CN205826768U - Detection device and and its supporting Active Power Filter-APF, power quality analyzer - Google Patents

Abstract

This utility model relates generally to detect device and and its supporting Active Power Filter-APF, power quality analyzer.First detection module is for detecting and extract first signal with first frequency scope from current information, first signal is at least used as forming the basis compensating electric current being injected into electrical network with its central harmonic wave opposite in phase equal in magnitude, and the first signal at least also serves as the foundation of the quality of power supply judging electrical network.Second detection module is for detecting and extract the secondary signal with second frequency scope from current information, and second frequency scope is more than first frequency scope, and secondary signal is at least used as judging the foundation of the quality of power supply of electrical network.3rd detection module is for detecting and extract the 3rd signal in the way of bandpass filtering from this current information, and the 3rd signal is used for comparing or add up it with default threshold value and exceedes the number of times of threshold value within the default time period and thereby judge whether it belongs to fault electric arc.

Description

Detection device and and its supporting Active Power Filter-APF, power quality analyzer

Technical field

This utility model is mainly concerned with detection equipment, exactly, is to provide a kind of with current sensor/transformer Detection device, apply on various types of electric energy on-line monitoring equipment, as Active Power Filter-APF APF or static reacance are sent out Raw device SVG or quality of power supply on-line computing model or other electric intelligent instruments etc., this detection equipment is humorous at detecting nonlinear load Electric arc can also be detected while ripple and the monitoring quality of power supply, ensure the normal operation of power system with this.

Background technology

Along with the fast development of Power Electronic Technique, the electrical equipment of different loads characteristic is had to enter our life on a large scale Living, therewith together, some nonlinear loads such as inverter, commutator and various Switching Power Supply are widely used, The harm of power supply grid is also on the rise by consequent harmonic wave.It is filled with greatly to electrical network during power electronic devices switch motion The harmonic wave of amount, makes the expection standard sine electric current in electrical network and voltage waveform serious distortion.Various to electric energy matter owing to also existing The equipment of amount rdativery sensitive, a large amount of uses of the domestic electric appliance such as such as computer equipment and air-conditioning, refrigerator, TV, to electricity The requirement of energy quality is more and more higher.All kinds of power failures caused by harmonic wave and Frequent Accidents, either to productive life also It is that national economic development all creates the biggest negative effect.Harmonic problem includes frequency analysis, harmonic detecting and harmonics restraint Etc. aspect, effectively suppression harmonic wave have become as and ensure one of requisite measure that power grid security, high-quality run.

In the cleanest electric power system, electric current and voltage are all sinusoidal wave.Containing only resistance, inductance and electric capacity etc. In the ball bearing made of linear element, the electric current flow through is directly proportional to the voltage of applying, and the electric current flow through is sinusoidal wave.Use Fourier Analysis can resolve into essential part and its multiple non-sinusoidal signal.The basic reason that harmonic wave produces is due to non-thread Property load caused.When electric current flows through load, presenting non-linear relation with added voltage, forming non-sinusoidal current i.e. has Harmonic wave produces.Switching manipulation and diode, the nonlinear characteristic of semiconductor thyristor, power system due to semiconductor thyristor Some equipment such as power converter may produce and bigger deviate from sinusoidal waveform.Under supply network impedance this The non-sinusoidal cuve electric current of sample causes the voltage drop of a non-sinusoidal cuve.Harmonic voltage is produced under supply network impedance Amplitude is equal to corresponding harmonic current and the product of the supply network impedance Z corresponding to this power frequency.Just there is the place of harmonic source There is harmonic wave.It is also feasible that harmonic component arrives user by supply network.Such as in the supply network operating of a user producer The harmonic wave that may be produced by another adjacent subscriber equipment disturbs.All of nonlinear load can produce harmonic current, The exemplary apparatus producing harmonic wave has: power supply under switching mode, electronics ballast of fluorescent lamp, speed-regulating actuator and uninterrupted electricity Source, magnetive cord equipment and some household electrical appliance such as television set etc..In order to ensure the safety of productive life electricity consumption and be normally carried out, It is essential that the detection of the quality of power supply is analyzed.The quality of power supply includes quality of voltage, current quality, power supply quality and power quality, Including causing the deviation of the voltage of electrical equipment fault or cisco unity malfunction, electric current or frequency, the present frequency of its endomorph is inclined Difference, voltage deviation, voltage fluctuation and flicker, three-phase imbalance, temporarily or transient overvoltage, wave distortion, harmonic wave, voltage are temporary Fall, interruption, temporarily liter and power supply continuity etc..These power quality problems can cause: protective relaying device is jeopardized by false triggering The operation of power supply safety, various electrical equipment produce added losses and heating and cause device damage or burn, increase loss and lead The uneconomic operation of cause equipment thus cause extra electric cost expenditure and ammeter metering outfit not precisely, reduce the transmission of signal Quality and destroy the normal delivery of signal, the resonance that may cause cause reactive compensation cabinet cannot normal operation, reduce equipment Service life, computer or detection control equipment is caused cannot normally to work and even crash.Therefore, in order to improve network system The quality of power supply, ensures the properly functioning of electric utility, needs to detect the quality of power supply of electrical network, the especially danger on electrical network The higher hamonic wave that evil is bigger, so high performance current detecting is to controlling the quality of power supply and maintaining power system to stablize the heaviest Want.

The conventional current sensors detecting power network current in prior art cannot detect higher hamonic wave accurately, the most scarce The weary detection to transient current, transient current is usually the μ other curent change of s Microsecond grade, and commonly referred to transient current is the most negative The phenomenons such as lotus switching action (i.e. switching device is used for realizing putting into/connecting and excise/turn off) or thunderbolt are likely to induce this Kind of transient current phenomenon, current current sensor basically can not detect transient current, and current current sensor When harmonic wave is serious, its error in dipping is bigger, it is impossible to high performance detection power quality parameter.

In order to improve reliability and the safety of electrical network in this external modern power systems, have been carried out huge effort To avoid the negative electric arc produced in network system, electric arc is a kind of not have rule and the high frequency variation phenomenon of instability, so And prior art is still not carried out gratifying solution to effective monitoring of electric arc.Foot is produced between two electrodes During the highest enough pressure reduction, electric arc it may happen that, this voltage causes the gas ionization between electrode, and plasma can gradually form, And electric current can flow in-between the electrodes, such plasma may be heated to thousand of degrees Celsius, and equipment can be caused to damage Go bad or catch fire.Electric arc potential in power system has a two types: parallel electric arc or serial electric arc.The parallel general electric power of electric arc Occur between positive pole and negative pole in system, or occur between some electrode and earth terminal GND wherein.Relative, Serial electric arc does not occurs between two circuits, but occur in the circuit of a current lead-through, in other words, serial Arc phenomenon is likely to occur between two different piece/fragments of same circuit, serial electric arc electric current quilt in the line Occurred during interruption (in the case of such as having connected contact switch or having destroyed plug/cable) is the most obvious.In order to reduce electric arc Negative effect, it is necessary to performing corresponding countermeasure such as breaking arc source as soon as possible, therefore electric arc is by reliably and in real-time Confirmation is very important monitoring item.Another defect of existing current sensor is to detect the electric arc letter of electrical network Number, this problem treats harshly solution.

Utility model content

In this utility model, provide a kind of detection device, there is the current sensor of current information in detection electrical network, Including first detection module, for detecting from current information and extraction has first frequency scope and (is such as generally in several In the band limits of ten HZ to tens KHZ) the first signal, it not only includes power frequency component and the most also includes some harmonic components Signal etc., and exported with the form of differential mode analog quantity, the acting body of this imitated output quantity is present: at least note in electrical network Enter with the first signal in the middle of harmonic wave is equal in magnitude but the compensation electric current of opposite in phase provides foundation, and at least can be also used for The information such as power frequency and the harmonic wave of electric current in monitoring electrical network, as one of foundation of the quality of power supply judging electrical network.

Detection device also includes the second detection module, and it may be used for detecting from above-mentioned current information and extraction has the Second letter of two frequency ranges (more much greater than power frequency scope, in the band limits for instance in tens KHZ to MHZ ranks) Number, and the form being converted into the magnitude of current exported, and limits the frequency range of second frequency more than first frequency scope, wherein shape One of effect becoming this magnitude of current is embodied in: for example, whether there occurs in electrical network that the such high-frequency impulse of similar surge provides Basis for estimation, therefore secondary signal is at least also used as one of foundation of the quality of power supply judging electrical network.

Detection device also includes the 3rd detection module, for detecting from this current information in the way of bandpass filtering and carrying Taking the 3rd signal, the effect of the 3rd signal is mainly reflected in: discriminate for monitoring on electrical network and identify that electric arc source of generation provides Not basis, especially, as judging that whether there is electric arc in electrical network provides foundation, if in the case of electrical network has electric arc, 3rd signal is also as judging that electric arc is the foundation of normal arc or fault electric arc.Such as, certain is exceeded at the 3rd signal pre- If threshold range time, one can consider that and on electrical network, create unexpected fault electric arc, and if the value of the 3rd signal exists Below threshold range, then it is believed that create the conventional electric arc in tolerance on electrical network.

Or, in time period that certain is preset, (the Millisecond duration that such as specifies, second level duration, minute level duration are even Hour level duration etc.) in judge that the 3rd signal exceedes the total degree of threshold value, if total degree is in admissible scope, electrical network In there may be the phenomenon that switch contact is bad, it should notify management personnel patrol and examine and investigate, eliminate this bad.If it is otherwise total Number of times not in admissible scope, then may have occurred unacceptable arc phenomenon, it should notify management personnel in electrical network Take tightened up counter-measure, such as, cut off electrical network or other operation.Therefore detection device can also include at one Reason device (MCU) receives the result of the 3rd detection module output, has been used for the 3rd signal and the comparison of threshold value or has added up the Three signals exceed the number of times of threshold value within the default time period.

Above-mentioned detection device, also includes alarm output module one submodule of processor (it can be), once its prison Control the 3rd signal exceed default threshold value or within the default time period, add up the 3rd signal exceed the number of times of threshold value and do not referring to Time in fixed numerical range, alarm output module will externally export effective indication signal (such as high low logic level), carrys out table Levy the 3rd signal and belong to fault electric arc, when receive this indication signal prior-warning device (such as it with switching device, relay, Communication device etc.) will be triggered to when receiving effective indication signal produce warning message, and perform various reply electric arc Measure, warning message can be the warning of visually (warning light flicker) or acoustically (rapid police whistle sound), it is also possible to be Circuit breaker tripping on communication information, e.g. notice electrical network turns off the communication information of electrical network.

Above-mentioned detection device, has a differential amplifier circuit in described first detection module, comprising: the first computing is put Big device and the second operational amplifier, the normal phase input end of each of which be respectively coupled to the pair of output of this current sensor with Capturing the first signal, connecting between their inverting input has the first resistance.

And connection has the second resistance between the inverting input and outfan of the first operational amplifier, with in the second fortune Calculate to connect between inverting input and the outfan of amplifier and have the second resistance, thereby the first operational amplifier outfan and Differential amplification signal is formed between the outfan of the second operational amplifier.It is harmonious that first signal for example, at least includes power frequency component Ripple signal, differential amplifier circuit provides imitated output quantity and non-binary digital output, and the output being because it needs to carry Supply various current collecting device or instrument, the most common electric instrument, quality of power supply on-line monitoring instrument, active electric power filter Ripple device APF, reacance generator SVG etc., it is contemplated that the communication speed of the corresponding binary code element of transmission speed of analog quantity Faster, Active Power Filter-APF can obtain and process analog quantity in time to produce compensation electric current so that is formed and compensates electric current Opportunity is relative to producing any more significantly time delay the opportunity gathering harmonic source hardly.

This differential amplifier circuit also includes one or more groups preset resistance R26 being serially connected and switching device S26, each Preset resistance R26 of group series connection and switching device S26 are both connected to inverting input and second computing of the first operational amplifier (also it is connected between node N1 and N2) between the inverting input of amplifier；When differential amplifier circuit is set to increase times magnification Number mode of operation time, one or more switching device S26 in an ON state with will these preset resistance R26 one or more with First resistance R25 gives parallel connection (resistance total in parallel between node N1 and N2 reduces)；Or when described differential amplifier circuit is set to When reducing the mode of operation of amplification, one or more switching device S26 are off with by one or more and the Preset resistance R26 in parallel for one resistance R25 is floating from described differential amplifier circuit, causes the resistance total in parallel between node N1 and N2 Value increases.

Above-mentioned detection device, also has an integrating circuit in the second detection module, integrating circuit includes the 3rd fortune Calculating amplifier, its positive and inverting input are respectively coupled to the pair of output of this current sensor to capture the second letter Number, form an active integrator by the 3rd operational amplifier.Notice that secondary signal e.g. frequency range is generally the most several The current pulse signal of the transient changing of ten KHZ to MHZ megahertz of ranks.

Above-mentioned detection device, described second detection module also includes voltage current adapter, and it is used for receiving described integration The output voltage of circuit also converts this voltage to the magnitude of current and is exported.Here secondary signal is converted into by the second detection module The magnitude of current mainly considers that the size of transmission line is the longest, in order to avoid the interference on extraneous circuit, advocates integration The output voltage of circuit transmits in the form of electric current, and follow-up can flowing to is similar to the such equipment of power quality analyzer, The time making the high-frequency input signal that the current signal of output and current sensor (such as Luo-coil) be supplied to integrating circuit is amassed Score value is approximated to proportional relationship, and power quality analyzer correspondence then can provide a current-to-voltage convertor to reduce this The magnitude of current becomes voltage signal, such as uses a resistance to flow through this resistance to reduce secondary signal by current signal.

Above-mentioned detection device, described 3rd detection module has a band filter, and it includes being respectively coupled to this electricity First input node N of the pair of output of flow sensor_{4_1}With the second input node N_{4_2}: the first input node N_{4_1}Logical with band A the 3rd resistance R41 and one first it is in series with between the inverting input of a four-operational amplifier in wave filter Electric capacity C41, the 3rd resistance R41 and the first electric capacity C41 the first interconnecting nodes N between the two_{4_3}Place is defeated with four-operational amplifier Go out to connect between end and have the second electric capacity C42, and the inverting input of four-operational amplifier and outfan connection have the 4th resistance R43；And the first interconnecting nodes N_{4_3}With the second input node N_{4_2}Namely be connected with between the normal phase input end of four-operational amplifier Resistance R42, notes the second input node N_{4_2}It is directly coupled to the normal phase input end of four-operational amplifier.It addition, the 3rd resistance The particular location of R41 and the first electric capacity C41 is: the 3rd resistance R41 is connected to the first input node N_{4_1}With the first interconnection joint Point N_{4_3}Between, the first electric capacity C41 is connected to the first interconnecting nodes N_{4_3}And between the inverting input of four-operational amplifier.

