A controllable power modulation system and method for testing grid-type converters.

Abstract

This application discloses a controllable power supply modulation system and method suitable for testing grid-connected converters, belonging to the field of converter testing technology. In the modulation system, a controllable power supply module, a real-time simulation module, and a modulation module are interconnected to form a modulation loop. The controllable power supply module is connected to the grid-connected converter. The real-time simulation module provides the grid connection point and its initial reference voltage, and determines the modulation wave based on the unlocking total signal of the controllable power supply module, its DC voltage, and the initial reference voltage. The modulation module determines a trigger pulse based on the modulation wave and the unlocking total signal, and uses the trigger pulse to make the controllable power supply module follow the initial reference voltage of the grid connection point. This application achieves a simulation of a realistic power grid environment through the grid connection point voltage provided by the real-time simulation module. Based on the modulation wave that closely reflects the dynamics of the real power grid, the modulation module generates a trigger pulse to modulate the controllable power supply module, thereby enhancing the realism of the modulation effect.

Description

Technical Field

[0001] This application relates to the field of converter testing technology, and in particular to a controllable power modulation system and method suitable for testing grid-type converters. Background Technology

[0002] As a voltage source with low series impedance and controlled amplitude and phase, grid-connected converters possess the ability to build their own internal potential and exhibit good self-synchronization performance without phase-locked loops, playing a vital supporting role in the stable operation of the power grid. However, due to the diversity of grid-connection technologies and the differences in implementation methods among different grid-connected converter manufacturers, the grid-connection characteristics of grid-connected converters vary.

[0003] In the grid performance testing of grid-connected converters, the modulation process of the controllable power supply is a critical step. Typically, the modulation process is directly controlled by a single controller. Such controllers are usually based on theoretical settings and lack the ability to simulate real-world grid environments, resulting in unrealistic modulation effects and impacting the accuracy and reliability of grid-connected converter testing. Summary of the Invention

[0004] This application provides a controllable power modulation system and method suitable for testing grid-type converters, which can provide a simulation of the real power grid environment and enhance the realism of the modulation effect.

[0005] In a first aspect, embodiments of this application provide a controllable power modulation system suitable for testing grid-type converters, applied in the testing process of grid-type converters. The modulation system includes:

[0006] Controllable power supply module, connected to grid-type converter;

[0007] The real-time simulation module is connected to the controllable power supply module. The real-time simulation module is used to provide the grid connection point of the controllable power supply module and the initial reference voltage of the grid connection point in real time. Based on the unlocking total signal of the controllable power supply module, the DC voltage of the controllable power supply module and the initial reference voltage, the modulated wave of the controllable power supply module is determined in real time.

[0008] The modulation module is connected to the controllable power supply module and the real-time simulation module respectively. The modulation module is used to determine the trigger pulse of the controllable power supply module in real time based on the modulation wave and the unlocking total signal, and send the trigger pulse to the controllable power supply module so that the controllable power supply module follows the initial reference voltage of the grid connection point.

[0009] In some embodiments, the real-time simulation module is used to determine the modulation wave of the controllable power supply module in real time based on the total unlocking signal of the controllable power supply module, the DC voltage of the controllable power supply module, and the initial reference voltage, including:

[0010] Based on the unlocking total signal and the initial reference voltage, the reference voltage of the grid connection point is determined in real time.

[0011] Based on the reference voltage and DC voltage, the modulation wave of the controllable power supply module is determined in real time.

[0012] In some embodiments, the total unlock signal includes a valid signal;

[0013] The real-time simulation module is used to determine the reference voltage at the grid connection point in real time based on the unlocking total signal and the initial reference voltage, including:

[0014] When the unlocking total signal is a valid signal, the reference voltage of the grid connection point is determined in real time based on the initial reference voltage of the grid connection point and the preset start-stop coefficient;

[0015] The preset start / stop coefficient is based on a first preset rate that increases from a first threshold to a second threshold.

[0016] In some embodiments, the total unlock signal includes an invalid signal;

[0017] The real-time simulation module is used to determine the reference voltage at the grid connection point in real time based on the unlocking total signal and the initial reference voltage, including:

[0018] When the unlock total signal is invalid, the reference voltage of the grid connection point is determined in real time based on the initial reference voltage and the preset start-stop coefficient.

[0019] The preset start / stop coefficient is based on the second preset rate, decreasing from the second threshold to the first threshold.

[0020] In some embodiments, the real-time simulation module is used to provide the grid connection point of the controllable power module and to provide the initial reference voltage of the grid connection point in real time, including:

[0021] A power model is constructed based on the real-time simulation module;

[0022] The grid connection point for the controllable power module is provided based on the power model, and the initial reference voltage of the grid connection point is provided in real time based on simulation calculation.

[0023] In some embodiments, the total unlock signal includes a valid signal and an invalid signal;

[0024] The modulation module is used to determine the trigger pulse of the controllable power supply module in real time based on the modulation wave and the total unlock signal, including:

[0025] When the unlock signal is valid, the trigger pulse of the controllable power module is determined in real time, wherein the controllable power module is in the start state;

[0026] When the unlock signal is invalid, the trigger pulse of the controllable power module is blocked, and the sending of trigger pulses to the controllable power module is stopped. The controllable power module is in a stopped state.

[0027] In some embodiments, when the real-time simulation module is used to provide a grid connection point, there are multiple controllable power supply modules, and each controllable power supply module is connected to the grid connection point and the modulation module respectively.

[0028] The total unlock signal is determined by logical operations on each controllable power module.

[0029] In some embodiments, the DC voltage of the controllable power supply module is determined by averaging the DC bus voltage of each controllable power supply module.

[0030] In some embodiments, when the real-time simulation module is used to provide multiple grid connection points, there are multiple controllable power supply modules and multiple modulation modules. Each grid connection point corresponds to one modulation module, and each modulation module is connected to at least one controllable power supply module. The controllable power supply module connected to each modulation module is connected to the grid connection point.

[0031] In some embodiments, the initial reference voltages at at least some of the grid connection points are different.

[0032] In some embodiments, the real-time simulation module and the modulation module communicate using the Aurora protocol, with a communication transmission rate greater than or equal to 1 Gbit / s.

[0033] Secondly, embodiments of this application also provide a controllable power supply modulation method suitable for testing grid-type converters, the method comprising:

[0034] Real-time determination of the total unlock signal and DC voltage of the controllable power module;

[0035] Based on the unlock total signal, DC voltage and the initial reference voltage of the controllable power module connection point, the modulation wave of the controllable power module is determined in real time.

[0036] Based on the modulation wave and the unlocking total signal, the trigger pulse of the controllable power module is determined in real time and sent to the controllable power module so that the controllable power module follows the initial reference voltage of the grid connection point.

[0037] This application provides a controllable power supply modulation system and method suitable for grid-connected converter testing. The modulation system includes a controllable power supply module, a real-time simulation module, and a modulation module. The controllable power supply module is connected to the grid-connected converter. The real-time simulation module is connected to the controllable power supply module and provides the grid connection point and initial reference voltage of the connection point in real time. Based on the unlocking total signal of the controllable power supply module, its DC voltage, and the initial reference voltage, the real-time simulation module determines the modulation wave of the controllable power supply module. The modulation module is connected to both the controllable power supply module and the real-time simulation module. Based on the modulation wave and the unlocking total signal, the modulation module determines the trigger pulse of the controllable power supply module in real time and sends the trigger pulse to the controllable power supply module, causing it to follow the initial reference voltage of the grid connection point. This application, through the grid connection point and initial reference voltage provided by the real-time simulation module, can provide a simulation of a realistic power grid environment, enabling the modulation system to simulate the dynamic changes of the real power grid environment and generate a realistic modulation wave. Subsequently, the modulation module generates a trigger pulse based on the modulation wave, enabling the controllable power supply module to accurately follow the initial reference voltage at the grid connection point, thereby enhancing the realism of the modulation effect. Furthermore, this application, through the collaborative work of the controllable power supply module, the real-time simulation module, and the modulation module, forms a highly efficient modulation mechanism capable of adjusting the modulation wave and trigger pulse in real time, significantly accelerating the modulation speed of the controllable power supply module during grid-connected converter testing. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0039] To gain a more complete understanding of this application and its beneficial effects, the following description will be provided in conjunction with the accompanying drawings, wherein the same reference numerals in the following description denote the same parts.

[0040] Figure 1 A schematic block diagram of a controllable power modulation system suitable for testing grid-type converters, provided in an embodiment of this application;

[0041] Figure 2 A schematic block diagram of another controllable power modulation system suitable for testing grid-type converters provided in this application embodiment;

[0042] Figure 3 A schematic block diagram of a modulation module provided in an embodiment of this application;

[0043] Figure 4A schematic block diagram of another controllable power modulation system for testing grid-type converters provided in this application embodiment;

[0044] Figure 5 A schematic block diagram of another modulation module provided in an embodiment of this application;

[0045] Figure 6 A schematic block diagram of another controllable power modulation system for testing grid-type converters provided in this application embodiment;

[0046] Figure 7 A schematic block diagram of another controllable power modulation system for testing grid-type converters provided in this application embodiment;

[0047] Figure 8 A schematic diagram of phase A bridge arm in the controllable power supply module provided in the embodiments of this application;

[0048] Figure 9 This is a schematic flowchart of a modulation method for a grid-type converter provided in an embodiment of this application. Detailed Implementation

[0049] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the protection scope of this application.

[0050] In the embodiments of this application, "at least one" refers to one or more; "multiple" refers to two or more. In the description of this application, the terms "first," "second," "third," etc., are used only for the purpose of distinguishing descriptions and should not be construed as indicating or implying relative importance, nor should they be construed as indicating or implying order.

[0051] References such as “one embodiment” or “some embodiments” as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the terms “comprising,” “including,” “having,” and variations thereof, as used in this specification, mean “including, but not limited to,” unless otherwise specifically emphasized.

[0052] In recent years, the construction of new power systems has accelerated, exhibiting a "dual-high" characteristic of high proportions of renewable energy and high proportions of power electronic equipment. As the penetration rate of new energy sources and other power electronic power sources in the system continues to increase, the proportion of synchronous generators is decreasing, system inertia is decreasing, and grid strength is weakening, posing a significant challenge to the stable operation of the power system.

[0053] A power converter is a device that uses power electronics technology to control electrical energy. Among them, the grid-type converter, as the core equipment, has the ability to actively construct the grid voltage and frequency, and can simulate the inertial response and damping characteristics of synchronous generators, providing dynamic support for modern power systems.

[0054] Grid-connected converters, as voltage sources with low series impedance and controlled amplitude and phase, possess the ability to build their own internal potential and exhibit good self-synchronization performance without a phase-locked loop (PLL). They play a crucial supporting role in the stable operation of the power grid. However, due to different technical approaches to grid-connection and variations in implementation methods among different grid-connected converter manufacturers, the response characteristics of grid-connected converters from different manufacturers vary. Therefore, it is necessary to construct a test platform suitable for testing grid-connected converters, tailored to power grid requirements, to provide an effective testing environment for verifying their characteristics and to differentiate the true grid-connection capabilities of different grid-connected converters.

[0055] In the grid performance testing of grid-connected converters, the modulation process of the controllable power supply is a critical step. Typically, the modulation process is directly controlled by a single controller. Such controllers are usually based on theoretical settings and lack the ability to simulate real-world grid environments, resulting in unrealistic modulation effects and impacting the accuracy and reliability of grid-connected converter testing.

[0056] In some embodiments, the testing methods for the grid-connected performance of grid-connected converters may include hardware-in-the-loop (HIL) simulation testing, third-party certified testing platform testing, and field fault testing. However, HIL simulation testing can only test the controller characteristics of the grid-connected converter and cannot verify the actual response capability of the primary equipment. Field testing is limited by grid safety operation constraints, allowing only a limited number of fault tests and failing to cover all operating conditions of the grid-connected converter. Existing certified testing platforms can simulate disturbances in the power system such as frequency, voltage, and phase, but their controllable power supply reference voltage is mainly set through mathematical functions, which cannot realistically simulate disturbances at different nodes in the power system or enable interaction between the tested grid-connected converter and the regional grid. Furthermore, for grid-connected converters of different capacities, the consistency of output characteristics among different controllable power supplies is poor when multiple controllable power supplies are connected in parallel on the AC side. Therefore, the testing methods for the grid-connected performance of grid-connected converters have many limitations, and the modulation process of the grid-connected converter cannot be effectively and comprehensively tested during the testing process.

[0057] In view of this, this application proposes a modulation method for a grid-type converter, aiming to solve at least one of the above-mentioned technical problems.

[0058] Please see Figure 1 As shown, Figure 1 This is a schematic block diagram of a controllable power supply modulation system suitable for testing grid-type converters, provided as an embodiment of this application. This application provides a controllable power supply modulation system suitable for testing grid-type converters. The modulation system includes a controllable power supply module, a real-time simulation module, and a modulation module. Through the collaborative work of the controllable power supply module, the real-time simulation module, and the modulation module, this application forms a highly efficient modulation mechanism that can adjust the modulation wave and trigger pulse in real time, significantly accelerating the modulation speed of the controllable power supply module during grid-type converter testing.

[0059] Please see Figure 2 As shown, Figure 2 This is a schematic block diagram of another controllable power modulation system for testing grid-type converters, provided as an embodiment of this application.

[0060] This application provides a controllable power modulation system suitable for testing grid-type converters. The modulation system, applied during the grid-type converter testing process, includes:

[0061] Controllable power supply module, connected to grid-type converter;

[0062] The real-time simulation module is connected to the controllable power supply module. The real-time simulation module is used to provide the grid connection point of the controllable power supply module and the initial reference voltage of the grid connection point in real time. Based on the unlocking total signal of the controllable power supply module, the DC voltage of the controllable power supply module and the initial reference voltage, the modulated wave of the controllable power supply module is determined in real time.

[0063] The modulation module is connected to the controllable power supply module and the real-time simulation module respectively. The modulation module is used to determine the trigger pulse of the controllable power supply module in real time based on the modulation wave and the unlocking total signal, and send the trigger pulse to the controllable power supply module so that the controllable power supply module follows the initial reference voltage of the grid connection point.

[0064] The controllable power supply module is used to simulate grid conditions. Based on the grid connection point voltage, it can simulate different grid conditions, such as voltage fluctuations, frequency changes, and harmonic interference, enabling the grid-connected converter to perform performance evaluations under various simulated environments. The controllable power supply module can include a rectifier and an inverter. The mains power supplies the rectifier, which in turn provides DC power to the inverter. The inverter connects AC power to the grid connection point, with its AC side connected to the grid-connected converter. This allows the controllable power supply module to modulate the actual grid-connected capability of the grid-connected converter, thus identifying its true grid-connected capability.

[0065] The real-time simulation module is used to build and simulate power models. Through power modeling, the dynamic behavior and response characteristics of grid-connected points in real power systems can be simulated. In this application, a power model can be constructed based on the real-time simulation module; based on the power model, the grid-connected point for the controllable power supply module can be provided, and the initial reference voltage of the grid-connected point can be provided in real time based on simulation calculations, enabling the controllable power supply module to follow the initial reference voltage of the grid-connected point. The real-time simulation module can employ RTDS (Real-Time Digital Simulator), RT-LAB (Real-Time Lab), etc., depending on the specific implementation requirements.

