Intro: Secret devices in power electronic devices
Silicon-controlled rectifiers (SCRs), additionally called thyristors, are semiconductor power tools with a four-layer triple joint structure (PNPN). Since its introduction in the 1950s, SCRs have actually been commonly used in commercial automation, power systems, home device control and other areas as a result of their high hold up against voltage, large present lugging capability, quick action and straightforward control. With the advancement of modern technology, SCRs have actually advanced into lots of types, including unidirectional SCRs, bidirectional SCRs (TRIACs), turn-off thyristors (GTOs) and light-controlled thyristors (LTTs). The differences in between these types are not only mirrored in the framework and functioning principle, yet likewise identify their applicability in different application situations. This write-up will certainly begin with a technical perspective, combined with particular specifications, to deeply evaluate the main distinctions and typical uses these four SCRs.
Unidirectional SCR: Basic and secure application core
Unidirectional SCR is the most fundamental and common sort of thyristor. Its structure is a four-layer three-junction PNPN plan, including three electrodes: anode (A), cathode (K) and gate (G). It only allows existing to stream in one instructions (from anode to cathode) and turns on after eviction is caused. As soon as turned on, also if the gate signal is eliminated, as long as the anode current is higher than the holding current (normally much less than 100mA), the SCR stays on.
(Thyristor Rectifier)
Unidirectional SCR has strong voltage and current tolerance, with an ahead repeated top voltage (V DRM) of approximately 6500V and a ranked on-state typical existing (ITAV) of as much as 5000A. As a result, it is extensively utilized in DC electric motor control, commercial heater, uninterruptible power supply (UPS) correction parts, power conditioning tools and other events that call for continual conduction and high power processing. Its advantages are easy framework, affordable and high reliability, and it is a core element of numerous conventional power control systems.
Bidirectional SCR (TRIAC): Ideal for AC control
Unlike unidirectional SCR, bidirectional SCR, also called TRIAC, can accomplish bidirectional transmission in both positive and adverse fifty percent cycles. This framework includes two anti-parallel SCRs, which allow TRIAC to be activated and turned on at any time in the air conditioner cycle without transforming the circuit connection technique. The in proportion conduction voltage variety of TRIAC is usually ± 400 ~ 800V, the optimum tons current has to do with 100A, and the trigger current is much less than 50mA.
Because of the bidirectional transmission attributes of TRIAC, it is especially appropriate for air conditioning dimming and speed control in household devices and consumer electronic devices. For instance, gadgets such as lamp dimmers, follower controllers, and air conditioning system fan speed regulatory authorities all count on TRIAC to achieve smooth power law. Additionally, TRIAC also has a reduced driving power requirement and is suitable for integrated design, so it has been widely used in clever home systems and small appliances. Although the power density and changing speed of TRIAC are not just as good as those of new power gadgets, its low cost and practical use make it an important player in the field of little and medium power air conditioning control.
Entrance Turn-Off Thyristor (GTO): A high-performance agent of active control
Gateway Turn-Off Thyristor (GTO) is a high-performance power gadget created on the basis of typical SCR. Unlike average SCR, which can just be switched off passively, GTO can be switched off proactively by applying an adverse pulse existing to eviction, thus achieving more adaptable control. This function makes GTO execute well in systems that need regular start-stop or rapid reaction.
(Thyristor Rectifier)
The technical criteria of GTO show that it has extremely high power taking care of ability: the turn-off gain is about 4 ~ 5, the maximum operating voltage can reach 6000V, and the optimum operating current depends on 6000A. The turn-on time has to do with 1μs, and the turn-off time is 2 ~ 5μs. These efficiency signs make GTO widely made use of in high-power circumstances such as electric locomotive traction systems, big inverters, commercial motor frequency conversion control, and high-voltage DC transmission systems. Although the drive circuit of GTO is fairly complex and has high changing losses, its performance under high power and high dynamic reaction demands is still irreplaceable.
Light-controlled thyristor (LTT): A reliable selection in the high-voltage isolation atmosphere
Light-controlled thyristor (LTT) utilizes optical signals rather than electrical signals to cause conduction, which is its greatest feature that identifies it from other kinds of SCRs. The optical trigger wavelength of LTT is usually in between 850nm and 950nm, the action time is determined in split seconds, and the insulation level can be as high as 100kV or above. This optoelectronic isolation mechanism significantly enhances the system’s anti-electromagnetic interference capability and safety and security.
LTT is generally made use of in ultra-high voltage direct present transmission (UHVDC), power system relay security gadgets, electro-magnetic compatibility security in clinical devices, and army radar communication systems and so on, which have extremely high demands for security and stability. For instance, several converter terminals in China’s “West-to-East Power Transmission” task have actually embraced LTT-based converter valve modules to make certain stable operation under incredibly high voltage problems. Some advanced LTTs can likewise be integrated with gate control to accomplish bidirectional transmission or turn-off features, additionally expanding their application range and making them an optimal option for solving 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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