SU609141A1 - Arrangement for obtaining characteristics of ship circuit breakers - Google Patents

Description

one

The invention relates to the field of testing of shipboard electrical equipment and can be used to determine the current and time of operation of shipboard circuit breakers in ship conditions.

The known devices for testing the protection of circuit breakers 1 comprise a controller connected to the primary circuit of a power transformer, the secondary winding of which through a sensor is connected to a circuit breaker, and a current meter connected to the sensor.

The maximum test current of such devices is insufficient to test high-power circuit breakers; the presence of a current transformer used as a sensor increases dimensions and weight. The current meter is not able to remember the readings, and therefore does not capture the current during the test of the circuit breaker.

Closest to the invention, the technical solution is device 2, which contains a power transformer, a voltage regulator included in the primary winding of the power transformer, a sensor connected to the secondary winding of the power transformer and a circuit breaker, a recording unit, made in the form of a measuring unit and storing the current connected to the sensor. However, the maximum test current in this device is not more than 5000 A, this is caused by the use of a current transformer as a sensor.

The current transformer introduces in the secondary circuit of a power transformer a resistance, commensurate with the resistance of the payload, due to transient resistances of the inductance of the primary winding and reduced to the primary winding

shunt resistance, which leads to an increase in the power of the power transformer, and, consequently, to an increase in the weight and size parameters of the device. The step-by-step current setting by the voltage regulator leads to

large errors when checking circuit breakers, and the absence of a unit for measuring and storing time makes the test incomplete, does not allow to remove the current-time characteristic, although the response time of circuit-breakers is governed by the technical conditions for their delivery and is a generic characteristic. The aim of the invention is to increase the maximum test current while maintaining the weight and size parameters of the device, providing a fusible adjustment of the test current and recording the response time of the circuit breaker. This goal is achieved in that the sensor is made inductively in the form of a coil with

an air gap with a magnetic core encompassing the cable connected to the circuit breaker, and the naïve regulator made in the form of throttles with a smoothly changing air gap of the magnetic circuit, the recording unit is equipped with an additional unit for measuring and storing time connected to the sensor.

Such an embodiment of the sensor does not add additional resistance to the secondary winding of the power transformer and allows to increase the test current, while maintaining the weight and dimensions of the device.

The drawing shows a schematic of a device for testing ship circuit breakers.

The voltage regulator 1 is connected to the primary winding of the power transformer 2, the secondary winding of which includes the tested circuit breaker 3 and the inductive sensor 4 connected to the recording unit 5, containing the current measuring and storing unit 6 and the time measuring and storing unit 7.

When the circuit breaker is on (its contacts are closed), the primary windings of the power transformer 2 and voltage regulator 1 are connected to the network. On the secondary winding of the power transformer 2 current flows. On the winding of the inductive sensor 4, an emf is induced, proportional to the current. The signal from inductive sensor 4 enters the current measuring and storing unit 6 and the time measuring and storing unit 7. The measuring and storing unit of current 6 consists of an electronic memory amplifier with a meter connected to its output. Based on the meter deflection, the current flowing through the circuit breaker 3 is determined. The time measurement and storage unit 7 is a digital counter in which the variable emf of sensor 4 is converted into counting pulses with a pulse frequency of 100 Hz. The number of pulses arriving at the counter is equal to the current flow time in hundredths of a second. Digital indicators highlight the time during which the shutdown occurred. In order to obtain the next point in the current-time characteristic, all operations are repeated again, changing only the resistance of the voltage regulator 1 and moving the ferromagnetic core relative to the fixed fixed coils.

Claims (2)

Invention Formula A device for characterizing ship breakers containing a power transformer, a voltage regulator included in the primary winding of a power transformer, a sensor connected to the secondary winding of a power transformer and a circuit breaker, a recording unit made as a current measuring and storing unit, coupled to a sensor, characterized in that, in order to increase the test current and its smooth control while maintaining the weight and weight of the device's indicators, impairing the recording of the response time of the circuit breakers; The registration unit is provided with an additional time measurement and storage unit and a switch to the sensor. Sources of information taken into account in the examination 1- B. Gandin, D. Magarshak, G., Sokolov L. G. Reference book but the repair of shipboard electrical equipment. L., “Shipbuilding, vol. I, 1964. 2. Ship electrical engineering and communications. L., “Sudostroenie., No. 36-37, p. 124-129, 1970. I