CN116915042A - Control method of EMI filter based on terminal load - Google Patents

Control method of EMI filter based on terminal load Download PDF

Info

Publication number
CN116915042A
CN116915042A CN202211512138.0A CN202211512138A CN116915042A CN 116915042 A CN116915042 A CN 116915042A CN 202211512138 A CN202211512138 A CN 202211512138A CN 116915042 A CN116915042 A CN 116915042A
Authority
CN
China
Prior art keywords
emi filter
terminal load
emi
load
circuit
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202211512138.0A
Other languages
Chinese (zh)
Inventor
周盼
仲隽伟
李小峰
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Shanghai Yingtong Electric Co ltd
Original Assignee
Shanghai Yingtong Electric Co ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Shanghai Yingtong Electric Co ltd filed Critical Shanghai Yingtong Electric Co ltd
Priority to CN202211512138.0A priority Critical patent/CN116915042A/en
Publication of CN116915042A publication Critical patent/CN116915042A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/44—Circuits or arrangements for compensating for electromagnetic interference in converters or inverters
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/12—Arrangements for reducing harmonics from ac input or output

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Power Conversion In General (AREA)

Abstract

The invention provides a control method of an EMI filter based on a terminal load, which adjusts the running state of a radiator of the terminal load according to the working temperature change data of the terminal load so that the terminal load can be in a heating-radiating balance state; then collecting working state parameters of a terminal load, determining whether an EMI filter circuit in the terminal load has a fault EMI filter, and when the EMI filter has the fault EMI filter, performing circuit switching on the EMI filter circuit so as to replace the fault EMI filter circuit; and then, the EMI filter circuit after circuit switching is subjected to higher-order harmonic current filtering treatment, so that the EMI filter of the terminal load can be automatically replaced, and meanwhile, the electromagnetic interference operation of the terminal load is always maintained in the replacement process, the time and labor cost for replacing the EMI filter are effectively reduced, and the working performance of the terminal load is improved from three aspects of heat dissipation performance, electromagnetic interference filtering performance and higher-order harmonic current filtering performance.

Description

Control method of EMI filter based on terminal load
Technical Field
The invention relates to the technical field of load power supply management, in particular to a control method of an EMI filter based on a terminal load.
Background
An EMI filter is a passive device for filtering electromagnetic interference components in a circuit. The EMI filter generally performs filtering processing on electromagnetic interference components in the ac power supply between the ac power supply and an external load, and when the EMI filter works for a long time, a situation of working relaxation is unavoidable, which makes the EMI filter unable to perform electromagnetic interference filtering processing normally and continuously, thereby affecting normal and stable operation of the external load. The prior art can only replace the EMI filter with reduced working performance or failure by manual replacement, which not only increases the time and labor cost of replacing the EMI filter, but also cannot reduce the degree of electromagnetic interference suffered by external loads during the replacement process.
Disclosure of Invention
Aiming at the defects existing in the prior art, the invention provides a control method of an EMI filter based on a terminal load, which adjusts the running state of a radiator of the terminal load according to the working temperature change data of the terminal load, so that the terminal load can be in a heating-radiating balance state; then collecting working state parameters of a terminal load, determining whether an EMI filter circuit in the terminal load has a fault EMI filter, and when the EMI filter has the fault EMI filter, performing circuit switching on the EMI filter circuit so as to replace the fault EMI filter circuit; and then, the EMI filter circuit after circuit switching is subjected to higher-order harmonic current filtering treatment, so that the EMI filter of the terminal load can be automatically replaced, and meanwhile, the electromagnetic interference operation of the terminal load is always maintained in the replacement process, the time and labor cost for replacing the EMI filter are effectively reduced, and the working performance of the terminal load is improved from three aspects of heat dissipation performance, electromagnetic interference filtering performance and higher-order harmonic current filtering performance.
The invention provides a control method of an EMI filter based on a terminal load, which comprises the following steps:
step S1, when a terminal load is connected with an alternating current power supply, collecting working temperature change data of the terminal load from starting work; according to the working temperature change data, determining the working heat accumulation state of the terminal load, and thus adjusting the operation state of a radiator of the terminal load;
step S2, when the terminal load is in a heating-radiating balance state, collecting working state parameters of the terminal load in the EMI filtering process of an EMI filter circuit which is arranged in series between the terminal load and an alternating current power supply, and determining whether a fault EMI filter exists in the EMI filter circuit;
step S3, when the existence of the fault EMI filter is determined, performing circuit switching on the EMI filter circuit to replace the fault EMI filter circuit; and then carrying out higher-order harmonic current filtering treatment on the EMI filter circuit after circuit switching.
Further, in the step S1, when the terminal load is connected to the ac power supply, the collecting the operating temperature change data of the terminal load from the start operation specifically includes:
when the terminal load is connected with the alternating current power supply, the working temperature of the terminal load is periodically acquired by taking a preset time interval as a reference in a time period from the starting of the terminal load to the time when the running power of the terminal load reaches the preset rated power, so that corresponding working temperature change data are obtained.
Further, in the step S1, determining the working heat accumulation state of the terminal load according to the working temperature change data, so as to adjust the operation state of the radiator of the terminal device specifically includes:
according to the working temperature change data, determining a first working temperature average increasing rate and a second working temperature average increasing rate which are respectively corresponding to a first half sub-time period and a second half sub-time period of the terminal load in the time period;
if the average increase rate of the second working temperature is larger than the average increase rate of the first working temperature and the average increase rate of the second working temperature is larger than a preset temperature rise rate threshold, determining that the terminal load is in an excessive working heat accumulation state currently; otherwise, determining that the terminal load is in a heating-radiating balance state currently;
when the terminal load is in an excessive working heat accumulation state, increasing the rotating speed of a cooling fan of the terminal load or reducing the temperature of cold air conveyed by a radiator of the terminal load;
when the terminal load is in a heat generating-heat dissipating balance state, the current running state of the radiator of the terminal load is kept unchanged.
Further, in the step S2, when the terminal load is in a heat generating-heat dissipating balance state, collecting the working state parameters of the terminal load in the EMI filtering process of the EMI filtering circuit connected in series between the terminal load and the ac power supply specifically includes:
when the terminal load is in a heating-radiating balance state, collecting respective working voltage state parameters of all sub-loads contained in the terminal load in the EMI filtering process of the EMI filtering circuit; the EMI filter circuit comprises a first EMI filter, a second EMI filter and a third EMI filter, wherein the first EMI filter is connected with the second EMI filter in series, the first EMI filter is connected with the third EMI filter in parallel, the first EMI filter and the third EMI filter are respectively connected with a terminal load through a first switch and a second switch which have interlocking relation, the first switch is kept in a closed state, and the second switch is kept in an open state.
Further, in the step S2, determining whether there is a faulty EMI filter in the EMI filter circuit includes:
obtaining a filtering weight value of the first EMI filter according to respective operating voltage state parameters of all sub-loads included in the terminal load by using the following formula (1),
in the above formula (1), W (t) represents a filtering weight value of the first EMI filter at time t; u (a) represents the operating voltage value of an a-th sub-load contained in the terminal load at the moment t; l (a) represents an operating voltage type determination value of an a-th sub-load included in the terminal load at time t, where if the operating voltage of the a-th sub-load is a dc operating voltage, L (a) =1, and if the operating voltage of the a-th sub-load is an ac operating voltage, L (a) =0; n (t) represents the total number of sub-loads in electrical communication with the AC power source at time t
Judging whether the filtering performance of the first EMI filter is reduced or not; and if the filtering performance of the first EMI filter is determined to be reduced, determining that the first EMI filter is a fault EMI filter.
Further, in the step S2, determining whether the filtering performance of the first EMI filter is degraded specifically includes:
using the following equation (2), it is determined whether the filtering performance of the first EMI filter is degraded,
in the above formula (2), Z represents a determination value of whether or not the filtering performance of the first EMI filter is degraded; t (T) 0 (i) Indicating the starting time corresponding to the ith EMI filter performing the EMI filtering operation; t (i) represents the corresponding ending time of the ith EMI filtering operation of the second EMI filter; t is t c Representing the current time; t is t 0 Indicating the moment when the first switch is closed; m represents the total number of times of performing the EMI filtering operation of the second EMI filter up to the current time position; w [ T (i)]Representing the result value obtained by substituting T (i) into the formula (1); w [ T ] 0 (i)]Representing T 0 (i) Substituting the result value into the result value obtained by the formula (1);
if Z is more than or equal to 0, the filtering performance of the first EMI filter is not reduced;
if Z <0, it indicates that the filtering performance of the first EMI filter is reduced, and the first EMI filter is determined to be a fault EMI filter.
Further, in the step S3, when it is determined that the faulty EMI filter exists, performing circuit switching on the EMI filter circuit to replace the faulty EMI filter circuit specifically includes:
when it is determined that the first EMI filter is a faulty EMI filter, the second switch is controlled to perform on/off state switching using the following equation (3),
in the above formula (3), E represents a control value for switching the on/off state of the second switch; g (EMI 1) represents a start-up status flag value corresponding to the first EMI filter at a time when the ac power source is in electrical communication with the terminating load, G (EMI 1) =1 when the first EMI filter starts up normally at a time when the ac power source is in electrical communication with the terminating load, G (EMI 1) =0 when the first EMI filter starts up abnormally at a time when the ac power source is in electrical communication with the terminating load; v represents a logical relationship or operation; Λ represents logical relationship and operation;
if e=1, the second switch is instructed to switch to a closed state, at this time, the first EMI filter is disconnected from the circuit between the ac power supply and the terminal load, and the third EMI filter is connected to the circuit between the ac power supply and the terminal load in series with the second filter, so as to complete the circuit switching;
if e=0, the second switch is instructed to maintain the current off state.
Further, in the step S3, the performing the higher-order harmonic current filtering process on the EMI filter circuit after the circuit switching specifically includes:
and separating the fundamental wave current component from the higher harmonic current component of the current output by the EMI filter circuit after circuit switching to the terminal load, and then filtering the higher harmonic current component obtained by separation.
Compared with the prior art, the control method of the EMI filter based on the terminal load adjusts the running state of the radiator of the terminal load according to the working temperature change data of the terminal load, so that the terminal load can be in a heating-radiating balance state; then collecting working state parameters of a terminal load, determining whether an EMI filter circuit in the terminal load has a fault EMI filter, and when the EMI filter has the fault EMI filter, performing circuit switching on the EMI filter circuit so as to replace the fault EMI filter circuit; and then, the EMI filter circuit after circuit switching is subjected to higher-order harmonic current filtering treatment, so that the EMI filter of the terminal load can be automatically replaced, and meanwhile, the electromagnetic interference operation of the terminal load is always maintained in the replacement process, the time and labor cost for replacing the EMI filter are effectively reduced, and the working performance of the terminal load is improved from three aspects of heat dissipation performance, electromagnetic interference filtering performance and higher-order harmonic current filtering performance.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims thereof as well as the appended drawings.