[0066] The modulation module is used to determine the trigger pulse of the controllable power supply module in real time based on the modulation wave and unlocking total signal of the controllable power supply module. Then, it modulates the controllable power supply module based on the trigger pulse, making the controllable power supply module follow the initial reference voltage of the grid connection point. The modulation module can use a controller configured with preset program code to determine the trigger pulse of the controllable power supply module. The controller can be a digital signal processor, microcontroller, field-programmable gate array (FPGA), etc. Using an FPGA can achieve rapid generation of the trigger pulse, thereby improving the modulation speed. The specific configuration depends on the actual implementation requirements.

[0067] It should be noted that the real-time simulation module can change the amplitude, frequency, phase, and other parameters of the initial reference voltage at the grid connection point by modifying the model structure and parameters of the constructed power model, thereby simulating disturbances such as system faults, frequency changes, and phase jumps in actual power systems. Understandably, the real-time simulation module can simulate various real-world scenarios and provide different voltage conditions in a timely manner to adapt to diverse power system scenarios. This allows it to cover a wide range of operating conditions for grid-connected converters, enabling the controllable power supply module to follow the initial reference voltage at the grid connection point, which helps in the in-depth evaluation of the grid-connected converter's grid performance.

[0068] like Figure 2 As shown, the collaborative operation of the controllable power supply module, real-time simulation module, and modulation module is exemplarily described below:

[0069] First, the controllable power supply module sends its unlock signal to the real-time simulation module and the modulation module respectively; and sends its DC bus voltage to the real-time simulation module.

[0070] Then, the real-time simulation module determines the modulation wave of the controllable power supply module in real time based on the unlocking total signal of the controllable power supply module, the DC voltage of the controllable power supply module, and the initial reference voltage; wherein, the unlocking total signal comes from the unlocking signal of the controllable power supply module, and the DC voltage comes from the DC bus voltage of the controllable power supply module.

[0071] Finally, based on the modulation wave and the unlocking total signal, the modulation module determines the trigger pulse of the controllable power supply module in real time, and sends the trigger pulse to the controllable power supply module so that the controllable power supply module follows the initial reference voltage of the grid connection point.

[0072] Through the above technical solution, this application provides a controllable power supply modulation system suitable for grid-connected converter testing, applied in the grid-connected converter testing process. This application, through the grid connection point and initial reference voltage provided by the real-time simulation module, can provide a simulation of a realistic power grid environment, enabling the modulation system to simulate the dynamic changes of the real power grid environment, thereby generating a realistic modulation wave. Subsequently, the modulation module generates a trigger pulse based on the modulation wave, allowing the controllable power supply module to accurately follow the initial reference voltage of the grid connection point, thus enhancing the realism of the modulation effect. Furthermore, this application, through the collaborative work of the controllable power supply module, the real-time simulation module, and the modulation module, forms a highly efficient modulation mechanism, capable of adjusting the modulation wave and trigger pulse in real time, significantly accelerating the modulation speed of the controllable power supply module during grid-connected converter testing. In addition, based on the enhanced realism of the modulation effect, this application results in better and more realistic grid-connected converter testing, thus facilitating the testing of the grid-connected converter's grid performance.

[0073] In some embodiments, the real-time simulation module is used to determine the modulation wave of the controllable power supply module in real time based on the total unlocking signal of the controllable power supply module, the DC voltage of the controllable power supply module, and the initial reference voltage, including:

[0074] Based on the unlocking total signal and the initial reference voltage, the reference voltage of the grid connection point is determined in real time.

[0075] Based on the reference voltage and DC voltage, the modulation wave of the controllable power supply module is determined in real time.

[0076] It's important to understand that the unlock signal is used to provide the start / stop status of the controllable power module. The initial reference voltage at the grid connection point provides the voltage reference condition that the controllable power module needs to follow. Calculating the reference voltage at the grid connection point reflects the current voltage state that needs to be followed and provides the basis for subsequent modulation wave generation. The modulation wave generation process considers the relationship between the reference voltage at the grid connection point and the DC voltage, ensuring that the output of the controllable power module can match the voltage state that needs to be followed.

[0077] For example, based on a reference voltage and half a DC voltage, the modulation wave of the controllable power supply module can be determined in real time. Specifically, the calculation formula for the modulation wave of the controllable power supply module is as follows:

[0078] .

[0079] Through the above technical solution, this application determines the modulation wave of the controllable power supply module in real time based on the unlocking total signal, DC voltage, and the initial reference voltage of the grid connection point. This allows the modulated wave to reflect the reference voltage of the grid connection point to be followed, thus enabling the controllable power supply module to follow the modulation wave, i.e., follow the reference voltage of the grid connection point. Consequently, the voltage provided by the real-time simulation module can be accurately reflected in the controllable power supply module.

[0080] In some embodiments, the total unlock signal includes a valid signal;

[0081] The real-time simulation module is used to determine the reference voltage at the grid connection point in real time based on the unlocking total signal and the initial reference voltage, including:

[0082] When the unlocking total signal is a valid signal, the reference voltage of the grid connection point is determined in real time based on the initial reference voltage of the grid connection point and the preset start-stop coefficient;

[0083] The preset start / stop coefficient is based on a first preset rate that increases from a first threshold to a second threshold.

[0084] For example, determining the reference voltage of the grid connection point based on the unlock total signal and the initial reference voltage includes: First, when the unlock total signal is a valid signal, determining the real-time reference voltage of the grid connection point based on the product of the real-time data of the initial reference voltage of the grid connection point and a preset start-stop coefficient. The preset start-stop coefficient increases from a first threshold to a second threshold at a first preset rate, causing the real-time value of the reference voltage of the grid connection point to increase based on the increase of the preset start-stop coefficient until it equals the initial reference voltage of the grid connection point, thereby enabling the controllable power module to follow the initial reference voltage of the grid connection point.

[0085] It should be noted that the first threshold can be greater than or equal to 0, the second threshold is 1, and the first threshold is less than the second threshold. The specific values ​​of the first and second thresholds are set according to the actual implementation requirements; for example, the first threshold can be 0 and the second threshold can be 1. The first preset rate can be a constant speed, for example, a constant speed of 0.2 units / second, with the start-stop coefficient increasing by 0.2 per second, reaching the second threshold of 1 after 5 seconds. The first preset rate can also be a uniform acceleration rate or a variable speed rate, and the first preset rate can be set based on the actual implementation requirements.

[0086] Through the above technical solution, the gradual adjustment of the preset start-stop coefficient during the modulation process of the controllable power module ensures a smooth voltage transition. By gradually increasing the preset start-stop coefficient, the controllable power module can slowly adjust its output voltage, allowing it to gradually follow the initial reference voltage of the grid connection point. This effectively reduces the impact of resonance phenomena on the controllable power module, ensuring it operates in a stable environment and helping to protect it.

[0087] In some embodiments, the total unlock signal includes an invalid signal;

[0088] The real-time simulation module is used to determine the reference voltage at the grid connection point in real time based on the unlocking total signal and the initial reference voltage, including:

[0089] When the unlock total signal is invalid, the reference voltage of the grid connection point is determined in real time based on the initial reference voltage and the preset start-stop coefficient.

[0090] The preset start / stop coefficient is based on the second preset rate, decreasing from the second threshold to the first threshold.

[0091] For example, determining the reference voltage of the grid connection point based on the unlock total signal and the initial reference voltage of the grid connection point includes: First, when the unlock total signal is invalid, determining the real-time reference voltage of the grid connection point based on the product of the real-time data of the initial reference voltage of the grid connection point connected to the controllable power module and a preset start-stop coefficient. The preset start-stop coefficient decreases from a second threshold to a first threshold at a second preset rate, causing the real-time value of the reference voltage of the grid connection point to decrease based on the decrease of the preset start-stop coefficient.

[0092] It should be noted that the second preset rate can be the same in magnitude as the first preset rate but in the opposite direction. Furthermore, the second preset rate can be a constant speed, for example, a constant speed of 0.2 units / second, with the start-stop coefficient decreasing by 0.2 per second, reaching the first threshold of 0 after 5 seconds. The second preset rate can also be a uniform acceleration rate or a variable speed rate, and the first preset rate can be set based on the requirements of the actual implementation scheme.

