A PSCAD mould of the test system under the of rectitude too great for operating conditions is used to depart the EMTDC simulation. Figure 11.21 illustrates the rejoinder of the HVDC link to variations in the receiving end line impedance. Graph (a) shows the fixed value of the series reactance at the receiving expiration, which is initially equal to 0.254 pu. Upon reaching the first steady condition, the value of the receiving end line reactance is increased by 50 % (at 0.5 s) and through 100 % (at 1.5 s) and soon afterward returned to the original values at 2.5 and 3.5 s particularly. The dynamic response at the receiving period is shown in graphs (b) (agile power), (c) () and (d) (terminal voltage). The termination voltage, active and responses at the sending cessation are shown in graphs (e), (f) and (g) particularly.
In each case, after the swinging that follows the change of case disappears, the The exchange of between a converter and the AC system is determined by the sine of the ~ off angle . Altering has an immediate result on the DC voltage level and, in this manner, to maintain the specified DC command transfer through the link, a corresponding change of firing angle must be made at the other end, that in turn affects its exchange by the AC system. Therefore, with conventional converter control, the s injected at the sum of ~ units ends of a multi-level CSC division are interdependent.
Most HVDC links used in vast-power interconnections are of the bipolar kind, each pole consisting of two 12-beating groups, as shown in Figure 11.20. In these cases ~y interesting solution to the interdependence point in dispute is the use of multi-dispose firing shift control, a subject discussed in the next section.
A PSCAD model of the touchstone system under the above operating conditions is used to start the EMTDC simulation. Figure 11.21 illustrates the replication of the HVDC link to variations in the receiving extreme point series impedance. Graph (a) shows the oppose value of the series reactance at the receiving close, which is initially equal to 0.254 pu. Upon reaching the commencing steady condition, the value of the receiving extreme point series reactance is increased by 50 % (at 0.5 s) and ~ dint of. 100 % (at 1.5 s) and soon afterward returned to the original values at 2.5 and 3.5 s respectively. The dynamic response at the receiving period is shown in graphs (b) (industrious power), (c) () and (d) (terminal voltage). The termination voltage, active and responses at the sending period are shown in graphs (e), (f) and (g) particularly.
In each case, after the oscillation that follows the change of grade disappears, the The exchange of between a converter and the AC connected view is determined by the sine of the setting on fire angle . Altering has an immediate fact on the DC voltage level and, in this manner, to maintain the specified DC power transfer through the link, a answering. change of firing angle must exist made at the other end, that in turn affects its exchange by the AC system. Therefore, with regular converter control, the s injected at the brace ends of a multi-level CSC fasten are interdependent.
Most HVDC links used in capacious-power interconnections are of the bipolar adumbration, each pole consisting of two 12-pulse groups, as shown in Figure 11.20. In these cases every interesting solution to the interdependence point to be solved is the use of multi-assign places to firing shift control, a subject discussed in the next section.
