CN109617023A - A kind of frequency converter over-current protection method, device and frequency converter - Google Patents
A kind of frequency converter over-current protection method, device and frequency converter Download PDFInfo
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- CN109617023A CN109617023A CN201811642242.5A CN201811642242A CN109617023A CN 109617023 A CN109617023 A CN 109617023A CN 201811642242 A CN201811642242 A CN 201811642242A CN 109617023 A CN109617023 A CN 109617023A
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- frequency converter
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- overcurrent protection
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- 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
- H02H7/1203—Circuits independent of the type of conversion
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Emergency Protection Circuit Devices (AREA)
Abstract
The invention discloses a kind of frequency converter over-current protection method, device and frequency converters, this method comprises: the current value of S1. monitoring frequency converter；S2. when the current value is more than or equal to preset first current threshold and the duration is more than or equal to preset first time threshold, frequency converter overcurrent protection enabling signal is triggered；S3. according to the frequency converter overcurrent protection enabling signal, start frequency converter overcurrent protection；The device includes current monitoring module, computing module and overcurrent protection module；The frequency converter includes the device.The present invention has the advantages of implementation is simple, can effectively realize multiple protective, high reliablity, not only can guarantee the safe and stable operation of frequency convertor system, but also can guarantee system not and will receive long-term extreme operating condition influence, greatly promote system stability.
Description
Technical field
The present invention relates to frequency converter overcurrent protection field more particularly to a kind of frequency converter over-current protection methods, device and change
Frequency device.
Background technique
Requirement with user to power and low-carbon energy-saving is constantly promoted, and Variable Frequency Drives are applied towards high-power, is
At most the trend development of platform frequency converter parallel connection, more and more big-power transducers begin trying used in parallel.
But since during used in parallel, every frequency converter has the successive of starting as desired in use, after
The frequency converter of investment is in the moment of access power grid, since the frequency converter with leading access power grid is there are voltage difference, cause to occur compared with
The dash current of big several times when normal work will trigger once dash current is more than protection threshold value since system fluctuation is larger
Frequency converter protects delay machine, system crash.Firstly, when the investment of separate unit frequency converter, all frequency converters all will be by whole system
Rush of current, it is however generally that, frequency converter has acquisition and threshold value protection to current value, once dash current is larger, that is, can trigger
Correlation protection, leads to frequency converter delay machine, and system operation is a greater impact.If secondly, having frequency converter delay machine in system, necessarily again
There is new frequency converter investment demand, puts into frequency converter equally exist risk again, cause vicious circle, the system of may cause collapses
It bursts.
For most of existing system only with separate unit frequency converter equipment, system stability is relatively high at present, rush of current
Although in the presence of, it is protecting within threshold value, the probability for overcurrent protection occur is smaller, generally only with the strategy of hardware protection,
Once protection just restarts, influence smaller.Under particular surroundings, rush of current is larger, generally only with relieving current protection door
Cancel the strategy of the protection in sill or certain time.When in parallel using multi-frequency converter or the work of separate unit frequency converter is in power grid wave
Move in biggish environment or system there are other loads, will greatly increase system exception possibility, cause dash current compared with
Greatly, system is frequently protected, and is unable to run.According to the method for promoting threshold protection value, it will be chronically at frequency converter larger
In the risk of rush of current, significant impact will be brought to frequency converter performance and related device for a long time.According to being taken in certain time
Disappear the strategy of overcurrent protection, equally exists above-mentioned possibility, in addition by huge current flow moment impact and damage device.Therefore,
How system frequency converter investment during stability and high efficiency is ensured, also ensuring that frequency converter, there are service life, property not due to rush of current
The risks such as energy, are a urgent problems to be solved.
Summary of the invention
The technical problem to be solved in the present invention is that, for technical problem of the existing technology, the present invention provides one
Kind implementation is simple, can effectively realize multiple protective, high reliablity, both can guarantee the safe and stable operation of frequency convertor system,
Can guarantee system again not and will receive that long-term extreme operating condition influences, greatly promote system stability frequency converter over-current protection method,
Device and frequency converter.
In order to solve the above technical problems, technical solution proposed by the present invention are as follows: a kind of frequency converter over-current protection method, including
Following steps:
S1. the current value of frequency converter is monitored；
S2. when the current value is more than or equal to preset first current threshold and the duration is more than or equal to preset first
When time threshold, frequency converter overcurrent protection enabling signal is triggered；
S3. according to the frequency converter overcurrent protection enabling signal, start frequency converter overcurrent protection.
It further include step S2a, specific steps as the further improvement of this method are as follows:
S2a. when occurring repeatedly the current value within the preset time cycle more than or equal to preset first electric current
Threshold value, but the duration be less than the preset first time threshold number be greater than preset early warning number when, trigger frequency conversion
Device overcurrent protection enabling signal.
It further include step S2b as the further improvement of this method, specific steps include:
S2b. when the current value is more than or equal to preset second current threshold, triggering frequency converter overcurrent protection is opened
Dynamic signal；Second current threshold is greater than first current threshold.
A kind of frequency converter overcurrent protective device, including current monitoring module, computing module and overcurrent protection module；The electricity
Stream monitoring modular is used to monitor the current value of frequency converter；The computing module is used to be more than or equal to preset the when the current value
When one current threshold and duration are more than or equal to preset first time threshold, frequency converter overcurrent protection enabling signal is triggered；
The overcurrent protection module is used to start frequency converter overcurrent protection according to the frequency converter overcurrent protection enabling signal.
As the further improvement of the present apparatus, the computing module is also used to work as and occur repeatedly within the preset time cycle
The current value is more than or equal to preset first current threshold, but the duration is less than the preset first time threshold
Number be greater than preset early warning number when, trigger frequency converter overcurrent protection enabling signal.
As the further improvement of the present apparatus, the computing module is also used to be more than or equal to described preset when the current value
The second current threshold when, trigger frequency converter overcurrent protection enabling signal；Second current threshold is greater than first electric current
Threshold value.
As the further improvement of the present apparatus, the current monitoring module is also used to when the current value is more than or equal to described
When preset second current threshold, frequency converter overcurrent protection enabling signal is triggered；Second current threshold is greater than described first
Current threshold.
A kind of frequency converter, including frequency converter overcurrent protective device as described above.
Compared with the prior art, the advantages of the present invention are as follows: implementation of the present invention is simple, it is only necessary to monitoring current value,
Multiple protective can be effectively realized in the case where not increasing additional hardware equipment by the protection type for defining different, so that
Under the rush of current of parallel connection transmission system, it can still guarantee the safe operation of frequency converter, guarantee system not will receive long-term pole
Operating condition is held to influence, significant increase system stability is at low cost, easy to spread.
Detailed description of the invention
Fig. 1 is specific embodiment of the invention flow diagram one.
Fig. 2 is specific embodiment of the invention flow diagram two.
Fig. 3 is frequency converter of the present invention protection triggering schematic diagram one.
Fig. 4 is frequency converter of the present invention protection triggering schematic diagram two.
Fig. 5 is frequency converter of the present invention protection triggering schematic diagram three.
Fig. 6 is frequency converter of the present invention protection triggering schematic diagram four.
Fig. 7 is specific embodiment of the invention structural schematic diagram one.
Fig. 8 is specific embodiment of the invention structural schematic diagram two.
Specific embodiment
Below in conjunction with Figure of description and specific preferred embodiment, the invention will be further described, but not therefore and
It limits the scope of the invention.
Embodiment one:
As shown in Figure 1, the present embodiment frequency converter over-current protection method, includes the following steps: the electric current of S1. monitoring frequency converter
Value；S2. when current value is more than or equal to preset first current threshold and the duration is more than or equal to preset first time threshold
When, trigger frequency converter overcurrent protection enabling signal；S3. according to frequency converter overcurrent protection enabling signal, start frequency converter overcurrent and protect
Shield.
It in the present embodiment, further include step S2a, specific steps are as follows: S2a. is repeatedly sent out when within the preset time cycle
Raw current value is more than or equal to preset first current threshold, but the duration is greater than less than the number of preset first time threshold
When preset early warning number, frequency converter overcurrent protection enabling signal is triggered.It further include step S2b, specific steps include: that S2b. works as
When current value is more than or equal to preset second current threshold, frequency converter overcurrent protection enabling signal is triggered；Second current threshold is big
In the first current threshold.
As shown in figure 3, the current value of the frequency converter monitored at the T0 moment is greater than preset first current threshold, then start to open
Dynamic timing, during timing, the current value of monitoring is always held at the state more than or equal to preset first current threshold,
When the time of timing being greater than preset first time threshold T, i.e., at the T1 moment, frequency converter overcurrent protection enabling signal is triggered,
Start the overcurrent protection of frequency converter.By such overcurrent protection strategy, frequency converter can be prevented to be in the shape of high current for a long time
State causes the damage of equipment.
As shown in figure 4, being greater than preset first current threshold, the current status in the current value that the T0 moment monitors frequency converter
Duration when not reaching preset first time threshold, the time difference between T1 and T0 is less than preset first time
Threshold value monitors that current value is greater than preset second current threshold, which is greater than the first electric current that is, at the T1 moment
Threshold value, at this point, directly triggering frequency converter overcurrent protection enabling signal.Alternatively, as shown in figure 5, monitoring frequency conversion at the T0 moment
The electric current of device is greater than big second current threshold, then directly triggers the overcurrent protection signal of frequency converter.Plan is protected by such process
Slightly, the impact caused by equipment of instantaneous high current can be prevented.
As shown in fig. 6, being greater than preset first current threshold in the current value that the T0 moment monitors frequency converter, also, in T1
At the moment, which falls after rise to less than the first current threshold, and in the process, T0 to the time difference between T1 is less than default
First time threshold, and within the time of T0 to T1, the current value monitored is not greater than preset second current threshold, then
Record frequency converter, which has occurred, once not to be needed to directly initiate the overcurrent of overcurrent protection.In the present embodiment, if it is preset pre-
Alert number is 3, is a time cycle for being greater than T0 to T5 time span in the preset time cycle.When monitoring at the T2 moment
Monitoring current value is greater than the first current threshold again, and when falling after rise to normal lower than the first current threshold at the T3 moment again, then
It is 2 that record frequency converter, which has occurred and do not need to directly initiate the number of the overcurrent of overcurrent protection, is monitored again when at the T4 moment
When being greater than the first current threshold to current value, then determines that 3 primary current overcurrents have occurred within the preset time cycle, then trigger change
The overcurrent protection signal of frequency device.
As shown in fig. 7, the present embodiment frequency converter overcurrent protective device, including current monitoring module, computing module and overcurrent
Protective module；Current monitoring module is used to monitor the current value of frequency converter；Computing module is used to preset when current value is more than or equal to
The first current threshold and the duration be more than or equal to preset first time threshold when, triggering frequency converter overcurrent protection starting letter
Number；Overcurrent protection module is used to start frequency converter overcurrent protection according to frequency converter overcurrent protection enabling signal.
Computing module is also used to electric more than or equal to preset first when occurring repeatedly current value within the preset time cycle
Flow threshold value, but the duration be less than preset first time threshold number be greater than preset early warning number when, trigger frequency converter
Overcurrent protection enabling signal.Computing module is also used to trigger frequency conversion when current value is more than or equal to preset second current threshold
Device overcurrent protection enabling signal；Second current threshold is greater than the first current threshold.In the present embodiment, the overcurrent protection of frequency converter
It is triggered by computing module.
A kind of frequency converter of the present embodiment, including frequency converter overcurrent protective device as described above.
Embodiment two:
The present embodiment and embodiment one are almost the same, the difference is that, frequency converter over-current protection method, as shown in Fig. 2,
The deterministic process of step S2b is before step S2.Which kind of certainly, monitoring current value is judged, according to strategy starting overcurrent
The sequence of protection can be adjusted flexibly as needed.In the present embodiment, as shown in figure 8, frequency converter overcurrent protective device passes through electric current
Monitoring modular judges monitoring current value, when current value is more than or equal to preset second current threshold, triggers frequency conversion
Device overcurrent protection enabling signal；Second current threshold is greater than the first current threshold.Since instantaneous high current may be extremely short
The damage of frequency converter is caused in time, and current monitoring module acquires current data, and is sent to computing module and calculate and divide
Analysis, when current value is greater than the second current threshold, triggering overcurrent protection is also required to execute the time, may cause guard delay, up to not
To optimal protecting effect, therefore, in the present embodiment, monitoring current value is judged by current monitoring module, when big
When the second current threshold, overcurrent protection signal is directly triggered by current monitoring module, frequency converter is started by overcurrent protection module
Overcurrent protection, thus the safe operation of effective protection frequency converter.The frequency converter of the present embodiment uses the overcurrent protection of the present embodiment
Device.
Above-mentioned only presently preferred embodiments of the present invention, is not intended to limit the present invention in any form.Although of the invention
It has been disclosed in a preferred embodiment above, however, it is not intended to limit the invention.Therefore, all without departing from technical solution of the present invention
Content, technical spirit any simple modifications, equivalents, and modifications made to the above embodiment, should all fall according to the present invention
In the range of technical solution of the present invention protection.
Claims (8)
1. a kind of frequency converter over-current protection method, which comprises the steps of:
S1. the current value of frequency converter is monitored；
S2. when the current value is more than or equal to preset first current threshold and the duration is more than or equal to preset first time
When threshold value, frequency converter overcurrent protection enabling signal is triggered；
S3. according to the frequency converter overcurrent protection enabling signal, start frequency converter overcurrent protection.
2. frequency converter over-current protection method according to claim 1, which is characterized in that further include step S2a, specific steps
Are as follows:
S2a. when occurring repeatedly the current value within the preset time cycle more than or equal to preset first current threshold,
But when the number that the duration is less than the preset first time threshold is greater than preset early warning number, trigger frequency converter overcurrent
Protect enabling signal.
3. frequency converter over-current protection method according to claim 1, which is characterized in that further include step S2b, specific steps
Include:
S2b. when the current value is more than or equal to preset second current threshold, triggering frequency converter overcurrent protection starting letter
Number；Second current threshold is greater than first current threshold.
4. a kind of frequency converter overcurrent protective device, it is characterised in that: including current monitoring module, computing module and overcurrent protection mould
Block；The current monitoring module is used to monitor the current value of frequency converter；The computing module be used for when the current value be greater than etc.
In preset first current threshold and when the duration is more than or equal to preset first time threshold, frequency converter overcurrent protection is triggered
Enabling signal；The overcurrent protection module is used to start frequency converter overcurrent according to the frequency converter overcurrent protection enabling signal and protect
Shield.
5. frequency converter overcurrent protective device according to claim 4, it is characterised in that: the computing module is also used to work as
The current value is occurred repeatedly in the preset time cycle more than or equal to preset first current threshold, but the duration is small
When the number of the preset first time threshold is greater than preset early warning number, triggering frequency converter overcurrent protection starting letter
Number.
6. frequency converter overcurrent protective device according to claim 4, it is characterised in that: the computing module is also used to work as institute
When stating current value more than or equal to preset second current threshold, frequency converter overcurrent protection enabling signal is triggered；Described second
Current threshold is greater than first current threshold.
7. frequency converter overcurrent protective device according to claim 4, it is characterised in that: the current monitoring module is also used to
When the current value is more than or equal to preset second current threshold, frequency converter overcurrent protection enabling signal is triggered；It is described
Second current threshold is greater than first current threshold.
8. a kind of frequency converter, it is characterised in that: including the described in any item frequency converter overcurrent protective devices of such as claim 4 to 7.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811642242.5A CN109617023A (en) | 2018-12-29 | 2018-12-29 | A kind of frequency converter over-current protection method, device and frequency converter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811642242.5A CN109617023A (en) | 2018-12-29 | 2018-12-29 | A kind of frequency converter over-current protection method, device and frequency converter |
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| Publication Number | Publication Date |
|---|---|
| CN109617023A true CN109617023A (en) | 2019-04-12 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811642242.5A Withdrawn CN109617023A (en) | 2018-12-29 | 2018-12-29 | A kind of frequency converter over-current protection method, device and frequency converter |
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| CN (1) | CN109617023A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111341084A (en) * | 2020-01-21 | 2020-06-26 | 深圳科绪技术有限公司 | Electric quantity early warning method, electric quantity early warning system and computer storage medium |
-
2018
- 2018-12-29 CN CN201811642242.5A patent/CN109617023A/en not_active Withdrawn
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111341084A (en) * | 2020-01-21 | 2020-06-26 | 深圳科绪技术有限公司 | Electric quantity early warning method, electric quantity early warning system and computer storage medium |
| CN111341084B (en) * | 2020-01-21 | 2021-09-03 | 深圳科绪技术有限公司 | Electric quantity early warning method, electric quantity early warning system and computer storage medium |
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| PB01 | Publication | ||
| PB01 | Publication | ||
| WW01 | Invention patent application withdrawn after publication |
Application publication date: 20190412 |
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| WW01 | Invention patent application withdrawn after publication |