Frequency modulation series resonance? Wuhan UHV specializes in the production of series resonance, with a wide range of product selection and professional electrical testing. To find series resonance, choose Wuhan UHV.
Under power frequency conditions, due to the large capacitance of the test object or high requirements for the test voltage, there are also high requirements for the power supply capacity of the test device. At present, a better method is to use frequency modulation series resonance equipment for voltage withstand testing. This frequency series resonance is designed for AC withstand voltage testing of high voltage and high current capacitive specimens such as power cables. Multiple protective measures have been adopted to make the experiment convenient and reliable; The inherent filtering effect of resonance ensures that the waveform output by the system fully meets the requirements of the test protocol.
Principle of Frequency Modulation Series Resonance
Using the principle of series resonance, the excitation transformer is used to excite the series resonance circuit, and the output frequency of the variable frequency controller is adjusted to make the circuit inductance L and the test sample C resonate in series. The resonance voltage is the voltage applied to the test sample.
Frequency modulation series resonance consists of an isolation transformer, a frequency modulation and voltage regulation power supply, an excitation transformer, a reactor, and a capacitive voltage divider. The capacitor and reactor of the test sample form a series resonant connection; The voltage divider is connected in parallel to the test sample to measure the resonant voltage on the test sample and provide an overvoltage protection signal; The frequency modulation power output is coupled to the series resonant circuit through an excitation transformer, providing excitation power for frequency conversion resonance.
Technical principle of frequency modulation resonance device
We know that when the circuit frequency f=1/2 π√ LC, resonance occurs in the circuit, and the voltage on the test sample is Q times the output voltage of the excitation transformer high voltage end. Q is the system quality factor, which is the voltage resonance multiple, generally ranging from tens to hundreds or more. First, adjust the output frequency of the variable frequency power supply to induce series resonance in the circuit, and then adjust the output voltage of the variable frequency power supply under the condition of circuit resonance to achieve the test value of the sample voltage. Due to the resonance of the circuit, a smaller output voltage of the variable frequency power supply can generate a higher test voltage on the test sample CX.
Characteristics of FM series resonant device
1. The device has protection functions such as overvoltage, overcurrent, zero start, and system detuning (flashing). The overvoltage and overcurrent protection values can be set according to user needs to trigger the flashing protection action when the test sample flashes, and the flashing voltage value can be recorded for experimental analysis
2. The entire device is lightweight and easy to use on site
3. The device has four working modes, which are convenient for users to flexibly choose according to the on-site situation and improve the test speed. The working modes are: fully automatic mode, manual mode, automatic tuning, and manual boost mode
4. Capable of storing and printing data in different locations, with numerical data numbers for easy identification and retrieval by users
5. When the device automatically scans the frequency, the starting point of the frequency can be set arbitrarily within the specified range, and the scanning direction can be selected upwards or downwards. At the same time, the LCD screen displays the scanning curve, making it convenient for users to intuitively understand whether they have found the resonance point
6. Adopting DSP platform technology, it is convenient to add or remove functions and upgrade according to user needs, making the human-machine exchange interface more user-friendly