An offshore oilfield island grid control method and system

Abstract

The application discloses an offshore oilfield island power grid control method and system. The method establishes a master-slave power supply strong coupling model, dynamically corrects the available capacity of a waste heat generator set, implements a three-level reverse power defense strategy based on the load margin of a main power supply, actively performs power limiting or off-grid control on wind power under a low-load working condition to guarantee the safety of the main power supply. The core of the application is to perform wind-fire-storage collaborative control based on the thermal inertia of waste heat, utilize an energy storage device to perform fast bidirectional power compensation, effectively fill the time difference between the adjustment action of a gas turbine and the response lag of a waste heat unit, realize system power suppression under the premise of avoiding load shedding, and simultaneously adopt a periodic rolling pre-computation mechanism to process faults. The application effectively solves the thermal response lag and reverse power risk problems under multi-energy coupling, and significantly guarantees the operation stability of an island power grid.

Description

Technical Field

[0001] This application relates to the field of power system automation control technology, specifically to a control method and system for an isolated power grid in an offshore oil field. Background Technology

[0002] As offshore oilfield development deepens, its energy structure is gradually shifting from traditional single-gas turbine power generation to a multi-energy integrated model of "gas turbine + waste heat utilization + offshore wind power". However, this islanded power grid with heterogeneous energy sources also faces significant stability challenges. One of the core problems of the current system is the neglect of the "thermal inertia lag" characteristic of waste heat units: their output depends on the exhaust gas of the gas turbine, and their response usually lags behind the turbine's operation by 5-8 seconds. When offshore wind power experiences severe fluctuations, although the turbine can adjust quickly, the waste heat output cannot follow immediately, leading to frequent instantaneous power deficits or surpluses in the system. The former often forces load shedding, while the latter may trigger turbine reverse power tripping. In addition, existing energy storage control strategies are relatively crude, usually only using energy storage as a general frequency regulation means, without designing precise complementary control for the specific physical process of "waste heat lag", which prevents energy storage from fully playing its role in filling power gaps and smoothing fluctuations. Meanwhile, the system also has shortcomings in reverse power defense and rapid fault response: on the one hand, it lacks direct defense logic based on the main power load rate, and on the other hand, the calculation and action after the fault takes a long time, which can easily lead to the frequency dropping too quickly and further threaten the safe and stable operation of the power grid. Summary of the Invention

[0003] The purpose of this application is to propose a control method and system for an isolated power grid in an offshore oilfield, in order to solve the technical problems faced by existing isolated microgrids in offshore oilfields after connecting a high proportion of wind power, such as complex multi-energy coupling, significant thermal inertia lag in the response of waste heat generator sets, and the risk of reverse power from the main power source under low load conditions.

[0004] To address the aforementioned technical problems, this application provides a method for controlling an isolated power grid in an offshore oilfield, applied to an energy management system (EMS). The power grid includes a gas turbine generator set as the main power source, a waste heat generator set relying on the exhaust gas from the main power source, an offshore wind turbine, and an energy storage device. The method includes the following steps: Real-time acquisition of the operating status of the gas turbine generator set; The effective output prediction value of the waste heat generator unit is dynamically calculated using a linear regression coupling model. The predicted effective output value of the waste heat generator set P wh_set The calculation formula is: P wh_set = Cbase + λ × β × P gt in: C base This refers to the fundamental thermal capacity constant of the associated gas turbine generator set under no-load conditions. λ The master-slave coupling coefficient of the gas turbine generator set; P gt For the real-time active power output of the associated gas turbine generator set; β This is a correction factor for flue gas heat loss. This predicted value is updated in real time to the total available capacity data of the power grid, along with the real-time active power output of the associated gas turbine generator units. P gt Below its minimum stable operating threshold P set_min At that time, forced P wh_set Set to 0 to perform master-slave power supply strong coupling capacity correction: The system uses a hysteresis response model to monitor wind turbine output fluctuations in real time. When a fluctuation is detected, it calculates the instantaneous power deviation caused by the gas turbine generator adjusting but the waste heat generator not yet responding. Then, it controls the energy storage device to perform bidirectional power compensation to smooth out the instantaneous power deviation. include: (1) Wind power sudden drop compensation: The power fluctuation rate threshold of the wind turbine is set as follows: D set When the downward fluctuation rate of wind turbine output is detected to exceed D set At that time, the EMS calculates the power gap between the issuance of the load increase command of the gas turbine generator set and the actual increase of the output of the waste heat generator set, and then controls the energy storage device to discharge rapidly to fill the gap until the output of the waste heat generator set rises to the steady state value. (2) Sudden increase in wind power absorption: When the upward fluctuation rate of wind turbine output is detected to exceed D set When the EMS calculates the total power surplus caused by the waste heat generator maintaining high output due to thermal inertia after the gas turbine generator set issues the load reduction command, it then controls the energy storage device to charge in order to absorb the surplus power and prevent the gas turbine generator set from triggering reverse power protection due to the delayed reduction of waste heat.

