Intro: Key devices in power electronics

Silicon-controlled rectifiers (SCRs), also known as thyristors, are semiconductor power devices with a four-layer three-way junction framework (PNPN). Since its intro in the 1950s, SCRs have been extensively made use of in industrial automation, power systems, home device control and other areas as a result of their high endure voltage, large current bring capability, rapid feedback and straightforward control. With the development of modern 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 kinds are not just mirrored in the structure and functioning concept, but likewise identify their applicability in various application situations. This post will start from a technological viewpoint, incorporated with details parameters, to deeply analyze the main differences and typical uses these 4 SCRs.

Unidirectional SCR: Fundamental and stable application core

Unidirectional SCR is the most basic 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 enables present to move in one instructions (from anode to cathode) and activates after eviction is triggered. When switched on, even if the gate signal is removed, as long as the anode current is more than the holding present (usually much less than 100mA), the SCR remains on.

(Thyristor Rectifier)

Unidirectional SCR has solid voltage and present tolerance, with an onward recurring peak voltage (V DRM) of approximately 6500V and a ranked on-state average current (ITAV) of up to 5000A. Consequently, it is commonly used in DC electric motor control, industrial heater, uninterruptible power supply (UPS) correction components, power conditioning tools and various other events that need continual conduction and high power processing. Its benefits are straightforward structure, affordable and high reliability, and it is a core component of lots of traditional power control systems.

Bidirectional SCR (TRIAC): Perfect for AC control

Unlike unidirectional SCR, bidirectional SCR, also called TRIAC, can attain bidirectional conduction in both favorable and negative half cycles. This framework includes 2 anti-parallel SCRs, which enable TRIAC to be activated and switched on at any time in the air conditioner cycle without transforming the circuit connection method. The balanced conduction voltage variety of TRIAC is normally ± 400 ~ 800V, the optimum lots current is about 100A, and the trigger current is much less than 50mA.

As a result of the bidirectional transmission characteristics of TRIAC, it is specifically ideal for a/c dimming and rate control in house devices and customer electronic devices. For example, devices such as lamp dimmers, follower controllers, and a/c follower speed regulators all rely upon TRIAC to accomplish smooth power law. On top of that, TRIAC additionally has a lower driving power demand and is suitable for integrated design, so it has actually been widely made use of in clever home systems and little appliances. Although the power thickness and changing speed of TRIAC are not comparable to those of brand-new power tools, its affordable and convenient usage make it a crucial player in the area of little and medium power AC control.

Gateway Turn-Off Thyristor (GTO): A high-performance agent of active control

Entrance Turn-Off Thyristor (GTO) is a high-performance power device created on the basis of typical SCR. Unlike normal SCR, which can only be turned off passively, GTO can be shut off actively by applying a negative pulse existing to the gate, hence accomplishing even more flexible control. This attribute makes GTO perform well in systems that need constant start-stop or quick response.

(Thyristor Rectifier)

The technical parameters of GTO reveal that it has extremely high power handling ability: the turn-off gain is about 4 ~ 5, the optimum operating voltage can reach 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 indications make GTO commonly used in high-power situations such as electrical engine traction systems, big inverters, industrial motor regularity conversion control, and high-voltage DC transmission systems. Although the drive circuit of GTO is relatively intricate and has high changing losses, its efficiency under high power and high vibrant response demands is still irreplaceable.

Light-controlled thyristor (LTT): A trusted choice in the high-voltage isolation setting

Light-controlled thyristor (LTT) makes use of optical signals instead of electrical signals to trigger transmission, which is its most significant feature that differentiates it from other kinds of SCRs. The optical trigger wavelength of LTT is normally between 850nm and 950nm, the feedback time is measured in nanoseconds, and the insulation degree can be as high as 100kV or above. This optoelectronic seclusion system significantly enhances the system’s anti-electromagnetic interference capacity and safety.

LTT is primarily utilized in ultra-high voltage direct present transmission (UHVDC), power system relay defense devices, electromagnetic compatibility defense in medical tools, and army radar interaction systems and so on, which have incredibly high requirements for safety and security and security. For example, several converter terminals in China’s “West-to-East Power Transmission” project have actually embraced LTT-based converter valve components to ensure steady operation under extremely high voltage problems. Some advanced LTTs can also be integrated with entrance control to attain bidirectional conduction or turn-off functions, additionally increasing their application variety and making them a perfect choice for addressing high-voltage and high-current control issues.

Provider

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)

All articles and pictures are from the Internet. If there are any copyright issues, please contact us in time to delete.

Inquiry us