The technical scheme of the invention is further described in detail through the drawings and the embodiments.
Drawings
In order to more clearly illustrate the embodiments of the invention or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, it being obvious that the drawings in the following description are only some embodiments of the invention, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
Fig. 1 is a flow chart of a control method of an EMI filter based on a terminal load according to the present invention.
Fig. 2 is a schematic circuit connection diagram of a termination load and an EMI filter in the control method of the EMI filter based on the termination load provided by the invention.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
Referring to fig. 1 to fig. 2, a flow diagram of a control method of an EMI filter based on a terminal load and a circuit connection diagram of the terminal load and the EMI filter according to an embodiment of the invention are shown respectively. The control method of the EMI filter based on the terminal load comprises the following steps:
step S1, when a terminal load is connected with an alternating current power supply, collecting working temperature change data of the terminal load from starting work; according to the working temperature change data, determining the working heat accumulation state of the terminal load, so as to adjust the operation state of a radiator of the terminal load;
step S2, when the terminal load is in a heating-radiating balance state, collecting working state parameters of the terminal load in the EMI filtering process of an EMI filter circuit which is arranged in series between the terminal load and an alternating current power supply, and determining whether a fault EMI filter exists in the EMI filter circuit;
step S3, when the existence of the fault EMI filter is determined, performing circuit switching on the EMI filter circuit to replace the fault EMI filter circuit; and then carrying out higher-order harmonic current filtering treatment on the EMI filter circuit after circuit switching.
The beneficial effects of the technical scheme are as follows: according to the control method of the EMI filter based on the terminal load, the operation state of a radiator of the terminal load is adjusted according to the working temperature change data of the terminal load, so that the terminal load can be in a heating-radiating balance state; then collecting working state parameters of a terminal load, determining whether an EMI filter circuit in the terminal load has a fault EMI filter, and when the EMI filter has the fault EMI filter, performing circuit switching on the EMI filter circuit so as to replace the fault EMI filter circuit; and then, the EMI filter circuit after circuit switching is subjected to higher-order harmonic current filtering treatment, so that the EMI filter of the terminal load can be automatically replaced, and meanwhile, the electromagnetic interference operation of the terminal load is always maintained in the replacement process, the time and labor cost for replacing the EMI filter are effectively reduced, and the working performance of the terminal load is improved from three aspects of heat dissipation performance, electromagnetic interference filtering performance and higher-order harmonic current filtering performance.
Preferably, in this step S1, when the terminal load is turned on the ac power supply, the acquisition of the operating temperature change data of the terminal load from the start-up operation specifically includes:
when the terminal load is connected with the alternating current power supply, the working temperature of the terminal load is periodically acquired by taking a preset time interval as a reference in a time period from the starting of the terminal load to the time when the running power of the terminal load reaches the preset rated power, so that corresponding working temperature change data are obtained.
The beneficial effects of the technical scheme are as follows: when the terminal load is connected with the alternating current power supply, the terminal load immediately enters an operating state, and the working heat accumulation and dissipation state of the terminal load can be quantized and accurately calculated by collecting the working temperature of the terminal load and forming working temperature change data.
Preferably, in the step S1, determining the operating heat accumulation state of the terminal load according to the operating temperature change data, so as to adjust the radiator operation state of the terminal device specifically includes:
according to the working temperature change data, determining a first working temperature average increasing rate and a second working temperature average increasing rate which are respectively corresponding to a first half sub-time period and a second half sub-time period of the terminal load in the time period;
if the average increase rate of the second working temperature is larger than the average increase rate of the first working temperature and the average increase rate of the second working temperature is larger than a preset temperature rise rate threshold, determining that the terminal load is in an excessive working heat accumulation state currently; otherwise, determining that the terminal load is in a heating-radiating balance state currently;
when the terminal load is in an excessive working heat accumulation state, increasing the rotating speed of a cooling fan of the terminal load or reducing the temperature of cold air conveyed by a radiator of the terminal load;
when the terminal load is in a heat generating-heat dissipating balance state, the current running state of the radiator of the terminal load is kept unchanged.
The beneficial effects of the technical scheme are as follows: the operating states of the terminal load in the first half sub-period and the second half sub-period of the period are different, and generally, the operating power in the first half sub-period is smaller than the operating power in the second half sub-period, that is, the operating heat generated in the first half sub-period is smaller than the operating heat generated in the second half sub-period. By comparing the magnitude relation among the average increase rate of the first working temperature, the average increase rate of the second working temperature and the preset temperature rise rate threshold, whether working heat generated by the terminal load in the latter half of the sub-time period is timely dissipated or not can be determined, if not, the terminal load is in an excessive working heat accumulation state currently, and if so, the terminal load is in a heating-heat dissipation balance state currently. The heat dissipation fan of the terminal load is then instructed to increase the rotational speed or the radiator to reduce the temperature of the cold air delivered, so that the heat accumulated excessively can be rapidly dissipated.
Preferably, in the step S2, when the terminal load is in a heat generating-heat dissipating balance state, collecting the operating state parameters of the terminal load during EMI filtering by the EMI filtering circuit disposed in series between the terminal load and the ac power supply specifically includes:
when the terminal load is in a heating-radiating balance state, collecting respective working voltage state parameters of all sub-loads contained in the terminal load in the EMI filtering process of the EMI filtering circuit; the EMI filter circuit comprises a first EMI filter, a second EMI filter and a third EMI filter, wherein the first EMI filter is connected with the second EMI filter in series, the first EMI filter is connected with the third EMI filter in parallel, the first EMI filter and the third EMI filter are respectively connected with a terminal load through a first switch and a second switch which have interlocking relation, the first switch is kept in a closed state, and the second switch is kept in an open state.
The beneficial effects of the technical scheme are as follows: the first EMI filter and the second EMI filter are connected in series and then can carry out filtering treatment on electromagnetic interference in a circuit, the first EMI filter and the third EMI filter are connected in parallel, so that the third EMI filter can be switched in by switching in the EMI filter when the first EMI filter fails through the first switch and the second switch which have interlocking relation, automatic replacement of the failed EMI filter is realized, and the second EMI filter can always carry out electromagnetic interference filtering on a terminal load in the automatic replacement process, thereby ensuring the persistence of electromagnetic interference filtering.
Preferably, in this step S2, determining whether there is a faulty EMI filter in the EMI filter circuit includes:
obtaining a filtering weight value of the first EMI filter according to respective operating voltage state parameters of all sub-loads included in the terminal load by using the following formula (1),
in the above formula (1), W (t) represents a filtering weight value of the first EMI filter at time t; u (a) represents the operating voltage value of an a-th sub-load contained in the terminal load at the moment t; l (a) represents an operating voltage type determination value of an a-th sub-load included in the terminal load at time t, where if the operating voltage of the a-th sub-load is a dc operating voltage, L (a) =1, and if the operating voltage of the a-th sub-load is an ac operating voltage, L (a) =0; n (t) represents the total number of sub-loads in electrical communication with the AC power source at time t
Judging whether the filtering performance of the first EMI filter is reduced or not; and if the filtering performance of the first EMI filter is determined to be reduced, determining that the first EMI filter is a fault EMI filter.
The beneficial effects of the technical scheme are as follows: and (2) obtaining the filtering weight of the first EMI filter according to the voltage value provided by the alternating current power supply to the terminal load and the type of the power supply voltage by utilizing the formula (1), so as to know the influence degree of the working condition of the current terminal load on the first EMI filter, and judging whether the first EMI filter works normally or not by the side face.
Preferably, in the step S2, determining whether the filtering performance of the first EMI filter is degraded specifically includes:
using the following equation (2), it is determined whether the filtering performance of the first EMI filter is degraded,
