Intro: Trick devices in power electronics
Silicon-controlled rectifiers (SCRs), additionally called thyristors, are semiconductor power tools with a four-layer triple junction framework (PNPN). Since its introduction in the 1950s, SCRs have been commonly utilized in industrial automation, power systems, home device control and other fields as a result of their high stand up to voltage, big present lugging capability, fast reaction and easy control. With the growth of modern technology, SCRs have actually developed into numerous types, consisting of unidirectional SCRs, bidirectional SCRs (TRIACs), turn-off thyristors (GTOs) and light-controlled thyristors (LTTs). The differences in between these types are not only shown in the framework and working concept, however also determine their applicability in various application situations. This article will begin with a technological viewpoint, incorporated with particular parameters, to deeply assess the main differences and normal uses of these four SCRs.
Unidirectional SCR: Standard and stable application core
Unidirectional SCR is one of the most standard and usual type of thyristor. Its framework is a four-layer three-junction PNPN arrangement, including 3 electrodes: anode (A), cathode (K) and gate (G). It just allows existing to stream in one direction (from anode to cathode) and switches on after eviction is set off. Once switched on, also if the gate signal is gotten rid of, as long as the anode current is above the holding existing (generally less than 100mA), the SCR remains on.
(Thyristor Rectifier)
Unidirectional SCR has solid voltage and current resistance, with a forward recurring top voltage (V DRM) of up to 6500V and a ranked on-state ordinary existing (ITAV) of as much as 5000A. For that reason, it is extensively used in DC motor control, commercial heater, uninterruptible power supply (UPS) correction parts, power conditioning devices and other occasions that require continuous transmission and high power processing. Its benefits are easy structure, affordable and high reliability, and it is a core component of many standard power control systems.
Bidirectional SCR (TRIAC): Suitable for air conditioning control
Unlike unidirectional SCR, bidirectional SCR, likewise called TRIAC, can accomplish bidirectional conduction in both favorable and unfavorable fifty percent cycles. This structure includes 2 anti-parallel SCRs, which enable TRIAC to be triggered and switched on at any moment in the air conditioner cycle without altering the circuit connection method. The in proportion conduction voltage variety of TRIAC is usually ± 400 ~ 800V, the optimum lots current is about 100A, and the trigger current is much less than 50mA.
Due to the bidirectional transmission characteristics of TRIAC, it is especially suitable for AC dimming and rate control in household devices and customer electronics. For instance, gadgets such as lamp dimmers, follower controllers, and ac system follower rate regulators all rely upon TRIAC to achieve smooth power law. Additionally, TRIAC likewise has a reduced driving power demand and appropriates for integrated style, so it has actually been commonly made use of in wise home systems and tiny home appliances. Although the power density and changing rate of TRIAC are not as good as those of new power tools, its inexpensive and practical usage make it a crucial gamer in the area of little and medium power air conditioner control.
Gateway Turn-Off Thyristor (GTO): A high-performance representative of active control
Entrance Turn-Off Thyristor (GTO) is a high-performance power gadget created on the basis of traditional SCR. Unlike common SCR, which can just be shut off passively, GTO can be turned off actively by using an unfavorable pulse existing to the gate, thus attaining even more adaptable control. This attribute makes GTO carry out well in systems that need frequent start-stop or quick reaction.
(Thyristor Rectifier)
The technical specifications of GTO reveal that it has exceptionally high power dealing with capability: 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 is about 1μs, and the turn-off time is 2 ~ 5μs. These efficiency indications make GTO extensively used in high-power situations such as electric locomotive grip systems, huge inverters, industrial electric motor regularity conversion control, and high-voltage DC transmission systems. Although the drive circuit of GTO is fairly intricate and has high switching losses, its efficiency under high power and high dynamic action demands is still irreplaceable.
Light-controlled thyristor (LTT): A trustworthy choice in the high-voltage isolation environment
Light-controlled thyristor (LTT) utilizes optical signals as opposed to electric signals to set off conduction, which is its most significant function that distinguishes it from other types of SCRs. The optical trigger wavelength of LTT is generally in between 850nm and 950nm, the response time is determined in nanoseconds, and the insulation degree can be as high as 100kV or above. This optoelectronic isolation mechanism greatly boosts the system’s anti-electromagnetic disturbance ability and safety.
LTT is generally made use of in ultra-high voltage direct current transmission (UHVDC), power system relay protection tools, electro-magnetic compatibility protection in medical tools, and armed forces radar interaction systems and so on, which have incredibly high demands for security and security. For instance, several converter stations in China’s “West-to-East Power Transmission” project have actually taken on LTT-based converter shutoff modules to make sure stable operation under incredibly high voltage conditions. Some advanced LTTs can likewise be combined with entrance control to accomplish bidirectional conduction or turn-off functions, even more expanding their application variety and making them an optimal option for fixing high-voltage and high-current control troubles.
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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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