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SCR power controllers, or silicon-controlled rectifiers, are essential for precise temperature control in a variety of industrial applications, such as heating, melting, drying and shaping.
These versatile devices offer impressive efficiencies of up to 99.8%, outperforming alternatives such as IGBT-based regulators. The main advantages of SCR power regulators include their wear-free switching capabilities, adaptability and compact design.
They excel at managing the flow of electricity to heating systems in industrial furnaces, ovens and heat treatment equipment, resulting in increased reliability, cost-effectiveness and energy efficiency.
By understanding these advantages, functions and performance, companies can take full advantage of SCR power controllers and optimize their industrial processes.
In the world of manufacturing, temperature control is essential for processes such as material heating, melting, drying and processing. Silicon-controlled rectifiers (SCRs), commonly referred to as SCR power controllers, play a crucial role in maintaining precise temperatures by managing the electrical flow from the mains to the heating elements of industrial furnaces, ovens and other heat treatment equipment.
Compared to other solutions such as IGBT-based controllers, SCR power controllers demonstrate superior efficiency, reaching up to 99.8%. What's more, the wear-free switching capabilities of thyristors make SCR power controllers an ideal replacement for contactors or relays, significantly improving reliability and product life.
Closed-loop system in which the SCR power controller skilfully manages the flow of energy between the network and a furnace, oven or heater. This system illustrates the adaptability and precision of SCR power controllers in industrial heating applications.
A temperature sensor or transmitter placed in the furnace provides direct feedback to a Fuji Electric Micrex programmable controller or to an external temperature controller . As a result, the Fuji Electric Micrex programmable controller or Fuji Electric PXF temperature controller sends an analog or digital setpoint to the SCR power controller. This setpoint is determined by the chamber temperature, setting and PID parameters.
The SCR power controller then uses this setpoint to regulate the flow of electricity to the heater, ensuring a precise and stable temperature inside the furnace. A high-quality SCR power controller can modulate current, voltage or power output according to process requirements and conditions, demonstrating its versatile functionality in a variety of industrial heating applications, in compliance withIEC 60947-4-3.
SCR power controllers are an integral part of a wide range of industrial manufacturing processes using electric heating. Industries that commonly use these controllers include:
SCR power controllers contribute to superior quality and cost-effectiveness thanks to their precision, adaptability, compact design and energy efficiency.
The accuracy of temperature control is often compromised by fluctuations in mains voltage and heating element resistance. Mains voltage can vary by up to ±10% or more, leading to temperature inconsistencies. SCR power controllers tackle this problem by using RMS voltage regulation to compensate for mains voltage fluctuations. In voltage regulation mode, the SCR's firing angle (phase angle) or duty cycle (zero crossing) is adjusted to maintain a stable output voltage relative to the setpoint.
Variations in heating element resistance are due to ageing, temperature coefficients and other material properties. SCR power controllers deal with these variations by regulating the rms output current. When both RMS current and RMS voltage regulation are applied, the power regulation mode is reached. Power regulation enables the SCR power controller to regulate actual power independently of variations in mains voltage or heating element resistance, ensuring the highest temperature control accuracy and process repeatability.
SCR power controllers with a wide range of operating modes and communication options guarantee optimum performance and seamless integration into any process.
For systems equipped with Fuji Electric controllers communicating digital setpoints to the SCR power controller, typical fieldbus protocols are as follows:
Connected SCR power controllers facilitate system rationalization by reducing the number of components and improving data collection. Fewer cables and communication boards cut costs and minimize potential points of failure, while shorter cable lengths increase efficiency and reduce energy consumption.
In the confined spaces of industrial manufacturing systems, SCR power controllers need to be compact without sacrificing functionality. State-of-the-art SCR power controllers offer a small footprint that meets these requirements.
Advanced SCR power controllers allow users to easily monitor and configure their SCR power controller through compatible Android and Apple apps. This user-friendly app offers a range of features to improve the efficiency and convenience of managing your power control unit.
Rising energy costs in the public and industrial sectors have increased demand for high-efficiency generation technologies to minimize capital and operating expenses, particularly in energy-intensive applications. With an impressive efficiency of 99.8%, SCR power regulators offer a clear advantage over alternative devices such as IGBT-based power supplies and converters.
In addition, contemporary SCR power controllers offer several control modes, enabling users to choose the control method best suited to their application. Ignition modes can be selected according to technical requirements such as minimizing THD or maximizing power resolution. Advanced control techniques such as grid load optimization can reduce peak load demand for multiple SCR units, resulting in lower energy tariffs.
SCR power controllers offer different ignition methods to optimize performance in industrial applications. These methods regulate power demand and minimize electrical interference, while ensuring efficient operation.
Phase angle mode (VAR) is a popular choice for heating applications because of its precise power resolution.
Phase-angle (PA) ignition is a method that enables precise control of the power supplied to the load by allowing the thyristor to conduct only for part of the AC power cycle. The power required determines the conduction angle, which progressively increases until almost the entire cycle is completed at 100% power.
Load power can be set from 0 to 100% according to the analog input signal, usually determined by a temperature controller or potentiometer. PA mode is commonly used with inductive loads, as it improves efficiency and adaptability in a variety of industrial applications.
However, this mode can generate excessive harmonics and a low power factor, which can interfere with the operation of other equipment.
Digital SCR power controllers with advanced functions offer several alternative ignition modes to overcome these limitations:
This full-wave switching mode generates minimal harmonics and is widely used in a variety of heating applications.
For multi-zone applications where overall power is high, light synchronization is necessary to avoid overvoltage and improve power factor during zero-crossing operation.
This is a very fast ignition used with short infrared elements to avoid the flicker and harmonics generated by phase-angle ignition.
SC is the fastest zero-crossing switching method. With an analog input, the unit adjusts the number of ON and OFF cycles according to the input signal. The microprocessor calculates and stores the ratio to provide precise control of power to the load.
Delayed tripping (DT) is a specially designed method of switching the primary coil of transformers when connected to standard resistive loads (no cold resistors) on the secondary side. DT effectively prevents the inrush current that can occur when zero voltage (ON-OFF) is used to switch the primary.
The thyristor switches off when the load voltage is negative and only switches on when it is positive, with a predefined delay for the initial half-cycle. This approach helps to improve performance, efficiency and reliability in various industrial applications involving transformers.
LF is a digital firing method performed inside the thyristor unit at zero volts, which means no EMC interference. With an analog input, the number of complete cycles required for 50% of the power demand must be specified. This value is between 1 and 255 complete cycles, which determines the firing speed. When set to 1, the ignition mode becomes a single cycle (SC).
S+BF is an additional function that combines soft start and wave train. In phase angle mode, the unit switches from zero to full voltage at a preset time before switching to full conduction. This method is ideal for switching small inductive loads, as it avoids overvoltage and minimizes electrical interference.
To counter the effects of supply voltage fluctuations, the voltage supplied to the load is measured and compared with the power requested by the controller. The error signal is used to automatically maintain the requested power level. Three control modes are available:
As an option, it is possible to switch from voltage control mode to power control mode by means of a simple digital control.
For heating resistors such as the MoSi2 element (Kanthal Super Elements TM), whose cold resistance is very low and increases sharply with temperature, it is essential to limit the current to the load by reducing the voltage using phase-angle ignition and current limiting to avoid oversizing the SCR power regulator in terms of current.
When the resistance value reaches a predetermined threshold, two operating methods can be selected:
By exploring these advanced ignition modes, users can optimize their heating processes while minimizing the disadvantages associated with the traditional phase-angle mode. The right choice of ignition mode will not only improve energy efficiency and process control, but also reduce interference with other equipment, ensuring smooth, efficient industrial operations.
SCR power controllers offer considerable cost savings thanks to their energy efficiency and numerous connectivity options.
SCR power controllers deliver substantial cost savings by offering a comprehensive range of communication and fieldbus options. One notable example is communication, which minimizes the need for numerous cables and communication cards, resulting in considerable cost savings:
By taking advantage of the energy efficiency and versatile connectivity options of SCR power controllers, companies can optimize their industrial heating processes while minimizing costs. This approach not only improves immediate performance, but also ensures future scalability and adaptability in an ever-changing technological landscape.
Eliminate redundant analog equipment
Reduce space and save time
Enhanced digital control
Scalable performance and functionality
Integrating communication bus modules into your industrial plant can considerably streamline operations and reduce costs. By minimizing the need for multiple bus cards, these modules offer the following advantages:
By integrating communication bus modules into your industrial processes, you can improve efficiency, reduce costs and guarantee seamless scalability.
SCR power regulator technology offers significant cost advantages thanks to its inherent energy efficiency. With an impressive efficiency of 99.8%, SCR power dimmers conserve energy by minimizing power losses (thermal load) compared to switch-mode power supplies. This efficiency offers several advantages:
In conclusion, digital SCR power controllers offer a multitude of possibilities for intelligently managing electrical energy in industrial furnaces, ovens and other thermal processes. Compared to their analog counterparts, digital SCRs offer superior power regulation, diagnostics, adaptability and bus connectivity. These capabilities have led to substantial improvements in thermal processes, including better quality, increased throughput and reduced energy expenditure. The compact design and user-friendly nature of digital SCRs are further advantages.
By making informed decisions about this critical component of your thermal process, you can gain a competitive edge to cope with rising energy costs, meet demands for increased throughput and ensure better quality. Embrace the future of industrial heating processes by harnessing the power of digital SCR power controllers with cutting-edge technology that promotes efficiency, sustainability and growth.
Discover the benefits of SCR power controllers, designed to optimize energy efficiency, reduce costs and improve industrial operations. These advanced devices offer precise power control, improved power factor and reliable protection for your sensitive equipment.
Don't let obsolete technology hold you back! With Fuji Electric's SCR power controllers, you can meet the challenges of energy management and stimulate your company's growth. Experience unrivalled control, robust performance and long-term savings, tailored to your specific needs.
