JPS624956B2 - - 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, the feeder section switch SW is connected only to the unit propulsion winding on which the vehicle is currently running or the unit propulsion winding that it is about to enter, via the feeder lines L _A and L _{B. 1} , SW ₂ ,...
Powered via.

Figure 3 is an equivalent circuit diagram of a feeding system, in which a feeding line with resistance R _f and inductance L _f and a unit propulsion winding with resistance R _n and inductance L _n are connected by the output voltage e _s of the power converter. Output current in _flows through. 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, f is a frequency and is proportional to the speed of the traveling 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, the conventional failure detection device described above has the following problems. In other words, since the power converter performs constant current control as mentioned above, even if a short circuit occurs at a point far away from the power converter, the difference current will hardly change, and therefore a failure will occur. In many cases, it cannot be detected. To deal with this problem, a system that also monitors the output voltage of the power conversion device may be used, but as shown in Figure 4, the output voltage changes depending on the vehicle position and vehicle speed, so the monitoring device is complicated. becomes.

An object of the present invention is to solve the above-mentioned problems in the prior art, and to detect failures occurring in feeder lines and unit propulsion windings while a vehicle is running, without being affected by the position and speed of the vehicle. The purpose is to provide a failure detection device that can.

In order to achieve the above object, the features of the present invention are as follows:
An AC power supply device that outputs an AC signal with a constant frequency, a distance calculation unit that calculates a distance from a vehicle position signal, and a reference impedance storage unit that measures and stores in advance the impedance with respect to the distance of the feeder line and unit propulsion winding. and an impedance measurement unit that actually measures the impedance of the feeder line and the unit propulsion winding due to the application of the output of the AC power supply, and compares the measured impedance with the reference impedance and outputs a failure signal when the difference exceeds a set value. The present invention has a configuration including a comparison section to perform the calculation.

Embodiments of the present invention will be described below with reference to FIGS. 6 to 8. FIG. 6 is a block diagram of one embodiment. In Figure 6, PW is an AC power supply device,
Outputs an AC signal having a frequency different from the output frequency of the power converter CC. BL is AC power supply
This is a blocking coil that prevents current from PW from flowing to the power converter CC. PD is a position detection signal obtained by detecting the vehicle position, and PDS is a distance calculation unit that calculates a distance from this position detection signal PD. PR is the reference impedance storage section,
It receives the distance signal from the distance calculation unit PDS as an input, and outputs the reference impedance corresponding to the input distance signal from the reference impedances for distances stored in advance to the comparison unit COM. on the other hand,
In the impedance measurement section CAL, the AC power supply
The output of PW is connected to the feeder wire (resistance R _f , inductance L
_f ) and the unit propulsion winding (resistance R _n , inductance L _{n )} to find the impedance.
The comparison unit COM compares the reference impedance and the measured impedance, and when the difference reaches a preset value or more, it is determined that a failure has occurred and a failure signal is output via the output unit OUT. Comparison section
The COM performs a comparison operation for each closing position of the feeder section switches SW ₁ , SW ₂ , etc., and when a failure occurs, outputs the fault position using the feeder section switch number.

FIG. 7 is a block diagram showing another embodiment of the present invention. This is a block configuration diagram showing another embodiment of the present invention. The impedance due to the output application of the AC power supply device PW is actually measured during the period until power supply by the converter starts.

Feeder section switch of feeder line to be detected
The current transformer CT confirms that SW _o is turned on, the gate block signal GB is generated, and the output current of the power converter CC is zero, and the measurement period determining unit SWC generates an output. Turn on the switchgear TH. As a result, power is supplied from the AC power supply device PW to the feeding circuit. Obtain the impedance by measuring the voltage and current of the AC power supply PW.
Thereafter, the switchgear TH is opened and the generation of the date block signal GB is canceled, so that the power converter CC starts supplying power. In this case as well, the blocking coil BL is provided so that even if there is a problem in switching the AC power supply PW, the power converter
This is to prevent the CC side from being influenced by the PW. Incidentally, if the configuration shown in FIG. 7 is adopted, there is an advantage that it is possible to immediately shift to the method of superimposing two power supply voltages in the case of FIG. 6.

In addition to the impedance comparison shown in Figures 6 and 7, Figure 8 shows a current comparison section that compares the current between each phase.
COM _i , 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 currents, impedance comparison units COM _i , COM _R , and the accelerometer TR _V are provided.
The output of the comparison section COM in the case of Figures 6 and 7 is also
It is also possible to detect a failed phase by inputting it to the failure determination unit HA along with the output of the phase. Even if one of the unit propulsion windings is short-circuited or disconnected, the accelerometer
Since abnormalities often appear in the TR _V , this accelerometer output is sent to the ground as a component of failure detection.

As explained above, according to the present invention, abnormalities in the feeder line and propulsion winding of a vehicle running by a linear motor can be detected by monitoring the impedance, without being affected by the position and speed of the vehicle.
can be detected.

[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 an illustration of changes in output voltage of a power converter. , FIG. 5 is a failure detection explanatory diagram, FIGS. 6 and 7 are block configuration diagrams of an embodiment of the present invention, and FIG.
The figure is a block diagram of another embodiment of the present invention. CC...Power conversion device, BL...Blocking coil, PW...AC power supply, PD...Position detection signal, PDS...Distance calculation section, PR...Reference impedance storage section, GB...Gate block signal ,
SWC: Measurement period setting section, CAL: Impedance measurement section, COM: Comparison section, TH: Switchgear, 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. A device for detecting a failure in a feeding circuit of a linear motor that runs a linear motor and a failure in each unit propulsion winding includes: an AC power supply device that outputs an AC signal of a constant frequency; a distance calculation section that calculates a distance from a vehicle position signal; a reference impedance storage unit that measures and stores in advance the impedance with respect to the distance of the electric wire and the unit propulsion winding; an impedance measurement unit that actually measures the impedance of the feeder line and the unit propulsion winding by applying the output of the AC power supply; A failure detection device for a linear motor, comprising: a comparison section that compares the measured impedance and the reference impedance and outputs a failure signal when the difference is greater than a set value. 2. In the device according to claim 1,
The AC power supply device is an AC power supply device that outputs alternating current at a frequency different from the output frequency from the power conversion device and its harmonic frequency, and whose output is superimposed on the output of the power conversion device. Failure detection device for linear motors. 3. In the device according to claim 1,
The impedance measurement unit that measures the actual impedance is an impedance measurement unit that measures the impedance due to the application of the output of the AC power supply device during a period from when the feeder section switch is turned on until the power conversion device starts feeding power. A failure detection device for a linear motor, characterized by the following.