Improved itm interface algorithm-based heterogeneous coordination simulation system for wind-solar power plant-grid interaction

Abstract

The application provides a wind and light plant network interaction heterogeneous collaborative simulation system based on an improved ITM interface algorithm, and comprises the following steps: a platform construction module is used for constructing a heterogeneous simulation platform composed of a new energy station simulator and a power grid simulator; a data communication module is used for establishing a high-speed serial communication link, and performing byte sequence reversal and reverse restoration before and after data transmission, respectively; a data interaction module adopts an improved ITM interface algorithm to couple electrical quantities, sets a variable cutoff frequency low-pass filter in the current feedback channel, virtually connects compensation impedances in the two digital models, respectively, realizes equivalent conversion of electrical quantities and stable interaction of numerical values, and through adaptive switching of three working modes driven by comprehensive impedance ratio, the compensation impedance and the filter cutoff frequency are adjusted in real time according to the impedance matching state, the standard ITM algorithm under the condition of stability is improved to global wide-range stability, and the stability and precision of cross-platform joint simulation are improved.

Description

Technical Field

[0001] This invention relates to the field of power system simulation, and in particular to a wind-solar-power plant-grid interactive heterogeneous collaborative simulation system based on an improved ITM interface algorithm. Background Technology

[0002] With the deepening of the dual-carbon strategy, my country's installed capacity of wind and solar power has continued to grow, and renewable energy is gradually becoming an important part of the power system. However, the randomness, volatility, and intermittency of high-proportion wind and solar power output pose a severe challenge to the power plant-grid interaction model. The uncertainty of wind and solar power output exacerbates the frequency deviation of the power grid and the difficulty of power balance, affecting the execution accuracy of power generation and control plans and the reliability of real-time regulation between power plants and the grid. Using multiple simulation platforms for joint real-time simulation is an important means to analyze the impact of wind and solar access on power plant-grid interaction. By running the new energy power plant side and the power grid side on dedicated real-time simulators and interacting through interfaces, the complex dynamic interaction process between the power generation side and the grid side after wind and solar access can be reproduced with high fidelity in a laboratory environment.

[0003] Existing cross-platform co-simulation technologies generally employ the ideal transformer method for electrical quantity coupling at the interface algorithm level. However, this algorithm is a conditionally stable algorithm, requiring the equivalent impedance magnitude on the voltage output side to be less than that on the current feedback side. The equivalent impedance on the new energy power station side changes dynamically with operating conditions such as power output level, grid connection mode, and control strategy switching, which can easily exceed the inherent stability boundary of the ITM algorithm, leading to numerical oscillations or even simulation divergence at the interface. Furthermore, in existing methods, impedance compensation methods often use hardware compensation with series resistors / inductors on the physical side, resulting in poor parameter adjustment flexibility. Pre-filtering methods use low-pass filters with fixed cutoff frequencies, which will sacrifice system bandwidth if set too low. Moreover, these two methods are used independently without forming a collaborative mechanism, reducing the adaptability of real-time adjustment of compensation parameters based on impedance matching status. Summary of the Invention

[0004] In view of this, the present invention proposes a heterogeneous collaborative simulation system for wind-solar-power plant-grid interaction based on an improved ITM interface algorithm. By combining an impedance-compensated ITM interface algorithm with pre-filtering and an adaptive switching mechanism for three working modes, the conditionally stable standard ITM interface algorithm is improved to a globally stable one. This effectively solves the problem of interface numerical oscillation caused by the wide-range dynamic changes in impedance of new energy power plants, and improves the stability and accuracy of cross-platform joint simulation of wind-solar-power plant-grid interaction.

[0005] The technical solution of this invention is implemented as follows: Firstly, this invention provides a wind-solar-powerhouse-grid interactive heterogeneous collaborative simulation system based on an improved ITM interface algorithm, comprising: The platform construction module is used to build a heterogeneous simulation platform including a new energy power plant simulator and a large power grid simulator. The new energy power plant simulator is used to simulate the dynamic control characteristics of wind power and photovoltaic power, and the large power grid simulator is used to simulate the operation characteristics of the large power grid. The data communication module is used to establish a serial communication link between the simulator on the new energy power plant side and the simulator on the large power grid side, and to perform byte order reversal and reverse restoration before data transmission and after data reception, respectively, to ensure the consistency of data transmission. The data interaction module is used to couple electrical quantities on the simulation interaction interface of the two simulators using an improved ITM interface algorithm. The new energy power plant simulator side is equivalent to a controlled current source, and the large power grid simulator side is equivalent to a controlled voltage source. The improved ITM interface algorithm sets a low-pass filter with a variable cutoff frequency in the current feedback channel and virtually series compensated impedances in the digital models of the two real-time simulators respectively. By sampling the boundary voltage and current to update the state of the controlled source, the equivalent physical interface conversion and numerical stable interaction of electrical quantities on both sides are realized. The timing coordination control module is used to control the new energy power plant simulator model to start first and perform state initialization when the joint simulation is started, and then control the large power grid simulator to start after the initialization is completed.

[0006] Based on the above technical solutions, preferably, the data communication module includes: The byte-flipping submodule at the sending end is used to flip the original memory byte sequence of the data to be sent from little-endian to big-endian before the new energy power station simulator sends the data, and then fill the flipped byte sequence into the communication protocol data frame before sending it. The new energy power station simulator is built using the Speedgoat real-time simulator, and its native byte order is little-endian. The receiving end reverse restoration submodule is used to extract data from the big-endian byte stream received from the communication link after the large power grid simulator receives data, restore the byte sequence to the native little-endian memory layout of the receiving end, and restore it to the original data type through type reinterpretation. The large power grid simulator is built using the RTDS real-time simulator, whose native byte order is little-endian, and the communication link is an Aurora fiber optic link, whose transmission byte order is big-endian.

[0007] Based on the above technical solutions, preferably, the improved ITM interface algorithm is executed iteratively with the simulation step size as the period, and the single-step iteration process is as follows: Obtain the port current fed back from the simulator side of the new energy power station in the previous simulation step, and obtain the filtered current after passing the corresponding port current in the previous simulation step through a first-order low-pass filter. The port output voltage at the current step size is calculated by subtracting the difference between its equivalent resistance and virtual compensation resistance from the internal power supply voltage on the large power grid simulator side and multiplying it by the filter current. The port output voltage is transmitted to the new energy power station simulator side. The new energy power station simulator side calculates the feedback current of the current step size based on the port output voltage of the current step size, the feedback current of the previous simulation step size, its own equivalent resistance, its own equivalent inductance, the inductance and resistance components of the virtual series compensation impedance, and the joint simulation step size, and completes the single-step iteration.

[0008] Based on the above technical solutions, preferably, the data interaction module further includes an impedance parameter constraint submodule, used to constrain the value of the compensation impedance in the virtual series connection, wherein: the lower limit of the compensation inductance is half the difference between the equivalent inductance on the large power grid simulator side and the equivalent inductance on the new energy power station simulator side, and the upper limit is the equivalent inductance on the large power grid simulator side; the lower limit of the compensation resistance is determined based on the difference between the equivalent resistance on the large power grid simulator side and the new energy power station simulator side and the equivalent total delay of the interface system, and the upper limit is the equivalent resistance on the large power grid simulator side.

