Adaptive load multi-parallel generator set cooperative control method and system

Abstract

The application discloses a kind of self-adapting load's multi-parallel generator set cooperative control method and system, by real-time acquisition each unit operation data, build communication state matrix screening can participate in cooperative allocation unit set, calculate system total load and load change rate;According to five kinds of operation mode;With the nonlinear mapping calculation adaptive allocation weight of the remaining available capacity, health status, communication reliability, operating efficiency, realize active, reactive power decoupling distribution;Combined with power error PI closed-loop correction and load change rate feedforward compensation generates control instruction and issues governor and automatic voltage regulator execution;Realize unit smooth switching ramping, communication fault tolerance and overload protection simultaneously, dynamically update weight and operation mode complete closed-loop cooperative control.The application can adapt steady state, impact load, communication anomaly, overload and other complex working conditions, improve parallel generator set power supply stability and operating economy, applicable to island, field emergency shelter and other power supply scenarios.

Description

Technical Field

[0001] This invention relates to the field of parallel operation control technology for generator sets, and in particular to a method and system for adaptive load-based coordinated control of multiple parallel generator sets. Background Technology

[0002] Parallel grid connection of multiple generator sets is a crucial power supply method in isolated power supply and emergency backup power systems. By operating multiple units in parallel, a larger power supply capacity can be achieved, while redundancy in the units enhances the overall reliability of the power supply system. Currently, parallel generator sets generally employ controllers to coordinate power among the units. Conventional parallel control schemes primarily rely on active power-frequency and reactive power-voltage droop control principles to achieve load sharing. Some systems add communication links to achieve centralized power dispatch. In practical engineering applications, parallel generator systems operate under complex conditions, facing various on-site challenges such as random load fluctuations, impulsive load switching, unit performance degradation, online unit commissioning and decommissioning, network communication disturbances, and short-term system overloads. The controller needs to continuously collect operating parameters such as voltage, current, power, and temperature to complete a series of control tasks, including power distribution, unit regulation, and fault protection, ensuring that the voltage and frequency indicators of the bus power supply meet the requirements of the electrical equipment.

[0003] Existing parallel control methods for generator sets can achieve load sharing and maintain basic power supply functions under ideal conditions where load conditions are stable, the status of each unit is consistent, and the communication link is stable and without abnormalities. However, under complex field conditions, existing control logic has limited consideration for individual differences among units and is difficult to adapt to dynamic changes in unit health status and power margin. The system's dynamic adjustment capability is limited when facing severe load disturbances. When communication quality deteriorates or the system is overloaded, existing protection and handling logic is inadequate, easily leading to power distribution imbalances, which in turn cause voltage and frequency deviations, unit overloads, unplanned disconnections, and other problems, adversely affecting the operational safety and economy of the power supply system. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide an adaptive load multi-parallel generator set collaborative control method and system, which can adapt to complex operating conditions such as steady-state load, dynamically changing load, impact load, communication anomaly, system overload, and generator set switching, thereby improving the power supply stability and operating economy of the multi-parallel generator set system.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A method for coordinated control of multiple parallel generator sets with adaptive load includes the following steps: S1: Real-time acquisition of operating status data for each generator set in a multi-parallel generator set. The collaborative controller acquires the operating status data of each generator set in real time through a local measurement module at a preset control cycle (e.g., 10ms). The operating status data includes active power, reactive power, output voltage, output frequency, unit temperature, unit health status, remaining available capacity, and communication link status. During the acquisition process, the raw data undergoes preprocessing such as moving average filtering to eliminate high-frequency noise interference and ensure data accuracy.

[0006] S2: Construct a multi-unit collaborative communication state matrix to determine the set of units that can participate in collaborative allocation. Based on the communication link status reported by each unit, construct the multi-unit collaborative communication state matrix. If a unit fails to receive a valid heartbeat packet or data verification fails for several consecutive cycles, its communication state is determined to be abnormal. Based on this matrix, select units with normal communication and healthy status as the set of units that can participate in collaborative allocation; for units with abnormal communication, transfer them to the communication fault-tolerant branch for processing.

[0007] S3: Calculate the total system load and load change rate. Sum the real-time active and reactive power of the units participating in the coordinated load sharing to calculate the total system active load P. total Total reactive load Q total The rate of change of load is calculated using the sliding differential algorithm. and It accurately characterizes the intensity of dynamic disturbances in the current system load and serves as the core criterion for adaptive switching of system operating modes.

[0008] S4: Determines the current system operating mode based on load change rate, capacity, and communication status. The system adaptively determines the current operating mode based on the load change rate, available unit capacity, and communication status, and incorporates a hysteresis comparison mechanism to prevent frequent mode fluctuations. Specifically, this includes: When the load change rate is lower than the preset first threshold and the communication link status is normal and the status of each generator set is normal, it enters the steady-state equal distribution mode. When the load change rate is higher than the preset first threshold and lower than the preset second threshold, the dynamic tracking mode is entered. When the load change rate exceeds the preset second threshold, the system enters the impact load suppression mode to limit the power change rate of a single unit. When the total system load exceeds the safe capacity threshold, it enters overload protection mode; When the communication link status of some units is abnormal, the communication fault tolerance mode is entered.

[0009] The first threshold, the second threshold, and the safety capacity threshold are set according to the system's rated capacity and the preset safety margin, respectively.

[0010] In communication fault-tolerant mode, the following fault-tolerant control strategies are implemented: S41: Retain the most recent valid communication data of the abnormal unit; S42: Estimate the total system load using local measurements; S43: Reduce the allocation weight of the communication abnormal unit; S44: Limit the power change rate of the normal unit; S45: Prohibit the communication abnormal unit from bearing impact loads; S46: When the duration of the communication abnormality exceeds a preset threshold, switch the abnormal unit to independent operation or safely exit parallel operation.

[0011] In overload protection mode, the following overload suppression strategies are executed: S47: Reduce non-critical loads according to preset priority; S48: Limit the power increase rate of each unit; S49: Start standby units; S410: Derated operation of overloaded units; S411: Execute disconnection protection for faulty units; S412: Recalculate the adaptive allocation weight of the remaining healthy units.

[0012] S5: Calculate the adaptive allocation weights. Obtain the remaining available capacity factor R of the i-th generator unit. i Health status factor H i Communication reliability factor C i and operating efficiency factor E i The values ​​of each factor are normalized to [0,1]. These are then adjusted using a nonlinear weighting function. , , , A nonlinear mapping is applied to the above factors to highlight the impact of critical states. The adaptive allocation weight W of the i-th generator unit is calculated using the following formula. i ; Here, α is the global normalization coefficient, ensuring that the sum of the weights of all participating units in the collaborative allocation satisfies the preset constraint (i.e., ΣWi=1). To ensure that the sum of the weights of all participating units in the collaborative allocation satisfies the constraint ΣWi=1, a global normalization coefficient α needs to be introduced. Its derivation process is as follows: Let W... i Substituting the expression into the summation formula and extracting the common factor α, we get α = 1 / Σ(φ R (Ri)·φ H (Hi) · φ C (Ci) · φ E (Ei)). Through this explicit calculation formula, the normalization coefficient can be accurately obtained, thereby ensuring the mathematical rigor of weight allocation and the stability of system coordinated control.

[0013] For reactive power allocation, the same calculation framework is used, only the input factors are replaced with excitation capability coefficient, voltage regulation capability coefficient and reactive power surplus capacity coefficient.

[0014] S6: Decouple active and reactive power allocation based on adaptive weighting to generate power reference commands. Calculate the active power reference command for the i-th generator unit using the following formula. : in, For the total active power load of the system, Let N be the active power allocation weight for the i-th generating unit, and N be the number of generating units currently eligible to participate in the coordinated allocation. The sum of the active power weights of all units participating in the collaborative allocation.

[0015] Calculate the reactive power reference command for the i-th generator set using the following formula. : in, The total reactive load of the system, The reactive power allocation weight for the i-th generating unit is determined using the same method as steps S51 to S53, based on the excitation capability coefficient, voltage regulation capability coefficient, and reactive power surplus capacity coefficient of the i-th generating unit. This is the sum of the reactive power weights of all units participating in the coordinated allocation.

[0016] For the generated and Output limiting clamping is performed to ensure that commands remain within the safe operating range of the unit. Decoupling of active and reactive power distribution effectively avoids the mutual interference problems inherent in traditional coupled control.

[0017] S7: Generates frequency and voltage correction values ​​based on power distribution errors, and feedforward compensation values ​​based on load change rate, synthesizing the final control command. All physical quantities are expressed in per-unit (pu). The active power reference value is selected from the rated power of a single unit in the system, the frequency reference value is selected from the rated frequency of the system, and the voltage reference value is selected from the rated line voltage of the system.

[0018] Calculate the active power error of the i-th generator unit. and reactive power error : in, Let i be the per-unit value of the current active power of the i-th generating unit. Let be the per-unit value of the current reactive power of the i-th unit. A correction value is generated using PI closed-loop control, and the frequency correction value is calculated using the following formula. : in, The proportional gain of the active power control channel. The integral gain of the active power control channel. Let t be the integral time variable, where t is the current control time.

[0019] An anti-saturation mechanism is incorporated into the integral stage to prevent overshoot caused by integral saturation. The voltage correction is calculated using the following formula. : in, The proportional gain of the reactive power control channel. This is the integral gain of the reactive power control channel.

[0020] Simultaneously, feedforward compensation is introduced to improve dynamic response. Specifically, this includes: S74: Calculate the active power feedforward compensation of the i-th generator unit according to the following formula. : S75: Calculate the reactive power feedforward compensation of the i-th generator set according to the following formula. : in, The active power feedforward gain coefficient is... This is the reactive power feedforward gain coefficient. This represents the per-unit value of the rate of change of the system's total active load with respect to time. This is the per-unit value of the rate of change of the system's total reactive load with respect to time. S76: Combine the final active power control command according to the formula. and final reactive power control command : in, This is the per-unit value for the frequency correction measure. This is the per-unit value for voltage correction. The final command is output-limited before being sent out.

[0021] S8: Control commands are sent to the speed governor and automatic voltage regulator for execution. The synthesized active power control command P... cmd,i The reactive power control command Q is sent to the speed governor of the corresponding generator set. cmd,i The command is sent to the automatic voltage regulator. Simultaneously, the co-controller continuously monitors communication timeouts; if no execution feedback is received after the command is issued, communication anomaly protection is triggered.

[0022] S9: Dynamic closed-loop control, including unit switching and load ramp-up control. The system executes steps S1 to S8 in a fixed cycle, and dynamically adjusts the adaptive allocation weights, operating modes and unit operating status according to system load changes, unit switching, communication anomalies or overload conditions.

[0023] When the system detects that the load change rate is between the first and second thresholds, it enters dynamic tracking mode. In dynamic tracking mode, the system executes the following control strategy: maintaining the adaptive weight allocation mechanism S53 in continuous operation, and updating the weights W in real time based on the status factors of each unit. i Simultaneously activate feedforward control channels S74 and S75, utilizing the load change rate. and Rapid pre-compensation is performed on active and reactive power commands to shorten the response lag of feedback regulation; PI feedback controllers S72 and S73 maintain normal operation and are responsible for eliminating steady-state errors. This mode ensures that the dynamic deviation of system frequency and voltage is controlled within the allowable range under medium-rate load changes through the triple coordination of 'weighted adaptive + feedforward pre-compensation + feedback steady-state correction'.

[0024] When system load increases and the remaining capacity of existing units is insufficient, the units to be put into operation are started. After voltage, frequency, and phase synchronization are checked, they are connected to the common bus. After grid connection, the initial load is set to zero or the lower safety limit, and the load is gradually increased according to the preset ramp rate. The ramp rate is dynamically adjusted based on the current load change rate, bus voltage deviation, and frequency deviation to prevent impact on the bus. After the load ramp-up is completed, the total system load is redistributed according to the latest adaptive allocation weight. When the system load decreases and a unit needs to be decommissioned, the decommissioned unit gradually reduces its load according to the reverse unloading curve. Once the load drops below the safety threshold, the disconnection operation is performed.

[0025] An adaptive load multi-parallel generator set cooperative control system for implementing the above method includes: Multi-parallel generator unit: includes multiple diesel generator sets operating in parallel, each unit containing an engine, generator, speed governor, automatic voltage regulator, circuit breaker and sensors; Local measurement module: used to collect voltage, current, frequency, active power, reactive power, speed, temperature and communication status data of each generator set, and to perform preprocessing; Communication network module: used for high-speed and reliable data exchange between each generator set controller and the co-controller; Coordination Controller: As the core computing unit, it is used to calculate the total system load, load change rate, available unit capacity and adaptive allocation weight, determine the operating mode, and generate active and reactive power allocation instructions for each unit. The execution control module is used to convert the allocation instructions generated by the co-controller into speed governor control signals and automatic voltage regulator control signals to drive the actuators. The status monitoring and protection module is used to monitor system overload, communication anomalies, and unit faults in real time, and to perform protective operations such as derating, disconnection, load redistribution, or safe shutdown when anomalies occur. The modules mentioned above interact with each other via an internal bus or communication network to jointly achieve adaptive and coordinated control of multiple parallel generator sets.

