Intro: Key gadgets in power electronics
Silicon-controlled rectifiers (SCRs), additionally referred to as thyristors, are semiconductor power tools with a four-layer triple joint framework (PNPN). Considering that its introduction in the 1950s, SCRs have been widely made use of in commercial automation, power systems, home appliance control and other areas as a result of their high withstand voltage, huge existing bring capacity, rapid action and simple control. With the development of technology, SCRs have evolved right into numerous kinds, including unidirectional SCRs, bidirectional SCRs (TRIACs), turn-off thyristors (GTOs) and light-controlled thyristors (LTTs). The distinctions between these types are not just reflected in the framework and working principle, but also establish their applicability in various application circumstances. This post will certainly begin with a technical viewpoint, incorporated with certain parameters, to deeply examine the primary distinctions and regular uses these four SCRs.
Unidirectional SCR: Fundamental and secure application core
Unidirectional SCR is the most standard and common type of thyristor. Its framework is a four-layer three-junction PNPN arrangement, including three electrodes: anode (A), cathode (K) and gate (G). It just allows existing to move in one direction (from anode to cathode) and switches on after the gate is triggered. When turned on, even if the gate signal is eliminated, as long as the anode current is above the holding existing (typically much less than 100mA), the SCR remains on.
(Thyristor Rectifier)
Unidirectional SCR has solid voltage and existing resistance, with an onward repeated peak voltage (V DRM) of approximately 6500V and a rated on-state ordinary existing (ITAV) of approximately 5000A. Consequently, it is widely used in DC motor control, commercial furnace, uninterruptible power supply (UPS) rectification components, power conditioning gadgets and other celebrations that need continual transmission and high power processing. Its advantages are simple framework, inexpensive and high integrity, and it is a core part of lots of typical power control systems.
Bidirectional SCR (TRIAC): Ideal for air conditioner control
Unlike unidirectional SCR, bidirectional SCR, additionally referred to as TRIAC, can accomplish bidirectional conduction in both positive and adverse half cycles. This structure consists of two anti-parallel SCRs, which enable TRIAC to be triggered and switched on at any time in the air conditioner cycle without changing the circuit link technique. The balanced transmission voltage range of TRIAC is usually ± 400 ~ 800V, the maximum tons current has to do with 100A, and the trigger current is less than 50mA.
Due to the bidirectional conduction attributes of TRIAC, it is especially ideal for AC dimming and speed control in home appliances and customer electronic devices. For example, tools such as lamp dimmers, fan controllers, and a/c follower rate regulatory authorities all count on TRIAC to achieve smooth power regulation. Furthermore, TRIAC additionally has a reduced driving power requirement and appropriates for incorporated design, so it has actually been extensively made use of in clever home systems and little appliances. Although the power density and switching rate of TRIAC are not as good as those of new power gadgets, its inexpensive and practical usage make it a vital gamer in the field of small and average power air conditioning control.
Gateway Turn-Off Thyristor (GTO): A high-performance representative of active control
Gate Turn-Off Thyristor (GTO) is a high-performance power gadget developed on the basis of traditional SCR. Unlike normal SCR, which can only be switched off passively, GTO can be turned off proactively by applying a negative pulse present to the gate, therefore achieving even more flexible control. This attribute makes GTO execute well in systems that need regular start-stop or fast response.
(Thyristor Rectifier)
The technological specifications of GTO reveal that it has very high power dealing with capacity: the turn-off gain has to do with 4 ~ 5, the maximum 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 indications make GTO extensively used in high-power circumstances such as electric engine grip systems, huge inverters, industrial electric motor frequency conversion control, and high-voltage DC transmission systems. Although the drive circuit of GTO is reasonably complicated and has high switching losses, its performance under high power and high dynamic action requirements is still irreplaceable.
Light-controlled thyristor (LTT): A dependable choice in the high-voltage isolation setting
Light-controlled thyristor (LTT) uses optical signals instead of electric signals to trigger transmission, which is its biggest function that identifies it from various other sorts of SCRs. The optical trigger wavelength of LTT is normally between 850nm and 950nm, the reaction time is measured in split seconds, and the insulation level can be as high as 100kV or above. This optoelectronic seclusion mechanism considerably boosts the system’s anti-electromagnetic interference capacity and safety and security.
LTT is mostly utilized in ultra-high voltage straight existing transmission (UHVDC), power system relay protection tools, electro-magnetic compatibility defense in medical equipment, and army radar communication systems etc, which have very high needs for safety and security and security. For instance, lots of converter stations in China’s “West-to-East Power Transmission” task have actually adopted LTT-based converter valve components to make sure steady procedure under exceptionally high voltage problems. Some advanced LTTs can also be integrated with gate control to accomplish bidirectional transmission or turn-off functions, better expanding their application variety and making them an optimal 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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