Selection and precautions of parametric regulated power supply
The parametric regulated power supply, that is, the ferromagnetic resonance type (or magnetic saturation type) regulated power supply, uses the nonlinearity of magnetic materials and the capacitance resonance method to achieve voltage stabilization. Due to the application of the principle of ferromagnetic resonance, it has some unique performance characteristics, such as:
1. High reliability (no electronic components, simple structure).
2. Strong anti-interference ability (can realize input and output two-way anti-interference).
3. No output overvoltage phenomenon.
4. Wide input voltage range (lower limit of input voltage can exceed 50% at half load).
5. Short response time (about 40ms).
At the same time, it also brings some inherent defects to the regulated power supply:
1. Poor load adaptability: Changes in the nature of the load may result in a reduction in the voltage regulation range. The output accuracy decreases and the temperature rise increases, so special attention must be paid when adapting to strong inductive, strong capacitive and impact loads (such as motors, machine tools, rectifiers, etc.).
2. Poor frequency characteristics: The ferroresonant power supply is very sensitive to the mains frequency. When the mains frequency changes by 1%, the output voltage changes by 2%. When the frequency deviation is too large, it may not be able to stabilize the voltage or even produce low-frequency oscillations. Therefore, It cannot be used in small hydropower and generator occasions in mountainous areas.
3. High temperature and high noise: Since part of the magnetic circuit of the transformer works in a saturated state, the design temperature of the main transformer is higher than that of ordinary transformers; the magnetic flux leakage caused by the saturated state is also relatively large, which makes the noise of the whole machine higher than that of ordinary voltage regulators. The power supply is larger.
Therefore, I would like to remind all partners or direct users to pay attention to the following:
1. Parameters The regulated power supply is very sensitive to the change of the mains frequency due to the principle. When the frequency changes by 1% (0.5HZ), the output voltage changes by 2% (4.4V). Therefore, it should be used with caution in areas with large frequency deviations and when generators supply power.
Second, in the actual use of the parameter regulated power supply, we must also pay attention to the size and nature of the load. Due to the different nature of the load, there are more failures that will have a significant impact on it. Common loads can be roughly divided into capacitive, inductive, resistive, impact, and nonlinear. Their influence on the parametric regulated power supply is as follows:
1. Capacitive: Capacitive load will increase the resonance capacity of the parameter stabilized power supply, increase the stability of the output voltage, and expand the range of voltage regulation, but at the same time it will also increase the output voltage value and the temperature rise of the transformer. Excessive temperature rise will damage the transformer insulation.
2. Inductive: Inductive load will reduce the resonant capacity of the parameter regulated power supply, resulting in a drop in output voltage, deteriorating the stability of the output voltage, and reducing the range of voltage regulation.
3. Resistivity: The performance index of the parametric regulated power supply is measured under a resistive load, which has little influence.
4. Impulse: Most of these loads are motors, whose starting inrush current is 5 to 7 times the normal operating current, which will cause a serious drop in the output voltage, causing the load to not move or oscillate.
5. Non-linearity: It means that the current and voltage of the load are not in a linear relationship. Its instantaneous pulse current is large, the average power is not large, but the instantaneous power is large, which will cause the output voltage of the parameter stabilized power supply to oscillate.
For the above loads, 1, 2, 3, and 4 can use the method of increasing the power of the voltage stabilizer to reduce the impact of the load. For nonlinear loads, it is recommended not to use parameter regulated power supplies and replace them with ZTY automatic AC stabilized power supplies. Piezoelectric power supply, JJW precision purification regulated power supply, UPS uninterruptible power supply and other power supplies. For high power, please choose SBW power compensation type voltage stabilizer and SJW microcomputer compensation type voltage stabilizer series power supply as the best.
