CN-114389446-B - Electromagnetic interference suppression circuit, method and electric equipment

Abstract

The invention discloses an electromagnetic interference suppression circuit, an electromagnetic interference suppression method and electric equipment. The electromagnetic interference suppression circuit comprises an interference cancellation module, a processing chip and a processing chip, wherein the interference cancellation module is grounded and used for outputting cancellation signals so as to cancel electromagnetic interference signals generated when a switching tube driving circuit of electric equipment outputs switching control signals, the processing chip is connected with the interference cancellation module and used for controlling output time of the cancellation signals according to the time point when the switching tube driving circuit outputs the switching control signals, and the direction of the cancellation signals is controlled according to the direction of the electromagnetic interference signals. According to the invention, active interference suppression can be realized according to the direction of the electromagnetic interference signal and the generated time point, and a good interference suppression effect can be generated on electromagnetic interference signals with different frequencies.

Inventors

• YANG FAN
• HE XIAOLIN
• LI XIUXIAN

Assignees

• 珠海格力电器股份有限公司

Dates

Publication Date

20260505

Application Date

20211222

Claims (9)

1. 1. An electromagnetic interference suppression circuit for use with a powered device having a switching tube drive circuit, the circuit comprising: The interference cancellation module is grounded and used for outputting cancellation signals so as to cancel electromagnetic interference signals generated when the switching tube driving circuit of the electric equipment outputs switching control signals; The processing chip is connected with the interference cancellation module and is used for controlling the output time of the cancellation signal according to the time point when the switching tube driving circuit outputs the switching control signal and controlling the direction of the cancellation signal according to the direction of the electromagnetic interference signal; The processing chip is also used for controlling the size of the counteraction signal according to the size of the electromagnetic interference signal, wherein the size of the counteraction signal is equal to the size of the electromagnetic interference signal; the processing chip is also specifically used for: Acquiring a preset time difference between the counteraction signal and the electromagnetic interference signal; Controlling the output time of the offset signal according to the preset time difference; the processing chip is also specifically used for: The direction of an electromagnetic interference signal generated when the switching tube driving circuit outputs a switching control signal is obtained; And controlling the interference cancellation module to output a cancellation signal with the opposite direction to the electromagnetic interference signal.
2. 2. The circuit of claim 1, wherein the circuit further comprises: And the first end of the sampling module is connected with the reference ground end of the switching tube driving circuit, the second end of the sampling module is grounded, and the third end of the sampling module is connected with the processing chip and is used for detecting the direction of an electromagnetic interference signal generated when the switching tube driving circuit outputs a switching control signal.
3. 3. The circuit of claim 2, wherein the sampling module is further configured to detect a magnitude of an electromagnetic interference signal generated when the switching tube driving circuit outputs a switching control signal.
4. 4. The circuit of claim 2, wherein the sampling module comprises: The first end of the first resistor is connected with the reference ground end of the switching tube driving circuit, and the second end of the first resistor is connected with the first end of the first capacitor; the second end of the first capacitor is grounded.
5. 5. The circuit of claim 4, wherein the circuit further comprises: And the low-pass filtering module is arranged between the third end of the sampling module and the processing chip.
6. 6. The circuit of claim 1, wherein the circuit further comprises: and the first end of the second capacitor is connected with the interference cancellation module, and the second end of the second capacitor is grounded.
7. 7. A powered device comprising an electromagnetic interference suppression circuit as recited in any one of claims 1-6.
8. 8. An electromagnetic interference suppression method applied to the electromagnetic interference suppression circuit as claimed in any one of claims 1 to 6, characterized in that the method comprises: Acquiring a time point of outputting a switch control signal by a switch tube driving circuit of electric equipment and a direction of an electromagnetic interference signal generated when the switch tube driving circuit outputs the switch control signal; Controlling the output time of the offset signal of the electromagnetic interference suppression circuit according to the time point of the switch control signal output by the switch tube driving circuit, and controlling the direction of the offset signal of the electromagnetic interference suppression circuit according to the direction of the electromagnetic interference signal; The method further comprises the steps of: controlling the size of the offset signal according to the size of an electromagnetic interference signal generated when the switching tube driving circuit outputs a switching control signal, wherein the size of the offset signal is equal to the size of the electromagnetic interference signal; controlling the output timing of the cancellation signal of the electromagnetic interference suppression circuit according to the time point of the switch control signal output by the switch tube driving circuit, comprising: Acquiring a preset time difference between the counteraction signal and the electromagnetic interference signal; controlling the output time of the offset signal according to the preset time difference; Controlling the direction of the cancellation signal of the electromagnetic interference suppression circuit according to the direction of the electromagnetic interference signal comprises controlling an interference cancellation module to output a cancellation signal opposite to the direction of the electromagnetic interference signal.
9. 9. A computer readable storage medium, on which a computer program is stored, characterized in that the program, when being executed by a processor, implements the method according to claim 8.

Description

Electromagnetic interference suppression circuit, method and electric equipment Technical Field The invention relates to the technical field of electronic power, in particular to an electromagnetic interference suppression circuit, an electromagnetic interference suppression method and electric equipment. Background Electromagnetic interference comprises three aspects of harmonic wave, conductive interference and radiation interference, and two schemes of passive and active power correction circuits (PFC) are usually adopted for the suppression of the harmonic wave, and a passive filtering mode is adopted for the conductive interference and the radiation interference at present, but the suppression is difficult because the conductive interference and the radiation interference are generally higher in frequency and are greatly influenced by a power grid, electric equipment, an interference source, parasitic parameters and a working environment. The passive filtering mode is a passive filtering mode, when the passive filtering circuit is adopted as an electromagnetic interference suppression circuit to suppress conducted interference and radiated interference, components commonly adopted in the passive filtering circuit are choking coils and capacitors, so that the defects of large material volume, high price and the like exist, and once the filtering parameters of the components are set, the filtering frequency characteristics of the components are determined, only interference signals with specific frequencies can be filtered out, the frequency range is limited, and when the interference signals generated by electric equipment exceed the frequency range, the interference suppression effect is poor. Aiming at the problem of limited frequency range applied by the passive electromagnetic interference suppression scheme in the prior art, no effective solution is proposed at present. Disclosure of Invention The embodiment of the invention provides an electromagnetic interference suppression circuit, an electromagnetic interference suppression method and electric equipment, which are used for solving the problem that a passive electromagnetic interference suppression scheme in the prior art cannot obtain a good interference suppression effect on electromagnetic interference signals outside a frequency range. In order to solve the technical problem, the present invention provides an electromagnetic interference suppression circuit applied to electric equipment with a switching tube driving circuit, which is characterized in that the circuit comprises: The interference cancellation module is grounded and used for outputting cancellation signals so as to cancel electromagnetic interference signals generated when the switching tube driving circuit of the electric equipment outputs switching control signals; And the processing chip is connected with the interference cancellation module and is used for controlling the output time of the cancellation signal according to the time point when the switching tube driving circuit outputs the switching control signal and controlling the direction of the cancellation signal according to the direction of the electromagnetic interference signal. Further, the circuit further comprises: And the first end of the sampling module is connected with the reference ground end of the switching tube driving circuit, the second end of the sampling module is grounded, and the third end of the sampling module is connected with the processing chip and is used for detecting the direction of an electromagnetic interference signal generated when the switching tube driving circuit outputs a switching control signal. Further, the sampling module is also used for detecting the magnitude of an electromagnetic interference signal generated when the switching tube driving circuit outputs a switching control signal; The processing chip is also used for controlling the size of the counteraction signal according to the size of the electromagnetic interference signal generated when the switching tube driving circuit outputs the switching control signal, wherein the size of the counteraction signal is equal to the size of the electromagnetic interference signal. Further, the sampling module includes: The first end of the first resistor is connected with the reference ground end of the switching tube driving circuit, and the second end of the first resistor is connected with the first end of the first capacitor; the second end of the first capacitor is grounded. Further, the circuit further comprises: And the low-pass filtering module is arranged between the third end of the sampling module and the processing chip. Further, the circuit further comprises: and the first end of the second capacitor is connected with the interference cancellation module, and the second end of the second capacitor is grounded. Further, the processing chip is specifically configured to: Acquiring a preset time difference between th