JP3588493B2 - Resolver - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to a resolver used for position detection and the like for speed control and the like of a rotary machine.
[0002]
[Prior art]
For example, in a rotating machine such as an induction machine or a synchronous machine, rotation speed control, torque control, and the like of a rotating body are performed to drive various machines and generate electric power. In such control, detection of the position and speed of the rotating body is indispensable, and a resolver is generally used. The resolver is a type of synchro electric machine, and has the same structure as a winding type induction machine.A two-phase winding with a 90 ° phase shift is arranged on the stator, and a rotor winding that rotates together with the rotor. Position detection is performed based on the phase of the induced voltage.
[0003]
The operation principle of this type of resolver will be described with reference to FIG.
[0004]
In the resolver, a stator winding 1a is applied to a stator 1, and a rotor winding 2a and a rotor winding 2b, which are electrically shifted from each other by 90 °, are arranged on a rotor 2. While the excitation voltage is applied to the stator winding 1a of the stator 1 at a predetermined frequency, the induced voltage Er1 is taken out from the output terminals R1 and R3 of the rotor winding 2a, and the induction voltage Er1 is taken out of the rotor winding 2b. The induced voltage Er2 is extracted from the output terminal R2 and the output terminal R4.
[0005]
Generally, the values of the induced voltage Er1 and the induced voltage Er2 are determined based on the amplitude of the voltage applied to the stator winding 1a and the angle θ of the rotor 2, the stator winding 1a, the rotor winding 2a, and the rotor winding. It is determined by the degree of magnetic coupling between the lines 2b. That is, the value of the induced voltage Er1 and the value of the induced voltage Er2 depend on the position of the rotor winding 2a and the rotor winding 2b, and the magnetic flux of the stator winding 1a and the chain of the rotor winding 2a and the rotor winding 2b. It is determined by the intersecting magnetic flux, and is proportional to sin and cos according to the angle of the rotor 2.
[0006]
For example, when the rotor angle θ of the rotor 2 (takes a counterclockwise direction when viewed from the shaft end side) is determined as in the relationship shown in FIG. 6, the induced voltage Er1 and the induced voltage Er2 are expressed by the following equation (1). This is indicated by (2).
[0007]
Er1 = KEscos θ ---- (1)
Er2 = KEssin θ-(2)
[0008]
Here, Es: exciting voltage of the stator K: coupling coefficient
When the above equations (1) and (2) are displayed using electric vectors, the excitation voltage Es of the stator winding 1a of the stator 1 of the resolver can be decomposed into rectangular coordinates as shown in FIG.
[0010]
Generally, a resolver based on two-phase winding excitation and two-phase winding output whose principle is shown in FIG. 8 is used. This resolver is obtained by disposing a stator winding 1a of a stator 1 and a stator winding 1b having a 90 ° phase angle in the principle diagram of the resolver shown in FIG. 6, and as shown in FIG. Vector can be displayed.
[0011]
Therefore, the induced voltage Er1 and the induced voltage Er2 are represented by the following equations (3) and (4) according to FIG.
[0012]
Er1 = K (Es1cosθ + Es2sinθ) --- (3)
Er2 = K (Es2cosθ−Es1sinθ) --- (4)
[0013]
Here, Es1 = excitation voltage of stator winding 1a Es2 = excitation voltage K of stator winding 1b = maximum coupling coefficient θ = counterclockwise angle from shaft end side (FIG. 9)
[0014]
In the above equations (3) and (4), the maximum coupling coefficient K, the excitation voltage Es1 of the stator winding 1a, the excitation voltage Es2 of the stator winding 1b, the first induction voltage Er1 of the rotor winding 2a, and the rotation Since the second induced voltage Er2 of the slave winding 2b is known, the angle θ is obtained by performing an arithmetic operation on the second induced voltage Er2, and the angle from the shaft end side of the rotating body, that is, the position of the rotating body is obtained.
[0015]
Generally, the excitation frequency of the stator winding 1a and the stator winding 1b is about 1 KHz, and if the rotating body is around 20 Hz, the rotor 2 represented by the above (3) and (4) is used. In the vicinity of the rotor angle θ is similar to the waveform of the excitation frequency of the stator winding 1a and the stator winding 1b, and is output with a predetermined phase difference.
[0016]
Further, the induced voltage Er1 and the induced voltage Er2 are taken out to the outside via a brush. However, in recent years, means for taking out the product without using a brush and without using a brush has been used.
