DE2102981C3 - Circuit arrangement for converting an angle of rotation into a proportional DC voltage - Google Patents

Description

a) a coding stage (11), the input of which receives the three rotor output signals (A, B, C) and an _{alternating reference voltage (U 0} ) and at the output of which three first logic signals (α, b, c) can be tapped with polarities such that the combination of which defines a sextant (S) of the rotor rotation angle (α);

b) a first logic circuit (13) connected downstream of the coding stage (11) which, depending on the three first logic signals (α, b, c), generates six indicator _{signals (F 0} , F ₁ , F ₂ , F ₃ , F ₄ , F ₅ ) for marking the sextant of the rotor rotation angle (α) supplies;

c) a voltage level generator (14) controlled by the indicator signals, which supplies _{a different DC voltage (F 1) at its output for each sextant marked by the indicator signals:}

d) a second logic circuit (16) acted upon by the indicator signals and the rotor output signals, at the output of which an alternating voltage (U _e ) can be tapped which is offset from the reference alternating voltage by a certain phase angle (Θ) which corresponds to the deflection of the rotor rotation angle within its Sextant matches;

e) a Phasenmeßstufe (17), which the output voltage (U ₀₎ of the second logic circuit (.16) and the reference alternating voltage (U ₀₎ are supplied at the input and at the output of a said phase angle (0) DC voltage proportional to (K ₂ ) can be tapped;

f) a summing stage (18) in which the direct voltage marking the sextant of the rotor rotation angle and the direct voltage corresponding to said phase angle are added to a direct voltage (V) representing the rotor rotation angle.

2. Circuit arrangement according to claim 1, characterized in that the second logical Circuit (16) has the following features:

g) a first selection circuit (61, 62, 63, K ₆ , K ₁ , K ₈ ) which, under the control of the indicator _{signals (F 0} to F ₅ ), optionally allows one of the three rotor output signals (A, B, C) to pass;

h) a phase shifter (64,65,66, K ₉ , K ₁₀ ) which, under control by the indicator signals, rotates the rotor output signal passed by the first selection circuit either leading or lagging by 90 °;

i) a second selection circuit (K _n to K ₅ ) which, under control by the indicator signals, optionally allows one of the six possible difference signals, divided by the factor fl, to pass between two of the three rotor output signals;

j) such a control of the two selection circuits and the phase shifter by the indicator signals that the vckioriello sum of the output signals of the phase shifter and the second selection circuit ( ± j U ₁ and U ₄ ) with respect to the reference _{AC voltage (U 0} ) formed at a summing amplifier (70) is offset by the said phase angle ((-)) .

3. Circuit arrangement according to claim 2, characterized in that the phase shifter consists of a 90 ° phase rotation device (64) and a downstream inverter (65), which by means of indicator signals (F ₀ , F ₂ , F ₄ ) controlled switching device (K ₉ , K ₁₀ ) can optionally be bridged.

4. A circuit arrangement as claimed in claim 2 or 3, characterized in that the second selection circuit to / I ₅ six differential amplifier (A _0; includes, each respectively, the rotor output signals (A, B, C) receives two and each of which one from a separate indicator signal (F ₀ to F ₅ ) controllable switch (K ₀ to K ₅ ) is connected downstream.

The invention relates to a circuit arrangement for reshaping the angular position of the rotor of a synchronous machine with three against each other, each rotor windings offset by 120 ° into a DC voltage proportional to the rotor rotation angle, with the angular position is derived from the three alternating voltages that can be tapped off at the rotor windings which, as rotor output signals, each have a phase shift of 120 ° from one another. The intended field of application of the invention

application is an analog computer in which the angle of rotation of a synchronous machine is a parameter that is defined in the bill is received.

In a synchronous machine of the type mentioned above, the stator which excites the rotor windings can be fed with an alternating current of, for example, 400 Hz. When the rotor of a receiving machine of the same construction is fed by currents which is removed via three conductors from three terminals of a synchronous transmission machine the rotor of the receiving machine adjusts itself electrically according to the rotation of the transmitting machine. To receive a DC voltage proportional to the angle of rotation of the transmission machine it is sufficient to pass the rotor of a precision potentiometer through the rotor of the receiving machine to drive. In this way, however, only a mediocre accuracy can be achieved, because a synchronous receiving machine has a very weak moment and the lowest resistance moment prevents the theoretically exact setting from being achieved. The accuracy of such The setting is thus limited to, for example, +2 ", which is insufficient for many cases.

