Optical-storage-flexible alternating current micro-grid construction equipment and stable operation system

Abstract

The invention relates to the technical field of intelligent micro-grids, and provides a light-storage-flexible alternating-current micro-grid construction device and a stable operation system, and the construction device provides an advanced control strategy for construction by changing demand operation characteristics, carrying out conversion topology selection and carrying out power equipment design and parameter design. The method comprises the following steps: carrying out network construction control and real-time protection monitoring on an alternating current micro-grid, carrying out front feedback separation of a state space, establishing an active and reactive fixed voltage frequency model, deploying an independent zero pole to carry out slow dynamic elimination work, protecting the safety of network construction in real time, and realizing high-bandwidth design of network construction voltage and current control. According to the stable operation system, a model of a no-difference adjustment mode is established, the simulation analysis capability is realized, the operation system can more stably carry out power distribution work of the island type micro-grid, and a multi-stage interconnection power model adopted by the island type micro-grid can realize the power distribution work of the island type micro-grid under the assistance of parameter adjustment and algorithm compensation. And the precision of power distribution is greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of smart microgrids, and specifically to photovoltaic-storage-flexible AC microgrid networking equipment and a stable operation system. Background Art

[0002] With the increasing pressure of environmental protection and energy depletion, clean renewable energy has received extensive attention. Microgrid is a small power generation system composed of distributed energy, energy storage devices, energy conversion devices, related loads and monitoring and protection devices. It can work in both grid-connected mode and island mode, and can give full play to the advantages of distributed power generation. It has important practical significance for alleviating environmental protection and energy depletion problems.

[0003] Smart microgrid is a small power generation and distribution system that integrates distributed power sources, energy storage devices, energy conversion devices, loads, and monitoring and protection devices. It uses advanced Internet and information technology to achieve flexible and efficient application of distributed power sources and has certain energy management functions.

[0004] In order to ensure the stability and precise operation of the smart microgrid and to generate a more intelligent management method, a photovoltaic-storage-flexible AC microgrid networking equipment and a stable operation system are needed. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention provides a photovoltaic-storage-flexible AC microgrid networking equipment and a stable operation system, which adopts simulation analysis of multiple simulation models to generate more accurate decisions and methods for microgrid management.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0007] Solar-storage-flexible AC microgrid networking equipment, including:

[0008] System design and parameter optimization framework, through the transformation of demand operation characteristics, transformation topology selection, power equipment design and parameter design;

[0009] Control strategy framework, used to provide advanced control strategies for networking to maintain the stability of the network;

[0010] The network control framework is used to establish the active and reactive fixed voltage-frequency model and discretize the multi-degree-of-freedom power controller.

[0011] Preferably, the control strategy framework includes:

[0012] System control and protection module, used for network control and real-time protection monitoring of AC microgrid.

[0013] The state space discretization module is used to separate the forward feedback in the state space and deploy independent zero poles to eliminate slow dynamics.

[0014] Preferably, the system control and protection module includes:

[0015] A modulation method unit, used for outputting a modulation method signal for network control;

[0016] Multi-level control unit, used to reduce the voltage stress and switching frequency of the network and improve the output capacity of the network;

[0017] The fault monitoring unit is used to monitor network faults and protect the security of the network in real time.

[0018] Preferably, the state space discretization module includes:

[0019] Feedforward separation unit, used to construct a new state space control structure with separated state feedback and feedforward;

[0020] Zero-pole independent unit, used for independent deployment of zero-pole;

[0021] The slow dynamic elimination unit utilizes the state space control structure and the properties of independently configurable zeros and poles, adopts the three-phase grid-forming energy storage converter to dominate the slow dynamic elimination voltage control algorithm, and realizes the high-bandwidth design of grid-forming voltage and current control.

[0022] The PV-storage-flexible AC microgrid stable operation system includes:

[0023] The power distribution framework for islanded microgrids is used to improve the accuracy of power distribution through parameter adjustment and algorithm compensation through multi-level interconnected power frequency models;

[0024] Microgrid modeling framework, used to model the power, frequency and phase angle small signals of the microgrid;

[0025] Simulation analysis framework, used to model and analyze the mathematical model of diesel engine system control;

[0026] An online decomposition framework for grid dispatching instructions is used to constrain the energy management model of multiple micro-sources and is based on any artificial intelligence algorithm such as genetic algorithm or deep learning.

[0027] Preferably, the microgrid model modeling framework includes:

[0028] A topology parameter and power model change module is used to generate topology parameter changes and power model changes of microgrid power, frequency and phase angle small signals;

[0029] The power model generation module is used to sequentially generate an interconnection power model and a microgrid power model according to changes in topology parameters and power models.

