CN219978384U - Fault detection circuit of motor rotary transformer circuit and motor rotary transformer circuit - Google Patents

Abstract

The utility model discloses a fault detection circuit of a motor rotation-transformation circuit and the motor rotation-transformation circuit. The filter circuit is connected with the digital signal processing system and the gain and bias circuit and is used for converting a pulse width modulation signal generated by the digital signal processing system into a sine wave signal; the gain and bias circuit is connected with the push-pull circuit and used for increasing the amplitude of the sine wave signal to a target amplitude; the push-pull circuit is connected with the voltage dividing and sampling circuit and is used for amplifying power of the target sine wave signal; the voltage dividing and sampling circuit is connected with the push-pull circuit and the digital signal processing system and is used for dividing the differential voltage at two ends of the output current limiting resistor of the push-pull circuit; and the digital signal processing system is used for determining whether the motor rotation circuit fails or not through the target voltage. The utility model solves the technical problem that the rotary circuit cannot be effectively protected because the prior art cannot comprehensively judge the fault type of the rotary circuit.

Description

Fault detection circuit of motor rotary transformer circuit and motor rotary transformer circuit

Technical Field

The utility model relates to the technical field of motor rotation control, in particular to a fault detection circuit of a motor rotation change circuit and the motor rotation change circuit.

Background

Resolver is commonly used to measure the angular displacement and angular velocity of a rotating shaft of a rotating object. When the rotary transformer works normally, an external excitation signal is required to drive an excitation winding of the rotary transformer. The excitation output belongs to an external port and needs to be connected to two ends of a motor side rotary transformer primary winding through a low-voltage line. In view of the aging of the wire harness for a long period of time and the unavoidable manual wiring errors, it is necessary to add a diagnostic circuit for the common faults of the excitation (e.g., short ground, short power supply, mutual short). In the related art, whether the rotary transformer circuit fails or not can be judged normally by detecting the amplitude of the feedback signal of the rotary transformer, and the faults such as the rotary transformer LOS and the like can be uploaded through an upper computer, but the fault type of the rotary transformer circuit cannot be judged comprehensively and the fault position cannot be positioned effectively.

In view of the above problems, no effective solution has been proposed at present.

Disclosure of Invention

The embodiment of the utility model provides a fault detection circuit of a motor rotary circuit and the motor rotary circuit, which at least solve the technical problem that the rotary circuit cannot be effectively protected because the fault type of the rotary circuit cannot be comprehensively judged in the prior art.

According to an aspect of an embodiment of the present utility model, there is provided a fault detection circuit of a motor rotation transformer circuit, including: the filter circuit is connected with the digital signal processing system and the gain and bias circuit and is used for converting the pulse width modulation signal generated by the digital signal processing system into a sine wave signal and inputting the sine wave signal into the gain and bias circuit for connection; the gain and bias circuit is connected with the push-pull circuit and used for increasing the amplitude of the sine wave signal to a target amplitude to obtain a target sine wave signal and inputting the target sine wave signal into the push-pull circuit; the push-pull circuit is connected with the voltage dividing and sampling circuit and is used for carrying out power amplification on the target sine wave signal to obtain a rotary excitation signal, and the rotary excitation signal is input to the rotary transformer; the voltage dividing and sampling circuit is connected with the push-pull circuit and the digital signal processing system and is used for dividing the differential voltage at two ends of the output current limiting resistor of the push-pull circuit to obtain a target voltage and inputting the target voltage into the digital signal processing system; and the digital signal processing system is used for determining whether the motor rotating circuit fails or not through the target voltage and determining the type and the position of the failure in the case of the failure.

Optionally, the digital signal processing system comprises: the signal generation module is used for generating a pulse width modulation signal; a processor for determining whether a motor rotating circuit is failed through a target voltage, and in the event of failure, the type and location of the failure; and the analog-to-digital conversion module is used for converting the target voltage from an analog signal to a digital signal.

Optionally, the filtering circuit includes: the first filter is respectively connected with the signal generation module and the gain and bias circuit and is used for converting the pulse width modulation signal into a sine wave signal; the second filter is respectively connected with the signal generation module and the gain and bias circuit and is used for converting the pulse width modulation signal into a sine wave signal; wherein the first filter and the second filter are low pass filters.

Optionally, the gain and bias circuit comprises: the first operational amplification circuit is connected with the first filter and is used for improving the amplitude of the sine wave signal to a target amplitude to obtain a target sine wave signal; and the second operational amplification circuit is connected with the second filter and is used for improving the amplitude of the sine wave signal to the target amplitude to obtain the target sine wave signal.

Optionally, the push-pull circuit includes: the first amplifier circuit is connected with the first operational amplifier circuit and is used for amplifying power of the target sine wave signal to obtain a rotary excitation signal; and the second amplifier circuit is connected with the second operational amplifier circuit and is used for amplifying the power of the target sine wave signal to obtain a rotary excitation signal.

Optionally, the push-pull circuit further comprises: the first resistor, the second resistor, the third resistor and the fourth resistor are connected in series in the first amplifier circuit, and the first resistor and the second resistor are output current limiting resistors of the first amplifier circuit; the third resistor and the fourth resistor are connected in series in the second amplifier circuit and are current limiting resistors for the output of the second amplifier circuit.

Optionally, the push-pull circuit further comprises: the first diode is connected in the first amplifier circuit and is used for setting a static working point for the first amplifier circuit so as to prevent crossover distortion of a rotation-varying excitation signal; the second diode is connected in the second amplifier circuit and is used for setting a static working point for the second amplifier circuit so as to prevent crossover distortion of the rotation-changing excitation signal.

Optionally, the voltage dividing and sampling circuit includes: the digital signal processing system comprises a first voltage dividing and sampling circuit, a second voltage dividing and sampling circuit, a third voltage dividing and sampling circuit and a fourth voltage dividing and sampling circuit, wherein the first voltage dividing and sampling circuit is used for acquiring voltages at two ends of a first resistor to obtain a first target voltage and inputting the first target voltage to the digital signal processing system; the second voltage dividing and sampling circuit is used for acquiring voltages at two ends of the second resistor to obtain a second target voltage and inputting the second target voltage to the digital signal processing system; the third voltage dividing and sampling circuit is used for collecting voltages at two ends of the third resistor to obtain a third target voltage, and inputting the third target voltage to the digital signal processing system; and the fourth voltage dividing and sampling circuit is used for collecting the voltages at two ends of the fourth resistor to obtain a fourth target voltage and inputting the fourth target voltage into the digital signal processing system.

Optionally, the first voltage dividing and sampling circuit, the second voltage dividing and sampling circuit, the third voltage dividing and sampling circuit, and the fourth voltage dividing and sampling circuit respectively include four resistors and two capacitors, wherein the four resistors include: fifth resistance, sixth resistance, seventh resistance and eighth resistance, two electric capacities include: a first capacitor and a second capacitor; the fifth resistor is connected with the first capacitor in parallel, and the formed parallel circuit is connected with the sixth resistor in series to form a first series circuit; the seventh resistor is connected with the second capacitor in parallel, and the formed parallel circuit is connected with the eighth resistor in series to form a second series circuit; the first series circuit and the second series circuit are connected in parallel to form a first voltage division and sampling circuit, a second voltage division and sampling circuit, a third voltage division and sampling circuit, or a fourth voltage division and sampling circuit.

According to another aspect of the embodiment of the present utility model, there is also provided a motor rotation transformer circuit including: the fault detection circuit of the motor rotation circuit; a rotary transformer; and the feedback conditioning circuit is connected with the rotary transformer and the digital signal processing system and is used for inputting sine feedback signals and cosine feedback signals which are generated by induction of the secondary winding of the rotary transformer into the digital signal processing system.

In an embodiment of the present utility model, there is provided a fault detection circuit of a motor rotation transformer circuit, including: the filter circuit is connected with the digital signal processing system and the gain and bias circuit and is used for converting the pulse width modulation signal generated by the digital signal processing system into a sine wave signal and inputting the sine wave signal into the gain and bias circuit for connection; the gain and bias circuit is connected with the push-pull circuit and used for increasing the amplitude of the sine wave signal to a target amplitude to obtain a target sine wave signal and inputting the target sine wave signal into the push-pull circuit; the push-pull circuit is connected with the voltage dividing and sampling circuit and is used for carrying out power amplification on the target sine wave signal to obtain a rotary excitation signal, and the rotary excitation signal is input to the rotary transformer; the voltage dividing and sampling circuit is connected with the push-pull circuit and the digital signal processing system and is used for dividing the differential voltage at two ends of the output current limiting resistor of the push-pull circuit to obtain a target voltage and inputting the target voltage into the digital signal processing system; the digital signal processing system is used for determining whether the motor rotating circuit breaks down through the target voltage and determining the type and the position of the fault under the condition of the fault, sampling the differential voltage at two ends of the output current limiting resistor of the exciting push-pull circuit in the motor rotating circuit, and diagnosing the type and the fault position of the motor rotating circuit breaking down through the characteristics of the sampling value, so that the purpose of comprehensively judging the fault type of the motor rotating circuit is achieved, the technical effect of effectively protecting the motor rotating circuit is achieved, and the technical problem that the motor rotating circuit cannot be effectively protected due to the fact that the fault type of the motor rotating circuit cannot be comprehensively judged in the prior art is solved.

Drawings

The accompanying drawings, which are included to provide a further understanding of the utility model and are incorporated in and constitute a part of this specification, illustrate embodiments of the utility model and together with the description serve to explain the utility model and do not constitute a limitation on the utility model. In the drawings:

fig. 1 is a schematic diagram of a fault detection circuit of a motor rotary transformer circuit according to an embodiment of the present utility model;

fig. 2 is a schematic diagram of a fault detection circuit of another motor rotary transformer circuit according to an embodiment of the present utility model;

fig. 3 is a schematic diagram of a fault detection circuit of another motor rotary transformer circuit according to an embodiment of the present utility model;

fig. 4 is a schematic structural diagram of a fault detection circuit of another motor rotary transformer circuit according to an embodiment of the present utility model;

fig. 5 is a schematic diagram of a fault detection circuit of another motor rotary transformer circuit according to an embodiment of the present utility model;

fig. 6 is a schematic diagram of a fault detection circuit of another motor rotary transformer circuit according to an embodiment of the present utility model;

fig. 7 is a schematic diagram of a fault detection circuit of another motor rotary transformer circuit according to an embodiment of the present utility model;

fig. 8 is a schematic diagram of a fault detection circuit of another motor rotary transformer circuit according to an embodiment of the present utility model;

fig. 9 is a schematic diagram of a fault detection circuit of another motor rotary transformer circuit according to an embodiment of the present utility model;

fig. 10 is a schematic diagram of a fault detection circuit of another motor rotary transformer circuit according to an embodiment of the present utility model;

fig. 11 is a schematic diagram of a motor rotary transformer circuit according to an embodiment of the present utility model.

Detailed Description

In order that those skilled in the art will better understand the present utility model, a technical solution in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in which it is apparent that the described embodiments are only some embodiments of the present utility model, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present utility model without making any inventive effort, shall fall within the scope of the present utility model.

It should be noted that the terms "first," "second," and the like in the description and the claims of the present utility model and the above figures are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that the embodiments of the utility model described herein may be implemented in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

In order to better understand the embodiments of the present utility model, technical terms related to the embodiments of the present utility model are explained as follows:

a rotary transformer: the rotary transformer is a short term for rotary transformers, and is commonly used for measuring the angular displacement and angular velocity of a rotating shaft of a rotating object. In general, in the field of vehicle-mounted motor controllers, a rotary transformer is generally used as an angle and position sensor of a motor, the rotary transformer comprises a primary exciting winding and two secondary windings, the two secondary windings are placed at 90 degrees, the primary side and the secondary windings of the rotary transformer are changed along with the angular displacement of a rotor relative to a magnetic coupling path, so that the magnitude of secondary side voltage is changed along with the angular displacement of the rotor, and the voltage amplitude of the two secondary windings and the rotor rotation angle are respectively in a sine and cosine function relationship.

In the related art, whether the resolver circuit fails or not is judged normally by detecting whether the amplitude of the resolver feedback signal is normal or not, but the failure position and the failure type cannot be located effectively. In another related art, the excitation output is sampled by adding a differential operational amplifier, the excitation fault is judged by the voltage value after the differential, the method can only identify the short circuit and the short power supply fault,

in summary, there is a problem that the fault type of the resolver circuit cannot be comprehensively determined. In order to solve the problem, the utility model provides a fault detection circuit of a motor rotary transformer circuit, which is described in detail below.

Fig. 1 is a schematic structural diagram of a fault detection circuit of a motor rotary transformer circuit according to an embodiment of the present utility model, and as shown in fig. 1, the fault detection circuit includes: filter circuit 102, gain and bias circuit 104, push-pull circuit 106, voltage dividing and sampling circuit 108, and digital signal processing system 110, wherein,

the filter circuit 102 is connected to the digital signal processing system 110 and the gain and bias circuit 104, and is configured to convert the pwm signal generated by the digital signal processing system 110 into a sine wave signal, and input the sine wave signal to the gain and bias circuit 104.

According to an alternative embodiment of the present utility model, the filtering circuit 102 converts the unipolar pulse width modulated signal from the digital signal processing system 110 into a sine wave signal having a frequency of 10kHz by means of a two-stage second order low pass filter.

A gain and bias circuit 104 connected to the push-pull circuit 106 for increasing the amplitude of the sine wave signal to a target amplitude to obtain a target sine wave signal, and inputting the target sine wave signal to the push-pull circuit 106

According to another alternative embodiment of the present utility model, since the initial excitation signal output by the filter in the filter circuit 102 is 3.3VVpp, and the requirements of 2Vrms to 10Vrms of the input voltage of the ramp cannot be met, the gain and bias circuit 104 increases the amplitude of the excitation signal to meet the requirements of the input voltage of the ramp by superimposing the sinusoidal excitation signal with a fixed gain and a voltage bias.

The push-pull circuit 106 is connected to the voltage dividing and sampling circuit 108, and is configured to amplify the power of the target sine wave signal, obtain a resolver excitation signal, and input the resolver excitation signal to the resolver.

In an alternative embodiment, push-pull circuit 106 achieves the current amplification requirement by power amplifying the output voltage of the op-amp in gain and bias circuit 104. In order to improve the output capability of excitation, a class A-B amplifier with a large capacitance at the output end is omitted through the push-pull circuit 106, and a static working point is arranged in the push-pull circuit 106 through a base diode, so that the condition of crossover distortion of excitation output is prevented.

The voltage dividing and sampling circuit 108 is connected to the push-pull circuit 106 and the digital signal processing system, and is configured to divide the differential voltage across the output current limiting resistor of the push-pull circuit 106 to obtain a target voltage, and input the target voltage to the digital signal processing system 110.

In some alternative embodiments of the present utility model, the common mode voltage to ground and the stimulus output voltage values across the current limiting resistor are close together, exceeding the common mode voltage input range of the digital signal processing system 110. The voltage dividing and sampling circuit 108 divides the differential voltage across the output current limiting resistor of the push-pull circuit 106, so that the differential voltage across the output current limiting resistor of the push-pull circuit 106 meets the range of the input voltage of the digital signal processing system 110.

The digital signal processing system 110 is used for determining whether the motor rotation circuit fails or not through the target voltage, and in the case of failure, the type and the position of the failure.

According to the circuit, the differential voltage at the two ends of the output current limiting resistor of the excitation push-pull circuit in the motor rotary transformer circuit is sampled, the type and the fault position of the motor rotary transformer circuit are diagnosed through the characteristics of the sampled value, the purpose of comprehensively judging the fault type of the motor rotary transformer circuit is achieved, and therefore the technical effect of effectively protecting the rotary transformer circuit is achieved.

Fig. 2 is a schematic structural diagram of a fault detection circuit of another motor resolver according to an embodiment of the present utility model, and as shown in fig. 2, a digital signal processing system 110 includes: a signal generation block 11002, a processor 11004, and a digital to analog conversion block 11006, wherein,

the signal generation module 11002 is configured to generate a pulse width modulated signal.

A processor 11004 for determining whether the motor rotation circuit has failed through the target voltage, and in case of failure, the type and location of the failure.

The analog-to-digital conversion module 11006 is configured to convert the target voltage from an analog signal to a digital signal.

According to an alternative embodiment of the present utility model, the digital signal processing system 110 sets a reference voltage value, and the processor 11004 determines whether the motor rotation circuit is faulty or not according to the result of comparing the reference voltage value with the target voltage value, and the processor 11004 also has a function of judging the type of fault and the location of the fault. The analog-to-digital conversion block 11006 contains multiple parallel digital-to-analog conversion channels, each of which can be independently applied to samples of a differential signal (target voltage).

Fig. 3 is a schematic structural diagram of a fault detection circuit of another motor resolver according to an embodiment of the present utility model, and as shown in fig. 3, a filter circuit 102 includes: a first filter 10202 and a second filter 10204, wherein,

the first filter 10202 is connected to the signal generation block 11002 and the gain and bias circuit 104, respectively, and converts the pulse width modulated signal into a sine wave signal.

The second filter 10204 is connected to the signal generating module 11002 and the gain and bias circuit 104, respectively, and is used for converting the pulse width modulated signal into a sine wave signal, wherein the first filter 10202 and the second filter 10204 are low-pass filters.

According to another alternative embodiment of the present utility model, the first filter 10202 and the second filter 10204 respectively convert the unipolar pwm signal sent from the signal generating module 11002 into a sine wave signal with a frequency of 10kHz through two-stage second-order low-pass filters, and the first filter 10202 and the second filter 10204 are both low-pass filters.

Fig. 4 is a schematic structural diagram of a fault detection circuit of another motor resolver according to an embodiment of the present utility model, and as shown in fig. 4, the gain and bias circuit 104 includes: a first operational amplifier circuit 10402 and a second operational amplifier circuit 10404, wherein,

the first operational amplifier circuit 10402 is connected to the first filter 10202, and is configured to boost the amplitude of the sine wave signal to a target amplitude, so as to obtain a target sine wave signal.

The second operational amplifier circuit 10404 is connected to the second filter 10204, and is configured to boost the amplitude of the sine wave signal to a target amplitude, so as to obtain a target sine wave signal.

Fig. 5 is a schematic structural diagram of a fault detection circuit of another motor resolver according to an embodiment of the present utility model, and as shown in fig. 5, a push-pull circuit 106 includes: a first amplifier circuit 10602 and a second amplifier circuit 10604, where,

the first amplifier circuit 10602 is connected to the first operational amplifier circuit 10402, and amplifies the power of the target sine wave signal to obtain a spin excitation signal.

The second amplifier circuit 10604 is connected to the second operational amplifier circuit 10404, and amplifies the power of the target sine wave signal to obtain a spin excitation signal.

The push-pull circuit 106 is configured to perform power amplification on the output voltage of the first operational amplifier circuit 10402 by the first amplifier circuit 10602 in order to satisfy the input current requirement of the resolver, thereby realizing the current amplification requirement; the 1 st amplifier circuit amplifies the output voltage of the second operational amplifier circuit 10404 to thereby realize the current amplification.

Fig. 6 is a schematic structural diagram of a fault detection circuit of another motor resolver according to an embodiment of the present utility model, and as shown in fig. 6, the push-pull circuit 106 further includes: first resistor 1060202, second resistor 1060204, third resistor 1060402, and fourth resistor 1060404, wherein,

the first resistor 1060202 and the second resistor 1060204 are connected in series in the first amplifier circuit 10602, and limit the output current of the first amplifier circuit 10602.

The third resistor 1060402 and the fourth resistor 1060404 are connected in series in the second amplifier circuit 10604, and limit the output current of the second amplifier circuit 10604.

Fig. 7 is a schematic structural diagram of a fault detection circuit of another motor resolver according to an embodiment of the present utility model, and as shown in fig. 7, the push-pull circuit 106 further includes: a first diode 160206 and a second diode 160406, wherein,

a first diode 160206 is connected to the first amplifier circuit 10602 for providing a static operating point for the first amplifier circuit 10602 to prevent crossover distortion of the gyratory excitation signal.

The second diode 160406 is connected to the second amplifier circuit 10604 for setting a static operating point for the second amplifier circuit 10604 to prevent crossover distortion of the gyratory excitation signal.

When the input voltage is low, the distortion generated by the cut-off of the triode is called crossover distortion, the crossover distortion usually occurs at the position passing through a zero value, and the method for eliminating the crossover distortion is the same as that of a common amplifying circuit, and a proper static working point is set so that the triode is micro-conductive in the static state.

Fig. 8 is a schematic structural diagram of a fault detection circuit of another motor rotation transformer circuit according to an embodiment of the present utility model, and as shown in fig. 8, a voltage dividing and sampling circuit 108 in a rotation transformer excitation signal protection circuit includes: a first voltage dividing and sampling circuit 10802, a second voltage dividing and sampling circuit 10804, a third voltage dividing and sampling circuit 10806, and a fourth voltage dividing and sampling circuit 10808, wherein,

the first voltage dividing and sampling circuit 10802 is configured to collect voltages at two ends of the first resistor 1060202 to obtain a first target voltage, and input the first target voltage to the digital signal processing system 110.

The second voltage dividing and sampling circuit 10804 is configured to collect voltages at two ends of the second resistor 1060204 to obtain a second target voltage, and input the second target voltage to the digital signal processing system 110.

The third voltage dividing and sampling circuit 10806 is configured to collect voltages at two ends of the third resistor 1060402 to obtain a third target voltage, and input the third target voltage to the digital signal processing system 110.

The fourth voltage dividing and sampling circuit 10808 is configured to collect voltages at two ends of the fourth resistor 1060404 to obtain a fourth target voltage, and input the fourth target voltage to the digital signal processing system 110.

Fig. 9 is a schematic diagram of a fault detection circuit of another motor resolver according to an embodiment of the present utility model, as shown in fig. 9, the first voltage dividing and sampling circuit 10802, the second voltage dividing and sampling circuit 10804, the third voltage dividing and sampling circuit 10806, and the fourth voltage dividing and sampling circuit 10808 respectively include four resistors and two capacitors, wherein,

the four resistors include: fifth resistor 1080202, sixth resistor 1080204, seventh resistor 1080206, and eighth resistor 1080208, the two capacitors comprising: a first capacitor 1080210 and a second capacitor 1080212.

The fifth resistor 1080202 and the first capacitor 1080210 are connected in parallel, and the combined parallel circuit and sixth resistor 1080204 are connected in series, and the first series circuit 108021 is combined.

The seventh resistor 1080206 and the second capacitor 1080212 are connected in parallel, and the resulting parallel circuit and the eighth resistor 1080208 are connected in series, forming a second series circuit 108022.

The first series circuit 108021 and the second series circuit 108022 are connected in parallel to constitute a first voltage dividing and sampling circuit 10802, or a second voltage dividing and sampling circuit 10804, or a third voltage dividing and sampling circuit 10806, or a fourth voltage dividing and sampling circuit 10808.

Fig. 9 illustrates an example in which the first voltage dividing and sampling circuit 10802 includes a first series circuit and a second series circuit.

Fig. 10 is a schematic structural diagram of a motor rotation-transformation circuit according to an embodiment of the present utility model, as shown in fig. 10, including:

a fault detection circuit 1002 of the resolver circuit;

it will be appreciated that the preferred embodiment of the fault detection circuit 1002 of a resolver circuit may be seen from the relevant description of the fault detection circuit of a resolver circuit described in any one of figures 1 to 9.

A rotary transformer 1004;

and the feedback conditioning circuit 1006 is connected with the digital signal processing system in the fault detection circuit 1002 of the rotary transformer 1004 and the rotary transformer circuit, and is used for inputting sine feedback signals and cosine feedback signals induced by the secondary winding of the rotary transformer 1004 into the digital signal processing system.

Fig. 11 is a schematic structural diagram of a fault detection circuit of another motor rotary transformer circuit according to an embodiment of the present utility model, and in fig. 11, the operation principle of each circuit is as follows:

and a filter circuit: a unipolar pulse width modulation signal sent by a signal generating module in a digital signal processing system is converted into a sine wave signal with the frequency of 10kHz through a two-stage second-order low-pass filter.

Gain and bias circuit: because the initial excitation signal output by the filter in the filter circuit is 3.3Vvpp and cannot meet the requirement of 2 Vrms-10 Vrms of the input voltage of the rotation change, the gain and bias circuit increases the amplitude of the excitation signal to meet the requirement of the input voltage of the rotation change in a mode of superposing the sine excitation signal with fixed gain and voltage bias.

Push-pull circuit: in order to improve the excitation output capability, a push-pull circuit is used for forming an A class-B amplifier without a large capacitance at the output end, and a base diode is used for setting a static working point for the circuit to prevent crossover distortion of the excitation output.

And the voltage dividing and sampling circuit: when the digital-to-ground conversion module works statically, the common-mode voltage values at the two ends of the current-limiting resistor are close to the excitation output voltage value, and the amplitude exceeds the common-mode voltage input range of the port of the digital-to-analog conversion module, so that the common-mode voltage values at the two ends of the resistor are required to be subjected to resistor voltage division and then sent to the digital-to-analog conversion module, wherein the voltage-reduction gain is G1.

In the voltage dividing and sampling circuit, R1 and R2 are connected in series to form a voltage dividing circuit, C2 and R1/R2 form a low-pass filter circuit, wherein R1/R2 refers to a circuit formed by connecting R1 and R2 in parallel.

And the analog-to-digital conversion module is used for: and sending the terminal voltage value with the proper common-mode voltage range into two ports of the channel of the analog-digital conversion module for differential processing to obtain the characteristic voltage value of the current-limiting resistor. When the rotary hardening piece is excited to work normally, the current flowing through the current limiting resistor is extremely small, and under the short-circuit working condition, the current is increased to hundreds of mA; therefore, voltages at two ends of the current limiting resistor are collected to reflect loop current, whether the rotation excitation fails or not can be judged through a processor of the digital signal processing system, and the faults can be classified according to voltage characteristics.

According to an alternative embodiment of the present utility model, since the excitation conditioning circuits of the excitation positive electrode and the excitation negative electrode are identical, a group of circuits is analyzed by taking the excitation conditioning circuit of the excitation negative electrode as an example, and the fault diagnosis principle is as follows:

1. exciting the negative electrode to short circuit to ground:

transistor Q1 operates in an amplifying state and Q2 operates in a blocking state.

Triode short-circuit current on push-pull circuit: (triode is Si tube, PN conduction voltage drop is 0.7V)

Drawing a curve of formula 1 and matching with h of triode _FE -I _c The characteristic curves are intersected to obtain the gain minimum value h of the triode _FEmin Substituting it into equation 2 yields:

2. exciting the positive electrode to ground short circuit:

3. excitation negative electrode short circuit to power KL 30:

transistor Q2 operates in an amplifying state and Q1 operates in a blocking state.

Transistor short-circuit current under push-pull circuit:

minimum value of gain h _FEmin Substituting formula 3 can result in:

4. the excitation positive electrode is short-circuited to the power supply KL 30:

5. excitation is short:

if the excitation output is short-circuited, the excitation output has clipping phenomenon, the differential voltage at two ends of the current-limiting resistor is filtered, and the differential voltage is approximately square-wave along with the short-circuit current, and the square-wave amplitude is

Substituting the gain minimum value hFEmin into the formula 5 to obtain

In h _FEmin For example, =100, k1=4.2v, k2=3.5v, k3=1v. The three characteristic values are input into a digital signal processing system and compared with voltages on four resistors (R8, R14, R23 and R27) acquired in real time by a digital-to-analog conversion module, so that the type and the position of the excitation fault can be accurately positioned.

The foregoing embodiment numbers of the present utility model are merely for the purpose of description, and do not represent the advantages or disadvantages of the embodiments.

In the foregoing embodiments of the present utility model, the descriptions of the embodiments are emphasized, and for a portion of this disclosure that is not described in detail in this embodiment, reference is made to the related descriptions of other embodiments.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

The foregoing is merely a preferred embodiment of the present utility model and it should be noted that modifications and adaptations to those skilled in the art may be made without departing from the principles of the present utility model, which are intended to be comprehended within the scope of the present utility model.

Claims (10)

1. A fault detection circuit for a motor rotary transformer circuit, comprising: a filter circuit, a gain and bias circuit, a push-pull circuit, a voltage dividing and sampling circuit and a digital signal processing system, wherein,

the filter circuit is connected with the digital signal processing system and the gain and bias circuit and is used for converting a pulse width modulation signal generated by the digital signal processing system into a sine wave signal and inputting the sine wave signal into the gain and bias circuit;

the gain and bias circuit is connected with the push-pull circuit and is used for increasing the amplitude of the sine wave signal to a target amplitude to obtain a target sine wave signal and inputting the target sine wave signal into the push-pull circuit;

the push-pull circuit is connected with the voltage dividing and sampling circuit and is used for carrying out power amplification on the target sine wave signal to obtain a rotary excitation signal, and the rotary excitation signal is input to a rotary transformer;

the voltage dividing and sampling circuit is connected with the push-pull circuit and the digital signal processing system and is used for dividing the differential voltage at two ends of the output current limiting resistor of the push-pull circuit to obtain a target voltage, and inputting the target voltage to the digital signal processing system;

the digital signal processing system is used for determining whether the motor rotation circuit fails according to the target voltage, and the type and the position of the failure in the case of the failure.

2. The fault detection circuit of claim 1, wherein the digital signal processing system comprises:

the signal generation module is used for generating the pulse width modulation signal;

a processor for determining whether a motor rotation circuit is failed by the target voltage, and in case of failure, the type and location of the failure;

and the analog-to-digital conversion module is used for converting the target voltage from an analog signal to a digital signal.

3. The fault detection circuit of claim 2, wherein the filter circuit comprises: a first filter and a second filter, wherein,

the first filter is respectively connected with the signal generation module and the gain and bias circuit and is used for converting the pulse width modulation signal into the sine wave signal;

the second filter is respectively connected with the signal generation module and the gain and bias circuit and is used for converting the pulse width modulation signal into the sine wave signal;

wherein the first filter and the second filter are low pass filters.

4. The fault detection circuit of claim 3, wherein the gain and bias circuit comprises:

the first operational amplification circuit is connected with the first filter and is used for improving the amplitude of the sine wave signal to a target amplitude to obtain the target sine wave signal;

and the second operational amplification circuit is connected with the second filter and is used for improving the amplitude of the sine wave signal to a target amplitude to obtain the target sine wave signal.

5. The fault detection circuit of claim 4, wherein the push-pull circuit comprises:

the first amplifier circuit is connected with the first operational amplifier circuit and is used for carrying out power amplification on the target sine wave signal to obtain the rotation excitation signal;

and the second amplifier circuit is connected with the second operational amplifier circuit and is used for carrying out power amplification on the target sine wave signal to obtain the rotation excitation signal.

6. The fault detection circuit of claim 5, wherein the push-pull circuit further comprises: a first resistor, a second resistor, a third resistor and a fourth resistor, wherein,

the first resistor and the second resistor are connected in series in the first amplifier circuit and are output current limiting resistors of the first amplifier circuit;

the third resistor and the fourth resistor are connected in series in the second amplifier circuit and are output current limiting resistors of the second amplifier circuit.

7. The fault detection circuit of claim 5, wherein the push-pull circuit further comprises: a first diode and a second diode, wherein,

the first diode is connected in the first amplifier circuit and is used for setting a static working point for the first amplifier circuit so as to prevent crossover distortion of the rotation excitation signal;

the second diode is connected in the second amplifier circuit and is used for setting a static working point for the second amplifier circuit so as to prevent crossover distortion of the rotation-varying excitation signal.

8. The fault detection circuit of claim 6, wherein the voltage dividing and sampling circuit comprises: a first voltage dividing and sampling circuit, a second voltage dividing and sampling circuit, a third voltage dividing and sampling circuit and a fourth voltage dividing and sampling circuit, wherein,

the first voltage dividing and sampling circuit is used for collecting voltages at two ends of the first resistor to obtain a first target voltage, and inputting the first target voltage to the digital signal processing system;

the second voltage dividing and sampling circuit is used for collecting voltages at two ends of the second resistor to obtain a second target voltage, and inputting the second target voltage to the digital signal processing system;

the third voltage dividing and sampling circuit is used for collecting voltages at two ends of the third resistor to obtain a third target voltage, and inputting the third target voltage to the digital signal processing system;

and the fourth voltage dividing and sampling circuit is used for collecting the voltages at two ends of the fourth resistor to obtain a fourth target voltage, and inputting the fourth target voltage to the digital signal processing system.

9. The fault detection circuit of claim 8, wherein the first voltage dividing and sampling circuit, the second voltage dividing and sampling circuit, the third voltage dividing and sampling circuit, and the fourth voltage dividing and sampling circuit each comprise four resistors and two capacitors, wherein,

the four resistors include: fifth resistor, sixth resistor, seventh resistor and eighth resistor, two electric capacities include: a first capacitor and a second capacitor;

the fifth resistor and the first capacitor are connected in parallel, and the formed parallel circuit and the sixth resistor are connected in series to form a first series circuit;

the seventh resistor and the second capacitor are connected in parallel, and the formed parallel circuit and the eighth resistor are connected in series to form a second series circuit;

the first series circuit and the second series circuit are connected in parallel to form the first voltage division and sampling circuit, the second voltage division and sampling circuit, the third voltage division and sampling circuit, or the fourth voltage division and sampling circuit.

10. A motor spin-on circuit, comprising:

a fault detection circuit for a motor spin-on circuit according to any one of claims 1 to 9;

a rotary transformer;

and the feedback conditioning circuit is connected with the rotary transformer and the digital signal processing system and is used for inputting sine feedback signals and cosine feedback signals which are induced and generated by the secondary winding of the rotary transformer into the digital signal processing system.