JP7131682B1 - FAILURE DETECTION DEVICE, POWER CONVERSION DEVICE, AND FAILURE DETECTION PROGRAM - Google Patents

Abstract

A failure detection device for a magnetic sensor is provided. A first detection value whose value increases as the magnetic flux density generated by the first phase current increases, and a second detection value whose value decreases as the magnetic flux density generated by the first phase current increases. A third detection value obtained from the first magnetic sensor and the second magnetic sensor, and increasing as the magnetic flux density generated by the second phase current increases, and The acquisition unit 210 that acquires the fourth detection value that decreases as the value decreases from the third magnetic sensor and the fourth magnetic sensor, respectively; An estimation unit 220 that calculates an estimated value, a second estimated value obtained by estimating the second phase current using the third detected value, and a third estimated value obtained by estimating the second phase current using the fourth detected value. and a detection unit 230 that detects failure of either the third magnetic sensor or the fourth magnetic sensor based on the first estimated value, the second estimated value, and the third estimated value. [Selection drawing] Fig. 1

Description

The present invention relates to a failure detection device, a power conversion device, a failure detection program, and a current detector.

Patent Document 1 describes a control device for a three-phase AC motor that controls the rotation of the three-phase AC motor using a motor control current based on values measured by current sensors provided in each phase of the phase AC motor. , a technology for improving the durability against failure of current sensors”.
[Prior art documents]
[Patent Literature]
[Patent Document 1] JP-A-2000-116176
[Patent Document 2] JP-A-2000-275279
[Patent Document 3] JP-A-2006-064462
[Patent Document 4] JP 2012-122897

A first aspect of the present invention provides a fault detection device. The fault detection device includes a first detection value whose value increases as the magnetic flux density generated by the first phase current increases and a second detection value whose value decreases as the magnetic flux density generated by the first phase current increases. Detected values are obtained from the first magnetic sensor and the second magnetic sensor, respectively, and a third detected value whose value increases as the magnetic flux density generated by the second phase current increases and the magnetic flux density generated by the second phase current An acquisition unit may be provided for acquiring, from the third magnetic sensor and the fourth magnetic sensor, a fourth detection value whose value decreases in accordance with an increase in . The failure detection device estimates the second phase current using a first estimated value obtained by estimating the second phase current using the first detected value and the second detected value, and the third detected value. An estimator may be provided that calculates a third estimated value obtained by estimating the second phase current using the second estimated value and the fourth detected value. The failure detection device detects a failure of one of the third magnetic sensor and the fourth magnetic sensor based on the first estimated value, the second estimated value, and the third estimated value. You may provide the detection part which carries out.

Based on the difference between the first estimated value and the second estimated value and the difference between the first estimated value and the third estimated value, the detection unit detects the third magnetic sensor and A failure of any of the fourth magnetic sensors may be detected.

The detection unit determines in advance only one of a difference between the first estimated value and the second estimated value and a difference between the first estimated value and the third estimated value. A failure of either the third magnetic sensor or the fourth magnetic sensor may be detected if the criteria are not met.

The detection unit may detect a failure of the third magnetic sensor when the difference between the first estimated value and the second estimated value does not satisfy the predetermined criterion.

The detection unit may detect a failure of the fourth magnetic sensor when the difference between the first estimated value and the third estimated value does not satisfy the predetermined criterion.

The estimating unit further estimates the first phase current using a fourth estimated value obtained by estimating the first phase current using the third detected value and the fourth detected value, and the first detected value. A sixth estimated value obtained by estimating the first phase current using the fifth estimated value and the second detected value may be calculated. The detection unit further detects a failure of either the first magnetic sensor or the second magnetic sensor based on the fourth estimated value, the fifth estimated value, and the sixth estimated value. may be detected.

Based on the difference between the fourth estimated value and the fifth estimated value and the difference between the fourth estimated value and the sixth estimated value, the detection unit detects the first magnetic sensor and A failure of any of the second magnetic sensors may be detected.

The detection unit determines in advance only one of a difference between the fourth estimated value and the fifth estimated value and a difference between the fourth estimated value and the sixth estimated value. A failure of either the first magnetic sensor or the second magnetic sensor may be detected if the criteria are not met.

The detection unit may detect a failure of the first magnetic sensor when the difference between the fourth estimated value and the fifth estimated value does not satisfy the predetermined criterion.

The detection unit may detect a failure of the second magnetic sensor when the difference between the fourth estimated value and the fifth estimated value does not satisfy the predetermined criterion.

A second aspect of the present invention provides a power converter. The power conversion device may include the failure detection device. The power conversion device may include an inverter circuit including semiconductor switch elements. The power conversion device may include a drive circuit that drives the semiconductor switch element. The power conversion device may include a control circuit that controls the drive circuit.

The control circuit may perform feedback control based on the estimated value calculated using the detection values from the magnetic sensors in which failure is not detected, when a failure is detected in any of the magnetic sensors.

Magnitudes of magnetic flux densities respectively detected by the first magnetic sensor and the second magnetic sensor are calculated on the board on which the control circuit is mounted, using the first detected value and the second detected value. An arithmetic circuit may be implemented that obtains an arithmetic result according to the sum.

The arithmetic circuit further calculates the sum of the magnitudes of the magnetic flux densities detected by the third magnetic sensor and the fourth magnetic sensor by performing calculations using the third detected value and the fourth detected value. Arithmetic results may be obtained.

A third aspect of the present invention provides a fault detection program. The failure detection program may be executed by a computer. The fault detection program causes the computer to detect a first detection value whose value increases as the magnetic flux density generated by the first phase current increases, and a value which increases as the magnetic flux density generated by the first phase current increases. A decreasing second detected value is acquired from each of the first magnetic sensor and the second magnetic sensor, and a third detected value whose value increases in accordance with an increase in the magnetic flux density generated by the second phase current and the second phase current It may function as an acquisition unit that acquires, from the third magnetic sensor and the fourth magnetic sensor, a fourth detection value whose value decreases as the generated magnetic flux density increases. The fault detection program causes the computer to generate the second phase current using the first estimated value obtained by estimating the second phase current using the first detected value and the second detected value, and the third detected value. It may function as an estimation unit that calculates a second estimated value of the current and a third estimated value of the second phase current using the fourth detected value. The failure detection program causes the computer to detect one of the third magnetic sensor and the fourth magnetic sensor based on the first estimated value, the second estimated value, and the third estimated value. may function as a detection unit that detects a failure of

In a fourth aspect of the invention, a current detector is provided. The current detector may include a first magnetic sensor that detects a first detection value that increases as the magnetic flux density generated by the current flowing through the conductor increases. The current detector may include a second magnetic sensor that detects a second detection value that decreases as the magnetic flux density generated by the current flowing through the conductor increases. The current detector performs calculations using the first detection value and the second detection value in accordance with the sum of the magnitudes of the magnetic flux densities detected by the first magnetic sensor and the second magnetic sensor, respectively. Arithmetic circuitry may be provided to obtain the result. The current detector may include an output unit that outputs the first detected value, the second detected value, and the calculation result.

It should be noted that the above summary of the invention does not list all the features of the invention. Subcombinations of these feature groups can also be inventions.

An example of a power conversion device 100 including a failure detection device 200 according to this embodiment is shown together with a power source 10 and a motor 20 . The configuration of the current detector 170 is shown together with the conductor 140, taking the first phase current detector 170u as an example. An example of a flow of detecting a failure of a magnetic sensor by the failure detection device 200 according to this embodiment is shown. It shows the relationship between the magnetic sensor whose failure has been detected by the failure detection device 200 according to the present embodiment and the current value used for feedback control. A modified example of a power conversion device 100' including a failure detection device 200 according to this embodiment is shown together with a power source 10 and a motor 20. FIG. 9900 illustrates an example computer 9900 in which aspects of the present invention may be embodied in whole or in part.

