CN109390914A - The guard method of frequency converter charging circuit and device - Google Patents
The guard method of frequency converter charging circuit and device Download PDFInfo
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- CN109390914A CN109390914A CN201710655015.5A CN201710655015A CN109390914A CN 109390914 A CN109390914 A CN 109390914A CN 201710655015 A CN201710655015 A CN 201710655015A CN 109390914 A CN109390914 A CN 109390914A
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- frequency converter
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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
- H02H7/1216—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 AC-AC converters
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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
- H02M5/00—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases
- H02M5/40—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into dc
- H02M5/42—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into dc by static converters
- H02M5/44—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into dc by static converters using discharge tubes or semiconductor devices to convert the intermediate dc into ac
- H02M5/453—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into dc by static converters using discharge tubes or semiconductor devices to convert the intermediate dc into ac using devices of a triode or transistor type requiring continuous application of a control signal
- H02M5/458—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into dc by static converters using discharge tubes or semiconductor devices to convert the intermediate dc into ac using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Dc-Dc Converters (AREA)
Abstract
This disclosure relates to guard method and the device of a kind of frequency converter charging circuit, for being protected to frequency converter charging circuit；This method comprises: being sampled after frequency converter charging circuit powers on to DC bus-bar voltage；Obtain the change rate of DC bus-bar voltage in real time according to the sampled value of DC bus-bar voltage；The voltage value when change rate for judging whether the change rate of DC bus-bar voltage meets the first preset condition, and recording DC bus-bar voltage meets the first preset condition is reference voltage value；Obtain current voltage value；Judge whether the voltage difference between current voltage value and reference voltage value meets the second preset condition, and determines that relay is improper connection status when meeting the second preset condition；Respond the output of improper connection status cutting frequency converter.Shell of frequency converter scaling loss caused by the disclosure can avoid because of charging resistor fever, to achieve the effect that protect frequency converter charging circuit.
Description
Technical field
This disclosure relates to guard method and the device of electroporation field more particularly to a kind of frequency converter charging circuit.
Background technique
Frequency converter is a kind of device of alternating current that the alternating current of constant voltage constant frequency is converted into variable voltage variable frequency, is handed over to meet
The needs of galvanic electricity motivation frequency control.
Main circuit of converter is to provide the power converting part of voltage regulation and frequency modulation power supply, and basic structure is as shown in Figure 1, packet
It includes: rectification circuit 10, charging circuit 20, braking circuit 30 and inverter circuit 40；Wherein, the charging circuit 20 includes charging electricity
Resistance 21 and storage capacitor 22, and it is parallel to the relay 23 of charging resistor 21.The working principle of the frequency converter is as follows: rectified current
The alternating current received is converted to direct current by road 10, is charged by charging resistor 21 to storage capacitor 22, when charging reaches one
Closing relay 23 is so that charging resistor 21 is short-circuit, to maintain the normal operation of frequency converter after determining degree.So, becoming
Frequency device powered on moment can limit charging current using charging resistor, be slowly increased the voltage at storage capacitor both ends, to realize
Protection to rectifier bridge.Based on above structure, when frequency converter is in operating status, if the relay 23 in charging circuit touches
Point disconnects, and DC current, which will flow through charging resistor 21, causes charging resistor 21 to be generated heat, and long-play easily makes the outer of frequency converter
Shell scaling loss.
It should be noted that information is only used for reinforcing the reason to the background of the disclosure disclosed in above-mentioned background technology part
Solution, therefore may include the information not constituted to the prior art known to persons of ordinary skill in the art.
Summary of the invention
A kind of guard method for being designed to provide frequency converter charging circuit of the disclosure and device, and then at least certain
One or more is overcome the problems, such as caused by the limitation and defect due to the relevant technologies in degree.
Other characteristics and advantages of the disclosure will be apparent from by the following detailed description, or partially by the disclosure
Practice and acquistion.
