The content of the invention
The embodiments of the invention provide a kind of detection method and equipment, to solve to run shape to wave filter in the prior art
The problem of state detects.
Specific technical scheme is as follows:
A kind of filter detection method, including:
When for the circuit of electricity generation system to be changed and exported to the electric power coversion system of power network and power network disconnection,
Output current value when detecting the converter output preset voltage value in electric power coversion system on the wave filter;
Obtain the difference between output current value and the standard output current value;
According to the difference and the comparative result of predetermined threshold value between the output current value and standard output current value, it is determined that
Whether the wave filter is in normal operating conditions.
Optionally, the difference obtained between output current value and pre-set current value, it is specially:
According to the wave filter both end voltage value and the wave filter can export under the magnitude of voltage current value it
Between corresponding relation, determine the wave filter corresponding standard output current value under the preset voltage value, obtain described defeated
The difference gone out between current value and standard output current value.
Optionally, the comparison knot of the difference and predetermined threshold value according between output current value and standard output current value
Fruit, determines whether the wave filter is in normal operating conditions, including:
When the difference between the output current value and standard output current value is more than the predetermined threshold value, it is determined that described
Wave filter is in abnormal operation, and generates output abnormality prompt message;
When the difference between the output current value and standard output current value is less than the predetermined threshold value, it is determined that described
Wave filter is in normal operating conditions.
Optionally, output current value of the wave filter in detecting electric power coversion system in the case where applying preset voltage value it
Before, in addition to:
Detection obtains the sample voltage value and sampled current value at electric capacity both ends in the wave filter;
Linear relationship between sample voltage value and sampled current value based on electric capacity, obtains the sampled current value pair
The reference current value answered;
According between the output voltage and wave filter both ends sample voltage value that alive converter is applied to the wave filter
Corresponding relation, determine reference voltage level corresponding to the sample voltage value at the electric capacity both ends;
According to the reference current value and the reference voltage level, the reference current value is determined and described with reference to electricity
Theoretical voltage value corresponding to pressure value, the preset voltage value that the theoretical voltage value exports as the converter.
Optionally, the corresponding relation between the sample voltage value and sampled current value according to the electric capacity both ends, is obtained
Reference current value corresponding to the sampled current value is taken, including:
According to formula(1)Determine the corresponding relation between electric capacity both ends sample voltage value and sampled current value;
Wherein, ia、ib、icThe three-phase sampled current value on the electric capacity collected for current sensor, C is capacitance,
uca、ucb、uccThe three-phase sample voltage value collected for voltage sensor;
Switching current value can pass through formula corresponding to electric capacity both ends sample voltage value and sampled current value(2)Obtain
Take;
Wherein, idAnd iqThe three-phase sampled current value i collected for current sensora、ib、icBy 3s/2r Coordinate Conversions
Switching current value afterwards, ucqAnd ucdThe three-phase sample voltage value u collected for voltage sensorca、ucb、uccSat by 3s/2r
Conversion voltage value after mark conversion, w are the conversion constant in Coordinate Conversion;
According to switching current value idAnd iq, determine the switching current value idAnd iqCorresponding reference current value.
Optionally, according to the output voltage and wave filter both ends sampled voltage that alive converter is applied to the wave filter
Corresponding relation between value, reference voltage level corresponding to the sample voltage value at the electric capacity both ends is determined, including:
According to formula(3)It is determined that apply pair between alive output voltage and wave filter both end voltage to the wave filter
It should be related to;
Wherein, R represents the resistance on loop, and L represents the inductance value of inductance in wave filter, ea、eb、ecRepresent the three of converter
Phase output voltage values, ia、ib、icThe three-phase sampled current value collected for current sensor, uca、ucb、uccFor voltage sensor
The three-phase sample voltage value collected,For differential operator;
Reference voltage level corresponding to the sample voltage value at the electric capacity both ends can be according to formula(4)Obtain;
Wherein, ucqAnd ucdThe three-phase collection voltages value u collected for voltage sensorca、ucb、uccBy 3s/2r coordinates
Conversion voltage value after conversion, idAnd iqThe three phase acquisition current value i collected for current sensora、ib、icSat by 3s/2r
Switching current value after mark conversion, edAnd eqFor converter three-phase output voltage ea、eb、ecTurn after 3s/2r Coordinate Conversions
Change magnitude of voltage;
According to conversion voltage value edAnd eq, determine the conversion voltage value edAnd eqCorresponding reference voltage level.
