Low-voltage powerline carrier communication test method and pilot system thereof
Technical field
The present invention relates to low voltage power cord carrier communication test system, by simulated field circuit environment, a kind of test method of the low-voltage carrier communication ability of detected carrier electric energy meter and other carrier communication product.Belong to the low-voltage powerline carrier communication technical field of measurement and test.
Background technology
Low-voltage powerline carrier communication refers to by carrier system the analog or digital signal loading be carried out the technology that signal transmits to low-voltage electricity transmission line.Because signal attenuation characteristic and interference characteristic on the low-voltage electricity transmission line are very complicated, and randomness, time variation are large, are difficult to find an accurately analytic expression or Mathematical Modeling specification and analysis in addition.Thereby, the low-voltage powerline carrier communication performance test is never found effective method.At present, to low-voltage powerline carrier communication performance, technical indicator advanced means and testing equipment for want of, still be difficult to carry out the quantitative test of system.To the carrier communication performance test of carrier electric energy meter and similar products, can only be confined to detect qualitatively, or its communication success rate of test goes to pass judgment on its communication performance again after adopting the erecting bed.Method of testing and test result lack dissemination, thereby impact is passed judgment on and large scale application the performance of this series products.
Summary of the invention
Purpose of the present invention is intended to overcome the existing defects of prior art, proposes a kind of test method for test low-voltage powerline carrier communication performance.The method measuring range covers low-voltage powerline carrier communication frequency range 9kHz~500kHz.The method provides a kind of test platform for the test carrier performance simultaneously.On this platform, by simulation low-voltage power line circuit environment, test carrier communication performance main performance index has been proposed, comprise the implementation of transmission level test, receiving sensitivity test and anti-interference test, the test of low-voltage circuit impedance variation etc.This testing scheme does not relate to way of realization and inner the leading to of carrier communication based on carrying out on the low-voltage power line that communicates between carrier wave transmitter and the carrier wave receiver
The letter agreement has good operability.These test events are to control by the test macro in house software, can realize single stepping test or all tests.Can carry out to the equipment in the system setting and the inquiry of important technological parameters; Realization is to general management functions such as rights management, testing scheme setting, test result judgement and the preservation of native system, data query, report generation, printings.
Technical solution of the present invention: it is characterized in that this test method comprises following method of testing: i carrier wave transmission level on-line testing method, ii carrier wave receiving sensitivity on-line testing method, the anti-interference on-line testing method of iii carrier communication, iv low-voltage circuit impedance variation on-line testing method and low voltage power cord carrier communication test system;
Described i carrier wave transmission level on-line testing method, the carrier wave transmission level is measured with frequency spectrograph, isolate electric wiring with a cover carrier wave isolator, simultaneously with a cover coupling device carrier signal that is coupled, consist of with reference to the artificial mains network who stipulates among the GB/T 6113F2, utilize series loop and the 50 Ω V-type artificial mains network in parallel of 50 μ H and 5 Ω, carrier signal is separated from low-voltage circuit, the artificial mains network guarantees that test data satisfies code requirement and has comparativity;
Described ii carrier wave receiving sensitivity on-line testing method, to set up one group with the phase-locked dual path isolation experiment power supply circuit of frequency, utilize power supply inverter to produce another group power environment, the same frequency of realizing two groups of power supplys by Phase Lock Technique is phase-locked, guarantee that tested carrier wave transmitter and carrier wave receiver are with frequently but test in the power environment of isolation, programmable attenuator is directly connected between the two-way insulating power supply, only carrier signal is decayed, programmable attenuator is made of resistor network, guarantee that frequency response is consistent in the reference carrier frequency, the resistor network of plural serial stage guarantees enough attenuations, and the carrier wave isolator guarantees that the isolation between the carrier transmitting-receiving signal satisfies the sensitivity test requirement; Another key point of receiving sensitivity on-line testing scheme is the online programmable attenuator of carrier signal.Programmable attenuator is directly connected between the two-way insulating power supply, only carrier signal is decayed.Programmable attenuator is made of resistor network, can guarantee that frequency response is consistent in the reference carrier frequency, and the resistor network of plural serial stage guarantees enough attenuations.The carrier wave isolator guarantees that the isolation between the carrier transmitting-receiving signal satisfies the sensitivity test requirement.
Another key point of receiving sensitivity on-line testing scheme is the online programmable attenuator of carrier signal.Programmable attenuator is directly connected between the two-way insulating power supply, only carrier signal is decayed.Programmable attenuator is made of resistor network, can guarantee that frequency response is consistent in the reference carrier frequency, and the resistor network of plural serial stage guarantees enough attenuations.The carrier wave isolator guarantees that the isolation between the carrier transmitting-receiving signal satisfies the sensitivity test requirement.
The anti-interference on-line testing method of described iii carrier communication, produce various noise signals with waveform generator, applied power amplifier and electrical network produce the zero cross fired signal with the frequency trigger equipment, trigger noise signal with frequently output or alien frequencies output, simulating grid co-channel interference and alien frequencies disturb;
Described iv low-voltage circuit impedance variation method of testing, with load simulator by on-line testing household electrical appliance impedance operator, set up corresponding electrical quantity model, again according to the different topological structure form of low-voltage power line distribution of impedance, by predefined control device, analog line impedance variation characteristic; The carrier signal output of the carrier sending device in the described low voltage power cord carrier communication test system and the signal input part of programmable attenuator join; The signal input part of the signal output part of programmable attenuator and tested carrier wave receiving system joins; Tested carrier wave receiving system is after receiving correct carrier signal and decoding, and the signal output part by tested carrier wave receiving system sends carrier signal again and replys communication; The carrier level that the carrier level that carrier sending device sends and tested carrier wave receiving system send is all measured by artificial mains network's access spectrum analyzer that is coupled after the sampling; Computer connects the spectrum analyzer interface and reads the carrier level test data; Input one tunnel and the noise simulator of tested carrier wave receiving system join, and noise simulator connects computer control; Another road of the input of tested carrier wave receiving system and load simulator join, and load simulator connects computer control; The output of power conditioner is delivered to respectively two-way carrier wave isolated power supply, and wherein the power supply of one tunnel isolation is as the working power of tested carrier sending device, and another road power supply is as the working power of tested carrier wave receiving system.Another key point of receiving sensitivity on-line testing scheme is the online programmable attenuator of carrier signal.Programmable attenuator is directly connected between the two-way insulating power supply, only carrier signal is decayed.Programmable attenuator is made of resistor network, can guarantee that frequency response is consistent in the reference carrier frequency, and the resistor network of plural serial stage guarantees enough attenuations.The carrier wave isolator guarantees that the isolation between the carrier transmitting-receiving signal satisfies the sensitivity test requirement.Described carrier wave isolator is serially connected between V-type artificial mains network and AC purified voltage stabilized power source;
The anti-interference on-line testing method of described iii carrier communication, the core of the anti-interference test of carrier communication is noise simulator, and the core of noise simulator is AWG (Arbitrary Waveform Generator), can produce various noise signals.Applied power amplifier and electrical network produce the zero cross fired signal with the frequency trigger equipment, and the triggering noise signal can simulating grid co-channel interference and alien frequencies interference with frequently exporting or alien frequencies output.
Described iv low-voltage circuit impedance variation method of testing, the core of low-voltage circuit testing impedance is load simulator, by on-line testing household electrical appliance impedance operator, set up corresponding electrical quantity model, again according to the different topological structure form of low-voltage power line distribution of impedance, by predefined control device, analog line impedance variation characteristic.
Advantage of the present invention: proposed a kind of new method and the implementation thereof of low-voltage powerline carrier communication test, so that the carrier communication product has had a test platform that can compare, certain insurance and supervision effect has been played in large scale application to carrier wave.Adopted artificial mains network's parameter model of GB/T 6113F2 regulation, standardization level is high, and test data has comparativity; Adopt the way that changes the carrier communication channel parameter to test, avoided the test problem that adopts different carrier communication schemes to bring; Adopt two-way with the phase-locked insulating power supply of frequency system, realized online sensitivity test; Adopted noise simulator simulation actual noise interference environment, so that test can carry out at any time, not affected by the environment factor such as outside weather; Adopted the line impedance simulator, can simulate actual track impedance variation environment, so that carrier communication becomes possibility to the analysis that line impedance changes.
Description of drawings
Accompanying drawing 1 is the low voltage power cord carrier communication test system composition frame chart.
The schematic diagram of accompanying drawing 2 carrier wave transmission level on-line testing methods.
3 one kinds of artificial mains network's schematic diagrames of accompanying drawing.
The schematic diagram of accompanying drawing 4 carrier wave receiving sensitivity on-line testing methods.
The schematic diagram of the anti-interference on-line testing method of accompanying drawing 5 carrier communications.
The schematic diagram of accompanying drawing 6 low-voltage circuit impedance variation on-line testing methods.
Embodiment
Contrast accompanying drawing 1, its structure is that the carrier signal output of the carrier sending device in the pilot system and the signal input part of programmable attenuator join; The signal input part of the signal output part of programmable attenuator and tested carrier wave receiving system joins; Tested carrier wave receiving system is after receiving correct carrier signal and decoding, and the signal output part by tested carrier wave receiving system sends carrier signal again and replys communication; The carrier level end that the carrier level that carrier sending device sends and tested carrier wave receiving system send is all measured by artificial mains network's access spectrum analyzer that is coupled after the sampling; Computer reads the carrier level test data by the spectrum analyzer interface; Input one tunnel and the noise simulator of tested carrier wave receiving system join, and noise simulator connects computer control; Another road of the input of tested carrier wave receiving system and load simulator join, and load simulator connects computer control; The output of power conditioner is delivered to respectively two-way carrier wave isolated power supply, guarantee the two-way power supply with frequently phase-locked work and have the carrier wave buffer action, as same frequently phase-locked low voltage experiment carrier communication circuit, wherein the power supply of one tunnel isolation is as the working power of tested carrier sending device, and another road power supply is as the working power of tested carrier wave receiving system.Oscilloscope is used for observing carrier signal.
The low-voltage powerline carrier communication test method comprises following method of testing:
I carrier wave transmission level on-line testing method:
Contrast Fig. 2, the control of carrier sending device is finished by computer interface.When computer sends the carrier communication order, carrier sending device sends carrier signal, carrier signal is transmitted in carrier channel, be sent to tested carrier wave receiving system, after the carrier wave receiving system receives correct carrier signal and decoding, send again carrier signal and carry out response mode communication, consisted of like this citation form of carrier communication.
The carrier level that the carrier level that carrier sending device sends and carrier wave receiving system send is all taken a sample by coupling device by the artificial mains network, is measured by the frequency spectrograph receiver.
A kind of artificial mains network as shown in Figure 3, the artificial mains network has provided a suitable test environment, guarantees that test data has comparativity.
Spectrum analyzer has high sensitivity great dynamic range receiving ability, suitable the frequency spectrograph parameter is set can obtains correct test result.Computer reads the carrier level test number by the frequency spectrograph interface.
Ii carrier wave receiving sensitivity on-line testing method:
Contrast Fig. 4, the control of carrier sending device is finished by computer interface.When computer sends the carrier communication order, carrier sending device sends carrier signal, carrier signal is sent to tested carrier wave receiving system through the carrier signal programmable attenuator, the carrier wave receiving system sends carrier signal again and carries out response mode communication after receiving correct carrier signal and decoding.
The communication process of computer control carrier transmitting-receiving device, number of times and the wrong yardage of record sending and receiving, the size of the calculating communication error rate.
The total yardage (formula 1) of yardage ÷ communication of the communication error rate=communication failure
Programmable attenuator is subjected to computer control, the attenuation of programmable attenuator can change, be used for regulating the size of carrier wave transmitted signal, also just changed the signal to noise ratio of carrier wave receiving terminal, cause that the carrier communication error rate rises, when reaching the error rate of setting, the pad value of this moment is relevant with receiving sensitivity.Computer reads attenuator numerical value, calculates the carrier wave receiving sensitivity according to carrier wave transmission level and attenuation value.
Carrier wave receiving sensitivity=carrier wave transmission level ÷ attenuation multiple (formula 2)
Attenuation multiple=10
Pad value/20(formula 3)
The carrier wave isolator is serially connected between V-type artificial mains network and AC purified voltage stabilized power source.
The anti-interference on-line testing method of iii carrier communication:
Contrast accompanying drawing 5, at the input of tested carrier wave receiving system, noise simulator applies certain other noise signal of level the carrier signal that carrier sending device sends is disturbed, and noise simulator is subjected to computer control.
Noise simulator can produce white noise, coloured background noise, narrow-band noise, synchronous and asynchronous periodic noise signal and random impulsive noise, and the output frequency of noise simulator and amplitude can change.Computer has preseted 1 grade to 30 grades noise intensity, output level, output frequency and waveform that corresponding noise simulator is different.Can revise as required noise intensity definition standard.
In the carrier communication process, apply the noise of different stage, the error rate delta data under recording noise disturbs is as the basis for estimation of the anti-noise jamming ability of carrier transmitting-receiving equipment.
The computational methods of the carrier communication error rate are equal to communication error rate calculation formula in the carrier wave receiving sensitivity.
Iv low-voltage circuit impedance variation on-line testing method:
Contrast accompanying drawing 6, at the input of carrier wave receiving system, load simulator is attempted by on the carrier loop, analog electrical line of force load impedance, load simulator is subjected to computer control.
Load simulator can be set the topological structure of dissimilar impedances, according to the cell impedance various combination model with connecting in parallel, produces the equiva lent impedance under the carrier frequency, and is redefined for 1 grade to 30 grades impedance model with computer.Can revise as required impedance model definition key element.
In the carrier communication process, change the rank of load simulator, also just changed the environment parameter of carrier communication channel, also just changed the communication error rate, the error rate under the different impedance ranks of computer recording, thus judge the anti-line load impedance variation of carrier transmitting-receiving equipment ability.
The computational methods of the carrier communication error rate are equal to communication error rate calculation formula in the carrier wave receiving sensitivity.