A simulation interface control method and system

Abstract

This invention discloses a simulation interface control method and system. The method includes: constructing a digital subsystem and a physical subsystem for a novel power distribution system; then: introducing a controlled current source into the digital subsystem circuit and a controlled voltage source into the physical subsystem circuit; real-time acquisition of the output voltage signal of the digital subsystem and the input voltage signal of the controlled voltage source in the physical subsystem within the same cycle; extracting the fundamental phase of the output and input voltage signals and calculating the difference to obtain the voltage phase difference; based on the voltage phase difference, using a deadbeat controller to perform delay compensation for the errors in the output and input voltage signals to eliminate signal tracking errors. The deadbeat controller includes a state observer and a repetitive predictive observer. By using this invention, interface delay compensation can be achieved while satisfying the real-time performance and stability of the simulation. This invention can be widely applied in the field of digital-physical hybrid simulation.

Description

Technical Field

[0001] This invention relates to the field of digital-physical hybrid simulation, and in particular to a simulation interface control method and system. Background Technology

[0002] With the large-scale clustering of distributed resources such as photovoltaics, wind power, energy storage, and electric vehicle charging piles, and the widespread use of power electronic devices, new power distribution systems exhibit the "dual high" characteristics of high proportion of new energy sources and high proportion of power electronic equipment. The strong uncertainty between source and load, and the high degree of power electronic integration between source, grid, and load are becoming increasingly prominent features. Therefore, it is urgent to study the operating characteristics of new power distribution systems and their impact on grid characteristics.

[0003] Power Hardware in-the-Loop (PHIL) simulation focuses on the simulation of control hardware and real physical components. It can effectively test power electronic devices and power system hardware, making it an important tool for the application of hybrid digital-physical simulation in power system simulation.

[0004] The Ideal Transformer Model (ITM) algorithm was the first proposed interface algorithm and is now widely used in PHIL simulations of power systems. However, most existing methods for compensating for ITM interface delays are only applicable to traditional power systems or power systems with low renewable energy penetration. For complex simulation scenarios of new distribution systems with "high energy consumption and high emissions" characteristics, the calculation steps are cumbersome and complicated, increasing the complexity and coupling of the system. This makes it impossible to quickly achieve signal tracking compensation and eliminate errors caused by time delays, which can easily lead to system instability. Summary of the Invention

[0005] In view of this, in order to solve the problem that existing ITM interface delay compensation methods cannot simultaneously meet the requirements of simulation real-time performance and stability, in a first aspect, the present invention proposes a simulation interface control method, the method comprising the following steps:

[0006] For the new power distribution system, a digital subsystem and a physical subsystem are built respectively. Then, a controlled current source is introduced into the digital subsystem circuit and a controlled voltage source is introduced into the physical subsystem circuit. The control signal of the controlled current source is the output current signal of the physical subsystem, and the control signal of the controlled voltage source is the output voltage signal of the digital subsystem.

[0007] The output voltage signal of the digital side subsystem and the input voltage signal of the controlled voltage source in the physical side subsystem are acquired in real time within the same cycle. The fundamental phase of the output and input voltage signals is extracted and the voltage phase difference is obtained by subtracting them.

[0008] Based on the voltage phase difference, a deadbeat controller is used to compensate for the error of the output and input voltage signals by delay, so as to eliminate the signal tracking error;

[0009] The principle of a deadbeat controller is to use the predicted value of the command voltage of the next control cycle, as well as the voltage and current signals of the current control cycle, to calculate the output voltage signal of the digital subsystem circuit of the current control cycle, thereby achieving the goal of zero voltage phase difference between the digital subsystem and the physical subsystem.

[0010] The deadbeat controller includes a state observer and a repetitive predictive observer. The voltage phase difference is sampled in the previous control cycle. The state observer provides the equivalent voltage source voltage signal and output current signal of the digital subsystem in the current cycle. The repetitive predictive observer provides the command voltage prediction value for the next control cycle, thereby calculating the command voltage of the current cycle, which is the output voltage signal of the digital subsystem.

[0011] Secondly, the present invention also proposes a simulation interface control system, the system comprising:

[0012] The system construction unit builds a digital side subsystem and a physical side subsystem for the new power distribution system. Then, a controlled current source is introduced into the digital side subsystem circuit and a controlled voltage source is introduced into the physical side subsystem circuit. The control signal of the controlled current source is the output current signal of the physical side subsystem, and the control signal of the controlled voltage source is the output voltage signal of the digital side subsystem.

[0013] The signal acquisition unit acquires the output voltage signal of the digital side subsystem and the input voltage signal of the controlled voltage source in the physical side subsystem in real time within the same cycle, extracts the fundamental phase of the output and input voltage signals, and calculates the voltage phase difference.

