Intro: Key tools in power electronics
Silicon-controlled rectifiers (SCRs), likewise known as thyristors, are semiconductor power tools with a four-layer three-way joint framework (PNPN). Considering that its introduction in the 1950s, SCRs have been widely utilized in commercial automation, power systems, home appliance control and other fields as a result of their high hold up against voltage, huge present lugging ability, rapid response and simple control. With the advancement of technology, SCRs have actually developed into many types, including unidirectional SCRs, bidirectional SCRs (TRIACs), turn-off thyristors (GTOs) and light-controlled thyristors (LTTs). The distinctions in between these types are not only reflected in the structure and working concept, however likewise identify their applicability in various application scenarios. This post will certainly start from a technological perspective, combined with specific specifications, to deeply assess the main distinctions and normal uses these four SCRs.
Unidirectional SCR: Standard and stable application core
Unidirectional SCR is one of the most basic and usual sort of thyristor. Its framework is a four-layer three-junction PNPN setup, consisting of three electrodes: anode (A), cathode (K) and entrance (G). It only permits existing to flow in one instructions (from anode to cathode) and turns on after eviction is set off. Once switched on, even if eviction signal is gotten rid of, as long as the anode current is above the holding existing (typically much less than 100mA), the SCR stays on.
(Thyristor Rectifier)
Unidirectional SCR has strong voltage and existing tolerance, with a forward repetitive peak voltage (V DRM) of as much as 6500V and a rated on-state typical current (ITAV) of up to 5000A. For that reason, it is widely used in DC electric motor control, industrial furnace, uninterruptible power supply (UPS) rectification parts, power conditioning tools and various other occasions that require continual conduction and high power handling. Its advantages are basic structure, affordable and high dependability, and it is a core element of many standard power control systems.
Bidirectional SCR (TRIAC): Perfect for AC control
Unlike unidirectional SCR, bidirectional SCR, additionally known as TRIAC, can achieve bidirectional conduction in both favorable and negative fifty percent cycles. This structure consists of two anti-parallel SCRs, which enable TRIAC to be triggered and turned on at any moment in the air conditioner cycle without changing the circuit connection method. The balanced transmission voltage variety of TRIAC is generally ± 400 ~ 800V, the optimum lots current has to do with 100A, and the trigger current is much less than 50mA.
As a result of the bidirectional conduction attributes of TRIAC, it is specifically appropriate for AC dimming and rate control in house home appliances and customer electronic devices. For example, gadgets such as lamp dimmers, follower controllers, and a/c fan speed regulatory authorities all rely upon TRIAC to accomplish smooth power regulation. On top of that, TRIAC also has a reduced driving power requirement and appropriates for incorporated style, so it has actually been widely made use of in clever home systems and tiny devices. Although the power thickness and switching speed of TRIAC are not like those of new power gadgets, its low cost and practical usage make it an important gamer in the field of small and medium power a/c control.
Entrance Turn-Off Thyristor (GTO): A high-performance rep of active control
Entrance Turn-Off Thyristor (GTO) is a high-performance power tool created on the basis of conventional SCR. Unlike regular SCR, which can only be shut off passively, GTO can be turned off actively by applying an adverse pulse existing to the gate, therefore accomplishing more flexible control. This attribute makes GTO perform well in systems that need frequent start-stop or rapid response.
(Thyristor Rectifier)
The technological specifications of GTO reveal that it has incredibly high power handling ability: the turn-off gain has to do with 4 ~ 5, the maximum operating voltage can get to 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 signs make GTO extensively made use of in high-power circumstances such as electric locomotive grip systems, large inverters, commercial motor regularity conversion control, and high-voltage DC transmission systems. Although the drive circuit of GTO is reasonably complicated and has high switching losses, its efficiency under high power and high vibrant action demands is still irreplaceable.
Light-controlled thyristor (LTT): A trustworthy choice in the high-voltage seclusion environment
Light-controlled thyristor (LTT) utilizes optical signals as opposed to electric signals to activate conduction, which is its largest attribute that identifies it from other types of SCRs. The optical trigger wavelength of LTT is normally in between 850nm and 950nm, the feedback time is gauged in milliseconds, and the insulation degree can be as high as 100kV or above. This optoelectronic seclusion device considerably boosts the system’s anti-electromagnetic disturbance capacity and safety.
LTT is mainly made use of in ultra-high voltage straight present transmission (UHVDC), power system relay security devices, electromagnetic compatibility security in clinical equipment, and army radar communication systems and so on, which have incredibly high requirements for safety and security and security. For example, many converter stations in China’s “West-to-East Power Transmission” job have embraced LTT-based converter shutoff modules to ensure steady operation under very high voltage problems. Some advanced LTTs can additionally be integrated with entrance control to attain bidirectional transmission or turn-off functions, better expanding their application variety and making them an excellent option 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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