阅读说明：本技术 即插即用的物联网电力宽带载波hplc系统 (Plug-and-play Internet of things power broadband carrier HP L C system ) 是由 叶丹 孙侃 于 2020-03-25 设计创作，主要内容包括：本申请涉及一种即插即用的物联网电力宽带载波系统,其特征在于,包括：分析单元,用于对智能配电网中的噪声来源根据波形特征划分为背景噪声、窄带噪声和脉冲噪声；建模单元,用于对分析单元确定的噪声来源分别建立其对物联网电力宽带载波系统的噪声模型；抗扰单元,用于根据建立的噪声模型相应地消除对应元件对物联网电力宽带载波系统的噪声影响。(The application relates to a plug-and-play's thing networking electric power broadband carrier system, its characterized in that includes: the analysis unit is used for dividing a noise source in the intelligent power distribution network into background noise, narrow-band noise and impulse noise according to waveform characteristics; the modeling unit is used for respectively establishing noise models of the noise sources determined by the analysis unit on the Internet of things power broadband carrier system; and the anti-interference unit is used for correspondingly eliminating the noise influence of the corresponding element on the Internet of things electric broadband carrier system according to the established noise model.)

1. The utility model provides a plug-and-play's thing networking electric power broadband carrier system which characterized in that includes:

the analysis unit is used for dividing a noise source in the intelligent power distribution network into background noise, narrow-band noise and impulse noise according to waveform characteristics;

the modeling unit is used for respectively establishing noise models of the noise sources determined by the analysis unit on the Internet of things power broadband carrier system;

and the anti-interference unit is used for correspondingly eliminating the noise influence of the corresponding element on the Internet of things electric broadband carrier system according to the established noise model.

2. The internet of things power broadband carrier system of claim 1, wherein the analysis unit determines impulse noise to include periodic impulse noise and random impulse noise.

3. The internet of things electric broadband carrier system of claim 2, wherein the analysis unit determining periodic impulse noise comprises: periodic impulse noise synchronous with the grid frequency, periodic impulse noise asynchronous with the grid frequency.

4. The internet-of-things electric broadband carrier system of claim 3, wherein the analysis unit determines that a silicon controlled rectifier generates periodic impulse noise synchronized with the grid frequency, which is turned on and off once each within one power frequency period, thus generating 2 impulse noises.

5. The internet of things electric broadband carrier system of claim 4, wherein the modeling unit models SCR noise for periodic impulse noise generated by a silicon controlled rectifier that is synchronous with a grid frequency.

6. The internet of things electric broadband carrier system of claim 5, wherein the modeling unit modeling SCR noise generated by a silicon controlled rectifier and synchronized with grid frequency periodic impulse noise comprises:

is provided with

n (t) is a time function of the noise of a single pulse, t is the time instant, A is the amplitude of the pulse, τ is the time constant of the decay, f is the pulse frequency,is the initial phase.

7. The internet of things electric broadband carrier system of claim 5, wherein the modeling unit modeling SCR noise generated by a silicon controlled rectifier and synchronized with grid frequency periodic impulse noise comprises:

is provided with

n (t) is a time function of the noise of a single pulse, t is the time, t_openIs the on time, t_closeFor the moment of turn-off, A_openIs the amplitude of the pulse conduction segment, A_closeIs the amplitude of the off-pulse segment, tau is the time constant of decay, f is the pulse frequency,in order to switch on the initial phase,to turn off the initial phase.

8. The internet of things electric broadband carrier system of claim 5, wherein the modeling unit modeling SCR noise generated by a silicon controlled rectifier and synchronized with grid frequency periodic impulse noise comprises:

is provided with

n (t) is a time function of the noise of a single pulse, t is the time, t_openIs the on time, t_closeFor the moment of turn-off, A_openIs the amplitude of the pulse conduction segment, A_closeAmplitude of the pulse-off section, τ_openTime constant, τ, for the decay of the conduction band_closeThe time constant for the decay of the off-segment, f is the pulse frequency,in order to switch on the initial phase,to turn off the initial phase, n is 0,1,2 …, and T is the period of the power frequency signal.

9. The internet of things electric broadband carrier system of claim 5, wherein the modeling unit modeling SCR noise generated by a silicon controlled rectifier and synchronized with grid frequency periodic impulse noise comprises:

is provided with

M silicon controlled rectifiers are connected into the power grid, and n (t) is a single silicon controlled rectifierTime function of impulse noise, t being the time, t_openIs the on time, t_closeFor the moment of turn-off, A_openIs the amplitude of the pulse conduction segment, A_closeAmplitude of the pulse-off section, τ_openTime constant, τ, for the decay of the conduction band_closeThe time constant for the decay of the off-segment, f is the pulse frequency,in order to switch on the initial phase,to turn off the initial phase, n is 0,1,2 …, and T is the period of the power frequency signal.

Technical Field

The application relates to the technical field of next generation information network industry, in particular to a plug-and-play Internet of things Power broadband Carrier HP L C (High-speed Power L ine Carrier) system.

Background

The HP L C is a high-speed power line carrier, also called a broadband power line carrier, and is a broadband power line carrier technology for data transmission on a low-voltage power line, the broadband power line carrier communication network is a communication network for realizing the aggregation, transmission and interaction of power consumption information of low-voltage power users by taking a power line as a communication medium, the broadband power line carrier mainly adopts an Orthogonal Frequency Division Multiplexing (OFDM) technology, a frequency band is 2MHz-12MHz, compared with the traditional low-speed narrowband power line carrier technology, the HP L C technology has large bandwidth and high transmission rate, and can meet higher requirements of low-voltage power line carrier communication.

Fig. 1 shows a power line channel noise amplitude-frequency characteristic diagram, and it can be seen that a power line channel is a nonlinear time-varying, fast fading system, and the estimation of channel delay and the cancellation of burst noise interference are very challenging works, a high data rate requires a high signal-to-noise ratio, and for an OFOM technology that operates well in wireless communication, the conventional HP L C cannot work reliably.

Noise characteristics are one of the important factors affecting the transmission of carrier communication signals. The noise of conventional power distribution networks is mainly composed of colored background noise and pulses. The conclusion that can be drawn by comparing the intelligent distribution network with the traditional distribution network is as follows: due to the large number of applications based on power electronics, the former will have far more sources of noise synchronized with the grid frequency than the latter, and the influence is more serious.

Disclosure of Invention

In order to overcome the problems in the related art, the application provides a plug-and-play internet of things power broadband carrier HP L C system.

According to the embodiment of the application, a plug-and-play Internet of things power broadband carrier system is provided, which is characterized by comprising:

the analysis unit is used for dividing a noise source in the intelligent power distribution network into background noise, narrow-band noise and impulse noise according to waveform characteristics;

the modeling unit is used for respectively establishing noise models of the noise sources determined by the analysis unit on the Internet of things power broadband carrier system;

and the anti-interference unit is used for correspondingly eliminating the noise influence of the corresponding element on the Internet of things electric broadband carrier system according to the established noise model.

Preferably, the analysis unit determines that the impulse noise includes periodic impulse noise and random impulse noise.

Preferably, the determining of the periodic impulse noise by the analysis unit includes: periodic impulse noise synchronous with the grid frequency, periodic impulse noise asynchronous with the grid frequency.

Preferably, the evaluation unit determines that a periodic impulse noise synchronized to the grid frequency is generated by the silicon controlled rectifier, which is switched on and off once in each case in a power frequency period, so that 2 impulse noises are generated.

Preferably, the modeling unit establishes an SCR noise model for periodic impulse noise generated by the silicon controlled rectifier and synchronized with the grid frequency.

Preferably, the modeling unit for establishing an SCR noise model for periodic impulse noise generated by the silicon controlled rectifier and synchronized with the grid frequency includes:

is provided with

n (t) is a time function of the noise of a single pulse, t is the time instant, A is the amplitude of the pulse, τ is the time constant of the decay, f is the pulse frequency,is the initial phase.

Preferably, the modeling unit for establishing an SCR noise model for periodic impulse noise generated by the silicon controlled rectifier and synchronized with the grid frequency includes:

is provided with

n (t) is a time function of the noise of a single pulse, t is the time, t_openIs the on time, t_closeFor the moment of turn-off, A_openIs the amplitude of the pulse conduction segment, A_closeIs the amplitude of the off-pulse segment, tau is the time constant of decay, f is the pulse frequency,in order to switch on the initial phase,to turn off the initial phase.

Preferably, the modeling unit for establishing an SCR noise model for periodic impulse noise generated by the silicon controlled rectifier and synchronized with the grid frequency includes:

is provided with

n (t) is a time function of the noise of a single pulse, t is the time, t_openIs the on time, t_closeFor the moment of turn-off, A_openIs the amplitude of the pulse conduction segment, A_closeAmplitude of the pulse-off section, τ_openTime constant, τ, for the decay of the conduction band_closeThe time constant for the decay of the off-segment, f is the pulse frequency, to turn off the initial phase, n is 0,1,2 …, and T is the period of the power frequency signal.

Preferably, the modeling unit for establishing an SCR noise model for periodic impulse noise generated by the silicon controlled rectifier and synchronized with the grid frequency includes:

is provided with

M silicon controlled rectifiers are connected into the power grid, n (t) is a time function of single pulse noise, t is time, t is_openIs the on time, t_closeFor the moment of turn-off, A_openIs the amplitude of the pulse conduction segment, A_closeAmplitude of the pulse-off section, τ_openIs the time constant of the decay of the on-state segment,τ_closethe time constant for the decay of the off-segment, f is the pulse frequency,in order to switch on the initial phase,to turn off the initial phase, n is 0,1,2 …, and T is the period of the power frequency signal.

The technical scheme provided by the embodiment of the application has the following beneficial effects that the plug-and-play Internet of things power broadband carrier HP L C system is provided, through analyzing the noise waveform in the intelligent power distribution network, three different noise sources, namely background noise, narrow-band noise and pulse noise are mainly found, and through establishing different noise models for the three noise sources respectively, corresponding anti-interference measures are realized, so that the noise interference in the intelligent power distribution network is remarkably reduced, and the plug-and-play Internet of things power broadband carrier HP L C system is realized.

Additional aspects and advantages of the present application will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the present application. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and together with the description, serve to explain the principles of the invention.

Fig. 1 is a schematic diagram illustrating a plug-and-play internet of things power broadband carrier HP L C system, according to an example embodiment;

FIG. 2 illustrates a schematic diagram of a coaxial cable shown in accordance with an exemplary embodiment;

FIG. 3 illustrates a schematic diagram of an L C L filter circuit shown in accordance with an exemplary embodiment;

FIG. 4 illustrates a schematic diagram of a single phase-band high-frequency impedance model of an asynchronous machine model, shown in accordance with an exemplary embodiment;

FIG. 5 illustrates a schematic diagram of an asynchronous machine model full phase band high frequency impedance model in accordance with an exemplary embodiment;

fig. 6 is a schematic diagram illustrating a plug-and-play internet of things power broadband carrier HP L C system, according to an example embodiment;

FIG. 7 illustrates a schematic diagram of a noise source, shown in accordance with an exemplary embodiment.

Detailed Description

Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the invention, as detailed in the appended claims.

The following disclosure provides many different embodiments, or examples, for implementing different features of the application. In order to simplify the disclosure of the present application, specific example components and arrangements are described below. Of course, they are merely examples and are not intended to limit the present application. Further, the present application may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. Further, examples of various specific processes and materials are provided herein, but one of ordinary skill in the art may recognize the applicability of other processes and/or the use of other materials. In addition, the structure of a first feature described below as "on" a second feature may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features are formed between the first and second features, such that the first and second features may not be in direct contact.

In the description of the present application, it should be noted that, unless otherwise specified and limited, the terms "mounted," "connected," and "connected" are to be interpreted broadly, and may be, for example, a mechanical connection or an electrical connection, a communication between two elements, a direct connection, or an indirect connection via an intermediate medium, and specific meanings of the terms may be understood by those skilled in the art according to specific situations.

Fig. 1 is a schematic diagram illustrating a plug-and-play internet of things power broadband carrier HP L C system according to an exemplary embodiment, and as shown, includes:

the classification unit 10 is used for classifying elements in the intelligent power distribution network into power lines, a new energy system and online power equipment;

the modeling unit 20 is used for respectively establishing noise models of the elements determined by the classification unit on the internet of things power broadband carrier system;

and the anti-interference unit 30 is used for correspondingly eliminating the noise influence of the corresponding element on the internet of things power broadband carrier system according to the established noise model.

Compared with the traditional power distribution network, the intelligent power distribution network has the conclusion that due to the fact that a large number of applications based on power electronic equipment are adopted, the source of noise synchronous with the power grid frequency is far higher than that of noise synchronous with the power grid frequency, and the influence degree is more serious.

Preferably, the classification unit determines that the power line is a coaxial cable, and the modeling unit builds a coaxial cable model for the coaxial cable.

The transmission line is obviously one of the most important elements in the intelligent power distribution network, and the coaxial cable is most popular in cities according to the construction time of the current intelligent power distribution network. The preferred embodiment establishes the noise model for the coaxial cable, thereby having a good application range and being capable of better inhibiting the coaxial cable noise.

Fig. 2 illustrates a schematic diagram of a coaxial cable shown in accordance with an exemplary embodiment.

Preferably, the modeling unit building a coaxial cable model for the coaxial cable includes:

setting the attenuation constant

Setting a phase constant

Wherein R is₀、C₀、L₀The resistance, the capacitance and the inductance of the coaxial cable in unit length are respectively, omega is the angular frequency of a power grid fundamental wave, α represents the amplitude attenuation when a signal propagates along the coaxial cable, and β represents the phase change when the signal is transmitted along the coaxial cable.

Preferably, the modeling unit for establishing a coaxial cable model for the coaxial cable further includes:

is provided with

Is provided with

Is provided with

Wherein R and R are respectively the radius of an inner conductor of the coaxial cable, the inner radius of the outer shielding layer and the equivalent dielectric constant of the middle insulating medium layer; rho₁、ρ₂The resistivities of the inner conductor and the outer shielding layer of the coaxial cable respectively; mu.s₁、μ₂The magnetic permeability of the inner conductor and the outer shielding layer of the coaxial cable respectively; f is the frequency of the alternating current.

The inventor tests the HP L C system in the coaxial cable construction of a plurality of cities by utilizing the modeling, and finds that the noise condition obtained by the test is highly consistent with the established coaxial cable model, so that in the subsequent noise analysis and suppression, the noise model is utilized to obtain a good communication effect, and the error rate is greatly reduced.

Preferably, the classification unit determines that the new energy system is an L C L filter circuit, and the modeling unit establishes L C L filter circuit models for the L C L filter circuit.

Photovoltaic power generation systems are becoming an important direction of new energy systems, and occupy higher and higher proportion in intelligent power distribution networks. The inventor analyzes a photovoltaic power generation system, and finds that the photovoltaic power generation system is connected to a power distribution network through an inverter, and a high-frequency switching device in the inverter generates a large amount of harmonic components when working, and the harmonic components cause serious noise pollution after entering the power distribution network and seriously affect the power distribution network environment, so a filter is usually connected between the inverter and the power distribution network.

Fig. 3 shows a schematic diagram of an L C L filter circuit according to an exemplary embodiment in practice, a photovoltaic power generation system generally employs a L C L filter as shown in fig. 3, and the present embodiment provides good noise reduction of the L C L filter by noise modeling the L C L filter.

Preferably, the modeling unit establishes a L C L filter circuit model for the L C L filter circuit, including:

setting a filter capacitance

Arranging inverter side inductor

Setting a grid side inductance L_g＝kL_f；

Setting damping resistance

Wherein λ is_I、P_NIs the reactive power proportion and the rated active power of a filter capacitor in the filter circuit of L C L respectively_IPreferably within 5%; omega, U_NThe angular frequency and the fundamental voltage effective value of the fundamental wave of the power grid are respectively; u shape_dcIs a direct current side voltage, f_k、λ₂Is the switching frequency of a switching device in an L C L filter circuit, the ratio of the ripple current of a filter inductor to the rated current of a system, I_LfMeasuring rated operating current, lambda, for the inverter ac₂Preferably 15 to 25 percent; f. of_resIs the resonant frequency of the L C L filter circuit.

Preferably, the resonant frequency f_resIs 10 times of the grid fundamental frequency f to 1/2 switching frequency f_kNamely:

is provided with

Through a great deal of practice, the inventor finds that the harmonic current content of the frequency band is low, the amplitude of the harmonic is small, and the switching frequency of the inverter can be avoided.

Preferably, the modeling unit establishing a L C L filter circuit model for the L C L filter circuit further comprises:

is provided with

The L C L filter obtained by the modeling can well block the high-frequency carrier signal in the HP L C system, namely, no interference is generated on the carrier signal on the power grid side no matter what mode the photovoltaic power generation system works in.

Preferably, the classification unit determines that the online power equipment is an asynchronous motor, and the modeling unit builds an asynchronous motor model for the asynchronous motor.

The asynchronous motor is widely applied in various intelligent household appliances, and the preferred embodiment is favorable for remarkably reducing the interference of the intelligent appliance with the asynchronous motor to the HP L C system by establishing a noise model for the asynchronous motor.

Fig. 4 is a schematic diagram illustrating a single-phase-band high-frequency impedance model of an asynchronous machine model according to an exemplary embodiment, and as shown, the modeling unit preferably includes:

setting a single-phase-band high-frequency impedance model of the motor to include inter-turn capacitance C between windings_weThe resistances of the system and the iron core are equivalent to R_weEquivalent to L_weThe capacitance between the winding and the motor shell is equivalent to C_ceThe equivalent resistance between the winding and the motor housing is R_ce；

R_weAnd L_weThe first branch circuit is connected in series;

C_wethe first branch circuit is connected with the second branch circuit in parallel, and the two parallel points form an input end;

C_ceand R_ceThe series connection is two third branches which are respectively connected with two parallel points, and the other ends of the third branches form output ends.

The model of the asynchronous motor is complex, and in the low frequency case, the current flows through the stator winding of the motor, and the impedance of the motor is mainly determined by the resistance and leakage reactance of the electronic winding, the excitation impedance, the resistance and leakage reactance of the rotor winding, and the mechanical load.

Fig. 5 is a schematic diagram illustrating an all-phase-band high-frequency impedance model of an asynchronous machine model according to an exemplary embodiment, and preferably, as shown in fig. 5, the modeling unit further includes:

the high-frequency impedance model of all the phase bands of the motor is formed by connecting a plurality of single phase band high-frequency impedance models in parallel.

L1, L2 and L3 in fig. 5 are respectively used for noise modeling of three-phase windings of the asynchronous motor, so that the high-frequency impedance of the phase band of the whole asynchronous motor can be well simulated, and the communication quality of the HP L C system can be remarkably improved by using the noise model.

FIG. 6 is a schematic diagram illustrating a plug-and-play Internet of things power broadband carrier HP L C system according to an exemplary embodiment, and as shown, includes:

the analysis unit 15 is used for dividing a noise source in the intelligent power distribution network into background noise, narrow-band noise and impulse noise according to waveform characteristics;

the modeling unit 25 is used for respectively establishing noise models of the noise sources determined by the analysis unit for the internet of things power broadband carrier system;

and the anti-interference unit 35 is used for correspondingly eliminating the noise influence of the corresponding element on the internet of things power broadband carrier system according to the established noise model.

Compared with the traditional power distribution network, the intelligent power distribution network has the conclusion that due to the fact that a large number of applications based on power electronic equipment are adopted, the sources of synchronous noise of the power distribution network and the frequency of the power distribution network are far more than those of synchronous noise of the power distribution network and the frequency of the power distribution network, and the influence degree of the synchronous noise is more serious.

FIG. 7 illustrates a schematic diagram of a noise source, shown in accordance with an exemplary embodiment. As shown, preferably, the analysis unit determines that the impulse noise includes periodic impulse noise and random impulse noise.

As shown in fig. 7, preferably, the determining of the periodic impulse noise by the analysis unit includes: periodic impulse noise synchronous with the grid frequency, periodic impulse noise asynchronous with the grid frequency.

Due to the large number of applications based on various power electronic devices, compared with the traditional power distribution network, the noise of the intelligent power distribution network has much more serious influence on the periodic impulse noise synchronized with the frequency of the power grid. Therefore, a noise model is established below starting from the source of this type of noise.

Preferably, the evaluation unit determines that a periodic impulse noise synchronized to the grid frequency is generated by the silicon controlled rectifier, which is switched on and off once in each case in a power frequency period, so that 2 impulse noises are generated.

Preferably, the modeling unit builds an SCR noise model for periodic impulse noise generated by the silicon controlled rectifier SCR that is synchronous with the grid frequency.

Preferably, the modeling unit for establishing an SCR noise model for periodic impulse noise generated by the silicon controlled rectifier and synchronized with the grid frequency includes:

is provided with

n (t) is a time function of the noise of a single pulse, t is the time instant, A is the amplitude of the pulse, τ is the time constant of the decay, f is the pulse frequency,is the initial phase.

The above-described embodiment expresses a noise model of periodic impulse noise synchronized with the grid frequency in the form of a sinusoidal signal.

Preferably, the modeling unit for establishing an SCR noise model for periodic impulse noise generated by the silicon controlled rectifier and synchronized with the grid frequency includes:

is provided with

n (t) is a function of time of the individual impulse noise, t is the time instant,t_openis the on time, t_closeFor the moment of turn-off, A_openIs the amplitude of the pulse conduction segment, A_closeIs the amplitude of the off-pulse segment, tau is the time constant of decay, f is the pulse frequency,in order to switch on the initial phase,to turn off the initial phase.

The above embodiments represent a noise model of periodic impulse noise synchronized with the grid frequency over one power frequency period.

Preferably, the modeling unit for establishing an SCR noise model for periodic impulse noise generated by the silicon controlled rectifier and synchronized with the grid frequency includes:

is provided with

n (t) is a time function of the noise of a single pulse, t is the time, t_openIs the on time, t_closeFor the moment of turn-off, A_openIs the amplitude of the pulse conduction segment, A_closeAmplitude of the pulse-off section, τ_openTime constant, τ, for the decay of the conduction band_closeThe time constant for the decay of the off-segment, f is the pulse frequency,in order to switch on the initial phase,to turn off the initial phase, n is 0,1,2 …, and T is the period of the power frequency signal.

The above embodiments express a noise model of periodic impulse noise synchronized with the grid frequency over the entire time domain.

Preferably, the modeling unit for establishing an SCR noise model for periodic impulse noise generated by the silicon controlled rectifier and synchronized with the grid frequency includes:

is provided with

M silicon controlled rectifiers are connected into the power grid, n (t) is a time function of single pulse noise, t is time, t is_openIs the on time, t_closeFor the moment of turn-off, A_openIs the amplitude of the pulse conduction segment, A_closeAmplitude of the pulse-off section, τ_openTime constant, τ, for the decay of the conduction band_closeThe time constant for the decay of the off-segment, f is the pulse frequency,in order to switch on the initial phase,to turn off the initial phase, n is 0,1,2 …, and T is the period of the power frequency signal.

While it is possible to access multiple SCRs simultaneously within an intelligent power distribution grid, the above-described embodiments express a noise model of periodic impulse noise synchronized to the grid frequency over the entire time domain when m SCRs are accessed.

Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.

It will be understood that the invention is not limited to the precise arrangements described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the invention is limited only by the appended claims.