JP2015010930A - Resolver excitation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inexpensively provide a resolver excitation device by suppressing the number of components.SOLUTION: The resolver excitation device creates a reversed-phase resolver excitation signal and a normal-phase resolver excitation signal to be supplied to an exciting coil of a resolver. The resolver excitation device includes: a sine-wave signal creation circuit for creating a sine-wave signal of a predetermined frequency; and a resolver excitation signal creation unit 22 including a first inverting amplifier circuit for creating a reversed-phase resolver excitation signal by inverting and amplifying the sine-wave signal, and a second inverting amplifier circuit for creating a normal-phase resolver excitation signal by inverting and amplifying the reversed-phase resolver excitation signal.

Description

  The present invention relates to a resolver excitation device.

  Conventionally, in a power motor such as an IPM (Internal Permanent Magnet) motor, a resolver is used as a rotation angle sensor that detects a rotation angle of a rotor. Since the resolver is basically composed simply of a coil and an iron core, it has a high environmental resistance and operates normally without being affected by temperature changes, dust or dirt. A sine wave signal is applied to the exciting coil of the resolver. The two output coils of the resolver output a two-phase output signal in which the excitation signal is amplitude-modulated in a sine wave shape according to the rotation angle of the rotor. And the output signal of each phase is detected for every predetermined period, and a rotation angle is calculated.

  In Patent Document 1 below, an excitation signal (sine wave signal) including an offset voltage (DC bias) is supplied to one end of an excitation coil of a resolver, and an inverted excitation signal including the same offset voltage is also applied to the other end of the excitation coil. A rotation angle detection device to be supplied is disclosed. This rotation angle detection device supplies an excitation signal that does not include an offset voltage to the excitation coil by prohibiting applying an offset voltage to the excitation signal and the inverted excitation signal when a ground fault of the excitation coil is detected. This prevents destruction of the element and disconnection of the exciting coil due to the offset voltage.

Japanese Patent No. 5067880

  By the way, the rotation angle detection device of Patent Document 1 generates a resolver excitation signal based on a sine wave signal, and generates an inverted resolver excitation signal based on a reverse phase signal of the sine wave signal. For this reason, since an inverter circuit for generating a reverse phase signal is required, there is a problem that the number of parts increases and the production cost increases.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide a resolver excitation device that can be configured at low cost by suppressing the number of components.

  In order to achieve the above object, according to the present invention, as a first solution, a resolver excitation device that generates a reverse-phase resolver excitation signal and a positive-phase resolver excitation signal to be supplied to an excitation coil of a resolver, A sine wave signal generating circuit that generates a sine wave signal of a frequency, a first inverting amplifier circuit that generates a negative phase resolver excitation signal by inverting and amplifying the sine wave signal, and a positive phase by inverting and amplifying the negative phase resolver excitation signal A resolver excitation signal generation unit including a second inverting amplifier circuit that generates a resolver excitation signal is used.

According to the present invention, as the second solution means, in the first solution means, a DC voltage generation circuit that outputs a first DC voltage is further provided, wherein the first inverting amplifier circuit includes the sine wave signal and the The first DC voltage is input, the negative phase resolver excitation signal is output with the first DC voltage as a DC bias, and the second inverting amplifier circuit uses the first DC voltage as a DC bias. The reverse phase resolver excitation signal and the first DC voltage are input, and the positive phase resolver excitation signal is output using the first DC voltage as a DC bias.

  In the present invention, as the third solving means, in the first or second solving means, when the sine wave signal includes a second DC voltage, the first inverting amplifier circuit is configured to provide the second inverting amplifier circuit. The reverse phase resolver excitation signal having the first DC voltage as a DC bias and the first DC voltage as an input is output.

 According to the present invention, the resolver excitation signal generation unit inverts and amplifies the sine wave signal to generate a reverse-phase resolver excitation signal, and the reverse-phase resolver excitation signal is inverted and amplified to perform positive-phase resolver excitation. Since the second inverting amplifier circuit for generating a signal is provided, an inverter circuit as in the prior art is unnecessary, and the number of components can be suppressed and the configuration can be reduced.

It is a block diagram which shows the structure of the rotation angle detection apparatus 1 which concerns on one Embodiment of this invention. It is a circuit diagram which shows the structure of the resolver excitation signal generation part 22 in one Embodiment of this invention. In one Embodiment of this invention, it is a wave form diagram which shows the voltage which arises at (a) a negative phase resolver excitation signal, (b) a normal phase resolver excitation signal, and (c) the both ends of the exciting coil L1. It is a circuit diagram which shows the structure of 22 A of resolver excitation signal generation parts in the modification of one Embodiment of this invention.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing a configuration of a rotation angle detection device 1 according to an embodiment of the present invention. The rotation angle detector 1 outputs a resolver 10, a resolver excitation signal 20 that outputs a resolver excitation signal to the resolver 10 and converts an output signal of the resolver 10 into a digital signal, and an output signal (angle data) of the resolver excitation device 20. MPU (Micro-Processing Unit) 30 that performs vector control of the motor on the basis thereof.

  The resolver 10 includes a rotor 11 that is a rotor, an excitation coil L1 disposed around the rotor 11, and a first output coil L2 and a second output coil L3 that are also disposed around the rotor 11. Yes. Around the rotor 11, a stator (not shown) in which magnetic poles (not shown) are formed along the circumferential direction is provided. The excitation coil L1 and the first and second output coils L2, L3 are individually wound around individual magnetic poles of the stator.

  The resolver excitation device 20 includes a sine wave signal generation circuit 21 that generates a sine wave signal, a resolver excitation signal generation unit 22 that generates a resolver excitation signal, and a resolver that converts an output signal (analog signal) of the resolver 10 into a digital signal. And a digital conversion unit 23. Although not shown, the resolver excitation device 20 also includes a single power supply circuit (plus power supply circuit) that supplies a positive power supply voltage to the sine wave signal generation circuit 21, the resolver excitation signal generation unit 22, and the resolver digital conversion unit 23. ing.

  The sine wave signal generation circuit 21 generates a sine wave signal having an angular frequency ω and outputs it to the resolver excitation signal generation unit 22. This angular frequency ω is, for example, 10 kHz. The sine wave signal generation circuit 21 operates with the positive power supply voltage Vcc. In this relation, the sine wave signal is DC biased to the intermediate voltage Vcc / 2 (first intermediate voltage) of the power supply voltage Vcc. AC signal.

  Based on the sine wave signal input from the sine wave signal generation circuit 21, the resolver excitation signal generation unit 22 is a positive phase resolver excitation signal and a negative phase resolver having a phase opposite to that of the resolver excitation signal (the phase is inverted by 180 degrees). Generate an excitation signal. The resolver excitation signal generator 22 outputs a normal phase resolver excitation signal to one end of the excitation coil L1, and an inverted resolver excitation signal to the other end of the excitation coil L1.

  The resolver digital conversion unit 23 is an output signal of the resolver 10 and digitally converts a sine function signal (analog signal) input from the first output coil L2 and a cosine function signal (analog signal) input from the second output coil L3. Convert to signal (angle data). In addition, the resolver digital conversion unit 23 outputs the angle data to the MPU 30.

  FIG. 2 is a circuit diagram showing a detailed configuration of the resolver excitation signal generator 22. The resolver excitation signal generator 22 includes two operational amplifiers 41 and 42 (operational amplifiers) and a ½ voltage dividing circuit 43 (DC voltage generating circuit) that divides the DC voltage Vb input from the single power supply circuit into 1/2. ) And seven resistors R1 to R7. The resolver excitation signal generator 22 operates with the positive power supply voltage Vb.

  The inverting input terminal of the operational amplifier 41 is connected to the output terminal of the operational amplifier 41 via the resistor R1. Further, the inverting input terminal of the operational amplifier 41 is connected to the output terminal of the sine wave signal generation circuit 21 via the resistor R2.

  The non-inverting input terminal of the operational amplifier 41 is connected to the output terminal of the 1/2 voltage dividing circuit 43 through the resistor R3, and for example, the intermediate voltage Vcc / 2 from the sine wave signal generation circuit 21 through the resistor R4. Is applied. The output terminal of the operational amplifier 41 is connected to the other end of the exciting coil L1, and is connected to the inverting input terminal of the operational amplifier 42 via the resistor R6.

  On the other hand, the inverting input terminal of the operational amplifier 42 is connected to the output terminal of the operational amplifier 42 via the resistor R5, and is connected to the output terminal of the operational amplifier 41 via the resistor R6. The non-inverting input terminal of the operational amplifier 42 is connected to the output terminal of the 1/2 voltage dividing circuit 43 via the resistor R7. The output terminal of the operational amplifier 42 is connected to one end of the exciting coil L1.

  In such resolver excitation signal generator 22, one operational amplifier 41 and resistors R1 to R4 constitute a first inverting amplifier circuit, and the other amplifier circuit 42 and resistors R5 to R7 are a second inverting amplifier. The circuit is configured. The 1/2 voltage dividing circuit 43 outputs the intermediate voltage Vb / 2 (second intermediate voltage) by dividing the power supply voltage Vb by 1/2.

Next, the effect of the rotation angle detection device 1 configured as described above will be described in detail.
In the rotation angle detection device 1, the generation processing of the reverse phase resolver excitation signal and the normal phase resolver excitation signal is performed in the resolver excitation signal generation unit 22 of the resolver excitation device 20. Then, the reverse-phase resolver excitation signal and the positive-phase resolver excitation signal are output from the resolver excitation device 20 to the resolver 10, whereby the sine function signal and the cosine function signal are output from the resolver 10 to the resolver excitation device 20.

  The sine function signal and cosine function signal are converted into angle data by the resolver digital conversion unit 23 of the resolver excitation device 20 and output to the MPU 30. Then, the MPU 30 performs vector control of the motor based on the angle data.

  Although the overall operation of the rotation angle detection device 1 is as described above, details of generation processing of the reverse-phase resolver excitation signal and the positive-phase resolver excitation signal in the resolver excitation signal generation unit 22 will be described in more detail. As shown in FIG. 2, a sine wave signal that is DC biased to the intermediate voltage Vcc / 2 is input to the inverting input terminal of the operational amplifier 41 via a resistor R2. On the other hand, the intermediate voltage Vcc / 2 is input to the non-inverting input terminal of the operational amplifier 41 through the resistor R4, and the DC voltage Vb / 2 output from the 1/2 voltage dividing circuit 43 is input through the resistor R3. Entered.

  In such an input state, the DC bias of the sine wave signal, that is, the intermediate voltage Vcc / 2 is canceled, and the negative phase resolver excitation signal having the DC voltage Vb / 2 as a new DC bias and the phase of the sine wave signal inverted is obtained. The signal is output from the output terminal of the operational amplifier 41 to one end of the exciting coil L1 (see FIG. 3A).

  Further, such a reverse-phase resolver excitation signal is input to the inverting input terminal of the operational amplifier 42 via the resistor R6. On the other hand, the DC voltage Vb / 2 output from the 1/2 voltage dividing circuit 43 is input to the non-inverting input terminal of the operational amplifier 42 via the resistor R7. In such an input state, a positive phase resolver excitation signal having a DC voltage Vb / 2 as a DC bias and having the phase of the reverse phase resolver excitation signal inverted is output from the output terminal of the operational amplifier 42 to the other end of the excitation coil L1. (See FIG. 3B).

  As a result, as shown in FIG. 3C, differential voltages of the positive phase resolver excitation signal and the negative phase resolver excitation signal, that is, the positive phase resolver excitation signal and the negative phase resolver excitation are provided at both ends of the excitation coil L1. A sinusoidal voltage having an amplitude twice the amplitude of each signal is applied. As a result, the sine function signal and the cosine function signal output from the first and second output coils L2 and L3 have large amplitudes, and hence the influence of noise is reduced, so that the detection accuracy of the rotation angle of the rotor 11 is improved. To do.

  According to such a rotation angle detection device 1, the resolver excitation signal generation unit 22 generates a reverse-phase resolver excitation signal with the first inverting amplifier circuit, and is connected in series to the first inverting amplifier circuit. Since the positive phase resolver excitation signal is generated by the second inverting amplifier circuit using the negative phase resolver excitation signal as an input signal, an inverter circuit as in the prior art is unnecessary, and thus the number of parts is reduced and the production cost is suppressed. Can be configured easily.

  The resolver excitation signal generation unit 22 cancels the DC bias (intermediate voltage Vcc / 2) of the sine wave signal input from the sine wave signal generation circuit 21, and converts the intermediate voltage Vb / 2 of its own power supply voltage Vb to DC. Since the positive-phase resolver excitation signal and the negative-phase resolver excitation signal to be biased are generated, the positive-phase resolver excitation signal and the negative-phase resolver excitation signal having the largest amplitude with respect to the power supply voltage Vb can be generated.

In addition, this invention is not limited to the said embodiment, For example, the following modifications can be considered.
(1) For example, instead of the resolver excitation signal generator 22 shown in FIG. 2, a resolver excitation signal generator 22A shown in FIG. 4 may be adopted. That is, the DC bias of the sine wave signal generated by the sine wave signal generation circuit 21 may be other than the intermediate voltage Vcc / 2 of the power supply voltage Vcc of the sine wave signal generation circuit 21. When the sine wave signal is an arbitrary DC voltage V1 (preferably a voltage in the vicinity of the intermediate voltage Vcc / 2), the DC voltage (second DC voltage) separately taken from the sine wave signal generation circuit 21 is also the DC voltage V1. It will be the same.

(2) Further, the resolver excitation signal generator 22 includes the 1/2 voltage dividing circuit 43 as a DC voltage generating circuit, whereby the reverse phase resolver excitation output from the first and second inverting amplifier circuits to the excitation coil L1. The DC bias of the signal and the positive phase resolver excitation signal is set to the intermediate voltage Vb / 2 of the power supply voltage Vb, but instead of the 1/2 voltage dividing circuit 43, the power supply voltage Vb is divided into the voltage dividing ratio β (0 <β <1). Is provided as a DC voltage generating circuit, so that the DC voltage (first DC voltage) output by the β voltage dividing circuit 43A is a DC bias of the negative phase resolver excitation signal and the positive phase resolver excitation signal. It is good. Even in this case, the voltage dividing ratio β is preferably a value in the vicinity of ½, that is, the DC bias is preferably a voltage in the vicinity of the intermediate voltage Vb / 2.

(3) For example, the resolver digital conversion unit 23 is not an essential component of the resolver excitation device 20, and the function of the resolver digital conversion unit 23 may be incorporated in the MPU 30, for example.

DESCRIPTION OF SYMBOLS 1 Rotation angle detection apparatus 10 Resolver 11 Rotor 20 Resolver excitation apparatus 21 Sine wave signal generation circuit 22 Resolver excitation signal generation part 41, 42 Operational amplifier 43 1/2 voltage dividing circuit (DC voltage generation circuit)
R1 to R7 Resistance L1 Excitation coil

Claims (3)

A resolver excitation device that generates a reverse-phase resolver excitation signal and a positive-phase resolver excitation signal to be supplied to an excitation coil of a resolver,
A sine wave signal generation circuit for generating a sine wave signal of a predetermined frequency;
A first inversion amplifier circuit that inverts and amplifies the sine wave signal to generate the negative phase resolver excitation signal, and a second inversion that inverts and amplifies the negative phase resolver excitation signal to generate the positive phase resolver excitation signal. And a resolver excitation signal generation unit comprising an amplifier circuit. A DC voltage generation circuit for outputting the first DC voltage;
The first inverting amplifier circuit receives the sine wave signal and the first DC voltage as inputs, and outputs the reverse-phase resolver excitation signal having the first DC voltage as a DC bias,
The second inverting amplifier circuit receives the negative phase resolver excitation signal having the first DC voltage as a DC bias and the first DC voltage as inputs, and the positive DC voltage using the first DC voltage as a DC bias. The resolver excitation device according to claim 1, wherein a phase resolver excitation signal is output.   When the sine wave signal includes a second DC voltage, the first inverting amplifier circuit receives the second DC voltage as an input and uses the first DC voltage as a DC bias. The resolver excitation device according to claim 1, wherein an excitation signal is output.

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