Variable frequency series resonance is the working principle of series resonance using variable frequency technology, which enables the circuit to generate resonant control voltage signals to be applied to the test sample. The analysis of variable frequency series resonance is currently mainly divided into two categories: variable frequency and inductive. Variable frequency series resonance is achieved by adjusting the output frequency of the variable frequency source in the market or adjusting the inductance of the adjustable reactor, so that the inductance L in the circuit and the test sample C can undergo variable frequency series resonance.
Variable frequency series resonance is mainly composed of variable frequency source (variable frequency type), high-voltage reactor, adjustable reactor (induction type), capacitive voltage divider, excitation transformer, etc It is widely used in power, metallurgy (content: extracted from ore metals or metal compounds), oil and chemical industries, capacitors, power cables, power transformers, hydroelectric generators, GIS high-capacity, high-voltage transfer testing and preventive testing!
Variable frequency series resonance has outstanding advantages in product characteristics such as high stability and reliability, powerful automatic tuning function, support for multiple test modes, friendly system human-machine interaction interface (each other), and complete protection function. Based on its characteristics, it has the advantages of small power supply capacity, small equipment weight and volume, improved output waveform, prevention of short-circuit current burns, and no recovery overvoltage in power system applications. Our company conducts frequency conversion technology series resonance according to GB50150-2006 and DL/T849.6-2004 standards, providing various optional reference design schemes such as network cable resonance structure test and detection device, generator motor resonance test research device, substation electrical and electronic equipment and resonance control device, CVT calibration resonant boost device, etc. The series resonant frequency has multiple national key technologies, coupled with the introduction of international advanced technology and equipment, reaching an international advanced level as a whole.
The frequency conversion technology series resonant structure test and detection device is mainly used for AC withstand voltage testing of 10kV, 35kV, 110kV cables, as well as 110kV and below power main transformers, busbar selection switches, and all other electrical main equipment of enterprises. The research and design can be manufactured. The reactor adopts multiple independent designs, which can meet the requirements of high voltage and low current equipment testing conditions, as well as the requirements of low voltage AC voltage testing such as 10kV cables. Variable frequency series resonance has a wide range of applications. Variable frequency series resonance is an ideal voltage resistant equipment for high voltage testing departments and power installation and maintenance engineering units at the local, municipal, and county levels.
Frequency conversion series resonance is mainly composed of a frequency conversion control power supply, an excitation transformer, a reactor, and a capacitive voltage divider.
Advantages of frequency conversion series resonance in power systems:
1. The required power capacity is greatly reduced. Frequency conversion series resonant power supply utilizes various resonant reactors and test capacitor resonance problems to generate high voltage and high current. In the entire management system, power technology only needs to provide the active consumption part of the information system. Therefore, the power output power required for experimental development is generally only 1/Q of the continuous test data capacity.
2. The weight and volume of the equipment are greatly reduced. In the variable frequency series resonant power supply, not only is the bulky high-power (referring to the amount of work done by an object in a unit of time) voltage regulating device and ordinary high-power power frequency test transformer (air pressure variable) eliminated, but the resonant excitation power supply only requires 1/Q of the test capacity, greatly reducing the weight and volume of the system, usually 1/10-1/30 of ordinary test devices.
3. Improvement of output voltage waveform. Resonant power supply is a resonant filtering processing circuit that can improve the distortion of the waveform of a voltage output by enterprises, obtain a good sine signal waveform, and effectively prevent the false breakdown of the test sample by harmonic peaks.
4. Prevent large short-circuit currents (Electron flow) from burning the fault point. When the insulation weak point of the test sample is broken down in the frequency conversion series resonance state, the circuit immediately loses resonance, and the circuit current rapidly decreases (drops) to 1/Q of the normal test current. Alternatively, when conducting a voltage withstand test using a parallel resonant converter, the breakdown current immediately increases several times, regardless of the comparison of the short-circuit current breakdown current difference between and times. So, the frequency conversion technology in series with a resonance can effectively find an insulation weakness, and there is no possibility of a large short-circuit calculation current burning the fault point.
5. No overvoltage recovery will occur. When the test sample breaks down, due to the loss of resonance conditions, the high voltage immediately disappears, the arc immediately extinguishes, and the process of re establishing and developing the working voltage takes a long time. It is easy to disconnect the power supply before learning to reach the flashover voltage again. This system voltage recovery production process is an intermittent oscillation process with continuous energy accumulation, which is long and will not result in any economic recovery overvoltage.