CN110137912B - No-load protection method for BOOST booster circuit - Google Patents
No-load protection method for BOOST booster circuit Download PDFInfo
- Publication number
- CN110137912B CN110137912B CN201910464855.2A CN201910464855A CN110137912B CN 110137912 B CN110137912 B CN 110137912B CN 201910464855 A CN201910464855 A CN 201910464855A CN 110137912 B CN110137912 B CN 110137912B
- Authority
- CN
- China
- Prior art keywords
- duty ratio
- preset
- output voltage
- boost circuit
- pwm wave
- 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
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
- G01R19/165—Indicating that current or voltage is either above or below a predetermined value or within or outside a predetermined range of values
- G01R19/16566—Circuits and arrangements for comparing voltage or current with one or several thresholds and for indicating the result not covered by subgroups G01R19/16504, G01R19/16528, G01R19/16533
- G01R19/16571—Circuits and arrangements for comparing voltage or current with one or several thresholds and for indicating the result not covered by subgroups G01R19/16504, G01R19/16528, G01R19/16533 comparing AC or DC current with one threshold, e.g. load current, over-current, surge current or fault current
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
- G01R19/165—Indicating that current or voltage is either above or below a predetermined value or within or outside a predetermined range of values
- G01R19/16566—Circuits and arrangements for comparing voltage or current with one or several thresholds and for indicating the result not covered by subgroups G01R19/16504, G01R19/16528, G01R19/16533
- G01R19/16576—Circuits and arrangements for comparing voltage or current with one or several thresholds and for indicating the result not covered by subgroups G01R19/16504, G01R19/16528, G01R19/16533 comparing DC or AC voltage with one threshold
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/10—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers
- H02H7/12—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers
- H02H7/1213—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers for DC-DC converters
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Dc-Dc Converters (AREA)
- Circuit Arrangement For Electric Light Sources In General (AREA)
Abstract
The invention relates to a BOOST drive circuit control technology, and solves the problems of high cost and poor protection effect in no-load protection of the conventional BOOST booster circuit. The technical scheme is summarized as follows: a BOOST booster circuit no-load protection method is based on the existing BOOST booster circuit, the output current and the output voltage of the BOOST booster circuit are judged through software, whether a load is open-circuited is judged according to the output current, whether output is overshot or not is judged according to the output voltage, the overshot frequency is recorded, the duty ratio of a PWM wave is correspondingly adjusted according to the judgment result, and the no-load protection function of the BOOST booster circuit is achieved. The beneficial effects are that: the invention does not need to add a new no-load protection hardware circuit, has lower cost, directly resets the duty ratio of the PWM wave to 0 when the output voltage overshoots, reduces the output voltage to the minimum and has better no-load protection effect. The invention is particularly applicable to solar lighting systems.
Description
Technical Field
The invention relates to a BOOST drive circuit control technology, in particular to a BOOST booster circuit no-load protection technology.
Background
The BOOST constant current circuit is one of important circuit functional modules, in a solar lighting system, the BOOST constant current circuit is often used for driving an LED load, however, the output voltage of the BOOST constant current circuit has an obvious overshoot phenomenon, that is, the output voltage is obviously higher than a target voltage when the BOOST constant current circuit is started, which brings a risk of damage to a back-end circuit and the LED load; in addition, when the load of the BOOST circuit is open, the output voltage of the BOOST circuit will continuously rise, which brings a risk of damage to the back-end circuit. The existing BOOST booster circuit no-load protection method is to restrain the output voltage of the BOOST booster circuit when the load is open by designing a hardware circuit, and has the following defects: hardware needs to be added newly, cost is high, a hardware circuit only relatively inhibits output voltage and cannot reduce the output voltage to the minimum, the risk that a rear-end circuit is damaged still exists, and protection effect is poor.
Disclosure of Invention
The invention provides a no-load protection method for a BOOST circuit, which aims to solve the problems of high cost and poor protection effect in the no-load protection of the existing BOOST circuit.
In order to solve the problems, the invention adopts the technical scheme that: the BOOST booster circuit no-load protection method comprises the following steps:
starting a BOOST circuit, initializing a count value of a preset counter to be 0, and controlling the duty ratio of a PWM wave input into the BOOST circuit according to a preset rule;
detecting the output current of the BOOST circuit, if the output current is smaller than a preset output current threshold value, executing a fourth step, otherwise executing a third step;
clearing the count value of the counter, and then executing the step two;
step four, detecting the output voltage of the BOOST circuit, setting the duty ratio of the PWM wave as a preset first duty ratio if the output voltage is greater than a preset output voltage threshold value, adding 1 to the count value of the counter, and then executing step five, otherwise executing step two;
and step five, judging whether the count value of the counter is greater than a preset count threshold value, if so, stopping controlling the duty ratio of the PWM wave according to a preset rule, setting the duty ratio of the PWM wave to be 0, and otherwise, executing the step two.
As a further optimization, the preset rule employs: and when the duty ratio of the PWM wave is larger than or equal to the preset second duty ratio, the duty ratio of the PWM wave is controlled by a preset duty ratio feedback loop.
As a further optimization, the third step further includes: controlling an operating state indicator lamp of the BOOST circuit to be normally on; the fourth step further comprises: if the output voltage is greater than the preset output voltage threshold value, controlling an operation state indicator lamp of the BOOST circuit to flicker; the fifth step further comprises: and if the count value of the counter is greater than the preset count threshold value, controlling the running state indicator lamp of the BOOST circuit to flicker.
As a further optimization, the initial value of the duty ratio of the PWM wave input to the BOOST voltage-boosting circuit in the first step is 0.
As a further optimization, the first duty cycle preset in the fourth step is 0.
The beneficial effects are that: based on the existing BOOST circuit, the output current and the output voltage of the BOOST circuit are judged through software, and corresponding control is performed according to the judgment result, so that the no-load protection function of the BOOST circuit is realized. The invention is particularly applicable to solar lighting systems.
Drawings
FIG. 1 is a flow chart of an embodiment of the present invention.
Detailed Description
The technical solution of the present invention will be described in detail with reference to examples.
The invention provides a BOOST booster circuit no-load protection method, which comprises the following steps:
starting a BOOST circuit, initializing a count value of a preset counter to be 0, and controlling the duty ratio of a PWM wave input into the BOOST circuit according to a preset rule; the BOOST circuit is started through the steps, so that the BOOST circuit can output voltage and current.
Detecting the output current of the BOOST circuit, if the output current is smaller than a preset output current threshold value, executing a fourth step, otherwise executing a third step; and judging the condition of the output current through the steps, wherein if the output current is smaller than the output current threshold value, the load is open-circuited, the BOOST circuit is in an idle state, if the output current is larger than or equal to the output current threshold value, the load is normal, and the BOOST circuit is in a normal output state.
Clearing the count value of the counter, and then executing the step two; when the load is normal, the overshoot times of the output voltage are counted again, and whether the load is open-circuited or not is judged in a circulating mode.
Step four, detecting the output voltage of the BOOST circuit, setting the duty ratio of the PWM wave as a preset first duty ratio if the output voltage is greater than a preset output voltage threshold value, adding 1 to the count value of a preset counter, and then executing step five, otherwise, executing step two; when the load is opened, the output voltage of the BOOST circuit can continuously rise, when the output voltage is larger than the output voltage threshold value, the output voltage is overshot, the duty ratio of a PWM wave is set to a small value to reduce the output voltage, the voltage overshooting frequency is added with 1, and then whether the voltage overshooting frequency reaches the overshooting frequency threshold value or not is judged; when the output voltage is smaller than or equal to the output voltage threshold value, the output voltage is not overshot, and whether the load is open-circuited or not is judged circularly at the moment.
And step five, judging whether the count value of the counter is greater than a preset count threshold value, if so, stopping controlling the duty ratio of the PWM wave according to a preset rule, setting the duty ratio of the PWM wave to be 0, and otherwise, executing the step two. The purpose of setting the overshoot frequency threshold is to eliminate the influence of a disturbance signal in the circuit on the judgment of the load state, when the voltage overshoot frequency is greater than the overshoot frequency threshold, the load is indicated to be actually opened, at this time, the control of the duty ratio of the PWM wave is stopped, and the duty ratio of the PWM wave is set to be 0, so that the output of the BOOST circuit is closed, and the back-end circuit is protected; when the voltage overshoot number is less than or equal to the overshoot number threshold, the output current condition of the BOOST circuit needs to be further judged to determine whether the load is actually open.
The above steps are further optimized, and specifically, the method may include:
the preset rule may be: and when the duty ratio of the PWM wave is larger than or equal to the preset second duty ratio, the duty ratio of the PWM wave is controlled by a preset duty ratio feedback loop. When the duty ratio of the PWM wave is smaller than a certain preset value, the duty ratio of the PWM wave is slowly increased to realize the soft start of the BOOST circuit and prevent the output voltage from overshooting in the starting process, and when the duty ratio of the PWM wave is larger than or equal to the preset value, the duty ratio of the PWM wave is adjusted through a normal feedback loop.
The third step may further include: controlling an operating state indicator lamp of the BOOST circuit to be normally on; the fourth step may further include: if the output voltage is greater than the preset output voltage threshold value, controlling an operation state indicator lamp of the BOOST circuit to flicker; the fifth step may further include: and if the count value of the counter is greater than the preset count threshold value, controlling the running state indicator lamp of the BOOST circuit to flicker. The running state of the BOOST circuit is fed back to relevant personnel through different lighting forms of the indicator lamp, so that the relevant personnel can know and process faults in time.
And adopting 0 as the initial value of the duty ratio of the PWM wave input into the BOOST circuit in the first step. At the time of starting, the duty ratio of the PWM wave is preferably increased gradually from 0, and the overshoot prevention effect is better.
And the first duty ratio preset in the fourth step is 0. When the output voltage overshoots, the duty ratio of the PWM wave is preferably directly reset to 0, the output voltage is reduced to the minimum, the rear-end circuit is prevented from being damaged due to overlarge output voltage, and the no-load protection effect is better.
Examples
The following specifically exemplifies the technical solution of the present invention.
The no-load protection method of the BOOST circuit in this embodiment, as shown in fig. 1, includes:
step S1, starting the BOOST circuit, initializing the count value of a preset counter to 0, and controlling the duty ratio of the PWM wave input into the BOOST circuit according to a preset rule, wherein the preset rule is as follows: the initial value of the duty ratio of the PWM wave is 0, when the duty ratio of the PWM wave is less than 30%, the duty ratio of the PWM wave is increased by steps of 0.01, and when the duty ratio of the PWM wave is greater than or equal to 30%, the duty ratio of the PWM wave is controlled by a preset duty ratio feedback loop.
And step S2, detecting the output current of the BOOST circuit, executing step S4 if the output current is smaller than a preset output current threshold, otherwise executing step S3.
Step S3: clearing the count value of the counter, controlling the running state indicator lamp of the BOOST circuit to be normally on, and then executing the step S2;
step S4, detecting the output voltage of the BOOST circuit, if the output voltage is larger than the preset output voltage threshold, executing step S5, otherwise executing step S2;
step S5: setting the duty ratio of the PWM wave to be 0, adding 1 to the count value of a preset counter, controlling an operation state indicator lamp of the BOOST circuit to flicker, and then executing the step S6;
step S6, judging whether the count value of the counter is greater than 3, if so, executing step S7, otherwise, executing step S2;
step S7: and stopping controlling the duty ratio of the PWM wave according to a preset rule, setting the duty ratio of the PWM wave to be 0, and controlling the running state indicator lamp of the BOOST circuit to flicker.
Claims (4)
- The BOOST booster circuit no-load protection method is characterized by comprising the following steps:starting a BOOST circuit, initializing a count value of a preset counter to be 0, and controlling the duty ratio of a PWM wave input into the BOOST circuit according to a preset rule;detecting the output current of the BOOST circuit, if the output current is smaller than a preset output current threshold value, executing a fourth step, otherwise executing a third step;clearing the count value of the counter, and then executing the step two;step four, detecting the output voltage of the BOOST circuit, setting the duty ratio of the PWM wave as a preset first duty ratio if the output voltage is greater than a preset output voltage threshold value, adding 1 to the count value of the counter, and then executing step five, otherwise executing step two;step five, judging whether the count value of the counter is larger than a preset count threshold value, if so, stopping controlling the duty ratio of the PWM wave according to a preset rule, setting the duty ratio of the PWM wave to be 0, and otherwise, executing the step two; the preset rule adopts: and when the duty ratio of the PWM wave is larger than or equal to the preset second duty ratio, the duty ratio of the PWM wave is controlled by a preset duty ratio feedback loop.
- 2. The BOOST circuit no-load protection method of claim 1, wherein:the third step further comprises: controlling an operating state indicator lamp of the BOOST circuit to be normally on;the fourth step further comprises: if the output voltage is greater than the preset output voltage threshold value, controlling an operation state indicator lamp of the BOOST circuit to flicker;the fifth step further comprises: and if the count value of the counter is greater than the preset count threshold value, controlling the running state indicator lamp of the BOOST circuit to flicker.
- 3. The BOOST circuit no-load protection method according to claim 1, wherein the initial value of the duty ratio of the PWM wave input to the BOOST circuit in the first step is 0.
- 4. The BOOST converter no-load protection method according to claim 1, wherein the first duty cycle preset in the fourth step is 0.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910464855.2A CN110137912B (en) | 2019-05-30 | 2019-05-30 | No-load protection method for BOOST booster circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910464855.2A CN110137912B (en) | 2019-05-30 | 2019-05-30 | No-load protection method for BOOST booster circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110137912A CN110137912A (en) | 2019-08-16 |
| CN110137912B true CN110137912B (en) | 2021-02-19 |
Family
ID=67583031
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910464855.2A Active CN110137912B (en) | 2019-05-30 | 2019-05-30 | No-load protection method for BOOST booster circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110137912B (en) |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106533151A (en) * | 2016-12-05 | 2017-03-22 | 广东美的制冷设备有限公司 | Control method and control device of partial PFC circuit and domestic appliance |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2087857U (en) * | 1991-02-06 | 1991-10-30 | 广州市番禺恒安电器厂 | High-frequency electronic ballast with no-load protective circuit |
| CN102955067B (en) * | 2012-10-24 | 2015-01-07 | 深圳市沛城电子科技有限公司 | Movable power supply discharging current detecting method and system |
| CN104218534B (en) * | 2013-05-30 | 2017-06-16 | 海洋王（东莞）照明科技有限公司 | DC DC switching modes circuits and light fixture with no-load protection |
| US9793790B2 (en) * | 2015-11-24 | 2017-10-17 | Infineon Technologies Austria Ag | Adaptive open-load overvoltage control method and circuit |
| CN205793525U (en) * | 2016-06-08 | 2016-12-07 | 中山市凯迪佳电子有限公司 | There is the dimming drive power of output no-load protection circuit |
| US10587110B2 (en) * | 2017-07-13 | 2020-03-10 | Dialog Semiconductor (Uk) Limited | Over voltage protection system and method |
-
2019
- 2019-05-30 CN CN201910464855.2A patent/CN110137912B/en active Active
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106533151A (en) * | 2016-12-05 | 2017-03-22 | 广东美的制冷设备有限公司 | Control method and control device of partial PFC circuit and domestic appliance |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110137912A (en) | 2019-08-16 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US8680884B2 (en) | Fault detection circuits for switched mode power supplies and related methods of operation | |
| US8294388B2 (en) | Driving system with inductor pre-charging for LED systems with PWM dimming control or other loads | |
| US9198256B2 (en) | Method and apparatus to limit current overshoot and undershoot in light driver | |
| US9192014B2 (en) | LED short circuit protection | |
| US8879217B2 (en) | Switching regulator with negative current limit protection | |
| US8400078B2 (en) | LED driving circuit and driving controller for controlling the same | |
| US20090295776A1 (en) | Light emitting diode driving circuit and controller thereof | |
| US20150373807A1 (en) | Light emitting diode driving apparatus capable of detecting whether current leakage phenomenon occurs on led load and light emitting diode driving method thereof | |
| KR102051694B1 (en) | Leakage currrent detection circuit, light apparatus comprising the same and leakage currrent detection method | |
| US8692471B2 (en) | LED driving system and method | |
| US10616971B1 (en) | LED auto-detect system for wide output voltage range LED drivers | |
| CN104303408A (en) | Power supply circuit for vehicle | |
| TWI434621B (en) | Control methods for led chains | |
| CN103889104A (en) | light emitting diode driving circuit and protection method thereof | |
| US8004333B2 (en) | Power management and control apparatus for resetting a latched protection in a power supply unit | |
| CN110137912B (en) | No-load protection method for BOOST booster circuit | |
| US20130069557A1 (en) | LED Lighting Circuit and LED Luminaire | |
| US20120235596A1 (en) | Led drivers with audible noise elimination and associated methods | |
| CN109541348B (en) | Converter valve submodule controller and driving fault judging method | |
| JP2008130821A (en) | Solenoid drive device | |
| US10447027B1 (en) | Method and apparatus for reverse over current protection | |
| JP2015219959A (en) | Lighting device | |
| CN110677041B (en) | Control method and control device for DC converter | |
| US8928250B2 (en) | Method and circuit for LED load managment | |
| KR20190034103A (en) | Led dimming |
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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |