase current at the port of the grid-type converter. Then, based on the known phase θ, the phase θ can be transformed to the dq coordinate system using the Park matrix, thereby obtaining the d-axis voltage component, q-axis voltage component, d-axis current component, and q-axis current component. Alternatively, the phase θ can be generated or calculated based on a control strategy. For example, the grid-side converter can calculate the phase θ based on the grid connection point rated frequency ω, DC voltage measurement, etc., using a specific control algorithm.

[0039] After obtaining the d-axis voltage component, q-axis voltage component, phase θ, d-axis current component, and q-axis current component, the oscillation energy can be calculated using the following formula: ; Where W represents the calculated oscillation energy of the grid-type converter. U d This represents the d-axis voltage component of the AC bus voltage of a grid-type converter. U q This represents the q-axis voltage component of the AC bus voltage of a grid-type converter. I d This represents the d-axis current component of the AC side output current of the grid-connected converter. I q θ represents the q-axis current component of the AC output current of the grid-connected converter, where θ is the phase.

[0040] In this embodiment, the oscillation energy calculation module can accurately collect the d-axis voltage component and q-axis voltage component of the grid-type converter bus, as well as the d-axis current component and q-axis current component, phase θ, and other key electrical quantities output from the grid-type converter port. Through a specific algorithm, the oscillation energy emitted or absorbed by the converter port is calculated in real time, generating accurate oscillation energy calculation results. This provides a basis for subsequent modules to judge the system damping performance and generate switching signals.

[0041] In one optional embodiment of this application, key control parameters include the gain parameter of the oscillation energy dissipation module; and a parameter adaptive adjustment module, specifically used for: When the calculated oscillation energy result is greater than 0, obtain the maximum gain of the oscillation energy dissipation module, and calculate the gain parameter based on the maximum gain and the calculated oscillation energy result. When the calculated oscillation energy is not greater than 0, the gain parameter is 1.

[0042] Specifically, after obtaining the oscillation energy calculation result, the maximum gain of the oscillation energy dissipation module can be obtained. Based on the maximum gain of the oscillation energy dissipation module and the magnitude of the oscillation energy calculation result, the gain parameter of the oscillation energy dissipation module is calculated using a parameter adaptive adjustment rule, so that the oscillation energy dissipation module has good damping performance adaptive adjustment capability. This parameter adaptive adjustment rule can be expressed by the following formula: ; in, K d The gain parameters for the oscillation energy dissipation module. K dmax Let e ​​be the maximum gain of the energy dissipation module, and e be the natural constant.

[0043] The aforementioned adaptive adjustment mechanism will proactively adjust the gain parameter of the oscillation energy dissipation module in the manner described above. A schematic diagram illustrating the adaptive adjustment of the gain parameter of the oscillation energy dissipation module based on the oscillation energy calculation results can be found in [reference needed]. Figure 3 As shown.

[0044] In this embodiment, the parameter adaptive adjustment module can dynamically generate key control parameters based on the oscillation energy calculation results, avoiding the limitations of fixed parameters that are difficult to adapt to different oscillation conditions. This ensures that the strength of the additional control signal output by the oscillation energy dissipation module is accurately matched with the real-time oscillation state, preventing both weak signals that cause ineffective suppression and strong signals that cause new fluctuations, thus providing highly adaptable parameter support for efficient vibration damping.

[0045] In one optional embodiment of this application, the oscillation energy dissipation controller switching module is specifically used for: When the calculated oscillation energy is greater than the preset threshold, the value of the controller switching signal is 1. When the calculated oscillation energy is less than or equal to 0, the value of the controller switching signal is 0.

[0046] It should be noted that the above-mentioned preset threshold can be customized according to actual needs. The oscillation energy dissipation module switching module can determine the value of the controller switching signal based on the oscillation energy calculation result, and decide whether to start the oscillation energy dissipation module based on the value of the controller switching signal.

[0047] Specifically, after obtaining the oscillation energy calculation result, the corresponding controller switching signal is generated based on the positive or negative sign of the oscillation energy calculation result and sent to the oscillation energy dissipation module. This can be expressed by the following formula: ; in, Ks This is the controller switching signal for the oscillation energy dissipation module. W th The preset threshold is denoted as W, which is the calculated oscillation energy of the grid-type converter.

[0048] Understandably, when the calculated oscillation energy exceeds a preset threshold, it indicates that the system oscillation has reached a level requiring intervention. At this point, the switching module will generate an "input signal" (i.e., ...). K s If the system oscillation energy dissipation module is activated (triggering an effective state), and the real-time oscillation energy does not exceed the preset threshold, the system oscillation is determined to be within an acceptable range or requires no additional intervention. The oscillation energy dissipation controller switching module does not generate an activation signal (i.e., ...). K s (Keep in an inactive state) to prevent the oscillation energy dissipation module from starting blindly.

