Introduction: Key tools in power electronics
Silicon-controlled rectifiers (SCRs), additionally called thyristors, are semiconductor power gadgets with a four-layer triple joint framework (PNPN). Because its introduction in the 1950s, SCRs have been extensively utilized in industrial automation, power systems, home appliance control and various other areas due to their high withstand voltage, huge present bring ability, quick reaction and basic control. With the advancement of technology, SCRs have developed into many kinds, consisting of unidirectional SCRs, bidirectional SCRs (TRIACs), turn-off thyristors (GTOs) and light-controlled thyristors (LTTs). The differences between these types are not just mirrored in the framework and functioning principle, yet also establish their applicability in various application circumstances. This short article will start from a technological point of view, integrated with details parameters, to deeply assess the primary distinctions and regular uses of these four SCRs.
Unidirectional SCR: Standard and stable application core
Unidirectional SCR is one of the most basic and typical sort of thyristor. Its framework is a four-layer three-junction PNPN plan, including 3 electrodes: anode (A), cathode (K) and gateway (G). It just enables current to move in one direction (from anode to cathode) and turns on after the gate is triggered. When switched on, also if eviction signal is eliminated, 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 solid voltage and current resistance, with an ahead repetitive optimal voltage (V DRM) of approximately 6500V and a rated on-state ordinary existing (ITAV) of up to 5000A. As a result, it is commonly made use of in DC motor control, industrial furnace, uninterruptible power supply (UPS) rectification components, power conditioning devices and various other events that need continual conduction and high power handling. Its benefits are basic framework, inexpensive and high reliability, and it is a core part of lots of typical power control systems.
Bidirectional SCR (TRIAC): Suitable for air conditioner control
Unlike unidirectional SCR, bidirectional SCR, additionally known as TRIAC, can accomplish bidirectional transmission in both positive and adverse fifty percent cycles. This structure consists of 2 anti-parallel SCRs, which permit TRIAC to be caused and activated at any time in the air conditioning cycle without changing the circuit connection method. The balanced conduction voltage series of TRIAC is normally ± 400 ~ 800V, the optimum tons current is about 100A, and the trigger current is less than 50mA.
Due to the bidirectional conduction attributes of TRIAC, it is specifically appropriate for a/c dimming and speed control in household appliances and customer electronic devices. As an example, tools such as light dimmers, fan controllers, and air conditioning system fan speed regulatory authorities all rely on TRIAC to attain smooth power regulation. Furthermore, TRIAC likewise has a reduced driving power need and is suitable for incorporated style, so it has been extensively used in clever home systems and small home appliances. Although the power density and changing speed of TRIAC are not just as good as those of new power tools, its low cost and hassle-free usage make it an important gamer in the field of tiny and medium power AC control.
Gateway Turn-Off Thyristor (GTO): A high-performance agent of energetic control
Gate Turn-Off Thyristor (GTO) is a high-performance power gadget developed on the basis of standard SCR. Unlike average SCR, which can just be switched off passively, GTO can be switched off actively by using a negative pulse current to the gate, thus accomplishing more flexible control. This function makes GTO carry out well in systems that need frequent start-stop or quick reaction.
(Thyristor Rectifier)
The technical specifications of GTO show that it has exceptionally high power managing ability: the turn-off gain is about 4 ~ 5, the maximum operating voltage can get to 6000V, and the optimum operating current is up to 6000A. The turn-on time is about 1μs, and the turn-off time is 2 ~ 5μs. These performance indicators make GTO extensively made use of in high-power scenarios such as electrical locomotive traction systems, big inverters, industrial electric motor frequency conversion control, and high-voltage DC transmission systems. Although the drive circuit of GTO is fairly intricate and has high switching losses, its performance under high power and high vibrant action requirements is still irreplaceable.
Light-controlled thyristor (LTT): A trustworthy option in the high-voltage isolation environment
Light-controlled thyristor (LTT) uses optical signals rather than electric signals to set off transmission, which is its most significant feature that identifies it from various other kinds of SCRs. The optical trigger wavelength of LTT is generally between 850nm and 950nm, the feedback time is determined in nanoseconds, and the insulation degree can be as high as 100kV or above. This optoelectronic seclusion device considerably boosts the system’s anti-electromagnetic interference capability and security.
LTT is generally utilized in ultra-high voltage direct current transmission (UHVDC), power system relay protection gadgets, electromagnetic compatibility defense in medical devices, and military radar communication systems and so on, which have exceptionally high requirements for security and security. As an example, several converter stations in China’s “West-to-East Power Transmission” project have adopted LTT-based converter valve components to ensure stable procedure under incredibly high voltage problems. Some progressed LTTs can likewise be integrated with gateway control to attain bidirectional transmission or turn-off functions, additionally expanding their application range and making them a suitable selection for solving high-voltage and high-current control troubles.
Vendor
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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