Simulation interface control method and system based on adaptive prediction lead phase compensation

Abstract

The invention discloses a simulation interface control method and system based on adaptive prediction lead phase compensation, and the method comprises the steps: building a digital side subsystem and a physical side subsystem for a novel power distribution network PHIL system, and carrying out the modeling of an interface system through a voltage source type ITM; a dual-second-order generalized integrator phase-locked loop is adopted to collect a port 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, and the difference is obtained to obtain a voltage phase difference; interpolation is carried out on the phase difference by combining sliding window prediction with a low-order polynomial extrapolation method, and a lead phase compensation signal is generated; and performing compensation according to the lead phase compensation signal. The system comprises a system construction module, a signal acquisition module, an interpolation module and a compensation module. According to the invention, the tracking compensation of the signal can be quickly realized, and the accuracy and real-time performance of simulation are ensured. 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 based on adaptive prediction leading phase compensation. Background Art

[0002] In recent years, digital-physical hybrid simulation technology has been increasingly used in the simulation of new distribution networks that include a high proportion of energy and a high proportion of power electronic equipment. This technology combines the real-time nature of digital simulation with the actual dynamic characteristics of physical simulation, providing theoretical guidance and engineering reference for the grid connection of distributed resources and the access of power electronic device systems.

[0003] Among digital-physical hybrid simulation technologies, Power Hardware in the Loop (PHIL) excels at co-verifying system-level control algorithms and hardware components. This adaptability to the multi-region, multi-element, and multi-scale simulation and analysis requirements of emerging power distribution systems makes it a crucial tool for simulating these systems. The Ideal Transformer Model (ITM) is the most traditional and easily implemented algorithm for PHIL interface systems. However, inherent signal transmission delays exist between the simulation systems on both sides of the PHIL, necessitating improvements to the ITM control method to compensate for these delays.

[0004] Some existing compensation methods for ITM interface delay have problems such as complex control architecture, cumbersome calculation steps, or inability to balance accuracy and real-time performance. It is difficult to quickly achieve signal tracking compensation, which affects the accuracy and real-time performance of the simulation and can even cause 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, the present invention proposes a simulation interface control method based on adaptive predictive advance phase compensation, which includes the following steps:

[0006] The digital side subsystem and the physical side subsystem of the new distribution network PHIL system are built separately. Then, the voltage source ITM is used to model the interface system. The physical side subsystem is equivalent to a controlled current source in the digital side subsystem, and its control quantity is the port current of the physical side subsystem; the digital side subsystem is equivalent to a controlled voltage source in the physical side subsystem, and its control quantity is the port voltage of the digital side subsystem.

[0007] A dual second-order generalized integrator phase-locked loop (DSOGI-PLL) is used to collect the port voltage signal of the digital side subsystem and the input voltage signal of the controlled voltage source of the physical side subsystem in real time within the same frequency. The fundamental phase of the positive sequence component of the voltage signals on both sides is extracted and the voltage phase difference is obtained by subtracting them.

[0008] The DSOGI-PLL decomposes the positive and negative sequence components of the voltage signal, extracts the positive sequence component of the input voltage signal for phase locking, and uses sliding window prediction combined with low-order polynomial extrapolation to interpolate the phase difference to generate an advanced phase compensation signal;

[0009] The advanced phase compensation signal is filtered and coordinate transformed for subsequent advanced phase compensation of the input current signal of the controlled current source, and the interface voltage delay is indirectly compensated through closed-loop feedback.

[0010] The present invention also proposes a simulation interface control system based on adaptive predictive leading phase compensation, which includes the following modules:

[0011] The system building module is used to build the digital side subsystem and the physical side subsystem of the new distribution network PHIL system respectively, and then use the voltage source type ITM to model the interface system;

[0012] The signal acquisition module, a dual-second-order generalized integrator phase-locked loop, collects the port voltage signal of the digital side subsystem and the input voltage signal of the controlled voltage source of the physical side subsystem in real time within the same frequency, and obtains the voltage phase difference by subtracting them.

[0013] The interpolation module decomposes the positive and negative sequence components of the voltage signal through DSOGI-PLL, and uses sliding window prediction combined with low-order polynomial extrapolation to interpolate the phase difference to generate an advanced phase compensation signal;

[0014] The compensation module filters and coordinates the advanced phase compensation signal, and is used to subsequently perform advanced phase compensation on the input current signal of the controlled current source, and indirectly compensates the interface voltage delay through closed-loop feedback.

[0015] Based on the above scheme, the present invention provides a simulation interface control method and system based on adaptive predictive advance phase compensation. This method uses a dual-quadrate generalized integrator phase-locked loop (PLL) instead of a traditional PLL, thereby reducing phase errors caused by harmonic interference or frequency waveforms. Furthermore, by decomposing the positive and negative sequence components of the voltage signal, the positive sequence component of the input voltage signal is extracted for phase locking, thereby improving the accuracy and stability of phase difference detection. Finally, the input current signal and voltage delay are compensated using the phase compensation signal. This method can quickly achieve signal tracking compensation, ensuring the accuracy and real-time performance of the simulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a flowchart of the steps of a simulation interface control method based on adaptive predictive leading phase compensation of the present invention;

[0017] Figure 2 This is a schematic diagram of a simulation interface system for a novel power distribution network PHIL system according to a specific embodiment of the present invention;

[0018] Figure 3 This is a schematic diagram of an equivalent circuit of a voltage source type ITM interface system according to a specific embodiment of the present invention;

[0019] Figure 4 Schematic diagram of the DSOGI-PLL control principle mentioned in a specific embodiment of the present invention;

[0020] Figure 5 A schematic diagram illustrating the principle of an adaptive prediction leading phase compensation method proposed in a specific embodiment of the present invention;

[0021] Figure 6 This is a waveform diagram of the effect of the advanced phase compensation signal verified by a specific embodiment of the present invention;

[0022] Figure 7 The present invention is a structural block diagram of a simulation interface control system based on adaptive prediction leading phase compensation. DETAILED DESCRIPTION

[0023] In addition to the problems existing in the existing compensation methods mentioned in the background technology, some compensation methods rely on the dynamic characteristics and stability of the phase-locked loop (PLL), which has certain limitations when applied to the simulation of "double-high" distribution networks.

[0024] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0025] It should be noted that, for ease of description, only the parts related to the invention are shown in the drawings. In the absence of conflict, the embodiments and features in the embodiments of this application can be combined with each other.

[0026] It should be understood that the terms "system," "device," "unit," and / or "module" used in this application are a method for distinguishing different components, elements, parts, portions, or assemblies at different levels. However, if other terms can achieve the same purpose, the terms may be replaced by other expressions.

[0027] As used in this application and the claims, unless the context clearly indicates an exception, the terms "a," "an," "an," and / or "the" are not intended to refer to the singular and may include the plural, unless the context clearly indicates otherwise. Generally speaking, the terms "comprises" and "include" only indicate the inclusion of the steps and elements specifically identified, and these steps and elements do not constitute an exclusive list. A method or apparatus may also include other steps or elements. The phrase "comprises a..." does not preclude the presence of additional identical elements in the process, method, product, or apparatus that includes the elements.

[0028] In the description of the embodiments of this application, "plurality" refers to two or more than two. The terms "first" and "second" below are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, features specified as "first" or "second" may explicitly or implicitly include one or more of the features.

[0029] In addition, flow charts are used in this 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 in exact order. Instead, the steps may be processed in reverse order or simultaneously. Furthermore, other operations may be added to these processes, or one or more operations may be removed from these processes.

[0030] Reference Figure 1 , which is a flow chart of an optional example of a simulation interface control method based on adaptive predictive advance phase compensation proposed in the present invention. This method can be applied to computer devices. The simulation interface control method proposed in this embodiment may include but is not limited to the following steps:

[0031] Step S1: Build a new PHIL simulation interface system for the power distribution network 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;

[0032] Among them, the digital side subsystem is a digital model of the new distribution network, including but not limited to the general IEEE 33-node distribution network model, IEEE 69-node distribution network model, etc., and a digital simulation model of distributed resources connected at each node. The physical side subsystem is a semi-physical simulation device, including but not limited to simulated lines, simulated loads, simulated distributed power generation equipment, etc.

