JPS624957B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a failure detection device for a linear motor,
In particular, linear motors are used to drive a vehicle by supplying power from a power conversion device via a feeder section switch to a large number of unit propulsion windings sequentially arranged on the track side, depending on the position of the vehicle. The present invention relates to a linear motor failure detection device that detects failures in feeder lines and unit propulsion windings.

The prior art and its problems will be explained with reference to FIGS. 1 to 5. Figure 1 is an overall configuration diagram of a linear motor.A running vehicle TR is equipped with field poles SCM magnetized to N and S poles, and a position detector PD for detecting the current position of the running vehicle. In the orbit of U,
A propulsion winding LSM consisting of three phases of V and W and a detection plate PDR for the position detector PD are provided. That is, the field pole SCM on the running vehicle TR and the propulsion winding on the track side
The vehicle is configured to run by detecting the relative position with the LMS using a position detector PD and passing current through each propulsion winding LSM one after another according to the position signal resulting from the detection.

Figure 2 is an explanatory diagram of the power supply system, and the propulsion winding LSM
A plurality of unit propulsion windings LM ₁ , LM ₂ , LM ₃ , ... are connected so that they are longer than the length of the traveling vehicle TR, and each of these unit propulsion windings LM ₁ , LM ₂ , ... Power is supplied via the feeder section switches SW ₁ , SW ₂ , ... From the two power converters CCA and CCB, a feeder section switch is connected only to the unit propulsion winding where the vehicle is running or the unit propulsion winding that it is about to enter, via the feeder lines L _A and L _B. SW ₁ , SW ₂ , ...
Powered via.

Figure 3 is an equivalent circuit diagram of a feeding system, in which the output voltage e _S of the power conversion device causes a feeding line with a resistance R _f and an inductance L _f , and a resistance R _n and an inductance.
Output _current in flows through the unit propulsion winding having Lm. When the vehicle is running, a back electromotive force e _n proportional to the speed is induced in the unit propulsion winding by the field pole on the vehicle. In the propulsion state, this back electromotive force e _n and the propulsion current i _n are controlled to be in phase, so
The power converter needs to be supplied with a voltage equal to or higher than this back electromotive force e _n . At this time, the following formula holds.

e _S =Z・i _n +e _n Z=√( _f + _n ) ² + [2( _f + _n )]
² However, is the frequency and is proportional to the speed of the vehicle. Furthermore, during regeneration, if _en is made negative, the relationship in the above equation holds true.

FIG. 4 is a diagram showing the relationship between the position of the traveling vehicle and the output voltage e _S of the power conversion device. When the traveling vehicle TR is in the unit propulsion winding LM ₁ in Fig. 2, the fourth
This is area A in the figure. Next unit propulsion winding in area B
Close the feeder section switch SW ₂ for LM ₂ and excite it by the power converter CCB. At this time, the vehicle is not yet on unit propulsion winding LM ₂ . C is the area where the vehicle further advances and partially rides on the unit propulsion winding LM ₂ until the entire vehicle rides on it. In this section region, the back electromotive force e _n increases as the vehicle advances.
The next region D is the state in which the vehicle is completely on the unit propulsion winding _LM2 . Since the back electromotive force e _n is proportional to the speed of the vehicle, if the vehicle is traveling at a constant speed, e _S will be a constant value in this region.

Region E is a section where the vehicle gradually enters next unit propulsion winding LM ₃ , and in region F it completely leaves unit propulsion winding LM ₂ and reaches LM ₃ . Stop the power converter CCB in area F, and switch off the power section switch in area G.
Release SW ₂ .

FIG. 5 is a block diagram of a conventional failure detection device. Failures usually occur when the vehicle is running, and rarely occur when the vehicle is stopped. Therefore, even if a separate power source is used to detect failures before the vehicle is running, it is not perfect. In addition, the power converter uses a constant current control method, so
Failure detection is impossible with simple overcurrent detection.
Therefore, conventionally, as shown in FIG. 5, the pattern current i _p output from the current pattern generator PAT is
The difference current δ is determined by comparing the output current from the power converter CC (CCA, CCB, etc. in Figure 2) with the output current i _c taken out through the current transformer CT, and this difference current δ is the set value. A comparator that determines that a failure has occurred when the value is exceeded and outputs a failure signal to the output circuit OUT side
A method of providing a COM was adopted.

However, in the conventional failure detection method described above, since constant current control is performed in the power converter as mentioned above, even if an abnormality such as a short circuit occurs at a point far away from the power converter, there is no difference There was a problem that the current hardly changed, making it impossible to detect failures.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described problems in the prior art and to provide a failure detection device that can always reliably detect failures regardless of the distance from the power converter.

In order to achieve the above object, the features of the present invention are as follows:
a first impedance calculation section that calculates an actual impedance by dividing the difference between the output voltage of the power converter and the back electromotive voltage determined from the vehicle position signal by the output current of the power converter; a second impedance calculation unit that uses the resistance and inductance of the unit propulsion winding to calculate a reference impedance from this and the vehicle position signal;
and an impedance comparator that compares the outputs of the second arithmetic unit and determines that a failure has occurred when there is a difference greater than a set value and outputs a signal.