[0049] In this embodiment, the oscillation energy dissipation controller switching module can not only ensure timely intervention when oscillation occurs and prevent the oscillation from worsening by setting a preset threshold and using a threshold-triggered decision mechanism, but also avoid unnecessary startup from interfering with the normal operation of the converter, thus achieving "on-demand switching" and improving control efficiency.

[0050] In an optional embodiment of this application, the above-mentioned oscillation energy dissipation module is specifically used for: Obtain the measured and rated values ​​of the target frequency on the AC side of the grid-type converter; obtain the d-axis additional control signal based on the controller switching signal, gain parameters, d-axis current component, measured value, and rated value; and generate the q-axis additional control signal based on the controller switching signal, gain parameters, q-axis current component, measured value, and rated value.

[0051] Specifically, after obtaining the controller switching signal and gain parameters, additional control signals can be generated. These additional control signals include additional control signals for different axes, namely: d-axis additional control signal and q-axis additional control signal.

[0052] Upon receiving the controller switching signal, the oscillation energy dissipation module uses the adaptive gain parameter output by the parameter adaptive adjustment stage. Combined with the d-axis and q-axis current components output by the grid-type converter, and the deviation between the measured and rated values ​​of the actual AC bus frequency, it calculates the d-axis and q-axis additional control signals and superimposes them into the current control stage of the grid-type converter. These d-axis and q-axis additional control signals can be expressed by the following formulas: ; Among them, s d Add a control signal to the d-axis, s qAdd control signals to the q-axis, where w and w0 are the measured and rated values ​​of the AC bus frequency of the grid-type converter, respectively.

[0053] Understandably, the frequency deviation between the measured frequency and the rated frequency directly reflects the dynamic characteristics of the system oscillation (e.g., the frequency will fluctuate away from the rated value during oscillation). Combining this with the current component allows for precise capture of the direction and magnitude of oscillation energy. The adaptive gain parameter ensures that the control strength dynamically adapts to the oscillation conditions; that is, the gain adaptability increases when the oscillation is strong, and decreases accordingly when the oscillation is weak. The final generated d-axis and q-axis additional control signals are superimposed on the current control loop, which is equivalent to injecting a damping component opposite to the oscillation characteristics into the converter. Through the rapid response of the current loop, the oscillation energy at the converter port is actively dissipated, fundamentally suppressing the growth of the oscillation amplitude or accelerating its convergence, achieving the effect of "precise damping and on-demand vibration reduction." This avoids interference from fixed control quantities on the normal operation of the system and ensures the targeted and efficient oscillation suppression.

[0054] In this embodiment, the oscillation energy dissipation module generates additional control commands based on the input signal, adaptive gain parameters, and current components, combined with the frequency deviation, and superimposes them onto the current control loop. This allows for precise injection of reverse damping components, active dissipation of oscillation energy, efficient suppression of oscillation, and adaptation to different oscillation conditions, thus avoiding interference with the normal operation of the system.

[0055] In an optional embodiment of this application, a grid-type converter is also provided, including an oscillation energy dissipation controller and a current loop controller as described in the above embodiments.

[0056] The oscillation energy dissipation controller is used to: calculate the oscillation energy at the port of the grid-type converter, generate additional control signals, and transmit them to the current loop controller; the current loop controller is used to: adjust the oscillation energy dissipation characteristics of the port of the grid-type converter according to the additional control signals; the additional control signals include: d-axis additional control signals and q-axis additional control signals.

[0057] In one optional embodiment of this application, the current loop controller is specifically used for: Obtain the proportional and integral gain of the current control loop, the d-axis current reference value, the q-axis current reference value, and the grid-connected line inductance of the converter; generate control commands based on the proportional and integral gain of the current control loop, the d-axis current reference value, the q-axis current reference value, the grid-connected line inductance of the converter, the d-axis additional control signal, and the q-axis additional control signal; based on the control commands, improve the oscillation energy dissipation characteristics of the grid-connected converter port to effectively dampen the oscillation.

[0058] It should be noted that the proportional and integral gains of the aforementioned current control loop can be customized according to actual needs. These proportional and integral gains are the core adjustment parameters of the current loop, determining the current tracking speed and steady-state accuracy, and serving as the fundamental parameters and reference targets for the current control loop. The d-axis and q-axis current reference values ​​are the target currents that the converter needs to output, matching the active and reactive power demands of the distribution network, respectively. The grid-connected line inductance reflects the electrical coupling characteristics between the converter and the grid, affecting current transmission and oscillation energy exchange. These parameters together constitute the basic framework of current control, ensuring that the control commands conform to the converter hardware characteristics and the grid operation requirements.

