A surplus power consumption method and device, terminal equipment and storage medium

Abstract

The application discloses a kind of surplus power consumption method, device, terminal equipment and storage medium, belong to energy storage control technical field, the method is: real-time acquisition load power and carry out working condition determination, based on load power generation first control instruction and issue to diesel generator, to make diesel generator carry out power compression;Real-time acquisition state of charge and battery temperature and carry out interval determination, based on state of charge and battery temperature generation second control instruction and issue to battery energy storage system, to make battery energy storage system carry out current float charging;Based on first surplus power generation third control instruction and issue to battery energy storage system, to make battery energy storage system carry out energy loss;Based on second surplus power generation fourth control instruction and issue to PCC grid-connected switch, to make PCC grid-connected switch carry out closure, complete surplus power consumption.Therefore, by implementing the present application, surplus power of municipal power-supply-energy storage-diesel integrated black start system can be realized layered consumption.

Description

Technical Field

[0001] This invention relates to the field of energy storage control technology, and in particular to a method, apparatus, terminal equipment, and storage medium for surplus power consumption. Background Technology

[0002] The integrated black-start system of diesel generator, battery storage, and mains power is a crucial defense against large-scale power outages and ensures power supply to core loads. During the islanded operation phase before mains power is restored, the system faces a severe conflict between source and load power constraints: the diesel generator, as the main power source, must operate at more than 30% of its rated power (i.e., there is a rigid minimum technical output) to prevent cylinder carbon buildup, black smoke in the exhaust, and operational instability. Simultaneously, the battery storage, as the only flexible regulation unit, is limited by electrochemical safety characteristics. When the state of charge (SOC) reaches a high limit (e.g., 90%), the battery management system (BMS) typically forcibly disconnects the charging circuit to prevent overcharging. When the core rigid load within the islanded grid is small (less than the diesel generator's minimum output) and the battery is already at a high charge level, the excess power generated by the diesel generator to maintain operation has nowhere to be utilized. This "power deadlock" phenomenon can lead to increased bus voltage, frequency drift, and even trigger system protection tripping, directly causing black-start failure. Therefore, how to safely and accurately balance this surplus power without cutting off important loads is an engineering problem that urgently needs to be solved.

[0003] Currently, engineering solutions to islanded grid power imbalance primarily rely on crude methods such as "physical expansion" or "performance sacrifice." The most common approach is to configure a high-power resistor box (dummy load) to convert excess electrical energy into heat through physical resistance. While reliable, this method significantly increases the size, weight, and heat dissipation costs of the black-start system, severely limiting the space utilization of mobile emergency power vehicles. Another approach is to forcibly reduce the diesel generator power below the minimum load rate, but this leads to incomplete combustion, severe carbon buildup, and shortened equipment lifespan or even accidental shutdown over long-term operation. In the field of control strategies, "virtual impedance" technology is often used for droop control in microgrids to maintain voltage stability, but it is rarely applied to energy management scenarios that "actively increase system losses." Furthermore, existing battery management strategies generally employ "hard boundary" logic, meaning charging stops immediately upon reaching the SOC threshold, lacking flexible means to nonlinearly adjust the charging current under extreme conditions. Summary of the Invention

[0004] This invention provides a method, apparatus, terminal equipment, and storage medium for surplus power consumption, which can realize the hierarchical consumption of surplus power in an integrated black start system of mains power-energy storage-diesel generator.

[0005] This invention provides a method for absorbing surplus power, applied to an energy management system. The energy management system is communicatively connected to an integrated black-start system comprising a mains power system connected to the same AC bus, a diesel generator, a battery energy storage system, and a core rigid load. The mains power system is connected to the AC bus via a PCC grid-connected switch. The method for absorbing excess power includes: The load power of the core rigid load is collected in real time, and the operating condition is determined based on the load power. When the determination result is that the operating condition is in surplus power condition, a first control command is generated based on the load power and sent to the diesel generator so that the diesel generator can compress power according to the first control command. The state of charge (SOC) and battery temperature of the battery energy storage system are collected in real time, and the SOC is used to determine the range. When the determination result is that the battery is in the flexible float charging range, a second control command is generated based on the SOC and battery temperature and sent to the battery energy storage system so that the battery energy storage system can perform current float charging according to the second control command. The first surplus power is calculated based on the load power, power compression result, and current float charging result. A third control command is generated based on the first surplus power and sent to the battery energy storage system so that the battery energy storage system performs energy loss according to the third control command. The energy loss is achieved through virtual impedance reconstruction and active loss modulation. The second surplus power is calculated based on the first surplus power and energy loss results. A fourth control command is generated based on the second surplus power and sent to the PCC grid-connected switch so that the PCC grid-connected switch closes according to the fourth control command, and the second surplus power is sent into the mains power system to complete the surplus power consumption.

[0006] This invention, through real-time acquisition of the load power of the core rigid load and condition determination, generates a first control command and sends it to the diesel generator for power compression when the condition is determined to be surplus power, thereby reducing the total amount of surplus power that needs to be subsequently absorbed from the source. It also acquires the state of charge (SOC) and temperature of the battery energy storage system in real-time and determines the charging range. When the range is determined to be flexible float charging, a second control command is generated and sent to the battery energy storage system for current float charging, utilizing the battery's short-term absorption capacity in the high SOC range to absorb some surplus power. Furthermore, it calculates the first surplus power based on the load power, power compression result, and current float charging result, generating a third control command and sending it to the battery energy storage system for energy dissipation, converting the first surplus power into internal heat dissipation without increasing the external braking resistor. Finally, it calculates the second surplus power based on the first surplus power and energy dissipation result, generating a fourth control command and sending it to the PCC grid-connected switch for closure, sending the second surplus power into the mains power system, transferring the remaining power to the external grid when the internal absorption capacity is saturated. Compared to existing technologies that cannot meet the requirements of highly integrated black start systems, this application realizes the hierarchical consumption of surplus power in an integrated black start system of mains power-energy storage-diesel generator.

[0007] Further, the real-time acquisition of the load power of the core rigid load, and the determination of the operating condition based on the load power, when the determination result is that it is in a surplus power operating condition, generates a first control command based on the load power and sends it to the diesel generator, so that the diesel generator performs power compression according to the first control command, including: The load power is compared with the minimum safe output of the diesel generator, and the operating condition is determined based on the comparison result; wherein, if the load power is less than the minimum safe output, the determination result is that it is in a surplus power operating condition. When the determination result is that the operating condition is in surplus power, a first control command is generated based on the load power, the minimum safe output and the preset dynamic safety margin. The first control command is sent to the diesel generator so that the diesel generator adjusts the throttle opening through the PID controller to compress the output power of the diesel generator to within a preset range.

[0008] The embodiments of the present invention determine the operating conditions by comparing the load with the minimum output and generate a first command to control the diesel generator PID to adjust the throttle compression output, which can accurately lock the output power of the diesel generator near the minimum safe output threshold, compressing the excess power to the minimum range from the source.

[0009] Further, the real-time acquisition of the state of charge (SOC) and battery temperature of the battery energy storage system, and the determination of the charging range based on the SOC, wherein when the determination result indicates that it is within the flexible float charging range, a second control command is generated based on the SOC and battery temperature and sent to the battery energy storage system, so that the battery energy storage system performs current float charging according to the second control command, including: The state of charge is compared with a preset initial value and a maximum value of the state of charge, and a range is determined based on the comparison result; wherein, if the state of charge is greater than or equal to the initial value of the state of charge and less than or equal to the maximum value of the state of charge, the determination result is that it is in the flexible float charging range. When the determination result is that it is in the flexible float charging range, a second control command is generated based on the rated charging current, state of charge decay factor and temperature safety factor of the battery energy storage system. The second control command is sent to the battery energy storage system so that the battery energy storage system controls the bidirectional DC-DC converter to perform current float charging through the energy storage converter.

[0010] This invention, by comparing the State of Charge (SOC) with a threshold range and generating a second instruction, controls the battery to float charge via the converter. This allows the charging current to decrease smoothly as the SOC increases, avoiding bus voltage surges caused by hard battery disconnection.

[0011] Furthermore, when the determination result indicates that the battery is in the flexible float charging range, a second control command is generated based on the rated charging current, state-of-charge degradation factor, and temperature safety factor of the battery energy storage system, including: A state of charge decay factor is constructed based on the state of charge, the initial state of charge value, and the maximum state of charge value; and a temperature safety factor is constructed based on the battery temperature. The charging current is calculated based on the rated charging current, the state of charge decay factor, and the temperature safety factor, and a second control command is generated based on the charging current.

[0012] The embodiments of the present invention construct a SOC attenuation factor and a temperature factor within the flexible float charging range and calculate the charging current to generate a second command. This enables the charging current to decrease non-linearly with increasing SOC within the flexible float charging range, ensuring that the battery absorbs power while not exceeding the temperature safety boundary.

[0013] Further, the step of calculating the first surplus power based on the load power, power compression result, and current float charging result, generating a third control command based on the first surplus power, and issuing it to the battery energy storage system so that the battery energy storage system performs energy dissipation according to the third control command includes: The current output power of the diesel generator after power compression and the current absorbed power of the battery energy storage system after current float charging are obtained. The first surplus power is calculated based on the load power, the current output power and the current absorbed power. The equivalent virtual resistance value is calculated based on the first surplus power and the voltage of the AC bus, and a third control command is generated based on the first surplus power and the equivalent virtual resistance value. The third control command is sent to the battery energy storage system so that the battery energy storage system corrects the voltage loop reference value of the energy storage converter according to the equivalent virtual resistance value to complete the virtual impedance reconstruction; and the first surplus power is mapped to the IGBT carrier frequency and zero-sequence voltage component to complete the active loss modulation.

[0014] This invention calculates the first surplus power by acquiring the output power of the diesel generator after compression and the power of the battery after float charging. Based on the first surplus power and the bus voltage, a virtual resistance is calculated and a third instruction is generated to control the battery to correct the voltage loop reference value to complete impedance reconstruction. At the same time, the first surplus power is mapped to the IGBT frequency and zero-sequence component to complete loss modulation. This enables the energy storage converter to introduce a virtual resistance in the voltage loop to absorb active power. Meanwhile, by increasing the switching frequency and injecting zero-sequence component, the internal device losses are increased, and the safe dissipation of the first surplus power is achieved without adding external hardware.

[0015] Further, after issuing the third control command to the battery energy storage system to enable the battery energy storage system to correct the voltage loop reference value of the energy storage converter according to the equivalent virtual resistance value, thereby completing virtual impedance reconstruction; and mapping the first surplus power to the IGBT carrier frequency and zero-sequence voltage component to complete active loss modulation, the method further includes: The IGBT junction temperature of the energy storage converter is collected in real time and compared with a preset temperature threshold range; Based on the comparison results, corresponding constraint coefficients are generated, and the equivalent virtual resistance value is corrected based on the constraint coefficients.

[0016] This invention, through comparison of IGBT junction temperature with a threshold range and generation of a limiting coefficient to correct the virtual resistance, can increase the virtual resistance value and reduce the current flowing through the IGBT when the IGBT junction temperature exceeds a set threshold, thus ensuring that the power absorption intensity is always automatically adjusted within the device's thermal safety boundary.

[0017] Further, the step of calculating the second surplus power based on the first surplus power and energy loss result, generating a fourth control command based on the second surplus power and issuing it to the PCC grid-connected switch, so that the PCC grid-connected switch closes according to the fourth control command, and sends the second surplus power into the mains power system to complete the surplus power absorption, includes: The current heat loss power of the battery energy storage system after energy loss is obtained, the second surplus power is calculated based on the first surplus power and the current heat loss power, and the fourth control command is generated based on the second surplus power. When the status data on both sides of the PCC grid-connected switch are detected to meet the pre-synchronization grid-connection conditions, the fourth control command is sent to the PCC grid-connected switch so that the PCC grid-connected switch closes according to the fourth control command, and the second surplus power is sent into the mains power system to complete the surplus power consumption.

[0018] This invention calculates the second surplus power by acquiring the thermal power after battery loss and generates a fourth instruction. When the pre-synchronization conditions are met on both sides of the grid-connected switch, an instruction is issued to control the switch to close. This can transfer the surplus power to the external power grid when the internal absorption capacity is saturated, avoiding the tripping of reverse power protection triggered by power backflow at the moment of grid connection.

[0019] Another embodiment of the present invention provides a surplus power consumption device applied to an energy management system; wherein the energy management system is communicatively connected to an integrated black start system of mains power-energy storage-diesel generator, the integrated black start system of mains power-energy storage-diesel generator includes a mains power system connected to the same AC bus, a diesel generator, a battery energy storage system and a core rigid load; the mains power system is connected to the AC bus through a PCC grid connection switch; The surplus power absorption device includes: a first surplus power absorption module, a second surplus power absorption module, a third surplus power absorption module and a fourth surplus power absorption module; The first surplus power absorption module is used to collect the load power of the core rigid load in real time and make a working condition judgment based on the load power. When the judgment result is that it is in a surplus power working condition, it generates a first control command based on the load power and sends it to the diesel generator so that the diesel generator performs power compression according to the first control command. The second surplus power absorption module is used to collect the state of charge and battery temperature of the battery energy storage system in real time, and make a range determination based on the state of charge. When the determination result is that it is in the flexible float charging range, a second control command is generated based on the state of charge and the battery temperature and sent to the battery energy storage system so that the battery energy storage system performs current float charging according to the second control command. The third surplus power absorption module is used to calculate the first surplus power based on the load power, power compression result, and current float charging result, generate a third control command based on the first surplus power, and send it to the battery energy storage system so that the battery energy storage system performs energy loss according to the third control command; wherein, the energy loss is achieved through virtual impedance reconstruction and active loss modulation; The fourth surplus power absorption module is used to calculate the second surplus power based on the first surplus power and energy loss results, generate a fourth control command based on the second surplus power and send it to the PCC grid-connected switch, so that the PCC grid-connected switch closes according to the fourth control command, and sends the second surplus power into the mains power system to complete the surplus power absorption.

[0020] Another embodiment of the present invention provides a terminal device, including: a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein when the processor executes the computer program, it implements the steps of a surplus power consumption method as described in the present invention.

[0021] Another embodiment of the present invention provides a computer-readable storage medium item, including: a stored computer program, which, when the computer program is running, controls the device where the computer-readable storage medium is located to perform the steps of a surplus power consumption method as described in the present invention. Attached Figure Description

[0022] Figure 1 A schematic flowchart of an embodiment of the surplus power consumption method provided by the present invention; Figure 2 This is a schematic diagram of a structure of an embodiment of the integrated black start system of mains power-energy storage-diesel generator provided by the present invention; Figure 3 A schematic diagram illustrating the effect of one embodiment of the flexible current float charging provided by the present invention; Figure 4 A flowchart illustrating an embodiment of virtual impedance reconstruction and active loss modulation provided by the present invention; Figure 5 A schematic flowchart of one embodiment of the thermo-electric closed-loop safety feedback provided by the present invention; Figure 6 A schematic flowchart of another embodiment of the surplus power consumption method provided by the present invention; Figure 7 This is a schematic diagram of one embodiment of the surplus power absorption device provided by the present invention. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0025] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0026] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0027] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0028] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0029] See Figure 1To address the problem that existing technologies cannot meet the requirements of highly integrated black start systems, an embodiment of the present invention provides a method for absorbing excess power, applied to an energy management system. The energy management system is communicatively connected to an integrated black start system comprising a mains power system connected to the same AC bus, a diesel generator, a battery energy storage system, and a core rigid load. The mains power system is connected to the AC bus via a PCC grid-connected switch.

[0030] In one embodiment, the overall architecture of the integrated black start system of mains power-energy storage-diesel generator is as follows: Figure 2 As shown, the system is built around a 380V AC bus. The physical equipment connected to the AC bus is mainly divided into four parts: First, a diesel generator responsible for providing basic power; second, the core battery energy storage system, which consists of battery packs, a battery management system (BMS), and a storage converter (PCS) integrating a virtual impedance loss algorithm and a cooling fan; third, core rigid loads that must ensure continuous power supply; and finally, the PCC grid-connection switch and pre-synchronization device for connecting to the external mains system. The energy management system (EMS) connects these physical devices through a communication bus, collects data in real time, and directs the flow of energy between the devices, thereby maintaining the stable operation of the entire isolated grid.

[0031] Specifically, the surplus power consumption method includes steps S101 to S104: Step S101: The load power of the core rigid load is collected in real time, and the operating condition is determined based on the load power. When the determination result is that the operating condition is in surplus power condition, a first control command is generated based on the load power and sent to the diesel generator so that the diesel generator can compress power according to the first control command.

[0032] It should be noted that the real-time acquisition of the load power of the core rigid load and the determination of the operating condition based on the load power, and when the determination result is that the system is in a surplus power condition, a first control command is generated based on the load power and sent to the diesel generator so that the diesel generator can compress power according to the first control command. This means that: the EMS collects the load power of the core rigid load in real time at a set sampling period and compares the load power with the minimum safe output threshold of the diesel generator; if the load power is less than the minimum safe output threshold, the system is determined to be in a surplus power condition; after the surplus power condition is determined, the EMS calculates and generates a first control command based on the load power, the minimum safe output threshold and the preset dynamic safety margin. The first control command includes the target power value of the diesel generator; the EMS sends the first control command to the diesel generator through the communication bus; the diesel generator adjusts the throttle opening through its internal PID controller according to the received first control command, reduces its output power and stabilizes it near the minimum safe output threshold, thereby compressing the total surplus power of the system to the minimum range from the source.

[0033] Preferably, the real-time acquisition of the load power of the core rigid load, and the determination of the operating condition based on the load power, wherein when the determination result indicates that the operating condition is in surplus power condition, a first control command is generated based on the load power and sent to the diesel generator, so that the diesel generator performs power compression according to the first control command, includes: The load power is compared with the minimum safe output of the diesel generator, and the operating condition is determined based on the comparison result; wherein, if the load power is less than the minimum safe output, the determination result is that it is in a surplus power operating condition. When the determination result is that the operating condition is in surplus power, a first control command is generated based on the load power, the minimum safe output and the preset dynamic safety margin. The first control command is sent to the diesel generator so that the diesel generator adjusts the throttle opening through the PID controller to compress the output power of the diesel generator to within a preset range.

[0034] In one embodiment, the load power of the core rigid load is assumed to be... The minimum safe output of a diesel generator is ,like If the speed is too high, the system is considered to be in a surplus power operating condition. In this case, the EMS does not directly maintain a fixed speed, but instead calculates the target power command for the diesel generator using the following logic. (i.e., the first control command): ; in, A preset dynamic safety margin (e.g., 3% of rated power) is used to cope with minor load fluctuations.

[0035] Furthermore, EMS will The power is sent to the controller of the diesel generator, which uses a PID closed-loop control to adjust the throttle opening and lock the output power within a preset range, thereby utilizing excess power at the source. Compress to the minimum size.

[0036] Step S102: Real-time acquisition of the state of charge and battery temperature of the battery energy storage system, and range determination based on the state of charge. When the determination result is in the flexible float charging range, a second control command is generated based on the state of charge and the battery temperature and sent to the battery energy storage system so that the battery energy storage system performs current float charging according to the second control command.

[0037] It should be noted that real-time acquisition of the state of charge (SOC) and battery temperature of the battery energy storage system, and interval determination based on the SOC, when the determination result indicates that it is within the flexible float charging interval, generates a second control command based on the SOC and battery temperature and sends it to the battery energy storage system, so that the battery energy storage system performs current float charging according to the second control command. This means that the EMS acquires the SOC and battery temperature of the battery energy storage system in real time and compares the SOC with a preset initial SOC value and a preset maximum SOC value; if the SOC is greater than or equal to the initial SOC value... If the current value is less than or equal to the maximum state of charge, the system is determined to be in the flexible float charging range. After determining that the system is in the flexible float charging range, the EMS generates a second control command based on the rated charging current of the battery energy storage system, the state of charge decay factor, and the temperature safety factor. The second control command contains the target charging current value. The EMS sends the second control command to the battery energy storage system through the communication bus. Based on the received second control command, the battery energy storage system controls the bidirectional DC-DC converter through its internal energy storage converter to perform current float charging, absorbing some excess power from the AC bus at the target charging current value.

[0038] Preferably, the real-time acquisition of the state of charge (SOC) and battery temperature of the battery energy storage system, and the determination of the charging range based on the SOC, wherein when the determination result indicates that the battery is in a flexible float charging range, a second control command is generated based on the SOC and battery temperature and sent to the battery energy storage system, so that the battery energy storage system performs current float charging according to the second control command, includes: The state of charge is compared with a preset initial value and a maximum value of the state of charge, and a range is determined based on the comparison result; wherein, if the state of charge is greater than or equal to the initial value of the state of charge and less than or equal to the maximum value of the state of charge, the determination result is that it is in the flexible float charging range. When the determination result is that it is in the flexible float charging range, a second control command is generated based on the rated charging current, state of charge decay factor and temperature safety factor of the battery energy storage system. The second control command is sent to the battery energy storage system so that the battery energy storage system controls the bidirectional DC-DC converter to perform current float charging through the energy storage converter.

[0039] Preferably, when the determination result indicates that the battery is in the flexible float charging range, a second control command is generated based on the rated charging current, state-of-charge degradation factor, and temperature safety factor of the battery energy storage system, including: A state of charge decay factor is constructed based on the state of charge, the initial state of charge value, and the maximum state of charge value; and a temperature safety factor is constructed based on the battery temperature. The charging current is calculated based on the rated charging current, the state of charge decay factor, and the temperature safety factor, and a second control command is generated based on the charging current.

[0040] In one embodiment, the EMS reads the current state of charge. and battery temperature The preset flexible float charging range is (For example, 90%~95%) This is the initial value of the state of charge. This represents the maximum state of charge. If The battery storage system is charged at its normal maximum capacity. If The EMS no longer issues constant power commands, but instead calculates and corrects the charging current commands in real time. (i.e., the second control command): ; in, This is the rated charging current; The charge state decay factor is represented by a quadratic function decreasing model, which is used as... As the voltage increases, the charging capacity decreases parabolically to prevent sudden voltage spikes. This is the temperature safety factor.

[0041] Furthermore, the battery energy storage system receives Subsequently, a small-current float charge is performed via PCS-controlled bidirectional DC-DC converter to absorb some of the excess power. The power absorbed by the battery energy storage system... for: ; in, This refers to the DC bus voltage of the battery energy storage system.

[0042] An embodiment of the present invention demonstrates the core difference between step S102 and the traditional BMS "rigid hard cut-off" strategy. For example... Figure 3 As shown in the figure, the horizontal axis represents the state of charge. The vertical axis represents the allowable charging current or power. The dashed line represents the existing technology, when... When the 90% threshold is reached, the charging current drops sharply to zero, which can easily cause a power surge; while the solid line represents the flexible boundary control of this invention. When the battery is in the high charge range of 90% to 95%, the charging current is no longer a constant value or directly cut off, but rather follows a smooth, non-linear decay curve (such as a parabola) that slowly decreases. The shaded area between the two curves represents the increased short-term battery absorption capacity of this invention. This buffer zone effectively avoids sawtooth oscillations of the isolated grid voltage, providing a smooth transition time for the subsequent step S103.

[0043] It is worth noting that the charging current decay curve of flexible current float charging is not limited to the quadratic function decreasing model mentioned above. In practical applications, exponential functions, sigmoid functions, piecewise linear decreasing models, or nonlinear curves based on fuzzy control rules can all be used, as long as it can achieve the desired effect. The technical effects of increasing power while smoothly reducing it, and avoiding hard cutting impact, are all within the scope of this invention.

