A local area network energy router with power management and flexible off-grid connection

Abstract

The present invention discloses a local area network energy router for power management and flexible grid connection and off-grid operation, comprising a flexible switch unit, a control unit, and at least one inverter voltage conversion unit. The control unit is respectively connected to the control end of the flexible switch unit and the control end of each inverter voltage conversion unit. The first end of the flexible switch unit is used to connect to the system side; the second end is simultaneously connected to one end of each inverter voltage conversion unit and is used to connect to the load side; the other end of each inverter voltage conversion unit is respectively used to connect to different energy storage units. When the control unit controls the flexible switch unit to turn on, the system side power supply charges the energy storage unit. After the charging reaches the set value, the thyristor module in the flexible switch unit controls the energy storage unit to maintain the set value; the control unit detects changes in the system side voltage and the load side current, and adjusts the inverter voltage conversion unit as a voltage source or current source to provide voltage or current to the load side according to the detection results, thereby realizing flexible grid connection and off-grid operation and power management.

Description

Technical Field

[0001] The present invention relates to the technical field of energy routers, and in particular to a local area network energy router capable of managing electric energy and being flexibly connected to and off-grid. Background Art

[0002] During the operation of the electric energy Internet, energy routers must reasonably control the flow of backbone energy, strictly control the power supply's voltage transformation, AC / DC conversion, and load to avoid problems during the flow process. Energy routers can also effectively monitor and manage the flow of power. If it is found that the quality of the injected power does not meet the requirements of the Internet supply quality standards, it needs to be adjusted in time to ensure the efficient and stable operation of the entire power Internet.

[0003] When the energy router on the local area network is disconnected from the system side, current quality problems will occur on the system side. Different loads have different requirements for power quality, and the demand for power quality for important loads is increasing. Unstable power supply voltage or frequent start-stops will produce defective products and even cause larger accidents.

[0004] Therefore, how to achieve the adjustment of power quality by energy routers is an urgent problem to be solved. Summary of the Invention

[0005] The purpose of the present invention is to provide a local area network energy router with power management and flexible off-grid connection, which is used to switch between the system side and the energy storage unit. When the voltage on the system side is disturbed, the system side power supply is disconnected, the direct current of the energy storage unit is converted into a first alternating current to power the load side, and the voltage amplitude of the first alternating current is adjusted to meet the load side demand. After the system side voltage is normal, the phase of the first alternating current is adjusted to be consistent with the phase of the system side, and the system side is connected to the load side. At the same time, the current on the system side is gradually increased and the current of the first alternating current is gradually reduced to ensure that the current on the load side is stable. Finally, the system side fully provides power to the load side, reducing the impact on the load side during voltage switching and achieving stable power supply to the load side.

[0006] In the first aspect, the above-mentioned object of the present invention is achieved through the following technical solutions:

[0007] A local area network energy router for electric energy management and flexible grid connection and off-grid operation includes a flexible switch unit, a control unit, and at least one inverter voltage conversion unit. The control unit is connected to the control end of the flexible switch unit and the control end of each inverter voltage conversion unit respectively. The first end of the flexible switch unit is used to connect to the system side; the second end is simultaneously connected to one end of each inverter voltage conversion unit and is used to connect to the load side; the other end of each inverter voltage conversion unit is used to connect to different energy storage units.

[0008] The present invention is further configured as follows: the flexible switch unit includes a thyristor module and a controllable switch module, the controllable switch module and the thyristor module are connected in parallel, and the two parallel points are respectively the two ends of the flexible switch unit.

[0009] The present invention is further configured as follows: the inverter voltage conversion unit includes an inverter module and a voltage conversion module that are interconnected, the inverter module is used for conversion between AC and DC, the voltage conversion module is used for conversion of DC voltage, one end of the inverter module is connected to the second end of the flexible switching unit, and the other end of the voltage conversion module is used to connect to the energy storage unit.

[0010] In a second aspect, the above-mentioned object of the present invention is achieved through the following technical solutions:

[0011] A local area network energy routing control method for power management and flexible grid-connected and off-grid operation is disclosed. When a control unit controls a flexible switch unit to turn on, a system-side power supply charges an energy storage unit through an inverter voltage conversion unit. After the charging reaches a set value, the control unit controls a controllable switch module in the flexible switch unit to turn off, and only controls the energy storage unit to maintain the set value through a thyristor module. The control unit detects changes in system-side voltage and load-side current, and adjusts the inverter voltage conversion unit as a voltage source or current source to provide voltage or current to the load side based on the detection results. When any one of the thyristor module, the inverter voltage conversion unit, or the energy storage unit fails, the control unit controls the controllable switch module to close, and power is provided to the load side from the system side.