[0017]
[Problems to be solved by the invention]
By the way, even if a rotating body or the like runs away due to a failure of the resolver, the conventional resolver could not immediately recognize that the resolver was the cause of the failure.
[0018]
That is, the stator winding 1a and the stator winding 1b of the resolver, the rotor winding 2a and the rotor winding 2b, and the like are disconnected, the brush is abnormally contacted, and furthermore, the connection between the resolver and the take-out connection part is lost. Normal position signals may not be output due to poor connection or the like.
[0019]
If the resolver fails, the control device becomes abnormal because the position and speed of the rotating body are different from the actual ones. If the drive source is an electric motor, overcurrent or overspeed (runaway) is caused. In such a case, conventionally, where the cause is in the entire apparatus including the resolver is examined. However, in the case of a large-sized apparatus, a lot of places for pursuing the cause are required and much time and labor are required to find out where the cause is.
[0020]
Therefore, an object of the present invention is to provide a resolver that can immediately detect a failure of the resolver.
[0021]
[Means for Solving the Problems]
The present invention arranges a stator winding on a stator and excites the stator winding at a predetermined excitation frequency, while providing a two-phase rotor winding on a rotor connected to a shaft of a rotating body. A first induction voltage and a second induction voltage are arranged so as to interlink with respective magnetic fluxes generated by the stator winding, and are arranged in accordance with the first induction voltage and the second induction voltage. A resolver for detecting a position of the rotating body, a first comparing means for outputting a first comparison signal when the first induced voltage is equal to or higher than a predetermined threshold value, and a second threshold for detecting the second induced voltage. A second comparison means for outputting a second comparison signal when the value is not less than a value, an OR operation means for outputting an OR signal of the first comparison signal and the second comparison signal, and an output time of the OR signal. Measurement, and only when the first measurement time is equal to or longer than a first predetermined time A first time limiter for outputting a set signal; and a second time measuring unit for measuring time and resetting the second measuring time when the reset signal is input within a second predetermined time. A second time limit means for outputting a failure signal to the outside when the time exceeds the second predetermined time is provided.
[0023]
[Action]
Therefore, if the resolver breaks down, it is immediately known that the resolver has broken down, so that the rotating body can be stopped and countermeasures can be taken. In addition, since the failure caused by the resolver can be immediately recognized, it is not necessary to check other related parts when the resolver fails, and when there is no failure in the device, the resolver is excluded when there is no failure, and Pursuit is quick, and in the event of a device failure, labor and time for seeking the cause can be reduced.
[0026]
【Example】
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0027]
FIG. 1 is a configuration diagram of a resolver showing a first embodiment of the present invention.
[0028]
The resolver 10 includes a transmission unit 11, a conversion unit 12, and a failure detection unit 13. The transmission unit 11 is of the two-phase winding excitation-two-phase voltage output type described with reference to FIG. 8, and the stator winding 1 a and the stator winding 1 b are arranged on the stator 1 with a phase difference of 90 °. In the rotor 2, a rotor winding 2a and a rotor winding 2b connected to a rotating body (not shown) have a phase difference of 90 ° with each other and rotate in conjunction with the rotating body.
[0029]
The conversion unit 12 takes in the respective excitation voltages Es1 and Es2 applied to the stator winding 1a and the stator winding 1b of the stator 1 provided in the transmission unit 11, and further converts the rotor winding 2 into the rotor winding An induction voltage Er1 and an induction voltage Er2 between the rotor 2a and the rotor winding 2b are taken, a predetermined operation is performed, and the angle θ of the rotating body is output as a position signal.
[0030]
The failure detection unit 13 receives the induction voltage Er1 and the induction voltage Er2, and detects a decrease in the output level of the induction voltage Er1 and the induction voltage Er2 of the rotor 2 as described later. Is output.
[0031]
FIG. 2 shows a detailed configuration of the above-described failure detection unit 13. The failure detection unit 13 includes a first comparison unit 13a, a second comparison unit 13b, an OR operation unit 13c, a first time-out unit 13d, and a second time-out unit 13d. Means 13e.
[0032]
The first comparing means 13a outputs a first comparison signal when the induced voltage Er1 is equal to or higher than a predetermined threshold. The second comparison means 13b outputs a second comparison signal when the induced voltage Er2 is equal to or higher than a predetermined threshold. The logical sum operation means 13c outputs a logical sum signal when the logical sum of the first comparison signal and the second comparison signal is established. The first time limiter 13d measures the output time of the OR signal and outputs a reset signal when the measured time is equal to or longer than a predetermined time. The second time limiter 13e measures the time, resets the measurement time when a reset signal is input within a predetermined time, and outputs a failure signal to the outside when the measurement time is outside the predetermined time. .
[0033]
With the above configuration, the excitation voltage Es1 and the excitation voltage Es2 are applied to the stator winding 1a and the stator winding 1b of the stator 1 provided in the transmission unit 11, respectively, so that the rotor 2 is at the position of the angle θ. And In this case, the induced voltage Er1 and the induced voltage Er2 according to the equations (3) and (4) described in the conventional example are output with a predetermined phase difference and a cycle of about 1 Kz, and the output waveform changes according to the angle θ.
[0034]
Here, first, referring to FIG. 3, the induced voltage Er1 and the induced voltage Er2 are input to the first comparing means 13a and the second comparing means 13b shown in FIG. It is compared with a predetermined threshold value LC set in the first comparing means 13a and the second comparing means 13b. As a result of this comparison, when the induced voltage Er2 is larger than the predetermined threshold value LC, the first comparing means 13a outputs an ON signal CR1 of that time width. When the induced voltage Er1 is larger than the predetermined threshold value LC, An ON signal CR2 of the time width is output from the second comparing means 13b.
[0035]
The ON signal CR1 and the ON signal CR2 are input to the OR operation unit 13c, and the OR operation unit 13c outputs the ON signal OR. When this ON signal OR is input to the first time limiter 13d, the first time limiter 13d measures time, and the output signal TD1, which is the measured time, is gradually increased toward a predetermined threshold L1. . At this time, the second time limiter 13e measures the time, gradually increases the output signal TD2, which is the measured time, and goes toward a predetermined threshold L2.
[0036]
Thus, at time t2, the output signal TD1 exceeds the predetermined threshold value LC, and the first time limiter 13d outputs the reset signal T1. When the reset signal T1 is input to the second time limiter 13e, the second time limiter 13e is reset by the reset signal T1.
[0037]
Similarly, a reset signal T1 is output at time t3 and time t4, and the measurement time of the second time limiter 13e is reset. In this case, by setting the predetermined threshold value L1 and the predetermined threshold value L2 to an appropriate value, a failure signal is not output to the outside as long as the transmitting unit 11 operates normally.
[0038]
Next, as shown in FIG. 4, when the stator winding 1b of the stator 1 is disconnected, the operation shown in FIG. 5 is performed.
[0039]
FIG. 5 shows an instantaneous state where the stator winding 1a is disconnected when the angle is about θ = 45 °, and shows the vicinity of the angle θ. The time interval between the time t1 and the time t2 is normal and the connection is broken at the time t3. Suppose you did.
[0040]
In this case, the maximum amount of the induced voltage Er1 is significantly reduced due to the disconnection of the stator winding 1b, and the induced voltage Er2 is reduced to a value close to zero. As a result, the ON signal CR2 is not output from the second comparing means 13b after the time t3. Therefore, the reset signal is not output from the first time limit means 13d to the second time limit means 13e after being output at time t2. As a result, at time t4, the output signal TD2 of the second time limiter 13e exceeds the predetermined threshold L2, and the failure signal T2 is output.
[0041]
As described above, when the induced voltages Er1 and Er2 are normal, the first comparison signal as the ON signal CR1 and the second comparison signal as the ON signal CR2 are normally output, and the OR operation means 13c performs the OR operation. A signal is output. Then, the measurement time of the first time limiter 13d becomes equal to or longer than a predetermined value, and a reset signal is output. By the input of the reset signal, the measurement time of the second time limiter 13e is reset, and the output of the failure signal is prohibited. On the other hand, if the resolver fails, the level of the induced voltage Er1, the induced voltage Er2, or both the induced voltage Er1 and the induced voltage Er2 decreases. For this reason, both or one of the first comparison signal and the second comparison signal becomes abnormal, and an OR signal with a short time width is output according to the situation. As a result, the measurement time of the first time limiter 13d is shortened, the measurement time does not reach the predetermined time, and the reset signal is not output. At this time, since the reset signal is not output, the measurement time of the second time limiter 13e exceeds the predetermined time, and the failure signal is output.
[0042]
Therefore, if the resolver breaks down, it is immediately known that the resolver has broken down, so that the rotating body can be stopped and countermeasures can be taken. In addition, since the failure caused by the resolver can be immediately recognized, it is not necessary to check other related parts when the resolver fails, and when there is no failure in the device, the resolver is excluded when there is no failure, and Since the pursuit can be performed, the cause can be quickly pursued, and when a failure occurs in the device, labor and time for pursuing the cause can be reduced.
[0043]
In this embodiment, the disconnection of one of the stator winding 1a and the stator winding 1b has been described. However, the stator winding 1a and the stator winding 1b may be disconnected at the same time, or a contact failure may occur. Occurs, the output level of the induced voltage Er1 and the induced voltage Er2 decreases, so that a failure can be detected.
[0044]
Further, even if a failure occurs in the rotor windings 2a and 2b, it can be detected. Further, the present invention can be applied to the two-phase winding excitation-single-phase winding output shown in FIG.
[0045]
【The invention's effect】
As described above, according to the present invention, the stator winding is arranged on the stator and the stator winding is excited at a predetermined excitation frequency, while the rotor connected to the shaft of the rotating body is excited. A two-phase rotor winding is arranged to interlink with respective magnetic fluxes generated by the stator winding to generate a first induced voltage and a second induced voltage, and the first induced voltage and the A resolver for detecting a position of the rotating body in accordance with a second induced voltage, a first comparing means for outputting a first comparison signal when the first induced voltage is equal to or higher than a predetermined threshold; A second comparison means for outputting a second comparison signal when the induced voltage of the second comparison signal is equal to or higher than a predetermined threshold value; and an OR operation means for outputting a logical sum signal of the first comparison signal and the second comparison signal; Measuring an output time of the OR signal, wherein the first measurement time is a first predetermined time; A first time-limit means for outputting a reset signal only when the time is equal to or more than a time, while resetting a second measurement time when the reset signal is input within a second predetermined time by measuring time; When the second measurement time is equal to or longer than the second predetermined time, the second time limit means for outputting a failure signal to the outside is provided. Therefore, if the resolver fails, the failure of the resolver can be immediately recognized. The effect is obtained that the vehicle can be stopped and countermeasures can be taken. In addition, since the failure caused by the resolver can be immediately recognized, it is not necessary to check other related parts when the resolver fails, and when there is no failure in the device, the resolver is excluded when there is no failure, and The pursuit is speeded up, and when a failure occurs in the device, the effect of reducing labor and time for pursuing the cause can be obtained.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a resolver showing a first embodiment of the present invention.
FIG. 2 is a configuration diagram of a failure detection unit provided in the resolver of FIG. 1;
FIG. 3 is an explanatory diagram illustrating a first operation of the failure detection unit in FIG. 2;
FIG. 4 is an explanatory diagram when a failure occurs in the resolver of FIG. 1;
FIG. 5 is an explanatory diagram illustrating a second operation of the failure detection unit in FIG. 2;
FIG. 6 is a principle diagram of a resolver having two-phase winding and one-phase winding output.
FIG. 7 is a vector diagram showing input and output of the resolver of FIG. 6;
FIG. 8 is a principle diagram of a two-phase winding-two-phase winding output resolver.
FIG. 9 is a vector diagram showing input and output of the resolver of FIG. 8;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Stator 1a, 1b Stator winding 2 Rotor 2a, 2b Rotor winding 10 Resolver 11 Transmitting part 12 Conversion part 13 Failure detecting part 13a First comparing means 13b Second comparing means 13c Logical sum calculating means 13d First Time limit means 13e Second time limit means CR1 ON signal CR2 of first comparison means ON signal OR of second comparison means ON signal TD1 of OR operation means Output signal TD2 of first time limit means Output signal T1 of second time limit means Reset signal T2 Failure signal

Claims (1)

A stator winding is arranged on a stator, and the stator winding is excited at a predetermined excitation frequency, while a two-phase rotor winding is mounted on a rotor connected to a shaft of a rotating body. Are arranged so as to generate a first induced voltage and a second induced voltage by interlinking with the respective magnetic fluxes generated by the first and second induced voltages. In a resolver that detects position,
First comparing means for outputting a first comparison signal when the first induced voltage is equal to or higher than a predetermined threshold;
Second comparing means for outputting a second comparison signal when the second induced voltage is equal to or higher than a predetermined threshold value;
OR operation means for outputting an OR signal of the first comparison signal and the second comparison signal;
First time-limit means for measuring an output time of the OR signal and outputting a reset signal only when the first measured time is equal to or longer than a first predetermined time;
When the time is measured and the reset signal is input within a second predetermined time, the second measurement time is reset. On the other hand, when the second measurement time is equal to or longer than the second predetermined time, A resolver comprising: a second time limiter for outputting a failure signal to the outside.

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