JPH03138831A - Diagnostic method for relay sequence circuit and device - Google Patents

Abstract

PURPOSE:To surely and quickly judge the defective action state of contacts by concurrently measuring the voltage across relay contacts and the power voltage of a control circuit, and comparing them with reference voltage values multiplied with respective voltage value and the power voltage by the preset constants. CONSTITUTION:Contact voltage values E1-E4 across points ch1-chn are measured, they are multiplied by constants alpha1-alpha4 determined in advance according to the control circuit power voltage E0 and the relay characteristics to determine reference voltage values E1s-E4s respectively. These reference voltage values E1s-E4s and contact voltage values E1-E4 are compared and calculated, if either contact voltage is judged to be larger than the reference voltage value, it is judged that a defective contact or a defective action occurs between the contacts, and the relay contact with the defective contact or defective action can be specified. The position of the relay contact with the defective contact or defective action is displayed, thus it can be surely and quickly detected.

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to a method and apparatus for diagnosing a relay sequence circuit.

<Conventional technology> Conventionally, when operating and controlling electric machines 23 such as motors and solenoid valves, a relay sequence circuit configured by combining multiple relay contacts in series or parallel has been used.
Generally, this is done by issuing start/stop or on/off signals while checking the seeding conditions one after another.

By the way, if a malfunction occurs in some of the relays or relay contacts that make up the relay sequence circuit as described above, it will not be possible to issue commands to the electrical equipment because the circuit conditions are not satisfied. There is a problem that the function will be interrupted and the equipment will be taken down.
It is necessary to disconnect the equipment 3 hours early and restore the faulty part.

Here, the diagnostic means for the relay sequence circuit will be explained using the second example as an example. This relay sequence circuit is
As shown in the figure, a voltage E0 is applied between the control power line PN, and the a-contacts A and B are connected in parallel between P and N, and the a-contact C
, D are connected in series, and relay R is connected in series to form ↑11. In this circuit, the line 1' for turning on relay R is the following two points.

■ Relay contact A or B must be turned on.

■ Relay contacts C and D must be turned on.

However, assuming that relay R does not turn on, the causes of malfunction in that case are: ■ Control ff1
1) The voltage drop between the power lines P and N should be small (the voltage drop in the 4 JU electric FA voltage).

■ There is a contact failure in one or more of relay contacts A, B, C, and D.

■ Between control power line P and relay contact Δ or B, between relay contact Δ or B and relay contact C, between relay contact C and relay contact D l:'1, between relay contact t] and relay R, between relay contact If a malfunction occurs, first visually check whether the relay contact (■) is turned on or off in the item above. Condition 61 L'J
The general method is to test the voltage between each contact point 6 and 3 in item (2) using a tester or the like.

<Problem to be solved by the invention> However, in the conventional diagnostic method as described above, voltage drop between control power lines P and N and relay contacts A and B are
, C, and D occur at the same time, not only will it be necessary to use multiple testers to investigate the cause of the occurrence, but it is also easy to overlook malfunctioning phenomena in the relay contacts, and it is also possible to It's a bad phenomenon! ! There is a problem in that fJlig and its identification require a long time.

In addition, when a malfunction occurs in such a relay sequence circuit, the equipment cannot be avoided in most cases, and especially in the case of equipment related to pollution control, it can cause major problems such as causing environmental pollution. ing.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a reliable and quick method and device for diagnosing a relay sequence circuit.

Means for Solving the Problems> The present invention is an iM that operates a relay coil by connecting a plurality of relay contacts in series between power lines that apply a predetermined voltage to both ends of a control circuit. This is a method for diagnosing a relay sequence circuit, in which the voltage of the relay contact 1 (n0) and the power supply voltage of the control circuit (n; 1; A method for diagnosing a relay sequence circuit, characterized in that a malfunctioning state of the contact is determined by comparing the value with a voltage value obtained by multiplying the power supply voltage by a predetermined constant.

The present invention also provides a device for diagnosing a relay sequence circuit that is composed of a power line that applies a predetermined voltage to both ends of a control circuit, and a plurality of relay contacts and relay coils that are connected in series between the power lines. A plurality of individual connection terminals for inputting the voltage between the relay contacts and T of the control circuit.
A voltage signal input section consisting of a common connection terminal into which the i source voltage is input, each of the voltage signals from the individual connection terminals in this voltage signal input section and the voltage signal from the common connection terminal is inputted to the relay. an input isolation amplifier that outputs a voltage signal for each contact, an analog processing section that calculates a voltage signal between the contacts for each of the relay contacts, and an analog processing section that converts the analog signal output from the analog processing section into a digital signal. Compare and judge the voltage signal between the contacts output from the digital converter and the analog/digital converter with the reference voltage signal represented by the product of the constant set by the constant setting unit and the power supply voltage signal of the control circuit. This relay sequence circuit diagnostic device is characterized in that it is comprised of a comparison and determination processing section that performs the following operations, and an alarm display section that outputs an alarm when a contact is determined to be defective as a result of the comparison and determination.