This band filter also includes one or more groups preset resistance R44 being serially connected and switching device S44, each group Preset resistance R44 of series connection and switching device S44 are both connected between inverting input and the outfan of four-operational amplifier； When described band filter is set to increase center angular frequency ω_OMode of operation time, one or more switching device S44 are in and connect Logical state to give parallel connection (four-operational amplifier anti-phase defeated by these preset resistance R44 one or more and the 4th resistance R43 The in parallel total resistance entered between end and outfan reduces)；Or when described band filter is set to reduce center angular frequency ω_O's During mode of operation, one or more switching device S44 are off with by one or more and the 4th resistance R43 parallel connection Preset resistance R44 is floating from band filter, and (parallel connection between inverting input and the outfan of four-operational amplifier is total Resistance increases).In view of bandwidth BW=ω_O/ Q, if quality factor Q is set to predetermined value, then center angular frequency ω_ORegulation meaning Taste bandwidth BW also correspondence and is conditioned.If or bandwidth BW is set to predetermined value conversely speaking, then center angular frequency ω_OTune Joint means that quality factor Q also correspondence is conditioned.

Above-mentioned detection device, as option, also in the first input node N_{4_1}With the second input node N_{4_2}Between connect There is over-voltage protection element, once when the first input node N_{4_1}With the second input node N_{4_2}Between voltage exceed protection specification value Time, the over-voltage protection element connection that is just triggered carrys out voltage stabilizing, it is achieved the suppression of surge.Over-voltage protection element e.g. transient voltage presses down In the middle of device processed, varistor, discharge tube etc. one, it is also possible to be that in the middle of them combination of any two is even by them together Being applied in combination, as a example by Transient Voltage Suppressor (TVS) D41, its anode cathode direction is at node N simultaneously_{4_1}And N_{4_2}Between Although arbitrary, but in a preferred embodiment, its anode links the second input node N_{4_2}And negative electrode links first Input node N_{4_1}。

Above-mentioned detection device, the first signal represents industrial frequency harmonic component, and secondary signal represents higher than industrial frequency harmonic frequency The electric current of transient changing, the 3rd signal represents arc signal.

Above-mentioned detection device, described current sensor is Roche hollow coil current-sensing device.

In another embodiment, this utility model additionally provides and detects the harmonics restraint system that matched with devices uses, Including and detection matched with devices use Active Power Filter-APF APF, for produce and some harmonic wave size phases in the first signal The compensation electric current that equiphase is contrary injects electrical network.

Above-mentioned harmonics restraint system, this Active Power Filter-APF includes: one by the differential mode analog quantity that received (by One detection module is converted into this differential mode analog quantity according to the first signal) transfer the 5th operational amplifier of single-ended voltage signal to； And an isolation coupling module performing one-way transmission signal, (this voltage signal is by the to be used for receiving this single-ended voltage signal Five operational amplifiers provide), and export and follow the change of this single-ended voltage signal and the linear current I of linear change_FOLLOW；Separately Outer also have the 6th operational amplifier, its positive input end grounding and connect at its inverting input and outlet chamber and have resistance R54, the 6th operational amplifier is for by this linear current I_FOLLOWBe converted into it outfan become line with this single-ended voltage signal The voltage signal V of sexual relationship_{OUT_F}.In some optional embodiments, Active Power Filter-APF APF can be to voltage signal V_{OUT_F}Sampling and perform ADC analog digital conversion, the unit such as supporting use on-site programmable gate array FPGA or Digital Signal Processing DSP Device/instrument calculates the size of current value needing to compensate according to the data of sampling.

In another embodiment, this utility model additionally provides and detects the power quality analysis that matched with devices uses Instrument, it includes a current-to-voltage convertor, and secondary signal is converted into the form of the magnitude of current and is exported by the second detection module, This magnitude of current is then reduced into the voltage characterizing secondary signal by the current-to-voltage convertor of power quality analyzer.I/V Transducer after being reduced into the voltage characterizing secondary signal by the magnitude of current, when we need to analyze the quality of power supply of electrical network Time, this voltage provides judging basis.In addition, power quality analyzer can also utilize the first signal to analyze electricity The quality of power supply netted, the first signal is at least that the power frequency weighing electric current provides basis for estimation with harmonic quality, and second believes Number then at least provide basis for estimation for weighing transient current (Transient current).This is external judges the quality of power supply On can also record the arc information of electrical network with the output of the 3rd detection module.Weigh the quality of power supply (Power Quality) leading indicator such as has voltage, frequency and waveform, generally believe it should include quality of voltage, current quality, Power supply quality and power quality.The problem of the quality of power supply can be defined as: causes electrical equipment fault or cisco unity malfunction The abnormal variation of voltage, electric current or frequency, its content includes that frequency departure, voltage deviation, voltage fluctuation and flicker, three-phase are uneven Weighing apparatus, instantaneous or transient overvoltage or wave distortion/harmonic wave, voltage dip, interruption, temporarily liter and power supply continuity etc..

In another embodiment, this utility model additionally provides a kind of electric arc detecting device, utilizes Luo-coil to sense Current information in device detection electrical network, and also include that a wave filter is preset to detect and to extract one from this current information Signal, for comparing with default threshold value, this preset signals thereby judges whether it belongs to fault electric arc.Wherein this filtering Utensil has first input node N of one group of outfan DSA and DSB being respectively coupled to Luo-coil (Rogowski)_{4_1}With second Input node N_{4_2}；First input node N_{4_1}And be in series with between the inverting input of an operational amplifier A 4 in wave filter An one resistance R41 and electric capacity C41, the interconnecting nodes N between resistance R41 and electric capacity C41_{4_3}Defeated with this operational amplifier A 4 Go out to connect between end and have another electric capacity C42, and the inverting input of this operational amplifier A 4 and outfan connection have another resistance R43；And this interconnecting nodes N_{4_3}With the second input node N_{4_2}Namely between the normal phase input end of operational amplifier, also it is connected with one Other resistance R42.Thus finally outfan in this operational amplifier A 4 produces the voltage signal characterizing this preset signals V_{OUT_AS}。

Above-mentioned electric arc detecting device, also includes one or more groups preset resistance R44 being serially connected and switch S44, often Preset resistance R44 of one group of series connection and switch S44 are both connected between inverting input and the outfan of this operational amplifier A 4, Wherein it is set to increase center angular frequency ω when this wave filter_OThe first mode of operation time, one or more switch S44 are in and connect Logical state is to be connected in parallel on (it between the inverting input of operational amplifier and outfan by these preset resistance R44 one or more And R43 in parallel)；Or when wave filter is set to reduce center angular frequency ω_OThe second mode of operation time, one or more switches Device S44 be off with by one or more preset resistance R44 from the inverting input of this operational amplifier A 4 and defeated Go out floating between end (they disconnect and the parallel relationship of R43).

Accompanying drawing explanation

Reading described further below and with reference to after the following drawings, feature of the present utility model and advantage will be apparent to:

Fig. 1 is the schematic diagram of the exemplary applications of a quality of power supply on-line monitoring of detection device of the present utility model.

Fig. 2 is the basic module configuration diagram of the detection device with sensor.

Fig. 3 is the structural representation of differential amplifier circuit.

Fig. 4 is the circuit structure that differential signal is reduced in Active Power Filter-APF single-ended signal.

Fig. 5 is the structure of integrating circuit and voltage current adapter.

Fig. 6 is the schematic diagram of arc-detection module.

Fig. 7 is the adjustable schematic diagram of amplification of differential amplifier circuit.

Fig. 8 is the adjustable schematic diagram of center angular frequency of band filter.

Detailed description of the invention

See Fig. 1, Active Power Filter-APF APF and mainly include two large divisions: instruction current computing module and compensation are electric There is circuit in stream, wherein compensate current occuring circuit be subdivided at least including current follow-up control module and drive circuit and Main circuit 105.Active Power Filter-APF can be generally divided into single-phase and three-phase two kinds, three-phase system be divided into again three-phase three-wire system and Three-phase four-wire system, the application hereinafter temporarily illustrates present invention spirit using phase three-wire three as example.

See Fig. 1, illustrate three-phase ac power supply E_SAAnd E_SBAnd E_SC, and born to load 110 by electrical network transmission power supply Carrying 110 usually nonlinear loads is also harmonic source and target compensation.Main circuit 105 breaker in middle group S1～S2 and switches set S3～ S4 and switches set S5～these three groups switches of S6 are parallel with one another, any one single switches set S1～S2 or S3～S4 or S5 in addition ～the most respectively with one DC voltage U of S6_DCIn parallel.Switching tube can be IGBT or MOSFET or BJT or GTO IGCT etc..? Junction point A between two switch S1～S2 of first group and offer power supply E_SAA phase grid branch between connect have inductance L, Injecting to the compensation electric current of this electrical network is I_CA.Junction point B between switch S3～S4 of second group and offer E_SBA phase electrical network Connecting between branch road and have inductance L, injecting to the compensation electric current of this electrical network is I_CB.And between two of the 3rd group switch S5～S6 Junction point C and provide E_SCA phase grid branch between connect and have an inductance L, injecting to the compensation electric current of this electrical network is I_CC.Value It is noted that in the main circuit 105 of the application, the factor such as the component type/quantity of switch S1～S6/concrete annexation As just an example of explaination/illustrate books application spirit, any main circuit/open that can realize identical function Close pipe topology be all applicable to this utility model and can be replaced it, so this is not intended that main circuit of the present utility model only limits It is formed on this specific topological classification.

See Fig. 1, compensate electric current substantially by DC capacitor voltage U_DCWith the supply voltage difference effect exchanging survey Produced by the inductance L that exchange is surveyed, DC capacitor voltage U_DCCan be DC source can also be storage capacitor provide DC voltage, when main circuit 105 produce compensate electric current be to use as inverter, if to energy storage such as the electric capacity of DC side Then as commutator during element charging.The operation of main circuit 105 be switches set S1～S2 or S3～S4 or S5～S6 connection and Turn off decision, the most each switches set (S1～S2 or S3～S4 or S5～S6) always has a switch be in conducting State, another switch is then in off state simultaneously.

See Fig. 1, assume that three phase mains sum meets E in advance_SA+E_SB+E_SC=0, according to Circuit theory, compensate to three-phase Electrical network bus respective compensation electric current sum meets I_CA+I_CB+I_CC=0, it is assumed that Ka and Kb and Kc is to set in advance according on off state Fixed switching coefficient, under the preferable and situation of rough calculation, mutually in compensate electric current and the differential equation of time t and alternating current Following functional relationship is there is also between source:

$L\frac{{\mathrm{dI}}_{CA}}{dt}=E_{SA}-K_a{U}_{DC}......\left(1\right);$

$L\frac{{\mathrm{dI}}_{CB}}{dt}=E_{SB}-K_b{U}_{DC}......\left(2\right);$

$L\frac{{\mathrm{dI}}_{CC}}{dt}=E_{SC}-K_c{U}_{DC}......\left(3\right);$

For convenience of discussion, hereinafter we temporarily take phase grid branch E therein_SAAs object of study, other Remaining a few phase grid branch E_SB～E_SCOperation principles the most substantially similar.See Fig. 1, the groundwork of Active Power Filter-APF Mechanism is, at load end by Hall current sensor 101 to load current I_LDetect, and by load current I_LInformation is transmitted To Active Power Filter-APF.Instruction current computing module detects the such as harmonic and reactive currents component etc. being compensated in object Information, it is assumed that load current I_LHarmonic component I in information_LHBeing detected, instruction current computing module is again by harmonic wave thereafter Component I_LHAs a command signal I* compensating electric current after reversed polarity_CA.Current follow-up control module receives from instruction current The command signal I* of computing module_CAAfter, produce pulse width modulating signal PWM and be transferred to drive circuit, allow driving further The higher drive circuit of ability drives the switch shape of each switches set in main circuit 105 (S1～S2 or S3～S4 or S5～S6) State, it is therefore an objective to make main circuit 105 produce real-time accurate tracking command signal I*_CACompensation electric current I_CA.If compensating electric current I_CA With load current I_LHarmonic component I_LHBut polarity equal in magnitude/in opposite direction, then both cancel out each other, and make power supply E_SAThere is provided Source current I_SAIn sinusoidal fundamental wave current component containing only intimate standard, be finally reached the mesh of harmonic wave in suppression source current 's.

Connection node A between first group two switch S1～S2 described above and power supply E is provided_SAA phase electrical network Connecting between branch road and have inductance L, being injected to the compensation electric current of this electrical network by inductance L from node A is I_CA, now with main circuit The A node of 105 is to providing power supply E_SAOne phase electrical network produce compensation electric current I_CADemonstrate the compensation machine of Active Power Filter-APF System.In the normal operation stage of Active Power Filter-APF APF, the compensation electric current I of main circuit 105 output_CAAt command signal I*_CA Fluctuating of value, generally can present zigzag to follow command signal I*_CAThe change of value.

$\frac{{\mathrm{dI}}_{CA}}{dt}=\frac{1}{L}(E_{SA}-K_a{U}_{DC})......\left(4\right);$

Its Chinese style (4) is the deformation of formula (1), it is desirable to compensate electric current I_CAAccurate tracking command signal I* in real time_CA, the most once Compensate electric current I_CAOccur any than compensating electric current I_CADeviation time, it should select turn on and off the switch in main circuit 105 S1～S2 reduces this deviation, and formula breaker in middle COEFFICIENT K a can take-1/3 or-2/3.Once when compensating electric current I_CALess than referring to Make signal I*_CA, this demonstrate compensation electric current I_CAShould increase to make great efforts near command signal I*_CA, this up-to-date style (4) the equation left side More than 0, namely should mean that switching the upper switching tube S1 in S1～S2 brachium pontis should turn off and lower switching tube S2 connection.Work as benefit Repay electric current I_CAMore than command signal I*_CA, indicate compensation electric current I_CAShould reduce and come near command signal I*_CA, this up-to-date style (4) The equation left side should be less than 0, it is meant that the upper switching tube S1 in switch S1～S2 brachium pontis should connect and lower switching tube S2 turns off. Namely realizing below scheme: current follow-up control module receives the command signal I* from instruction current computing module_CAAfter, will connect The command signal I* received_CAWith the actual compensation electric current I captured_CACompare, produce pulse-width signal PWM and be transferred to drive Circuit, allow the higher drive circuit of driving force to drive each switches set in main circuit 105 (S1～S2 or S3～S4 or S5～ S6) on off state, makes compensation electric current I_CAAccurate tracking command signal I* in real time_CA。

It is with compensation harmonic component I above_LHMode explain the operation of whole system.The most hereinafter content is sayed The electric current that compensates being injected into electrical network of formation and harmonic wave opposite in phase equal in magnitude be i.e. based on compensation mechanism above.

Seeing Fig. 2, air core coil sensor 102 is used for replacing the Hall current sensor 101 of Fig. 1, and this air core coil passes Sensor 102 is used for detecting load current I_LThe various components of information, air core coil 102 does not the most use similar Hall electricity The such magnetic core containing ferrimagnet of flow sensor 101, its coil is wrapped in and plays the flexibility of physical support effect or firm Property skeleton on constitute Circular Winding, its skeleton be not magnetic core so air core coil 102 is without hysteresis effect, do not have yet phase error and Magnetic saturation phenomenon, the bandwidth of response is from 0.1HZ to several MHZ.The theoretical foundation of air core coil sensor 102 is Faradic electricity Law of magnetic induction and Ampere circuit law, the load current I of electrical network_LAlong the axis coil by air core coil sensor 102 During center, the magnetic field of corresponding change can be produced in the volume range that the Circular Winding structure of its coil is surrounded, at the two of coil The induced voltage U that end produces₁(t)=M × (di/dt), the differential side of the alternating current i that it changes with the t in time that need to measure Journey is directly proportional, and M is the mutual inductance of coil windings.Air core coil sensor 102 one of the advantages is that the voltage that it exports is equal Belong to the category of light current, compare the forceful electric power of Hall current sensor 101 output, or produced when comparing any one-level APF of unloading Raw electric arc, air core coil sensor 102 has more preferably safety effect.When air core coil sensor 102 carries for other equipment During for load current information, the crystal connector that Active Power Filter-APF can utilize similar home phone line to be connected with telephone set is real Now docking air core coil sensor 102.Hall current sensor cannot ensure the similar high-frequency harmonic with spike composition It is accurately detected, and the non-constant width of alternating current detection bandwidth of air core coil sensor, conventional spike harmonic wave can Catch in the way of not loss of accuracy.

Shown in Figure 2, the detection device of the application is except the current sensor 102 of current information in detection electrical network, also Including first detection module 211, for detecting and extract first signal with first frequency scope from current information, and with The form of differential mode analog quantity is exported, and the acting body of this imitated output quantity is present: for injecting in electrical network and in the first signal Some harmonic components are equal in magnitude but the compensation electric current of opposite in phase provides foundation.In view of the first signal at least includes that power frequency is believed Breath and harmonic component information, it also serves as the foundation of the quality of power supply judging electrical network.

Detection device also includes the second detection module 311, and it is for detecting and extraction has the from above-mentioned current information The secondary signal of two frequency ranges, and it is converted into magnitude of current I_SETForm exported.Limit second frequency scope than the first frequency The frequency of rate scope wants height, it is understood that: the smallest limit value in this band limits of second frequency scope should be more than the Maximum upper limit in this band limits of one frequency range.Form this magnitude of current I_SETActing body present: be used as learn electrical network The approach of the middle quality of power supply, can be whether to there occurs in electrical network that the such high-frequency impulse of similar surge provides basis for estimation, the Binary signal at least includes transient current information more higher than work frequency, and it also serves as the foundation judging the quality of power supply.

Detection device also includes the 3rd detection module 411, is used in the way of bandpass filtering (Band-pass) from this electric current Detecting and extract the 3rd signal in information, the effect of the 3rd signal is mainly reflected in: as judging whether there is electricity in electrical network Arc provides foundation, if in the case of having electric arc in electrical network, the 3rd signal is also as judging that electric arc is normal arc or event The foundation of barrier electric arc.Such as, when the sizes values at the 3rd signal exceedes certain threshold range preset, one can consider that at electricity Create unexpected fault electric arc on the net, if the value of the 3rd signal is below threshold range, then it is believed that do not have at electrical network There is the conventional electric arc (non-faulting electric arc) producing electric arc or creating in tolerance.Detection device can also possess one Processor 412 (MCU) receives result V of the 3rd detection module 411 output_{OUT_AS}, because this result V_{OUT_AS}Characterize the 3rd The sizes values of signal, so processor can utilize this result to complete the 3rd signal and the comparison of threshold value or statistics the 3rd Signal exceedes the number of times of threshold value within the default time period.

Seeing Fig. 3, first detection module 211 the most at least includes the differential amplification that can detect current signal Circuit 211, based on present invention spirit, the amplification of differential amplifier circuit 211 can utilize amplification to control mould Block is controlled, and additionally can pass to Active Power Filter-APF in time to avoid in view of the signal detected by air core coil Cause any unnecessary delay, signal analog quantity that differential amplifier circuit 211 detects (and unconventional 1/0 binary system Code element digital quantity) flow to Active Power Filter-APF, in order to achieve a butt joint with differential amplifier circuit 211, Active Power Filter-APF One the 5th operational amplifier A 5 of application is realized the reception of differential analog signal.

Seeing Fig. 3, amplifying circuit 211 includes the first operational amplifier A 1 and the second operational amplifier A 2, and wherein Roche is empty Two ends DSA, DSB correspondence of wire-core coil is respectively coupled to the normal phase input end V of the first operational amplifier_IN1With the second operation amplifier The normal phase input end V of device A2_IN2.The DSA end of Fig. 3 coil and normal phase input end V_IN1Between connect have resistance R21, and coil DSB end and normal phase input end V_IN2Between connect have resistance R22, the most also at the normal phase input end of the first operational amplifier A 1 V_IN1Normal phase input end V with the second operational amplifier A 2_IN2Between connect have an electric capacity C21, when input signal frequency relatively Time low, the capacitive reactance of electric capacity C21 makes the most greatly the input impedance of differential amplifier circuit the highest.See Fig. 3, in the first operational amplifier A 1 Inverting input (node N1) and the inverting input (node N2) of the second operational amplifier A 2 between connect have the first resistance R25, and at the inverting input of the first operational amplifier A 1 and its outfan V_OUT1Between connect have the second resistance R23, With at the inverting input of the second operational amplifier A 2 and its outfan V_OUT2Between connect have the second resistance R24, resistance R23 Can be identical with the resistance value size of R24, but the resistance of they and R25 can be the same or different.

See Fig. 3, under the most rough calculated case, outfan V_OUT1～V_OUT2Between differential voltage V_OUT2-V_OUT1 Generally more equal to (V_IN2-V_IN1) × (1+2 × R23/R25), wherein V_IN2-V_IN1Equal to Roche air core coil two ends DSA and Faradism pressure reduction between DSB two ends, thus we can be implemented in the first operational amplifier A 1 and the second operational amplifier A 2 Respective outfan V_OUT1～V_OUT2Between, the induced voltage that acquisition senses to air core coil two ends DSA～DSB easily Differential amplification signal.Fig. 7 is the improvement structure of difference channel in Fig. 3.

See Fig. 7, it is known that the inverting input of node N1 and the first operational amplifier A 1 is connected, node N2 and the second computing The inverting input of amplifier A2 is connected, and the first resistance R25 is connected between node N1 and N2.Differential amplifier circuit can be learned 211 also include one or more groups resistance R26 being serially connected and switching device S26, and the resistance R26 of each group of series connection and opening Close device S26 and be both connected to (i.e. node N1～N2 between the first and second respective inverting inputs of operational amplifier A 1～A2 Between), it is therefore intended that, it is intended that entire gain or the title amplification of amplifying circuit 211 are adjustable.Node N1～N2 it Between in addition to the first resistance R25 originally existed, the S26 in each group of resistance R26 being serially connected and switching device S26 During connection, the resistance R26 in this group and the first resistance R25 is just allowed to be connected in parallel between node N1～N2.So at node N1～N2 Between the resistance R26 (S26 connections) of effective status that introduces the most, the always resistance in parallel between node N1～N2 is the least, instead As the same, the resistance R26 (S26 disconnection) cast out between node N1～N2 is the most, the resistance in parallel total between node N1～N2 The biggest.The low and high level that can be exported by the processor 412 in Fig. 7 that turns on and off of switch S26 drives switch S26 to carry out Switching.When needing the amplification increasing differential amplifier circuit 211, connect one or more switching device S26 to realize inciting somebody to action One or more this resistance R26 and the first resistance R25 give parallel connection.Or when needing the amplification reducing amplifying circuit 211, Disconnect one or more switching device S26 to realize resistance R26 in parallel to one or more scripts and the first resistance R25 from putting In big circuit floating (floating), floating resistance R26 is high-impedance state.

See Fig. 4, active filter APF has a differential mode analog quantity exported by first detection module 211 and transfers to 5th operational amplifier A 5 of single-ended voltage signal, in the differential amplifier circuit 211 in Fig. 3 between two amplifier each outfans Differential amplification signal (the V of output_OUT2-V_OUT1) it is coupled to normal phase input end and the anti-phase input of the 5th operational amplifier A 5 End.The outfan V of such as the second operational amplifier A 2 in Fig. 3_OUT2It is coupled to the 5th operational amplifier A 5 by resistance R52 Normal phase input end V_INB, the outfan V of the first operational amplifier A 1 in Fig. 3_OUT1It is coupled to the 5th computing by resistance R51 put The inverting input V of big device A5_INA, and connection has feedback between inverting input and the outfan of the 5th operational amplifier A 5 Resistance R53, is equivalent to the 5th operational amplifier A 5 and is configured to an active proportional amplifier.Therefore the 5th operational amplifier A 5 By this differential amplification signal (V_OUT2-V_OUT1) transfer the single-ended voltage signal that self outfan exports to.Active filter APF The differential data that receives of the 5th operational amplifier A 5 be High Speed Analog amount, the resistance of R31 and R32 can be identical or different, Rough calculation differential voltage V_OUT2-V_OUT1The single-ended voltage signal being converted into the 5th operational amplifier A 5 approximates (V_OUT2- V_OUT1)×R33/R31.In other alternative embodiment, a reference voltage VREF can be loaded into the 5th operational amplifier The normal phase input end V of A5_INB, make difference value V_OUT2-V_OUT1Slightly upward lifting and be easier to sensed.

See the isolation that Fig. 4, active filter APF also include making front stage circuits and late-class circuit realize electrical isolation Coupling module 515, as example, isolation coupling module 515 can be with light emitting diode and sensitive device (such as photosensitive semiconductor Pipe) cooperate to provide output electric current, isolation coupling module 515 completes the conversion of the signal of telecommunication optical signal signal of telecommunication, rises To input signal and the buffer action of output signal.Owing to being mutually isolated between the input and output of isolation coupling module 515, the signal of telecommunication Transmission has unidirectional feature, thus has good electrical isolation capabilities and capacity of resisting disturbance.So isolation coupling module 515 Signal to noise ratio can be greatly improved as terminal isolation element in transmission information.Isolation coupling module 515 receives in this application The single-ended voltage signal of the 5th operational amplifier A 5 output, and generate and the single ended voltage letter of the 5th operational amplifier A 5 output Number remain the linear current I of linear relationship_FOLLOW.5th operational amplifier A 5 acts at least two, before and after first is realization The electrical isolation of level, second is that the single-ended voltage signal being formed and followed by the 5th operational amplifier A 5 output changes and linearly becomes The linear current changed.

Seeing Fig. 4, active filter APF and also include the 6th operational amplifier A 6, it is by linear current I_FOLLOWConversion reduction Become final desired magnitude of voltage.The current output terminal of isolation coupling module 515 output is coupled to and the 6th operational amplifier The node N3 that the inverting input of A6 is connected, the positive input end grounding of the 6th operational amplifier A 6 and also anti-phase at it Input and outlet chamber connect resistance R54, although be not expressly shown in figure, resistance R54 can be arranged to adjustable resistance or Person directly connects an adjustable resistance with it.The line that 6th operational amplifier A 6 will be absorbed at this node N3 by resistance R54 Property electric current I_FOLLOWIt is converted into the voltage signal V of its output_OUT-F.Owing to defining linear current I before_FOLLOWWith the 5th computing The single-ended voltage signal of amplifier A5 output keeps linear relationship, then the voltage signal V of the 6th operational amplifier A 6 output_OUT-FAlso Linear relationship is kept with the single-ended voltage signal of the 5th operational amplifier A 5 output.As preference, it is also possible in the 6th computing Connecting one between inverting input and the outfan of amplifier A6 and compensate electric capacity C51, it is in parallel with resistance R54, compensates electric capacity C51 for improve circuit stability and reduce the bandwidth of operation of circuit output noise and limiting circuit about about 10kHz with In.

Seeing Fig. 5, in the second detection module 311, it is detected from above-mentioned current information and extraction has second frequency The secondary signal of scope, and it is converted into magnitude of current I_SETForm exported, figure not illustrating, power quality analyzer can With the current-to-voltage convertor that is configured with for by this magnitude of current I_SETIt is reduced into the voltage characterizing secondary signal.Such as electricity Stream electric pressure converter is a resistance, magnitude of current I_SETFlow through this resistance and will be reduced into voltage, the electric energy matter on electrical network Amount (Power Quality) can emerge from out completely from the voltage waveform that this is reduced.Wherein the second detection mould One integrating circuit 311A of block 311 includes the 3rd operational amplifier A 3, its normal phase input end V_INDBy a resistance R32 is coupled to the one in two-terminal DSA of this air core coil and DSB, its inverting input V_INCBy a resistance R31 coupling Close the another one in two-terminal DSA and DSB of this air core coil.Thus the 3rd operational amplifier A 3 can be from current sensor The pair of output of 102 is to capture secondary signal, the most also at inverting input and the outfan of the 3rd operational amplifier A 3 Between connect and have electric capacity C31 and connection to have resistance R33, resistance R33 and electric capacity C31 in parallel, and the 3rd operational amplifier A 3 is joined Put one integrator of formation.Seeing Fig. 2 and Fig. 5, the second detection module 311 also includes voltage current adapter (V/I Converter) 311B, transducer 311B are used for receiving the output voltage of the 3rd operational amplifier A 3, and by Voltage to current transducer This voltage of device 311B output is converted into magnitude of current I_SETExported.The current-to-voltage convertor of power quality analyzer configuration (I/V converter) 611 magnitude of current I being responsible for exporting voltage current adapter 311B_SETIt is reduced into magnitude of voltage.Electric energy Mass-synchrometer can also support the use field-programmable gate array to the magnitude of voltage sampling being reduced into and execution ADC analog digital conversion The row components and parts such as FPGA or Digital Signal Processing DSP/instrument is according to the size of the data reproduction secondary signal of sampling.

Seeing Fig. 6, the 3rd detection module 411 has a band filter, and it includes being coupled to this current sensor 102 First input node N of a lead-out terminal DSA_{4_1}, also include the second input joint being coupled to another lead-out terminal DSB Point N_{4_2}, the first input node N_{4_1}And connect between the inverting input of a four-operational amplifier A4 in band filter The position having a 3rd resistance R41 and a first electric capacity C41, the 3rd resistance R41 and the first electric capacity C41 interconnection is provided with One the first interconnecting nodes N_{4_3}, the first interconnecting nodes N_{4_3}And it is connected between the outfan of four-operational amplifier A4 and has the second electricity Hold C42, and the inverting input of four-operational amplifier A4 and outfan connection have the 4th resistance R43.Thus the 4th computing is put Big device A4 is configured to band filter.

Note at the first interconnecting nodes N_{4_3}With the second input node N_{4_2}(this second input node N_{4_2}Put with the 4th computing The normal phase input end of big device A4 is directly coupled together) between be connected with resistance R42, other 3rd resistance R41 and the first electric capacity C41 two The particular location of person is: the 3rd resistance R41 is connected to the first input node N_{4_1}With the first interconnecting nodes N_{4_3}Between, the first electric capacity C41 is connected to the first interconnecting nodes N_{4_3}And between the inverting input of four-operational amplifier A4.

See Fig. 6, as option, also in the first input node N_{4_1}With the second input node N_{4_2}Between connect have similar Transient Voltage Suppressor or discharge tube or the such over-voltage protection element of varistor, with Transient Voltage Suppressor D41 as example, Its anode cathode direction is at node N_{4_1}With node N_{4_2}It is arbitrary between although, namely anode links the first input node N_{4_1}Time negative electrode link the second input node N_{4_2}, or anode links the second input node N_{4_2}Negative electrode links the first input node N_{4_1}, but in a preferred embodiment, we select the latter.

In order to understand the band filter examination for electric arc intuitively, its several parameters such as center angular frequency ω_OShould sufficiently be explained with bandwidth BW and quality factor Q.Be merely for convenience of analysis and not to of the present utility model Content does any restriction, it is assumed that the most relatively (capacitance of such as C41 is the capacitance of electric capacity C42 and electric capacity C41 Fluctuate on the basis of the capacitance of electric capacity C42 the 50% of C42, i.e. C again₄₂±C₄₂× 50%), at the most rough meter Under the conditions of calculation, the center angular frequency ω of band filter_OSubstantially meet following functional relation:

${\mathrm{\ω}}_O=\sqrt{(\frac{1}{R_{41}}+\frac{1}{R_{42}})\×\frac{1}{R_{43}\×{C^2}_{42}}}......\left(5\right);$

Seeing Fig. 8, band filter also includes one or more groups preset resistance R44 being serially connected and switch S44, each Preset resistance R44 of group series connection and switching device S44 are both connected to inverting input and the outfan of four-operational amplifier A4 Between (in parallel with resistance R43 again after they concatenations).When band filter is set to increase center angular frequency ω_OMode of operation Time, one or more switching device S44 are in an ON state with by these preset resistance R44 one or more and the 4th resistance R43 Give parallel connection (the in parallel total resistance between inverting input and the outfan of four-operational amplifier A4 reduces).Or when band Bandpass filter is set to reduce center angular frequency ω_OMode of operation time, the most one or more switching device S44 are in disconnection shape State is with by preset resistance R44 floating (the 4th operation amplifier from band filter one or more and that the 4th resistance R43 is in parallel In parallel total resistance between inverting input and the outfan of device A4 increases).Turning on and off of S44 of switch can be by Fig. 8 The low and high level of processor 412 output drives switch S44 to switch over.In view of bandwidth BW=ω_O/ Q, if quality factor Q is set to predetermined value, then center angular frequency ω_ORegulation mean that bandwidth BW also correspondence is conditioned.If or conversely speaking, Bandwidth BW is set to predetermined value, then center angular frequency ω_ORegulation mean that quality factor Q also correspondence is conditioned.It addition, wave filter Another critically important parameter be bandpass center center angular frequency ω_OVoltage amplification factor A at place_UO=-R43/ (2R41). If being parallel with R44 between the inverting input of four-operational amplifier A4 and outfan, then resistance R43 in above formula should Replaced by the in parallel total resistance between inverting input and the outfan of four-operational amplifier A4.

6th operational amplifier A 6 produce output result V in band filter_{OUT_AS}, detect the process that device possesses Device 412 is also used for receiving this result V of the 3rd detection module 411 output_{OUT_AS}, because result V_{OUT_AS}Characterize detected The sizes values of three signals, so this can be utilized to characterize the output result of the 3rd signal for processor 412 and threshold value compares Relatively, or statistics the 3rd signal exceedes the number of times of threshold value within the default time period.Such as, exceed certain at the 3rd signal to preset Threshold range time, one can consider that and on electrical network, create unexpected fault electric arc, and if the value of the 3rd signal is at threshold Below value scope, then it is believed that create the conventional electric arc in tolerance on electrical network.Such that it is able to we utilize the 3rd Signal is as judging that whether there is electric arc in electrical network provides foundation.If it addition, in the case of having electric arc in electrical network, the 3rd Signal is also as judging that electric arc is the foundation of normal arc or fault electric arc.If it is said that in general, the 3rd signal is relative to ginseng The bias examining frequency spectrum allows bias to be then defined as normal arc, otherwise relative to the bias of reference spectrum less than threshold value Bias is allowed then to be defined as improper fault electric arc more than threshold value.In order to avoid or reduce electric arc negative effect, it should Start the countermeasure in breaking arc source as soon as possible, the arc-detection mechanism that therefore this utility model provides, can fast as far as possible and Reliably determining electric arc, maintenance or supervision staff for power system are provided convenience.

Above, by explanation and accompanying drawing, the exemplary embodiments of the ad hoc structure of detailed description of the invention, above-mentioned practicality are given Novel propose existing preferred embodiment, but these contents are not intended as limitation.For a person skilled in the art, read After reading described above, various changes and modifications will be apparent to undoubtedly.Therefore, appending claims should be regarded as and contains this The true intention of utility model and whole variations and modifications of scope.The model of any and all equivalence in Claims scope Enclose and content, be all considered as still belonging in intention of the present utility model and scope.

Claims (17)

1. a detection device, it is characterised in that there is the current sensor of current information in detection electrical network, also include:

First detection module, for detecting and extract first signal with first frequency scope from this current information, first Signal is at least used as forming the calculating compensating electric current being injected into electrical network with its central harmonic wave opposite in phase equal in magnitude and depends on According to, and the first signal at least also serves as the foundation of the quality of power supply judging electrical network；

Second detection module, for detecting and extract the secondary signal with second frequency scope from this current information, second Frequency range is higher than the frequency of first frequency scope, and secondary signal is at least used as judging the foundation of the quality of power supply of electrical network；

3rd detection module, for detecting and extract the 3rd signal in the way of bandpass filtering from this current information, the 3rd letter Number it is used for comparing or to add up it with default threshold value within the default time period, to exceed the number of times of threshold value thereby judge Whether it belongs to fault electric arc.

Detection device the most according to claim 1, it is characterised in that there is in described first detection module a difference and put Big circuit, comprising:

First, second operational amplifier, the normal phase input end of each of which is respectively coupled to a pair output of this current sensor End, to capture the first signal, connects between their inverting input and has the first resistance；And

Connect between the first and second respective inverting inputs of operational amplifier and respective outfan and have the second resistance, mat This forms differential amplification signal between the outfan of first, second operational amplifier.

Detection device the most according to claim 2, it is characterised in that this differential amplifier circuit also includes one or more groups phase The preset resistance connected mutually and switching device, preset resistance and the switching device of each group of series connection are both connected to first, second fortune Calculate between the inverting input of amplifier；

When described differential amplifier circuit is set to the mode of operation increasing amplification, one or more switching devices are in connection State is to give parallel connection by these preset resistance one or more and the first resistance；Or

When described differential amplifier circuit is set to the mode of operation reducing amplification, one or more switching devices are in disconnection State with by the preset resistance of one or more and the first resistor coupled in parallel from described differential amplifier circuit floating.

Detection device the most according to claim 1, it is characterised in that described second detection module has an integration electricity Road, comprising:

3rd operational amplifier, its positive and inverting input are respectively coupled to the pair of output of this current sensor to pick Take secondary signal, form an integrator by the 3rd operational amplifier.

Detection device the most according to claim 4, it is characterised in that described second detection module also includes that voltage x current turns Parallel operation, it is used for receiving the output voltage of described integrating circuit and converting this voltage to the magnitude of current being exported.

Detection device the most according to claim 1, it is characterised in that described 3rd detection module has a bandpass filtering Device, it includes the first and second input nodes being respectively coupled to the pair of output of this current sensor:

It is in series with the 3rd between the inverting input of a four-operational amplifier in the first input node and band filter Resistance and the first electric capacity, at the first interconnecting nodes of the 3rd resistance and the first electric capacity and between the outfan of four-operational amplifier Connect and have the second electric capacity, and the inverting input of four-operational amplifier and outfan connection have the 4th resistance；And

It is connected with another resistance between the normal phase input end of the first interconnecting nodes and the second input node namely four-operational amplifier.

Detection device the most according to claim 6, it is characterised in that this band filter also includes that one or more groups is mutual The preset resistance of series connection and switching device, preset resistance and the switching device of each group of series connection are both connected to four-operational amplifier Inverting input and outfan between；

When described band filter is set to the mode of operation increasing center angular frequency, one or more switching devices are in connection State is to give parallel connection by these preset resistance one or more and the 4th resistance；Or

When described band filter is set to the mode of operation reducing center angular frequency, one or more switching devices are in disconnection State with by the preset resistance of one or more and the 4th resistor coupled in parallel from described band filter floating.

Detection device the most according to claim 6, it is characterised in that connect between the first and second input nodes and have overvoltage Protection element, over-voltage protection element is one of Transient Voltage Suppressor, discharge tube, varistor or combinations thereof.

Detection device the most according to claim 1, it is characterised in that the first signal at least includes power frequency information harmony wavelength-division Amount information, secondary signal at least includes transient current information more higher than work frequency.

Detection device the most according to claim 1, it is characterised in that described current sensor is Roche air core coil electricity Flow sensor.

11. detection devices according to claim 1, it is characterised in that also include alarm output module, output of once reporting to the police Module monitors to the 3rd signal exceed default threshold value or within the default time period the 3rd signal exceed the number of times of threshold value and do not exist Time in the numerical range specified, cause this alarm output module output indication signal to characterize the 3rd signal and belong to fault electric arc, And trigger the prior-warning device generation warning message receiving this indication signal further.

12. 1 kinds and the Active Power Filter-APF of detection matched with devices use as claimed in claim 1, it is characterised in that use Electrical network is injected with the compensation electric current of harmonic wave opposite in phase equal in magnitude in the first signal in producing.

13. Active Power Filter-APFs according to claim 12, it is characterised in that including:

One the 5th operational amplifier that the differential mode analog quantity that first detection module exports is transferred to single-ended voltage signal；

One isolation coupling module performing one-way transmission signal, is used for receiving this single-ended voltage signal, and this list is followed in output The change of terminal voltage signal and the linear current of linear change；

One the 6th operational amplifier, its positive input end grounding and connect in its inverting input and outlet chamber and have resistance, use In the voltage signal linear with this single-ended voltage signal that this linear current is converted into its outfan.

14. 1 kinds and the power quality analyzer of detection matched with devices use as claimed in claim 1, it is characterised in that bag Including a current-to-voltage convertor, secondary signal is converted into the form of the magnitude of current and is exported by the second detection module, electric energy matter This magnitude of current is reduced into the voltage characterizing secondary signal by the current-to-voltage convertor of component analysis instrument；And

The power frequency that first signal passes judgment on electric current for power quality analyzer provides basis for estimation with harmonic quality, and secondary signal is electricity Transient current information offer basis for estimation can be weighed by mass-synchrometer.

15. 1 kinds of electric arc detecting devices, it is characterised in that utilize the current information in Luo-coil sensor detection electrical network, and And also include a wave filter to detect and to extract a preset signals from this current information, this preset signals for and preset Threshold value compare or add up this preset signals and within the default time period, exceed the number of times of threshold value thereby whether judge it Belong to fault electric arc；Wherein

This wave filter has the first and second input nodes of the one group of outfan being respectively coupled to Luo-coil sensor；

A resistance and one it is in series with between the inverting input of an operational amplifier in the first input node and wave filter Individual electric capacity, is connected between interconnecting nodes and the outfan of this operational amplifier between this resistance and electric capacity and has another electric capacity, and should The inverting input of operational amplifier and outfan connect another resistance；And

A resistance also it is connected with between the normal phase input end of this interconnecting nodes and the second input node namely operational amplifier；

Thus produce at the outfan of this operational amplifier and characterize the voltage signal of this preset signals.

16. electric arc detecting devices according to claim 15, it is characterised in that this wave filter also includes one or more groups phase The preset resistance connected mutually and switching device, preset resistance and the switching device of each group of series connection are both connected to this operational amplifier Inverting input and outfan between；

When described wave filter is set to the mode of operation increasing center angular frequency, one or more switching devices are in connection shape State is to be connected in parallel on these preset resistance one or more between the inverting input of operational amplifier and outfan；Or

When described wave filter is set to the mode of operation reducing center angular frequency, one or more switching devices are in disconnection shape State with by one or more preset resistance from floating between the inverting input and outfan of this operational amplifier.

17. electric arc detecting devices according to claim 15, it is characterised in that also include alarm output module, once report Alert output module monitor the 3rd signal exceed default threshold value or within the default time period the 3rd signal exceed threshold value time When number is not in the numerical range specified, causes this alarm output module to export effective indication signal and characterize the 3rd signal genus In fault electric arc, and trigger the prior-warning device generation warning message receiving this indication signal further.