Modelica-based DC isolated grid power system modeling simulation method and device, storage medium and electronic device

Abstract

The invention belongs to the technical field of power system simulation, and particularly relates to a Modelica-based DC isolated grid power system modeling simulation method and device, a storage medium and an electronic device. Comprising the steps that a real direct-current isolated grid power system topological structure is decomposed to obtain power simulation component models, and the power simulation component models comprise a generator component model, a transformer component model, a power transmission line component model, a load component model, an energy storage component model and corresponding component data models; and establishing a basic model library according to the electric power simulation component model. The method has the beneficial effects that a plurality of power simulation component models are obtained through decomposition according to the topological structure of a real direct-current isolated grid power system, so that the modeling difficulty of simulation analysis is greatly reduced, the model reusability is improved, and a cross-professional joint simulation function is expanded.

Description

Technical Field

[0001] The present invention belongs to the technical field of power system simulation, and particularly relates to a method and device for modeling and simulating a DC islanded power system based on Modelica, a storage medium, and an electronic device. Background Art

[0002] A DC islanded power system is a power system whose output power frequency is not affected by the speed regulation performance of the prime mover. It has a high power density, is compatible with distributed energy storage or other power sources, and has simple control. It has stronger adaptability than AC power sources and is the preferred form of shipboard power grid systems.

[0003] During the design, simulation, and analysis of a DC islanded power system, currently, the causal modeling method (i.e., the procedural modeling method) is mainly used to develop the model and obtain the operating state of the entire network, including the voltage of each bus, the power distribution in the DC islanded network, and power losses, etc. The causal modeling method not only requires decoupling analysis of complex power grid systems, clearly defining the input and output of the model and the solution order of equations, but also requires mastering the compilation and solution techniques of complex system models. The overall modeling and solution process is relatively complex. For large-scale multi-device complex power systems such as ships, this method makes the modeling process complex and difficult, and the developed model has low reusability, generality, and scalability, and is insufficient in modularization and parameterization.

[0004] Secondly, the traditional simulation modeling in the electrical field uses single-specialty modeling and simulation software. With the increasing demand for high-precision simulation of the entire system in the research and development of large-scale thermoelectric conversion systems for the coupled simulation of multiple systems such as power systems, thermoelectric conversion thermohydraulics, instrument control, and machinery, the above traditional power system modeling methods are difficult to achieve cross-specialty joint simulation. Summary of the Invention

[0005] The purpose of the present invention is to provide a method and device for modeling and simulating a DC islanded power system based on Modelica, a storage medium, and an electronic device, which can solve the problems of complex modeling, simulation, and analysis of complex DC islanded power systems, low model reusability, and inadaptability to cross-specialty joint simulation.

[0006] The technical solution of the present invention is as follows: A method for modeling and simulating a DC islanded power system based on Modelica includes decomposing the topology structure of a real DC islanded power system to obtain a power simulation component model.

[0007] The power simulation component model includes: a generator component model, a transformer component model, a transmission line component model, a load component model, an energy storage component model, and corresponding component data models.

[0008] Establish a basic model library according to the power simulation component model.

[0009] The basic model library includes: an interface model, a component model, an electrical equipment model, an instrument control model, and an equipment integration model; connectors are preset according to the transfer mode of device physical quantities between different models to connect the interface model, the component model, and the electrical equipment model according to a preset modeling method, and a power system simulation system is established. The system sub-models included in the power system simulation system include: a generator component model, a transformer component model, a transmission line component model, a load component model, an energy storage component model, and corresponding component data models, where the power system simulation system is obtained by simulating the real DC islanded power system based on Modelica; according to the task requirements of the DC islanded power system modeling and simulation system, the DC islanded power system is simulated.

[0010] The interface model is used to simulate the transfer mode of physical quantities between different model modules. The interface model provides a unified standard connector type for the transfer of different types of physical quantities, including an electrical connector that defines voltage and current as potential and flow variables, a thermal connector that defines temperature and heat flow, a translational mechanical connector, a rotational mechanical connector, and an instrument control signal connector that defines signal input and output. Through the interface model, data coupling and interaction of voltage, current, rotational speed, torque, temperature, control signal, or command signal are realized between components.

