Thyristor power regulators
Power or voltage delivered to a load is controlled using Thyristor Power Controllers (SCR power controllers). Typical applications are found when power needs to be adjusted and converted into thermal energy. Thyristor power controllers are single-phase or three-phase alternating voltage devices. They vary the mains voltage for the load's activation time and are controlled by a controller.
The Thyristor Controller can reliably and consistently control the process according to the control signal. They offer a seamless method of adjusting the amount of power given to the load. Thyristors don't have any electromechanical movement, unlike contractors, which could result in arcing, sparking, and the creation of carbon. They increase the load's operational life by gradually supplying electricity to the load and preventing electrical surges and transients.
Thyristor Operation Modes
There are three operating modes for thyristors. They include
• Forward Blocking
• Reverse Blocking
• Forward Conducting
The thyristor is mainly used
• In variable-speed motor drives
• To control electrical applications requiring high power
• Mainly used in AC motors, lights, welding equipment, etc.
• In circuit breakers and fault current limiters
• To control the speed of electric fans
• In ignition switches for cars
• Easy to control and requires less time to operate
• Can control AC power and can handle large voltage/ current
• Thyristor switches have a high operating frequency
• When compared to mechanical switches, it requires less space
• Can be used for heavy-duty operations
• Thyristor maintenance costs are quite low
• Extremely simple to use for complex controls
• Thyristors only conduct current in one direction and can be coupled in parallel or series to give electronic control at high power levels
• They can be used as oscillators in digital circuits
Options available in Phase Angle and Zero Cross control
Thyristor Switches for Capacitors
Thyristor Switches provide transient-free switching by eliminating inrush currents linked to electromechanical contactor switching. They also work without noise. The capacitors can withstand an infinite number of switching operations. Because of the seamless connection and disconnection, capacitor life increases the normal life.
Static switches with specific capacitors for power factor banks are used
1 Phase / 3 Phase SSRs
When an external voltage (AC or DC) is applied across the control terminals of a solid-state relay (SSR), the device turns on or off electronically. They perform the same task as an electromechanical relay but are more durable because solid-state electronics don't have any moving parts.
SSRs are made up of three parts:
They can be designed to switch either AC or DC loads. To switch currents up to about 100 amperes, packaged SSRs require power semiconductor components such as thyristors and transistors.