CN102901849A - Distorted power grid signal simulating device - Google Patents

Abstract

The invention relates to a distorted power grid signal simulating device. The device comprises an upper computer unit, a signal generation unit, a modulation unit and a filtering unit, wherein the upper computer unit communicates with the signal generation unit to transmit signal fundamental wave and frequency, amplitude value and phase deviation parameter of harmonics of each time in real time; the signal generation unit is used for acquiring the required analogue distorted power grid signal by overlapping corresponding times of harmonic signals based on the basic wave according to the requirements on the generated distorted power grid voltage and the current signal, and inputting the analogue distorted power grid signal to the modulation unit; the modulation unit is used for finishing pulse-width modulation (PWM) of the analogue distorted power grid signal and outputting the waveform of the distorted power grid PWM to the filtering unit; and the filtering unit is used for filtering high-frequency harmonic components in the PWM waveform to acquire the required analogue distorted power grid voltage and current signal. The device is simple in composition and principle and low in cost; and moreover, with the device, the steady-state distortion of the power grid and the current signal can be simulated, and the dynamic distortion of the power grid and the current signal can be simulated.

Description

Network deformation signal imitation device

Technical field

The present invention relates to a kind of network deformation signal imitation device, specifically, relate to a kind of hyperchannel weak electric signal source apparatus that can simulate single-phase, three-phase even heterogeneous network deformation voltage and current.

Background technology

During the problems such as phaselock technique, Technology of Frequency Measurement by Using and power measurement in research electrical network when distortion, need can the simulating grid voltage and current stable state and the signal source of dynamical distortion.So-called steady-state distortion refers to that amplitude, phase place and the frequency of first-harmonic and each harmonic do not change; So-called dynamical distortion refers to that amplitude, phase place and the frequency dynamic ground of first-harmonic and each harmonic changes.Existing various relay protection of power system tester only can be simulated the distorted signal of stable state; although what various signal generators had can export random waveform; but; the passage of the output of a signal generator is generally two; be difficult to realize the output of multichannel transient distortion signal; many signal generators are combined, and nonsynchronous problem between the signal can occur again.

Summary of the invention

The object of the invention is to the problems referred to above for existing electrical network distorted signal analogue means existence, the analogue means of the various complex electric network signals of a kind of simulation based on the PWM technology is provided.

Technical scheme of the present invention is: a kind of analogue means of electrical network distorted signal, this device comprises host computer unit, signal generation unit, modulating unit and filter unit, wherein, communicate by letter with the signal generation unit in the host computer unit, transmit in real time the parameters such as amplitude, frequency and phase place of first-harmonic and each harmonic, the signal generation unit is according to the requirement of the network deformation voltage and current signal of required generation, according to formula

Produce one road electrical network distortion simulation signal, other road signal also can be according to producing after the corresponding parameter of this formula substitution.Wherein, A _iBe fundamental voltage amplitude, A _iBe i subharmonic amplitude, ω ₁Be the angular frequency of fundamental signal, θ ₁Be the initial phase of fundamental signal, ω _iBe the angular frequency of i subharmonic, θ _iIt is the initial phase of i subharmonic.The network deformation signal that the signal generation unit is produced outputs to modulating unit, modulating unit is finished the PWM modulation of simulating signal, output PWM ripple is to filter unit, and the high-frequency harmonic composition in the filter unit filtering PWM waveform obtains needed simulation network deformation voltage and current signal.

Beneficial effect of the present invention is: (1) network deformation signal imitation of the present invention device not only can simulating grid and current signal steady-state distortion, and can simulate their dynamical distortion; (2) the present invention's distortion simulation signal of output multi-channel voltage and current according to actual needs, and has an extensibility, keep synchronously between the multiple signals of expansion, and existing signal generator and relay protection of power system tester can't be accomplished this point; (3) system's composition of the present invention and principle are simple, and cost is low; (4) interface of output signal of the present invention is weak electric signal, and is the same with signal source, need not pass through sensor and ratio amplifying circuit, directly can receive signal acquisition and processing system and analyze and process.

Description of drawings

Fig. 1 is structural representation of the present invention.

Fig. 2 is the network deformation signal schematic representation of the standard analog that obtains of Matlab/simulink emulation.

Fig. 3 is the network deformation signal schematic representation that utilizes the present invention's simulation that oscillograph observation obtains.

Fig. 4 is the phase distortion simulating signal fft analysis result schematic diagram that the present invention obtains.

Embodiment

The invention will be further described below in conjunction with accompanying drawing.

A kind of network deformation signal imitation device, this device comprises host computer unit 1, signal generation unit 2, modulating unit 3 and filter unit 4, wherein, communicate by letter with signal generation unit 2 in host computer unit 1, real-time transmission of signal fundamental frequency, the amplitude of first-harmonic and each harmonic and phase deviation parameter, signal generation unit 2 is according to the network deformation voltage and current semaphore request of required generation, harmonic signal at the corresponding number of times of first-harmonic basis stack, write frequency according to formula (1), phase place and amplitude sudden change program, obtain required simulation network deformation signal, input to modulating unit 3, modulating unit 3 is finished the PWM modulation of simulating signal, output network deformation PWM waveform is to filter unit 4, and the high-frequency harmonic composition in the filter unit 4 filtering PWM waveforms obtains needed three-phase simulation network deformation signal.

$\sin \_f_A=A_1\·\sin ({\mathrm{\ω}}_{1}t+{\mathrm{\θ}}_1)+\underset{i=2}{\overset{N}{\mathrm{\Σ}}}{A}_i\·\sin ({\mathrm{\ω}}_{i}t+{\mathrm{\θ}}_i)---\left(1\right)$

Wherein, A ₁Be fundamental voltage amplitude, A _iBe i subharmonic amplitude, ω ₁Be the angular frequency of fundamental signal, θ ₁Be the initial phase of fundamental signal, ω _iBe the angular frequency of i subharmonic, θ _iIt is the initial phase of i subharmonic.

Consist of example with the three-phase simulation network deformation signal shown in the table 1 and illustrate that the present invention simulates network deformation voltage and the current signal under the various situations.

Table 1 is that three-phase simulation network deformation signal forms tabulation

Fig. 2 is the standard three-phase network deformation signal that Matlab/simulink emulation obtains, and Fig. 3 is the distorted signal that the weak electric signal source apparatus of the present invention that utilizes oscillograph observation to obtain produces.Very good by relatively finding out distorted signal and the standard distorted signal goodness of fit.

Fig. 4 is for to simulate mutually the result that the network deformation signal carries out fft analysis to one, this shows, A simulates mutually the network deformation signal and comprises 50Hz first-harmonic, 3 times, 5 times, 7 subharmonic, and the amplitude of each ingredient of A phase distortion signal is identical in the voltage magnitude of each ingredient and the table 1.This has illustrated the validity of the scheme that the application proposes.

Claims (2)

1. network deformation signal imitation device, it is characterized in that: this device comprises the host computer unit, the signal generation unit, modulating unit and filter unit, wherein, communicate by letter with the signal generation unit in the host computer unit, the frequency of real-time transmission of signal first-harmonic and each harmonic, amplitude and phase deviation parameter, the signal generation unit is according to the network deformation voltage and current semaphore request of required generation, harmonic signal at the corresponding number of times of first-harmonic basis stack, obtain required simulation network deformation signal, input to modulating unit, modulating unit is finished the PWM modulation of simulation network deformation signal, output network deformation PWM waveform is to filter unit, high-frequency harmonic composition in the filter unit filtering PWM waveform obtains needed simulation network deformation voltage and current signal.

2. weak electric signal source apparatus according to claim 1 is characterized in that: the expression formula that the signal stack is adopted is:

$\sin \_f_A=A_1\·\sin ({\mathrm{\ω}}_{1}t+{\mathrm{\θ}}_1)+\underset{i=2}{\overset{N}{\mathrm{\Σ}}}{A}_i\·\sin ({\mathrm{\ω}}_{i}t+{\mathrm{\θ}}_i)$

Wherein, A ₁Be fundamental voltage amplitude, A _iBe i subharmonic amplitude, ω ₁Be the angular frequency of fundamental signal, θ ₁Be first-harmonic initial phase, ω _iBe the angular frequency of i subharmonic, θ _iIt is the initial phase of i subharmonic.

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