Introduction: Trick devices in power electronics

Silicon-controlled rectifiers (SCRs), likewise called thyristors, are semiconductor power devices with a four-layer three-way joint framework (PNPN). Because its introduction in the 1950s, SCRs have been extensively utilized in industrial automation, power systems, home appliance control and various other areas because of their high withstand voltage, huge existing carrying capacity, rapid response and easy control. With the advancement of technology, SCRs have evolved into numerous types, consisting of unidirectional SCRs, bidirectional SCRs (TRIACs), turn-off thyristors (GTOs) and light-controlled thyristors (LTTs). The distinctions between these kinds are not only mirrored in the structure and functioning concept, yet likewise determine their applicability in different application scenarios. This write-up will certainly begin with a technological viewpoint, integrated with specific criteria, to deeply evaluate the main differences and common uses these 4 SCRs.

Unidirectional SCR: Fundamental and stable application core

Unidirectional SCR is one of the most fundamental and common sort of thyristor. Its framework is a four-layer three-junction PNPN plan, including 3 electrodes: anode (A), cathode (K) and entrance (G). It only permits existing to stream in one direction (from anode to cathode) and switches on after eviction is triggered. As soon as switched on, even if eviction signal is removed, as long as the anode current is greater than the holding present (typically much less than 100mA), the SCR stays on.

(Thyristor Rectifier)

Unidirectional SCR has strong voltage and existing tolerance, with an ahead repeated height voltage (V DRM) of approximately 6500V and a ranked on-state average current (ITAV) of approximately 5000A. Therefore, it is commonly used in DC electric motor control, commercial heating unit, uninterruptible power supply (UPS) rectification components, power conditioning tools and other events that call for continual transmission and high power processing. Its benefits are basic structure, inexpensive and high integrity, and it is a core part of lots of standard power control systems.

Bidirectional SCR (TRIAC): Suitable for air conditioner control

Unlike unidirectional SCR, bidirectional SCR, also known as TRIAC, can achieve bidirectional conduction in both favorable and adverse fifty percent cycles. This framework includes two anti-parallel SCRs, which permit TRIAC to be triggered and switched on at any time in the air conditioning cycle without transforming the circuit connection approach. The in proportion conduction voltage range of TRIAC is generally ± 400 ~ 800V, the optimum tons current has to do with 100A, and the trigger current is much less than 50mA.

Because of the bidirectional conduction qualities of TRIAC, it is especially ideal for air conditioner dimming and rate control in family home appliances and customer electronic devices. For instance, tools such as light dimmers, fan controllers, and ac unit follower speed regulatory authorities all depend on TRIAC to achieve smooth power policy. Furthermore, TRIAC additionally has a reduced driving power demand and appropriates for incorporated style, so it has been extensively made use of in clever home systems and small home appliances. Although the power density and switching rate of TRIAC are not like those of brand-new power devices, its low cost and hassle-free usage make it an important player in the area of tiny and medium power air conditioning control.

Entrance Turn-Off Thyristor (GTO): A high-performance representative of energetic control

Entrance Turn-Off Thyristor (GTO) is a high-performance power gadget created on the basis of traditional SCR. Unlike regular SCR, which can only be turned off passively, GTO can be turned off actively by using an unfavorable pulse present to eviction, therefore achieving even more flexible control. This feature makes GTO do well in systems that call for frequent start-stop or fast reaction.

(Thyristor Rectifier)

The technological specifications of GTO reveal that it has exceptionally high power dealing with capacity: the turn-off gain is about 4 ~ 5, the maximum operating voltage can get to 6000V, and the optimum operating current depends on 6000A. The turn-on time has to do with 1μs, and the turn-off time is 2 ~ 5μs. These performance signs make GTO widely utilized in high-power situations such as electric engine grip systems, huge inverters, commercial electric motor frequency conversion control, and high-voltage DC transmission systems. Although the drive circuit of GTO is relatively complicated and has high changing losses, its efficiency under high power and high vibrant reaction requirements is still irreplaceable.

Light-controlled thyristor (LTT): A dependable selection in the high-voltage seclusion environment

Light-controlled thyristor (LTT) makes use of optical signals as opposed to electrical signals to cause conduction, which is its biggest function that distinguishes it from various other sorts of SCRs. The optical trigger wavelength of LTT is generally between 850nm and 950nm, the action time is gauged in milliseconds, and the insulation level can be as high as 100kV or above. This optoelectronic isolation device considerably boosts the system’s anti-electromagnetic disturbance ability and safety and security.

LTT is primarily utilized in ultra-high voltage straight present transmission (UHVDC), power system relay defense gadgets, electromagnetic compatibility protection in clinical tools, and armed forces radar interaction systems etc, which have incredibly high needs for security and security. For example, many converter stations in China’s “West-to-East Power Transmission” project have taken on LTT-based converter shutoff components to make certain stable procedure under extremely high voltage conditions. Some progressed LTTs can also be combined with gateway control to attain bidirectional transmission or turn-off functions, additionally broadening their application array and making them a perfect option for resolving high-voltage and high-current control issues.

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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