Summary of the invention
It is an object of the invention to provide a kind of current transformer harmonic error and measure system, this system can know that electric current is mutual
Sensor error when to harmonic measure, and then obtain measured signal and the normalized current that tested current transformer is exported by harmonic wave
The impact of error (ratio difference, angular difference) between the standard signal of transformer output, facilitates and follow-up carries out tested current transformer
Improve and the accurate of harmonic wave is measured.
For solving above-mentioned technical problem, the invention provides a kind of current transformer harmonic error and measure system, including:
For receiving and according to user's input to the first-harmonic of host computer, 3 subharmonic, 5 subharmonic until the parameter of n times harmonic wave
Generating the harmonic wave high-current generation device of the big electric current of harmonic wave, wherein, described parameter includes described first-harmonic until the containing of n times harmonic wave
Amount, amplitude, phase place and frequency, N is the odd number not less than 3；
It is connected with described harmonic wave high-current generation device, measures for electric current big to described harmonic wave, obtain standard letter
Number standard current transformer；
It is connected with described harmonic wave high-current generation device, measures for electric current big to described harmonic wave, obtain tested letter
Number tested current transformer；
Be connected with described standard current transformer and described tested current transformer respectively, for by described standard signal and
Described measured signal is converted into pending signal and sends the harmonic current measurement device to described host computer；
It is connected with described harmonic wave high-current generation device and described harmonic current measurement device respectively, for according to described
Pending signal obtains described first-harmonic until the content of n times harmonic wave, ratio and angular difference, and then obtains described tested current transformer
Measure described first-harmonic until the described host computer of error during n times harmonic wave.
Preferably, N is the odd number more than 9, and described harmonic wave high-current generation device includes:
It is connected with described host computer, for receiving the first-harmonic of described host computer foundation user's input, 3 subharmonic, 5 subharmonic
Until the parameter of n times harmonic wave correspondence respectively generates first-harmonic generates instruction until 7 subharmonic generate instruction and 9-N combined harmonic
Generate a FPGA of instruction；
Input is connected with a described FPGA, for generating the first-harmonic merit of instruction generation fundamental signal according to described first-harmonic
Rate source；
Input is connected, generates for foundation 3 subharmonic 3 times of instruction generation 3 rd harmonic signal with a described FPGA
Harmonic power source；
Input is connected, generates for foundation 5 subharmonic 5 times of instruction generation 5 rd harmonic signal with a described FPGA
Harmonic power source；
Input is connected with a described FPGA, for generating instruction generation 7 rd harmonic signal according to described 7 subharmonic
7 subharmonic power sources；
Input is connected with a described FPGA, for generating 9-N time again according to described 9-N combined harmonic generation instruction
Close the combined harmonic power source of harmonic signal；
Respectively with the outfan in described fundamental power source, the outfan of 3 subharmonic power sources, 5 subharmonic power sources defeated
Go out end, the outfan of the outfan of 7 subharmonic power sources and combined harmonic power source connects, for by described fundamental signal, 3
The up-flow that rd harmonic signal, 5 rd harmonic signal, 7 rd harmonic signal and 9-N combined harmonic signal carry out coupling and amplifying
Device.
Preferably, N is 19.
Preferably, described standard current transformer is the current transformer of 0.05S level.
Preferably, described standard current transformer is high-accuracy current divider.
Preferably, described tested current transformer is the current transformer of 0.2 grade.
Preferably, described tested current transformer is electronic current mutual inductor.
Preferably, described harmonic current measurement device includes:
The relay module that is sequentially connected with, AD sampling module, the 2nd FPGA, stm32 and switch, wherein, described in continue
Electrical appliance module includes that sampling resistor, described AD sampling module include ADC sampling A/D chip, and described switch is with described host computer even
Connect；
Described harmonic current measurement device also includes:
The synchronization module being connected with described 2nd FPGA and FT3 module；
The first electrical network mouth, the second electrical network mouth, the first smooth network interface and the second smooth network interface being connected with described switch；
The 3rd smooth network interface being connected with described switch by the 3rd FPGA.
The invention provides a kind of current transformer harmonic error and measure system, this system includes for generating the big electricity of harmonic wave
The harmonic wave high-current generation device of stream；Measure for electric current big to harmonic wave, obtain the standard current transformer of standard signal；
Measure for electric current big to harmonic wave, obtain the tested current transformer of measured signal；For by standard signal and tested letter
Number it is converted into pending signal and sends the harmonic current measurement device to host computer；For obtaining first-harmonic according to pending signal
Until the content of n times harmonic wave, ratio and angular difference, and then obtain tested current transformer and measure first-harmonic until mistake during n times harmonic wave
The host computer of difference.Visible, the application simulates power system ring by generating the harmonic wave high-current generation device of the big electric current of harmonic wave
Border, then according to the tested current transformer that electric current big to harmonic wave measures respectively and standard current transformer record tested
Signal and standard signal obtain first-harmonic and the content of n times harmonic wave, ratio and angular difference, by the ratio with standard current transformer
Relatively, just would know that current transformer error when to harmonic measure, and then obtain what tested current transformer was exported by harmonic wave
The impact of error (ratio difference, angular difference) between the standard signal of measured signal and standard current transformer output, it is follow-up right to facilitate
Tested current transformer improves and measures the accurate of harmonic wave.
Detailed description of the invention
The core of the present invention is to provide a kind of current transformer harmonic error and measures system, and this system can know that electric current is mutual
Sensor error when to harmonic measure, and then obtain measured signal and the normalized current that tested current transformer is exported by harmonic wave
The impact of error (ratio difference, angular difference) between the standard signal of transformer output, facilitates and follow-up carries out tested current transformer
Improve and the accurate of harmonic wave is measured.
For making the purpose of the embodiment of the present invention, technical scheme and advantage clearer, below in conjunction with the embodiment of the present invention
In accompanying drawing, the technical scheme in the embodiment of the present invention is clearly and completely described, it is clear that described embodiment is
The a part of embodiment of the present invention rather than whole embodiments.Based on the embodiment in the present invention, those of ordinary skill in the art
The every other embodiment obtained under not making creative work premise, broadly falls into the scope of protection of the invention.
Refer to Fig. 1, Fig. 1 and measure the structural representation of system for a kind of current transformer harmonic error that the present invention provides
Figure, this test system includes:
For receiving and according to user's input to the first-harmonic of host computer 5,3 subharmonic, 5 subharmonic until the ginseng of n times harmonic wave
Number generates the harmonic wave high-current generation devices 1 of the big electric currents of harmonic wave, and wherein, parameter includes first-harmonic until the content of n times harmonic wave, width
Value, phase place and frequency, N is the odd number not less than 3；
Specifically, fundamental frequency here can be 50Hz, then the frequency of n times harmonic wave is N*50Hz.Certainly, base here
Wave frequency can also be other numerical value, and the present invention is not particularly limited at this.
As preferably, N is the odd number more than 9, and harmonic wave high-current generation device 1 includes:
It is connected with host computer 5, for receiving first-harmonic that host computer 5 inputs, 3 subharmonic, 5 subharmonic according to user until N
The parameter of subharmonic correspondence respectively generates first-harmonic and generates instruction until 7 subharmonic generate instruction and 9-N combined harmonic generates
Oneth FPGA of instruction；
Input and a FPGA connect, for generating the fundamental power source of fundamental signal according to first-harmonic generation instruction；
Input and a FPGA connect, for generating 3 subharmonic of 3 rd harmonic signal according to 3 subharmonic generation instructions
Power source；
Input and a FPGA connect, for generating 5 subharmonic of 5 rd harmonic signal according to 5 subharmonic generation instructions
Power source；
Input and a FPGA connect, for generating 7 subharmonic of 7 rd harmonic signal according to 7 subharmonic generation instructions
Power source；
Input and a FPGA connect, for generating 9-N combined harmonic letter according to 9-N combined harmonic generation instruction
Number combined harmonic power source；
Respectively with the outfan in fundamental power source, the outfan of 3 subharmonic power sources, the outfan of 5 subharmonic power sources,
The outfan of 7 subharmonic power sources and the outfan of combined harmonic power source connect, for by fundamental signal, 3 subharmonic letters
Number, 5 rd harmonic signal, 7 rd harmonic signal and 9-N the combined harmonic signal current lifting device that carries out coupling and amplifying.
It is understood that the harmonic wave high-current generation device 1 that the present invention provides is by each harmonic power source and current lifting device
Combining, wherein, first-harmonic, 3 subharmonic, 5 subharmonic and 7 subharmonic are independently exported by respective harmonic wave electron source, 9-N time
Combined harmonic is synthesized output by combined harmonic generator after linear power amplifier, and each harmonic is put by current lifting device coupling
The output big electric current of combined harmonic after big, the content meeting the first-harmonic in the big electric current of harmonic wave and each harmonic can be fed back by measurement
After be automatically adjusted.
In addition, it is necessary to explanation, first-harmonic, 3 subharmonic, 5 subharmonic and 7 subharmonic are individually exported by the application,
And 9-N subharmonic is combined output and is because the occupancy volume of first-harmonic, 3 subharmonic, 5 subharmonic and 7 subharmonic very greatly, can account for
About the 90% of the big electric current of combined harmonic, and the content of the harmonic wave after 9 times is the most considerably less, therefore, 9-N subharmonic is combined defeated
Go out.
It is understood that the formula of first-harmonic, 3 subharmonic, 5 subharmonic and 7 subharmonic is as follows:
In formula (1): x_{m}T () is m rd harmonic signal, m is overtone order, is first-harmonic during m=1, m can take 1,3,5 and
7；A_{m}For first-harmonic or harmonic amplitude；For first-harmonic or harmonic wave initial phase；ω_{0}=2 π/T_{0},T_{0}For the signal primitive period.
X in formula (2)_{9}T () is 9-N combined harmonic signal, n is the odd number of 9≤n≤N.For first-harmonic or harmonic wave initial phase
Position；ω_{0}=2 π/T_{0},T_{0}For the signal primitive period.
Visible, harmonic wave high-current generation device 1 provided herein has the following characteristics that
1) there is the independent harmonic wave electron source Tong Bu with first-harmonic that phase place is controlled；
2) there is the combined harmonic generator Tong Bu with first-harmonic that phase place is controlled；
3) having can be to the current lifting device of multichannel coupling.
The operation principle of this harmonic wave high-current generation device 1 is:
1) first on host computer 5 interface the first-harmonic of established standards passage until the parameter of n times harmonic wave；
2) host computer 5 by according to first-harmonic until n times harmonic wave parameter generate corresponding harmonic generation instruction sent out by UDP
Deliver to a FPGA；
3) fundamental power source is until n times harmonic power source generates instruction according to corresponding first-harmonic and harmonic generation instruction is raw
Become corresponding first-harmonic and harmonic wave；
4) current lifting device is compound humorous to fundamental signal, 3 rd harmonic signal, 5 rd harmonic signal, 7 rd harmonic signal and 9-N time
Ripple signal couples and amplifies.
It is connected with harmonic wave high-current generation device 1, measures for electric current big to harmonic wave, obtain the standard of standard signal
Current transformer 2；
Specifically, the big current signal of harmonic wave obtains standard secondary current signal by standard current transformer 2, this standard two
Primary current signal is as standard signal.
It is connected with harmonic wave high-current generation device 1, measures for electric current big to harmonic wave, obtain the tested of measured signal
Current transformer 3；
Specifically, the big current signal of harmonic wave obtains tested secondary current signal by tested current transformer 3, and these are tested two years old
Primary current signal is as measured signal.
As preferably, N is 19.
As preferably, standard current transformer 2 is the current transformer of 0.05S level.
As preferably, standard current transformer 2 is high-accuracy current divider.
Specifically, high-accuracy current divider here is precision resister, test time, using the voltage at diverter two ends as
Standard signal.
As preferably, tested current transformer 3 is the current transformer of 0.2 grade.
As preferably, tested current transformer 3 is electronic current mutual inductor.
It is understood that for standard current transformer 2, can be selected for the current transformer of 0.05S level, for high accuracy
Current transformer for, owing to its acquisition precision is the highest, it is believed that its first-harmonic gathered and harmonic wave are very accurate, therefore
Can be as the standard of tested current transformer 3, it addition, high-accuracy current divider should be used when testing frequency higher than 400Hz.
Tested current transformer 3 can select different types of current transformer, tested current transformer 3 can be common as required
0.2 grade or 0.5 grade of conventional current transformer, it is possible to for electronic current mutual inductor, it is to be understood that conventional current mutual inductance
The output rated secondary current of device can be 5A or 1A, the electronic current mutual inductor exportable simulation the most exportable numeral of small voltage
Amount (IEC61850 or FT3).
Specifically, refer to Fig. 2 and Fig. 3, wherein, the another kind of current transformer that Fig. 2 and Fig. 3 is present invention offer is humorous
Wave error measures the structural representation of system.
In Fig. 2 and Fig. 3, what CT0 represented is standard current transformer, and it is conventional current transformer, CTx represent by
Survey current transformer.MU is the combining unit being connected with electronic current mutual inductor.In sum, the harmonic wave electricity that the present invention provides
Stream error measurement apparatus, it is possible to take into account conventional current transformer and electronic current mutual inductor, has complete test and multiple
Miscellaneous function.Stress_responsive genes precision is reached 0.1 grade, first-harmonic error precision 0.02 grade.For the electronics having combining unit to export
Formula current transformer, harmonic current error measuring means support synchronizes and the mode of asynchronous measurement, and synchronizing signal can be defeated
The pulse per second (PPS) entered or export and IRIG-B.
It is connected with standard current transformer 2 and tested current transformer 3 respectively, for standard signal and measured signal are turned
Change pending signal into and send the harmonic current measurement device 4 to host computer 5；
As preferably, harmonic current measurement device 4 includes:
The relay module that is sequentially connected with, AD sampling module, the 2nd FPGA, stm32 and switch, wherein, relay
Module includes that sampling resistor, AD sampling module include that ADC sampling A/D chip, switch are connected with host computer 5；
Specifically, AD sampling module here includes 24 high-precision adc sampling A/D chip.
Harmonic current measurement device 4 also includes:
The synchronization module being connected with the 2nd FPGA and FT3 module；
The first electrical network mouth, the second electrical network mouth, the first smooth network interface and the second smooth network interface being connected with switch；
The 3rd smooth network interface being connected with switch by the 3rd FPGA.
Specifically, refer to the schematic diagram of a kind of harmonic current measurement device that Fig. 4, Fig. 4 provide for the present invention.
Wherein, standard channel data process:
When standard channel connects standard current transformer 2 analog quantity (5A/1A) port, select 5A range and 1A at host computer 5
Range, host computer 5 sends instruction by udp protocol to stm32, and stm32 controls relay module according to instruction and is switched to specify
Range path, the big electric current of input changes into voltage signal through sampling resistor and delivers to AD sampling module；AD sampling module is the most right
Voltage signal processes through channel selecting, programming amplifying, differential attenuation etc., is sent to ADC sampling A/D chip and (is specifically as follows
AD127X analog-to-digital conversion chip)；2nd FPGA controls ADC sampling A/D chip according to synchronizing signal and analog sampling value is changed into numeral
Amount is also stored by SPI protocol data of reading back；Stm32 uses the agreement of FSMC bus to will be stored in the data in the 2nd FPGA
The form reading out and being packaged into UDP message delivers to host computer 5, host computer 5 standard harmonic amount data are carried out calculation process；
When standard channel connects simulation small voltage port, the small voltage of input is directly sent to AD sampling module；AD sampling module
Voltage signal is sent to ADC sampling A/D chip after channel selecting, programming amplifying, differential attenuation etc. process；2nd FPGA according to
Synchronizing signal controls ADC sampling A/D chip and analog sampling value changes into digital quantity and stores by SPI protocol data of reading back；
Stm32 uses the agreement of FSMC bus to will be stored in the data read-out in the 2nd FPGA to come and be packaged into the form of UDP message to send
To host computer 5, host computer 5 standard harmonic amount data are carried out calculation process；
Tested channel data processes:
When tested passage connects big electric current (5A/1A) port, selecting 5A range and 1A range at host computer 5, host computer 5 passes through
Udp protocol sends instruction to stm32, and stm32 controls relay module according to instruction and is switched to specify range path, input big
Electric current changes into voltage signal through sampling resistor and delivers to AD sampling module；AD sampling module to voltage signal through channel selecting,
Programming amplifying, differential attenuation etc. are sent to ADC sampling A/D chip after processing；2nd PFGA controls ADC sampling A/D chip according to synchronizing signal
Analog sampling value is changed into digital quantity and stores by SPI protocol data of reading back；The agreement of stm32 employing FSMC bus will
The data read-out being stored in the 2nd PFGA is come and is packaged into the form of UDP message to deliver to host computer 5, by host computer 5 to tested
Harmonic content data carry out calculation process；
When tested passage connects simulation small voltage port, the small voltage of input is directly sent to AD sampling module；AD sampling module
Voltage signal is sent to ADC sampling A/D chip after channel selecting, programming amplifying, differential attenuation etc. process；2nd PFGA according to
Synchronizing signal controls ADC sampling A/D chip and analog sampling value changes into digital quantity and stores by SPI protocol data of reading back；
Stm32 uses the agreement of FSMC bus to will be stored in the data read-out in the 2nd PFGA to come and be packaged into the form of UDP message to send
To host computer 5, host computer 5 tested harmonic content data are carried out calculation process；
Be measured as digital quantity, use IEC61850 agreement, when having synchronizing signal, optical fiber is according to tail optical fiber type (ST/SC)
Being connected on the first smooth network interface or the second smooth network interface, twisted-pair feeder can be connected on any one electrical network mouth (the first electrical network mouth or second
Electrical network mouth) on, IEC61850 message is directly sent to host computer 5 by switch, by host computer 5 analytic message, takes out tested humorous
Ripple amount data, row operation of going forward side by side processes；Be measured as digital quantity, use IEC61850 agreement, without synchronizing signal time, optical fiber is connect
3rd smooth network interface (only supports SC mouth)；IEC61850 message is delivered at the 3rd PFGA, by the 3rd PFGA analytic message and
Inside delivers to host computer 5 by network interface through switch again plus temporal information, and host computer 5 is according to the tested harmonic content in message
Data and temporal information carry out calculation process；
When being measured as digital quantity employing FT3 agreement, selecting FT3 port, FT3 signal is sent after opto-electronic conversion by signal
On the 2nd PFGA, the data that inside is comprised by the 2nd PFGA by resolving FT3 message are taken out and are stored, stm32 adopt
After reading to walk by data with FSMC bus protocol, the form being packaged into UDP message in stm32 delivers to host computer 5, and host computer 5 will
Tested harmonic content data parsing in UDP message out carries out calculation process.
It is connected with harmonic wave high-current generation device 1 and harmonic current measurement device 4 respectively, for according to pending signal
Obtain first-harmonic until the host computer 5 of error of the content of n times harmonic wave, ratio and angular difference.
It is understood that the pending signal that harmonic current measurement device 4 is transmitted by host computer 5 carries out Fourier transformation
Computing, just can calculate first-harmonic and the content of each harmonic, ratio and angular difference.
The formula of Fourier transformation is as follows:
$x\left(t\right)={a}_{0}+\underset{n=1}{\overset{\mathrm{\∞}}{\Σ}}({a}_{n}\mathrm{cos}{\mathrm{n\ω}}_{0}t+{b}_{n}\mathrm{sin}{\mathrm{n\ω}}_{0}t),n=1,2,3,...$
Fourier coefficient:
${a}_{0}=\frac{1}{T}{\∫}_{-\frac{T}{2}}^{\frac{T}{2}}x\left(t\right)dt$
${a}_{n}=\frac{2}{T}{\∫}_{-\frac{T}{2}}^{\frac{T}{2}}x\left(t\right)\mathrm{cos}{\mathrm{n\ω}}_{0}tdt$
${b}_{n}=\frac{2}{T}{\∫}_{-\frac{T}{2}}^{\frac{T}{2}}x\left(t\right)\mathrm{sin}{\mathrm{n\ω}}_{0}tdt$
In formula: T is the cycle；ω_{0}For fundamental frequency, ω_{0}=2 π/T_{0},T_{0}For the signal primitive period.
The another kind of form of trigonometric function expansion:
In formula: a_{0}For the DC component of signal, A_{n}For n times harmonic amplitude, n ω is n times harmonic frequency,For n times harmonic wave phase
Angle,For n times harmonic wave.
The ratio angular difference of first-harmonic and each harmonic:
In formula: K_{n}For nth harmonic ratio, δ_{n}For nth harmonic angular difference.
Visible, the nth harmonic impact on current transformer can be obtained according to the content of nth harmonic, ratio and angular difference, also
I.e. error during current transformer collection nth harmonic.
It addition, host computer 5 meets multiple test request, rich interface, it is possible to various electron sources are carried out first-harmonic and harmonic wave
The control of content, and automatically carry out slope according to setting, receive various electricity and error that stress_responsive genes instrument sends simultaneously
Data signal, forms test record inside local data base, facilitates follow-up analysis and inquiry.
To sum up, the present invention can be known the big electric current of harmonic wave that harmonic wave high-current generation device produces according to harmonic wave mechanism,
Can know harmonic wave on current transformer once, the impact of secondary current signal, and then obtain harmonic wave to tested current transformer
The impact of error (ratio difference, angular difference) between the standard signal of the measured signal of output and standard current transformer output；Can
Know the harmonic current error measuring means ratio to measured signal under the analysis of harmonic signal and each harmonic with standard signal
Difference, angular difference.
The invention provides a kind of current transformer harmonic error and measure system, this system includes for generating the big electricity of harmonic wave
The harmonic wave high-current generation device of stream；Measure for electric current big to harmonic wave, obtain the standard current transformer of standard signal；
Measure for electric current big to harmonic wave, obtain the tested current transformer of measured signal；For by standard signal and tested letter
Number it is converted into pending signal and sends the harmonic current measurement device to host computer；For obtaining first-harmonic according to pending signal
Until the host computer of the content of n times harmonic wave, ratio and angular difference.Visible, the application is by generating the big electricity of harmonic wave of the big electric current of harmonic wave
Flow generating apparatus simulates power system environment, then according to the tested current transformer that electric current big to harmonic wave measures respectively with
And the measured signal that records of standard current transformer and standard signal obtain first-harmonic and the content of n times harmonic wave, ratio and angular difference,
By the comparison with standard current transformer, just would know that current transformer error when to harmonic measure, and then obtain humorous
Error (ratio between measured signal and the standard signal of standard current transformer output that tested current transformer is exported by ripple
Difference, angular difference) impact, facilitate follow-up tested current transformer being improved and accurate measurement to harmonic wave.
It should be noted that in this manual, the relational terms of such as first and second or the like is used merely to one
Individual entity or operation separate with another entity or operating space, and not necessarily require or imply these entities or operate it
Between exist any this reality relation or order.And, term " includes ", " comprising " or its any other variant are intended to
Contain comprising of nonexcludability, so that include that the process of a series of key element, method, article or equipment not only include those
Key element, but also include other key elements being not expressly set out, or also include for this process, method, article or set
Standby intrinsic key element.In the case of there is no more restriction, statement " including ... " key element limited, it is not excluded that
Other identical element is there is also in including the process of described key element, method, article or equipment.
Described above to the disclosed embodiments, makes professional and technical personnel in the field be capable of or uses the present invention.
Multiple amendment to these embodiments will be apparent from for those skilled in the art, as defined herein
General Principle can realize without departing from the spirit or scope of the present invention in other embodiments.Therefore, the present invention
It is not intended to be limited to the embodiments shown herein, and is to fit to and principles disclosed herein and features of novelty phase one
The widest scope caused.