RU2015616C1 - Phase shifter error determination device - Google Patents

Abstract

FIELD: digital measurement technology. SUBSTANCE: device for determining errors of phase-shifters has phase-shifter 1, drive 2, programme unit 3, adder 4, pulse generator 5, frequency divider 6, power supply source 7, null device 8, two pulse shapers 9, 10, flip-flop 11, normalizer 12, filter 13, reference voltage source 14, analogue subtracter 15 and meter 16 operatively connected to each other. EFFECT: enhanced accuracy and reliability. 2 dwg

Description

 The invention relates to digital measuring equipment and can be used in instrumentation, for example, when measuring the output characteristics of sine-cosine rotating transformers in the phase shifter mode.

 A device for determining the error of the phase shifters, comprising a two-phase power source, a controlled phase shifter, two comparators, three And elements, a time interval meter, a pulse generator, a trigger, a counter, a decoder, three single vibrators, a code adjuster, an accumulating adder and a block of And elements [1] .

 The disadvantage of this device is not a sufficiently high measurement accuracy due to the presence of an error in the resolution of the conversion and the error due to noise.

 The closest technical solution to the proposed one is a device for measuring the error of the converter of the angle of rotation of the shaft into phase, containing a program unit (together with a shaper of the reference code and a shaper of the period code), the first group of outputs of which is connected to the first group of inputs of the adder, and the second group of outputs with the inputs of the drive kinematically connected with the phase shifter shaft, a pulse generator, a power source, the outputs of which are connected to the inputs of the phase shifter, the output of which is through a zero organ inen with the input of the first pulse shaper, consisting of a trigger, a delay element and an element And, the second pulse shaper, which consists of a trigger, a delay element and an element And, and the outputs of the first and second pulse shapers are connected to the inputs of the trigger, the output of which is connected to one input element And, the other input of which is connected to the generator, and the output is connected to the input of the adder, the outputs of which are connected to the playback unit [2].

 The disadvantage of this device is the low measurement accuracy caused by the presence of a discreteness error due to the algorithm for determining the phase shifter error by digitizing the angle and subtracting codes, the presence of frequency synchronization and instability of the pulse generator and the power source.

 The aim of the invention is to improve the accuracy of measuring the error of the phase shifter.

 The goal is achieved by the fact that in the device for measuring the error of the phase shifter, comprising a drive kinematically connected to the shaft of the tested phase shifter, the output of which through a zero-organ is connected to the input of the first pulse shaper, a pulse generator, a power source, the output of which is connected to the input of the phase shifter, the second shaper pulses, and the outputs of the first and second pulse shapers are connected to the inputs of the trigger, a program unit, the first group of outputs of which are connected to the inputs of the first group ora, and the second group of outputs - with the input of the drive, a frequency divider, a normalizer, a filter, a reference voltage source, an analog subtractor and a meter are introduced, while the output of the pulse generator through a frequency divider is connected to the input of the power source and to the inputs of the second group of the adder, the output of which connected to the input of the second pulse former, the direct and inverse outputs of the trigger are connected to the information inputs of the normalizer, the output of which through the filter is connected to the first input of the analog subtractor, the second input is anal pulling the subtractor output is connected to one reference voltage, the other output of which is connected to the reference input of a normalizer analog subtractor output is connected to an input of measuring result output device.

The essence of the proposed device lies in another algorithm for converting and measuring the error of the phase shifter. The error of the phase shifter is determined by converting the phase shift of the output voltage of the phase shifter into the time interval t _ISM , comparing this time interval with the estimated time interval t _calc . The difference in time intervals (t _calculation - t _ISM ), proportional to the error of the phase shifter, is converted to voltage.

 The formation of the error of the phase shifter without intermediate conversion of the angle into a code was made possible by constructing the proposed device with tight binding of the output voltages of the quadrature power source to the frequency grid formed by the frequency divider. Furthermore, further conversion of the time interval of the error into voltage does not require high conversion accuracy and allows digitizing the error with high resolution. In addition, synchronization of the output voltages of the quadrature power source with the frequency of the pulse generator eliminates the error from the non-synchronism of the frequency of the generator and the supply phase shifter voltage.

 The block diagram of the device is shown in FIG. 1; diagram of its operation - in FIG. 2.

 The device contains a test phase shifter 1, drive 2, program unit 3, adder 4, pulse generator 5, frequency divider 6, power supply 7, zero-organ 8, first pulse shaper 9, second pulse shaper 10, trigger 11, normalizer 12, filter 13, a reference voltage source 14, an analog subtractor 15, a meter 16.

 A device for measuring the error of the phase shifters operates as follows.

The test phase shifter 1 by means of drive 2 occupies a sequence of N known discrete angular positions, the number of which is determined by program unit 3. For the binary number of exposed points, N = 2 ⁿ , where n is the number of binary bits of program unit 3 that specifies the number of the exposed point. The program unit sends to the adder 4 an n-bit binary potential code corresponding to the number of the exposed point. The pulse generator 5 generates a frequency-stable pulse voltage, which the frequency divider 6 divides to a frequency F _{about the} power of the phase shifter 1. At the output of the frequency divider 6, the reference meanders U _onsin and U _{on cos of the} frequency F _{o are formed} (Fig. 2a, b), which the input of the quadrature power supply 7. The power supply 7 generates quadrature supply voltages of the phase shifter windings U _sin and U _cos (Fig. 2c, d), the zero phases of which are rigidly synchronized with the edges of the reference meanders U _{on sin} and U _{on cos,} respectively (Fig. 2 a-d). At the output of the phase shifter 1, an output voltage is generated (Fig. 2e), the phase of which is proportional to the angle of rotation of the rotor.

 The zero-organ 8 forms the phase meanders (Fig. 2e) at the moment when the output voltage of the phase shifter 1 has a zero value. The first pulse shaper 9 generates negative phase pulses along the positive front of the phase meanders (Fig. 2i), i.e. at the time of the zero phase of the output voltage of the phase shifter 1.

When the supply voltages of the phase shifter 1 are tightly coupled to the reference meanders of the frequency divider 6, the temporal position of the phase pulse at the output of the zero-organ 8 relative to the reference meander t _ISM (Fig. 2i) linearly depends on the angular position of the phase shifter 1. The phase pulse is applied to the setup input to the trigger unit 11, to the input of the installation to the zero of which there comes a grid pulse (Fig. 2h), the temporary position of which corresponds to a given angle t _calc . The grid pulse (Fig. 2h) is generated by the second pulse shaper 10 along the negative front (Fig. 2g) of the grid meander coming from the output of the adder 4.

 The adder 4 sums the potential n-bit code that specifies the number of the exposed point, with the current code value specified by the frequency divider 6.

At the first inputs of adder 4 comes a potential n-bit binary code from the output of program block 3, at the second inputs of adder 4 from the output of frequency divider 6, frequency meanders f _o x 2 ⁿ and transfer pulses of the highest order of frequency divider 6 come. The transfer pulse records the potential code in the adder 4. At the output of the adder 4, meanders are generated (Fig. 2g), shifted relative to the reference meanders of the frequency divider 6 by a time interval t _calculation proportional to the given angle.

At the outputs of the trigger 11 pulses are formed, the duration of which is modulated by an error signal (Fig. 2 k) - PWM voltage. With a zero error of the phase shifter 1 t _calc. = t _meas. the fronts of the phase meanders and the meanders of the grid coincide, while meanders with a duty cycle of Q = 2 are formed at the outputs of the trigger 11.

Прямая (фиг. 2 к) и инверсная последовательности импульсов поступают на информационные входы нормализатора 12, на опорный вход которого приходит напряжение U_о с выхода источника 14 опорного напряжения. С выхода нормализатора 12 последовательность импульсов, модулированная по длительности погрешностью фазовращателя 1, поступает на вход фильтра 13, который формирует постоянное напряжение U₁, величина которого пропорциональна ошибке фазовращателя:
U₁= U_o

, где Т₁ - длительность положительного импульса.When the error of the phase shifter 1 is a positive sign (α _calculation > α _measurement or t _calculation >> t _measurement ), the duration of the positive pulse is more than 1/2 of the period T _about the value of t _calculation. - t _rev . The angular error of the phase shifter 1Δ α is defined as Δ α (angular hail) = α _{calc. -} α _rev. = 360 / T _about. (t _calc. - t _meas.), where T _{about - the} period of the supply phase shifter 1 voltage, T _o =

Direct (Fig. 2 k) and inverse sequences of pulses are fed to the information inputs of the normalizer 12, to the reference input of which voltage U _о comes from the output of the reference voltage source 14. From the output of the normalizer 12, the pulse train, modulated by the duration of the error of the phase shifter 1, is fed to the input of the filter 13, which generates a constant voltage U ₁ , the value of which is proportional to the error of the phase shifter:
U ₁ = U _o

where T ₁ - the duration of the positive pulse.

± Δt , где Δ t = t_расч. - t_изм.T ₁ =

± Δt, where Δ t = t _calc. - t _rev .

±

=

± ΔU , где ΔU = U_o

.Hence U ₁ =

±

=

± ΔU, where ΔU = U _o

.

= ± ΔU = ± U_o

.The analog subtractor 15 subtracts from the voltage U ₁ supplied to its input from the output of the filter 13, the voltage U _o / 2 supplied to its other input from the source 14 of the reference voltage. As a result, a voltage difference is formed at its output, proportional to the error of the phase shifter 1:
U ₁ -

= ± ΔU = ± U _o

.

 The voltage sign corresponds to the error sign. The meter 16 measures the DC voltage at the output of the analog subtractor 15.

Claims (1)

 DEVICE FOR DETERMINING THE ERROR OF PHASERS, containing a drive kinematically connected to the phase shifter shaft, a pulse generator, a power source, the outputs of which are connected to the inputs of the phase shifter, the output of which is connected to the input of the zero-organ, the output of which through the first pulse shaper is connected to the installation input in "1 "trigger, the input of the setting to" 0 "which is connected to the output of the second pulse shaper, a program unit, the first group of outputs of which is connected to the inputs of the first group of the adder, and the second the output block of the program unit is connected to the input of the drive, characterized in that in order to increase the accuracy of measurement, a frequency divider, a normalizer, a filter, a voltage reference source, an analog subtractor and a meter are introduced into it, and the output of the pulse generator is connected to the input of the frequency divider, the output of which connected to the input of the power source and the inputs of the second group of the adder, the output of which is connected to the input of the second pulse shaper, the direct and inverse outputs of the trigger are connected respectively to the information and the inputs of the normalizer, the output of which through the filter is connected to the first input of the analog subtractor, the first output of the reference voltage source is connected to the reference input of the normalizer, and the second output of the reference voltage source is connected to the second input of the analog subtractor, the output of which is connected to the input of the device output result meter.

Images