[0059] After obtaining the aforementioned basic parameters, dynamic adjustment quantities related to oscillation suppression (d / q-axis additional control signals generated by the oscillation energy dissipation module) can be introduced onto them and integrated with the basic parameters and reference values. The final control command is then generated through the current loop control algorithm. In this embodiment, the additional control signal is essentially a damping compensation term designed for the current oscillation characteristics. Its combination with the basic parameters allows the control objective of the current loop to be upgraded from "simply tracking the current reference value" to "tracking the reference value + suppressing oscillation." For example, when the system experiences d-axis current fluctuations due to oscillations, the d-axis additional control signal will adjust the converter output current through control commands to offset the oscillation energy corresponding to the fluctuations.

[0060] After generating control commands, the converter is driven to operate based on these commands, directly improving the energy dissipation characteristics of port oscillations. The control commands are converted into PWM drive signals for the converter's switching devices, adjusting the amplitude and phase of the output current. This prevents the converter port from passively bearing oscillation energy, instead actively dissipating excess oscillation energy through current regulation. For example, when oscillations caused by frequency deviations are detected, the aforementioned control commands will control the converter to output a current component opposite to the oscillation direction, rapidly reducing the oscillation amplitude and ultimately achieving effective damping of distribution network oscillations. At the same time, it ensures that the converter can still stably track the d / q axis current reference value, without affecting its active / reactive power support function for the grid.

[0061] The aforementioned control commands include: d-axis control commands and q-axis control commands; the current loop controller is specifically used for: Based on the proportional and integral gain of the current control loop, the d-axis current component, the d-axis current reference value, the d-axis additional control signal, the measured value, and the converter grid-connected line inductance, the d-axis control command is generated; and based on the proportional and integral gain of the current control loop, the q-axis current component, the q-axis current reference value, the q-axis additional control signal, the measured value, and the converter grid-connected line inductance, the q-axis control command is generated.

[0062] Specifically, after obtaining the proportional and integral gains of the current control loop, the d-axis current component, the d-axis current reference value, the d-axis additional control signal, the measured value, and the grid-connected line inductance of the converter, the d-axis control command and the q-axis control command can be calculated using the following formulas: ; Where, p d The d-axis control command generated for the current loop controller, p q The q-axis control command generated for the current loop controller, K p and K i For the proportional and integral gains of the current control loop, I dref and I qref These are the d-axis and q-axis current reference values ​​for the grid-type converter. L g This refers to the inductance of the converter's grid-connected line. Please refer to [link / reference]. Figure 4 As shown, Figure 4 This is a schematic diagram of the current control loop containing the oscillation energy dissipation module in an embodiment of this application. The d-axis control command p can be accurately determined based on the above calculation method. d and q-axis control command p q .

[0063] In this embodiment, the current loop controller, based on an additional control signal, enables the current control loop to not only meet the conventional current regulation requirements but also to have oscillation suppression capabilities. This ensures that the grid-type converter has good oscillation energy dissipation and oscillation damping capabilities, thereby enhancing the stability of the entire system.

[0064] In one optional embodiment of this application, the above-mentioned oscillation energy dissipation controller for grid-type converter is activated at a first preset time after the grid-type converter is applied to the distribution network test system and the system oscillation is excited, so as to suppress different oscillation types; the oscillation types include weakly damped type and oscillation instability type.

[0065] It should be noted that the first preset time mentioned above can be customized according to actual needs, for example, it can be 3 seconds.

[0066] For example, please see Figure 5As shown, simulation tests are conducted based on a distribution network test system, which can be a Cigre distribution network test system. This system also includes: Synchronous Generators (G): Devices marked "G1, G2" are traditional synchronous power sources that provide inertia through rotor motion and participate in frequency and voltage regulation. Transformers (T): Including T0, T1…T15, used to achieve voltage level transformation (e.g., high-voltage to low-voltage connection to load / grid), ensuring voltage compatibility for different equipment and loads. Loads (L): Such as La, Lb, Lc, L3…L15, representing electrical equipment in the distribution network (which can be understood as residential, industrial, and commercial loads, etc.), serving as the energy consumption end. External Grid: Represents the connection between this distribution network and the upper-level / mainstream grid, enabling power exchange (e.g., receiving power during faults, supplying power during power surplus).

[0067] An islanded operation state was constructed for the distribution network test system. This islanded operation state refers to being disconnected from the external power grid, which further tests the stability of the internal source-load-storage system. The power supply configuration of this distribution network test system includes: two diesel generators with a total capacity of 9.8MVA, installed on buses T10 and T14; and two energy storage systems with a capacity of 3MVA, installed on buses T3 and T8, denoted as GFM1 and GFM2, simulating a hybrid power supply of "traditional synchronous machine + grid-connected converter (GFM)". The total network load is 7.805MW, simulating the actual power demand of the distribution network. The grid-connected converter (GFM) is the core for achieving inertia support and voltage / frequency regulation, and can simulate the characteristics of a synchronous machine, providing stable support for the distribution network. Other parameters may include the core parameters of the converter and synchronous generator (such as capacity, voltage, inertia time constant, etc., see Table 1 below). Table 1

[0068] The simulation test system described above was used to verify the effect of the oscillation energy dissipation controller designed in this application on suppressing the oscillation problem of the grid converter.

[0069] As one feasible approach, taking a first preset time of 3 seconds as an example, for weakly damped conditions, setting a transient three-phase short-circuit fault (occurring in 1 second and disappearing after 2 seconds) on lines T3-T8 is a carefully designed disturbance scenario based on the operating characteristics of the grid-type converter. The oscillation energy dissipation controller is activated at the 3rd second. The comparison of the converter's active power and d-axis voltage before and after the controller activation is as follows: Figure 6 and Figure 7As shown, T3 and T8 are connected to two energy storage systems (GFM1 and GFM2) respectively. This line fault directly affects the grid connection point voltage and power transmission of the grid-connected converter, representing a typical disturbance that significantly impacts the converter's operating state. When a short-circuit fault occurs, the system power balance is instantly disrupted, and the fault current changes rapidly, which can induce coupled oscillations between the grid-connected converter and the grid. This scenario simulates common line fault conditions in distribution networks, effectively exposing the oscillation hazards of the system under weakly damped conditions, and providing a rigorous "stress test" environment for controller performance verification.

[0070] from Figure 6 and Figure 7 A clear contrast can be observed: Before the controller is engaged (1-3s): After the fault disappears, the converter output active power and d-axis voltage exhibit large periodic fluctuations with high oscillation amplitude and slow decay. This phenomenon confirms the weak damping characteristics of the grid-type converter after disturbance. Due to the strong inductance and insufficient damping of the equivalent impedance in the virtual synchronous control, coupled with the dynamic coupling of multi-loop control, the system cannot autonomously and quickly dissipate the oscillation energy, resulting in long-term deviations of power and voltage from steady state. If the duration is too long, it may trigger the converter protection action and lock out.

[0071] After the controller is activated (3 seconds and beyond), the oscillation amplitude of active power and d-axis voltage decreases rapidly, and the fluctuation frequency gradually decreases, stabilizing and converging to a steady-state value by about 6 seconds. This indicates that the controller, through its specifically designed energy dissipation mechanism (such as actively introducing damping components and suppressing resonant frequency components), effectively compensates for the system's damping defects, accelerates the decay of oscillation energy, and proves that it can quickly restore system stability after disturbances.

[0072] The results above show that, without control, the grid-type converter exhibits uncontrolled oscillations in weakly damped scenarios, characterized by large amplitude and difficulty in convergence. However, after implementing an oscillation energy dissipation controller in the grid-type converter... The oscillation energy is quickly dissipated and the power is restored stably, thus proving that the controller can solve the wideband oscillation problem of grid-type converters and provide support for the stable operation of the distribution network.

[0073] As another feasible approach, to further verify the damping performance of the provided oscillation energy dissipation controller, a transient three-phase short-circuit fault (occurring at 1 second and disappearing after 0.5 seconds) was set on lines T3-T8, extending the fault duration from 0.2 seconds to 0.5 seconds to deliberately create a more severe disturbance. The longer the short-circuit fault lasts, the more severe the system power imbalance, and the faster the coupling oscillation accumulation speed between the grid-connected converter and the distribution network, directly triggering "oscillation instability." That is, without intervention, the power / voltage will continue to diverge, eventually leading to converter protection activation and system collapse. This extreme scenario accurately simulates the "instability risk caused by weak damping characteristics after a severe fault in the distribution network," which is more challenging for the controller performance than the previous "weak damping scenario." The oscillation energy dissipation controller was activated at 3 seconds. The active power of the converter before and after activation was as follows: Figure 8 As shown, the output d-axis voltage of the current control loop is compared to... Figure 9 As shown.

[0074] Depend on Figure 8 and Figure 9 As can be seen, a short-circuit fault occurs at 1 second, and the active power and d-axis voltage of the converter immediately begin to oscillate. Since the fault lasts for 0.5 seconds, the accumulated disturbance energy in the system is greater, and the oscillation amplitude increases rapidly. After the fault disappears (after 1.5 seconds), "oscillation instability" occurs, and the system's own damping is completely unable to offset the oscillation energy. If the controller is not activated, the converter will be blocked by overvoltage / overcurrent protection, directly causing local power grid "power disconnection and load outage." After the oscillation energy dissipation controller is activated at 3 seconds, the oscillation amplitude of the active power is instantly "suppressed," changing from divergence to rapid convergence, returning to the steady-state value in about 2 seconds (after 5 seconds). The voltage fluctuation in the d-axis voltage changes from "growing larger with each oscillation" to rapid decay, stabilizing at the rated value in about 5 seconds.

[0075] This demonstrates that the oscillating energy dissipation controller can actively inject damping and dissipate accumulated oscillating energy during the critical stage of oscillation instability, forcefully reversing the trend of "divergent collapse" into "convergent stability." Compared to the weakly damped scenario, this more extreme test further verifies the strong robustness and rapid response capability of the oscillating energy dissipation controller, namely, recovery to stability in about 2 seconds.

[0076] As another feasible approach, to further verify the suppression effect of the oscillation energy dissipation controller on different oscillation amplitudes, under the same short-circuit fault condition, the oscillation energy dissipation controller was activated at 3s, 5s, and 7s respectively. For the converter active power at different control activation times, please refer to [link to relevant documentation]. Figure 10 and Figure 11 As shown, Figure 10 This is a schematic diagram comparing the active power at different times under weak damping conditions, provided in an embodiment of this application. Figure 11This is a schematic diagram comparing the active power at different times during power instability scenarios, provided in an embodiment of this application.

[0077] From the above Figure 10 and Figure 11 The comparison reveals that, in scenarios where the system oscillation amplitude has shown a gradual convergence trend, the oscillation energy dissipation controller designed in this application, applied at three different time points (3s, 5s, and 7s), effectively suppresses the oscillation. Furthermore, the system fully recovers to stability within 3s after each application. This result demonstrates that even when the original control parameters of the converter cannot be adjusted due to operating conditions, the controller, by introducing angular velocity deviation values ​​into the additional control term, can still perceive and adaptively adjust the strength of the additional control signal based on the dynamic changes in system oscillation (such as oscillation amplitude and frequency). This avoids the problem of insufficient adaptability caused by fixed control parameters and ensures accurate dissipation of oscillation energy at different stages of oscillation development, ultimately achieving rapid system stabilization. This further verifies the rationality of the additional control term design and the robustness of the controller.

[0078] The oscillation energy dissipation controller in this embodiment does not require adding more measurement signals to the original measurement signals. Its controller structure is simple and has parameter adaptive capability. It can change the controller parameters in real time according to the changes in the degree of system oscillation, thereby ensuring that the grid-type converter has good oscillation energy dissipation capability and oscillation damping capability, and enhancing the stability of the entire system.

[0079] In one embodiment, when the grid converter is applied to a multi-node system and oscillation is generated, the grid converter is connected at a preset bus in the multi-node system. When the oscillation type is weakly damped, the oscillation energy dissipation controller is activated at the first preset time to suppress the oscillation; when the oscillation type is oscillation instability, the oscillation energy dissipation controller is activated at the first preset time to suppress the oscillation.

[0080] The second preset time can be customized according to actual needs, for example, it can be the 7th second.

[0081] For example, taking a 39-node system as an example, please refer to [link to relevant documentation]. Figure 12 As shown, the Figure 12The 39-node system including a grid-type converter provided in this application embodiment includes: a GFM (grid-type converter): the core for inertia support and voltage / frequency regulation, which can simulate synchronous machine characteristics and provide stable support for the system; G (synchronous generator): devices labeled "G1, G2...G10", which are traditional synchronous power sources, providing inertia through rotor motion and participating in frequency and voltage regulation; nodes 1-39, representing the "bus" or "connection point" of the power system, which are the connection hubs of generators, loads, and lines; and various lines, which are line segments connecting the nodes, representing transmission lines, realizing power transmission, for example, after G1 generates power, it sends power to node 39 and other nodes through the line. The grid-type converter is connected to the system at bus 9 to verify the effectiveness of this design.

[0082] As one feasible approach, taking a first preset time of 2 seconds as an example, for the case of weak damping, to verify the damping performance of the provided oscillation energy dissipation controller, a momentary three-phase short-circuit fault (occurring at 1 second and disappearing after 0.2 seconds) is set on line L6-8, thereby stimulating the system to undergo reduced-amplitude oscillation. After a period of time, the system returns to stability. At the 3rd second, the oscillation energy dissipation controller is activated in the multi-node system, thus obtaining a schematic diagram comparing the output active power and d-axis voltage of the grid converter after the oscillation energy dissipation controller is activated in the weak damping scenario, as shown in the figure. Figure 13 and Figure 14 As shown in the figure above, it can be seen that the oscillation amplitude is effectively suppressed after about 2 seconds of oscillation energy dissipation controller control, and the system gradually returns to stability by the 7th second.

[0083] As another feasible approach, taking a second preset time of 7 seconds as an example, for the oscillation instability scenario, to further verify the damping performance of the proposed oscillation energy dissipation controller, a transient three-phase short-circuit fault (occurring at 1 second and disappearing after 0.6 seconds) is set in line L6-8, thereby inducing oscillation instability in the system. The oscillation energy dissipation controller branch is activated at 7 seconds, thus obtaining a schematic diagram comparing the output active power and d-axis voltage of the grid converter after the oscillation energy dissipation controller is activated in the oscillation instability scenario, as shown in the diagram. Figure 15 and Figure 16 As shown in the figure above, it can be seen that the oscillation energy dissipation controller can effectively suppress oscillations after being put into the system. After the control is put into operation, the divergent trend turns into a convergent trend, and the system tends to stabilize within 2 seconds after the control is put into operation.

[0084] This embodiment addresses the frequency stability control problem during islanded operation of distribution networks by proposing a distributed energy storage collaborative control scheme for active suppression of power disturbances in islanded distribution networks. This method utilizes the interaction between frequency and active power in the islanded distribution network to design a decoupled control loop for power disturbance observation, power disturbance distribution, and energy storage converter. The designed oscillation energy dissipation controller does not require adding more measurement signals to the existing measurement signals. Furthermore, the controller has a simple structure and adaptive parameter capability, allowing it to change its parameters in real time according to changes in the system's oscillation state. This ensures that the grid-type converter has good oscillation energy dissipation and oscillation damping capabilities, enhancing the stability of the entire system.

[0085] On the other hand, please see Figure 17 The energy dissipation control method provided in this application embodiment is applied to the oscillation energy dissipation controller for a grid-type converter as provided in the above embodiment, and includes the following steps 201-203: Step 201: Calculate the oscillation energy emitted or absorbed at the port of the grid-type converter to obtain the oscillation energy calculation result.

[0086] Step 202: Based on the oscillation energy calculation results, determine the damping performance of the grid-type converter, generate the controller switching signal, and generate key control parameters based on the oscillation energy calculation results.

[0087] Step 203: Based on the controller switching signal and key control parameters, calculate the additional control signal, so as to regulate the oscillation energy dissipation characteristics of the grid-type converter port by means of the current loop controller according to the additional control signal.

[0088] Specifically, the oscillation energy calculation module acquires the d-axis voltage and q-axis voltage components of the AC side bus of the grid-type converter, as well as the d-axis and q-axis current components and phase θ of the grid-type converter port output. Based on the d-axis voltage and q-axis voltage components, as well as the d-axis and q-axis current components and phase θ of the grid-type converter port output, it calculates the oscillation energy emitted or absorbed by the grid-type converter port, obtains the oscillation energy calculation result, and transmits it to the oscillation energy dissipation controller switching module. The oscillation energy dissipation controller switching module determines the damping performance of the grid-type converter based on the sign of the oscillation energy calculation result, generates a controller switching signal, and transmits it to the oscillation energy dissipation module. The parameter adaptive adjustment module generates key gain parameters based on the oscillation energy calculation result and transmits them to the oscillation energy dissipation module. The oscillation energy dissipation module calculates additional control signals based on the controller switching signal and key control parameters and transmits them to the current loop controller. These additional control signals include d-axis additional control signals and q-axis additional control signals.

[0089] After receiving the d-axis and q-axis additional control signals, the current loop controller generates d-axis and q-axis control commands based on the d-axis and q-axis additional control signals. In response to the corresponding d-axis and q-axis control commands, the controller adjusts the oscillation energy dissipation characteristics of the grid-type converter port to effectively dampen the oscillation.

[0090] This application provides an energy dissipation control method. This method uses an oscillation energy calculation module to accurately calculate the oscillation energy at the converter port, providing a data foundation for subsequent control. A parameter adaptive adjustment module dynamically generates key control parameters based on the energy calculation results, ensuring control adapts to different oscillation conditions and possesses parameter adaptive capability, able to change controller parameters in real time according to changes in the system's oscillation state. An oscillation energy dissipation controller switching module judges the system's damping performance based on the energy calculation results and intelligently generates a switching signal to avoid ineffective control or delayed intervention. The oscillation energy dissipation module outputs additional parameters based on the switching signal and key parameters. The control signal is sent to the current loop controller, which ultimately uses this additional signal to optimize the oscillation energy dissipation characteristics of the converter port. This ensures that the grid-type converter has good oscillation energy dissipation and oscillation damping capabilities, preserving the grid-type converter's ability to support the voltage and frequency of the distribution network. At the same time, the hierarchical collaborative control module completely suppresses the oscillation risk, significantly improving the power quality of the distribution network. Through the collaborative design of the oscillation energy dissipation controller and the current loop controller, the problems of distribution network oscillation deterioration, expanded propagation range, and power quality degradation caused by the inherent oscillation characteristics of traditional grid-type converters are effectively solved, enhancing the stability of the entire system.

[0091] It should be understood that although the steps in the flowchart 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 constraint on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the diagram may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the sub-steps or stages of other steps.

[0092] In one embodiment, a control system for a grid-type converter is provided, the control system including the oscillation energy dissipation controller for a grid-type converter provided in the above embodiment.

[0093] Compared with existing technologies, the control system in this application includes an oscillation energy dissipation controller for a grid-type converter. An oscillation energy calculation module accurately calculates the oscillation energy at the converter port, providing a data foundation for subsequent control. A parameter adaptive adjustment module dynamically generates key control parameters based on the energy calculation results, ensuring control adaptability to different oscillation conditions and possessing parameter adaptive capability, capable of changing controller parameters in real time according to changes in the system's oscillation state. An oscillation energy dissipation controller switching module determines the system's damping performance based on the energy calculation results and intelligently generates switching signals to avoid ineffective control or delayed intervention. The oscillation energy dissipation module, based on the switching signal and the control... The key parameter outputs an additional control signal to the current loop controller. Ultimately, the current loop controller uses this additional signal to optimize the oscillation energy dissipation characteristics of the converter port, ensuring that the grid-type converter has good oscillation energy dissipation and oscillation damping capabilities. This not only preserves the grid-type converter's ability to support the voltage and frequency of the distribution network, but also completely suppresses oscillation risks through hierarchical collaborative control modules, significantly improving the power quality of the distribution network. Through the collaborative design of the oscillation energy dissipation controller and the current loop controller, the problems of distribution network oscillation deterioration, expanded propagation range, and power quality degradation caused by the inherent oscillation characteristics of traditional grid-type converters are effectively solved, enhancing the stability of the entire system.

[0094] In one embodiment, an electronic device is provided, the internal structure of which can be as follows: Figure 18 As shown. The computer device includes a processor, memory, network interface, and database connected via a system bus. The processor provides computing and control capabilities. The memory includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores the operating system, computer programs, and the database. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage medium. The database stores data. The network interface communicates with external terminals via a network connection. When the computer program is executed by the processor, it implements an autonomous driving simulation method as described above. It includes: memory and a processor; the memory stores the computer program; and the processor executes the computer program to implement any step of the autonomous driving simulation method described above.

[0095] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, can perform any of the steps in the above-described autonomous driving simulation method.

[0096] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0097] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0098] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0099] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0100] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0101] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. An oscillation energy dissipation controller for a grid-type converter, characterized in that, At least including: The oscillation energy calculation module is used to calculate the oscillation energy at the port of the grid-type converter, obtain the oscillation energy calculation results, and transmit them to the oscillation energy dissipation controller switching module and the parameter adaptive module. The oscillation energy dissipation controller switching module is used to determine the damping performance of the grid-type converter based on the oscillation energy calculation result, generate a controller switching signal, and transmit it to the oscillation energy dissipation module. The parameter adaptive adjustment module is used to generate key control parameters based on the oscillation energy calculation results and transmit them to the oscillation energy dissipation module. The oscillation energy dissipation module is used to calculate additional control signals based on the controller switching signal and the key control parameters, and transmit them to the current loop controller so that the current loop controller can adjust the oscillation energy dissipation characteristics of the grid-type converter port according to the additional control signals.

2. The oscillation energy dissipation controller for a grid-type converter according to claim 1, characterized in that, The oscillation energy calculation module is specifically used for: Obtain the d-axis voltage component and q-axis voltage component of the AC side bus of the grid-type converter, as well as the d-axis current component and q-axis current component and phase θ of the output of the grid-type converter port; The oscillation energy is calculated based on the d-axis voltage component, q-axis voltage component, phase θ, d-axis current component, and q-axis current component.