According to one aspect of the disclosure, a kind of guard method of frequency converter charging circuit is provided, for filling to frequency converter
Circuit is protected；The frequency converter charging circuit include the charging resistor being connected on DC bus and with the charging
The relay of resistor coupled in parallel；The guard method includes:
After the frequency converter charging circuit powers on, DC bus-bar voltage is sampled；
Obtain the change rate of the DC bus-bar voltage in real time according to the sampled value of the DC bus-bar voltage；
Judge whether the change rate of the DC bus-bar voltage meets the first preset condition, and in the DC bus-bar voltage
Change rate when meeting first preset condition, the change rate for recording the DC bus-bar voltage meets the described first default item
Voltage value when part is reference voltage value；
Obtain current voltage value；
Judge whether the voltage difference between the current voltage value and the reference voltage value meets the second preset condition,
And the voltage difference between the current voltage value and the reference voltage value determines institute when meeting second preset condition
Stating relay is improper connection status；
Respond the output of the improper connection status cutting frequency converter.
In a kind of exemplary embodiment of the disclosure, second preset condition are as follows: the current voltage value and the ginseng
The voltage difference examined between voltage value is greater than reference voltage difference.
In a kind of exemplary embodiment of the disclosure, second preset condition are as follows: the current voltage value and the ginseng
It examines the voltage difference between voltage value and is greater than the duration of the reference voltage difference more than preset time.
In a kind of exemplary embodiment of the disclosure, the guard method further include:
After determining that the relay is improper connection status, the response improper connection status, which sounds an alarm, to be mentioned
Show failure.
In a kind of exemplary embodiment of the disclosure, described pair power on after DC bus-bar voltage carry out sampling include:
The DC bus-bar voltage is measured using divider resistance or voltage transformer or isolation optocoupler.
According to another aspect of the disclosure, a kind of protective device of frequency converter charging circuit is provided, for frequency converter
Charging circuit is protected；The frequency converter charging circuit includes the charging resistor being connected on DC bus and fills with described
The relay of electric resistor coupled in parallel；The protective device includes:
Sampling module, for being sampled to DC bus-bar voltage after the frequency converter charging circuit powers on；
First detection module, for obtaining the DC bus-bar voltage in real time according to the sampled value of the DC bus-bar voltage
Change rate；
First determination module, for judging whether the change rate of the DC bus-bar voltage meets the first preset condition, and
When the change rate of the DC bus-bar voltage meets first preset condition, the change rate of the DC bus-bar voltage is recorded
Voltage value when meeting first preset condition is reference voltage value；
Second detection module, for obtaining current voltage value
Second determination module, for whether judging the voltage difference between the current voltage value and the reference voltage value
Meet the second preset condition, and the voltage difference between the current voltage value and the reference voltage value meets described second
When preset condition, determine that the relay is improper connection status；
Control module, for responding the output of the improper connection status cutting frequency converter.
In a kind of exemplary embodiment of the disclosure, second preset condition are as follows: the current voltage value and the ginseng
The voltage difference examined between voltage value is greater than reference voltage difference.
In a kind of exemplary embodiment of the disclosure, second preset condition are as follows: the current voltage value and the ginseng
It examines the voltage difference between voltage value and is greater than the duration of the reference voltage difference more than preset time.
In a kind of exemplary embodiment of the disclosure, the protective device further include:
Alarm module, for responding the improper connection after determining that the relay is improper connection status
State sounds an alarm prompt failure.
In a kind of exemplary embodiment of the disclosure, the sampling module includes:
Divider resistance, for being measured using the divider resistance to the DC bus-bar voltage；Alternatively,
Voltage transformer, for being measured using the voltage transformer to the DC bus-bar voltage；Alternatively,
Isolation optocoupler, for being measured using the isolation optocoupler to the DC bus-bar voltage.
The guard method of frequency converter charging circuit provided by disclosure illustrative embodiments and device are straight by detecting
The connection status of stream busbar voltage changed to judge relay, and the cutting frequency converter in the improper connection of judgement relay
Output, to achieve the purpose that protect frequency converter charging circuit.On the one hand, the connection of relay is judged according to voltage change difference
State, can the influence that generates by measurement error caused by signal interference to the judging result of reduction as far as possible；On the other hand, exist
The output that frequency converter is automatically cut off when the improper connection of relay, can effectively avoid due to DC current flows through charging resistor
Caused resistance heating phenomenon prevents the shell scaling loss of frequency converter, thus the intelligentized guarantor for solving frequency converter charging circuit
Shield problem.
