Introduction: Trick devices in power electronics
Silicon-controlled rectifiers (SCRs), also known as thyristors, are semiconductor power gadgets with a four-layer triple joint framework (PNPN). Considering that its introduction in the 1950s, SCRs have been commonly utilized in commercial automation, power systems, home device control and other areas as a result of their high endure voltage, big current carrying capacity, fast feedback and simple control. With the development of innovation, SCRs have progressed right into several types, consisting of unidirectional SCRs, bidirectional SCRs (TRIACs), turn-off thyristors (GTOs) and light-controlled thyristors (LTTs). The distinctions in between these types are not just mirrored in the structure and working principle, but additionally determine their applicability in various application circumstances. This write-up will start from a technical perspective, combined with certain specifications, to deeply examine the main differences and regular uses these four SCRs.
Unidirectional SCR: Standard and stable application core
Unidirectional SCR is one of the most fundamental and common kind of thyristor. Its framework is a four-layer three-junction PNPN plan, consisting of 3 electrodes: anode (A), cathode (K) and gate (G). It only allows present to move in one instructions (from anode to cathode) and switches on after eviction is caused. When turned on, also if the gate signal is removed, as long as the anode current is higher than the holding existing (usually less than 100mA), the SCR continues to be on.
(Thyristor Rectifier)
Unidirectional SCR has strong voltage and existing tolerance, with an onward repeated peak voltage (V DRM) of as much as 6500V and a rated on-state average present (ITAV) of as much as 5000A. Therefore, it is extensively utilized in DC motor control, industrial heating systems, uninterruptible power supply (UPS) correction components, power conditioning devices and other events that call for constant transmission and high power handling. Its advantages are straightforward framework, affordable and high integrity, and it is a core component of numerous traditional power control systems.
Bidirectional SCR (TRIAC): Ideal for a/c control
Unlike unidirectional SCR, bidirectional SCR, additionally called TRIAC, can attain bidirectional conduction in both positive and negative fifty percent cycles. This framework contains 2 anti-parallel SCRs, which permit TRIAC to be caused and switched on at any moment in the air conditioner cycle without altering the circuit connection approach. The in proportion transmission voltage series of TRIAC is generally ± 400 ~ 800V, the optimum load current has to do with 100A, and the trigger current is less than 50mA.
As a result of the bidirectional transmission qualities of TRIAC, it is specifically suitable for air conditioning dimming and rate control in family devices and customer electronic devices. As an example, gadgets such as lamp dimmers, fan controllers, and air conditioner follower speed regulatory authorities all count on TRIAC to attain smooth power regulation. Furthermore, TRIAC additionally has a reduced driving power requirement and appropriates for integrated design, so it has been commonly utilized in clever home systems and little home appliances. Although the power thickness and switching speed of TRIAC are not just as good as those of new power gadgets, its affordable and practical usage make it an essential gamer in the field of tiny and medium power air conditioning control.
Gateway Turn-Off Thyristor (GTO): A high-performance representative of active control
Gateway Turn-Off Thyristor (GTO) is a high-performance power device created on the basis of traditional SCR. Unlike ordinary SCR, which can just be switched off passively, GTO can be turned off proactively by applying a negative pulse present to eviction, thus attaining more adaptable control. This feature makes GTO do well in systems that need constant start-stop or fast reaction.
(Thyristor Rectifier)
The technical criteria of GTO show that it has exceptionally high power managing capability: the turn-off gain has to do with 4 ~ 5, the optimum operating voltage can reach 6000V, and the maximum operating current is up to 6000A. The turn-on time has to do with 1μs, and the turn-off time is 2 ~ 5μs. These performance signs make GTO commonly utilized in high-power scenarios such as electrical engine grip systems, huge inverters, commercial motor regularity conversion control, and high-voltage DC transmission systems. Although the drive circuit of GTO is relatively complex and has high changing losses, its performance under high power and high vibrant action demands is still irreplaceable.
Light-controlled thyristor (LTT): A reputable option in the high-voltage isolation setting
Light-controlled thyristor (LTT) utilizes optical signals rather than electrical signals to activate transmission, which is its greatest function that distinguishes it from other sorts of SCRs. The optical trigger wavelength of LTT is usually between 850nm and 950nm, the action time is measured in nanoseconds, and the insulation degree can be as high as 100kV or above. This optoelectronic seclusion system greatly improves the system’s anti-electromagnetic interference ability and safety.
LTT is primarily made use of in ultra-high voltage straight current transmission (UHVDC), power system relay security tools, electro-magnetic compatibility security in clinical equipment, and military radar communication systems and so on, which have exceptionally high needs for safety and security and security. For instance, several converter stations in China’s “West-to-East Power Transmission” task have adopted LTT-based converter valve modules to ensure secure operation under extremely high voltage problems. Some progressed LTTs can additionally be combined with gate control to achieve bidirectional transmission or turn-off features, additionally broadening their application range and making them an excellent selection for addressing high-voltage and high-current control issues.
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Luoyang Datang Energy Tech Co.Ltd focuses on the research, development, and application of power electronics technology and is devoted to supplying customers with high-quality transformers, thyristors, and other power products. Our company mainly has solar inverters, transformers, voltage regulators, distribution cabinets, thyristors, module, diodes, heatsinks, and other electronic devices or semiconductors. If you want to know more about , please feel free to contact us.(sales@pddn.com)
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