JPH08214523A - Resolver - Google Patents

Abstract

PURPOSE: To immediately detect the fault of a resolver by detecting the fault when the output time of the OR signal between the first comparison signal and the second comparison signal is under a specified value. CONSTITUTION: The fault detector 13 of a resolver 10 is composed of a first comparison means 13a, the second comparison means 13b, an OR operation means 13c, a first time limiting means 13d, and a second time limit means 13e. And the first comparison means 13a outputs a first comparison signal when the induced voltage Er1 is not less than the specified threshold, and a second comparison means 13b outputs a second comparison signal when the induced voltage Er2 is not less than the specified threshold. Moreover, the OR operation means 13c output an OR signal when the OR of the first comparison signal and the second comparison signal materializes, and the second time limiting means 13e measures time and resets the measurement time when a reset signal is inputted within the specified time and outputs a fault signal to outside when the measured time exceeds the specified value. As a result, the rotor can be stopped immediately and countermeasure can be taken.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resolver used for position detection for speed control of rotating machinery.

[0002]

2. Description of the Related Art For example, in rotating machines such as induction machines and synchronous machines, rotational speed control and torque control of rotating bodies are performed in order to drive various machines and generate electric power.
In such control, it is essential to detect the position and speed of the rotating body, and a resolver is generally used. The resolver
This is a type of synchro electric machine and has the same structure as a winding type induction machine. Two-phase windings with a 90 ° phase shift are arranged in the stator, and the induced voltage of the rotor winding that rotates together with the rotor is The position is detected by the phase.

The operating principle of this type of resolver is shown in FIG.
Will be described with reference to.

In the resolver, the stator winding 1a is applied to the stator 1, and the rotor winding 2 electrically deviated from the rotor 2 by 90 °.
a and the rotor winding 2b are arranged to each other. An excitation voltage is applied to the stator winding 1a of the stator 1 at a predetermined frequency, while an induced voltage Er1 is taken out from the output terminal R1 and the output terminal R3 of the rotor winding 2a, so that the rotor winding 2a The induced voltage E is output from the output terminals R2 and R4.
r2 is taken out.

The values of the induction voltage Er1 and the induction voltage Er2 are generally determined by the amplitude of the voltage applied to the stator winding 1a and the angle θ of the rotor 2 between the stator winding 1a and the rotor winding 2a. It depends on the degree of magnetic coupling between the rotor windings 2b. That is, the induced voltage Er1 and the induced voltage Er
The value of 2 is determined by the magnetic flux of the stator winding 1a and the interlinkage magnetic flux of the rotor winding 2a and the rotor winding 2b depending on the positions of the rotor winding 2a and the rotor winding 2b. Proportional to sin and cos according to the angle of.

For example, as shown in the relationship shown in FIG. 6, the rotor angle θ of the rotor 2 (takes a counterclockwise direction when viewed from the shaft end side).
Then, the induced voltage Er1 and the induced voltage Er2 are expressed by the following equations (1) and (2).

Er1 = KEscos θ −−−− (1) Er2 = KEssin θ −−−− (2)

Here, Es: exciting voltage of the stator K: coupling coefficient

When the above equations (1) and (2) are expressed 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. You can

By the way, in general, a resolver based on two-phase winding excitation-two-phase winding output whose principle is shown in FIG. 8 is used. In this resolver, the stator winding 1a of the stator 1 and the stator winding 1b having a 90 ° phase angle are arranged in the principle diagram of the resolver shown in FIG. 6, and as shown in FIG. Vectors can be displayed.

Therefore, the induced voltage Er1 and the induced voltage Er2
9 is represented by the following equations (3) and (4).

Er1 = K (Es1cosθ + Es2sinθ) --- (3) Er2 = K (Es2cosθ-Es1sinθ) --- (4)

Here, Es1 = excitation voltage of stator winding 1a Es2 = excitation voltage of stator winding 1b K = maximum coupling coefficient θ = counterclockwise angle from shaft end side (FIG. 9)

In the above equations (3) and (4), the maximum coupling coefficient K, the excitation voltage Es1 of the stator winding 1a and the stator winding 1
Since the excitation voltage Es2 of b, the first induced voltage Er1 of the rotor winding 2a, and the second induced voltage Er2 of the rotor winding 2b are known, the angle θ can be obtained by calculating these, and the angle θ can be obtained. The angle from the shaft end side of, that is, the position of the rotating body is obtained.

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, it is represented by the above (3) and (4). The waveform in the vicinity of the rotor angle θ of the rotor 2 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.

Further, the induced voltage Er1 and the induced voltage Er2
Is taken out to the outside via a brush, but in recent years, a means to take out without a brush has been used instead of going through a brush.

[0017]

However, even if the rotating body or the like runs away due to a failure of the resolver, the conventional resolver cannot immediately find out that the resolver is the cause of the failure.

That is, the stator winding 1a of the resolver described above.
A normal position signal is output due to disconnection of the stator winding 1b, rotor winding 2a and rotor winding 2b, contact failure of the brush, and poor connection between the resolver and extraction connection. It may not be done.

If the resolver fails, the position and speed of the rotor will be different from the actual ones, and the control device will become abnormal. If the drive source is an electric motor, overcurrent or overspeed (runaway) will occur.
Cause In such a case, conventionally, where the cause of the entire apparatus including the resolver is investigated, but in a large-sized apparatus, it takes a lot of time and labor to find out where there are many places to pursue the cause.

Therefore, an object of the present invention is to provide a resolver which can immediately detect a failure of the resolver.

[0021]

According to a first aspect of the present invention, a stator winding is arranged on a stator to excite the stator winding at a predetermined excitation frequency, while being connected to a shaft of a rotating body. A two-phase rotor winding is arranged in the rotor so as to link with each magnetic flux generated by the stator winding to generate a first induced voltage and a second induced voltage, and the first induced voltage And a resolver for detecting the position of the rotating body according to the second induced voltage, the first comparing means outputting a first comparison signal when the first induced voltage is equal to or higher than a predetermined threshold value; Second comparing means for outputting the second comparison signal when the induced voltage of the above is greater than or equal to a predetermined threshold value, and when the output time of the logical sum signal of the first comparison signal and the second comparison signal is less than the predetermined time. A failure detection unit having means for detecting a failure is provided.

According to a second aspect of the present invention, in the resolver according to the first aspect, the failure detection section outputs first comparison signals when the first induced voltage is equal to or higher than a predetermined threshold value, and first comparison means, Second comparison means for outputting a second comparison signal when the second induced voltage is equal to or higher than a predetermined threshold value; first comparison signal; and second
A logical sum operation means for outputting a logical sum signal with the comparison signal,
A first time limit means for measuring the output time of the logical sum signal and outputting the reset signal only when the first measurement time becomes equal to or longer than the first predetermined time, and the second predetermined time means for measuring the time. The second measuring time is reset when the reset signal is input within the time, while the second time measuring means is provided for outputting the failure signal to the outside when the second measuring time is equal to or longer than the second predetermined time. It is the one.

[0023]

According to the resolver of the first aspect, the output time of the logical sum signal of the first comparison signal and the second comparison signal is determined from the decrease of the output level of the first induction voltage and the second induction voltage. If less than time, a failure is detected. As a result, if the resolver fails, the failure of the resolver can be immediately recognized, so that the rotating body can be stopped and a countermeasure can be taken. Therefore,
When a resolver fails, it is not necessary to look at other relevant parts because the failure caused by the resolver is immediately known.
Also, when a failure occurs in the device, it can be understood that there is no failure in the resolver, so it is possible to search for the cause by excluding the resolver.
It is possible to reduce the labor and time for pursuing the cause.

According to the resolver of the second aspect, when the first induced voltage and the second induced voltage are normal, the first comparison signal and the second comparison signal are normally output, and the OR operation means A logical sum signal is output. Then, the measurement time of the first time limiter becomes equal to or more than the predetermined value, and the reset signal is output. By inputting the reset signal, the measurement time of the second time delay means is reset and the failure signal is prohibited from being output. On the other hand, when the resolver fails, the levels of the first induced voltage, the second induced voltage, or both the first induced voltage and the second induced voltage decrease. Therefore, either or both of the first comparison signal and the second comparison signal become abnormal, and a logical sum signal with a short time width is output depending on the situation. This shortens the measurement time of the first time delay means,
The measurement time does not reach the predetermined time, and the reset signal is no longer output. At this time, since the reset signal is not output, the measurement time of the second time delay means exceeds the predetermined time,
A fault signal is output.

Therefore, if the resolver fails, the failure of the resolver can be immediately recognized, so that the rotating body can be stopped and appropriate measures can be taken. Also, since the failure caused by the resolver can be immediately known, it is not necessary to check other related parts when the resolver fails, and when the failure occurs in the device and when there is no failure in the resolver, the cause is excluded by the resolver. The pursuit is speeded up, and when the device has a failure, the labor and time for pursuing the cause can be reduced.

[0026]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of a resolver showing a first embodiment of the present invention.

The resolver 10 includes a transmitter 11 and a converter 12.
And the failure detection unit 13. Transmitter 11
Is a two-phase winding excitation-two-phase voltage output type described in FIG. 8, in which the stator winding 1a and the stator winding 1b are arranged with a 90 ° phase difference, 2, a rotor winding 2a and a rotor winding 2b which are connected to a rotor (not shown)
Have a phase difference of 90 ° with each other and rotate in conjunction with the rotating body.

The converter 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 transmitter 11, and further rotates from the rotor 2. The induced voltage Er1 and the induced voltage Er2 of the child winding 2a and the rotor winding 2b are taken in and a predetermined calculation is performed to output the angle θ of the rotor as a position signal.

The failure detecting section 13 inputs the induced voltage Er1 and the induced voltage Er2 and detects a decrease in the output levels of the induced voltage Er1 and the induced voltage Er2 of the rotor 2 and causes a failure as described later. When a fault signal is output.

FIG. 2 shows the detailed structure of the above-mentioned failure detecting section 13, which includes a first comparing means 13a, a second comparing means 13b, a logical sum calculating means 13c, and a first time delaying means 13d. It is composed of the second time limiter 13e.

The first comparison means 13a outputs a first comparison signal when the induced voltage Er1 is equal to or higher than a predetermined threshold value. The second comparison means 13b outputs a second comparison signal when the induced voltage Er2 is equal to or higher than a predetermined threshold value. The logical sum calculation 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 a predetermined time or longer. The second time limiter 13e resets the measurement time when the time is measured and a reset signal is input within the predetermined time, and outputs a failure signal to the outside when the measurement time is outside the predetermined time. .

With the above configuration, the exciting voltage Es1 and the exciting voltage Es2 are applied to the stator winding 1a and the stator winding 1b of the stator 1 provided in the transmitter 11, respectively, so that the rotor 2 has an angle θ. Suppose it is in a position. 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 at a cycle of about 1 Kz, and the output waveform changes according to the angle θ.

First, with reference to FIG. 3, the induced voltage Er1 and the induced voltage Er2 are the first comparing means 13a and the second comparing means 13 shown in FIG.
b and is input to the first comparing unit 13a and the second comparing unit 13a at time t1.
It is compared with a predetermined threshold value LC set in the comparison means 13b. By this comparison, when the induced voltage Er2 is larger than the predetermined threshold value LC, the ON signal CR1 of the time width is output from the first comparison means 13a, and when the induced voltage Er1 is larger than the predetermined threshold value LC, 2 comparison means 13
The ON signal CR2 of that time width is output from b.

The ON signal CR1 and the ON signal CR2 are input to the logical sum calculating means 13c to be added to the logical sum calculating means 13c.
c outputs an ON signal OR. This ON signal OR is the first
When input to the time delay means 13d, the first time delay means 13d measures time, and the output signal TD1 which is the measured time is gradually increased toward a predetermined threshold value L1. At this time, the second time limiter 13e measures the time and gradually increases the output signal TD2, which is the measured time, toward the predetermined threshold L2.

As a result, at time t2, the output signal TD1 exceeds the predetermined threshold value LC and the first time limiter 1
3d outputs the reset signal T1. Reset signal T1
Is input to the second time limiter 13e, the reset signal T
The 1 resets the second time limiter 13e.

Similarly, the reset signal T1 is output at time t3 and time t4, and the measurement time of the second time delay means 13e is reset. In this case, by setting the predetermined threshold value L1 and the predetermined threshold value L2 to appropriate values, the failure signal is not output to the outside as long as the transmitter 11 is operating normally.

Next, as shown in FIG. 4, when the stator winding 1b of the stator 1 is broken, the operation shown in FIG. 5 is performed.

FIG. 5 shows an instantaneous state in which the stator winding 1a is disconnected when the angle is about θ = 45 °, and shows the vicinity of the angle θ. t
Suppose that the wire is broken to 3.

In this case, the maximum amount of the induced voltage Er1 is greatly reduced by the breakage of the stator winding 1b, and the induced voltage Er2 is reduced to a value close to zero. As a result, time t
After 3, the second comparison means 13b does not output the ON signal CR2. Therefore, the reset signal is not output from the first time limiter 13d to the second time limiter 13e after being output at time t2. As a result, at the time t4, the second time delay means 13
The output signal TD2 of e exceeds the predetermined threshold value L2, and the failure signal T2 is output.

Thus, the induced voltage Er1 and the induced voltage Er are
When 2 is 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 logical sum signal is output from the logical sum calculation means 13c. Then, the measurement time of the first time limiter 13d becomes a predetermined value or more, and the reset signal is output. By inputting the reset signal, the measurement time of the second time delay means 13e is reset and the failure signal is prohibited from being output. On the other hand, when the resolver fails, the levels of the induced voltage Er1, the induced voltage Er2, or both the induced voltage Er1 and the induced voltage Er2 decrease. Therefore, either or both of the first comparison signal and the second comparison signal become abnormal,
Depending on the situation, a logical sum signal having a short time width is output. As a result, the measurement time of the first time limiter 13d becomes shorter,
The measurement time does not reach the predetermined time, and the reset signal is no longer 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.

Therefore, if the resolver fails, the failure of the resolver can be immediately recognized, so that the rotating body can be stopped and appropriate measures can be taken. Also, since the failure caused by the resolver can be immediately known, it is not necessary to check other related parts when the resolver fails, and when the failure occurs in the device and when there is no failure in the resolver, the cause is excluded by the resolver. Since the pursuit can be pursued, the pursuit of the cause can be expedited, and when the device has a failure, the labor and time for pursuing the cause can be reduced.

In this embodiment, one of the stator winding 1a and the stator winding 1b has been described as a disconnection, but the stator winding 1a and the stator winding 1b may be disconnected together. Even if a contact failure occurs, the output levels of the induced voltage Er1 and the induced voltage Er2 decrease, so that the failure can be detected.

Further, even if a failure occurs in the rotor winding 2a and the rotor winding 2b, it can be detected. Further, it can be applied to the two-phase winding excitation-single-phase winding output shown in FIG.

[0045]

As described above, according to the first aspect of the present invention, the logical sum signal of the first comparison signal and the second comparison signal is derived from the decrease in the output level of the first induction voltage and the second induction voltage. When the output time of is less than the specified time, the resolver failure is detected, so the rotating body can be stopped immediately and countermeasures can be taken.When the resolver fails, it is necessary to check other related parts. Moreover, when there is no failure in the resolver, the resolver can be excluded to quickly search for the cause, and the labor and time for searching for the cause can be reduced.

According to the second aspect of the invention, the level of the first induced voltage and the level of the second induced voltage decrease, so that either or both of the first comparison signal and the second comparison signal become abnormal. Depending on the situation, the OR signal with a short time width is output, and the failure signal is output by shortening the measurement time of the first time delay means. Therefore, the failure of the resolver is immediately recognized, so the rotor is stopped, and the countermeasure is taken. Measures can be taken, in case of resolver failure, there is no need to investigate other related parts, and when there is no failure in the resolver, the resolver can be excluded to quickly search for the cause, and there is a failure in the device. In this case, it is possible to reduce the labor and time for pursuing the cause.

[Brief description of 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 included in the resolver of FIG.

FIG. 3 is an explanatory diagram showing a first action of the failure detection unit of FIG.

FIG. 4 is an explanatory diagram when a failure occurs in the resolver of FIG.

FIG. 5 is an explanatory diagram showing a second action of the failure detection unit of FIG.

FIG. 6 is a principle diagram of a two-phase winding-one-phase winding output resolver.

7 is a vector diagram showing input / output of the resolver of FIG.

FIG. 8 is a principle diagram of a two-phase winding-two-phase winding output resolver.

9 is a vector diagram showing input / output of the resolver of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Stator 1a, 1b Stator winding 2 Rotor 2a, 2b Rotor winding 10 Resolver 11 Sending section 12 Converting section 13 Failure detecting section 13a First comparing means 13b Second comparing means 13c Logical sum computing means 13d First Time delay means 13e Second time delay means CR1 ON signal of the first comparison means CR2 ON signal of the second comparison means OR OR signal of the OR operation means TD1 Output signal of the first time delay means TD2 Output signal of the second time delay means T1 Reset signal T2 Failure signal

Claims (2)

[Claims] 1. A stator winding is arranged on a stator to excite the stator winding at a predetermined excitation frequency,
A two-phase rotor winding is linked to each magnetic flux generated by the stator winding to generate a first induced voltage and a second induced voltage in a rotor connected to a shaft of a rotating body. In a resolver that is arranged and detects the position of the rotating body according to the first induced voltage and the second induced voltage, a first comparison signal is output when the first induced voltage is equal to or higher than a predetermined threshold value. First comparing means for outputting, second comparing means for outputting a second comparing signal when the second induced voltage is equal to or higher than a predetermined threshold value, logic of the first comparing signal and the second comparing signal A resolver comprising a failure detection unit including means for detecting a failure when the output time of the sum signal is less than a predetermined time. 2. The failure detection unit includes 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 the second induced voltage has a predetermined threshold value. A second comparison means for outputting a second comparison signal when the value is equal to or more than a value; a logical sum operation means for outputting a logical sum signal of the first comparison signal and the second comparison signal; and an output time of the logical sum signal. A first time limiter that measures and outputs a reset signal only when the first measured time is equal to or longer than a first predetermined time; and the reset signal is measured within a second predetermined time by measuring time. When the second measurement time is reset, the second measurement time is reset, and when the second measurement time is equal to or longer than the second predetermined time, a second time limit means for outputting a failure signal to the outside is provided. The resolver according to claim 1.