[0093] Through the above technical solution, a smooth voltage transition can be achieved by gradually adjusting the preset start-stop coefficient during the modulation process of the controllable power module. Furthermore, by ensuring that the preset start-stop coefficient returns to the first threshold, and thus, when the unlocking total signal is valid, the controllable power module can gradually follow the initial reference voltage of the grid connection point to gradually increase, improving system stability and optimizing the power module's response capability.

[0094] In some embodiments, the total unlock signal includes a valid signal and an invalid signal;

[0095] The modulation module is used to determine the trigger pulse of the controllable power supply module in real time based on the modulation wave and the total unlock signal, including:

[0096] When the unlock signal is valid, the trigger pulse of the controllable power module is determined in real time, wherein the controllable power module is in the start state;

[0097] When the unlock signal is invalid, the trigger pulse of the controllable power module is blocked, and the sending of trigger pulses to the controllable power module is stopped. The controllable power module is in a stopped state.

[0098] It should be noted that an active unlock signal indicates the controllable power module is in the start-up state, meaning it can modulate via trigger pulses and follow the reference voltage at the grid connection point. An inactive unlock signal indicates the controllable power module is in the stop state, meaning it neither modulates nor follows the reference voltage, and all power devices within the module are disconnected. When the controllable power module transitions from the stop state to the start state, the unlock signal changes from inactive to active. This transition allows the controllable power module to begin modulating and gradually follow the reference voltage at the grid connection point. When the controllable power module needs to be stopped, the unlock signal changes from active to inactive. This transition causes the controllable power module to stop modulating and enter the stop state.

[0099] It should be noted that when the unlocking total signal changes from an active state to an inactive state, the real-time simulation module determines the reference voltage of the grid connection point in real time based on the initial reference voltage and the preset start-stop coefficient. The preset start-stop coefficient decreases from a second threshold to a first threshold at a second preset rate. The real-time simulation module is used to decrease the preset start-stop coefficient from the second threshold to the first threshold, ensuring that the preset start-stop coefficient can return to the first threshold, preparing for the next time the unlocking total signal changes from an inactive state to an active state. Furthermore, when the unlocking total signal changes from an active state to an inactive state, the trigger pulse of the controllable power supply module is blocked, that is, the generation of trigger pulses stops, and the sending of trigger pulses to the controllable power supply module stops.

[0100] Please see Figure 2 As shown below, the modulation process of a controllable power supply modulation system suitable for grid-type converter testing is illustrated by an example:

[0101] Figure 2 This is an example of a scenario in this application where the modulation system includes a single controllable power supply module. Figure 2 The modulation system includes one real-time simulation module, one modulation module, and one controllable power supply module. The real-time simulation module can be either RTDS or RT-LAB, and the controllable power supply module can be one of a two-level grid converter, a three-level grid converter, or a modular multilevel grid converter.

[0102] First, the process by which the real-time simulation module determines the modulation wave of the controllable power supply module is as follows:

[0103] Step 1: The real-time simulation module calculates the initial reference voltage of the grid connection point based on the constructed power model, which is the initial reference voltage of the grid connection point connected to the controllable power supply module. Furthermore, the real-time simulation module provides a grid connection point for the controllable power supply module. By changing the model structure and parameters of the constructed power model, the real-time simulation module can alter the amplitude, frequency, phase, and other parameters of the initial reference voltage of the grid connection point, thereby simulating disturbances such as system faults, frequency changes, and phase jumps in actual power systems. Understandably, the real-time simulation module can simulate various real-world scenarios and provide the initial reference voltage of the grid connection point under different scenarios in a timely manner.

[0104] Step 2: The real-time simulation module calculates the reference voltage of the grid connection point based on the initial reference voltage of the grid connection point and the unlocking total signal corresponding to the controllable power supply module.

[0105] Specifically, the initial reference voltage at the grid connection point is multiplied by a preset start-stop coefficient to obtain the reference voltage at the grid connection point. When the real-time simulation module detects a valid unlock signal, it increases the preset start-stop coefficient from 0 to 1 at a preset first rate, thereby starting the controllable power supply module and causing it to follow the reference voltage. When the real-time simulation module detects an invalid unlock signal, it decreases the preset start-stop coefficient from 1 to 0 at a preset second rate, thereby shutting down the controllable power supply module.

[0106] Step 3: The real-time simulation module calculates the modulation wave of the controllable power supply module based on the reference voltage at the grid connection point and the DC voltage of the controllable power supply module.

[0107] Then, the process of the modulation module generating the trigger pulse for the controllable power supply module is as follows:

[0108] Please see Figure 3 As shown, Figure 3 This is a schematic block diagram of a modulation module provided in an embodiment of this application. In the diagram, the modulation module rapidly generates a trigger pulse based on the modulation wave provided by the real-time simulation module and the unlock total signal. The trigger pulse is then sent to the controllable power supply module to control the inverter within the controllable power supply module, thereby causing the controllable power supply module to follow the reference voltage. The unlock total signal is generated by the unlock signal of the controllable power supply module. It should be noted that when the modulation module detects that the unlock total signal is valid, it rapidly converts the received modulation wave into a trigger pulse and sends it to the controllable power supply module; when it detects that the unlock total signal is invalid, it immediately blocks the trigger pulse, thereby blocking the controllable power supply module. In the modulation module, the trigger pulse unlocking and blocking are performed according to a specific timing sequence, thereby reducing the stress impact on the power module during the unlocking and blocking process.

[0109] In some embodiments, when the real-time simulation module is used to provide a grid connection point, there are multiple controllable power supply modules, and each controllable power supply module is connected to the grid connection point and the modulation module respectively.

[0110] The total unlock signal is determined by logical operations on each controllable power module.

[0111] It's important to understand that the overall unlock signal is determined through logical operations based on the unlock signals of each controllable power module. Both the real-time simulation module and the modulation module require the overall unlock signal for processing. Therefore, both the real-time simulation module and the modulation module can be configured with programs or structural units corresponding to the logical operations, allowing them to determine the overall unlock signal of each controllable power module based on logical operations after each module sends its unlock signal. It's crucial to know that a valid unlock signal indicates the controllable power module is in the start state, while an invalid unlock signal indicates it is in the stop state. A valid overall unlock signal means that the unlock signals of each controllable power module are valid, while an invalid overall unlock signal means that the unlock signal of at least one controllable power module is invalid. To protect all controllable power modules connected to a single grid point, when the overall unlock signal is invalid (i.e., at least one controllable power module's unlock signal is invalid), each controllable power module is in the stop state.

[0112] It is also necessary to understand that when the real-time simulation module is used to provide a grid connection point, a grid connection point can provide an initial reference voltage for multiple controllable power supply modules. After a modulation module generates a trigger pulse, the trigger pulse can be sent to each controllable power supply module, so that each controllable power supply module follows the reference voltage.

[0113] It should be noted that when the real-time simulation module is used to provide grid connection points, if multiple controllable power supply modules are required, the primary AC side of the inverter in each module should be connected to the grid-connected converter. This means that the primary AC side of the inverter in each controllable power supply module is connected to the same bus as the primary AC side of the inverter in the grid-connected converter. When the capacity of the grid-connected converter is large, and a single controllable power supply module cannot meet the corresponding capacity requirements, multiple controllable power supply modules need to be connected to the grid-connected converter on the same bus. This allows multiple controllable power supply modules to effectively drive the grid-connected converter, ensuring that the conditions for evaluating the actual grid-connected capability of the grid-connected converter can be met. Furthermore, it is known that when there is only one controllable power supply module, the unlock signal of that module also undergoes an AND logic operation, and the overall unlock signal state after the operation is the same as the unlock signal state of that specific controllable power supply module.

[0114] In some embodiments, the DC voltage of the controllable power supply module is determined by averaging the DC bus voltage of each controllable power supply module.

[0115] It's important to understand that the DC voltage is determined by averaging the DC bus voltage of each controllable power supply module. The real-time simulation module requires DC voltage processing; therefore, it can be configured with a program or structural unit for averaging, allowing each controllable power supply module to send its DC bus voltage to the real-time simulation module. The real-time simulation module can then determine the DC voltage of each controllable power supply module based on the averaging calculation. In essence, through averaging, the real-time simulation module can calculate the average DC voltage of all controllable power supply modules. This averaging method helps smooth out voltage differences between modules, ensuring system stability and consistency.

[0116] It should be noted that when the real-time simulation module provides a single grid connection point, there are multiple controllable power supply modules, each connected to both the grid connection point and the modulation module. Specifically, the inverters of multiple controllable power supply modules connect AC power to the grid connection point, meaning multiple controllable power supply modules are connected in parallel. The modulation wave output by the real-time simulation module is sent to a modulation module, which generates trigger pulses that are sent to each controllable power supply module, thereby modulating each module and ensuring that each module follows the initial reference voltage provided by the real-time simulation module. Furthermore, it is known that when there is only one controllable power supply module, its DC bus voltage is also averaged, and the resulting DC voltage is the same as the DC bus voltage of that controllable power supply module.

[0117] In summary, when the real-time simulation module provides a single grid connection point, there are multiple controllable power supply modules and one modulation module. The grid connection point corresponds to each modulation module, and each controllable power supply module is connected to both the grid connection point provided by the real-time simulation module and the modulation module. It's important to note that the connection between the controllable power supply module and the grid connection point provided by the real-time simulation module is a simulated connection; that is, the real-time simulation module provides the initial reference voltage for the grid connection point corresponding to the controllable power supply module. Similarly, the connection between the modulation module and the grid connection point is also simulated; that is, the real-time simulation module provides the reference voltage for the grid connection point corresponding to the modulation module. Ultimately, this allows the controllable power supply module to follow the initial reference voltage of the grid connection point provided by the real-time simulation module.

[0118] Please see Figure 4 As shown, Figure 4 This is a schematic block diagram of another controllable power supply modulation system suitable for testing grid-type converters, provided in an embodiment of this application. The modulation process of the controllable power supply modulation system suitable for testing grid-type converters is illustrated below by way of an example:

[0119] Figure 4 This application provides an example of a modulation system that includes multiple controllable power supply modules. Figure 4 In this system, the modulation system includes one real-time simulation module, one modulation module, and n controllable power supply modules. The AC and DC sides of the n controllable power supply modules operate in parallel.

[0120] First, the process by which the real-time simulation module determines the modulation wave of the controllable power supply module is as follows:

[0121] Step 1: The real-time simulation module calculates the initial reference voltage of the grid connection point based on the constructed power model, which is the initial reference voltage of the grid connection point connected to the controllable power supply module. Furthermore, the real-time simulation module provides a grid connection point for the controllable power supply module. The real-time simulation module can change the amplitude, frequency, phase, and other parameters of the initial reference voltage of the grid connection point by modifying the model structure and parameters of the constructed power model, thereby simulating disturbances such as system faults, frequency changes, and phase jumps in the actual power system. Understandably, the real-time simulation module can simulate various real-world scenarios and provide the initial reference voltage of the grid connection point under different scenarios in a timely manner.

[0122] Step 2: The real-time simulation module calculates the reference voltage of the grid connection point based on the initial reference voltage of the grid connection point and the total unlocking signal corresponding to the n controllable power supply modules. Specifically, the initial reference voltage of the grid connection point is multiplied by a preset start-stop coefficient to obtain the reference voltage of the grid connection point. When the real-time simulation module detects that the total unlocking signal is valid, it increases the preset start-stop coefficient from 0 to 1 at a preset first rate, thereby starting the controllable power supply modules and making them follow the reference voltage. When the real-time simulation module detects that the total unlocking signal is invalid, it decreases the preset start-stop coefficient from 1 to 0 at a preset second rate, thereby stopping the controllable power supply modules. The real-time simulation module obtains the total unlocking signal of the controllable power supply modules by performing AND logic calculations on the unlocking signal of each controllable power supply module.

[0123] Step 3: The real-time simulation module calculates the modulation wave of the controllable power supply module based on the reference voltage at the grid connection point and the DC voltage of the controllable power supply module. Specifically, the real-time simulation module averages the DC bus voltage of each controllable power supply module to obtain its DC voltage. The real-time simulation module then outputs a modulation wave.

[0124] Then, the process of the modulation module generating the trigger pulse for the controllable power supply module is as follows:

[0125] Please see Figure 5 As shown, Figure 5This is a schematic block diagram of another modulation module provided in an embodiment of this application. In a scenario where multiple controllable power supply modules are connected in parallel on both AC and DC sides, the modulation module in the diagram simultaneously receives the unlocking signals from n controllable power supply modules and the modulation wave U provided by the real-time simulation module. ref The system synthesizes the unlock signals from n controllable power modules into a total unlock signal through logic calculation. Then, based on the modulation wave provided by the real-time simulation module and the total unlock signal, trigger pulses are rapidly generated and sent to each of the n controllable power modules, enabling rapid trigger control and ensuring that the n controllable power modules follow the initial reference voltage. It's important to note that when the modulation module detects that all unlock signals from the n controllable power modules are valid, it quickly converts the received modulation wave into trigger pulses and sends them to the controllable power modules; when any unlock signal from any of the n controllable power modules is invalid, the trigger pulses are immediately blocked, thus blocking the controllable power module. In the modulation module, pulse unlocking and blocking are performed according to a specific timing sequence, thereby reducing the stress impact on the power modules within the controllable power modules during the unlocking and blocking process. In this example, the trigger pulses sent by the modulation module to the n controllable power modules are the same set of signals.

[0126] In some embodiments, when the real-time simulation module is used to provide multiple grid connection points, there are multiple controllable power supply modules and multiple modulation modules. Each grid connection point corresponds to one modulation module, and each modulation module is connected to at least one controllable power supply module. The controllable power supply module connected to each modulation module is connected to the grid connection point.

[0127] In some embodiments, the initial reference voltages at at least some of the grid connection points are different.

[0128] It is important to understand that the initial reference voltages of at least some grid connection points are different, which means that the real-time simulation module can provide different initial reference voltages for each grid connection point, and the real-time simulation module can also provide different initial reference voltages for some grid connection points and the same initial reference voltages for other grid connection points, and the real-time simulation module can also provide the same initial reference voltage for each grid connection point.

[0129] It's also important to understand that the real-time simulation module can build and simulate a power model, providing initial reference voltages for the grid connection points based on their different locations within the model, thus ensuring that at least some grid connection points have different initial reference voltages. The real-time simulation module can also build and simulate multiple power models, each corresponding to at least one grid connection point, and then provide initial reference voltages for each grid connection point based on its location within each model, again ensuring that at least some grid connection points have different initial reference voltages.

[0130] It should be noted that when the real-time simulation module is used to provide multiple grid connection points, there are multiple controllable power supply modules and multiple modulation modules. Each grid connection point corresponds to one modulation module, and each modulation module is connected to at least one controllable power supply module. The controllable power supply modules connected to each modulation module are connected to the grid connection point. Specifically, controllable power supply modules corresponding to the same modulation module are connected in parallel via a bus, while controllable power supply modules connected to different modulation modules are connected in parallel via different buses. This means that controllable power supply modules connected to the same modulation module are connected in parallel via the same bus, while controllable power supply modules connected to different modulation modules are connected in parallel via different buses. This ensures independence between them and avoids mutual interference. Furthermore, controllable power supply modules connected to different modulation modules can be connected to different grid-type converters, enabling simultaneous performance testing of multiple grid-type converters and providing broader testing capabilities and flexibility.

[0131] Understandably, when the real-time simulation module is used to provide multiple grid connection points, each grid connection point corresponds to a modulation module, and each modulation module is connected to at least one controllable power supply module. Each controllable power supply module connected to a modulation module is also connected to the grid connection point. This simultaneously enables multi-point access of controllable power supply modules and rapid synchronous triggering control of multiple controllable power supply modules, providing a foundation for flexible expansion of the controllable power supply module capacity. Furthermore, it allows a single real-time simulation module to simulate various real-world scenarios and provide different voltage conditions in a timely manner to adapt to various power system scenarios. This covers the operating conditions of a wider range of controllable power supply modules, modulating the initial reference voltage of the controllable power supply modules to follow the grid connection point, which helps in the in-depth evaluation of the grid-connected converter's grid performance.

[0132] In some embodiments, when the real-time simulation module is used to provide multiple grid connection points, there are multiple controllable power supply modules and multiple modulation modules. Each grid connection point corresponds to one modulation module, each modulation module is connected to one controllable power supply module, and the controllable power supply module connected to each modulation module is connected to the grid connection point. Please refer to [link to relevant documentation]. Figure 6 As shown, Figure 6 This is a schematic block diagram of another controllable power modulation system suitable for testing grid-type converters, provided in an embodiment of this application. The modulation process of the controllable power modulation system suitable for testing grid-type converters is illustrated below by way of an example:

[0133] Figure 6 This application provides an example of a scenario where a real-time simulation module is provided with multi-node access, each grid connection point corresponds to a modulation module, and each modulation module is connected to a controllable power supply module. Figure 6In this embodiment, the modulation system includes one real-time simulation module, m modulation modules, and m controllable power supply modules. Each modulation module corresponds to a reference voltage at one grid connection point, and each controllable power supply module corresponds to both one modulation module and the initial reference voltage at one grid connection point. The AC sides of the m controllable power supply modules operate independently; that is, the AC sides of the m controllable power supply modules are not interconnected.

[0134] The real-time simulation module calculates the modulation wave corresponding to each controllable power supply module in real time. Taking the j-th controllable power supply module as an example, the real-time simulation module obtains the DC voltage and total unlocking signal of the j-th controllable power supply module based on its DC bus voltage and unlocking signal. Based on the initial reference voltage of the j-th grid connection point corresponding to the j-th controllable power supply module, the DC voltage of the j-th controllable power supply module, and the total unlocking signal, the module calculates the modulation wave U of the j-th controllable power supply module in real time. refj The modulated wave is then transmitted to the j-th modulation module via high-speed communication.

[0135] The process by which the real-time simulation module determines the modulation wave corresponding to the j-th controllable power supply module is as follows:

[0136] Step 1: The real-time simulation module calculates the initial reference voltage of the j-th grid connection point based on the constructed power model, i.e., the initial reference voltage of the j-th grid connection point connected to the j-th controllable power supply module. The real-time simulation module can change the amplitude, frequency, phase, and other parameters of the initial reference voltage of the grid connection point by modifying the model structure and parameters of the constructed power model, thereby simulating disturbances such as system faults, frequency changes, and phase jumps in the actual power system. Understandably, the real-time simulation module can simulate various real-world scenarios and provide the initial reference voltage of the grid connection point under different scenarios in a timely manner.

[0137] Step 2: The real-time simulation module calculates the reference voltage of the grid-connected point based on the initial reference voltage of the j-th grid-connected point and the unlocking total signal corresponding to the j-th controllable power supply module. Specifically, the initial reference voltage of the j-th grid-connected point is multiplied by a preset start-stop coefficient to obtain the reference voltage of the j-th grid-connected point. When the real-time simulation module detects that the unlocking total signal corresponding to the j-th controllable power supply module is valid, it increases the preset start-stop coefficient from 0 to 1 at a preset first rate, thereby starting the grid-connected converter and causing the j-th controllable power supply module to follow the initial reference voltage of the j-th grid-connected point. When the real-time simulation module detects that the unlocking total signal corresponding to the j-th controllable power supply module is invalid, it decreases the preset start-stop coefficient from 1 to 0 at a preset second rate, thereby shutting down the j-th controllable power supply module. It should be noted that the real-time simulation module calculates the total unlocking signal of each controllable power supply module after performing AND logic calculations on the unlocking signal, and then substitutes it into the corresponding grid-connected point to calculate the reference voltage.

[0138] Step 3: The real-time simulation module calculates the modulation wave of the j-th controllable power supply module based on the reference voltage of the j-th grid connection point and the DC voltage corresponding to the j-th controllable power supply module. It should be noted that the real-time simulation module obtains the DC voltage of each controllable power supply module by averaging the DC bus voltage corresponding to each module, and then substitutes this value into the corresponding grid connection point to calculate the modulation wave.

[0139] The process by which the modulation module generates the trigger pulse for the controllable power supply module is as follows:

[0140] In scenarios with multiple nodes connected, each grid connection point corresponding to a modulation module, and each modulation module connected to a controllable power supply module, the modulation module is as follows: Figure 3 As shown in the figure. The j-th modulation module in the figure modulates the waveform U provided by the real-time simulation module. ref The unlocking signal provided by the j-th controllable power module is rapidly used to generate a trigger pulse, which is then sent to the j-th controllable power module to achieve rapid trigger control. When the j-th modulation module detects that the unlocking signal provided by the j-th controllable power module is valid, it quickly converts the received modulation wave into a trigger pulse and sends it to the j-th controllable power module; when it detects that the unlocking signal provided by the j-th controllable power module is invalid, it immediately blocks the trigger pulse, thereby blocking the j-th controllable power module. In the j-th modulation module, pulse unlocking and blocking are performed according to a specific timing sequence, thereby reducing the stress impact on the power module during the unlocking and blocking process.

[0141] In other embodiments, when the real-time simulation module is used to provide multiple grid connection points, there are multiple controllable power supply modules and multiple modulation modules. Each grid connection point corresponds to one modulation module, and each modulation module is connected to multiple controllable power supply modules. The controllable power supply modules connected to each modulation module are connected to the grid connection point.

[0142] Please see Figure 7 As shown, Figure 7 This is a schematic block diagram of another controllable power supply modulation system suitable for testing grid-type converters, provided in an embodiment of this application. The modulation process of the controllable power supply modulation system suitable for testing grid-type converters is illustrated below by way of an example:

[0143] Figure 7 This application provides an example of a scenario where a real-time simulation module is provided with multi-node access, each grid connection point corresponds to a modulation module, and each modulation module is connected to multiple controllable power supply modules. Figure 7 The testing system includes one real-time simulation module and m modulation modules. A controllable power supply module is provided. In this embodiment, one modulation module corresponds to the reference voltage of one grid connection point, and the j-th modulation module corresponds to the n-th modulation module. j Taiwan controllable power supply module, and n j The controllable power supply modules are connected in parallel on both the AC and DC sides. For ease of description, the n modules corresponding to the j-th modulation module will be referred to below. j The controllable power supply module is defined as the j-th group of controllable power supply modules.

[0144] The real-time simulation module calculates the modulation wave of each controllable power supply module in real time. Taking the j-th group of controllable power supply modules corresponding to the j-th modulation module as an example, the real-time simulation module acquires the DC bus voltage and unlocking signal of the j-th group of controllable power supply modules in real time. Based on the DC bus voltage provided by the j-th group of controllable power supply modules, it calculates the average DC bus voltage as the DC voltage. The unlocking signal provided by the j-th group of controllable power supply modules is used to calculate the total unlocking signal through logical operations. Then, based on the initial reference voltage of the j-th grid connection point corresponding to the j-th group of controllable power supply modules, the DC voltage corresponding to the j-th group of controllable power supply modules, and the total unlocking signal, the module calculates the modulation wave of the j-th group of controllable power supply modules in real time and sends the modulation wave to the modulation module via high-speed communication. When all j-th group of controllable power supply modules are running, the unlocking signal of the controllable power supply module is in an active state. When any converter in the j-th group of controllable power supply modules stops or is locked by protection, the unlocking signal of the controllable power supply module changes from active to inactive.

[0145] The process by which the real-time simulation module determines the modulation wave corresponding to the j-th group of controllable power supply modules is as follows:

[0146] Step 1: The real-time simulation module calculates the initial reference voltage of the j-th grid connection point based on the constructed power model. This is the initial reference voltage of the grid connection point connected to the j-th group of controllable power supply modules. The real-time simulation module can change the amplitude, frequency, phase, and other parameters of the initial reference voltage of the grid connection point by modifying the model structure and parameters of the constructed power model, thereby simulating disturbances such as system faults, frequency changes, and phase jumps in the actual power system. Understandably, the real-time simulation module can simulate various real-world scenarios and provide the initial reference voltage of the grid connection point under different scenarios in a timely manner.

[0147] Step 2: The real-time simulation module calculates the reference voltage of the j-th grid-connected point based on the initial reference voltage of the j-th grid-connected point and the unlocking total signal corresponding to the j-th group of controllable power modules. The initial reference voltage of the j-th grid-connected point is multiplied by the start-stop coefficient to obtain the reference voltage of the j-th grid-connected point. When the real-time simulation module detects that the unlocking total signal corresponding to the j-th group of controllable power modules is valid, it increases the preset start-stop coefficient from 0 to 1 at a preset first rate, thereby starting the j-th group of controllable power modules. When the real-time simulation module detects that the unlocking total signal corresponding to the j-th group of controllable power modules is invalid, it decreases the preset start-stop coefficient from 1 to 0 at a preset second rate, thereby stopping the j-th group of controllable power modules.

[0148] Step 3: The real-time simulation module calculates the modulation wave U of the j-th group of controllable power supply modules based on the reference voltage of the j-th grid connection point and the DC voltage corresponding to the j-th group of controllable power supply modules. refj .

[0149] In a scenario with multiple nodes connected, each grid connection point corresponding to a modulation module, and each modulation module connected to multiple controllable power modules, the j-th modulation module simultaneously receives the unlocking signal from the j-th group of controllable power modules and the j-th modulation wave provided by the real-time simulation module. It synthesizes the unlocking signal from the j-th group of controllable power modules into a total unlocking signal using logic. Then, based on the j-th modulation wave provided by the real-time simulation module and the total unlocking signal from the j-th group of controllable power modules, it quickly generates a trigger pulse and sends it to the j-th group of controllable power modules, achieving rapid trigger control of all controllable power modules in the j-th group. When the modulation module detects that the unlocking signals provided by all controllable power modules in the j-th group are valid, it quickly converts the received j-th modulation wave into a trigger pulse and sends it to all controllable power modules in the j-th group. When the unlocking signal provided by any controllable power module in the j-th group is invalid, it immediately blocks the trigger pulse, thereby blocking all controllable power modules in the j-th group. In the j-th modulation module, pulse unlocking and blocking are performed according to a specific timing sequence, thereby reducing the stress impact on the power modules during the unlocking and blocking process. In this example, the unlock signal sent by the j-th modulation module to all controllable power modules in the j-th group is the same signal.

[0150] In some embodiments, the real-time simulation module and the modulation module communicate using the Aurora protocol, with a communication transmission rate greater than or equal to 1 Gbit / s.

[0151] Understandably, communication based on the Aurora protocol enables a communication transmission rate greater than or equal to 1 Gbit / s, allowing the real-time simulation module to transmit data to the modulation module quickly and accurately, thereby improving the modulation process rate.

[0152] Please see Figure 8 As shown, Figure 8 This is a schematic diagram of phase A bridge arm in the controllable power supply module provided in this application embodiment. The process by which the modulation module determines the trigger pulse of the controllable power supply module in real time based on the modulation wave and the unlocking total signal is as follows: After receiving the modulation wave, the modulation module compares it with its own preset triangular carrier wave, thereby controlling the on / off state of the switching elements in the controllable power supply module, and thus realizing the control of the modulation wave U... ref Modulation. For example, a grid connection point of the simulation module can provide initial reference voltages for the three-phase AC power (phase A, phase B, and phase C). The simulation module can then determine the modulation waves corresponding to the three-phase AC power in real time based on the unlocking signal of the controllable power module, the DC voltage of the controllable power module, and the initial reference voltages of the three phases, and send them to the modulation module. The modulation module, based on the received modulation waves corresponding to the three-phase AC power, compares the three-phase modulation waves with the triangular carrier waves it pre-generates, thereby controlling the on / off state of the corresponding switching elements in the controllable power module to modulate the modulation wave Uref.

[0153] The following explanation uses phase A as an example. The topology of phase A is as follows: Figure 8 As shown in the diagram, phase A bridge arm contains six switching elements, designated T1 to T6. T1, T4, T5, and T6 are high-frequency switching elements, while T2 and T3 are power frequency switching elements. T5 and T6 are called clamping transistors, T1 and T4 are external transistors, and T2 and T3 are internal transistors. Additionally, in the diagram, P represents the positive terminal, N represents the negative terminal, C1, C2, and C3 represent capacitors, L represents inductance, O represents the DC midpoint, and Vout represents the output of phase A bridge arm.

[0154] When the modulation module receives the A-phase modulation wave U ref When the value is greater than zero, T2 and T6 are normally open, and T3 and T4 are normally closed. During this period, if the modulation wave U of phase A is... ref If the amplitude is greater than the triangular carrier wave, then T1 is turned on and T5 is turned off; conversely, if the amplitude of phase A modulated wave U is less than the triangular carrier wave... ref If the signal is less than or equal to the triangular carrier wave, then T1 is turned off and T5 is turned on.

[0155] When the modulation module receives the A-phase modulation wave U ref When the value is less than zero, T1 and T2 are normally closed, and T3 and T5 are normally open. During this period, if the modulation wave U of phase A is... ref If the sum of phase A and phase 1 is less than the triangular carrier wave, then T4 is on and T6 is off; otherwise, if the sum of phase A and phase 1 is less than the triangular carrier wave, then phase A is on and phase 1 is off. ref If the sum of T4 and T6 is greater than or equal to the triangular carrier wave, then T4 is turned off and T6 is turned on.

[0156] During the above conduction process, the pulses between T1 and T5, T2 and T3, and T4 and T6 are complementary, which requires the addition of a dead zone. The dead zone width is usually 3μs.

[0157] It should be noted that, in order to achieve rapid triggering, the modulation module in this application can use FPGA to implement high-speed calculation, with a calculation delay of less than 2μs.

[0158] Please see Figure 9 As shown, Figure 9 This is a schematic flowchart of a modulation method for a grid-type converter provided in an embodiment of this application.

[0159] This application also provides a controllable power supply modulation method suitable for testing grid-type converters, the method comprising:

[0160] Real-time determination of the total unlock signal and DC voltage of the controllable power module;

[0161] Based on the unlock total signal, DC voltage and the initial reference voltage of the controllable power module connection point, the modulation wave of the controllable power module is determined in real time.

[0162] Based on the modulation wave and the unlocking total signal, the trigger pulse of the controllable power module is determined in real time and sent to the controllable power module so that the controllable power module follows the initial reference voltage of the grid connection point.

[0163] It is important to understand that the modulation method specifically includes: First, determining the real-time unlocking total signal and DC voltage of the controllable power module. Then, based on the real-time data of the unlocking total signal, the real-time data of the DC voltage of the controllable power module, and the real-time data of the initial reference voltage of the grid connection point to which the controllable power module is connected, determining the real-time modulation wave of the controllable power module. Finally, based on the real-time modulation wave and the real-time unlocking total signal of the controllable power module, determining the real-time trigger pulse of the controllable power module, so as to modulate the controllable power module through the trigger pulse, enabling the controllable power module to follow the initial reference voltage of the grid connection point, ensuring that the controllable power module can effectively adapt to the dynamic changes of the power grid and maintain a stable grid connection state. This application uses real-time data to determine the modulation wave and trigger pulse, ensuring that the controllable power module can flexibly respond to changes in the power grid.

[0164] In summary, this application provides a controllable power supply modulation system and method suitable for grid-connected converter testing. Applied to the grid-connected converter testing process, the modulation system includes a controllable power supply module, a real-time simulation module, and a modulation module. The real-time simulation module calculates the modulation wave in real time based on a simulated power model and transmits the modulation wave to the modulation module via high-speed communication. The modulation module simultaneously receives the modulation wave provided by the real-time simulation module and the unlocking signal provided by the controllable power supply module. When the unlocking signal provided by the controllable power supply module is valid, the modulation wave is quickly converted into a trigger pulse and sent to the controllable power supply module, ultimately achieving rapid trigger control of the power modules in the controllable power supply module. When the unlocking signal provided by any controllable power supply module is invalid, the trigger pulse is immediately blocked, thereby blocking the controllable power supply module. This application constructs a modulation system including a controllable power supply module, a real-time simulation module, and a modulation module. The real-time simulation module can generate the required voltage as the initial reference voltage for the grid connection point. The real-time simulation module can simulate real-world scenarios and provide voltage in a timely manner, ensuring that the simulated voltage is accurately reflected in the connected controllable power supply module, thus facilitating the modulation of the controllable power supply module. Furthermore, the controllable power supply module, real-time simulation module, and modulation module form a fast-response modulation system, enabling the controllable power supply module to quickly adjust to match the initial reference voltage of the grid connection point provided by the real-time simulation module. This accelerates the modulation speed of the controllable power supply module during testing, thereby improving the testing efficiency of the grid-connected converter. This application also effectively solves the problem of rapid modulation of the controllable power supply, realizing multi-point access of the controllable power supply module and rapid synchronous trigger control of multiple controllable power supply modules, providing a foundation for flexible expansion of the controllable power supply module capacity. Additionally, by providing the same trigger pulse to multiple controllable power supply modules at the same grid connection point through a single modulation module, circulating current between different controllable power supply modules can be effectively reduced, thereby improving the consistency of the output voltage of different controllable power supply modules.

[0165] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0166] The above are merely preferred embodiments of this application and are not intended to limit this application in any way. Although this application has disclosed preferred embodiments as above, it is not intended to limit this application. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the technical solution of this application. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of this application without departing from the scope of the technical solution of this application shall still fall within the scope of the technical solution of this application.

Claims

1. A controllable power modulation system suitable for testing grid-type converters, characterized in that, The modulation system, applied in the testing process of the grid-type converter, includes: A controllable power supply module is connected to the grid-type converter; A real-time simulation module is connected to the controllable power supply module. The real-time simulation module provides the grid connection point of the controllable power supply module and the initial reference voltage of the grid connection point in real time. Based on the unlocking total signal of the controllable power supply module, the DC voltage of the controllable power supply module, and the initial reference voltage, it determines the modulation wave of the controllable power supply module in real time. A power model is constructed based on the real-time simulation module. The grid connection point of the controllable power supply module is provided based on the power model, and the initial reference voltage of the grid connection point is provided in real time based on simulation calculations. A modulation module is connected to both the controllable power supply module and the real-time simulation module. The modulation module determines the trigger pulse of the controllable power supply module in real time based on the modulation wave and the unlocking total signal, and sends the trigger pulse to the controllable power supply module, causing the controllable power supply module to follow the initial reference voltage of the grid connection point. The unlocking total signal includes valid and invalid signals. When the unlocking total signal is valid, the trigger pulse of the controllable power supply module is determined in real time, and the controllable power supply module is in a start-up state. When the unlocking total signal is invalid, the trigger pulse of the controllable power supply module is blocked, and the sending of trigger pulses to the controllable power supply module stops, and the controllable power supply module is in a stop state.

2. The controllable power modulation system for testing grid-type converters according to claim 1, characterized in that, The real-time simulation module is used to determine the modulation wave of the controllable power supply module in real time based on the unlocking total signal of the controllable power supply module, the DC voltage of the controllable power supply module, and the initial reference voltage, including: Based on the total unlock signal and the initial reference voltage, the reference voltage of the grid connection point is determined in real time. Based on the reference voltage and the DC voltage, the modulation wave of the controllable power supply module is determined in real time.

3. The controllable power modulation system for testing grid-type converters according to claim 2, characterized in that, The total unlock signal includes valid signals; The real-time simulation module is used to determine the reference voltage of the grid connection point in real time based on the unlocking total signal and the initial reference voltage, including: When the total unlock signal is the valid signal, the reference voltage of the grid connection point is determined in real time based on the initial reference voltage of the grid connection point and the preset start-stop coefficient; The preset start / stop coefficient is based on a first preset rate and increases from a first threshold to a second threshold.

4. The controllable power modulation system for testing grid-type converters according to claim 2, characterized in that, The total unlock signal includes invalid signals; The real-time simulation module is used to determine the reference voltage of the grid connection point in real time based on the unlocking total signal and the initial reference voltage, including: When the total unlock signal is the invalid signal, the reference voltage of the grid connection point is determined in real time based on the initial reference voltage and the preset start-stop coefficient. The preset start / stop coefficient is based on a second preset rate, decreasing from a second threshold to a first threshold.

5. The controllable power modulation system for testing grid-type converters according to claim 1, characterized in that, When the real-time simulation module is used to provide a grid connection point, there are multiple controllable power supply modules, and each controllable power supply module is connected to the grid connection point and the modulation module respectively; The total unlock signal is determined by a logical operation on each of the controllable power modules.

6. The controllable power modulation system for testing grid-type converters according to claim 5, characterized in that, The DC voltage of the controllable power supply module is determined by averaging the DC bus voltage of each controllable power supply module.

7. The controllable power modulation system for testing grid-type converters according to claim 1, characterized in that, When the real-time simulation module is used to provide multiple grid connection points, there are multiple controllable power supply modules and multiple modulation modules. Each grid connection point corresponds to one modulation module, and each modulation module is connected to at least one controllable power supply module. The controllable power supply module connected to each modulation module is connected to the grid connection point.

8. The controllable power modulation system for testing grid-type converters according to claim 7, characterized in that, The initial reference voltages of at least some of the grid connection points are different.

9. The controllable power modulation system for testing grid-type converters according to claim 1, characterized in that, The real-time simulation module and the modulation module communicate using the Aurora protocol, with a communication transmission rate greater than or equal to 1 Gbit / s.

10. A controllable power supply modulation method suitable for testing grid-type converters, characterized in that, The controllable power module is connected to the grid-type converter during the testing process. The modulation method includes: Real-time determination of the total unlock signal and DC voltage of the controllable power module; Based on the unlocking total signal, the DC voltage, and the initial reference voltage of the grid connection point of the controllable power module, the modulation wave of the controllable power module is determined in real time; wherein, a power model is constructed based on a real-time simulation module; the grid connection point of the controllable power module is provided based on the power model, and the initial reference voltage of the grid connection point is provided in real time based on simulation calculations; Based on the modulated wave and the unlocking total signal, the trigger pulse of the controllable power module is determined in real time, and the trigger pulse is sent to the controllable power module so that the controllable power module follows the initial reference voltage of the grid connection point; wherein, the unlocking total signal includes a valid signal and an invalid signal. When the unlocking total signal is the valid signal, the trigger pulse of the controllable power module is determined in real time, and the controllable power module is in the start state; when the unlocking total signal is the invalid signal, the trigger pulse of the controllable power module is blocked, the sending of trigger pulses to the controllable power module is stopped, and the controllable power module is in the stop state.

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