CN105068003B - Use the method for the best efficiency point measure automobile-used direct current generator actual power of electrical salf-walking - Google Patents

Abstract

The invention provides a kind of method that the automobile-used direct current generator actual power of electrical salf-walking is determined using best efficiency point.The method of the invention, can be in the case where not being apprised of power of motor, by " efficiency power output " curve for measuring a motor, use graphing method, the best efficiency point of motor is searched out on curve, the principle for the characteristics of specified power points of reality of motor is necessarily designed to efficiency peak using designer, determine the actual power of the automobile-used direct current generator of electrical salf-walking.After method of testing provided by the invention can effectively solve the automobile-used direct current generator of electrical salf-walking empty mark " small to mark greatly ", the problem of can not assert.Allow in national electric bicycle vehicle standard, power of motor cannot be greater than the regulation of certain power, turn into the index that can be examined.

Description

Use the method for the best efficiency point measure automobile-used direct current generator actual power of electrical salf-walking

Technical field

The present invention relates to a kind of assay method of motor actual power, specifically one kind is determined electronic using best efficiency point The method of the actual power of bicycle use direct current generator.

Background technology

Electric bicycle standard GB17761-1999 provides that the automobile-used direct current generator power of electrical salf-walking is not more than 240W, mesh The preceding motor used indicates that rated power is 350W, in practice to allow electric bicycle to run faster, more, the motor of load Power the more does the more big, but the power on nameplate only indicates 450W.The phenomenon of " small to mark greatly " largely be present.Fortune is run on similar highway Defeated truck, it is obviously to carry 20 tons, 8 tons is but indicated on driving license.

At present, the method for testing of all motors both at home and abroad, during test, is all referring initially to the power on motor nameplate, then makes Motor rated power is progressively loaded into various dynamometer machines, under nominal power, reads electrical power parameter (voltage, the electricity of input Stream, power, power factor (PF)), while the mechanical output (torque, rotating speed) of output is read, further according to power output and input power Ratio calculate the efficiency of motor.This method is actually the checking to nameplate data.If power of motor does not reach nameplate Show, motor will turn motionless, so this conventional test methodologies can measure motor " big with small tenon ", but can not measure electricity Machine " small to mark greatly ".

Study motor electromagnetic design and find that, in order to allow motor to operate power saving, efficiency is use up when electrical power changes into mechanical output May be high, designer is inevitable to be designed to efficiency peak the specified power points of reality of motor.Inspired from this point, by determining electricity The best efficiency point of machine, it is possible to determine the real rated power of motor.

The content of the invention

The purpose of the present invention is in the case where not knowing the true rated power of motor, is tested using with conventional motors Identical tester, the test thinking of contrary, to determine its actual rated power.

The method of the present invention that the automobile-used direct current generator actual power of electrical salf-walking is determined using best efficiency point is included Following steps：

(1) treat measured motor using magnetic hysteresis Dynamometer Control instrument to be loaded, input is recorded by DC parameter instrument point by point Electrical parameter, including voltage U, electric current I, input power P_Input, the output mechanical parameter of synchronous recording motor, including torque N, rotating speed R, power output P_Output；

Motor efficiency：

(2) progressively loaded from zero load, until motor rotation blockage, measures the parameter of multiple points, one is made using computer " efficiency-power output " curve；

(3) take the best efficiency point of the curve to decline 3%~25% and make a horizontal line, the horizontal line and " efficiency-defeated Going out power " curve has two intersection points, try to achieve the abscissa P of intersection point_{Output 1}And P_{Output 2}；

(4) P is sought_{Output 1}And P_{Output 2}Arithmetic mean of instantaneous value Pn, as the actual rated power of motor measured.

Specifically, the parameter that 40~50 points are typically measured in step (2) is used to make " efficiency-power output " curve.

According to method of testing provided by the invention, can effectively solve the automobile-used direct current generator of electrical salf-walking " small to mark greatly " After void mark, the problem of can not assert.Allow in national electric bicycle vehicle standard, power of motor cannot be greater than the rule of certain power It is fixed, turn into the index that can be examined.

Brief description of the drawings

Fig. 1 is motor electrical wiring and mechanical connection figure.

Fig. 2 is electromechanical testing " efficiency-power output " curve.

Embodiment

The present invention surveys in the case where not knowing the true rated power of motor using with conventional motors test identical Test instrument, the test thinking of contrary.Complete " efficiency-power output " curve for motor is first measured, using graphing method, is looked for The best efficiency point gone out on curve, and corresponding power output is obtained, the specified work(using this power points found as motor Rate.Rated power input electrical parameter (voltage, electric current, power, power factor) is carried out again, and the mechanical parameter of output (torque, turns Speed) test.

The theoretical foundation of the present invention is, " efficiency-power output " curve of (1) motor necessarily a convex and left and right base This symmetrical curve.(2) in motor electromagnetic design, it is necessary to the best efficiency point of motor is designed to main in motor actual use Load, nominal load point, could allow motor operation is most stable, temperature rise is suitable, most economical.

The invention will be further described with reference to the accompanying drawings and examples.

The specific assay method of the present invention is as follows：

(1) according to Fig. 1 connect test equipment and unknown actual rated power the automobile-used direct current generator of electrical salf-walking (or The motor of void mark rated power).

(2) motor is loaded using magnetic hysteresis Dynamometer Control instrument, records input electricity ginseng point by point by DC parameter instrument Number (voltage U, electric current I, input power P_Input), per output mechanical parameter (torque N, rotating speed r, the output work of point synchronous recording motor Rate P_Output)。

Motor input power:P_Input=UI

Output power of motor:

Motor efficiency：

(3) progressively loaded from unloaded (zero load), until motor rotation blockage, is measured 40~50 points, done using computer Go out complete " efficiency-power output " curve, such as Fig. 2.

(4) because the test discreteness of motor is larger, in actual test, the top highest of " efficiency-power output " curve Efficient point is a more flat garden arc, specific corresponding P_OutputIt is not difficult to find.Therefore take best efficiency point to decline 3%~25% and (implement 10%) one horizontal line of work is taken in example, seeks the abscissa of " efficiency-power output " curve and horizontal two intersection points, it is corresponding horizontal Power points P on axle_{Output 1}And P_{Output 2}。

(5) P is sought_{Output 1}And P_{Output 2}Arithmetic mean of instantaneous value Pn, as the measure actual rated power of the direct current generator.

It is a specific embodiment below.

One most common nameplate of test indicates that power is 350W, and voltage is direct current 48V, rotating speed 330r/min, torque For the 13N.m automobile-used DC brushless motor of electrical salf-walking.

The range and precision of used instrument are as follows：

(1) ZTV-1 types direct-current single-phase electrical parameter table

Voltage range:50V, precision：0.25% × reading+0.25% × range

Current range:50A, precision：0.25% × reading+0.25% × range

(2) ZC50 types magnetic hysteresis dynamometer system

Torque range:50N.m, maximum operation power 3000W, precision：0.5%

Rotating speed range:≤ 3000r/min, precision：0.2%

(3) D.C. regulated power supply

Voltage output range：0-50V, irregularity of wave form≤6%.

Specific implementation step：

(1) mechanical erection, because the automobile-used DC brushless motor of electrical salf-walking is external rotor electric machine, on dynamometer machine When, it is necessary to by a transition apparatus, the rotation of motor housing, be connected on the axle of magnetic hysteresis dynamometer machine, as shown in Figure 1.

(2) it is electrically connected, importation connects direct-current single-phase electrical parameter instrument by D.C. regulated power supply, reconnects tested motor (actual connection electric machine controller) output par, c, torque, rotating speed inside magnetic hysteresis dynamometer machine are directly connected to by signal wire and turned Square rotational speed detector.

(3) motor is loaded using magnetic hysteresis Dynamometer Control instrument, in the case where keeping DC voltage 48V constant, Increase the exciting current of magnetic hysteresis Dynamometer Control instrument, the power output observed on torque rotary speed tester is shown, is progressively increased from zero Greatly, when increasing to 1100W, motor turns motionless, and stall occurs.

(4) above procedure, general power often increase 20W, measure a point, measure altogether at 40~50 points, the data each put Including input electrical parameter (voltage U, electric current I, input power P_Input), export mechanical parameter (torque N, rotating speed r, power output P_Output), and the every point efficiency η calculated.

(5) it is power output P to draw abscissa_Output,Ordinate is " efficiency-power output " curve, such as Fig. 2 of efficiency.Can Tentatively to find out, motor peak efficiency is about 84%, and corresponding power is about 800W.

(6) best efficiency point is taken to decline 10%, about 74% makees a horizontal line, tries to achieve " efficiency-power output " curve and water The abscissa P of two intersection points of horizontal line_{Output 1}And P_{Output 2}.P is found in actual measurement_{Output 1}=761W, P_{Output 2}=845W.

(7) P is sought_{Output 1}And P_{Output 2}Arithmetic mean of instantaneous value Pn is 803W.Tested more than, it may be determined that the reality of the motor is specified Power is 803W.

Claims (2)

1. using the method for the best efficiency point measure automobile-used direct current generator actual power of electrical salf-walking, it is characterized in that, including it is following Step：

(1) treat measured motor using magnetic hysteresis Dynamometer Control instrument to be loaded, record input electricity ginseng point by point by DC parameter instrument Number, including voltage U, electric current I, input power P_Input, the output mechanical parameter of synchronous recording motor, including it is torque N, rotating speed r, defeated Go out power P_Output；

Motor efficiency：

(2) progressively loaded from zero load, until motor rotation blockage, measures the parameter of multiple points, " an effect is made using computer Rate-power output " curve；

(3) take the best efficiency point of the curve to decline 3%~25% and make a horizontal line, the horizontal line and " efficiency-output work Rate " curve has two intersection points, tries to achieve the abscissa P of intersection point_{Output 1}And P_{Output 2}；

(4) P is sought_{Output 1}And P_{Output 2}Arithmetic mean of instantaneous value Pn, as the actual rated power of motor measured.

2. the method for the automobile-used direct current generator actual power of electrical salf-walking is determined using best efficiency point as claimed in claim 1, its It is characterized in, the parameter that step (2) measures 40~50 points is used to make " efficiency-power output " curve.