Function> The principle of the present invention will be explained below based on FIGS. 3 and 4.

First, assuming that relay contacts Δ, B, C, and D and relay R are normal, relay R is energized when relay contacts A, C, and D are in the on state, and at that time, each point c not shown in FIG.
The voltage signals E+, Eo, and E between the contacts between h1+ Cht * Ch3+ Cha are almost 0, although some contact resistance bone voltage is detected, and between the contacts between both ends of the relay R, that is, between the points cL and chz. The voltage signal E4 is equal to the control circuit power supply voltage E.

Next, as shown in Figure 4, relay contact C has a contact failure and relay 1? is not turned on, each point ch
+ , chz , chs + Cha + chz
Among the contact voltage signals IE, ,E, ,E, ,E,”
j+E, , E becomes approximately 0, but E2 does not become O and becomes a voltage approximately equal to the control circuit power supply voltage E if it is in a completely off state, although it depends on the degree of poor contact.

From this, each point ch+ + cht + chs
+ cha +ch, , , , , , , , , , , , , , , , + cha + ch
, E4 are determined, and these are determined by controlling the control circuit power supply voltage E and constants α1 . α2. α3.
α.

Multiply the reference voltage value E+s+ Exs+ E3! +
Eat is calculated using the following formulas (1) to (4), and E+s-α,・Eo'−・・・・・・−・・−(
1) E word 3 = α□ ・Eo ・・・・・・
−・・・・・・・(2) Ess−α,・E, −・・
・・・・・・・・・・・・(3) E4. =α4・E,
・・−・−・・・−・−・ ・・−・−・・(4
) Then, these reference voltage values EI8. E! ! ＋L
! +E4S and the contact pressures E+, Ex, Es, and Ea are compared and calculated, and if it is determined that any of the contact pressures is greater than its reference voltage value, there is a poor contact or It is possible to determine that a malfunction has occurred and to identify the contact or malfunctioning relay contact.

Therefore, by displaying the location of the relay contact where a contact failure or malfunction has occurred, it can be quickly detected.

Note that the above-mentioned constant α1. α:, α1. Regarding α4, its lower limit is determined by measuring the mold pressure between each contact when a malfunction occurs, and
The measured value is divided by the control circuit power supply voltage E, taking the safety factor into consideration, and the upper limit is determined by measuring each contact voltage during normal operation, and taking the safety factor into consideration and dividing the measured value by the control circuit power supply voltage E. It is sufficient to determine the values divided by the voltage E0 and set them within these ranges.

<Example> Below, an example of the relay sequence circuit diagnostic device according to the present invention will be described in detail with reference to FIG.

In the figure, l is a voltage signal receiving unit that inputs a voltage signal between each contact from a relay sequence circuit S configured by connecting a plurality of relay contacts and a relay coil in series; Connection terminal ch, , chg...
- Consists of 10 terminals: ・ch, and one common connection terminal cbH.

2 is an input isolation amplifier, and each amplifier is connected to the signal lines of individual connection terminals ah, , chz...ch, and the signal line of common connection terminal ch, 4. Amplified voltage signal e++el...e.

Output. Note that here, the voltage signal e1 is equal to the control circuit power supply voltage E0.

Reference numeral 3 denotes an analog arithmetic processing unit, which calculates an inter-terminal voltage signal El for each individual connection terminal according to the following formula based on the output signal from the input isolation amplifier 2.

E + = ei e l+ + ---
------- (5) Here, i=2 to 9 4 is an analog/digital converter that converts the analog signal output from the analog arithmetic processing unit 3 into a digital signal.

5 is a constant setting section, which is preset as a constant α+(i=2 to 9) for each individual check terminal.

Reference numeral 6 denotes a comparison/judgment processing section, which inputs the voltage signal output from the analog/digital conversion section 4 and the setting signal from the constant setting section 5, and calculates the above equations (1) to (4). Accordingly, each reference voltage value E i S is calculated using the following equation (6).