[0009] Based on the above technical solutions, preferably, the value of the compensation impedance and the value of the filter cutoff frequency also jointly satisfy the comprehensive stability condition: The inductance stability condition is that the equivalent inductance on the large power grid simulator side is less than the sum of the equivalent inductance on the new energy power station simulator side and twice the compensation inductance, plus the sum of the equivalent resistance on the new energy power station simulator side and the compensation resistance divided by the filter cutoff angular frequency. The resistance stability condition is as follows: Calculate the sum of the equivalent resistance on the new energy power station simulator side and twice the compensation resistance to obtain the first component; calculate the sum of the equivalent inductance on the main grid simulator side and the equivalent inductance on the new energy power station simulator side, multiply it by two, and then divide it by the equivalent total delay of the interface system to obtain the second component; calculate the sum of the equivalent resistance on the new energy power station simulator side and the compensation resistance, divide it by the filter cutoff angular frequency, multiply it by two, and then divide it by the equivalent total delay of the interface system to obtain the third component; add the first, second, and third components to obtain the comprehensive impedance threshold; the equivalent resistance on the main grid simulator side is less than the comprehensive impedance threshold.

[0010] Based on the above technical solutions, preferably, the data interaction module further includes a mode adaptive switching submodule, used to adjust the compensation impedance and filter cutoff frequency according to the system impedance matching state; wherein: The comprehensive impedance ratio is defined as the larger of the ratio of the equivalent inductance on the large power grid simulator side to the equivalent inductance on the new energy power station simulator side, and the ratio of the equivalent resistance on the large power grid simulator side to the equivalent resistance on the new energy power station simulator side. When the overall impedance ratio is less than the first preset threshold, the system is in normal mode, the compensation inductor is zero, the compensation resistor is zero, and the filter cutoff frequency remains at the highest value. When the overall impedance ratio is greater than or equal to the first preset threshold and less than the second preset threshold, the system is in an early warning mode. The compensation inductor is calculated as the product of the difference between the overall impedance ratio and the first preset threshold, divided by the difference between the second preset threshold and the first preset threshold, and then multiplied by the maximum value of the compensation inductor. The compensation resistor is calculated as the product of the difference between the overall impedance ratio and the first preset threshold, divided by the difference between the second preset threshold and the first preset threshold, and then multiplied by the maximum value of the compensation resistor. The filter cutoff frequency is calculated as the product of the highest filter cutoff frequency minus the difference between the highest and lowest filter cutoff frequencies, multiplied by the difference between the overall impedance ratio and the first preset threshold, divided by the difference between the second preset threshold and the first preset threshold. When the overall impedance ratio is greater than or equal to the second preset threshold, the system is in critical mode, the compensation inductor is set to the maximum value, the compensation impedance is set to the maximum value, and the filter cutoff frequency is set to the minimum value.

[0011] Based on the above technical solutions, preferably, the maximum value of the compensation inductor is the equivalent inductance on the power grid simulator side multiplied by a first safety factor; the maximum value of the compensation resistor is the equivalent resistance on the power grid simulator side multiplied by a second safety factor; and the minimum value of the filter cutoff frequency is the highest effective simulation frequency of the system multiplied by the bandwidth retention factor.

[0012] Based on the above technical solutions, preferably, the timing coordination control module further includes a step size synchronization submodule, which is used to run with a preset fixed step size during the joint simulation operation phase, and dynamically match the simulation step size on both sides through step size negotiation and clock alignment.

[0013] Secondly, this invention also provides a heterogeneous collaborative simulation method for wind-solar-power-grid interaction based on an improved ITM interface algorithm, implemented using a heterogeneous collaborative simulation system for wind-solar-power-grid interaction based on an improved ITM interface algorithm, comprising the following steps: A heterogeneous simulation platform is constructed, comprising a new energy power plant simulator and a large power grid simulator. The new energy power plant simulator is used to simulate the dynamic control characteristics of wind power and photovoltaic power, while the large power grid simulator is used to simulate the operating characteristics of the large power grid. A serial communication link is established between the simulator on the new energy power station side and the simulator on the large power grid side, and byte order reversal and reverse restoration are performed before data transmission and after data reception, respectively, to ensure the consistency of data transmission. On the simulation interaction interface of the two simulators, an improved ITM interface algorithm is used to couple electrical quantities, so that the new energy power station simulator side is equivalent to a controlled current source and the large power grid simulator side is equivalent to a controlled voltage source. The improved ITM interface algorithm sets a low-pass filter with a variable cutoff frequency in the current feedback channel and virtual series compensation impedances in the digital models of the two real-time simulators respectively. By sampling the boundary voltage and current to update the state of the controlled source, the equivalent physical interface conversion and numerical stable interaction of electrical quantities on both sides are realized. When the joint simulation is started, the new energy power plant simulator model is started first and its state is initialized. After the initialization is completed, the large power grid simulator is started.

[0014] Thirdly, the present invention also provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the function of a wind-solar-power plant-grid interactive heterogeneous collaborative simulation system based on an improved ITM interface algorithm.

[0015] The wind-solar-power-grid interactive heterogeneous collaborative simulation system based on the improved ITM interface algorithm of this invention has the following advantages over the prior art: (1) Through the collaboration of four modules—platform construction, data communication, data interaction, and timing coordination—a complete technical closed loop from physical link, data parsing, numerical calculation to timing control was constructed, solving the problems of data parsing consistency, interface numerical oscillation, and timing coordination in the cross-platform joint simulation of wind and solar access plant-grid interaction, and improving the stability and accuracy of the cross-platform joint simulation of wind and solar access plant-grid interaction. (2) By connecting virtual positive and negative impedances in series in the digital model to expand the stability margin, and introducing a variable cutoff frequency low-pass filter in the feedback current channel to suppress high-frequency residual oscillations, the conditional stability is improved to global large-scale stability through the joint adjustment of the compensation impedance and the filter cutoff frequency, and the algebraic loop oscillation and numerical divergence of the interface are suppressed. (3) By establishing an automatic adjustment mechanism based on the comprehensive index of inductance matching and resistance matching, when the impedances on both sides are well matched, no compensation or filtering is applied, and the simulation bandwidth is fully preserved; when the impedance is close to the stability boundary, the compensation amount increases linearly with the degree of imbalance and the filtering intensity increases linearly in sync, so as to achieve a smooth transition; when the impedance has crossed the stability boundary, both compensation and filtering are switched to the maximum working state to ensure numerical stability. This mechanism enables the interface algorithm to take into account both stability and simulation accuracy under all working conditions, and enables the interface algorithm to maintain numerical stability under all working conditions with a wide range of dynamic changes in the impedance of new energy power stations, thus eliminating the risk of numerical oscillation at the interface. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a system architecture diagram of the present invention; Figure 2 This is a diagram of the communication architecture of the joint real-time simulation platform of the present invention; Figure 3 This is a flowchart of the communication architecture of the present invention; Figure 4 This is a data processing flowchart of the present invention; Figure 5 This is a diagram of the real-time simulation step size synchronization mechanism of the present invention; Figure 6 This is a diagram illustrating the Aurora protocol encoding method of the present invention; Figure 7 This is a schematic diagram of the interface algorithm interaction of the simulation device of the present invention; Figure 8 This is a diagram of the standard ITM interface algorithm of the present invention; Figure 9 The equivalent circuit diagram of the standard ITM algorithm of this invention is shown below; Figure 10 The equivalent circuit diagram of the improved interface algorithm of this invention; Figure 11 The real-time waveform of the wind turbine before the addition of the improved ITM algorithm in this invention is shown. Figure 12 The real-time waveform diagram of the wind turbine after incorporating the improved ITM algorithm in this invention; Figure 13 The waveform of the wind turbine output before the addition of the improved ITM algorithm in this invention is shown. Figure 14 The output waveform of the wind turbine after incorporating the improved ITM algorithm in this invention is shown. Detailed Implementation

[0018] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0019] like Figure 1-14As shown, this invention provides a heterogeneous collaborative simulation system for wind, solar, power plant, and grid interaction based on an improved ITM interface algorithm, comprising: The platform construction module is used to build a heterogeneous simulation platform that includes a new energy power plant simulator and a large power grid simulator. The new energy power plant simulator is used to simulate the dynamic control characteristics of wind power and photovoltaic power, and the large power grid simulator is used to simulate the operating characteristics of a large power grid.

[0020] It should be noted that the new energy power plant simulator uses the Speedgoat real-time simulator, and the model is developed and deployed based on the Matlab / Simulink software environment. The Speedgoat real-time simulator is a high-performance, fast control prototyping and hardware-in-the-loop simulation system that supports seamless deployment and real-time operation of Simulink models. It has powerful computing capabilities and rich input / output interfaces, and can meet the high-precision simulation requirements of complex control strategies of new energy power generation systems at microsecond-level step sizes.

[0021] The new energy power station simulator is used to simulate the dynamic control characteristics of wind power and photovoltaic power, specifically including the control characteristics of wind turbine generators and the control characteristics of photovoltaic power generation systems. The control characteristics of wind turbines include maximum power point tracking control, pitch angle control, converter control, high voltage ride-through and low voltage ride-through control strategies. The topology of a wind turbine includes a complete electrical structure such as generator, turbine-side converter, DC bus, grid-side converter, filter circuit and transformer. Its operating characteristics are affected by a variety of factors such as wind speed changes, grid voltage fluctuations, and frequency deviations. High-precision real-time simulation is required to accurately reflect its dynamic response behavior.

[0022] The control characteristics of photovoltaic power generation systems include maximum power point tracking algorithm tracking, inverter control, grid-connected operation testing, etc.; the output power of photovoltaic arrays is affected by changes in light intensity and temperature, and the control strategy of its grid-connected inverter directly affects the power quality and dynamic response characteristics injected into the grid.

[0023] The core function of the new energy power station simulator is to accurately simulate the underlying dynamic control characteristics of wind and solar power generation systems on a microsecond time scale, including the switching dynamics of converters, the response delay of controllers, and the tracking accuracy of power commands. The accurate simulation of these dynamic characteristics requires high-frequency data interaction with the grid simulator, which places extremely high demands on the bandwidth and latency of the communication link.

[0024] The large power grid simulator uses the RTDS real-time simulator, which is based on the built-in RSCAD software environment for model building and simulation. RTDS is the international mainstream real-time simulation platform in the field of electromagnetic transient simulation of power systems. It has high parallel computing capabilities and an accurate power system component model library, and is widely used in the study of electromagnetic transient characteristics of large power grids.

[0025] Large power grid simulators are used to simulate the operating characteristics of large power grids, including power grid frequency fluctuation characteristics, line power flow distribution, and various power grid fault scenarios.

[0026] The power grid frequency fluctuation characteristics simulate the dynamic frequency change process caused by the imbalance between power generation and load, including primary frequency regulation response and secondary frequency regulation response; the line power flow distribution simulates the distribution characteristics of voltage, current, active power and reactive power of transmission and distribution lines, as well as operating states such as line overload and voltage exceeding limits; various power grid fault scenarios simulate symmetrical and asymmetrical fault types such as three-phase short circuit, two-phase short circuit, and single-phase ground fault, as well as the dynamic characteristics of the entire process of fault occurrence, development and clearance.

[0027] The core function of a large power grid simulator is to accurately simulate the operating behavior of a large power grid on an electromagnetic transient time scale. Its simulation step size is usually 50 microseconds, which can depict the transient changes in voltage and current within several cycles after a fault occurs, thereby providing accurate power grid response data for the verification of power plant-grid interaction control strategies.

[0028] The data communication module is used to establish a serial communication link between the simulator on the new energy power plant side and the simulator on the large power grid side, and to perform byte order reversal and reverse restoration before data transmission and after data reception, respectively, to ensure the consistency of data transmission. The data communication module includes: The byte-flipping submodule at the sending end is used to flip the original memory byte sequence of the data to be sent from little-endian to big-endian before the new energy power station simulator sends the data, and then fill the flipped byte sequence into the communication protocol data frame before sending it. The new energy power station simulator is built using the Speedgoat real-time simulator, and its native byte order is little-endian. The receiving end reverse restoration submodule is used to extract data from the big-endian byte stream received from the communication link after the large power grid simulator receives data, restore the byte sequence to the native little-endian memory layout of the receiving end, and restore it to the original data type through type reinterpretation. The large power grid simulator is built using the RTDS real-time simulator, whose native byte order is little-endian, and the communication link is an Aurora fiber optic link, whose transmission byte order is big-endian.

[0029] It should be noted that the new energy power plant simulator and the large power grid simulator are physically directly connected via optical fiber through an SFP interface, and the Aurora protocol is used as the underlying high-speed serial communication protocol. The Aurora protocol is a lightweight, high-bandwidth, low-latency point-to-point serial communication protocol provided by the Xilinx FPGA platform.

[0030] Building upon the established physical communication link, the data communication module needs to address the byte order mismatch issue in cross-platform data transmission. The new energy power plant simulator is built using the Speedgoat real-time simulator, which is based on an x86 architecture processor and uses little-endian data storage by default, meaning the least significant byte of multi-byte data is stored at a lower memory address and the most significant byte at a higher memory address. The large power grid simulator is built using the RTDS real-time simulator, which is based on a PowerPC architecture processor and also uses little-endian data storage by default. However, the Aurora fiber optic link protocol specifies a big-endian byte order, meaning the most significant byte of multi-byte data is transmitted first, followed by the least significant byte, consistent with industry standard network order.

[0031] Because both the new energy power plant simulator and the large power grid simulator use little-endian byte order, while the Aurora fiber optic link specifies big-endian byte order, direct transmission without processing will lead to serious errors in the parsing of floating-point numbers, integers, and other data types when the receiving end parses the received data according to its own little-endian byte order. For example, a single-precision floating-point number stored in little-endian will result in a completely incorrect value when parsed in big-endian byte order. This will cause unpredictable deviations in the measured and calculated values ​​of physical quantities such as voltage, current, and power, ultimately rendering the simulation results invalid. Therefore, explicit byte order adjustment must be performed at both the transmitting and receiving ends.

[0032] The byte reversal submodule at the transmitting end performs a byte order reversal operation before the new energy power station simulator sends data. Specifically, this module completely reverses the original memory byte sequence of the data to be sent, rearranges it into big-endian order, and then fills the reversed byte sequence into the Aurora protocol data frame payload and sends it through optical fiber. The byte reversal is completed synchronously at the start of the 50-microsecond simulation step to ensure that the byte order mapping on both sides of the interface is aligned.

[0033] The receiving end reverse restoration submodule performs a byte order reverse restoration operation after the large power grid simulator receives the data. Specifically, this module extracts the data from the big-endian byte stream received from the Aurora link, performs the byte reversal operation again, restores the byte sequence to the original little-endian memory layout of the receiving end, and restores it to the original data type through type reinterpretation. The flipping at the sending end and the restoration at the receiving end are inverse operations of each other, and the numerical parsing of the original data before and after cross-platform transmission remains completely consistent.

[0034] This explicit byte order adjustment mechanism ensures the consistency of numerical parsing for various data types, such as floating-point numbers and integers, before and after cross-platform transmission. It avoids errors in parsing physical quantity values ​​due to end-order mismatch and guarantees the physical authenticity of the interactive data. This mechanism is completed synchronously at the start of the 50-microsecond simulation step, ensuring that the byte order mapping on both sides of the interface is aligned.

[0035] The physical layer communication link and byte order adaptation mechanism together constitute a complete data communication module, providing reliable data transmission guarantee for the electrical quantity coupling and numerical stability interaction of the improved ITM interface algorithm in the data interaction module.

[0036] The data interaction module is used to couple electrical quantities on the simulation interaction interface of the two simulators using an improved ITM interface algorithm. The new energy power plant simulator side is equivalent to a controlled current source, and the large power grid simulator side is equivalent to a controlled voltage source. The improved ITM interface algorithm sets a low-pass filter with a variable cutoff frequency in the current feedback channel and virtually series compensated impedances in the digital models of the two real-time simulators respectively. By sampling the boundary voltage and current to update the state of the controlled source, the equivalent physical interface conversion and numerical stable interaction of electrical quantities on both sides are realized.

[0037] like Figure 8 As shown, the standard Ideal Transformer Method (ITM) treats the RTDS side as a controlled voltage source and the Speedgoat side as a controlled current source on the heterogeneous simulation host interface.

[0038] The circuit equivalent effect of the standard ITM algorithm is as follows: Figure 9 As shown, its principle is mainly based on the AC power grid subsystem being modeled as a controlled voltage source in the power electronic subsystem, with a capacitor at the interface, and the capacitor voltage not changing abruptly within a short time window of tens of microseconds.

[0039] The current value of the controlled current source is controlled by the inductor current, and the voltage value of the controlled voltage source is controlled by the capacitor voltage. Such an interface between voltage and current sources transforms the electrical connection between the power electronics part and the AC power grid part into mutual influence through value transmission, thereby realizing the decomposition and parallel simulation of the system.

[0040] The complete power system is divided into two digital subsystems at the interface: Subsystem A (RTDS side): Electromagnetic transient model of a large power grid, including voltage source EA and equivalent impedance Z. A =R A +jωL A ω is the angular frequency, where j is an imaginary number.

[0041] Subsystem B (Speedgoat side): Control model for new energy power stations, including equivalent impedance Z B =R B +jωL B .

[0042] The recursive equations of the standard ITM algorithm are as follows: ; In the formula, uk For the first k Step interface port voltage, i k For the first k Current flows through the interface. k For discrete time step index, E A,k For the voltage source in subsystem A in the first... k The instantaneous value of the step. R A Let Thevenin equivalent resistance of subsystem A as seen from the interface. L A The Thevenin equivalent inductance of subsystem A as seen from the interface. L B The equivalent inductance of subsystem B as seen from the interface. R B The Thevenin equivalent resistance of subsystem B as seen from the interface.

[0043] For continuous systems, neglecting non-factors such as delay and filters, the stability condition of the standard ITM algorithm is: |Z| A ∣<∣Z B |

[0044] That is, the equivalent impedance magnitude on the voltage side is less than the equivalent impedance magnitude on the current side. When the system does not meet this condition, the interface will produce numerical oscillations or even divergence, which can be elaborated as follows: ; When the system does not meet this condition, the interface will generate numerical oscillations or even divergence. In the simulation of wind and solar power grid interaction, the equivalent impedance of the new energy power station side (subsystem B) changes dynamically with the operating conditions, causing the impedance matching relationship to fluctuate frequently, which is very easy to break through the inherent stability boundary of the ITM algorithm.

[0045] For the ITM algorithm with impedance compensation, the specific measures are as follows: To expand the stability margin, this invention modifies the equivalent impedances on both sides in the digital model: In the digital model of subsystem A, a negative impedance -Z is connected in series. c (i.e. -R) c -jωL c ); In the digital model of subsystem B, a positive impedance +Z is connected in series. c (i.e. +R) c +jωL c ).

[0046] The total impedance of the system remains unchanged before and after compensation (-Z) c +Z c =0), but from the perspective of the ITM interface algorithm, the equivalent impedance on both sides becomes: ; Among them, Z c =R c +jωL c The virtual compensation impedance set in the digital model exists only in mathematical calculations and does not add any hardware.

[0047] After introducing impedance compensation, the recursive equation of the standard ITM algorithm is corrected as follows: A-side (RTDS) voltage output equation: The equivalent impedance on the digital side becomes Z. A '=Z A -Z c ,therefore: ; B-side (Speedgoat) current feedback equation: The physical side equivalent impedance becomes Z. B '=Z B +Z c ,therefore: ; The stability condition after compensation is extended to: ; Compensation impedance Z c The introduction of T significantly increases the right-hand side of the stability condition, thereby improving the stability margin. total This is the equivalent total delay of the interface system.

[0048] Correspondingly, impedance compensation also has value boundaries. That is, the data interaction module also includes an impedance parameter constraint submodule, which is used to constrain the value of the compensation impedance in the virtual series connection. Specifically, the lower limit of the compensation inductance is half the difference between the equivalent inductance on the large power grid simulator side and the equivalent inductance on the new energy power station simulator side, and the upper limit is the equivalent inductance on the large power grid simulator side. The lower limit of the compensation resistance is determined based on the difference between the equivalent resistance on the large power grid simulator side and the new energy power station simulator side and the equivalent total delay of the interface system, and the upper limit is the equivalent resistance on the large power grid simulator side.

[0049] Lower limit: ; Maximum: ; Based on the above conditions, the value of the compensation impedance must satisfy the following: ; For the ITM algorithm of pre-filtering, the specific measures are as follows: A low-pass filter is added to the feedback current measurement channel, and its transfer function is: ; in, ω c =2π f c , ω c This is the filter cutoff angular frequency. f c This is the filter cutoff frequency.

[0050] After introducing filtering, the open-loop transfer function of the interface system becomes: ; Compare the open-loop transfer function of the standard ITM: ; The introduction of a filtering stage reduces the open-loop gain at high frequencies, thereby improving the stability margin of the system.

[0051] Will G filt ( s Substituting into the closed-loop characteristic equation and using the Routh criterion, the stability condition after filtering is: ; As can be seen from the above equation, the introduction of the filter adds a positive term to the right side of the stability condition, and the lower the cutoff frequency, the greater the stability margin.

[0052] After introducing pre-filter, the feedback current i k First, it passes through a low-pass filter before being used for calculation: ; in, α is the filter coefficient.

[0053] The corrected recurrence equation is: ; In the formula, Δt represents the filter current, and Δt represents the co-simulation step size.

[0054] The model-level impedance compensation (ITM) algorithm with pre-filtering of this invention specifically includes: Impedance compensation and pre-low-pass filtering are performed in a layered and coordinated manner: Outer layer (impedance compensation layer): The equivalent impedance on both sides is virtually modified in the mathematical model to expand the stability margin from the root.

[0055] Inner layer (filter layer): pre-filters the feedback current to suppress high-frequency residual oscillations that impedance compensation cannot completely eliminate.

[0056] Combining the above formulas, we obtain the complete recursive equation system of this invention: ; in, , ω c =2π f c .

[0057] The improved ITM interface algorithm is executed iteratively with the simulation step size as the period. The single-step iteration process is as follows: Obtain the port current fed back from the simulator side of the new energy power station in the previous simulation step, and obtain the filtered current after passing the corresponding port current in the previous simulation step through a first-order low-pass filter. The port output voltage at the current step size is calculated by subtracting the difference between its equivalent resistance and virtual compensation resistance from the internal power supply voltage on the large power grid simulator side and multiplying it by the filter current. The port output voltage is transmitted to the new energy power station simulator side. The new energy power station simulator side calculates the feedback current of the current step size based on the port output voltage of the current step size, the feedback current of the previous simulation step size, its own equivalent resistance, its own equivalent inductance, the inductance and resistance components of the virtual series compensation impedance, and the joint simulation step size, and completes the single-step iteration.

[0058] By combining the stability condition of impedance compensation with the stability condition of pre-filtering, we obtain the comprehensive stability condition of the algorithm of this invention: ; The values ​​of the compensation impedance and the filter cutoff frequency together satisfy the overall stability condition: The inductance stability condition is that the equivalent inductance on the large power grid simulator side is less than the sum of the equivalent inductance on the new energy power station simulator side and twice the compensation inductance, plus the sum of the equivalent resistance on the new energy power station simulator side and the compensation resistance divided by the filter cutoff angular frequency. The resistance stability condition is as follows: Calculate the sum of the equivalent resistance on the new energy power station simulator side and twice the compensation resistance to obtain the first component; calculate the sum of the equivalent inductance on the main grid simulator side and the equivalent inductance on the new energy power station simulator side, multiply it by two, and then divide it by the equivalent total delay of the interface system to obtain the second component; calculate the sum of the equivalent resistance on the new energy power station simulator side and the compensation resistance, divide it by the filter cutoff angular frequency, multiply it by two, and then divide it by the equivalent total delay of the interface system to obtain the third component; add the first, second, and third components to obtain the comprehensive impedance threshold; the equivalent resistance on the main grid simulator side is less than the comprehensive impedance threshold.

[0059] Compared with the stability conditions of the standard ITM, this invention expands the stability domain of the system by jointly adjusting the three degrees of freedom of compensation impedance and filter cutoff frequency, fundamentally suppressing the algebraic loop oscillation and numerical divergence of the interface.

[0060] The data interaction module further includes a mode adaptive switching submodule, used to adjust the compensation impedance and filter cutoff frequency according to the system impedance matching status; wherein: The comprehensive impedance ratio is defined as the larger of the ratio of the equivalent inductance on the large power grid simulator side to the equivalent inductance on the new energy power station simulator side, and the ratio of the equivalent resistance on the large power grid simulator side to the equivalent resistance on the new energy power station simulator side. When the overall impedance ratio is less than the first preset threshold, the system is in normal mode, the compensation inductor is zero, the compensation resistor is zero, and the filter cutoff frequency remains at the highest value. When the overall impedance ratio is greater than or equal to the first preset threshold and less than the second preset threshold, the system is in an early warning mode. The compensation inductor is calculated as the product of the difference between the overall impedance ratio and the first preset threshold, divided by the difference between the second preset threshold and the first preset threshold, and then multiplied by the maximum value of the compensation inductor. The compensation resistor is calculated as the product of the difference between the overall impedance ratio and the first preset threshold, divided by the difference between the second preset threshold and the first preset threshold, and then multiplied by the maximum value of the compensation resistor. The filter cutoff frequency is calculated as the product of the highest filter cutoff frequency minus the difference between the highest and lowest filter cutoff frequencies, multiplied by the difference between the overall impedance ratio and the first preset threshold, divided by the difference between the second preset threshold and the first preset threshold. When the overall impedance ratio is greater than or equal to the second preset threshold, the system is in critical mode, the compensation inductor is set to the maximum value, the compensation impedance is set to the maximum value, and the filter cutoff frequency is set to the minimum value.

[0061] The maximum value of the compensation inductor is the equivalent inductance on the large power grid simulator side multiplied by the first safety factor; the maximum value of the compensation resistor is the equivalent resistance on the large power grid simulator side multiplied by the second safety factor; the minimum value of the filter cutoff frequency is the highest effective simulation frequency of the system multiplied by the bandwidth preservation factor.

[0062] To adapt to the wide range of dynamic changes in the equivalent impedance of new energy power plants under varying operating conditions, this invention establishes a system based on the comprehensive impedance ratio. r The three working modes have an adaptive switching mechanism.

[0063] Define two dimensionless indices for the current impedance matching state of the system: ; Define the composite impedance ratio r for: ; in, r L and r R These respectively reflect the impedance matching degree of the system's inductance and resistance. r When <1, the system satisfies the standard ITM stability condition; whenr When the value is ≥1, the system does not meet the stability condition and improvement measures must be initiated.

[0064] Compensation impedance Z c The range of values ​​for: Compensating inductor L c The value can be: ; Compensation resistor R c The value can be: ; To facilitate subsequent adjustment algorithm design, a maximum usable value for the compensation inductor is defined. L c,max and the maximum available value of the compensation resistor R c,max .

[0065] ; Where, γ L For the inductance safety factor, γ R This is a resistance safety factor used to ensure the equivalent impedance Z on the compensated digital side. A -Z c It will not produce negative impedance due to parameter tuning errors, thus avoiding the risk of new numerical instability.

[0066] Filter cutoff frequency f c The range of values To ensure system stability, the filter's cutoff angular frequency ω c Must meet: ; like L A ≥ L B If the denominator of the above conditions is negative or zero, it indicates that filtering alone cannot maintain stability and must be combined with impedance compensation. After introducing compensation impedance, the overall stability requirements are: ; To ensure stability, a maximum cutoff frequency is defined. f max and minimum cutoff frequency f min The expression is: f max = f sys ; in, f sysThe highest effective simulation frequency of the system (determined by the highest harmonic order of the simulated system; for example, if an accurate simulation down to the 20th harmonic is required, then...). f sys =20×50=1000Hz).

[0067] ; Where η is the bandwidth retention factor, which means that even under the worst impedance conditions, the system retains at least η times the original bandwidth to avoid completely losing the ability to simulate high-frequency dynamics.

[0068] Based on the overall impedance ratio r The relationship with the threshold is defined by the following switching criterion: Normal mode r < r th1 The impedance matching is good, and no improvement measures are required; Early warning mode r th1 ≤ r < r th2 The impedance is close to the limit, and appropriate intervention is required; Critical mode, r ≥ r th2 The impedance has exceeded the limit, and maximum intervention is required.

[0069] In the formula, r th1 The first preset threshold, r th2 This is the second preset threshold.

[0070] Define the compensation inductor L c (r) is a function that continuously adjusts with respect to the impedance ratio r: ; Similarly, compensation resistor R c ( r The continuous adjustment function is: ; Physical meaning: When the system is in normal mode (r < 0.7), no compensation is applied (L c =0,R c =0), to maintain the highest simulation bandwidth and accuracy. When the system enters the warning mode (0.7≤r<1.0), the compensation impedance increases linearly from 0. The closer the impedance ratio is to the boundary value of 1.0, the larger the compensation amount. When the system enters the critical mode, the compensation impedance takes the maximum available value. L c,max and Rc,max This is to ensure numerical stability to the greatest extent possible.

[0071] Define cutoff frequency f c (r) is a function that continuously adjusts with respect to the impedance ratio r: ; Physical meaning: Maintaining the highest cutoff frequency when the system is in normal mode. f max Without sacrificing system bandwidth, when the system enters warning mode, the cutoff frequency is from... f max The cutoff frequency initially decreases linearly; the closer the impedance ratio is to the boundary value of 1.0, the lower the cutoff frequency and the stronger the filtering effect. When the system enters the critical mode, the cutoff frequency drops to... f min This law suppresses numerical oscillations with maximum filtering capability; the regulation law works in synergy with the compensation impedance regulation law, that is, when the impedance ratio increases, the cutoff frequency decreases at the same time, and the two work together to ensure system stability.

[0072] in, r th1 and r th2 Preset threshold: r th1 =0.7, r th2 =1.0; r th1 =0.7 is a reserved stability margin coefficient to ensure that the system still has sufficient response time when entering the early warning mode; r th2 =1.0 corresponds to the theoretical stability boundary of the standard ITM algorithm, when r When the value is ≥1, the system no longer meets the standard stability condition.

[0073] This adaptive adjustment mechanism enables the present invention to achieve the best balance between stability and bandwidth under different operating conditions, solving the problem that existing improved methods cannot adaptively adjust to the wide range of dynamic changes in the impedance of new energy power plants.

[0074] In actual digital simulation, the following steps are executed within each simulation step Δt: Measure the equivalent impedance R on both sides. A L A R B and L B ; Calculate the current composite impedance ratio r = max {L A / L B , R A / RB}; Based on the current r value, determine the current mode according to the switching conditions of the three working modes, and calculate the corresponding step size. L c (r), R c (r), f c (r); Will L c (r), R c (r), f c (r) Substitute the recursive equations and filtering equations of the improved ITM interface algorithm, perform single-step iteration, enter the next simulation step, and repeat the above steps.

[0075] The interactive module, through a dual-layer collaborative mechanism of impedance compensation layer and pre-filter layer and adaptive switching of three working modes, solves the numerical oscillation problem caused by the conditional stability of the ITM algorithm at the interface of the heterogeneous simulation platform. The impedance compensation layer virtually series negative and positive impedances in the digital models of the two simulators respectively, expanding the stability margin from the mathematical model level. The pre-filter layer introduces a variable cutoff frequency low-pass filter in the feedback current channel to reduce the open-loop gain in the high-frequency band to suppress residual oscillations. Through the joint adjustment of the compensation impedance and the filter cutoff frequency (three degrees of freedom), the conditional stability of the standard ITM interface algorithm is improved to global large-range stability. The adaptive switching mechanism of the three working modes further adjusts the compensation intensity and filtering depth in real time according to the comprehensive impedance ratio, maintaining the highest bandwidth accuracy when the impedance matching is good, smoothly transitioning when approaching the stability boundary, and ensuring stability when the instability threshold is reached. This allows the interface algorithm to achieve the best balance between stability and bandwidth under different operating conditions, solving the problem of interface oscillation caused by the wide-range dynamic change of impedance in new energy power plants.

[0076] The timing coordination control module is used to control the new energy power plant simulator model to start first and perform state initialization when the joint simulation is started, and then control the large power grid simulator to start after the initialization is completed.

[0077] The timing coordination control module also includes a step size synchronization submodule, which is used to run with a preset fixed step size during the joint simulation operation phase, and dynamically match the simulation step size on both sides through step size negotiation and clock alignment.

[0078] It should be noted that when the cross-platform co-simulation is started, the timing coordination control module forces the execution of a specific model startup order to solve the problem that the interface state variables do not converge or the data is misaligned at the initial moment due to the difficulty in strictly aligning the startup time, initialization completion time and data ready time of heterogeneous simulators.

[0079] The specific model startup sequence is as follows: the new energy power station simulator side model is started first, followed by the large power grid simulator side model.

[0080] The specific startup process is as follows: The timing-coordinated control module first sends a start command to the new energy power station simulator to control the start-up and operation of the model on the new energy power station simulator side.

[0081] After the new energy power station simulator model starts, it performs initialization operations on the interface state variables of the wind and solar system, including but not limited to: setting the initial values ​​of port voltage and current, assigning initial state values ​​to the controller, initial phase locking of the phase-locked loop, and initial establishment of the converter modulation signal. This initialization process is usually completed within tens of microseconds to several milliseconds, and the specific duration depends on the complexity of the model.

[0082] After the new energy power station simulator model completes initialization, it sends a ready signal to the timing coordination control module. This signal includes the precise timestamp of the current simulation moment and the initialization completion identifier of the interface state variables.

[0083] After receiving the ready signal, the timing coordination control module sends a start command to the large power grid simulator after a preset waiting time, and then controls the large power grid simulator side model to start.

[0084] After the large power grid simulator model is started, it uses the timestamp in the ready signal sent by the new energy power station simulator as a reference benchmark to align its own simulation clock with the timestamp, ensuring the consistency of the simulation start time of both parties, and then connects to the large power grid for operation.

[0085] At the initial moment of the simulation, the state variables such as voltage and current at the interface must be established by one side first before the other side can perform calculations and responses based on these established values. If both sides start simultaneously, the interface state variables will not converge at the initial moment, which may lead to numerical anomalies and cause simulation divergence. This invention forces the new energy power plant simulator to start first and the large power grid simulator to start later, so that the interface state variables have definite physical values ​​at the initial moment. The new energy power plant side completes the initialization of control variables first, and then the large power grid side connects and achieves seamless connection with the state variables of the new energy power plant side. This avoids numerical anomalies caused by uninitialized or conflicting interface variables due to simultaneous startup of both sides, and ensures the timing consistency of heterogeneous simulators on the microsecond time scale from the source.

[0086] During the joint simulation operation phase, the step size synchronization submodule of the timing coordination control module is responsible for coordinating the simulation step size of the two simulators to ensure that both sides advance in coordination under a unified time reference.

[0087] The step-size synchronization mechanism is achieved through the coordinated operation of the following four sub-mechanisms: Step size negotiation and clock alignment: Before simulation starts, the step size synchronization submodule negotiates the step size between the two simulators via a dedicated synchronization signal line. Specifically, the local clock of the new energy power plant simulator is used as the reference clock, and the local clock of the large power grid simulator is locked to the reference clock using phase-locked loop (PLL) technology. This ensures that the frequency deviation between the two clocks is controlled within ±50 ppm and the phase deviation within ±1 microsecond. During simulation operation, after each simulation step is completed, both simulators report the completion time of the current step to the step size synchronization submodule. The submodule compares the time deviations between the two simulators in real time. If the deviation exceeds the preset allowable range, compensation is made by fine-tuning the simulation step size of the large power grid simulator, ensuring that both simulators always advance collaboratively under the same virtual synchronous clock.

[0088] Buffer Management: To absorb minor jitter during data arrival, the step-size synchronization submodule sets up a double-buffered data area at the receiving end of each simulator. Data received within the current simulation step is written to BufferA, while data from the previous simulation step in BufferB is used for calculation in the current simulation step. The buffer size is set according to the maximum amount of data that may be received within a single simulation step, typically 2-5 steps. When a data packet arrives late due to communication jitter, the step-size synchronization submodule automatically maintains the current calculation step size, waiting for the data to arrive before assigning values ​​and performing calculations. This effectively absorbs data jitter at the nanosecond to microsecond level, ensuring that the data required for calculation within each step is complete before execution, avoiding empty calculations or calculation errors caused by incomplete data.

[0089] Flow control mechanism: The flow control mechanism is used to prevent data overload from causing buffer overflow and data loss. The step-size synchronization submodule monitors the water level of the receive buffer in real time. When the buffer water level exceeds the preset high water level, it sends a flow control signal to the sender, requesting the sender to reduce the data transmission rate or suspend the transmission of non-critical data, prioritizing the transmission of critical data. When the buffer water level drops below the preset low water level, it sends a resume transmission signal to the sender, restoring normal data transmission. This mechanism, together with the aforementioned buffer management, forms a complete data flow control closed loop, preventing buffer overflow and data loss caused by sudden large-volume data bursts.

[0090] The timeout management fault tolerance mechanism provides protection in case of communication anomalies. The step-size synchronization submodule sets a timeout timer for each data packet waiting to be received, with the timeout duration preset to 3-5 times the normal transmission delay. If the target data is not received when the timeout timer reaches zero, the timeout fault tolerance process is triggered: First, the step-size synchronization submodule records this timeout event for subsequent fault analysis; second, if the timeout event occurs during the reception of non-critical data, historical data from the previous simulation step is used to replace it to ensure simulation continuity; if the timeout event occurs during the reception of critical data, a safety shutdown process is triggered, notifying both simulators to pause operation to prevent the propagation of errors caused by data loss.

[0091] The coordinated operation of the above four mechanisms ensures that both parties advance together under a virtual synchronous clock, realizing high-fidelity synchronous interaction between the electromagnetic transients of the power grid and the high-frequency control characteristics of new energy sources. This provides a timing guarantee for the entire system to achieve long-term stable joint simulation.

[0092] Secondly, this invention also provides a heterogeneous collaborative simulation method for wind-solar-power-grid interaction based on an improved ITM interface algorithm, implemented using a heterogeneous collaborative simulation system for wind-solar-power-grid interaction based on an improved ITM interface algorithm, comprising the following steps: A heterogeneous simulation platform is constructed, comprising a new energy power plant simulator and a large power grid simulator. The new energy power plant simulator is used to simulate the dynamic control characteristics of wind power and photovoltaic power, while the large power grid simulator is used to simulate the operating characteristics of the large power grid. A serial communication link is established between the simulator on the new energy power station side and the simulator on the large power grid side, and byte order reversal and reverse restoration are performed before data transmission and after data reception, respectively, to ensure the consistency of data transmission. On the simulation interaction interface of the two simulators, an improved ITM interface algorithm is used to couple electrical quantities, so that the new energy power station simulator side is equivalent to a controlled current source and the large power grid simulator side is equivalent to a controlled voltage source. The improved ITM interface algorithm sets a low-pass filter with a variable cutoff frequency in the current feedback channel and virtual series compensation impedances in the digital models of the two real-time simulators respectively. By sampling the boundary voltage and current to update the state of the controlled source, the equivalent physical interface conversion and numerical stable interaction of electrical quantities on both sides are realized. When the joint simulation is started, the new energy power plant simulator model is started first and its state is initialized. After the initialization is completed, the large power grid simulator is started.

[0093] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0094] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working process of the system and modules described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0095] In the embodiments provided by this invention, it should be understood that the disclosed systems and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0096] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0097] In addition, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0098] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, essentially, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, ROM, RAM, magnetic disks, or optical disks.

[0099] Furthermore, it should be noted that in the system and method of the present invention, it is obvious that the components or steps can be decomposed and / or recombined. These decompositions and / or recombinations should be considered equivalent solutions of the present invention. Moreover, the steps performing the above series of processes can naturally be executed in the order described, but are not necessarily required to be executed in chronological order; some steps can be executed in parallel or independently of each other. Those skilled in the art will understand that all or any step or component of the method and apparatus of the present invention can be implemented in any computing device (including processors, storage media, etc.) or network of computing devices, in hardware, firmware, software, or a combination thereof. This is something that those skilled in the art can achieve by using their basic programming skills after reading the description of the present invention.

[0100] Therefore, the object of the present invention can also be achieved by running a program or a set of programs on any computing system. The computing system can be a known general-purpose system. Therefore, the object of the present invention can also be achieved simply by providing a program product containing program code implementing the method or apparatus. That is, such a program product also constitutes the present invention, and the storage medium storing such a program product also constitutes the present invention. Obviously, the storage medium can be any known storage medium or any storage medium developed in the future. It should also be noted that in the apparatus and method of the present invention, it is obvious that the components or steps can be decomposed and / or recombined. These decompositions and / or recombinations should be considered equivalent to the present invention. Furthermore, the steps performing the above series of processes can naturally be performed in the order described, but are not necessarily required to be performed in chronological order. Some steps can be performed in parallel or independently of each other.

[0101] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A heterogeneous collaborative simulation system for wind-solar-power plant-grid interaction based on an improved ITM interface algorithm, characterized in that, include: The platform construction module is used to build a heterogeneous simulation platform including a new energy power plant simulator and a large power grid simulator. The new energy power plant simulator is used to simulate the dynamic control characteristics of wind power and photovoltaic power, and the large power grid simulator is used to simulate the operation characteristics of the large power grid. The data communication module is used to establish a serial communication link between the simulator on the new energy power plant side and the simulator on the large power grid side, and to perform byte order reversal and reverse restoration before data transmission and after data reception, respectively, to ensure the consistency of data transmission. The data interaction module is used to couple electrical quantities on the simulation interaction interface of the two simulators using an improved ITM interface algorithm. The new energy power plant simulator side is equivalent to a controlled current source, and the large power grid simulator side is equivalent to a controlled voltage source. The improved ITM interface algorithm sets a low-pass filter with a variable cutoff frequency in the current feedback channel and virtually series compensated impedances in the digital models of the two real-time simulators respectively. By sampling the boundary voltage and current to update the state of the controlled source, the equivalent physical interface conversion and numerical stable interaction of electrical quantities on both sides are realized. The timing coordination control module is used to control the new energy power plant simulator model to start first and perform state initialization when the joint simulation is started, and then control the large power grid simulator to start after the initialization is completed.

2. The wind-solar-powerhouse-grid interactive heterogeneous collaborative simulation system based on the improved ITM interface algorithm as described in claim 1, characterized in that, The data communication module includes: The byte-flipping submodule at the sending end is used to flip the original memory byte sequence of the data to be sent from little-endian to big-endian before the new energy power station simulator sends the data, and then fill the flipped byte sequence into the communication protocol data frame before sending it. The new energy power station simulator is built using the Speedgoat real-time simulator, and its native byte order is little-endian. The receiving end reverse restoration submodule is used to extract data from the big-endian byte stream received from the communication link after the large power grid simulator receives data, restore the byte sequence to the native little-endian memory layout of the receiving end, and restore it to the original data type through type reinterpretation. The large power grid simulator is built using the RTDS real-time simulator, whose native byte order is little-endian, and the communication link is an Aurora fiber optic link, whose transmission byte order is big-endian.

