CN116581821B - Method for improving running stability of PFC weak current network - Google Patents
Method for improving running stability of PFC weak current network Download PDFInfo
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
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- 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
- H02M1/42—Circuits or arrangements for compensating for or adjusting power factor in converters or inverters
- H02M1/4208—Arrangements for improving power factor of AC input
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
- Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
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Abstract
The invention relates to the field of power systems, in particular to a method for improving the running stability of a PFC weak power grid, which comprises the following steps of S1, replacing a bridged PFC circuit in the power grid by using a bridgeless PFC circuit; step S2, judging whether the running condition of the power grid accords with a preset standard according to the absolute value of the difference value of the two peak values; step S3, regulating the resistance values of a first resistor and a second resistor which are connected in series between an MOS tube and the ground in the bridgeless PFC circuit or regulating the threshold voltage for starting driving of the bridgeless PFC circuit; according to the absolute value of the difference value of the calculated two average values, the resistance values of the first resistor and the second resistor are reduced to corresponding values; step S4, judging whether to adjust the resistance value of the load resistor of the power grid by the MCU module according to the time interval; and S5, judging whether the resistance values of the first resistor and the second resistor and the adjustment amplitude of the resistance value of the load resistor of the power grid are corrected according to the duration, and effectively improving the running stability of the power grid.
Description
Technical Field
The invention relates to the field of power systems, in particular to a method for improving the running stability of a PFC weak power grid.
Background
In the traditional bridge PFC, the sine wave voltage of the power grid is converted into a pulsating direct current voltage through a rectifier bridge in advance, the main control MCU does not need to judge the positive and negative polarities of the power grid, and when the power grid is in any half cycle, the driving rule of the MOS tube is consistent; however, in the bridgeless PFC, the driving methods of the positive and negative half cycles are different, so that the driving needs to be changed at the zero crossing point of the power grid, for example, the power grid enters the positive half cycle from the negative half cycle, and the power frequency MOS needs to be turned from the upper tube opening to the lower tube opening. If the grid repeatedly crosses positive and negative half cycles at zero crossing points, the driving logic will switch frequently, which puts high demands on the running speed of the existing DSP processor. Furthermore, if the power grid voltage is distorted at certain phase points, for example, the effective value is abnormally increased or decreased, the DSP is required to quickly change the driving method, and the DSP control is also challenged.
Chinese patent publication No.: CN110829489B discloses a method for estimating a weak power grid and a series compensation power grid without disturbance signal injection, which comprises a direct-current side voltage source, a three-phase full-bridge inverter circuit, a three-phase LC filter, a three-phase line impedance and a three-phase power grid, wherein the method estimates the weak power grid and the series compensation power grid by detecting PCC point voltage and current, and is further used for inverter self-adaptive control; it follows that the prior art has the following problems: when the PFC circuit crosses the zero point of the power grid, the voltage is too small, so that the stability of the power grid is poor, and if the amplitude of the power grid in two adjacent periods is too large, the variation amplitude of the main pipe on time is too large, so that the running stability of the power grid is affected.
Disclosure of Invention
Therefore, the invention provides a method for improving the running stability of a PFC weak current network, which is used for solving the problems that in the prior art, when a PFC circuit crosses a zero point of a power grid, the voltage is too small, so that the stability of the power grid is poor, and if the amplitude of the power grid in two adjacent periods is too large, the amplitude of the change of the main pipe on time is too large, and the running stability of the power grid is affected.
In order to achieve the above object, the present invention provides a method for improving the operation stability of a PFC weak current network, including:
step S1, replacing a bridged PFC circuit in a power grid by using a bridgeless PFC circuit;
step S2, when the running time of the power grid reaches integer times of a first preset time, the MCU module respectively calculates peak values of the power grid in two adjacent preset periods according to first waveforms of the power grid in two adjacent preset periods output by a first oscilloscope arranged at the output end of the power grid, and judges whether the running condition of the power grid accords with a preset standard according to the absolute value of the difference value of the two peak values;
step S3, when the MCU module preliminarily judges that the running condition of the power grid does not meet a preset standard, judging whether to adjust the resistance of a first resistor and a second resistor which are connected in series between a MOS tube and the ground in the bridgeless PFC circuit or the threshold voltage for starting to drive the bridgeless PFC circuit according to the frequency of the voltage zero crossing point of the first waveform obtained by the first oscilloscope; when the MCU module judges that the running condition of the power grid does not meet the preset standard, the resistance values of the first resistor and the second resistor are reduced to corresponding values according to the absolute value of the difference value of the calculated two average values;
Step S4, when the MCU module judges that the running condition of the power grid meets a preset standard or completes the adjustment of the first resistor and the second resistor, the MCU module acquires a time node of which the frequency and the amplitude of the waveform are changed simultaneously through a second waveform output by a second oscilloscope arranged at the source electrode of the MOS tube in the bridgeless PFC circuit and records the time interval of two adjacent time nodes, and judges whether to adjust the resistance value of the load resistor of the power grid according to the time interval;
and S5, when the MCU module completes the judgment of whether the running condition of the power grid meets the preset standard, recording the time length from the time of receiving the first waveform to the time of sending the corresponding instruction, and judging whether to correct the resistance values of the first resistor and the second resistor and the adjustment amplitude of the resistance value of the load resistor of the power grid according to the time length.
Further, the MCU module calculates peak values of voltages of two adjacent periods according to first waveforms of the power grid output by the first oscilloscope in two adjacent preset periods under a first preset condition, calculates absolute values of difference values of the two peak values, and marks the absolute values as peak value difference values, and determines whether the running condition of the power grid meets a power grid judging mode of a preset standard according to the obtained peak value difference values, wherein:
The first power grid judging mode is that the MCU module preliminarily judges that the running condition of the power grid meets a preset standard, the MCU module obtains a time node of which the frequency and the amplitude are changed simultaneously according to the second waveform, records the time interval of two adjacent time nodes, marks the time interval as the conduction time of a main pipe, and further judges whether the running condition of the power grid meets the preset standard according to the conduction time; the first power grid judging mode meets the condition that the peak value difference value is smaller than or equal to a first preset peak value difference value;
the second power grid judging mode is that the MCU module judges that the running condition of the power grid does not meet a preset standard, and the MCU module judges that the threshold voltage of the power grid or the resistance values of the first resistor and the second resistor in the bridgeless PFC circuit are adjusted to corresponding values according to the frequency of the voltage zero crossing point of the power grid in the first waveform, which is obtained by the first oscilloscope; the second power grid judging mode meets the condition that the peak value difference value is smaller than or equal to a second preset peak value difference value and larger than the first preset peak value difference value, and the first preset peak value difference value is smaller than the second preset peak value difference value;
The third power grid judging mode is that the MCU module judges that the running condition of the power grid does not accord with a preset standard, the MCU module calculates the difference value between the peak value difference value and the first preset peak value difference value and marks the difference value as a voltage difference value, and the MCU module reduces the resistance values of the first resistor and the second resistor to corresponding values according to the calculated voltage difference value; the third power grid judging mode meets the condition that the peak value difference value is larger than the second preset peak value difference value;
the first preset condition is that the operation time length of the power grid reaches an integral multiple of the first preset time length.
Further, the MCU module determines, in the second power grid determination mode, an adjustment mode for the bridgeless PFC circuit according to the number of times of voltage zero crossing of the power grid output by the first waveform at the first waveform, where:
the first adjusting mode is that the MCU module adjusts the resistance values of the first resistor and the second resistor to corresponding values according to the obtained voltage difference value; the first regulation judging mode meets the condition that the frequency of the voltage zero crossing point is smaller than or equal to the preset frequency;
the second adjusting mode is that the MCU module increases the threshold voltage of the bridgeless PFC circuit which starts to drive to a corresponding value according to the difference value between the frequency of the voltage zero crossing point of the power grid obtained from the first waveform and the preset frequency; the second adjusting mode meets the condition that the times of the zero crossing points are larger than the preset times.
Further, the MCU module determines a resistance adjustment mode for the first resistor and the second resistor according to the voltage difference under a second preset condition, where:
the first resistance value adjusting mode is that the MCU module uses a first resistance value adjusting coefficient to adjust the resistance values of the first resistor and the second resistor down to corresponding values; the first resistance value adjusting mode meets the condition that the voltage difference value is smaller than or equal to a first preset voltage difference value;
the second resistance value adjusting mode is that the MCU module uses a second resistance value adjusting coefficient to adjust the resistance values of the first resistor and the second resistor down to corresponding values; the second resistance value adjusting mode meets the condition that the voltage difference value is smaller than or equal to a second preset voltage difference value and larger than the first preset voltage difference value, and the first preset voltage difference value is smaller than the second preset voltage difference value;
the third resistance value adjusting mode is that the MCU module uses a third resistance value adjusting coefficient to adjust the resistance values of the first resistor and the second resistor down to corresponding values; the third resistance value adjusting mode meets the condition that the voltage difference value is larger than the second preset voltage difference value;
and the second preset condition is that the MCU module finishes judging the power grid in the third power grid judging mode or the first adjusting mode.
Further, the MCU module records the difference between the number of zero crossing points of the voltage of the power grid obtained from the first waveform and the preset number of times as a number difference under the second adjustment mode, and determines a threshold voltage adjustment mode of a threshold voltage of the bridgeless PFC circuit according to the obtained number difference, wherein:
the MCU module uses a first voltage regulation coefficient to regulate the threshold voltage to a corresponding value in a first threshold voltage regulation mode; the first threshold voltage adjusting mode meets the condition that the frequency difference value is smaller than or equal to a first preset frequency difference value;
the MCU module uses a second voltage regulation coefficient to regulate the threshold voltage to a corresponding value in a second threshold voltage regulation mode; the second threshold voltage adjusting mode meets the condition that the frequency difference is smaller than or equal to a second preset frequency difference and larger than the first preset frequency difference, and the first preset frequency difference is smaller than the second preset frequency difference;
a third threshold voltage adjusting mode is adopted, and the MCU module uses a third voltage adjusting coefficient to adjust the threshold voltage to a corresponding value; the third threshold voltage adjusting mode meets the condition that the frequency difference is larger than the second preset frequency difference.
Further, the MCU module obtains a time node of the frequency and amplitude of the waveform and records a time interval between two adjacent time nodes according to the second waveform under a third preset condition, the MCU module marks the time interval as a conducting time of the main pipe, and the MCU module determines whether the running condition of the power grid meets a preset standard determining mode according to the obtained conducting time, wherein:
the first judging mode is that the MCU module judges that the operation parameters of the power grid accord with preset standards and does not adjust the operation parameters of the power grid; the first judging mode meets the condition that the conduction time is less than or equal to a preset conduction time;
the second judging mode is that the MCU module judges that the operation parameters of the power grid do not meet the preset standard, and the resistance value of the load resistor of the bridgeless PFC circuit is reduced to a corresponding value according to the difference value of the obtained on-time and the preset on-time; the second judging mode meets the condition that the conduction time length is longer than the preset conduction time length;
and the third preset condition is that the MCU module finishes judging whether the running condition of the power grid meets a preset standard or not in the first power grid judging mode or finishes adjusting the resistance values of the first resistor and the second resistor.
Further, the MCU module calculates a difference between the on-time and a preset on-time in the second determination mode, and marks the difference as an on-time difference, and determines an adjustment mode of a load resistance of the bridgeless PFC circuit according to the obtained on-time difference, where:
the first load resistance value adjusting mode is that the MCU module uses a first load resistance value adjusting coefficient to adjust the resistance value of the load resistor down to a corresponding value; the first load resistance value adjusting mode meets the condition that the conduction difference value is smaller than or equal to a first preset conduction difference value;
the second load resistance value adjusting mode is that the MCU module uses a second load resistance value adjusting coefficient to adjust the resistance value of the load resistor down to a corresponding value; the second load resistance value adjusting mode meets the condition that the conduction difference value is smaller than or equal to a second preset conduction difference value and larger than the first preset conduction difference value, and the first preset conduction difference value is smaller than the second preset conduction difference value;
the third load resistance value adjusting mode is that the MCU module uses a third load resistance value adjusting coefficient to adjust the resistance value of the load resistor down to a corresponding value; the third load resistance adjustment mode meets the condition that the conduction difference value is larger than the second preset conduction difference value.
Further, the MCU module records a time length from receiving the first waveform to sending the corresponding instruction under a fourth preset condition, and marks the time length as a response time length, and determines whether an operation parameter of the MCU module meets a module determination mode of a preset standard according to the response time length, wherein:
the first module judging mode is that the MCU module judges that the operation parameters of the MCU module accord with preset standards and does not adjust the operation parameters of the power grid; the first module judges that the response time length is less than or equal to a first preset response time length;
the second module judging mode is that the MCU module judges that the operation parameters of the MCU module do not accord with preset standards, and the first correction coefficient is used for correcting the adjustment coefficients for the first resistance value and the second resistance value and the adjustment coefficient for the load resistor; the second module judges that the response time length is smaller than or equal to a second preset response time length and larger than the first preset response time length, and the first preset response time length is smaller than the second preset response time length;
the third module judges that the running parameters of the MCU module do not meet the preset standard, and corrects the adjusting coefficients for the first resistance value and the second resistance value and the adjusting coefficient for the load resistor by using a second correcting coefficient; the third module judges that the response time length is longer than the second preset response time length;
And the fourth preset condition is that the MCU module completes the judgment of whether the running condition of the power grid meets a preset standard.
Further, the MCU module corrects the first resistance value adjusting coefficient A1, the second resistance value adjusting coefficient A2 and the third resistance value adjusting coefficient A3 to corresponding values by using the first correction coefficient alpha 1 under the second module judging mode;
setting the i-th resistance value adjusting coefficient Ai 'after adjustment as Aixα1, wherein i is 1,2,3, ai is the initial i-th resistance value adjusting coefficient, and Ai' is the i-th resistance value adjusting coefficient after adjustment by using the first correction coefficient;
the MCU module corrects the first resistance value adjusting coefficient A1, the second resistance value adjusting coefficient A2 and the third resistance value adjusting coefficient A3 to corresponding values respectively by using a second correction coefficient alpha 2 under the third module judging mode;
setting the i-th resistance value adjusting coefficient Ai 'after adjustment as Aixα2, wherein i is 1,2,3, ai is the initial i-th resistance value adjusting coefficient, and Ai' is the i-th resistance value adjusting coefficient after adjustment by using the second correction coefficient.
Further, the MCU module corrects the first load resistance adjustment coefficient B1, the second load resistance adjustment coefficient B2 and the third load resistance adjustment coefficient B3 to corresponding values by using the first correction coefficient alpha 1 under the second module judging mode;
Setting an adjusted j-th load resistance adjustment coefficient Bj 'to Bj× (1-alpha 1), wherein j is 1,2,3, bj is an initial j-th load resistance adjustment coefficient, and Bj' is a j-th load resistance adjustment coefficient adjusted by using the first correction coefficient;
the MCU module corrects the first load resistance value adjusting coefficient B1, the second load resistance value adjusting coefficient B2 and the third load resistance value adjusting coefficient B3 to corresponding values by using a second correction coefficient alpha 2 under the third module judging mode;
setting the adjusted j-th load resistance adjustment coefficient Bj 'as Bj× (1-alpha 2), wherein j is 1,2,3, bj is the initial j-th load resistance adjustment coefficient, and Bj' is the j-th load resistance adjustment coefficient adjusted by using the second correction coefficient.
Compared with the prior art, the invention has the beneficial effects that the bridge PFC circuit is replaced by the bridgeless PFC circuit, so that the power loss is effectively reduced.
Further, if the amplitude of the power grid in two adjacent periods is too large, the amplitude of the change of the main pipe on time is too large, the MCU module calculates the absolute value of the difference value of the voltage peak values of the two adjacent periods according to the waveforms of the power grid in the two adjacent preset periods when the operation time of the power grid reaches the integral multiple of the first preset time so as to judge whether the operation condition of the power grid meets the preset standard, monitors the operation parameters of the power grid in time, and makes corresponding countermeasures when the operation condition of the power grid does not meet the preset standard, so that the operation stability of the power grid is further effectively improved.
Further, when the bridgeless PFC circuit is at the zero crossing point of the power grid, due to the characteristics of small voltage, poor power grid stability and the like, all the drives are required to be closed in one section, the wave generation logic is started after the absolute value of the voltage is larger than the threshold voltage, and the MCU module increases the threshold voltage for starting the wave generation drive aiming at the power grid which is repeatedly traversed by the zero crossing point; the MCU module preliminarily judges whether the running condition of the power grid meets the preset standard according to the number of zero-crossing points of the power grid in two adjacent preset periods of the first waveform, which is obtained by the first oscilloscope, when the running condition of the power grid does not meet the preset standard, namely, the threshold voltage is regulated when the number of the zero-crossing points is larger than the preset number; and when the number of the zero crossing points is smaller than or equal to the preset number, judging that the conduction time of the main pipe is too long, adjusting the first resistor and the second resistor, and adjusting the operation parameters of the bridgeless PFC circuit according to the operation condition of the power grid in time, so that the operation stability of the power grid is further effectively improved.
Further, the MCU module calculates the conduction time of the main pipe of the bridgeless PFC circuit, and further judges whether the running condition of the power grid meets the preset standard according to the conduction time of the main pipe, and the running condition of the power grid is accurately detected, and meanwhile, the running stability of the power grid is further effectively improved.
Further, when the MCU module judges that the operation parameters of the power grid do not meet the preset standard in the second judging mode, the resistance value of the load resistor of the bridgeless PFC circuit is reduced to a corresponding value according to the difference value between the obtained conduction time and the preset conduction time, and the load resistor is adjusted to reduce the conduction time of the main pipe, so that the operation stability of the power grid is further effectively improved.
Further, the MCU module judges whether the operation parameters of the MCU module meet the module judging mode of the preset standard according to the obtained response time length, judges whether the first resistance value adjusting coefficient, the second resistance value adjusting coefficient and the third resistance value adjusting coefficient are adjusted to corresponding values and adjusts the first load resistance value adjusting coefficient, the second load resistance value adjusting coefficient and the third load resistance value adjusting coefficient to corresponding values when judging that the operation parameters of the MCU module do not meet the preset standard, so that delay of the MCU module is ensured to be compensated, and the stability of power grid operation is further effectively improved.
Drawings
Fig. 1 is a flowchart of a method for improving operation stability of a PFC weak current network according to an embodiment of the present invention;
fig. 2 is a block diagram of a method for improving operation stability of a PFC weak network according to an embodiment of the present invention;
Fig. 3 is a circuit diagram of a bridgeless PFC circuit according to an embodiment of the present invention;
fig. 4 is a flowchart of a power grid determination mode in which the MCU module determines whether the operation condition of the power grid meets a preset standard according to the obtained peak value difference.
