CN102707171A - System for testing service life of electromagnetic relay coil and service life evaluation method - Google Patents

Abstract

The invention discloses a system for testing the service life of an electromagnetic relay coil and a service life evaluation method. By matched control of a voltage-stabilizing power supply, a timing switch and an alternation aging box, a plurality of groups of relays are respectively subjected to accelerated aging test and measured by a thermocouple temperature sensor, a resistance measurer and an insulating resistance measurer to obtain coil aging sensitivity parameters such as coil enameled wire average temperature, coil direct current resistance and coil insulating resistance, the average operating time of a plurality of groups of test is calculated by using a reliability theory, and the activation energy of a coil enameled wire is calculated by using a least square method, so parameters in a service life evaluation model are determined, and the average operating time (service life) of the relay coil can be evaluated by using the service life evaluation model with the determined parameters.

Description

Electromagnetic relay coil service life experiment system and lifetime estimation method

Technical field

The present invention relates to the electromagnetic relay coil service life experiment system, also relate to the electromagnetic relay coil lifetime estimation method.

Background technology

Electromagnetic relay is a kind of variation when input quantity (energizing quantity) when reaching regulation and requiring, and in electric output circuit, makes controlled volume that the electrical equipment that predetermined step changes takes place, and generally is made up of iron core, coil, armature, contact reed etc.In use can there be aging degradation in electromagnetic relay, mainly is divided into wearing out of contact and wearing out of coil.The aging of contact mainly is because in long-term use, contact surface can generate all kinds of superficial films, thereby influences contact performance, and wherein the carbonization zone of contact surface deposition is the most outstanding to its influence.Coil aging is because relay is under rated voltage (electric current) excited state continuously for a long time, will cause that the weak insulating point of coil (insulation air gap etc.) locates temperature rise, thereby the aging degradation of the enameled wire that causes causes the coil insulation grade to descend.

Because it is very extensive that relay is used in each field, its reliability has received extensive concern, and therefore, the test of relay and electrical endurance test are the key areas of domestic and international electric academia research always.Test to electromagnetic relay has at present had a lot of methods or equipment; Relay synthetic test macro (can measure various electrical quantitys) etc. for example; But electrical endurance test is basically all carried out to relay contact, does not see the research to the durability test aspect of relay coil as yet.

Summary of the invention

The method that the purpose of this invention is to provide the electromagnetic relay coil service life experiment system and come based on the measurement data of this pilot system the life-span of electromagnetic relay coil is assessed.

For achieving the above object, the present invention has adopted following technical scheme: a kind of electromagnetic relay coil service life experiment system comprises

Can be the stabilized voltage supply of the relay of a plurality of parallel connections power supply;

Can cut off the time switch of said stabilized voltage supply power supply at setting-up time;

Can hold said a plurality of parallel connections relay and can be according to the alternation ageing oven of test temperature in the time control box;

Can measure the thermocouple temperature sensor of the coil varnish envelope curve temperature of said relay;

Can measure the resistance measuring instrument of the coil direct current resistance of said relay;

Can measure the Insulation Resistance Tester of the coil insulation resistance of said relay;

Can gather, store and export the data collector of the data of the data of said coil varnish envelope curve temperature, said coil direct current resistance and said coil insulation resistance.

Use above-mentioned electromagnetic relay coil service life experiment system to assess the method for life of relay, comprise

(1) supplies power to the relay group in said alternation ageing oven through said stabilized voltage supply; And cut off the power supply of said stabilized voltage supply at setting-up time through said time switch, and realize that the high temperature of pilot relay group is charged, the alternate cycles operation of low temperature outage, implement accelerated aging test; The relay group has three groups; The relay that a plurality of parallel connections are arranged in every group relay, the test temperature of three group relay groups is different, need carry out accelerated aging test respectively;