It should be understood that above general description and following detailed description be only it is exemplary and explanatory, not
The disclosure can be limited.
Detailed description of the invention
The drawings herein are incorporated into the specification and forms part of this specification, and shows the implementation for meeting the disclosure
Example, and together with specification for explaining the principles of this disclosure.It should be evident that the accompanying drawings in the following description is only the disclosure
Some embodiments for those of ordinary skill in the art without creative efforts, can also basis
These attached drawings obtain other attached drawings.
Fig. 1 schematically shows the structural schematic diagram of main circuit of converter in the prior art；
Fig. 2 schematically shows the guard method schematic diagram of the frequency converter charging circuit in disclosure exemplary embodiment；
Fig. 3 schematically shows the sampling curve of the DC bus-bar voltage in disclosure exemplary embodiment；
Fig. 4 schematically shows relay in disclosure exemplary embodiment and disconnects post filtering capacitor, output electric current, direct current mother
The change curve schematic diagram of line current；
Fig. 5 schematically shows the protective device schematic diagram of the frequency converter charging circuit in disclosure exemplary embodiment.
Specific embodiment
Example embodiment is described more fully with reference to the drawings.However, example embodiment can be with a variety of shapes
Formula is implemented, and is not understood as limited to example set forth herein；On the contrary, thesing embodiments are provided so that the disclosure will more
Fully and completely, and by the design of example embodiment comprehensively it is communicated to those skilled in the art.Described feature, knot
Structure or characteristic can be incorporated in any suitable manner in one or more embodiments.In the following description, it provides perhaps
More details fully understand embodiment of the present disclosure to provide.It will be appreciated, however, by one skilled in the art that can
It is omitted with technical solution of the disclosure one or more in the specific detail, or others side can be used
Method, constituent element, device, step etc..In other cases, be not shown in detail or describe known solution to avoid a presumptuous guest usurps the role of the host and
So that all aspects of this disclosure thicken.
In addition, attached drawing is only the schematic illustrations of the disclosure, it is not necessarily drawn to scale.Identical attached drawing mark in figure
Note indicates same or similar part, thus will omit repetition thereof.Some block diagrams shown in the drawings are function
Energy entity, not necessarily must be corresponding with physically or logically independent entity.These function can be realized using software form
Energy entity, or these functional entitys are realized in one or more hardware modules or integrated circuit, or at heterogeneous networks and/or place
These functional entitys are realized in reason device device and/or microcontroller device.
A kind of guard method of frequency converter charging circuit is proposed in this example embodiment, it is electric for charging to frequency converter
It is protected on road.Refering to what is shown in Fig. 1, the circuit structure of the frequency converter may include: rectification circuit 10, charging circuit 20, system
Dynamic circuit 30 and inverter circuit 40；The charging circuit 20 includes that a charging resistor 21 being connected on DC bus and one are in parallel
In the relay 23 and storage capacitor 22 of the charging resistor 21；Wherein, described in the input terminal connection of the charging resistor 21
The output end of rectification circuit 10, the output end of the storage capacitor 22 connect the input terminal of the braking circuit 30.
Based on this, as shown in Fig. 2, the guard method of the frequency converter charging circuit may include:
S1, after the frequency converter charging circuit powers on, DC bus-bar voltage is sampled；
S2, the change rate for obtaining the DC bus-bar voltage in real time according to the sampled value of the DC bus-bar voltage；
S3, judge whether the change rate of the DC bus-bar voltage meets the first preset condition, and in the DC bus
When the change rate of voltage meets first preset condition, the change rate for recording the DC bus-bar voltage meets described first in advance
If voltage value when condition is reference voltage value；
S4, current voltage value is obtained；
S5, judge whether the voltage difference between the current voltage value and the reference voltage value meets the second default item
Part, and when the voltage difference between the current voltage value and the reference voltage value meets second preset condition, sentence
The fixed relay is improper connection status；
The output of S6, the response improper connection status cutting frequency converter.
The guard method of frequency converter charging circuit provided by disclosure illustrative embodiments, by detecting DC bus
The variation of voltage judges the connection status of relay, and in the output for determining to cut off frequency converter when the improper connection of relay,
To achieve the purpose that protect frequency converter charging circuit.On the one hand, the connection status of relay is judged according to voltage change difference,
It can the reduction as far as possible judging result is generated by measurement error caused by signal interference influence；On the other hand, in relay
The output that frequency converter is automatically cut off when the improper connection of device, can effectively avoid causing because DC current flows through charging resistor
Resistance heating phenomenon, the shell scaling loss of frequency converter is prevented, so that the intelligentized protection for solving frequency converter charging circuit is asked
Topic.
Each step of the guard method of frequency converter charging circuit in this example embodiment will be carried out below detailed
Explanation.
In step sl, after the frequency converter charging circuit powers on, DC bus-bar voltage is sampled.
Wherein, the DC bus-bar voltage is the waveform of a consecutive variations, is sampled to the DC bus-bar voltage,
Multiple sampled values based on a certain sample frequency can be obtained, adopting for a consecutive variations can be drawn out according to multiple sampled value
Sample curve, the sampling curve reflect the changing rule of the DC bus-bar voltage.
It is described to power on the charging process for referring to frequency converter, in particular to charge to frequency converter in this example embodiment
The process that storage capacitor 22 in circuit charges；After charging complete, control circuit will be charged by the contact of relay 23
21 short circuit of resistance, to complete the power up of frequency converter.
For example, when powering on to frequency converter charging circuit 20, rectification circuit 10 is converted to the alternating current received
Direct current gives storage capacitor 22 to charge by charging resistor 21, and after charging reaches a certain level, control circuit is by relay 23
It is closed so that 21 short circuit of charging resistor, completes the power up of frequency converter, start to sample DC bus-bar voltage at this time, obtain
To sampling curve shown in Fig. 3.
On this basis, it is described to DC bus-bar voltage carry out sampling can specifically include following methods:
The DC bus-bar voltage is measured using divider resistance；That is, a divider resistance in parallel on DC bus
Network implementations measures the DC bus-bar voltage, and the voltage signal that partial pressure obtains is sent to control centre by operation
Processing obtains DC bus-bar voltage；
Alternatively, being measured using voltage transformer to the DC bus-bar voltage；Its principle is by DC bus-bar voltage
As input, a secondary voltage and DC bus-bar voltage for voltage transformer is at corresponding ratio；Alternatively,
The DC bus-bar voltage is measured using isolation optocoupler；I.e..One linear isolation is set on DC bus
Optocoupler measures the DC bus-bar voltage by optical coupling based on the input terminal of linear optical coupling device and output end.
This example embodiment is not specifically limited the method for sampling of DC bus-bar voltage, can also use above-mentioned
Other methods except three kinds of methods carry out sampled measurements.
In step s 2, the variation of the DC bus-bar voltage is obtained in real time according to the sampled value of the DC bus-bar voltage
Rate.
In this example embodiment, the change rate of the DC bus-bar voltage refers to DC bus-bar voltage in the unit time
Changing value, which is able to reflect out the variation degree (including amplitude of variation and variation speed) of DC bus-bar voltage.
For example, when DC bus-bar voltage mutates, i.e. the moment that DC bus-bar voltage reduces suddenly in Fig. 3,
The change rate △ V of the DC bus-bar voltage at the moment that mutates can be obtained according to the sampled value of the DC bus-bar voltage；It is false
If the first preset condition is △ V0The change rate △ V=5.2V of > 5V, DC bus-bar voltage, by by change rate △ V and first
Preset condition compares it is found that change rate △ V meets first preset condition, can carry out at this time in next step
Suddenly, otherwise continue to sample DC bus-bar voltage and obtain the change rate of DC bus-bar voltage.
In step s3, judge whether the change rate of the DC bus-bar voltage meets the first preset condition, and described
When the change rate of DC bus-bar voltage meets first preset condition, the change rate for recording the DC bus-bar voltage meets institute
Voltage value when stating the first preset condition is reference voltage value.
Wherein, first preset condition refers to the threshold value of the variation degree of DC bus-bar voltage；That is, working as DC bus
It when the change rate of voltage reaches the threshold value, needs further to detect the DC bus-bar voltage, to obtain relevant electricity
Change information is pressed, otherwise without the concern for the variation.
In this example embodiment, the reference voltage value is that the change rate of DC bus-bar voltage meets the first default item
Voltage value when part is a particular value within a certain voltage change period, but in the whole work process of frequency converter, the ginseng
It is continually changing for examining voltage value.For example, promutation has occurred in DC bus-bar voltage, and the change rate of promutation is full
The first preset condition of foot, needs to record at this time corresponding voltage value and is worth as the reference voltage；But in the next steps also into one
Step is provided with whether work on the condition limited to frequency converter, and if voltage change this time is unsatisfactory for subsequent item
Part, frequency converter will work normally, then DC bus-bar voltage is just it is also possible to occur telomutation；If DC bus is electric
The change rate of the telomutation of pressure also meets the first preset condition, then reference voltage value at this time is just different from first time
Reference voltage value.
It is to be noted that the change rate that the voltage value that this step is recorded is DC bus-bar voltage meets the first default item
Voltage value when part, rather than voltage value when starting to sample DC bus-bar voltage.
For example, refering to what is shown in Fig. 3, mutation takes place in T1 moment DC bus-bar voltage, and according to real-time detection
The change rate of DC bus-bar voltage meets the first preset condition this moment known to data, then the voltage value V1 for recording this moment makees
For reference voltage value；Assuming that the change rate △ V=5.2V of T1 moment DC bus-bar voltage, meets the first preset condition △ V0> 5V,
Recording voltage value V1=6V is worth as the reference voltage at this time.
In step s 4, current voltage value is obtained.
In this example embodiment, voltage value that the real-time detection that the current voltage value refers to arrives.It is female in the direct current
The change rate of line voltage meets the voltage value recorded when the first preset condition and is worth as the reference voltage, after this DC bus
Voltage may be constantly in variable condition, at this time real-time detection to voltage value be current voltage value.
For example, refering to what is shown in Fig. 3, obtaining current voltage value V2 in real time after record V1 is worth as the reference voltage,
Voltage difference, that is, V2-V1 so between current voltage value and reference voltage value；Assuming that reference voltage value V1=6V, current voltage
Value V2=0.9V, voltage difference V2-V1=5.1V at this time.
In step s 5, judge whether the voltage difference between the current voltage value and the reference voltage value meets
Two preset conditions, and the voltage difference between the current voltage value and the reference voltage value meets the second default item
When part, determine that the relay is improper connection status.
In this example embodiment, the relay is that improper connection status is to indicate that the contact of the relay is disconnected
It opens, when the contact of the relay is in an off state, DC current, which will flow through, fills resistance, so as to cause charging resistor
Fever, and the duration too long shell scaling loss that can also further cause frequency converter occur in order to prevent this phenomenon, need and
When cut off frequency converter output.
In this step, second preset condition can be set are as follows: the current voltage value and the reference voltage value
Between voltage difference be greater than reference voltage difference.
That is, second preset condition is door set by voltage difference between current voltage value and reference voltage value
Threshold value when only the voltage difference is more than the threshold value, need to just determine the connection status of relay.
For example, after record V1 is worth as the reference voltage, current voltage value V2 is obtained in real time, then current voltage
Be worth voltage difference, that is, V2-V1 between reference voltage value, voltage difference V2-V1 and reference voltage difference are carried out pair at this time
Than；Assuming that reference voltage value V1=6V, current voltage value V2=0.9V, reference voltage difference is 5V, at this time the voltage difference
V2-V1=5.1V is greater than reference voltage difference 5V, it can thus be appreciated that the electricity between the current voltage value and the reference voltage value
Pressure difference meets the second preset condition.
On this basis, it is contemplated that the circuit structure of frequency converter is complicated and changeable, any one component goes wrong all
It is likely to result in the variation of DC bus-bar voltage, is judged by accident caused by being disconnected in order to prevent because of non-relay, the second default item
Part can also be further arranged to: the voltage difference between the current voltage value and the reference voltage value is greater than the benchmark
The duration of voltage difference is more than preset time.
That is, voltage difference of second preset condition only between current voltage value and reference voltage value sets base
Quasi- voltage difference as the first threshold value, while also for the voltage difference be greater than reference voltage difference duration set it is pre-
If the time as the second threshold value, only meets the two conditions simultaneously, need to just determine the connection status of relay, with
Ensure to cause to judge by accident because of the other reasons that non-relay disconnects.
For example, after record V1 is worth as the reference voltage, current voltage value V2 is obtained in real time, then current voltage
Voltage difference, that is, V2-V1 between value and reference voltage value, and the voltage difference maintains a period of time △ T；First should at this time
Voltage difference V2-V1 is compared with reference voltage difference, the case where voltage difference V2-V1 is greater than reference voltage difference
Under, further the duration of this state is compared with preset time, if the duration also greater than preset time,
Voltage difference between the so described current voltage value and the reference voltage value meets the second preset condition, it is possible thereby to determine
The relay is improper connection status；Assuming that reference voltage value V1=6V, current voltage value V2=0.9V, reference voltage are poor
Value is 5V, preset time 30s, and the voltage difference V2-V1=5.1V is greater than reference voltage difference 5V and continue at this time
1min, it can thus be appreciated that the voltage difference between the current voltage value and the reference voltage value meets the second preset condition.
In step s 6, the output of the improper connection status cutting frequency converter is responded.
Wherein, after determining that the relay is improper connection status, the improper connection shape can first be responded
State is sounded an alarm to prompt failure, then cuts off the output of frequency converter.
For example, when determining the relay is improper connection status, illustrate that the contact of relay is already off,
Frequency converter can be sounded an alarm to prompt failure at this time, and alarm sounds mode therein can be light prompt or auditory tone cues
Deng；On this basis, charging resistor overheats in order to prevent, should also cut off the output of frequency converter in time.
Fig. 4 show the variation schematic diagram that relay disconnects post filtering capacitor, output electric current and DC bus current.?
After relay disconnects, DC current flows through charging resistor, the voltage decline of filter capacitor, DC bus current and output electric current
It simultaneously declines.
A kind of protective device of frequency converter charging circuit is proposed in this example embodiment, it is electric for charging to frequency converter
It is protected on road.Refering to what is shown in Fig. 1, the circuit structure of the frequency converter may include: rectification circuit 10, charging circuit 20, system
Dynamic circuit 30 and inverter circuit 40；The charging circuit 20 includes that a charging resistor 21 being connected on DC bus and one are in parallel
In the relay 23 and storage capacitor 22 of the charging resistor 21；Wherein, described in the input terminal connection of the charging resistor 21
The output end of rectification circuit 10, the output end of the storage capacitor 22 connect the input terminal of the braking circuit 30.
Based on this, as shown in figure 5, the protective device of the frequency converter charging circuit may include:
Sampling module 501, for being sampled to DC bus-bar voltage after the frequency converter charging circuit powers on；
First detection module 502, for obtaining the DC bus in real time according to the sampled value of the DC bus-bar voltage
The change rate of voltage；
First determination module 503, for judging whether the change rate of the DC bus-bar voltage meets the first preset condition,
And when the change rate of the DC bus-bar voltage meets first preset condition, the variation of the DC bus-bar voltage is recorded
Voltage value when rate meets first preset condition is reference voltage value；
Second detection module 504, for obtaining current voltage value；
Second determination module 505, for judging the voltage difference between the current voltage value and the reference voltage value
Whether second preset condition is met, and described in the voltage difference satisfaction between the current voltage value and the reference voltage value
When the second preset condition, determine that the relay is improper connection status；
Control module 506, for responding the output of the improper connection status cutting frequency converter.
The protective device of frequency converter charging circuit provided by disclosure illustrative embodiments, by detecting DC bus
The variation of voltage judges the connection status of relay, and in the output for determining to cut off frequency converter when the improper connection of relay,
To achieve the purpose that protect frequency converter charging circuit.
In this example embodiment, the sampling module 501 may include:
Divider resistance, for being measured using the divider resistance to the DC bus-bar voltage；Alternatively,
Voltage transformer, for being measured using the voltage transformer to the DC bus-bar voltage；Alternatively,
Isolation optocoupler, for being measured using the isolation optocoupler to the DC bus-bar voltage.
It should be understood that this example embodiment is not specifically limited the sampling apparatus of DC bus-bar voltage,
Sampled measurements can also be carried out to DC bus-bar voltage using other devices.
In this example embodiment, second preset condition can be with are as follows: the current voltage value and described with reference to electricity
Voltage difference between pressure value is greater than reference voltage difference.That is, second preset condition is for current voltage value and with reference to electricity
Threshold value set by voltage difference between pressure value.
On this basis, it is contemplated that the circuit structure of frequency converter is complicated and changeable, any one component goes wrong all
It is likely to result in the variation of DC bus-bar voltage, is judged by accident caused by being disconnected in order to prevent because of non-relay, the second default item
Part can also be further arranged to: the voltage difference between the current voltage value and the reference voltage value is greater than the benchmark
The duration of voltage difference is more than preset time.That is, second preset condition is not only current voltage value and reference voltage
Voltage difference between value sets reference voltage difference as the first threshold value, while being also greater than benchmark electricity for the voltage difference
The duration of pressure difference sets preset time as the second threshold value.
In this example embodiment, the protective device can also include: alarm module 507, for determining institute
It states relay and sounds an alarm prompt failure after improper connection status, to respond the improper connection status, hereafter cut again
The output of disconnected frequency converter can prompt the working condition of frequency converter, to staff in time so in order to be safeguarded；
Wherein, the alarm sounds mode can be light prompt or auditory tone cues etc..
It should be understood that the detail of each modular unit exists in the protective device of the frequency converter charging circuit
It is described in detail in the guard method of corresponding frequency converter charging circuit, therefore which is not described herein again.
It should be noted that although being referred to several modules or list for acting the equipment executed in the above detailed description
Member, but this division is not enforceable.In fact, according to embodiment of the present disclosure, it is above-described two or more
Module or the feature and function of unit can embody in a module or unit.Conversely, an above-described mould
The feature and function of block or unit can be to be embodied by multiple modules or unit with further division.
In addition, although describing each step of method in the disclosure in the accompanying drawings with particular order, this does not really want
These steps must be executed in this particular order by asking or implying, or having to carry out step shown in whole could realize
Desired result.Additional or alternative, it is convenient to omit multiple steps are merged into a step and executed by certain steps, and/
Or a step is decomposed into execution of multiple steps etc..
Through the above description of the embodiments, those skilled in the art is it can be readily appreciated that example described herein is implemented
Mode can also be realized by software realization in such a way that software is in conjunction with necessary hardware.Therefore, according to the disclosure
The technical solution of embodiment can be embodied in the form of software products, which can store non-volatile at one
Property storage medium (can be CD-ROM, USB flash disk, mobile hard disk etc.) in or network on, including some instructions are so that a calculating
Equipment (can be personal computer, server, mobile terminal or network equipment etc.) is executed according to disclosure embodiment
Method.
Those skilled in the art after considering the specification and implementing the invention disclosed here, will readily occur to its of the disclosure
Its embodiment.This application is intended to cover any variations, uses, or adaptations of the disclosure, these modifications, purposes or
Person's adaptive change follows the general principles of this disclosure and including the undocumented common knowledge in the art of the disclosure
Or conventional techniques.The description and examples are only to be considered as illustrative, and the true scope and spirit of the disclosure are by appended
Claim is pointed out.
Claims (10)
1. a kind of guard method of frequency converter charging circuit, for being protected to frequency converter charging circuit；The frequency converter fills
Circuit includes the charging resistor being connected on DC bus and the relay being in parallel with the charging resistor；Its feature exists
In the guard method includes:
After the frequency converter charging circuit powers on, DC bus-bar voltage is sampled；
Obtain the change rate of the DC bus-bar voltage in real time according to the sampled value of the DC bus-bar voltage；
Judge whether the change rate of the DC bus-bar voltage meets the first preset condition, and in the change of the DC bus-bar voltage
When rate meets first preset condition, when recording the change rate of the DC bus-bar voltage and meeting first preset condition
Voltage value be reference voltage value；
Obtain current voltage value；
Judge whether the voltage difference between the current voltage value and the reference voltage value meets the second preset condition, and
When voltage difference between the current voltage value and the reference voltage value meets second preset condition, determine it is described after
Electric appliance is improper connection status；
Respond the output of the improper connection status cutting frequency converter.
2. the guard method of frequency converter charging circuit according to claim 1, which is characterized in that second preset condition
Are as follows: the voltage difference between the current voltage value and the reference voltage value is greater than reference voltage difference.
3. the guard method of frequency converter charging circuit according to claim 2, which is characterized in that second preset condition
Are as follows: the voltage difference between the current voltage value and the reference voltage value is greater than the duration of the reference voltage difference
More than preset time.
4. the guard method of frequency converter charging circuit according to any one of claims 1 to 3, which is characterized in that described
Guard method further include:
After determining that the relay is improper connection status, responds the improper connection status and sound an alarm prompt event
Barrier.
5. the guard method of frequency converter charging circuit according to claim 1, which is characterized in that described pair power on after it is straight
Stream busbar voltage carries out sampling
The DC bus-bar voltage is measured using divider resistance or voltage transformer or isolation optocoupler.
6. a kind of protective device of frequency converter charging circuit, for being protected to frequency converter charging circuit；The frequency converter fills
Circuit includes the charging resistor being connected on DC bus and the relay being in parallel with the charging resistor；Its feature exists
In the protective device includes:
Sampling module, for being sampled to DC bus-bar voltage after the frequency converter charging circuit powers on；
First detection module, for obtaining the change of the DC bus-bar voltage in real time according to the sampled value of the DC bus-bar voltage
Rate；
First determination module, for judging whether the change rate of the DC bus-bar voltage meets the first preset condition, and in institute
When stating the change rate of DC bus-bar voltage and meeting first preset condition, the change rate for recording the DC bus-bar voltage meets
Voltage value when first preset condition is reference voltage value；
Second detection module, for obtaining current voltage value
Whether the second determination module, the voltage difference for judging between the current voltage value and the reference voltage value meet
Second preset condition, and the voltage difference between the current voltage value and the reference voltage value meets described second and presets
When condition, determine that the relay is improper connection status；
Control module, for responding the output of the improper connection status cutting frequency converter.
7. the protective device of frequency converter charging circuit according to claim 6, which is characterized in that second preset condition
Are as follows: the voltage difference between the current voltage value and the reference voltage value is greater than reference voltage difference.
8. the protective device of frequency converter charging circuit according to claim 7, which is characterized in that second preset condition
Are as follows: the voltage difference between the current voltage value and the reference voltage value is greater than the duration of the reference voltage difference
More than preset time.
9. according to the protective device of the described in any item frequency converter charging circuits of claim 6 to 8, which is characterized in that described
Protective device further include:
Alarm module, for responding the improper connection status after determining that the relay is improper connection status
Sound an alarm prompt failure.
10. the protective device of frequency converter charging circuit according to claim 6, which is characterized in that the sampling module packet
It includes:
Divider resistance, for being measured using the divider resistance to the DC bus-bar voltage；Alternatively,
Voltage transformer, for being measured using the voltage transformer to the DC bus-bar voltage；Alternatively,
Isolation optocoupler, for being measured using the isolation optocoupler to the DC bus-bar voltage.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710655015.5A CN109390914B (en) | 2017-08-03 | 2017-08-03 | Protection method and device for charging circuit of frequency converter |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710655015.5A CN109390914B (en) | 2017-08-03 | 2017-08-03 | Protection method and device for charging circuit of frequency converter |
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| Publication Number | Publication Date |
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| CN109390914A true CN109390914A (en) | 2019-02-26 |
| CN109390914B CN109390914B (en) | 2020-03-27 |
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| CN201710655015.5A Active CN109390914B (en) | 2017-08-03 | 2017-08-03 | Protection method and device for charging circuit of frequency converter |
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| CN112701767A (en) * | 2020-12-10 | 2021-04-23 | 珠海格力电器股份有限公司 | Charging control device and method of motor controller and motor |
| CN114295974A (en) * | 2021-12-30 | 2022-04-08 | 上海儒竞智控技术有限公司 | Detection method and detection circuit for failure of pre-charging relay |
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Also Published As
| Publication number | Publication date |
|---|---|
| CN109390914B (en) | 2020-03-27 |
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