[0005] Furthermore, the method also includes the steps of: real-time monitoring of the real-time total load rate of the gas turbine generator set; when the load rate is lower than a preset safety threshold, triggering a graded suppression strategy for the wind turbine generator set to prevent the gas turbine generator set from entering the reverse power condition. The reverse power protection is implemented based on the main power supply load margin and includes the following three levels of protection logic: (1) Level 1 load limiting control: Set the first load warning threshold for the gas turbine generator set. P limit_1 When in fact, always exert effort P main < P limit_1 At that time, EMS will forcibly constrain the upper limit of wind turbine dispatch output to a preset safety value. P w_safe the following; (2) Secondary soft cut-off control: Set the second load emergency threshold for the gas turbine generator set. P limit_2 ;when P main < P limit_2 Or, if reverse power is detected in the gas turbine generator set and the duration exceeds the set delay, it indicates that the generator set is experiencing a power outage. T delay At that time, EMS issued a soft shutdown command to the wind turbine. (3) Level 3 hard cut-off protection: When the reverse power value of the gas turbine generator set is detected to exceed the protection setting value, or when the output of the wind turbine is not detected to return to zero within the set time after the Level 2 soft shutdown command is issued, the EMS directly controls the grid-connected circuit breaker of the wind turbine to open.

[0006] Furthermore, the method also includes the following steps: When the power grid is operating normally, the EMS calculates the instantaneous power balance index of the system assuming a typical fault occurs in a set cycle. P bal The corresponding tiered load offloading strategy is pre-matched and stored in a preset fast storage unit of the EMS; when a physical fault signal is detected, the strategy in the preset fast storage unit is directly read and the offloading action is executed, including: (1) Rolling calculation: The EMS backend calculates the instantaneous power balance index of the system cyclically at a preset period: P bal = P sys_cap - P loss - P load_sum - σ in, P sys_cap The total available capacity of the entire network system at the current moment (including) P wh_set ), P lossThis assumes the rated power loss of the faulty unit (i.e., the power deficit caused by the unit tripping). P load_sum This represents the total real-time load of the entire network. σ The threshold is dynamically adjusted for safety. (2) Table lookup mapping: when P bal When < 0, based on its absolute value, the preset load level offload matrix table is queried in real time to lock the load level to be cut off and update it to memory; (3) Instantaneous action: When a fault occurs, skip the calculation process and directly execute the load removal instruction locked in memory.

[0007] Another aspect of this application provides a wind-storage collaborative compensation system for waste heat hysteresis in an isolated offshore oilfield, comprising: Data acquisition and execution module: used to collect the operating status of the gas turbine generator set in real time; Multi-energy coupling calculation module: used to dynamically calculate the predicted effective output value of the waste heat generator unit using a linear regression coupling model; The predicted effective output value of the waste heat generator set P wh_set The calculation formula is: P wh_set = C base + λ × β × P gt in: C base This refers to the fundamental thermal capacity constant of the associated gas turbine generator set under no-load conditions. λ The master-slave coupling coefficient of the gas turbine generator set; P gt For the real-time active power output of the associated gas turbine generator set; β This is a correction factor for flue gas heat loss. This predicted value is updated in real time to the total available capacity data of the power grid, along with the real-time active power output of the associated gas turbine generator units. P gt Below its minimum stable operating threshold P set_min At that time, forced P wh_set Set to 0 to perform master-slave power supply strong coupling capacity correction: Wind-Storage Co-control Module: Used to monitor wind turbine output fluctuations in real time. When a wind turbine output fluctuation is detected, it calculates the instantaneous power deviation caused by the gas turbine generator set adjusting but the waste heat generator set not yet responding. Then, it controls the energy storage device to perform bidirectional power compensation to smooth out the instantaneous power deviation. include: (1) Wind power sudden drop compensation: The power fluctuation rate threshold of the wind turbine is set as follows: D set When the downward fluctuation rate of wind turbine output is detected to exceed D set At that time, the EMS calculates the power gap between the issuance of the load increase command of the gas turbine generator set and the actual increase of the output of the waste heat generator set, and then controls the energy storage device to discharge rapidly to fill the gap until the output of the waste heat generator set rises to the steady state value. (2) Sudden increase in wind power absorption: When the upward fluctuation rate of wind turbine output is detected to exceed D set When the EMS calculates the total power surplus caused by the waste heat generator maintaining high output due to thermal inertia after the gas turbine generator set issues the load reduction command, it then controls the energy storage device to charge in order to absorb the surplus power and prevent the gas turbine generator set from triggering reverse power protection due to the delayed reduction of waste heat.

[0008] Furthermore, the system also includes a reverse power defense module: used to monitor the real-time total load rate of the gas turbine generator set; when the load rate is lower than the preset safety threshold, it triggers a graded suppression strategy for the wind turbine generator set to prevent the gas turbine generator set from entering the reverse power condition. The reverse power protection is implemented based on the main power supply load margin and includes the following three levels of protection logic: (1) Level 1 load limiting control: Set the first load warning threshold for the gas turbine generator set. P limit_1 When in fact, always exert effort P main < P limit_1 At that time, EMS will forcibly constrain the upper limit of wind turbine dispatch output to a preset safety value. P w_safe the following; (2) Secondary soft cut-off control: Set the second load emergency threshold for the gas turbine generator set. P limit_2 ;when P main < P limit_2 Or, if reverse power is detected in the gas turbine generator set and the duration exceeds the set delay, it indicates that the generator set is experiencing a power outage. T delayAt that time, EMS issued a soft shutdown command to the wind turbine. (3) Level 3 hard cut-off protection: When the reverse power value of the gas turbine generator set is detected to exceed the protection setting value, or when the output of the wind turbine is not detected to return to zero within the set time after the Level 2 soft shutdown command is issued, the EMS directly controls the grid-connected circuit breaker of the wind turbine to open.

[0009] Furthermore, the system also includes a pre-calculated stability module for performing periodic rolling calculations and rapid memory cell updates. The periodic rolling pre-calculation includes: (1) Rolling calculation: The EMS backend calculates the instantaneous power balance index of the system cyclically at a preset period: P bal = P sys_cap - P loss - P load_sum - σ in, P sys_cap This represents the total available capacity of the entire network system at the current moment. P loss Assuming the rated power loss of the faulty unit, P load_sum This represents the total real-time load of the entire network. σ The threshold is adjusted dynamically for safety.

[0010] (2) Table lookup mapping: when P bal When < 0, based on its absolute value, the preset load level offload matrix table is queried in real time to lock the load level to be cut off and update it to memory; (3) Instantaneous action: When a fault occurs, skip the calculation process and directly execute the load removal instruction locked in memory.

[0011] Compared with the prior art, this application has the following advantages: (1) Solved the problem of thermal inertia lag: In response to the common "gas turbine + waste heat utilization" mode in offshore oil fields, this application innovatively introduces an energy storage device to compensate for the thermal inertia lag of waste heat power generation. When the wind power fluctuates drastically, the millisecond-level response characteristics of energy storage are used to fill the time difference between the gas turbine regulation and the output change of the waste heat unit, effectively suppressing the power impact of the system and avoiding frequency overruns caused by regulation lag.

[0012] (2) A multi-level reverse power defense system was constructed: By monitoring the load margin of the main power supply in real time, a defense-in-depth mechanism was established for wind power, consisting of first-level limiting, second-level soft cut-off, and third-level hard cut-off. This effectively prevented the gas turbine generator unit from tripping due to absorbing backfeed power under low load and high wind speed conditions, ensuring the safe operation of the core supporting power source of the isolated power grid. Attached Figure Description

[0013] Figure 1 This is a system control logic architecture diagram of an embodiment of this application.

[0014] Figure 2 This is a timing logic diagram of the wind-fire-storage collaborative compensation for waste heat lag in the embodiments of this application.

[0015] Figure 3 This is a flowchart of a three-level reverse power defense system based on the main power load rate in an embodiment of this application.

[0016] Figure 4 This is a flowchart of the fault emergency pre-calculation and action process in the embodiments of this application. Detailed Implementation

[0017] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0018] Example 1: System Architecture and Basic Model like Figure 1 As shown in this embodiment, the offshore oilfield island power grid control system mainly includes four types of core equipment in its physical layer: gas turbine generator sets that provide voltage and frequency support as the main power source, waste heat generator sets driven by the high-temperature exhaust gas of the gas turbine, offshore wind turbine sets with strong random fluctuations, and energy storage devices with rapid bidirectional adjustment capabilities.

[0019] The control center of the entire system is the Energy Management System (EMS). The EMS collects electrical analog quantities (voltage, current, power, frequency) and switch status quantities of each node in the network in real time. After processing by the internal core algorithm, it issues active power dispatch, start-stop, limit, and charge / discharge commands to the controllers of each power generation equipment.

[0020] Given the unique strong coupling relationship between gas turbines and waste heat boilers in offshore oilfield power grids, the EMS (Energy Management System) first needs to accurately assess the available capacity of the power source. In this embodiment, the EMS uses a linear regression coupling model to dynamically calculate the predicted current effective output of the waste heat generator unit. Pwh_set : P wh_set = C base + λ × β × P gt in: C base This refers to the fundamental thermal capacity constant of the associated gas turbine generator set under no-load conditions. λ The master-slave coupling coefficient of the gas turbine generator set; P gt For the real-time active power output of the associated gas turbine generator set; β This is a correction factor for flue gas heat loss; when the real-time active power output of the associated gas turbine generator unit... P gt Below its minimum stable operating threshold P set_min At that time, forced P wh_set Set to 0.

[0021] EMS will calculate P wh_set Real-time aggregation of total available capacity across the entire network system P sys_cap This ensures that subsequent scheduling and fault calculations are based on actual effective output, rather than rated capacity.

[0022] Example 2: Coordinated Control of Wind-Fire-Storage Based on Waste Heat Thermal Inertia Offshore oilfield power grids have extremely high requirements for power supply reliability, and it is essential to avoid cutting off critical production loads due to frequency fluctuations caused by power supply regulation lags. The core control logic of this embodiment utilizes the millisecond-level response characteristics of energy storage devices to bridge the time difference between the gas turbine regulation action and the waste heat unit's thermal response. For example... Figure 2 The sequential logic shown includes two typical scenarios: Scenario A: A sudden drop in wind power output, such as Figure 2 As shown on the left, when the offshore wind power output is monitored at... t A rapid decline begins at moment 1 (the rate of fluctuation exceeds the set threshold). D set The EMS (Electronic Management System) issues a command to the main power supply gas turbine to increase its output to maintain power balance. The gas turbine's output... P gt It then rapidly climbs, but due to the thermal inertia of the waste heat boiler, the rise in exhaust temperature and steam parameters takes time, resulting in a decrease in the actual output of the waste heat unit. P wh_actual Unable to follow immediatelyP gt As the power increases, a significant instantaneous power gap arises between the two (shaded area A in the figure). At this point, the EMS calculates this instantaneous power gap in real time and instructs the energy storage device to quickly enter a discharge state. The discharge power of the energy storage device... P ess_dis The system deficiencies were quickly filled. As time went on... t 2. As heat accumulates in the waste heat boiler, the output of the waste heat unit gradually increases to a new steady-state value, and the discharge power of the energy storage device controlled by the EMS gradually decreases to zero. This process smooths the total output curve and avoids the system from hitting the low-frequency load shedding threshold due to instantaneous active power deficit.

[0023] Scenario B: A sudden increase in wind power, such as Figure 2 As shown on the right, when the wind power output is t When the frequency increases rapidly at time 3, in order to maintain frequency stability, the EMS commands the gas turbine to rapidly reduce its load. P gt The temperature drops rapidly. Also due to thermal inertia, the heat inside the waste heat boiler cannot dissipate immediately, and the waste heat unit remains hot for a period of time. t 3 to t 4) The system maintains a high output level, indicating "artificially high" output (shaded area B in the diagram), causing the total power generation to exceed the total load. If left unchecked, this surplus power may force the gas turbine into reverse power operation. At this point, the EMS commands the energy storage device to switch to charging mode, with its charging power P... ess_chg The system absorbs excess power. As the output of the waste heat unit gradually decreases due to the reduction in heat source, the energy storage charging power also decreases accordingly. This process prevents the gas turbine from being forced to shut down due to excess energy in the system.

[0024] Example 3: Three-level reverse power defense mechanism To prevent reverse power tripping of the main power supply gas turbine under low load and high wind speed conditions, this embodiment designs a three-level defense strategy based on the main power supply load rate, such as... Figure 3 As shown. The rated capacity of the main power supply is set to... C rated EMS monitors the total output of the main power supply in real time. P main .

[0025] Level 1 amplitude limiting control (prevention zone): When P main Below the first warning threshold (e.g., 20%) C rated When the system's regulation margin is low, the EMS proactively issues a limiting command to the wind farm to confine its output within a safe range and prevent further decline in the main power load rate.

[0026] Secondary soft resection control (emergency area): when P main Continue to decline until below the second critical threshold (e.g., 10%) C rated If the EMS detects that the main power supply has experienced slight reverse power and the duration exceeds the set delay (e.g., 2 seconds), the EMS will determine that the primary control has failed and immediately issue a soft shutdown command to the wind turbine, requiring it to exit operation in an orderly manner at the specified rate.

[0027] Level 3 Hard Cut-off Protection (Fault Zone): When the reverse power value of the main power supply exceeds the protection setting, or when the wind power output has not returned to zero within a set time after the Level 2 soft shutdown command is issued, the EMS skips the communication command and directly controls the wind turbine grid-connected circuit breaker to trip, forcibly cutting off the wind power and ensuring the safety of the main power supply.

[0028] Example 4: Fault Emergency Pre-calculation and Instantaneous Action To address the risk of rapid frequency collapse caused by equipment tripping in isolated power grids, this embodiment employs a strategy of "pre-calculation and rapid execution during the event," such as... Figure 4 As shown.

[0029] When the power grid is operating normally, the EMS backend performs the following calculations on a rolling basis at a preset periodic frequency (e.g., one cycle per second): assuming that a large-capacity unit (such as the largest gas turbine or wind farm) suddenly trips at the current moment, calculate the instantaneous power balance index of the system. P bal : P bal = P sys_cap - P loss - P load_sum - σ in, P sys_cap The total available capacity of the entire network system at the current moment (including) P wh_set ), P loss This assumes the rated power loss of the faulty unit (i.e., the power deficit caused by the unit tripping). P load_sum This represents the total real-time load of the entire network. σ The threshold is adjusted dynamically for safety.

[0030] If the calculation result P balA value < 0 indicates that the system will experience a power deficit if the hypothetical failure occurs. Based on the size of the deficit, the EMS matches the load levels that need to be cut off (e.g., some levels from L1 to L15) according to a preset priority table, and pre-writes the cutting-off strategy (e.g., "cut off L1-L3 loads") into the fast storage unit (memory flag) at the bottom layer of the EMS.

[0031] When an actual equipment tripping fault occurs, the EMS, upon receiving the circuit breaker change signal or protection action signal, no longer performs time-consuming balancing calculations. Instead, it directly reads the pre-stored strategy in the current fast storage unit and initiates the corresponding load shedding action.

[0032] The above embodiments illustrate only one implementation method of this application, but the implementation methods of this application are not limited to the above examples. It should be noted that any modifications, alterations, substitutions, combinations, or simplifications made without departing from the spirit and principle of this application shall be considered equivalent substitutions and shall fall within the protection scope of this application. Therefore, the protection scope of this patent application shall be determined by the appended claims.