[0011] The component model is used to simulate the self-characteristics of the device, reflecting the performance parameters and behavioral characteristics of the device at the physical level. The characteristics include mechanical characteristics, thermal characteristics, material properties, and electrical characteristics. By abstracting and parameterizing the body parameters and dynamic behaviors of a single physical device, the component model provides a basis for the subsequent modeling and integration of the power system. The component model interacts with other devices through a unified interface model for physical quantity transfer.

[0012] The electrical equipment model is used to simulate the electrical properties of actual physical devices in the power system, where the electrical properties include voltage, current, power, impedance, frequency, and their dynamic electrical quantities and related mechanisms. Through the electrical equipment model, the working state of the device in the power system is accurately characterized, and the simulation of the electrical energy transmission, transformation, and control process is realized according to the interaction of the electrical topological structures between electrical equipment.

[0013] The instrument control model is used to obtain system state quantities through signal connectors and output control signals to the electrical equipment model, simulating the closed-loop control and optimal scheduling of the power system operation state.

[0014] The device integration model models and connects the interface model, component model, electrical equipment model, and instrument control model to establish a system integration model of the overall operating characteristics of the DC isolated network power system, and simulates the dynamic response of the real power system under given inputs, boundary conditions, and control strategies.

[0015] When establishing the simulation model of the PMSM permanent magnet synchronous generator for the generator component described, it includes a moment of inertia model, a fixed support model, an air gap model, a permanent magnet model, and a thermal calculation model. Among them, the moment of inertia model of the rotation is used to simulate the inertial characteristics of the motor rotor, the fixed support model is used to simulate the mechanical support structure of the motor, the air gap model is used to simulate the magnetic field distribution and magnetic flux in the air gap, the permanent magnet model is used to simulate the magnetic properties of the permanent magnets in the PMSM, and the thermal calculation model is used to simulate the thermal effects during the operation of the motor. All the above models are used to simulate the actual working characteristics of the PMSM.

[0016] The transformer component establishes a transformation unit, and according to the principle of the ideal transformer, describes the relationship between voltage, current, and power.

[0017] The formula for establishing the simulation model of the transformation unit is as follows:

[0018] Voltage relationship:

[0019]

[0020] Among them, V1 and V2 are the voltages of the primary winding and secondary winding respectively, and N1 and N2 are the number of turns of the primary winding and secondary winding respectively;

[0021] Current relationship:

[0022]

[0023] Among them, I1 and I2 are the currents of the primary winding and secondary winding respectively;

[0024] Power relationship:

[0025] P1 = P2

[0026] Among them, P1 and P2 are the powers of the primary winding and secondary winding respectively.

[0027] The energy storage component establishes an energy storage unit, and the energy storage unit includes

[0028] Open-circuit voltage:

[0029] V oc = K(SOC - SOC0) + V0

[0030] In the formula, V ocrepresents the open-circuit voltage of the energy storage device, K is the slope coefficient, SOC is the charge and discharge state of the energy storage device, SOC0 is the reference charge and discharge state, and V0 is the reference voltage.

[0031] The attenuation effect of the internal resistance of the energy storage device on the current:

[0032] E = V - IR

[0033] Among them, E represents the electromotive force of the energy storage device, V represents the actual voltage of the energy storage device, I represents the current, and R represents the internal resistance of the energy storage device.

[0034] A DC isolated network power system modeling and simulation device based on Modelica, comprising:

[0035] A splitting module, configured to decompose a plurality of power simulation system sub-models according to the topology of the actual DC isolated network power system;

[0036] A basic model module, configured to establish a basic model library according to the plurality of power simulation system sub-models, wherein the basic model library includes: an interface model, a component model, an electrical equipment model, and a system model;

[0037] A simulation module, configured to connect the interface model, the component model, and the electrical equipment model according to a preset connector according to a preset modeling method to establish a power system simulation system, wherein the power system simulation system is obtained by modeling and simulating the actual DC isolated network power system based on Modelica;

[0038] A calculation module, configured to perform simulation of the DC isolated network power system according to the task requirements of the DC isolated network power system modeling and simulation system.

[0039] A computer-readable storage medium, in which a computer program is stored, wherein the computer program is set to execute the method when running.

[0040] An electronic device, comprising a memory and a processor, wherein a computer program is stored in the memory, and the processor is set to run the computer program to execute the method.

[0041] The beneficial effects of the present invention are as follows: By decomposing the true DC islanded power system topology structure to obtain multiple power simulation component models, and then based on the multiple power simulation component models, using the Modelica non-causal modeling specification to establish a basic model library. By connecting the interface model, the component model, the electrical equipment model, and the instrument control model according to a preset connector in accordance with a preset modeling method, a power system simulation system is established, meeting the task requirements of building a simulation system for the DC islanded power system. It has a multi-professional joint simulation interface and can perform joint simulation of the thermoelectric conversion thermal fluid system, instrument control, machinery, and the DC islanded power system, thereby greatly reducing the modeling difficulty of simulation analysis, improving the model reusability, and expanding the cross-professional joint simulation function. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 FIG. is a flowchart of a method for modeling and simulating a DC islanded power system based on Modelica provided by the present invention;

[0043] Figure 2 FIG. is a schematic diagram for modeling a permanent magnet synchronous motor;

[0044] Figure 3 FIG. is a schematic diagram for modeling a transformer unit model;

[0045] Figure 4 FIG. is a schematic diagram for modeling an energy storage unit model;

[0046] Figure 5 FIG. is a schematic diagram for modeling a load shedding unit model;

[0047] Figure 6 FIG. is a Modelica topology schematic diagram of a DC islanded power system;

[0048] Figure 7 FIG. is a schematic diagram of the photovoltaic output voltage of a DC islanded power system;

[0049] Figure 8 FIG. is a schematic diagram of the photovoltaic output current of a DC islanded power system;

[0050] Figure 9 FIG. is a schematic diagram of the load input voltage of a DC islanded power system;

[0051] Figure 10 FIG. is a schematic diagram of the load input current of a DC islanded power system;

[0052] Figure 11 FIG. is a schematic diagram of the battery input voltage of a DC islanded power system;

[0053] Figure 12 FIG. is a schematic diagram of the battery input current of a DC islanded power system;

[0054] Figure 13 Schematic diagram of three-phase voltage output by the inverter of the DC islanded power system

[0055] Figure 14 Schematic diagram of three-phase current output by the inverter of the DC islanded power system Specific implementation manners

[0056] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0057] Modelica applied in the present invention is a multi-domain unified modeling language for physical systems based on non-causal expression equations, which meets the requirements of the development direction of modeling and simulation and is applicable to various subsystem models such as mechanical, electrical, hydraulic, and control, as well as large-scale complex heterogeneous physical systems. The overall logic is to decompose the real system into component-level models (power simulation component models), establish a basic model library according to the requirements of the component-level models, build component-level models based on the basic model library, and then build a DC islanded power system simulation model according to the real topology connection.

[0058] A method for modeling and simulating a DC islanded power system based on Modelica includes: decomposing the topology structure of the real DC islanded power system to obtain the power simulation component models required for building the DC islanded power system simulation, where the power simulation component models include: generator component models, transformer component models, transmission line component models, load component models, energy storage component models, and corresponding component data models; further decomposing the power simulation component models to establish a basic model library, where the basic model library includes: interface models, electrical equipment models, instrument control models, power simulation component models, and DC islanded power system models. Presetting connectors to connect the interface models, component models, and electrical equipment models according to the transfer manner of device physical quantities between different models, and establishing a power system simulation system, where the system sub-models included in the power system simulation system include: generator component models, transformer component models, transmission line component models, load component models, energy storage component models, and corresponding component data models, where the power system simulation system is obtained by simulating the real DC islanded power system based on Modelica; performing DC islanded power system simulation according to the task requirements of the DC islanded power system modeling and simulation system.

[0059] The interface model is used to simulate the transfer mode of physical quantities between different model modules. The interface model provides a unified standard connector type for the transfer of different types of physical quantities, including electrical connectors (defining voltage and current as potential and flow variables), thermal connectors (defining temperature and heat flow), translational mechanical connectors, rotational mechanical connectors (defining variables such as rotational speed, torque, or speed and force for rotational and linear motion), and instrument control signal connectors (defining signal input and output). Through these interface models, data coupling and interaction of physical quantities or command signals such as voltage, current, rotational speed, torque, temperature, and control signals can be achieved between components.

[0060] The preset connector is obtained as follows: Design the connector according to the connection mode of the power simulation component model in the DC isolated network power system based on the interface model. The connector connects different power simulation component models to form a DC isolated network power system simulation model, reducing the development difficulty of the model, improving the reusability of the model, effectively shortening the development cycle of the electrical program, and improving the design efficiency of the project, thereby solving the technical problems of low engineering efficiency in the modeling and simulation of the DC isolated network power system and being unable to support multi-disciplinary simulation. Connectors include electrical connectors, thermal connectors, translational mechanical connectors, instrument control signal connectors, and rotational mechanical connectors. The variables of the connector include flow variables and potential variables.

[0061] The power simulation component model presets connectors according to the transfer mode of device physical quantities between different models, and sequentially builds the interface model and the models in the basic model library to simulate the self-characteristics of the device and reflect the performance parameters and behavioral characteristics of the device at the physical level. These characteristics usually include mechanical characteristics, thermal characteristics, material properties, and electrical characteristics. By abstracting and parameterizing the body parameters and dynamic behaviors of individual physical devices, the component model provides a basis for the subsequent modeling and integration of the power system. The component model interacts with other devices through a unified interface model for physical quantities.

[0062] The instrument control model is used to obtain system state quantities through signal connectors and output control signals to electrical equipment models, simulating the closed-loop control and optimal scheduling of the operation state of the power system.

[0063] The electrical equipment model is used to simulate the electrical properties of actual physical devices in the power system, where the electrical properties include voltage, current, power, impedance, frequency, and their dynamic change electrical quantities and related mechanisms. Through the electrical equipment model, the working state of the device in the power system is accurately characterized, the simulation of the electrical energy transmission, transformation, and control process is realized, and the interaction is based on the electrical topological structure between electrical equipment.

[0064] The DC isolated power system model models and connects the interface model, electrical equipment model, instrument control model, and power simulation component model according to the topology of the real DC isolated power system to establish a system integration model of the overall operating characteristics of the DC isolated power system, which can simulate the dynamic response of the real power system under given inputs, boundary conditions, and control strategies. The DC isolated power system simulation model is obtained based on Modelica through the real DC isolated power system; according to the task requirements of the DC isolated power system modeling and simulation system, the DC isolated power system is simulated.

[0065] When establishing the simulation model of the PMSM permanent magnet synchronous generator for the generator component described above, it includes a moment of inertia model, a fixed support model, an air gap model, a permanent magnet model, and a thermal calculation model. Among them, the moment of inertia model of the rotation is used to simulate the inertial characteristics of the motor rotor, the fixed support model is used to simulate the mechanical support structure of the motor, the air gap model is used to simulate the magnetic field distribution and magnetic flux in the air gap, the permanent magnet model is used to simulate the magnetic properties of the permanent magnets in the PMSM, and the thermal calculation model is used to simulate the thermal effect of the motor during operation. All of the above models are used to simulate the actual working characteristics of the PMSM:

[0066] Taking the two-phase moving coordinate system DQ coordinate system as a reference, each physical quantity is transformed to the DQ coordinate system through the Park transformation, and then there is:

[0067]

[0068] Among them,

[0069] T = p[L sd i sq i f -(L sd -L sq )i sd i sq

[0070] According to the mathematical model of the permanent magnet synchronous motor, its text model is established using the Modelica language, leaving mechanical rotation interfaces, electrical interfaces, and thermal interfaces.

[0071] The transformer component establishes a voltage transformation unit, and according to the principle of the ideal transformer, describes the relationship between voltage, current, and power.

[0072] When establishing the simulation model of the voltage transformation unit, the main principle of the ideal transformer is as follows:

[0073] Voltage relationship:

[0074]

[0075] ​Among them, V1 and V2 are the voltages of the primary winding and the secondary winding respectively, and N1 and N2 are the number of turns of the primary winding and the secondary winding respectively.

[0076] Current relationship:

[0077]

[0078] Among them, I1 and I2 are the currents of the primary winding and the secondary winding respectively.

[0079] Power relationship:

[0080] P1 = P2

[0081] Among them, P1 and P2 are the powers of the primary winding and the secondary winding respectively. Since transformer losses are not considered, the power remains constant in the transformer.

[0082] According to the mathematical model of the voltage transformation unit, its text model is established using Modelica language, and electrical interfaces are reserved to receive input signals and transmit output signals.

[0083] The energy storage component establishes an energy storage unit:

[0084] For the energy storage unit, when establishing the simulation model of the energy storage unit, the influence of the internal resistance on the charge and discharge process is considered, and the SOC is calculated.

[0085] Open-circuit voltage:

[0086] V oc = K(SOC - SOC0) + V0

[0087] In the formula, V oc represents the open-circuit voltage of the energy storage device, K is the slope coefficient, SOC is the charge and discharge state of the energy storage device, SOC0 is the reference charge and discharge state, and V0 is the reference voltage.

[0088] The attenuation effect of the internal resistance of the energy storage device on the current:

[0089] E = V - IR

[0090] Among them, E represents the electromotive force of the energy storage device, V represents the actual voltage of the energy storage device, I represents the current, and R represents the internal resistance of the energy storage device.

[0091] According to the mathematical model of the energy storage unit, its text model is established using Modelica language, and electrical interfaces and control interfaces are reserved to receive input signals and transmit output signals.

[0092] The load component establishes a unloading unit:

[0093] The unloading unit is mainly based on Ohm's law, which describes the relationship between current, voltage, and resistance. The theoretical formula is:

[0094] V = I * R

[0095] The power switch is mainly developed based on semiconductor devices. When the control signal reaches the threshold signal, that is, when unloading is required, the switch closes; otherwise, it opens. The theoretical formula is:

[0096] V = i * Roll(G.v ≥ Vth)

[0097] V = i / Goff(G.v < Vth)

[0098] According to the mathematical model of the unloading unit, its text model is established using Modelica language, reserving electrical interfaces and control interfaces to receive input signals and transmit output signals.

[0099] The basic model library is established according to the sub-model of the power simulation system, where the basic model library includes: interface model, component model, electrical equipment model, instrument control model, system model, including: each of the component models of the power system simulation system is established separately using the object-oriented declarative modeling method; the physical model of the component model is transformed into a mathematical model expressed by equations, and the mathematical model is transformed into a numerical model; based on boundary conditions and initial values, the numerical model is used for simulation; the numerical model is implemented using Modelica language to obtain the component model; the component model is connected to the system model for simulation, and if the two match, the component model passes the verification.

[0100] Furthermore, multiple power simulation system sub-models are obtained by decomposing the topology structure of the real DC isolated power grid system, including: based on a preset processing scheme of data abstraction, interface separation, and modularization, multiple power simulation system sub-models are obtained by decomposing the topology structure of the real DC isolated power grid system, where the data abstraction is used to extract the common features in the model and express them with an abstract model; the interface separation is used to separately model different component and equipment models and declare component attributes during the model instantiation process; the modularization includes: the interface model of the power system simulation system, various component models, and the electrical system model.

[0101] Further, according to the task requirements of the DC isolated power system modeling and simulation system, DC isolated power system simulation is performed, including: based on the established DC isolated power system modeling and simulation system of Modelica, DC isolated power system simulation is carried out. According to the preset grid architecture and the given network parameters and component parameters, the current power system simulation system is built and configured using the component models, where the components are connected through connectors, and the balance equations of voltage and current are established in the system through the connection relationships of the connectors. The following figure is an example of the DC isolated power system modeling based on Modelica of the present invention, including photovoltaic panels, energy storage batteries, DC / AC, transformers, and loads.

[0102] Further, the data interaction relationships among the models involve multiple physical domains such as electrical, mechanical, thermal, and instrumentation control signals: in the electrical domain, when component models such as generators, energy storage units, loads, and voltage transformation units are interconnected through electrical connectors, the Modelica solver automatically generates voltage and current balance equations based on potential and flow variables. The voltage and current fluctuations caused by the change of the generator torque will be transmitted to the load and the energy storage unit through the transmission line model, causing dynamic adjustment of electrical quantities and power flow. In the mechanical domain, when the load changes through the mechanical connector, the motor speed and torque distribution change accordingly. The instrumentation control model obtains information such as voltage, current, power, SOC, and switch status in real time through the signal connector and outputs control instructions to the electrical equipment model to achieve closed-loop control and optimal scheduling; after the above modeling, the component models of generators, transformers, transmission lines, energy storage devices, and loads are combined and connected according to the actual topology and operation task requirements of the DC isolated power system, and the initial conditions and boundary conditions are set for the system model in the Modelica environment, and then the solver is run to solve the non-linear equations composed of the component model equations, connector balance equations, and initial conditions, so as to obtain the dynamic response curves of voltage, current, speed, and power evolving with time on different components. Through the analysis of the simulation results, the effectiveness of the control strategy and the impact of system parameter changes on stability can be evaluated, and the model parameters and control schemes can be iteratively optimized according to engineering requirements.

[0103] To achieve the above object, according to another aspect of the present invention, there is provided a DC isolated power system modeling and simulation device based on Modelica, including:

[0104] A splitting module, configured to decompose a real DC isolated power system topology structure into multiple power simulation system sub-models;

[0105] A basic model module, configured to establish a basic model library according to the multiple power simulation system sub-models, where the basic model library includes: interface models, component models, electrical equipment models, and system models;

[0106] A simulation module, configured to connect the interface model, the component model, and the electrical equipment model according to a preset connector according to a preset modeling method to establish a power system simulation system, where the power system simulation system is obtained by modeling and simulating the real DC isolated power system based on Modelica;

[0107] A calculation module, configured to perform DC isolated power system simulation according to the task requirements of the DC isolated power system simulation system.

[0108] To achieve the above object, according to another aspect of the present invention, there is provided a computer-readable storage medium, in which a computer program is stored, and wherein the computer program is configured to execute the method when running.

[0109] To achieve the above object, according to still another aspect of the present invention, there is provided an electronic device, including a memory and a processor, where a computer program is stored in the memory, and the processor is configured to run the computer program to execute the method.

Claims

1. A DC isolated grid power system modeling and simulation method based on Modelica, characterized by: Including obtaining power simulation component models by decomposing the topological structure of the real DC isolated power system, The power simulation component model includes: a generator component model, a transformer component model, a transmission line component model, a load component model, an energy storage component model and a corresponding component data model; Establishing a basic model library according to the power simulation component model; The basic model library includes: interface model, component model, electrical equipment model, instrumentation and control model, and equipment integration model; according to the transmission method of physical quantities of equipment between different models, a connector is preset to connect the interface model, the component model, and the electrical equipment model according to a preset modeling method to establish a power system simulation system, and the system sub-models included in the power system simulation system include: generator component model, transformer component model, transmission line component model, load component model, energy storage component model and corresponding component data model, wherein the power system simulation system is obtained by simulating the real DC isolated power system based on Modelica; according to the task requirements of the DC isolated power system modeling and simulation system, the DC isolated power system is simulated.

2. A DC isolated grid power system modeling and simulation method based on Modelica as claimed in claim 1, characterized in that: The interface model is used to simulate the transmission mode of physical quantities between different model modules. The interface model provides a unified standard connector type for different types of physical quantity transmission, including electrical connectors that define voltage and current as potential and flow variables, thermal connectors that define temperature and heat flow, translational mechanical connectors, rotational mechanical connectors, and instrumentation signal connectors that define signal input and output. The interface model is used to realize data coupling and interaction between components of voltage, current, speed, torque, temperature, control signals, or command signals.

3. A DC isolated grid power system modeling and simulation method based on Modelica as claimed in claim 1, characterized in that: The component model is used to simulate the characteristics of the device itself, reflecting the performance parameters and behavioral characteristics of the device at the physical level. The characteristics include mechanical characteristics, thermal characteristics, material properties and electrical characteristics. By abstracting and parameterizing the entity parameters and dynamic behavior of a single physical device, the component model provides a basis for the modeling and integration of subsequent power systems. The component model interacts with other devices through a unified interface model.

4. A DC isolated grid power system modeling and simulation method based on Modelica as claimed in claim 1, characterized in that: The electrical equipment model is used to simulate the electrical properties of actual physical equipment in the power system, wherein the electrical properties include voltage, current, power, impedance, frequency and its dynamically changing electrical quantities and related mechanisms. Through the electrical equipment model, the working state of the equipment in the power system is accurately characterized, and the simulation of the electrical energy transmission, conversion and control process is realized, based on the interaction between the electrical topological structures of the electrical equipment.

5. The method for modeling and simulating a DC isolated grid power system based on Modelica as claimed in claim 1, characterized in that: The instrumentation and control model is used to obtain system state quantities through a signal connector and output control signals to the electrical equipment model, simulating closed-loop control and optimal scheduling of the power system operating status.

6. A DC isolated grid power system modeling and simulation method based on Modelica as claimed in claim 1, characterized in that: The device integration model connects the interface model, component model, electrical equipment model and instrumentation model to establish a system integration model of the overall operating characteristics of the DC isolated power system, and simulates the dynamic response of the real power system under given input, boundary conditions and control strategies.

7. The method for modeling and simulating a DC isolated grid power system based on Modelica as claimed in claim 1, characterized in that: When the generator assembly establishes a simulation model of the PMSM permanent magnet synchronous generator, it includes a moment of inertia model, a fixed support model, an air gap model, a permanent magnet model, and a thermal calculation model, wherein the rotating moment of inertia model is used to simulate the inertia characteristics of the motor rotor, the fixed support model is used to simulate the mechanical support structure of the motor, the air gap model is used to simulate the magnetic field distribution and magnetic flux in the air gap, the permanent magnet model is used to simulate the magnetic properties of the permanent magnet in the PMSM, and the thermal calculation model is used to simulate the thermal effect of the motor during operation, and all of the above models are used to simulate the actual working characteristics of the PMSM.

8. The method for modeling and simulating a DC isolated grid power system based on Modelica as claimed in claim 1, characterized in that: The transformer assembly establishes a transformer unit and describes the relationship between voltage, current and power according to the ideal transformer principle. The formula for establishing the simulation model of the transformer unit is as follows: Voltage relationship: Where V1 and V2 are the voltages of the main winding and the secondary winding respectively, and N1 and N2 are the number of turns of the main winding and the secondary winding respectively; Current relationship: Among them, I1 and I2 are the currents of the main winding and the secondary winding respectively; Power relationship: P1=P2 Among them, P1 and P2 are the powers of the main winding and the secondary winding respectively.

9. The method for modeling and simulating a DC isolated grid power system based on Modelica as claimed in claim 1, characterized in that: The energy storage assembly forms an energy storage unit, and the energy storage unit includes: Open circuit voltage: IN oc =K(SOC-SOC0)+V0 Where V oc represents the open circuit voltage of the energy storage device, K is the slope coefficient, SOC is the charge and discharge state of the energy storage device, SOC0 is the reference charge and discharge state, V0 is the reference voltage, The attenuation effect of the internal resistance of the energy storage device on the current: E=V-IR Wherein, E represents the electromotive force of the energy storage device, V represents the actual voltage of the energy storage device, I represents the current, and R represents the internal resistance of the energy storage device.

10. A DC isolated grid power system modeling and simulation device based on Modelica, characterized in that: include: A splitting module is used to decompose the real DC isolated power system topology structure to obtain multiple power simulation system sub-models; A basic model module, used to establish a basic model library according to the multiple power simulation system sub-models, wherein the basic model library includes: an interface model, a component model, an electrical equipment model, and a system model; A simulation module, used for connecting the interface model, the component model, and the electrical equipment model according to a preset modeling method according to a preset connector to establish a power system simulation system, wherein the power system simulation system is obtained by modeling and simulating the real DC isolated power system based on Modelica; The calculation module is used to simulate the DC isolated power system according to the task requirements of the DC isolated power system modeling and simulation system.

11. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, wherein the computer program is configured to execute the method of claims 1-10 when executed.

12. An electronic device, characterized in that: The method comprises a memory and a processor, wherein a computer program is stored in the memory, and the processor is configured to run the computer program to execute the method according to claims 1 to 10.

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