Heterogeneous energy flow composite energy supply system semi-physical semi-simulation dynamic regulation and control experimental device

Abstract

The invention relates to a semi-physical semi-simulation dynamic regulation and control experimental device for a heterogeneous energy flow composite energy supply system. The heterogeneous energy flow composite energy supply system comprises a photovoltaic cell, a supercritical carbon dioxide power cycle, an electrochemical energy storage battery and a user load. The device comprises a source side part, a storage side part, a load side part and a control and monitoring module. The source side part, the storage side part and the load side part form a direct-current micro-grid and are connected to an alternating-current large power grid through an energy storage bidirectional converter, and the direct-current micro-grid and the alternating-current large power grid form a grid side part. The source side part comprises a conventional energy power generation simulator and a new energy power generation simulator which are connected into a direct current bus through an AC-DC converter and a DC-DC converter respectively; the storage side part comprises an electrochemical energy storage battery simulator which is connected into a direct current bus through a DC-DC converter; and the load side part is a programmable direct current load. The heterogeneous energy flow composite energy supply system is a typical'source-network-load-storage 'energy system, and real-time monitoring and control are achieved through an energy management system developed through self-programming.

Description

Technical Field

[0001] The present invention belongs to the field of energy management and control of a "source-grid-load-storage" integrated energy system, and specifically relates to a semi-physical and semi-simulation dynamic control experimental device for a heterogeneous energy flow composite energy supply system. Background Art

[0002] In the new power system dominated by new energy, the power generation of new energy is characterized by intermittency, volatility and randomness. Large-scale grid connection has brought serious impact on the balance and stability of the power system. In order to ensure the smooth consumption of new energy and the safety of the power grid, it is necessary to enhance the complementarity between different energy sources and the interactivity of the "source-grid-load-storage" side. Therefore, it is urgent to develop a "source-grid-load-storage" type heterogeneous energy flow composite energy supply system. The system has typical "three more" characteristics, namely, multi-energy, multi-scale and multi-variable. Multi-energy is manifested in the diversity of energy forms, energy categories, and subsystems; multi-scale is manifested in the multi-time scale of real-time response and long-term planning and the multi-spatial scale of source, storage, and load across regions; multi-variable is manifested in the differences and complexity of the physical characteristics and parameters of the subsystems, as well as the strong volatility of the parameters on the time scale. In order to make the heterogeneous energy flow composite energy supply system operate efficiently and stably, dynamic regulation experimental verification research is essential.

[0003] Most of the existing system dynamic control experiments are simulation experiments based on software such as Matlab Simulink. The operating data can only illustrate the theoretical feasibility of the system, and cannot take into account practical problems such as actual power fluctuations, inertial hysteresis, physical limitations, and transmission losses. Directly using physical equipment such as thermal systems for experiments poses safety risks due to complex dynamic nonlinear characteristics and unclear safe operation boundaries. Summary of the invention

[0004] In order to break through the existing bottleneck and address the shortcomings of the existing dynamic control experimental device, the purpose of the present invention is to provide a semi-physical and semi-simulation dynamic control experimental device based on a heterogeneous energy flow composite energy supply system, so as to provide experimental support for the efficient and stable operation of the "source-grid-load-storage" heterogeneous energy flow composite energy supply system under bilateral random and real-time dynamic complex working conditions.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] The heterogeneous energy flow composite energy supply system includes new energy power generation equipment, conventional energy power generation equipment, electrochemical energy storage batteries and user loads. The semi-physical and semi-simulation dynamic control experimental device of the heterogeneous energy flow composite energy supply system of the present invention correspondingly includes a source side part, a storage side part, a load side part and a control and monitoring module. The source side part, the storage side part and the load side part constitute a DC microgrid, and are connected to the AC large power grid through an energy storage bidirectional converter. The DC microgrid and the AC large power grid constitute the grid side part. The DC microgrid supports customized DC bus voltage, AC bus frequency and other power parameters.

[0007] The source side includes a conventional energy power generation simulator and a new energy power generation simulator, which are connected to the DC bus through AC-DC converters and DC-DC converters respectively. For example, the conventional energy power generation simulator is a supercritical carbon dioxide power cycle power generation simulator, which simulates the supercritical carbon dioxide power cycle power generation characteristics through an AC-DC-AC back-to-back programmable power supply. The heat source forms include but are not limited to solar energy, coal, nuclear energy, etc., and supports customized power generation characteristic curves such as power and efficiency. The new energy power generation simulator is a photovoltaic power generation simulator, which simulates photovoltaic power generation characteristics through a programmable DC power supply. Photovoltaic cell types include but are not limited to polysilicon, thin film, perovskite, etc., and supports customized lighting conditions and photovoltaic module voltage, current, series and parallel number and other parameters.

[0008] The storage side includes an electrochemical energy storage battery simulator, which is connected to the DC bus through a DC-DC converter. The electrochemical energy storage battery simulator uses a programmable bidirectional DC power supply. The battery forms include but are not limited to lithium-ion batteries, lead-acid batteries, sodium-sulfur batteries, all-vanadium liquid flow batteries, etc., and supports customized battery characteristic curves such as voltage, current, power, and efficiency.

[0009] The load side is a programmable DC load, and the power, voltage and other curves can be customized through USB.

[0010] The control and monitoring module is controlled and monitored in real time through the energy management system which is self-programmed based on ST language.

[0011] The heterogeneous energy flow composite energy supply system is a typical "source-grid-load-storage" energy system. The control and monitoring modules can use Beckhoff microgrid controllers, etc. Its energy management system is completed based on ST language secondary development for real-time control and monitoring. The specific operation logic is:

[0012] ① Grid-connected operation logic: The power generation of new energy and the user load power are input by a custom curve, the power generation of conventional energy and the discharge power of the electrochemical energy storage battery are manually adjusted freely, and the DC bus voltage of the system is maintained stable through the energy storage bidirectional converter; when the sum of the power generation of new energy, the power generation of conventional energy and the discharge power of the electrochemical energy storage battery is greater than the user load power, the energy storage bidirectional converter will connect the excess power to the grid; when the sum of the power generation of new energy, the power generation of conventional energy and the discharge power of the electrochemical energy storage battery is less than the user load power, the energy storage bidirectional converter will take power from the grid to supplement the insufficient power;

[0013] ② Island operation logic: The new energy power generation power and the user load power are input by a custom curve, and the conventional energy power generation power is initially set to 60-80% of the rated value. The system DC bus voltage is maintained stable through the electrochemical energy storage battery; when the sum of the new energy power generation power and the conventional energy power generation power is greater than the user load power, the electrochemical energy storage battery is charged, and when the battery SOC is 80-100%, the conventional energy power generation power is reduced to a low load (40-60% rated power); when the sum of the new energy power generation power and the conventional energy power generation power is less than the user load power, the electrochemical energy storage battery is discharged, and when the battery SOC is 0-20%, the conventional energy power generation power is increased to a high load (80-100% rated power).

[0014] The maximum power of the photovoltaic power generation simulator, supercritical carbon dioxide cycle power generation simulator, electrochemical energy storage simulator and user load are 6kW, 10kW, 10kW and 10kW respectively. Under the maximum configuration conditions, the proportion of new energy is 37.5% and the proportion of energy storage configuration is 62.5%.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] 1. It is scalable. The source side, storage side, load side, etc. of the present invention can adopt modular design, integrate circuit components into power containers, reserve unified standardized power and communication interfaces, and can be connected to other distributed energy systems as needed.

[0017] 2. It is flexible. The present invention uses a programmable power supply to simulate the external characteristics of various energy systems through secondary development. The secondary development process can transmit data and interact with other test benches (such as power cycle power generation test benches, photovoltaic power generation test benches, all-vanadium liquid flow battery energy storage test benches, etc.). The present invention can also use actual power generation equipment (such as photovoltaic panels, synchronous generators, etc.) to replace the programmable power supply.

[0018] 3. The present invention takes into account the nonlinear characteristics of the thermal system and the easy-to-regulate characteristics of the power system through the semi-physical and semi-simulation secondary development method, overcoming the dangers of complex thermal systems in the experimental process and the inaccuracy of computer simulation.

[0019] In summary, the present invention can realize the dynamic control experiment of the "source-grid-load-storage" type heterogeneous energy flow composite energy supply system under bilateral random and real-time dynamic complex working conditions, which helps to absorb a high proportion of new energy and the efficient and stable operation of new power systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of heterogeneous energy flow composite energy supply system.

[0021] Figure 2 This is the flow chart of the semi-physical and semi-simulation dynamic control experimental device.

