KR19990039695A - Simulation of inertial load by resistance-capacitor combination - Google Patents

Abstract

The present invention relates to an inertial load testing apparatus, and more particularly, to an inertial load simulating apparatus using a resistor-capacitor combination in which a mechanical inertial load is electrically equivalent-converted to improve a disadvantage of a conventional mechanical inertial load experiment apparatus.

In the past, experiments were conducted by coupling a circular iron disk with an electric motor in order to test the inertial load characteristics of the experimental motor. However, even if the iron disk is standardized, the experimental method requires a lot of cost to change the inertia caused by the coupling and to manufacture and use the iron disk. The biggest disadvantage is that the inertia can not be changed during operation .

The present invention improves the disadvantages of the mechanical inertial load test apparatus by electrically equivalent conversion of the mechanical inertial load test apparatus, thereby solving the problems of the coupling failure and dead-band caused by the mechanical coupling, A mechanical device member coupled to the test motor 100 and a corresponding DC generator 200 through a coupling so that an inertia load test can be performed; And an electrical device member (300) composed of a plurality of variable resistors and a variable capacitor connected together so as to be variably adjustable to a voltage output terminal of the DC generator (200) of the mechanical device member, _{J L = K t K dc φ} TM φ dc C s , The inertia moment J is calculated by the equation C _s , And the viscous friction coefficient B is similar to the inverse 1 / R of the resistance, so that the mechanical inertial load experiment is equivalent to the electrical inertial load experiment.

Description

Simulation of inertial load by resistance-capacitor combination

The present invention relates to an inertial load testing apparatus, and more particularly, to an apparatus for simulating an inertial load by a resistance-condenser combination in which a mechanical inertial load is electrically equivalent converted to improve a disadvantage of a conventional mechanical inertial load experiment apparatus will be.

Inertial load testing is indispensable to test the characteristics of an electric motor or an industrial servomotor that enters a joint of a robot arm.

In order to actually perform such an inertial load test, it is common to use a mechanical iron disk to couple to the shaft of a motor. This inertial load experiment apparatus makes inertia using the diameter and weight of the iron disk.

1, an experiment was conducted by coupling a circular iron disk 11 with an electric motor 20 in order to test an inertial load characteristic of an experimental motor 10.

However, even if the iron disk (11) is standardized, this experimental method requires a lot of expenses for the inertia change caused by the coupling and the manufacturing and using of the iron disk (11). The biggest disadvantage is the inertia It does not change it.

If the inertia is changed during operation, there is a problem that it is impossible to perform a precise experiment because there is a coupling failure between couplings or a dead-band coupling.

Therefore, accurate inertial load tests can not be performed and there is a limit to the experiment.

Also, in the case of a mechanical iron disk type inertial load test system, the experiment is difficult because the motor can not add or subtract inertia or external load during operation.

In order to compensate for these drawbacks, it is the motivation of this study to find a new method to make an electrical simulated inertial load experiment device after converting a mechanical inertial load experiment device into an electrical equivalent model.

In order to solve such a problem, the present invention has improved the disadvantages of the mechanical inertial load test apparatus by electrically equivalent conversion of the mechanical inertial load test apparatus, The present invention has been made to solve the above problems and to provide an apparatus for simulating an inertial load using a resistor-capacitor combination which enables a more accurate inertial load test.

1 is a schematic structural view of a conventional inertial load experiment apparatus.

2 is a conceptual diagram of an experimental apparatus for an inertial load simulator according to the present invention.

3 is a block diagram of a simulated load experiment apparatus according to an embodiment of the present invention.

4 is a configuration diagram of an experimental apparatus for simulated inertial load simulator according to an embodiment of the present invention.

FIG. 5 (a) is a graph showing the relationship between the resistance

(b) is an embodiment of a capacitor portion serving as a simulated inertia in the present invention.

(c) is an embodiment of an equivalent resistor acting as a simulated frictional force in the present invention.

DESCRIPTION OF THE REFERENCE NUMERALS

100: Experimental motor 200: DC generator

300: electric field

In order to achieve the above object, the present invention proposes a simulated inertial load device capable of equivalently converting a mechanical inertial load into an electrical inertial load and performing an inertial load test by an electrical switch operation. The mathematical equivalent expression .

BRIEF DESCRIPTION OF THE DRAWINGS Fig.

FIG. 2 is a conceptual diagram of an experimental apparatus for an inertial load simulator according to the present invention, wherein an inertial load simulator changes a mechanical inertial load system to an electrical equivalent circuit, and uses an inductor and a capacitor instead of a mechanical iron disk, And an experimental apparatus capable of testing frictional force.

The experimental setup is to test the load by attaching a DC generator to the shaft of the motor to be tested and connecting an electrical load to the output power terminal of the DC generator.

The reason for connecting the dc generator here is to serve as an intermediate converter for changing the mechanical load to the electrical load.

FIG. 3 is a block diagram of a simulated load test apparatus according to the present invention. In order to test the load capacity of a motor in general, as shown in FIG. 3, a motor is connected to a DC generator and a resistor is connected to the output of the DC generator, We are experimenting with characteristics.

The mathematical characteristics of these systems are as follows. First, the relation between the motor output, torque and speed is P _e = KωT _e And the torque equation is as follows.

K _t = : Torque constant

φ _TM = Magnetic flux of the motor to be tested

J _TM = Moment of inertia of the motor to be tested

B _TM = Frictional force of the motor to be tested

P _TM = Number of poles of the motor to be tested

However, in this experimental apparatus, the current flowing through the resistor can be mechanically driven only by the functions of friction force and external load.

The simulated inertial load simulator, which is a conceptual diagram of an experimental apparatus for simulated inertial load simulator according to the present invention, complements the functions of the experimental apparatus discussed in FIGS. 2 and 3, and is based on the apparatus of FIG.

Fig. 4 is an example of a preferred simulated inertial load simulator experimental apparatus, which can perform various types of inertial load experiments. Ideally, a mechanical system is equivalently converted into an electrical system. However, It is.

The electric torque equation and the mechanical torque equation of the motor when a mechanical load is connected to the motor as shown in Fig. 1 are given as follows

(One)

The above equation (1) will be described in more detail.

There are two forces required to move an object with a mass that is stationary in the physical world.

Among these powers is inertia, which is the force that keeps itself in the current state of motion, that is, the force that is at rest, that is, the object that keeps stopping; A moving object is a force that moves continuously.

The friction force refers to the force due to the friction that occurs as the object rubs against the surrounding object continuously while moving.

This inertial force is mathematically And the frictional force is expressed by B _TMω Lt; / RTI >

In addition, the force generated by the motor depends on the "law of the right screw" T _e = K _t φ _TM i _a Lt; / RTI >

Since the dynamic equation of this force is applied equally to the mechanical object used as the load, the above-mentioned relation is established.

The electric torque equation of the system shown in FIG. 2 is as follows.

(2)

(1) and (2), the mechanical inertial load modeling is converted into the electric inertial model equation as follows.

(3)

(4)

(5)

(6)

_{J L = K t K dc φ} TM φ dc C s , (7)

here,

V _dc = K _dc ? _Dc ? : Organic electromotive force of DC generator ω The speed of the dc generator)

K _t = : Torque constant

φ _TM = Magnetic flux of the motor to be tested

J _TM = Moment of inertia of the motor to be tested

B _TM = Frictional force of the motor to be tested

C _s = Capacitor for inertial load simulator

R = Resistance for inertial load simulator

P _TM = Number of poles of the motor to be tested

V _dc = DC generator voltage

P _dc = Pole number of dc generator

φ _dc = Flux of DC generator

K _dc = Organic electromotive force constant of dc generator

J _L = Inertia load moment

B _L = Inertia load frictional force

P _e = DC power rating power.

As can be seen from equation (7), the moment of inertia, J, C _s , And the viscous friction coefficient B is similar to the inverse 1 / R of the resistance.

However, since the voltage drop due to the motor resistance is negligibly small, it is ignored here.

Therefore, it is possible to experimentally test inertial load and frictional force by connecting a capacitor and a resistor to the output terminal of a DC generator by connecting a DC generator to an electric motor without using an existing iron disk type inertia part.

The above description describes an ideal simulated inertial load simulator, and there are many limitations in the case of actually trying to experiment.

For example, when a mechanical inertial load is actually connected to a motor and an electric capacitor is used, the response slope and the peak value are different. Therefore, a resistor for limiting the current peak value is added to the front end of the capacitor as shown in FIG. 4 In order to test various kinds of frictional force, a variable resistor was used as a load resistance.

In addition, several capacitors are used to perform various inertia tests because capacitors are difficult to change. When several capacitors are used in parallel, various values of capacitors can be obtained.

FIG. 4 shows an experimental apparatus of a simulated inertial load simulator of the present invention, which is coupled to an experimental motor 100 to attach a DC generator 200.

Connect the select switch to the voltage output terminal of the dc generator and attach a resistor for limiting the peak current to the switch.

A load of various conditions is set by the select switch and an experiment is performed accordingly.

Next, connect capacitors, which are used for inertial loads, and variable resistors, which are used for frictional forces or external loads.

Further, as shown in FIG. 5, each of the overcurrent limiting resistor (a), inertia simulating capacitor (b), and frictional force simulating resistor (c) have various values in combination.

Another main advantage of the present invention is that the variable resistance value is changed or the capacitor value is connected in parallel to have a function of a variable capacitor, so that a more accurate experiment can be performed.

The inertial load simulator according to the present invention is an experimental apparatus that can change the mechanical inertial load system to an electric equivalent circuit and experiment the inertia or frictional force of the mechanical system using a resistor and a capacitor instead of a mechanical iron disk. Ideally, a mechanical inertial load experiment can be equivalently converted to an electrical system, and a mechanical inertial load experiment can be equivalently converted to an electrical inertial load experiment.

Since various capacitors can be obtained by connecting the capacitors in parallel in the electrical system, it is possible to perform inertia tests of various values, and when a variable capacitor such as a small varicolone is connected in parallel to the system, If load test is possible, it can be used to adjust zero point of inertia value.

Therefore, the present invention can arbitrarily change the inertial load change value of the simulated inertia simulator, and thus is a useful technique for performing very precise and various experiments.

Claims (4)

An experimental apparatus capable of changing the mechanical inertial load system to an electrical equivalent circuit and experimenting with inertia or frictional force of the mechanical system using a resistor and a capacitor in place of a mechanical iron disk. The experimental motor 100 and the corresponding direct current A mechanical member formed by connecting a generator (200) with a coupling; And an electrical device member (300) composed of a plurality of variable resistors and a variable capacitor connected together so as to be variably adjustable to a voltage output terminal of the DC generator (200) of the mechanical device member, _{J L = K t K dc φ} TM φ dc C s , The inertia moment J is calculated by the equation C _s , And the viscous friction coefficient B is similar to the inverse 1 / R of the resistance, so that the mechanical inertial load experiment is equivalently converted by the electrical inertial load experiment. The method according to claim 1, The electric device member 300 includes a variable resistance unit for varying a load resistance so as to test various types of frictional force; A plurality of parallel-connected variable capacitors for varying the capacitance to perform various kinds of inertia tests; And an additional resistor is additionally provided at a front end of the capacitor to limit a current peak value. 3. The method according to claim 1 or 2, The variable capacitor section A plurality of series-connected capacitors are connected in parallel between both terminals, the terminals of the series-connected capacitors are connected to each other again, and at both ends of the parallel-connected terminals, variable capacitors Wherein the inertial load simulator is configured to simulate an inertial load by using a resistor-capacitor combination. The method of claim 3, Wherein the parallel-connected capacitors constituting the variable capacitor unit are variable capacitors, respectively.