Power factor correction method and device, air conditioner and electric appliance

Abstract

The invention belongs to the field of electric appliances and provides a power factor correction (PFC) method and device, an air conditioner and an electric appliance. A current detection module detects the input current of a PFC circuit module, an input voltage detection module detects the input voltage of the PFC circuit module, an output voltage detection module detects the output voltage of the PFC circuit module, a driving module generates a variable-frequency driving signal which has at least two frequencies within a specific frequency range based on the input current detected by the current detection module, the input voltage detected by the input voltage detection module and the output voltage detected by the output voltage detection module according to the first algorithm, and the variable-frequency driving signal is used for controlling on-off of a switch module in the PFC circuit module. The energy of EMI noise caused by on-off of the switch module is dissipated into multiple frequency components, and therefore the margins of EMI noise in different frequency components can meet the national standard even if no EMI filter circuit is added to the PFC circuit module.

Description

Technical field [0001] The invention belongs to the field of electrical appliances, and particularly relates to a method and device for power factor correction, air conditioners and electrical appliances. Background technique [0002] At present, many electrical appliances require DC power supply, and the required DC power is obtained by rectifying the mains (single-phase or three-phase AC power) by a rectifier circuit. Because the rectifier circuit does not control the phase of the output voltage and the current, if the direct current obtained by the rectifier circuit directly supplies power to the nonlinear load module (such as a motor), the power factor of the circuit is low; at the same time, the load module The power electronic devices will also produce a large number of harmonics, causing pollution to the power grid. In order to reduce the current harmonics and reactive power generated by electrical appliances and improve the power quality of the power grid, my country has...

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Problems solved by technology

[0005] The purpose of the present invention is to provide power factor correction method and device, air conditioner and electrical appliances, to solve the EMI noise concentrated in the frequency that is a multiple of the single frequency due to the single-cycle control mode. The cost caused by the need to use an EMI filter circuit additional questions

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