[0044] Step S103: Calculate the first surplus power based on the load power, power compression result, and current float charging result; generate a third control command based on the first surplus power and send it to the battery energy storage system so that the battery energy storage system performs energy loss according to the third control command; wherein, the energy loss is achieved through virtual impedance reconstruction and active loss modulation.

[0045] It should be noted that calculating the first surplus power based on the load power, power compression result, and current float charging result, and generating a third control command based on the first surplus power and sending it to the battery energy storage system so that the battery energy storage system can control energy loss according to the third control command, means that: the EMS obtains the current output power of the diesel generator after power compression and the current absorbed power of the battery energy storage system after current float charging; calculates the first surplus power based on the load power, current output power, and current absorbed power through the bus power balance relationship; the EMS calculates the equivalent virtual resistance value based on the first surplus power and the AC bus voltage, and generates a third control command based on the first surplus power and the equivalent virtual resistance value; the EMS transmits the third control command through the communication bus. The command is sent to the battery energy storage system; the battery energy storage system performs energy loss through its internal energy storage converter according to the received third control command; the energy loss is achieved through virtual impedance reconstruction and active loss modulation: in virtual impedance reconstruction, the energy storage converter corrects its voltage loop reference value according to the equivalent virtual resistance value, so that it is equivalent to a resistive load in electrical characteristics and absorbs active power from the AC bus; in active loss modulation, the energy storage converter maps the first surplus power to the IGBT carrier frequency and zero-sequence voltage component, increases the IGBT switching loss by increasing the switching frequency, and increases the inductor copper loss and magnetic core loss by injecting the zero-sequence component to form a circulating current between the internal inductor and capacitor, thereby converting the absorbed active power into heat dissipation of power devices and inductors.

[0046] Preferably, the step of calculating the first surplus power based on the load power, power compression result, and current float charging result, generating a third control command based on the first surplus power, and issuing it to the battery energy storage system so that the battery energy storage system performs energy dissipation according to the third control command includes: The current output power of the diesel generator after power compression and the current absorbed power of the battery energy storage system after current float charging are obtained. The first surplus power is calculated based on the load power, the current output power and the current absorbed power. The equivalent virtual resistance value is calculated based on the first surplus power and the voltage of the AC bus, and a third control command is generated based on the first surplus power and the equivalent virtual resistance value. The third control command is sent to the battery energy storage system so that the battery energy storage system corrects the voltage loop reference value of the energy storage converter according to the equivalent virtual resistance value to complete the virtual impedance reconstruction; and the first surplus power is mapped to the IGBT carrier frequency and zero-sequence voltage component to complete the active loss modulation.

[0047] In one embodiment, let the current output of the diesel generator after power compression be... The current absorbed power of the battery energy storage system after completing current float charging is Then the first surplus power .

[0048] Furthermore, EMS according to Calculate the equivalent virtual resistance value : ; in, This refers to the voltage of the AC bus. The PCS introduces this voltage into the outer loop of the dual-loop voltage control. In the dq coordinate system, correct the voltage loop reference value: ; in, and These are the voltage loop reference values ​​corrected for the d-axis and q-axis, respectively. and These are the original voltage loop reference values ​​for the d-axis and q-axis, respectively; and These are the real-time feedback currents for the d-axis and q-axis, respectively. This algorithm makes the PCS behave like a load in terms of electrical characteristics, forcing the system to output active power.

[0049] It is worth noting that the implementation of the virtual impedance algorithm is not limited by the coordinate system. Besides correcting the reference values ​​of the d-axis and q-axis voltage loops in the dq rotating coordinate system, it can also be implemented in... The virtual impedance can be implemented using a proportional resonant (PR) controller in a stationary coordinate system, or directly calculated based on instantaneous power theory in a three-phase natural coordinate system (abc). The type of virtual impedance can be expanded from a single virtual resistance to a complex domain impedance including virtual inductance or virtual capacitance, depending on the actual power grid support requirements.

[0050] Furthermore, the underlying FPGA / DSP controller of the PCS establishes the IGBT carrier frequency. With the first surplus power The mapping relationship between them will Boosted linearly from the standard 3kHz to a maximum of 10kHz: ; in, and These are the maximum carrier frequency and the minimum carrier frequency, respectively. This represents the maximum dissipable power; meanwhile, the switching loss principle of the IGBT is as follows: ; in, This refers to switching power loss. This is the proportionality coefficient; This is for output current. By increasing the IGBT carrier frequency... This increases switching losses and converts electrical energy into heat energy in the IGBT module.

[0051] Furthermore, in three-phase modulated waves In the superposition of zero-sequence voltage components in phase This component cancels out in the three-phase line voltage and does not affect the islanded grid voltage quality, but it creates a high-frequency circulating current between the filter inductor and DC capacitor inside the PCS. : ; in, This is the impedance of the LCL filter. The copper loss and core loss of the inductor coil are used to further aid in power absorption, reducing the heat dissipation pressure on the IGBT.

[0052] It is worth noting that, in addition to linearly increasing the GBT carrier frequency, power dissipation can also be increased by using methods such as Random Pulse Width Modulation (RandomPWM), Specific Harmonic Injection (SHE-PWM), dynamically adjusting the dead time, or controlling the zero-sequence circulating current between multi-module parallel systems. In terms of hardware configuration, the core control unit can be implemented by any chip or combination with computing capabilities, such as a DSP, FPGA, ARM processor, PLC, or industrial computer. The energy storage medium can also be completely replaced by other devices with controllable charging capabilities, such as flow batteries, supercapacitors, flywheel energy storage, or sodium-ion batteries. The PCS topology can also be extended to a three-level or modular multilevel (MMC) architecture. All these logical transformations and hardware selections based on the technical concept of this invention should be covered within the patent protection scope of this invention.

[0053] An embodiment of the present invention illustrates the overall workflow of step S103. For example... Figure 4 As shown, the third control command is split into two paths: the upper path is the impedance reconstruction loop, based on the first surplus power. Calculate the equivalent virtual resistance This is combined with real-time current to generate a virtual voltage drop, which directly corrects the voltage loop reference value, forcing the inverter port to exhibit resistive load characteristics to absorb active power; the path below is the loss modulation loop, which maps the power command to the IGBT carrier frequency. and zero-sequence voltage component By increasing the IGBT carrier frequency and injecting a high-frequency circulating current, the switching losses of the IGBT and the magnetic losses of the inductor are actively increased. The two control signals ultimately converge at the SVPWM modulation module to generate specific drive pulses, which accurately convert the specified electrical energy into device heat energy and dissipate it through the heat dissipation system without affecting the external power quality.

[0054] Preferably, after issuing the third control command to the battery energy storage system to enable the battery energy storage system to correct the voltage loop reference value of the energy storage converter according to the equivalent virtual resistance value, thereby completing virtual impedance reconstruction; and mapping the first surplus power to the IGBT carrier frequency and zero-sequence voltage component to complete active loss modulation, the method further includes: The IGBT junction temperature of the energy storage converter is collected in real time and compared with a preset temperature threshold range; Based on the comparison results, corresponding constraint coefficients are generated, and the equivalent virtual resistance value is corrected based on the constraint coefficients.

[0055] This invention, through comparison of IGBT junction temperature with a threshold range and generation of a limiting coefficient to correct the virtual resistance, can increase the virtual resistance value and reduce the current flowing through the IGBT when the IGBT junction temperature exceeds a set threshold, thus ensuring that the power absorption intensity is always automatically adjusted within the device's thermal safety boundary.

[0056] In one embodiment, the PCS samples the IGBT junction temperature in real time. ,like If the temperature exceeds a safety threshold (e.g., 80℃), the PID controller will automatically intervene and adjust the virtual impedance. The coefficient (which increases resistance and reduces power consumption) ensures the equipment does not overheat. The specific workflow is as follows: Figure 5 As shown, when In The following conditions are considered "normal operating range" with a limit factor. Set to 1 to allow the system to absorb the maximum instruction; when Climb to - When the interval is reached, it enters the "linear depreciation zone". Follow The increase is linearly decreasing, relative to the original virtual impedance. Perform a multiplicative correction to forcibly reduce the power absorption capacity and suppress temperature rise; once the temperature exceeds the limit... The red line immediately triggers the "overheat protection zone". Forced zeroing cuts off the energy dissipation path. This closed-loop design ensures that the system always automatically finds the "maximum allowable power dissipation" within the thermal safety boundary, effectively preventing physical damage to equipment caused by excessive pursuit of energy dissipation.

[0057] Step S104: Calculate the second surplus power based on the first surplus power and energy loss results, generate a fourth control command based on the second surplus power and send it to the PCC grid-connected switch, so that the PCC grid-connected switch closes according to the fourth control command, and sends the second surplus power into the mains power system to complete the surplus power consumption.

[0058] It should be noted that the process of calculating the second surplus power based on the first surplus power and energy loss results, generating a fourth control command based on the second surplus power and sending it to the PCC grid-connected switch, so that the PCC grid-connected switch closes according to the fourth control command, and sends the second surplus power into the mains power system, and completing the surplus power absorption means that: the EMS obtains the current heat loss power of the battery energy storage system after energy loss, calculates the second surplus power based on the first surplus power and the current heat loss power; the EMS generates a fourth control command based on the second surplus power, which includes a closing command for the PCC grid-connected switch; the EMS monitors the status data on both sides of the PCC grid-connected switch in real time, and when it detects that the voltage, frequency and phase on both sides of the PCC grid-connected switch meet the pre-synchronization grid connection conditions, it sends the fourth control command to the PCC grid-connected switch; the PCC grid-connected switch closes according to the received fourth control command, and sends the second surplus power from the AC bus into the mains power system, completing the final absorption of surplus power.

[0059] Preferably, the step of calculating the second surplus power based on the first surplus power and energy loss result, generating a fourth control command based on the second surplus power and issuing it to the PCC grid-connected switch, so that the PCC grid-connected switch closes according to the fourth control command, and sends the second surplus power into the mains power system to complete the surplus power consumption, includes: The current heat loss power of the battery energy storage system after energy loss is obtained, the second surplus power is calculated based on the first surplus power and the current heat loss power, and the fourth control command is generated based on the second surplus power. When the status data on both sides of the PCC grid-connected switch are detected to meet the pre-synchronization grid-connection conditions, the fourth control command is sent to the PCC grid-connected switch so that the PCC grid-connected switch closes according to the fourth control command, and the second surplus power is sent into the mains power system to complete the surplus power consumption.

[0060] In one embodiment, after steps S101 to S103 are completed, if the system remains stable, the EMS controls the voltage, frequency, and phase on both sides of the grid-connected circuit breaker (PCC grid-connected switch) to capture these parameters. A weak power outflow trend is maintained using the second surplus power to prevent reverse power surges during grid connection. Finally, the PCC grid-connected switch is closed, supplying the remaining power to the mains power system. The second surplus power is obtained by subtracting the current heat loss power of the battery energy storage system after energy depletion from the first surplus power.

[0061] This invention, through real-time acquisition of the load power of the core rigid load and condition determination, generates a first control command and sends it to the diesel generator for power compression when the condition is determined to be surplus power, thereby reducing the total amount of surplus power that needs to be subsequently absorbed from the source. It also acquires the state of charge (SOC) and temperature of the battery energy storage system in real-time and determines the charging range. When the range is determined to be flexible float charging, a second control command is generated and sent to the battery energy storage system for current float charging, utilizing the battery's short-term absorption capacity in the high SOC range to absorb some surplus power. Furthermore, it calculates the first surplus power based on the load power, power compression result, and current float charging result, generating a third control command and sending it to the battery energy storage system for energy dissipation, converting the first surplus power into internal heat dissipation without increasing the external braking resistor. Finally, it calculates the second surplus power based on the first surplus power and energy dissipation result, generating a fourth control command and sending it to the PCC grid-connected switch for closure, sending the second surplus power into the mains power system, transferring the remaining power to the external grid when the internal absorption capacity is saturated. Compared to existing technologies that cannot meet the requirements of highly integrated black start systems, this application realizes the hierarchical consumption of surplus power in an integrated black start system of mains power-energy storage-diesel generator.

[0062] Optionally, in this embodiment of the invention, the real-time acquisition of the load power of the core rigid load, and the determination of the operating condition based on the load power, wherein when the determination result is that the operating condition is in surplus power condition, a first control command is generated based on the load power and sent to the diesel generator, so that the diesel generator performs power compression according to the first control command, includes: The load power is compared with the minimum safe output of the diesel generator, and the operating condition is determined based on the comparison result; wherein, if the load power is less than the minimum safe output, the determination result is that it is in a surplus power operating condition. When the determination result is that the operating condition is in surplus power, a first control command is generated based on the load power, the minimum safe output and the preset dynamic safety margin. The first control command is sent to the diesel generator so that the diesel generator adjusts the throttle opening through the PID controller to compress the output power of the diesel generator to within a preset range.

[0063] The embodiments of the present invention determine the operating conditions by comparing the load with the minimum output and generate a first command to control the diesel generator PID to adjust the throttle compression output, which can accurately lock the output power of the diesel generator near the minimum safe output threshold, compressing the excess power to the minimum range from the source.

[0064] Optionally, in this embodiment of the invention, the real-time acquisition of the state of charge (SOC) and battery temperature of the battery energy storage system, and the determination of the charging range based on the SOC, wherein when the determination result indicates that the battery is in a flexible float charging range, a second control command is generated based on the SOC and the battery temperature and sent to the battery energy storage system, so that the battery energy storage system performs current float charging according to the second control command, includes: The state of charge is compared with a preset initial value and a maximum value of the state of charge, and a range is determined based on the comparison result; wherein, if the state of charge is greater than or equal to the initial value of the state of charge and less than or equal to the maximum value of the state of charge, the determination result is that it is in the flexible float charging range. When the determination result is that it is in the flexible float charging range, a second control command is generated based on the rated charging current, state of charge decay factor and temperature safety factor of the battery energy storage system. The second control command is sent to the battery energy storage system so that the battery energy storage system controls the bidirectional DC-DC converter to perform current float charging through the energy storage converter.

[0065] This invention, by comparing the State of Charge (SOC) with a threshold range and generating a second instruction, controls the battery to float charge via the converter. This allows the charging current to decrease smoothly as the SOC increases, avoiding bus voltage surges caused by hard battery disconnection.

[0066] Optionally, in this embodiment of the invention, when the determination result indicates that the battery is in the flexible float charging range, generating a second control command based on the rated charging current, state-of-charge decay factor, and temperature safety factor of the battery energy storage system includes: A state of charge decay factor is constructed based on the state of charge, the initial state of charge value, and the maximum state of charge value; and a temperature safety factor is constructed based on the battery temperature. The charging current is calculated based on the rated charging current, the state of charge decay factor, and the temperature safety factor, and a second control command is generated based on the charging current.

[0067] The embodiments of the present invention construct a SOC attenuation factor and a temperature factor within the flexible float charging range and calculate the charging current to generate a second command. This enables the charging current to decrease non-linearly with increasing SOC within the flexible float charging range, ensuring that the battery absorbs power while not exceeding the temperature safety boundary.

[0068] Optionally, in this embodiment of the invention, the step of calculating the first surplus power based on the load power, power compression result, and current float charging result, generating a third control command based on the first surplus power, and issuing it to the battery energy storage system so that the battery energy storage system performs energy dissipation according to the third control command includes: The current output power of the diesel generator after power compression and the current absorbed power of the battery energy storage system after current float charging are obtained. The first surplus power is calculated based on the load power, the current output power and the current absorbed power. The equivalent virtual resistance value is calculated based on the first surplus power and the voltage of the AC bus, and a third control command is generated based on the first surplus power and the equivalent virtual resistance value. The third control command is sent to the battery energy storage system so that the battery energy storage system corrects the voltage loop reference value of the energy storage converter according to the equivalent virtual resistance value to complete the virtual impedance reconstruction; and the first surplus power is mapped to the IGBT carrier frequency and zero-sequence voltage component to complete the active loss modulation.

[0069] This invention calculates the first surplus power by acquiring the output power of the diesel generator after compression and the power of the battery after float charging. Based on the first surplus power and the bus voltage, a virtual resistance is calculated and a third instruction is generated to control the battery to correct the voltage loop reference value to complete impedance reconstruction. At the same time, the first surplus power is mapped to the IGBT frequency and zero-sequence component to complete loss modulation. This enables the energy storage converter to introduce a virtual resistance in the voltage loop to absorb active power. Meanwhile, by increasing the switching frequency and injecting zero-sequence component, the internal device losses are increased, and the safe dissipation of the first surplus power is achieved without adding external hardware.

[0070] Optionally, in this embodiment of the invention, after issuing the third control command to the battery energy storage system to enable the battery energy storage system to correct the voltage loop reference value of the energy storage converter according to the equivalent virtual resistance value, thereby completing virtual impedance reconstruction; and mapping the first surplus power to the IGBT carrier frequency and zero-sequence voltage component to complete active loss modulation, the method further includes: The IGBT junction temperature of the energy storage converter is collected in real time and compared with a preset temperature threshold range; Based on the comparison results, corresponding constraint coefficients are generated, and the equivalent virtual resistance value is corrected based on the constraint coefficients.

[0071] This invention, through comparison of IGBT junction temperature with a threshold range and generation of a limiting coefficient to correct the virtual resistance, can increase the virtual resistance value and reduce the current flowing through the IGBT when the IGBT junction temperature exceeds a set threshold, thus ensuring that the power absorption intensity is always automatically adjusted within the device's thermal safety boundary.

[0072] Optionally, in this embodiment of the invention, the step of calculating the second surplus power based on the first surplus power and energy loss result, generating a fourth control command based on the second surplus power and issuing it to the PCC grid-connected switch, so that the PCC grid-connected switch closes according to the fourth control command, and sends the second surplus power into the mains power system to complete the surplus power consumption, includes: The current heat loss power of the battery energy storage system after energy loss is obtained, the second surplus power is calculated based on the first surplus power and the current heat loss power, and the fourth control command is generated based on the second surplus power. When the status data on both sides of the PCC grid-connected switch are detected to meet the pre-synchronization grid-connection conditions, the fourth control command is sent to the PCC grid-connected switch so that the PCC grid-connected switch closes according to the fourth control command, and the second surplus power is sent into the mains power system to complete the surplus power consumption.

[0073] This invention calculates the second surplus power by acquiring the thermal power after battery loss and generates a fourth instruction. When the pre-synchronization conditions are met on both sides of the grid-connected switch, an instruction is issued to control the switch to close. This can transfer the surplus power to the external power grid when the internal absorption capacity is saturated, avoiding the tripping of reverse power protection triggered by power backflow at the moment of grid connection.

[0074] like Figure 6 As shown, based on the above-mentioned method embodiment, another embodiment of the surplus power consumption method is provided. This embodiment uses the surplus power calculated in real time as the trigger condition and executes a four-level response mechanism in sequence according to priority, including steps S1 to S4.

[0075] Step S1 (Level 1 Strategy) reduces the output of the diesel generator to the minimum safety threshold, thereby reducing the supply from the source; where executing step S1 is equivalent to executing the action of step S101.

[0076] Step S2 (Secondary Strategy): If there is still surplus power after Step S1, the flexible float charging algorithm of the battery energy storage system is activated, utilizing... The high-level buffering capacity is absorbed; wherein, executing step S2 is equivalent to executing step S102.

[0077] Step S3 (Level 3 Strategy): When the battery in the battery energy storage system approaches saturation, the virtual impedance and active loss mode of the PCS are activated to convert electrical energy into heat energy for physical dissipation; wherein, executing step S3 is equivalent to executing the action of step S103.

[0078] Step S4 (Level 4 Strategy): Under the premise of system stability, perform pre-synchronization detection and close the PCC switch to send the remaining surplus power to the mains power system; wherein, performing step S4 is equivalent to performing the action of step S104.

[0079] By employing a step-by-step reduction and dynamic fallback logic, this embodiment of the invention can ensure voltage stability and power balance of an isolated grid under extreme black-start conditions.

[0080] like Figure 7 As shown, based on the above method embodiments, corresponding apparatus embodiments are provided; One embodiment of the present invention provides a surplus power consumption device applied to an energy management system; wherein, the energy management system is communicatively connected to an integrated black start system of mains power-energy storage-diesel generator, the integrated black start system of mains power-energy storage-diesel generator includes a mains power system connected to the same AC bus, a diesel generator, a battery energy storage system and a core rigid load; the mains power system is connected to the AC bus through a PCC grid connection switch; The surplus power absorption device includes: a first surplus power absorption module 701, a second surplus power absorption module 702, a third surplus power absorption module 703 and a fourth surplus power absorption module 704. The first surplus power absorption module 701 is used to collect the load power of the core rigid load in real time, and make a working condition judgment based on the load power. When the judgment result is that it is in a surplus power working condition, it generates a first control command based on the load power and sends it to the diesel generator so that the diesel generator performs power compression according to the first control command. The second surplus power absorption module 702 is used to collect the state of charge and battery temperature of the battery energy storage system in real time, and make a range determination based on the state of charge. When the determination result is that it is in the flexible float charging range, a second control command is generated based on the state of charge and the battery temperature and sent to the battery energy storage system so that the battery energy storage system performs current float charging according to the second control command. The third surplus power absorption module 703 is used to calculate the first surplus power based on the load power, power compression result and current float charging result, generate a third control command based on the first surplus power and send it to the battery energy storage system so that the battery energy storage system performs energy loss according to the third control command; wherein, the energy loss is achieved through virtual impedance reconstruction and active loss modulation; The fourth surplus power absorption module 704 is used to calculate the second surplus power based on the first surplus power and energy loss result, generate a fourth control command based on the second surplus power and send it to the PCC grid-connected switch, so that the PCC grid-connected switch closes according to the fourth control command, and sends the second surplus power into the mains power system to complete the surplus power absorption.

[0081] Optionally, in this embodiment of the invention, the first surplus power absorption module 701 includes: a working condition determination submodule, a first control command generation submodule, and a first control command issuance submodule; The operating condition determination submodule is used to compare the load power with the minimum safe output of the diesel generator and determine the operating condition based on the comparison result; wherein, if the load power is less than the minimum safe output, the determination result is that it is in a surplus power operating condition. The first control command generation submodule is used to generate a first control command based on the load power, the minimum safe output, and the preset dynamic safety margin when the determination result is that the operating condition is in surplus power condition. The first control command sending submodule is used to send the first control command to the diesel generator so that the diesel generator adjusts the throttle opening through the PID controller and compresses the output power of the diesel generator to within a preset range.

[0082] The embodiments of the present invention determine the operating conditions by comparing the load with the minimum output and generate a first command to control the diesel generator PID to adjust the throttle compression output, which can accurately lock the output power of the diesel generator near the minimum safe output threshold, compressing the excess power to the minimum range from the source.

[0083] Optionally, in this embodiment of the invention, the second surplus power absorption module 702 includes: an interval determination submodule, a second control command generation submodule, and a second control command issuing submodule; The interval determination submodule is used to compare the state of charge with a preset initial value and a maximum value of the state of charge, and to determine the interval based on the comparison result; wherein, if the state of charge is greater than or equal to the initial value of the state of charge and less than or equal to the maximum value of the state of charge, the determination result is that it is in the flexible float charging interval. The second control command generation submodule is used to generate a second control command based on the rated charging current, state of charge decay factor and temperature safety factor of the battery energy storage system when the determination result is that it is in the flexible float charging range. The second control command sending submodule is used to send the second control command to the battery energy storage system so that the battery energy storage system controls the bidirectional DC-DC converter to perform current float charging through the energy storage converter.

[0084] This invention, by comparing the State of Charge (SOC) with a threshold range and generating a second instruction, controls the battery to float charge via the converter. This allows the charging current to decrease smoothly as the SOC increases, avoiding bus voltage surges caused by hard battery disconnection.

[0085] Optionally, in this embodiment of the invention, the second control instruction generation submodule includes: a factor construction unit and an instruction generation unit; The factor construction unit is used to construct a state of charge decay factor based on the state of charge, the initial state of charge value, and the maximum state of charge value, and to construct a temperature safety factor based on the battery temperature. The instruction generation unit is used to calculate the charging current based on the rated charging current, the state of charge decay factor and the temperature safety factor, and to generate a second control instruction based on the charging current.

[0086] The embodiments of the present invention construct a SOC attenuation factor and a temperature factor within the flexible float charging range and calculate the charging current to generate a second command. This enables the charging current to decrease non-linearly with increasing SOC within the flexible float charging range, ensuring that the battery absorbs power while not exceeding the temperature safety boundary.

[0087] Optionally, in this embodiment of the invention, the third surplus power absorption module 703 includes: a first surplus power calculation submodule, a third control command generation submodule, and a third control command issuing submodule; The first surplus power calculation submodule is used to obtain the current output power of the diesel generator after power compression and the current absorbed power of the battery energy storage system after current float charging, and calculate the first surplus power based on the load power, the current output power and the current absorbed power; The third control instruction generation submodule is used to calculate the equivalent virtual resistance value based on the first surplus power and the voltage of the AC bus, and generate a third control instruction based on the first surplus power and the equivalent virtual resistance value. The third control command issuing submodule is used to issue the third control command to the battery energy storage system, so that the battery energy storage system corrects the voltage loop reference value of the energy storage converter according to the equivalent virtual resistance value to complete the virtual impedance reconstruction; and maps the first surplus power to the IGBT carrier frequency and zero-sequence voltage component to complete active loss modulation.

[0088] This invention calculates the first surplus power by acquiring the output power of the diesel generator after compression and the power of the battery after float charging. Based on the first surplus power and the bus voltage, a virtual resistance is calculated and a third instruction is generated to control the battery to correct the voltage loop reference value to complete impedance reconstruction. At the same time, the first surplus power is mapped to the IGBT frequency and zero-sequence component to complete loss modulation. This enables the energy storage converter to introduce a virtual resistance in the voltage loop to absorb active power. Meanwhile, by increasing the switching frequency and injecting zero-sequence component, the internal device losses are increased, and the safe dissipation of the first surplus power is achieved without adding external hardware.

[0089] Optionally, in this embodiment of the invention, after the third control command issuing submodule, the system further includes: an interval comparison submodule and a virtual resistance correction submodule; The interval comparison submodule is used to collect the IGBT junction temperature of the energy storage converter in real time and compare the IGBT junction temperature with a preset temperature threshold range. The virtual resistance correction submodule is used to generate a corresponding constraint coefficient based on the comparison result, and to correct the equivalent virtual resistance value based on the constraint coefficient.

[0090] This invention, through comparison of IGBT junction temperature with a threshold range and generation of a limiting coefficient to correct the virtual resistance, can increase the virtual resistance value and reduce the current flowing through the IGBT when the IGBT junction temperature exceeds a set threshold, thus ensuring that the power absorption intensity is always automatically adjusted within the device's thermal safety boundary.

[0091] Optionally, in this embodiment of the invention, the fourth surplus power absorption module 704 includes: a fourth control command generation submodule and a fourth control command issuing submodule; The fourth control command generation submodule is used to obtain the current heat loss power of the battery energy storage system after the energy loss is completed, calculate the second surplus power based on the first surplus power and the current heat loss power, and generate the fourth control command based on the second surplus power. The fourth control command issuing submodule is used to issue the fourth control command to the PCC grid-connected switch when the status data on both sides of the PCC grid-connected switch are detected to meet the pre-synchronization grid-connection conditions, so that the PCC grid-connected switch closes according to the fourth control command and sends the second surplus power into the mains power system to complete the surplus power consumption.

[0092] This invention calculates the second surplus power by acquiring the thermal power after battery loss and generates a fourth instruction. When the pre-synchronization conditions are met on both sides of the grid-connected switch, an instruction is issued to control the switch to close. This can transfer the surplus power to the external power grid when the internal absorption capacity is saturated, avoiding the tripping of reverse power protection triggered by power backflow at the moment of grid connection.

[0093] It is understood that the above-described device embodiments correspond to the method embodiments of the present invention, and can implement the surplus power consumption method provided by any of the above-described method embodiments of the present invention.

[0094] In this embodiment of the invention, the first surplus power absorption module 701 collects the load power of the core rigid load in real time and determines the operating condition. When the condition is determined to be surplus power, a first control command is generated and sent to the diesel generator for power compression, which can reduce the total amount of surplus power that needs to be absorbed later from the source. The second surplus power absorption module 702 collects the state of charge and temperature of the battery energy storage system in real time and determines the range. When the range is determined to be flexible float charging range, a second control command is generated and sent to the battery energy storage system for current float charging, which can utilize the battery's short-term absorption capacity in the high SOC range to absorb part of the surplus power. The third surplus power absorption module 703 calculates the first surplus power based on the load power, power compression result, and current float charging result, and generates a third control command which is sent to the battery energy storage system for energy dissipation. This allows the first surplus power to be converted into internal heat dissipation without increasing the external braking resistor. The fourth surplus power absorption module 704 calculates the second surplus power based on the first surplus power and energy dissipation result, and generates a fourth control command which is sent to the PCC grid-connected switch for closing, sending the second surplus power into the mains power system. This allows the remaining power to be transferred to the external grid when the internal absorption capacity is saturated. Compared to existing technologies that cannot meet the requirements of highly integrated black start systems, this application achieves hierarchical absorption of surplus power in an integrated mains-energy storage-diesel generator black start system.

[0095] It should be noted that the device embodiments described above are merely illustrative, and some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Furthermore, in the accompanying drawings of the device embodiments provided by this invention, the connection relationships between modules indicate that they have communication connections, which can specifically be implemented as one or more communication buses or signal lines. Those skilled in the art can understand and implement this without any creative effort.

[0096] Based on the above-described embodiment of a method for absorbing excess power, another embodiment of the present invention provides a terminal device, which includes a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, it implements a method for absorbing excess power according to any embodiment of the present invention.

[0097] For example, in this embodiment, the computer program can be divided into one or more modules, which are stored in the memory and executed by the processor to complete the present invention. The one or more modules may be a series of computer program instruction segments capable of performing a specific function, which describe the execution process of the computer program in the terminal device.

[0098] The terminal device may be a desktop computer, laptop, handheld computer, or cloud server, etc. The terminal device may include, but is not limited to, a processor and a memory.

[0099] The processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor or any conventional processor. The processor is the control center of the terminal device, connecting all parts of the terminal device via various interfaces and lines.

[0100] Based on the above-described method embodiments, another embodiment of the present invention provides a computer-readable storage medium including a stored computer program, wherein, when the computer program is executed, it controls the device where the computer-readable storage medium is located to execute a surplus power consumption method as described in any of the above-described method embodiments of the present invention.

[0101] The modules / units integrated in the device / terminal equipment, if implemented as software functional units and sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the above embodiments of the present invention can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include: any entity or device capable of carrying the computer program code, a recording medium, a USB flash drive, a portable hard drive, a magnetic disk, an optical disk, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium, etc.

[0102] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A method for absorbing surplus power, characterized in that, This system is applied to an energy management system; wherein the energy management system is communicatively connected to an integrated black start system of mains power-energy storage-diesel generator, and the integrated black start system of mains power-energy storage-diesel generator includes a mains power system connected to the same AC bus, a diesel generator, a battery energy storage system, and a core rigid load; the mains power system is connected to the AC bus through a PCC grid connection switch; The method for absorbing excess power includes: The load power of the core rigid load is collected in real time, and the operating condition is determined based on the load power. When the determination result is that the operating condition is in surplus power condition, a first control command is generated based on the load power and sent to the diesel generator so that the diesel generator can compress power according to the first control command. The state of charge (SOC) and battery temperature of the battery energy storage system are collected in real time, and the SOC is used to determine the range. When the determination result is that the battery is in the flexible float charging range, a second control command is generated based on the SOC and battery temperature and sent to the battery energy storage system so that the battery energy storage system can perform current float charging according to the second control command. The first surplus power is calculated based on the load power, power compression result, and current float charging result. A third control command is generated based on the first surplus power and sent to the battery energy storage system so that the battery energy storage system performs energy loss according to the third control command. The energy loss is achieved through virtual impedance reconstruction and active loss modulation. The second surplus power is calculated based on the first surplus power and energy loss results. A fourth control command is generated based on the second surplus power and sent to the PCC grid-connected switch so that the PCC grid-connected switch closes according to the fourth control command, and the second surplus power is sent into the mains power system to complete the surplus power consumption.

2. The method for absorbing surplus power as described in claim 1, characterized in that, The real-time acquisition of the load power of the core rigid load, and the determination of the operating condition based on the load power, when the determination result is that it is in a surplus power operating condition, generates a first control command based on the load power and sends it to the diesel generator, so that the diesel generator performs power compression according to the first control command, including: The load power is compared with the minimum safe output of the diesel generator, and the operating condition is determined based on the comparison result; wherein, if the load power is less than the minimum safe output, the determination result is that it is in a surplus power operating condition. When the determination result is that the operating condition is in surplus power, a first control command is generated based on the load power, the minimum safe output and the preset dynamic safety margin. The first control command is sent to the diesel generator so that the diesel generator adjusts the throttle opening through the PID controller to compress the output power of the diesel generator to within a preset range.

3. The method for absorbing surplus power as described in claim 1, characterized in that, The system collects the state of charge (SOC) and battery temperature of the battery energy storage system in real time, and determines the charging range based on the SOC. When the determination result indicates that the battery is in a flexible float charging range, a second control command is generated based on the SOC and battery temperature and sent to the battery energy storage system to enable the battery energy storage system to perform current float charging according to the second control command. This includes: The state of charge is compared with a preset initial value and a maximum value of the state of charge, and a range is determined based on the comparison result; wherein, if the state of charge is greater than or equal to the initial value of the state of charge and less than or equal to the maximum value of the state of charge, the determination result is that it is in the flexible float charging range. When the determination result is that it is in the flexible float charging range, a second control command is generated based on the rated charging current, state of charge decay factor and temperature safety factor of the battery energy storage system. The second control command is sent to the battery energy storage system so that the battery energy storage system controls the bidirectional DC-DC converter to perform current float charging through the energy storage converter.

4. The method for absorbing surplus power as described in claim 3, characterized in that, When the determination result indicates that the battery is in the flexible float charging range, a second control command is generated based on the rated charging current, state-of-charge decay factor, and temperature safety factor of the battery energy storage system, including: A state of charge decay factor is constructed based on the state of charge, the initial state of charge value, and the maximum state of charge value; and a temperature safety factor is constructed based on the battery temperature. The charging current is calculated based on the rated charging current, the state of charge decay factor, and the temperature safety factor, and a second control command is generated based on the charging current.

5. A method for absorbing surplus power as described in claim 3, characterized in that, The step of calculating a first surplus power based on the load power, power compression result, and current float charging result, generating a third control command based on the first surplus power, and issuing it to the battery energy storage system so that the battery energy storage system can perform energy dissipation according to the third control command includes: The current output power of the diesel generator after power compression and the current absorbed power of the battery energy storage system after current float charging are obtained. The first surplus power is calculated based on the load power, the current output power and the current absorbed power. The equivalent virtual resistance value is calculated based on the first surplus power and the voltage of the AC bus, and a third control command is generated based on the first surplus power and the equivalent virtual resistance value. The third control command is sent to the battery energy storage system so that the battery energy storage system corrects the voltage loop reference value of the energy storage converter according to the equivalent virtual resistance value to complete the virtual impedance reconstruction; and the first surplus power is mapped to the IGBT carrier frequency and zero-sequence voltage component to complete the active loss modulation.

6. The method for absorbing surplus power as described in claim 5, characterized in that, The third control command is sent to the battery energy storage system so that the battery energy storage system corrects the voltage loop reference value of the energy storage converter according to the equivalent virtual resistance value, so as to complete the virtual impedance reconstruction. After mapping the first surplus power to the IGBT carrier frequency and zero-sequence voltage component to complete active loss modulation, the method further includes: The IGBT junction temperature of the energy storage converter is collected in real time and compared with a preset temperature threshold range; Based on the comparison results, corresponding constraint coefficients are generated, and the equivalent virtual resistance value is corrected based on the constraint coefficients.

7. The method for absorbing surplus power as described in claim 1, characterized in that, The process of calculating the second surplus power based on the first surplus power and energy loss results, generating a fourth control command based on the second surplus power, and issuing it to the PCC grid-connected switch, so that the PCC grid-connected switch closes according to the fourth control command, sending the second surplus power into the mains power system to complete the surplus power absorption, includes: The current heat loss power of the battery energy storage system after energy loss is obtained, the second surplus power is calculated based on the first surplus power and the current heat loss power, and the fourth control command is generated based on the second surplus power. When the status data on both sides of the PCC grid-connected switch are detected to meet the pre-synchronization grid-connection conditions, the fourth control command is sent to the PCC grid-connected switch so that the PCC grid-connected switch closes according to the fourth control command, and the second surplus power is sent into the mains power system to complete the surplus power consumption.

8. A device for absorbing excess power, characterized in that, This system is applied to an energy management system; wherein the energy management system is communicatively connected to an integrated black start system of mains power-energy storage-diesel generator, and the integrated black start system of mains power-energy storage-diesel generator includes a mains power system connected to the same AC bus, a diesel generator, a battery energy storage system, and a core rigid load; the mains power system is connected to the AC bus through a PCC grid connection switch; The surplus power absorption device includes: a first surplus power absorption module, a second surplus power absorption module, a third surplus power absorption module and a fourth surplus power absorption module; The first surplus power absorption module is used to collect the load power of the core rigid load in real time and make a working condition judgment based on the load power. When the judgment result is that it is in a surplus power working condition, it generates a first control command based on the load power and sends it to the diesel generator so that the diesel generator performs power compression according to the first control command. The second surplus power absorption module is used to collect the state of charge and battery temperature of the battery energy storage system in real time, and make a range determination based on the state of charge. When the determination result is that it is in the flexible float charging range, a second control command is generated based on the state of charge and the battery temperature and sent to the battery energy storage system so that the battery energy storage system performs current float charging according to the second control command. The third surplus power absorption module is used to calculate the first surplus power based on the load power, power compression result, and current float charging result, generate a third control command based on the first surplus power, and send it to the battery energy storage system so that the battery energy storage system performs energy loss according to the third control command; wherein, the energy loss is achieved through virtual impedance reconstruction and active loss modulation; The fourth surplus power absorption module is used to calculate the second surplus power based on the first surplus power and energy loss results, generate a fourth control command based on the second surplus power and send it to the PCC grid-connected switch, so that the PCC grid-connected switch closes according to the fourth control command, and sends the second surplus power into the mains power system to complete the surplus power absorption.

9. A terminal device, characterized in that, It includes a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein when the processor executes the computer program, it implements a surplus power consumption method as described in any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, include: A stored computer program, wherein, when the computer program is executed, it controls the device containing the computer-readable storage medium to perform a surplus power consumption method as described in any one of claims 1-7.

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