Hereinafter, the present invention will be described through embodiments of the invention, but the following embodiments do not limit the invention according to the claims. Also, not all combinations of features described in the embodiments are essential for the solution of the invention.

FIG. 1 shows an example of a power conversion device 100 including a failure detection device 200 according to this embodiment, together with a power supply 10 and a motor 20. As shown in FIG. The power conversion device 100 controls the motor 20 by converting the power supplied from the power supply 10 and supplying the converted power to the motor 20 .

The power supply 10 is a source that supplies power for controlling the motor 20 . The power supply 10 may be, for example, a 200V three-phase AC power supply. The power supply 10 supplies power to the motor 20 via the power converter 100 .

The motor 20 is a device that converts electrical energy (electric power) into mechanical energy (power). The motor 20 converts electric power supplied from the power supply 10 and converted by the power converter 100 into motive power.

The power conversion device 100 converts the power obtained from the power source 10 by controlling the voltage, frequency, etc., and supplies the converted power to the motor 20 in order to operate the motor 20 at a desired rotation speed and torque. The power converter 100 includes a rectifier circuit 110 , a smoothing capacitor 120 , an inverter circuit 130 , a conductor 140 , a control circuit 150 , a drive circuit 160 , a current detector 170 and a failure detection device 200 .

The rectifier circuit 110 has six diodes connected in a bridge and rectifies the AC output of the power supply 10 .

Smoothing capacitor 120 is connected between the DC output terminals of rectifier circuit 110 and smoothes the output of rectifier circuit 110 .

The inverter circuit 130 is connected between the DC output terminals of the rectifier circuit 110 , converts the output of the rectifier circuit 110 and supplies it to the motor 20 . The inverter circuit 130 may be, for example, a three-phase voltage-controlled inverter circuit, converts the DC voltage output from the rectifier circuit 110 into a three-phase AC voltage, and supplies it to the motor 20, which is a three-phase AC motor. At this time, the speed of the motor 20 can be changed by changing the output frequency of the inverter circuit 130 . Such an inverter circuit 130 is configured, for example, by connecting first to third arm circuits in parallel. Each arm circuit includes two semiconductor switch elements composed of transistors connected in series, and diodes connected in anti-parallel between the emitters and collectors of the transistors constituting these semiconductor switch elements. In addition, in this figure, a case where the semiconductor switch element is an IGBT (Insulated Gate Bipolar Transistor) is shown as an example. However, it is not limited to this. Various switching elements such as transistors and MOS-FETs may be used as semiconductor switching elements. Connection points of two semiconductor switch elements in each arm circuit constitute an output point U, an output point V, and an output point W, respectively.

The conductors 140 are wiring through which a U-phase current, a V-phase current, and a W-phase current (also referred to as “motor current”) flow. (collectively referred to as "conductors 140"). One end of each of the three-phase conductors 140 is connected to the output point of the inverter circuit 130, and the other end is connected to the end of the exciting winding of the motor 20, which is a three-phase induction motor. That is, the U-phase conductor 140 u has one end connected to the output point U and the other end connected to the end of the U-phase excitation winding of the motor 20 . The V-phase conductor 140 v has one end connected to the output point V and the other end connected to the end of the V-phase excitation winding of the motor 20 . The W-phase conductor 140 w has one end connected to the output point W and the other end connected to the end of the W-phase excitation winding of the motor 20 .

The control circuit 150 controls the drive circuit 160 by giving command signals necessary for controlling the motor 20 to the drive circuit 160 according to various measured physical quantities (current, voltage, rotation speed, etc.).

The drive circuit 160 drives the gates of the transistors forming the semiconductor switch elements. Drive circuit 160 drives the gates of the transistors that form the semiconductor switch elements included in inverter circuit 130 based on, for example, a control command from control circuit 150, such as a PWM (Pulse Width Modulation) command signal.

In such a power converter 100, feedback control based on the motor current is performed by feeding back the motor current. Therefore, the power conversion device 100 is provided with a current detector 170 on the conductor 140 through which the motor current flows.

The current detector 170 includes a pair of magnetic sensors, each detecting a value corresponding to the magnetic flux density generated by the current flowing through the conductor 140 . Details of the current detector 170 will be described later. In the present embodiment, such a current detector 170 may be provided in at least two phase conductors 140 among the three phase conductors 140 . In this figure, a case is shown as an example where the U phase in the three-phase alternating current is defined as the "first phase" and the W phase is defined as the "second phase". That is, the U-phase conductor 140u and the W-phase conductor 140w are provided with a first-phase current detector 170u and a second-phase current detector 170w (collectively referred to as "current detectors 170"), respectively. . However, it is not limited to this. Current detector 170 may be provided on U-phase conductor 140u and V-phase conductor 140v, or may be provided on V-phase conductor 140v and W-phase conductor 140w. Further, in the above description, the case where the current detectors 170 are provided only for the two-phase conductors 140 out of the three-phase conductors 140 is shown as an example, but the current detectors 170 are provided for all three phases. It does not exclude cases. That is, the current detector 170 may be provided for all of the U-phase conductor 140u, the V-phase conductor 140v, and the W-phase conductor 140w.

The failure detection device 200 obtains a detection value from the magnetic sensor included in the current detector 170 and estimates the phase current. Then, failure detection device 200 detects failure of any magnetic sensor included in current detector 170 based on the estimated value of the phase current.

Failure detection device 200 includes acquisition section 210 , estimation section 220 , and detection section 230 . Note that these blocks are functional blocks that are functionally separated from each other, and do not necessarily match the actual device configuration. That is, in this figure, one block does not necessarily consist of one device. Also, in this figure, even though they are shown as separate blocks, they do not necessarily have to be configured by separate devices. In addition, in this figure, failure detection device 200 is shown as a block different from control circuit 150 and drive circuit 160, but part or all of failure detection device 200 is part of control circuit 150 and drive circuit 160. It may be configured integrally with at least one of them. As an example, the control circuit 150 and the failure detection device 200 may be configured integrally, and these functions may be realized by one CPU.

The obtaining unit 210 obtains a first detection value whose value increases as the magnetic flux density generated by the first phase current (U-phase current) increases and a value which decreases as the magnetic flux density generated by the first phase current increases. A second detection value is obtained from each of the first magnetic sensor and the second magnetic sensor. Here, the first magnetic sensor is one magnetic sensor included in the first phase current detector 170u, and the second magnetic sensor is the other magnetic sensor included in the first phase current detector 170u. . Similarly, the acquisition unit 210 obtains a third detection value whose value increases as the magnetic flux density generated by the second phase current (W-phase current) increases, and A decreasing fourth detection value is obtained from each of the third magnetic sensor and the fourth magnetic sensor. Here, the third magnetic sensor is one magnetic sensor included in the second phase current detector 170w, and the fourth magnetic sensor is the other magnetic sensor included in the second phase current detector 170w. .

At this time, if the current detector 170 includes an arithmetic circuit, which will be described later, the obtaining unit 210 may obtain the first arithmetic result and the second arithmetic result together. The acquisition unit 210 supplies the acquired first detection value, second detection value, third detection value, and fourth detection value, and the first calculation result and the second calculation result to the estimation unit 220 .

The estimating unit 220 generates a first estimated value obtained by estimating the second phase current using the first detected value and the second detected value, a second estimated value obtained by estimating the second phase current using the third detected value, Then, a third estimated value is calculated by estimating the second phase current using the fourth detected value. Similarly, the estimating unit 220 further estimates the first phase current using the third and fourth detection values to estimate the first phase current. 5 and a sixth estimated value obtained by estimating the first phase current using the second detected value. The estimation unit 220 supplies the calculated first estimated value, second estimated value, third estimated value, fourth estimated value, fifth estimated value, and sixth estimated value to the detected unit 230. do.

Detection unit 230 detects a failure of either the third magnetic sensor or the fourth magnetic sensor based on the first estimated value, the second estimated value, and the third estimated value. Similarly, the detection unit 230 further detects failure of either the first magnetic sensor or the second magnetic sensor based on the fourth estimated value, the fifth estimated value, and the sixth estimated value. . Then, the detection unit 230 supplies an estimated value according to the detection result to the control circuit 150 . In response to this, the control circuit 150 performs feedback control based on the estimated value supplied from the detection section 230 . This will also be described later.

FIG. 2 shows the configuration of the current detector 170 together with the conductor 140, taking the first phase current detector 170u as an example. The first phase current detector 170u includes a first magnetic sensor 171, a second magnetic sensor 172, a first arithmetic circuit 175u, and a first output section 176u.

The first magnetic sensor 171 and the second magnetic sensor 172 are arranged to face each other across the U-phase conductor 140u, and the first magnetic sensor 171 and the second magnetic sensor 172 constitute a pair of magnetic sensors. is doing.

In the first magnetic sensor 171, the direction of the magnetic flux generated by the first phase current flowing in the U-phase conductor 140u may be substantially the same as the detection direction (axis) of the sensor. That is, the first magnetic sensor 171 may detect the first detection value iu_det1 whose value increases as the magnetic flux density generated by the first phase current flowing through the U-phase conductor 140u increases. More preferably, the first magnetic sensor 171 may detect the first detection value iu_det1 whose value increases in proportion to the magnetic flux density generated by the first phase current flowing through the U-phase conductor 140u. The first magnetic sensor 171 supplies the detected first detection value iu_det1 to the first arithmetic circuit 175u and the first output section 176u.

In the second magnetic sensor 172, the direction of the magnetic flux generated by the first phase current flowing in the U-phase conductor 140u may be substantially opposite to the detection direction (axis) of the sensor. That is, the second magnetic sensor 172 may detect the second detection value iu_det2 whose value decreases as the magnetic flux density generated by the first phase current flowing through the conductor 140u increases. More preferably, the second magnetic sensor 172 may detect the second detection value iu_det2 whose value decreases in proportion to the magnetic flux density generated by the first phase current flowing through the conductor 140u. The second magnetic sensor 172 supplies the detected second detection value iu_det2 to the first arithmetic circuit 175u and the first output section 176u.

In this way, the first magnetic sensor 171 and the second magnetic sensor 172 are arranged to face each other across the conductor 140 through which the target current flows. The other detection direction is substantially opposite to the direction of the magnetic flux generated by the target current. That is, the first magnetic sensor 171 and the second magnetic sensor 172 are configured to be able to detect the first detection value iu_det1 and the second detection value iu_det2, which have substantially the same magnitude and different polarities, respectively.

The first arithmetic circuit 175u inputs the first detection value iu_det1 and the second detection value iu_det2. Then, the first arithmetic circuit 175u calculates the sum of the magnetic flux densities detected by the first magnetic sensor 171 and the second magnetic sensor 172 by calculation using the first detection value iu_det1 and the second detection value iu_det2. obtain a first operation result iu_det according to . The first arithmetic circuit 175u may be any circuit capable of obtaining such arithmetic results. As an example, the first arithmetic circuit 175u may be a differential circuit, and may obtain the first arithmetic result iu_det by differential arithmetic using the first detection value iu_det1 and the second detection value iu_det2. At this time, the first arithmetic circuit 175u inputs the first detection value iu_det1 to the non-inverting input terminal of the difference circuit, inputs the second detection value iu_det2 to the inverting input terminal, and sets the gain to 1 to obtain the first It is possible to obtain the first calculation result iu_det corresponding to approximately twice the one-phase current. The first arithmetic circuit 175u supplies the obtained first arithmetic result iu_det to the first output section 176u. In the above description, the case where the first arithmetic circuit 175u sets the gain to 1 and obtains the first arithmetic result iu_det corresponding to approximately twice the first phase current is shown as an example, but the present invention is limited to this. not a thing The first arithmetic circuit 175u may obtain the first arithmetic result iu_det corresponding to substantially the same multiple as the first phase current by adjusting the gain. Therefore, the term "first calculation result iu_det according to the sum of magnitudes of magnetic flux densities detected by the first magnetic sensor 171 and the second magnetic sensor 172" described above includes the first magnetic sensor 171 and the second magnetic sensor 172. In addition to the calculation result corresponding to the sum of the magnitudes of the magnetic flux densities detected by the two magnetic sensors 172, it is defined to include such gain-adjusted calculation results. In addition, the "total" described in this specification is to calculate by combining two or more values, and the calculation may include the four arithmetic operations of sum, difference, product, quotient and other calculations.

The first output unit 176u outputs the first detection value iu_det1, the second detection value iu_det2, and the first calculation result iu_det.

Although the description is omitted here, the second-phase current detector 170w may be configured in the same manner as the first-phase current detector 170u. That is, the second phase current detector 170w may include a third magnetic sensor 173, a fourth magnetic sensor 174, a second arithmetic circuit 175w, and a second output section 176w. Here, the "first arithmetic circuit 175u" and the "second arithmetic circuit 175w" are collectively referred to as "the arithmetic circuit 175". Also, the "first output section 176u" and the "second output section 176w" are collectively referred to as the "output section 176". In this case, the third magnetic sensor 173 may detect the third detection value iw_det1 whose value increases as the magnetic flux density generated by the second phase current flowing through the W-phase conductor 140w increases. Similarly, the fourth magnetic sensor 174 may detect a fourth detection value iw_det2 whose value decreases as the magnetic flux density generated by the second phase current flowing through the W-phase conductor 140w increases. In addition, the second arithmetic circuit 175w calculates the sum of the magnetic flux densities detected by the third magnetic sensor 173 and the fourth magnetic sensor 174 by calculation using the third detected value iw_det1 and the fourth detected value iw_det2. may obtain a second operation result iw_det according to . Then, the second output unit 176w may output the third detection value iw_det1, the fourth detection value iw_det2, and the second calculation result iw_det.

The failure detection device 200 according to the present embodiment thus acquires detection values from the current detectors 170 provided in the conductors 140 of at least two phases to estimate phase currents. Then, the failure detection device 200 according to the present embodiment detects failure of any magnetic sensor included in the current detector 170 based on the estimated value of the phase current. This will be described in detail using a flow.

FIG. 3 shows an example of a flow in which the fault detection device 200 according to this embodiment detects a fault in the magnetic sensor.

In step S310, failure detection device 200 obtains the first to fourth detection values and the first to second calculation results. For example, the acquisition unit 210 obtains a first detection value iu_det1 whose value increases as the magnetic flux density generated by the first phase current increases and a first detection value iu_det1 whose value decreases as the magnetic flux density generated by the first phase current increases. The second detection value iu_det2 is obtained from the first magnetic sensor 171 and the second magnetic sensor 172 included in the first phase current detector 170u through the first output section 176u. The acquisition unit 210 also acquires the first calculation result iu_det from the first calculation circuit 175u included in the first phase current detector 170u via the first output unit 176u.

Similarly, the obtaining unit 210 obtains a third detection value iw_det1 whose value increases as the magnetic flux density generated by the second phase current increases and whose value decreases as the magnetic flux density generated by the second phase current increases. A fourth detection value iw_det2 is obtained from the third magnetic sensor 173 and the fourth magnetic sensor 174 included in the second phase current detector 170w through the second output section 176w. The acquisition unit 210 also acquires the second calculation result iw_det from the second calculation circuit 175w included in the second phase current detector 170w via the second output unit 176w.

It should be noted that the term “obtain” here is not limited to direct acquisition from the current detector 170 . The acquisition unit 210 may acquire these detection values and calculation results, for example, via other devices, networks, etc., may acquire them via various memory devices, or may acquire them via user input. You may

In the above description, the case where the obtaining unit 210 obtains the first calculation result iu_det and the second calculation result iw_det from the first phase current detector 170u and the second phase current detector 170w is taken as an example. , but is not limited to this. If at least one of the first calculation result iu_det and the second calculation result iw_det is not supplied from the first phase current detector 170u and the second phase current detector 170w (for example, if the current detector 170 is not included), the obtaining unit 210 may obtain at least one of the first calculation result iu_det and the second calculation result iw_det by executing the same calculation as the calculation circuit 175. .