It is known that this disadvantage can be remedied by a locking device. This is because, under favorable conditions, the recommendation machine can carry a light visor on which a local control drive device adjusts the control element, for example the potentiometer runner. Such a device, which delivers an accuracy of ± 0.5 " , corresponds to the usual practice today.

Such a device, however, has disadvantages, in particular it is relatively heavy and takes up a relatively large amount of space. For example, in a ship, which is used for evaluation It is necessary to correct the ship's speed based on the results given by an echo sounder is, a measured value of this · speed on the navigating bridge in the form of an angle of rotation of a Synchronous machine available, which is driven by the airspeed indicator. Since the Oi If the computer has to be accommodated in a narrow stowage space of the ship, it is desirable for the conversion the angle of rotation of the synchronous machine into a proportional DC voltage a space-saving Facility to be provided.

hs is therefore the object of the invention, the conversion to convert an angle of rotation into a proportional DC voltage in a purely electrical manner, because you can design electrical circuit arrangements with wc-.t smaller dimensions than movable ones mechanical parts.

On the basis of a circuit arrangement of the type described at the outset, this object is achieved according to the invention solved by combining the following features:

a) a coding stage, the input of which is the three rotor output signals and receives a reference AC voltage and at its output three first logical ones Signals with such polarities can be tapped that their combination creates a sextant of the Rotor rotation angle specifies;

b) a first logic circuit connected downstream of the coding stage, which, as a function of the three first logical signals six indicator signals to mark the sextant of the rotor rotation angle supplies;

c) a voltage level generator controlled by the indicator signals, which at its output a different DC voltage for each sextant marked by the indicator signals supplies;

d) one of the indicator signals and the rotor output signals acted upon second logic Circuit at the output of which an alternating voltage can be tapped, which is against the reference alternating voltage is offset by a certain phase angle that corresponds to the impact of the rotor rotation angle corresponds within his sextant;

e) a phase measuring stage to which the output voltage of the second logic circuit and the reference AC voltage are fed at the input, and at the output of which a DC voltage proportional to said phase angle can be tapped;

Γ) a summation level in which the sextants of the rotor rotation angle marking DC voltage and the phase angle corresponding to said DC voltage added to a DC voltage representing the rotor rotation angle will,

In the invention, the angle to be reshaped is represented by two summands: u = S * 60 ^r + (-). S is an integer between 0 and 5. The whole circle is divided into six sextants, so that a measure for the angle </ is formed from the ordinal number of the sextant S and an overflow (-) ίο.

The principle according to the invention consists in comparing three alternating voltages, which by pairwise combination of the terminals of a synchronous machine are obtained to derive logic signals, with which the sextant of the rotor rotation angle can be defined. This definition takes over the first logic circuit. The voltage level generator is then carried out according to the Definition of a equal voltage level proportional to the value S. At the same time, by means of the second logic circuit and the phase measuring stage a DC voltage generated, which the overflow Θ, d. H. your exact deflection of the rotor rotation angle within the defined sextant S, is proportional. By adding both DC voltages the output signal proportional to the entire rotor rotation angle is then obtained.

In an advantageous embodiment of the invention, the second logic circuit contains a first selection circuit, which optionally allows one of the three rotor output signals to pass through, as well as a phase shifter, which phase shifts the rotor output signal passed by the first selection circuit either leading or lagging by 90 °, and finally a second selection circuit which optionally lets through one of the six possible difference signals divided by the factor * [7> between two of the three rotor output signals. The indicator signals of the first logic circuit determine which signals are allowed through by the selection circuits and in which direction the phase shift of the phase shifter takes place.

The selection circuits and the phase shifter are controlled by the indicator signals in such a way that the vector sum of the output signals of the phase shifter and the second selection circuit is offset from the reference AC voltage by the phase angle mentioned (ie by the partial angle Θ).

Further details of the invention are given below using an exemplary embodiment on the basis of Drawings explained.