[0012] The present invention is further configured as follows: when the system side supplies power to the load side, the control unit detects the load side current; when a current quality problem occurs on the load side, the inverter voltage conversion unit extracts the current characteristics, modulates a qualified current and provides it to the load side, and the inverter voltage conversion unit acts as a current source; the control unit detects the system side voltage, and when a disturbance occurs in the system side voltage, the inverter voltage conversion unit is started, and the inverter voltage conversion unit acts as a voltage source, outputting a qualified voltage to power the load.

[0013] The present invention is further configured such that: the inverter voltage conversion unit extracts current characteristics, and when a harmonic problem is detected, an active power filtering method is used for processing; when a three-phase imbalance is detected, compensation is performed according to the three-phase imbalance degree.

[0014] The present invention is further configured to: calculate harmonics, and perform harmonic compensation when the active power filtering method is turned on; when the active power filtering method is not turned on, perform harmonic restart, and when the restart is successful, enable the harmonics; when the restart is unsuccessful, disable the harmonics.

[0015] The present invention is further configured as follows: when the voltage on the system side is disturbed, it is determined whether compensation is to be performed. When compensation is required, the flexible switching unit is disconnected from the system side, the inverter voltage conversion unit converts DC power into a first AC power to provide power to the load side, adjusts the voltage amplitude of the first AC power, and uses the first AC power to perform voltage compensation on the load side; when it is detected that the voltage on the system side is normal, the first AC power phase parameter of the inverter voltage conversion unit is adjusted to be the same as the AC power phase parameter on the system side, the thyristor module is controlled to be turned on, the system side supplies power to the load side, and charges the energy storage unit; when compensation is not required, exception processing is performed.

[0016] The present invention is further configured as follows: when the voltage disturbance on the system side ends and the system side supplies power to the load side, the control unit controls the inverter voltage conversion unit to operate in a virtual synchronous generator mode, and the current provided by the inverter voltage conversion unit to the load side gradually decreases, while gradually increasing the system side current to ensure the stability of the load side current; finally, the system side provides all the current to the load side, realizing seamless replacement of the system side AC power with the AC power converted from the energy storage end.

[0017] In a third aspect, the above-mentioned object of the present invention is achieved through the following technical solutions:

[0018] A local area network energy router terminal for power management and flexible off-grid operation includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the method described in the present application is implemented.

[0019] Compared with the prior art, the beneficial technical effects of this application are:

[0020] 1. This application detects the current and voltage quality in the line, controls the opening or closing of the flexible switch unit, controls the disconnection or connection between the system side and the energy storage side, and realizes the flexible connection and disconnection of the energy router and the system side;

[0021] 2. Furthermore, the present application adjusts the parameters of the first AC power converted from the energy storage DC power. When the system-side AC power is abnormal, the application switches to the energy storage power supply. When the system-side AC power returns to normal, the parameters of the first AC power converted from the energy storage power supply are adjusted to be the same as the system-side AC parameters, and the application switches to the energy storage power supply. This ensures that the power quality provided to the load is constant.

[0022] 3. Furthermore, the present application detects the quality of the load-side current. When there is a quality problem with the load-side current, the energy router is controlled to compensate the AC power to ensure a stable load-side current.

[0023] 4. Furthermore, after the voltage disturbance on the system side ends, the present application controls the first AC phase to be consistent with the system side AC phase, controls the connection between the system side and the load side, gradually increases the system side current and correspondingly reduces the current provided by the energy storage, and finally realizes the provision of electric energy by the system side, ensures the stability of the load side current, and reduces the impact on the load side during voltage switching. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of the power supply structure of the system side and the load side of a specific embodiment of the present application;

[0025] Figure 2 This is a control flow diagram of a specific embodiment of the present application;

[0026] Figure 3 This is a schematic diagram of a control flow of an energy storage unit as a voltage source in a specific embodiment of the present application;

[0027] Figure 4 This is a schematic diagram of a control flow of an energy storage unit as a current source in a specific embodiment of the present application;

[0028] Figure 5 This is a schematic diagram of the APF operation mode control flow of a specific embodiment of the present application;

[0029] Figure 6 This is a schematic diagram of the DPA operation mode control flow of a specific embodiment of the present application. DETAILED DESCRIPTION

[0030] The present invention will be further described in detail below with reference to the accompanying drawings.

[0031] The present application is a local area network energy router for power management and flexible off-grid connection, which is applied between the system side and the load side, such as Figure 1As shown, it includes a flexible switch unit, a control unit, and N inverter voltage conversion units, where N is a positive integer greater than or equal to 1. The control unit is used to control the opening or closing of the flexible switch unit; to control the inverter voltage conversion unit to charge the energy storage unit, or the energy storage unit to provide electrical energy to the load side; when the system side provides electrical energy to the load side, if the system side voltage is disturbed, it is necessary to compensate the load side, disconnect the system side from the load side, and use the inverter voltage conversion unit as a voltage source to provide electrical energy to the load side. In this process, the output voltage amplitude of the inverter voltage conversion unit is adjusted. After the disturbance ends, the first AC phase of the energy storage end is adjusted to be consistent with the AC phase of the system side, and the system side and the energy storage provide electrical energy to the load at the same time, and gradually increase the current on the system side and correspondingly reduce the current provided by the energy storage end. Finally, the system side provides current to ensure that the load side current is stable; when there is a quality problem with the load side current, the inverter voltage conversion unit is controlled to be a current source to provide electrical energy to the load side.

[0032] The control unit is respectively connected to the control end of the flexible switch unit and the control end of each inverter voltage conversion unit. The first end of the flexible switch unit is used to connect to the system side; the second end is simultaneously connected to the first end and the load side of each inverter voltage conversion unit; the second end of each inverter voltage conversion unit is respectively used to connect to different energy storage units.

[0033] A first switch QF1 is provided between the flexible switch unit and the system side for disconnecting or connecting the flexible switch unit and the system side; a second switch unit QF2 is provided between the flexible switch unit and the load side for disconnecting or connecting the flexible switch unit and the load side.

[0034] The flexible switch unit includes a thyristor module and a controllable switch module QF. The controllable switch module QF is connected in parallel with the thyristor module. The two parallel points are the two ends of the flexible switch unit. The control end of the thyristor module and the control end of the controllable switch module QF are connected to the control unit respectively.

[0035] The inverter voltage conversion unit includes an inverter module AC-DC and a voltage conversion module DC-DC that are interconnected. The inverter module is used for conversion between AC and DC power, and the voltage conversion module is used for conversion of DC voltage. One end of the inverter module is connected to the second end of the flexible switching unit, and the other end of the voltage conversion module is used to connect to the energy storage unit.

[0036] The control unit controls the flexible switch unit to be turned on, that is, when the controllable switch module QF is controlled to be turned off and the thyristor module is turned on, the system side power supply provides power to the load side. At the same time, the system side AC power is converted into DC power through the inverter voltage conversion unit to charge the energy storage unit. After the charging reaches the set value, the control unit controls the switch module to be disconnected, and only controls the energy storage unit to be maintained at the set value through the thyristor module; the control unit detects the changes in the system side voltage and the load side current, and adjusts the inverter voltage conversion unit as a voltage source or current source to provide voltage or current to the load side according to the detection results, thereby realizing power management and flexible grid connection and disconnection.

[0037] When any one of the thyristor module, the inverter voltage conversion unit, and the energy storage unit fails, the control unit controls the controllable switch module QF to be turned on, and the system side provides power to the load side.

[0038] When the control unit detects a voltage disturbance on the system side, which refers to a voltage increase or decrease, the flexible switching unit disconnects from the system side, isolates the system side voltage, and simultaneously controls the inverter voltage conversion unit to convert DC power into a first AC power to provide power to the load side, and adjusts the voltage amplitude of the first AC power to meet the load side requirements. The system side includes the power grid.

[0039] Both the first AC power and the system-side AC power meet the AC power parameters required by the load side. This is just for distinction and does not mean that the parameters of the two are different.

[0040] After the voltage disturbance ends and the voltage on the system side returns to normal, the control unit adjusts the phase value, frequency and other parameters of the first AC power to be the same as the phase value, frequency and other parameters of the system AC power, controls the thyristor module to be turned on, and the system side and the energy storage provide power to the load side at the same time. At the same time, the current provided by the energy storage is gradually reduced, and the current provided by the system side is gradually increased. Finally, the compensation of the energy storage unit is ended, and the system side provides power to the load side, realizing seamless connection between the first AC power and the system side AC power.

[0041] After the energy router is started, the system side charges the energy storage unit. When the charge reaches the set value, it detects whether the AC voltage on the system side is disturbed. If a voltage disturbance occurs, the connection between the system side and the load side is disconnected, and the inverter voltage conversion unit provides power to the load side in the form of a voltage source, while adjusting the voltage amplitude of the first AC power output by the inverter voltage conversion unit; if there is a quality problem with the load side current, the inverter voltage conversion unit compensates the load side power in the form of a current source.

[0042] Specifically, if Figure 2 As shown, the operation of the energy router includes the following steps:

[0043] S1, start;

[0044] S2, initialization;

[0045] S3, the device waits for the start command;

[0046] S4: Is the start command received? If yes, go to the next step. If not, go to S3.

[0047] S5, charging the energy storage unit;

[0048] S6: Is the energy storage voltage ready? If so, go to the next step. If not, go to S5.

[0049] S7, check whether the system side voltage is disturbed, if so, go to the next step, if not, go to S9;

[0050] S8, providing electric energy in energy storage voltage source mode, and then going to S7;

[0051] S9, check whether there is any quality problem with the load side current, if so, proceed to the next step, if not, continue testing;

[0052] S10: Provide electric energy in energy storage current source mode, and then go to S7.

[0053] When the inverter voltage conversion unit provides power in voltage source mode, it detects and modulates the parameters of the output power, including voltage amplitude, phase value, frequency, etc. Phase modulation includes coarse adjustment and fine adjustment.

[0054] When the system-side voltage is disturbed, it detects whether compensation is required. If compensation is required, it initializes parameters and isolates the system side. After confirming the isolation of the system side, it adjusts the voltage amplitude of the first AC output by the inverter voltage conversion unit to meet the voltage requirement of the load side. At the same time, it detects whether the system-side voltage has returned to normal. If the system-side voltage has returned to normal, it tracks the phase of the system-side AC and adjusts the phase of the first AC. When the phase of the first AC is the same as the phase of the system-side AC, it controls the thyristor module to conduct, and the system side and energy storage provide current to the load simultaneously. At the same time, the current provided by the energy storage is gradually reduced, and the current provided by the system side is correspondingly gradually increased. Finally, the energy storage current is disconnected, and the system side provides power to the load side, while the system side charges the energy storage.

[0055] Adjust the phase of the first AC power output by the energy storage. First, perform a coarse phase adjustment. After the coarse adjustment is completed, continue to track the phase and then perform a fine phase adjustment. After the fine adjustment is completed, if the AC phase on the system side is the same as the first AC phase, two methods are used to end the compensation, including gradual termination and one-time termination.

[0056] Gradual termination method: Gradually reduce the first AC current provided by the energy storage, and correspondingly increase the AC current on the system side to ensure a stable current on the load side. Finally, the energy storage current is terminated, and the system side provides all the current to the load side.

[0057] Primary termination method: Directly switch the current provided by the energy storage to the current provided by the system side, ending the power supply on the energy storage side.

[0058] If the voltage disturbance on the system side does not require compensation, exception handling is performed.

[0059] Specifically, when the system side voltage is disturbed, the energy router works, e.g. Figure 3 As shown, the following steps are included:

[0060] A1. Determine whether compensation is prepared. If so, proceed to the next step. If not, go to A4.

[0061] A2. Parameter initialization;

[0062] A3. Enter the system-side isolation mode and go to A1.

[0063] A4. Determine whether to perform system-side isolation. If yes, proceed to the next step. If not, go to A8.

[0064] A5. Conduct isolation and control;

[0065] A6: Determine whether the isolation is complete. If so, proceed to the next step. If not, go to A1.

[0066] A7, enter the voltage regulation mode of the first AC power, go to A1;

[0067] A8, determining whether to adjust the voltage of the first AC power; if so, proceed to the next step; if not, go to A12;

[0068] A9. Adjusting the amplitude of the first AC voltage;

[0069] A10. Check whether the system voltage returns to normal. If so, proceed to the next step. If not, go to A1.

[0070] A11, enter the first-level phase tracking mode, turn to A1;

[0071] A12, determine whether to perform the first-level phase tracking, if yes, go to the next step, if not, go to A16;

[0072] A13, perform phase coarse adjustment;

[0073] A14: Determine whether the coarse adjustment is completed. If so, proceed to the next step. If not, go to A1.

[0074] A15, enter the second-level phase tracking mode, turn to A1;

[0075] A16, determine whether to perform the second-level phase tracking, if yes, go to the next step, if not, go to A20;

[0076] A17, perform phase fine adjustment;

[0077] A18: Determine whether fine-tuning is complete. If so, proceed to the next step. If not, go to A1.

[0078] A19: Compensation completed, go to A21;

[0079] A20, handle exceptions;

[0080] A21, voltage compensation ends.

[0081] When the system voltage is stable, the system detects whether current compensation is required. To address harmonics, an active power filter (APF) is used to suppress harmonics and compensate for reactive power. To address three-phase imbalance, the degree of imbalance is calculated and dynamic power adjustment (DPA) is used for adjustment.

[0082] In another specific embodiment of the present application, it is determined whether it is necessary to operate in a virtual synchronous generator (VSG) mode. When the virtual synchronous generator is not operating in a VSG mode or the system side voltage is not disturbed, it is detected whether current compensation is performed. For harmonic problems, an active power filter is used to handle them, and for three-phase imbalance, dynamic power supply regulation is used to adjust them.

[0083] In the virtual synchronous generator (VSG) mode, the electrical parameters of the first AC power output by the inverter voltage conversion unit are the same as those of the system-side AC power. The current value of the first AC power is gradually reduced, and correspondingly, the current of the system-side AC power is gradually increased to keep the current on the load side stable. Finally, the system side provides power to the load side, the energy storage side is disconnected from the load side, and the system side charges the energy storage.

[0084] Specifically, after the voltage compensation is completed, the energy router works as follows: Figure 4 As shown, the following steps are included:

[0085] B1. Determine whether to enter VSG mode. If not, proceed to the next step. If yes, go to B7.

[0086] B2. Determine whether to enter harmonic compensation mode. If not, proceed to the next step. If yes, go to B6.

[0087] B3. Determine whether to enter the three-phase unbalance adjustment mode. If not, proceed to the next step. If yes, go to B5.

[0088] B4, standby operation, go to B10;

[0089] B5. Run the dynamic power adjustment DPA mode and go to B10;

[0090] B6. Run the active power filter APF mode and go to B10;

[0091] B7, run VSG mode;

[0092] B8. Check whether the VSG mode is running successfully. If yes, go to the next step. If not, go to B7.

[0093] B9, the energy router enters the ready state;

[0094] B10. Check the voltage on the system side.

[0095] After calculating the system-side harmonic components, the system determines whether to enter the active power filter mode. If so, it performs harmonic compensation. After successful compensation, it restarts the APF mode. If the active power filter mode is not required but the APF mode restart is required, it restarts the APF mode. Otherwise, no action is taken. After a successful restart, the APF mode is run. If the restart is unsuccessful, the APF mode is disabled.

[0096] Specifically, the APF operation mode of the energy router, such as Figure 5 As shown, the following steps are included:

[0097] D1, APF operation;

[0098] D2. Calculate harmonics;

[0099] D3, determine whether the APF mode is running, if yes, go to the next step, if not, go to D7;

[0100] D4, perform harmonic compensation;

[0101] D5. Check whether harmonic compensation is successful. If yes, proceed to the next step. If not, go to D4.

[0102] D6, restart APF mode, go to D12;

[0103] D7: Do you want to restart the APF mode? If yes, go to the next step. If not, go to D12.

[0104] D8. Restart APF mode;

[0105] D9: Check whether the restart is successful. If so, go to the next step. If not, go to D11.

[0106] D10, run APF mode, turn to D12;

[0107] D11, prohibit APF mode operation;

[0108] D12. End APF mode.

[0109] After extracting the fundamental wave active power, the three-phase imbalance is calculated, and the maximum compensation capacity of the energy router is calculated to compensate for the three-phase imbalance.

[0110] Specifically, the dynamic power adjustment (DPA) of the energy router, such as Figure 6 As shown, the following steps are included:

[0111] F1, DPA operation;

[0112] F2. Extract fundamental wave active power;

[0113] F3. Calculate the three-phase imbalance;

[0114] F4. Calculate the maximum compensation capacity of the energy router;

[0115] F5, compensation for three-phase imbalance;

[0116] F6, end.

[0117] The energy router of the present application charges the energy storage unit through the energy router when the AC voltage on the system side is normal. When the AC voltage on the system side is disturbed, the energy router uses the AC converted from the energy storage to power the load. After the AC voltage on the system side returns to normal, the energy router seamlessly exits the power supply to the load side, and the system side continues to power the load.

[0118] The Energy Router monitors both system-side voltage and current. If system-side voltage is disturbed and the energy storage system is supplying power, the energy router adjusts the voltage amplitude of the AC power provided by the energy storage system. Once the system-side voltage returns to normal, the phase of the AC power provided by the energy storage system is aligned with the system-side AC phase, and the system-side power supply is switched to the load. If load-side current quality issues are detected, harmonic compensation and three-phase imbalance adjustments are performed, achieving dual monitoring of system-side voltage and current to provide high-quality power to the load.

