System Features and Benefits
Mitsubishi Electric’s SVCs employ light triggered Thyristors (LTT). By initiating the gating mechanism via a direct light source, SSD creates a superior signaling solution versus indirect opto electronic devices. This removes the possible source of latency, the complexity of opto-electronic feedback loops and the costs associated with an external device.
More importantly, the triggering and monitoring of a full system illustrates the second most important aspect of the SSD direct light triggered thyristor. In this illustration, the comparison of valve triggering and monitoring represents a significant simplicity in total system; as compared to indirect light triggering or mechanical triggering.
The advantages of SSD light triggered thyristors can be seen in the comparison of the common indirect light triggering (or slower mechanical triggering) and the SSD direct light triggering. In this illustration, the direct light triggering method does not rely on an external subassembly to control the light signal. With SSD’s direct method the light energy is provides by the light pulse from ground level.
Thyristor valves are used to control the level of inductive or capacitive reactive power. The thyristor valves use solid-state silicon-controlled rectifiers (thyristors) connected in anti-parallel pairs to control AC current. These anti-parallel pairs are then connected in series to operate at distribution voltages. The thyristors control the reactors and capacitors in the circuit, and can operate on a per-cycle basis, allowing fast, precise voltage control.
Mitsubishi Electric has developed a high efficiency liquid cooling system for our FACTS installations using a combination of deionized water and propylene glycol. These cooling systems come complete with filters and deionizers to remove excess heat generated in each thyristor. Designs are fully redundant for reliability, compact, and ensure that the thyristors operate at their maximum capability.
SSD SVC systems incorporate a wide range of components and SSD Turnkey Services allow for the visualization and design necessary to meet and exceed each system requirements.