F i g. 1 shows the circle divided into sextants with an angle a shown, for example, in sextant 3;

F i g. 2 shows a block diagram of the entire inventive concept Circuit arrangement;

Figure 3 is a block diagram of the invention Coding level;

F i g. 4 shows a block diagram of the first logic circuit according to the invention;

F i g. 5 shows a block diagram of the embodiment according to the invention second logic circuit;

F i g. 6 ⁶ S illustrated in a vector diagram the formation of the Phasenmeßstufe supplied phase-shifted alternating voltage,

As in Fig. 1, six sextants can be distinguished on the reference circle, which start with 0 to 5

are numbered. An angle ”as shown in FIG. I is specified. is formed by the sum of a whole number of sextants S = s · 60 with s = 3 and an overflow (-) , so that u = s · 60 + (-> results.

According to the illustration in FIG. 2, a synchronous machine 10 with three rotor windings arranged on 120 ', which is fed, for example, at a frequency of 400 Hz by a stator (not shown), supplies three alternating voltages T ₁ , T 2 to three output terminals P. Q, R , 7 ',. from which three single-phase voltages / I, ß, C are taken,

A between T, and T ,,
ß between T, and T ₂ ,
C between 7 ' ₂ and T ₁ ,

where A, B, C each represent the following values:

/ I = K sin κ B = K sin (. <+ 120)

C = K sin (.i + 240 ") with K = E ₀ cos <> f.

It can also be written:

-A = K sin («- 180")
- ß = K sin (»i - 60 °)
-C = K sin (-ι + 60 ")

Using a reference phase 12 supplied by the 400 Hz network, the synchronous sampling performed by a comparator 11 by an arrangement shown below in FIG. 3, logic signals a, b, c, the polarity of which changes + or - according to the value of s in accordance with the following table:

3
4th
5

With these three signals a, b, c , a logic 13 forms six logic functions F ₀ , F ₁ , ... F ₅ . only one of which is 0 in the sextant with the same index and the other five are 1: for example in the sextant 0, F ₀ = 0, F, = F ₂ ... F ₅ = 1, etc. The structure of the Loeik 13 is described below (see Fig. 4).

Each of the functions F ₀ ... _{F 5} is received on the one hand in a voltage level generator 14 which is fed by a DC reference voltage 15. The generator 14 supplies a voltage scale V ₁ = KS, where K is an integer, the value of which has the index of the voltage F, which is equal to zero.

A logic 16 receives on the one hand the sinusoidal quantities A, B, C. on the other hand the functions F and supplies an alternating voltage U. at the output which forms an angle (-) with the reference alternating voltage U _0. The voltage U _e and the voltage U ₀ . which comes from the reference source 12 with 400Hz, are led to a phase measuring device 17, which on the other hand receives the reference voltage with 4 (X) Hz U ₀ , which comes from a source 12 'and delivers a direct voltage V ₂ = K ■ θ at the output.

A summation element 18, which the DC voltages Vl and V 2 receives, delivers on one

ίο output terminal 19 the voltage V, which is searched is:

V = K (a- 60 ° + (-)) = K-ii.-

The logic 16 is described with reference to FIG. 5 described. The phase measuring device 17 is any known device. For example, the voltages can be converted into logic signals, which are calibrated by classifiers and fed to an exclusive OR circuit, which supplies square-wave pulses at the output with a width proportional to the phase shift (-> . A series with the exclusive OR circuit switched integrator supplies a direct voltage proportional to the angle (-).

In the same way, the summing device 18 can be any known device.

It is unnecessary to describe these known organs in detail because it makes the description unnecessary would be extended.

As shown in FIG. 3, the comparator 11 comprises at the input three isolating transformers 21, 22, 23, the primary winding of which is between the terminals of the synchronous machine T ₁ and T, (size A), T, and T ₂ (size β), T ₂ and T ₁ (size C) is switched.

A fourth transformer 20 with terminals T _n . T _n receives a reference voltage of 400 Hz U _n . The four transformers have their asymmetrical secondary windings with a terminal to ground and each have an output terminal f _n . / ,. r ₂ . i _t . On ( ₀ a reference voltage E _{n is} received, r, delivers E ₀ sin «. ( ₂ delivers E _n sin (n 4-120 °), r, delivers E ₀ sin in + 240").

These four voltages are each transformed into rectangular waves by four classifying devices 24, 25, 26, 27. The outputs of the classifying devices 25, 26, 27 are each connected to the input "Signal" of the bistable Tilt stages 30.31. 32nd connected. These drd bistable Flip-flops 30. 31. 32 have a control "enable", which is connected in parallel with the output of a monostable multivibrator 29, that of a monostable Flipper 28 is connected downstream, which is acted upon by the output of the classifying device 24 For a 400 Hz supply, the monostable flip-flop 28 has a relaxation time of the same magnitude Order of 600 as. While the monostable tilting stage 29 has a relaxation time in the order of magnitude of 50 μ5.

The bistable flip-flops 30,31, 32 deliver the logic signals a, b, c at the output.

The operation of the facility is as follows:
The monostable flip-flop 28, which has a positive edge that comes from the classifying device 2 when the voltage E passes through zero, causes the flip-flop 29 to tilt back: The flip-flop 29 therefore delivers a square pulse, the duration of which is between time 600 and 650 1 after the reference voltage has passed

J. h. frames the Zcitpunkl 625 ys symmetrically, which at 4001 represents Iz T 4. This means. ¹ SM the logical signals can be picked up in the area of passage through the maximum of the corresponding sinusoidal voltages.

As shown in FIG. 4, the logic is 13 constructed in the following way:

The signals </, h. c arrive on three clamps. each with u, h. c and which are multiplied in parallel on six branches, each of which delivers the functions at the output:

= a · h · e for the Branch O. / ■> = a ■ h ■ c for the Branch I. F, = a '* ■ c ■ h for the Branch 2. F ₁ = ■ - ii ■ h ■ c for the Branch 3. F ₄ - h t cn for the Branch 4. = ah for the Branch?.

With reference to the table above and with the convention I = I .- = ⁰ , the sextant is 0

F ₀ = 0 and F ₁ ... F ₅ = 1

and for the sextant I.

F _x = 0 and F ". F ₁ ... F ₅ = I and so on.

Branch 0 comprises a logic ODkR circuit 41. which picks up ο and h , and a logical AND circuit 42. which picks up c , and the output of 41.

Branch 1 contains an AND circuit 43, which receives α at its two inputs, and an AND circuit 44, which receives b and c , and the output of 43.

Branch 2 comprises an OR circuit 45, which picks up α and c , and a DND circuit 46, which picks up h , and the output of 45.

The branch comprises an AND circuit 47 which on ih ren receives two inputs, and an AND Schaltung48 which receives α and h, and the output of the 47th

Branch 4 comprises an O DER circuit 49 which receives /) and c , and an UN D circuit 50 which receives α , and the output of 49.

The branch 5 comprises an AND circuit 51, WCL che b receives on its two inputs, and an AND circuit 52 which receives and α c, and the output of the 51st

F i g. 5 shows that part of the circuit arrangement according to the invention which forms an alternating voltage U _{e from the alternating voltages tapped from the rotor and the logic functions F 0} to F ₅ , which is offset by the phase angle θ with respect to the reference _{alternating voltage U 0.} Like the vector diagram of FIG. 6 shows, this alternating voltage U _e applied to phase measuring device 17 (FIG. 2) is achieved by vector addition of an alternating voltage ± jU _x and an alternating voltage U ₄ .

The variable U ₁ is optionally one of the values A, B, C, which is passed on via one of the three contacts K ₆ , K ₇ and K _{8 as a function of the defined sextant S.} K ₆ is controlled by the output of an AND circuit 61, which is acted upon _{by the functions F 0} and F _3. K ₁ is controlled by an AND circuit 62 which _{receives F 1 and F 4} and K ₈ is controlled by an AND circuit 63 which receives _{F 2} and F _5. The signal U obtained at e _x is phase-shifted by 90 by a circuit 64.

