Resource efficient regulation and control method and system based on charge and discharge station microgrid

Abstract

The invention discloses an efficient resource regulation and control method and system based on a charge and discharge station micro-grid, and the method comprises the steps: firstly constructing a charge and discharge station micro-grid model, and then carrying out the measurement and calculation of the autonomous capability of the charge and discharge station micro-grid based on the charge and discharge station micro-grid model, and obtaining an autonomous capability measurement and calculation result. Calculating the interaction capability between the charging and discharging station micro-grid and the power distribution network based on the charging and discharging station micro-grid model, and obtaining an interaction capability calculation result; by adopting a night energy storage and daytime release mode, the charging requirement of the electric vehicle can be met, and the power utilization peak period load of the public power grid can be reduced; meanwhile, the photovoltaic power generation capacity of the micro-grid, the optimal scheduling of an energy storage system, the response characteristic of an electric vehicle charging load and the stability and the benefit of the whole regulation and control system under different operation conditions can be comprehensively measured and calculated through the constructed charge and discharge station micro-grid model, so that the efficient, safe and sustainable operation of the regulation and control system is ensured; and the device is suitable for wide popularization and use.

Description

Technical Field

[0001] The present invention relates to the technical field of microgrid control, and in particular to a method and system for efficiently controlling resources based on a microgrid of a charging and discharging station. Background Art

[0002] As global climate change and energy crisis issues intensify, more and more countries and regions have begun to pay attention to the development of renewable energy, thereby promoting the transformation of energy structure. In this context, microgrids, as a new type of power system, have gradually become one of the important directions of global energy development because they can improve energy utilization efficiency, ensure power supply reliability and promote the access of renewable energy. Microgrids are small, independent power systems that can use local renewable energy and energy storage equipment to achieve self-regulation and management of electricity while connected to the main power grid or operating independently. Microgrids can not only improve energy utilization efficiency, but also ensure the power supply security of critical loads in extreme weather or power grid failures.

[0003] At present, most electric vehicles are charged by connecting charging stations to the power grid, which results in a sharp increase in load in a short period of time after a large number of electric vehicles are connected to the distribution network. The access of electric vehicles will affect the reliability, stability and safety of the distribution network during operation, and the random and disordered charging of vehicles is also difficult to control. At the same time, photovoltaic power generation and energy storage batteries are also used irrationally. Therefore, it is necessary to design a resource efficient control method and system based on the microgrid of charging and discharging stations. Summary of the invention

[0004] The purpose of the present invention is to overcome the deficiencies of the prior art, and to better and effectively solve the current charging method of electric vehicles, which is mostly charged by charging stations connected to the power grid, resulting in a large number of electric vehicles being connected to the distribution network, causing a sharp increase in load in a short period of time. In this way, the access of electric vehicles will affect the reliability, stability and safety of the distribution network in operation, and the random and disordered charging of vehicles is also difficult to control. At the same time, there is also the problem of unreasonable utilization of photovoltaic power generation and energy storage batteries. A resource efficient control method and system based on a microgrid of a charging and discharging station is provided, which realizes the function of integrating photovoltaic units, energy storage units, electric vehicle charging units and other load units, and adopts the form of nighttime energy storage and daytime release to not only meet the charging needs of electric vehicles, but also reduce the peak load of public power grid electricity consumption. At the same time, the constructed microgrid model of the charging and discharging station can comprehensively calculate the photovoltaic power generation capacity of the microgrid, the optimal scheduling of the energy storage system, the response characteristics of the electric vehicle charging load and the stability and benefits of the overall control system under different operating conditions, which provides a scientific basis for the resource allocation and operation strategy of the microgrid, and ensures the efficient, safe and sustainable operation of the control system.

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

[0006] The resource efficient control method based on the microgrid of the charging and discharging station includes the following steps:

[0007] Step A, constructing a microgrid model of a charging and discharging station;

[0008] Step B, based on the charging and discharging station microgrid model, the autonomous capability of the charging and discharging station microgrid is calculated to obtain the autonomous capability calculation result;

[0009] Step C, based on the charging and discharging station microgrid model, the interaction capability between the charging and discharging station microgrid and the distribution network is calculated to obtain the interaction capability calculation result;

[0010] Step D: According to the autonomous capability calculation results and the interactive capability calculation results, the resource of the charging and discharging station microgrid is regulated to complete the efficient resource regulation operation of the charging and discharging station microgrid.

[0011] The above-mentioned resource efficient control method based on the charging and discharging station microgrid, step A, constructing a charging and discharging station microgrid model, wherein the charging and discharging station microgrid includes a photovoltaic unit, an energy storage unit, an electric vehicle charging unit and other load units, the photovoltaic unit uses a Boost circuit to transmit electric energy to the bus, the energy storage unit uses a three-port converter to exchange energy with the bus, the electric vehicle charging unit uses a bidirectional charging pile to obtain electric energy from the bus, the other load units use an AC / DC converter to obtain electric energy from the bus, and the bus uses a bidirectional AC / DC converter to connect to the public power grid. The specific steps are as follows:

[0012] Step A1, constructing a photovoltaic unit model, specifically, the photovoltaic cell is equivalent to a photocurrent source and an equivalent resistor, as shown in formula (1),

[0013]

[0014] Among them, I sh is the bypass current, U d is the total diffusion voltage, R sh is the bypass resistance, I d is the total diffusion current, I0 is the reverse saturation current of the diode, q is the charge constant, A is the diode constant factor, k is the Boltzmann constant, T is the absolute temperature, U is the PV and I PV are the output voltage and output current of the photovoltaic cell, R s is the equivalent series resistance, U PV is the photovoltaic cell terminal voltage, I ph It is the photocurrent of the PN junction inside the photovoltaic cell;

[0015] Step A2, constructing an energy storage unit model, specifically using a dynamic electrochemical model to simulate the charging and discharging behavior of a lithium-ion battery under different working conditions, wherein the performance parameters of the lithium-ion battery include the state of charge SOC, the state of health SOH, and the charging and discharging efficiency, the input parameters of the energy storage unit model include the battery rated capacity, the charging and discharging rate, the efficiency curve, and the temperature effect, and the output parameters of the energy storage unit model include the real-time state of charge SOC, the charging and discharging power, and the energy loss;

[0016] Step A3, constructing an electric vehicle charging unit model, specifically using a power system load model to simulate electric vehicle charging behavior and load characteristics, wherein the electric vehicle charging behavior parameters include different charging methods, charging time distribution and user behavior, the electric vehicle charging unit model input parameters include charging pile power, charging efficiency, electric vehicle battery capacity and charging habit survey data, and the electric vehicle charging unit model output parameter is a charging load curve.

[0017] The above-mentioned resource efficient control method based on the charging and discharging station microgrid, step B, based on the charging and discharging station microgrid model, calculates the autonomy capability of the charging and discharging station microgrid to obtain the autonomy capability calculation result, wherein the autonomy capability includes the self-sufficiency rate, the self-consumption rate and the autonomy capability under extreme conditions. The specific steps are as follows:

[0018] Step B1, calculate the self-sufficiency rate of the charging and discharging station microgrid, where the self-sufficiency rate is the ratio of the local power generation in the charging and discharging station microgrid to the total load demand, as shown in formula (2),

[0019]

[0020] Step B2, calculate the self-consumption rate of the microgrid of the charging and discharging station, where the self-consumption rate is the proportion of local power generation directly consumed by local loads, as shown in formula (3):

[0021]

[0022] Step B3, calculating the autonomous capability of the microgrid of the charging and discharging station under extreme conditions, wherein the autonomous capability under extreme conditions refers to the energy supply capability and microgrid stability of the microgrid of the charging and discharging station under extreme conditions, and the extreme conditions include continuous rainy days, extremely high temperatures, and extremely low temperatures.

[0023] The above-mentioned resource efficient control method based on the charging and discharging station microgrid, step C, based on the charging and discharging station microgrid model, measures the interaction capability between the charging and discharging station microgrid and the distribution network to obtain the interaction capability measurement result, wherein the interaction capability between the charging and discharging station microgrid and the distribution network includes power regulation capability and demand response capability. The specific steps are as follows:

[0024] Step C1, the power regulation capability between the charging and discharging station microgrid and the distribution network is measured, wherein the power regulation capability is the range in which the charging and discharging station microgrid can regulate power within a time period, and the power regulation capability specifically includes absorbing excess electric energy and releasing stored electric energy, as shown in formula (4),

[0025]

[0026] Step C2, the demand response capability between the charging and discharging station microgrid and the distribution network is calculated, wherein the demand response capability is the ability of the charging and discharging station microgrid to adjust the load in response to the electricity price signal or the emergency dispatch instruction of the power system. The specific calculation process is to simulate the demand response events under different electricity prices and different load conditions and calculate the load adjustment range and response time.

[0027] The above-mentioned efficient resource control method based on the charging and discharging station microgrid, step D, controls the resources of the charging and discharging station microgrid according to the autonomous capability calculation results and the interactive capability calculation results, and completes the efficient resource control operation of the charging and discharging station microgrid, wherein the resource control includes energy management, load control, energy storage unit control and distributed energy control. The specific steps are as follows:

[0028] Step D1, performing energy management on the microgrid of the charging and discharging station, wherein the energy management optimization goal is to maximize the utilization rate of renewable energy and minimize the operating cost;

[0029] Step D2, load regulation of the microgrid of the charging and discharging station, wherein the load regulation target is to balance power supply and demand and reduce peak-to-valley difference;

[0030] Step D3, regulating the energy storage unit of the microgrid of the charging and discharging station, wherein the energy storage unit regulation is to optimize the charging and discharging strategy of the energy storage unit;

[0031] Step D4, performing distributed energy control on the microgrid of the charging and discharging station, wherein the distributed energy control is to optimize the operation mode of the distributed energy.

[0032] The resource efficient control system based on the charging and discharging station microgrid includes a model construction module, an autonomous capability calculation module, an interactive capability calculation module and a resource control module; the model construction module is used to construct a charging and discharging station microgrid model; the autonomous capability calculation module is used to calculate the autonomous capability of the charging and discharging station microgrid based on the charging and discharging station microgrid model and obtain the autonomous capability calculation result; the interactive capability calculation module is used to calculate the interactive capability between the charging and discharging station microgrid and the distribution network based on the charging and discharging station microgrid model and obtain the interactive capability calculation result; the resource control module is used to control the resources of the charging and discharging station microgrid according to the autonomous capability calculation result and the interactive capability calculation result and complete the resource efficient control operation of the charging and discharging station microgrid.

[0033] In the aforementioned resource efficient control system based on the charging and discharging station microgrid, the charging and discharging station microgrid model in the model construction module includes a photovoltaic unit model, an energy storage unit model and an electric vehicle charging unit model.

[0034] In the aforementioned resource efficient control system based on the charging and discharging station microgrid, the autonomy capability of the charging and discharging station microgrid in the autonomy capability calculation module includes the self-sufficiency rate, the self-consumption rate and the autonomy capability under extreme conditions.

[0035] In the aforementioned resource efficient control system based on the charging and discharging station microgrid, the interactive capability between the charging and discharging station microgrid and the distribution network in the interactive capability measurement module includes power regulation capability and demand response capability.

[0036] The aforementioned resource efficient control system based on the charging and discharging station microgrid, the resource control in the resource control module includes energy management, load control, energy storage unit control and distributed energy control.

[0037] The beneficial effects of the present invention are as follows: the resource efficient control method and system based on the charging and discharging station microgrid of the present invention first constructs a charging and discharging station microgrid model, then measures the autonomous capability of the charging and discharging station microgrid based on the charging and discharging station microgrid model and obtains the autonomous capability calculation result, then measures the interactive capability between the charging and discharging station microgrid and the distribution network based on the charging and discharging station microgrid model and obtains the interactive capability calculation result, then controls the resource of the charging and discharging station microgrid according to the autonomous capability calculation result and the interactive capability calculation result, and completes the resource efficient control operation of the charging and discharging station microgrid; the present invention effectively realizes the function of integrating photovoltaic units, energy storage units, electric vehicle charging units and other load units, and adopts the form of nighttime energy storage and daytime release, which can not only meet the charging needs of electric vehicles, but also reduce the peak load of the public power grid, and at the same time, through the constructed charging The discharge station microgrid model can comprehensively measure the photovoltaic power generation capacity of the microgrid, the optimal scheduling of the energy storage system, the response characteristics of the electric vehicle charging load, and the stability and benefits of the overall control system under different operating conditions. This provides a scientific basis for the microgrid resource allocation and operation strategy, and ensures the efficient, safe and sustainable operation of the control system. The present invention can determine the optimal operating parameters and configuration scheme of the microgrid through the comprehensive measurement of autonomy and interaction capabilities. The autonomy ensures the maximum utilization of local energy and the self-sufficiency of the charging and discharging station microgrid, while the interaction capability enhances the flexibility and adaptability of the charging and discharging station microgrid, which provides a reliable means of regulation for the stable operation of the power system. In this way, through the buffering of the energy storage system in the battery swap station, electric vehicles can be connected to the distribution network as mobile distributed energy storage units, thereby improving the power supply safety, flexibility and utilization rate of new energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a flow chart of the resource efficient control method based on the charging and discharging station microgrid of the present invention;

[0039] Figure 2 It is a schematic diagram of the control principle of the resource efficient control system based on the charging and discharging station microgrid of the present invention.

[0040] Figure 3 is a graph showing the PU characteristic of photovoltaic cells at different light intensities in an embodiment of the present invention;

[0041] Figure 4 is a graph showing the IU characteristic curves of photovoltaic cells with different light intensities in an embodiment of the present invention;

[0042] Figure 5 is a graph showing the PU characteristics of photovoltaic cells at different temperatures in an embodiment of the present invention;

[0043] Figure 6 is a graph showing the IU characteristic curves of photovoltaic cells at different temperatures in an embodiment of the present invention;

[0044] Figure 7 is a diagram of photovoltaic MPPT control output power under different light intensities in an embodiment of the present invention;

[0045] Figure 8 is a diagram of DC bus voltage under different lighting conditions in an embodiment of the present invention; DETAILED DESCRIPTION

[0046] The present invention will be further described below in conjunction with the accompanying drawings.

[0047] like Figure 1 As shown, the resource efficient control method based on the charging and discharging station microgrid of the present invention includes the following steps:

[0048] Step A, constructing a charging and discharging station microgrid model, wherein the charging and discharging station microgrid includes a photovoltaic unit, an energy storage unit, an electric vehicle charging unit and other load units, the photovoltaic unit uses a Boost circuit to transmit electric energy to the bus, the energy storage unit uses a three-port converter to exchange energy with the bus, the electric vehicle charging unit uses a bidirectional charging pile to obtain electric energy from the bus, the other load units use an AC / DC converter to obtain electric energy from the bus, and the bus is connected to the public power grid using a bidirectional AC / DC converter. The specific steps are as follows:

[0049] Step A1, constructing a photovoltaic unit model, specifically, the photovoltaic cell is equivalent to a photocurrent source and an equivalent resistor, as shown in formula (1),

[0050]

[0051] Among them, Ish is the bypass current, U d is the total diffusion voltage, R sh is the bypass resistance, I d is the total diffusion current, I0 is the reverse saturation current of the diode, q is the charge constant, A is the diode constant factor, k is the Boltzmann constant, T is the absolute temperature, U is the PV and I PV are the output voltage and output current of the photovoltaic cell, R s is the equivalent series resistance, U PV is the photovoltaic cell terminal voltage, I ph It is the photocurrent of the PN junction inside the photovoltaic cell;

[0052] Step A2, constructing an energy storage unit model, specifically using a dynamic electrochemical model to simulate the charging and discharging behavior of a lithium-ion battery under different working conditions, wherein the performance parameters of the lithium-ion battery include the state of charge SOC, the state of health SOH, and the charging and discharging efficiency, the input parameters of the energy storage unit model include the battery rated capacity, the charging and discharging rate, the efficiency curve, and the temperature effect, and the output parameters of the energy storage unit model include the real-time state of charge SOC, the charging and discharging power, and the energy loss;

[0053] Step A3, constructing an electric vehicle charging unit model, specifically using a power system load model to simulate electric vehicle charging behavior and load characteristics, wherein the electric vehicle charging behavior parameters include different charging methods, charging time distribution and user behavior, the electric vehicle charging unit model input parameters include charging pile power, charging efficiency, electric vehicle battery capacity and charging habit survey data, and the electric vehicle charging unit model output parameter is a charging load curve.

[0054] Step B, based on the charging and discharging station microgrid model, the autonomous capability of the charging and discharging station microgrid is calculated to obtain the autonomous capability calculation result, wherein the autonomous capability includes the self-sufficiency rate, the self-consumption rate and the autonomous capability under extreme conditions. The specific steps are as follows:

[0055] Step B1, calculate the self-sufficiency rate of the charging and discharging station microgrid, where the self-sufficiency rate is the ratio of the local power generation in the charging and discharging station microgrid to the total load demand, as shown in formula (2),

[0056]

[0057] Step B2, calculate the self-consumption rate of the microgrid of the charging and discharging station, where the self-consumption rate is the proportion of local power generation directly consumed by local loads, as shown in formula (3):

[0058]

[0059] Step B3, calculating the autonomous capability of the microgrid of the charging and discharging station under extreme conditions, wherein the autonomous capability under extreme conditions refers to the energy supply capability and microgrid stability of the microgrid of the charging and discharging station under extreme conditions, and the extreme conditions include continuous rainy days, extremely high temperatures, and extremely low temperatures.

[0060] Step C, based on the charging and discharging station microgrid model, the interaction capability between the charging and discharging station microgrid and the distribution network is calculated to obtain the interaction capability calculation result, wherein the interaction capability between the charging and discharging station microgrid and the distribution network includes power regulation capability and demand response capability. The specific steps are as follows:

[0061] Step C1, the power regulation capability between the charging and discharging station microgrid and the distribution network is measured, wherein the power regulation capability is the range in which the charging and discharging station microgrid can regulate power within a time period, and the power regulation capability specifically includes absorbing excess electric energy and releasing stored electric energy, as shown in formula (4),

[0062]

[0063] Step C2, the demand response capability between the charging and discharging station microgrid and the distribution network is calculated, wherein the demand response capability is the ability of the charging and discharging station microgrid to adjust the load in response to the electricity price signal or the emergency dispatch instruction of the power system. The specific calculation process is to simulate the demand response events under different electricity prices and different load conditions and calculate the load adjustment range and response time.

[0064] Step D: According to the autonomous capability calculation results and the interactive capability calculation results, the microgrid of the charging and discharging station is regulated and controlled to complete the efficient resource regulation of the microgrid of the charging and discharging station. The resource regulation includes energy management, load regulation, energy storage unit regulation and distributed energy regulation. The specific steps are as follows:

[0065] Step D1, performing energy management on the microgrid of the charging and discharging station, wherein the energy management optimization goal is to maximize the utilization rate of renewable energy and minimize the operating cost;

[0066] Step D2, load regulation of the microgrid of the charging and discharging station, wherein the load regulation target is to balance power supply and demand and reduce peak-to-valley difference;

[0067] Step D3, regulating the energy storage unit of the microgrid of the charging and discharging station, wherein the energy storage unit regulation is to optimize the charging and discharging strategy of the energy storage unit;

[0068] Step D4, performing distributed energy control on the microgrid of the charging and discharging station, wherein the distributed energy control is to optimize the operation mode of the distributed energy.

[0069] like Figure 2As shown, the resource efficient control system based on the charging and discharging station microgrid includes a model construction module, an autonomous capability calculation module, an interactive capability calculation module and a resource control module; the model construction module is used to construct a charging and discharging station microgrid model; the autonomous capability calculation module is used to calculate the autonomous capability of the charging and discharging station microgrid based on the charging and discharging station microgrid model and obtain the autonomous capability calculation result; the interactive capability calculation module is used to calculate the interactive capability between the charging and discharging station microgrid and the distribution network based on the charging and discharging station microgrid model and obtain the interactive capability calculation result; the resource control module is used to control the resources of the charging and discharging station microgrid according to the autonomous capability calculation result and the interactive capability calculation result and complete the resource efficient control operation of the charging and discharging station microgrid.

[0070] Specifically, the charging and discharging station microgrid model in the model building module includes a photovoltaic unit model, an energy storage unit model and an electric vehicle charging unit model.

[0071] Specifically, the autonomy capability of the charging and discharging station microgrid in the autonomy capability calculation module includes self-sufficiency rate, self-consumption rate and autonomy capability under extreme conditions.

[0072] Specifically, the interactive capability between the charging and discharging station microgrid and the distribution network in the interactive capability measurement module includes power regulation capability and demand response capability.

[0073] Specifically, the resource control in the resource control module includes energy management, load control, energy storage unit control and distributed energy control.

[0074] In order to better illustrate the use effect of the present invention, a specific embodiment of the present invention is described below. According to the microgrid model of the charging and discharging station, PU and IU characteristic curves under different ambient temperatures T and different light intensities S are respectively plotted.

[0075] (1) When the temperature T is maintained at 25°C, the light intensity S is 800W / m 2 , 1000W / m 2 and 1200W / m 2 , the photovoltaic characteristic curve is obtained as Figure 3 and Figure 4 As shown. Figure 3 and Figure 4 It can be obtained that when T remains unchanged and S gradually increases, the short-circuit current and output power of the photovoltaic cell increase significantly, but the increase in terminal voltage is not very obvious; in the PU curve, the output power of the photovoltaic cell will first increase and then decrease with the increase of the terminal voltage, and this maximum point is the maximum power point of the photovoltaic operation.

[0076] (2) Maintain the light intensity S at 1000W / m 2When the temperature T is 15℃, 25℃ and 35℃ respectively, the photovoltaic characteristic curve is as follows Figure 5 and Figure 6 As shown. Figure 5 and Figure 6 It can be obtained that when S remains unchanged and T gradually increases, the open circuit voltage of the photovoltaic cell increases slightly and the short circuit current decreases slightly; the output power of the photovoltaic cell is greatly affected by the light intensity S, but less affected by the temperature T.

[0077] (3) A photovoltaic MPPT simulation model was built in the MATLAB / Simulink environment, where the circuit inductance L = 5mH and the capacitance C = 550uF. Assume that the ambient temperature remains unchanged at 25℃ and the initial light intensity is 1000W / m 2 , at 0.2s, reduce the light intensity to 600W / m 2 , and then rise to 800W / m at 0.4s 2 The simulation results of output power are as follows: Figure 7 and Figure 8 As shown. Figure 7 and Figure 8 It can be seen that at 0.2s, the light intensity is 1000W / m 2 Reduced to 600W / m 2 The photovoltaic output power decreases accordingly. At 0.4s, the light intensity is 600W / m 2 Up to 800W / m 2 , the photovoltaic output power increases and is in a stable state. It can be seen from the DC bus voltage diagram that when the light intensity decreases at 0.2s, the DC bus drops slightly, but quickly stabilizes at 700V. When the light intensity increases at 0.4s, the DC bus rises slightly, but can also quickly stabilize at 700V.

[0078] In summary, the method and system for efficient resource control based on the microgrid of the charging and discharging station of the present invention first constructs a microgrid model of the charging and discharging station, then measures the autonomous capability of the microgrid of the charging and discharging station based on the microgrid model and obtains the autonomous capability calculation result, then measures the interactive capability between the microgrid of the charging and discharging station and the distribution network based on the microgrid model of the charging and discharging station and obtains the interactive capability calculation result, then controls the resources of the microgrid of the charging and discharging station according to the autonomous capability calculation result and the interactive capability calculation result, and completes the efficient resource control operation of the microgrid of the charging and discharging station; the present invention effectively realizes the function of integrating photovoltaic units, energy storage units, electric vehicle charging units and other load units, and adopts the form of storing energy at night and releasing it during the day, which can not only meet the charging needs of electric vehicles, but also reduce the peak load of the public power grid, and at the same time, through the constructed charging and discharging station The microgrid model can comprehensively measure the photovoltaic power generation capacity of the microgrid, the optimal scheduling of the energy storage system, the response characteristics of the electric vehicle charging load, and the stability and efficiency of the overall control system under different operating conditions. This provides a scientific basis for the microgrid resource allocation and operation strategy, and ensures the efficient, safe and sustainable operation of the control system. The present invention can determine the optimal operating parameters and configuration scheme of the microgrid through the comprehensive measurement of autonomy and interaction capabilities. The autonomy ensures the maximum utilization of local energy and the self-sufficiency of the charging and discharging station microgrid, while the interaction capability enhances the flexibility and adaptability of the charging and discharging station microgrid, which provides a reliable means of regulation for the stable operation of the power system. In this way, through the buffering of the energy storage system in the battery swap station, electric vehicles can be connected to the distribution network as mobile distributed energy storage units, thereby improving the power supply safety, flexibility and utilization rate of new energy.

[0079] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A resource efficient control method based on a microgrid of a charging and discharging station, characterized in that: The following steps are included: Step A, constructing a microgrid model of a charging and discharging station; Step B, based on the charging and discharging station microgrid model, the autonomous capability of the charging and discharging station microgrid is calculated to obtain the autonomous capability calculation result; Step C, based on the charging and discharging station microgrid model, the interaction capability between the charging and discharging station microgrid and the distribution network is calculated to obtain the interaction capability calculation result; Step D: According to the autonomous capability calculation results and the interactive capability calculation results, the resource of the charging and discharging station microgrid is regulated to complete the efficient resource regulation operation of the charging and discharging station microgrid.

2. The resource efficient control method based on the charging and discharging station microgrid according to claim 1 is characterized in that: Step A, constructing a charging and discharging station microgrid model, wherein the charging and discharging station microgrid includes a photovoltaic unit, an energy storage unit, an electric vehicle charging unit and other load units, the photovoltaic unit uses a Boost circuit to transmit electric energy to the bus, the energy storage unit uses a three-port converter to exchange energy with the bus, the electric vehicle charging unit uses a bidirectional charging pile to obtain electric energy from the bus, the other load units use an AC / DC converter to obtain electric energy from the bus, and the bus is connected to the public power grid using a bidirectional AC / DC converter. The specific steps are as follows: Step A1, constructing a photovoltaic unit model, specifically, the photovoltaic cell is equivalent to a photocurrent source and an equivalent resistor, as shown in formula (1), Among them, I sh is the bypass current, U d is the total diffusion voltage, R sh is the bypass resistance, I d is the total diffusion current, I0 is the reverse saturation current of the diode, q is the charge constant, A is the diode constant factor, k is the Boltzmann constant, T is the absolute temperature, U is the PV and I PV are the output voltage and output current of the photovoltaic cell, R s is the equivalent series resistance, U PV is the photovoltaic cell terminal voltage, I ph It is the photocurrent of the PN junction inside the photovoltaic cell; Step A2, constructing an energy storage unit model, specifically using a dynamic electrochemical model to simulate the charging and discharging behavior of a lithium-ion battery under different working conditions, wherein the performance parameters of the lithium-ion battery include the state of charge SOC, the state of health SOH, and the charging and discharging efficiency, the input parameters of the energy storage unit model include the battery rated capacity, the charging and discharging rate, the efficiency curve, and the temperature effect, and the output parameters of the energy storage unit model include the real-time state of charge SOC, the charging and discharging power, and the energy loss; Step A3, constructing an electric vehicle charging unit model, specifically using a power system load model to simulate electric vehicle charging behavior and load characteristics, wherein the electric vehicle charging behavior parameters include different charging methods, charging time distribution and user behavior, the electric vehicle charging unit model input parameters include charging pile power, charging efficiency, electric vehicle battery capacity and charging habit survey data, and the electric vehicle charging unit model output parameter is a charging load curve.

3. The resource efficient control method based on the charging and discharging station microgrid according to claim 2 is characterized in that: Step B, based on the charging and discharging station microgrid model, the autonomous capability of the charging and discharging station microgrid is calculated to obtain the autonomous capability calculation result, wherein the autonomous capability includes the self-sufficiency rate, the self-consumption rate and the autonomous capability under extreme conditions. The specific steps are as follows: Step B1, calculate the self-sufficiency rate of the charging and discharging station microgrid, where the self-sufficiency rate is the ratio of the local power generation in the charging and discharging station microgrid to the total load demand, as shown in formula (2), Step B2, calculate the self-consumption rate of the microgrid of the charging and discharging station, where the self-consumption rate is the proportion of local power generation directly consumed by local loads, as shown in formula (3): Step B3, calculating the autonomous capability of the microgrid of the charging and discharging station under extreme conditions, wherein the autonomous capability under extreme conditions refers to the energy supply capability and microgrid stability of the microgrid of the charging and discharging station under extreme conditions, and the extreme conditions include continuous rainy days, extremely high temperatures, and extremely low temperatures.

4. The resource efficient control method based on the charging and discharging station microgrid according to claim 3 is characterized in that: Step C, based on the charging and discharging station microgrid model, the interaction capability between the charging and discharging station microgrid and the distribution network is calculated to obtain the interaction capability calculation result, wherein the interaction capability between the charging and discharging station microgrid and the distribution network includes power regulation capability and demand response capability. The specific steps are as follows: Step C1, the power regulation capability between the charging and discharging station microgrid and the distribution network is measured, wherein the power regulation capability is the range in which the charging and discharging station microgrid can regulate power within a time period, and the power regulation capability specifically includes absorbing excess electric energy and releasing stored electric energy, as shown in formula (4), Step C2, the demand response capability between the charging and discharging station microgrid and the distribution network is calculated, wherein the demand response capability is the ability of the charging and discharging station microgrid to adjust the load in response to the electricity price signal or the emergency dispatch instruction of the power system. The specific calculation process is to simulate the demand response events under different electricity prices and different load conditions and calculate the load adjustment range and response time.

5. The resource efficient control method based on the charging and discharging station microgrid according to claim 4 is characterized in that: Step D: According to the autonomous capability calculation results and the interactive capability calculation results, the microgrid of the charging and discharging station is regulated and controlled to complete the efficient resource regulation of the microgrid of the charging and discharging station. The resource regulation includes energy management, load regulation, energy storage unit regulation and distributed energy regulation. The specific steps are as follows: Step D1, performing energy management on the microgrid of the charging and discharging station, wherein the energy management optimization goal is to maximize the utilization rate of renewable energy and minimize the operating cost; Step D2, load regulation of the microgrid of the charging and discharging station, wherein the load regulation target is to balance power supply and demand and reduce peak-to-valley difference; Step D3, regulating the energy storage unit of the microgrid of the charging and discharging station, wherein the energy storage unit regulation is to optimize the charging and discharging strategy of the energy storage unit; Step D4, performing distributed energy control on the microgrid of the charging and discharging station, wherein the distributed energy control is to optimize the operation mode of the distributed energy.

6. A resource efficient control system based on a microgrid of a charging and discharging station, wherein the resource control method of the resource efficient control system is based on the resource efficient control method according to any one of claims 1 to 5, characterized in that: It includes model building module, autonomous capability calculation module, interactive capability calculation module and resource control module; The model building module is used to build a charging and discharging station microgrid model; The autonomous capability calculation module is used to calculate the autonomous capability of the charging and discharging station microgrid based on the charging and discharging station microgrid model and obtain the autonomous capability calculation result; The interactive capacity calculation module is used to calculate the interactive capacity between the charging and discharging station microgrid and the distribution network based on the charging and discharging station microgrid model and obtain the interactive capacity calculation result; The resource control module is used to control the resources of the charging and discharging station microgrid according to the autonomous capacity calculation results and the interactive capacity calculation results and complete the resource efficient control operation of the charging and discharging station microgrid.

7. The resource efficient control system based on the charging and discharging station microgrid according to claim 6 is characterized in that: The charging and discharging station microgrid model in the model building module includes a photovoltaic unit model, an energy storage unit model and an electric vehicle charging unit model.

8. The resource efficient control system based on the charging and discharging station microgrid according to claim 6 is characterized in that: The autonomy capability of the charging and discharging station microgrid in the autonomy capability calculation module includes self-sufficiency rate, self-consumption rate and autonomy capability under extreme conditions.

9. The resource efficient control system based on the charging and discharging station microgrid according to claim 6 is characterized in that: The interactive capability between the charging and discharging station microgrid and the distribution network in the interactive capability calculation module includes power regulation capability and demand response capability.

10. The resource efficient control system based on the charging and discharging station microgrid according to claim 6 is characterized in that: The resource control in the resource control module includes energy management, load control, energy storage unit control and distributed energy control.

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