A kind of filter detection equipment, including:
Current sensor, it is used to change the circuit of electricity generation system and export to the electrical power conversion system of power network for working as
When system disconnects with power network, output electricity when detecting the converter output preset voltage value in electric power coversion system on the wave filter
Flow valuve;
Processor, it is connected with the current sensor, for obtaining between output current value and standard output current value
Difference, according to the difference between the output current value and standard output current value, judge the filter in the electric power coversion system
Whether ripple device is in normal working condition.
Optionally, the processor is specifically used for according to the wave filter both end voltage value and described under the magnitude of voltage
Corresponding relation between the current value that wave filter can export, determine the wave filter corresponding mark under the preset voltage value
Quasi- output current value, obtain the difference between output current value and the standard output current value.
Optionally, the processor is specifically used for when the difference between the output current value and standard output current value is big
When the predetermined threshold value, determine that the wave filter is in abnormal operation, and generate output abnormality prompt message;When described
When difference between output current value and standard output current value is less than the predetermined threshold value, determine that the wave filter is in normal
Working condition.
Optionally, the equipment includes:
Voltage sensor, the sample voltage value at electric capacity both ends in the wave filter is obtained for detecting;
The processor, it is additionally operable to, according to the linear relationship between the electric capacity both end voltage value and output current value, obtain
Take reference current value corresponding to the output current value, according to applied to the wave filter output voltage of alive converter with
Corresponding relation between wave filter both end voltage, reference voltage level corresponding to the magnitude of voltage at the electric capacity both ends is determined, to described
Reference current value and the reference voltage level are handled, it is determined that the predeterminated voltage for being applied to the wave filter both ends
Value.
In embodiments of the present invention by wave filter apply predeterminated voltage after, the output current value of Fault detection filter,
Then by the output current value detected compared with standard output current value corresponding to the predeterminated voltage, if output current
When being less than predetermined threshold value with standard output current difference, then illustrate that wave filter is in normal working condition, it is evident that the present invention
The promptly and accurately detection to electric power coversion system median filter working condition by simple circuit realiration in embodiment, for electricity
The normal operation of Force system provides reliable guarantee.
Embodiment
Currently, due to the raising to power quality standard, therefore for directly affecting the electric power coversion system of the quality of power supply
Running status it is also proposed that high requirement, so requires the wave filter in electric power coversion system to be in normal operating conditions.
In order to be detected in real time to the wave filter in electric power coversion system, the embodiments of the invention provide one kind
Filter detection method, this method include:Turn when for being changed and being exported to the electric power of power network the circuit of electricity generation system
When changing system with power network disconnection, output current value of the electric power coversion system median filter under preset voltage value is detected, is obtained
Take the difference between output current value and the standard output current value, when the output current value and standard output current value it
Between difference when being less than predetermined threshold value, then generate one and characterize the control information that the wave filter be in normal operating conditions so that
The real-time monitoring to electric power coversion system median filter working condition is realized, ensure that the normally and efficiently fortune of electric power coversion system
OK.
Technical solution of the present invention is described in detail below by accompanying drawing and specific embodiment, it will be appreciated that this
Particular technique feature in inventive embodiments and embodiment is not simply to limit to the explanation of technical solution of the present invention.
It is a kind of filter detection method in the embodiment of the present invention as shown in Figure 1, this method includes:
S101, break when for being changed and being exported to the electric power coversion system of power network the circuit of electricity generation system with power network
When opening, output current value when detecting the converter output preset voltage value in electric power coversion system on the wave filter;
As shown in Fig. 2 electricity generation system is required for carrying out electric energy conversion process before power network is transferred electrical energy into, and this
Individual conversion process is exactly to be completed by electric power coversion system, and converter, current sensor, filter are comprised at least in electric power coversion system
Ripple device, main switch, converter are used to carry out voltage conversion process, and current sensor can then detect the big of current value in circuit
Small, wave filter is then that electric energy is filtered processing, and main switch is then to be used to control to disconnect with power network or be connected with power network.
When needing to detect wave filter, it is necessary first to close main switch so that power network is female for the direct current of converter
Line is charged, and ensures that the voltage of converter dc bus is higher than the inverter voltage of converter output, naturally it is also possible to pass through it
He charges at extraneous power supply to dc bus, does not limit specific charging modes here.
In the voltage mostly predetermined value of dc bus, then main switch is disconnected, and now inverter voltage is output to by converter
On loop, due to other components being not present on loop, therefore the inverter voltage can be considered as and be just applied directly on wave filter,
Certain inverter voltage is the voltage for setting magnitude of voltage, and then the current sensor in circuit is by the defeated of Fault detection filter
Go out current value, and the output current value detected is uploaded to controller.
S102, obtain the difference between output current value and standard output current value;
After the current value of current sensor upload is obtained, the controller determines in preset voltage value pair controller first
The standard output current value that the wave filter should export, the controller can be by obtained output current values and standard output current value
Between make the difference, and obtain the absolute value of the difference, such as, it is 84A to get the output current value under predetermined voltage, and this is default
Standard output current value under voltage is 85A, then the difference between output circuit value and pre-set current value is 1A, certainly herein
Absolute value during difference.Herein it should be noted that standard output current value is wave filter applies default electricity in normal operation
The current value that should be exported after pressure value.
S103, according to the difference and the comparative result of predetermined threshold value between output current value and standard output current value, really
Determine whether wave filter is in normal operating conditions.
When the difference between output current and standard output electric current is less than predetermined threshold value, such as output current value and mark
Difference between quasi- output current value is 1A, and predetermined threshold value is 1.5A, then illustrates output current and under the preset voltage value
Standard output current value it is essentially identical, further relate to the wave filter and be in normal working condition, when output circuit and standard
When difference between output current is more than predetermined threshold value, then illustrates that output current and standard output current difference are larger, now say
The bright filtering is in abnormal state, and generates abnormal prompt information, to prompt the wave filter to be in abnormality.
In the above-described embodiments by wave filter apply predeterminated voltage after, the output current value of Fault detection filter, so
Afterwards by the output current value detected compared with standard output current value corresponding to the predeterminated voltage, if output current with
When standard output current difference is less than predetermined threshold value, then illustrate that wave filter is in normal working condition, it is evident that the present invention is real
The promptly and accurately detection to electric power coversion system median filter working condition has been applied in example by simple circuit realiration, has been electric power
The normal operation of converting system provides reliable guarantee.
Such as controller can send output predeterminated voltage u instruction, converter to converter first in figure 3
Predeterminated voltage u, such as magnitude of voltage u=100V can be exported to wave filter based on the instruction, now the current sensor on circuit
By the current value on Fault detection filter, due to only existing wave filter on loop, therefore the circuit values of wave filter are exactly the electricity of electric capacity
Flow valuve, what is detected herein is three-phase electricity flow valuve, i.e.,:ia、ib、ic, if when wave filter does not occur abnormal, apply 100V
Voltage on wave filter, the standard three-phase current now detected should beThen three will detected
Phase current is matched with normalized current, if the difference between the current value and standard current value that so detect is less than pre-
If during threshold value, now illustrate that electric capacity is in normal condition in the wave filter.
Further, typically can all there is impedance in circuit, under conditions of it impedance be present, the defeated output voltage of converter is not
It is all to be applied on wave filter, such as the voltage of converter output is 100V, due to the presence of impedance, is really applied to filter
Magnitude of voltage on ripple device may only have the current value standard corresponding with 100V that 60V is either lower, and now use detects again
Output current value compares, then erroneous judgement occurs.
In embodiments of the present invention in order to which the voltage ensured to be applied on wave filter can reach given voltage, avoid judging by accident
Disconnected situation occurs, and adds processor in the controller of the embodiment of the present invention, the processor is by based on wave filter both ends
The output current of voltage and wave filter determines that converter needs the voltage that exports, and its specific determination process is as follows:
In the embodiment of the present invention in the case where applying same voltage u to wave filter, the same of filter to output current is gathered
When, can also be by the voltage sensor Fault detection filter output voltage that is linked on wave filter(As shown in Figure 4), on loop only
Wave filter accesses, therefore the output voltage of wave filter is exactly the voltage at electric capacity both ends in wave filter, such as:The three-phase detected
Voltage is respectively uca、ucb、ucc, corresponding three-phase electricity flow valuve is ia、ib、ic, pass through the relation between voltage, electric capacity and electric currentObtain following relational expression(1)It is shown:
In addition, based on the converter output voltage property equal with all element terminal voltage sums on loop, obtain simultaneously
The KVL equations of converter, it is specific such as relational expression(2)It is shown:
Wherein, R represents the resistance on loop, and L represents the inductance value of inductance in wave filter, ea、eb、ecRepresent the three of converter
Phase output voltage values.
Respectively by above-mentioned relational expression(1)And relational expression(2)Three phase static coordinate is carried out between two cordic phase rotators
Conversion, i.e.,:3s/2r is changed, relational expression(1)Relational expression is obtained after 3s/2r is changed(3), relational expression(2)By 3s/2r
Relational expression is obtained after conversion(4), relational expression(3)And relational expression(4)It is specific as follows:
Wherein, idAnd iqFor the three-phase sampled current value i collecteda、ib、icCurrent value after 3s/2r Coordinate Conversions,
ucqAnd ucdFor the three-phase sample voltage value u collectedca、ucb、uccMagnitude of voltage after 3s/2r Coordinate Conversions, w turn for coordinate
Conversion constant in changing.
Wherein, edMiddle eqFor ea、eb、ecMagnitude of voltage after 3s/2r Coordinate Conversions, wherein P are differential operator
Pass through relational expression(3)Relational expression after being converted(5), relational expression(4)Relational expression is obtained after conversion(6),
It is specific as follows:
By relational expression(5)In obtained idAnd iqInput PI controllers simultaneously obtain reference current valueWith
By relational expression(6)Laplace transform is carried out, obtains relational expression(7), it is specific as follows:
Relational expression(5)In obtainWithAnd relational expression(7)Obtained edAnd eqHandle to obtain by PI controllers pre-
If magnitude of voltageWithNowWithThe magnitude of voltage that converter needs to export just is characterized, also with regard to saying it is to need electric capacity
Reach the voltage e specified on devicea、eb、ecWhen, the output voltage of the converter should beWithSuch as, it is necessary to electric capacity
For the voltage stabilization at both ends in 100V, then the output voltage of converter should be just 150V.
Work as output voltage stabilization, i.e.,WithWhen stable, the electric current now detected can serve as and standard output
The reference current that electric current is compared.
In addition, PI controllers can be replaced using the device of the identical functions such as PR controllers in embodiments of the present invention,
It is not construed as limiting in embodiments of the present invention.
In addition, method in embodiments of the present invention is except that can detect LC wave filters, naturally it is also possible to for detecting LCL
Wave filter.
Caused by presence due to loop middle impedance can effectively being avoided by the above embodiments to accuracy of measurement
Influence, therefore can there is the effective print for excluding impedance loop to influence by the method in above-described embodiment so that wave filter
The magnitude of voltage specified can be applied on electric capacity, the current value so detected there will not be larger error, improve pair
The degree of accuracy of filter detection.
Based on same invention thinking, the embodiment of the present invention additionally provides a kind of filter detection equipment, is illustrated in figure 5 this
A kind of structural representation of filter detection equipment, the equipment include in inventive embodiments:
Current sensor 501, it is used to change the circuit of electricity generation system and export to the electric power of power network to turn for working as
It is defeated on the wave filter when detecting the converter output preset voltage value in electric power coversion system when changing system with power network disconnection
Go out current value;
Processor 502, it is connected with the current sensor 501, for obtaining between output current value and standard current value
Difference, according to the difference between the output current value and standard output current value, judge in the electric power coversion system
Whether wave filter is in normal working condition.
Further, processor 501 in embodiments of the present invention, specifically for according to the wave filter both end voltage value with
Corresponding relation between the current value that the wave filter can export under the magnitude of voltage, determine the wave filter described default
Corresponding standard output current value under magnitude of voltage, obtains the difference between output current value and the standard output current value.
Further, processor 501 in embodiments of the present invention, specifically for when the output current value and standard output electricity
When difference between flow valuve is more than the predetermined threshold value, determine that the wave filter is in abnormal operation, and it is different to generate output
Normal prompt message;When the difference between the output current value and standard output current value is less than the predetermined threshold value, it is determined that
The wave filter is in normal operating conditions.
Further, filter detection equipment in embodiments of the present invention also includes voltage sensor 601(Such as Fig. 6 institutes
Show), when filtering detection device includes voltage sensor 601, processor 501, are additionally operable to basis in embodiments of the present invention
Linear relationship between the electric capacity both end voltage value and output current value, obtains reference current corresponding to the output current value
Value, according to the corresponding relation applied to the wave filter between the output voltage of alive converter and wave filter both end voltage,
Reference voltage level corresponding to determining the magnitude of voltage at the electric capacity both ends, enters to the reference current value and the reference voltage level
Row processing, it is determined that the preset voltage value for being applied to the wave filter both ends.
The present invention is with reference to method according to embodiments of the present invention, equipment(System)And the flow of computer program product
Figure and/or block diagram describe.It should be understood that can be by every first-class in computer program instructions implementation process figure and/or block diagram
Journey and/or the flow in square frame and flow chart and/or block diagram and/or the combination of square frame.These computer programs can be provided
The processors of all-purpose computer, special-purpose computer, Embedded Processor or other programmable data processing devices is instructed to produce
A raw machine so that produced by the instruction of computer or the computing device of other programmable data processing devices for real
The device for the function of being specified in present one flow of flow chart or one square frame of multiple flows and/or block diagram or multiple square frames.
These computer program instructions, which may be alternatively stored in, can guide computer or other programmable data processing devices with spy
Determine in the computer-readable memory that mode works so that the instruction being stored in the computer-readable memory, which produces, to be included referring to
Make the manufacture of device, the command device realize in one flow of flow chart or multiple flows and/or one square frame of block diagram or
The function of being specified in multiple square frames.
These computer program instructions can be also loaded into computer or other programmable data processing devices so that counted
Series of operation steps is performed on calculation machine or other programmable devices to produce computer implemented processing, so as in computer or
The instruction performed on other programmable devices is provided for realizing in one flow of flow chart or multiple flows and/or block diagram one
The step of function of being specified in individual square frame or multiple square frames.
Although preferred embodiments of the present invention have been described, but those skilled in the art once know basic creation
Property concept, then can make other change and modification to these embodiments.So appended claims be intended to be construed to include it is excellent
Select embodiment and fall into having altered and changing for the scope of the invention.
Obviously, those skilled in the art can carry out the essence of various changes and modification without departing from the present invention to the present invention
God and scope.So, if these modifications and variations of the present invention belong to the scope of the claims in the present invention and its equivalent technologies
Within, then the present invention is also intended to comprising including these changes and modification.