[0026] Compared with the prior art, the present invention has the following beneficial effects: (1) By adopting four-dimensional factors of remaining capacity, health status, communication reliability and operating efficiency, and combining nonlinear mapping to calculate adaptive weights, the load allocation and the actual capacity of the unit are accurately matched, effectively avoiding the overloading of deteriorated units and improving the economy and lifespan of the system. (2) By establishing five operating modes—steady-state equal distribution, dynamic tracking, impact suppression, overload protection, and communication fault tolerance—and by using a hysteresis switching mechanism to adapt to complex and ever-changing working conditions, the environmental adaptability of the system has been enhanced. (3) By adopting a composite control strategy that combines active and reactive power decoupling distribution with PI closed-loop error correction and feedforward compensation, the steady-state distribution accuracy and dynamic disturbance rejection capability are taken into account, and the voltage and frequency fluctuations caused by impact loads are significantly suppressed. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the flow structure of the control method; Figure 2 This is a schematic diagram of the system structure. Detailed Implementation

[0028] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of the invention.

[0029] Example 1: like Figures 1-2As shown, this embodiment 1 system includes four 200kW rated diesel generator sets, operating in parallel on an isolated industrial and mining power supply bus without large power grid support; a collaborative controller is configured, and industrial Ethernet is used for communication between the generator sets and the collaborative controller. The system's rated total capacity is 800kW, with the following settings: first threshold for load change rate is 20kW / s, second threshold is 80kW / s; system safety capacity threshold is 720kW (90% of the total rated capacity); communication anomaly judgment threshold: packet loss rate > 10% or one-way delay > 80ms; communication anomaly duration threshold is 10s. The system control cycle is set to 20ms. The per-unit reference values ​​selected in this embodiment are as follows: reference power Sb = 200kW (single unit rated power), reference frequency fB = 50Hz, reference voltage VB = 400V (system rated line voltage). All physical quantities such as active power, reactive power, frequency, and voltage are normalized to the corresponding reference values ​​to obtain dimensionless per-unit values. Specifically, the formulas for calculating per-unit values ​​are: power per-unit value = actual power value / Sb; frequency per-unit value = actual frequency value / fB; voltage per-unit value = actual voltage value / VB.

[0030] S1: Real-time acquisition of operating status data of each generator set in multiple parallel generator sets. The collaborative controller issues acquisition commands with a control cycle of 20ms. The local measurement module of each unit collects operating status data: active power, reactive power, output voltage, output frequency, unit temperature (engine cylinder temperature, generator stator winding temperature), unit health status, remaining available capacity, and communication link status.

[0031] Active and reactive power, voltage, and frequency are acquired by voltage and current transmitters; unit temperature is acquired by temperature transmitters; unit health status is assessed by integrating winding temperature exceeding limits, cylinder temperature alarms, vibration exceeding limits, and internal fault indicators, outputting a normalized 0-1 health status; remaining available capacity is calculated by subtracting the current actual active power output from the unit's current maximum allowable output, then normalizing to obtain a 0-1 interval factor; communication link status is assessed by acquiring Ethernet packet loss rate, round-trip time, and communication interruption indicators. The raw data is filtered using a 3-point moving average filter to remove transient pulse interference; the filtered operating status data is then uploaded to the collaborative controller.

[0032] S2: Construct a multi-unit collaborative communication state matrix based on the communication link status, and determine the set of units that can participate in collaborative allocation. Construct a 4×4 multi-unit collaborative communication state matrix, with each row of the matrix corresponding to one unit. The matrix unit stores the corresponding unit's packet loss rate, round-trip delay, and communication interruption flag. The collaborative controller determines each unit individually: if the unit's packet loss rate is ≤10%, round-trip delay is ≤80ms, and there is no communication interruption flag, then it is included in the set of units that can participate in collaborative allocation; otherwise, it is excluded from the set, and the communication fault tolerance logic is invoked. In the initial operating condition of this embodiment, all four units communicate normally, and all four units enter the set of units that can participate in collaborative allocation.

[0033] S3: Calculate the total active and reactive loads of the system based on the active and reactive power of each generator set, and calculate the load change rate. Statistics are only performed on units within the co-location group that can participate in the coordinated load distribution. The total active load of the system is obtained by summing the real-time active power of each unit within the group. The total reactive load of the system is obtained by adding the real-time reactive power of each unit within the set. .

[0034] A 5-point sliding differential window algorithm is used to suppress differential noise and calculate the total active power load change rate. Total reactive load change rate The load change rate is used as the input for S4 mode discrimination.

[0035] S4: Based on the load change rate, the remaining available capacity of each generator set, and the communication status, determine the current operating mode of the system and the mode discrimination rule. Add hysteresis during mode switching (threshold back is set to 80% of the original threshold) to prevent frequent mode jumps under critical conditions. The determination of this 80% backoff coefficient is based on the following: In a parallel generator set system, the load change rate signal contains measurement noise and communication delay. If the backoff coefficient is too large (e.g., >90%), the hysteresis width is insufficient, and the system is prone to frequent mode switching near the threshold due to signal jitter, leading to control command oscillation. If the backoff coefficient is too small (e.g., <70%), the hysteresis is too wide, and the system's response from advanced mode (e.g., impact load suppression mode) back to steady-state even-sharing mode is severely delayed, affecting power supply quality. Through simulation and actual measurement verification in this embodiment, the 80% backoff coefficient can achieve the optimal balance between suppressing mode jitter (switching frequency <0.5Hz) and ensuring timely mode response (return delay <2s). This coefficient is suitable for a system configuration with a rated capacity of 800kW and a control cycle of 20ms.

[0036] During the stable production phase of industrial and mining operations, The power output is less than the first threshold of 20kW / s; all units communicate normally and there are no alarms in the units, and the system enters the steady-state distribution mode.

[0037] When high-power motors in industrial and mining facilities are started directly, the load increases instantaneously. =95kW / s, exceeding the second threshold of 80kW / s, the system switches to the impact load suppression mode, limiting the maximum rate of change of active power of each unit to no more than 60kW / s, to prevent the impact load from falling entirely on a single unit. When all industrial and mining equipment is running, the total active load of the system reaches 740kW, exceeding the safe capacity threshold of 720kW, the system enters the overload protection mode, executing the overload suppression strategy S47-S412: S47 reduces non-critical loads such as fans and lighting according to preset load priorities; S48 limits the rate of increase of power of all units; S49 starts the standby 200kW standby unit; S410 performs derating operation on already overloaded units; S411 if a unit fault is detected, the disconnection protection is executed; S412 removes the faulty / overloaded unit and recalculates the adaptive allocation weight of the remaining healthy units.

[0038] If, during operation, Unit 2 experiences a packet loss rate of 15% on the Ethernet, exceeding the communication threshold, while the other three units communicate normally, the system enters communication fault-tolerant mode and executes strategies S41-S46: S41 saves the most recent valid operating data frame of Unit 2; S42 estimates the total system load based on local measurements from Units 1, 3, and 4; S43 reduces the allocation weight of Unit 2; S44 limits the power change rate of normal Units 1, 3, and 4; S45 prohibits Unit 2 from bearing impulsive loads; S46 continuously times the circuit breaker of Unit 2, and if the duration of the communication anomaly exceeds a preset threshold of 10 seconds, safely disconnects Unit 2 from the parallel bus.

[0039] S5: Calculate adaptive allocation weights based on the remaining available capacity, health status, communication reliability, and operating efficiency of each generator set. S51: Obtain the remaining available capacity factor for the i-th generator set. Health status factors Communication reliability factor and operating efficiency factor Normalization of all factors limits the range of values. In this embodiment, under steady-state conditions, the stator winding temperature of generator unit 1 is too high, with a health condition factor H1 = 0.7; the other three units are in good condition. , , All are close to 1.

[0040] S52: Weight Adjustment Function , , , A sigmoid nonlinear mapping function is selected to perform nonlinear mapping on various factors, achieving rapid decay of the mapping output of units in poor condition. Specifically, the sigmoid nonlinear mapping function is the Sigmoid function, whose mathematical expression is: φ(x) = 1 / (1 + exp(-k·(x - x0))), where x is the input state factor (such as remaining fuel rate Ri, health Hi, etc.), k is the curve steepness coefficient, and x0 is the mapping center point (i.e., the input value corresponding to an output of 0.5). When the input factor x is lower than x0, the function output decays exponentially, thereby mathematically forcing a reduction in the weight allocation ratio of units in poor condition. The parameter ranges of the Sigmoid function corresponding to each state factor and the input-output correspondence are shown in the table below: Note: The parameters k and x0 mentioned above can be adjusted within ±20% according to the actual characteristics of the unit. The adjustment principle is: take a larger k value for critical safety factors (such as φC) to achieve hard cutoff, and take a smaller k value for non-critical factors (such as φE) to achieve soft transition.

[0041] S53: According to the formula: Calculate the active power adaptive allocation weight for each unit. ; The global normalization coefficients satisfy... Normalization constraint. Because Unit 1's H1 value is too low, its active power weight automatically decreases after mapping, while the weights of the other three healthy units increase accordingly. Reactive power allocation weight. The input is replaced with the excitation capability coefficient, voltage regulation capability coefficient, and reactive power remaining capacity coefficient. The reactive power adaptive allocation weight is calculated by reusing the same process as S51-S53.

[0042] S6: Based on the adaptive allocation weights, active power and reactive power are decoupled and allocated, generating active power reference commands and reactive power reference commands for each generator set. S61: Active power reference command: N represents the number of generating units currently eligible for collaborative allocation; simultaneously, for Set upper and lower limit clamps to ensure the active power output does not exceed the unit's maximum and minimum allowable active power output. S62, Reactive Power Reference Instruction: Similarly, output limiting is applied to the reactive power reference command. Active and reactive power operations are independent and decoupled, and are not coupled. Due to the reduced weight, the active and reactive power reference commands obtained by Unit 1 are automatically reduced, thus reducing the load on the deteriorated unit.

[0043] S7: Generate frequency correction and voltage correction based on the power distribution error, and generate feedforward compensation S71 based on the load change rate, and calculate the power error: , ; , The actual active and reactive power outputs of the i-th unit are set; an error limit is set to prevent excessive error from causing controller saturation.

[0044] S72, the frequency correction amount is calculated using PI: This embodiment is set =0.02 (per unit value), corresponding to the actual value 0.02 × 50 / 200 = 0.005 Hz / kW. =0.05 (per unit value), corresponding to the actual value 0.05 × 50² / 200 = 0.625 Hz·s / kW; the PI stage adds integral anti-saturation, and stops integral accumulation when the integral output exceeds the limit.

[0045] S73, Voltage Correction Amount: This embodiment is set up =0.03 (per unit value), corresponding to the actual value 0.03 × 400 / 200 = 0.06 V / kVAR. =0.06 (per unit value), corresponding to the actual value 0.06 × 400² / 200 = 48 V·s / kVAR; the integral anti-saturation logic is also configured.

[0046] S74 calculates the active power feedforward compensation: ; S75 calculates reactive power feedforward compensation: ; In this embodiment, the feedforward gain is taken as... =0.15 (per unit value), corresponding to an actual value of 0.15 × 400 / 200 = 0.03V / kVAR; =0.12 (per unit value), corresponding to the actual value 0.12 × 400² / 200 = 96 V·s / kVAR; the feedforward output is set to limit the amplitude to avoid excessive dynamic compensation output.

[0047] S76 Synthesizes Final Control Commands: , After the synthesis is completed, the upper and lower limits of the overall power are clamped again to obtain the final control command to be issued to the unit.

[0048] S8: The active power reference command, reactive power reference command, frequency correction, voltage correction, and feedforward compensation are sent to the speed governor and automatic voltage regulator of the corresponding generator set. The coordinating controller then sends all control quantities to the local controller of each unit via industrial Ethernet. Active power related commands are sent to the speed governor to adjust the engine throttle opening; reactive power and voltage related commands are sent to the automatic voltage regulator to adjust the excitation current. Communication timeout detection is configured for the sent commands: if a single command receives no response after three consecutive attempts, the unit is marked as having a communication error and jumps to the S4 communication fault-tolerant mode.

[0049] S9: Based on system load changes, generator switching, communication anomalies, or overload conditions, the adaptive allocation weights, operating modes, and generator operating states are dynamically adjusted to achieve adaptive coordinated control of multiple parallel generator units. Specifically, the system executes S1-S8 in a cyclical manner with a period of 20ms.

[0050] When load, communication, or unit status changes, all factors are updated in real time, weights are recalculated, and operating modes are switched.

[0051] Simultaneously execute dynamic unit switching and load ramping control: S91: The system load continues to rise, and the total remaining available capacity of the existing 4 units is insufficient. Start the standby 200kW unit; collect the output voltage, frequency, and phase of the unit to be started. When the voltage difference is less than 5% of the rated voltage, the frequency difference is less than 0.2Hz, and the phase difference is less than 5°, the synchronization condition is determined to be met, and the circuit breaker is closed and connected to the common bus.

[0052] S92: Grid connection completed, initial load set to 0kW; ramp rate is not fixed, dynamically calculated based on load change rate, bus voltage deviation, and bus frequency deviation; when bus voltage and frequency deviations are large, ramp rate is automatically reduced to prevent impact on the bus.

[0053] S93: Load ramping is complete. The standby unit is included in the set of units that can participate in collaborative allocation. The adaptive allocation weights of all units are recalculated and they participate in the total load allocation.

[0054] S94: When the system load decreases, the number of units to be removed should be reduced. The load of the units to be removed should be gradually reduced according to the preset reverse unloading curve. When the load is reduced to the safety lower limit (10% of rated power), the units should be disconnected and the circuit breaker should be disconnected to exit the parallel connection.

[0055] The embodiments of the present invention are given for illustrative and descriptive purposes only, and are not intended to be exhaustive or to limit the invention to the forms disclosed. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described in order to better illustrate the principles and practical application of the invention, and to enable those skilled in the art to understand the invention and to design various embodiments with various modifications suitable for a particular purpose.

Claims

1. A method for coordinated control of multiple parallel generator sets with adaptive load, characterized in that, Includes the following steps: S1: Real-time acquisition of operating status data of each generator set in the multi-parallel generator set. The acquisition is performed with a preset control cycle. The raw data is preprocessed by moving average filtering. The operating status data includes active power, reactive power, output voltage, output frequency, unit temperature, unit health status, remaining available capacity and communication link status. S2: Construct a multi-unit collaborative communication state matrix based on the communication link status, and determine the set of units that can participate in collaborative allocation; S3: Calculate the total active load and total reactive load of the system based on the active and reactive power of each generator set, and calculate the load change rate; S4: Determine the current operating mode of the system based on the load change rate, the remaining available capacity of each generator set and the communication status. The operating modes include steady-state distribution mode, dynamic tracking mode, impact load suppression mode, overload protection mode and communication fault tolerance mode. S5: Calculate adaptive allocation weights based on the remaining available capacity, health status, communication reliability, and operating efficiency of each generator set; S6: Based on the adaptive allocation weight, decouple the active power and reactive power allocation to generate active power reference commands and reactive power reference commands for each generator set. S7: Generate frequency correction and voltage correction based on power distribution error, and generate feedforward compensation based on the load change rate; S8: Send the active power reference command, reactive power reference command, frequency correction amount, voltage correction amount and feedforward compensation amount to the speed governor and automatic voltage regulator of the corresponding generator set for execution; S9: Based on system load changes, unit switching, communication anomalies, or overload conditions, dynamically adjust the adaptive allocation weights, operating modes, and unit operating states to achieve adaptive coordinated control of multiple parallel generator units.

2. The adaptive load multi-parallel generator set cooperative control method according to claim 1, characterized in that, In step S5, the adaptive allocation weight is calculated based on the remaining available capacity, health status, communication reliability, and operating efficiency of each generator set, specifically including: S51: Obtain the remaining available capacity factor of the i-th generator set. Health status factors Communication reliability factor and operating efficiency factor The range of values ​​for each factor is [missing information]. ; S52: Using weight adjustment functions respectively , , , Perform nonlinear mapping on the above factors; S53: Calculate the adaptive allocation weight of the i-th generator set according to the following formula. : Where α is the global normalization coefficient, and its calculation formula is α = 1 / Σ(φ) R (Ri)·φ H (Hi) · φ C (Ci) · φ E (Ei)), where the summation iterates through all the units participating in the collaborative allocation to ensure that the sum of the weights of all units ΣWi=1.

3. The adaptive load multi-parallel generator set cooperative control method according to claim 1, characterized in that, In step S6, the active power and reactive power are decoupled and allocated based on adaptive allocation weights, specifically including: S61: Calculate the active power reference command for the i-th generator set according to the following formula. : in, For the total active power load of the system, Let N be the active power allocation weight for the i-th generating unit, and N be the number of generating units currently eligible to participate in the coordinated allocation. The sum of the active power weights of all units participating in the coordinated allocation; S62: Calculate the reactive power reference command for the i-th generator set according to the following formula. : in, The total reactive load of the system, The reactive power allocation weight for the i-th generating unit is determined using the same method as steps S51 to S53, based on the excitation capability coefficient, voltage regulation capability coefficient, and reactive power surplus capacity coefficient of the i-th generating unit. This is the sum of the reactive power weights of all units participating in the coordinated allocation.

4. The adaptive load multi-parallel generator set cooperative control method according to claim 1, characterized in that, In step S7, generating frequency correction and voltage correction amounts based on power allocation errors specifically includes: S71: Calculate the active power error of the i-th generator set. and reactive power error : in, Let i be the per-unit value of the current active power of the i-th generating unit. Let i be the per-unit value of the current reactive power of the i-th generating unit; S72: Calculate the frequency correction amount using the following formula. : in, The proportional gain of the active power control channel. The integral gain of the active power control channel. Let t be the integral time variable, where t is the current control time. S73: Calculate the voltage correction amount using the following formula. : in, The proportional gain of the reactive power control channel. This is the integral gain of the reactive power control channel.

5. The adaptive load multi-parallel generator set cooperative control method according to claim 4, characterized in that, In step S7, generating the feedforward compensation amount based on the load change rate specifically includes: S74: Calculate the active power feedforward compensation of the i-th generator unit according to the following formula. : S75: Calculate the reactive power feedforward compensation of the i-th generator set according to the following formula. : in, The active power feedforward gain coefficient is... This is the reactive power feedforward gain coefficient. This represents the per-unit value of the rate of change of the system's total active load with respect to time. This is the per-unit value of the rate of change of the system's total reactive load with respect to time. S76: Combine the final active power control command according to the formula. and final reactive power control command : in, This is the per-unit value for the frequency correction measure. This is the per-unit value for voltage correction.

6. The adaptive load multi-parallel generator set cooperative control method according to claim 1, characterized in that, Step S4, which determines the current system operating mode based on the load change rate, available unit capacity, and communication status, specifically includes: When the load change rate is lower than a preset first threshold and the communication link is in normal status and the status of each generator set is normal, the steady-state equal distribution mode is entered. When the load change rate is higher than a preset first threshold and lower than a preset second threshold, the dynamic tracking mode is entered. When the load change rate is higher than the preset second threshold, the system enters the impact load suppression mode to limit the power change rate of a single unit. When the total system load exceeds the safe capacity threshold, it enters overload protection mode; When the communication link status of some units is abnormal, the communication fault tolerance mode is entered. The first threshold, the second threshold, and the safety capacity threshold are set according to the system's rated capacity and a preset safety margin, respectively. The mode switching employs a hysteresis comparison mechanism; when switching from a high threshold mode to a low threshold mode, the switching threshold is lowered to 80% of the original threshold.

7. The adaptive load multi-parallel generator set cooperative control method according to claim 1, characterized in that, Step S9 also includes dynamic unit switching and load ramping control steps: S91: When the system load increases and the remaining capacity of the existing units is insufficient, start the units to be put into operation, and after judging the voltage, frequency and phase synchronization, close the switch and connect them to the common bus. S92: After grid connection, the initial load is set to zero or a safety lower limit, and the load is gradually increased according to the preset ramp rate. The ramp rate is dynamically adjusted according to the load change rate, bus voltage deviation and frequency deviation. S93: After the load ramp-up is completed, the total system load is redistributed according to the adaptive allocation weights; S94: When the system load decreases, the decommissioned unit will gradually reduce the load according to the reverse unloading curve and then disconnect from the grid.

8. The adaptive load multi-parallel generator set cooperative control method according to claim 1, characterized in that, In step S4, the following fault-tolerant control strategy is executed in the communication fault-tolerant mode: S41: Retain the most recent valid communication data of the abnormal unit; S42: Estimate the total system load using local measurements; S43: Reduce the allocation weight of the communication abnormal unit; S44: Limit the power change rate of the normal unit; S45: Prohibit the communication abnormal unit from bearing impact loads; S46: When the duration of the communication abnormality exceeds a preset threshold, switch the abnormal unit to independent operation or safely exit parallel operation.

9. The adaptive load multi-parallel generator set cooperative control method according to claim 8, characterized in that, In step S4, the following overload suppression strategy is executed in overload protection mode: S47: Reduce non-critical loads according to preset priority; S48: Limit the power increase rate of each unit; S49: Start standby units; S410: De-rated operation of overloaded units; S411: Execute disconnection protection for faulty units; S412: Recalculate the adaptive allocation weight of the remaining healthy units.

10. A cooperative control system for multiple parallel generator sets with adaptive load, characterized in that, include: Multiple parallel generator unit, each generator unit includes an engine, generator, speed governor, automatic voltage regulator, circuit breaker and sensor; The local measurement module is used to collect data on voltage, current, frequency, active power, reactive power, speed, temperature, and communication status of each generator set. The communication network module is used for data interaction between each generator set controller and the coordination controller. The collaborative controller is used to calculate the total system load, load change rate, available unit capacity and adaptive allocation weight, and generate active and reactive power allocation instructions for each unit. An execution control module is used to convert the allocation command into a speed governor control signal and an automatic voltage regulator control signal; The status monitoring and protection module is used to monitor overload, communication anomalies and unit failures, and to perform derating, disconnection, load redistribution or safe shutdown operations.

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