Distributed coordination control method applied to AC / DC hybrid multi-microgrid system of building group, storage medium and equipment

Abstract

The invention discloses a distributed coordination control method applied to an AC-DC hybrid multi-microgrid system of a building group, a storage medium and equipment, and the method comprises the steps: obtaining a real-time charge state and a charge-discharge mode of each energy storage unit in the AC-DC hybrid multi-microgrid system, and dynamically adjusting a droop coefficient of the energy storage unit, calculating the actual output active power of the energy storage unit; calculating an output active power reference value of the energy storage unit according to the voltage fluctuation of the common DC bus; the deviation between the actual output active power of the energy storage unit and the output active power reference value is calculated, a current loop control instruction is generated through PI adjustment, a PWM signal for driving a bidirectional AC-DC converter or a bidirectional DC-DC converter in the AC-DC hybrid multi-microgrid system is generated, the charging and discharging current of the energy storage unit is dynamically adjusted, and the energy storage unit is controlled. And the stability and the operation efficiency of the alternating-current and direct-current hybrid multi-microgrid system are improved.

Description

Technical Field

[0001] This invention belongs to the field of building energy technology, specifically relating to a distributed coordinated control method, storage medium, and device for an AC / DC hybrid multi-microgrid system applied to building complexes. Background Technology

[0002] With the acceleration of urbanization and the advancement of "dual carbon" goals, the transformation of energy consumption in the building sector is crucial. Modern building complexes have gradually evolved from single energy consumers into prosumers integrating photovoltaics, small-scale wind power, energy storage systems, and diverse loads. However, the power supply and distribution systems of traditional building complexes are mainly designed based on industrial frequency AC power, which exposes significant limitations when facing distributed power sources that generate DC power, such as photovoltaic panels, and a large number of increasingly common DC loads such as LED lighting, servers, electric vehicle charging stations, and variable frequency air conditioners.

[0003] Traditional pure AC microgrid architecture is the mainstream solution for current building complex energy systems. In this architecture, DC photovoltaic power generated by the building itself needs to be converted to AC by an inverter and fed into the microgrid. However, to power numerous DC loads, the AC power must be converted back to DC by a rectifier. This multiple "DC-AC-DC" conversion process inevitably leads to energy loss, with each conversion resulting in an efficiency loss of approximately 2%-5%, thus reducing the overall energy efficiency of the building complex energy system. Conversely, while a pure DC microgrid architecture can efficiently match DC loads, it is difficult to accommodate the large number of existing traditional AC loads within the building complex, such as induction motors, conventional lighting, and the mains AC power grid, thus limiting the flexibility and scalability of the building complex energy system.

[0004] Meanwhile, to mitigate the intermittency of distributed power sources and the volatility of loads, energy storage units have become an indispensable component of building cluster energy systems. Existing technologies mostly employ fixed-parameter droop control to proportionally distribute power among parallel energy storage units. However, this control method has significant drawbacks: it fails to consider the differences in the individual states of each energy storage unit, particularly their State of Charge (SOC). Under the complex and variable operating conditions of building clusters, some energy storage units may reach their SOC limits before others due to prolonged heavy loads, forcing them to shut down. This not only shortens the lifespan of the energy storage units but also shifts their power burden to the remaining units, potentially triggering cascading failures and seriously threatening the reliability of the system's power supply. Current solutions lack preventative control mechanisms for flexible power limiting before the SOC exceeds its limit.

[0005] Furthermore, compared to traditional large power grids, building cluster microgrids have lower system inertia, especially the DC microgrid bus, which lacks the physical characteristics of rotational inertia similar to AC systems. When frequent switching of high-power loads or drastic fluctuations in distributed power output occur within the building cluster, the response speed of the fixed-parameter control system is limited, easily causing severe fluctuations or even instantaneous collapse of the DC bus voltage. This transient voltage instability can seriously affect the normal operation of sensitive DC loads and also poses a challenge to the safe operation of power electronic converters. Existing technologies typically suppress voltage fluctuations by increasing bus capacitance or improving controller bandwidth, but this increases hardware costs and may introduce stability risks. Summary of the Invention

[0006] To address the problems existing in the prior art, this invention provides a distributed coordinated control method, storage medium, and device for AC / DC hybrid multi-microgrid systems applied to building complexes. By adopting an AC / DC hybrid multi-microgrid system, it adapts to the energy structure characteristics of building complexes and, combined with distributed coordinated control, improves the operating efficiency and stability of the AC / DC hybrid multi-microgrid system.

[0007] To achieve the above technical objectives, the present invention adopts the following technical solution:

[0008] A distributed coordinated control method for an AC / DC hybrid multi-microgrid system applied to a building complex is described below: Deploy a hybrid AC / DC microgrid system on the building complex, including at least one DC microgrid and at least one AC microgrid connected in parallel on a common DC bus; The real-time state of charge and charging / discharging mode of each energy storage unit in the AC / DC hybrid microgrid system are obtained, and the droop coefficient of the DC microgrid or AC microgrid to which the energy storage unit belongs is dynamically adjusted. The actual output active power of the energy storage unit in the AC microgrid is calculated based on the droop factor of the AC microgrid, and the actual output active power of the energy storage unit in the DC microgrid is calculated based on the droop factor of the DC microgrid. Based on the voltage fluctuation of the common DC bus, the reference values ​​of the output active power of the energy storage unit in the AC microgrid and the reference values ​​of the output active power of the energy storage unit in the DC microgrid are calculated respectively. The deviation between the actual output active power of the energy storage unit in the AC microgrid and the reference value of the output active power is calculated. The current loop control command of the AC microgrid is generated by PI regulation, and the PWM signal driving the bidirectional AC-DC converter in the AC microgrid is generated to dynamically adjust the charging and discharging current of the energy storage unit in the AC microgrid. The deviation between the actual output active power of the energy storage unit in the DC microgrid and the reference value of the output active power is calculated. The current loop control command of the DC microgrid is generated by PI regulation, and the PWM signal driving the bidirectional DC-DC converter in the DC microgrid is generated to dynamically adjust the charging and discharging current of the energy storage unit in the DC microgrid.

[0009] Furthermore, the DC microgrid includes: a DC distributed power source, a DC load, an energy storage unit, a boost converter, a buck-boost converter, and a bidirectional DC-DC converter. The DC load is connected to the DC bus, the DC distributed power source is connected to the DC bus through the boost converter, and the energy storage unit is connected to the DC bus through the buck-boost converter. The DC bus is connected to the common DC bus through the bidirectional DC-DC converter.

[0010] Furthermore, the AC microgrid includes: AC distributed power sources, AC loads, energy storage units, power-type AC-DC converters, and bidirectional AC-DC converters. The AC loads are connected to the AC bus, and the AC distributed power sources and energy storage units are both connected to the AC bus via power-type AC-DC converters. The AC bus is connected to a common DC bus via bidirectional AC-DC converters.

[0011] Furthermore, the adjustment process for the droop coefficient of the DC microgrid or AC microgrid to which the energy storage unit belongs is as follows: When the real-time state of charge of the energy storage unit Within normal working range At that time, the droop coefficient of the DC microgrid or AC microgrid to which the energy storage unit belongs. The initial droop coefficient is set. ; When the energy storage unit is in a charging state and the real-time state of charge of the energy storage unit satisfies At that time, the droop coefficient of the DC microgrid or AC microgrid to which the energy storage unit belongs. Adjusted to:

[0012] When the energy storage unit is in a discharging state and the real-time state of charge of the energy storage unit satisfies At that time, the droop coefficient of the DC microgrid or AC microgrid to which the energy storage unit belongs. Adjusted to:

[0013] in, This indicates the upper limit of the real-time state of charge. This represents the lower limit of the allowable real-time state of charge.

[0014] Furthermore, the actual output active power of the energy storage unit in the AC microgrid The calculation process is as follows:

[0015] in, This represents the active power output of the energy storage unit in an AC microgrid under rated conditions. Indicates the frequency rating of the AC microgrid. This represents the actual frequency value of the AC microgrid. This represents the droop factor of an AC microgrid.

[0016] Furthermore, the actual output active power of the energy storage unit in the DC microgrid The calculation process is as follows:

[0017] in, This represents the active power output of the energy storage unit in a DC microgrid under rated conditions. This indicates the rated value of the DC bus voltage in a DC microgrid. This represents the actual value of the DC bus voltage in a DC microgrid. This represents the droop coefficient of a DC microgrid.

[0018] Furthermore, the reference value of the output active power of the energy storage unit in the AC microgrid The calculation process is as follows:

[0019] in, This represents the active power output of the energy storage unit in an AC microgrid under rated conditions. This represents the capacitance of the bidirectional AC-DC converter on the common DC bus side in an AC microgrid. Indicates the frequency rating of the AC microgrid. Represents the virtual inertia coefficient. This indicates the rated capacity of the bidirectional AC-DC converter. This represents the droop factor of an AC microgrid. Indicates the rated voltage of the common DC bus. This indicates the actual voltage of the common DC bus.

[0020] Furthermore, the reference value of the output active power of the energy storage unit in the DC microgrid The calculation process is as follows:

[0021] in, This represents the active power output of the energy storage unit in a DC microgrid under rated conditions. This indicates the rated value of the DC bus voltage in a DC microgrid. This represents the capacitance of the bidirectional DC-DC converter on the common DC bus side in a DC microgrid. This represents the capacitance of the bidirectional DC-DC converter on the DC microgrid side in a DC microgrid. This represents the droop factor of a DC microgrid. Indicates the rated voltage of the common DC bus. This indicates the actual voltage of the common DC bus.

[0022] Furthermore, the present invention also provides a computer-readable storage medium storing a computer program that causes a computer to execute the distributed coordinated control method for an AC / DC hybrid microgrid system applied to a building complex.

[0023] Furthermore, the present invention also provides an electronic device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, it implements the distributed coordinated control method for an AC / DC hybrid microgrid system applied to a building complex.

[0024] Compared with the prior art, the present invention has the following beneficial effects: (1) The distributed coordinated control method of the present invention applied to the AC / DC hybrid multi-microgrid system of building complex adopts the AC / DC hybrid multi-microgrid system, which can match the increasing DC source load in the building complex, reduce unnecessary AC / DC conversion links, and thus improve the overall energy utilization efficiency of the AC / DC hybrid multi-microgrid system. (2) The distributed coordination control method of the present invention applied to the AC / DC hybrid multi-microgrid system of building complex dynamically and autonomously adjusts the droop coefficient of the DC microgrid or AC microgrid to which the energy storage unit belongs based on the real-time charge state of each energy storage unit. While effectively preventing overcharging and over-discharging of the energy storage unit and extending its service life, it realizes intelligent on-demand power allocation within the AC / DC hybrid multi-microgrid system, enhances the autonomous adjustment capability and operational reliability of the AC / DC hybrid multi-microgrid system in response to random fluctuations in distributed power sources and loads, and does not require real-time communication across microgrids. (3) The distributed coordinated control method of the present invention applied to the AC / DC hybrid multi-microgrid system of the building complex calculates the reference value of the output active power of the energy storage unit based on the voltage fluctuation of the common DC bus, and uses the voltage of the common DC bus as the unified power balance signal of the AC / DC hybrid multi-microgrid system, so that the energy storage units distributed in each AC / DC microgrid in the building complex can quickly and collaboratively respond to the overall power change of the AC / DC hybrid multi-microgrid system, realize seamless power mutual assistance and autonomous coordination between cross-type microgrids, and greatly improve the overall operational stability and dynamic response speed of the building complex integrated energy system; (4) The distributed coordinated control method of the present invention applied to the AC-DC hybrid multi-microgrid system of building complexes generates PWM signals to drive bidirectional AC-DC converters and bidirectional DC-DC converters based on the deviation between the actual output active power of the energy storage unit and the reference value of the output active power. By generating PWM drive through real-time power closed-loop control, it can ensure that the bidirectional AC-DC converter and bidirectional DC-DC converter can quickly and accurately track the reference value of the output active power of the energy storage unit. Thus, when the load of the building complex fluctuates frequently or the output of the distributed power source changes, it can achieve accurate power allocation and rapid balance, effectively maintain the stability of the bus voltage and AC frequency of each microgrid in the AC-DC hybrid multi-microgrid system, and improve power quality. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the topology of the AC / DC hybrid multi-microgrid system in this invention; Figure 2 This is a flowchart of the distributed coordinated control method of the present invention applied to an AC / DC hybrid multi-microgrid system in a building complex; Figure 3 This is a schematic diagram of the control strategy for the bidirectional AC-DC converter in this invention; Figure 4 This is a schematic diagram of the control strategy for the bidirectional DC-DC converter in this invention; Figure 5 This is a schematic diagram illustrating the effect of the distributed coordinated control method of the present invention on the AC / DC hybrid multi-microgrid system in an embodiment. Figure 5 (a) in the figure is the DC bus voltage waveform of MG1. Figure 5 (b) in the diagram shows the power waveform of the bidirectional DC-DC converter MG1. Figure 5 (c) in the diagram shows the DC bus voltage waveform of MG2. Figure 5 In the diagram, (d) shows the power waveform of the bidirectional DC-DC converter of MG2. Figure 5 In the diagram, (e) shows the AC bus frequency waveform of MG3. Figure 5 In the diagram, (f) shows the power waveform of the bidirectional AC-DC converter of MG3. Figure 5 (g) in the figure represents the waveform of the common DC bus voltage. Detailed Implementation

[0026] The technical solution of the present invention will be further explained and described below with reference to the accompanying drawings.

[0027] Deploying AC / DC hybrid microgrid systems on building complexes, such as Figure 1 The system comprises at least one DC microgrid and at least one AC microgrid connected in parallel to a common DC bus. The DC microgrid includes: DC distributed generation (DGs), DC loads, energy storage units, a boost converter, a buck-boost converter, and a bidirectional DC-DC converter. The DC loads are connected to the DC bus, the DC DGs are connected to the DC bus via the boost converter, the energy storage units are connected to the DC bus via the buck-boost converter, and the DC bus is connected to the common DC bus via the bidirectional DC-DC converter. The AC microgrid includes: AC distributed generation (DGs), AC loads, energy storage units, a power-type AC-DC converter, and a bidirectional AC-DC converter. The AC loads are connected to the AC bus, and both the AC DGs and the energy storage units are connected to the AC bus via the power-type AC-DC converter. The AC bus is connected to the common DC bus via the bidirectional AC-DC converter. This hybrid AC / DC multi-microgrid system can match the increasing DC loads within building complexes, reduce unnecessary AC / DC conversion steps, and improve the overall energy efficiency of the DC hybrid multi-microgrid system.

[0028] When power fluctuations occur within a microgrid, the energy storage units in the AC / DC hybrid multi-microgrid system absorb the unbalanced power. This requires coordinated control among the multiple microgrids in the AC / DC hybrid multi-microgrid system. One microgrid can be considered as one system, while the other microgrids connected in parallel to the common DC bus are equivalent to another system. The AC / DC hybrid multi-microgrid system can be simplified into a structure of two interconnected systems. The common DC bus of the two systems always has the same voltage level. Therefore, the energy storage units in each microgrid can be considered as equivalently connected in parallel. Thus, by setting an appropriate droop factor, the power of each energy storage unit can be distributed according to its rated capacity.

[0029] like Figure 2 This invention provides a distributed coordinated control method for an AC / DC hybrid multi-microgrid system applied to building complexes, the specific process of which is as follows: This system acquires the real-time state of charge and charging / discharging mode of each energy storage unit in an AC / DC hybrid microgrid system, dynamically adjusts the droop coefficient of the DC or AC microgrid to which the energy storage unit belongs, and prevents overcharging or over-discharging of the energy storage unit. This significantly extends the service life of the energy storage unit and improves the operational reliability of the AC / DC hybrid microgrid system under complex and variable loads in building clusters, without relying on real-time communication across microgrids. Specifically: When the real-time state of charge of the energy storage unit Within normal working range At that time, the droop coefficient of the DC or AC microgrid to which the energy storage unit belongs. The initial droop coefficient is set. ; When the energy storage unit is in a charging state and the real-time state of charge of the energy storage unit satisfies At that time, the droop coefficient of the DC or AC microgrid to which the energy storage unit belongs. Adjustments were made to limit the charging power of the energy storage unit by increasing the droop factor:

[0030] When the energy storage unit is in a discharging state and the real-time state of charge of the energy storage unit satisfies At that time, the droop coefficient of the DC or AC microgrid to which the energy storage unit belongs. Adjustments were made to limit the discharge power of the energy storage unit by increasing the droop factor:

[0031] in, This indicates the upper limit of the real-time state of charge. This represents the lower limit of the allowable real-time state of charge.

[0032] Adjusting the droop coefficient of each microgrid in the aforementioned AC / DC hybrid microgrid system can prevent the energy storage unit from prematurely exiting operation and impacting the AC / DC hybrid microgrid system. This is achieved when the real-time state of charge... When approaching the charge / discharge limit, the charging and discharging power of the energy storage unit is restricted. This adaptive droop coefficient adjustment strategy based on SOC achieves a balance between power regulation and equipment protection in the AC / DC hybrid multi-microgrid system while ensuring the safety of the energy storage unit. It is an intelligent control method that combines economy, safety, and reliability.

[0033] Calculate the actual output active power of the energy storage unit in the AC microgrid based on the droop factor. :

[0034] in, This represents the active power output of the energy storage unit in an AC microgrid under rated conditions. Indicates the frequency rating of the AC microgrid. This represents the actual frequency value of the AC microgrid. This represents the droop factor of an AC microgrid.

[0035] Calculate the actual output active power of the energy storage unit in the DC microgrid based on the droop factor. :

[0036] in, This represents the active power output of the energy storage unit in a DC microgrid under rated conditions. This indicates the rated value of the DC bus voltage in a DC microgrid. This represents the actual value of the DC bus voltage in a DC microgrid. This represents the droop coefficient of a DC microgrid.

[0037] For hybrid AC / DC microgrid systems, the capacity and scale are larger than those of a single microgrid during operation, and the system has stronger anti-interference capabilities when power disturbances occur. Furthermore, it can improve resource utilization. When a microgrid has excess active power that it cannot absorb, to avoid wind and solar power curtailment, the excess power can be received by other microgrids through a common DC bus, thus achieving rational power dispatch. The active power balance of each microgrid can be directly determined through the voltage of the common DC bus. Therefore, based on the voltage fluctuation of the common DC bus, the reference values ​​of the output active power of energy storage units in AC microgrids and DC microgrids can be calculated separately. Using the common DC bus voltage as a unified coordination signal for the power balance of the hybrid AC / DC microgrid system, autonomous power coordination across AC / DC boundaries is achieved. This scheme uniformly maps the overall power surplus or shortage state of the hybrid AC / DC microgrid system to a small offset in the voltage of the common DC bus. Each microgrid's energy storage unit only needs to detect this voltage locally to adaptively adjust its output through the corresponding control law. There is no need to lay complex interconnection communication between microgrids. At the same time, it ensures the speed and consistency of power exchange between AC and DC heterogeneous networks, and greatly improves the overall autonomy, dynamic response speed and structural reliability of AC-DC hybrid multi-microgrid systems in the face of random fluctuations and faults.

[0038] The calculation process for the reference value of the output active power of the energy storage unit in the AC microgrid of this invention is as follows: An AC microgrid exchanges energy with a common DC bus via a bidirectional AC-DC converter. The AC side frequency and DC side voltage satisfy the following relationship:

[0039] in, Represents the virtual inertia coefficient. This indicates the rated capacity of the bidirectional AC-DC converter. Indicates the frequency rating of the AC microgrid. This represents the capacitance of the bidirectional AC-DC converter on the common DC bus side in an AC microgrid. This indicates the actual voltage of the common DC bus; Integrating the above equation and simplifying it using Taylor expansion, we get:

[0040] in, Indicates the rated voltage of the common DC bus; Because the active power output of energy storage units in an AC microgrid depends on The drooping characteristics include:

[0041] Combining the two formulas above, we can convert them into the corresponding droop formula for common DC bus voltage fluctuations:

[0042] in, This refers to the reference value of the output active power of the energy storage unit in the AC microgrid. This represents the droop coefficient of an AC microgrid. .

[0043] The calculation process for the reference value of the output active power of the energy storage unit in the DC microgrid of this invention is as follows: A DC microgrid exchanges energy with a common DC bus through a bidirectional DC-DC converter, and the DC voltages on both sides of the converter satisfy the following relationship:

[0044] in, This represents the capacitance of the bidirectional DC-DC converter on the common DC bus side in a DC microgrid. This represents the capacitance of the bidirectional DC-DC converter on the DC microgrid side in a DC microgrid. This indicates the actual voltage of the common DC bus; Since the active power output of energy storage units in a DC microgrid depends on P - U The drooping characteristics include:

[0045] Combining the two formulas above, and through simplification and Taylor expansion, we can obtain the corresponding droop formula when converting to common DC bus voltage fluctuations:

[0046] in, This refers to the reference value of the output active power of the energy storage unit in a DC microgrid. Indicates the rated voltage of the common DC bus. This represents the droop-like coefficient of a DC microgrid. .

[0047] The deviation between the actual output active power of the energy storage unit in the AC microgrid and the reference value of the output active power is calculated. The current loop control command of the AC microgrid is generated by PI regulation, and the PWM signal driving the bidirectional AC-DC converter in the AC microgrid is generated to dynamically adjust the charging and discharging current of the energy storage unit in the AC microgrid.

[0048] The deviation between the actual output active power of the energy storage unit in the DC microgrid and the reference value of the output active power is calculated. The current loop control command of the DC microgrid is generated by PI regulation, and the PWM signal driving the bidirectional DC-DC converter in the DC microgrid is generated to dynamically adjust the charging and discharging current of the energy storage unit in the DC microgrid.

[0049] This invention generates PWM signals to drive bidirectional AC-DC converters and bidirectional DC-DC converters, and generates PWM drives through real-time power closed-loop control. This ensures that the bidirectional AC-DC converters and bidirectional DC-DC converters can quickly and accurately track the output active power reference value of the energy storage unit. Thus, when the load of the building complex fluctuates frequently or the output of distributed power sources changes, it can achieve accurate power distribution and rapid balancing, effectively maintain the stability of the bus voltage and AC frequency of each microgrid in the AC / DC hybrid microgrid system, and improve power quality.

[0050] In one technical solution of the present invention, such as Figure 3 The control strategy for the bidirectional AC-DC converter is as follows: The positive direction is defined as active power flowing from the common DC bus side into the AC microgrid side. Under normal operation, the actual output active power of the energy storage unit in the AC microgrid should be equal to the reference value of the output active power. Therefore, the deviation between the actual output active power of the energy storage unit in the AC microgrid and the reference value of the output active power is calculated, and a preliminary d-axis current loop control command component is output after PI regulation. ; To reduce the frequency overshoot of the AC microgrid during power fluctuations, feedforward control of the frequency deviation is introduced:

[0051] in, Indicating frequency deviation d Shaft current loop control command components. This represents the frequency adjustment feedforward coefficient. express d Voltage component of the shaft current loop; The d-axis current loop control command component of the frequency deviation With the initial d-axis current loop control command components The values ​​are superimposed and together constitute the reference value for the d-axis current loop control command. ; Reference value of reactive power output of energy storage unit in AC microgrid With actual output reactive power The deviation is adjusted by a PI controller to output the q-axis current reference value for reactive power control. ; Set the d-axis current loop control command reference value d-axis current q-axis current reference value and q-axis current The input current loop controller generates a PWM signal to drive the bidirectional AC-DC converter in the AC microgrid, dynamically adjusting the charging and discharging current of the energy storage unit in the AC microgrid.

[0052] In one technical solution of the present invention, such as Figure 4 The control strategy for the bidirectional DC-DC converter is as follows: The positive direction is defined as active power flowing from the common DC bus side to the DC microgrid side. Under normal operation, the actual output active power of the energy storage unit in the DC microgrid should be equal to the reference value of the output active power. Therefore, the deviation between the actual output active power of the energy storage unit in the DC microgrid and the reference value of the output active power is calculated, and a preliminary current loop control command component is output after PI regulation. ; To reduce the overshoot of the DC microgrid voltage during power fluctuations, feedforward control of the DC voltage change rate is introduced:

[0053] in, This represents the current loop control command component under the DC voltage change rate. Represents complex frequency. Represents the time constant. This represents the voltage regulation feedforward coefficient; The current loop control command component under the DC voltage change rate With the initial current loop control command component These values ​​are superimposed to form the final inductor current reference value. ; The final inductor current reference value The actual inductor current of the energy storage unit in the DC microgrid The difference is generated and, through PI regulation, a PWM signal is produced to drive the bidirectional DC-DC converter in the DC microgrid, dynamically adjusting the charging and discharging current of the energy storage unit in the DC microgrid.

[0054] This invention relates to a distributed coordinated control method for AC / DC hybrid multi-microgrid systems in building complexes. This method employs adaptive droop control based on the state of charge (SOC) of the energy storage units within each microgrid. The droop coefficient is dynamically adjusted according to the SOC value, automatically limiting charging and discharging power while maintaining stable bus voltage or frequency to prevent overcharging and over-discharging of the energy storage. In this AC / DC hybrid multi-microgrid system, each microgrid can autonomously adjust its power and achieve power sharing with adjacent microgrids using only locally measured voltage or frequency information, without the need for an upper-level controller or high-speed communication. This distributed coordinated control method can achieve reasonable power allocation and rapid balancing under various operating conditions, effectively restoring the voltage and frequency of each microgrid, and improving the stability, economy, and power quality of the AC / DC hybrid multi-microgrid system. It is particularly suitable for building complex scenarios, improving energy utilization efficiency, system stability, and reliability.

[0055] Example The AC / DC hybrid microgrid system used in this embodiment includes two DC microgrids MG1 and MG2 and one AC microgrid MG3. Taking DC microgrid MG1 as an example, MG1 is equivalent to system 1, and DC microgrid MG2 and AC microgrid MG3 are equivalent to system 2. The voltage of the bus of system 1 can characterize the active power balance of the microgrid, and the voltage of the bus of system 2 can be used to determine the active power balance of system 2.

[0056] Under stable operating conditions, the bus voltages of System 1 and System 2 should have the same voltage level, and the system is in a dynamic equilibrium state. At this time, no wind or solar power curtailment or load shedding will occur in any of the microgrids.

[0057] 1) When system 1 experiences an active power deficit, its bus voltage decreases. At this time, the active power flowing from system 2 to system 1 should be increased or the active power flowing from system 1 to system 2 should be decreased until a new steady state is reached. 2) When the active power of system 1 is excessive, the bus voltage rises. At this time, the active power flowing from system 1 to system 2 should be increased or the active power flowing from system 2 to system 1 should be decreased until a new steady state is reached. 3) When system 2 experiences an active power deficit, the voltage of the common DC bus decreases. At this time, the active power flowing from system 1 to system 2 should be increased or the active power flowing from system 2 to system 1 should be decreased until a new steady state is reached. 4) When the active power of system 2 is excessive, the voltage of the common DC bus increases. At this time, the active power flowing from system 2 to system 1 should be increased or the active power flowing from system 1 to system 2 should be decreased until a new stable state is reached.

[0058] To verify the rationality of the distributed coordinated control method of this invention applied to AC / DC hybrid multi-microgrid systems in building complexes, the energy storage units configured in each microgrid are assumed to have the same parameters and a rated active power of 50kW. Then, when the energy storage unit's... satisfy At that time, the output power of each energy storage unit is the same. Let , , , , The rated voltage of the common DC bus is 800V, the rated voltage of the DC microgrid MG1 and MG2 buses is 400V, the rated frequency of the AC microgrid MG3 is 50Hz, the initial droop factor of the DC microgrid is 0.4V / kW, and the initial droop factor of the AC microgrid is 0.004Hz / kW.

[0059] When the AC / DC hybrid microgrid system starts operating, it operates stably at rated conditions during the period t < 1s, at which time the output power of each energy storage unit is 0. When t = 1s, the load changes within each microgrid are as follows: the DC load P of MG1... L1 Increase the DC load P of MG2 by 20kW L2 Reduce the AC load P of MG3 by 10kW L3 Adding 20kW results in power deficits for MG1 and MG3, while MG2 has excess power. The overall AC / DC hybrid microgrid system suffers from a power deficit. After adjustment using the distributed coordinated control method of this invention, as shown... Figure 5 As shown in (b), (d), and (f), the power flowing into each microgrid from the common DC bus is 10kW, -20kW, and 10kW, respectively, and the output power of each microgrid energy storage unit is 10kW. Figure 5 As shown in (a), (c), (e), and (g), the DC bus voltage of MG1 is 396V, the DC bus voltage of MG2 is 396V, the AC bus frequency of MG3 is 49.96Hz, and the common DC bus voltage is 792V. When t=3s, the DC load P of MG1... L1 Reduce the DC load P of MG2 by 10kW L2 Reduce the AC load P of MG3 by 10kW L3 Reducing the power by 30kW results in a power deficit in MG1, while MG2 and MG3 have excess power, leading to overall power excess in the AC / DC hybrid multi-microgrid system. This can be addressed by adjusting the system using the distributed coordinated control method of this invention. Figure 5 As shown in (b), (d), and (f), the power flowing into each microgrid from the common DC bus is 16.67kW, -13.33kW, and -3.33kW, respectively, and the output power of each microgrid energy storage unit is -6.67kW. Figure 5As shown in (a), (c), (e), and (g), the DC bus voltage of MG1 is 402.5V, the DC bus voltage of MG2 is 402.5V, the AC bus frequency of MG3 is 50.025Hz, and the common DC bus voltage is 805V. When t=5s, the DC load P of MG1... L1 Add 5kW, DC load P of MG2 L2 Add 10kW to the AC load P of MG3 L3 Adding 5kW results in a power deficit in MG1, an excess in MG2 and MG3, and an overall DGs output power equal to the load's required power in the AC / DC hybrid multi-microgrid system. After reaching a new steady state... Figure 5 As shown in (b), (d), and (f), the power flowing into each microgrid from the common DC bus is 15kW, -10kW, and -5kW, respectively, and the output power of each microgrid energy storage unit is 0. Figure 5 As shown in (a), (c), (e) and (g), the DC bus voltage of MG1 is 400V, the DC bus voltage of MG2 is 400V, the AC bus frequency of MG3 is 50Hz, and the common DC bus voltage is 800V. This control strategy realizes the coordinated operation of multiple microgrids.

[0060] In one embodiment of the present invention, a computer-readable storage medium is also provided, storing a computer program that enables a computer to execute the distributed coordinated control method of the present invention applied to an AC / DC hybrid microgrid system in a building complex.

[0061] In one technical solution of the present invention, an electronic device is also provided, including: a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the distributed coordinated control method of the present invention applied to an AC / DC hybrid multi-microgrid system in a building complex.

[0062] In the embodiments disclosed in this application, a computer storage medium may be a tangible medium that may contain or store programs for use by or in conjunction with an instruction execution system, apparatus, or device. The computer storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. More specific examples of computer storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, and portable compact disc read-only memory (CD). ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0063] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed in this application can be implemented in electronic hardware or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0064] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should be considered within the scope of protection of the present invention.

Claims

1. A distributed coordinated control method for an AC / DC hybrid multi-microgrid system applied to a building complex, characterized in that, The specific process is as follows: Deploy a hybrid AC / DC microgrid system on the building complex, including at least one DC microgrid and at least one AC microgrid connected in parallel on a common DC bus; The real-time state of charge and charging / discharging mode of each energy storage unit in the AC / DC hybrid microgrid system are obtained, and the droop coefficient of the DC microgrid or AC microgrid to which the energy storage unit belongs is dynamically adjusted. The actual output active power of the energy storage unit in the AC microgrid is calculated based on the droop factor of the AC microgrid, and the actual output active power of the energy storage unit in the DC microgrid is calculated based on the droop factor of the DC microgrid. Based on the voltage fluctuation of the common DC bus, the reference values ​​of the output active power of the energy storage unit in the AC microgrid and the reference values ​​of the output active power of the energy storage unit in the DC microgrid are calculated respectively. The deviation between the actual output active power of the energy storage unit in the AC microgrid and the reference value of the output active power is calculated. The current loop control command of the AC microgrid is generated by PI regulation, and the PWM signal driving the bidirectional AC-DC converter in the AC microgrid is generated to dynamically adjust the charging and discharging current of the energy storage unit in the AC microgrid. The deviation between the actual output active power of the energy storage unit in the DC microgrid and the reference value of the output active power is calculated. The current loop control command of the DC microgrid is generated by PI regulation, and the PWM signal driving the bidirectional DC-DC converter in the DC microgrid is generated to dynamically adjust the charging and discharging current of the energy storage unit in the DC microgrid.

2. The distributed coordinated control method for an AC / DC hybrid multi-microgrid system applied to a building complex according to claim 1, characterized in that, The DC microgrid includes: DC distributed power sources, DC loads, energy storage units, boost converters, buck-boost converters, and bidirectional DC-DC converters. The DC loads are connected to the DC bus, the DC distributed power sources are connected to the DC bus via boost converters, and the energy storage units are connected to the DC bus via buck-boost converters. The DC bus is connected to a common DC bus via bidirectional DC-DC converters.

3. The distributed coordinated control method for an AC / DC hybrid multi-microgrid system applied to a building complex according to claim 1, characterized in that, The AC microgrid includes: AC distributed power sources, AC loads, energy storage units, power-type AC-DC converters, and bidirectional AC-DC converters. The AC loads are connected to the AC bus. The AC distributed power sources and energy storage units are both connected to the AC bus via power-type AC-DC converters. The AC bus is connected to a common DC bus via bidirectional AC-DC converters.

4. The distributed coordinated control method for an AC / DC hybrid multi-microgrid system applied to a building complex according to claim 1, characterized in that, The adjustment process for the droop coefficient of the DC or AC microgrid to which the energy storage unit belongs is as follows: When the real-time state of charge of the energy storage unit Within normal working range At that time, the droop coefficient of the DC microgrid or AC microgrid to which the energy storage unit belongs. The initial droop coefficient is set. ; When the energy storage unit is in a charging state and the real-time state of charge of the energy storage unit satisfies At that time, the droop coefficient of the DC microgrid or AC microgrid to which the energy storage unit belongs. Adjusted to: When the energy storage unit is in a discharging state and the real-time state of charge of the energy storage unit satisfies At that time, the droop coefficient of the DC microgrid or AC microgrid to which the energy storage unit belongs. Adjusted to: in, This indicates the upper limit of the real-time state of charge. This represents the lower limit of the allowable real-time state of charge.

5. The distributed coordinated control method for an AC / DC hybrid multi-microgrid system applied to a building complex according to claim 1, characterized in that, The actual output active power of the energy storage unit in the AC microgrid The calculation process is as follows: in, This represents the active power output of the energy storage unit in an AC microgrid under rated conditions. Indicates the frequency rating of the AC microgrid. This represents the actual frequency value of the AC microgrid. This represents the droop factor of an AC microgrid.

6. The distributed coordinated control method for an AC / DC hybrid multi-microgrid system applied to a building complex according to claim 1, characterized in that, The actual output active power of the energy storage unit in the DC microgrid The calculation process is as follows: in, This represents the active power output of the energy storage unit in a DC microgrid under rated conditions. This indicates the rated value of the DC bus voltage in a DC microgrid. This represents the actual value of the DC bus voltage in a DC microgrid. This represents the droop coefficient of a DC microgrid.

7. The distributed coordinated control method for an AC / DC hybrid multi-microgrid system applied to a building complex according to claim 1, characterized in that, The reference value of the output active power of the energy storage unit in the AC microgrid The calculation process is as follows: in, This represents the active power output of the energy storage unit in an AC microgrid under rated conditions. This represents the capacitance of the bidirectional AC-DC converter on the common DC bus side in an AC microgrid. Indicates the frequency rating of the AC microgrid. Represents the virtual inertia coefficient. This indicates the rated capacity of the bidirectional AC-DC converter. This represents the droop factor of an AC microgrid. Indicates the rated voltage of the common DC bus. This indicates the actual voltage of the common DC bus.

8. The distributed coordinated control method for an AC / DC hybrid multi-microgrid system applied to a building complex according to claim 1, characterized in that, Reference value of active power output of energy storage unit in the DC microgrid The calculation process is as follows: in, This represents the active power output of the energy storage unit in a DC microgrid under rated conditions. This indicates the rated value of the DC bus voltage in a DC microgrid. This represents the capacitance of the bidirectional DC-DC converter on the common DC bus side in a DC microgrid. This represents the capacitance of the bidirectional DC-DC converter on the DC microgrid side in a DC microgrid. This represents the droop factor of a DC microgrid. Indicates the rated voltage of the common DC bus. This indicates the actual voltage of the common DC bus.

9. A computer-readable storage medium storing a computer program, characterized in that, The computer program causes the computer to execute the distributed coordinated control method for an AC / DC hybrid microgrid system applied to a building complex as described in any one of claims 1-8.

10. An electronic device, characterized in that, include: The system includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the computer program, implements the distributed coordinated control method for an AC / DC hybrid microgrid system applied to a building complex as described in any one of claims 1-8.

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