2. The method of determining the insulation parameters in three-phase electrical networks with isolated neutral with voltages up to and above 1000 V

As a result of the measurement values of the modules of the line voltage and phase voltage C and A with respect to the ground, taking into account the magnitude of the additional active conductivity by mathematical formulas, the following

Special Issues of Ensuring Electrical Safety in Networks with Isolated Neutral Voltage…

<sup>y</sup> <sup>¼</sup> <sup>1</sup>:73UlU<sup>А</sup> U2 <sup>C</sup>‐U<sup>2</sup> A

> <sup>l</sup> � <sup>3</sup>U<sup>2</sup> A � �

<sup>b</sup> <sup>¼</sup> <sup>y</sup><sup>2</sup> � <sup>g</sup><sup>2</sup> � �<sup>0</sup>:<sup>5</sup>

The method developed in the implementation does not require the creation of a special measuring device, since the measuring devices, that is, voltmeters, available in the service manual. The PE-200 resistance is used as an active additional conductivity with R = 1000 Ohms, where by means of parallel and serial connection provides the required power dissipation. To switch, the active standby is used more

The developed method provides satisfactory accuracy and is simple and safe in its implementation in the three-phase electrical networks with isolated neutral

2.3 Analysis of error of method determining the insulation parameters in an

The obtained mathematical dependences for determining the total and active conductance of electrical network insulation provide easy and safe work of electri-

Error analysis of the developed method for determining the insulation parameters in symmetrical three-phase electrical networks with isolated neutral which is based on measurement of unit line voltage, phase voltage C and A relative to the earth, after the active connection of additional conduction between phase A and the

To improve the efficiency of the developed method for determining the parameters of isolation in a symmetrical three-phase network with isolated neutral, based on error analysis, for each specific network, additional active conductivity is selected, in order to ensure satisfactory accuracy of required quantities.

Random relative error in determining the total conductivity of insulation and its components in three-phase balanced networks with voltage up to and beyond 1000, based on the measurement values of the modules of the line voltage, phase voltage

C and A with respect to the ground, after connecting the active additional

where Ul is the line voltage; U<sup>А</sup> is the A phase voltage with respect to the ground; U<sup>С</sup> is C the phase voltage with respect to the ground; and go is the addi-

go, (1)

0:5go, (2)

, (3)

• the total conductance of network insulation

DOI: http://dx.doi.org/10.5772/intechopen.81384

• the active conductance of network insulation

• capacitive conductance of network insulation

tional active conductance.

conductivity cell load switch.

voltages up to and above 1000 V.

electrical network with isolated neutral

electric network and earth is performed.

53

cal installations with voltage up to and above 1000 V.

<sup>g</sup> <sup>¼</sup> <sup>3</sup>U<sup>2</sup>

<sup>l</sup> U<sup>2</sup>

U2 <sup>C</sup> � <sup>U</sup><sup>2</sup> A � �<sup>2</sup> � <sup>1</sup> !

are defined:
