CN104198872B - Online equipment for monitoring power quality and method - Google Patents
Online equipment for monitoring power quality and method Download PDFInfo
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- CN104198872B CN104198872B CN201410514383.4A CN201410514383A CN104198872B CN 104198872 B CN104198872 B CN 104198872B CN 201410514383 A CN201410514383 A CN 201410514383A CN 104198872 B CN104198872 B CN 104198872B
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Abstract
The invention provides a kind of online equipment for monitoring power quality and method.Wherein, the device includes：Signal acquisition module, voltage signal and current signal for gathering current power system according to the sampling window length of setting and sampling period；Wherein, the sampling window length is the voltage signal of power system or the integral multiple in fundamental frequency signal cycle in current signal；Sampling period is the integral multiple of local clock cycles；Analog-to-digital conversion module, for carrying out analog-to-digital conversion respectively to the voltage signal and current signal that collect, obtains digital voltage signal and digital current signal；Electrical energy parameter analyzes computing module, for carrying out analysis calculating to digital voltage signal and digital current signal, obtains corresponding electrical energy parameter；Running situation determining module, the running situation for determining power system according to above-mentioned electrical energy parameter.By means of the invention it is possible to effectively prevent spectral leakage, the synchronism of sampling is improved, and then improves the accuracy of electric energy quality monitoring.
Description
Technical field
The present invention relates to electric power energy and microelectronics technology, filled in particular to online electric energy quality monitoring
Put and method.
Background technology
The fast development of power industry causes distribution system increasingly complicated, before slight electrical problems become substantially,
Industrial plants distribution system may be close to collapse.Electric power is used as a kind of special commodity, its general merchandise that can not be broken away from
Attribute --- " quality of power supply " problem is increasingly subject to the attention for electricity consumption both sides, the quality of power supply is carried out monitoring in real time also therewith by
Gradually turn into a kind of inevitable requirement, still, with silicon controlled rectifier (SCR), electric arc furnaces, rolling mill, electric locomotive, computer and various
Communication apparatus etc. (non-linear, impact and asymmetry load) largely comes into operation, and makes the non-linear, no of power network supply voltage
Stability and asymmetry are on the rise.It is small to be damaged to computer corruption, hard disk, it is big to stop to transformer overheat, enterprise's production line
A series of accident of power supplys caused by the quality of power supply such as production happen occasionally.The deterioration of the quality of power supply threatens the peace of national economy
Entirely, normal operation.How to improve and ensure that the quality of power supply has become the major issue that China's power system faces.In order to improve
The quality of power supply provides necessary foundation with the control measures and policy formulated about the quality of power supply, and power department need to be to the quality of power supply
Continuously monitored.It is on the one hand right because the various devices that power electronic devices is constituted are widely used in power system
The quality of power supply of power system proposes higher requirement, and new pollution is on the other hand brought to power system, electricity is degrading
Can quality, traditional power quality index system is not adapted to news, force proposition and carry out the new quality of power supply and refer to
Mark system, so that traditional electric energy quality monitor destiny on the verge of being replaced, develops and use the new high-performance quality of power supply
Monitor turns into inevitable.
With the development and the progress of science and technology of power system, especially in the late two decades, microelectric technique, computer
Technology, precision machinery technology, highly dense encapsulation technique, special processing technology, integrated technology, thin film technique, network technology, nanometer skill
The new and high technologies such as art, laser technology, superconductor technology obtain fast development.This background and situation, constantly to the quality of power supply
Monitoring propose it is higher, update, it is more require, such as require speed faster, sensitivity is higher, stability is more preferable, using more square
Just, cost is less expensive etc..At present, electric energy quality monitoring is fast towards the direction of computerization, networking, intellectuality, multifunction
Speed development, and due to a large amount of achievement in research, comprehensive Design interdisciplinary, high-grade, precision and advanced manufacture skills using high-and-new science and technology
The practical application of art and strict science so that it also just towards more at a high speed, it is sensitiveer, more reliable, more quickly and easily obtain quilt
Analysis, detection, the direction of control object full spectrum information are advanced with big strides.As can be seen that high-technicalization not still modern electric energy matter
The principal character of monitoring is measured, is also the Developing mainstream of new century electric energy quality monitoring.The high-technicalization of electric energy quality monitoring product,
It is increasingly becoming the Developing mainstream of electric energy quality monitoring science and technology and industry.
At present, online electric energy quality monitor because the setting in sampling window length and sampling period it is not reasonable, easily
There is spectral leakage, and then influence the accuracy of electric energy quality monitoring, for this problem, effective solve not yet is proposed at present
Scheme.
The content of the invention
In view of this, it is an object of the invention to provide a kind of online equipment for monitoring power quality and method, to solve
Above-mentioned the problem of.
A kind of online equipment for monitoring power quality is provided in an embodiment of the present invention, including：Signal acquisition module,
Voltage signal and current signal for gathering current power system according to the sampling window length of setting and sampling period；Its
In, sampling window length is the voltage signal of power system or the integral multiple in fundamental frequency signal cycle in current signal；Sampling period
For the integral multiple of local clock cycles；Analog-to-digital conversion module, for the voltage signal and electric current collected to signal acquisition module
Signal carries out analog-to-digital conversion respectively, obtains digital voltage signal and digital current signal；Electrical energy parameter analyzes computing module, is used for
The digital voltage signal and digital current signal obtained to analog-to-digital conversion module carries out analysis calculating, obtains corresponding electric energy ginseng
Number；Running situation determining module, the electrical energy parameter for being calculated according to electrical energy parameter analysis computing module determines power system
Running situation.
A kind of online electric energy quality monitoring method is additionally provided in an embodiment of the present invention, including：
The voltage signal and current signal of current power system are gathered according to the sampling window length of setting and sampling period；
Wherein, sampling window length is the voltage signal of power system or the integral multiple in fundamental frequency signal cycle in current signal；Sampling week
Phase is the integral multiple of local clock cycles；Analog-to-digital conversion is carried out respectively to the voltage signal and current signal collected, counted
Word voltage signal and digital current signal；Analysis calculating is carried out to digital voltage signal and digital current signal, obtains corresponding
Electrical energy parameter；The running situation of power system is determined according to electrical energy parameter.
Method and apparatus provided in an embodiment of the present invention, when carrying out signal acquisition, the sampling window length used is this
The integral multiple in fundamental frequency signal cycle in the voltage signal or current signal of power system；And the sampling period is local clock cycles
Integral multiple, the voltage signal and current signal of current power system is gathered based on the sampling window length and sampling period, so
Spectral leakage can be effectively prevented, the synchronism of sampling is improved, and then improves the accuracy of electric energy quality monitoring.
To enable the above objects, features and advantages of the present invention to become apparent, preferred embodiment cited below particularly, and coordinate
Appended accompanying drawing, is described in detail below.
Brief description of the drawings
In order to illustrate the technical solution of the embodiments of the present invention more clearly, below will be attached to what is used required in embodiment
Figure is briefly described, it will be appreciated that the following drawings illustrate only certain embodiments of the present invention, therefore should not be seen as pair
The restriction of scope, for those of ordinary skill in the art, on the premise of not paying creative work, can also be according to this
A little accompanying drawings obtain other related accompanying drawings.
Fig. 1 shows the structured flowchart of online equipment for monitoring power quality provided in an embodiment of the present invention；
Fig. 2 shows the structured flowchart of another online equipment for monitoring power quality provided in an embodiment of the present invention；
Fig. 3 shows the hardware architecture diagram of online electric energy quality monitor provided in an embodiment of the present invention；
Fig. 4 shows MCU provided in an embodiment of the present invention structured flowchart；
Fig. 5 shows the structured flowchart of PC104 buses provided in an embodiment of the present invention and HPI bus bridge circuits；
Fig. 6 shows DSP provided in an embodiment of the present invention structured flowchart；
Fig. 7 shows the structured flowchart of synchronized sampling circuit provided in an embodiment of the present invention；
Fig. 8 shows the software system architecture structured flowchart of monitor provided in an embodiment of the present invention；
Fig. 9 shows the operation schematic diagram of the software systems of monitor provided in an embodiment of the present invention；
Figure 10 shows the interaction schematic diagram of HPI interaction protocols provided in an embodiment of the present invention；
Figure 11 (a), 11 (b) and 11 (c) respectively illustrate the base provided in an embodiment of the present invention obtained after digital filtering
Waveform after the waveform diagram of ripple signal, two neighboring positive slope zero crossing (becoming positive zero crossing by negative) amplification nearby shows
It is intended to；
Figure 12 shows the flow chart of online electric energy quality monitoring method provided in an embodiment of the present invention.
Embodiment
Below in conjunction with accompanying drawing in the embodiment of the present invention, the technical scheme in the embodiment of the present invention is carried out clear, complete
Ground is described, it is clear that described embodiment is only a part of embodiment of the invention, rather than whole embodiments.It is right below
The description only actually of at least one exemplary embodiment is illustrative, is not intended as to the present invention and its application or uses
Any limitation.Based on embodiments of the invention, those skilled in the art are obtained on the premise of creative work is not made
The every other embodiment obtained, belongs to the scope of protection of the invention.
The structured flowchart of online equipment for monitoring power quality shown in Figure 1, the device is included with lower module：
Signal acquisition module 12, for gathering current power system according to the sampling window length of setting and sampling period
Voltage signal and current signal；Wherein, the sampling window length is fundamental frequency in the voltage signal or current signal of the power system
The integral multiple of signal period；The sampling period is the integral multiple of local clock cycles；Here local clock refers to electric energy matter
Measure the system clock of monitoring device；
Analog-to-digital conversion module 14, is connected with signal acquisition module 12, for the voltage collected to signal acquisition module 12
Signal and current signal carry out analog-to-digital conversion respectively, obtain digital voltage signal and digital current signal；
Electrical energy parameter analyzes computing module 16, is connected with analog-to-digital conversion module 14, for being obtained to analog-to-digital conversion module 14
Digital voltage signal and digital current signal carry out analysis calculating, obtain corresponding electrical energy parameter；
Running situation determining module 18, is connected with electrical energy parameter analysis computing module 16, for being analyzed according to electrical energy parameter
The electrical energy parameter that computing module 16 is calculated determines the running situation of power system.
The device of the present embodiment is when carrying out signal acquisition, and the sampling window length used is believed for the voltage of the power system
Number or current signal in the fundamental frequency signal cycle integral multiple；And the sampling period is the integral multiple of local clock cycles, adopted based on this
Sample length of window and sampling period gather the voltage signal and current signal of current power system, so can effectively prevent frequency spectrum
Leakage, improves the synchronism of sampling, and then improve the accuracy of electric energy quality monitoring.In view of in practical power systems,
Electric voltage frequency is it some times happens that fluctuate, and in sampling window length, the sampling number collected in each sampling period may
Can be different, and then follow-up electrical energy parameter analysis is influenceed with calculating, based on this, on the basis of above-mentioned Fig. 1 shown devices, this hair
Bright embodiment additionally provides the structured flowchart of another online equipment for monitoring power quality shown in Fig. 2, and the device is except bag
Include outside the modules shown in Fig. 1, in addition to：Signal supplies module 22, with analog-to-digital conversion module 14 and electrical energy parameter analysis meter
Module 16 is calculated to be connected, for when the number of samples in each sampling period is different, the electricity collected in 14 pairs of analog-to-digital conversion module
Pressure signal and current signal are carried out after analog-to-digital conversion respectively, set the sampling of number to number of samples deficiency using Newton interpolating method
Digital voltage signal and digital current signal in cycle carry out supplying operation.
It is more difficult to be realized in view of Complete Synchronization sampling, and the embodiment of the present invention employs the mode of windowed function, based on this,
Above-mentioned signal acquisition module 12 can include：Window widens unit, for being added using rectangular window or Hanning window to sampling window
It is wide；Signal gathering unit, for based on window widen the sampling window after unit is widened according to setting sampling window length and
Sampling period gathers the voltage signal and current signal of current power system.This adding window mode, can be effectively reduced frequency spectrum
Leakage, aliasing and " fence " effect.
Said apparatus, can be disposably accurately from the electricity of complex electric network using FFT detection harmonic waves and m-Acetyl chlorophosphonazo is improved
The integer and fractional component between 0~sample frequency/2 are obtained in pressure and electric current, acquisition modes facilitate more rapidly, preferably dropped
The low influence of " fence " effect and frequency leakage.
Understand the running situation of power system in time for the ease of human observer, said apparatus can also include：Running situation
Display module, is connected with running situation determining module 18, the running situation for showing power system in display interface.And/or,
Said apparatus can also include：Running situation transport module, is connected with running situation determining module 18, for passing through mobile network
Or the running situation of power system is transferred to target terminal by internet.
Based on said apparatus, when implementing, the hardware of the online electric energy quality monitor shown in Fig. 3 can be used
Dotted portion is optional component/extended function part in structural representation, figure.The hardware of the monitor is mainly m-Acetyl chlorophosphonazo/transient state
Monitoring modular；A/D converter 1 is low-frequency sampling A/D converter, and A/D converter 2 is high frequency sampling A/D converter；DSP1 and
DSP2 input signal is the output signal (DSP2 is used as m-Acetyl chlorophosphonazo monitoring modular) of A/D converter 1, or, DSP1 input
Signal is the output signal of A/D converter 1, and (DSP2 is used as transient state for the output signal of A/D converter 2 for DSP2 input signal
Monitoring modular or m-Acetyl chlorophosphonazo and transient state monitoring modular).
The A/D converter of the present embodiment can be using 16 A/D converters at a high speed, current transformer and voltage transformer point
Current signal and voltage signal Yong Yu not be gathered, the signal that current transformer and voltage transformer are collected is transferred to respective connection
Buffer amplifier, then analog-to-digital conversion is carried out to each phase current, voltage via A/D converter and DSP high-speed digital signals, by
DSP completes the measurement (or to calculate) and analysis work to basic electric parameter, harmonic wave, flickering etc..Calculating obtained data can
To carry out data exchange by high speed HPI communication interfaces and management level (MCU i.e. in figure)；Management level are using advanced embedded
PC104 industrial computers and stable operating system are (for example：Android operation system) composition, it is main complete display, data statistics,
The work such as storage, communication.
Control logic module in Fig. 3 is used to send control instruction to all parts, is acted accordingly.Also wrapped in figure
Power supply, the power management module being connected with power supply are included, and data keep battery, meter reading battery, for for online electricity
Energy quality monitor offer work electricity consumption etc..
Lower mask body introduces the various pieces of monitor shown in Fig. 3：
(1)MCU
MCU (being referred to as logic management module or supervisor) in the embodiment of the present invention using PC104 mainboards+
Android embedded system.MCU as shown in Figure 4 structured flowchart, the MCU includes PC104 mainboards (or for PC104 master
Machine, main frame), the mainboard be connected with hard disk and CF cards, its control signal connection logical combination unit, and via driving and monitor
Bus connection；PC104 mainboards connect bus driver by data wire, and the bus driver is also connected with the bus of monitor.
PC104 mainboards include a serial communication port, ethernet communication mouthful, miniature EIDE interface, GPIO interface,
Two USB2.0 high-speed interfaces, VGA liquid crystal interface, RJ45 interfaces and a PS2 interface, serial communication port can be coupled any
RS-232 asynchronous communication devices, Ethernet interface supports ICP/IP protocol.The branch of the installation motherboard (abbreviation interface board) of PC104 mainboards
Hold circuit be mainly the bus of EIDE, COM, VGA, LAN, PS2, double-USB interface plug-in unit conversion line and PC104 mainboards with
Bridgt circuit between HPI buses is (containing level translation, address decoding-use CPLD logics decoding, and relevant control electricity
Road).
PC104 mainboards can use BGA package cpu chip, without fan in 0~60 DEG C of working range, thoroughly solve
Because fan failure causes the problem of reliability is reduced.The stability and reliability of system are added in plate CPU and SDRAM,
LCD interfaces on the plate can support TFT LCD screens, the ﹑ 800 × 600,1024 × 768 of resolution ratio 640 × 480.44PIN IDE
Interface can meet DOM (Disk On Module), or mating CF adapters, hard disk or DOC.It is this to take setting for 8 layers of pcb board
Meter, adds the ability of its anti-electromagnetic interference.
PC104 mainboards can use PCC-3568 mainboards, and it is integrated with 586 CPU with multimedia function of low-power consumption.Plate
It is upper have CRT/LCD Xian show 1 10/100Mbps network interface of Jie Kou ﹑, support 2 serial ports, parallel port, two USB interfaces,
COBBAIF, floppy drive interface, 16 grades of WatchDog Timers, the input of 8 bit digitals, 8 bit digitals are exported, in plate 128/64/32M
SDRAM, a micro hard disk interface, can support two hard disk drives, there is provided expansion for 115.2Kbps infrared interface
The standard PC/104 interfaces filled.
(2) bus and HPI bus bridge circuits
Data exchange is carried out using the HPI buses of high speed between DSP and PC104 mainboards.The HPI interfaces of PC104 mainboards are
One parallel port, PC104 mainboards administer the ownership of the interface, and DSP whole memory space can be directly accessed by it.
The mode that PC104 mainboards simulate HPI interface control signals by using address bus administers DSP HPI and direct
Read and write HPI control registers and access DSP memory space.In view of the connection of long range and backboard plug at a high speed between bus
Design bus interface circuit is needed to carry out matching for sequential and control signal between mode, PC104 buses and HPI both buses
Work.
PC104 buses shown in Figure 5 and the structured flowchart of HPI bus bridge circuits, it is negative in PC104 sources and DSP
The matching way that end uses terminal coupling resistor network is carried, the matching way of resistance-capacitance network is used at backboard plug-in unit, while by
Bus interference and insulation is mismatched and considers in DSP and PC104 interface levels, bus signals are laggard by Bus isolation driver
Go out source and load end.
(3) high speed measurement module (i.e. DSP)
DSP shown in Figure 6 structured flowchart, the structure of the DSP is similar with traditional DSP architecture, sampled signal warp
Cross after transformer, enter A/D converter through signal condition loop (i.e. buffer amplifier)；Produced after A/D conversion ends in one
Break signal is to notify DSP to read data, after DSP is by the corresponding A/D converter of address choice and related channel program, and 16 data are read
Return.DSP directly accesses the outer high-speed data processing device of piece and program storage by 32bit high performance externals memory interface (EMIF)
Device, its address distribution is determined by programmable logic array.DSP extends out ferroelectric memory and (contains each passage to access fixed parameter
Data correction, operational mode etc. parameter).DSP extends a RS-232 serial ports by TL16C550, and the serial line interface can be coupled
Any RS-232 asynchronous communication devices, are mainly used in debugging single board use.
HPI interfaces carry out the data-interface of high-speed communication as DSP and MCU, and by DSP HPI interfaces, MCU can be high
Speed accesses DSP whole memory space.
(4) A/D converter
The A/D conversion chips that A/D converter is used can be ADS8364.ADS8364 is high speed, low-power consumption, and six passages are complete
Complete 16 independent gradually-appoximant analog-digital converters.Its use+5V operating voltage, and the fully differential with 80dB common mode inhibitions is defeated
Enter passage and analog-digital converter, the six difference sampling amplifiers of six 4 μ s continuous approximations.In addition, in REFIN and REFOUT
Pin inner portions also carry+2.5V reference voltages and high speed parallel interface.ADS8364 six simulation inputs are divided into three groups of (A, B
And C), each input has an ADCs to keep signal to ensure that several passages can be while being sampled and being changed.
When ADS8364 controls conversion using 5MHz external clock, its sampling rate is 250kHz, is corresponded to simultaneously
4 μ s maximum throughput rate, so, sampling and conversion need to spend 20 clock cycle altogether.In addition, when external clock uses 5MHz
When, ADS8364 conversion time is 3.2 μ s, and corresponding acquisition time is 0.8 μ s.Therefore, in order to obtain maximum output data
Rate, reading data can be carried out in next transition period.
(5) synchronized sampling circuit
Synchronized sampling circuit mainly completes the function of frequency-tracking, and the circuit can ensure to be A/ in a power frequency period
D converters provide 256 points of sampled signal, so as to realize the function of genlock.
The structured flowchart of synchronized sampling circuit shown in Figure 7, it includes：Blocking filter circuit, Zero-cross comparator circuit,
Phase selection circuit, phase-locking frequency multiplication circuit (also referred to as PLL circuit) and A/D converter.Phase selection circuit can automatically select the separate of voltage,
And follow-up PLL circuit is supplied to according to choosing separate voltage to produce zero cross signal, adopted with the phase locking frequency multiplying for realizing 256 times
Sample.In the case where frequency changes, circuit also can guarantee that the sampling of every 256 points of cycle.Phase selection circuit is using A phase voltages as optimal
What is first considered is separate, and A phases zero cross signal is regard as synchronizing signal, locking B, C phase when A phases have voltage；After A phase power down, with B phases
Zero cross signal is used as synchronizing signal, locking C phases；Power down when A, B are identical, synchronizing signal is used as using C phase zero cross signals.It is alternate enter
, at this moment will production due to the delay of circuit parameter and circuit in itself, it may appear that the blank of one section of locking when line synchronising signal switches
A raw fault interrupt signal notifies DSP, and the synchronous sampling signal of this blank time is provided by DSP.When three-phase voltage is whole
After failure, then synchronous sampling signal is independently produced by DSP, 256 points of sampling is carried out with 50Hz power frequencies.
The software system architecture of above-mentioned monitor can use structure of block diagram as shown in Figure 8, specially client layer, application
Service layer and data Layer.Client layer includes：User interface, interface processing layer, interface processing communication layers, service communication intermediate layer；
Application service layer includes：Business Facade, plan of operation layer, entity key-course, physical layer data, canonical parameter and system are matched somebody with somebody
Put；Data Layer includes data access layer and document storage system.Following 4 subsystems can be designed to complete the function of system,
Subsystem is respectively：Display subsystem, initialization and parameter setting subsystem, applied business processing subsystem, DSP reading and writing datas
Subsystem.
Display subsystem function is mainly the display interaction for completing user and electric energy quality monitor, is mainly set including parameter
Put interaction, basic electricity show, the quality of power supply show, electric energy is shown, event is shown, System self-test presentation of information and correlation and
Communication process of applied business processing subsystem etc..Initialization and parameter setting subsystem mainly complete MCU and application system
Initial work and to system carry out various parameters setting work, mainly by way of shared drive and message queue to
Service process subsystem provides various canonical parameters the parameter setting work related to progress.
Applied business processing subsystem is mainly used to handle all core business, wherein mainly handled including statistical analysis,
Data storage and deletion, data query, data communication processing, system administration, power down process etc., wherein handling mould with statistical analysis
Block is the most complicated, when there is data arrival DSP parts, by DSP reading and writing datas subsystem by HPI bus timings inquiry mode or
Interrupt mode reads DSP partial datas, reads one semaphore to applied business processing subsystem of generation after the completion of data, should
Received with service process subsystem after semaphore, start related statistic analysis.
The operation schematic diagram of the software systems of monitor shown in Figure 9, first, system are initialized and self-inspection；
Then data ready mark is checked whether there isIf data ready mark, the calculating of basic electricity, and follow-up electricity are carried out
Pressure fluctuation and the calculating of the calculating of flickering, the calculating of harmonic wave and m-Acetyl chlorophosphonazo, the calculating of three-phase imbalance, voltage and frequency departure；
If there is no data ready mark, continue to monitor.
DSP reading and writing datas subsystem mainly completes all read-write operations to dsp board, and concrete operations mainly include DSP and joined
Number is set, DSP communications are read with management, DSP real time datas, DSP recorder datas are read etc..
The interaction schematic diagram of HPI interaction protocols shown in Figure 10, HPI can be considered as four areas：Self-detection result area, set
Put parameter interactive areas, initial command interactive areas and data interactive areas；Wherein, inspection fruiting area, arrange parameter interactive areas correspond to DSP
Buffering area；Initial command interactive areas MCU corresponding with data interactive areas.
The specific algorithm and embodiment of operation are as follows in DSP：
1st, instantaneous value
Instantaneous value includes：(1) A, B, C three-phase voltage value；(2) A, B, C three-phase electricity flow valuve；Instantaneous value passes through A/D converter
Sampling is obtained.
2nd, virtual value
2.1 real effective
The definition of virtual value：
The T- cycles；Sampling number in N- cycle Ts；X (t)-instantaneous value；x(tn)-sampled value, tn- the n-th sampled point
Time (the 0th sampled point starts timing)；
By the definition of virtual value calculate obtained virtual value also known as real effective.The virtual value bag calculated according to definition
Include：
(1) real effective of phase (line) voltage of A, B, C three-phase；
(2) real effective of phase (line) electric current of A, B, C three-phase；
Three-phase voltage real effective：
Three-phase current real effective
Time of integration T=1/f1, f1For fundamental frequency.
2.2 fundamental waves and harmonic wave, the virtual value of m-Acetyl chlorophosphonazo
The virtual value calculated according to FFT includes：
(1) virtual value of A, B, C three-phase fundamental wave phase (line) voltage；
(2) virtual value of A, B, C three-phase fundamental wave phase (line) electric current；
(3) virtual value of A, B, C three phase harmonic and phase (line) voltage of m-Acetyl chlorophosphonazo；
(4) virtual value of A, B, C three phase harmonic and phase (line) electric current of m-Acetyl chlorophosphonazo；
2.3 positive sequences, negative phase-sequence, the virtual value of zero-sequence component
The virtual value calculated according to symmetrical component method includes：
(1) virtual value of A, B, C three-phase fundamental positive sequence phase (line) voltage；
(2) virtual value of A, B, C three-phase fundamental positive sequence phase (line) electric current；
(3) virtual value of A, B, C three-phase fundamental wave negative sequence phase (line) voltage；
(4) virtual value of A, B, C three-phase fundamental wave negative sequence phase (line) electric current；
(5) virtual value of A, B, C three-phase fundamental wave zero sequence phase (line) voltage；
(6) virtual value of A, B, C three-phase fundamental wave zero sequence phase (line) electric current；
(7) virtual value of A, B, C three phase harmonic positive sequence phase (line) voltage；
(8) virtual value of A, B, C three phase harmonic positive sequence phase (line) electric current；
(9) virtual value of A, B, C three phase harmonic negative phase-sequence phase (line) voltage；
(10) virtual value of A, B, C three phase harmonic negative phase-sequence phase (line) electric current；
(11) virtual value of A, B, C three phase harmonic zero sequence phase (line) voltage；
(12) virtual value of A, B, C three phase harmonic zero sequence phase (line) electric current；
(13) virtual value of A, B, C three-phase positive sequence phase (line) voltage；
(14) virtual value of A, B, C three-phase positive sequence phase (line) electric current；
(15) virtual value of A, B, C three-phase negative/positive phase (line) voltage；
(16) virtual value of A, B, C three-phase negative/positive phase (line) electric current；
(17) virtual value of A, B, C three-phase zero sequence phase (line) voltage；
(18) virtual value of A, B, C three-phase zero sequence phase (line) electric current；
3rd, mean power and power factor
3.1 apparent energy
(1) fundamental wave of each phase of A, B, C, harmonic wave and total apparent energy, the total apparent energy of three-phase phasor；, according to apparent energy, have
The relation of work(power, reactive power：(or)；
(2) the total apparent energy of three-phase arithmetic
According to the relation between apparent energy, the total apparent energy S of three-phase arithmetic∑=Sa+Sb+Sc；
3.2 active power
(1) phase (or alternate) average active power
Defined according to average active power：T is sine wave (fundamental wave) week
Phase；
(2) active power of fundamental wave and harmonic wave：Uk、IkFor kth (k=1 ...) secondary voltage, electric current
Virtual value, φkFor phase difference of the kth time between sine-wave current and voltage.
3.3 reactive power
(1) true reactive power
Method 1：
Each voltage, the virtual value of current harmonics and phase angle are obtained using FFT, is tried to achieve according to above formula.
Method 2：Hilbert transform methods, Hilbert conversion frequency domain characteristic be：
It is the linear change that amplitude versus frequency characte carries out 900 phase shifts, positive frequency component -900 phase shifts of progress for 1, negative frequency component
Change.It can be realized to each phase shift 900 or -900 simultaneously of the individual harmonic current in electric current using Hilbert conversion.If
It is i ' (t) that i (t) Hilbert, which is converted and filtered off direct component,.
So as to constitute equation below：
(2) reactive power of fundamental wave and harmonic wave：
Uk、IkFor kth (k=1 ...) secondary voltage, the virtual value of electric current, φkFor kth time sine wave
Phase difference between electric current and voltage.
3.4 power factor
(1) phasor power factor：
(2) arithmetic power factor：
4th, deviation
Δ x=x (t)-Xs=x (tn)-Xs；Wherein, XsFor standard value.
Deviation, which is calculated, to be included：
(1) voltage deviation
The phase voltage of A, B, C three-phase, the voltage deviation of line voltage；
(2) frequency departure
The phase voltage of A, B, C three-phase, the frequency departure of line voltage；
5th, fluctuation and flickering
5.1 fluctuation
Voltage pulsation refers to a series of variations or continuous change of voltage r.m.s. (virtual value), i.e.,：
Or
U- virtual values, UN- rated value.Umin- minimum value, Umax- maximum
The number of times of unit interval variation in voltage is referred to as frequency, and r is represented.Unit is general with min-1Or s-1Represent.
Method：The virtual value of each cycle (20ms) is measured in 1 point of kind, then above-mentioned virtual value is compared, taken
Maximum difference (Umax-Umin)。
5.2 flickering
Instantaneous vermicularizing alloy (Instantaneous Flicker Sensation Level) S：Voltage pulsation causes photograph
Subjective sensation of the degree fluctuation to people.Instantaneous vermicularizing alloy S unit of measurement, i.e. S=1 are generally used as using degree of perceiving F=50%
Degree of perceiving unit (Unit Of Perceptibility).
The visual sense degree COEFFICIENT K that UIE and IEC recommendsf。
If the instantaneous vermicularizing alloy S values that measurement is obtained are classified from minimum to maximum (is usually not less than 64
Level), for i-stage, cumulative probability CPF (i) is defined as follows：
The testing time of cumulative time/total of CPF (i)=exceed i-stage visual sense angle value；
The statistical nature of flickering is divided into short time flicker value Pst(typically taking 10min) and long-time flickering value Plt(typically take
For dozens of minutes or some hours) weigh.
(1)Pst：
Method：Voltage pulsation and its corresponding instantaneous vermicularizing alloy were measured in 10 minutes, by instantaneous vermicularizing alloy
Classification, tries to achieve cumulative probability function CPF=f (S), P is tried to achieve according to CPFst。
(IEC standard).
In formula, P0.1﹑ P1﹑ P3﹑ P10﹑ P50In respectively 10 minutes time of measuring, cumulative probability CPF values more than 0.1%,
(the easy practice can sort S (t) from small to large 1%, 3%, 10% and 50% visual sense angle value, take its 99.9% ﹑
The ﹑ 90% of 99% ﹑ 97% and the big value of 50% probability).
(2)P1t：In dozens of minutes or measurement voltage pulsation and its corresponding instantaneous vermicularizing alloy in some hours, by wink
When the classification of flickering visual sense degree, try to achieve cumulative probability function CPF=f (S).Claim corresponding to CPF for 1% instantaneous vermicularizing alloy S
For long-time flickering value P1t。
Method：Long-time flickering value P1t, this index can be by n continuous PstValue, which is calculated as follows, to be obtained.
(IEC standard)
The principle for carrying out flicker measurement using IEC standard includes：Voltage sensor signals input U (t), carries out square examination
Obtain signal U2(t), then to U2(t) it is demodulated filtering → visual sense degree weighted filtering → square operation → smothing filtering → system
Meter processing → flickering evaluation.
6th, three-phase imbalance
6.1 three-phases are not to weighing apparatus degree
Definition：Three-phase voltage asymmetry degree：
Three-phase voltage not degree of weighing：
Wherein, U1--- positive sequence voltage virtual value, negative sequence voltage virtual value U2、I1Forward-order current virtual value, I2Negative-sequence current
Virtual value；
Method：
In having the three-phase system of zero-sequence component, using to component amount method, positive-sequence component and negative sequence component are obtained respectively, is pressed
Following formula obtains degree of unbalancedness；
Three-phase voltage not degree of weighing：
In the three-phase system without zero-sequence component (such as three-phase line voltage, line current, Y be three-phase phase voltage in Δ system,
Phase current), when known three-phase A, B, C voltage and electric current, degree of unbalancedness (voltage unbalance factor) is sought with following formula：
In formula,
Current unbalance factor is similarly.
6.2 symmetrical components include positive-sequence component, negative sequence component and zero-sequence component, according to symmetrical component method：
Positive sequence：
Negative phase-sequence：
Zero sequence：
7th, mains frequency
Electric voltage frequency：The fundamental frequency of the line voltage of A phase voltages or A, B phase.
Method：
Digital filtering is carried out to the sampled data signal obtained with ac sampling method first, filtered out after fundamental wave therein, is led to
At the time of crossing interpolation and seek waveform pass zero point, and then the method for asking its cycle, principle is as follows：
It is assumed that shown in the waveform of the fundamental signal obtained after digital filtering such as Figure 11 (a), Figure 11 (b) and Figure 11 (c) are
Waveform after two neighboring positive slope zero crossing (becoming positive zero crossing by negative) amplification nearby, in the figure, A0And A1Respectively
The forward and backward sampled value of first positive slope zero crossing, ANAnd AN+lThe forward and backward sampled value of respectively second positive slope zero crossing,
TsFor the cycle of sampling, TL0And TR0Respectively A0And AlTime of the sampling instant away from first positive slope zero crossing moment, TLNWith
TRNRespectively ANAnd AN+lTime of the sampling instant away from second positive slope zero crossing moment.
In Figure 11 (b), A0And A1Between one section of curve should be sine curve, but the sampling period enough in short-term, can be near
Like being a straightway, so can easily it draw：
Similarly, it can be drawn by accompanying drawing (c)
If having N between two positive slope zero crossings0Secondary sampling, then the cycle of the sine wave be：T1=N0T1+TR0+
TLN；After the cycle of sine wave is obtained, its frequency can be easily obtained.
8th, harmonic wave and m-Acetyl chlorophosphonazo
Harmonic wave and m-Acetyl chlorophosphonazo, phase are calculated according to windowing FFT method：
If according to windowing FFT, trying to achieve UrAnd U (k)i(k)。
K times voltage harmonic phase is：
Wherein, Ur(k)-voltage real part, Ui(k)-voltage imaginary part.
K harmonic contents：
In power system, generally containing for the subharmonic is reacted relative to the percentage of fundamental voltage amplitude with next harmonic amplitude
Amount, i.e.,
Total harmonic distortion THD (Total Harmonic Distortion) reacts total harmonic content, and it is defined as：
At present, the principle of the fft analysis method of harmonic wave is solved very well, but also there is frequency in actual applications
Spectrum leakage, three problems of aliasing and " fence " effect.For periodic signal, measured using FFT, topmost problem be leakage and
Aliasing Problem.The embodiment of the present invention solves leakage and aliasing using following measure.
(1) synchronized sampling
The problem of Data processing one is extremely important is exactly synchronized sampling problem.In discrete system, the present invention is implemented
Example, which is used, to be intercepted the wherein one section sequence for having limit for length (length is N) from the time series of an endless to be used as system defeated
Enter, known according to sampling system theory analysis, in order to suppress spectral leakage, this N is the integral multiple of fundamental frequency in input signal.No
Only in this way, actually N selection is also constrained by many factors, such as：In the design of low pass filter, N be odd number or
Even number will change the algorithm of wave filter；N=2 is required in FFT computingsσ, σ is any positive integer etc. here.Therefore when selection
When window width N is exactly equal to a cycle T of fundamental wave, if taking N=256, T=20ms, then require that the sampling period is necessary for
TS=0.078125ms, and TSIt is clock cycle TPIntegral multiple, otherwise because the truncated error in sampling period will equally cause
Frequency spectrum is sewed.
Due to sampling period TSIt is stable, therefore once after N determinations, each intercept signal sequence length remains base
The a cycle of ripple, here it is synchronized sampling.But the frequency of power network is often fluctuated, according to national regulations ±
Belong to normal allow in the range of 0.2Hz (even can arrive ± 0.5Hz during low capacity).
The method of oneself synchronized sampling through proposition is substantially all for two kinds of considerations at present：One is to maintain sampling period TSNo
Become, change sampling number N when frequency F changes to adapt to it；Two to be to maintain sampling number N constant, is adjusted when frequency F changes
Sampling period TS is adapted to.But both approaches all existing defects.In view of the A/D converter for intending using in hardware system
(AD73360) it is not allow to change sampling period TS, it is that this embodiment of the present invention proposes another side for realizing synchronized sampling
Case.Its dominant ideas is when frequency F shifts ± Δ F, due to sampling period TSIt is constant, so actual samples points will become
For N ', the data of N ' are transformed to N point datas using Newton interpolating method under conditions of integral area is constant, so as to keep N
And TSAll constant synchronized sampling effect, its calculation formula is：
AI=aj+k(aj+1-aj) i=0,1,2 ..., n
J=i+INT (β)
K=β-INT (β) A0=a0
β=n* Δs N/N.
