monopole transmission system. The second conductor is either unused or used as electrode line or connected in parallel with the other (as in case of Baltic-Cable). 2.5.2 Bipolar In bipolar transmission a pair of conductors is used, each at a high potential with respect to ground, in opposite polarity. Since these conductors must be insulated for the full voltage, transmission line cost is higher than a monopole with a return conductor. Figure 2: Block diagram of a bipolar system that also has an earth return. Electrical & Electronics Engineering, FISAT 11 HVDC TECHNOLOGY AND SHORT CIRCUIT CONTRIBUTION OF HVDC LIGHT However, there are a number of advantages to bipolar transmission which can make it the attractive option. Under normal load, negligible earth-current flows, as in the case of monopolar transmission with a metallic earth-return. This reduces earth return loss and environmental effects. When a fault develops in a line, with earth return electrodes installed at each end of the line, approximately half the rated power can continue to flow using the earth as a return path, operating in monopolar mode. Since for a given total power rating each conductor of a bipolar line carries only half the current of monopolar lines, the cost of the second conductor is reduced compared to a monopolar line of the same rating.
monopole transmission system. The second conductor is either unused or used as electrode line or connected in parallel with the other (as in case of Baltic-Cable). 2.5.2 Bipolar In bipolar transmission a pair of conductors is used, each at a high potential with respect to ground, in opposite polarity. Since these conductors must be insulated for the full voltage, transmission line cost is higher than a monopole with a return conductor. Figure 2: Block diagram of a bipolar system that also has an earth return. Electrical & Electronics Engineering, FISAT 11 HVDC TECHNOLOGY AND SHORT CIRCUIT CONTRIBUTION OF HVDC LIGHT However, there are a number of advantages to bipolar transmission which can make it the attractive option. Under normal load, negligible earth-current flows, as in the case of monopolar transmission with a metallic earth-return. This reduces earth return loss and environmental effects. When a fault develops in a line, with earth return electrodes installed at each end of the line, approximately half the rated power can continue to flow using the earth as a return path, operating in monopolar mode. Since for a given total power rating each conductor of a bipolar line carries only half the current of monopolar lines, the cost of the second conductor is reduced compared to a monopolar line of the same rating.
53681216-Seminar-Hvdc-Technology-and-Short-Circuit-Contribution-of-HVDC-Light.docx