Introduction: Trick gadgets in power electronics
Silicon-controlled rectifiers (SCRs), additionally referred to as thyristors, are semiconductor power gadgets with a four-layer three-way junction structure (PNPN). Considering that its introduction in the 1950s, SCRs have actually been widely used in commercial automation, power systems, home device control and other fields as a result of their high endure voltage, big existing lugging capacity, rapid action and basic control. With the advancement of modern technology, SCRs have actually advanced right into many types, consisting of unidirectional SCRs, bidirectional SCRs (TRIACs), turn-off thyristors (GTOs) and light-controlled thyristors (LTTs). The differences in between these kinds are not just mirrored in the structure and functioning concept, however likewise determine their applicability in various application circumstances. This post will certainly begin with a technological perspective, integrated with certain specifications, to deeply examine the primary differences and common uses these four SCRs.
Unidirectional SCR: Fundamental and secure application core
Unidirectional SCR is one of the most standard and usual type of thyristor. Its framework is a four-layer three-junction PNPN setup, including three electrodes: anode (A), cathode (K) and gateway (G). It only enables existing to flow in one instructions (from anode to cathode) and switches on after the gate is set off. As soon as switched on, even if the gate signal is gotten rid of, as long as the anode current is above the holding existing (typically less than 100mA), the SCR stays on.
(Thyristor Rectifier)
Unidirectional SCR has strong voltage and present tolerance, with an ahead recurring peak voltage (V DRM) of approximately 6500V and a ranked on-state average existing (ITAV) of up to 5000A. For that reason, it is extensively made use of in DC electric motor control, commercial heater, uninterruptible power supply (UPS) rectification components, power conditioning tools and other occasions that need continual conduction and high power handling. Its benefits are straightforward framework, affordable and high dependability, and it is a core part of numerous traditional power control systems.
Bidirectional SCR (TRIAC): Ideal for air conditioning control
Unlike unidirectional SCR, bidirectional SCR, also known as TRIAC, can attain bidirectional transmission in both favorable and unfavorable half cycles. This framework includes 2 anti-parallel SCRs, which enable TRIAC to be activated and turned on at any moment in the air conditioning cycle without transforming the circuit link method. The symmetrical conduction voltage series of TRIAC is generally ± 400 ~ 800V, the maximum load current is about 100A, and the trigger current is much less than 50mA.
Due to the bidirectional transmission features of TRIAC, it is especially appropriate for air conditioner dimming and rate control in house devices and consumer electronic devices. For instance, tools such as lamp dimmers, fan controllers, and air conditioner fan speed regulatory authorities all rely upon TRIAC to achieve smooth power law. Furthermore, TRIAC additionally has a reduced driving power demand and is suitable for incorporated design, so it has actually been commonly used in wise home systems and small home appliances. Although the power thickness and switching speed of TRIAC are not like those of new power devices, its affordable and convenient usage make it an essential player in the field of tiny and average power air conditioning control.
Gateway Turn-Off Thyristor (GTO): A high-performance rep of energetic control
Entrance Turn-Off Thyristor (GTO) is a high-performance power gadget established on the basis of traditional SCR. Unlike average SCR, which can just be switched off passively, GTO can be turned off actively by applying an unfavorable pulse current to the gate, thus attaining more adaptable control. This function makes GTO carry out well in systems that require frequent start-stop or fast action.
(Thyristor Rectifier)
The technological parameters of GTO reveal that it has extremely high power handling capability: the turn-off gain is about 4 ~ 5, the maximum operating voltage can reach 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 performance indications make GTO commonly made use of in high-power circumstances such as electrical locomotive grip systems, huge inverters, industrial electric motor frequency conversion control, and high-voltage DC transmission systems. Although the drive circuit of GTO is reasonably complex and has high switching losses, its efficiency under high power and high dynamic response demands is still irreplaceable.
Light-controlled thyristor (LTT): A reliable option in the high-voltage isolation atmosphere
Light-controlled thyristor (LTT) makes use of optical signals instead of electric signals to set off transmission, which is its greatest feature that distinguishes it from various other types of SCRs. The optical trigger wavelength of LTT is normally between 850nm and 950nm, the action time is measured in nanoseconds, and the insulation degree can be as high as 100kV or above. This optoelectronic seclusion system greatly boosts the system’s anti-electromagnetic interference capacity and safety and security.
LTT is primarily made use of in ultra-high voltage straight current transmission (UHVDC), power system relay security gadgets, electro-magnetic compatibility defense in clinical tools, and army radar communication systems and so on, which have extremely high demands for safety and security. For example, many converter stations in China’s “West-to-East Power Transmission” project have embraced LTT-based converter valve modules to ensure secure procedure under incredibly high voltage conditions. Some advanced LTTs can additionally be incorporated with gate control to achieve bidirectional conduction or turn-off functions, better expanding their application variety and making them a perfect selection for resolving high-voltage and high-current control problems.
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)
All articles and pictures are from the Internet. If there are any copyright issues, please contact us in time to delete.
Inquiry us