Wherein, the physical significance of parameters is same as above, repeats no more here.
(2) windowed function
In theory, as long as sample frequency is more than 2 times of highest frequency component in analyzed signal, and being capable of Complete Synchronization
Sampling, with regard to leakage and aliasing can be completely eliminated.But, in current practical application, this 2 points may all be difficult to do completely
Arrive.Therefore the embodiments of the invention provide further step, i.e. windowed function method.Apply the window function in harmonic measure
A lot, influence of the different window functions to harmonic measure is different, even same window function, and parameter selection is different,
Influence is also different.Under the same conditions, the width L of sampling number N and window function increases simultaneously when, frequency leakage is reduced.
At present, using it is most be rectangular window and Hanning window, the embodiment of the present invention uses Hanning window.
M-Acetyl chlorophosphonazo measurement equally can be with the FFT of the decimation in time of base 2 (DIT).But, due to sampling period TSAfter being to determine,
Signal sequence length N can not be confined to the sampling number in a primitive period again, still should be adopting in M primitive period
Number of samples.And with M increase, the resolution ratio on frequency spectrum also increases, the m-Acetyl chlorophosphonazo number of measurement also increases.
When measuring m-Acetyl chlorophosphonazo and subharmonic using FFT, leakage, aliasing and " fence " effect all become very prominent, because
To be less than due to the frequency interval between adjacent m-Acetyl chlorophosphonazo even much smaller than fundamental wave, the leakage of harmonic wave is easy to cover near it
M-Acetyl chlorophosphonazo or subharmonic, also make adjacent m-Acetyl chlorophosphonazo be easier occur aliasing.Meanwhile, " fence " effect may cover big m-Acetyl chlorophosphonazo
And subharmonic.These three problems of m-Acetyl chlorophosphonazo and subharmonic FFT measurements are solved, what is used when can measure harmonic wave with FFT is upper
State synchronized sampling and adding window method.
Corresponding to said apparatus, the embodiment of the present invention additionally provides a kind of online electric energy quality monitoring method, referring to figure
The flow chart of online electric energy quality monitoring method shown in 12, this method comprises the following steps：
Step S1202, the voltage signal of current power system is gathered according to the sampling window length of setting and sampling period
And current signal；Wherein, the sampling window length is the fundamental frequency signal cycle in the voltage signal or current signal of the power system
Integral multiple；The sampling period is the integral multiple of local clock cycles；
Step S1204, analog-to-digital conversion is carried out to the voltage signal and current signal collected respectively, obtains digital voltage letter
Number and digital current signal；
Step S1206, carries out analysis calculating to above-mentioned digital voltage signal and digital current signal, obtains corresponding electric energy
Parameter；
Step S1208, the running situation of power system is determined according to above-mentioned electrical energy parameter.
The method of the present embodiment is when carrying out signal acquisition, and the sampling window length used is believed for the voltage of the power system
Number or current signal in the fundamental frequency signal cycle integral multiple；And the sampling period is the integral multiple of local clock cycles, adopted based on this
Sample length of window and sampling period gather the voltage signal and current signal of current power system, so can effectively prevent frequency spectrum
Leakage, improves the synchronism of sampling, and then improve the accuracy of electric energy quality monitoring.
In view of in practical power systems, electric voltage frequency is it some times happens that fluctuate, and in sampling window length, each adopt
The sampling number collected in the sample cycle may be different, and then influence follow-up electrical energy parameter analysis with calculating, based on this, on
Stating method also includes：When the number of samples in each sampling period is different, in the voltage signal and current signal point to collecting
Carry out not be after analog-to-digital conversion, the digital voltage set using Newton interpolating method to number of samples deficiency in the sampling period of number is believed
Number and digital current signal carry out supply operation.
It is more difficult to be realized in view of Complete Synchronization sampling, and the embodiment of the present invention employs the mode of windowed function, based on this,
The above-mentioned voltage signal and current signal for gathering current power system according to the sampling window length of setting and sampling period includes：
Sampling window is widened using rectangular window or Hanning window, based on sampling window length of the sampling window after widening according to setting
The voltage signal and current signal of current power system are gathered with the sampling period.
Understand the running situation of power system in time for the ease of human observer, the above method can also include：On display circle
Face shows the running situation of power system.Or, the above method also includes：By mobile network or internet by power system
Running situation is transferred to target terminal.
To sum up, what such scheme was to provide is that electric energy quality monitor apparatus and method can be online, the electricity of monitoring
Energy mass parameter is included：Mains frequency, voltage deviation, 2~50 subharmonic voltage containing ratios and the total harmonic distortion of virtual value, voltage
Rate, 2~50 subharmonic current containing ratios and virtual value, current total harmonic distortion rate, three-phase voltage/current unbalance factor, voltage
Fluctuation and flickering value (long-term flickering value and short-term flickering value), voltage/current real effective, fundamental voltage/current effective value, base
Ripple apparent energy, fundamental active power, First Harmonic Reactive Power, power factor etc..Its technique effect reached is embodied in：
(1) using improving FFT detection harmonic waves and m-Acetyl chlorophosphonazo, can rapidly disposable high accuracy from the voltage of complex electric network,
The integer and fractional component between 0~sample frequency/2 are easily obtained in electric current, preferably reduce " fence " effect and
The influence of frequency leakage.
(2) equipment for monitoring power quality is presently used for as the core parts of electric energy quality monitoring using Floating-point DSP
DSP is generally fixed DSP.Floating-point DSP is with respect to fixed DSP, and one side precision is relatively high, programming is easy, can develop in a short time
Go out high-precision electric energy meter；On the other hand, dynamic range is big, improves the robustness of equipment for monitoring power quality.
(3) using Embedded operating system (such as Android operation system), using the very high MCU of cost performance and
Android operating systems, with high-precision data processing and powerful internet management ability, data processing and managerial ability
Meet or exceed current domestic state-of-the-art equipment for monitoring power quality.
One of ordinary skill in the art will appreciate that realizing that all or part of step of above-described embodiment can be by hardware
To complete, by program related hardware can also be specified to complete, described program can be stored in computer-readable storage medium
In matter, and above-mentioned storage medium can be read-only storage, disk or CD etc..
Though those of ordinary skill in the art it should be appreciated that the present invention described preferred embodiment as above, it is to be understood that on
State disclosed content and be not used to limit embodiments of the invention, it covers a variety of changes and similar configuration, in this hair
Within bright spirit and principle, any modification, equivalent substitution and improvements made etc. should be included in protection scope of the present invention
Within.
Claims (3)
1. a kind of online equipment for monitoring power quality, it is characterised in that including：
Signal acquisition module, the voltage for gathering current power system according to the sampling window length of setting and sampling period is believed
Number and current signal；Wherein, the sampling window length is believed for fundamental frequency in the voltage signal or current signal of the power system
The integral multiple in number cycle；Sampling period is the integral multiple of local clock cycles；
Analog-to-digital conversion module, the voltage signal and current signal for being collected to the signal acquisition module are carried out respectively
Analog-to-digital conversion, obtains digital voltage signal and digital current signal；
Electrical energy parameter analyzes computing module, for the digital voltage signal and the numeral electricity obtained to the analog-to-digital conversion module
Flow signal and carry out analysis calculating, obtain corresponding electrical energy parameter；
Running situation determining module, for analyzing the electrical energy parameter determination that computing module is calculated according to the electrical energy parameter
The running situation of the power system；
The signal acquisition module includes：Synchronized sampling circuit；The analog-to-digital conversion module includes A/D converter 1 and A/D is changed
Device 2；The electrical energy parameter analysis computing module includes：DSP1 and DSP2；
A/D converter 1 is low-frequency sampling A/D converter, and A/D converter 2 is high frequency sampling A/D converter；DSP1's and DSP2
Input signal is the output signal of A/D converter 1；Or, DSP1 input signal is the output signal of A/D converter 1, DSP2
Input signal be A/D converter 2 output signal；
The A/D conversion chips that A/D converter is used is ADS8364；ADS8364 is high speed, low-power consumption, and six passages are completely self-contained
16 gradually-appoximant analog-digital converters；A/D converter use+5V operating voltages, and the fully differential with 80dB common mode inhibitions is defeated
Enter passage and analog-digital converter, the six difference sampling amplifiers of six 4 μ s continuous approximations；ADS8364 REFIN and
REFOUT pin inner portions also carry+2.5V reference voltages and high speed parallel interface；ADS8364 six simulation inputs are divided into three
Group (A, B and C), each input has an ADCs to keep signal to ensure that several passages can be while being sampled and being turned
Change；
When ADS8364 controls conversion using 5MHz external clock, its sampling rate is 250kHz, while corresponding to 4 μ s
Maximum throughput rate, so, sampling and conversion need to spend 20 clock cycle altogether；In addition, when external clock uses 5MHz,
ADS8364 conversion time is 3.2 μ s, and corresponding acquisition time is 0.8 μ s；
Synchronized sampling circuit mainly completes the function of frequency-tracking, and the circuit can ensure for A/D to turn in a power frequency period
Parallel operation provides 256 points of sampled signal, so as to realize the function of genlock；
Synchronized sampling circuit includes：Blocking filter circuit, Zero-cross comparator circuit, phase selection circuit, phase-locking frequency multiplication circuit and A/D conversions
Device；Phase selection circuit can automatically select the separate of voltage, and be supplied to subsequently according to choosing separate voltage to produce zero cross signal
Phase-locking frequency multiplication circuit, with realize 256 times phase locking frequency multiplying sample；In the case where frequency changes, synchronized sampling circuit also can
Ensure the sampling per 256 points of cycle；
It is separate that phase selection circuit is considered using A phase voltages as override, and A phases zero cross signal is regard as synchronization when A phases have voltage
Signal, locking B, C phase；After A phase power down, using B phases zero cross signal as synchronizing signal, locking C phases；Power down when A, B are identical, with C
Phase zero cross signal is used as synchronizing signal；
It is alternate synchronize signal switching when, due to the delay of circuit parameter and circuit in itself, it may appear that one section of locking
Blank, at this moment will produce a fault interrupt signal and notify DSP, the synchronous sampling signal of this blank time is provided by DSP；When
Three-phase voltage all after failure, then independently produces synchronous sampling signal by DSP, and 256 points of sampling is carried out with 50Hz power frequencies；
The specific algorithm of operation is as follows in DSP1 and 2,
Harmonic wave and m-Acetyl chlorophosphonazo are calculated as follows：
Harmonic wave and m-Acetyl chlorophosphonazo, phase are calculated according to windowing FFT method：
If according to windowing FFT, trying to achieve UrAnd U (k)i(k)；
K times voltage harmonic phase is：
Wherein, Ur(k) it is voltage real part, Ui(k) it is voltage imaginary part；
K harmonic content calculations are as follows：
In power system, the content of the subharmonic generally is reacted relative to the percentage of fundamental voltage amplitude with next harmonic amplitude,
I.e.
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Described device also includes：
Signal supplies module, for when the number of samples in each sampling period is different, in the analog-to-digital conversion module to collection
To the voltage signal and current signal carry out respectively after analog-to-digital conversion, using Newton interpolating method to number of samples deficiency set
Digital voltage signal and digital current signal in the sampling period of number carry out supplying operation；
The signal acquisition module includes：
Window widens unit, for being widened using rectangular window or Hanning window sampling window；
Signal gathering unit is long according to the sampling window of setting for widening the sampling window after unit is widened based on the window
Degree and sampling period gather the voltage signal and current signal of current power system.
2. device according to claim 1, it is characterised in that described device also includes：
Running situation display module, the running situation for showing the power system in display interface.
3. device according to claim 1, it is characterised in that described device also includes：
Running situation transport module, for the running situation of the power system to be transferred into mesh by mobile network or internet
Mark terminal.
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| TWI635289B (en) * | 2017-11-17 | 2018-09-11 | 財團法人工業技術研究院 | Sensing method for power consumption and sensing device |
| RU2790926C1 (en) * | 2022-06-01 | 2023-02-28 | Федеральное государственное бюджетное образовательное учреждение высшего образования "Сибирский государственный индустриальный университет", ФГБОУ ВО "СибГИУ" | Device for measuring semi-fixed power consumption (sfpc) and fixed power consumption (fpc) in production |
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