Acquisition unit 210 estimates the acquired first detection value iu_det1, second detection value iu_det2, third detection value iw_det1, and fourth detection value iw_det2, as well as first calculation result iu_det and second calculation result iw_det. supply to section 220;

In step S320, failure detection device 200 calculates a first estimated value, a second estimated value, and a third estimated value of the second phase current. For example, the estimating unit 220 estimates the second phase current using the first detected value iu_det1 and the second detected value iu_det2 to estimate the second phase current using the first estimated value iw_est(U) and the third detected value iw_det1. and a third estimated value iw_est(W2) of the second phase current using the fourth detected value iw_det2. This will be described in detail using mathematical formulas.

Each current detector 170 detects the magnetic flux generated by the other-phase current in addition to the magnetic flux generated by the own-phase current. Here, Kuv is the magnetic flux coupling parameter between the U and V phases, Kvw is the magnetic flux coupling parameter between the V and W phases, and Kvw is the magnetic flux coupling parameter between the W and U phases. be Kwu. Also, let iu be the U-phase current, iv be the V-phase current, and iw be the W-phase current. Here, if iu+iv+iw=0, the first detection value iu_det1 detected by the first magnetic sensor 171 included in the first phase current detector 170u is expressed by the following equation.

A second detection value iu_det2 detected by the second magnetic sensor 172 included in the first phase current detector 170u is expressed by the following equation.

Therefore, the sum of the first detection value iu_det1 and the second detection value iu_det2 is given by the following equation.

Also, the difference between the first detection value iu_det1 and the second detection value iu_det2 is given by the following equation.

Here, (Equation 4) is transformed into the following equation.

Then, by substituting (Equation 5) into (Equation 3), the estimation unit 220 obtains the first detection value iu_det1 obtained from the first magnetic sensor 171 and the second magnetic sensor 172 and Using the second detected value iu_det2, it is possible to calculate a first estimated value iw_est(U) that is an estimated second phase current. That is, the estimation unit 220 can estimate the second phase current without using the third detection value iw_det1 and the fourth detection value iw_det2 obtained from the third magnetic sensor 173 and the fourth magnetic sensor 174 .

A third detection value iw_det1 detected by the third magnetic sensor 173 included in the second phase current detector 170w is expressed by the following equation.

A fourth detection value iw_det2 detected by the fourth magnetic sensor 174 included in the second phase current detector 170w is expressed by the following equation.

Here, by arranging iw in (Equation 7) as iw_est(W1), the estimation unit 220 uses the third detection value iw_det1 acquired from the third magnetic sensor 173 as shown in the following equation. , a second estimate iw_est(W1) of the second phase current can be calculated. That is, the estimation unit 220 can estimate the second phase current without using the fourth detection value iw_det2 acquired from the fourth magnetic sensor 174 .

Similarly, by arranging iw in (Equation 8) as iw_est(W2), estimation unit 220 uses fourth detection value iw_det2 obtained from fourth magnetic sensor 174 as shown in the following equation: , a third estimated value iw_est(W2) of the second phase current can be calculated. That is, the estimation unit 220 can estimate the second phase current without using the third detection value iw_det1 acquired from the third magnetic sensor 173 .

For example, in this manner, the estimating unit 220 estimates the second phase current using the first detected value iu_det1 and the second detected value iu_det2, and uses the first estimated value iw_est(U) and the third detected value iw_det1. A second estimated value iw_est(W1) obtained by estimating the second phase current and a third estimated value iw_est(W2) obtained by estimating the second phase current using the fourth detected value iw_det2 can be calculated. . The estimator 220 supplies the calculated first estimated value iw_est(U), second estimated value iw_est(W1), and third estimated value iw_est(W2) to the detector 230 .

In step S330, the fault detection device 200 determines the difference between the first estimated value iw_est(U) and the second estimated value iw_est(W1), the first estimated value iw_est(U) and the third estimated value iw_est Determine whether only one of the differences in (W2) does not meet the criteria. For example, the detection unit 230 determines whether the absolute value of the difference between the first estimated value iw_est(U) and the second estimated value iw_est(W1) exceeds a predetermined threshold, and whether the first estimated value It is determined whether or not the absolute value of the difference between iw_est(U) and the third estimated value iw_est(W2) exceeds a predetermined threshold. Then, when only one of them exceeds the threshold, the detection unit 230 determines that only one of them does not satisfy the criterion (Yes). In this case, the detection unit 230 detects the third detected value iw_det1 used when calculating the second estimated value iw_est(W1) and the fourth detected value iw_est(W2) used when calculating the third estimated value iw_est(W2). Inferring that any one of the detected values iw_det2 is an abnormal value detects the failure of either the third magnetic sensor 173 or the fourth magnetic sensor 174 that detected the third detected value iw_det1 and the third detected value iw_det2. do. Thus, the detection unit 230 detects the difference between the first estimated value iw_est(U) and the second estimated value iw_est(W1), the first estimated value iw_est(U) and the third estimated value iw_est If only one of the differences from (W2) does not satisfy a predetermined criterion, a failure of either the third magnetic sensor 173 or the fourth magnetic sensor 174 is detected. Then, failure detection device 200 advances the process to step S335.

In step S335, the failure detection device 200 determines whether the difference between the first estimated value iw_est(U) and the second estimated value iw_est(W1) does not meet the criteria. For example, the detection unit 230 determines whether or not the absolute value of the difference between the first estimated value iw_est(U) and the second estimated value iw_est(W1) exceeds a predetermined threshold. If the difference exceeds the threshold, the detection unit 230 determines that the difference between the first estimated value iw_est(U) and the second estimated value iw_est(W1) does not meet the criteria (Yes). Then, failure detection device 200 advances the process to step S340.

In step S<b>340 , the failure detection device 200 detects failure of the third magnetic sensor 173 . For example, the detection unit 230 determines that the difference between the first estimated value iw_est(U) and the third estimated value iw_est(W2) satisfies the criterion, whereas the first estimated value iw_est(U) and the second estimated value iw_est(W2) satisfy the criterion. When the difference from the estimated value iw_est(W1) of the value does not satisfy the criterion, it is inferred that the third detected value iw_det1 used in calculating the second estimated value iw_est(W1) is an abnormal value. , the failure of the third magnetic sensor 173 that detected the third detection value iw_det1 is detected. That is, if the difference between the first estimated value iw_est(U) and the third estimated value iw_est(W2) satisfies the criterion, the first detection value used in calculating the first estimated value iw_est(U) There is a high probability that the value iu_det1, the second detection value iu_det2, and the fourth detection value iw_det2 used to calculate the third estimated value iw_est(W2) are normal values. In such a case, the fact that only the difference between the first estimated value iw_est(U) and the second estimated value iw_est(W1) does not satisfy the criterion indicates the probability that the third detected value iw_det1 is an abnormal value. is high. Therefore, in such a case, the detection unit 230 detects a failure of the third magnetic sensor 173 that detected the third detection value iw_det1. In this way, the detection unit 230 detects the failure of the third magnetic sensor 173 when the difference between the first estimated value iw_est(U) and the second estimated value iw_est(W1) does not satisfy a predetermined criterion. to detect

On the other hand, in step S335, if the absolute value of the difference between the first estimated value iw_est(U) and the second estimated value iw_est(W1) is equal to or less than the predetermined threshold value, the failure detection device 200 starts the process. Proceed to step S350.

In step S<b>350 , failure detection device 200 detects failure of fourth magnetic sensor 174 . For example, the detection unit 230 determines that the difference between the first estimated value iw_est(U) and the second estimated value iw_est(W1) satisfies the criterion, whereas the first estimated value iw_est(U) and the third estimated value iw_est(W1) satisfy the criterion. When the difference from the estimated value iw_est (W2) of the above does not satisfy the criterion, it is inferred that the fourth detected value iw_det2 used in calculating the third estimated value iw_est (W2) is an abnormal value. , the failure of the fourth magnetic sensor 174 that detected the fourth detection value iw_det2 is detected. In this way, detection unit 230 detects failure of fourth magnetic sensor 174 when the difference between first estimated value iw_est(U) and third estimated value iw_est(W2) does not satisfy a predetermined criterion. to detect

In this way, detection unit 230 detects third magnetic sensor 173 and Any failure of the fourth magnetic sensor 174 is detected. More specifically, the detection unit 230 detects the difference between the first estimated value iw_est(U) and the second estimated value iw_est(W1), and the first estimated value iw_est(U) and the third estimated value iw_est(U). A failure of either the third magnetic sensor 173 or the fourth magnetic sensor 174 can be detected based on the difference from iw_est(W2).

On the other hand, in step S330, the absolute value of the difference between the first estimated value iw_est(U) and the second estimated value iw_est(W1), the first estimated value iw_est(U) and the third estimated value iw_est( If both the absolute values of the difference of W2) are equal to or less than the predetermined threshold value, or if both exceed the predetermined threshold value, failure detection device 200 advances the process to step S360.

In step S360, failure detection device 200 calculates a fourth estimated value, a fifth estimated value, and a sixth estimated value of the first phase current. For example, the estimation unit 220 estimates the first phase current using the third detection value iw_det1 and the fourth detection value iw_det2 to estimate the first phase current using the fourth estimation value iu_est(W) and the first detection value iu_det1 and a sixth estimated value iu_est(U2) of the first phase current using the second detected value iu_det2.

A third detection value iw_det1 detected by the third magnetic sensor 173 included in the second-phase current detector 170u is expressed by the following equation.

A fourth detection value iw_det2 detected by the fourth magnetic sensor 174 included in the second phase current detector 170w is expressed by the following equation.

Therefore, the sum of the third detection value iw_det1 and the fourth detection value iw_det2 is given by the following equation.

Also, the difference between the third detection value iw_det1 and the fourth detection value iw_det2 is given by the following equation.

Here, (Equation 14) is transformed into the following equation.

Then, by substituting (Equation 15) into (Equation 13), the estimating unit 220 obtains the third detection value iw_det1 obtained from the third magnetic sensor 173 and the fourth magnetic sensor 174 and A fourth estimated value iu_est(W) of the first phase current can be calculated using the fourth detected value iw_det2. That is, the estimation unit 220 can estimate the first phase current without using the first detection value iu_det1 and the second detection value iu_det2 obtained from the first magnetic sensor 171 and the second magnetic sensor 172 .

A first detection value iu_det1 detected by the first magnetic sensor 171 included in the first phase current detector 170u is expressed by the following equation.

A second detection value iu_det2 detected by the second magnetic sensor 172 included in the first phase current detector 170u is expressed by the following equation.

Here, by arranging iu in (Expression 17) as iu_est(U1), the estimation unit 220 uses the first detection value iu_det1 acquired from the first magnetic sensor 171 as shown in the following equation. , a fifth estimated value iu_est(U1) of the first phase current can be calculated. That is, the estimation unit 220 can estimate the first phase current without using the second detection value iu_det2 acquired from the second magnetic sensor 172 .

Similarly, by arranging iu in (Equation 18) as iu_est(U2), estimation unit 220 uses second detection value iu_det2 obtained from second magnetic sensor 172 as shown in the following equation: , a sixth estimate iu_est(U2) of the first phase current can be calculated. That is, the estimation unit 220 can estimate the first phase current without using the first detection value iu_det1 acquired from the first magnetic sensor 171 .

In this way, the estimation unit 220 uses the fourth estimated value iu_est(W) obtained by estimating the first phase current using the third detected value iw_det1 and the fourth detected value iw_det2, and the first detected value iu_det1 to estimate the first phase current. A fifth estimated value iu_est(U1) obtained by estimating the phase current and a sixth estimated value iu_est(U2) obtained by estimating the first phase current using the second detected value iu_det2 can be calculated. The estimation unit 220 supplies the calculated fourth estimated value iu_est(W), fifth estimated value iu_est(U1), and sixth estimated value iu_est(U2) to the detection unit 230 .

In step S370, the fault detection device 200 determines the difference between the fourth estimated value iu_est(W) and the fifth estimated value iu_est(U1), the fourth estimated value iu_est(W) and the sixth estimated value iu_est Determine if only one of the differences in (U2) does not meet the criteria. For example, the detection unit 230 determines whether the absolute value of the difference between the fourth estimated value iu_est(W) and the fifth estimated value iu_est(U1) exceeds a predetermined threshold, and whether the fourth estimated value It is determined whether or not the absolute value of the difference between iu_est(W) and the sixth estimated value iu_est(U2) exceeds a predetermined threshold. Then, when only one of them exceeds the threshold, the detection unit 230 determines that only one of them does not satisfy the criterion (Yes). In this case, the detection unit 230 detects the first detected value iu_det1 used when calculating the fifth estimated value iu_est(U1) and the second detected value iu_est(U2) used when calculating the sixth estimated value iu_est(U2). Inferring that one of the detected values iu_det2 is an abnormal value detects a failure of either the first magnetic sensor 171 or the second magnetic sensor 172 that detected the first detected value iu_det1 and the second detected value iu_det2. do. Thus, the detection unit 230 detects the difference between the fourth estimated value iu_est(W) and the fifth estimated value iu_est(U1), the fourth estimated value iu_est(W) and the sixth estimated value iu_est A failure of either the first magnetic sensor 171 or the second magnetic sensor 172 is detected when only one of the differences from (U2) does not satisfy a predetermined criterion. Then, failure detection device 200 advances the process to step S375.

In step S375, the failure detection device 200 determines whether the difference between the fourth estimated value iu_est(W) and the fifth estimated value iu_est(U1) does not meet the criteria. For example, the detection unit 230 determines whether the absolute value of the difference between the fourth estimated value iu_est(W) and the fifth estimated value iu_est(U1) exceeds a predetermined threshold. If the difference exceeds the threshold, the detection unit 230 determines that the difference between the fourth estimated value iu_est(W) and the fifth estimated value iu_est(U1) does not meet the criteria (Yes). Then, failure detection device 200 advances the process to step S380.

In step S<b>380 , the failure detection device 200 detects failure of the first magnetic sensor 171 . For example, the detection unit 230 determines that the difference between the fourth estimated value iu_est(W) and the sixth estimated value iu_est(U2) satisfies the criterion, whereas the fourth estimated value iu_est(W) and the fifth estimated value iu_est(W) satisfy the criterion. If the difference from the estimated value iu_est(U1) does not satisfy the criterion, it is inferred that the first detected value iu_det1 used to calculate the fifth estimated value iu_est(U1) is an abnormal value. , the failure of the first magnetic sensor 171 that detected the first detection value iu_det1 is detected. That is, if the difference between the fourth estimated value iu_est(W) and the sixth estimated value iu_est(U2) satisfies the criterion, the third detection value used in calculating the fourth estimated value iu_est(W) There is a high probability that the value iw_det1, the fourth detected value iw_det2, and the second detected value iu_det2 used to calculate the sixth estimated value iu_est(U2) are normal values. In such a case, the fact that only the difference between the fourth estimated value iu_est(W) and the fifth estimated value iu_est(U1) does not satisfy the criterion indicates the probability that the first detected value iu_det1 is an abnormal value. is high. Therefore, in such a case, the detection unit 230 detects a failure of the first magnetic sensor 171 that detected the first detection value iu_det1. In this way, the detection unit 230 detects the failure of the first magnetic sensor 171 when the difference between the fourth estimated value iu_est(W) and the fifth estimated value iu_est(U1) does not satisfy a predetermined criterion. to detect

On the other hand, in step S375, if the absolute value of the difference between the fourth estimated value iu_est(W) and the fifth estimated value iu_est(U1) is equal to or less than the predetermined threshold value, failure detection device 200 starts the process. Proceed to step S390.

In step S<b>390 , failure detection device 200 detects failure of second magnetic sensor 172 . For example, the detection unit 230 determines that the difference between the fourth estimated value iu_est(W) and the fifth estimated value iu_est(U1) satisfies the criterion, whereas the fourth estimated value iu_est(W) and the sixth estimated value iu_est(W) satisfy the criterion. If the difference from the estimated value iu_est(U2) does not satisfy the criterion, it is inferred that the second detected value iu_det2 used in calculating the sixth estimated value iu_est(U2) is an abnormal value. , the failure of the second magnetic sensor 172 that detected the second detection value iu_det2 is detected. In this way, the detection unit 230 detects the failure of the second magnetic sensor 172 when the difference between the fourth estimated value iu_est(W) and the sixth estimated value iu_est(UW2) does not satisfy a predetermined criterion. to detect

On the other hand, in step S390, the absolute value of the difference between the fourth estimated value iu_est(W) and the fifth estimated value iu_est(U1), the fourth estimated value iu_est(W) and the sixth estimated value iu_est( If both the absolute values of the difference between U2) are less than or equal to a predetermined threshold value, or if both exceed a predetermined threshold value, the failure detection device 200 detects failure of any magnetic sensor. end the flow.

In this way, the detection unit 230 detects the first magnetic sensor 171 and the Any failure of the second magnetic sensor 172 is detected. More specifically, the detection unit 230 detects the difference between the fourth estimated value iu_est(W) and the fifth estimated value iu_est(U1), and the fourth estimated value iu_est(W) and the sixth estimated value iu_est(W). A failure of either the first magnetic sensor 171 or the second magnetic sensor 172 can be detected based on the difference from iu_est(U2).

The failure detection device 200 can identify which of the first magnetic sensor 171, the second magnetic sensor 172, the third magnetic sensor 173, and the fourth magnetic sensor 174 has failed, for example, through such a flow. is. Therefore, the power conversion device 100 preferably executes feedback control based on the detection result by such failure detection device 200 .

FIG. 4 shows the relationship between the magnetic sensor whose failure has been detected by the failure detection device 200 according to this embodiment and the current value used for feedback control. As shown in this figure, when the number of magnetic sensors in which a failure is detected is "None", that is, when no failure is detected in any magnetic sensor, the U-phase current used for feedback control is (number 5) may be used. That is, a value obtained by dividing the difference between the first detection value iu_det1 and the second detection value iu_det2 by 2, in other words, a value obtained by dividing the first calculation result iu_det by 2 may be used. Similarly, iw shown in (Equation 15) may be used as the W-phase current used for feedback control. That is, a value obtained by dividing the difference between the third detection value iw_det1 and the fourth detection value iw_det2 by 2, in other words, a value obtained by dividing the second calculation result iw_det by 2 may be used.

If the magnetic sensor that detected the failure is the "first magnetic sensor 171", it is not preferable to use the value calculated using the first detection value iu_det1 detected by the first magnetic sensor 171 for feedback control. Therefore, in such a case, the sixth estimated value iu_est(U2) shown in (Equation 20) may be used as the U-phase current used for feedback control. Similarly, when the magnetic sensor in which the failure is detected is the "second magnetic sensor 172," the value calculated using the second detection value iu_det2 detected by the second magnetic sensor 172 cannot be used for feedback control. I don't like it. Therefore, in such a case, the fifth estimated value iu_est(U1) shown in (Equation 19) may be used as the U-phase current used for feedback control.

Further, when the magnetic sensor in which the failure is detected is the "third magnetic sensor 173", it is preferable to use the value calculated using the third detection value iw_det1 detected by the third magnetic sensor 173 for feedback control. do not have. Therefore, in such a case, the third estimated value iw_est(W2) shown in (Equation 10) may be used as the W-phase current used for feedback control. Similarly, when the magnetic sensor in which the failure is detected is the "fourth magnetic sensor 174", the value calculated using the fourth detection value iw_det2 detected by the fourth magnetic sensor 174 cannot be used for feedback control. I don't like it. Therefore, in such a case, the second estimated value iw_est(W1) shown in (Equation 9) may be used as the W-phase current used for feedback control.

Therefore, the detection unit 230 preferably supplies an estimated value according to the detection result to the control circuit 150 when a failure of any magnetic sensor is detected. In response to this, the control circuit 150 performs feedback control based on the estimated value supplied from the detection section 230 . As a result, when a failure is detected in any of the magnetic sensors, the control circuit 150 performs feedback control based on the estimated value calculated using the detected values from the magnetic sensors in which failure has not been detected. be able to.

FIG. 5 shows a modification of a power conversion device 100' including a failure detection device 200 according to this embodiment, together with a power source 10 and a motor 20. As shown in FIG. In FIG. 5, members having the same functions and configurations as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted except for differences. In the above-described embodiment, the case where the first phase current detector 170u and the second phase current detector 170w respectively include the first arithmetic circuit 175u and the second arithmetic circuit 175w is shown as an example. However, in this modification, the first-phase current detector 170u′ and the second-phase current detector 170w′ do not include the first arithmetic circuit 175u and the second arithmetic circuit 175w, and are used for power conversion. The device 100' comprises an arithmetic circuit 175'. In this case, the arithmetic circuit 175' may perform the functions of the first arithmetic circuit 175u and the second arithmetic circuit 175w.

At this time, for example, when the control circuit 150 and the failure detection device 200 are integrally configured and these functions are realized by one CPU, the arithmetic circuit 175' is mounted on the board on which the CPU is mounted. good too. In this way, the magnetic flux densities detected by the first magnetic sensor 171 and the second magnetic sensor 172, respectively, are calculated on the board on which the control circuit 150 is mounted, using the first detected value iu_det1 and the second detected value iu_det2. The magnitudes of the magnetic flux densities detected by the third magnetic sensor 173 and the fourth magnetic sensor 174 are obtained by calculation using the calculation result according to the sum of the magnitudes and the third detection value iw_det1 and the fourth detection value iw_det2. An arithmetic circuit 175' that obtains an arithmetic result corresponding to the sum of the differences may be implemented.

In the above description, the case where the control circuit 150 and the failure detection device 200 are configured integrally and these functions are realized by one CPU is shown as an example. However, it is not limited to this. The failure detection device 200 according to the present embodiment is a computer such as a PC (personal computer), a tablet computer, a smartphone, a workstation, a server computer, or a general-purpose computer configured separately from the power conversion device 100. Alternatively, it may be a computer system in which a plurality of computers are connected. Such a computer system is also a broadly defined computer. Further, failure detection apparatus 200 may be implemented by one or more virtual computer environments that can be executed within a computer. Alternatively, fault detection apparatus 200 may be a dedicated computer designed for fault detection, or may be dedicated hardware implemented by dedicated circuitry. Further, if the failure detection device 200 can be connected to the Internet, the failure detection device 200 may be realized by cloud computing.

In this way, failure detection device 200 acquires the detected value from the magnetic sensor included in current detector 170 and estimates the phase current. Then, failure detection device 200 detects failure of any magnetic sensor included in current detector 170 based on the estimated value of the phase current. As a result, according to the failure detection device 200, even if the current detectors 170 are provided only for two phases in the three-phase alternating current, it is possible to detect that any magnetic sensor has failed. In particular, the fault detection device 200 detects the difference between the first estimated value iw_est(U) and the second estimated value iw_est(W1), the first estimated value iw_est(U) and the third estimated value iw_est( W2), the failure of either the third magnetic sensor 173 or the fourth magnetic sensor 174 is detected. Further, the failure detection device 200 calculates the difference between the fourth estimated value iu_est(W) and the fifth estimated value iu_est(U1), the fourth estimated value iu_est(W) and the sixth estimated value iu_est( U2), the failure of either the first magnetic sensor 171 or the second magnetic sensor 172 is detected. Thereby, according to the fault detection device 200, the faulty magnetic sensor can be identified. Moreover, in this embodiment, the power conversion device 100 provided with such a failure detection device 200 is provided. As a result, redundancy can be achieved without providing the current detectors 170 for all the three phases even in the power conversion device 100 that requires redundant current detection means in order to ensure reliability. Therefore, according to such a power conversion device 100, the total volume of the current detector 170 can be reduced, miniaturization can be achieved, and cost reduction can be achieved. At this time, the arithmetic circuit 175 may be incorporated in the current detector 170 . According to such a current detector 170, in addition to the detection values respectively detected by the pair of magnetic sensors, it is possible to output calculation results obtained by calculation using these detection values. Alternatively, the arithmetic circuit 175' may be incorporated in the power conversion device 100, and such an arithmetic circuit 175' may be mounted on the substrate on which the control circuit 150 is mounted. According to such a power conversion device 100, even when the current detector 170' that does not include the arithmetic circuit 175 is used, a calculation result similar to that of the arithmetic circuit 175 can be obtained on the same substrate as the control circuit 150. be able to.

Various embodiments of the invention may be described with reference to flowchart illustrations and block diagrams, where blocks refer to (1) steps in a process in which operations are performed or (2) devices responsible for performing the operations. may represent a section of Certain steps and sections may be implemented by dedicated circuitry, programmable circuitry provided with computer readable instructions stored on a computer readable medium, and/or processor provided with computer readable instructions stored on a computer readable medium. you can Dedicated circuitry may include digital and/or analog hardware circuitry, and may include integrated circuits (ICs) and/or discrete circuitry. Programmable circuits include logic AND, logic OR, logic XOR, logic NAND, logic NOR, and other logic operations, memory elements such as flip-flops, registers, field programmable gate arrays (FPGAs), programmable logic arrays (PLAs), etc. and the like.

Computer-readable media may include any tangible device capable of storing instructions to be executed by a suitable device, such that computer-readable media having instructions stored thereon may be designated in flowcharts or block diagrams. It will comprise an article of manufacture containing instructions that can be executed to create means for performing the operations described above. Examples of computer-readable media may include electronic storage media, magnetic storage media, optical storage media, electromagnetic storage media, semiconductor storage media, and the like. More specific examples of computer readable media include floppy disks, diskettes, hard disks, random access memory (RAM), read only memory (ROM), erasable programmable read only memory (EPROM or flash memory), Electrically Erasable Programmable Read Only Memory (EEPROM), Static Random Access Memory (SRAM), Compact Disc Read Only Memory (CD-ROM), Digital Versatile Disc (DVD), Blu-ray (RTM) Disc, Memory Stick, Integration Circuit cards and the like may be included.

The computer readable instructions may be assembler instructions, Instruction Set Architecture (ISA) instructions, machine instructions, machine dependent instructions, microcode, firmware instructions, state setting data, or instructions such as Smalltalk, JAVA, C++, etc. any source or object code written in any combination of one or more programming languages, including object-oriented programming languages, and conventional procedural programming languages such as the "C" programming language or similar programming languages; may include

Computer readable instructions may be transferred to a processor or programmable circuitry of a general purpose computer, special purpose computer, or other programmable data processing apparatus, either locally or over a wide area network (WAN), such as a local area network (LAN), the Internet, or the like. ) and may be executed to create means for performing the operations specified in the flowcharts or block diagrams. Examples of processors include computer processors, processing units, microprocessors, digital signal processors, controllers, microcontrollers, and the like.

FIG. 6 illustrates an example computer 9900 in which aspects of the invention may be implemented in whole or in part. Programs installed on the computer 9900 may cause the computer 9900 to function as one or more sections of an operation or apparatus associated with an apparatus according to embodiments of the invention, or Sections may be executed and/or computer 9900 may be caused to execute processes or steps of processes according to embodiments of the present invention. Such programs may be executed by CPU 9912 to cause computer 9900 to perform certain operations associated with some or all of the blocks in the flowcharts and block diagrams described herein.

Computer 9900 according to this embodiment includes CPU 9912 , RAM 9914 , graphics controller 9916 , and display device 9918 , which are interconnected by host controller 9910 . Computer 9900 also includes input/output units such as communication interface 9922 , hard disk drive 9924 , DVD drive 9926 , and IC card drive, which are connected to host controller 9910 through input/output controller 9920 . The computer also includes legacy input/output units such as ROM 9930 and keyboard 9942 , which are connected to input/output controller 9920 through input/output chip 9940 .

The CPU 9912 operates according to programs stored in the ROM 9930 and RAM 9914, thereby controlling each unit. Graphics controller 9916 retrieves image data generated by CPU 9912 into a frame buffer or the like provided in RAM 9914 or itself and causes the image data to be displayed on display device 9918 .

Communication interface 9922 communicates with other electronic devices over a network. Hard disk drive 9924 stores programs and data used by CPU 9912 within computer 9900 . DVD drive 9926 reads programs or data from DVD-ROM 9901 and provides programs or data to hard disk drive 9924 via RAM 9914 . The IC card drive reads programs and data from IC cards and/or writes programs and data to IC cards.

ROM 9930 has stored therein such as a boot program that is executed by computer 9900 upon activation and/or programs that depend on the hardware of computer 9900 . Input/output chip 9940 may also connect various input/output units to input/output controller 9920 via parallel ports, serial ports, keyboard ports, mouse ports, and the like.

A program is provided by a computer-readable medium such as a DVD-ROM 9901 or an IC card. The program is read from a computer-readable medium, installed in hard disk drive 9924, RAM 9914, or ROM 9930, which are also examples of computer-readable medium, and executed by CPU 9912. The information processing described within these programs is read by computer 9900 to provide coordination between the programs and the various types of hardware resources described above. An apparatus or method may be configured by implementing manipulation or processing of information in accordance with the use of computer 9900 .

For example, when communication is performed between the computer 9900 and an external device, the CPU 9912 executes a communication program loaded into the RAM 9914 and sends communication processing to the communication interface 9922 based on the processing described in the communication program. you can command. The communication interface 9922 reads transmission data stored in a transmission buffer processing area provided in a recording medium such as a RAM 9914, a hard disk drive 9924, a DVD-ROM 9901, or an IC card under the control of the CPU 9912, and transmits the read transmission data. Data is transmitted to the network, or received data received from the network is written to a receive buffer processing area or the like provided on the recording medium.

In addition, the CPU 9912 causes the RAM 9914 to read all or necessary portions of files or databases stored in an external recording medium such as a hard disk drive 9924, a DVD drive 9926 (DVD-ROM 9901), an IC card, etc. Various types of processing may be performed on the data. CPU 9912 then writes back the processed data to the external recording medium.

Various types of information, such as various types of programs, data, tables, and databases, may be stored on recording media and subjected to information processing. CPU 9912 performs various types of operations, information processing, conditional judgments, conditional branches, unconditional branches, information retrieval, as described throughout this disclosure and specified by instruction sequences of programs, on data read from RAM 9914 . Various types of processing may be performed, including /replace, etc., and the results written back to RAM 9914 . Also, the CPU 9912 may search for information in a file in a recording medium, a database, or the like. For example, if multiple entries each having an attribute value of a first attribute associated with an attribute value of a second attribute are stored in the recording medium, the CPU 9912 determines that the attribute value of the first attribute is specified. search the plurality of entries for an entry that matches the condition, read the attribute value of the second attribute stored in the entry, and thereby associate it with the first attribute that satisfies the predetermined condition. An attribute value of the second attribute obtained may be obtained.

The programs or software modules described above may be stored in a computer readable medium on or near the computer 9900 . In addition, a recording medium such as a hard disk or RAM provided in a server system connected to a dedicated communication network or the Internet can be used as a computer-readable medium, thereby providing the program to the computer 9900 via the network. do.

Although the present invention has been described above using the embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It is obvious to those skilled in the art that various modifications and improvements can be made to the above embodiments. It is clear from the description of the scope of claims that forms with such modifications or improvements can also be included in the technical scope of the present invention.

The execution order of each process such as actions, procedures, steps, and stages in the devices, systems, programs, and methods shown in the claims, the specification, and the drawings is particularly "before", "before etc., and it should be noted that they can be implemented in any order unless the output of the previous process is used in the subsequent process. Regarding the operation flow in the claims, the specification, and the drawings, even if the description is made using "first," "next," etc. for the sake of convenience, it means that it is essential to carry out in this order. not a thing

10 Power supply 20 Motor 100 Power converter 110 Rectifier circuit 120 Smoothing capacitor 130 Inverter circuit 140 Conductor 150 Control circuit 160 Drive circuit 170 Current detector 171 First magnetic sensor 172 Second magnetic sensor 173 Third magnetic sensor 174 Fourth magnetic sensor 175 Arithmetic circuit 176 Output unit 200 Failure detection device 210 Acquisition unit 220 Estimation unit 230 Detection unit 9900 Computer 9901 DVD-ROM
9910 Host controller 9912 CPU
9914 RAM
9916 graphics controller 9918 display device 9920 input/output controller 9922 communication interface 9924 hard disk drive 9926 DVD drive 9930 ROM
9940 input/output chip 9942 keyboard

Claims (15)

A first detection value whose value increases with an increase in the magnetic flux density generated by the first phase current and a second detection value whose value decreases with an increase in the magnetic flux density generated by the first phase current are referred to as a first magnetic field. A third detection value obtained from the sensor and the second magnetic sensor, and having a value that increases as the magnetic flux density generated by the second phase current increases, and a value that increases as the magnetic flux density generated by the second phase current increases. an acquisition unit that acquires a fourth detection value that decreases from the third magnetic sensor and the fourth magnetic sensor,
a first estimated value obtained by estimating the second phase current using the first detected value and the second detected value; a second estimated value obtained by estimating the second phase current using the third detected value; and an estimating unit that calculates a third estimated value obtained by estimating the second phase current using the fourth detected value;
a detection unit that detects a failure of one of the third magnetic sensor and the fourth magnetic sensor based on the first estimated value, the second estimated value, and the third estimated value; ,
The first detected value is iu_det1, the second detected value is iu_det2, the third detected value is iw_det1, the fourth detected value is iw_det2, and the magnetic flux coupling parameter between the first phase and the second phase is Kuv , the coupling parameter of the magnetic flux between the second phase and the third phase is Kvw, the coupling parameter of the magnetic flux between the third phase and the first phase is Kwu, the first estimated value is iw_est(U), Assuming that the second estimated value is iw_est(W1), the third estimated value is iw_est(W2), and the second phase current is iw ,
The estimation unit

Calculate the first estimated value by

calculating the second estimate by

A failure detection device that calculates the third estimated value by Based on the difference between the first estimated value and the second estimated value and the difference between the first estimated value and the third estimated value, the detection unit detects the third magnetic sensor and 2. The failure detection device according to claim 1, which detects failure of any one of said fourth magnetic sensors. The detection unit determines in advance only one of a difference between the first estimated value and the second estimated value and a difference between the first estimated value and the third estimated value. 3. The fault detection device according to claim 2, which detects a fault in either said third magnetic sensor or said fourth magnetic sensor when a criterion is not satisfied. 4. The detector according to claim 3, wherein said detection unit detects a failure of said third magnetic sensor when a difference between said first estimated value and said second estimated value does not satisfy said predetermined criterion. fault detection device. 5. The detection unit detects a failure of the fourth magnetic sensor when the difference between the first estimated value and the third estimated value does not satisfy the predetermined criterion. The failure detection device according to . The estimator further estimates the first phase current using a fourth estimated value obtained by estimating the first phase current using the third detected value and the fourth detected value, and the first detected value. calculating a sixth estimated value obtained by estimating the first phase current using the fifth estimated value and the second detected value;
The detection unit further detects a failure of one of the first magnetic sensor and the second magnetic sensor based on the fourth estimated value, the fifth estimated value, and the sixth estimated value. detect and
Assuming that the fourth estimated value is iu_est(W), the fifth estimated value is iu_est(U1), the sixth estimated value is iu_est(U2), and the first phase current is iu ,
The estimation unit

Calculate the fourth estimated value by

Calculate the fifth estimated value by

The fault detection device according to any one of claims 1 to 5, wherein the sixth estimated value is calculated by: Based on the difference between the fourth estimated value and the fifth estimated value and the difference between the fourth estimated value and the sixth estimated value, the detection unit detects the first magnetic sensor and 7. The failure detection device according to claim 6, which detects failure of any one of said second magnetic sensors. The detection unit determines in advance only one of a difference between the fourth estimated value and the fifth estimated value and a difference between the fourth estimated value and the sixth estimated value. 8. The failure detection device according to claim 7, which detects a failure of either said first magnetic sensor or said second magnetic sensor when a criterion is not satisfied. 9. The detection unit according to claim 8, wherein said detection unit detects a failure of said first magnetic sensor when a difference between said fourth estimated value and said fifth estimated value does not satisfy said predetermined criterion. fault detection device. 10. The detection unit detects a failure of the second magnetic sensor when a difference between the fourth estimated value and the fifth estimated value does not satisfy the predetermined criterion. The failure detection device according to . a failure detection device according to any one of claims 1 to 10;
an inverter circuit including a semiconductor switch element;
a drive circuit for driving the semiconductor switch element;
a control circuit that controls the drive circuit;
A power conversion device comprising: The control circuit, when a failure of any of the magnetic sensors is detected, performs feedback control based on an estimated value calculated using a detection value from a magnetic sensor in which no failure has been detected. 12. The power converter according to 11. Magnitudes of magnetic flux densities respectively detected by the first magnetic sensor and the second magnetic sensor are calculated on the substrate on which the control circuit is mounted, using the first detection value and the second detection value. 13. The power converter according to claim 11 or 12, wherein an arithmetic circuit for obtaining an arithmetic result corresponding to the sum is mounted. The arithmetic circuit further calculates the sum of the magnitudes of the magnetic flux densities detected by the third magnetic sensor and the fourth magnetic sensor by performing calculations using the third detected value and the fourth detected value. 14. The power conversion device according to claim 13, which obtains a calculation result. executed by a computer, said computer comprising:
A first detection value whose value increases with an increase in the magnetic flux density generated by the first phase current and a second detection value whose value decreases with an increase in the magnetic flux density generated by the first phase current are referred to as a first magnetic field. A third detection value obtained from the sensor and the second magnetic sensor, and having a value that increases as the magnetic flux density generated by the second phase current increases, and a value that increases as the magnetic flux density generated by the second phase current increases. an acquisition unit that acquires a fourth detection value that decreases from the third magnetic sensor and the fourth magnetic sensor,
a first estimated value obtained by estimating the second phase current using the first detected value and the second detected value; a second estimated value obtained by estimating the second phase current using the third detected value; and an estimating unit that calculates a third estimated value obtained by estimating the second phase current using the fourth detected value;
A detection unit that detects a failure of one of the third magnetic sensor and the fourth magnetic sensor based on the first estimated value, the second estimated value, and the third estimated value make it work,
The first detected value is iu_det1, the second detected value is iu_det2, the third detected value is iw_det1, the fourth detected value is iw_det2, and the magnetic flux coupling parameter between the first phase and the second phase is Kuv , the coupling parameter of the magnetic flux between the second phase and the third phase is Kvw, the coupling parameter of the magnetic flux between the third phase and the first phase is Kwu, the first estimated value is iw_est(U), Assuming that the second estimated value is iw_est(W1), the third estimated value is iw_est(W2), and the second phase current is iw,
The estimation unit

Calculate the first estimated value by

calculating the second estimate by

A fault detection program for calculating the third estimated value by

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