in the above formula (2), Z represents a determination value of whether or not the filtering performance of the first EMI filter is degraded; t (T) 0 (i) Indicating the starting time corresponding to the ith EMI filter performing the EMI filtering operation; t (i) represents the corresponding end time of the ith EMI filtering operation of the second EMI filter；t c Representing the current time; t is t 0 Indicating the moment when the first switch is closed; m represents the total number of times of performing the EMI filtering operation of the second EMI filter up to the current time position; w [ T (i)]Representing the result value obtained by substituting T (i) into the formula (1); w [ T ] 0 (i)]Representing T 0 (i) Substituting the result value into the result value obtained by the formula (1);
if Z is more than or equal to 0, the filtering performance of the first EMI filter is not reduced;
if Z <0, it indicates that the filtering performance of the first EMI filter is reduced, and the first EMI filter is determined to be a fault EMI filter.
The beneficial effects of the technical scheme are as follows: by using the formula (2), whether the filtering capability of the first EMI filter is reduced is judged according to the starting condition of the second EMI filter and the filtering weight of the first EMI filter, and further whether the filtering capability of the first EMI filter is reduced is judged according to the comprehensive consideration of the direct factor and the indirect factor, so that the filtering capability of the first EMI filter can be more finely judged, and the first EMI filter can be filtered and replaced for a long time as long as possible in a normal filtering state, so that the material cost of the filter is saved.
Preferably, in the step S3, when it is determined that the faulty EMI filter exists, the EMI filter circuit is switched to replace the faulty EMI filter circuit specifically includes:
when it is determined that the first EMI filter is a faulty EMI filter, the second switch is controlled to perform on/off state switching using the following equation (3),
in the above formula (3), E represents a control value for switching the on/off state of the second switch; g (EMI 1) represents a start-up status flag value corresponding to the first EMI filter at a time when the ac power source is in electrical communication with the terminating load, G (EMI 1) =1 when the first EMI filter starts up normally at a time when the ac power source is in electrical communication with the terminating load, G (EMI 1) =0 when the first EMI filter starts up abnormally at a time when the ac power source is in electrical communication with the terminating load; v represents a logical relationship or operation; Λ represents logical relationship and operation;
if e=1, the second switch is instructed to switch to a closed state, at this time, the first EMI filter is disconnected from the circuit between the ac power supply and the terminal load, and the third EMI filter is connected to the circuit between the ac power supply and the terminal load in series with the second filter, so as to complete the circuit switching;
if e=0, the second switch is instructed to maintain the current off state.
The beneficial effects of the technical scheme are as follows: the opening and closing states of the second interlocking switch are controlled by utilizing the formula (3) according to the starting condition of the first EMI filter at the moment of starting the alternating current power supply and the judging result of the formula (2), and then the first EMI filter is replaced under the condition of continuous power failure by controlling the opening and closing states of the second interlocking switch, so that the efficiency is improved, and the normal operation of a terminal load can be ensured.
Preferably, in the step S3, the performing a higher-order harmonic current filtering process on the EMI filter circuit after the circuit switching specifically includes:
and separating the fundamental wave current component from the higher harmonic current component of the current output by the EMI filter circuit after circuit switching to the terminal load, and then filtering the higher harmonic current component obtained by separation.
The beneficial effects of the technical scheme are as follows: and separating fundamental wave current components from higher harmonic current components of the current output by the EMI filter circuit after circuit switching is completed to the terminal load, and then filtering the separated higher harmonic current components, so that the harmonic impact degree of the higher harmonic current components on the terminal load can be reduced, and the normal and stable operation of the terminal load is ensured.
As can be seen from the foregoing embodiments, the control method of the EMI filter based on the terminal load adjusts the operation state of the radiator of the terminal load according to the operating temperature change data of the terminal load, so that the terminal load can be in a heat generating-heat dissipating balanced state; then collecting working state parameters of a terminal load, determining whether an EMI filter circuit in the terminal load has a fault EMI filter, and when the EMI filter has the fault EMI filter, performing circuit switching on the EMI filter circuit so as to replace the fault EMI filter circuit; and then, the EMI filter circuit after circuit switching is subjected to higher-order harmonic current filtering treatment, so that the EMI filter of the terminal load can be automatically replaced, and meanwhile, the electromagnetic interference operation of the terminal load is always maintained in the replacement process, the time and labor cost for replacing the EMI filter are effectively reduced, and the working performance of the terminal load is improved from three aspects of heat dissipation performance, electromagnetic interference filtering performance and higher-order harmonic current filtering performance.
It will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention also include such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.

Claims (8)

1. A method for controlling an EMI filter based on a termination load, comprising the steps of:
step S1, when a terminal load is connected with an alternating current power supply, collecting working temperature change data of the terminal load from starting work; according to the working temperature change data, determining the working heat accumulation state of the terminal load, and thus adjusting the operation state of a radiator of the terminal load;
step S2, when the terminal load is in a heating-radiating balance state, collecting working state parameters of the terminal load in the EMI filtering process of an EMI filter circuit which is arranged in series between the terminal load and an alternating current power supply, and determining whether a fault EMI filter exists in the EMI filter circuit;
step S3, when the existence of the fault EMI filter is determined, performing circuit switching on the EMI filter circuit to replace the fault EMI filter circuit; and then carrying out higher-order harmonic current filtering treatment on the EMI filter circuit after circuit switching.
2. The method for controlling an EMI filter based on a termination load as set forth in claim 1, wherein:
in the step S1, when the terminal load is connected to the ac power supply, the collecting the working temperature change data of the terminal load from the start operation specifically includes:
when the terminal load is connected with the alternating current power supply, the working temperature of the terminal load is periodically acquired by taking a preset time interval as a reference in a time period from the starting of the terminal load to the time when the running power of the terminal load reaches the preset rated power, so that corresponding working temperature change data are obtained.
3. The method for controlling an EMI filter based on a termination load as set forth in claim 2, wherein:
in the step S1, determining the working heat accumulation state of the terminal load according to the working temperature change data, so as to adjust the operation state of the radiator of the terminal device specifically includes:
according to the working temperature change data, determining a first working temperature average increasing rate and a second working temperature average increasing rate which are respectively corresponding to a first half sub-time period and a second half sub-time period of the terminal load in the time period;
if the average increase rate of the second working temperature is larger than the average increase rate of the first working temperature and the average increase rate of the second working temperature is larger than a preset temperature rise rate threshold, determining that the terminal load is in an excessive working heat accumulation state currently; otherwise, determining that the terminal load is in a heating-radiating balance state currently;
when the terminal load is in an excessive working heat accumulation state, increasing the rotating speed of a cooling fan of the terminal load or reducing the temperature of cold air conveyed by a radiator of the terminal load;
when the terminal load is in a heat generating-heat dissipating balance state, the current running state of the radiator of the terminal load is kept unchanged.
4. A method of controlling an EMI filter based on a termination load as set forth in claim 3, wherein:
in the step S2, when the terminal load is in a heat generating-heat dissipating balance state, collecting the working state parameters of the terminal load in the EMI filtering process of the EMI filtering circuit connected in series between the terminal load and the ac power supply specifically includes:
when the terminal load is in a heating-radiating balance state, collecting respective working voltage state parameters of all sub-loads contained in the terminal load in the EMI filtering process of the EMI filtering circuit; wherein the method comprises the steps of
The EMI filter circuit includes a first EMI filter, a second EMI filter, and a third EMI filter, the first EMI filter is connected in series with the second EMI filter, the first EMI filter is connected in parallel with the third EMI filter, the first EMI filter and the third EMI filter are connected to the terminal load through a first switch and a second switch having an interlocking relationship, respectively, and the first switch is kept in a closed state, and the second switch is kept in an open state.
5. The method for controlling an EMI filter based on a termination of claim 4, wherein:
in said step S2, determining whether a faulty EMI filter is present in the EMI filter circuit comprises:
obtaining a filtering weight value of the first EMI filter according to respective operating voltage state parameters of all sub-loads included in the terminal load by using the following formula (1),
in the above formula (1), W (t) represents a filtering weight value of the first EMI filter at time t; u (a) represents the operating voltage value of an a-th sub-load contained in the terminal load at the moment t; l (a) represents an operating voltage type determination value of an a-th sub-load included in the terminal load at time t, where if the operating voltage of the a-th sub-load is a dc operating voltage, L (a) =1, and if the operating voltage of the a-th sub-load is an ac operating voltage, L (a) =0; n (t) represents the total number of sub-loads in electrical communication with the AC power source at time t
Judging whether the filtering performance of the first EMI filter is reduced or not; and if the filtering performance of the first EMI filter is determined to be reduced, determining that the first EMI filter is a fault EMI filter.
6. The method for controlling an EMI filter based on a termination of claim 5, wherein:
in the step S2, determining whether the filtering performance of the first EMI filter is degraded specifically includes: using the following equation (2), it is determined whether the filtering performance of the first EMI filter is degraded,
in the above formula (2), Z represents a determination value of whether or not the filtering performance of the first EMI filter is degraded; t (T) 0 (i) Indicating the starting time corresponding to the ith EMI filter performing the EMI filtering operation; t (i) represents the corresponding ending time of the ith EMI filtering operation of the second EMI filter; t is t c Representing the current time; t is t 0 Indicating the moment when the first switch is closed; m represents the total number of times of performing the EMI filtering operation of the second EMI filter up to the current time position; w [ T (i)]Representing the result value obtained by substituting T (i) into the formula (1); w [ T ] 0 (i)]Representing T 0 (i) Substituting the result value into the result value obtained by the formula (1);
if Z is more than or equal to 0, the filtering performance of the first EMI filter is not reduced;
if Z <0, it indicates that the filtering performance of the first EMI filter is reduced, and the first EMI filter is determined to be a fault EMI filter.
7. The method for controlling a dead-end based EMI filter of claim 6, wherein:
in the step S3, when it is determined that the faulty EMI filter exists, performing circuit switching on the EMI filter circuit to replace the faulty EMI filter circuit specifically includes:
when it is determined that the first EMI filter is a faulty EMI filter, the second switch is controlled to perform on/off state switching using the following equation (3),
in the above formula (3), E represents a control value for switching the on/off state of the second switch; g (EMI 1) represents a start-up status flag value corresponding to the first EMI filter at a time when the ac power source is in electrical communication with the terminating load, G (EMI 1) =1 when the first EMI filter starts up normally at a time when the ac power source is in electrical communication with the terminating load, G (EMI 1) =0 when the first EMI filter starts up abnormally at a time when the ac power source is in electrical communication with the terminating load; v represents a logical relationship or operation; Λ represents logical relationship and operation;
if e=1, the second switch is instructed to switch to a closed state, at this time, the first EMI filter is disconnected from the circuit between the ac power supply and the terminal load, and the third EMI filter is connected to the circuit between the ac power supply and the terminal load in series with the second filter, so as to complete the circuit switching;
if e=0, the second switch is instructed to maintain the current off state.
8. The method for controlling a dead-end based EMI filter of claim 7, wherein:
in the step S3, the filtering process of the higher-order harmonic current of the EMI filter circuit after the circuit switching specifically includes:
and separating the fundamental wave current component from the higher harmonic current component of the current output by the EMI filter circuit after circuit switching to the terminal load, and then filtering the higher harmonic current component obtained by separation.
CN202211512138.0A 2022-11-29 2022-11-29 Control method of EMI filter based on terminal load Pending CN116915042A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202211512138.0A CN116915042A (en) 2022-11-29 2022-11-29 Control method of EMI filter based on terminal load

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202211512138.0A CN116915042A (en) 2022-11-29 2022-11-29 Control method of EMI filter based on terminal load

Publications (1)

Publication Number Publication Date
CN116915042A true CN116915042A (en) 2023-10-20

Family

ID=88365447

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202211512138.0A Pending CN116915042A (en) 2022-11-29 2022-11-29 Control method of EMI filter based on terminal load

Country Status (1)

Country Link
CN (1) CN116915042A (en)

Similar Documents

Publication Publication Date Title
CN108808161B (en) Management control method and device of battery thermal management system of electric bus
CN109067353B (en) Active bypass control device and method for photovoltaic module
CN108292574B (en) Switching device and method for controlling at least one switching device
CN113432241A (en) Air conditioner indoor and outdoor unit communication fault processing method, control system and air conditioner
CN104967301B (en) Voltage swells protective device, the method for pfc circuit in frequency-conversion domestic electric appliances equipment
CN116915042A (en) Control method of EMI filter based on terminal load
CN110445421B (en) Starting circuit of motor, control method of starting circuit and engineering machinery
CN116317154A (en) Intelligent monitoring equipment for 5G communication power supply
CN114198889B (en) Air-cooled chiller system, control method thereof, controller and storage medium
CN113595234B (en) Power configuration adjustment method, adjustment device and system of uninterruptible power supply
CN109458695A (en) A kind of demagnetization guard method of power-off compressor and device
CN113323906B (en) Adjusting and controlling method for cooling fan of switch cabinet
CN110350846A (en) A kind of motor speed control method and device
CN1566824A (en) Central management method for multi-room air-conditioner
US20220128286A1 (en) Air conditioner and preheating operation method
CN105071724A (en) Electronic voltage regulator, AC generator and engine idle speed control method
JP2004286239A (en) Method of controlling cooling device
CN110768254B (en) Power supply circuit, control method and device of power supply circuit and air conditioner
CN111525494B (en) Drive control circuit, control method, device, compressor, air conditioner and medium
CN116742760B (en) New energy battery electronic load complementary energy discharging device and control method
CN107623465A (en) A kind of braking method, brake unit and robot
CN211061618U (en) Auxiliary device for judging working state output signal of alternating current electrical equipment
CN112339613B (en) Battery pack management device and management method and electric vehicle
CN212627302U (en) Novel lighting system power control circuit
CN104134982B (en) Overvoltage protection, over-voltage protection method and air-conditioner for air-conditioner

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination