The Design Of1.5kW Digital AC Voltage Regulator

Currently there are two AC regulation modes:one is based on the AC transformer, and the disadvantages of this equipment are large bulk, heavy weight, low regulation accuracy or step regulation and poor reliability; another is based on the phase-control regulator made of thyristors, and the disadvantages of this equipment are low power factor, large harmonic, slow dynamic response and large bulk of filter. With the development of power electronics and microelectronics technology, high frequency, high efficiency and low pollution have been the major direction of development, and AC chopper technology is developed rapidly. This technology can continuously regulate AC output voltage and has some characteristics, such as good output waveforms, accurate control, etc. Thus, the AC regulator is researched and designed based on the principle of AC chopper.Based on the mentioned principle above, a1.5kW program-controlled digital regulator is designed. In the system, four switches are used to make up the main chopping circuit, two are applied to chop the positive and negative waveform of input voltage, and the other two are used to follow current. In order to improve output efficiency and depress switch dissipation, the soft switch technology is used to realize zero voltage or zero current switching. The frequency of higher harmonics becomes higher with the increasing switch frequency in the AC chopped system. In this regulator, a1Ouf capacitance is used in the system to filter10kHz chopped frequency, and makes a good output waveform. Complementary control mode and non-complementary control mode are used in AC chopped regulation. Non-complementary mode is used in this regulator to overcome runaway field when the load is inductive, and makes the output waveform not to be affected by the load. Otherwise, the output voltage is digitally controlled in system design, in order to realize remote control and make the system use widely and conveniently.According to the design and analysis above, The AC regulator designed in the paper not only has a characteristic that the output waveform is not affected by the load, but also realize digital control. Therefore, the regulator has some advantages such as the system power factor only depends on the power factor of load, fast dynamic response, wide linear regulation range, input and output are easy to filter, etc.