E ls=α1 ・Eo ・−−−−−−−−−
-------(6) Furthermore, this reference voltage value Els
is compared with the inter-terminal voltage signal voltage E1 for each individual connection terminal to determine whether there is an individual connection terminal for which the following (force formula) holds. In other words, E+ ≧E, s ''--・-- −−・−−−
−−−−−−−−−−−−−−−−(7) If an individual connection terminal for which formula (7) is satisfied is detected, it is assumed that the relay contact is malfunctioning or has a contact failure. can be determined.

Reference numeral 7 denotes an alarm display unit that outputs an alarm when a contact is determined to be defective as a result of the comparison and judgment in the comparison and judgment processing unit 6, and is constituted by, for example, an alarm lamp or a digital display.

The operation of the relay sequence circuit diagnostic device configured as described above will be described below.

(2) Connect the required number of individual connection terminals ch+, cht...chv and the common connection terminal chH of the diagnostic device to the relay sequence circuit S.

■ A constant α cage suitable for each individual connection terminal is set in the constant setting section 5, respectively.

■ When the comparison/judgment processing section 6 detects an individual connection terminal that generates a voltage signal between the terminals that satisfies the above equation (7), it immediately outputs the signal to the alarm display section 7 and displays the part of the corresponding individual connection terminal. An alarm will be sent to display the message.

■ This alarm prompts the operator to check the relay contact of the individual connection terminal and repair or replace it to restore normal operation.

In addition, in the above-mentioned example, individual contact f,, 4 respects i! Although the number of children has been described as nine, it may be determined at any time depending on the configuration of the relay sequence circuit to be diagnosed.

Furthermore, the input isolation amplifier 2 and the analog calculation processing section 3 in the above embodiments are also included. Analog/digital converter 4. Although it has been explained that it is necessary to arrange the number of comparison/determination processing units 6, etc. as many as the number of individual connections O::1 child, it is possible to arrange the comparison/judgment processing units 6, etc. by the number of individual connections O::1, but it is also possible to provide a scanner for example on the output side of the voltage signal input unit 1, so that a fixed frequency j
It goes without saying that if each individual connection terminal is configured to be sequentially scanned by IJl, each of the subsequent processing circuits can be shared by the I system.

<Effects of the Invention> As explained above, according to the relay sequence circuit diagnosing method and device of the present invention, it is possible to quickly identify the location where a contact failure or malfunction of a relay or relay contact occurs. Therefore, it is possible to quickly implement recovery measures, and it is possible to increase the operating rate of the equipment.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of a relay sequence circuit diagnostic device according to the present invention, and the second part is a circuit diagram showing an example of a relay sequence circuit. 3 and 4 are circuit diagrams illustrating the present invention in detail. l... Voltage signal receiving section. 2...Input isolation amplifier. 3...Analog calculation processing section 4...Analog/digital conversion section 5...Constant setting section 6...Comparison/judgment processing section 7...Alarm display section. Δ. B. C9 D...Relay contact. B...Voltage R...Relay coil. S...Relay sequence circuit. ah1 ah.・・・chq ・・・Individual connection terminal. Ch. ...Common connection terminal.

Claims (1)

[Claims] 1. Diagnosis of a relay sequence circuit configured to operate a relay coil by connecting a plurality of relay contacts in series between power lines that apply a predetermined voltage to both ends of a control circuit. In this method, the voltage between the relay contacts and the power supply voltage of the control circuit are simultaneously measured to obtain respective voltage values, and a reference voltage value is obtained by multiplying the voltage value and the power supply voltage by a predetermined constant. A method for diagnosing a relay sequence circuit, characterized in that a malfunctioning state of the contact is determined by comparing the . 2. A power line that applies a predetermined voltage to both ends of the control circuit;
A device for diagnosing a relay sequence circuit consisting of a plurality of relay contacts and a relay coil connected in series between the power lines, the device comprising a plurality of individual connection terminals for inputting the voltage between the relay contacts and the control device. A voltage signal input section consisting of a common connection terminal for inputting the power supply voltage of the circuit, and voltage signals from the individual connection terminals in this voltage signal input section and voltage signals from the common connection terminal are inputted to the relay. an input isolation amplifier that outputs a voltage signal for each contact, an analog processing section that calculates a voltage signal between the contacts for each of the relay contacts, and an analog processing section that converts the analog signal output from the analog processing section into a digital signal. Compare and judge the voltage signal between the contacts output from the digital converter and the analog/digital converter with the reference voltage signal represented by the product of the constant set by the constant setting unit and the power supply voltage signal of the control circuit. 1. A diagnostic device for a relay sequence circuit, comprising: a comparison/determination processing section for performing the comparison and determination; and an alarm display section for outputting an alarm when a contact is determined to be defective as a result of the comparison and determination.