Power Factor Correction Circuit Design Of Anti-electromagnetic Interference

Nowadays, with the rapid development of high technology, the technology of electromagnetic interference is continuously deep into all spheres of life which, while high-low electronic devices and electromagnetic compatibility requirements are also increasingly valued by the people and deepen. Electromagnetic compatibility (EMC) of the definition:"a certain degree of technical means used to make the same electromagnetic environment in a variety of electronic and electrical equipment is working properly, and does not interfere with the normal operation of other equipment, which is electromagnetic compatibility." In other words, a variety of electronic equipment in some of the electromagnetic environment can interfere with each other to work, then they are compatible. In the electromagnetic compatibility of electronic equipment design, one must ensure that anti-electromagnetic interference, the second generation of electromagnetic interference to ensure the limits are not exceeded.In electronic product design process, the various current conversion circuit, including the exchange of DC, DC-AC, AC variable AC, DC-DC, have already been in many professional fields of application of universal, while in engineering and industrial production The circuit design of electronic components for use of these energy conversion technologies are already very mature, followed by new problems will be more, such as in power factor correction circuit which, we must first consider the circuit to achieve higher power factor, while the circuit of electronic switching devices to achieve the purpose of electromagnetic compatibility. Power factor related to power quality, lower power factor circuit of the harmonic components generated by the greater use of energy will inevitably mean that the efficiency of the circuit will be lower, even when serious harmonic pollution of the entire circuit. To achieve the purpose of high-energy and low energy consumption, we must design a wide range of power factor correction circuit to solve this problem, the success of a design not only for power factor correction circuit power factor close to 1, but also can greatly reduce the circuit each harmonic current caused by the energy loss.At present, research on and application of electromagnetic interference have several years of history, and in some electronic circuit design, a variety of electronic devices of electromagnetic compatibility problems between the preliminary design phase in the system to be more and more people pay attention to it. For example, switching power supply circuit that is an important indicator is the high power factor hard to reach this target, in the power circuit design is necessary to choose a variety of electronic switch components, to the power of transformation. So the actual work, the power circuit of the electronic devices are based on high frequency switching times for each state. So, the higher the frequency of electronic devices to convert the working condition, will inevitably lead to power factor correction circuit of electronic interference between components, which is defined by industry and academic electromagnetic noise phenomenon. Under normal circumstances, the circuit of EMI noise transfer there are several ways, such as the coupling of electronic devices work, the connection between electronic devices and electromagnetic signals to the space radiation, etc., no matter which way through, the noise ultimately will affect other devices in the circuit, when it will seriously affect the circuit system interference and noise signal disturbance sensitive switch devices, this time the error will cause the power switch motor response and other issues, so some of the world developed countries and some special power equipment manufacturing industry of electronic products, electromagnetic compatibility have made a clear specification. Under normal circumstances, in order to achieve the purpose of electromagnetic compatibility, engineers in the design of power circuits, noise suppression is frequently used approach is to block noise transmission path of the effective and rational design of circuit components and line layout.In this paper, power factor and filter criteria to meet under the premise of the power factor correction circuit works, interference causes and types of noise, and try to power factor correction circuit was designed to study anti-electromagnetic interference, all need to use Power factor correction circuit to circuit, provides a differential mode filter circuit based on the anti-electromagnetic interference design ideas.