Intro: Secret tools in power electronics

Silicon-controlled rectifiers (SCRs), additionally referred to as thyristors, are semiconductor power devices with a four-layer three-way joint framework (PNPN). Since its intro in the 1950s, SCRs have been widely used in commercial automation, power systems, home appliance control and other areas as a result of their high stand up to voltage, large existing bring capability, rapid feedback and basic control. With the growth of modern technology, SCRs have actually progressed into many types, consisting of 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 framework and working principle, however also identify their applicability in various application situations. This write-up will certainly begin with a technical perspective, integrated with details specifications, to deeply evaluate the major distinctions and regular uses of these 4 SCRs.

Unidirectional SCR: Basic and steady application core

Unidirectional SCR is one of the most fundamental and usual sort of thyristor. Its structure is a four-layer three-junction PNPN arrangement, including 3 electrodes: anode (A), cathode (K) and entrance (G). It just permits existing to stream in one direction (from anode to cathode) and activates after eviction is set off. As soon as activated, also if eviction signal is gotten rid of, as long as the anode current is more than the holding present (normally much less than 100mA), the SCR remains on.

(Thyristor Rectifier)

Unidirectional SCR has strong voltage and present resistance, with a forward repetitive top voltage (V DRM) of as much as 6500V and a ranked on-state average current (ITAV) of as much as 5000A. Consequently, it is commonly utilized in DC motor control, commercial heating unit, uninterruptible power supply (UPS) rectification components, power conditioning devices and various other events that call for continual transmission and high power processing. Its benefits are simple structure, inexpensive and high integrity, and it is a core component of lots of standard power control systems.

Bidirectional SCR (TRIAC): Ideal for air conditioning control

Unlike unidirectional SCR, bidirectional SCR, also called TRIAC, can attain bidirectional conduction in both favorable and negative fifty percent cycles. This structure consists of 2 anti-parallel SCRs, which permit TRIAC to be activated and activated at any time in the air conditioner cycle without altering the circuit link method. The symmetrical conduction voltage variety of TRIAC is generally ± 400 ~ 800V, the optimum load current is about 100A, and the trigger current is less than 50mA.

Because of the bidirectional transmission characteristics of TRIAC, it is specifically appropriate for AC dimming and speed control in house devices and consumer electronic devices. For instance, tools such as light dimmers, fan controllers, and a/c follower speed regulatory authorities all rely upon TRIAC to attain smooth power guideline. Furthermore, TRIAC likewise has a lower driving power requirement and appropriates for incorporated design, so it has been widely utilized in clever home systems and tiny devices. Although the power thickness and changing speed of TRIAC are not just as good as those of brand-new power tools, its inexpensive and hassle-free use make it an important gamer in the area of tiny and medium power a/c control.

Gate Turn-Off Thyristor (GTO): A high-performance agent of energetic control

Gate Turn-Off Thyristor (GTO) is a high-performance power gadget created on the basis of conventional SCR. Unlike regular SCR, which can only be turned off passively, GTO can be turned off actively by using an unfavorable pulse present to the gate, thus achieving even more flexible control. This feature makes GTO carry out well in systems that need regular start-stop or quick action.

(Thyristor Rectifier)

The technical criteria of GTO show 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 maximum operating current depends on 6000A. The turn-on time is about 1μs, and the turn-off time is 2 ~ 5μs. These efficiency indicators make GTO widely used in high-power circumstances such as electrical engine traction systems, huge inverters, industrial electric motor regularity conversion control, and high-voltage DC transmission systems. Although the drive circuit of GTO is relatively intricate and has high switching losses, its performance under high power and high dynamic action needs is still irreplaceable.

Light-controlled thyristor (LTT): A dependable option in the high-voltage isolation atmosphere

Light-controlled thyristor (LTT) makes use of optical signals instead of electrical signals to activate transmission, which is its biggest function that distinguishes it from various other sorts of SCRs. The optical trigger wavelength of LTT is normally in between 850nm and 950nm, the action time is determined in nanoseconds, and the insulation degree can be as high as 100kV or over. This optoelectronic isolation device considerably enhances the system’s anti-electromagnetic disturbance capacity and safety and security.

LTT is mainly used in ultra-high voltage straight present transmission (UHVDC), power system relay defense devices, electromagnetic compatibility protection in medical tools, and army radar communication systems etc, which have incredibly high needs for security and security. As an example, numerous converter terminals in China’s “West-to-East Power Transmission” task have actually adopted LTT-based converter shutoff components to make certain steady procedure under exceptionally high voltage conditions. Some progressed LTTs can also be combined with entrance control to achieve bidirectional transmission or turn-off functions, even more expanding their application range and making them an excellent option for addressing high-voltage and high-current control problems.

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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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