Method for reduction of non-linear current distortion in non-linear composite load and device for its implementation

FIELD: electricity.

SUBSTANCE: invention is related to the field of electric engineering and may be used in industries for in-process control of articles represented by non-linear composite loads. Method for reduction of a non-linear current distortion in a non-linear composite load is characterised by representation of alternating current setting current in the circuit with the non-linear composite load as Fourier series, calculation of coefficients for these Fourier series when compensation is made for higher harmonics formed in result of the impact of the non-linear composite load by means of Fourier inversion and on the basis of calculated coefficients formation of alternating voltage, which sets current in the circuit with the non-linear composite load with a less level of non-linear distortion. The device for reduction of the non-linear current distortion in the non-linear composite load includes an amplifier, a control unit, a digital-to-analogue converter, the non-linear composite load, an analogue-to-digital converter and a current sensor.

EFFECT: reduction of the level of the non-linear current distortion in the circuit with the non-linear composite load and increase of efficiency factor.

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The invention relates to the field of electronic technology and can be used in the production of the technological control products, representing complex nonlinear load, as well as research experimental facilities, which include elements representing complex nonlinear load.

There is a method of reducing non-linear distortion of a device using feedback. The feedback parameters are chosen in such a way as to compensate for nonlinearity of a particular device, for example, complex nonlinear load. For compensation of nonlinear distortion signal is received from the circuit with nonlinear device via feedback (US 7020447, IPC H04B 1/04, publ. 28.03.2006).

The disadvantage of this method is the necessity of experimental parameters selection feedback for each nonlinear device load, and, consequently, the need for changes in realizing it device.

A device for reducing the harmonic distortion of the current in the nonlinear complex load, consisting of serially connected non-linear distortion in the current. You will need to use an AC voltage, which sets the current in the circuit with nonlinear whom the integrated load with a large amplitude range and output power, greatly exceeding the allocated load (Horowitz, Whill. Art circuitry, so 1, Per. s angl. edited by Halperin M.V. M.: Mir, 1986. P.47 - 55).

A disadvantage of the known device is the low efficiency.

The technical result is to reduce the level of harmonic distortion of the current flowing in a circuit with nonlinear complex load and increase the efficiency of the device, which requires the transmission of harmonic current through the nonlinear complex load.

The invention consists in that in the method of reducing harmonic distortion of the current in the nonlinear complex load AC voltage, which sets the current in the circuit with nonlinear complex load, are in the form of Fourier series, calculate the coefficients of this Fourier series, in which the compensation of the higher harmonic current generated due to the influence of nonlinear complex load, then using the inverse Fourier transform on the basis of the calculated coefficients form an alternating voltage which sets the current in the circuit with nonlinear complex load with a lower level of nonlinear distortion. The set of coefficients of Fourier series, in which the harmonic distortion of the current minimum, RAS is citybeat by direct brute force. The set of coefficients of Fourier series, in which the harmonic distortion of the current minimum, calculated using the methods of mathematical programming.

Device for reducing the harmonic distortion of the current in the nonlinear complex load includes a control unit connected to the digital to analog Converter, the output soedinenii with the input of the amplifier, the output of which is connected to series-connected complex nonlinear load and a current sensor connected to analog-to-digital Converter connected to the control unit.

In the inventive solution, the reduction of harmonic distortion of the current in the nonlinear complex load is achieved by selection of the form of alternating voltage at the output of the source electrical signal, which sets the current in the circuit with nonlinear complex load, which results in the payment of higher harmonics of the current generated due to the influence of nonlinear complex load. Selection of the form of the voltage is carried out by determining the corresponding coefficients of the Fourier series, which can decompose this signal. The role of these factors are the amplitude and initial phase of the harmonics of the Fourier series. Selection of the coefficients of the Fourier series can be made by direct enumeration or by using the appropriate mathematical methods, customizemenu methods of mathematical programming. In the practical application of the described method uses a finite number of harmonics of the Fourier series. This number is determined based on the specific conditions of use of this method.

Figure 1 shows the functional diagram of the device for reducing the harmonic distortion of the current in the nonlinear complex load.

The device includes a control unit 1 connected to the d / a Converter 2. The output of the digital to analogue Converter 2 is connected to the input of the amplifier 3. To the output of amplifier 3 is connected in series United complex non-linear load 4 and the current sensor 5. The current sensor 5 is connected to an analog-to-digital Converter 6, which is connected to the control unit 1.

The method is as follows. D / a Converter 2 and the amplifier 3 are a source of an electrical signal, which sets the current in the circuit with complex non-linear load 4. You can use as a source of an electrical signal only d / a Converter 2, an amplifier 3. The control unit 1 performs the calculation of the coefficients of the Fourier series (amplitudes and initial phases of the harmonics), and based on them using the inverse Fourier transform generates a signal, discrete samples which are received at the digital-to-analog Converter 2. Digital to analogue Preobrazovatel is 2 based on information received from the control unit 1 discrete samples of the signal generates a voltage corresponding form. This voltage is then amplified by the amplifier 3 and is fed to a complex load 4, creating a current through it. The waveform of this current is registered by the analog-digital Converter 6 from the current sensor 5 and is transmitted to the control unit 1. The control unit 1 by the received current waveform calculates the total harmonic current distortion for each set of coefficients of Fourier series and defines a set of these coefficients, in which the harmonic distortion of the current minimum. The set of coefficients of Fourier series, in which the harmonic distortion of the current minimum, can be calculated by the control unit 1 by the brute force or using appropriate mathematical methods. Based on this set by using the inverse Fourier transform of the control unit 1 calculates the shape of the voltage applied to complex non-linear load 4, in which the harmonic distortion of the current flowing through this complex nonlinear load, minimum. D / a Converter 2 and the amplifier 3 and then reproduce the voltage of this form and submit it to the complex non-linear load 4.

The proposed solution in comparison with the known solutions can reduce the level of harmonic distortion of the current flowing in a circuit with nonlinear complex load, by selecting this form peremennog the voltage, sets the current in the circuit with nonlinear complex load, in which there is a compensation of higher harmonics of the current generated due to the influence of nonlinear complex load. The proposed solution allows to increase the efficiency of the device by eliminating the use of cascaded nonlinear complex loading large linear resistance, so all the power is applied to complex nonlinear load.

1. The way to reduce harmonic distortion of the current in the nonlinear complex load, characterized in that the alternating voltage, which sets the current in the circuit with nonlinear complex load, are in the form of Fourier series, calculate the coefficients of this Fourier series, in which the compensation of the higher harmonic current generated due to the influence of nonlinear complex load, then using the inverse Fourier transform on the basis of the calculated coefficients form an alternating voltage which sets the current in the circuit with nonlinear complex load with a lower level of harmonic distortion.

2. The method according to claim 1, characterized in that the set of coefficients of Fourier series, in which the harmonic distortion of the current minimum, calculated by direct brute force.

3. The method according to claim 1, characterized those who, the set of coefficients of Fourier series, in which the harmonic distortion of the current minimum, calculated using the methods of mathematical programming.

4. Device for reducing the harmonic distortion of the current in the nonlinear complex load, including the amplifier, wherein the control unit is connected to digital-to-analog Converter, the output soedinenii with the input of the amplifier, the output of which is connected to series-connected complex nonlinear load and a current sensor connected to analog-to-digital Converter connected to the control unit.