Method for determining energy-saving optimizing switching point of electric vehicle and operation methodThe application relates to a divisional application of a patent application named as an energy-saving optimizing switching point determining method and an operating method of an electric vehicle, wherein the application date of the original application is 11 months 04 days in 2019, and the application number is 201911064018.7.
Technical Field
The application relates to the field of power-saving operation of electric vehicles, in particular to a method for determining an energy-saving optimizing switching point of an electric vehicle and an operation method.
Background
Electric vehicles, high-speed trains and subway trains with more than 1 driving motor are configured, a large amount of electric energy is consumed every day, and the energy-saving and high-efficiency operation significance of the vehicles is great. In the running of these vehicles, the number of driving motors and the running speed of the vehicles are operated according to a certain relation, and the distribution method of the load and the number of the driving motors determines the overall running energy efficiency and the energy-saving quality of these vehicles.
The crowd who drives a single person to get on and off duty in the city is huge, and conventional electric automobile is driven by 1 motor, is in extremely low load running state often, adds weather, road conditions and frequent start-stop scheduling problem again, and the energy waste is serious, replaces the power of 1 driving motor with 2-4 driving motors, can realize more energy-conserving operation through optimizing, and the energy waste that can alleviate these problems and cause is expected to improve electric automobile's continuation of journey mileage, is hopeful to become the mainstream direction of electric automobile in the future. The high-speed train is generally driven by a plurality of motors, and due to the fact that passenger flow is large in change and high in running speed, and the influence of weather, wind resistance and uphill and downhill factors, load is large in light and heavy change, and the motors are driven to optimally control, the overall running energy efficiency can be improved, and the running energy consumption can be reduced. At present, urban rail transit-subways with great development are obtained, and many of the urban rail transit-subways are driven by 2-3 motors, and the optimized operation of the driving motors can also have a remarkable influence on reducing the energy consumption of the subways.
The currently known designs for these vehicles are carried out according to conventional design specifications, but the design specifications do not have a device allocation method and a quantized energy-saving design means for ensuring that a plurality of driving motors realize the most power-saving operation, the operation efficiency of the driving motors and corresponding speed regulators is also changed due to the resistance and speed change in the speed regulation process, the efficiency change curves of the motors under different speeds and different load rates are not provided in the factory data of the motors, the speed regulation driver manufacturer also does not provide the efficiency change curves under different frequencies and different load rates, and based on these factors, the determination of the best power-saving operation mode of these vehicles after speed regulation operation is very difficult.
The chinese patent No. ZL201010265930.1, which presents a general device load adjustment and quantity control method, is a milestone application in this field, but does not present a method of determining and acquiring the optimum switching point of the number of operations between driving motors.
Disclosure of Invention
In order to provide a searching method and an optimal operation method for determining the optimal switching points of the running numbers of driving motors in engineering of electric vehicles, high-speed trains and subway trains with multiple driving motors, the application provides an energy-saving optimizing switching point determining method and an operation method for electric vehicles, which can be conveniently and directly applied to engineering.
The technical scheme adopted for solving the technical problems is as follows: in an electric vehicle driven by k+k1 drive motors, there are k sets A of the same type drive motors equipped with the same type speed regulator and the same type transmission, k is an integer greater than 1, there are k1 other types of drive motors, k1 is greater than or equal to 0, and the electric vehicle is operated at a speed Vs The total torque output by all driving motors of the unit A is MA The total input power of all the speed regulators in the unit A is PA Any one driving motor in the unit A is designated as a 1 st driving motor, and the torque output by an i-th driving motor in the unit A is Mi The input power of the speed regulator corresponding to the ith driving motor is Pi ，MA ＝M1 +M2 +…+Mk ，PA ＝P1 +P2 +…+Pk 。
For unit A, at Vs Derived at a speed ofThe curve is used as a working curve w, which can be called a working equation or a working function, and the optimal switching point and the optimal operation method of the unit A are obtained>λ, μ, β, δ, ζ and σ are coefficients, β+.0, +.>And mu cannot be equal to 0,/at the same time>And δ cannot be equal to 0 at the same time, σ and δ cannot be equal to 0 at the same time, and σ and μ cannot be equal to 0 at the same time.
Specifically, at electric vehicle running speed Vs The output torque M of the 1 st driving motor in the recording unit A1 Speed regulator input power P corresponding to No. 1 driving motor1 ；
Output torque M of drive motor according to 1 st stage1 And the input power P of the speed regulator corresponding to the 1 st driving motor1 Determining a working curve w of 1 driving motor in operation1 The method comprises the steps of carrying out a first treatment on the surface of the Wherein M is1Max (Vs )≥M1 ≥0，M1Max (Vs ) For electric vehicle operation at speed Vs Maximum output torque of lower 1 st driving motor, MA ＝M1 ，PA ＝P1 ；
Using formula MA ＝(m-1)M1 And PA ＝(m-1)P1 Determining an operating curve w of m-1 drive motors operating at the same output torquem-1 The method comprises the steps of carrying out a first treatment on the surface of the Wherein m is a positive integer, k is greater than or equal to m and greater than or equal to 2, M1 ＝M2 ＝…＝Mm-1 ，P1 ＝P2 ＝…＝Pm-1 ；
Using formula MA ＝mM1 And PA ＝mP1 Determining a working curve w of m driving motors operated under the same output torquem The method comprises the steps of carrying out a first treatment on the surface of the Wherein M is1 ＝M2 ＝…＝Mm ，P1 ＝P2 ＝…＝Pm ；
If the working curve wm-1 And a working curve wm With the intersection point, the working curve wm-1 And a working curve wm The intersection point of the m-1 driving motors and the m driving motors is the running speed V of the electric vehicles The lower optimal switching point; m at the optimal switching pointA ＝Mm-1,m And PA ＝Pm-1,m ；Mm-1,m For optimum switching point expressed in terms of total output torque of unit A, Pm-1,m An optimal switching point expressed by the total input power of all the speed regulators in the unit A; at the intersection point, the efficiency of the m-1 running drive motors is the same as that of the m running drive motors, called "equivalent switching";
if the working curve wm-1 And a working curve wm If there is no intersection point, the M-1 running drive motor and the M running drive motor are switched to the M-1 running drive motor to operate at the highest output torque M1Max (Vs ) Is a point of (2); when m=2, the optimal switching point is MA ＝M1,2 And PA ＝P1,2 When m=k, the optimal switching point is MA ＝Mk-1,k And PA ＝Pk-1,k 。
Alternatively, M is maintained while the M-1 drive motors are running1 ＝M2 ＝…＝Mm-1 ，P1 ＝P2 ＝…＝Pm-1 The method comprises the steps of carrying out a first treatment on the surface of the When M driving motors are running, M is maintained1 ＝M2 ＝…＝Mm ，P1 ＝P2 ＝…＝Pm I.e. the same type of drive motor in operation, maintains the same load, called "same machine same load".
Alternatively, in engineering applications, M is takenm-1,m And Pm-1,m As the optimal switching point for the operation of the unit a.
In the engineering, two field process values which are absolutely equal cannot be found, only an approximate value near the optimal switching point can be found, the instrument itself has errors, if the electric vehicle requires that the starting and stopping intervals of the driving motors are limited in time, frequent switching of the running number of the driving motors near the optimal switching point is avoided, various factors are comprehensively considered, the value of the actual switching point is a value within a range near the optimal switching point, in the unit A,when the number of driving motors increases from m-1 to m, the actual switching point is the value of the optimal switching point multiplied by (1+θ), 0.15 is more than or equal to 0, and when the number of driving motors decreases from m to m-1, the actual switching point is the value of the optimal switching point multiplied by (1- ε), and 0.15 is more than or equal to 0. That is, the number near the optimal switching point is used as the actual switching point number, the number of driving motors is increased when the number is larger than the actual switching point number, the number of driving motors is reduced when the number is smaller than the actual switching point number, and the number of driving motors is maintained or switched when the number is actually switched, wherein the actual switching points are approximate to the optimal switching points; for different electric vehicle operating speeds Vs In the same way, different optimal switching points and different actual switching points are obtained.
When δ=1, ζ=1, σ= -1 and β=β1, βmAδ Vsξ PAσ ＝β1 MA Vs /PA ，β1 MA Vs /PA Represents the operating efficiency eta (V)s )，β1 As a coefficient, the unit A operates at the vehicle running speed Vs Under the condition, the optimal switching point is adopted to switch the running number of the driving motors, MA ≥M1,2 When the unit A operates, the operating efficiency eta (Vs )≥β1 M1,2 Vs /P1,2 The unit A operates in a high-efficiency area.
The beneficial effects of the application are as follows: first, 1 driving motor is operated at the vehicle speed Vs The method is easy to realize in engineering, and the switching and speed regulation control of the number of driving motors are carried out according to the optimal switching points, so that the unit A can be ensured to operate in a high-efficiency state.
Drawings
In order to more clearly illustrate the embodiments of the present application or the technical solutions of the prior art, the drawings that are needed in the embodiments will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
Fig. 1 is M for k=3A -PA The curves are used as working curves to obtain the optimal switching points and the schematic diagram of the optimal load distribution method.
Fig. 2 is a graph of M for k=3A -MA /PA The curves are used as working curves to obtain the optimal switching points and the schematic diagram of the optimal load distribution method.
Detailed Description
The following description of the embodiments of the present application will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present application, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.
In FIG. 1, 3 driving motors jointly drive a subway train, 3 driving motors of the same type equipped with the same speed governor and the same transmission form a set A, 0 driving motors of other types are provided, and the subway train is operated at a speed Vs Under the condition, the total torque output by the unit A is MA The total input power of all the speed regulators in the unit A is PA Any one driving motor in the unit A is designated as a 1 st driving motor, and the torque output by an i-th driving motor in the unit A is Mi The input power of the speed regulator corresponding to the ith driving motor is Pi ，MA ＝M1 +M2 +M3 ，PA ＝P1 +P2 +P3 Taking outλ＝0，μ＝0，β＝1，δ＝0，ξ＝0，σ＝1，/>Becomes MA -PA ，MA -PA As a working curve w.
At subway train running speed Vs The output torque M of the 1 st driving motor in the recording unit A1 Corresponding M1 Is input power P of the speed regulator1 ，M1Max (Vs )≥M1 ≥0，M1Max (Vs ) For subway train running at speed Vs The highest output torque of the lower 1 st driving motor; m is MA ＝M1 ，PA ＝P1 Obtaining a working curve w of the operation of 1 driving motor1 。
Taking MA ＝2M1 And PA ＝2P1 Obtaining the working curve w of 2 running driving motors running under the same output torque2 Hold M1 ＝M2 P is then1 ＝P2 。
Taking MA ＝3M1 And PA ＝3P1 Obtaining the working curve w of 3 running driving motors running under the same output torque3 Hold M1 ＝M2 ＝M3 P is then1 ＝P2 ＝P3 。
Working curve w1 And a working curve w2 The intersection point of (2) is C point, and C point is that 1 driving motor runs and 2 driving motors run at locomotive running speed Vs Optimum switching point at MA ＝M1 2 and PA ＝P1,2 。
Working curve w2 And a working curve w3 The intersection point of (2) and (3) is D point, and D point is that 2 driving motors are operated and 3 driving motors are operated at locomotive running speed Vs Optimum switching point at MA ＝M2,3 And PA ＝P2,3 The method comprises the steps of carrying out a first treatment on the surface of the P selection1,2 And P2,3 As the optimal switching point for the operation of the unit a.
In engineering applications, the process requires a drive motor to be started and stoppedIn order to avoid frequent switching of the number of driving motors in the vicinity of the optimum switching point, the number of switching points is within a range in the vicinity of the optimum switching point, and the subway train is operated at a speed Vs When the number of driving motors is increased from 1 to 2, the switching point is P1,2 (1+0.1), when the number of driving motors is reduced from 2 to 1, the switching point is P1,2 (1-0.1), the switching point is P when the number of driving motors increases from 2 to 32,3 (1+0.1), when the number of driving motors is reduced from 3 to 2, the switching point is taken as P2,3 (1-0.1)。
That is, the number near the optimum switching point is used as the actual switching point number, the number of driving motors is maintained at the actual switching point, the number of driving motors is increased when the number is larger than the switching point number, and the number of driving motors is decreased when the number is smaller than the switching point number, and the actual switching points are approximate to the optimum switching point.
1.1P1,2 ≥PA And keeping 1 driving motor running when the speed is more than or equal to 0. P (P)A ＞1.1P1,2 Switching to 2 driving motors to operate and keeping M1 ＝M2。1.1P2,3 ≥PA ≥1.1P1,2 Keeping 2 driving motors running and M1 ＝M2 。PA ＞1.1P2,3 Switching to 3 driving motors to operate and keeping M1 ＝M2 ＝M3 。PA ≥0.9P2,3 When the driving motor keeps running, 3 driving motors keep running, and M1 ＝M2 ＝M3 。0.9P2,3 ＞PA Switching to 2 driving motors to operate and keeping M1 ＝M2 。1.1P2,3 ≥PA ≥
1.1P1,2 When using 2 driving motors to operate, and maintain M1 ＝M2 。0.9P1,2 ＞PA And then switching to 1 driving motor operation. 1.1P1,2 ≥PA And keeping 1 driving motor running when the speed is more than or equal to 0. For different subway train running speeds Vs By the same method, different best results are obtainedA good switching point and a different actual switching point.
In fig. 2, 3 driving motors jointly drive an electric vehicle, 3 driving motors of the same type equipped with the same speed regulator and the same transmission device form a set A, the driving motors of other types are 0, and the electric vehicle runs at a speed Vs Under the condition, the total torque output by the unit A is MA The total input power of all the speed regulators in the unit A is PA Any one driving motor in the unit A is designated as a 1 st driving motor, and the torque output by an i-th driving motor in the unit A is Mi The input power of the speed regulator corresponding to the ith driving motor is Pi ，MA ＝M1 +M2 +M3 ，PA ＝P1 +P2 +P3 Taking outλ＝0，μ＝0，β＝1，δ＝1，ξ＝0，σ＝-1，/>Becomes MA -MA /PA ，MA -MA /PA As a working curve w.
At the running speed V of the electric automobiles The output torque M of the 1 st driving motor in the recording unit A1 Corresponding M1 Is input power P of the speed regulator1 ，M1Max (Vs )≥M1 ≥0，M1Max (Vs ) For the electric automobile to run at the speed Vs The highest output torque of the lower 1 st driving motor; m is MA ＝M1 ，PA ＝P1 Obtaining a working curve y of the operation of 1 driving motor1 。
Taking MA ＝2M1 And PA ＝2P1 Obtaining the working curve y of 2 running driving motors running under the same output torque2 Hold M1 ＝M2 P is then1 ＝P2 。
Taking MA ＝3M1 And PA ＝3P1 Obtaining the working curve y of 3 running driving motors running under the same output torque3 Hold M1 ＝M2 ＝M3 P is then1 ＝P2 ＝P3 。
Working curve y1 And a working curve y2 The intersecting point of the (C) is C, and the C is the running speed V of the electric automobile when 1 driving motor runs and 2 driving motors runs Optimum switching point at MA ＝M1,2 。
Working curve y2 And a working curve y3 The intersecting point of the (2) driving motors is the point D, and the point D is the running speed V of the electric automobile when the 2 driving motors run and the 3 driving motors runs Optimum switching point at MA ＝M2,3 。
In engineering application, when the process requires that the start and stop intervals of the driving motors are limited in time, in order to avoid frequent switching of the number of driving motors near the optimal switching point, the value of the actual switching point is a value within a range near the optimal switching point, and when the number of driving motors increases from 1 to 2, the actual switching point is M1,2 (1+0.1), when the number of driving motors is reduced from 2 to 1, the actual switching point is M1,2 (1-0.1), when the number of driving motors is increased from 2 to 3, the actual switching point is M2,3 (1+0.1), when the number of driving motors is reduced from 3 to 2, the actual switching point is M2,3 (1-0.1)。
That is, the number near the optimum switching point is used as the actual switching point number, the number of driving motors is maintained at the actual switching point, the number of driving motors is increased when the number is larger than the switching point number, and the number of driving motors is decreased when the number is smaller than the switching point number, and the actual switching points are approximate to the optimum switching point.
1.1M1,2 ≥MA And keeping 1 driving motor running when the speed is more than or equal to 0. M is MA >1.1M1,2 Switching to 2 driving motors to operate and keeping M1 ＝M2 。1.1M2,3 ≥MA ≥1.1M1,2 Keeping 2 driving motors running and M1 ＝M2 。MA ＞1.1M2,3 Switching to 3 driving motors to operate and keeping M1 ＝M2 ＝M3 。MA ≥0.9M2,3 When the driving motor keeps running, 3 driving motors keep running, and M1 ＝M2 ＝M3 。0.9M2,3 ＞MA Switching to 2 driving motors to operate and keeping M1 ＝M2 。1.1M2,3 ≥MA ≥1.1M1,2 When using 2 driving motors to operate, and maintain M1 ＝M2 。0.9M1,2 ＞MA And then switching to 1 driving motor operation. 1.1M12 ≥MA And keeping 1 driving motor running when the speed is more than or equal to 0. For different running speeds V of electric vehicless In the same way, different optimal switching points and different actual switching points are obtained.
Those skilled in the art will recognize that many modifications may be made without departing from the spirit and scope of the application, such as described using other letters, changing the names of the terms, changing the number of drive motors, changing the number and form of data used, multiplying or dividing by a constant or coefficient, changing the structure of the expression, such as with MA /Vs -PA As a working curve, because of Vs Constant value, working curve and MA -PA Similarly, etc., it will be apparent to those skilled in the art that the present application may be embodied in other forms without departing from the spirit of the application, and thus, other embodiments are within the scope of the appended claims.