KR100290575B1 - Apparatus for monitoring insulation of non-grounded power line - Google Patents

Abstract

PURPOSE: An apparatus for monitoring insulation of a non-grounded power line is provided to prevent the dangerous condition due to a poor insulation of the non-grounded power line by measuring continuously an insulation thereof. CONSTITUTION: A relay(RY1) is connected to a rectifying section and operates a leakage current detecting unit(15) by connecting a relay contact point as the power is supplied. A constant-voltage device(ZCV) is comprised of Zener diodes(Z1,Z4), a diode(D1), and a plurality of distribution resistors(R2-R7) and receives the power from the rectifying section to supply a DC(Direct Current) power. A differential amplifying unit(11) amplifies output voltage of the constant voltage device(ZCV) and the leakage current detecting unit(15) to compare the amplified output voltage with a reference voltage. An alarm detecting IC(Integrated Circuit)(U102) delays the output of the differential amplifying unit(11) during a predetermined time to output the delayed output to a speaker. A meter driving unit(14) receives the output of the leakage current detecting unit(15) to supply the received output to a meter and is comprised of resistors(R11,R12) and a capacitor(C10).

Description

Insulation monitoring device of ungrounded live line

The present invention relates to an insulation monitoring device (GROUND MONITOR) of the non-grounded live line, in particular, a device used in ship switchboards, motor starters, heater regulators, etc., the insulation is continuously measured without instructing the power supply to instruct the meter to monitor The present invention relates to an insulation monitoring apparatus of an ungrounded conductive line in which an insulated state of an ungrounded line is always known and a bad insulation value of a dangerous state can be audible through an alarm device by a setting circuit to remove a hazard.

In the current heavy chemical plant (petrochemical, gas plant), ship distribution, etc., some of the secondary wiring lines or the entire system such as ships are ungrounded, and in the case of oil tankers, gas, fuel oil pump motors, etc. It is an essential safety system for large vessels handling dangerous goods such as oil tankers and LNG vessels because a single transformer is constructed with a motor in an ungrounded state to protect it from ignition and explosion due to poor insulation.

Such facilities had a point where a continuous insulation state could not be expressed numerically because the leakage breaker (ELB) of the secondary line was not grounded and the state was impossible to detect and detect.

In addition, when measuring the insulation state, cut off the power one by one, measure the insulation with MEGGER TESTER, and turn on the power again.Inconvenient state to stop the operation of the whole system when the power is cut off, and the insulation state that may worsen when It was not possible to measure continually while electricity was energized.

In general, in the case of general leakage current detection devices, devices that generate an alarm sound by comparing different reference voltages with reference voltages and measured leakage currents are commonly used.However, in the case of such leakage current detection devices, peak voltage or noise Malfunctions often occur, causing the reliability of the product to fall.

In addition, if the causes of the circuits to measure leakage current are eliminated in advance, more reliability can be given, but since there is no countermeasure yet, there is a problem that it is usually inconvenient to take post-alarm measures after the alarm sound is generated. .

Accordingly, an object of the present invention is to continuously monitor the insulation state of a non-grounded electric line while energizing, display the state continuously with an indicator, and ring an alarm signal by a predetermined alarm circuit to prevent danger in advance. To solve the problem.

In particular, when an alarm sound is generated, a certain delay time is given to eliminate the cause of the malfunction, and the means for generating the alarm sound is separated from the leak detection circuit so that the operation due to the (photocoupler) can be completely removed. will be.

Another object is to detect the deterioration state of circuits that want to measure leakage current in advance so that the cause of the deterioration can be eliminated in advance. This causes the deterioration state to be displayed in meters so that the monitor can easily recognize it. An object of the present invention is to provide an insulation monitoring device for a conductive line.

As a specific means of the present invention for achieving the above object, through a bridge diode and a filter coil is supplied through a capacitor, supplying power to the constant voltage device (ZCV) through a resistance, and measuring the insulation of the live wire with the supplied power And ground through the relay contact point, and select a plurality of resistors through the output of the alarm detection IC by the selection switch, delay the 3 seconds by the delay timer IC through the transistor to operate the relay through the transistor, This is accomplished by connecting the indicator to the meter by amplification of the IC.

The constant voltage device (ZCV) continuously measures the insulation of the live line to drive the indicator by the converter IC, and at the same time, the alarm circuit operates as a relay and alarm detection IC so that the watcher can see and hear the insulation state. It features.

The plurality of resistors are selected in 12 steps by a selection switch.

1 is a circuit diagram of an insulation monitoring device of an ungrounded conductive line of the present invention.

2 is one embodiment of FIG.

* Explanation of symbols for main parts of the drawings

T1: Power Supply Transformer

BD1, BD2, BD3: Bridge diode for rectifying AC power

L1, L2, L3: Noise Reduction Filter Coil

V11, V12, V13: Constant Voltage Regulator

U101: Converter IC U102: Alarm Detection IC

U103: Delay timer IC RY1: Grounding relay

RY2: Alarm signal external output relay

C1 to C23: Capacitor PC1: Photocoupler (Optical Signal Transistor)

Q1, Q2: Transistors D1, D2, D3: Diode

R1 to R35: resistors LP1, LP2, LP3: LEDs for operation display

Z1, Z4: constant voltage diode SW1: selector switch

VR1, VR2, VR3: Variable resistor 10: Leakage current maintenance circuit

11: differential amplifier 12: alarm signal generator

14 meter drive unit 15 leakage current detection unit

Hereinafter, described in detail with reference to the accompanying drawings, preferred embodiments of the present invention.

FIG. 1 is a circuit diagram of an insulation monitoring apparatus of an ungrounded conductive line of the present invention, and FIG. 2 is a block diagram diagram thereof.

As shown in FIG. 1, the rectifiers of the upper, middle, and lower stages are respectively configured on the secondary side of the transformer T1, and the upper and lower rectifiers provide stable operation power to the integrated devices connected to the rear stages, respectively. Each integrated element is driven by this power supply.

The intermediate rectifier circuit on the secondary side of the transformer T1 is connected to the constant voltage device ZCV at the rear end, and the rear side constant voltage device ZCV is configured to supply stable power for measuring leakage current.

The rectifier circuit at the upper end is full-wave rectified by the bridge diode BD3, and the capacitor C13 14 and the constant voltage regulator V13 have a stable constant voltage through the noise removing filter coil L3. -1), (U102-2), (U103).

A light emitting diode LP2 is connected to the rear end of the regulator V13 through a resistor R19 to identify whether power is supplied, and the rectifier is supplied with power to the relay RY1 through a resistor R20. Consists of. Here, the diode D10 is for protection. When this relay RY1 is driven, the relay contact RRY1 is connected.

The alarm detection IC U102 is composed of resistors R12, capacitors C13, and C15, and constitutes a leakage current correction circuit 10 to be applied to the differential amplifier 11. The differential amplifier 11 is configured to be applied to one side of the amplification IC (U102-2) as a reference voltage through the resistors R23, R26, and the variable resistor VR3, and the resistors R24 and The comparison voltage divided by the resistors R36-R48 is configured to be applied. Other capacitors are for ripple rejection.

The transistor Q1 and the light emitting diode LP1 are connected to the output of the differential amplifier IC 102-2 so that the output is checked when a leakage current occurs. The output of the transistor Q1 has an alarm signal generator 12 connected thereto. The alarm signal generator 12 has a resistor R31-R35 and a capacitor C21-C23 having a delay timer IC U103. After a delay of 3 seconds in connection with the circuit, its output is configured to drive transistor Q2 through photocoupler PC1, and relay RY2 and light emitting diode LP3 are driven when transistor Q2 is driven. . When the relay RY2 is driven, the relay contacts RYL2 are configured to supply power to the speaker connected to the rear stages of the relay contacts RYL2.

Where ①, ②, ③, ④, ⑤ .... are the connection terminals of the board.

Next, the rectifier circuit of the secondary side of the transformer T1 is also full-wave rectified by the bridge diode BD1, and the capacitors C13 and 14 and the resistors R1 and R2 are passed through the filter coil L1 for noise removal. Is connected to the constant voltage device (ZCV). This constant voltage device (ZCV) consists of zener diodes (Z1), (Z4), diodes (D1), and distribution resistors (R2-R7). As a diode which does not flow in, the blocking with the measuring power supply, that is, the zener diodes Z1 and Z4 is maintained.

The constant voltage of the constant voltage device ZCV is applied to the comparison voltage of the alarm detection IC U102-1 through the capacitor C3, and the output of the alarm detection IC U102 is low during normal operation without leakage. The potential state is maintained.

The rectifier circuit at the lower side of the secondary side of the transformer T1 is also full-wave rectified by the bridge diode BD2, and the capacitors C6-C8 and the constant voltage regulators V11 and V12 through the noise removing filter coil L2. The stable constant voltage is applied to the converter IC (U101) at a later stage to supply power for the converter IC (U101) to perform normal operation.

The converter IC (U101) is connected to an input terminal through a DC component correction resistor (R11), (R12), and a capacitor (C10), and the other variable resistors (VR1) and resistors (R13-R17) are selected. Component according to the specification.

The leakage current detection unit 15 connected to one of the three-phase circuit lines R, S, and T of the AC power supply is connected to the AC component path capacitor through the resistors R19, R20, and R21. C5) and an overcurrent protection resistor R44 are configured to supply power distributed to the resistor R55 and the variable resistor VR2, and to one side of the alarm detection IC U102 through the constant voltage device ZCV. Is applied to one side of the converter IC (U101) of the meter driver (14) via the resistor (R11) and the capacitor (C10).

The present invention configured as described above will first be described with a block diagram of FIG.

The connection terminals 1 and 2 shown here are shown in original letters as in Fig. 1.

In FIG. 2, power of the secondary side of the transformer is rectified and applied as driving power of the monitoring device. However, as shown in FIG. 1, a separate power source can be used.

The relay contact RYL1 is connected by such a drive power supply, and this monitoring apparatus is driven. At this time, if leakage current flows in through terminal ⑧ connected between three-phase wires (R), (S), and (T), the monitoring device operates and immediately knows through the meter and the relay contact (RYL2) is connected to the alarm device. By supplying power to the speaker will inform that the abnormal state.

This will be described in detail with reference to FIG. 1.

The three-stage (up, middle, and lower) rectifier circuits formed on the secondary side of the transformer (T) serve to supply a constant DC power in the same manner, and a detailed description thereof will be omitted.

The principle is that after the full-wave rectification of the AC source induced on the transformer secondary side by the bridge diode BD1-BD3, the capacitor C1-C8 and the accumulator V11-V13 through the filter coils L1-L3, respectively. It supplies stable DC power through), and the integrated ICs of the next stage are driven by this DC power. As a result, the upper and lower rectifier circuits differ only in the supply power according to the specifications, and are used as the operation power of the rear end circuit, and the rectifier circuit in the middle is a separate constant voltage device (ZCV) for supplying the DC power added to the leakage current. Is supplied.

In the present invention, the DC power applied through the rectifier circuit at the top turns on the light emitting diode LP2 so that the user recognizes that the power is supplied.

In addition, the relay contact RYL1 is supplied to the relay RY1 to connect the relay contact RYL1 so that the leakage current detection unit 15 can operate by forming a closed circuit, and among the three-phase wires R, S, and T. The leakage current detection unit 15 connected to any line is connected to the detection device of the present invention, the relay contact (RYL1) is connected to form a closed circuit connected to the ground.

On the other hand, the constant voltage device ZCV outputs a constant constant voltage by the zener diodes Z1 and Z4, and the power supply e1 distributed to the resistors R2-R6 is connected to the terminal of the alarm detection IC U102-1. After amplified and amplified by (# 3), it is applied to one side of the differential amplifier IC (U102-2) through the resistor R36-R48 at the rear stage, and the other side of the differential amplifier IC (U102-2) is a resistor (R23). ), The voltage divided by the variable resistor VR3 and the resistor R26 (reference voltage) is applied to amplify the difference to drive the transistor Q1 in the subsequent stage.

Therefore, in the normal state in which the leakage current does not occur, the divided voltage applied through the resistors R36 to R48 is lower than the reference voltage, so that the transistor Q1 of the rear stage is not operated, but the leakage current is applied. In this case, the output of the differential amplifier IC U102-2 is maintained at a high level, thereby turning on the transistor of the next stage.

These resistors (R36-R48) can select the resistance set by the ship switchboard, motor starter, heater regulator, etc. to be monitored, and the variable resistor (VR3) can control the minute variation of the vehicle, respectively. It is easy to measure the leakage current generated by the device and can be adjusted in 12 steps by each resistance.

Looking at the case where the leakage current is applied through the three-phase wire in such a state, if the leakage current is applied through the resistors R19, R20, and R21, the leakage current of this AC component is bypass capacitor C5. The alternating current of the -component flows through the resistor R2 to the diode D1, and only the + component power is distributed to the resistors R2, R3, and R6, so that the resistors R5, R16, Since the relay contact (RYL1) and the resistor (R22) flow to the ground, when the leakage current is generated, the voltage (e1) is applied to the leakage current by adding an electrostatic source of the constant voltage device (ZCV), and outputting this output to an alarm detection IC ( Through U102 is applied to the comparison voltage of the differential amplifier IC (U102-2). In this case, the resistor R44 is for preventing overcurrent from flowing through the resistor R55 and the variable resistor VR2.

When the transistor Q1 is turned on when the leakage current is generated in this way, the light emitting diode LP1 is turned on to indicate the occurrence of the current leakage current and to apply the output to the alarm detection IC U102. However, since the alarm signal indicates a danger, it is necessary to prevent the alarm signal from being driven by momentary overcurrent or abnormal peak voltage.

Therefore, in the present invention, when the continuous leakage current is applied for 3 seconds by giving a delay time of 3 seconds by the resistor R31 and the capacitor C22 connected to the alarm detection IC U102 of the alarm signal generator 12. The transistor Q2 is turned on via the rear photocoupler PC1.

The resistor R30 and the capacitor C21 in the alarm signal generator 12 are for noise removal, and the other resistors are resistors in the specification connected to the alarm detection IC U102.

The delay time prevents malfunction due to instantaneous leakage current, but also prevents malfunction due to other signals by a photocoupler composed of a light emitting part and a light receiving part in order to prevent malfunction due to other peak voltages (noise). It can only be driven by leakage current.

In addition, when the transistor Q2 is turned on, the light emitting diode LP3 is turned on to recognize the leakage current, and the relay RY2 operates to connect the relay contact RYL2, and terminals ① and ③ are connected to each other. Power on the loudspeaker, the alarm sounds.

In addition, the present invention can also monitor the current leakage by using a meter (measurement meter), even if the state of leakage is not enough to alarm, deterioration in ship switchboards, motor starters, heater regulators, etc. by long-term use When leakage occurs and gradually occurs, it is necessary to prepare for this, and in the present invention, it is possible to check this by the meter, and there is a feature that can be prepared in advance.

That is, when the circuits are hardened and a small leakage current is continuously generated, the alarm circuits do not operate and thus cannot be recognized by the user. However, in the present invention, the power distributed by the variable resistor VR2 and the resistor R55 is provided. (e2) is applied to the input terminal of the converter IC U101 through the resistor R11. At this time, the AC component passed as described above by the AC power supply bypass capacitor C5 is removed and then applied through the resistor R11. Here, the resistor R11 and the capacitor C10 are for correcting the DC component, and many other resistors and capacitors are elements on the specification sheet of the converter IC U101. As a result, the output of this converter IC (U101) is an output proportional to the leakage resistance value so that the change of ∞ to 0 ohms is changed to a constant current signal of 0 to 1 mA so that the monitor can always recognize the insulation state. It is applied to meters not shown connected to ④ and ⑤.

As described above, the present invention prevents malfunction due to peak voltage or noise, and can generate an alarm sound only by leakage current accurately, and also detects a deterioration state of a circuit to be measured in ordinary times with a meter. There is a characteristic that a point can be removed.

In the above, the present invention is smooth through a capacitor through a bridge diode and a filter coil, supplies power to a constant voltage device (ZCV) through a resistance, measures the insulation of the live wire with the supplied power, and outputs the output of the alarm detection IC. By selecting a plurality of resistors through the selector switch, and delaying for a certain time by the delay timer IC through the transistor to operate the relay through the transistor to emit an alarm sound, and the output of the leakage current sensing unit is a converter IC By the amplification of, it is effective to detect the deterioration state of the circuit to be measured by the indication by the meter in advance so that the supervisor can recognize the risk that can be caused by the poor insulation of the ship's electrical wiring in advance and can eliminate the dangerous state. It has an effect.

Claims (3)

A constant voltage is supplied through a plurality of bridge diodes and a rectifier composed of a capacitor and a regulator through a filter coil to drive the integrated devices in the next stage, and the reference voltage generated by the constant voltage and the comparison voltage generated by the leakage current. In the leakage detection circuit for generating an alarm sound by comparing each other, the relay (RY1) and the zener diode (Z1) which is connected to the rear end of the rectifier, and connects a relay contact when the power is turned on to operate the leakage current detection unit 15; ), (Z4) and a diode (D1) and a plurality of distribution resistors (R2-R7), a constant voltage device (ZCV) for supplying a constant DC electrostatic source under the power of the rectifier, and the constant voltage device (ZCV) The differential amplifier 11 compares the comparison voltage generated by amplifying the output of the output and the leakage current detector 15 with the reference voltage, and the output of the differential amplifier 12 An alarm detection IC (U102) outputs to a speaker that is not delayed and outputs, and a power is supplied to the meter by receiving the output of the leakage current sensing unit 15 composed of a plurality of resistors and capacitors, and the resistors R11 and R12. Insulation monitoring device of an ungrounded conductive line, characterized in that consisting of a meter drive unit 14 and a capacitor (C10). 2. The alarm signal generator 12 composed of the alarm detection IC U102 has a photocoupler PC1 and a relay RY2 at a rear end of the alarm detection IC U102 in order to prevent malfunction. Insulation monitoring device of an ungrounded conductive line, characterized in that configured to drive only by the leakage current. 2. The insulation monitoring apparatus for an ungrounded conductive line according to claim 1, wherein the resistors (R36 to R48) for distributing and supplying the comparison voltage are selected in 12 steps by a selection switch (SW1).