[0022] Figure 3 This is a real picture of the semi-physical and semi-simulation dynamic control experimental device. In the picture: 1- monitoring screen, 2- control console, 3- photovoltaic power generation subsystem & vanadium battery energy storage subsystem, 4- S-CO2 cycle power generation subsystem, 5- user load, 6- energy storage bidirectional converter, 7- power distribution cabinet. DETAILED DESCRIPTION

[0023] In conjunction with the accompanying drawings, a semi-physical and semi-simulation dynamic control experimental device for a heterogeneous energy flow composite energy supply system is described in detail below.

[0024] like Figure 1 As shown, the working process of the heterogeneous energy flow composite energy supply system is as follows:

[0025] (1) First, in the supercritical carbon dioxide power generation subsystem, the boiler burns the chemical energy in the coal to release heat energy, which is then transferred to the heat energy of carbon dioxide. The high-temperature and high-pressure carbon dioxide drives the turbine to work and drives the synchronous generator to generate electricity, realizing the conversion of "thermal energy-mechanical energy-electrical energy". At the same time, in the photovoltaic power generation subsystem, photovoltaic panels convert solar energy into electrical energy. The solar energy that is not converted into electrical energy is converted into thermal energy through the collector, and is provided to users together with the waste heat of the supercritical carbon dioxide power generation subsystem for use.

[0026] (2) Then, photovoltaic power generation and supercritical carbon dioxide power generation are converted into alternating current with voltage and frequency that meet the requirements through power electronic equipment such as inverters and transformers, forming a micro power supply network.

[0027] (3) Furthermore, electric energy is connected to the user load end in the microgrid through the transmission system. In order to achieve efficient power generation, load smoothing, and flexible grid connection of the system, the energy storage subsystem is connected, which is the process of storing and replenishing electricity. When the total system power generation is greater than the user's demand, the electrochemical energy storage battery converts the remaining electric energy into chemical energy to achieve peak power consumption and storage; when the total system power generation is less than the user's demand, the electrochemical energy storage battery converts chemical energy into electrical energy to ensure the power supply during valley hours.

[0028] (4) Finally, the power generation of the supercritical carbon dioxide power generation subsystem is regulated to ensure that the charge state of the electrochemical energy storage battery is in the optimal working range. The system has flexible response to changing operating conditions. Through the coordinated cooperation of the supercritical carbon dioxide power generation subsystem variable load regulation and the real-time charging and discharging of the electrochemical energy storage subsystem, the intermittent solar power generation can be effectively absorbed on the "source" side, and the continuous and reliable energy supply can be provided to users on the "load" side, thereby achieving the balance and stability of the power on the "grid" side.

[0029] like Figure 2 As shown, the present invention is a semi-physical and semi-simulation dynamic control experimental device for a heterogeneous energy flow composite energy supply system, including a source side part, a storage side part, a load side part and a control and monitoring module. The source side part, the storage side part and the load side part constitute a DC microgrid, and are connected to the AC large power grid through an energy storage bidirectional converter. The DC microgrid and the AC large power grid constitute the grid side part. The source side part includes a conventional energy generation simulator and a new energy generation simulator, which are respectively connected to the DC bus through an AC-DC converter and a DC-DC converter.

[0030] Among them, the conventional energy power generation simulator is a supercritical carbon dioxide power cycle power generation simulator, which simulates the supercritical carbon dioxide power cycle power generation characteristics through an AC-DC-AC back-to-back programmable power supply. The new energy power generation simulator is a photovoltaic power generation simulator, which simulates the photovoltaic power generation characteristics through a programmable DC power supply.

[0031] The storage side includes an electrochemical energy storage battery simulator, which is connected to the DC bus through a DC-DC converter. The electrochemical energy storage battery simulator is a programmable bidirectional DC power supply. The load side is a programmable DC load.

[0032] The heterogeneous energy flow composite energy supply system of the present invention is a typical "source-grid-load-storage" energy system. The control and monitoring module uses the Beckhoff microgrid controller, and the energy management system is completed based on the ST language secondary development. The specific operation logic is:

[0033] ①Grid-connected operation logic: Photovoltaic power generation and user load power are input by custom curves, supercritical carbon dioxide power cycle power generation and battery discharge power (power during charging is negative) are manually adjusted freely, and the system DC bus voltage is maintained stable through the energy storage bidirectional converter. When the sum of photovoltaic power generation, supercritical carbon dioxide power cycle power generation and battery discharge power is greater than the user load power, the energy storage bidirectional converter will connect the excess power to the grid; when the sum of photovoltaic power generation, supercritical carbon dioxide power cycle power generation and battery discharge power is less than the user load power, the energy storage bidirectional converter will take power from the grid to supplement the insufficient power.

[0034] ② Island operation logic: The new energy power generation power and the user load power are input by a custom curve, and the conventional energy power generation power is initially set to 60-80% of the rated value. The system DC bus voltage is maintained stable through the electrochemical energy storage battery; when the sum of the new energy power generation power and the conventional energy power generation power is greater than the user load power, the electrochemical energy storage battery is charged, and when the battery SOC is 80-100%, the conventional energy power generation power is reduced to a low load (40-60% rated power); when the sum of the new energy power generation power and the conventional energy power generation power is less than the user load power, the electrochemical energy storage battery is discharged, and when the battery SOC is 0-20%, the conventional energy power generation power is increased to a high load (80-100% rated power).

[0035] like Figure 3 The figure shows a physical picture of a semi-physical and semi-simulation dynamic control experimental device of a heterogeneous energy flow composite energy supply system, which shows a monitoring screen 1, a control console 2, a photovoltaic power generation simulator and an electrochemical energy storage simulator 3, an S-CO2 cycle power generation simulator 4, a programmable load 5, an energy storage bidirectional converter 6 and a distribution cabinet 7.

[0036] Among them, the maximum power of photovoltaic simulator, supercritical carbon dioxide cycle power generation simulator, electrochemical energy storage simulator and user load are 6kW, 10kW, 10kW and 10kW respectively. Under the maximum configuration conditions, the proportion of new energy is 37.5%, and the proportion of energy storage configuration is 62.5%. The photovoltaic power generation simulator supports custom lighting conditions and parameters such as voltage, current, and number of series and parallel connections of photovoltaic modules; the supercritical carbon dioxide power cycle power generation simulator supports custom power, efficiency and other power generation characteristic curves; the electrochemical energy storage simulator supports custom voltage, current, power, efficiency and other battery characteristic curves; programmable loads can customize power, voltage and other curves through USB; DC microgrids and AC large grids support custom DC bus voltage, AC bus frequency and other power parameters.

[0037] The complete process of semi-physical and semi-simulation dynamic control in the present invention is as follows: (1) the supercritical carbon dioxide cycle power generation simulator and the photovoltaic simulator generate electricity, which is converted into alternating current with voltage and frequency that meet the requirements through power electronic equipment such as inverters and transformers, forming a micro power supply network; (2) the electric energy is connected to the programmable load through the transmission system; (3) the photovoltaic power generation power and the programmable load power are input by a custom curve, and the supercritical carbon dioxide cycle power generation simulator is initially set to 60-80% of the rated value, and the system DC bus voltage is maintained stable through the electrochemical energy storage simulator; (4) when the sum of the photovoltaic simulator power and the supercritical carbon dioxide cycle power generation power is greater than the programmable load power, the electrochemical energy storage simulator is charged, and when the battery SOC is 80-100%, the supercritical carbon dioxide power generation power is reduced to a low load (40-60% rated power); when the sum of the photovoltaic simulator power and the supercritical carbon dioxide cycle power generation simulator power is less than the programmable load power, the electrochemical energy storage battery is discharged, and when the battery SOC is 0-20%, the supercritical carbon dioxide cycle power generation power is increased to a high load (80-100% rated power).

[0038] The present invention provides a semi-physical and semi-simulation dynamic control experimental device based on a heterogeneous energy flow composite energy supply system. The present invention can realize the dynamic control experimental research of the "source-grid-load-storage" type heterogeneous energy flow composite energy supply system under double-sided random and real-time dynamic complex working conditions, and help high-proportion new energy consumption and efficient and stable operation of new power systems.

Claims

1. A semi-physical and semi-simulation dynamic control experimental device for a heterogeneous energy flow composite energy supply system, characterized in that: The experimental device includes a source side part, a storage side part, a load side part and a control and monitoring module; the source side part, the storage side part and the load side part constitute a DC microgrid, and are connected to an AC large grid through a storage bidirectional converter, and the DC microgrid and the AC large grid constitute a grid side part; the source side part includes a conventional energy generation simulator and a new energy generation simulator, which are respectively connected to the DC bus through an AC-DC converter and a DC-DC converter; the storage side part includes an electrochemical energy storage battery simulator, which is connected to the DC bus through a DC-DC converter; the load side part is a programmable DC load; the control and monitoring module is controlled and monitored in real time through an energy management system self-programmed based on the ST language.

2. According to claim 1, the semi-physical and semi-simulation dynamic control experimental device of the heterogeneous energy flow composite energy supply system is characterized in that: The conventional energy power generation simulator is a supercritical carbon dioxide power cycle power generation simulator, which simulates the supercritical carbon dioxide power cycle power generation characteristics through an AC-DC-AC back-to-back programmable power supply. The heat source forms include solar energy, coal, and nuclear energy, and supports customized power generation characteristic curves including power and efficiency.

3. According to claim 1, the semi-physical and semi-simulation dynamic control experimental device of the heterogeneous energy flow composite energy supply system is characterized in that: The new energy power generation simulator is a photovoltaic power generation simulator, which simulates photovoltaic power generation characteristics through a programmable DC power supply. Photovoltaic cell types include polysilicon, thin film, and perovskite. It supports customized lighting conditions and parameters of photovoltaic components including voltage, current, and number of series and parallel connections.

4. According to claim 1, the semi-physical and semi-simulation dynamic control experimental device of heterogeneous energy flow composite energy supply system is characterized in that: The electrochemical energy storage battery simulator adopts a programmable bidirectional DC power supply. The battery types include lithium-ion batteries, lead-acid batteries, sodium-sulfur batteries, and all-vanadium liquid flow batteries. It supports customizing battery characteristic curves including voltage, current, power, and efficiency.

5. According to claim 1, the semi-physical and semi-simulation dynamic control experimental device of the heterogeneous energy flow composite energy supply system is characterized in that: The DC microgrid supports customization of power parameters including DC bus voltage and AC bus frequency.

6. According to claim 1, the semi-physical and semi-simulation dynamic control experimental device of heterogeneous energy flow composite energy supply system is characterized in that: The load side part customizes the curve including power and voltage through USB.

7. The semi-physical and semi-simulation dynamic control experimental device of the heterogeneous energy flow composite energy supply system according to any one of claims 1 to 6, characterized in that: The energy management system of the control and monitoring module is completed based on the secondary development of ST language, and the specific operation logic is as follows: ① Grid-connected operation logic: The power generation of new energy and the user load power are input by a custom curve, the power generation of conventional energy and the discharge power of the electrochemical energy storage battery are manually adjusted freely, and the DC bus voltage of the system is maintained stable through the energy storage bidirectional converter; when the sum of the power generation of new energy, the power generation of conventional energy and the discharge power of the electrochemical energy storage battery is greater than the user load power, the energy storage bidirectional converter will connect the excess power to the grid; when the sum of the power generation of new energy, the power generation of conventional energy and the discharge power of the electrochemical energy storage battery is less than the user load power, the energy storage bidirectional converter will take power from the grid to supplement the insufficient power; ② Island operation logic: The new energy generation power and the user load power are input by a custom curve, and the conventional energy generation power is initially set to 60-80% of the rated value, and the system DC bus voltage is maintained stable through the electrochemical energy storage battery; when the sum of the new energy generation power and the conventional energy generation power is greater than the user load power, the electrochemical energy storage battery is charged, and when the battery SOC is 80-100%, the conventional energy generation power is reduced to a low load, that is, 40-60% of the rated power); when the sum of the new energy generation power and the conventional energy generation power is less than the user load power, the electrochemical energy storage battery is discharged, and when the battery SOC is 0-20%, the conventional energy generation power is increased to a high load, that is, 80-100% of the rated power.

8. According to claim 1, the semi-physical and semi-simulation dynamic control experimental device for heterogeneous energy flow composite energy supply system is characterized in that: The source side part, storage side part and load side part adopt a modular design, integrate the circuit elements into a power container, and reserve a unified standardized power and communication interface, so that the device has scalability and can be connected to the distributed energy system according to demand.

9. According to claim 1, the semi-physical and semi-simulation dynamic control experimental device of heterogeneous energy flow composite energy supply system is characterized in that: Each simulator uses a programmable power supply and can transmit data and interact with other experimental platforms, making the device flexible.

10. The semi-physical and semi-simulation dynamic control experimental device of heterogeneous energy flow composite energy supply system according to claim 1 is characterized in that: Replace the corresponding simulators with actual power generation equipment.

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