A method of power matching for a triple-engine / twin-engine configuration helicopter engine
By employing a power trim method for three-engine/twin-engine helicopter configurations, and utilizing the engine power control system to automatically or manually switch between torque trim and Ng trim modes, the problem of low engine power trim accuracy under low power conditions is solved. This achieves precise matching between the engine and the helicopter, improving human-machine interface efficiency and engine lifespan.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CHINA HELICOPTER RES & DEV INST
- Filing Date
- 2023-11-09
- Publication Date
- 2026-07-24
AI Technical Summary
Existing technology has low engine power trim accuracy under low power conditions and cannot automatically adjust according to engine power status, resulting in large differences in engine power, which is not conducive to stable helicopter flight.
The three-engine/twin-engine configuration helicopter engine power trim method utilizes the engine power control system to automatically or manually switch between torque trim and Ng trim modes via the cockpit power trim switch and engine electronic controller, thereby achieving power trim between engines and ensuring that engine parameters are within the accuracy range.
It improves power trim accuracy under low power conditions, reduces pilot workload, ensures engine-helicopter matching, improves human-machine efficiency and economy, and protects engine parameters from exceeding limits.
Smart Images
Figure CN117386514B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of helicopter power system design, flight / engine control, and specifically to a power trim method and apparatus for three-engine / twin-engine helicopter engines. Background Technology
[0002] The engine provides the power source for the helicopter and directly affects its overall performance. High-tonnage helicopters have a wide range of applications, including transporting multiple passengers, delivering water for firefighting, or carrying heavy equipment. High-tonnage helicopters are generally equipped with two or more engines. Under normal circumstances, the engines on a helicopter experience similar wear and tear, allowing them to operate at their maximum capacity simultaneously. However, due to performance degradation or significant installation losses, appropriate trim settings are necessary to balance the power demand of the helicopter on each engine and ensure that relevant engine parameters do not exceed limits.
[0003] Currently, domestically produced engines generally use a torque / temperature balancing method. This means that temperature balancing is selected when an engine's performance degrades or installation losses are significant, while torque balancing is used under normal circumstances. However, torque sensors have lower measurement accuracy at low power levels, which can easily lead to large differences in engine power output, making it unsuitable for use at low power. Furthermore, the current balancing method does not automatically differentiate based on engine power status.
[0004] Therefore, it is necessary to develop an engine power trimming method that can solve the problem of low measurement accuracy under low power conditions, ensure that engine parameters do not exceed limits, and automatically select power trimming based on power condition adaptability, thereby reducing the pilot's workload. Summary of the Invention
[0005] The purpose of this invention is to provide a power trim method and apparatus for three-engine / twin-engine helicopter engines to ensure the matching between the engine and the helicopter, and further improve human-machine efficiency.
[0006] To achieve the above objectives, the present invention employs the following technical solution:
[0007] A method for power trim of a three-engine / twin-engine helicopter engine, wherein the method utilizes an engine power control system to achieve trim; the method includes:
[0008] Step 1: The cockpit power trim switch is in the torque trim position by default. When the pilot observes the engine operation, if the difference in the gas turbine outlet temperature (ITT) between the two or three engines is less than the preset temperature threshold and the percentage difference in Ng is less than the preset speed threshold, the cockpit power trim switch is not operated, and the current torque trim state is maintained.
[0009] In torque balancing mode, the engine electronic controller switches the engine balancing mode according to the engine torque;
[0010] Step 2: When the pilot observes that the ITT difference between different engines is greater than the preset temperature threshold and the NG percentage difference is greater than the preset speed threshold, and considers that the performance difference between different engines is large, the pilot will manually switch the cockpit power trim switch to the Ng trim position.
[0011] After receiving the Ng balancing gear information, the engine electronic controller performs Ng balancing;
[0012] Step 3: After the engine starts and enters the default torque balancing mode, the electronic controllers of different engines begin to exchange information, share their respective engine speed and torque, and adjust the current engine torque.
