New Type AC Power Supply with Voltage Stabilization and Harmonic Suppression
At present, harmonic suppression in the power grid has become a very important task for the power supply department. In recent years, with the development of power electronics technology, active power filtering has become a promising filtering method for solving voltage distortion in power grids. A new type of power supply, called Serial Power Quality Controller (SPQC), has been developed using series active power filtering method to stabilize voltage and suppress harmonics, similar to voltage dynamic restorer in foreign countries. This product not only stabilizes voltage but also suppresses grid harmonics, and can be called a voltage stabilizing filter. This voltage regulator can also dynamically compensate for three-phase unbalanced voltage flicker, drops, surges, spikes, etc. The mains voltage is unstable and has harmonic pollution. After instantaneous dynamic voltage compensation, the instrument produces a pure three-phase sine balanced voltage on the load.
A three matched load with a capacity of 15kVA voltage regulator filter, when the input voltage is between 170~210V, the total harmonic distortion rate of the voltage is 8.8%. With an inductive motor and switch power supply load, the output voltage is between 219~224, and the total harmonic distortion rate of the voltage decreases to 2.8%, while the output waveform shows significant improvement.
The use of this type of power supply is undoubtedly a good choice for precision instruments used in petroleum exploration, signal light power supply at various stations along electrified railways, and precision instruments in areas with poor power grid quality.
3. Medical dedicated power supply
The medical system CT machine has been widely used in various hospitals. If the power supply is not properly configured, it can cause poor resolution of CT images, which makes it difficult for doctors to diagnose and may also lead to misdiagnosis of the condition. The characteristics of the power supply used by the CT machine itself are as follows: 1. When the lesion is exposed to light, a stable power supply is required to output a large current and a small voltage drop, and no adjustment is made at this moment; 2, CT itself has a rectification circuit that generates harmonics, which affects the correct control of the regulated power supply. With more than ten years of experience in providing power supplies for GE-CT, the internal resistance of the regulated power supply is reduced, harmonic filtering devices are added to the output, and locking and surge absorption circuits are added to the control circuit. A series of measures have been taken to design it as a medical dedicated power supply to meet user needs.
4. AC voltage regulating and stabilizing power supply
In recent years, the market demand has gradually increased, and most of them require a relatively large capacity. This type of product that combines voltage regulation and stabilization functions is called a "voltage regulation and stabilization power supply" or an adjustable and stable voltage regulator. The products include induction, power electronics, and transformer types of voltage regulating and stabilizing power supplies, each with its own characteristics and disadvantages, which will not be described here. A closed-loop column voltage regulator is composed of multi-stage voltage regulation and column compensation AC voltage regulator, which regulates voltage while maintaining stable output voltage. This type of voltage regulator has developed rapidly in recent years, with a capacity range of 30kVA to 200kVA. Compared with inductive regulators, it does not have fixed rotor or air gap, has low no-load current and no-load loss, no waveform distortion (waveform distortion<0.5%), fast voltage regulation speed, strong instantaneous overload capacity, and has been widely used.
