Polar region multi-energy micro-grid real-time power balance control method and device

Abstract

The invention provides a real-time power balance control method and device for a polar region multi-energy micro-grid, and belongs to the field of micro-grid real-time power balance control. The problem that an existing control method is poor in stability is solved. The method is suitable for a wind-light-hydrogen storage system, and comprises the following steps: obtaining the on-off states of an AC bus and a DC bus and the corresponding output of equipment; the system is divided into scenes 1-4: scene 1: alternating current bus disconnection and direct current outgoing line disconnection, and a core control target is electric power balance; scene 2: the AC bus is disconnected and the DC bus is closed, and the core control target is to preferentially maintain the power balance in the grid and consider the flexibility of the DC side; scene 3: the AC bus is closed and the DC bus is disconnected, and the core control target is to preferentially maintain the power balance in the grid and consider the flexibility of the grid-connected test; scene 4: the AC bus is closed and the DC bus is closed, and the core control target is to preferentially maintain power balance in the grid; jumping to different control logics according to the corresponding scenes; the method is applied to the micro-grid.

Description

Technical Field

[0001] This application relates to the technical field of real-time control of multi-energy coupled microgrids, and particularly to a real-time power balance control method and device for polar multi-energy microgrids. Background Art

[0002] Distributed renewable energy represented by wind energy, solar energy, and energy storage has important application prospects. The wind-solar-hydrogen-storage-load system can not only promote the green transformation of energy, but also independently form a microgrid in remote areas (islands, mountains) and special mission scenarios (polar expeditions, deep space exploration) to ensure power supply. Driven by this demand, how to scientifically consider the stable operation of the wind-solar-hydrogen-storage-load system has become an important and challenging issue. The randomness and volatility of distributed renewable energy and the characteristics of small inertia of the wind-solar-hydrogen-storage-load system will lead to stability problems in multi-energy microgrids. Facing greater power fluctuations and smaller system inertia, the frequency and voltage regulation control in traditional power systems cannot ensure the safe and stable operation of the wind-solar-hydrogen-storage-load system. Summary of the Invention

[0003] To solve the above technical problems, this application proposes a real-time power balance control method and device for polar multi-energy microgrids. By real-time monitoring of the system state, the output of distributed energy is quickly adjusted to ensure real-time power balance within the wind-solar-hydrogen-storage-load system. This real-time control method combined with the energy management system of the multi-energy microgrid can ensure the safe and stable operation of the multi-energy microgrid under non-fault conditions.

[0004] The technical solution adopted in this application is as follows: A real-time power balance control method for a polar multi-energy microgrid, applicable to a wind-solar-hydrogen-storage-load system, includes the following steps: S1: Obtain the opening and closing states of the AC bus, the opening and closing state of the DC bus, the AC bus voltage, the AC bus frequency, the output of the wind turbine, the output of the photovoltaic, and the output of the fuel cell; S2: According to the opening and closing states of the AC bus and the DC bus, the system is divided into different application scenarios, namely: Scenario 1: The AC bus is open and the DC outgoing line is open; Scenario 2: The AC bus is open and the DC bus is closed; Scenario 3: The AC bus is closed and the DC bus is open; Scenario 4: The AC bus is closed and the DC bus is closed; S3: Jump to different control logics according to the corresponding scenarios. Among them, the core control objective in Scenario 1 is power balance, the core control objective in Scenario 2 is to preferentially maintain power balance within the network while considering the flexibility of the DC side, the core control objective in Scenario 3 is to preferentially maintain power balance within the network while considering the flexibility of the grid connection side, and the core control objective in Scenario 4 is to preferentially maintain power balance within the network.

[0005] Furthermore, the wind-solar-hydrogen-storage-load system includes multiple groups of wind turbines, multiple groups of photovoltaics, multiple groups of fuel cells, two energy storages and a load. In Scenario 1, the system is in an island operation mode. Assuming that Energy Storage 1 is the balancing power source, it is necessary to control to make Energy Storage 1 flexible; In Scenario 1, when the system power is insufficient, the control priorities are as follows: reducing new energy curtailment > reducing the charging output of Energy Storage 2 > increasing the discharging output of Energy Storage 2 > increasing load shedding; When the system power is excessive, the control priorities are as follows: reducing the amount of load shedding > reducing the discharging output of Energy Storage 2 > increasing the charging output of Energy Storage 2 > increasing new energy curtailment.

[0006] Furthermore, the specific control logic of Scenario 1 is as follows: Judge whether the power of Energy Storage 1 is out of bounds. When neither the charging power nor the discharging power of Energy Storage 1 is out of bounds, no regulation is carried out. When the charging power of Energy Storage 1 is too large, judge whether the controllable load power is less than the rated power. When the controllable load power is less than the rated power, increase the controllable load power in a fixed small step; when the controllable load power is greater than or equal to the rated power, judge whether the power of Energy Storage 2 is out of bounds. When the power of Energy Storage 2 is not out of bounds, reduce the power of Energy Storage 2 in a fixed small step. When the power of Energy Storage 2 is out of bounds, judge whether the power of the wind turbine unloader is less than the maximum value. When the power of the wind turbine unloader is less than the maximum value, increase the set value of the wind turbine unloader in a fixed small step. When the power of the wind turbine unloader is greater than or equal to the maximum value, then judge whether the photovoltaic output set value is greater than zero. When the photovoltaic output set value is greater than zero, reduce the photovoltaic output set value in a fixed small step. When the photovoltaic output set value is less than or equal to zero, issue an alarm of exceeding control ability; When the discharging power of Energy Storage 1 is too large, judge whether the photovoltaic output set value is greater than the rated value. When the photovoltaic output set value is less than or equal to the rated value, increase the photovoltaic output set value in a fixed small step. When the photovoltaic output set value is greater than the rated value, judge whether the power of the wind turbine unloader is greater than zero. When the power of the wind turbine unloader is greater than zero, reduce the set value of the wind turbine unloader in a fixed small step. When the power of the wind turbine unloader is less than or equal to zero, judge whether the power of Energy Storage 2 is out of bounds. When the power of Energy Storage 2 is not out of bounds, increase the power of Energy Storage 2 in a fixed small step. When the power of Energy Storage 2 is out of bounds, judge whether the controllable load power is greater than zero. When the controllable load power is less than or equal to zero, issue an alarm of exceeding control ability. When the controllable load power is greater than zero, reduce the controllable load power in a fixed small step.

[0007] Furthermore, the wind-solar-hydrogen-storage-load system includes multiple groups of wind turbines, multiple groups of photovoltaics, multiple groups of fuel cells, two energy storages and a load. In Scenario 2, assuming that Energy Storage 1 is the balancing power source, it is necessary to control to make Energy Storage 1 flexible; When the system power is insufficient in Scenario 2, the control priority is: reducing new energy curtailment > reducing DC external transmission power > reducing the charging output of Energy Storage 2 > increasing the discharging output of Energy Storage 2 > increasing DC reverse transmission power > increasing load shedding; When the system power is excessive, the control priority is: reducing the amount of load shedding > reducing DC reverse transmission power > reducing the discharging output of Energy Storage 2 > increasing the charging output of Energy Storage 2 > increasing DC external transmission power > increasing new energy curtailment.

[0008] Furthermore, the specific control logic of Scenario 2 is as follows: Judge whether the power of Energy Storage 1 is out of bounds. When neither the charging power nor the discharging power of Energy Storage 1 is out of bounds, no regulation is performed. When the charging power of Energy Storage 1 is too large, judge whether the controllable load power is less than the rated power. When the controllable load power is less than the rated power, increase the controllable load power in a fixed small step; when the controllable load power is greater than or equal to the rated power, judge whether the power of the DC bus inverter is greater than zero and less than the maximum value. When the power of the DC bus inverter is greater than zero and less than the maximum value, increase the power of the DC bus inverter in a fixed small step. When the power of the DC bus inverter is greater than the maximum value or less than zero, judge whether the power of Energy Storage 2 is out of bounds. When the power of Energy Storage 2 is not out of bounds, reduce the power of Energy Storage 2 in a fixed small step. When the power of Energy Storage 2 is out of bounds, judge whether the power of the DC bus inverter is less than zero and greater than the minimum value. When the power of the DC bus inverter is less than zero and greater than the minimum value, reduce the power of the DC bus inverter in a fixed small step. When the power of the DC bus inverter is less than the minimum value, judge whether the power of the fan unloader is less than the maximum value. When the power of the fan unloader is less than the maximum value, increase the fan unloader setting value in a fixed small step. When the power of the fan unloader is greater than or equal to the maximum value, then judge whether the PV output setting value is greater than zero. When the PV output setting value is greater than zero, reduce the PV output setting value in a fixed small step. When the PV output setting value is less than or equal to zero, issue an alarm of exceeding control capacity; When the discharge power of energy storage 1 is too large, determine whether the PV output set value is greater than the rated value. When the PV output is less than or equal to the rated value, increase the PV output set value in a fixed small step. When the PV output set value is greater than the rated value, determine whether the power of the fan unloader is greater than zero. When the power of the fan unloader is greater than zero, decrease the fan unloader set value in a fixed small step. When the power of the fan unloader is less than or equal to zero, determine whether the power of the DC bus inverter is less than zero and greater than the minimum value. When the power of the DC bus inverter is less than zero and greater than the minimum value, decrease the power of the DC bus inverter in a fixed small step. When the power of the DC bus inverter is less than the minimum value, determine whether the power of energy storage 2 is out of bounds. When the power of energy storage 2 is not out of bounds, increase the power of energy storage 2 in a fixed small step. When the power of energy storage 2 is out of bounds, determine whether the power of the DC bus inverter is greater than zero and less than the maximum value. When the power of the DC bus inverter is greater than zero and less than the maximum value, increase the power of the DC bus inverter in a fixed small step. When the power of the DC bus inverter is greater than the maximum value or less than zero, determine whether the power of the controllable load is greater than zero. When the power of the controllable load is less than or equal to zero, issue an alarm for exceeding the control capacity. When the power of the controllable load is greater than zero, decrease the power of the controllable load in a fixed small step.

[0009] Furthermore, the wind-solar-hydrogen-energy storage-load system includes multiple groups of wind turbines, multiple groups of PVs, multiple groups of fuel cells, two energy storages, and a load. Under scenario 3, both energy storages are set to constant power control, and the AC grid connection line serves as the balance point. When the system power is insufficient under scenario 3, the control priority is: reducing new energy curtailment > reducing energy storage charging power > increasing energy storage discharge output > increasing AC bus power supply > increasing load shedding. When the system power is excessive, the control priority is: reducing load shedding > reducing AC bus power supply > reducing energy storage discharge output > increasing energy storage charging power > increasing new energy curtailment.

[0010] Furthermore, the specific control logic of scenario 3 is as follows: Judge whether the AC bus power exceeds the limit. When the AC bus power does not exceed the limit, no regulation is carried out. When the power flowing out of the AC bus is too large, judge whether the controllable load power is less than the rated power. When the controllable load power is less than the rated power, increase the controllable load power in a fixed small step. When the controllable load power is greater than or equal to the rated power, judge whether the energy storage power exceeds the limit. When the energy storage power does not exceed the limit, consider the SOC balance and decrease the energy storage power in a fixed small step. When the energy storage power exceeds the limit, judge whether the fan unloading device power is less than the maximum value. When the fan unloading device power is less than the maximum value, increase the set value of the fan unloading device in a fixed small step. When the fan unloading device power is greater than or equal to the maximum value, judge whether the PV output set value is greater than zero. When the PV output set value is greater than zero, decrease the PV output set value in a fixed small step. When the PV output set value is less than or equal to zero, issue an alarm indicating that the control ability has been exceeded; When the power flowing into the AC bus is too large, judge whether the PV output set value is greater than the rated value. When the PV output set value is greater than the rated value, decrease the PV output set value in a fixed small step. When the PV output set value is less than or equal to the rated value, judge whether the fan unloading device power is greater than zero. When the fan unloading device power is greater than zero, decrease the set value of the fan unloading device in a fixed small step. When the fan unloading device power is less than or equal to zero, judge whether the energy storage power exceeds the limit. When the energy storage power does not exceed the limit, consider the SOC balance and increase the energy storage power in a fixed small step. When the energy storage power exceeds the limit, judge whether the controllable load power is greater than zero. When the controllable load power is greater than zero, decrease the controllable load power in a fixed small step. When the controllable load power is less than or equal to zero, issue an alarm indicating that the control ability has been exceeded.

[0011] Furthermore, the wind-solar-hydrogen-energy storage-load system includes multiple groups of wind turbines, multiple groups of PVs, multiple groups of fuel cells, two energy storages and a load. Under scenario 4, both of the two energy storages are under constant power control, and the AC grid connection inlet serves as the balance point; Under scenario 4, when the system power is insufficient, the control priority is: reducing new energy curtailment > reducing DC power transmission > reducing energy storage charging power > increasing energy storage discharging power > increasing AC bus power > increasing load shedding; When the system power is excessive, the control priority is: reducing load shedding > reducing DC reverse power transmission > reducing AC bus power supply > reducing energy storage discharging power > increasing energy storage charging power > increasing DC power transmission > increasing new energy curtailment.

[0012] Furthermore, the specific control logic of scenario 4 is as follows: Judge whether the AC bus power is out of bounds. When the AC bus power is not out of bounds, no regulation is performed. When the power flowing out of the AC bus is too large, judge whether the controllable load power is less than the rated power. When the controllable load power is less than the rated power, increase the controllable load power in a fixed small step. When the controllable load power is greater than or equal to the rated power, judge whether the DC bus inverter power is greater than zero and less than the maximum value. When the DC bus inverter power is greater than zero and less than the maximum value, increase the DC bus inverter power in a fixed small step. When the DC bus inverter power is less than zero or greater than the maximum value, judge whether the energy storage power is out of bounds. When the energy storage power is not out of bounds, consider SOC balance and decrease the energy storage power in a fixed small step. When the energy storage power is out of bounds, judge whether the DC bus inverter power is less than zero and greater than the minimum value. When the DC bus inverter power is less than zero and greater than the minimum value, decrease the DC bus inverter power in a fixed small step. When the DC bus inverter power is less than the minimum value, judge whether the fan unloading device power is less than the maximum value. When the fan unloading device power is less than the maximum value, increase the fan unloading device setting value in a fixed small step. When the fan unloading device power is greater than or equal to the maximum value, judge whether the PV output setting value is greater than zero. When the PV output setting value is greater than zero, decrease the PV output setting value in a fixed small step. When the PV output setting value is less than or equal to zero, issue an alarm indicating that the control capacity has been exceeded; When the power flowing into the AC bus is too large, judge whether the PV output setting value is greater than the rated value. When the PV output setting value is less than or equal to the rated value, increase the PV output setting value in a fixed small step. When the PV output setting value is less than the rated value, judge whether the fan unloading device power is greater than zero. When the fan unloading device power is greater than zero, decrease the fan unloading device setting value in a fixed small step. When the fan unloading device power is less than or equal to zero, judge whether the DC bus inverter power is less than zero and greater than the minimum value. When the DC bus inverter power is less than zero and greater than the minimum value, decrease the DC bus inverter power in a fixed small step. When the DC bus inverter power is less than or equal to the minimum value, judge whether the energy storage power is out of bounds. When the energy storage power is not out of bounds, consider SOC balance and increase the energy storage power in a fixed small step. When the energy storage power is out of bounds, judge whether the DC bus inverter power is greater than zero and less than the maximum value. When the DC bus inverter power is greater than zero and less than the maximum value, increase the DC bus inverter power in a fixed small step. When the DC bus inverter power is less than zero or greater than the maximum value, judge whether the controllable load power is greater than zero. When the controllable load power is less than or equal to zero, issue an alarm indicating that the control capacity has been exceeded. When the controllable load power is greater than zero, decrease the controllable load power in a fixed small step.

[0013] A computer device includes a memory, a processor, and a computer program stored on the memory. The processor executes the computer program to implement the steps of the method.

[0014] The beneficial effects of the present application compared with the prior art are as follows: The present application obtains the system state through an electric energy measurement system. At the same time, considering the real-time control requirements, a set of rule-based control logics is proposed. Based on this control logic, the output control of each distributed energy source can be quickly realized through the communication system, ensuring the real-time balance of power within the wind-solar-hydrogen-storage-load system. The combination of this real-time control method and the energy management system of the multi-energy microgrid can ensure the safe and stable operation of the multi-energy microgrid under non-fault conditions. Brief Description of the Drawings

[0015] The following further describes the present application with reference to the drawings: Figure 1 is a schematic structural diagram of a typical wind-solar-hydrogen-storage-load system; Figure 2 is the control block diagram of Scenario 1 provided in this embodiment; Figure 3 is the control block diagram of Scenario 2 provided in this embodiment; Figure 4 is the control block diagram of Scenario 3 provided in this embodiment; Figure 5 is the control block diagram of Scenario 4 provided in this embodiment. Detailed Description of the Embodiment

[0016] As Figures 1 to 5 shown, the present application provides a real-time power balance control method for a polar multi-energy microgrid, which is applicable to a wind-solar-hydrogen-storage-load system as Figure 1 shown. The system state is obtained through an electric energy measurement system. At the same time, considering the real-time control requirements, a set of rule-based control logics is proposed. Based on this control logic, the output control of each distributed energy source can be quickly realized through the communication system.

[0017] As Figure 1 shown, the wind-solar-hydrogen-storage-load system includes Wind Turbine 1, Wind Turbine 2, Photovoltaic 1, Photovoltaic 2, Fuel Cell 1, Fuel Cell 2, Energy Storage 1, Energy Storage 2, and Load. The AC bus and the DC bus are respectively connected to Wind Turbine 1, Wind Turbine 2, Photovoltaic 1, Photovoltaic 2, Fuel Cell 1, Fuel Cell 2, Energy Storage 1, Energy Storage 2, and Load. The following input quantities are required during real-time control: AC bus opening state, DC bus opening state, AC bus voltage, AC bus frequency, wind turbine output, photovoltaic output, and fuel cell output. Based on the Figure 1 system structure, the control rules can be classified as follows: 1. AC bus opening + DC bus opening In this scenario, the system is in island operation mode, and the core control objective is power balance. Assuming that Energy Storage 1 is the balancing power source and provides grid-forming function (voltage support), then other power sources need to be controlled so that Energy Storage 1 has sufficient flexibility to cope with disturbances.

[0018] When the system power is insufficient, the control priority is: reducing new energy curtailment > reducing the charging output of Energy Storage 2 > increasing the discharging output of Energy Storage 2 > increasing load shedding.

[0019] When the system power is excessive, the control priority is: reducing the amount of load shedding > reducing the discharging output of Energy Storage 2 > increasing the charging output of Energy Storage 2 > increasing new energy curtailment.

[0020] The control block diagram for this scenario is shown in Figure 2 , and the specific control logic is as follows: Judge whether the power of Energy Storage 1 exceeds the limit. When neither the charging power nor the discharging power of Energy Storage 1 exceeds the limit, no regulation is performed. When the charging power of Energy Storage 1 is too large, judge whether the controllable load power is less than the rated power. When the controllable load power is less than the rated power, increase the controllable load power in a fixed small step; when the controllable load power is greater than or equal to the rated power, judge whether the power of Energy Storage 2 exceeds the limit. When the power of Energy Storage 2 does not exceed the limit, reduce the power of Energy Storage 2 in a fixed small step. When the power of Energy Storage 2 exceeds the limit, judge whether the power of the wind turbine unloader is less than the maximum value. When the power of the wind turbine unloader is less than the maximum value, increase the set value of the wind turbine unloader in a fixed small step. When the power of the wind turbine unloader is greater than or equal to the maximum value, then judge whether the PV output set value is greater than zero. When the PV output set value is greater than zero, reduce the PV output set value in a fixed small step. When the PV output set value is less than or equal to zero, issue an alarm of exceeding control capacity.

[0021] When the discharging power of Energy Storage 1 is too large, judge whether the PV output set value is greater than the rated value. When the PV output set value is less than or equal to the rated value, increase the PV output set value in a fixed small step. When the PV output set value is greater than the rated value, judge whether the power of the wind turbine unloader is greater than zero. When the power of the wind turbine unloader is greater than zero, reduce the set value of the wind turbine unloader in a fixed small step. When the power of the wind turbine unloader is less than or equal to zero, judge whether the power of Energy Storage 2 exceeds the limit. When the power of Energy Storage 2 does not exceed the limit, increase the power of Energy Storage 2 in a fixed small step. When the power of Energy Storage 2 exceeds the limit, judge whether the controllable load power is greater than zero. When the controllable load power is less than or equal to zero, issue an alarm of exceeding control capacity. When the controllable load power is greater than zero, reduce the controllable load power in a fixed small step.

[0022] 2. AC bus open + DC bus closed In this scenario, the system is connected to the DC bus. The core control objective is to prioritize maintaining power balance within the network while considering the flexibility of the DC side. Assume that Energy Storage 1 is the balancing power source and provides network-forming function (voltage support). Then, other power sources need to be controlled so that Energy Storage 1 has sufficient flexibility to cope with disturbances.

[0023] When the system power is insufficient, the control priority is: reducing new energy curtailment > reducing DC power transmission out > reducing the charging output of Energy Storage 2 > increasing the discharging output of Energy Storage 2 > increasing DC power reverse transmission > increasing load shedding.

[0024] When the system power is excessive, the control priority is: reducing the amount of load shedding > reducing DC power reverse transmission > reducing the discharging output of Energy Storage 2 > increasing the charging output of Energy Storage 2 > increasing DC power transmission out > increasing new energy curtailment.

[0025] The control block diagram for this scenario is shown in Figure 3 , and the specific control logic is as follows: Judge whether the power of Energy Storage 1 exceeds the limit. When neither the charging power nor the discharging power of Energy Storage 1 exceeds the limit, no regulation is performed. When the charging power of Energy Storage 1 is too large, judge whether the controllable load power is less than the rated power. When the controllable load power is less than the rated power, increase the controllable load power in a fixed small step; when the controllable load power is greater than or equal to the rated power, judge whether the power of the DC bus inverter is greater than zero and less than the maximum value. When the power of the DC bus inverter is greater than zero and less than the maximum value, increase the power of the DC bus inverter in a fixed small step. When the power of the DC bus inverter is greater than the maximum value or less than zero, judge whether the power of Energy Storage 2 exceeds the limit. When the power of Energy Storage 2 does not exceed the limit, reduce the power of Energy Storage 2 in a fixed small step. When the power of Energy Storage 2 exceeds the limit, judge whether the power of the DC bus inverter is less than zero and greater than the minimum value. When the power of the DC bus inverter is less than zero and greater than the minimum value, reduce the power of the DC bus inverter in a fixed small step. When the power of the DC bus inverter is less than the minimum value, judge whether the power of the fan unloader is less than the maximum value. When the power of the fan unloader is less than the maximum value, increase the set value of the fan unloader in a fixed small step. When the power of the fan unloader is greater than or equal to the maximum value, then judge whether the PV output set value is greater than zero. When the PV output set value is greater than zero, reduce the PV output set value in a fixed small step. When the PV output set value is less than or equal to zero, issue an alarm indicating that the control ability has been exceeded.

[0026] When the discharge power of energy storage 1 is too large, judge whether the PV output set value is greater than the rated value. When the PV output is less than or equal to the rated value, increase the PV output set value in a fixed small step. When the PV output set value is greater than the rated value, judge whether the power of the fan unloading device is greater than zero. When the power of the fan unloading device is greater than zero, decrease the set value of the fan unloading device in a fixed small step. When the power of the fan unloading device is less than or equal to zero, judge whether the power of the DC bus inverter is less than zero and greater than the minimum value. When the power of the DC bus inverter is less than zero and greater than the minimum value, decrease the power of the DC bus inverter in a fixed small step. When the power of the DC bus inverter is less than the minimum value, judge whether the power of energy storage 2 is out of bounds. When the power of energy storage 2 is not out of bounds, increase the power of energy storage 2 in a fixed small step. When the power of energy storage 2 is out of bounds, judge whether the power of the DC bus inverter is greater than zero and less than the maximum value. When the power of the DC bus inverter is greater than zero and less than the maximum value, increase the power of the DC bus inverter in a fixed small step. When the power of the DC bus inverter is greater than the maximum value or less than zero, judge whether the power of the controllable load is greater than zero. When the power of the controllable load is less than or equal to zero, issue an alarm of exceeding control capacity. When the power of the controllable load is greater than zero, decrease the power of the controllable load in a fixed small step.

[0027] 3. AC bus closed + DC bus open In this scenario, the system is connected to the AC bus. The core control objective is to prioritize maintaining the power balance within the grid while considering the flexibility of the grid connection side. Both energy storages are under constant power control. The AC grid connection line serves as the balance point, ensuring no reverse power flow and trying to maintain the balance within the grid.

[0028] When the system power is insufficient, the control priority is: reducing new energy curtailment > reducing energy storage charging power > increasing energy storage discharge output > increasing AC bus power supply > increasing load shedding.

[0029] When the system power is excessive, the control priority is: reducing load shedding > reducing AC bus power supply > reducing energy storage discharge output > increasing energy storage charging power > increasing new energy curtailment.

[0030] The control block diagram for this scenario is shown in Figure 4 , and the specific control logic is as follows: Judge whether the AC bus power exceeds the limit. When the AC bus power does not exceed the limit, no regulation is carried out. When the power flowing out of the AC bus is too large, judge whether the controllable load power is less than the rated power. When the controllable load power is less than the rated power, increase the controllable load power in a fixed small step. When the controllable load power is greater than or equal to the rated power, judge whether the energy storage power exceeds the limit. When the energy storage power does not exceed the limit, consider the SOC balance and decrease the energy storage power in a fixed small step. When the energy storage power exceeds the limit, judge whether the power of the fan unloading device is less than the maximum value. When the power of the fan unloading device is less than the maximum value, increase the set value of the fan unloading device in a fixed small step. When the power of the fan unloading device is greater than or equal to the maximum value, judge whether the PV output set value is greater than zero. When the PV output set value is greater than zero, decrease the PV output set value in a fixed small step. When the PV output set value is less than or equal to zero, issue an alarm of exceeding the control ability.

[0031] When the power flowing into the AC bus is too large, judge whether the PV output set value is greater than the rated value. When the PV output set value is greater than the rated value, decrease the PV output set value in a fixed small step. When the PV output set value is less than or equal to the rated value, judge whether the power of the fan unloading device is greater than zero. When the power of the fan unloading device is greater than zero, decrease the set value of the fan unloading device in a fixed small step. When the power of the fan unloading device is less than or equal to zero, judge whether the energy storage power exceeds the limit. When the energy storage power does not exceed the limit, consider the SOC balance and increase the energy storage power in a fixed small step. When the energy storage power exceeds the limit, judge whether the controllable load power is greater than zero. When the controllable load power is greater than zero, decrease the controllable load power in a fixed small step. When the controllable load power is less than or equal to zero, issue an alarm of exceeding the control ability.

[0032] 4. AC bus closed + DC bus closed In this scenario, the system is connected to the AC and DC buses. The core control objective is to give priority to maintaining the power balance in the network. Both energy storages are under constant power control, and the AC grid connection line is used as the balance point to ensure the balance in the network first.

[0033] When the system power is insufficient, the control priority is: reducing new energy curtailment > reducing DC power transmission > reducing energy storage charging power > increasing energy storage discharging power > increasing AC bus power > increasing load shedding.

[0034] When the system power is excessive, the control priority is: reducing load shedding > reducing DC reverse power transmission > reducing AC bus power supply > reducing energy storage discharging power > increasing energy storage charging power > increasing DC power transmission > increasing new energy curtailment.

[0035] The control block diagram of this scenario is shown in Figure 5 , and the specific control logic is as follows: Judge whether the AC bus power is out of bounds. When the AC bus power is not out of bounds, no regulation is performed. When the outgoing power of the AC bus is too large, judge whether the controllable load power is less than the rated power. When the controllable load power is less than the rated power, increase the controllable load power in a fixed small step. When the controllable load power is greater than or equal to the rated power, judge whether the DC bus inverter power is greater than zero and less than the maximum value. When the DC bus inverter power is greater than zero and less than the maximum value, increase the DC bus inverter power in a fixed small step. When the DC bus inverter power is less than zero or greater than the maximum value, judge whether the energy storage power is out of bounds. When the energy storage power is not out of bounds, consider SOC balance and decrease the energy storage power in a fixed small step. When the energy storage power is out of bounds, judge whether the DC bus inverter power is less than zero and greater than the minimum value. When the DC bus inverter power is less than zero and greater than the minimum value, decrease the DC bus inverter power in a fixed small step. When the DC bus inverter power is less than the minimum value, judge whether the fan unloading device power is less than the maximum value. When the fan unloading device power is less than the maximum value, increase the fan unloading device setting value in a fixed small step. When the fan unloading device power is greater than or equal to the maximum value, judge whether the PV output setting value is greater than zero. When the PV output setting value is greater than zero, decrease the PV output setting value in a fixed small step. When the PV output setting value is less than or equal to zero, issue an alarm indicating that the control capacity has been exceeded.

[0036] When the incoming power of the AC bus is too large, judge whether the PV output setting value is greater than the rated value. When the PV output setting value is less than or equal to the rated value, increase the PV output setting value in a fixed small step. When the PV output setting value is less than the rated value, judge whether the fan unloading device power is greater than zero. When the fan unloading device power is greater than zero, decrease the fan unloading device setting value in a fixed small step. When the fan unloading device power is less than or equal to zero, judge whether the DC bus inverter power is less than zero and greater than the minimum value. When the DC bus inverter power is less than zero and greater than the minimum value, decrease the DC bus inverter power in a fixed small step. When the DC bus inverter power is less than or equal to the minimum value, judge whether the energy storage power is out of bounds. When the energy storage power is not out of bounds, consider SOC balance and increase the energy storage power in a fixed small step. When the energy storage power is out of bounds, judge whether the DC bus inverter power is greater than zero and less than the maximum value. When the DC bus inverter power is greater than zero and less than the maximum value, increase the DC bus inverter power in a fixed small step. When the DC bus inverter power is less than zero or greater than the maximum value, judge whether the controllable load power is greater than zero. When the controllable load power is less than or equal to zero, issue an alarm indicating that the control capacity has been exceeded. When the controllable load power is greater than zero, decrease the controllable load power in a fixed small step.

[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A real-time power balance control method for a polar multi-energy microgrid, characterized in that: Applicable to the wind-solar-hydrogen energy storage-load system, including the following steps: S1: Obtain the opening and closing status of the AC bus, the opening and closing status of the DC bus, the AC bus voltage, the AC bus frequency, the wind turbine output, the PV output, and the fuel cell output; S2: According to the opening and closing status of the AC bus and the DC bus, divide the system into different application scenarios, namely: Scenario 1: The AC bus is open and the DC outgoing line is open; Scenario 2: The AC bus is open and the DC bus is closed; Scenario 3: The AC bus is closed and the DC bus is open; Scenario 4: The AC bus is closed and the DC bus is closed; S3: Jump to different control logics according to the corresponding scenarios. Among them, the core control objective in Scenario 1 is power balance. The core control objective in Scenario 2 is to give priority to maintaining the power balance in the grid while considering the flexibility of the DC side. The core control objective in Scenario 3 is to give priority to maintaining the power balance in the grid while considering the flexibility of the grid connection side. The core control objective in Scenario 4 is to give priority to maintaining the power balance in the grid.

2. A real-time power balance control method for a polar multi-energy microgrid according to claim 1, characterized in that: The wind-solar-hydrogen energy storage-load system includes multiple groups of wind turbines, multiple groups of PVs, multiple groups of fuel cells, two energy storages, and a load. In Scenario 1, the system is in an island operation mode. Assuming that Energy Storage 1 is the balancing power source, it is necessary to control to make Energy Storage 1 flexible; In Scenario 1, when the system power is insufficient, the control priority is as follows: reducing new energy curtailment > reducing the charging output of Energy Storage 2 > increasing the discharging output of Energy Storage 2 > increasing load shedding; When the system power is excessive, the control priority is as follows: reducing the load shedding amount > reducing the discharging output of Energy Storage 2 > increasing the charging output of Energy Storage 2 > increasing new energy curtailment.

3. A real-time power balance control method for a polar multi-energy microgrid according to claim 2, characterized in that: The specific control logic of Scenario 1 is as follows: Judge whether the power of Energy Storage 1 exceeds the limit. When neither the charging power nor the discharging power of Energy Storage 1 exceeds the limit, no regulation is carried out. When the charging power of Energy Storage 1 is too large, judge whether the controllable load power is less than the rated power. When the controllable load power is less than the rated power, increase the controllable load power in a fixed small step; when the controllable load power is greater than or equal to the rated power, judge whether the power of Energy Storage 2 exceeds the limit. When the power of Energy Storage 2 does not exceed the limit, reduce the power of Energy Storage 2 in a fixed small step. When the power of Energy Storage 2 exceeds the limit, judge whether the power of the wind turbine unloader is less than the maximum value. When the power of the wind turbine unloader is less than the maximum value, increase the set value of the wind turbine unloader in a fixed small step. When the power of the wind turbine unloader is greater than or equal to the maximum value, then judge whether the PV output set value is greater than zero. When the PV output set value is greater than zero, reduce the PV output set value in a fixed small step. When the PV output set value is less than or equal to zero, issue an alarm of exceeding the control capacity; When the discharge power of energy storage 1 is too large, determine whether the PV output power set value is greater than the rated value. When the PV output power set value is less than or equal to the rated value, increase the PV output power set value in a fixed small step. When the PV output power set value is greater than the rated value, determine whether the fan unloading device power is greater than zero. When the fan unloading device power is greater than zero, decrease the fan unloading device set value in a fixed small step. When the fan unloading device power is less than or equal to zero, determine whether the power of energy storage 2 is out of bounds. When the power of energy storage 2 is not out of bounds, increase the power of energy storage 2 in a fixed small step. When the power of energy storage 2 is out of bounds, determine whether the controllable load power is greater than zero. When the controllable load power is less than or equal to zero, issue an alarm indicating that the control capacity has been exceeded. When the controllable load power is greater than zero, decrease the controllable load power in a fixed small step.

4. A real-time power balance control method for a polar multi-energy microgrid according to claim 1, characterized in that: The wind-solar-hydrogen-storage-load system includes multiple groups of wind turbines, multiple groups of PV, multiple groups of fuel cells, two energy storages, and a load. In Scenario 2, it is assumed that energy storage 1 is a balancing power source, and it is necessary to control to make energy storage 1 flexible; When the system power is insufficient in Scenario 2, the control priority is: reducing new energy curtailment > reducing DC power transmission out > reducing the charging output of energy storage 2 > increasing the discharging output of energy storage 2 > increasing DC power reverse transmission > increasing load shedding; When the system power is excessive, the control priority is: reducing load shedding > reducing DC power reverse transmission > reducing the discharging output of energy storage 2 > increasing the charging output of energy storage 2 > increasing DC power transmission out > increasing new energy curtailment.

5. A real-time power balance control method for a polar multi-energy microgrid according to claim 4, characterized in that: The specific control logic of Scenario 2 is as follows: Determine whether the power of energy storage 1 is out of bounds. When neither the charging power nor the discharging power of energy storage 1 is out of bounds, no regulation is performed. When the charging power of energy storage 1 is too large, determine whether the controllable load power is less than the rated power. When the controllable load power is less than the rated power, increase the controllable load power in a fixed small step; when the controllable load power is greater than or equal to the rated power, determine whether the DC bus inverter power is greater than zero and less than the maximum value. When the DC bus inverter power is greater than zero and less than the maximum value, increase the DC bus inverter power in a fixed small step. When the DC bus inverter power is greater than the maximum value or less than zero, determine whether the power of energy storage 2 is out of bounds. When the power of energy storage 2 is not out of bounds, decrease the power of energy storage 2 in a fixed small step. When the power of energy storage 2 is out of bounds, determine whether the DC bus inverter power is less than zero and greater than the minimum value. When the DC bus inverter power is less than zero and greater than the minimum value, decrease the DC bus inverter power in a fixed small step. When the DC bus inverter power is less than the minimum value, determine whether the fan unloading device power is less than the maximum value. When the fan unloading device power is less than the maximum value, increase the fan unloading device set value in a fixed small step. When the fan unloading device power is greater than or equal to the maximum value, then determine whether the PV output power set value is greater than zero. When the PV output power set value is greater than zero, decrease the PV output power set value in a fixed small step. When the PV output power set value is less than or equal to zero, issue an alarm indicating that the control capacity has been exceeded; When the discharge power of energy storage 1 is too large, determine whether the photovoltaic output set value is greater than the rated value. When the photovoltaic output is less than or equal to the rated value, increase the photovoltaic output set value in a fixed small step. When the photovoltaic output set value is greater than the rated value, determine whether the fan unloading device power is greater than zero. When the fan unloading device power is greater than zero, decrease the fan unloading device set value in a fixed small step. When the fan unloading device power is less than or equal to zero, determine whether the DC bus inverter power is less than zero and greater than the minimum value. When the DC bus inverter power is less than zero and greater than the minimum value, decrease the DC bus inverter power in a fixed small step. When the DC bus inverter power is less than the minimum value, determine whether the power of energy storage 2 is out of bounds. When the power of energy storage 2 is not out of bounds, increase the power of energy storage 2 in a fixed small step. When the power of energy storage 2 is out of bounds, determine whether the DC bus inverter power is greater than zero and less than the maximum value. When the DC bus inverter power is greater than zero and less than the maximum value, increase the DC bus inverter power in a fixed small step. When the DC bus inverter power is greater than the maximum value or less than zero, determine whether the controllable load power is greater than zero. When the controllable load power is less than or equal to zero, issue an alarm indicating that the control capacity has been exceeded. When the controllable load power is greater than zero, decrease the controllable load power in a fixed small step.

6. A real-time power balance control method for a polar multi-energy microgrid according to claim 1, characterized in that: The wind-solar-hydrogen energy storage-load system includes multiple groups of wind turbines, multiple groups of photovoltaics, multiple groups of fuel cells, two energy storages and a load. Under scenario 3, both energy storages are set to constant power control, and the AC grid connection line is used as the balance point. Under scenario 3, when the system power is insufficient, the control priority is: reducing new energy curtailment > reducing energy storage charging power > increasing energy storage discharge output > increasing AC bus power supply > increasing load shedding. When the system power is excessive, the control priority is: reducing load shedding > reducing AC bus power supply > reducing energy storage discharge output > increasing energy storage charging power > increasing new energy curtailment.

7. A real-time power balance control method for a polar multi-energy microgrid according to claim 6, characterized in that: The specific control logic of scenario 3 is as follows: Determine whether the AC bus power is out of bounds. When the AC bus power is not out of bounds, no regulation is performed. When the AC bus outgoing power is too large, determine whether the controllable load power is less than the rated power. When the controllable load power is less than the rated power, increase the controllable load power in a fixed small step. When the controllable load power is greater than or equal to the rated power, determine whether the energy storage power is out of bounds. When the energy storage power is not out of bounds, considering SOC balance, decrease the energy storage power in a fixed small step. When the energy storage power is out of bounds, determine whether the fan unloading device power is less than the maximum value. When the fan unloading device power is less than the maximum value, increase the fan unloading device set value in a fixed small step. When the fan unloading device power is greater than or equal to the maximum value, determine whether the photovoltaic output set value is greater than zero. When the photovoltaic output set value is greater than zero, decrease the photovoltaic output set value in a fixed small step. When the photovoltaic output set value is less than or equal to zero, issue an alarm indicating that the control capacity has been exceeded. When the power flowing into the AC bus is too large, judge whether the PV output setting value is greater than the rated value. When the PV output setting value is greater than the rated value, reduce the PV output setting value in a fixed small step. When the PV output setting value is less than or equal to the rated value, judge whether the fan unloading device power is greater than zero. When the fan unloading device power is greater than zero, reduce the fan unloading device setting value in a fixed small step. When the fan unloading device power is less than or equal to zero, judge whether the energy storage power is out of bounds. When the energy storage power is not out of bounds, consider SOC balance and increase the energy storage power in a fixed small step. When the energy storage power is out of bounds, judge whether the controllable load power is greater than zero. When the controllable load power is greater than zero, reduce the controllable load power in a fixed small step. When the controllable load power is less than or equal to zero, issue an alarm for exceeding the control capacity.

8. A real-time power balance control method for a polar multi-energy microgrid according to claim 1, characterized in that: The wind-solar-hydrogen-storage-load system includes multiple groups of wind turbines, multiple groups of PVs, multiple groups of fuel cells, two energy storages and a load. Under scenario 4, both of the two energy storages are under constant power control, and the AC grid connection incoming line is used as the balance point; Under scenario 4, when the system power is insufficient, the control priority is: reducing new energy curtailment > reducing DC power transmission > reducing energy storage charging power > increasing energy storage discharging power > increasing AC bus power > increasing load shedding; When the system power is excessive, the control priority is: reducing load shedding > reducing DC reverse power transmission > reducing AC bus power supply > reducing energy storage discharging power > increasing energy storage charging power > increasing DC power transmission > increasing new energy curtailment.

9. A real-time power balance control method for a polar multi-energy microgrid according to claim 8, characterized in that: The specific control logic of scenario 4 is as follows: Judge whether the AC bus power is out of bounds. When the AC bus power is not out of bounds, no regulation is performed. When the power flowing out of the AC bus is too large, judge whether the controllable load power is less than the rated power. When the controllable load power is less than the rated power, increase the controllable load power in a fixed small step. When the controllable load power is greater than or equal to the rated power, judge whether the DC bus inverter power is greater than zero and less than the maximum value. When the DC bus inverter power is greater than zero and less than the maximum value, increase the DC bus inverter power in a fixed small step. When the DC bus inverter power is less than zero or greater than the maximum value, judge whether the energy storage power is out of bounds. When the energy storage power is not out of bounds, consider SOC balance and reduce the energy storage power in a fixed small step. When the energy storage power is out of bounds, judge whether the DC bus inverter power is less than zero and greater than the minimum value. When the DC bus inverter power is less than zero and greater than the minimum value, reduce the DC bus inverter power in a fixed small step. When the DC bus inverter power is less than the minimum value, judge whether the fan unloading device power is less than the maximum value. When the fan unloading device power is less than the maximum value, increase the fan unloading device setting value in a fixed small step. When the fan unloading device power is greater than or equal to the maximum value, judge whether the PV output setting value is greater than zero. When the PV output setting value is greater than zero, reduce the PV output setting value in a fixed small step. When the PV output setting value is less than or equal to zero, issue an alarm for exceeding the control capacity; When the power flowing into the AC bus is too large, determine whether the PV output set value is greater than the rated value. When the PV output set value is less than or equal to the rated value, increase the PV output set value in a fixed small step. When the PV output set value is less than the rated value, determine whether the fan unloading device power is greater than zero. When the fan unloading device power is greater than zero, decrease the fan unloading device set value in a fixed small step. When the fan unloading device power is less than or equal to zero, determine whether the DC bus inverter power is less than zero and greater than the minimum value. When the DC bus inverter power is less than zero and greater than the minimum value, decrease the DC bus inverter power in a fixed small step. When the DC bus inverter power is less than or equal to the minimum value, determine whether the energy storage power is out of bounds. When the energy storage power is not out of bounds, consider SOC balance and increase the energy storage power in a fixed small step. When the energy storage power is out of bounds, determine whether the DC bus inverter power is greater than zero and less than the maximum value. When the DC bus inverter power is greater than zero and less than the maximum value, increase the DC bus inverter power in a fixed small step. When the DC bus inverter power is less than zero or greater than the maximum value, determine whether the controllable load power is greater than zero. When the controllable load power is less than or equal to zero, issue an alarm indicating that the control capacity has been exceeded. When the controllable load power is greater than zero, decrease the controllable load power in a fixed small step.

10. A computer device, comprising a memory, a processor, and a computer program stored on the memory, characterized in that, The processor executes the computer program to implement the steps of the method according to any one of claims 1-9.

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