[0013] Furthermore, in the torque balancing state, the engine electronic controller switches the engine balancing mode according to the engine torque, including:
[0014] When the torque information obtained by the engine torque sensor determines the change of the engine from low torque to high torque, if the minimum torque measured by the engine is less than the first torque threshold, the engine torque trim function is not controlled by the cockpit power trim switch, and the engine electronic controller automatically performs Ng trim; if the minimum torque measured by the engine is greater than the first torque threshold, the engine power trim function is controlled by the cockpit power trim switch.
[0015] Furthermore, when the torque information obtained by the engine torque sensor determines the change of the engine from a high torque state to a low torque state, if the minimum torque measured by the engine is greater than the second torque threshold, the engine is controlled by the power balance switch; if the minimum torque measured by the engine is less than the second torque threshold, the engine power balance function is automatically executed by the engine electronic controller for Ng balance.
[0016] Furthermore, the first torque threshold is 150–180 N·m, and the second torque threshold is 100–130 N·m.
[0017] Furthermore, the control system includes: a cockpit power trim switch, a multi-function display, an electromechanical management system, electronic controllers for three / two engines, an engine torque sensor, and an engine Ng speed sensor, wherein:
[0018] The cockpit power trim switch is located on the cockpit control panel and is used to select whether the engine enters the torque trim state. The power trim switch has two settings: torque trim and Ng trim, which are selected by the pilot. After the cockpit power trim switch selects a setting, the setting information is sent to the electronic controller.
[0019] A multi-function display is located on the dashboard in the cockpit to display engine torque information and Ng speed information;
[0020] The electromechanical management system is used to receive engine torque information and Ng speed information from the engine electronic controller and send these parameters to the multi-function display.
[0021] The engine's electronic controller receives gear information, as well as engine torque and Ng speed information, and performs torque or Ng balancing functions based on the torque value or gear information.
[0022] Furthermore, the electronic controllers of different engines have information exchange functions. The electronic controller of the current engine receives torque information and Ng speed information sent by the electronic controllers of other engines, and uses this information to control the current engine to increase or decrease torque or Ng, so that the torque and Ng of all engines are within the balance accuracy range. The balance accuracy range is: the percentage difference of torque of all engines is within a first preset range, and the percentage difference of Ng speed is within a second preset range.
[0023] Furthermore, the electronic controllers of the different engines begin to exchange information, sharing their respective engine speeds and torques, and adjusting the current engine torque, including:
[0024] When there are two engines: When the electronic controller of the current engine receives a Ng speed of the other engine that is greater than the Ng speed of the current engine, it controls the current engine to increase the fuel supply and increase the Ng speed of the current engine. At this time, the electronic controller of the other engine controls the engine to reduce the fuel supply and reduce the Ng speed of the engine until the Ng percentage difference between the two engines is less than the second preset range.
[0025] Furthermore, when there are three engines: the engine with the highest Ng speed is selected as the balancing target, and the electronic controllers of the other two engines control the engines to increase their Ng speed. At the same time, the engine with the highest Ng speed gradually decreases its Ng speed until the Ng percentage difference of the three engines is less than the second preset range.
[0026] Furthermore, the cockpit power trim switch is in the torque trim position by default.
[0027] Furthermore, the first preset range is 1% to 5%, and the second preset range is 0.5% to 2%.
[0028] Furthermore, the preset temperature threshold is 20–40°C, and the preset rotation speed threshold is 1%–5%.
[0029] A power trim device for a three-engine / twin-engine helicopter configuration, the device achieving trim using an engine power control system; the device includes:
[0030] The torque trim setting module ensures that the cockpit power trim switch is in the torque trim position by default. When the pilot observes engine operation, if the difference in the gas turbine outlet temperature (ITT) between the two or three engines is less than a preset temperature threshold, and the percentage difference in Ng is less than a preset speed threshold, the cockpit power trim switch is not operated, and the current torque trim state is maintained. In the torque trim state, the engine electronic controller switches the engine trim mode according to the engine torque.
