High-Voltage Motor Variable Frequency Starting Technology
Nancal Aviation Military Industry Test Bench Technology Solution Series (I)
Recently, Nancal won the approval of certain aeronautics and military engineering institute on its experimental system larger-power high-voltage motor variable frequency starting system project in the high-level "One-To-Three + One-To-Four" high-voltage variable frequency starting system technology scheme, which fully reflected the comprehensive technology advances and rich project engineering experience of scheme design and system integration in the field of high-voltage motor variable frequency starting.
The high-voltage motor adopts the variable frequency starting mode and may be not affected by the power grid capacity conditions, the large motor may be started in the power grid system of any quality and condition, the high-voltage motor of various starting working conditions and various starting load types may be started in rated current and rated torque of high-voltage motor; by use of the up-cut and down-cut technology synchronous to the power grid started in high-performance variable frequency, the stable and controllable soft starting and soft stop of high-voltage motor and technology equipment may be realized, which may effectively reduce the electric and machinery impact on power grid, motor and technology equipment caused by the motor starting process, get rid of voltage fluctuation and prolong the use life of motor.
Figure 1: Typical “One-To-Two” Variable Frequency Starting Schematic Drawing
Nancal possesses the rich engineering technology and project implementation experience in the aspect of high-voltage variable frequency soft starting application, and has provided dozens of sets of high-voltage variable frequency starting system for petroleum and petrochemical engineering, metallurgy, power, aerospace, etc. As the variable frequency soft starting equipment, high-voltage variable frequency needs special considerations in the aspect of calculation, configuration and model selection, which could guarantee the safe and reliable operation of variable frequency starting. Based own rich engineering experience in soft starting field, deep understanding on various load starting working conditions and engineering calculation capacity of complete high-voltage variable frequency starting application, Nancal ensures the scientific allocation, safe control and reliable operation of high-voltage variable frequency soft starting system.
Figure 2: Nancal Variable Frequency Soft Starting Calculation and Model Selection Software
Based Nancal high-voltage variable-frequency VSV patent technology, after the high-voltage variable frequency starting equipment completes the starting task of high-voltage motor, the high-performance reactive compensation VSG function with the same capacity as the high-voltage variable frequency equipment may be provided, which may greatly improve the usage rate of high-voltage variable-frequency starting equipment and effective rate of investment.
VSV technology is a technology of Nancal able to realize variable frequency control and power quality governance by time sharing based on the high-voltage VFD platform development, possessing two working modes of variable frequency operation and reactive compensation, able to both realize the variable frequency control on the motor and realize the reactive compensation on the power grid according to the onsite operation demand, which possessing the following features:
■ The same hardware platform, with different control modes inside, has the high availability of system
■ Strong reactive compensation capacity; output reactive possible within the full power scope
■ Multi-level PWM, high output waveform quality, without harmonic influence on the power grid at compensation
■ Have no need to independently add SVG and reduce the equipment investment cost and maintenance cost
Figure 3: “Two-To-Seven” Redundant Variable Frequency Starting + VSV Reactive
Nancal will continue to increase the research & development and promotion of high-voltage variable frequency starting system technology scheme and continue to provide the high-level high-voltage variable frequency starting system solution and system integration service for research institutes of air military engineering and other industries.