Grid connection control method for engine
By setting timing and delay periods to clear step size adjustments in PTO mode, the problem of PTO control data interference is solved, system stability and resource optimization are achieved, and data analysis is simplified.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- GUANGXI YUCHAI MARINE & GENSET POWER CO LTD
- Filing Date
- 2025-10-29
- Publication Date
- 2026-06-18
AI Technical Summary
The control data from the PTO can interfere with subsequent control during engine grid connection, leading to system instability and resource waste.
After grid connection in PTO mode, the step size adjustment is cleared by setting the timing period and delay period, the initial step size is restored, and the subsequent grid connection process is optimized based on the step size adjustment record to ensure system stability and resource optimization.
This avoids system instability, reduces resource consumption, improves system efficiency, simplifies data analysis, and ensures data consistency and interpretability.
Smart Images
Figure CN2025130822_18062026_PF_FP_ABST
Abstract
Description
An engine grid connection control method Technical Field
[0001] This invention relates to generator grid connection, and more specifically, to a method for controlling generator grid connection. Background Technology
[0002] When generators are used in power generation systems, they sometimes need to be electrically connected to adjacent power systems for power exchange, i.e., grid connection. Traditional grid connection requires a power divider for stable power exchange and is only suitable for modes where engine speed can be adjusted via an instrument panel. It is not suitable for modes where engine speed needs to be manually adjusted, such as PTO (Power Transfer Unit). However, there are now DCUs (Digital Control Units) that can control stable speed droop. Without a power divider, they correct the target speed based on a filter coefficient to prevent fluctuations in the torque percentage (the ratio of current output fuel to external characteristic limit fuel), thus achieving stable speed and power control and completing grid connection. In PTO mode, the speed is adjusted by pressing the PTO button to automatically distribute the load. Droop control is deactivated after the droop prevention switch is closed. However, during this process, the PTO control data often interferes with subsequent control. Summary of the Invention
[0003] The technical problem to be solved by the present invention is to provide an engine grid connection control method that addresses the shortcomings of the prior art and solves the problem that PTO control data will interfere with subsequent control.
[0004] The present invention discloses an engine grid-connected control method, which is as follows: after entering PTO mode, a timing cycle is started, and when the timing cycle ends, the adjusted step size is cleared to restore it to the initial step size, and the engine speed is restored to the drooping speed.
[0005] Preferably, the start time of the timing cycle is:
[0006] After the grid connection switch is pressed, the timing cycle is started, and the engine involved in the grid connection begins to distribute power according to the PTO mode. At the same time, it is determined whether the engine speed is stable and whether the power distribution meets the preset target. If so, the grid connection is completed and the grid connection control is exited.
[0007] Preferably, during the engine grid connection process, if the droop prevention switch is closed, the droop control is disengaged and the engine speed is restored to the speed before PTO grid connection.
[0008] Preferably, the engine speed before PTO grid connection is the engine's idle speed.
[0009] Preferably, the timing period is 15-35 seconds.
[0010] Preferably, after the engine is connected to the grid, a timeout is started, and after the timeout ends, the adjusted step size is cleared again.
[0011] Preferably, the delay time is 25-40 seconds.
[0012] Preferably, during the PTO mode grid connection process, the step size adjustment record and grid connection time during the PTO mode process are obtained, the average step size adjustment is calculated based on the step size adjustment record, and then a new adjustment step size is evaluated based on the grid connection time and the average step size adjustment; and the adjustment step size is used as the reference step size for the subsequent grid connection process.
[0013] Preferably, the relationship between the grid connection time and a preset time threshold is determined. If the grid connection time is greater than the time threshold, the initial step size is increased within the average step size adjustment range so that the grid connection time is less than or equal to a target multiple of the timing cycle. Beneficial effects
[0014] The advantages of this invention are: by setting a time limit, the system can revert to the original step size after adjustment, thereby avoiding potential instability caused by step size adjustment. Furthermore, dynamically clearing the step size can reduce unnecessary resource consumption, improve the overall efficiency of the system, and clearing temporarily adjusted step sizes helps maintain data consistency and interpretability, facilitating subsequent analysis and optimization. Attached Figure Description
[0015] Figure 1 is a schematic flowchart of the engine grid connection control method of the present invention. Detailed Implementation
[0016] The present invention will be further described below with reference to embodiments, but this does not constitute any limitation on the present invention. Any limited modifications made by any person within the scope of the claims of the present invention are still within the scope of the claims of the present invention.
[0017] Referring to Figure 1, an engine grid connection control method of the present invention includes the following steps:
[0018] Step 1: After pressing the grid connection switch (i.e., PTO enable switch), the engine speed rises to the initial speed, and a timing cycle begins. In this embodiment, the timing cycle is selected as 20 seconds. In no-load or light-load mode, adjust the PTO+ and PTO- buttons to adjust the speed increase / decrease, activate the droop mode, and the engine involved in grid connection begins power distribution.
[0019] The second step is to determine whether the engine speed is stable and whether the power distribution meets the preset target. If so, the grid connection is completed and the grid connection control is exited; otherwise, the PTO mode is continued.
[0020] Third, after the timing cycle ends, clear the adjusted step size to restore it to the initial step size, and simultaneously restore the engine speed to the drooping speed. Clearing the adjusted step size within a set time can be achieved through reasonable time limits and effective techniques. This ensures stable system operation, optimizes resource utilization, simplifies data analysis, and ensures that the adjusted step size does not cause system instability, thus avoiding the instability issues that may arise after clearing the step size.
[0021] Step 4: Determine if the drooping prohibition switch is closed. If the drooping prohibition switch is closed, exit drooping control, restore the speed to the speed before PTO grid connection, i.e., idle speed, and grid connection terminates; otherwise, reset the timing cycle and repeat step 2.
[0022] In this embodiment, after the engine is connected to the grid, a delay timer is initiated, specifically for 30 seconds. After the delay timer expires, the adjusted step size is cleared again to ensure that the control parameters generated in PTO mode are completely cleared and restored to the initial step size. Generally, the initial step size is 2 r / min, while the initial engine speed in PTO mode is 1500 r / min.
[0023] During PTO (Plan-to-Connect) grid connection, the step size adjustment records and grid connection time are acquired. The average step size adjustment is calculated based on these records, and a new adjustment step size is then determined by evaluating the grid connection time and the average step size adjustment. This new adjustment step size is then used as a reference step size for subsequent grid connection processes. Recording and evaluating the step size adjustment process provides a more effective reference for subsequent adjustments and can significantly improve the grid connection time when using PTO mode.
[0024] The specific evaluation process involves determining the relationship between the grid connection time and the preset time threshold. If the grid connection time is greater than the time threshold, the initial step size is increased within the average step size adjustment range so that the grid connection time is less than or equal to the target multiple of the timing cycle. The increased initial step size is then used as the reference step size.
[0025] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several modifications and improvements without departing from the structure of the present invention, and these will not affect the effectiveness of the implementation of the present invention or the practicality of the patent.
Claims
1. A method for controlling engine grid connection, characterized in that, The method is as follows: after entering PTO mode, start a timing cycle. When the timing cycle ends, clear the adjusted step size to restore it to the initial step size, and at the same time restore the engine speed to the droop speed.
2. The engine grid-connected control method according to claim 1, characterized in that, The start time of the timing cycle is: After the grid connection switch is pressed, the timing cycle is started, and the engine involved in the grid connection begins to distribute power according to the PTO mode. At the same time, it is determined whether the engine speed is stable and whether the power distribution meets the preset target. If so, the grid connection is completed and the grid connection control is exited.
3. The engine grid-connected control method according to claim 1, characterized in that, During the engine grid connection process, if the droop prevention switch is closed, the droop control will be discontinued and the engine speed will return to the speed before PTO grid connection.
4. The engine grid-connected control method according to claim 3, characterized in that, The engine speed before PTO grid connection is the engine's idle speed.
5. The engine grid-connected control method according to claim 1, characterized in that, The timing period is 15-35 seconds.
6. The engine grid-connected control method according to claim 1, characterized in that, After the engine is connected to the grid, a timeout is started, and after the timeout ends, the adjusted step size is cleared again.
7. The engine grid-connected control method according to claim 6, characterized in that, The delay time is 25-40 seconds.
8. The engine grid-connected control method according to claim 1, characterized in that, During the PTO mode grid connection process, the step size adjustment record and grid connection time during the PTO mode process are obtained. The step size adjustment mean is calculated based on the step size adjustment record. Then, a new adjustment step size is evaluated based on the grid connection time and the step size adjustment mean. The adjustment step size is used as the reference step size for the subsequent grid connection process.
9. The engine grid-connected control method according to claim 8, characterized in that, Determine the relationship between the grid connection time and the preset time threshold. If the grid connection time is greater than the time threshold, increase the initial step size within the average step size adjustment range so that the grid connection time is less than or equal to the target multiple of the timing cycle.