[0033] Step S2: using DSOGI-PLL to collect voltage signals of ports on both sides within the same frequency to obtain a voltage phase difference;

[0034] Step S3: interpolating the voltage phase difference using sliding window prediction combined with low-order polynomial extrapolation to obtain an advanced phase compensation signal;

[0035] Among them, under ideal steady-state operating conditions, the phase difference between two AC voltages of the same frequency is a constant that does not change with time and is a fixed value. When the simulation system undergoes dynamic changes, such as load changes, frequency fluctuations caused by distributed resource grid connection, or various short-circuit faults, the phase difference will change in real time with system parameters. The principle of the adaptive prediction and compensation unit is to analyze and process the phase difference in the form of a time series, use sliding window prediction combined with low-order polynomial extrapolation to adaptively predict the phase difference, and output a phase compensation signal.

[0036] Step S4: Compensate the input current signal and the interface voltage delay according to the advanced phase compensation signal.

[0037] In some feasible embodiments, step S1 specifically includes:

[0038] S1.1, such as Figure 2 As shown in Figure 1, a new distribution network PHIL simulation system is built. The digital side subsystem is an IEEE 33-node standard distribution network. The photovoltaic power generation system is connected at node 14, the permanent magnet direct-drive wind power generation system is connected at node 32, and the passive distribution network feeder is connected at node 18 through the voltage source ITM interface. The equivalent circuit of the voltage source ITM interface is shown in the figure. Figure 3 As shown in the figure: U D 、U P is the equivalent power supply of the digital side subsystem and the physical side subsystem; Z1 and Z2 are the equivalent impedances of the digital side subsystem and the physical side subsystem; T d is the transmission delay of the power amplifier, T s is the transmission delay of the signal;

[0039] S1.2. In the forward channel of the ITM interface, set the delay for the signal to be transmitted from the digital side subsystem to the physical side subsystem to 100 μs.

[0040] S1.3. In the feedback channel of the ITM interface, set the delay for the signal to be transmitted from the physical side subsystem to the digital side subsystem to 80 μs.

[0041] In some feasible embodiments, step S2 specifically includes:

[0042] S2.1. Collect the port voltage signals on both sides of the digital side subsystem and the physical side subsystem respectively, perform abc / αβ coordinate transformation, and convert the three-phase AC quantity into two-phase static orthogonal components;

[0043] S2.2. SOGI is applied to the α and β channels respectively to generate quadrature signals and filter out harmonics. The transfer functions of SOGI are shown in Equations (1) and (2), where q represents the quadrature component:

[0044]

[0045] Where: k is the damping coefficient, take the typical value ω0 is the center frequency (the initial value is set to the fundamental angular frequency ω0 = 100πrad / s;

[0046] S2.3. Separate the positive sequence component of the orthogonal signal generated by SOGI described in S2.2 to eliminate the influence of the negative sequence component and harmonics of the power grid. When the power grid voltage is unbalanced, only track the phase of the positive sequence component. The calculation process is shown in formula (3):

[0047]

[0048] Where: v α + 、v β + v α 、v β The positive sequence component, v' α 、qv' α and v' β 、qv' β v α 、v β The orthogonal signal after SOGI processing, where q = e -jπ / 2 ;

[0049] S2.4, use the estimated phase angle θ' to convert the positive sequence component to the dq axis to form a closed-loop feedback. The goal is to be in the phase-locked state, v q tends to zero for phase alignment, v d Reflects the voltage amplitude;

[0050] S2.5、v q The frequency is adjusted by the PI controller to drive the phase error to converge, as shown in formula (4):

[0051] Δω=K p v q +K i ∫v q dt (4)

[0052] Where: K p , K i are proportional and integral gains respectively, Δω is the integral frequency deviation;

[0053] S2.6. The phase angle θ' is obtained by integrating the frequency deviation Δω from the center frequency ω0 as shown in formula (5):

[0054] θ′=∫(ω0+Δω)dt (5)

[0055] Based on the contents of S2.1 to S2.6, the control principle of the DSOGI-PLL used in the present invention to extract the voltage phase difference is as follows: Figure 4 As shown in the figure: u abc is the input voltage signal; ω0 is the fundamental frequency; u α 、u β are the voltage α and β axis components obtained by Clark transformation; u' and q'u' are the orthogonal voltage output signals after SOGI processing, u' α 、q'u' α and u' β 、q'u' β u α 、u β The orthogonal signal after SOGI processing, where q'=e -jπ / 2 ;u α + 、u β + u α 、u β The positive sequence component of ω is the system frequency; ε and k are the error signal and damping coefficient respectively; ω' is the resonant frequency; θ is the phase-locked loop output angle;

[0056] S2.7. Differ the phase angles of the interface voltages on both sides to obtain the voltage phase difference Δθ.

