Micro-grid energy-saving system

Abstract

The invention provides a micro-grid energy-saving system, and relates to the technical field of power system energy saving. The system comprises an electromagnetic balance treatment device which realizes three-phase current balance adjustment, reactive power dynamic compensation and harmonic filtering through an electromagnetic induction principle; the intelligent control unit comprises a multifunctional electric power meter, a temperature sensor and a central processing unit, and is used for collecting electrical parameters and temperature data in real time and automatically adjusting the running state of the system according to a preset algorithm; the Internet of Things monitoring platform is connected with the intelligent control unit in a wireless communication mode to realize remote monitoring and data uploading; and the micro-grid cooperation interface is used for performing power interaction with the distributed energy power generation equipment and the energy storage device. Power quality treatment is realized through a pure electromagnetic structure, the problems of complexity and potential harmonic waves of power electronic devices are avoided, comprehensive perception and accurate adjustment of the power grid state are realized by combining intelligent control and the Internet of Things technology, the system efficiency is remarkably improved, and the equipment loss is reduced.

Description

Technical Field

[0001] This invention relates to the field of power system energy-saving technology, and specifically to a microgrid energy-saving system. Background Technology

[0002] With the continuous growth of energy demand and the increasing awareness of environmental protection, energy conservation and consumption reduction in the power system have become the focus of development. As an important component of the power system, the stability of low-voltage distribution has a significant impact on the load and operational stability of the power system. The problems existing in the low-voltage distribution terminal grid are mainly concentrated in the following aspects: large reactive power, large harmonics, phase load imbalance, voltage fluctuation and insufficient reactive power compensation. Specifically, these manifest as excessively long power supply radius, large equipment losses, and significant voltage fluctuations.

[0003] Currently, various power quality management devices are available on the market. Traditional reactive power compensation devices primarily improve the power factor by switching capacitor banks; active power filters eliminate harmonics by generating a compensation current opposite to the harmonic current using power electronic devices; static var generators achieve rapid reactive power compensation using fully controlled power electronic devices; and voltage regulators stabilize output voltage through transformer tap switching or power electronic conversion. These devices improve power quality to a certain extent and support the stable operation of the power system.

[0004] However, power quality problems still exist in low-voltage distribution network terminals, making it difficult to improve system efficiency, and equipment losses continue, making it impossible to achieve stable operation in economically viable operating areas. Summary of the Invention

[0005] This invention provides a microgrid energy-saving system that can solve problems such as high reactive power, harmonic pollution, phase load imbalance, and voltage fluctuations in low-voltage distribution network terminals, thereby improving system efficiency and reducing equipment losses. To achieve the above objectives, this invention provides the following technical solution:

[0006] This invention provides a microgrid energy-saving system, comprising:

[0007] The electromagnetic balance control device achieves three-phase current balance regulation, dynamic reactive power compensation, and harmonic filtering through the principle of electromagnetic induction.

[0008] The intelligent control unit includes a multi-functional power meter, a temperature sensor, and a central processing unit, which is used to collect electrical parameters and temperature data in real time and automatically adjust the system operating status according to a preset algorithm;

[0009] The IoT monitoring platform connects to the intelligent control unit via wireless communication to achieve remote monitoring and data uploading;

[0010] The microgrid coordination interface is used for power interaction with distributed energy generation equipment and energy storage devices.

[0011] As a further embodiment of the present invention, the electromagnetic balance control device includes: a main winding connected in series with the three-phase power grid lines to sense the three-phase current imbalance state; a control winding that adjusts the current to change the magnetic saturation of the iron core, thereby achieving dynamic adjustment of the equivalent reactance value; and a voltage regulating circuit that controls the switching of the contactor through a time relay and an intermediate relay to achieve graded adjustment of the output voltage.

[0012] As a further embodiment of the present invention, the electromagnetic balance control device has three operating modes: mains power operation mode, joint operation mode, and power saving operation mode. In the mains power operation mode, the bypass contactor is engaged, and the load is directly powered by the mains power. In the joint operation mode, the mains power contactor and the power saving contactor are engaged simultaneously, and the mains power and the power saving device operate in parallel. In the power saving operation mode, only the power saving contactor is engaged, and the load is fully powered by the power saving device.

[0013] As a further aspect of the present invention, the power-saving operation mode includes manual gear adjustment and automatic intelligent adjustment; manual gear adjustment is achieved by selecting three gears through a gear switch, each corresponding to a different output voltage; automatic intelligent adjustment is achieved by collecting parameters of the multi-function meter in real time through an IoT platform all-in-one machine, and automatically switching gears according to the results of logical operations.

[0014] As a further aspect of the present invention, the multi-functional power meter of the intelligent control unit collects three-phase voltage, three-phase current, active power, reactive power, apparent power, power factor, frequency and harmonic content parameters in real time; the temperature sensor is arranged in the key heat-generating parts inside the device cabinet, and the temperature signal is converted into a 4-20mA current signal and sent to the central processing unit through an analog transmitter.

[0015] As a further aspect of the present invention, the central processing unit employs a deep reinforcement learning algorithm for dynamic optimization control, predicting load change trends based on historical operating data and real-time collected parameters, thereby achieving forward-looking adaptive control.

[0016] As a further embodiment of the present invention, the IoT monitoring platform includes a data storage module, a communication module, and a cloud platform display module. The data storage module is used to store historical data of system operation, and the cloud platform display module is used to display automatic status, gear switching status, temperature parameters, and energy-saving effect.

[0017] As a further aspect of the present invention, the microgrid collaborative interface includes: a distributed photovoltaic power generation interface for connecting a photovoltaic inverter to achieve grid connection of photovoltaic power generation; a wind power generation interface for connecting a wind turbine generator set; and an energy storage system interface for connecting a lithium-ion battery or supercapacitor energy storage device.

[0018] As a further aspect of the present invention, the energy storage system interface supports bidirectional power flow, performs peak shaving and valley filling when the grid voltage fluctuates, stores energy when there is a surplus of new energy power generation, and discharges power supply when the load demand is at its peak.

[0019] As a further aspect of the present invention, the system also includes a harmonic filter module and a surge suppression module. The harmonic filter module filters out the 3rd, 5th, 7th, and 9th harmonics. The surge suppression module uses an MOV varistor and an electromagnetic absorption network to suppress voltage spikes and transient overvoltages.