[0031] The trim module is used when the pilot observes that the ITT difference between different engines is greater than the preset temperature threshold, or the NG percentage difference is greater than the preset speed threshold, and considers that the performance difference between different engines is large. In this case, the pilot manually switches the cockpit power trim switch to the Ng trim position. After receiving the Ng trim position information, the engine electronic controller performs Ng trim.
[0032] The torque adjustment module is used to enable information exchange between the electronic controllers of different engines after the engine starts and enters the default torque balance mode, sharing the Ng speed and torque of their respective engines, and adjusting the current engine torque.
[0033] Compared with the prior art, the present invention has the following technical features:
[0034] 1. This invention, while ensuring improved power trim accuracy under low power conditions, further reduces the pilot's workload. At the same time, through power trim methods using torque or Ng, it ensures the matching between the engine and the helicopter, further improving human-machine efficiency and economy.
[0035] 2. Under different power changes and different critical points, the ESC can automatically determine the critical value. Under the control range of the ESC, the ESC can automatically perform Ngc balancing, improve the power balancing accuracy at low power, and improve human-machine efficiency. Under the control range of the power switch, it can set two balancing modes: torque and Ng, to meet the power distribution of multiple engines working under different losses, protect the relevant engine parameters from exceeding the limit, and increase the service life of the engine. Attached Figure Description
[0036] Figure 1 This is the control logic diagram of the method of the present invention. Detailed Implementation
[0037] This invention provides a power trim method for three-engine / twin-engine helicopter engines. The method utilizes an engine power control system to achieve trim. The control system includes: a cockpit power trim switch, a multi-function display, an electromechanical management system, electronic controllers for three / two engines, an engine torque sensor, and an engine Ng speed sensor, wherein:
[0038] The cockpit power trim switch is located on the cockpit control panel and is used to select whether the engine enters torque trim mode. The power trim switch has two settings: torque trim and Ng trim, which are selected by the pilot. The default setting is torque trim. After the cockpit power trim switch selects a setting, the setting information is sent to the electronic controller.
[0039] A multi-function display is located on the dashboard in the cockpit to show engine torque information, Ng speed information, and other engine status parameters.
[0040] The electromechanical management system is used to receive engine torque information and Ng speed information from the engine electronic controller and send these parameters to the multi-function display.
[0041] The engine's electronic controller receives gear information, as well as engine torque information and Ng speed information, and performs torque balancing or Ng balancing functions based on the torque value or gear information.
[0042] The electronic controllers of different engines have information exchange functions. The electronic controller of the current engine receives torque information and Ng speed information sent by the electronic controllers of other engines. It uses this information to control the current engine to increase or decrease torque or Ng so that the torque and Ng of all engines are within the balance accuracy range. The balance accuracy range is: the percentage difference of torque of all engines is within the range of 1% to 5%, and the percentage difference of Ng speed is within the range of 0.5% to 2%.
[0043] Based on the above-mentioned engine power control system, the engine power balancing method of the present invention includes:
[0044] Step 1: The cockpit power trim switch is in the torque trim position by default. When the pilot observes the engine operation, if the difference in ITT (gas turbine outlet temperature) between the two or three engines is less than 20-40°C and the percentage difference in Ng is less than 1%-5%, the cockpit power trim switch is not operated, and the current torque trim state is maintained.
[0045] In torque-balanced mode, the engine electronic controller switches the engine balance mode based on the engine torque:
[0046] When the torque information obtained by the engine torque sensor determines the change of the engine from low torque to high torque, if the minimum measured torque of the engine is less than 150-180 N·m, the engine torque trim function is not controlled by the power trim switch in the cockpit, and the engine electronic controller automatically performs Ng trim; if the minimum measured torque of the engine is greater than 150-180 N·m, the engine power trim function is controlled by the power trim switch in the cockpit.
[0047] When the torque information obtained by the engine torque sensor determines the change of the engine from a high torque state to a low torque state, if the minimum torque measured by the engine is greater than 100-130 N·m, the engine is controlled by the power balance switch; if the minimum torque measured by the engine is less than 100-130 N·m, the engine power balance function is automatically executed by the engine electronic controller for Ng balance.
[0048] Step 2: When the pilot observes that the ITT difference between different engines is greater than 20-40°C and the NG percentage difference is greater than 1%-5%, it is considered that the performance difference between different engines is large. Then, the pilot manually switches the cockpit power trim switch to the Ng trim position.
[0049] After receiving the Ng balancing gear information, the engine electronic controller performs Ng balancing.
[0050] Step 3: After the engine starts and enters the default torque balancing mode, the electronic controllers of different engines begin to exchange information, sharing their respective engine speed and torque (Ng), and adjusting the current engine torque. The specific method is as follows:
[0051] When there are two engines: When the electronic controller of the current engine receives a Ng speed of the other engine that is greater than that of the current engine, it controls the current engine to increase the fuel supply and increase the Ng speed of the current engine. As a result, the output power of the current engine increases. Under the condition that the total utilization rate of the helicopter is constant, the output power of the other engine should decrease. At this time, the electronic controller of the other engine controls the engine to reduce the fuel supply and reduce the Ng speed of the engine until the Ng percentage difference between the two engines is less than 0.5% to 2%.
[0052] When there are three engines: select the engine with the highest Ng speed as the balance target, and control the electronic controllers of the other two engines to increase the Ng speed. At the same time, the engine with the highest Ng speed gradually decreases the Ng speed until the Ng percentage difference of the three engines is less than 0.5% to 2%.
[0053] The torque balancing method for two or three engines is the same as the Ng balancing method mentioned above. The difference is that the electronic controller compares the engine torque during balancing, and the final percentage difference range is 1% to 5%.
[0054] Compared to other helicopter power trim methods, the innovation of this invention lies in: simultaneously controlling three or two engines for torque / Ng power trim via a cockpit switch; based on the torque status, the engine electronic speed controller (ESC) determines the minimum torque value of the three engines in the corresponding state, and performs automatic Ng trim or manual torque / Ng trim via the power switch according to the power change status; the ESC can determine the minimum torque range based on power changes and automatically perform Ng power trim within the corresponding range, improving the power trim accuracy under low power conditions, reducing pilot workload, and improving human-machine interface efficiency.
[0055] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.
Claims
1. A method for power trim of a three-engine / twin-engine helicopter engine, characterized in that, The method utilizes an engine power control system to achieve power balancing; the method includes: Step 1: The cockpit power trim switch is in the torque trim position by default. When the pilot observes the engine operation, if the difference in the gas turbine outlet temperature (ITT) between the two or three engines is less than the preset temperature threshold and the percentage difference in Ng is less than the preset speed threshold, the cockpit power trim switch is not operated, and the current torque trim state is maintained. In torque balancing mode, the engine electronic controller switches the engine balancing mode according to the engine torque; Step 2: When the pilot observes that the ITT difference between different engines is greater than the preset temperature threshold and the NG percentage difference is greater than the preset speed threshold, and considers that the performance difference between different engines is large, the pilot will manually switch the cockpit power trim switch to the Ng trim position. After receiving the Ng balancing gear information, the engine electronic controller performs Ng balancing; Step 3: After the engine starts and enters the default torque balancing mode, the electronic controllers of different engines begin to exchange information, share their respective engine speed and torque, and adjust the current engine torque.
2. The power trim method for three-engine / twin-engine helicopter engines according to claim 1, characterized in that, In the torque balancing state, the engine electronic controller switches the engine balancing mode according to the engine torque, including: When the torque information obtained by the engine torque sensor determines the change of the engine from low torque to high torque, if the minimum torque measured by the engine is less than the first torque threshold, the engine torque trim function is not controlled by the cockpit power trim switch, and the engine electronic controller automatically performs Ng trim; if the minimum torque measured by the engine is greater than the first torque threshold, the engine power trim function is controlled by the cockpit power trim switch.
3. The power trim method for three-engine / twin-engine helicopter engines according to claim 2, characterized in that, When the torque information obtained by the engine torque sensor determines the change of the engine from a high torque state to a low torque state, if the minimum torque measured by the engine is greater than the second torque threshold, the engine is controlled by the power balance switch. When the minimum torque measured by the engine is less than the second torque threshold, the engine power balancing function is automatically executed by the engine electronic controller to balance the Ng.
4. The power trim method for three-engine / twin-engine helicopter engines according to claim 3, characterized in that, The first torque threshold is 150–180 N·m, and the second torque threshold is 100–130 N·m.
5. The power trim method for three-engine / twin-engine helicopter engines according to claim 1, characterized in that, The control system includes: a cockpit power trim switch, a multi-function display, an electromechanical management system, electronic controllers for three or two engines, an engine torque sensor, and an engine Ng speed sensor, wherein: The cockpit power trim switch is located on the cockpit control panel and is used to select whether the engine enters the torque trim state. The power trim switch has two settings: torque trim and Ng trim, which are selected by the pilot. After the cockpit power trim switch selects a setting, the setting information is sent to the electronic controller. A multi-function display is located on the dashboard in the cockpit to display engine torque information and Ng speed information; The electromechanical management system is used to receive engine torque information and Ng speed information from the engine electronic controller and send these parameters to the multi-function display. The engine's electronic controller receives gear information, as well as engine torque and Ng speed information, and performs torque or Ng balancing functions based on the torque value or gear information.
6. The power trim method for three-engine / twin-engine helicopter engines according to claim 5, characterized in that, The electronic controllers of different engines have information exchange functions. The electronic controller of the current engine receives torque information and Ng speed information sent by the electronic controllers of other engines. It uses this information to control the current engine to increase or decrease torque or Ng so that the torque and Ng of all engines are within the balance accuracy range. The balance accuracy range is: the percentage difference of torque of all engines is within a first preset range, and the percentage difference of Ng speed is within a second preset range.
7. The power trim method for three-engine / twin-engine helicopter engines according to claim 1, characterized in that, The electronic controllers of the different engines begin to exchange information, sharing their respective engine speeds and torques, and adjusting the current engine torque, including: When there are two engines: When the electronic controller of the current engine receives a Ng speed of the other engine that is greater than the Ng speed of the current engine, it controls the current engine to increase the fuel supply and increase the Ng speed of the current engine. At this time, the electronic controller of the other engine controls the engine to reduce the fuel supply and reduce the Ng speed of the engine until the Ng percentage difference between the two engines is less than the second preset range.
8. The power trim method for three-engine / twin-engine helicopter engines according to claim 1, characterized in that, When there are three engines: select the engine with the highest Ng speed as the balance target, and control the electronic controllers of the other two engines to increase the Ng speed. At the same time, the engine with the highest Ng speed gradually decreases the Ng speed until the Ng percentage difference of the three engines is less than the second preset range.
9. The power trim method for three-engine / twin-engine helicopter engines according to claim 1, characterized in that, The first preset range is 1% to 5%, and the second preset range is 0.5% to 2%.
10. A power trim device for a three-engine / twin-engine helicopter engine, characterized in that, The device utilizes an engine power control system to achieve power balancing; the device includes: The torque trim setting module ensures that the cockpit power trim switch is in the torque trim position by default. When the pilot observes engine operation, if the difference in the gas turbine outlet temperature (ITT) between the two or three engines is less than a preset temperature threshold, and the percentage difference in Ng is less than a preset speed threshold, the cockpit power trim switch is not operated, and the current torque trim state is maintained. In the torque trim state, the engine electronic controller switches the engine trim mode according to the engine torque. The trim module is used when the pilot observes that the ITT difference between different engines is greater than the preset temperature threshold, or the NG percentage difference is greater than the preset speed threshold, and considers that the performance difference between different engines is large. In this case, the pilot manually switches the cockpit power trim switch to the Ng trim position. After receiving the Ng trim position information, the engine electronic controller performs Ng trim. The torque adjustment module is used to enable information exchange between the electronic controllers of different engines after the engine starts and enters the default torque balance mode, sharing the Ng speed and torque of their respective engines, and adjusting the current engine torque.