[0119] The embodiments of this specific implementation method are all preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for controlling local area network energy routing with power management and flexible on-grid and off-grid operation, characterized by: A local area network energy router for power management and flexible grid connection and off-grid connection is provided. The local area network energy router for power management and flexible grid connection and off-grid connection includes a flexible switch unit, a control unit, and at least one inverter voltage conversion unit. The control unit is connected to the control end of the flexible switch unit and the control end of each inverter voltage conversion unit respectively. The first end of the flexible switch unit is used to connect to the system side; the second end is simultaneously connected to one end of each inverter voltage conversion unit and is used to connect to the load side; the other end of each inverter voltage conversion unit is used to connect to different energy storage units. The flexible switch unit includes a thyristor module and a controllable switch module. The controllable switch module and the thyristor module are connected in parallel, and the two parallel points are the two ends of the flexible switch unit respectively. The inverter voltage conversion unit includes an inverter module and a voltage conversion module that are connected to each other. The inverter module is used for converting between AC and DC power, and the voltage conversion module is used for converting DC voltage. One end of the inverter module is connected to the second end of the flexible switch unit, and the other end of the voltage conversion module is used to connect to the energy storage unit. The method for controlling local area network energy routing for power management and flexible grid-connected and off-grid connection includes: when the control unit controls the flexible switch unit to turn on, the system-side power supply charges the energy storage unit through the inverter voltage conversion unit; after the charging reaches a set value, the control unit controls the controllable switch module in the flexible switch unit to turn off, and only controls the energy storage unit to maintain the set value through the thyristor module; the control unit detects changes in the system-side voltage and the load-side current, and adjusts the inverter voltage conversion unit as a voltage source or current source to provide voltage or current to the load side according to the detection results; when any one of the thyristor module, the inverter voltage conversion unit, and the energy storage unit fails, the control unit controls the controllable switch module to close, and the system side provides power to the load side; When the system side supplies power to the load side, the control unit detects the load side current. When there is a current quality problem on the load side, the inverter voltage conversion unit extracts the current characteristics and modulates a qualified current to provide to the load side. The inverter voltage conversion unit acts as a current source. The control unit detects the system side voltage. When the system side voltage is disturbed, the inverter voltage conversion unit is started. The inverter voltage conversion unit acts as a voltage source and outputs a qualified voltage to power the load. When the voltage on the system side is disturbed, it is determined whether compensation is to be performed. When compensation is required, the flexible switch unit is disconnected from the system side, and the inverter voltage conversion unit converts DC power into a first AC power to provide power to the load side, adjusts the voltage amplitude of the first AC power, and uses the first AC power to perform voltage compensation on the load side; when it is detected that the voltage on the system side is normal, the first AC power phase parameter of the inverter voltage conversion unit is adjusted to be the same as the AC power phase parameter on the system side, the thyristor module is controlled to be turned on, the system side supplies power to the load side, and the energy storage unit is charged; when compensation is not required, abnormal processing is performed.

2. The method for controlling local area network energy routing for power management and flexible on-grid and off-grid operation according to claim 1, characterized in that: The inverter voltage conversion unit extracts current characteristics and uses active power filtering to process harmonic problems when they are detected; when three-phase imbalance is detected, compensation is performed according to the degree of three-phase imbalance.

3. The method for controlling local area network energy routing for power management and flexible on-grid and off-grid operation according to claim 2, characterized in that: Calculate harmonics and perform harmonic compensation when the active power filtering method is turned on; when the active power filtering method is not turned on, perform harmonic restart, and when the restart is successful, enable harmonics; when the restart is unsuccessful, disable harmonics.

4. A method for controlling local area network energy routing for power management and flexible on-grid and off-grid operation according to claim 1 or 3, characterized in that: When the voltage disturbance on the system side ends and the system side supplies power to the load side, the control unit controls the inverter voltage conversion unit to operate in virtual synchronous generator mode. The current provided to the load side by the inverter voltage conversion unit gradually decreases, while gradually increasing the system side current to ensure the stability of the load side current. Finally, the system side provides all the current to the load side, realizing seamless replacement of the system side AC power with the AC power converted from the energy storage end.

5. A local area network energy router terminal for power management and flexible off-grid operation, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the method according to any one of claims 1 to 4 is implemented.

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