3. The oscillation energy dissipation controller for a grid-type converter according to claim 1, characterized in that, The key control parameters include the gain parameter of the oscillation energy dissipation module; the parameter adaptive adjustment module is specifically used for: When the calculated oscillation energy result is greater than 0, the maximum gain of the oscillation energy dissipation module is obtained, and the gain parameter is calculated based on the maximum gain and the calculated oscillation energy result. When the calculated oscillation energy is not greater than 0, the gain parameter is 1.

4. The oscillation energy dissipation controller for a grid-type converter according to claim 3, characterized in that, The oscillation energy dissipation controller switching module is specifically used for: When the calculated oscillation energy is greater than a preset threshold, the value of the controller switching signal is 1. When the calculated oscillation energy is less than or equal to 0, the value of the controller switching signal is 0.

5. The oscillation energy dissipation controller for a grid-type converter according to claim 4, characterized in that, The additional control signals include: d-axis additional control signal and q-axis additional control signal; The oscillation energy dissipation module is specifically used for: Obtain the measured and rated values ​​of the target frequency on the AC side of the grid-type converter; The additional control signal for the d-axis is obtained based on the controller switching signal, gain parameter, d-axis current component, measured value, and rated value; and the additional control signal for the q-axis is generated based on the controller switching signal, gain parameter, q-axis current component, measured value, and rated value.

6. A grid-type converter, characterized in that, Includes the oscillation energy dissipation controller and current loop controller as described in any one of claims 1-5 above; The oscillation energy dissipation controller is used to: calculate the oscillation energy at the port of the grid-type converter, generate additional control signals, and transmit them to the current loop controller; The current loop controller is used to: regulate the oscillation energy dissipation characteristics of the grid-type converter port according to the additional control signal; The additional control signals include: d-axis additional control signal and q-axis additional control signal.

7. The grid-type converter according to claim 6, characterized in that, The current loop controller is specifically used for: Obtain the proportional and integral gain of the current control loop, the d-axis current reference value, the q-axis current reference value, and the grid-connected line inductance of the converter; Based on the proportional and integral gain of the current control loop, the d-axis current reference value, the q-axis current reference value, the grid-connected line inductance of the converter, the additional control signal on the d-axis, and the additional control signal on the q-axis, a control command is generated. Based on the control commands, the oscillation energy dissipation characteristics of the ports of the grid converter are improved to effectively dampen the oscillation.

8. The grid-type converter according to claim 7, characterized in that, The control commands include: d-axis control commands and q-axis control commands; The current loop controller is specifically used for: Based on the proportional and integral gain of the current control loop, the d-axis current component, the d-axis current reference value, the d-axis additional control signal, the measured value, and the grid-connected line inductance of the converter, a d-axis control command is generated; and based on the proportional and integral gain of the current control loop, the q-axis current component, the q-axis current reference value, the q-axis additional control signal, the measured value, and the grid-connected line inductance of the converter, a q-axis control command is generated.

9. The grid-type converter according to claim 6, characterized in that, When the grid-type converter is applied to the distribution network test system and induces system oscillation, the controller is activated at a first preset time to suppress different oscillation types; the oscillation types include weakly damped type and oscillation instability type.

10. The grid-type converter according to claim 9, characterized in that, When the grid-type converter is applied to a multi-node system and oscillation is generated, the grid-type converter is connected at a preset bus in the multi-node system. When the oscillation type is weakly damped, the oscillation energy dissipation controller is activated at the first preset time to suppress the oscillation. When the oscillation type is oscillation instability, the oscillation energy dissipation controller is activated at a first preset time to suppress the oscillation.

11. A control system for a grid-type converter, characterized in that, Including the grid-type converter as described in any one of claims 6-10 above.

12. A control method, characterized in that, The method, applied to an oscillation energy dissipation controller for a grid-type converter as described in any one of claims 1-5, comprises: The oscillation energy emitted or absorbed at the port of the grid-type converter is calculated to obtain the oscillation energy calculation result. Based on the oscillation energy calculation results, the damping performance of the grid-type converter is determined to generate the controller switching signal, and key control parameters are generated based on the oscillation energy calculation results. Based on the controller switching signal and the key control parameters, an additional control signal is calculated, so that the current loop controller can adjust the oscillation energy dissipation characteristics of the grid-type converter port according to the additional control signal.

13. An electronic device, comprising: A memory and a processor, the memory storing a computer program, characterized in that the processor, when executing the computer program, implements the steps of the method according to any one of claims 1 to 5.

14. 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 5.

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