Claims

1. A control method for an isolated power grid in an offshore oilfield, applied to an energy management system (EMS) for an isolated power grid in an offshore oilfield, wherein the power grid includes a gas turbine generator set, a waste heat generator set, an offshore wind turbine generator set, and an energy storage device; characterized in that... The method includes the following steps: Real-time acquisition of the operating status of the gas turbine generator set; The effective output prediction value of the waste heat generator unit is dynamically calculated using a linear regression coupling model. The predicted effective output value of the waste heat generator set P wh_set The calculation formula is: P wh_set = C base + λ × β × P gt in: C base This refers to the fundamental thermal constant of the associated gas turbine generator set under no-load conditions. λ The master-slave coupling coefficient of the gas turbine generator set; P gt For the real-time active power output of the associated gas turbine generator set; β This is a correction factor for flue gas heat loss. This predicted value is updated in real time to the total available capacity data of the power grid, along with the real-time active power output of the associated gas turbine generator units. P gt Below its minimum stable operating threshold P set_min At that time, forced P wh_set Set to 0 to perform master-slave power supply strong coupling capacity correction: The hysteresis response model monitors wind turbine output fluctuations in real time. When a wind turbine output fluctuation is detected, the instantaneous power deviation caused by the gas turbine generator set adjusting but the waste heat generator set not yet responding is calculated in real time. Then, the energy storage device is controlled to perform bidirectional power compensation to smooth out the instantaneous power deviation, including: (1) Wind power sudden drop compensation: The power fluctuation rate threshold of the wind turbine is set as follows: D set When the downward fluctuation rate of wind turbine output is detected to exceed D set At that time, the EMS calculates the power gap between the issuance of the load increase command of the gas turbine generator set and the actual increase of the output of the waste heat generator set, and then controls the energy storage device to discharge rapidly to fill the gap until the output of the waste heat generator set rises to the steady state value. (2) Sudden increase in wind power absorption: When the upward fluctuation rate of wind turbine output is detected to exceed D set When the EMS calculates the total power surplus caused by the waste heat generator maintaining high output due to thermal inertia after the gas turbine generator set issues the load reduction command, it then controls the energy storage device to charge in order to absorb the surplus power and prevent the gas turbine generator set from triggering reverse power protection due to the delayed reduction of waste heat.

2. The method according to claim 1, characterized in that... The steps also include: real-time monitoring of the real-time total load rate of the gas turbine generator set; when the load rate is lower than the preset safety threshold, triggering a graded suppression strategy for the wind turbine generator set to prevent the gas turbine generator set from entering the reverse power condition. The reverse power protection is implemented based on the main power supply load margin and includes the following three levels of protection logic: (1) Level 1 load limiting control: Set the first load warning threshold for the gas turbine generator set. P limit_1 When it is actually always working P main < P limit_1 At that time, EMS will forcibly constrain the upper limit of wind turbine dispatch output to a preset safety value. P w_safe the following; (2) Secondary soft cut-off control: Set the second load emergency threshold for the gas turbine generator set. P limit_2 ;when P main < P limit_2 Or, if reverse power is detected in the gas turbine generator set and the duration exceeds the set delay, it indicates that the generator set is experiencing a power outage. T delay At that time, EMS issued a soft shutdown command to the wind turbine. (3) Level 3 hard cut-off protection: When the reverse power value of the gas turbine generator set is detected to exceed the protection setting value, or when the output of the wind turbine is not detected to return to zero within the set time after the Level 2 soft shutdown command is issued, the EMS directly controls the grid-connected circuit breaker of the wind turbine to open.

3. The method according to claim 1, characterized in that... It also includes the following steps: When the power grid is operating normally, the EMS calculates the instantaneous power balance index of the system assuming a typical fault occurs in a set cycle. P bal And pre-matched corresponding tiered load offloading strategies are stored in the EMS's preset fast storage units; When a physical fault signal is detected, the strategy in the preset fast storage unit is directly read to execute an unloading action, including: (1) Rolling calculation: The EMS backend calculates the instantaneous power balance index of the system cyclically at a preset period: P bal = P sys_cap － P loss － P load_sum － σ in, P sys_cap This represents the total available capacity of the entire network system at the current moment. P loss Assuming the rated power loss of the faulty unit, P load_sum This represents the total real-time load of the entire network. σ The threshold is dynamically adjusted for safety. (2) Table lookup mapping: when P bal When < 0, based on its absolute value, the preset load level unloading matrix table is queried in real time to lock the load level to be cut off and update it to memory; (3) Instantaneous action: When a fault occurs, skip the calculation process and directly execute the load removal instruction locked in memory.