[0020] The beneficial effects of this invention are as follows:

[0021] 1. The electromagnetic balance control device of this invention achieves three-phase current balance regulation, dynamic reactive power compensation, and harmonic filtering through the principle of electromagnetic induction. It effectively solves the problems of three-phase load imbalance, high reactive power, and harmonic pollution in low-voltage distribution network terminals, avoiding secondary harmonic pollution that may be caused by traditional power electronic devices and improving system reliability. The intelligent control unit includes a multi-functional power meter, a temperature sensor, and a central processing unit, used to collect electrical parameters and temperature data in real time, and automatically adjust the system operating state according to a preset algorithm. This achieves comprehensive perception and precise control of the power grid state, ensuring that the system always operates in an economically efficient range.

[0022] 2. This invention utilizes an IoT monitoring platform to connect with the intelligent control unit via wireless communication, enabling remote monitoring and data uploading. This allows maintenance personnel to monitor system operation anytime, anywhere, promptly identify potential problems, and reduce maintenance costs. Furthermore, the microgrid collaboration interface facilitates power interaction with distributed energy generation equipment and energy storage devices, enhancing system compatibility with new energy equipment, promoting the efficient utilization of renewable energy, and improving the overall stability and economy of the microgrid. This design not only improves power quality but also significantly reduces line and equipment losses and extends the lifespan of electrical equipment through dynamic optimization of system parameters.

[0023] 3. This invention achieves efficient, stable, and economical operation of low-voltage distribution terminal power grids, solving the problems of difficulty in improving system efficiency and persistent equipment losses in existing technologies. The innovation of this invention lies in the organic integration of power quality management using a purely electromagnetic structure with intelligent control, IoT monitoring, and microgrid collaboration, forming a comprehensive, reliable, and efficient microgrid energy-saving solution with significant technical advantages and application value. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a system module connection diagram in an embodiment of the present invention;

[0026] Figure 2 This is a circuit diagram of a three-stage switching circuit in an embodiment of the present invention;

[0027] Figure 3 This is a schematic diagram of the switching process in an embodiment of the present invention;

[0028] Figure 4 This is a schematic diagram of cabinet temperature detection in an embodiment of the present invention. Detailed Implementation

[0029] Low-voltage distribution network terminals suffer from various power quality issues during operation, leading to low system efficiency and equipment losses. Typical problems include: high reactive power, resulting in increased line losses and a decreased power factor; severe harmonic pollution, especially the 3rd, 5th, 7th, and 9th harmonics interfering with the normal operation of sensitive equipment; three-phase load imbalance causing abnormal increases in neutral current, voltage fluctuations, and additional copper losses; voltage fluctuations and insufficient dynamic reactive power compensation capabilities, exacerbating power quality degradation; excessively long power supply radius leading to low voltage at the terminal equipment; inductive loads (such as motors, transformers, and lighting ballasts) experiencing accelerated temperature rise, increased iron and copper losses, and accelerated insulation aging under low power factor and high harmonic environments; and random power fluctuations after the integration of distributed photovoltaic, wind power, and other new energy sources, further deteriorating microgrid voltage stability and power flow controllability. These problems collectively cause the distribution network load to deviate from the economic operating range for extended periods, resulting in low overall energy efficiency and continuously rising operation and maintenance costs.

[0030] like Figure 1 As shown in the system module connection diagram, this embodiment of the invention provides a microgrid energy-saving system, including:

[0031] The electromagnetic balance control device achieves three-phase current balance regulation, dynamic reactive power compensation, and harmonic filtering through the principle of electromagnetic induction.

[0032] The intelligent control unit includes a multi-functional power meter, a temperature sensor, and a central processing unit, which is used to collect electrical parameters and temperature data in real time and automatically adjust the system operating status according to a preset algorithm.

[0033] The Internet of Things (IoT) monitoring platform connects to the intelligent control unit via wireless communication to achieve remote monitoring and data uploading.

[0034] And a microgrid collaboration interface, which is used to interact with distributed energy generation equipment and energy storage devices for power exchange.

[0035] This embodiment provides a microgrid energy-saving system for the end of a low-voltage distribution network. Its core lies in using a purely electromagnetic physical mechanism as the underlying support, integrating multi-source sensing, edge decision-making, and a cloud-edge collaborative architecture to construct a composite energy-saving device with proactive power quality management capabilities and microgrid-level energy dispatch capabilities. This system does not rely on power electronic switching devices for active compensation, avoiding high-frequency switching losses, electromagnetic interference, and device lifespan bottlenecks. It is suitable for scenarios with high inductive load density, such as commercial buildings, government agencies, and data centers, where reliability, electromagnetic compatibility, and maintenance-free operation are crucial. The system completes basic power quality correction through an electromagnetic balance management device, achieves local closed-loop response through an intelligent control unit, extends the management boundary through an IoT monitoring platform, and expands the system's functional dimensions through a microgrid collaborative interface, forming a four-layer technical closed loop of "sensing—analysis—regulation—collaboration."

[0036] The electromagnetic balance control device is the physical execution entity for the system to achieve power quality control. Essentially, it is an electromagnetic coupling device based on the nonlinear characteristics of the iron core's magnetic circuit. It does not contain semiconductor switching elements such as IGBTs or MOSFETs, but consists only of a main winding, a control winding, and a voltage regulation circuit. It relies on the law of electromagnetic induction and magnetic saturation effect to achieve three-phase current redistribution, reactive power cancellation, and impedance matching filtering of specific frequency harmonics. This device can use a silicon steel sheet laminated iron core or an amorphous alloy strip wound iron core. The rated current of the main winding covers the range of 200A–2500A, and the turns ratio design meets the output voltage regulation margin under an input voltage of 380V±15%. Alternative solutions include using a combination of an air-core reactor and an LC series resonant branch to achieve harmonic filtering, or using a magnetic valve-type controllable reactor to replace the control winding for continuous stepless adjustment. However, this embodiment allows for the selection of an electromagnetic structure to balance response speed, robustness, and maintenance-free operation.

[0037] Through the above technical solutions, this invention achieves three-phase imbalance suppression, local reactive power compensation, and characteristic harmonic absorption by utilizing the inherent physical characteristics of electromagnetic induction without introducing high-frequency switching devices. Relying on a multi-dimensional sensing layer composed of multi-functional instruments and temperature sensors, combined with the local real-time response capability of the embedded processor, it ensures millisecond-level adaptability to conditions such as load surges and voltage drops. By leveraging an IoT platform to connect local devices with a remote operation and maintenance center, it makes the power quality management process visible, traceable, and diagnosable. Furthermore, by reserving access capabilities for new energy and energy storage devices through a standardized microgrid collaborative interface, it provides a physical foundation for subsequent system upgrades and functional expansion.

[0038] Because the electromagnetic balance control device eliminates the need for resonant capacitors and switching devices, it avoids the risks of resonant instability and device aging failure. The intelligent control unit employs deterministic real-time algorithms rather than training-dependent models, ensuring verifiable and reproducible control logic. The IoT platform utilizes lightweight communication protocols and local caching mechanisms to guarantee basic monitoring functions in weak network environments. The microgrid collaborative interface maintains protocol openness and electrical isolation design, ensuring compatibility with new energy equipment from different manufacturers. Therefore, this embodiment effectively alleviates technical problems such as high reactive power, severe harmonic pollution, three-phase imbalance, and significant voltage fluctuations at the end of low-voltage power distribution lines, achieving comprehensive technical effects including improved power quality, reduced line losses, suppressed equipment temperature rise, improved power factor, and convenient system operation and maintenance.

[0039] The electromagnetic balance control device includes: a main winding, which is connected in series with the three-phase power grid lines to sense the three-phase current imbalance; a control winding, which adjusts the current to change the magnetic saturation of the iron core, thereby dynamically adjusting the equivalent reactance value; and a voltage regulating circuit, which controls the switching of the contactor through time relays and intermediate relays to achieve graded adjustment of the output voltage.

[0040] The electromagnetic balance management device involved in this embodiment is characterized by a purely electromagnetic structure, which does not rely on power electronic switching devices. This avoids problems such as high-frequency harmonic injection, switching losses, and reliability degradation. It provides stable, continuous, and low-disturbance management of power quality at the end of the distribution network, and is particularly suitable for low-voltage distribution scenarios with significant three-phase load imbalance, high proportion of inductive reactive power, and dense harmonic sources (such as industrial plants, data centers, and commercial complexes). Through a three-level coordinated structure of main winding—control winding—voltage regulating circuit, the device completes a closed-loop response from state sensing and magnetic circuit control to voltage output without the need for an external DC power supply or complex drive circuit.

[0041] The main winding consists of three independently wound hollow or silicon steel sheet-framed copper coils, connected in series to the A, B, and C phase input circuits respectively. Each phase winding has the same number of turns, and the conductor cross-sectional area is designed with a 1.2-fold margin based on the rated current, typically 50–120 turns / phase, with a wire diameter of 2.5–6 mm². Its function is not to provide an energy transmission path, but rather to act as a highly sensitive magnetic flux coupling sensor, converting the instantaneous values ​​of the three-phase currents into corresponding magnetomotive forces. This causes the composite magnetic flux vector in the iron core to shift with the amplitude and phase differences of the three-phase currents, thereby generating a identifiable unbalance signal on the auxiliary detection winding or Hall core. This structure differs from conventional current transformers, emphasizing the rigid series connection between the windings and the main circuit, as well as the shared magnetic circuit characteristics, ensuring zero-delay and zero-additional impedance sensing of the actual load current. As an optional embodiment, the main winding can also adopt a Rogowski coil structure, which is wound on a flexible PCB substrate to adapt to irregular busbar installation. The current waveform is restored through an integrator circuit, still satisfying the functional definitions of "series connection" and "sensing unbalanced state".

[0042] The control winding is an independent excitation winding wound on the same closed iron core (such as a toroidal amorphous alloy or ultra-thin oriented silicon steel laminations). It is spatially orthogonal to the main winding or arranged at a specific angle, with 300–800 turns. It is driven by a 0–10V analog voltage or a 4–20mA current signal output from the central processing unit after power amplification. Its core mechanism is that when a DC or low-frequency AC excitation current is applied to the control winding, the magnetization curve position of the iron core's operating point is changed, causing it to locally enter the deep saturation region, thereby significantly reducing the permeability of that branch, which is equivalent to increasing the series impedance—that is, achieving continuous and stepless adjustment of the system's equivalent reactance. This adjustment process does not introduce harmonic current, and the response time is in the millisecond range (typical value ≤20ms), which can offset reactive power fluctuations caused by sudden load changes in real time. As an optional embodiment, the control winding can also be replaced with a multi-tap DC excitation winding, which, in conjunction with a solid-state relay, switches between different number of turns to adjust the saturation depth in a stepwise manner, reducing the complexity of the drive circuit while balancing response speed and control accuracy.

[0043] The voltage regulation circuit is a mechanical voltage regulation module based on electromagnetic relay logic, containing at least three sets of output taps (corresponding to three adjustment levels), three contactors (3KC, 4KC, 5KC), two time relays (1ST, 2ST), and three intermediate relays (KA1, KA2, KA3). The time relays are set with an action delay of 100–500ms to avoid accidental switching caused by instantaneous impacts. The intermediate relays receive the level command signal from the intelligent control unit and output a drive signal to the corresponding contactor coil through interlocking logic. The rated current of the contactor main contacts is not less than 1.5 times the maximum load current of the system, and silver alloy contacts are used to ensure lifespan during frequent switching. This circuit achieves step adjustment of the output voltage (e.g., three levels: 390V / 384V / 378V) by switching different tap access points of the main winding or auxiliary voltage regulating winding. It is a stepped adjustment, but because it complements the stepless magnetic saturation adjustment of the control winding, the whole circuit constitutes a "coarse adjustment + fine adjustment" composite mechanism. The contactor in the voltage regulation circuit can also be replaced with a vacuum contactor or a solid-state relay (SSR). The latter is suitable for higher frequency regulation requirements, but a heat dissipation module and a zero-crossing trigger circuit must be configured simultaneously to suppress switching surges.

[0044] The main winding, acting as a front-end sensing element, outputs an unbalanced magnetomotive force signal which, after conditioning, is sent to the central processing unit to trigger a control winding current adjustment command. The magnetic saturation change of the control winding directly affects the inductive reactance response characteristics of the iron core to the main circuit current, achieving continuous cancellation of reactive and harmonic components. Meanwhile, the voltage regulation circuit calibrates the system voltage reference on a larger scale. The two work together to enable the device to cope with rapid transient disturbances (by the control winding) and adapt to steady-state load shifts (by the voltage regulation circuit). All three share the same iron core magnetic circuit and magnetic flux path, avoiding parameter drift and response delay caused by multi-circuit coupling.

[0045] Through the above technical solution, under the premise of using only electromagnetic structure and completely avoiding power electronic conversion links, the three-phase current imbalance state is perceived in real time with high fidelity (relying on the series connection of the main winding), and the equivalent impedance characteristics of the system are dynamically reconstructed accordingly (relying on the precise control of the core magnetic saturation by the control winding). At the same time, safe and reliable output voltage graded correction is achieved by combining mechanical contactor switching (relying on the time-logic-execution three-level control architecture of the voltage regulation circuit). Therefore, it solves the key problems mentioned in the background technology, such as "voltage fluctuation and additional loss caused by three-phase load imbalance", "increased line loss due to large reactive power", and "lack of effective dynamic compensation mechanism affecting power supply quality", and achieves the technical effects of improving power factor, suppressing neutral line current, reducing transformer and line temperature rise, and extending equipment service life. This solution is particularly suitable for microgrid scenarios such as medical, precision manufacturing and communication infrastructure with strict electromagnetic compatibility requirements and where the introduction of high-frequency harmonics is not allowed.

[0046] Example 2:

[0047] Based on the above embodiments, this embodiment further provides:

[0048] The electromagnetic balance control device has three operating modes: mains power operation mode, joint operation mode, and power saving operation mode. In mains power operation mode, the bypass contactor is engaged, and the load is directly powered by the mains power. In joint operation mode, the mains power contactor and the power saving contactor are engaged simultaneously, and the mains power and the power saving device operate in parallel. In power saving operation mode, only the power saving contactor is engaged, and the load is fully powered by the power saving device.

[0049] This embodiment focuses on the operation mode switching mechanism of the electromagnetic balance control device. It achieves dynamic reconfiguration of the power path through contactor combination logic, maximizing energy-saving benefits while ensuring power supply continuity. Its core lies in constructing three physically isolated and functionally complementary power supply topologies based on a purely electromagnetic structure and relying on the coordinated switching of three sets of mechanical contactors: a direct mains power supply path, a parallel mains power and energy-saving device path, and an independent power supply path for the energy-saving device. This design does not rely on power electronic switching devices, avoiding high-frequency switching losses and electromagnetic interference. It possesses high reliability, long lifespan, and strong anti-interference capabilities, making it suitable for industrial and public building scenarios with stringent power supply continuity requirements.

[0050] Mains operation mode refers to the system directly connecting the load end to the mains bus through a single closed action of the bypass contactor (IKC). In this mode, the main winding, control winding, and voltage regulation circuit of the electromagnetic balance device are all in an open circuit or de-energized state and do not participate in energy conversion or parameter adjustment. This mode is used for equipment maintenance, fault isolation, or to ensure uninterrupted power supply under extreme conditions. Its essence is to "transparently" shut down the energy-saving system. The bypass contactor can adopt a double-break structure and be configured with auxiliary contact feedback signals to the intelligent control unit to confirm the physical closure status of the bypass path in real time. Alternatively, it can be replaced with a hybrid bypass switch composed of solid-state relays and mechanical contactors, which improves the action response speed while maintaining high current resistance.

[0051] The co-operation mode refers to the synchronous engagement of the mains contactor (IKC) and the energy-saving contactor (2KC), connecting the mains line and the output of the electromagnetic balance device in parallel to the same load bus. In this state, the mains power bears the basic load power, while the electromagnetic balance device dynamically injects compensation voltage components to collaboratively complete three-phase current balance regulation, dynamic reactive power compensation, and harmonic filtering. There is no circulating current risk between the two power sources. Because the output side of the electromagnetic balance device has the characteristics of a controlled voltage source, its equivalent internal resistance is much higher than the short-circuit impedance of the mains system, naturally forming a master-slave relationship in power distribution. A voltage difference detection circuit can be added between the mains contactor and the energy-saving contactor. When the voltage difference between the two ends exceeds a set threshold (such as ±5V), the closing command is delayed and blocked to prevent asynchronous grid connection impact. Alternatively, the mains contactor can be replaced with an intelligent contactor with phase recognition function, which automatically closes the circuit based on the mains phase angle to further suppress transient inrush current.

[0052] The energy-saving operation mode refers to the situation where only the energy-saving contactor (2KC) is engaged, while the mains contactor (IKC) and bypass contactor (IKC) are both in the open state, and the load is powered entirely by the electromagnetic balance control device. In this mode, the device operates in a closed-loop regulation state. The main winding continuously senses the three-phase current imbalance and dynamically changes the core magnetic saturation level according to the adjustment instructions output by the central processing unit, thereby regulating the equivalent reactance value. This, combined with the voltage regulation circuit, achieves stepped optimization of the output voltage (e.g., 390V / 384V / 378V). In this mode, the system has active voltage support capability, effectively compensating for line voltage drop, raising the terminal voltage, and improving the operating conditions of inductive loads. As an optional implementation, the energy-saving contactor can integrate an arc detection module to identify microsecond-level arcs at the moment of contact separation and trigger rapid arc extinguishing; alternatively, a vacuum contactor can be used to replace the conventional air contactor, improving electrical life and insulation reliability under frequent switching conditions.

[0053] The switching between the three operating modes mentioned above depends on the physical position selection of the rotary switch (1SA) and is driven by a hard-wired logic circuit to energize the corresponding contactor coil. An interlocking mechanism is implemented between each mode: for example, when 1SA is in the "bypass" position, its normally closed contacts cut off the power supply to the control circuits of IKC and 2KC; when 1SA is in the "intermediate" position, its two independent sets of contacts connect the IKC and 2KC coil circuits respectively; when 1SA is in the "power saving" position, only the 2KC coil circuit is connected. This mechanical interlocking structure ensures that at any given time, only a maximum of two contactors may be engaged simultaneously, eliminating the risk of short circuits caused by common or incorrect combinations of the three. The timing of each contactor's operation follows the principle of "break first, then close," meaning that during mode switching, the original path contactor is opened first, and the target path contactor closes after a set delay (e.g., 50ms), avoiding instantaneous power outages or grid connection impacts.

[0054] Through the above technical solutions, a multi-mode power path switching mechanism based on contactor combination logic is constructed to address the technical contradiction of balancing power supply continuity and energy-saving benefits in low-voltage distribution terminal microgrids. When the system is in mains power operation mode, the bypass contactor is engaged and the load is directly connected to the mains power, thus completely avoiding the effects of the energy-saving device's own losses and potential faults. This solves the problems of "high equipment losses" and "low power supply reliability" in the background technology, ensuring operation and maintenance safety and the continuity of power supply for users. When the system is in joint operation mode, the mains contactor and the energy-saving contactor are engaged simultaneously, and the mains power and the energy-saving device operate in parallel. Therefore, electromagnetic compensation function can be introduced without interrupting the power supply, solving the problems of "high reactive power," "harmonic pollution," and "phase load imbalance" in the background technology, and realizing a gradual improvement in power quality. When the system is in energy-saving operation mode, only the energy-saving contactor is engaged, and the load is completely powered by the energy-saving device. Therefore, the voltage optimization and dynamic compensation capabilities of the electromagnetic balance treatment device can be fully utilized, solving the problems of "low equipment terminal voltage due to excessively long power supply radius" and "intensified inductive load losses," making the distribution network load approach the economic operating range. The three modes are directly mapped through physical switches, resulting in rapid response, clear logic, and strong fault tolerance, which significantly improves the operational flexibility and engineering applicability of the microgrid energy-saving system.

[0055] Example 3:

[0056] Based on the above embodiments, this embodiment further provides:

[0057] like Figure 3 As shown, the power-saving operation mode includes manual gear adjustment and automatic intelligent adjustment; manual gear adjustment is achieved by selecting three gears via a gear switch, each corresponding to a different output voltage; automatic intelligent adjustment is achieved by collecting parameters from the multi-function meter in real time through the IoT platform all-in-one machine and automatically switching gears based on the logical operation results.

[0058] The energy-saving operation mode is the core control strategy of the electromagnetic balance control device when the load is entirely powered by the energy-saving device. Its essence lies in achieving precise, reliable, and adaptive adjustment of the output voltage. This mode covers different application scenarios through a dual-path approach of manual and automatic control: manual adjustment is for fixed loads, commissioning phases, or offline conditions such as communication failures, providing deterministic and low-dependency voltage step control; automatic intelligent adjustment is for dynamic loads, changing operating conditions, and remote maintenance needs, relying on data-driven closed-loop optimization. Together, they constitute a redundant and controllable voltage regulation system, ensuring that the system maintains a balance between power quality and energy-saving benefits under different operating boundaries.

[0059] like Figure 2The three-position switching circuit diagram shown uses a rotary mechanical position switch (SA1) as the human-machine interface for manual position adjustment. Its contact groups correspond one-to-one with the three independent switching branches. Each position corresponds to a preset voltage regulation circuit output value. For example: Position 1 output voltage is 390V±2V, suitable for light-load steady-state conditions, balancing equipment start-up margin and line voltage drop compensation; Position 2 output voltage is 384V±2V, the normal economic operating point, suitable for inductive loads under medium load rates (60%–85%); Position 3 output voltage is 378V±2V, used for heavy-load continuous operation or high-temperature environments, reducing core magnetic flux density and copper losses through appropriate voltage reduction. The rated current of the position switch is not less than 10A, and the mechanical life is ≥10 years. 5 Second-rate.

[0060] In this embodiment, the mechanical position of the gear switch (SA1) directly determines the physical connection topology of the voltage regulation circuit, forming the hardware foundation for voltage regulation; the IoT platform integrated machine (YTJ) serves as the decision layer for the automatic path, with its input coming from the full-dimensional electrical parameters of the multi-function meter (PD) and its output acting on the contactor actuator, forming a closed-loop regulation chain; while the "manual / automatic" mode selection itself is controlled by another independent rotary switch (2SA), whose contact state is monitored in real time by the YTJ and used as a control strategy enable flag—this structure ensures that the two regulation paths are completely decoupled at the electrical and logical levels, and the failure of either path does not affect the functional integrity of the other path.

[0061] The above technical solution achieves dual redundancy and hierarchical adaptation of the voltage regulation mechanism in the power-saving operation mode. When manual gear adjustment is used, the operator directly selects a gear among 390V / 384V / 378V based on the reading of the on-site voltmeter or historical operation records. The voltage regulation circuit controls the switching of contactors (3KC-5KC) through the combination of time relays (1ST, 2ST) and intermediate relays (KA1–KA3), changing the turns ratio of the main winding and the control winding. This achieves discrete step adjustment of the output voltage without changing the mains frequency. This process requires no external communication or algorithm calculation, has a response time of ≤100ms, strong anti-interference capability, and solves the technical problem of system loss of control when communication is interrupted or the controller fails. When automatic intelligent adjustment is used, YTJ continuously analyzes the real-time parameters uploaded by PD to identify whether the current load is in the light load (P<30% of rated load), medium load (30%≤P<85%), or heavy load (P≥85%) range. It then dynamically determines the optimal voltage level based on conditions such as whether cosφ is below 0.92 and whether THDv exceeds limits. For example, when P=72kW, cosφ=0.85, and THDv=6.2%, YTJ determines that the voltage needs to be increased to improve the power factor and suppress harmonics. It then issues an upgrade command, switching the output from 378V to 384V, thereby reducing the effective current value, decreasing line I²R losses, and mitigating harmonic amplification effects. Therefore, this technical solution, without adding power electronic conversion stages, solves the technical problems of unreleased energy-saving potential and increased power quality fluctuations caused by rigid voltage settings at the low-voltage distribution end through the combination of inherent electromagnetic structure characteristics and intelligent decision-making. This achieves the technical effects of improving energy-saving accuracy, enhancing system robustness, and extending equipment lifespan.

[0062] Example 4:

[0063] Based on the above embodiments, this embodiment further provides:

[0064] The intelligent control unit's multi-functional power meter collects three-phase voltage, three-phase current, active power, reactive power, apparent power, power factor, frequency, and harmonic content parameters in real time; temperature sensors are arranged in key heat-generating parts inside the device cabinet, and the temperature signal is converted into a 4-20mA current signal and sent to the central processing unit through an analog transmitter.

[0065] Among them, the multi-functional power meter of the intelligent control unit collects three-phase voltage, three-phase current, active power, reactive power, apparent power, power factor, frequency and harmonic content parameters in real time; the temperature sensor is arranged in the key heat-generating parts in the device cabinet, and the temperature signal is converted into a 4-20mA current signal and sent to the central processor through the analog transmitter.

[0066] Among them, the multi-functional power meter is an embedded digital power quality monitoring device that can simultaneously analyze the amplitude, phase, and total harmonic distortion (THD) of characteristic harmonics such as the 3rd, 5th, 7th, and 9th harmonics. Its voltage input range is AC 0–450V, and its current input is compatible with 0.5A–5A through-type or external Rogowski coil sensors. The communication interface supports the RS485 Modbus RTU protocol and is connected to the central processing unit via an isolated serial bus.

[0067] like Figure 4 As shown, the temperature sensor is a platinum resistance temperature sensor (PT100), with a temperature measurement range of -20℃ to +120℃ and an accuracy class of ±0.15℃. The installation location covers four key heat-generating parts: the end of the main winding of the electromagnetic balance control device, the surface of the control winding core, the rear side of the contactor contacts of the voltage regulating circuit, and the heat sink base of the central processing unit. The resistance signals output by each sensor are converted into industrial standard 4–20mA current signals by an analog transmitter. This transmitter has a conversion characteristic with linearity better than ±0.05%FS, an input / output isolation withstand voltage of ≥1500V AC, and a wide temperature range operating capability of -40℃ to +85℃.

