CN-114476096-B - OEI state control requirement and cabin indication method for turboshaft engine

Abstract

The invention discloses a control requirement and a cabin indication method for the OEI state of a turboshaft engine, which comprises the steps of firstly establishing a mathematical model of the component level of the turboshaft engine, then controlling the steady-state process of the turboshaft engine based on an incremental PID algorithm and a steady-state PID control method, ensuring that the steady-state process of the turboshaft engine in the OEI state can run stably, controlling the dynamic process of the turboshaft engine by combining the steady-state control method and the OEI state control requirement in the OEI state of the turboshaft engine through a method combining total distance feedforward control and feedback control, ensuring that the turboshaft engine can run stably in the OEI state and formulating the cabin indication requirement according to the running state of the engine.

Inventors

• ZHOU WENXIANG
• PENG WENHUI
• XIE YUYANG
• PU CHENGHAN
• LIU JIA
• LUO SUMING

Assignees

• 南京航空航天大学

Dates

Publication Date

20260512

Application Date

20211224

Claims (3)

1. 1. A cabin indication method under the OEI state control requirement of a turboshaft engine, characterized in that the OEI state control requirement: (1) When the current value of at least 1 parameter index in the OEI state performance parameter indexes of the engine is greater than or equal to the limit value of the OEI state entering a certain level, the control system determines that the engine enters the OEI state of the certain level; (2) In the process of steady-state control of one stage of OEI, the performance parameter index of the OEI state of the engine cannot exceed the limit value of the OEI state of the upper stage; (3) Under the condition of single failure, the OEI controller automatically releases the limit of the OEI state performance parameter index, and automatically adjusts the increment of the fuel flow based on the current engine power condition by controlling the constant rotation speed of the power turbine so as to enable the engine to enter a corresponding OEI state; (4) When the current value of each OEI state performance parameter of the engine is lower than the current OEI state exit judgment value, the control system determines to exit the OEI state and stops timing; The cabin indication method specifically comprises the following steps: step L1, dividing OEI state into two limiting stages of 30 seconds and 2 minutes, and when no less than 1 OEI state limiting value exceeding 30 seconds or 2 minutes exists in the OEI state performance indexes of the engine, entering the quasi-OEI state of the engine and starting timing; L2, when the engine is at a stage of 2 minutes and enters a quasi OEI state for more than 5 seconds, the engine formally enters the OEI state, when the engine is at a stage of 30 seconds and enters the quasi OEI state for more than 3 seconds, the engine formally enters the OEI state, at the moment, a cabin OEI state indicator lamp is turned on, the use time of the OEI state begins to be recorded, the OEI state comprises the quasi OEI state duration time, and when the OEI state performance parameter index exceeds a previous stage OEI limit value or the engine exits the current OEI state within a certain time, the quasi OEI state duration time and the use times are recorded independently; And step L3, when the time of the engine at the limit level of 30 seconds reaches the upper limit, the cockpit gives a warning to the pilot and prompts the pilot to choose to enter the limit level of 2 minutes or end the OEI state, and when the time of the engine at the limit level of 2 minutes reaches the upper limit, the cockpit should give an alarm to the pilot and recommend to exit the OEI state.
2. 2. The cabin indication method under the OEI state control requirement of the turboshaft engine according to claim 1, wherein the combination of total distance feedforward control and feedback control ensures that the turboshaft engine can stably run under the OEI state and the cabin indication requirement is formulated according to the running state of the engine; Setting the OEI state of an engine control system to be in a transition state, wherein the transition state control method comprises total distance feedforward control and feedback control, wherein the feedback control adopts a power turbine rotating speed control loop and a gas generator rotating speed change rate control loop to form cascade control, so that the rotating speed change rate of the gas generator is used As a control object, a typical PID control law is adopted as follows: Wherein, the Is a proportionality coefficient of the PID control, Is the integral coefficient of the PID control, Is a derivative coefficient of the PID control, Is a complex variable; The total distance feedforward control adopts a total distance compensation mode, a fuel quantity command is corrected in advance according to the mapping relation between the angle of the total distance rod and the fuel quantity by pre-estimating the change of the angle of the total distance rod, the response speed of the output power of the engine to the power change required by the helicopter is accelerated, the feedforward compensation value of the fuel quantity is obtained by interpolation of a mapping curve between the total angle of a rotor wing and the fuel quantity, and the fuel quantity is regulated in real time according to the curve when the total distance is changed.
3. 3. The cabin indication method under the OEI state control requirement of the turboshaft engine according to claim 1, wherein after the turboshaft engine enters the OEI state, a steady-state process of the turboshaft engine is controlled by adopting an incremental PID algorithm and a steady-state PID control method, so that the turboshaft engine can stably run under the OEI state; s1, establishing a component level mathematical model of a turboshaft engine; Step S2, the incremental PID algorithm controller outputs an increment between the actual value of the current system control quantity and the actual value of the control quantity of the last step length, and the increment is specifically expressed as follows: Wherein the method comprises the steps of Is in the system The control variable of the moment of time, Is in the system The control variable of the moment of time, Indicating the control increment(s), In order to achieve a proportional gain, As an integral coefficient of the power supply, As a result of the differential coefficient, The current error of the system; S3, the steady-state PID control method is cascade control, the control system comprises an inner loop and an outer loop, each loop is respectively provided with a controller, and the outer loop is the rotating speed of the power turbine The inner loop is the rotation speed of the gas generator By controlling the fuel quantity Rotating the power turbine Tracking a given rotational speed ; When the rapid collective command is changed, the rotor power is changed, and the engine power is not matched with the load, so that Greatly drooping or overshoot, and the outer loop is set according to the rotating speed of the power turbine Deviation from the actual value, the gas turbine speed command value is adjusted by PID control, and the control law is expressed as follows: Wherein, the Is a proportionality coefficient of the PID control, Is the integral coefficient of the PID control, Is a derivative coefficient of the PID control, Is a complex variable; taking the output result of the outer loop controller as the given value of the inner loop, according to the rotating speed of the gas turbine Is used for adjusting the fuel quantity by adopting an incremental PID algorithm The control law is expressed as follows: meanwhile, an integral separation part is added to the outer loop, an integral saturation resisting part is added to the inner loop, the dynamic performance of the system is improved, steady-state errors are reduced, and steady-state control of the turboshaft engine is realized.

Description

OEI state control requirement and cabin indication method for turboshaft engine Technical Field The invention relates to the technical field of aero-engines, in particular to a vortex shaft engine OEI state control requirement and cabin indication method. Background When an aircraft is in air operation, engine shutdown may occur in some cases due to poor engine fueling and air intake, engine mechanical failure, or improper use of ice build-up in the cloud and anti-icing systems. Airworthiness regulations require that commercial aircraft must ensure that the aircraft can safely end its flight without accidents when it encounters an engine failure at any time during its mission. In order to meet the requirements of safety and navigability, most of the current internationally common commercial aircrafts are provided with two or more engines, especially large and medium-sized transportation aircrafts. When one engine fails, the power required for the aircraft to fly will be provided by the remaining engines. One engine failure may occur in any stage of a flight mission spectrum, wherein in the flight stages of taking off, catapult-assisted take-off or landing and the like requiring high power, the pneumatic and operational performance of the whole aircraft are greatly influenced, and the engine failure is a stage requiring important attention in safety analysis. For a fixed wing aircraft, under given weight, gusts and atmospheric conditions, the runway is required to have a sufficient length, and the aircraft can be ensured to take off or the take off is interrupted when an engine fails at the expected key point of the take-off track. In order to enable the helicopter to still have enough power to realize safe landing or rapid landing after emergency climbing when one engine fails in the critical flight stages of taking off or landing and the like, which are usually vertical taking off and landing, a main current design method is to require the rest engine to operate in a short-time high-emergency power state, which is usually higher than a normal taking off or maximum continuous rated power state, possibly resulting in damage and life loss of engine parts, and thus corresponding use limitation and maintenance and repair requirements after use are provided for the state. An engine non-working state (One Engine Inoperative) used in the helicopter emergency state is a single-shot failure state, namely an OEI state for short. In view of the particularity of OEI status and the impact on helicopter flight safety, civil aviation authorities in various countries have increased new OEI status design, verification, use and maintenance related airworthiness terms in engine airworthiness regulations over the last decade. In CCAR-33-R2 of aviation engine aviation regulation published by China Civil Aviation Agency (CAAC) in 2012, the design, verification and aviation limit clause requirements (the requirement of forced inspection and maintenance after the OEI is used) of OEI states are comprehensively increased, and out of 53 clauses applicable to the CCAR-33-R2 text turbine engine, 9 clauses related to the OEI states are totally added, and the frequency of the OEI appearing in the whole text reaches 68. It can be said that OEI status airworthiness requirements for helicopter engines (typically turboshaft engines) are one major difference between CCAR-33-R2 version and CCAR-33-R1. Furthermore, OEI status requirements are one of the main differences between military and civilian turboshaft engine development requirements. Most of the main commercial scroll engines on the market today have OEI rated power state settings, such as Arriel 2C, PT6-67C, TM333 2B, 30 seconds OEI rated power, 2 minutes OEI rated power, and continuous OEI rated power. However, the technology of determining the OEI state of the civil turboshaft engine and analyzing, verifying and maintaining and evaluating the corresponding navigable requirements in China is still blank, and the uncertainty risk is brought to the research and development of the domestic civil turboshaft engine. Therefore, the method has very important significance for researching OEI state control rules and cabin indication. Disclosure of Invention Aiming at the problems in the background technology, the invention provides a steady-state control method and a cabin indication method of a turboshaft engine in an OEI state, realizes steady-state control of the turboshaft engine in a single failure state based on a nonlinear mathematical model of the turboshaft engine, ensures that the turboshaft engine can stably run in the OEI state by combining total distance feedforward control and feedback control, and establishes cabin indication requirements according to the running state of the engine. The technical scheme adopted by the invention is as follows: The OEI state control requirement and cabin indication method for the turboshaft engine is characterized in that the OEI state control r