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

Figure 6 is a block diagram of one embodiment _.
is the first impedance calculation section, CAL ₂ is the second impedance calculation section, and COM is the impedance comparison section. The first impedance calculation section is
The output voltage signal of the power conversion device CC detected by the voltage detection device PT, the output current signal of the power conversion device CC detected by the current detection device CT, and the back electromotive force sent from the back electromotive force calculation unit E _en It receives a voltage signal as input and calculates the measured impedance. The back electromotive force calculation unit E _en is a frequency calculation unit that processes the position detection signal PD and calculates the speed (frequency).
A distance calculation unit that calculates distance by processing the speed signal from the VF and the position detection signal PD.
It receives two inputs, the distance signal from the PDS, and calculates the back electromotive force. The measured impedance _Z1 is calculated as _Z1 =(output voltage signal from PT)-(back electromotive force signal from _Een )/(output current signal from CT).

On the other hand, the second impedance calculation unit CAL ₂ uses the speed signal from the frequency calculation unit VF, the distance signal from the distance calculation unit PDS, and the data of resistance and inductance with respect to distance and speed that have been actually measured in advance. Impedance Z ₂ is calculated from Z ₂ =√( _n + _f ) ² + [2( _n + _f )] ² .

These two impedances Z ₁ and Z ₂ are compared by the impedance comparator COM, and if there is a difference of more than a certain set value, it is determined that a failure has occurred and the output section is
Generates an abnormal signal via OUT.

FIG. 7 is a block configuration diagram showing another embodiment of the present invention, which calculates the measured impedance Z ₁ within the period when the back electromotive force is zero (region B in FIG. 3). By doing so, impedance calculation is facilitated, and a failure in the feeding system can be detected before the vehicle approaches. In order to detect region B, the distance signal from the distance calculation section PDS and the gate block signal GB are input to the first impedance calculation section _CAL1 . That is, the impedance _Z1 is calculated from the CC output voltage signal from the voltage detection device PT and the CC output current from the current detection device PT within a period in which the vehicle advances a certain distance after the gate block is released. The other reference impedance _Z2 is determined in the same manner as in the embodiment of FIG.

FIG. 8 is a block configuration diagram of still another embodiment of the present invention, in which, in addition to the impedance comparison shown in FIGS. 6 and 7, there is also a current comparison section that compares the current between each phase.
COM _i , voltage comparison section that compares the voltage between each phase
COM _v , an impedance comparison unit COM _R that compares the impedance between each phase, and an accelerometer TR _v that detects acceleration on the vehicle are provided, and these outputs are also input to the fault determination unit HA along with the output of the comparison unit COM. , it is also possible to detect a failed phase.
The figure shows the case of a three-phase linear motor. The output current is compared with the pattern current PAT _i and each phase output current to determine which phase among the three phases is abnormal. Similarly, abnormalities in the output voltage are compared between phases. However, since there is no standard voltage, it is difficult to determine which phase is correct and which phase is abnormal, so the pattern current PAT _i is taken into account. Note that the distance information calculated by the distance calculation unit PDS and the switching information of the feeder section switch SW _o are not only used to calculate the impedance Z ₁ but also used to store the fault location.

As described above, according to the present invention, failures in the feeder line and the propulsion winding can be detected by impedance comparison regardless of distance.

[Brief explanation of the drawing]

Figures 1 to 5 are explanatory diagrams of the prior art. Figure 1 is an overall configuration diagram, Figure 2 is a power supply system diagram, Figure 3 is an equivalent circuit diagram, and Figure 4 is a diagram of changes in output voltage of the power converter. , FIG. 5 is an explanatory diagram of failure detection, and FIGS. 6, 7, and 8 are block configuration diagrams of embodiments of the present invention. CC...Power converter, CAL ₁ ...First impedance calculation unit, CAL ₂ ...Second impedance calculation unit, E _en ...Back electromotive force calculation unit, PD...Position detection signal, VF...Frequency Calculation section, PDS...Distance calculation section, GB...Gate block signal, COM...
...Impedance comparison section, PAT _i ...Pattern current, TR _v ...Accelerometer, HA...Failure determination section.

Claims (1)

[Scope of Claims] 1. The vehicle is powered by supplying power from a power conversion device via a feeder section switch to a large number of unit propulsion windings sequentially arranged on the track side in accordance with the position of the traveling vehicle. In a device that detects failures in the feeding circuit and each unit propulsion winding of the linear motor that runs the A first impedance calculation unit that calculates the measured impedance by dividing, and a second impedance calculation unit that uses the resistance and inductance of the feeder line and the unit propulsion winding that have been measured in advance to calculate the reference impedance from this and the vehicle position signal. A linear motor comprising: a calculation section; and an impedance comparison section that compares the outputs of the first and second impedance calculation sections and determines a failure when there is a difference greater than a set value and outputs a signal. failure detection device. 2. In the device according to claim 1, the first impedance calculation section calculates the actual measurement during a period when the back electromotive force is zero because a running vehicle has not yet entered the unit propulsion winding that is being powered. A failure detection device for a linear motor, characterized in that it is an impedance calculation section that calculates impedance.