For the sextants I. 3 and 5, the phase of the signal U i obtained must be reversed. This phase reversal takes place by an inverter circuit 65 connected in series with the circuit 64

ίο the sextants 1. 3 and 5 inserted by a relay is, whose normally open contact K ,, at the output of the circuit 65 and its normally closed contact K, “at the input of the Circuit 65 is located. This relay is controlled by the output of an AND circuit 66.

which receives the functions F ₀ , F ₂ and F _4.

At the common connection of the contacts K ₉ and K ₁₀ , the size ^ jU _{x is} achieved, which is given to the input C _{4 of} an amplifier 70 via a resistor 67.

The size U ₄ is obtained from the difference between two of the signals A. B and C, which are formed by six amplifiers / I ₀ to As, with two inputs. The inputs are designated with C ₂ and c, respectively. / I ₁₁ receives B and C: A _x receives A and C:

A ₁ receives A and β: / i, receives B and C: / I ₄ receives A and C; / I ₅ receives A and B.

The output of each amplifier is in series with a normally closed contact K ₀ ... K ₅ . which is operated by the functions F ₀ ... F ₅ . This contact is closed when the function F controlling it has the value zero. The common connection of the contacts K ₀ to K ₅ is connected to the input t> _{4 of} the amplifier 70 via a resistor 68. The input e ₄ is connected to ground via a capacitor 69 in order to suppress harmonics that can occur in the aforementioned signals p.

The scheme according to FIG. 5 is to be understood symbolically, in reality the switches are electronic components made up of integrated circuits.

The following is the mode of operation of the in FIG. 5 explained logic circuit:

Three alternating voltages appear at inputs A. B and C:

A = II sin u

B = H sin («+ 120)

C = H sin (, (+ 240)

The variable H is equivalent to E ₀ -cos int. One of the voltages A, B and C is selected as the variable U ₁ , while the other two voltages represent the variables U ₂ and U. An alternating voltage should now be _{generated for U 4} , which is proportional to cos (-):

U ₄ . = E ₀ - cos ο t ■ cos Θ

Such an alternating voltage can be obtained by calculating the difference between U ₂ and U ₃ . U ₇ can be written in the following form:

U ₂ = -E ₀ - cosf.f - sin β - -L cos (-) 1

6s U ₃ can be written in the following form:

[1 1Γ3 η

- sin (-) + - cos θ.

309 650/37;

In the difference U ₂ - U, the element sin (■) becomes liminicrl. So one can get the above precursors: t / .ungcn nrfüUcnucs U ₄ :

U, - U, "

^{,, 3} = £ ,, ■ cos.

COS <-).

t ',, c ₂ and c, as shown in the table below:

Such a U appears at the common output .ler switch K ₁ to K _{5 of} the circuit according to H i g. 5.

If you turn the phase of the signal U ₁ by 90. you get:

/ 1 ', - L · ,, sin> .i (■ sin <->

The total sum of U ₄ and / U ₁ is:

U "- Zi ₀ (COs ι ·. / · Cos H t- sin ei / · <->)

~ / - ,, COS (Ml - H)

The ί · ιη output of the amplifier 70 appearing signal U,., Thus forms the angle (-) with the reference voltage

The in Γ i g. The logic circuit shown in FIG. 5 delivers the desired signal U _H when the switches K ₁ to K "are controlled in such a way that the quantities A, B and C in the various sextants S are sent to the inputs A B C A B C in this way

Ii Λ A. C. C. B.

C. C. B. B.

A. A.

After generating a phase angle (-> proportional DC voltage in the device 17 and adding this DC voltage is obtained with the delivered from Spannungsstuicngencrator 14 and corresponding to the sextant concerned GleichspannungssUife a highly accurate analog signal for the Rotordrehwinkcl n With voltage increments of 1.2 V. which approximately. 0.1 mV are calibrated exactly, which can be carried out without great difficulty, results in a total voltage of 7.2 V for 360. One decimal degree corresponds to an amplitude of 2 mV.

1 sheet of drawings

Claims (1)

Patent claims: 1. Circuit arrangement for reshaping the angular position of the rotor of a synchronous machine with three against each other, each offset by 120 ° Rotor windings into a DC voltage proportional to the rotor rotation angle, the angular position is derived from the three alternating voltages that can be tapped at the rotor windings, which as rotor output signals each have a phase shift of 120 ° from one another, characterized by the combination of the following features: