RU2675248C1 - Coupling capacitor control sensor - Google Patents

Abstract

FIELD: electrical equipment.SUBSTANCE: invention relates to the electrical equipment and is intended for the coupling capacitors at power facilities condition monitoring, can be used to determine the coupling capacitor destruction process beginning and its timely replacement. To achieve the said technical result, a coupling capacitor monitoring sensor is proposed, which includes input and output connectors, a transformer, which primary winding through the input connector is included in the gap between the coupling capacitor bottom plate and the connection filter, a diode bridge, to which the transformer secondary winding terminals are connected, first resistor and two capacitors, connected in parallel and connected to the diode bridge terminals; forming the output current the second and third resistors, one of which is the trimming resistor, which second terminals are connected to the output connector pins.EFFECT: technical result of the claimed invention is development of the device providing the coupling capacitors condition continuous monitoring at a power facility in order to determine their destruction process beginning, and the corresponding signal generation about this process beginning and development in the current time mode.1 cl, 2 dwg

Description

The invention relates to electrical engineering and is intended to monitor the condition of communication capacitors at power facilities, can be used to determine the beginning of the process of destruction of the communication capacitor and its timely replacement.

At the moment, there are no solutions that can provide control over the operability of the communication capacitors of the power facility, determine the beginning of the process of destruction of the communication capacitor, leading to its explosion.

A device for measuring the capacitance of electric capacitors is known from the prior art (patent application No. RU 93047134, published July 10, 1996), comprising a direct current source, a power switch, a current meter, a field effect transistor, a set of reference capacitors, a measured capacitor, a switch of measurement limits, switch "measurement", a resistor in the source circuit and a resistor in the drain circuit of the field effect transistor.

However, the use of this device is based on the principle of measuring the voltage across a capacitor charged with a calibrated electric charge and is not applicable for measuring the capacitance of a coupling capacitor included in the circuit and under voltage.

The closest technical solution is a device for measuring the capacitance of a capacitor (patent for invention No. RU 2173859 dated 10.11.2000), comprising an AC voltage source, one terminal of which is connected to a common bus, and the second terminal is connected through the isolation capacitor to the first terminals of the first and second pairs of series-connected diodes, with the first and second pairs of diodes connected in opposite directions, the connection point of the diodes of the first pair is connected to the output of the reference capacitor, the connection point of the diodes of the second pair is connected measured at the conclusion of the capacitor, and the second terminals of the capacitors of the measured and model are connected to a common bus; a series-connected first storage capacitor and a first resistor connected to the output of the isolation capacitor and a common bus, and a low-pass filter from a series-connected resistor and capacitor that is connected between the output of the separation capacitor and the common bus. The peculiarity is that an additional second storage capacitor is connected to it, connected in parallel with the second pair of diodes; an additional second resistor connected between the second terminal of the second pair of diodes and a common bus; and an additional output resistor included between the connection point of the resistor and the low-pass filter capacitor and the common bus; wherein the connection point of the first storage capacitor and the first resistor is connected to the second terminal of the first pair of diodes.

However, this device is not applicable for determining the beginning of the process of destruction of the coupling capacitor at an existing power facility, but is intended only to expand the range of measurement of capacitance and increase the sensitivity of measurement.

The technical result of the claimed invention is the creation of a device that provides constant monitoring of the state of the coupling capacitors at the power plant in order to determine the beginning of the process of their destruction and the formation of the corresponding signal about the beginning and development of this process in the current time mode.

To achieve the technical result, a coupling capacitor monitoring sensor is proposed that includes input and output connectors, a transformer, the primary winding of which, through the input connector, is connected to the gap between the lower coupling capacitor plate and the connection filter, a diode bridge to which the transformer secondary windings are connected, the first resistor and two capacitors connected in parallel and connected to the terminals of the diode bridge, the second and third resistors forming the output current, one of which is a tuned resistor, the second pins of which are connected to the contacts of the output connector.

The coupling capacitor monitoring sensor continuously measures the current flowing through the coupling capacitor, an increase of which indicates an increase in the capacitance of the coupling capacitor. The control sensor KS is installed in the circuit between the lower lining of the coupling capacitor and the connection filter (FP), the signal from the sensor through the connecting cables enters the controller, the signal is digitized in the controller, and calculations are performed with the results being displayed. The free terminals of the second and third resistors are connected via a connected or control cable to the analog input of the controller of the monitoring system for the status of the communication capacitor.

An example of a structural diagram of a communication capacitor monitoring system using a communication capacitor monitoring sensor is shown in FIG. 1.

The figure 2 shows an example of a schematic diagram of a sensor monitoring the capacitor of communication, where:

X1 - input connector;

X2 - output connector;

T1 - transformer;

VD1 - diode bridge;

R1 is the first resistor;

C1, C2 - capacitors;

R2 is the second resistor;

R4 is the third resistor (tuning).

Transformer T1 is designed to generate a control voltage of industrial frequency proportional to the current of industrial frequency flowing through its primary winding. The diode bridge VD1 rectifies the output voltage of the transformer T1. Resistor R1 is a constant voltage diode bridge load for partial stabilization (the current through resistor R1 is approximately 1 mA). Capacitors C1 and C2 are necessary to smooth the ripple of the output voltage of the transformer T1. Resistors R2 and R4 form the DCKS output current. Resistor R4 - tuning. Through the resistor R4 during commissioning, the initial output current of the DCC is set to 5 mA.

The sensor monitoring the coupling capacitor operates as follows.

When the coupling capacitor monitoring sensor (DCCS) flows through the primary winding of the transformer T1, the industrial frequency current is due to the reactance of the coupling capacitor, voltage is generated between its terminals due to its resistance to the industrial frequency current, which is transformed to the secondary winding of the DCC transformer T1. The alternating voltage of the secondary winding of the transformer T1 is rectified by the diode bridge VD1, and in the form of a signal "active current loop 4-20 mA" is output to the output connector X2 DCKS.

Claims (1)

 Communication capacitor monitoring sensor, consisting of input and output connectors, resistors and capacitors, characterized in that it includes a transformer, the primary winding of which, through the input connector, is connected to the gap between the lower lining of the communication capacitor and the connection filter, a diode bridge to which the terminals of the secondary winding are connected transformer, the first resistor and two capacitors connected in parallel and connected to the terminals of the diode bridge, the second and third resistors forming the output current, one of the second is tuning, the second conclusions of which are connected to the contacts of the output connector.

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