[0014] The signal compensation unit, based on the voltage phase difference, uses a deadbeat controller to perform delay compensation for the errors in the output and input voltage signals, thereby eliminating signal tracking errors.

[0015] The deadbeat controller includes a state observer and a repetitive predictive observer. The voltage phase difference is sampled in the previous control cycle. The state observer provides the equivalent voltage source voltage signal and output current signal of the digital subsystem in the current cycle. The repetitive predictive observer provides the command voltage prediction value for the next control cycle, thereby calculating the command voltage of the current cycle, which is the output voltage signal of the digital subsystem.

[0016] Based on the above scheme, this invention provides a simulation interface control method and system, which adopts the deadbeat control concept and combines SVPWM, predictive control and other technologies. It is applied to inverter control and permanent magnet synchronous motor control in power systems. The method proposed in this invention is aimed at the power hardware-in-the-loop simulation interface compensation scenario of new power distribution systems with high penetration of new energy and high proportion of power electronic devices, expanding the theoretical and engineering application scope of deadbeat control algorithms. In addition, the repetitive control applied in this method integrates the error of each control cycle by setting the coefficient of the periodic integral link, accumulates the error periodically and adjusts the output voltage signal in integral form, avoiding the unlimited increase of compensation due to the inability to completely eliminate prediction errors during repeated prediction calculations, thus improving the reliability and stability of interface delay compensation. Finally, voltage / current signals are collected by a state observer. For simulation scenarios of new power distribution systems with high penetration of new energy grid connection and high proportion of power electronic devices, the state observer can provide more flexible and accurate estimates, better cope with high-frequency disturbances and rapid dynamic changes in system parameters such as frequency, phase and voltage, thereby improving the real-time performance and accuracy of system simulation. Attached Figure Description

[0017] Figure 1 This is a flowchart of the steps of a simulation interface control method according to the present invention;

[0018] Figure 2 This is a schematic diagram of a novel power distribution system simulation interface system according to a specific embodiment of the present invention;

[0019] Figure 3 This is a schematic diagram of the voltage response at the physical side subsystem interface in a specific embodiment of the present invention. Detailed Implementation

[0020] Existing methods for improving ITM interface algorithms have the following shortcomings:

[0021] (1) Damped impedance matching method. Based on the traditional ITM, an impedance branch is added, which significantly improves the system's anti-interference and stability margin. However, when the physical layer is subjected to disturbances such as current surges, this algorithm will lead to the amplification of harmonic currents. At the same time, due to the existence of interface devices and calculation delays, the impedance matching process will cause an equivalent impedance propagation delay, thus affecting the accuracy of the algorithm.

[0022] (2) Virtual Circuit Compensation Method. Based on the traditional ITM, a virtual circuit is added between the digital and physical sides. The virtual current can not only compensate for system stability but also compensate for the phase difference between the two sides of the interface based on the virtual power. This method effectively eliminates interface delay and stability compensation errors, while simplifying the selection process of interface parameters and improving simulation accuracy and system stability. However, when applied to complex new power systems, the introduction of virtual circuits may increase the complexity and coupling of the system, making analysis and control protection more difficult.

[0023] 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 some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0024] It should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings. Unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0025] It should be understood that the terms "system," "unit," and / or "module" used in this application are a method of distinguishing different components, elements, parts, sections, or assemblies at different levels. However, if other terms can achieve the same purpose, they may be replaced by other expressions.

[0026] As indicated in this application and claims, unless the context clearly indicates otherwise, the words "a," "an," "a," and / or "the" are not specifically singular and may include the plural. Generally, the terms "comprising" and "including" only indicate the inclusion of expressly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements. An element defined by the phrase "comprising an..." does not exclude the presence of other identical elements in the process, method, product, or apparatus that includes the element.

[0027] Furthermore, flowcharts are used in this application to illustrate the operations performed by the system according to embodiments of this application. It should be understood that the preceding or following operations are not necessarily performed precisely in sequence. Instead, the steps can be processed in reverse order or simultaneously. Additionally, other operations can be added to these processes, or one or more steps can be removed from them.

[0028] Reference Figure 1The diagram below is a schematic flowchart of an optional example of the simulation interface control method proposed in this invention. This method can be applied to computer devices, and the control method proposed in this embodiment may include, but is not limited to, the following steps:

[0029] Step S1: Build a new power distribution system simulation interface system, divide the circuit into a digital side subsystem and a physical side subsystem, and connect the digital side subsystem and the physical side subsystem through a voltage source type ITM interface;

[0030] The digital side subsystem mainly includes a digital model of the new power distribution system, while the physical side subsystem is a semi-physical simulation device, including but not limited to simulated lines, simulated loads, and simulated distributed generation equipment.

[0031] Step S2: Based on the new power distribution system simulation interface system, collect the output voltage signal of the digital side subsystem and the input voltage signal of the physical side subsystem within the same cycle, and calculate the voltage phase difference;

[0032] Step S3: Based on the novel power distribution system simulation interface system described in Step S1, interface delay compensation control is completed based on a deadbeat controller, wherein the deadbeat controller includes a state observer and a repetitive predictive observer.

[0033] In some feasible embodiments, step S1 specifically includes:

[0034] S1.1, such as Figure 2 As shown, a new power distribution system simulation interface system is built. The digital side subsystem is the IEEE 33-node standard power distribution network. A photovoltaic power generation system is connected at node 22, an electric vehicle charging station is connected at node 4, and a passive power distribution network feeder is connected at node 18 through the voltage source ITM interface.

[0035] S1.2 In the forward channel of the ITM interface, the delay of signal transmission from the digital side subsystem to the physical side subsystem is set to 120μs;

[0036] S1.3 In the feedback channel of the ITM interface, set the delay of signal transmission from the physical side subsystem to the digital side subsystem to 100μs.

[0037] In some feasible embodiments, step S3 specifically includes:

[0038] A state observer module is introduced, which provides the equivalent voltage source voltage signal and output current signal of the digital side subsystem for the current cycle. A repetitive predictive state observer module is also introduced, setting the periodic integral coefficient Q(z) of the repetitive control to 0.95. The repetitive predictive observer integrates the error for each control cycle, accumulates the error periodically, and adjusts the input voltage signal in integral form to generate a compensation signal to correct the error for the next cycle. This provides the predicted command voltage value for the next control cycle, thereby calculating the command voltage for the current cycle. The calculation of the repetitive prediction is shown below:

[0039]

[0040] in, for The output voltage signal of the digital side subsystem at each step; for The input voltage signal of the physical side subsystem at each step; for The output voltage signal of the digital side subsystem at the previous step; for The output voltage signal of the compensated digital subsystem at each step; The compensation amount is 200 sampling times N within each fundamental frequency, so 200 steps constitute one control cycle; 0.95 is the coefficient of the integral element of the repetitive control cycle. for The cumulative error between the output voltage signal of the digital side subsystem and the input signal of the physical side subsystem.

[0041] Specifically:

[0042] S3.1 Perform abc / dq coordinate transformation on the equivalent voltage source voltage value, output current value, and output voltage value on the digital side, and obtain the voltage phase difference through the state observer module in the current control cycle;

[0043] S3.2. Add the voltage phase difference to the voltage phase difference value accumulated and sampled before the current control cycle;

[0044] S3.3 Input the superimposed voltage phase difference value into the deadbeat control module, and calculate the command voltage prediction value for the next control cycle by comparing it with the equivalent voltage source voltage value and output current value on the digital side under the dq coordinate in the current control cycle. Then, calculate the command voltage for the current control cycle.

[0045] S3.4 Perform dq inverse transformation on the command voltage signal to obtain the output voltage signal of the digital side subsystem, and introduce the output voltage signal into the controlled voltage source of the physical side subsystem for control.

[0046] To verify the compensation effect of the method proposed in this invention, this embodiment sets up a steady-state scenario and performs simulation. The voltage response at the interface of the adaptive lead phase compensation physical subsystem is recorded to verify the error compensation effect of this method.

[0047] The specific verification process includes:

[0048] In the steady-state operation of the new power distribution system simulation interface system built in S1.1, the simulation step size is set to 10μs and the running time is 0.6s.

[0049] During the steady-state operation of the system, comparing the simulation interface system model circuit of the original novel power distribution system without segmentation with the original ITM algorithm without delay compensation, the voltage response at the physical side subsystem interface is as follows: Figure 3 As shown, the method proposed in this invention effectively reduces the errors introduced by transmission delay and power amplifier delay, thereby improving the simulation accuracy of the system.

[0050] A simulation interface control system, comprising:

[0051] The system building unit builds a new power distribution system simulation interface system, which divides the circuit into a digital side subsystem and a physical side subsystem. The digital side subsystem and the physical side subsystem are connected through a voltage source type ITM interface.

[0052] The digital side subsystem mainly includes a digital model of the new power distribution system, while the physical side subsystem is a semi-physical simulation device, including but not limited to simulated lines, simulated loads, and simulated distributed generation equipment.

[0053] The signal acquisition unit, based on the new power distribution system simulation interface system, acquires the output voltage signal of the digital side subsystem and the input voltage signal of the physical side subsystem within the same cycle, and calculates the voltage phase difference.

[0054] The signal compensation unit, based on the aforementioned novel power distribution system simulation interface system, performs interface delay compensation control based on a deadbeat controller, wherein the deadbeat controller includes a state observer and a repetitive predictive observer.

[0055] The content of the above method embodiments is applicable to this system embodiment. The specific functions implemented in this system embodiment are the same as those in the above method embodiments, and the beneficial effects achieved are also the same as those achieved in the above method embodiments.

[0056] A simulation interface control device:

[0057] At least one processor;

[0058] At least one memory for storing at least one program;

[0059] When the at least one program is executed by the at least one processor, the at least one processor implements a simulation interface control method as described above.

[0060] The content of the above method embodiments is applicable to the device embodiments. The specific functions implemented by the device embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0061] A storage medium storing processor-executable instructions, which, when executed by a processor, are used to implement a simulation interface control method as described above.

[0062] The content of the above method embodiments is applicable to this storage medium embodiment. The specific functions implemented in this storage medium embodiment are the same as those in the above method embodiments, and the beneficial effects achieved are also the same as those achieved in the above method embodiments.

[0063] The above is a detailed description of the preferred embodiments of the present invention. However, the present invention is not limited to the embodiments described. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention. All such equivalent modifications or substitutions are included within the scope defined by the claims of this application.

Claims

1. A simulation interface control method, characterized in that, Includes the following steps: For power distribution systems, establish digital and physical subsystems; The output voltage signal of the digital side subsystem and the input voltage signal of the physical side subsystem are acquired within the same cycle, and the voltage phase difference is calculated. Based on the voltage phase difference, the input voltage signal of the physical side subsystem is delayed and compensated by a deadbeat controller. The deadbeat controller includes a state observer and a repeating predictive observer; The state observer provides the equivalent voltage source voltage signal and output current signal of the digital side subsystem for the current cycle; The error of each control cycle is integrated by the repetitive predictive observer, and the error is accumulated periodically and the input voltage signal of the physical side subsystem is adjusted in integral form. The calculation of the repeating predictive observer is as follows: Where u1(k) is the output voltage signal of the digital subsystem at step k; u2(k) is the input voltage signal of the physical subsystem at step k; u1(k-1) is the output voltage signal of the digital subsystem one step before k; u1*(k-1) is the compensated output voltage signal of the digital subsystem at step k-1; Δu1 is the compensation amount; and e(k) is the accumulated error value between the output voltage signal of the digital subsystem and the input signal of the physical subsystem at step k.

2. The simulation interface control method according to claim 1, characterized in that, The step of building a digital side subsystem and a physical side subsystem for the power distribution system also includes: A controlled power supply is connected at the partitioning point between the digital side subsystem circuit and the physical side subsystem circuit.

3. The simulation interface control method according to claim 2, characterized in that, The step of connecting the digital-side subsystem circuit and the physical-side subsystem circuit by adding a controlled power supply at the partitioning point further includes: A controlled current source is introduced into the digital subsystem, and its control signal is the output current signal of the physical subsystem. A controlled voltage source is introduced into the physical side subsystem, and its control signal is the output voltage signal of the digital side subsystem.

4. The simulation interface control method according to claim 3, characterized in that, The step of performing delay compensation on the output voltage signal of the digital side subsystem and the input voltage signal of the physical side subsystem based on the voltage phase difference using the deadbeat controller specifically includes: The equivalent voltage source voltage value, output current value, and output voltage value on the digital side are transformed by abc / dq coordinates, and the voltage phase difference is obtained by sampling through the state observer in the current control cycle. The voltage phase difference is superimposed with the voltage phase difference value accumulated and sampled before the current control cycle; Based on the superimposed voltage phase difference, the equivalent voltage source voltage and output current value of the digital side under the dq coordinate in the current control cycle are calculated to obtain the command voltage prediction value for the next control cycle. Generate a command voltage signal based on the predicted command voltage value; The command voltage signal is subjected to inverse dq transformation to obtain the output voltage signal of the digital side subsystem; The output voltage signal is introduced into the controlled voltage source of the physical side subsystem for control.

5. A simulation interface control system, characterized in that, For executing the simulation interface control method as described in claim 1, comprising: The system building unit is designed for power distribution systems, and includes both digital and physical subsystems. The signal acquisition unit acquires the output voltage signal of the digital side subsystem and the input voltage signal of the physical side subsystem within the same cycle, and calculates the voltage phase difference; The signal compensation unit, based on the voltage phase difference, performs delay compensation on the output voltage signal of the digital side subsystem and the input voltage signal of the physical side subsystem through a deadbeat controller; The deadbeat controller includes a state observer and a repeating predictive observer; The state observer provides the equivalent voltage source voltage signal and output current signal of the digital side subsystem for the current cycle; The error of each control cycle is integrated by the repetitive predictive observer, and the error is accumulated periodically and the input voltage signal is adjusted in integral form.

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