[0030] Preferably, the simulation analysis framework includes:

[0031] The delayed inertia modeling module is used to handle the modeling of the diesel engine system control mathematical model and perform simulation analysis after the modeling is completed;

[0032] The coefficient data import module is used to import the inertia coefficient, proportional coefficient and integral coefficient for overall delay modeling.

[0033] Preferably, the plurality of energy management models are based on any one of a photovoltaic processing model and an energy storage output model.

[0034] Preferably, the energy management model is constrained by using any one of power balance constraints, power generation constraints, energy storage charging and discharging constraints, and frequency and voltage dynamic constraints.

[0035] Preferably, the establishment of the mathematical model of diesel-electric system control is based on the overall equivalent of the delay of each relief of the differential speed control system to a first-order inertia link, and the mathematical model of diesel-electric system control is in a zero-difference regulation mode.

[0036] The present invention provides a photovoltaic-storage-flexible AC microgrid networking equipment and a stable operation system.

[0037] Beneficial effects:

[0038] 1. The present invention constructs a mathematical model of diesel-generator system control, imports various coefficient data, and performs an overall delay construction method to establish a model of zero-difference regulation mode, realize simulation analysis capabilities, and enable the operating system to more stably distribute power in the islanded microgrid. The multi-level interconnected power model adopted by the islanded microgrid, with the assistance of parameter adjustment and algorithm compensation, greatly improves the accuracy of power distribution.

[0039] 2. The present invention realizes a high-bandwidth design of network voltage and current control through a multi-level control unit and a slow dynamic elimination voltage control algorithm. This design not only reduces voltage stress and switching frequency, but also improves output capacity, thereby enhancing the microgrid's ability in voltage and frequency control, ensuring the quality and stability of power supply, and using simulation analysis of multiple simulation models to generate more accurate decisions and methods for microgrid management. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 This is a system diagram of the photovoltaic-storage-flexible AC microgrid networking equipment of the present invention;

[0041] Figure 2 A schematic diagram of the control strategy framework system of the photovoltaic-storage-flexible AC microgrid networking equipment of the present invention;

[0042] Figure 3 A schematic diagram of a system control and protection module system for the photovoltaic-storage-flexible AC microgrid networking equipment of the present invention;

[0043] Figure 4 A schematic diagram of a state space discretization module system of the photovoltaic-storage-flexible AC microgrid networking equipment of the present invention;

[0044] Figure 5 Schematic diagram of the stable operation system of the photovoltaic-storage-flexible AC microgrid of the present invention;

[0045] Figure 6 A schematic diagram of a microgrid model modeling framework system of a photovoltaic-storage-flexible AC microgrid stable operation system of the present invention;

[0046] Figure 7 Schematic diagram of the simulation analysis framework system of the solar-storage-flexible AC microgrid stable operation system of the present invention. DETAILED DESCRIPTION

[0047] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0048] Example:

[0049] As one aspect of this application, please see the attached Figure 1 -Attached Figure 4 The embodiment of the present invention provides a photovoltaic-storage-flexible AC microgrid networking equipment, including:

[0050] System design and parameter optimization framework, through the transformation of demand operation characteristics, transformation topology selection, power equipment design and parameter design;

[0051] The control strategy framework is used to provide advanced control strategies for the network to maintain the stability of the network, including:

[0052] A modulation method unit, used for outputting a modulation method signal for network control;

[0053] Multi-level control unit, used to reduce the voltage stress and switching frequency of the network and improve the output capacity of the network;

[0054] Fault monitoring unit, used to monitor network faults and protect the security of the network in real time;

[0055] The network control framework is used to establish the active and reactive fixed voltage-frequency model and discretize the multi-degree-of-freedom power controller.

[0056] The control strategy framework includes:

[0057] System control and protection module, used for network control and real-time protection monitoring of AC microgrid.

[0058] The state space discretization module is used to separate the forward feedback in the state space and deploy independent zeros and poles to eliminate slow dynamics, including:

[0059] Feedforward separation unit, used to construct a new state space control structure with separated state feedback and feedforward;

[0060] Zero-pole independent unit, used for independent deployment of zero-pole;

[0061] The slow dynamic elimination unit utilizes the state space control structure and the properties of independently configurable zeros and poles, adopts the three-phase grid-forming energy storage converter to dominate the slow dynamic elimination voltage control algorithm, and realizes the high-bandwidth design of grid-forming voltage and current control.

[0062] By considering and analyzing the power conversion needs under different operating scenarios such as photovoltaics and energy storage, the operating characteristics of the photovoltaic and energy storage flexible access to the microgrid, and domestic devices, analyzing the advantages and disadvantages of various power conversion topologies, and adding factors such as switching frequency design, busbar design, and heat dissipation, the photovoltaic and energy storage flexible multi-port integrated access AC-DC-AC high-efficiency flexible interconnected power conversion device has a state space control structure with separated state feedback and feedforward, and based on the state space control structure, it simultaneously utilizes the property that the zeros and poles can be independently configured, and the three-phase grid-forming energy storage converter dominates the slow dynamic elimination voltage control algorithm, which can achieve a high-bandwidth design of grid voltage and current control.

[0063] Based on the above-mentioned solar-storage-flexible AC microgrid networking equipment, please refer to Figure 5 -Attached Figure 7 The PV-storage-flexible AC microgrid stable operation system includes:

[0064] The power distribution framework for islanded microgrids is used to improve the accuracy of power distribution through parameter adjustment and algorithm compensation through multi-level interconnected power frequency models;

[0065] The microgrid model modeling framework is used to model the power, frequency and phase angle small signals of the microgrid. The microgrid model modeling framework includes:

[0066] A topology parameter and power model change module is used to generate topology parameter changes and power model changes of microgrid power, frequency and phase angle small signals;

[0067] The power model generation module is used to sequentially generate an interconnection power model and a microgrid power model according to changes in topology parameters and power models.

[0068] The simulation analysis framework is used to model and analyze the mathematical model of the diesel engine system control. The simulation analysis framework includes:

[0069] The delayed inertia modeling module is used to handle the modeling of the diesel engine system control mathematical model and perform simulation analysis after the modeling is completed;

[0070] The coefficient data import module is used to import the inertia coefficient, proportional coefficient and integral coefficient for overall delay modeling.

[0071] The online decomposition framework of power grid dispatching instructions is used to constrain the energy management models of multiple micro-sources. The multiple energy management models are based on any one of the photovoltaic processing model and the energy storage output model. Among them, the energy management model is constrained by any one of the power balance constraint, the power generation constraint, the energy storage charging and discharging constraint and the frequency and voltage dynamic constraint, and is based on any one of the artificial intelligence algorithms such as genetic algorithms or deep learning.

[0072] Based on the PV-storage flexible microgrid topology, the transmission model of active power and reactive power of the transmission line in the microgrid is derived;

[0073] Based on the power transmission model, a small signal power-frequency-phase angle small signal model of the microgrid is established.

[0074] The frequency and voltage stability control method of the isolated island microgrid based on the hierarchical and segmented control method can improve the operation performance of the isolated island microgrid.

[0075] Based on the above-mentioned photovoltaic-storage-flexible AC microgrid networking equipment and photovoltaic-storage-flexible AC microgrid networking equipment, the stable operation of the photovoltaic-storage-flexible AC microgrid is based on: the photovoltaic power generation processing model, energy storage equipment discharge model, diesel engine output model and photovoltaic-storage-diesel network topology model that are simulated and integrated. The above-mentioned multiple integrated models are used as the system output characteristics, and the simulated integrated photovoltaic penetration rate constraints, energy storage battery constraints, diesel generator constraints and power balance constraints are added as the stable operation boundaries. The system output characteristics and stable operation boundaries are used as the model basis of the photovoltaic-storage-flexible AC microgrid to generate this optimization configuration strategy. The total investment cost, annual compound power shortage rate and new energy utilization rate processed by the genetic algorithm optimization configuration model are used as the configuration basis of the photovoltaic-storage-flexible AC microgrid networking equipment and the photovoltaic-storage-flexible AC microgrid networking equipment after simulation verification.

[0076] Considering factors such as solar radiation intensity, solar altitude angle, temperature, etc., a photovoltaic power generation output model is established based on historical data information;

[0077] Considering factors such as charging efficiency, discharging efficiency, and cycle life, a battery charging and discharging model is established;

[0078] Considering the power flow control characteristics of flexible interconnected devices, the corresponding model is established.

[0079] Considering the constraints of photovoltaic systems, energy storage, flexible interconnection devices and power balance, the capacity of each micro source is set as a variable. It is planned to establish an adequacy evaluation model for the photovoltaic-storage-flexible hybrid system. The hybrid system with different operating strategies uses the stable operating boundary to determine the reliability constraints of the power grid operation.

[0080] It is planned to establish an optimization configuration model with the total system investment cost, annual load power shortage rate, and new energy utilization rate as optimization targets. It is planned to use genetic algorithms to optimize and simulate the specific capacity configuration of each micro-source in the system, and to verify the capacity configuration strategy by building a typical network example to meet the control, optimization and scheduling needs of the photovoltaic-storage-flexible microgrid system.

[0081] Based on the above-provided light-storage-flexible AC microgrid networking equipment and light-storage-flexible AC microgrid networking equipment, we obtain:

[0082] Microgrid fault analysis method, based on the operation status of the microgrid, under the premise of following the control strategy and power supply operation characteristics, can be used to conduct case simulation verification to analyze the fault of the microgrid;

[0083] The active current limiting method of the microgrid is based on the fault overcurrent characteristics, and the period overcurrent capacity assisted by the active current limiting and fault identification is verified through simulation examples to generate the active current limiting method of the microgrid to assist the current limiting work of the microgrid;

[0084] Microgrid island detection method,This detection method is divided into two monitoring methods: active monitoring and passive monitoring.,After example simulation verification, the microgrid is tested for islanding.

[0085] The microgrid fault blocking method selects the current limiting scheme based on the fault characteristics and then performs fault blocking and control. The example simulation verification is carried out to assist the fault blocking work of the microgrid.

[0086] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. Photovoltaic-storage-flexible AC microgrid networking equipment, characterized by: include: System design and parameter optimization framework, through the transformation of demand operation characteristics, transformation topology selection, power equipment design and parameter design; Control strategy framework, used to provide advanced control strategies for networking to maintain the stability of the network; The network control framework is used to establish the active and reactive fixed voltage-frequency model and discretize the multi-degree-of-freedom power controller.

2. The photovoltaic-storage-flexible AC microgrid networking equipment according to claim 1 is characterized in that: The control strategy framework includes: System control and protection module, used for network control and real-time protection monitoring of AC microgrid. The state space discretization module is used to separate the forward feedback in the state space and deploy independent zero poles to eliminate slow dynamics.

3. The photovoltaic-storage-flexible AC microgrid networking equipment according to claim 2 is characterized in that: The system control and protection module includes: A modulation method unit, used for outputting a modulation method signal for network control; Multi-level control unit, used to reduce the voltage stress and switching frequency of the network and improve the output capacity of the network; The fault monitoring unit is used to monitor network faults and protect the security of the network in real time.

4. The photovoltaic-storage-flexible AC microgrid networking equipment according to claim 2 is characterized in that: The state space discretization module comprises: Feedforward separation unit, used to construct a new state space control structure with separated state feedback and feedforward; Zero-pole independent unit, used for independent deployment of zero-pole; The slow dynamic elimination unit utilizes the state space control structure and the properties of independently configurable zeros and poles, adopts the three-phase grid-forming energy storage converter to dominate the slow dynamic elimination voltage control algorithm, and realizes the high-bandwidth design of grid-forming voltage and current control.

5. A photovoltaic-storage-flexible AC microgrid stable operation system, using the photovoltaic-storage-flexible AC microgrid networking equipment according to any one of claims 1 to 4, characterized in that: include: The power distribution framework for islanded microgrids is used to improve the accuracy of power distribution through parameter adjustment and algorithm compensation through multi-level interconnected power frequency models; Microgrid modeling framework, used to model the power, frequency and phase angle small signals of the microgrid; Simulation analysis framework, used to model and analyze the mathematical model of diesel engine system control; An online decomposition framework for grid dispatching instructions is used to constrain the energy management model of multiple micro-sources and is based on any artificial intelligence algorithm such as genetic algorithm or deep learning.

6. The solar-storage-flexible AC microgrid stable operation system according to claim 5 is characterized in that: The microgrid model modeling framework includes: A topology parameter and power model change module is used to generate topology parameter changes and power model changes of microgrid power, frequency and phase angle small signals; The power model generation module is used to sequentially generate an interconnection power model and a microgrid power model according to changes in topology parameters and power models.

7. The solar-storage-flexible AC microgrid stable operation system according to claim 5 is characterized in that: The simulation analysis framework includes: The delayed inertia modeling module is used to handle the modeling of the diesel engine system control mathematical model and perform simulation analysis after the modeling is completed; The coefficient data import module is used to import the inertia coefficient, proportional coefficient and integral coefficient for overall delay modeling.

8. The solar-storage-flexible AC microgrid stable operation system according to claim 5 is characterized in that: The plurality of energy management models are based on any one of a photovoltaic processing model and an energy storage output model.

9. The solar-storage-flexible AC microgrid stable operation system according to claim 5 is characterized in that: The energy management model is constrained by using any one of power balance constraints, power generation constraints, energy storage charging and discharging constraints, and frequency and voltage dynamic constraints.

10. The solar-storage-flexible AC microgrid stable operation system according to claim 5 is characterized in that: The establishment of the mathematical model of diesel-electric system control is based on the fact that the time delays of various reliefs of the differential speed regulation system are equivalent to the first-order inertia link as a whole, and the mathematical model of diesel-electric system control is in a zero-difference regulation mode.

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