[0057] In some feasible embodiments, step S3 specifically includes:

[0058] S3.1. Preprocess the historical voltage phase difference Δθ data by using a first-order low-pass filter;

[0059] S3.2, the sliding window length N is set to 3, and the data in the window are fitted with a quadratic polynomial, as shown in formula (6):

[0060] y=at 2 +bt+c (6)

[0061] Where: a, b, c are the coefficients of the equation to be solved;

[0062] S3.3, extrapolate the predicted value of the leading phase compensation signal of the next control cycle and substitute it into t k+1 As shown in formula (7):

[0063] y=at k+1 2 +bt k+1 +c (7)

[0064] Each time new data arrives, the oldest data in the window is deleted, the data is refitted, and steps S3.1 to S3.3 are executed cyclically.

[0065] In some feasible embodiments, step S4 specifically includes:

[0066] S4.1. Perform abc / dq coordinate transformation on the control current of the controlled current source of the digital side subsystem to obtain the current signal value under the dq axis;

[0067] S4.2. The advanced phase compensation signal obtained in S3 is passed through a moving average filter (MAF) to suppress periodic noise, as shown in formula (9):

[0068]

[0069] Where: N is the window length, which can be adjusted according to the noise frequency and sampling rate;

[0070] S4.3. Input the advanced phase compensation signal filtered by MAF in S4.2 into the transformation matrix of dq / abc coordinate transformation as shown in formula (10):

[0071]

[0072] Where: θ c The advanced phase compensation signal is generated by Park inverse transform, which is used as the control quantity of the controlled current source and acts on the digital side subsystem to achieve advanced compensation of the next step length voltage.

[0073] In order to verify the compensation effect of the method proposed in the present invention, the embodiment of the present invention sets a transient scenario and performs simulation, and verifies the error compensation effect of the method by recording the waveform of the leading phase compensation signal.

[0074] The specific verification process includes:

[0075] Set the new distribution system simulation interface system built in S1.1, set the simulation step size to 10μs, the running time to 1s, set a short-circuit fault at point D on the physical side feeder, and test the stability of the interface algorithm when an AC fault occurs.

[0076] It is set that a phase A short circuit fault occurs at t=0.3s and lasts for 0.1s; a three-phase short circuit grounding fault occurs at t=0.7s and lasts for 0.1s. The waveform of the leading phase compensation signal is shown in the figure below, comparing the traditional compensation method based on dq coordinate transformation of PLL and the leading phase compensation method based on adaptive prediction of the present invention. Figure 6 shown.

[0077] Depend on Figure 6 It can be seen that under a single-phase short-circuit fault, the leading phase compensation signal waveforms of the traditional compensation method based on PLL dq coordinate transformation and the adaptive prediction leading phase compensation method proposed in the present invention are basically the same; under a three-phase short-circuit grounding fault, the leading phase compensation signal waveform output by the traditional method shows obvious fluctuations, and it is impossible to accurately track the voltage phase difference during the fault period. However, the signal waveform output by the method proposed in the present invention is smooth, can well track the voltage phase difference, and has good stability and accuracy.

[0078] like Figure 7 As shown, a simulation interface control system based on adaptive predictive leading phase compensation includes:

[0079] A system building module, configured to execute step S1;

[0080] A signal acquisition module, configured to execute step S2;

[0081] An interpolation module, configured to execute step S3;

[0082] The compensation module is used to execute step S4.

[0083] 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.

[0084] A simulation interface control device based on adaptive prediction leading phase compensation:

[0085] at least one processor;

[0086] at least one memory for storing at least one program;

[0087] 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 based on adaptive predictive advance phase compensation as described above.

[0088] 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.

[0089] A storage medium stores instructions executable by a processor, wherein the instructions executable by the processor are used to implement the above-mentioned simulation interface control method based on adaptive prediction leading phase compensation when executed by the processor.

[0090] The contents of the above method embodiments are all applicable to the present storage medium embodiment. The functions specifically implemented by the present storage medium embodiment 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.

[0091] 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 can 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 based on adaptive predictive leading phase compensation, characterized in that: The following steps are involved: Build a new PHIL simulation interface system for distribution network system, divide the circuit into digital side subsystem and physical side subsystem, and connect the digital side subsystem and physical side subsystem through voltage source type ITM interface; A dual-quad generalized integrator phase-locked loop is used to collect the voltage signals of the two ports in the same cycle to obtain the voltage phase difference. interpolating the voltage phase difference to obtain an advanced phase compensation signal; The input current signal and the interface voltage delay are compensated according to the advanced phase compensation signal.

2. The simulation interface control method based on adaptive predictive leading phase compensation according to claim 1, characterized in that: The step of using a biquad generalized integrator phase-locked loop to collect voltage signals of ports on both sides within the same cycle to obtain a voltage phase difference specifically includes: Collect port voltage signals on both sides of the digital side subsystem and the physical side subsystem respectively; Performing coordinate transformation on the port voltage signals respectively and generating orthogonal signals through SOGI; separating a positive sequence component from the orthogonal signal; Converting the positive sequence component to the dq axis based on the estimated phase angle to obtain a phase angle by calculation; The phase angles of the interface voltages on both sides are subjected to difference processing to obtain a voltage phase difference.

3. The simulation interface control method based on adaptive predictive leading phase compensation according to claim 2, characterized in that: The calculation formula of the positive sequence component is expressed as follows: Among them, v α + 、v β + v α 、v β The positive sequence component, v' α 、qv' α and v' β 、qv' β v α 、v β The orthogonal signal after SOGI processing, v α is the port voltage signal of α channel, v β is the port voltage signal of the β channel.

4. The simulation interface control method based on adaptive predictive leading phase compensation according to claim 2, characterized in that: The step of interpolating the voltage phase difference to obtain the leading phase compensation signal specifically includes: Obtain historical voltage phase difference data; Processing the historical voltage phase difference data based on a sliding window, fitting the data within the window with a quadratic polynomial to obtain a predicted value; The voltage phase difference is interpolated according to the predicted value to obtain an advanced phase compensation signal.

5. The simulation interface control method based on adaptive predictive leading phase compensation according to claim 2, further comprising: Perform first-order low-pass filtering on the historical voltage phase difference data.

6. The simulation interface control method based on adaptive predictive leading phase compensation according to claim 2, characterized in that: The step of compensating the input current signal and the interface voltage delay according to the advanced phase compensation signal specifically includes: Perform abc / dq coordinate transformation on the control current of the controlled current source of the digital side subsystem to obtain the current signal value under the dq axis; Filtering the advanced phase compensation signal to obtain a filtered compensation signal; Inputting the filtered compensation signal into an inverse transformation matrix to generate a compensated current signal; The compensated current signal is used as the control amount of the controlled current source to compensate the input current signal, and the interface voltage delay is compensated through closed-loop feedback.

7. The simulation interface control method based on adaptive predictive leading phase compensation according to claim 4, characterized in that: The formula of the inverse transformation matrix is ​​as follows: Among them, θ c Indicates the leading phase compensation signal.

8. A simulation interface control system based on adaptive predictive leading phase compensation, characterized in that: include: A system building module is used to build a new PHIL simulation interface system for the distribution network system, dividing the circuit into a digital side subsystem and a physical side subsystem, which are connected via a voltage source type ITM interface; The signal acquisition module is used to collect the voltage signals of the ports on both sides within the same cycle using a biquad generalized integrator phase-locked loop to obtain the voltage phase difference; an interpolation module, configured to interpolate the voltage phase difference to obtain an advanced phase compensation signal; The compensation module is used to compensate for the input current signal and the interface voltage delay according to the advanced phase compensation signal.

9. A simulation interface control device based on adaptive prediction leading phase compensation, characterized in that: include: at least one processor; at least one memory for storing at least one program; 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 based on adaptive predictive advance phase compensation as described in any one of claims 1 to 7.

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