[0068] The deployment methods, signal types, and access paths of the aforementioned multifunctional power meters and temperature sensors together constitute a hierarchical heterogeneous sensing architecture: electrical parameters reflect the macroscopic energy flow characteristics and power quality degradation of the system, while temperature parameters characterize the local thermal stress state and potential failure risks of the equipment; the two are sampled synchronously in the time dimension and complementaryly deployed in the spatial dimension, enabling the central processing unit to obtain a state snapshot covering both "electrical performance and thermal behavior" dimensions, providing extensive and in-depth raw data support for subsequent control strategies.

[0069] Through the above technical solution, during the operation of the microgrid energy-saving system, when the load undergoes a step change or the output of new energy sources fluctuates, causing a sudden change in the three-phase current, the multi-functional power meter can capture voltage drops, harmonic surges, and power factor deterioration phenomena in real time with a millisecond-level response. At the same time, the temperature sensor synchronously monitors that the temperature rise of the contactor contacts in the voltage regulation circuit exceeds the threshold (e.g., >75℃), and the analog transmitter converts the abnormal temperature into a 4–20mA current signal and stably transmits it to the central processing unit. Based on this, the central processing unit determines that it is currently in a high-load harmonic superposition overheating condition and triggers a protective downshifting adjustment command. This process relies entirely on the sensing configuration and signal link defined in this embodiment and does not require the introduction of the deep reinforcement learning algorithm, IoT platform all-in-one machine, or automatic shifting logic described in subsequent specific embodiments. Therefore, the dual-modal data acquisition capability of electrical and temperature as defined in this embodiment alone can support basic-level state identification and safety boundary monitoring, effectively solving the risks of equipment overheating and malfunction caused by power quality problems such as "large reactive power, harmonic pollution, phase load imbalance, and large equipment loss" mentioned in the background technology, and improving the system's operational reliability and early fault warning capability.

[0070] Example 5:

[0071] Based on the above embodiments, this embodiment further provides:

[0072] The central processing unit uses deep reinforcement learning algorithms for dynamic optimization control. Based on historical operating data and real-time collected parameters, it predicts load change trends and achieves forward-looking adaptive control.

[0073] In this embodiment, the central processing unit (CPU), as the core computing module of the intelligent control unit, undertakes system-level decision-making functions. It does not rely on a preset rule base or fixed threshold criteria, but instead constructs a State-Action-Reward (SACR) Markov decision process model to learn online the mapping relationship between the power grid load evolution law and the response characteristics of the electromagnetic balance management device, thereby generating a time-forward control strategy. This control strategy directly applies to the voltage regulation circuit of the electromagnetic balance management device, the power dispatching commands of the microgrid collaborative interface, and the data upload priority configuration of the IoT monitoring platform, forming a closed-loop feedback optimization circuit.

[0074] At the start of each control cycle, the central processing unit loads the historical sequence of the most recent N time windows (N=288, i.e., 24 hours) from the local database and concatenates it with the latest 12-dimensional state vector at the current time t, forming a time-series tensor of length (N+1)×12, which is then input to the encoder layer of the TD3 network. The action vector output by the network is executed after being verified by the safety constraint module—for example, the main winding reactance adjustment step size is limited to ±3 levels / cycle, the control winding current change rate does not exceed 5A / s, and the mode switching command must satisfy the contactor mechanical interlocking logic (IKC and 2KC must not be de-energized simultaneously). This mechanism ensures that the learning process always remains within the physically feasible domain, avoiding equipment malfunctions caused by exploratory behavior.

[0075] This invention achieves multi-step rolling prediction capability based on the implicit state representation of the strategy network: at time t, during the forward propagation of the network, its LSTM hidden layer state h_t carries implicit information such as load inertia, daily load curve characteristics, and weather correlation; when a virtual disturbance sequence is input (such as simulating a sudden 20% drop in photovoltaic output or the start of an air conditioning cluster), the power factor degradation slope, neutral line current peak probability, and cabinet temperature rise inflection point can be deduced within the next 3–15 minutes, thereby triggering the switching of the energy-saving contactor or the pre-charging command of the energy storage system in advance.

[0076] In this embodiment, a multi-functional power meter and a temperature sensor constitute the perception layer, providing high-quality input data for deep reinforcement learning; a central processing unit hardware platform provides real-time inference computing power support; the TD3 algorithm architecture endows the system with generalization decision-making capabilities under unknown operating conditions; the reward function design transforms power quality indicators into optimizable mathematical objectives; a safety constraint module ensures that all actions comply with the physical limits of electrical equipment; and the final output control commands drive the execution layer, including the electromagnetic balance management device and the microgrid collaborative interface, to complete closed-loop regulation.

[0077] Through the above technical solution, this invention uses a deep reinforcement learning algorithm in the central processing unit to construct a state-action mapping relationship and integrates historical operating data with real-time parameters for rolling prediction. Therefore, it can identify the evolution trend of the load before significant changes occur, thereby actively adjusting the equivalent reactance and output voltage level of the electromagnetic balance management device and coordinating the charging and discharging behavior of the energy storage system. This solves the technical problems that prevent the distribution network from operating in economic areas, such as "voltage fluctuations caused by excessively long power supply radius, system instability exacerbated by the access of new energy sources, and adjustment lag caused by passive response of traditional control".

[0078] Example 6:

[0079] Based on the above embodiments, this embodiment further provides:

[0080] The IoT monitoring platform includes a data storage module, a communication module, and a cloud platform display module. The data storage module is used to store historical system operation data, and the cloud platform display module is used to display automatic status, gear switching status, temperature parameters, and energy-saving effects.

[0081] As the core of remote digital management for microgrid energy-saving systems, the IoT monitoring platform focuses on the local acquisition, reliable transmission, long-term storage, and visualization of operational data. It aims to solve technical problems in traditional power distribution systems, such as numerous monitoring blind spots, lack of historical data, high reliance on manual inspections, and lack of visibility into operational status. Specifically, these problems manifest as: the system lacks the ability to continuously record automatic control processes, making it impossible to trace the timing of shift changes and corresponding operating conditions; abnormal temperature trends are difficult to identify in advance; energy-saving effects lack quantitative evidence, leading to strong subjectivity in energy efficiency assessments and a lack of data support for management decisions; and remote access is limited, resulting in delayed operation and maintenance responses. The technical solution involved in this embodiment does not involve power quality management itself, but is specifically designed to build a traceable, verifiable, and interactive digital monitoring closed loop, belonging to system-level operation and maintenance support technology.

[0082] During the continuous operation of the microgrid energy-saving system, a stable data upload channel is established by the communication module, enabling locally collected operating parameters to be uploaded to the cloud in real time, completely, and securely. The data storage module ensures the traceability of all key process data (especially gear switching events and temperature change trajectories), providing original evidence for fault root cause analysis and energy efficiency auditing. The cloud platform display module transforms abstract data into intuitive, layered, and interactive visual information, allowing maintenance personnel to grasp the execution status of the system's automatic control logic, hardware temperature rise trends, and actual energy-saving effects without going to the site. Because of its local structured storage capability, the technical problem of historical data loss leading to the inability to verify energy-saving effects is solved. Because of the adoption of dual-mode communication and network interruption resumption mechanism, the monitoring interruption problem caused by unstable signals at remote sites is solved. Because the cloud platform integrates gear status and temperature parameters, the problem of difficulty in judging the overall health status of equipment by displaying isolated single parameters is solved. Ultimately, the technical effects of remote visualized operation and maintenance, quantifiable verification of energy-saving effects, and early warning of equipment risks are achieved.

[0083] Example 7:

[0084] Based on the above embodiments, this embodiment further provides:

[0085] The microgrid coordination interface includes: a distributed photovoltaic (PV) power generation interface, which is used to connect PV inverters to achieve grid connection of PV power generation; a wind power generation interface, which is used to connect wind turbine generators; and an energy storage system interface, which is used to connect lithium-ion batteries or supercapacitor energy storage devices.

[0086] This embodiment focuses on the structural composition and functional adaptability of the microgrid collaborative interface. Its core lies in constructing a standardized, scalable, and electrically-information-coupled physical access layer for multi-source heterogeneous distributed energy. This interface is not a single communication port or simple terminal block, but rather a composite hardware unit with power matching capabilities, electrical isolation characteristics, protocol compatibility, and security protection mechanisms. It supports bidirectional interaction of energy and information flows, enabling the microgrid energy-saving system to act as a coordination hub, organically integrating external clean energy inputs and flexible energy storage responses. Specifically, the distributed photovoltaic power generation interface, wind power generation interface, and energy storage system interface are arranged modularly in parallel in the rear busbar area of ​​the system's main control cabinet. Each interface is equipped with an independent circuit breaker, reverse connection protection diode, DC / AC voltage adapter circuit, and RS485 Modbus communication interface.

[0087] The distributed photovoltaic (PV) power generation interface is a DC-side access unit. Its input terminal connects to the output terminal of the PV string via an MC4 quick-connect connector. Internally, it integrates a DC / DC boost converter circuit and a maximum power point tracking (MPPT) controller. It is compatible with an input voltage range of 200V–1000V DC and a rated current of not less than 32A. This interface provides grid-connected synchronization trigger pulses to the connected PV inverter through a built-in isolated DC / AC synchronization signal generator. It also receives real-time active / reactive power output, DC-side voltage, insulation impedance, and fault codes from the inverter, enabling closed-loop monitoring of the power generation status.

[0088] The three interfaces share the same underlying driver firmware and unified communication protocol stack at the system level. Their electrical ports are interconnected via copper busbars or shielded cables to achieve power bus interconnection, while the information ports are aggregated to the IoT monitoring platform via an industrial Ethernet switch. The start / stop, power limits, and operating mode switching of each interface are all uniformly scheduled by the intelligent control unit according to preset strategies. For example, during peak photovoltaic power generation periods, the energy storage system interface is prioritized for charging, while the reactive power absorption depth of the wind power interface is reduced. During peak load periods, the energy storage is released in conjunction with the wind power reactive power support capability. This collaborative mechanism does not rely on external master station commands and completes closed-loop decisions entirely based on local real-time parameters.

[0089] In microgrid energy-saving systems, a physical access layer with multi-energy adaptability is constructed. The distributed photovoltaic (PV) power generation interface provides MPPT tracking and grid synchronization capabilities for PV arrays, solving the technical problem that traditional microgrid interfaces cannot simultaneously address DC-side efficiency optimization and AC-side power quality constraints. The wind power generation interface integrates wideband phase-locked loop (PLL) and dynamic reactive power support functions, resolving voltage fluctuations and frequency instability issues caused by asynchronous / direct-drive wind turbine access. The energy storage system interface adopts a SiC-based bidirectional converter architecture and supports access to multiple types of energy storage media, solving the technical problem that a single energy storage interface cannot simultaneously meet energy-type and power-type response requirements. The synergistic effect of these three elements makes the microgrid collaborative interface a key hub connecting external energy resources and internal system governance capabilities. Without adding additional communication gateways and protocol conversion equipment, it significantly improves the microgrid's inclusiveness towards distributed power sources, robustness to power fluctuations, and compatibility with diverse energy storage methods, thereby supporting the entire microgrid energy-saving system to continuously operate within an economically efficient range under complex operating conditions.

[0090] The energy storage system interface supports bidirectional power flow, enabling peak shaving and valley filling during grid voltage fluctuations, energy storage when there is a surplus of new energy generation, and power supply during peak load demand.

[0091] The energy storage system interface is a crucial physical channel for realizing the spatiotemporal transfer and dynamic regulation of energy in a microgrid energy-saving system. Its core function is to establish a controllable, reversible, and highly responsive power interaction path between energy-saving devices and external energy storage units. This interface is not a simple electrical connection port, but rather an intelligent power coupling unit integrating bidirectional converter control logic, voltage / current closed-loop feedback loops, islanding detection mechanisms, and communication protocol adaptation modules. It coordinates the system-level energy dispatch strategy with the real-time operating status of local energy storage devices. Its technical benefits include improved system transient stability, enhanced renewable energy absorption capacity, reduced peak-valley difference rate, and support for smooth switching between grid-connected and off-grid modes in microgrids.

[0092] As the execution terminal, the energy storage system interface receives power commands generated by the intelligent control unit based on the triple inputs of voltage fluctuations, renewable energy output, and load trends. Its bidirectional power flow capability provides it with operational freedom. The three operating conditions of peak shaving and valley filling, energy storage, and power discharge correspond to the three major objectives of voltage stability, renewable energy consumption, and power supply reliability, respectively, and can overlap in time sequence. For example, during the peak photovoltaic power generation period at noon, the interface performs energy storage and simultaneously participates in voltage boosting (through reactive power support); during the evening peak load period combined with the photovoltaic power output decay stage, it simultaneously starts power discharge and harmonic compensation.

[0093] Because the energy storage system interface supports bidirectional power flow, the microgrid energy-saving system can inject or absorb power instantly when voltage fluctuations occur, thereby suppressing bus voltage over-limits. This solves the problems of "voltage fluctuations and insufficient reactive power compensation" and "low voltage at the equipment end due to excessive power supply radius" in the background technology, and improves the stability of power supply quality. By storing energy when there is a surplus of renewable energy generation, the electricity that might otherwise be curtailed (solar and wind power) is converted into dispatchable resources, alleviating system disturbances caused by "renewable energy fluctuations" and improving the utilization rate of distributed energy. By discharging power during peak load demand, the system effectively fills the load gap, reduces the peak dependence on the grid power, and alleviates the situation where "distribution network load cannot operate in the economic operating area," thereby improving the overall system energy efficiency and economy.

[0094] Example 8:

[0095] Based on the above embodiments, this embodiment further provides:

[0096] The system also includes a harmonic filter module and a surge suppression module. The harmonic filter module filters out the 3rd, 5th, 7th and 9th harmonics. The surge suppression module uses MOV varistors and electromagnetic absorption networks to suppress voltage spikes and transient overvoltages.

[0097] This embodiment addresses the dual requirements of harmonic and transient overvoltage mitigation by constructing an embedded power quality end-point protection structure. The harmonic filter module and surge suppression module, as passive protection units connected in parallel to the main circuit, respectively perform frequency-domain selective filtering and time-domain energy clamping functions. Together, they enhance the system's overall tolerance to non-sinusoidal distortion and pulse-type interference. This design does not rely on the dynamic response of active devices, possessing high reliability, zero delay, and maintenance-free characteristics, making it suitable for applications with limited space and complex electromagnetic environments within microgrid distribution cabinets.

[0098] When a microgrid system encounters a lightning strike on the distribution network side or a transient overvoltage caused by the switching of large equipment, the MOV array in the surge suppression module quickly breaks down and conducts after the voltage exceeds the 420V AC threshold, discharging the peak energy to ground. At the same time, the electromagnetic absorption network attenuates the residual high-frequency oscillation components, limiting the voltage envelope applied to the ports of subsequent equipment to a safe envelope (typically, the peak value after clamping is <1.2kV). Meanwhile, during continuous system operation, each tuning branch in the harmonic filter module presents an approximately zero-impedance path for the 3rd, 5th, 7th, and 9th harmonic currents, diverting the corresponding harmonic currents to the nearest capacitor branch, significantly reducing the harmonic current content injected into the main grid (measured THDv decreased from 12.3% to below 3.8%), thereby reducing transformer eddy current losses, suppressing cable dielectric aging, and preventing maloperation of protection relays. Because the harmonic filter module and surge suppression module are jointly deployed at the system inlet, without adding active control links or requiring additional communication and power supply, the robustness of the microgrid energy-saving system to power quality disturbances and the equipment-level protection capability are significantly enhanced without changing the original system control logic. This solves the problems of abnormal equipment temperature rise, insulation degradation and shortened lifespan caused by the superposition of "harmonic pollution" and "voltage fluctuation" in the background technology, and improves the stability and economy of the system in long-term operation.

[0099] All content not described in detail in this specification is prior art known to those skilled in the art, and the model parameters of each electrical appliance are not specifically limited; conventional equipment can be used. Electrical control components not mentioned in this technical solution are not shown in the figures because they are prior art, and will not be described further here.

[0100] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A micro-grid energy saving system, characterized in that, The utility model relates to a kind of electromagnetic balance management devices, intelligent control units, internet of things monitoring platforms and micro-grid coordination interfaces, which are used for realizing three-phase current balance adjustment, reactive power dynamic compensation and harmonic filtering by electromagnetic induction principle, real-time acquisition of electrical parameters and temperature data, remote monitoring and data uploading by wireless communication mode, and power interaction with distributed energy generation equipment and energy storage device. The electromagnetic balance management device includes a main winding, a control winding and a voltage regulating circuit. The main winding is connected in series with three-phase line of power grid for sensing three-phase current imbalance state. The control winding changes the magnetic saturation degree of iron core by adjusting current to realize dynamic adjustment of equivalent reactance value. The voltage regulating circuit controls the switching of contactor by time relay and intermediate relay to realize step adjustment of output voltage.

2. The microgrid energy saving system of claim 1, wherein, The electromagnetic balance management device has three operating modes: commercial power operating mode, common operating mode and power-saving operating mode. In the commercial power operating mode, bypass contactor is attracted, and load is directly powered by commercial power. In the common operating mode, commercial power contactor and power-saving contactor are simultaneously attracted, and commercial power and power-saving device are operated in parallel.

3. The microgrid energy saving system of claim 2, wherein, In the power-saving operating mode, only power-saving contactor is attracted, and load is completely powered by power-saving device. The power-saving operating mode includes manual gear adjustment and automatic intelligent adjustment. The manual gear adjustment selects three adjustment gears by gear switch, corresponding to different output voltages. The automatic intelligent adjustment collects multifunctional meter parameters in real time by internet of things platform all-in-one machine and automatically switches gears according to logical operation results.

4. The microgrid energy conservation system of claim 3, wherein, The multifunctional power meter of the intelligent control unit collects three-phase voltage, three-phase current, active power, reactive power, apparent power, power factor, frequency and harmonic content parameters in real time.

5. The microgrid energy conservation system of claim 1, wherein, The temperature sensor is arranged at key heating parts in device cabinet, and converts temperature signal into 4-20mA current signal to send to central processor by analog quantity transmitter.

6. The microgrid energy conservation system of claim 5, wherein, The central processor uses deep reinforcement learning algorithm for dynamic optimization control, predicts load change trend according to historical operation data and real-time acquisition parameters, and realizes forward-looking adaptive control.

7. The microgrid energy conservation system of claim 1, wherein, The internet of things monitoring platform includes data storage module, communication module and cloud platform display module.

8. The microgrid energy conservation system of claim 1, wherein, The data storage module is used for storing system operation historical data. The cloud platform display module is used for displaying automatic state, gear switching state, temperature parameter and power-saving effect. The micro-grid coordination interface includes distributed photovoltaic power generation interface, wind power generation interface and energy storage system interface. The distributed photovoltaic power generation interface is used for connecting photovoltaic inverter to realize photovoltaic power generation grid connection. The wind power generation interface is used for connecting wind turbine generator. The energy storage system interface is used for connecting lithium ion battery or supercapacitor energy storage device.

9. The microgrid energy conservation system of claim 8, wherein, The energy storage system interface supports bidirectional power flow, carries out peak clipping and valley filling when the grid voltage fluctuates, stores energy when new energy generation is excessive, and discharges power supply when the load demand is high.

10. The microgrid energy conservation system of claim 1, wherein, The system also comprises a harmonic filter module and a surge suppression module, the harmonic filter module filters 3, 5, 7 and 9 harmonics, and the surge suppression module uses MOV voltage-sensitive resistor and electromagnetic absorption network to suppress voltage peak and transient overvoltage.

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