Introduction: Secret tools in power electronic devices
Silicon-controlled rectifiers (SCRs), also called thyristors, are semiconductor power gadgets with a four-layer triple junction framework (PNPN). Because its intro in the 1950s, SCRs have been widely used in industrial automation, power systems, home appliance control and other fields as a result of their high endure voltage, big present carrying capability, fast response and easy control. With the advancement of modern technology, SCRs have developed into many types, consisting of unidirectional SCRs, bidirectional SCRs (TRIACs), turn-off thyristors (GTOs) and light-controlled thyristors (LTTs). The distinctions in between these types are not only reflected in the structure and functioning concept, yet likewise establish their applicability in various application situations. This article will start from a technological point of view, incorporated with certain criteria, to deeply evaluate the main differences and regular uses of these 4 SCRs.
Unidirectional SCR: Basic and stable application core
Unidirectional SCR is the most basic and common kind of thyristor. Its structure is a four-layer three-junction PNPN plan, consisting of three electrodes: anode (A), cathode (K) and entrance (G). It just allows present to stream in one direction (from anode to cathode) and turns on after the gate is caused. Once switched on, also if eviction signal is gotten rid of, as long as the anode current is higher than the holding existing (typically less than 100mA), the SCR stays on.
(Thyristor Rectifier)
Unidirectional SCR has strong voltage and current resistance, with a forward repetitive optimal voltage (V DRM) of up to 6500V and a rated on-state ordinary present (ITAV) of approximately 5000A. Consequently, it is commonly used in DC electric motor control, industrial heating systems, uninterruptible power supply (UPS) correction components, power conditioning gadgets and various other occasions that call for constant transmission and high power processing. Its advantages are simple framework, inexpensive and high dependability, and it is a core part of several traditional power control systems.
Bidirectional SCR (TRIAC): Ideal for AC control
Unlike unidirectional SCR, bidirectional SCR, likewise called TRIAC, can attain bidirectional conduction in both favorable and unfavorable half cycles. This structure consists of 2 anti-parallel SCRs, which enable TRIAC to be set off and turned on at any moment in the AC cycle without transforming the circuit link method. The balanced conduction voltage variety of TRIAC is normally ± 400 ~ 800V, the optimum tons current is about 100A, and the trigger current is much less than 50mA.
As a result of the bidirectional conduction attributes of TRIAC, it is specifically appropriate for air conditioning dimming and rate control in home appliances and customer electronics. As an example, tools such as lamp dimmers, follower controllers, and ac unit fan rate regulators all rely on TRIAC to accomplish smooth power guideline. In addition, TRIAC additionally has a reduced driving power need and is suitable for incorporated style, so it has been widely made use of in clever home systems and tiny home appliances. Although the power thickness and changing rate of TRIAC are not just as good as those of brand-new power devices, its inexpensive and hassle-free usage make it a vital player in the field of little and average power air conditioning control.
Gate Turn-Off Thyristor (GTO): A high-performance rep of active control
Gate Turn-Off Thyristor (GTO) is a high-performance power gadget created on the basis of traditional SCR. Unlike average SCR, which can just be turned off passively, GTO can be turned off proactively by applying an adverse pulse present to eviction, therefore attaining more flexible control. This attribute makes GTO do well in systems that require regular start-stop or fast response.
(Thyristor Rectifier)
The technological criteria of GTO show that it has incredibly high power dealing with 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 extensively used in high-power situations such as electric engine traction systems, huge inverters, industrial 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 performance under high power and high dynamic response needs is still irreplaceable.
Light-controlled thyristor (LTT): A trusted selection in the high-voltage seclusion atmosphere
Light-controlled thyristor (LTT) utilizes optical signals as opposed to electrical signals to set off conduction, which is its largest attribute that differentiates it from other kinds of SCRs. The optical trigger wavelength of LTT is usually between 850nm and 950nm, the reaction time is gauged in split seconds, and the insulation degree can be as high as 100kV or over. This optoelectronic isolation device substantially improves the system’s anti-electromagnetic disturbance ability and security.
LTT is mainly used in ultra-high voltage direct present transmission (UHVDC), power system relay defense tools, electromagnetic compatibility protection in clinical devices, and armed forces radar communication systems and so on, which have incredibly high demands for safety and security and security. For instance, many converter stations in China’s “West-to-East Power Transmission” job have actually taken on LTT-based converter shutoff modules to make certain stable operation under very high voltage conditions. Some progressed LTTs can additionally be incorporated with gateway control to attain bidirectional conduction or turn-off features, further broadening their application variety and making them an excellent 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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