(2) under corresponding test temperature; Obtain the data of every group relay group in each circular flow cycle in the coil varnish envelope curve medial temperature of synchronization; And the data of coil direct current resistance and coil insulation resistance; According to the comparison of the data of the coil direct current resistance in a plurality of circular flow cycle and coil insulation resistance, reflect the degree of the insulation degradation that the coil of relay group takes place, adopt based on the reliability theory of Weibull distribution and average order computing method and assess; Obtain every group relay coil under corresponding test temperature, insulation is downgraded to the required average operating time of preassigned degree;

The life appraisal model of relay coil adopts lnt=lnA+Ea/ (RT), and wherein t is an average operating time, and T is a coil varnish envelope curve medial temperature, and A is a undetermined constant; R is a Boltzmann constant, and Ea is the activation energy of coil varnish envelope curve, sets y=lnt, x=1/T; A=Ea/R, b=lnA then obtains y=ax+b; Utilize least square method to carry out curve fitting, calculate a and b

$a=\frac{\mathrm{N\Σxy}-\mathrm{\Σx\Σy}}{\mathrm{N\Σ}{x}^2-{\left(\mathrm{\Σx}\right)}^2}$ $b=\frac{\mathrm{\Σy}-\mathrm{a\Σx}}{N}$

Draw Ea and A according to a and b, then can carry out the average operating time of relay coil or be called the assessment in life-span according to the life appraisal model of said relay coil.

During practical implementation, in step (1), the high temperature of three group relay groups is charged, the alternate cycles operation of low temperature outage refers to:

One group relay group earlier 100 ℃ of operations 90 hours under the electric condition ,-25 ℃ of operations 10 hours under outage condition then, follow-up repeat electric 100 ℃ of 90 hours ,-25 ℃ of such circular flows in 10 hours of outage;

An other group relay group earlier 110 ℃ of operations 90 hours under the electric condition ,-25 ℃ of operations 10 hours under outage condition then, follow-up repeat electric 110 ℃ of 90 hours ,-25 ℃ of such circular flows in 10 hours of outage;

The 3rd group relay earlier 120 ℃ of operations 90 hours under the electric condition ,-25 ℃ of operations 10 hours under outage condition then, follow-up repeat electric 120 ℃ of 90 hours ,-25 ℃ of such circular flows in 10 hours of outage.

Because the utilization of technique scheme; The present invention compared with prior art has advantage: through the cooperation control of stabilized voltage supply, time switch and alternation ageing oven; Many group relaies are carried out accelerated aging test respectively; The aging sensitive parameter of the coil-coil varnish envelope curve medial temperature, coil direct current resistance and the coil insulation resistance that measure through thermocouple temperature sensor, resistance measuring instrument and Insulation Resistance Tester again; The application reliability Theoretical Calculation is organized the average operating time of test more; Utilize least square method to calculate the activation energy of coil varnish envelope curve, thereby confirm the life appraisal Model parameter, then confirm that through parameter good life appraisal model can carry out the average operating time of relay coil or be called the assessment in life-span.

Description of drawings

Accompanying drawing 1 is a synoptic diagram of the present invention.

Embodiment

Come further to set forth the present invention below in conjunction with accompanying drawing.

Referring to Fig. 1; A kind of electromagnetic relay coil service life experiment system; Comprise stabilized voltage supply 1, time switch 8, alternation ageing oven 9, thermocouple temperature sensor 4, resistance measuring instrument 3, Insulation Resistance Tester 10, data collector 6, stabilized voltage supply 1 is in series with relay 2 and time switch 8, and stabilized voltage supply 1 is relay 2 power supplies; Here relay 2 is the relay group; Comprise a plurality of relays that are in parallel, time switch 8 can cut off the power supply of stabilized voltage supply 1 at setting-up time, makes relay 2 be in off-position.In Fig. 1; Relay 2 is in the alternation ageing oven 9, and alternation ageing oven 9 can be according to test temperature in the time control box, like this when carrying out relay 2 coil durability tests; High temperature that can pilot relay 2 is charged, the alternate cycles operation of low temperature outage, implements accelerated aging test.The coil varnish envelope curve temperature of thermocouple temperature sensor 4 measuring relays 2; The coil direct current resistance of resistance measuring instrument 3 measuring relays 2; The coil insulation resistance of Insulation Resistance Tester 10 measuring relays 2; The contact pick-up voltage and the release voltage of multimeter 5 measuring relays 2 among Fig. 1; Data collector 6 can be gathered, the data of data, coil direct current resistance and the coil insulation resistance of storage and output winding enameled wire temperature and the data of contact pick-up voltage and release voltage, and the assessment in relay coil life-span here is to rely on the data of data, coil direct current resistance and the coil insulation resistance of coil varnish envelope curve temperature to carry out.On behalf of the aging sensitive parameter data of coil, data collector 6 outputs give life appraisal system 7, realizes life appraisal.

Use above-mentioned electromagnetic relay coil service life experiment system to assess the method for life of relay 2, comprising:

(1) supplies power to the relay group in alternation ageing oven 9 through stabilized voltage supply 1; And through the power supply of time switch 8 in setting-up time cut-out stabilized voltage supply 1; Realize the alternate cycles that high temperature is charged, low temperature the cuts off the power supply operation of pilot relay group, implement accelerated aging test, the relay group has three groups; The relay that a plurality of parallel connections are arranged in every group relay group; The test temperature of many group relaies group is different, need carry out accelerated aging test respectively, in the specific implementation; The high temperature of three group relay groups is charged, the operation of the alternate cycles of low temperature outage refer to respectively be a group relay earlier 100 ℃ of operations 90 hours under the electric condition ,-25 ℃ of operations 10 hours under outage condition then, follow-up repeat electric 100 ℃ of 90 hours ,-25 ℃ of such circular flows in 10 hours of outage; An other group relay group earlier 110 ℃ of operations 90 hours under the electric condition ,-25 ℃ of operations 10 hours under outage condition then, follow-up repeat electric 110 ℃ of 90 hours ,-25 ℃ of such circular flows in 10 hours of outage; The 3rd group relay earlier 120 ℃ of operations 90 hours under the electric condition ,-25 ℃ of operations 10 hours under outage condition then, follow-up repeat electric 120 ℃ of 90 hours ,-25 ℃ of such circular flows in 10 hours of outage.Electric, outage is the cooperation control through stabilized voltage supply 1, time switch 8, alternation ageing oven 9 can be according to the test temperature in the time control box;

(2) alternate cycles charged at the high temperature of three group relay groups, the low temperature outage is in service; In each circular flow cycle; Obtain the data of every group relay in the coil varnish envelope curve medial temperature of synchronization; And the data of coil direct current resistance and coil insulation resistance, according to the comparison of the data of the coil direct current resistance in a plurality of circular flow cycle and coil insulation resistance, reflect the degree of the insulation degradation that the coil of relay group takes place; For example; Set the coil direct current resistance and reduce the degree that 10% i.e. representative insulation is downgraded to appointment, adopt based on the reliability theory of Weibull distribution and average order computing method and assess, obtain every group relay coil under corresponding test temperature; Insulation is downgraded to the required average operating time of preassigned degree; Computing method referenced patent open source literature " fuse life characteristic data test and evaluating system and the appraisal procedure thereof " CN101915887 of average operating time, though this patent publication us disclosed be the calculating of the average operating time of fuse, the calculating of the average operating time of relay coil is identical with it.The coil varnish envelope curve medial temperature that three group relay coils obtain and the test figure of average operating time are as shown in the table:

Test temperature/℃	T 1	T 2	T 3
				Test termination time/h	τ 1	τ 2	τ 3

The life appraisal model of relay coil adopts lnt=l nA+Ea/ (RT), and wherein t is an average operating time, and T is a coil varnish envelope curve medial temperature, and A is a undetermined constant; R is a Boltzmann constant, and Ea is the activation energy of coil varnish envelope curve, sets y=lnt, x=1/T; A=Ea/R, b=lnA then obtains y=ax+b; Utilize least square method to carry out curve fitting, calculate a and b

$a=\frac{\mathrm{N\Σxy}-\mathrm{\Σx\Σy}}{\mathrm{N\Σ}{x}^2-{\left(\mathrm{\Σx}\right)}^2}$ $b=\frac{\mathrm{\Σy}-\mathrm{a\Σx}}{N}$

Draw Ea and A according to a and b, then can carry out the average operating time of relay coil or be called the assessment in life-span according to the life appraisal model of relay coil.

Claims (3)

1. an electromagnetic relay coil service life experiment system is characterized in that: comprise

Can be the stabilized voltage supply of the relay of a plurality of parallel connections power supply;

Can cut off the time switch of said stabilized voltage supply power supply at setting-up time;

Can hold said a plurality of parallel connections relay and can be according to the alternation ageing oven of test temperature in the time control box;

Can measure the thermocouple temperature sensor of the coil varnish envelope curve temperature of said relay;

Can measure the resistance measuring instrument of the coil direct current resistance of said relay;

Can measure the Insulation Resistance Tester of the coil insulation resistance of said relay;

Can gather, store and export the data collector of the data of the data of said coil varnish envelope curve temperature, said coil direct current resistance and said coil insulation resistance.

2. use electromagnetic relay coil service life experiment system as claimed in claim 1 to assess the method for life of relay, it is characterized in that: comprise

(1) supplies power to the relay group in said alternation ageing oven through said stabilized voltage supply; And cut off the power supply of said stabilized voltage supply at setting-up time through said time switch, and realize that the high temperature of pilot relay group is charged, the alternate cycles operation of low temperature outage, implement accelerated aging test; The relay group has three groups; The relay that a plurality of parallel connections are arranged in every group relay, the test temperature of three group relay groups is different, need carry out accelerated aging test respectively;

(2) under corresponding test temperature; Obtain the data of every group relay group in each circular flow cycle in the coil varnish envelope curve medial temperature of synchronization; And the data of coil direct current resistance and coil insulation resistance; According to the comparison of the data of the coil direct current resistance in a plurality of circular flow cycle and coil insulation resistance, reflect the degree of the insulation degradation that the coil of relay group takes place, adopt based on the reliability theory of Weibull distribution and average order computing method and assess; Obtain every group relay coil under corresponding test temperature, insulation is downgraded to the required average operating time of preassigned degree;

The life appraisal model of relay coil adopts lnt=lnA+Ea/ (RT), and wherein t is an average operating time, and T is a coil varnish envelope curve medial temperature, and A is a undetermined constant; R is a Boltzmann constant, and Ea is the activation energy of coil varnish envelope curve, sets y=lnt, x=1/T; A=Ea/R, b=l nA then obtains y=ax+b; Utilize least square method to carry out curve fitting, calculate a and b

$a=\frac{\mathrm{N\Σxy}-\mathrm{\Σx\Σy}}{\mathrm{N\Σ}{x}^2-{\left(\mathrm{\Σx}\right)}^2}$ $b=\frac{\mathrm{\Σy}-\mathrm{a\Σx}}{N}$

Draw Ea and A according to a and b, then can carry out the average operating time of relay coil or be called the assessment in life-span according to the life appraisal model of said relay coil.

3. method according to claim 2 is characterized in that: in step (1), the high temperature of three group relay groups is charged, the alternate cycles operation of low temperature outage refers to:

One group relay group earlier 100 ℃ of operations 90 hours under the electric condition ,-25 ℃ of operations 10 hours under outage condition then, follow-up repeat electric 100 ℃ of 90 hours ,-25 ℃ of such circular flows in 10 hours of outage;

An other group relay group earlier 110 ℃ of operations 90 hours under the electric condition ,-25 ℃ of operations 10 hours under outage condition then, follow-up repeat electric 110 ℃ of 90 hours ,-25 ℃ of such circular flows in 10 hours of outage;

The 3rd group relay earlier 120 ℃ of operations 90 hours under the electric condition ,-25 ℃ of operations 10 hours under outage condition then, follow-up repeat electric 120 ℃ of 90 hours ,-25 ℃ of such circular flows in 10 hours of outage.