Introduction: Secret gadgets in power electronics
Silicon-controlled rectifiers (SCRs), also known as thyristors, are semiconductor power gadgets with a four-layer three-way joint framework (PNPN). Given that its intro in the 1950s, SCRs have actually been extensively used in industrial automation, power systems, home device control and various other fields due to their high hold up against voltage, big current bring capability, rapid feedback and straightforward control. With the development of modern technology, SCRs have advanced right into many types, including unidirectional SCRs, bidirectional SCRs (TRIACs), turn-off thyristors (GTOs) and light-controlled thyristors (LTTs). The differences between these types are not just reflected in the structure and functioning principle, however additionally establish their applicability in different application circumstances. This article will start from a technological point of view, combined with particular parameters, to deeply examine the main distinctions and normal uses of these 4 SCRs.
Unidirectional SCR: Fundamental and secure application core
Unidirectional SCR is the most fundamental 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 current to stream in one instructions (from anode to cathode) and turns on after eviction is activated. Once turned on, also if eviction signal is gotten rid of, as long as the anode current is greater than the holding existing (generally much less than 100mA), the SCR remains on.
(Thyristor Rectifier)
Unidirectional SCR has strong voltage and present resistance, with an onward recurring height voltage (V DRM) of up to 6500V and a rated on-state average present (ITAV) of as much as 5000A. For that reason, it is extensively utilized in DC electric motor control, industrial heating systems, uninterruptible power supply (UPS) rectification parts, power conditioning tools and other events that call for constant transmission and high power processing. Its benefits are basic structure, inexpensive and high reliability, and it is a core component of lots of standard power control systems.
Bidirectional SCR (TRIAC): Perfect for a/c control
Unlike unidirectional SCR, bidirectional SCR, also known as TRIAC, can attain bidirectional transmission in both favorable and adverse fifty percent cycles. This structure consists of two anti-parallel SCRs, which allow TRIAC to be triggered and turned on at any moment in the a/c cycle without transforming the circuit link approach. The in proportion transmission voltage series of TRIAC is normally ± 400 ~ 800V, the optimum tons current is about 100A, and the trigger current is much less than 50mA.
Due to the bidirectional transmission qualities of TRIAC, it is specifically ideal for a/c dimming and speed control in household devices and consumer electronic devices. As an example, tools such as lamp dimmers, fan controllers, and air conditioning system follower speed regulators all rely on TRIAC to attain smooth power guideline. In addition, TRIAC likewise has a reduced driving power need and appropriates for integrated style, so it has actually been widely used in clever home systems and little appliances. Although the power thickness and changing rate of TRIAC are not as good as those of brand-new power gadgets, its affordable and convenient use make it an important gamer in the area of little and average power a/c control.
Gateway Turn-Off Thyristor (GTO): A high-performance representative of active control
Gateway Turn-Off Thyristor (GTO) is a high-performance power gadget developed on the basis of standard SCR. Unlike regular SCR, which can only be turned off passively, GTO can be shut off proactively by using a negative pulse existing to eviction, therefore accomplishing more flexible control. This attribute makes GTO execute well in systems that require regular start-stop or quick response.
(Thyristor Rectifier)
The technical specifications of GTO show that it has incredibly high power taking care of capacity: the turn-off gain is about 4 ~ 5, the maximum operating voltage can get to 6000V, and the maximum operating current depends on 6000A. The turn-on time is about 1μs, and the turn-off time is 2 ~ 5μs. These performance indicators make GTO widely utilized in high-power situations such as electric locomotive traction systems, huge inverters, industrial 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 performance under high power and high vibrant reaction requirements is still irreplaceable.
Light-controlled thyristor (LTT): A reputable choice in the high-voltage seclusion atmosphere
Light-controlled thyristor (LTT) makes use of optical signals as opposed to electric signals to set off transmission, which is its biggest function that differentiates it from various other types of SCRs. The optical trigger wavelength of LTT is usually in between 850nm and 950nm, the action time is measured in split seconds, and the insulation degree can be as high as 100kV or above. This optoelectronic seclusion system substantially enhances the system’s anti-electromagnetic disturbance ability and safety.
LTT is mostly utilized in ultra-high voltage direct existing transmission (UHVDC), power system relay security devices, electromagnetic compatibility defense in medical equipment, and military radar communication systems etc, which have exceptionally high needs for security and security. As an example, numerous converter terminals in China’s “West-to-East Power Transmission” job have actually taken on LTT-based converter valve modules to make certain stable procedure under extremely high voltage problems. Some advanced LTTs can additionally be combined with gateway control to attain bidirectional conduction or turn-off features, further increasing their application array and making them an optimal choice for fixing 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 silicon control, please feel free to contact us.(sales@pddn.com)
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