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

Abstract

The application discloses a simulation interface control method and system based on adaptive prediction leading phase compensation, and the method comprises the following steps: a digital side subsystem and a physical side subsystem are respectively built for a new power distribution network PHIL system, and a voltage source type ITM is used to model the interface system; a double second-order generalized integrator phase-locked loop is used to collect the port voltage signal of the digital side subsystem and the input voltage signal of the controlled voltage source in the physical side subsystem in the same cycle, and the voltage phase difference is obtained by subtracting the two signals; a sliding window prediction combined with a low-order polynomial extrapolation method is used to interpolate the phase difference, so as to generate a leading phase compensation signal; and the leading phase compensation signal is compensated. The system comprises a system construction module, a signal collection module, an interpolation module and a compensation module. By using the application, the tracking compensation of the signal can be quickly realized, and the accuracy and real-time performance of the simulation are ensured. The application can be widely applied to the field of digital-physical hybrid simulation.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of digital-physical hybrid simulation, and in particular to a simulation interface control method and system based on adaptive predictive lead phase compensation. BACKGROUND

[0002] In recent years, digital-physical hybrid simulation technology has been increasingly applied to the simulation of new power distribution networks containing a high proportion of energy and power electronic devices. This technology combines the real-time performance of digital simulation and the actual dynamic characteristics of physical simulation, providing theoretical guidance and engineering reference for the integration of distributed resources and the access of power electronic device systems.

[0003] In digital-physical hybrid simulation technology, Power Hardware in-the-loop (PHIL) is specialized in the collaborative verification of system-level control algorithms and partial hardware, and is suitable for the simulation analysis requirements of new power distribution systems in terms of multiple regions, elements, and scales, making it an important tool in the simulation of new power systems. The Ideal Transformer Model (ITM) is the most traditional and convenient algorithm applied to PHIL interface systems. However, there is inherent signal transmission delay between the two simulation systems of PHIL, which requires improvement of the ITM control method to achieve delay compensation.

[0004] Some existing methods for compensating for the delay of the ITM interface have problems such as complex control architecture, tedious calculation steps, or the inability to balance accuracy and real-time performance, making it difficult to quickly achieve signal tracking compensation, thereby affecting the accuracy and real-time performance of the simulation, and in severe cases, leading to system instability. SUMMARY

[0005] Therefore, in order to solve the problem that existing ITM interface delay compensation methods cannot simultaneously satisfy the simulation real-time performance and stability, the present application proposes a simulation interface control method based on adaptive predictive lead phase compensation, which includes the following steps:

[0006] A digital side subsystem and a physical side subsystem are built for the PHIL system of the new power distribution network, and then a voltage source type ITM is used to model the interface system. The physical side subsystem is equivalent to a controlled current source in the digital side subsystem, with the control quantity being the port current of the physical side subsystem. The digital side subsystem is equivalent to a controlled voltage source in the physical side subsystem, with the control quantity being the port voltage of the digital side subsystem.

[0007] The dual second-order generalized integrator phase locked loop (DSOGI-PLL) is used to collect the port voltage signals of the digital side subsystem and the input voltage signals of the controlled voltage source in the physical side subsystem in real time, extract the fundamental phase of the positive sequence components of the voltage signals on both sides, and obtain the voltage phase difference by difference;

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

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

[0010] The application further provides a simulation interface control system based on adaptive predictive lead phase compensation, which comprises the following modules:

[0011] A system construction module is used to build the digital side subsystem and the physical side subsystem of the new power distribution network PHIL system, and then a voltage source type ITM is used to model the interface system.

[0012] A signal collection module is used to collect the port voltage signals of the digital side subsystem and the input voltage signals of the controlled voltage source in the physical side subsystem in real time by the DSOGI-PLL, and obtain the voltage phase difference by difference.

[0013] An interpolation module is used to decompose the positive and negative sequence components of the voltage signals by the DSOGI-PLL, interpolate the phase difference by the sliding window prediction combined with the low-order polynomial extrapolation method, and generate the lead phase compensation signal.

[0014] A compensation module is used to filter and coordinate-transform the lead phase compensation signal, which is used for subsequent lead phase compensation of the input current signal of the controlled current source, and indirectly compensates for the interface voltage delay through closed-loop feedback.

[0015] Based on the above scheme, the application provides a simulation interface control method and system based on adaptive predictive leading phase compensation, adopts a double second-order generalized integrator phase-locked loop to replace a traditional PLL, so as to reduce phase errors caused by harmonic interference or frequency waveform; further, by decomposing positive and negative sequence components of a voltage signal, the positive sequence component of the input voltage signal is extracted for phase locking, so as to improve the accuracy and stability of phase difference detection; finally, the input current signal and voltage delay are compensated by a phase compensation signal. The application can quickly realize tracking compensation of the signal, and ensures the accuracy and real-time performance of simulation. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is a step flow chart of the simulation interface control method based on adaptive predictive leading phase compensation of the application;

[0017] Figure 2 is a schematic diagram of the simulation interface system of the novel distribution network PHIL system of the embodiment of the application;

[0018] Figure 3 is a schematic diagram of the equivalent circuit of the voltage source type ITM interface system of the embodiment of the application;

[0019] Figure 4 is a schematic diagram of the DSOGI-PLL control principle mentioned in the embodiment of the application;

[0020] Figure 5 is a schematic diagram of the adaptive predictive leading phase compensation method principle mentioned in the embodiment of the application;

[0021] Figure 6 is a waveform diagram of the effect of the leading phase compensation signal verified in the embodiment of the application;

[0022] Figure 7 is a structural block diagram of the simulation interface control system based on adaptive predictive leading phase compensation of the application. DETAILED DESCRIPTION

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

[0024] The technical solutions in the embodiments of the application will be described clearly and completely below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the application.

[0025] It should be noted that only the parts related to the present application are shown in the drawings for the convenience of description. The embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0026] It should be understood that the terms “system”, “apparatus”, “unit” and / or “module” used in the present application are a method for distinguishing different components, elements, parts, sections or assemblies at different levels. However, if other words can achieve the same purpose, the words can be replaced by other expressions.

[0027] As shown in the present application and claims, unless the context clearly indicates otherwise, the words “one”, “a”, “an” and / or “the” do not mean to specify a single number, but can also include a plurality. Generally, the terms “comprise” and “include” only indicate that the steps and elements explicitly identified are included, and these steps and elements do not constitute an exclusive list, and the method or device can also include other steps or elements. The element defined by the statement “comprising a” does not exclude the presence of additional identical elements in the process, method, product or device comprising the element.

[0028] In the description of the embodiments of the present application, “a plurality of” means two or more than two. The following terms “first”, “second” are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with “first”, “second” can explicitly or implicitly include one or more of the features.

[0029] In addition, flowcharts 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 subsequent operations are not necessarily performed in sequence. On the contrary, each step can be processed in reverse order or simultaneously. At the same time, other operations can be added to these processes, or one or more steps of the operation can be removed from these processes.

[0030] Referring to Figure 1 The flowchart of an optional example of the simulation interface control method based on adaptive prediction lead phase compensation proposed in the present application can be applied to a computer device. The simulation interface control method proposed in the present embodiment can include but is not limited to the following steps:

[0031] Step S1, a new type of power distribution network system PHIL simulation interface system is built, the circuit is divided 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;

[0032] Wherein, 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, the IEEE 69-node distribution network model, etc., and the digital simulation model of the distributed resource connected at each node, and the physical side subsystem is a semi-physical simulation device, including but not limited to a simulated line, a simulated load, a simulated distributed power generation device, etc.

[0033] Step S2, the DSOGI-PLL is used to collect the voltage signals of the two sides of the port in the same cycle to obtain the voltage phase difference;

[0034] Step S3, the voltage phase difference is interpolated by using the sliding window prediction combined with the low-order polynomial extrapolation method to obtain the lead phase compensation signal;

[0035] Wherein, under the ideal steady-state operating condition, the phase difference value between the two AC voltages of the same frequency is a constant that does not change with time, and is a certain value; when the simulation system has dynamic characteristic changes, such as load changes, frequency fluctuations caused by the grid connection of distributed resources, or various short-circuit faults, etc., the phase difference will change in real time with the system parameters, and the principle of the adaptive prediction compensation unit is to analyze and process the phase difference in the form of time series, and to adaptively predict the phase difference by using the sliding window prediction combined with the low-order polynomial extrapolation method, and to output the phase compensation signal;

[0036] Step S4, the input current signal and the interface voltage delay are compensated according to the lead phase compensation signal.

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

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

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

[0040] S1.3, the delay of the signal transmitted from the physical side subsystem to the digital side subsystem in the feedback channel of the ITM interface is 80 μs;

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

[0042] S2.1, the port voltage signals on both sides of the digital side subsystem and the physical side subsystem are collected respectively, abc / αβ coordinate transformation is performed, and three-phase power flow is converted into two-phase static orthogonal components;

[0043] S2.2, SOGI is applied to the α and β channels respectively, orthogonal signals are generated and harmonics are filtered out, and the transfer function of SOGI is shown in formula (1) and formula (2), wherein q represents the orthogonal component:

[0044]

[0045] In the formula, k is a damping coefficient, and a typical value is taken ω0 is a center frequency (the initial value is set as the fundamental angular frequency ω0=100π rad / s;

[0046] S2.3, the orthogonal signals generated by the SOGI in S2.2 are separated into positive sequence components to eliminate the influence of grid negative sequence components and harmonics, and only the phase of the positive sequence component is tracked when the grid voltage is unbalanced, and the calculation process is shown in formula (3):

[0047]

[0048] In the formula, v α + , v β + are positive sequence components of v α , v β , v' α , qv' α and v' β , qv' β are orthogonal signals of v α , v β processed by SOGI, wherein q=e -jπ / 2 ;

[0049] S2.4, the positive sequence component is converted to dq axis by using the estimated phase angle θ', and a closed-loop feedback is formed, and the target is that, in the phase-locked state, v q tends to zero for phase alignment, and v d reflects the voltage amplitude;

[0050] S2.5, v q is adjusted by a PI controller to adjust the frequency, and the phase error is converged, as shown in formula (4):

[0051] Δω = K p v q +K i ∫v q dt (4)

[0052] wherein: K p , K i are proportional, integral gain, Δω is integral frequency deviation;

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

[0054] θ' = ∫(ω0 + Δω)dt (5)

[0055] The control principle of the DSOGI-PLL applied to the voltage phase difference extraction of the application is shown in Figure 4 , wherein: u abc is the input voltage signal; ω0 is the fundamental frequency; u α , u β are the voltage α, β axis components obtained by Clark transformation; u', q'u' are the orthogonal voltage output signals after SOGI processing; u' α , q'u' α and u' β , q'u' β are the orthogonal signals of u α , u β after SOGI processing, wherein q' = e -jπ / 2 ; u α + , u β + are the positive sequence components of u α , u β ; ω is the system frequency; ε, 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, the phase angles of the two side interface voltages are subtracted to obtain the voltage phase difference Δθ.

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

[0058] S3.1, pre-process the historical voltage phase difference Δθ data, and adopt first-order low-pass filtering;

[0059] S3.2, the sliding window length N is 3, and the data in the window is fitted by a quadratic polynomial, as shown in equation (6):

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

[0061] In the formula: a, b, c are coefficients to be solved in the equation;

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

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

[0064] At each time of new data, the oldest data in the window is deleted, the data is refitted, and steps S3.1-S3.3 are executed in a loop.

[0065] In some possible embodiments, step S4 specifically comprises:

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

[0067] S4.2, the lead phase compensation signal obtained in S3 is filtered through a moving average filter (MAF), for suppressing periodic noise, as shown in formula (9):

[0068]

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

[0070] S4.3, the lead phase compensation signal filtered through the MAF in S4.2 is input into the transformation matrix of the dq / abc coordinate transformation, as shown in formula (10):

[0071]

[0072] In the formula: θ c is the lead phase compensation signal, the lead phase compensation current signal generated through the Park inverse transformation is used as the control quantity of the controlled current source, and is applied to the digital side subsystem, so as to realize the lead compensation of the next step voltage.

[0073] In order to verify the compensation effect of the method proposed in the application, the embodiment of the application sets a transient state scene and performs simulation, and verifies the error compensation effect of the method by recording the waveform of the lead phase compensation signal.

[0074] The specific verification process comprises:

[0075] The new power distribution system simulation interface system built in the setting S1.1 is set, the simulation step is 10us, the running time is 1s, the short circuit fault is set at the physical side feeder D point, and the stability of the interface algorithm when the alternating current fault occurs is tested.

[0076] The A-phase short circuit fault occurs at t=0.3s, and the duration is 0.1s; the three-phase short circuit grounding fault occurs at t=0.7s, and the duration is 0.1s, and the lead phase compensation signal waveforms of the traditional compensation method based on the dq coordinate transformation of the PLL and the lead phase compensation method based on the adaptive prediction of the application are compared as shown in Figure 6 .

[0077] As shown in Figure 6 It can be seen that under the single-phase short circuit fault, the waveforms of the lead phase compensation signals of the traditional compensation method based on the dq coordinate transformation of the PLL and the lead phase compensation method based on the adaptive prediction of the application are basically coincided; under the three-phase short circuit grounding fault, the waveform of the lead phase compensation signal output by the traditional method appears obvious fluctuation, and cannot accurately track the voltage phase difference during the fault, while the waveform of the signal output by the method of the application is smooth, can well track the voltage phase difference, and has good stability and accuracy.

[0078] As shown in Figure 7 , a simulation interface control system based on adaptive prediction lead phase compensation comprises:

[0079] The system construction module is used for executing step S1.

[0080] The signal acquisition module is used for executing step S2.

[0081] The interpolation module is used for executing step S3.

[0082] The compensation module is used for executing step S4.

[0083] The contents in the above method embodiments are all applicable to the system embodiments, the system embodiments specifically realize the same functions as the above method embodiments, and achieve the same beneficial effects as the above method embodiments.

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

[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 realizes the simulation interface control method based on the adaptive prediction lead phase compensation.

[0088] The contents in the method embodiments are applicable to the device embodiments, the device embodiments specifically implement the functions same as the method embodiments, and achieve the beneficial effects same as the method embodiments.

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

[0090] The contents in the method embodiments are applicable to the storage medium embodiments, the storage medium embodiments specifically implement the functions same as the method embodiments, and achieve the beneficial effects same as the method embodiments.

[0091] The above is a specific description of the preferred embodiments of the application, but the application is not limited to the embodiments, and those skilled in the art can make various equivalent modifications or replacements without departing from the spirit of the application, and these equivalent modifications or replacements are all included in the scope defined by the claims of the application.

Claims

1. A simulation interface control method based on adaptive predictive lead phase compensation, characterized in that, The method comprises the following steps: A new power distribution network system PHIL simulation interface system is built, a circuit is divided 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; A double second-order generalized integrator phase-locked loop is used to collect voltage signals at two sides of a port in the same cycle to obtain a voltage phase difference; The voltage phase difference is interpolated to obtain a leading phase compensation signal; The input current signal and the interface voltage delay amount are compensated according to the leading phase compensation signal; The step of collecting the voltage signals at two sides of the port in the same cycle by using the double second-order generalized integrator phase-locked loop to obtain the voltage phase difference specifically comprises the following steps: The port voltage signals at two sides of the digital side subsystem and the physical side subsystem are collected respectively; The port voltage signals are subjected to coordinate transformation respectively, and quadrature signals are generated through SOGI; The quadrature signals are separated into positive sequence components; The positive sequence components are converted to dq axes based on an estimated phase angle, and the phase angle is calculated; The phase angles of the interface voltages at two sides are subtracted to obtain the voltage phase difference; The calculation formula of the positive sequence components is as follows: wherein, , are respectively , positive sequence components, , and , are respectively , quadrature signals after SOGI processing, is a port voltage signal of the channel, is a port voltage signal of the channel; The step of interpolating the voltage phase difference to obtain the leading phase compensation signal specifically comprises the following steps: Historical voltage phase difference data is obtained; The historical voltage phase difference data is processed based on a sliding window, data in the window is fitted by using a quadratic polynomial to obtain a predicted value; The voltage phase difference is interpolated according to the predicted value to obtain the leading phase compensation signal.

2. The simulation interface control method based on adaptive prediction leading phase compensation according to claim 1, further comprising: The historical voltage phase difference data is subjected to first-order low-pass filtering processing.

3. The simulation interface control method based on adaptive predictive lead phase compensation according to claim 1, characterized in that, The step of compensating the input current signal and the interface voltage delay amount according to the leading phase compensation signal specifically comprises the following steps: The control current abc / dq coordinate transformation of the digital side subsystem controlled current source is performed to obtain current signal values in the dq axes; The leading phase compensation signal is filtered to obtain a filtered compensation signal; The filtered compensation signal is input into an inverse transformation matrix to generate a compensated current signal; The compensated current signal is used as a control amount of the controlled current source to compensate the input current signal, and the interface voltage delay amount is compensated through closed-loop feedback action.

4. The simulation interface control method based on adaptive predictive lead phase compensation according to claim 3, characterized in that, The formula of the inverse transformation matrix is as follows: wherein represents a leading phase compensation signal.

5. A simulation interface control system based on adaptive predictive lead phase compensation, characterized by, The simulation interface control method based on adaptive prediction leading phase compensation according to claim 1 is executed by using the following device: A system construction module is configured to build a new power distribution network system PHIL simulation interface system, divide a 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; A signal collection module is configured to collect voltage signals at two sides of a port in the same cycle by using a double second-order generalized integrator phase-locked loop to obtain a voltage phase difference; An interpolation module is configured to interpolate the voltage phase difference to obtain a leading phase compensation signal; The compensation module is used to compensate for the delay of the input current signal and the interface voltage based on the leading phase compensation signal.

6. A simulation interface control device based on adaptive predictive lead phase compensation, characterized by, 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 lead phase compensation as described in any one of claims 1-4.

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