CN102404892B - Power supply soft start method of variable-frequency microwave oven - Google Patents
Power supply soft start method of variable-frequency microwave oven Download PDFInfo
- Publication number
- CN102404892B CN102404892B CN201110304437.0A CN201110304437A CN102404892B CN 102404892 B CN102404892 B CN 102404892B CN 201110304437 A CN201110304437 A CN 201110304437A CN 102404892 B CN102404892 B CN 102404892B
- Authority
- CN
- China
- Prior art keywords
- power supply
- frequency
- microwave oven
- duty ratio
- soft start
- 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.)
- Active
Links
Images
Landscapes
- Control Of High-Frequency Heating Circuits (AREA)
Abstract
The invention discloses a power supply soft start method for power supply of a variable-frequency microwave oven. Input power of a switching tube of the power supply of the microwave oven is increased in a pulse width modulation manner under the condition that a switching frequency is slightly higher than a working frequency of the microwave oven in normal operation so as to realize the soft start, and the power is increased again in a manner of frequency modulation after the soft start is completed. The power supply soft start method cannot lead to the collapse of a system caused by excessively high working frequency passing through an IGBT (Insulated Gate Bipolar Translator) of the switching tube during the start and has the advantages of small starting stress of the switching tube IGBT and good power supply starting reliability; and therefore, a control system of the power supply can be simplified due to narrower range of the working frequency of the power supply.
Description
[technical field]
The present invention relates to frequency-conversion microwave oven power supply, relate in particular to the method for a kind of frequency-conversion microwave oven power supply soft start.
[background technology]
The Soft Start-up Process of traditional microwave oven variable frequency power supply as shown in Figure 1, the framework of variable frequency microwave power supply is resonance oscillation semi-bridge, in the time that starting shooting, power supply make the power switch pipe of resonance oscillation semi-bridge first be operated in the highest switching frequency, conventionally in 120KHz left and right, then progressively reduce switching frequency, make power supply enter soft on off state, finally reach rated output power.This kind of starting method is called to variable frequency soft start.Because the operating frequency of current power switch pipe IGBT is lower, when when work, frequency is too high, power switch pipe IGBT can cause system crash because of smearing.And, because the operating frequency range of system is too wide, make control system become complicated.
[summary of the invention]
The technical problem to be solved in the present invention is to provide one can reduce power supply start stress, the frequency-conversion microwave oven power supply soft-starting method that power supply can reliably start.
In order to solve the problems of the technologies described above, the technical solution used in the present invention is, a kind of frequency-conversion microwave oven power supply soft-starting method, when the switching tube of microwave oven supply power is normally worked a little more than microwave oven at switching frequency, under the condition of maximum operating frequency, improve input power by pulse width modulated mode and realize soft start, after soft start completes, improve power in the mode of frequency modulation again.
Above-described frequency-conversion microwave oven power supply soft-starting method, comprises the following steps:
When power supply starting, the switching frequency of power supply resonance oscillation semi-bridge switching tube is the 110-200% of microwave oven maximum operating frequency while normally working, highest frequency during a little more than normal work, the initial duty cycle of switching tube is 1-15%, under the constant condition of maintained switch frequency, progressively increase duty ratio, in the time that duty ratio reaches 25-45%, soft start completes; Keep subsequently duty ratio constant, improve power by the mode of frequency modulation and carry out filament pre-heating.
Above-described frequency-conversion microwave oven power supply soft-starting method, the stride of duty ratio adjustment is that each switch periods increases 0.1-1%.
Above-described frequency-conversion microwave oven power supply soft-starting method, the drive level of the top tube and down tube of power supply resonance oscillation semi-bridge is complementary in sequential, and not etc., top tube and down tube duty ratio sum does not add that Dead Time is 100% to pulsewidth; The duty ratio of above-mentioned switching tube is progressively increased by initial duty cycle, and referring to pulsewidth in two switching tubes is progressively increased by initial duty cycle compared with the duty ratio of P cock pipe.
Slightly under the condition of lower operating frequency, improve input power by pulse width modulated mode realizes soft start to frequency-conversion microwave oven power supply soft-starting method of the present invention, after soft start completes, improves power again in the mode of frequency modulation; Can because when starting crosses, the operating frequency of switching tube IGBT is too high cause system crash, the start stress of switching tube IGBT is little, and power supply starting reliability is good; And because the operating frequency range of power supply is narrower, the control system of power supply can be simplified.
[accompanying drawing explanation]
Below in conjunction with the drawings and specific embodiments, the present invention is further detailed explanation.
Fig. 1 is the flow chart of frequency-conversion microwave oven power supply soft-starting method embodiment of the present invention.
Fig. 2 is the driving sequential chart of the top tube and down tube of frequency-conversion microwave oven power supply soft-starting method embodiment power supply resonance oscillation semi-bridge of the present invention.
Fig. 3 is frequency-conversion microwave oven power supply soft-starting method embodiment power supply starting oscillogram of the present invention.
Fig. 4 is frequency-conversion microwave oven power supply soft-starting method embodiment electric power output voltage oscillogram of the present invention.
[embodiment]
Fig. 1, shown in the embodiment of frequency-conversion microwave oven power supply soft-starting method of the present invention in, frequency-conversion microwave oven power supply detecting exchange AC power supplies input normal after, start Soft Start-up Process.First, it is 60KHz that microwave oven is set initial switch frequency, highest frequency 30KHz-50KHz during a little more than normal work, and the duty ratio of setting the upper pipe of power supply resonance oscillation semi-bridge is 10%, then progressively increase the duty ratio of the upper pipe of power supply resonance oscillation semi-bridge, and maintained switch frequency 60KHz is constant, the stride of duty ratio adjustment is that each switch periods increases by 0.5%.After the duty ratio of the upper pipe of power supply resonance oscillation semi-bridge reaches 30%, the resonant circuit of whole power supply has also reached poised state, now, setpoint power output is 200W, carry out the work of frequency conversion adjusting power according to the difference of input voltage, now, the duty ratio of the upper pipe of power supply resonance oscillation semi-bridge still keeps 30% constant.Its benefit is the impulse current that can limit after the magnetron starting of oscillation of microwave oven, prevents that variable frequency power supply from collapsing because of the operating state sudden change that impulse current causes.
When just starting, as shown in Figure 2, H is that upper pipe drives sequential chart to the drive waveforms of the top tube and down tube of power supply resonance oscillation semi-bridge, and L is that lower pipe drives sequential chart.The drive level of the top tube and down tube of power supply resonance oscillation semi-bridge is complementary in sequential, and not etc., both duty ratio sums do not add that Dead Time is 100% to pulsewidth; The duty ratio of upper switching tube is progressively increased by initial duty cycle 10%, and the duty ratio of lower switching tube approaches 90% by initial duty cycle and gradually reduces (in Fig. 2, Dead Time is not drawn).Wide by the asymmetric tune to pipe up and down, effectively control the resonant energy of resonance oscillation semi-bridge, thereby controlled the power of output.
Fig. 3 shows the microwave oven supply power starting oscillogram of the present embodiment, and at its starting initial stage, its switching frequency is fixing 60KHZ, and its duty ratio progressively increases since 10%.
Fig. 4 shows the microwave oven supply power output voltage waveform of the present embodiment, because the restriction of duty ratio, its output voltage is limited in 6000V, has had larger improvement with respect to the 11000V of conventional microwave oven, and the stress of output diode is reduced greatly.
The present invention has produced following beneficial effect simultaneously: the operating frequency of switching tube IGBT is reduced, without using expensive High Speed I GBT pipe; Switching device current stress is effectively suppressed; Be the output voltage that has reduced power supply, can prevent that overvoltage is added on magnetron, and be conducive to improve the reliability of rear class rectifying tube.
Claims (3)
1. a frequency-conversion microwave oven power supply soft-starting method, it is characterized in that, when power supply starting, the switching frequency of power supply resonance oscillation semi-bridge switching tube is the 110-200% of microwave oven maximum operating frequency while normally working, the highest frequency during a little more than normal work, and the initial duty cycle of switching tube is 1-15%, under the constant condition of maintained switch frequency, progressively increase duty ratio, in the time that duty ratio reaches 25-45%, soft start completes; Keep subsequently duty ratio constant, improve power by the mode of frequency modulation and carry out filament pre-heating.
2. frequency-conversion microwave oven power supply soft-starting method according to claim 1, is characterized in that, the stride of duty ratio adjustment is that each switch periods increases 0.1-1%.
3. frequency-conversion microwave oven power supply soft-starting method according to claim 1, is characterized in that, the drive level of the top tube and down tube of power supply resonance oscillation semi-bridge is complementary in sequential, and not etc., top tube and down tube duty ratio sum does not add that Dead Time is 100% to pulsewidth; The duty ratio of above-mentioned switching tube is progressively increased by initial duty cycle, and referring to pulsewidth in two switching tubes is progressively increased by initial duty cycle compared with the duty ratio of P cock pipe.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201110304437.0A CN102404892B (en) | 2011-10-10 | 2011-10-10 | Power supply soft start method of variable-frequency microwave oven |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201110304437.0A CN102404892B (en) | 2011-10-10 | 2011-10-10 | Power supply soft start method of variable-frequency microwave oven |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102404892A CN102404892A (en) | 2012-04-04 |
| CN102404892B true CN102404892B (en) | 2014-06-04 |
Family
ID=45886541
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201110304437.0A Active CN102404892B (en) | 2011-10-10 | 2011-10-10 | Power supply soft start method of variable-frequency microwave oven |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102404892B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9590492B2 (en) * | 2014-12-18 | 2017-03-07 | Infineon Technologies Austria Ag | System and method for a switched-mode power supply |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0074391B1 (en) * | 1981-03-11 | 1987-09-02 | Ncr Corporation | Regulated power supply |
| KR930011812B1 (en) * | 1990-12-29 | 1993-12-21 | 주식회사 금성사 | Control circuit of microwave oven |
| CN1293882A (en) * | 1999-01-13 | 2001-05-02 | 通用电气公司 | Combanation oven using radiant and microwave energy |
| CN101336016A (en) * | 2008-08-04 | 2008-12-31 | 深圳和而泰智能控制股份有限公司 | Micro-wave oven soft starting method and starting apparatus |
| CN101399504A (en) * | 2007-09-27 | 2009-04-01 | 智原科技股份有限公司 | Full digital soft starting circuit and electric supply system applying the circuit |
| CN201319677Y (en) * | 2008-12-02 | 2009-09-30 | 佛山市顺德区瑞德电子实业有限公司 | Switch power supply for microwave oven magnetron |
| CN201967173U (en) * | 2011-03-18 | 2011-09-07 | 德州学院 | Soft-start computer-controlled microwave oven |
-
2011
- 2011-10-10 CN CN201110304437.0A patent/CN102404892B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0074391B1 (en) * | 1981-03-11 | 1987-09-02 | Ncr Corporation | Regulated power supply |
| KR930011812B1 (en) * | 1990-12-29 | 1993-12-21 | 주식회사 금성사 | Control circuit of microwave oven |
| CN1293882A (en) * | 1999-01-13 | 2001-05-02 | 通用电气公司 | Combanation oven using radiant and microwave energy |
| CN101399504A (en) * | 2007-09-27 | 2009-04-01 | 智原科技股份有限公司 | Full digital soft starting circuit and electric supply system applying the circuit |
| CN101336016A (en) * | 2008-08-04 | 2008-12-31 | 深圳和而泰智能控制股份有限公司 | Micro-wave oven soft starting method and starting apparatus |
| CN201319677Y (en) * | 2008-12-02 | 2009-09-30 | 佛山市顺德区瑞德电子实业有限公司 | Switch power supply for microwave oven magnetron |
| CN201967173U (en) * | 2011-03-18 | 2011-09-07 | 德州学院 | Soft-start computer-controlled microwave oven |
Also Published As
| Publication number | Publication date |
|---|---|
| CN102404892A (en) | 2012-04-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103138541B (en) | Drive transformer isolation self-adaptation drive circuit | |
| CN104600998A (en) | Method for controlling uniform heating of switch device of switch power source | |
| CN110719035B (en) | Topological structure of single-stage DAB-LLC hybrid bidirectional DC-DC converter | |
| CN108422065B (en) | Pulse MIG welding power supply system based on CAN field bus and LLC resonant converter and control method thereof | |
| CN111682769B (en) | Self-adaptive synchronous rectification digital control method of active clamp forward converter | |
| CN102097970B (en) | Soft switching inverting circuit and control method thereof | |
| CN108631604B (en) | Environment-friendly double-transformer type zero-current resonance three-level direct current converter | |
| CN103986315A (en) | Active grid current control mode-based insulated gate bipolar transistor (IGBT) current source and control method thereof | |
| CN201623652U (en) | Full bridge inverter circuit and unidirection inverter power supply comprising the same | |
| CN103066826B (en) | Soft-start system of switching power supply converter | |
| CN115642805A (en) | ZVS-based six-switch buck-boost converter | |
| CN112069758A (en) | LLC converter soft start parameter optimization method based on simplified numerical model | |
| CN105763034B (en) | A kind of full-bridge LLC converters digital soft start method | |
| CN109698627B (en) | Full-bridge DC/DC converter based on switched capacitor and modulation strategy thereof | |
| CN101232752B (en) | Microwave oven supply power soft switch high-frequency converter | |
| CN100588092C (en) | Controlling circuit of zero voltage zero current soft-switching arc welding inverter | |
| CN102404892B (en) | Power supply soft start method of variable-frequency microwave oven | |
| CN104300780B (en) | Large power non-isolation DC/DC soft switching circuit | |
| CN108809137A (en) | A kind of auxiliary resonance pole inverter circuit simple in structure | |
| CN110224605B (en) | Full-bridge conversion circuit | |
| CN109462334B (en) | DC/DC bidirectional inverter circuit and control method thereof | |
| CN103475198B (en) | What be applicable to two-tube soft switch transducer determines ON time Mode Feedback control circuit | |
| CN110086368B (en) | Light load efficiency optimization scheme of full-bridge inverter based on intermittent current mode | |
| CN201918896U (en) | Controlling circuit for improving working current of switched reluctance motor and direct-current motor | |
| CN111064360A (en) | BUCK converter and control method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20170818 Address after: 412000 No. 1728, Taishan Road, Tianyuan District, Hunan, Zhuzhou Patentee after: Zhuzhou Megmeet Electrical Co., Ltd. Address before: 518000 Shenzhen science and technology zone, Nanshan District Province, North District, road, No. 13, Thunis science and Technology Park, layer 5 Patentee before: Shenzhen Megmeet Electrical Co., Ltd. |