JPH11341855A - Phase sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a phase sensor excluding the possibility whereby it outputs an erroneous phase, even when a plurality of phase computers output simultaneously improper values. SOLUTION: A phase sensor has a phase-tolerance computer 5 for computing the phase tolerance of a following period based on the outputs of an estimation- phase computer 2 and a phase-difference computer 4. Heren, there is further provided a tolerance determining means 6, which determines whether the output of phase computers 8, 8 lies within the range of the output of the phase- tolerance computer 5 or not, after determining that the outputs of the plurality of phase computers 8, 8 are identical with each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a phase detector,
In particular, the present invention relates to a phase detector for detecting a phase of a synchronous AC motor for driving a vehicle.

[0002]

2. Description of the Related Art Conventionally, in a vehicle driven by a synchronous AC motor, an inverter is used for controlling the motor.
The control is performed by the following configuration. In FIG. 2, the control device 10 controls the motor 11 to operate in accordance with the command value 9.
Generates and controls three-phase AC, but it is necessary to detect the phase of the motor 11 in order to determine the phase of the three-phase AC to be output. In order to detect this phase, a phase detector 12 is attached to the electric motor 11, and the phase detection signal is sent to the control device 1
0 is configured.

FIG. 3 shows a configuration of a conventional phase detector used in the system. In FIG. 3, a conventional phase detector 12 is configured such that a pair of phase calculators 8, 8 calculates a phase at predetermined time intervals from a phase signal of the electric motor 11 detected by the detection means 7, Determine if the results are equal. Further, there is provided a phase difference calculator 4 for calculating a difference between the output of the storage means 1 for storing the output of the phase detector one cycle before and the current phase detector output. The estimated phase calculator 2 outputs the estimated phase of the next cycle from the output of the phase calculator.

[0004] The selector 3 is based on the output of the judgment means 13,
If the outputs of the two phase calculators 8 are equal, the phase calculator 8
If the outputs are not equal, the output of the estimated phase calculator 2 is used as the output of the phase detector 12.

[0005]

The phase calculator 8 in the prior art sometimes outputs an incorrect calculation result due to external factors such as noise.
Errors are removed from the output of the phase detector by taking in and comparing the outputs of one or more phase calculators 8. However, when used in a vehicle, it is often exposed to an adverse environment such as noise.
Is superimposed on the output, the output of both phase calculators 8 becomes an erroneous value. In this case, in the prior art shown in FIG. 3, if the outputs of the two phase calculators 8 and 8 are equal, the phase calculation is performed. In order to use the output of the detector 8 as the output of the phase detector 12, there is a possibility that an incorrect phase is output.

The present invention has been made in view of the problems of the prior art, and
An object of the present invention is to provide a phase detector that eliminates the possibility of outputting an incorrect phase even when the outputs of two phase calculators are equal.

[0007]

According to the first aspect of the present invention,
As shown in FIG. 1, from a phase signal detected by the detecting means 7, a plurality of phase calculators 8 and 8 respectively calculate the phases at regular intervals, and if the outputs of the plurality of phase calculators 8 and 8 are equal. A phase allowable range calculator for calculating the allowable range of the phase in the next cycle in a phase detector in which the output of the phase calculator 8 is not equal and the output of the estimated phase calculator 2 is the output of the phase detector. 5, a first determining means 13 for determining whether or not the outputs of the plurality of phase calculators 8 are equal, and determining whether or not the output of the phase calculator 8 is within the range of the output of the phase allowable range calculator 5. A second determining means 6 for determining a plurality of phase calculators 8, 8 in the first determining means 13;
Are determined to be equal to each other, if the output of the phase calculator 8 is within the range of the output of the phase allowable range calculator 5 by the second determination means 6, the output of the phase calculator 8 is included. When there is no output, the output of the estimated phase calculator 2 is used as the output of the phase detector.

The phase allowable range calculator 5 calculates the difference between the output of the phase detector one cycle before and the output of the current phase detector, and ,
It is preferable to use a phase allowable range calculator for calculating the allowable range of the phase in the next cycle from the output of the estimated phase calculator 2.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to an embodiment shown in the drawings. However, unless otherwise specified, dimensions, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the invention, but are merely illustrative examples.

FIG. 1 shows a configuration of an embodiment of a phase detector when the present invention is applied to a synchronous three-phase AC motor. In the phase detector according to the embodiment of the present invention, the phase calculators 8 and 8 calculate the phase at predetermined time intervals from the phase signal of the electric motor detected and output by the detection means 7, and the determination means 13
Is used to determine whether the two operation results are equal.

Further, there is provided a phase difference calculator 4 for calculating a difference between the output of the storage means 1 for storing the output of the phase detector one cycle before (T-1) and the current output of the phase detector. The estimated phase calculator 2 outputs the estimated phase of the next cycle from the output of the calculator 4 and the current output of the phase calculator. Further, there is provided a phase allowable range calculator 5 for calculating the allowable range of the phase in the next cycle from the output of the estimated phase calculator 2 and the output of the phase difference calculator 4, and the output of the phase calculator 8 calculates the phase allowable range. The allowable range determining means 6 determines whether the output is within the range of the output of the vessel 5.

The selector 3 inputs the outputs of the judging means 13 and the allowable range judging means 6 to the AND gate 19, the outputs of the two arithmetic units 8, 8 are equal, and the output is the output of the phase allowable range arithmetic unit 5. Arithmetic unit 8 only when it is within the range
Is the output of the phase detector, otherwise the output of the estimated phase calculator 2 is the output of the phase detector.

The operation of the phase detector disclosed in FIG. 1 will be described below with reference to FIGS. 4 (A) shows the output waveform of one phase calculator 8, FIG. 4 (B) shows the output waveform of the other phase calculator 8, and FIG. 5 (A) shows the phase detector output from selector 3 in the prior art. FIG. 5B shows an output waveform of the phase allowable range calculator 5 of the embodiment of the present invention, and FIG. 5C shows an output waveform of the phase detector of the embodiment of the present invention.

The outputs of the two phase calculators 8 and 8 are as shown in FIGS. 4A and 4B when the motor is rotating forward, and repeatedly output a value between 0 and 360 degrees. . These outputs include inappropriate values such as due to noise. In the related art, when the two output values do not match, the output of the phase detector is corrected by the estimated value, as shown in FIG. In FIG. 4A,
When only one of the outputs is inappropriate as in (1), correction based on the estimated value is performed.
In the case where inappropriate values are output at the same time as in (B), in the prior art shown in FIG.
Are equal, the output of the phase calculator 8 is used as the output of the phase detector.
As described above, an inappropriate value is included in the output of the phase detector.

Therefore, in the embodiment of the present invention, it is further determined by the allowable range determining means 6 whether or not the output of the phase calculator 8 is within the allowable range. The calculated allowable range indicated by hatching is set for the output of the phase allowable range calculator 5 as shown in FIG.

Therefore, when inappropriate values are output at the same time as shown in FIGS. 4A and 4B, even if the outputs of the two phase calculators 8 are equal to each other. When the output of the phase calculator 8 is out of the permissible range, the correction is performed, and as a result, the output of the phase detector becomes as shown in FIG.
Inappropriate values are removed as in

[0017]

As described above, according to the present invention, the outputs of the plurality of phase calculators 8 are equal, and more specifically, the output of the phase calculator 8 is output even when inappropriate values are output simultaneously. Since it is determined by the allowable range determining means 6 whether or not the phase is within the allowable range, the possibility of outputting an incorrect phase can be eliminated.

[Brief description of the drawings]

FIG. 1 shows a configuration diagram of an embodiment of a phase detector when the present invention is applied to a synchronous three-phase AC motor.

FIG. 2 is a control configuration diagram of a synchronous AC motor for a vehicle to which the present invention is applied.

FIG. 3 shows a configuration diagram of a related art of a phase detector when applied to a synchronous three-phase AC motor.

FIGS. 4 and 5 are graphs showing the operation of the phase detector of FIGS. 1 and 3, wherein (A) is the output waveform of one phase calculator and (B) is the output of the other phase calculator. Each waveform is shown.

5A is an output waveform of a phase detector output by a selector 3 according to the related art, FIG. 5B is an output waveform of a phase allowable range calculator 5 according to the embodiment of the present invention, and FIG. 4 is an output waveform of the phase detector according to the embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 storage means 2 estimated phase calculator 3 selector 4 phase difference calculator 5 phase allowable range calculator 6 allowable range determination means 7 detection means 8 phase calculator 9 command value 10 control device 11 motor 12 phase detector 13 determination means

Claims (2)

[Claims] 1. A plurality of phase calculators respectively calculate a phase from a phase signal detected by a detecting means at regular time intervals. If the outputs of the plurality of phase calculators are equal, the outputs of the phase calculators are equal. Otherwise, the output of the estimated phase calculator is the output of the phase detector, and the output of the plurality of phase calculators is a phase tolerance calculator that calculates the tolerance of the phase in the next cycle. First determining means for determining whether or not they are equal to each other; and second determining means for determining whether or not the output of the phase calculator is within the range of the output of the phase allowable range calculator. Means for judging that the outputs of the plurality of phase calculators are equal to each other, and when the output of the phase calculator falls within the range of the output of the phase allowable range calculator by the second determination means, Output, if not, estimated position The output of the arithmetic unit, a phase detector, characterized in that the respective outputs of the phase detector. 2. The method according to claim 1, wherein the allowable range calculator calculates an output of a phase difference calculator for calculating a difference between a phase detector output one cycle before and a current phase detector output, and an output of the estimated phase calculator. 2. The phase detector according to claim 1, wherein the phase detector is a phase allowable range calculator for calculating the allowable range of the phase in the next cycle.