Working Principle of NRRQV soft starter: A Comprehensive Analysis of Cassless voltage regulation Soft Start of Thyristor

High-voltage high-power motor has many problems such as large starting shock, large disturbance of power grid and serious mechanical damage. Traditional methods such as direct starting, self-coupled voltage reduction starting and liquid-resistance starting are either fixed voltage reduction gear and rigid start-stop block, or they are complex and have high failure rate, and cannot meet the high accuracy and stability of modern industry. NRRQV high voltage solid-state soft starter relies on mature thyristor stepless voltage regulation technology to achieve steady linear growth in voltage, current and speed. Is the most scientific, the most stable high voltage motor soft start solution. This paper comprehensively analyzes the core structure, working logic and general working principle of NRQV soft starter.
The core control core NRRQV high-voltage solid-state soft starter is thyristor power module+microcomputer intelligent control system. Unlike the traditional graded voltage reduction starting jumper, it adopts AC phase control principle to achieve real continuous pressure control. The high voltage main circuit of this equipment adopts high-quality high-voltage thyristor series modules with high voltage resistance and stability, suitable for high voltage levels motor of 2.3kV to 13.8kV. Equipped with a high-precision digital control chip, we can collect grid voltage, motor current, operating load and so on in real time. We can adjust the conduction angle of thyristor accurately in milliseconds.
The core logic of CVM soft start is to control the output voltage by changing the conduction angle of the thyristor. In the initial phase of motor starting, the control system delays the conduction time of thyristor, the a small conduction angle and the output voltage is very low. The motor slowly builds low voltage and low current torque. As the startup process progresses, the main control chip continuously and steadily magnifies the thyristor conduction angle, and the output voltage is continuously linear from zero. The current of motor increases steadily and the speed increases evenly. There was no sudden change or shift in gear, completely eliminating instantaneous surge currents. It can steadily limit the starting current to 2-3 times the rated current, avoiding power grid voltage drop and equipment shaking.
The startup process is divided into four stages: voltage stabilization preparation, stepless boost, full speed switching and standby protection. The first phase is power supply preparation phase, in which the equipment detects the state of the power grid, the state of the lines and the temperature of the modules. The second stage is the core soft start stage, in which the system continuously raises voltage, current, steady pressure and steady flow according to a predetermined start curve. The motor accelerates smoothly, effectively relieving the mechanical impact of heavy equipment such as blower, water pumps and crusher. The third stage is the frequency switching. When the motor speed reaches the rated standard and the current falls back to the normal range, the device automatically shuts down the bypass, the thyristor module exits operation and the motor enters normal frequency operation. Finally, the device monitors the running data in real time and enters the continuous protection state.
Compared with liquid resistance, magnetic control and self-coupling start, NRRQV thyristor have irreplaceable technical advantages in stepless voltage regulation. Traditional starter devices use segmented voltage reduction, which results in a sudden increase in voltage and still a secondary shock. Liquid resistance equipment rely on the physical properties of electrolytes to regulate pressure, which are highly influenced by temperature, unstable curves, high losses and require constant maintenance. The NRRQV all-electronic intelligent control, no mechanical action, no liquid consumables and can set the starting curve freely to suit different working conditions such as light load, heavy load and full load. The starting consistency is extremely high, multiple starting and stopping times have no parameter deviation, and meet the needs of continuous and standardized production.
At the same time, the stepless voltage regulation technology combined with the intelligent monitoring system to realize the integration of start and protection. In the process of soft start of equipment, the fault of thyristor such as phase loss, overflow, overheating and anomaly is monitored in real time. If something goes awry, lock the output and trigger an alarm to stop the machine working, protecting the motor and power grid equipment. A smooth soft start process can not only protect the motor winding, bearing and transmission structure and prolong the service life of equipment, but also stabilize the quality of the power grid in the factory area and avoid interference of high-power equipment starting and other precision electrical equipment. NRRQV high-voltage solid-state soft starter has become the mainstream equipment of choice for high voltage motor starting in mining, chemical industry, water conservancy and electric power industry.