Embodiment
Below in conjunction with the accompanying drawing in the utility model, the technical scheme in the utility model is clearly and completely described.
Figure 1 shows that the structural representation of the absolute time delay pick-up unit of the utility model intelligent substation mutual inductor data acquisition system (DAS), described pick-up unit comprises three-phase programmable power supply 1, Hall element 2, electronic mutual inductor 3, controls workstation 4, merge cells 5 and optical fiber 6.Three-phase programmable power supply 1, Hall element 2, electronic mutual inductor 3 connect successively, the control end of three-phase programmable power supply 1 is connected with the control signal output terminal of controlling workstation 4, the output terminal of Hall element 2 is connected with an input end controlling workstation 4, the output terminal of electronic mutual inductor 3 is connected with the input end of merge cells 5 by optical fiber 6, and the output terminal of merge cells 5 is connected with another input end of controlling workstation 4.
Three-phase programmable power supply 1 obtains energy from electrical network, receives from the instruction of controlling workstation 4, and the voltage and current of waveform is specified in output.The simulating signal of the output of Hall element 2 is as the standard signal that detects time delay, an input end of input control workstation 4; The voltage and current signal that electronic mutual inductor 3 gathers after treatment, is sent to merge cells 5 by optical fiber 6.Another input end of controlling workstation 4 gathers the signal from merge cells 5, and itself and the described standard signal received are analyzed, and draws absolute time delay Δ t.
Referring to Fig. 2, described control workstation 4 comprises instruction waveform generation module 7, collection of simulant signal module 8, merge cells receiver module 9, setting module 10, data analysis module 11 and display module 12.
Described instruction waveform generation module 7, with the control end of three-phase programmable power supply 1, be connected, for sending the coded order signal, make three-phase programmable power supply 1 output specify the voltage and current of waveform modulation voltage and the modulated current signal of coded message (with), described coded order signal is transferred to the control end of three-phase programmable power supply 1 by the control signal output terminal of described control workstation 4;
Described collection of simulant signal module 8, for receiving the simulating signal transmitted from Hall element 2, and become digital signal by above-mentioned simulating signal through the A/D sample conversion;
Described merge cells receiver module 9, the digital signal transmitted for receiving merge cells 5;
Described setting module 10, for realizing the setting to whole sensed system parameter and function, pass through man-machine interface, setting comprises the coded order of three-phase programmable power supply, the selection of Frame passage to be measured, the setting of proving installation time delay ξ t, the setting parameter that delayed data shows and the current/voltage phase differential shows, and will reach three-phase programmable power supply control panel and data analysis module 11 under parameter information to realize corresponding function;
Described data analysis module 11, with collection of simulant signal module 8, with merge cells receiver module 9, be connected, for receiving from the digital signal through the A/D sampling of collection of simulant signal module 8 transmission and the digital signal of merge cells receiver module 9 transmission, comparative analysis after the digital signal transmitted with merge cells receiver module 9 after the digital signal of A/D sampling that collection of simulant signal module 8 is transmitted is carried out interpolation algorithm, draw absolute time delay Δ t, detailed process refers to hereinafter method of testing workflow;
Described data analysis module 11, also for being combined the voltage of unit 5 outputs, the data of electric current after closeization of interpolation algorithm are carried out perunit value, amplitude by the value of each data point of voltage divided by voltage, the value of each data point of electric current is divided by the amplitude of electric current, then with reference to the Waveform Matching method in step g, waveform after waveform after voltage data is initial by workstation clock t0 and current data workstation clock t1 are initial is complementary, the mistiming corresponding voltage of t0 and t1, the relative time delay amount of the data of electric current, can be converted into by the power frequency 50Hz cycle phase differential of electric current and voltage.
Described display module 12, be connected with described data analysis module 11, for showing in real time tables of data and the curve map of absolute time delay Δ t.
Referring to Fig. 3, three-phase programmable power supply 1 comprises a three-phase isolation transformer 13 and three inverter power unit 14 that are connected with the output terminal of three-phase isolation transformer 13.A, B, C three-phase voltage are sent into respectively corresponding inverter power unit 14 through three-phase isolation transformer 13, three-phase signal is carried out to the phase-splitting processing, an inverter power unit 14 often joins, 14 of inverter power unit adopt synchronous optical fiber to connect, the inner ac-dc-ac inverter circuit that adopts in inverter power unit 14, can realize the functions such as frequency modulation phase modulation amplitude modulation of signal by the ac-dc-ac inverter circuit, three-phase signal postpones 120 ° of phase places successively, produces the controlled pulsewidth voltage of three-phase, current signal.
Referring to Fig. 4, described inverter power unit 14 mainly comprises four parts: not control rectifying circuit 15, buck chopper circuit 16, SPWM inverter circuit 17, voltage, current filtering circuit 18.Civil power has been realized the conversion of AC-to DC through control rectifying circuit 15 not, adjusting to the controllable electric power output voltage generally has the direct pressure regulation of pair output AC voltage and Converting Unit input vertical compression is regulated to two kinds of methods, the method that the present embodiment adopts straightening to press, in buck chopper circuit 16 links, DC voltage is carried out to the step-down processing, circuit is after step-down is processed, through adopting the inverter circuit 17 of SPWM modulation system, the AC power waveform of output codified, alternating current is again through superpotential, current filtering circuit 18 generates and meets the controllable voltage of controlling the workstation instruction, current waveform (being the described voltage and current with coded message).
Referring to Fig. 5, the sinusoidal wave production process of encoding is as follows: at first, control workstation 4 and send coded order to three-phase programmable power supply 1 according to the sinusoidal wave form of required generation, concrete, adopt the SPWM modulation system, using the sine wave of required generation as the reference signal, with carrier wave ratio after, produce coded order, coded order essence is a series of coded pulses, the break-make of the IGBT of SPWM inverter circuit 17 in control chart 4, thus it is sinusoidal wave to produce coding.It is 50Hz for frequency that diagram produces sine wave, the sine wave that amplitude is 100V, and according to a cycle sine, a cycle 0, two cycle sines, 0, three cycle sine of 2 cycles, the mode of three the cycle 0...... gained of being encoded, the zero level of take realizes the uniqueness of waveform position is judged as sign.
Referring to Fig. 6, workflow comprises: configuration testing loop, system go out initialization, Site Detection, generation monitoring result etc.At first, access host computer (controlling workstation 4), connect circuit, after power turn-on, system is debugged, debug complete, merge cells receiver module 9, collection of simulant signal module 8, display module 12, the data analysis module 11 of controlling workstation 4 carried out to initialization, carry out the isoparametric setting of instruction waveform simultaneously.After initialization and setting complete, power turn-on, system completes the comparative analysis of the generation of controlled pulsewidth waveform, signal synchronous collection and waveform automatically, finally obtains in real time definitely delay data, generates the real time data table and shows by display screen.
Described method of testing workflow is as follows:
A. three-phase programmable power supply 1 requires the adjustable voltage of output amplitude, phase place and frequency, electric current (being the described modulation voltage with coded message and modulated current signal) according to what control workstation 4 steering orders;
B. detect the coding waveforms of three-phase programmable power supply 1 output after ovennodulation by Hall element 2, using the voltage signal of collection as voltage standard signal u0, the current signal gathered is as current standard signal i0, through the A/D sampling thief high-speed sampling in the collection of simulant signal module, be stored to and control workstation 4, the voltage signal of all collections, current signal are beaten markers by the workstation clock;
C. the analog quantity electric current of three-phase programmable power supply 1 output, voltage signal, by electronic mutual inductor 3, through the A/D conversion, are output as digital signal, and through optical fiber 6, data are delivered to merge cells (MU) 5;
D. merge cells 5 receives digital voltage, the current signal that gathers output from electronic mutual inductor 3, and above-mentioned digital voltage, current signal are delivered to and controlled workstation 4 according to the frame format of IEC60044-8 standard code;
E. control digital voltage, the current signal that workstation 4 transmits merge cells 5 and stored by the unified clock frequency, record voltage, the current standard signal through the A/D sampling that gather from Hall element 2 simultaneously;
F. 11 pairs of electronic mutual inductors of data analysis module 3 of controlling workstation 4 gather digital voltage, the current signal exported by merge cells 5 and carry out linearity or Lagrange's interpolation algorithm reduction processing by the unified clock frequency, by its interpolation for Hall element 2, gather through the sample data group of identical sampling rate of A/D, and press the common storage of workstation clock order with voltage, current standard signal data through the A/D sampling that Hall element 2 gathers, for the time delay of g step, calculate.;
G. the data through the A/D sampling that the data of merge cells 5 outputs of 11 pairs of treated mistakes of upper step of data analysis module and Hall element 2 gather contrast coupling, draw the voltage between the data of data through the A/D sampling that Hall element 2 gathers and merge cells 5, the current waveform corresponding relation, as shown in Figure 7, the data storing through the A/D sampling that Hall element 2 gathers is at internal memory A, the data storing of merge cells 5 is at internal memory B, by both data zero-times of workstation clock synchronous, can complete the coupling corresponding relation of both data by coding characteristic, it is Data Matching after data and bn after a0, the corresponding workstation clock of a0 t0, the corresponding workstation clock of bn t1, the mistiming of above-mentioned both the Data Matching points of comparative analysis can calculate the absolute time delay of both waveforms: i.e. Δ t=t1-t0-ξ t, Δ t is the absolute time delay of equipment under test, ξ t is the tester time delay, comprise the time delay of absolute time delay pick-up unit inner high speed A/D sampling, and hardware signal processing time delay, but be fixing measured value.Then two groups of Wave datas being given to the display module 12 of controlling workstation 4 is shown; The data receiver part of data analysis module 11 is simultaneously to analog output amount and MU digital quantity vanning (by data acquisition graftabl appointed area), according to controlling workstation unified clock frequency, store, realize synchronizeing of imitated output quantity and MU digital quantity by the workstation internal clocking, method is as described in f, do not rely on equipment under test to the time system.
Instruction waveform generation module 7 modulation generates the classes ripple of encoding as shown in Figure 5, to test waveform, is identified, and solves the error that poor integer time waveform brings.
H. set three-phase programmable power supply 1 output voltage by instruction waveform generation module 7, the synchronous power frequency test signal of electric current, through above-mentioned b to the f process, be combined the voltage of unit output, the data of electric current after closeization of interpolation algorithm are carried out perunit value, amplitude by the value of each data point of voltage divided by voltage, the value of each data point of electric current is divided by the amplitude of electric current, then with reference to the Waveform Matching method in g, waveform after waveform after voltage data is initial by workstation clock t0 and current data workstation clock t1 are initial is complementary, the mistiming corresponding voltage of t0 and t1, the relative time delay amount of the data of electric current, can be converted into by the power frequency 50Hz cycle phase differential of electric current and voltage,
I. complete test report, finish test job.