说明：  高压直流输电仿真模型，基于晶闸管控制的12脉波MATLAB/SIMULINK仿真
(The example in this section illustrates modeling of a high-voltage direct current (HVDC) transmission link using 12-pulse thyristor converters [1]. Perturbations are applied to examine the system performance. The objectives of this example are to demonstrate the use of SimPowerSystems blocks in combination with Simulink blocks in the simulation of a complete pole of a 12-pulse HVDC transmission system. The Discrete HVDC Controller block is a generic control available in the Discrete Control Blocks library of the SimPowerSystems Extras library. In the same library you can find the Discrete Gamma Measurement block used in the inverter control subsystem.)