RU2201477C1 - Procedure testing resistance of insulation between electrolyzer and ground and gear for its implementation - Google Patents

Abstract

FIELD: non-ferrous metallurgy. SUBSTANCE: procedure testing resistance of insulation between electrolyzer and ground consists in transmission of current through filter and its measurement. Alternating current with frequency not multiple of frequency of D C network is transmitted through D C filter. Active component of alternating current and active component of alternating voltage are measured. Resistance of insulation is found as ratio of measured values. Gear testing resistance of insulation between electrolyzer and ground incorporates source of electric energy and measuring devices. Gear is equipped with A C generator, current pickup, D C filter, voltage pickup, two synchronous detectors, analog divider and indicator of resistance of insulation. One output of generator is connected to frame of electrolyzer through D C filter. Second output of generator is connected to ground through current pickup. Control output of generator is connected to control inputs of two synchronous detectors. Other inputs of detectors are connected to output of current pickup and output of voltage pickup. Inputs of voltage pickup are connected to frame of electrolyzer and to ground. Outputs of synchronous detectors are connected to two inputs of analog divider. Output of analog divider is connected to input of indicator of resistance of insulation. EFFECT: measurement of resistance of insulation between electrolyzer and ground independent whether electrolyzer in operative or inoperative condition. 2 cl, 1 dwg

Description

 The invention relates to the field of production of magnesium or aluminum and can be used to control the insulation resistance between the electrolyzer and the earth.

 A known method (R. V. Melikyants et al. Automation of aluminum electrolysis cells. Part 1. Moscow, Tsvetmetinformatsiya, 1976, pp. 26-28) and a device for monitoring the insulation resistance between the electrolyzer and the ground, in which a current is passed between the electrolyzer and the ground and measured his.

 The disadvantage of this method and device is the effect of direct current leakage between the electrolyzer and earth on the direct current flowing in the measuring circuit of the insulation resistance control, this affects the accuracy of the measurements.

 An object of the invention is to obtain data on the change in resistance between the cell and the earth, regardless of its mode of operation and inoperative.

 The solution to the technical problem lies in the fact that in the method of controlling the insulation resistance between the electrolyzer and the ground, in which current is passed through the filter and measured, an alternating current of a multiple frequency of the direct current network is passed through the direct current filter, the active component of the alternating current, the active component of the alternating current are measured voltage and insulation resistance are defined as the ratio of measured values.

 The device for insulation resistance between the electrolyzer and the ground includes a current source and measuring instruments, is equipped with an alternating current generator, a direct current filter, a voltage sensor, two synchronous detectors, an analog divider and an insulation resistance indicator, while one generator output is connected to the housing through a direct current filter the electrolyzer and the second output is connected via a current sensor to the ground, and the control output of the generator is connected to the control inputs of two synchronous detectors, the other inputs of which are connected to the output of the current sensor and the voltage sensor output, the inputs of which are attached to the body of the cell and the ground, and the outputs of the synchronous detectors attached to the two inputs of an analog divider the output of which is connected to input indicator insulation resistance.

 A device that implements the method shown in the drawing.

 The device 1 is equipped with an alternating current generator with a frequency that is not a multiple of the frequency of the alternating current network 2, a current sensor 3, a direct current filter 4, two synchronous detectors 5, 6, a voltage sensor 7, an analog divider 8, an insulation resistance indicator 9.

 One output of the alternator 2 through a DC filter 4 is connected to the casing of the electrolyzer 10, and the second output is connected via a current sensor 3 to ground 11, while the control output of the alternator 2 is connected to the control inputs of two synchronous detectors 5, 6, other inputs which are connected to the casing of the electrolyzer 10 and the earth 11, while the outputs of two detectors 5, 6 are connected to two inputs of an analog divider, the output of which is connected to the input of the indicator of insulation resistance 9.

 When the cell is operating or inoperative, a current with a frequency that is not a multiple of the frequency of the DC network is passed between the cell and the ground through the current sensor 3 and the DC filter 4, while the voltage from the control input of the alternator 2 is supplied to the control inputs two synchronous detectors 5, 6, the other inputs of which receive voltage from a current sensor and a voltage sensor. Synchronous detectors 5, 6 separate the active component of voltage and the active component of current, which from the output of synchronous detectors 5, 6 are fed to the input of an analog divider 8, in which these voltages are divided, the result of which is the amount of resistance between the electrolyzer and ground, which is input indicator 9, where it is shown, for example, in numbers (Ohm, kOhm) regardless of the operation mode of the electrolyzer and inoperative.

где U - напряжение между электролизером и землей, В;
I - ток, перетекающий между электролизером и землей, А;
U_на - активная составляющая напряжения между электролизером и землей, В;
U_та - активная составляющая напряжения, пропорциональная току, протекающему между электролизером и землей, В.The insulation resistance R between the cell and earth is determined from the condition

where U is the voltage between the cell and the ground, V;
I is the current flowing between the electrolyzer and the ground, A;
U _on - the active component of the voltage between the cell and the ground, V;
U _that is the active component of the voltage, proportional to the current flowing between the electrolyzer and the ground, V.

Claims (2)

 1. A method of monitoring the insulation resistance between the cell and the ground, in which a current is passed between the cell and the ground through the filter and measured, characterized in that alternating current is passed with a frequency not a multiple of the DC network frequency through the DC filter, the active component of the alternating current is measured current, the active component of the alternating voltage and insulation resistance are defined as the ratio of the measured values.  2. A device for monitoring the insulation resistance between the electrolyzer and the earth, including a current source and measuring instruments, characterized in that it is equipped with an alternating current generator, a current sensor, a DC filter, a voltage sensor, two synchronous detectors, an analog divider and an insulation resistance indicator, in this case, one output of the generator through a DC filter is connected to the housing of the electrolyzer and the second output is connected through a current sensor to the ground, and the control output of the generator is connected to branching inputs of two synchronous detectors, the other inputs of which are connected to the output of the current sensor and the output of the voltage sensor, the inputs of which are connected to the cell body and ground, and the outputs of synchronous detectors are connected to two inputs of an analog divider, the output of which is connected to the input of the insulation resistance indicator.