3. The wind-solar-powerhouse-grid interactive heterogeneous collaborative simulation system based on the improved ITM interface algorithm as described in claim 1, characterized in that, The improved ITM interface algorithm is executed iteratively with the simulation step size as the period. The single-step iteration process is as follows: Obtain the port current fed back from the simulator side of the new energy power station in the previous simulation step, and obtain the filtered current after passing the corresponding port current in the previous simulation step through a first-order low-pass filter. The port output voltage at the current step size is calculated by subtracting the difference between its equivalent resistance and virtual compensation resistance from the internal power supply voltage on the large power grid simulator side and multiplying it by the filter current. The port output voltage is transmitted to the new energy power station simulator side. The new energy power station simulator side calculates the feedback current of the current step size based on the port output voltage of the current step size, the feedback current of the previous simulation step size, its own equivalent resistance, its own equivalent inductance, the inductance and resistance components of the virtual series compensation impedance, and the joint simulation step size, and completes the single-step iteration.

4. The wind-solar-powerhouse-grid interactive heterogeneous collaborative simulation system based on the improved ITM interface algorithm as described in claim 3, characterized in that, The data interaction module also includes an impedance parameter constraint submodule, which is used to constrain the value of the compensation impedance in the virtual series connection. The lower limit of the compensation inductance is half the difference between the equivalent inductance on the large power grid simulator side and the equivalent inductance on the new energy power station simulator side, and the upper limit is the equivalent inductance on the large power grid simulator side. The lower limit of the compensation resistance is determined based on the difference between the equivalent resistance on the large power grid simulator side and the new energy power station simulator side and the equivalent total delay of the interface system, and the upper limit is the equivalent resistance on the large power grid simulator side.

5. The wind-solar-power-grid interactive heterogeneous collaborative simulation system based on the improved ITM interface algorithm as described in claim 4, characterized in that, The values ​​of the compensation impedance and the filter cutoff frequency together satisfy the overall stability condition: The inductance stability condition is that the equivalent inductance on the large power grid simulator side is less than the sum of the equivalent inductance on the new energy power station simulator side and twice the compensation inductance, plus the sum of the equivalent resistance on the new energy power station simulator side and the compensation resistance divided by the filter cutoff angular frequency. The resistance stability condition is: calculate the sum of the equivalent resistance on the new energy power station simulator side and twice the compensation resistance to obtain the first component; The second component is obtained by multiplying the sum of the equivalent inductance on the large power grid simulator side and the equivalent inductance on the new energy power station simulator side by two times and then dividing by the equivalent total delay of the interface system. The third component is obtained by multiplying the sum of the equivalent resistance on the new energy power station simulator side and the compensation resistance by the filter cutoff angular frequency, then multiplying by two times and then dividing by the equivalent total delay of the interface system. The first, second, and third components are added together to obtain the comprehensive impedance threshold. The equivalent resistance on the large power grid simulator side is less than the comprehensive impedance threshold.

6. The wind-solar-power plant-grid interactive heterogeneous collaborative simulation system based on the improved ITM interface algorithm as described in claim 5, characterized in that, The data interaction module further includes a mode adaptive switching submodule, used to adjust the compensation impedance and filter cutoff frequency according to the system impedance matching status; wherein: The comprehensive impedance ratio is defined as the larger of the ratio of the equivalent inductance on the large power grid simulator side to the equivalent inductance on the new energy power station simulator side, and the ratio of the equivalent resistance on the large power grid simulator side to the equivalent resistance on the new energy power station simulator side. When the overall impedance ratio is less than the first preset threshold, the system is in normal mode, the compensation inductor is zero, the compensation resistor is zero, and the filter cutoff frequency remains at the highest value. When the overall impedance ratio is greater than or equal to the first preset threshold and less than the second preset threshold, the system is in an early warning mode. The compensation inductor is calculated as the product of the difference between the overall impedance ratio and the first preset threshold, divided by the difference between the second preset threshold and the first preset threshold, and then multiplied by the maximum value of the compensation inductor. The compensation resistor is calculated as the product of the difference between the overall impedance ratio and the first preset threshold, divided by the difference between the second preset threshold and the first preset threshold, and then multiplied by the maximum value of the compensation resistor. The filter cutoff frequency is calculated as the product of the highest filter cutoff frequency minus the difference between the highest and lowest filter cutoff frequencies, multiplied by the difference between the overall impedance ratio and the first preset threshold, divided by the difference between the second preset threshold and the first preset threshold. When the overall impedance ratio is greater than or equal to the second preset threshold, the system is in critical mode, the compensation inductor is set to the maximum value, the compensation impedance is set to the maximum value, and the filter cutoff frequency is set to the minimum value.

7. The wind-solar-powerhouse-grid interactive heterogeneous collaborative simulation system based on the improved ITM interface algorithm as described in claim 6, characterized in that, The maximum value of the compensation inductor is the equivalent inductance on the large power grid simulator side multiplied by the first safety factor; the maximum value of the compensation resistor is the equivalent resistance on the large power grid simulator side multiplied by the second safety factor; the minimum value of the filter cutoff frequency is the highest effective simulation frequency of the system multiplied by the bandwidth preservation factor.

8. The wind-solar-powerhouse-grid interactive heterogeneous collaborative simulation system based on the improved ITM interface algorithm as described in claim 1, characterized in that, The timing coordination control module also includes a step size synchronization submodule, which is used to run with a preset fixed step size during the joint simulation operation phase, and dynamically match the simulation step size on both sides through step size negotiation and clock alignment.

9. A heterogeneous collaborative simulation method for wind-solar-power plant-grid interaction based on an improved ITM interface algorithm, characterized in that, The system, implemented using any one of claims 1-8, is a heterogeneous collaborative simulation system for wind, solar, power plant, and grid interaction based on an improved ITM interface algorithm, comprising the following steps: A heterogeneous simulation platform is constructed, comprising a new energy power plant simulator and a large power grid simulator. The new energy power plant simulator is used to simulate the dynamic control characteristics of wind power and photovoltaic power, while the large power grid simulator is used to simulate the operating characteristics of the large power grid. A serial communication link is established between the simulator on the new energy power station side and the simulator on the large power grid side, and byte order reversal and reverse restoration are performed before data transmission and after data reception, respectively, to ensure the consistency of data transmission. On the simulation interaction interface of the two simulators, an improved ITM interface algorithm is used to couple electrical quantities, so that the new energy power station simulator side is equivalent to a controlled current source and the large power grid simulator side is equivalent to a controlled voltage source. The improved ITM interface algorithm sets a low-pass filter with a variable cutoff frequency in the current feedback channel and virtual series compensation impedances in the digital models of the two real-time simulators respectively. By sampling the boundary voltage and current to update the state of the controlled source, the equivalent physical interface conversion and numerical stable interaction of electrical quantities on both sides are realized. When the joint simulation is started, the new energy power plant simulator model is started first and its state is initialized. After the initialization is completed, the large power grid simulator is started.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the functions of the wind-solar-power plant-grid interactive heterogeneous collaborative simulation system based on the improved ITM interface algorithm as described in any one of claims 1 to 8.

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