4. A power grid control system for isolated offshore oil fields, characterized in that, include: Data acquisition and execution module: used to collect the operating status of the gas turbine generator set in real time; Multi-energy coupling calculation module: used to dynamically calculate the predicted effective output value of the waste heat generator unit using a linear regression coupling model; The predicted effective output value of the waste heat generator set P wh_set The calculation formula is: P wh_set = C base + λ × β × P gt in: C base This refers to the fundamental thermal constant of the associated gas turbine generator set under no-load conditions. λ The master-slave coupling coefficient of the gas turbine generator set; P gt For the real-time active power output of the associated gas turbine generator set; β This is a correction factor for flue gas heat loss. This predicted value is updated in real time to the total available capacity data of the power grid, along with the real-time active power output of the associated gas turbine generator units. P gt Below its minimum stable operating threshold P set_min At that time, forced P wh_set Set to 0 to perform master-slave power supply strong coupling capacity correction: Wind-Storage Coordinated Control Module: Used for real-time monitoring of wind turbine output fluctuations. When a wind turbine output fluctuation is detected, it calculates in real-time the instantaneous power deviation caused by the gas turbine generator set adjusting but the waste heat generator set not yet responding. Then, it controls the energy storage device to perform bidirectional power compensation to smooth out the instantaneous power deviation, including: (1) Wind power sudden drop compensation: The power fluctuation rate threshold of the wind turbine is set as follows: D set When the downward fluctuation rate of wind turbine output is detected to exceed D set At that time, the EMS calculates the power gap between the issuance of the load increase command of the gas turbine generator set and the actual increase of the output of the waste heat generator set, and then controls the energy storage device to discharge rapidly to fill the gap until the output of the waste heat generator set rises to the steady state value. (2) Sudden increase in wind power absorption: When the upward fluctuation rate of wind turbine output is detected to exceed D set When the EMS calculates the total power surplus caused by the waste heat generator maintaining high output due to thermal inertia after the gas turbine generator set issues the load reduction command, it then controls the energy storage device to charge in order to absorb the surplus power and prevent the gas turbine generator set from triggering reverse power protection due to the delayed reduction of waste heat.

5. The control system according to claim 4, characterized in that, It also includes a reverse power defense module: used to monitor the real-time total load rate of the gas turbine generator set; when the load rate is lower than the preset safety threshold, it triggers a graded suppression strategy for the wind turbine generator set to prevent the gas turbine generator set from entering the reverse power condition; The reverse power protection is implemented based on the main power supply load margin and includes the following three levels of protection logic: (1) Level 1 load limiting control: Set the first load warning threshold for the gas turbine generator set. P limit_1 When it is actually always working P main < P limit_1 At that time, EMS will forcibly constrain the upper limit of wind turbine dispatch output to a preset safety value. P w_safe the following; (2) Secondary soft cut-off control: Set the second load emergency threshold for the gas turbine generator set. P limit_2 ;when P main < P limit_2 Or, if reverse power is detected in the gas turbine generator set and the duration exceeds the set delay, it indicates that the generator set is experiencing a power outage. T delay At that time, EMS issued a soft shutdown command to the wind turbine. (3) Level 3 hard cut-off protection: When the reverse power value of the gas turbine generator set is detected to exceed the protection setting value, or when the output of the wind turbine is not detected to return to zero within the set time after the Level 2 soft shutdown command is issued, the EMS directly controls the grid-connected circuit breaker of the wind turbine to open.

6. The control system according to claim 4, characterized in that, It also includes a pre-calculated stability module: used to perform periodic rolling calculations and fast memory unit updates. The periodic rolling pre-calculation includes: (1) Rolling calculation: The EMS backend calculates the instantaneous power balance index of the system cyclically at a preset period: P bal = P sys_cap － P loss － P load_sum － σ in, P sys_cap This represents the total available capacity of the entire network system at the current moment. P loss Assuming the rated power loss of the faulty unit, P load_sum This represents the total real-time load of the entire network. σ The threshold is dynamically adjusted for safety. (2) Table lookup mapping: when P bal When < 0, based on its absolute value, the preset load level unloading matrix table is queried in real time to lock the load level to be cut off and update it to memory; (3) Instantaneous action: When a fault occurs, skip the calculation process and directly execute the load removal instruction locked in memory.

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