Simulation interface control method and system

Abstract

The invention discloses a simulation interface control method and system, and the method comprises the steps: building a digital-side subsystem and a physical-side subsystem for a novel power distribution system, and then introducing a controlled current source into a digital-side subsystem circuit and introducing a controlled voltage source into a physical-side subsystem circuit; acquiring an output voltage signal of the digital side subsystem and an input voltage signal of a controlled voltage source in the physical side subsystem in the same cycle in real time, extracting fundamental wave phases of the output voltage signal and the input voltage signal, and making a difference to obtain a voltage phase difference; based on the voltage phase difference, a dead-beat controller is adopted to carry out delay compensation on errors of the output voltage signal and the input voltage signal so as to eliminate tracking errors of the signals, and the dead-beat controller comprises a state observer and a repeated prediction type observer. According to the invention, the real-time performance and stability of simulation can be satisfied while interface delay compensation is realized. The method can be widely applied to the field of digital physical hybrid simulation.

Description

Technical Field

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

[0002] With the large-scale cluster access of distributed resources such as photovoltaic, wind power, energy storage, and electric vehicle charging piles, as well as the widespread use of power electronic devices, the new distribution system presents the "double high" characteristics of high proportion of new energy and high proportion of power electronic equipment, strong uncertainty of source-load, and high power electronicization of source-grid-load, etc. Therefore, it is urgent to study the operating characteristics of the new distribution system and its impact on the characteristics of the power grid.

[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 equipment and power system hardware, making it an important tool for the application of digital-physical hybrid simulation in power system simulation.

[0004] The Ideal Transformer Model (ITM) algorithm is the first interface algorithm proposed and has been widely used in PHIL simulation of power systems. However, most of the existing compensation methods for ITM interface delay are only applicable to traditional power system simulations or those with low penetration of new energy sources. For complex simulation scenarios of new distribution systems with "double high" characteristics, the calculation steps are cumbersome and complex, which will increase the complexity and coupling of the system, making it impossible to quickly achieve signal tracking compensation and eliminate the 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 the existing ITM interface delay compensation method cannot simultaneously meet the 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] A digital side subsystem and a physical side subsystem are respectively constructed for the new power distribution system, and 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, wherein 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;

[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 within the same frequency are collected in real time, the fundamental phase of the output and input voltage signals is extracted, and the voltage phase difference is obtained by difference;

[0008] Based on the voltage phase difference, a deadbeat controller is used to delay the error of the output and input voltage signals to eliminate the tracking error of the signal.

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

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

[0011] In a second aspect, the present invention further proposes a simulation interface control system, the system comprising:

[0012] The system building unit builds a digital side subsystem and a physical side subsystem for the new power distribution system respectively, and then: introduces a controlled current source into the digital side subsystem circuit and introduces a controlled voltage source into the physical side subsystem circuit, wherein 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 collects 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 obtains the voltage phase difference by difference;

[0014] The signal compensation unit uses a deadbeat controller to perform delay compensation on the error of the output and input voltage signals based on the voltage phase difference to eliminate the tracking error of the signal.

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

[0016] Based on the above scheme, the present invention provides a simulation interface control method and system, which adopts the deadbeat control idea, combines SVPWM, predictive control and other technologies, and is applied to inverter control and permanent magnet synchronous motor control of power systems. The method proposed in the present invention is oriented to the power hardware-in-the-loop simulation interface compensation scenario of a new distribution system with high penetration rate of new energy and high proportion of power electronic devices, and expands the theoretical and engineering application scope of the deadbeat control algorithm; in addition, the repeated control applied by the method integrates the error of each control cycle by setting the periodic integral link coefficient, accumulates the error according to the cycle and adjusts the output voltage signal in the form of integration, avoids the unlimited increase of the compensation amount due to the inability to completely eliminate the prediction error during repeated prediction calculation, and improves the reliability and stability of the interface delay compensation; finally, the voltage / current signal is collected through the state observer. For the simulation scenario of a new distribution system with high penetration rate of new energy grid connection and high proportion of power electronic devices, the state observer can provide more flexible and accurate estimation, better cope with high-frequency disturbances and the rapid dynamic changes of system parameters such as frequency, phase, and voltage, thereby improving the real-time performance and accuracy of system simulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a flow chart of steps of a simulation interface control method of the present invention;

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

[0019] Figure 3 It is a schematic diagram of voltage response at the physical side subsystem interface of a specific embodiment of the present invention. DETAILED DESCRIPTION

[0020] Some existing methods for improving the ITM interface algorithm have the following shortcomings:

[0021] (1) Damped impedance matching method. Based on the traditional ITM, an impedance branch is added, which significantly improves the anti-interference and stability margin of the system. However, when the physical layer of this algorithm is disturbed by current shocks, it will cause the amplification of harmonic currents. At the same time, due to the existence of interface devices and calculation delays, the equivalent impedance transmission delay will be caused during the impedance matching process, thus affecting the accuracy of the algorithm.

