The filter is symmetrical components of the electrical signal

 

The invention relates to measurement devices, and more specifically to devices designed to highlight the components of the negative sequence voltage, and can be used in the composition of measurement devices, protection and alarm systems three-phase alternating current systems. The technical result consists in obtaining the full spectrum of the symmetric components of the electric signal at high speed and the accuracy of the measurement signal in the transient operation modes. The filter is symmetrical components of the electric signal terminal phase And the monitored signal is connected to the first input of the first adder, the clamp phase connected through inverting input of the first block of differentiation with the second input of the first adder, and after inverting input of the first proportional block with the third input of the first adder. The clamp phase connected through a non-inverting input of the second block of differentiation with the fourth input of the first adder, and after inverting input of the second proportional block with the fifth input of the first adder, the output of which through the non-inverting input of the third proportional block associated with the first output device. It contains the third is aim phase And is additionally connected to the first input of the second adder and the first input of the third adder. The clamp phase additionally connected to the second input of the second adder, the second input of the third adder is connected via a non-inverting input of the third block of differentiation, and with the third input of the third adder - via inverting input of the first proportional block. The output of the second adder through a non-inverting input of the fourth proportional block associated with the second output device, the terminal phase With additionally connected to the third input of the second adder, with the fourth input of the third adder is connected across the inverting input of the fourth block of differentiation, and with the fifth input of the third adder - via inverting input of the second proportional block, and the output of the third adder through a non-inverting input of the fifth proportional block associated with the third output device. When the device is in non-stationary mode, the first output component is formed of an electrical signal back to the zero sequence, the second output - zero sequence, the third output is a direct zero-sequence. 1 Il.

The invention relates to measurement devices, and more specifically to devices intended the TV measurement protection and alarm systems three-phase alternating current systems.

Known measuring transducer symmetric components of the electrical quantities (see ed. mon. The USSR 1432425 on CL IPC7G 01 R 29/16), containing the first phase-shifting element and an adder whose output is the output of the measuring transducer, the second and third phase shifting elements and four scaling (or proportional) block, and the input of each phase shifting element connected respectively to the terminal phase of the input electric quantity, the outputs of the first phase shifting element directly, and the second and third through the first and second scaling (proportional to) the blocks are connected to the inputs of the adder, the inputs of the second and third phase shifting elements combined with inputs respectively of the third and fourth scaling (proportional) blocks, the outputs are connected to the fourth and fifth inputs of the adder.

This device has a high accuracy when the frequency deviation of the monitored signal, but its performance is limited by the presence of inertial elements. In addition, the device prototype primary signal is converted not only on the Mach can lead to additional measurement error.

Known filter voltage reverse order (see RF patent 2159939 on CL IPC7G 01 R 29/16) closest to the claimed technical solution and adopted as a prototype, in which the terminal phase And connected to the first input of the adder, the clamp phase connected through inverting input of the first block of differentiation with the second input of the adder, and after inverting input of the first proportional block with the third input of the adder, the clamp phase connected through a non-inverting input of the second block of differentiation with the fourth input of the adder, and after inverting input of the second proportional block with the fifth input of the adder, the output of which is connected to the input of the third proportional block so the output of the third proportional block is the output device.

This filter, with its high performance and measurement accuracy, is able to allocate only the electrical signal reverse order, which limits its use in the devices of relay protection and automatics.

The present invention allows to obtain a complete range of symmetrical components of the electric signal at high speed and the accuracy of the measurement signals are the different components of an electrical signal, in which the terminal phase And the monitored signal is connected to the first input of the first adder, the clamp phase connected through inverting input of the first block of differentiation with the second input of the first adder, and after inverting input of the first proportional block with the third input of the first adder, the clamp phase connected through a non-inverting input of the second block of differentiation with the fourth input of the first adder, and after inverting input of the second proportional block with the fifth input of the first adder, the output of which through the non-inverting input of the third proportional block associated with the first access device further comprises third and fourth blocks differentiation, the second and third adders and the fourth and fifth proportional blocks, and terminal phase And is additionally connected to the first input of the second adder and to the first input of the third adder, the clamp phase additionally connected to the second input of the second adder, the second input of the third adder is connected via a non-inverting input of the third block of differentiation, and with the third input of the third adder - via inverting input of the first proportional block, and the output of the second summatory With additionally connected to the third input of the second adder, with the fourth input of the third adder is connected across the inverting input of the fourth block of differentiation, and with the fifth input of the third adder - via inverting input of the second proportional block, and the output of the third adder through a non-inverting input of the fifth proportional block associated with the third output device.

When the device is in non-stationary mode, the first output component is formed of an electrical signal reverse sequence, the second output - zero sequence, the third output - direct sequence.

All elements of the proposed device can be implemented on instantaneous elements, which ensures its high performance under all possible operating modes. The selection of the full range of symmetrical components of an electrical signal without converting the phase of the primary signal, in turn, significantly increases the functionality of the filter at high precision.

The drawing shows a block diagram of the filter is symmetrical components of the electrical signal.

The filter contains the first 1 and second 2 proportional blocks, the first 3, the third 4, the second 5 and the fourth 6 blocks trim is proportional to the blocks.

The terminal phase And the monitored signal is connected to the first input of the first adder 7, the first input of the second adder 8 and the first input of the third adder 9.

The clamp phase is connected to the second input of the second adder 8 directly to the second input of the first adder 7 is connected across the inverting input of the first block of differentiation 3, and with the second input of the third adder 9 is connected via a non-inverting input of the third block of differentiation 4. With the third input of the first adder 7 and the third input of the third adder 9 clamp phase connected through inverting input of the first proportional block 1.

The clamp phase is connected to the third input of the second adder 8 directly, with the fourth input of the first adder 7 is connected through a non-inverting input of the second block of differentiation 5, and the fourth input of the third adder 9 is connected across the inverting input of the fourth block of differentiation 6. With the fifth input of the first adder 7 and the fifth input of the third adder 9 clamp phase connected through inverting input of the second proportional block 2.

The output of the adder 7 is connected with reinvestiruet the entrance to the third proportional block 10, the output of which is the first wyhoon block 11, the output is the second output of the device in question.

The output of the adder 9 is connected to reinvestiruet entrance of the fifth proportional block 12, the output of which is the third release of the device in question Blocks 1-6 and 10-12 can be implemented using operational amplifiers. The gain is proportional to units 1, 2, 10-12 is determined by the ratio of the resistances at the input of the amplifier and the feedback circuit. Blocks differentiation 3-6 at the entrance contain a capacitor and feedback resistor.

The action of the device is based on the use of the method of symmetrical components. Let be a system of phases a, b and C, with clamps which are removed electrical signalsaccordingly, the values of which can be identified by the expressionwhere UandUband Uwith- the amplitude values of the signals of the phases a, b and C;angular frequency of the signal,= 2f; f is the signal frequency;1- the angle at which a signalahead signal2- polii with the specified method the expression for the component of the direct sequencean electrical signal phase And is
where a is the operator of the three-phase system;
e=2,71828... .

The expression for the component of the return sequencean electrical signal phase And is

The expression for the component of the zero sequencean electrical signal phase And is

Multiply the vector phase to three-phase system operators. Using the formula of the trigonometric sine decomposition of two angles, we get


A similar calculation was performed for phase:


Express in expressions (5) - (8) second components through derivative signalsrespectively


Substituting formula (9), (10) in expression (5) to (8), we obtain




where K12=was 2.7610-3C.

We will substitute the expressions (11), (14) in expression (2) and expression (12), (13) in expression (3), the result will be


where K3=1/3.

From expressions (15) and (16) it follows that for signal receiving direct or reverse order of one phase (e.g., phase A), must submit to the appropriate adder signal of this phase, scaled inverted signals of the other two phases (the scaling factor K1=0.5), the non-inverted scaled signal is the derivative of the signal phase and scaled inverted signal of the derivative of the signal phase for direct sequence, scaled inverted signal of the derivative of the signal phase and non-inverted scaled signal derived signal is phase - reversed sequence (at frequency voltage 50 Hz scale factor2=was 2.7610-3C). To obtain the zero-sequence signal enough to put in the appropriate adder signals of all three phases according to the expression (4).

In order to distinguish the signal direct, reverse or zero multiply by the scaling factor K3=1/3.

The device operates as follows.

The controlled signal is taken from the terminals of the phases a, b and C. the Signal uandwith clamp phase And goes directly to the first input of the first adder 7, the first input of the second adder 8 and the first input of the third adder 9. The signal ubwith clamp phase In forks to the inverting input of the first block of differentiation 3, at the non-inverting input of the third block of differentiation 4, to the inverting input of the first proportional block 1 and to the second input of the second adder 8.

In the first block of differentiation 3 signal ubis inverted, is differentiated and multiplied by the scaling factor K2. At the output of block 3 is formed by the signal-To2ubthat is supplied to the second input of the first adder 7.

In the third block of differentiation 4 signal ubdifferentiated and multiplied by the scaling factor K2. At the output of block 4 is formed by the signal +K2ubthat is supplied to the second input of the third adder 9.

In proportional block 1 signal phase ubinverted and scaled. The resulting signal-To1ubfrom the output of the block 1 is supplied to the third is to a non-inverting input of the second block of differentiation 5, to the inverting input of the fourth block of differentiation 6, to the inverting input of the second proportional block 2 and the third input of the second adder 8.

In the second block of differentiation 3 signal ucdifferentiated and multiplied by the scaling factor K2. At the output unit 5, a signal is generated +K2ucwhich is supplied to the fourth input of the first adder 7.

In the fourth block of differentiation 6 signal ucis inverted, is differentiated and multiplied by the scaling factor K2. At the output of block 6, a signal is generated To2ucthat comes to the fourth input of the third adder 9.

In proportional block 2 signal phase ucinverted and scaled. The resulting signal-To1ucfrom the output unit 2 is supplied to the fifth input of the first adder 7 and the fifth input of the third adder 9.

In the result of summation of the input signals at the output of the first adder 7 is formed a signal equal to three times the signal value of the negative sequence phase a, i.e. 3uA2that comes to the non-inverting input of the third proportional block 10, where it is multiplied by a factor K3. That is Mirovaya input signals at the output of the second adder 8, a signal is generated, equal to three times the value of the signal zero-sequence phase a, i.e. 3uA0that comes to the non-inverting input of the fourth proportional block 11, which is multiplied by a factor K3. Thus, the output of block 11, a signal is generated zero sequence uA0.

In the result of summation of the input signals at the output of the third adder 9 is formed a signal equal to three times the value of the signal direct sequence phase a, i.e. 3uA1that comes to the non-inverting input of the fifth proportional block 12, where it is multiplied by a factor K3. Thus, the output of block 12 is formed the signal direct sequence uA1.

The proposed device by introducing the third and fourth blocks differentiation, second and third adders, fourth and fifth proportional blocks, while the terminal phase And is additionally connected to the first input of the second adder and to the first input of the third adder, the clamp phase additionally connected to the second input of the second adder, the second input of the third adder is connected via a non-inverting input of the third block of differentiation, and with the third input and the third is C non-inverting input of the fourth proportional block associated with the second output device, terminal phase With additionally connected to the third input of the second adder, with the fourth input of the third adder is connected across the inverting input of the fourth block of differentiation, and with the fifth input of the third adder - via inverting input of the second proportional block, and the output of the third adder through a non-inverting input of the fifth proportional block associated with the third output of the device, while maintaining the high performance and accuracy of measurement of an electrical signal in the transient operation modes, simultaneously with the component reverse order to obtain the components of the forward and reverse sequences, which significantly extends the functionality of the device.


Claims

The filter is symmetrical components of the electrical signal, in which the terminal phase And the monitored signal is connected to the first input of the first adder, the clamp phase connected through inverting input of the first block of differentiation with the second input of the first adder, and after inverting input of the first proportional block with the third input of the first adder, the clamp phase is connected through a non-inverting input vtorinnih block - with the fifth input of the first adder, the output of which through the non-inverting input of the third proportional block associated with the first output device, characterized in that it additionally introduced the third and fourth blocks differentiation, second and third adders and the fourth and fifth proportional blocks, and terminal phase And is additionally connected to the first input of the second adder and to the first input of the third adder, the clamp phase additionally connected to the second input of the second adder, the second input of the third adder is connected via a non-inverting input of the third block of differentiation, and with the third input of the third adder - via inverting input of the first proportional block, and the output of the second adder through a non-inverting input of the fourth proportional block associated with the second output device, the terminal phase With additionally connected to the third input of the second adder, with the fourth input of the third adder is connected across the inverting input of the fourth block of differentiation, and with the fifth input of the third adder - via inverting input of the second proportional block, and the output of the third adder through a non-inverting input of the fifth proportional the

 

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