Detailed Description
In order that the objects and advantages of the invention will become more apparent, the invention will be further described with reference to the following examples; it should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.
Preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are merely for explaining the technical principles of the present invention, and are not intended to limit the scope of the present invention.
It should be noted that, in the description of the present invention, terms such as "upper," "lower," "left," "right," "inner," "outer," and the like indicate directions or positional relationships based on the directions or positional relationships shown in the drawings, which are merely for convenience of description, and do not indicate or imply that the apparatus or elements must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present invention.
Furthermore, it should be noted that, in the description of the present invention, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention can be understood by those skilled in the art according to the specific circumstances.
Referring to fig. 1, fig. 2, fig. 3, and fig. 4, which are respectively a flowchart of steps of a method for improving the operation stability of a PFC weak power network, a block diagram of a method for improving the operation stability of a PFC weak power network, a circuit diagram of a bridgeless PFC circuit, and a flowchart of a power network determination method in which an MCU module determines whether the operation condition of a power network meets a preset standard according to a calculated peak value difference; the method for improving the running stability of the PFC weak current network comprises the following steps:
step S1, replacing a bridged PFC circuit in a power grid by using a bridgeless PFC circuit;
step S2, when the running time of the power grid reaches integer times of a first preset time, the MCU module respectively calculates peak values of the power grid in two adjacent preset periods according to first waveforms of the power grid in two adjacent preset periods output by a first oscilloscope arranged at the output end of the power grid, and judges whether the running condition of the power grid accords with a preset standard according to the absolute value of the difference value of the two peak values;
Step S3, when the MCU module preliminarily judges that the running condition of the power grid does not meet a preset standard, judging whether to adjust the resistance of a first resistor and a second resistor which are connected in series between a MOS tube and the ground in the bridgeless PFC circuit or the threshold voltage for starting to drive the bridgeless PFC circuit according to the frequency of the voltage zero crossing point of the first waveform obtained by the first oscilloscope; when the MCU module judges that the running condition of the power grid does not meet the preset standard, the resistance values of the first resistor and the second resistor are reduced to corresponding values according to the absolute value of the difference value of the calculated two average values;
step S4, when the MCU module judges that the running condition of the power grid meets a preset standard or completes the adjustment of the first resistor and the second resistor, the MCU module acquires a time node of which the frequency and the amplitude of the waveform are changed simultaneously through a second waveform output by a second oscilloscope arranged at the source electrode of the MOS tube in the bridgeless PFC circuit and records the time interval of two adjacent time nodes, and judges whether to adjust the resistance value of the load resistor of the power grid according to the time interval;
and S5, when the MCU module completes the judgment of whether the running condition of the power grid meets the preset standard, recording the time length from the time of receiving the first waveform to the time of sending the corresponding instruction, and judging whether to correct the resistance values of the first resistor and the second resistor and the adjustment amplitude of the resistance value of the load resistor of the power grid according to the time length.
Specifically, the MCU module calculates peak values of voltages of two adjacent periods according to first waveforms of the power grid output by the first oscilloscope in two adjacent preset periods under a first preset condition, calculates absolute values of difference values of the two peak values, and marks the absolute values as peak value difference values, and determines whether the running condition of the power grid meets a power grid judging mode of a preset standard according to the obtained peak value difference values, wherein:
the first power grid judging mode is that the MCU module preliminarily judges that the running condition of the power grid meets a preset standard, the MCU module obtains a time node of which the frequency and the amplitude are changed simultaneously according to the second waveform, records the time interval of two adjacent time nodes, marks the time interval as the conduction time of a main pipe, and further judges whether the running condition of the power grid meets the preset standard according to the conduction time; the first power grid judging mode meets the condition that the peak value difference value is smaller than or equal to a first preset peak value difference value;
the second power grid judging mode is that the MCU module judges that the running condition of the power grid does not meet a preset standard, and the MCU module judges that the threshold voltage of the power grid or the resistance values of the first resistor and the second resistor in the bridgeless PFC circuit are adjusted to corresponding values according to the frequency of the voltage zero crossing point of the power grid in the first waveform, which is obtained by the first oscilloscope; the second power grid judging mode meets the condition that the peak value difference value is smaller than or equal to a second preset peak value difference value and larger than the first preset peak value difference value, and the first preset peak value difference value is smaller than the second preset peak value difference value;
The third power grid judging mode is that the MCU module judges that the running condition of the power grid does not accord with a preset standard, the MCU module calculates the difference value between the peak value difference value and the first preset peak value difference value and marks the difference value as a voltage difference value, and the MCU module reduces the resistance values of the first resistor and the second resistor to corresponding values according to the calculated voltage difference value; the third power grid judging mode meets the condition that the peak value difference value is larger than the second preset peak value difference value;
the first preset condition is that the operation time length of the power grid reaches integer times of the first preset time length;
the first preset time length is 72h, the first preset peak value difference value is 1, the second preset peak value difference value is 5, and the single preset period is 20ms.
Specifically, the MCU module determines, in the second power grid determination mode, an adjustment mode for the bridgeless PFC circuit according to the number of times of voltage zero crossing of the power grid output by the first waveform at the first waveform, where:
the first adjusting mode is that the MCU module adjusts the resistance values of the first resistor and the second resistor to corresponding values according to the obtained voltage difference value; the first regulation judging mode meets the condition that the frequency of the voltage zero crossing point is smaller than or equal to the preset frequency;
The second adjusting mode is that the MCU module increases the threshold voltage of the bridgeless PFC circuit which starts to drive to a corresponding value according to the difference value between the frequency of the voltage zero crossing point of the power grid obtained from the first waveform and the preset frequency; the second regulation mode satisfies that the number of times of the zero crossing points is larger than the preset number of times;
wherein the preset times are 4.
Specifically, the MCU module determines, under a second preset condition, a resistance adjustment manner for the first resistor and the second resistor according to the voltage difference, where:
the first resistance value adjusting mode is that the MCU module uses a first resistance value adjusting coefficient to adjust the resistance values of the first resistor and the second resistor down to corresponding values; the first resistance value adjusting mode meets the condition that the voltage difference value is smaller than or equal to a first preset voltage difference value;
the second resistance value adjusting mode is that the MCU module uses a second resistance value adjusting coefficient to adjust the resistance values of the first resistor and the second resistor down to corresponding values; the second resistance value adjusting mode meets the condition that the voltage difference value is smaller than or equal to a second preset voltage difference value and larger than the first preset voltage difference value, and the first preset voltage difference value is smaller than the second preset voltage difference value;
The third resistance value adjusting mode is that the MCU module uses a third resistance value adjusting coefficient to adjust the resistance values of the first resistor and the second resistor down to corresponding values; the third resistance value adjusting mode meets the condition that the voltage difference value is larger than the second preset voltage difference value;
the second preset condition is that the MCU module finishes judging the power grid in the third power grid judging mode or the first adjusting mode;
the first preset voltage difference is 5, the second preset voltage difference is 80, the first resistance value adjusting coefficient is 0.9, the second resistance value adjusting coefficient is 0.8, and the third resistance value adjusting coefficient is 0.7.
Specifically, the MCU module records the difference between the number of zero-crossing points of the voltage of the power grid obtained from the first waveform and the preset number of zero-crossing points as a number difference value, and determines a threshold voltage adjustment mode of a threshold voltage of the bridgeless PFC circuit according to the obtained number difference value, wherein:
the MCU module uses a first voltage regulation coefficient to regulate the threshold voltage to a corresponding value in a first threshold voltage regulation mode; the first threshold voltage adjusting mode meets the condition that the frequency difference value is smaller than or equal to a first preset frequency difference value;
The MCU module uses a second voltage regulation coefficient to regulate the threshold voltage to a corresponding value in a second threshold voltage regulation mode; the second threshold voltage adjusting mode meets the condition that the frequency difference is smaller than or equal to a second preset frequency difference and larger than the first preset frequency difference, and the first preset frequency difference is smaller than the second preset frequency difference;
a third threshold voltage adjusting mode is adopted, and the MCU module uses a third voltage adjusting coefficient to adjust the threshold voltage to a corresponding value; the third threshold voltage adjusting mode meets the condition that the frequency difference is larger than the second preset frequency difference;
the first preset times difference is 5, the second preset times difference is 8, the first voltage regulating coefficient is 1.15, the second voltage regulating coefficient is 1.2, and the third voltage regulating coefficient is 1.25.
Specifically, the MCU module obtains a time node of the frequency and amplitude of the waveform and records a time interval between two adjacent time nodes according to the second waveform under a third preset condition, the MCU module marks the time interval as a conducting time of a main pipe, and the MCU module determines whether the running condition of the power grid meets a preset standard determining mode according to the obtained conducting time, wherein:
The first judging mode is that the MCU module judges that the operation parameters of the power grid accord with preset standards and does not adjust the operation parameters of the power grid; the first judging mode meets the condition that the conduction time is less than or equal to a preset conduction time;
the second judging mode is that the MCU module judges that the operation parameters of the power grid do not meet the preset standard, and the resistance value of the load resistor of the bridgeless PFC circuit is reduced to a corresponding value according to the difference value of the obtained on-time and the preset on-time; the second judging mode meets the condition that the conduction time length is longer than the preset conduction time length;
the third preset condition is that the MCU module finishes judging whether the running condition of the power grid meets a preset standard or not in the first power grid judging mode or finishes adjusting the resistance values of the first resistor and the second resistor;
wherein, the preset conduction time is 2ms.
Specifically, the MCU module calculates a difference between the on-time and a preset on-time in the second determination mode, and marks the difference as an on-time difference, and determines an adjustment mode of a load resistance of the bridgeless PFC circuit according to the obtained on-time difference, where:
The first load resistance value adjusting mode is that the MCU module uses a first load resistance value adjusting coefficient to adjust the resistance value of the load resistor down to a corresponding value; the first load resistance value adjusting mode meets the condition that the conduction difference value is smaller than or equal to a first preset conduction difference value;
the second load resistance value adjusting mode is that the MCU module uses a second load resistance value adjusting coefficient to adjust the resistance value of the load resistor down to a corresponding value; the second load resistance value adjusting mode meets the condition that the conduction difference value is smaller than or equal to a second preset conduction difference value and larger than the first preset conduction difference value, and the first preset conduction difference value is smaller than the second preset conduction difference value;
the third load resistance value adjusting mode is that the MCU module uses a third load resistance value adjusting coefficient to adjust the resistance value of the load resistor down to a corresponding value; the third load resistance value adjusting mode meets the condition that the conduction difference value is larger than the second preset conduction difference value;
the first preset conduction difference value is 2ms, and the second preset conduction difference value is 3ms; the first load resistance adjustment coefficient is 0.95, the second load resistance adjustment coefficient is 0.9, and the third load resistance adjustment coefficient is 0.87.
Specifically, the MCU module records the duration from the time of receiving the first waveform to the time of sending the corresponding instruction under a fourth preset condition, and marks the duration as a response duration, and determines, according to the response duration, whether the operation parameters of the MCU module meet the module determination mode of the preset standard, where:
The first module judging mode is that the MCU module judges that the operation parameters of the MCU module accord with preset standards and does not adjust the operation parameters of the power grid; the first module judges that the response time length is less than or equal to a first preset response time length;
the second module judging mode is that the MCU module judges that the operation parameters of the MCU module do not accord with preset standards, and the first correction coefficient is used for correcting the adjustment coefficients for the first resistance value and the second resistance value and the adjustment coefficient for the load resistor; the second module judges that the response time length is smaller than or equal to a second preset response time length and larger than the first preset response time length, and the first preset response time length is smaller than the second preset response time length;
the third module judges that the running parameters of the MCU module do not meet the preset standard, and corrects the adjusting coefficients for the first resistance value and the second resistance value and the adjusting coefficient for the load resistor by using a second correcting coefficient; the third module judges that the response time length is longer than the second preset response time length;
the fourth preset condition is that the MCU module completes the judgment of whether the running condition of the power grid meets a preset standard or not;
The first preset response time is 4ms, the second preset response time is 6ms, the first correction coefficient is 0.7, and the second correction coefficient is 0.6.
Specifically, the MCU module corrects the first resistance adjustment coefficient A1, the second resistance adjustment coefficient A2, and the third resistance adjustment coefficient A3 to corresponding values using the first correction coefficient α1 in the second module determination mode;
setting the i-th resistance value adjusting coefficient Ai 'after adjustment as Aixα1, wherein i is 1,2,3, ai is the initial i-th resistance value adjusting coefficient, and Ai' is the i-th resistance value adjusting coefficient after adjustment by using the first correction coefficient;
the MCU module corrects the first resistance value adjusting coefficient A1, the second resistance value adjusting coefficient A2 and the third resistance value adjusting coefficient A3 to corresponding values respectively by using a second correction coefficient alpha 2 under the third module judging mode;
setting the i-th resistance value adjusting coefficient Ai 'after adjustment as Aixα2, wherein i is 1,2,3, ai is the initial i-th resistance value adjusting coefficient, and Ai' is the i-th resistance value adjusting coefficient after adjustment by using the second correction coefficient.
Specifically, the MCU module corrects the first load resistance adjustment coefficient B1, the second load resistance adjustment coefficient B2, and the third load resistance adjustment coefficient B3 to corresponding values using the first correction coefficient α1 in the second module determination mode;
Setting an adjusted j-th load resistance adjustment coefficient Bj 'to Bj× (1-alpha 1), wherein j is 1,2,3, bj is an initial j-th load resistance adjustment coefficient, and Bj' is a j-th load resistance adjustment coefficient adjusted by using the first correction coefficient;
the MCU module corrects the first load resistance value adjusting coefficient B1, the second load resistance value adjusting coefficient B2 and the third load resistance value adjusting coefficient B3 to corresponding values by using a second correction coefficient alpha 2 under the third module judging mode;
setting the adjusted j-th load resistance adjustment coefficient Bj 'as Bj× (1-alpha 2), wherein j is 1,2,3, bj is the initial j-th load resistance adjustment coefficient, and Bj' is the j-th load resistance adjustment coefficient adjusted by using the second correction coefficient.
Example 1
When the running time of the power grid reaches 72h, the MCU module calculates the peak value of the voltage of two adjacent periods according to the first waveform of the power grid output by the first oscilloscope in the two adjacent preset periods, the calculated peak value of the voltage of the first period is 311V, the calculated peak value of the voltage of the second period is 311V, so the peak value difference is 0V, the MCU module acquires the time node of which the frequency and the amplitude of the waveform change simultaneously according to the second waveform and records the time interval of two adjacent time nodes as 3ms, the MCU module marks the time interval as the conducting time of a main pipe, the MCU module judges that the running parameter of the power grid does not accord with the preset standard, and adjusts the resistance value of the load resistor to the corresponding value according to the difference value of the calculated conducting time and the preset conducting time, and the MCU module uses a first load resistance value adjusting coefficient to adjust the resistance value of the load resistor to the corresponding value, wherein the first load resistance value adjusting coefficient is 0.95; the MCU module records the time length from the time of receiving the first waveform to the time of sending the corresponding instruction as 13ms, and records the time length as a response time length, and corrects the adjusting coefficients for the first resistance value and the second resistance value and the adjusting coefficient for the load resistance by using a second correction coefficient of 0.6.
Example 2
When the running time of the power grid reaches 432 hours, the MCU module calculates the peak value of the voltage of two adjacent periods according to the first waveform of the power grid in two adjacent preset periods output by the first oscilloscope, the calculated peak value of the voltage of the first period is 308V, the calculated peak value of the voltage of the second period is 311V, so the peak value difference value is 3V, the MCU module judges that the running condition of the power grid does not accord with the preset standard, the frequency of the power grid at the voltage zero crossing point of the first waveform obtained by the first oscilloscope is 6, the MCU module adjusts the threshold voltage to a corresponding value according to the difference value of the frequency 6 of the voltage zero crossing point of the power grid obtained by the first waveform and the preset frequency 4 by using a first voltage adjusting coefficient of 1.15; the MCU module records that the time length from the time of receiving the first waveform to the time of sending the corresponding instruction is 3ms, and the operation parameters of the power grid are not adjusted.
Example 3
When the running time of the power grid reaches 648h, the MCU module calculates the peak value of the voltage of two adjacent periods according to the first waveform of the power grid in two adjacent preset periods output by the first oscilloscope, the calculated peak value of the voltage of the first period is 309V, the calculated peak value of the voltage of the second period is 311V, so the peak value difference is 2V, the MCU module judges that the running condition of the power grid does not accord with the preset standard, the frequency of the power grid at the voltage zero crossing point of the first waveform obtained by the first oscilloscope is 4, the MCU module adjusts the resistance values of the first resistor and the second resistor to corresponding values by using a first resistance value adjusting coefficient of 0.9 according to the obtained voltage difference value of the MCU module; the MCU module acquires a time node with the frequency and amplitude of the waveform changed simultaneously according to the second waveform, records that the time interval between two adjacent time nodes is 1.5ms, and does not adjust the operation parameters of the power grid; the MCU module records the time length from the receiving of the first waveform to the sending of the corresponding instruction to be 4.5ms, and corrects the adjusting coefficient for the first resistance value and the second resistance value and the adjusting coefficient for the load resistance by using a first correction coefficient of 0.7.
Thus far, the technical solution of the present invention has been described in connection with the preferred embodiments shown in the drawings, but it is easily understood by those skilled in the art that the scope of protection of the present invention is not limited to these specific embodiments. Equivalent modifications and substitutions for related technical features may be made by those skilled in the art without departing from the principles of the present invention, and such modifications and substitutions will be within the scope of the present invention.
The foregoing description is only of the preferred embodiments of the invention and is not intended to limit the invention; various modifications and variations of the present invention will be apparent to those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (9)
1. The method for improving the operation stability of the PFC weak current network is characterized by comprising the following steps of:
step S1, replacing a bridged PFC circuit in a power grid by using a bridgeless PFC circuit;
step S2, when the running time of the power grid reaches integer times of a first preset time, the MCU module respectively calculates peak values of the power grid in two adjacent preset periods according to first waveforms of the power grid output by a first oscilloscope arranged at the output end of the power grid in the two adjacent preset periods, and judges whether the running condition of the power grid accords with a preset standard according to the absolute value of the difference value of the two peak values;
Step S3, when the MCU module preliminarily judges that the running condition of the power grid does not meet the preset standard, judging whether to adjust the resistance of a first resistor and a second resistor which are connected in series between an MOS tube and the ground in the bridgeless PFC circuit or the threshold voltage for starting to drive the bridgeless PFC circuit according to the frequency of the voltage zero crossing point of the first waveform obtained by the first oscilloscope; when the MCU module judges that the running condition of the power grid does not meet the preset standard, the resistance values of the first resistor and the second resistor are reduced to corresponding values according to the absolute value of the difference value of the calculated two average values;
step S4, when the MCU module judges that the running condition of the power grid meets a preset standard or completes the adjustment of the first resistor and the second resistor, the MCU module judges whether the resistance value of the load resistor of the power grid is adjusted according to the time interval by acquiring a time node of the frequency and the amplitude of the second waveform which are simultaneously changed and recording the time interval of two adjacent time nodes through a second waveform output by a second oscilloscope arranged at the source electrode of the MOS tube in the bridgeless PFC circuit;
step S5, when the MCU module completes the judgment of whether the running condition of the power grid accords with a preset standard, recording the time length from the time of receiving the first waveform to the time of sending a corresponding instruction, and judging whether to correct the resistance values of the first resistor and the second resistor and the adjustment amplitude of the resistance value of the load resistor of the power grid according to the time length;
The MCU module calculates the peak value of the voltage of two adjacent periods according to the first waveform of the power grid output by the first oscilloscope in two adjacent preset periods under the first preset condition, calculates the absolute value of the difference value of the two peak values, marks the absolute value as the peak value difference value, and determines whether the running condition of the power grid accords with the power grid judging mode of the preset standard according to the obtained peak value difference value, wherein the MCU module comprises a power grid judging module, a power grid judging module and a power grid judging module, wherein the power grid judging module comprises a power grid judging module, the power grid judging module and a power grid judging module, and the power grid judging module is connected with the power grid judging module.
The first power grid judging mode is that the MCU module preliminarily judges that the running condition of the power grid meets a preset standard, the MCU module records the time interval between two adjacent time nodes according to the obtained time node in which the frequency and the amplitude of the second waveform are changed simultaneously and records the time interval as the conducting duration of a main pipe, and judges whether the running condition of the power grid meets the preset standard according to the conducting duration; the first power grid judging mode meets the condition that the peak value difference value is smaller than or equal to a first preset peak value difference value;
the second power grid judging mode is that the MCU module judges that the running condition of the power grid does not meet a preset standard, and the MCU module judges that the threshold voltage of the bridgeless PFC circuit aiming at the power grid or the resistance values of the first resistor and the second resistor in the bridgeless PFC circuit are adjusted to corresponding values according to the frequency of voltage zero crossing points of the power grid in the first waveform, which is obtained by the first oscilloscope; the second power grid judging mode meets the condition that the peak value difference value is smaller than or equal to a second preset peak value difference value and larger than the first preset peak value difference value, and the first preset peak value difference value is smaller than the second preset peak value difference value;
The third power grid judging mode is that the MCU module judges that the running condition of the power grid does not accord with a preset standard, the MCU module calculates the difference value between the peak value difference value and the first preset peak value difference value and marks the difference value as a voltage difference value, and the MCU module reduces the resistance values of the first resistor and the second resistor to corresponding values according to the calculated voltage difference value; the third power grid judging mode meets the condition that the peak value difference value is larger than the second preset peak value difference value;
the first preset condition is that the operation time length of the power grid reaches an integral multiple of the first preset time length.
2. The method for improving the running stability of a PFC weak current network according to claim 1, wherein the MCU module determines, in the second power grid determination mode, an adjustment mode for the bridgeless PFC circuit according to the number of times of voltage zero-crossing of the power grid output by the first waveform at the first waveform, and wherein:
the first adjusting mode is that the MCU module adjusts the resistance values of the first resistor and the second resistor to corresponding values according to the obtained voltage difference value; the first regulation mode meets the condition that the frequency of the voltage zero crossing point is smaller than or equal to the preset frequency;
the second adjusting mode is that the MCU module increases the threshold voltage of the bridgeless PFC circuit which starts to drive to a corresponding value according to the difference value between the frequency of the voltage zero crossing point of the power grid obtained from the first waveform and the preset frequency; the second adjusting mode meets the condition that the times of the zero crossing points are larger than the preset times.
3. The method for improving the running stability of a PFC weak current network according to claim 2, wherein the MCU module determines a resistance adjustment manner for the first resistor and the second resistor according to the voltage difference under a second preset condition, wherein:
the first resistance value adjusting mode is that the MCU module uses a first resistance value adjusting coefficient to adjust the resistance values of the first resistor and the second resistor down to corresponding values; the first resistance value adjusting mode meets the condition that the voltage difference value is smaller than or equal to a first preset voltage difference value;
the second resistance value adjusting mode is that the MCU module uses a second resistance value adjusting coefficient to adjust the resistance values of the first resistor and the second resistor down to corresponding values; the second resistance value adjusting mode meets the condition that the voltage difference value is smaller than or equal to a second preset voltage difference value and larger than the first preset voltage difference value, and the first preset voltage difference value is smaller than the second preset voltage difference value;
the third resistance value adjusting mode is that the MCU module uses a third resistance value adjusting coefficient to adjust the resistance values of the first resistor and the second resistor down to corresponding values; the third resistance value adjusting mode meets the condition that the voltage difference value is larger than the second preset voltage difference value;
And the second preset condition is that the MCU module finishes judging the power grid in the third power grid judging mode or the first adjusting mode.
4. The method for improving the running stability of a PFC weak current network according to claim 3, wherein the MCU module determines, in the second adjustment mode, a difference between the number of zero-crossing points of the voltage of the power network obtained from the first waveform and a preset number of times and records the difference as a number of times difference, and determines an adjustment mode of a threshold voltage in which the bridgeless PFC circuit starts to drive according to the obtained number of times difference, wherein:
the MCU module uses a first voltage regulation coefficient to regulate the threshold voltage to a corresponding value in a first threshold voltage regulation mode; the first threshold voltage adjusting mode meets the condition that the frequency difference value is smaller than or equal to a first preset frequency difference value;
the MCU module uses a second voltage regulation coefficient to regulate the threshold voltage to a corresponding value in a second threshold voltage regulation mode; the second threshold voltage adjusting mode meets the condition that the frequency difference is smaller than or equal to a second preset frequency difference and larger than the first preset frequency difference, and the first preset frequency difference is smaller than the second preset frequency difference;
A third threshold voltage adjusting mode is adopted, and the MCU module uses a third voltage adjusting coefficient to adjust the threshold voltage to a corresponding value; the third threshold voltage adjusting mode meets the condition that the frequency difference is larger than the second preset frequency difference.
5. The method for improving the running stability of a PFC weak current network according to claim 4, wherein the MCU module records a time interval between two adjacent time nodes and records the time interval as a main pipe according to the obtained time node in which the frequency and the amplitude of the second waveform change simultaneously under a third preset condition, and determines whether the running condition of the power network meets a preset standard determination mode according to the obtained time interval, where:
the first judging mode is that the MCU module judges that the operation parameters of the power grid accord with preset standards and does not adjust the operation parameters of the power grid; the first judging mode meets the condition that the conduction time is less than or equal to a preset conduction time;
the second judging mode is that the MCU module judges that the operation parameters of the power grid do not meet the preset standard, and the resistance value of the load resistor of the bridgeless PFC circuit is reduced to a corresponding value according to the difference value of the obtained on-time and the preset on-time; the second judging mode meets the condition that the conduction time length is longer than the preset conduction time length;
And the third preset condition is that the MCU module finishes judging whether the running condition of the power grid meets a preset standard or not under the first power grid judging mode or finishes adjusting the resistance values of the first resistor and the second resistor.
6. The method for improving the running stability of a PFC weak current network according to claim 5, wherein the MCU calculates a difference between the on-time and a preset on-time in the second determination mode and marks the difference as an on-time difference, and determines an adjustment mode of a load resistance of the bridgeless PFC circuit according to the obtained on-time difference, where:
the first load resistance value adjusting mode is that the MCU module uses a first load resistance value adjusting coefficient to adjust the resistance value of the load resistor down to a corresponding value; the first load resistance value adjusting mode meets the condition that the conduction difference value is smaller than or equal to a first preset conduction difference value;
the second load resistance value adjusting mode is that the MCU module uses a second load resistance value adjusting coefficient to adjust the resistance value of the load resistor down to a corresponding value; the second load resistance value adjusting mode meets the condition that the conduction difference value is smaller than or equal to a second preset conduction difference value and larger than the first preset conduction difference value, and the first preset conduction difference value is smaller than the second preset conduction difference value;
The third load resistance value adjusting mode is that the MCU module uses a third load resistance value adjusting coefficient to adjust the resistance value of the load resistor down to a corresponding value; the third load resistance adjustment mode meets the condition that the conduction difference value is larger than the second preset conduction difference value.
7. The method for improving the operation stability of a PFC weak network according to claim 6, wherein,
the MCU module records the time length from the reception of the first waveform to the emission of the corresponding instruction under a fourth preset condition, and records the time length as a response time length, and the MCU module determines whether the operation parameters of the MCU module meet the module judgment mode of the preset standard according to the response time length, wherein:
the first module judging mode is that the MCU module judges that the operation parameters of the MCU module accord with preset standards and does not adjust the operation parameters of the power grid; the first module judges that the response time length is less than or equal to a first preset response time length;
the second module judging mode is that the MCU module judges that the operation parameters of the MCU module do not accord with preset standards, and the first correction coefficient is used for correcting the adjustment coefficient of the resistance values of the first resistor and the second resistor and the adjustment coefficient of the load resistor; the second module judges that the response time length is smaller than or equal to a second preset response time length and larger than the first preset response time length, and the first preset response time length is smaller than the second preset response time length;
The third module judges that the running parameters of the MCU module do not accord with the preset standard, and corrects the adjusting coefficients of the resistance values of the first resistor and the second resistor and the adjusting coefficient of the load resistor by using the second correcting coefficient; the third module judges that the response time length is longer than the second preset response time length;
and the fourth preset condition is that the MCU module completes the judgment of whether the running condition of the power grid meets the preset standard.
8. The method for improving the running stability of a PFC weak current network according to claim 7, wherein the MCU module corrects the first resistance adjustment coefficient A1, the second resistance adjustment coefficient A2, and the third resistance adjustment coefficient A3 to corresponding values using a first correction coefficient α1 in the second module determination mode, respectively;
setting, wherein i=1, 2,3, ai is an initial i-th resistance adjustment coefficient, and Ai' is an i-th resistance adjustment coefficient adjusted by using a first correction coefficient;
the MCU module corrects the first resistance value adjusting coefficient A1, the second resistance value adjusting coefficient A2 and the third resistance value adjusting coefficient A3 to corresponding values respectively by using a second correction coefficient alpha 2 under the third module judging mode;
Setting, the i-th resistance adjustment coefficient Ai "=ai×α2 after adjustment, wherein i=1, 2,3, ai is the initial i-th resistance adjustment coefficient, and Ai" is the i-th resistance adjustment coefficient after adjustment using the second correction coefficient.
9. The method for improving the running stability of a PFC weak current network according to claim 8, wherein the MCU module corrects the first load resistance adjustment coefficient B1, the second load resistance adjustment coefficient B2, and the third load resistance adjustment coefficient B3 to corresponding values using the first correction coefficient α1 in the second module determination mode, respectively;
setting, namely, an adjusted j-th load resistance adjustment coefficient Bj '=Bj× (1-alpha 1), wherein j=1, 2,3 and Bj are initial j-th load resistance adjustment coefficients, and Bj' is a j-th load resistance adjustment coefficient adjusted by using a first correction coefficient;
the MCU module corrects the first load resistance value adjusting coefficient B1, the second load resistance value adjusting coefficient B2 and the third load resistance value adjusting coefficient B3 to corresponding values by using a second correction coefficient alpha 2 under the third module judging mode;
setting, the adjusted j-th load resistance adjustment coefficient Bj "=bj× (1- α2), where j=1, 2,3, bj is the initial j-th load resistance adjustment coefficient, and Bj" is the j-th load resistance adjustment coefficient adjusted by using the second correction coefficient.
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| CN106452046A (en) * | 2016-10-13 | 2017-02-22 | 广州视源电子科技股份有限公司 | Switching tube control method and device of PFC circuit |
| CN212909347U (en) * | 2020-07-28 | 2021-04-06 | 深圳天邦达科技有限公司 | Fixed direct current output extension load capacity adjustable circuit |
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