[0022] (2) Virtual line compensation method. On the basis of traditional ITM, a virtual line is added between the digital side and the physical side. The virtual current can not only compensate for the stability of the system, but also compensate for the phase difference on both sides of the interface according to the virtual power. This method effectively eliminates the interface delay and stability compensation error, simplifies the interface parameter selection process, and improves the simulation accuracy and system stability. However, when applied to complex new power systems, the introduction of virtual circuits may increase the complexity and coupling degree of the system, making analysis and control protection more difficult.

[0023] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0024] It should be noted that, for the convenience of description, only the parts related to the relevant invention are shown in the drawings. In the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other.

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

[0026] As shown in this application and claims, unless the context clearly indicates an exception, the words "a", "an", "a kind" and / or "the" do not refer to the singular, but also include the plural. Generally speaking, the terms "include" and "comprise" only indicate the inclusion of clearly identified steps and elements, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements. The elements defined by the sentence "includes a..." do not exclude the existence of other identical elements in the process, method, commodity or device that includes the elements.

[0027] In addition, flow charts are used in the present application to illustrate the operations performed by the system according to the embodiments of the present application. It should be understood that the preceding or following operations are not necessarily performed accurately in order. On the contrary, the various steps may be processed in reverse order or simultaneously. At the same time, other operations may also be added to these processes, or a certain step or several steps of operations may be removed from these processes.

[0028] Reference Figure 1, is a flow chart of an optional example of the simulation interface control method proposed in the present invention, which can be applied to computer equipment. The control method proposed in this embodiment may include but is not limited to the following steps:

[0029] Step S1, building a new power distribution system simulation interface system, dividing the circuit into a digital side subsystem and a physical side subsystem, and the digital side subsystem and the physical side subsystem are connected through a voltage source type ITM interface;

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

[0031] Step S2: Based on the new power distribution system simulation interface system, the output voltage signal of the digital side subsystem and the input voltage signal of the physical side subsystem in the same frequency are collected, and the voltage phase difference is calculated;

[0032] Step S3: Based on the new 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 prediction observer.

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

[0034] S1.1, if Figure 2 As shown, a new distribution system simulation interface system is built. The digital side subsystem is an IEEE 33-node standard distribution network. The photovoltaic power generation system is connected at node 22, the electric vehicle charging station is connected at node 4, and the passive 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, set the delay of the signal from the digital side subsystem to the physical side subsystem to 120 μs;

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

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

[0038] A state observer module is introduced, and the state observer gives the voltage signal and output current signal of the equivalent voltage source of the digital side subsystem in the current cycle; a repetitive prediction state observer module is introduced, and the periodic integral link coefficient Q(z) of the repetitive control is set to 0.95. The repetitive prediction observer integrates the error of each control cycle, accumulates the error by cycle, and adjusts the input voltage signal in the form of integration to generate a compensation signal to correct the error of the next cycle, and provide the command voltage prediction value of the next control cycle, thereby calculating the command voltage of the current cycle. The calculation of the repetitive prediction is as follows:

[0039]

[0040] Among them, u1(k) is the output voltage signal of the digital side subsystem at step k; u2(k) is the input voltage signal of the physical side subsystem at moment k; u1(k-1) is the output voltage signal of the digital side subsystem at the previous step k; u1*(k-1) is the compensated output voltage signal of the digital side subsystem at step k-1; Δu1 is the compensation amount; the number of sampling times N in each fundamental wave is 200, then 200 steps is a control cycle; 0.95 is the integral link coefficient of the repeated control cycle; e(k) is the error value between the output voltage signal of the digital side subsystem at moment k and the input signal of the physical side subsystem.

[0041] Specifically:

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

[0043] S3.2, superimposing the voltage phase difference with 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 equivalent voltage source voltage value and output current value of the digital side under the dq coordinates of the current control cycle to obtain the command voltage prediction value of the next control cycle, and then calculate the command voltage of the current control cycle;

[0045] S3.4, perform dq inverse transformation on the command voltage signal to obtain an 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] In order to verify the compensation effect of the method proposed in the present invention, the embodiment of the present invention sets a steady-state scenario and performs simulation, and verifies the error compensation effect of the method by recording the voltage response at the interface of the physical side subsystem of the adaptive leading phase compensation.

[0047] The specific verification process includes:

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

[0049] During the steady-state operation of the system, the voltage response at the subsystem interface on the physical side is shown in the following figure, comparing the undivided original new distribution system simulation interface system model circuit and the original ITM algorithm without delay compensation. Figure 3 As shown, it can be seen that the method proposed in the present invention effectively reduces the error introduced by transmission delay and power amplifier delay, thereby improving the simulation accuracy of the system.

[0050] A simulation interface control system, comprising:

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

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

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

[0054] The signal compensation unit, based on the above-mentioned novel power distribution system simulation interface system, completes the interface delay compensation control based on the deadbeat controller, wherein the deadbeat controller includes a state observer and a repeated prediction observer.

[0055] The contents of the above method embodiments are all applicable to the present system embodiments. The functions specifically implemented by the present system 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.

[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 the simulation interface control method as described above.

[0060] The contents of the above method embodiments are all applicable to the present device embodiments. The functions specifically implemented by the present 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 stores instructions executable by a processor, wherein the instructions executable by the processor are used to implement a simulation interface control method as described above when executed by the processor.

[0062] The contents of the above method embodiments are all applicable to the present storage medium embodiments. The functions specifically implemented by the present storage medium 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.

[0063] The above is a specific description of the preferred implementation of the present invention, but the invention is not limited to the embodiments. Those skilled in the art may make various equivalent modifications or substitutions without violating the spirit of the present invention. These equivalent modifications or substitutions are all included in the scope defined by the claims of this application.

Claims

1. A simulation interface control method, characterized in that: The following steps are involved: For the power distribution system, build digital side subsystem and physical side subsystem; Collect the output voltage signal of the digital side subsystem and the input voltage signal of the physical side subsystem within the same frequency, and calculate the voltage phase difference; Based on the voltage phase difference, delay compensation is performed on the input voltage signal of the physical side subsystem by the deadbeat controller; The deadbeat controller includes a state observer and a repetitive prediction observer; The state observer provides an equivalent voltage source voltage signal and an output current signal of the digital side subsystem in the current cycle; The repetitive prediction observer integrates the error of each control cycle, accumulates the error periodically, and adjusts the input voltage signal of the physical side subsystem in an integrated form.

2. The simulation interface control method according to claim 2, characterized in that: The calculation of the repeated prediction observer is as follows: Among them, u1(k) is the output voltage signal of the digital side subsystem at step k; u2(k) is the input voltage signal of the physical side subsystem at moment k; u1(k-1) is the output voltage signal of the digital side subsystem at the previous step k; u1*(k-1) is the compensated output voltage signal of the digital side subsystem at step k-1; Δu1 is the compensation amount; e(k) is the error value between the output voltage signal of the digital side subsystem and the input signal of the physical side subsystem at moment k.

3. 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 pairing system also includes: At the partition cutting point between the digital side subsystem circuit and the physical side subsystem circuit, a controlled power supply is added for connection.

4. A simulation interface control method according to claim 3, characterized in that: The step of adding a controlled power supply for connection at the partition cutting point between the digital side subsystem circuit and the physical side subsystem circuit also includes: A controlled current source is introduced into the digital side subsystem, and its control signal is the output current signal of the physical side 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.

5. A simulation interface control method according to claim 4, 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 by the deadbeat controller based on the voltage phase difference specifically includes: Perform abc / dq coordinate transformation on the voltage value, output current value and output voltage value of the digital side equivalent voltage source, and obtain the voltage phase difference through state observer sampling in the current control cycle; Superimposing the voltage phase difference with the voltage phase difference value accumulated and sampled before the current control cycle; Based on the superimposed voltage phase difference value, the equivalent voltage source voltage value and output current value of the digital side under the dq coordinates of the current control cycle are calculated to obtain the command voltage prediction value of the next control cycle; generating a command voltage signal according to the command voltage prediction value; Performing a dq inverse transformation on the command voltage signal to obtain an output voltage signal of the digital side subsystem; The output voltage signal is introduced into a controlled voltage source of a physical side subsystem for control.

6. A simulation interface control system, characterized in that: include: The system building unit is oriented to the power distribution system and builds the digital side subsystem and the physical side subsystem; The signal acquisition unit collects the output voltage signal of the digital side subsystem and the input voltage signal of the physical side subsystem within the same frequency, and calculates the voltage phase difference; a signal compensation unit, which performs delay compensation on an output voltage signal of the digital side subsystem and an input voltage signal of the physical side subsystem through the deadbeat controller based on the voltage phase difference; The deadbeat controller includes a state observer and a repetitive prediction observer; The state observer provides an equivalent voltage source voltage signal and an output current signal of the digital side subsystem in the current cycle; The repetitive prediction observer integrates the error of each control cycle, accumulates the error periodically, and adjusts the input voltage signal in an integrated form.

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