Diesel engine work control method adaptive to altitude

Abstract

The invention relates to the technical field of internal combustion locomotives, in particular to an altitude-adaptive locomotive diesel engine work control method, which comprises the following steps of: acquiring optimal diesel engine power corresponding to the rotating speed of a diesel engine in different altitude height ranges; fitting the rotating speed of the diesel engine with the corresponding optimal diesel engine power to respectively obtain quadratic polynomial formulas M in different altitude ranges; and fitting the altitude with the coefficients in the formula M to obtain a linear polynomial formula of the coefficients in the formula M, and substituting the linear polynomial formula into the quadratic polynomial formula M to obtain a diesel engine working curve power formula N. The real-time diesel engine rotating speed is detected, the altitude measuring instrument is used for measuring altitude parameters, the parameters are used for automatically updating the diesel engine rotating speed and power curve, self-adaptive adjustment of the diesel engine on the continuous altitude is obtained, and the working point of the diesel engine is better.

Description

Technical Field

[0001] The invention relates to the technical field of internal combustion locomotives, and in particular to an altitude-adaptive locomotive diesel engine operation control method. Background Art

[0002] During the operation of diesel locomotives, they need to adapt to working in different altitude environments. The continuously changing altitude has a great impact on the operation of diesel engines. The power generated by the diesel engine within its own speed range will also be affected by the altitude change. The traditional method is to set the segmented altitude fixedly, and the diesel engine speed and power curve also adopts a piecewise function. However, this method has the following disadvantages: it cannot always reflect the unique working state of the diesel engine at a certain altitude, and it cannot work at the ideal working point. Summary of the invention

[0003] The present invention aims to solve the above-mentioned defects and provides a locomotive diesel engine operation control method with adaptive altitude.

[0004] In order to overcome the defects in the background technology, the technical solution adopted by the present invention to solve the technical problem is: a method for controlling the operation of a locomotive diesel engine with adaptive altitude, characterized in that it includes the following steps: S1, obtaining the optimal diesel engine power corresponding to the diesel engine speed within different altitude ranges; S2, the diesel engine speed is fitted with the corresponding optimal diesel engine power, and the quadratic polynomial formula M in different altitude ranges is obtained: y = Ax² - Bx + C, where y is the power and x is the diesel engine speed; S3, fitting the altitude with the coefficients A, B, C of X², X¹ and Xº in the quadratic polynomial formula M, respectively obtaining the first-order polynomial formulas of the coefficients A, B, C in the quadratic polynomial formula M at different altitudes, and substituting the first-order polynomial formulas of the coefficients A, B, C into the quadratic polynomial formula M to obtain the diesel engine working curve power formula N; S4, substitute the real-time speed of the diesel engine and the altitude into the power formula N of the diesel engine working curve to obtain the diesel engine power, use the diesel engine power as the given value of the PID controller, and use the power of the traction motor on the locomotive as the process value of the PID controller. The PID controller controls the chopper amplifier to control the excitation current of the brushless excitation main generator, thereby adjusting the output power of the brushless excitation main generator.

[0005] Further improvement includes, in step S3, the diesel engine operating curve power formula N: y=(-7E-07h+0.0043)x²-(-0.0006h+3.0351)x+(-0.1332h+653.99), where x is the speed of the diesel engine, y is the power, and h is the altitude.

[0006] A further improvement, included in the S1, is the acquisition of altitude via an altimeter.

[0007] The beneficial effects of the present invention are as follows: the present invention uses a curve fitting method to obtain a curve of a diesel engine speed and power when the diesel engine is operating at different altitudes, uses the curve fitting method to obtain various coefficients of a formula of a diesel engine operating curve at different altitudes, uses an altitude measuring instrument to measure altitude parameters, and uses the parameters to automatically update the diesel engine speed and power curve, obtains adaptive adjustment of the diesel engine at continuous altitudes, and makes the diesel engine operating point better. In addition, the present design uses curve fitting technology and an altitude measuring instrument to obtain altitude parameters in real time, so that the engine can operate more accurately in the entire domain at all altitudes, thereby overcoming the problem that the original altitude piecewise function and the diesel engine speed and power curve are also piecewise functions and cannot operate at an ideal operating point. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0009] Figure 1 is a linear graph of a first-order polynomial with coefficient A in the present invention; Figure 2 is a linear graph of a first-order polynomial with coefficient B in the present invention; Figure 3 is a linear graph of a first-order polynomial with coefficient C in the present invention; Figure 4 is a block diagram of a control system for a diesel locomotive according to the present invention; DETAILED DESCRIPTION

[0010] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0011] A method for controlling a locomotive diesel engine with self-adaptive altitude comprises the following steps: S1, obtaining the optimal diesel engine power corresponding to the diesel engine speed in different altitude ranges, as shown in Table 1 below;

[0012] From Table 1, we can see the relationship between the speed and power of a diesel engine. The higher the speed of the diesel engine, the greater the power; the higher the altitude, the smaller the power.

[0013] S2, the diesel engine speed is fitted with the corresponding optimal diesel engine power, and the quadratic polynomial formula M in different altitude ranges is obtained: y = Ax² - Bx + C, where y is the power and x is the diesel engine speed, specifically: Altitude 0-700: 0.0041x² - 2.8888x+619.99; Altitude 700-1000: 0.0037x²-2.5996x+552.54; Altitude 1000-1500: 0.0034x²-2.3229x+489.83; Altitude 1500-2000: 0.003x²-2.0295x+420.98; Altitude 2000-2500: 0.0027x²-1.7432x+355.54; Altitude 2500-3000: 0.0023x²-1.4594x+289.42; 3000-3500 meters above sea level: 0.0019x²-1.1553x+217.58; 3500-4000 meters above sea level: 0.0016x²-0.881x+155.53; The formulas for the diesel engine speed and power in different altitude ranges are obtained. At this time, different altitude ranges correspond to different quadratic polynomial formulas.

[0014] S3. Fit the altitude with the coefficients A, B, and C of X², X¹, and Xº in the quadratic polynomial formula M, and obtain the first-order polynomial formulas of the coefficients A, B, and C in the quadratic polynomial formula M at different altitudes, as shown in Table 2 below. Substitute the first-order polynomial formulas of the coefficients A, B, and C into the quadratic polynomial formula M to obtain the diesel engine working curve power formula N. Fit the formula to the data in Table 2 to obtain the function formula of the altitude and the coefficients X², X¹, and Xº of the quadratic polynomial.

[0015]

[0016] The coefficients of the quadratic polynomials X², X¹, and Xº are calculated based on the altitude: A = -7E-07h + 0.0043; B = -0.0006h + 3.0351; C = -0.1332h + 653.99; Where h is the altitude. Since the diesel locomotive is equipped with an altitude measuring instrument, h can be measured, and the values ​​of A, B, and C can be calculated, such as Figure 1 , Figure 2 and Figure 3 As shown; According to the diesel engine speed, the values ​​of A, B, and C are substituted into the quadratic polynomial formula M to calculate the diesel engine working curve power formula N: y=(-7E-07h+0.0043)x²-(-0.0006h+3.0351)x+(-0.1332h+653.99), where x is the speed of the diesel engine, y is the power, and h is the altitude; The purpose of the invention patent is to obtain the current altitude parameters of the diesel locomotive by installing an altitude measuring instrument on the diesel locomotive, and calculate the quadratic polynomial coefficients in the diesel engine speed and power formula through a fitting formula, so as to calculate the optimal power output of the diesel engine through a known diesel engine speed.

[0017] S4, such as Figure 4 As shown, specifically, by receiving the pulse sent by the encoder on the diesel engine shaft, the locomotive microcomputer receives the pulse, measures its frequency, calculates the real-time diesel engine speed, substitutes the real-time diesel engine speed and the altitude into the diesel engine working curve power formula N to obtain the diesel engine power, and calculates the diesel engine optimal power of the internal combustion engine. Then, under the condition that the voltage limit and the current limit are not exceeded, the calculated diesel engine optimal power is used as the given value of the PID controller, and the power of the traction motor on the locomotive is used as the process value of the PID controller. The PID controller controls the chopper amplifier to control the excitation current of the brushless excitation main generator, thereby adjusting the output power of the brushless excitation main generator, and finally achieving the purpose of controlling the diesel engine to output the optimal power.

[0018] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for controlling a locomotive diesel engine with adaptive altitude, characterized in that: The following steps are involved: S1, obtaining the optimal diesel engine power corresponding to the diesel engine speed within different altitude ranges; S2, the diesel engine speed is fitted with the corresponding optimal diesel engine power, and the quadratic polynomial formula M in different altitude ranges is obtained: y = Ax² - Bx + C, where y is the power and x is the diesel engine speed; S3, fitting the altitude with the coefficients A, B, C of X², X¹ and Xº in the quadratic polynomial formula M, respectively obtaining the first-order polynomial formulas of the coefficients A, B, C in the quadratic polynomial formula M at different altitudes, and substituting the first-order polynomial formulas of the coefficients A, B, C into the quadratic polynomial formula M to obtain the diesel engine working curve power formula N; S4, substitute the real-time speed of the diesel engine and the altitude into the power formula N of the diesel engine working curve to obtain the diesel engine power, use the diesel engine power as the given value of the PID controller, and use the power of the traction motor on the locomotive as the process value of the PID controller. The PID controller controls the chopper amplifier to control the excitation current of the brushless excitation main generator, thereby adjusting the output power of the brushless excitation main generator.

2. The method for controlling a locomotive diesel engine with adaptive altitude according to claim 1, characterized in that: In step S3, the diesel engine operating curve power formula N is: y=(-7E-07h+0.0043)x²-(-0.0006h+3.0351)x+(-0.1332h+653.99), where x is the speed of the diesel engine, y is the power, and h is the altitude.

3. The method for controlling a locomotive diesel engine with adaptive altitude according to claim 1, characterized in that: In S1, the altitude is obtained by an altimeter.

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