DE112018006745T5 - ENGINE MONITORING DEVICE, ENGINE CONTROL SYSTEM, STEEL ROLLING SYSTEM AND ENGINE MONITORING METHOD - Google Patents

Abstract

A state of an electric motor can be detected accurately at a low cost. To this end, an electric motor monitoring device comprises: an operating unit (42-1, 42-2) connected to an electric motor control system comprising: a plurality of electric motors each of which includes a rotary shaft; a plurality of rotating wheels connected to the plurality of rotating shafts; one or more inverters that supply an alternating current to the plurality of electric motors; a control unit that controls the inverter; and a current sensor that detects a current value (I, I, I, I) flowing through each of the electric motors, the operation unit (42-1, 42-2) determining a speed (ω, ω) of the corresponding electric motor according to each of the Operates current values (I, I, I, I); and a determination unit (44, 48) that detects an overheating state of any one of the electric motors and / or an abnormality of a diameter difference between the plurality of rotating gears based on the current value and the rotation speed.

Description

Technical area

The present invention relates to an electric motor monitoring device, an electric motor control system, a steel rolling system and an electric motor monitoring method.

State of the art

A technique for monitoring a state of a plurality of electric motors while the electric motors are being driven in parallel is known.

For example, PTL 1 discloses an electric motor overtemperature protection device applicable to a railroad vehicle drive system in which multiple electric motors are driven in parallel using one or more inverter devices. The electric motor overtemperature protection device includes a control device 14th showing the operation of an inverter device 10 controls, and a protection device 20th that is an overtemperature that is in the electric motors 12a , 12b can be generated on the basis of a frequency signal fs with frequency information when the inverter device 10 a control performs a voltage-frequency ratio on the electric motors 12a , 12b keep constant, and at least single-phase currents I1 , I2 driven by the electric motors 12a , 12b flow, detected, an overtemperature protection signal Tf generated, which the electric motors 12a , 12b protects against overtemperature, and the overtemperature protection signal Tf to the control device 14th outputs (see summary).

PTL 2 describes that “an electric vehicle protection system in which electric motor currents from first and second induction electric motor groups are compared to each other to detect a difference in electric motor currents, thereby determining a difference between a diameter of a wheel connected to the first induction electric motor group and a diameter of a wheel that is connected to the second induction electric motor group is detected and an electric vehicle is protected if the difference is greater than or equal to a permissible value ”(see left field on page 1).

Citation list

Patent literature

• PTL 1: WO 2013/035185 A1
• PTL 2: JP 61-210801 A

Summary of the invention

Technical problem

However, in the technique of PTL 1, which focuses on the relative current difference between the plurality of electric motors, there is a problem that detection becomes difficult when these electric motors are overheated at the same time. It is difficult to determine whether the temperature rise is caused by a difference in an installation environment of each electric motor or a difference in the diameter of the rotating wheel. In the technique of PTL 2, it is difficult to determine whether the current difference between the plurality of electric motors is caused by a difference in wheel diameter or other factors.

Furthermore, it is necessary in the art of PTL 2 to use sensors such as e.g. B. to mount a temperature sensor and a speed sensor for each monitoring target, so that there is a problem that the number of associated devices including the sensors increases, which increases the cost of the whole equipment. There is also a problem in that it is difficult to mount the sensor when there is a dimensional restriction in the installation location of the electric motor or under a severe environmental condition. As the number of sensors increases, it becomes more difficult to ensure the reliability of the sensor group, and the monitoring accuracy is deteriorated. For this reason, there is a need to reduce the number of sensors used as much as possible.

If the number of sensors can be reduced, maintenance and reliability will be greatly improved. In particular, the maintenance and inspection work of sensors can be reduced, system shutdown due to sensor failure can be prevented in advance, and equipment wiring for the sensor system can be reduced, so that labor costs can be reduced. Furthermore, a risk of a wiring problem can be reduced.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an electric motor monitoring device, an electric motor control system, a steel rolling system and an electric motor monitoring method which are capable of accurately detecting a state of an electric motor at a low cost.

Solution to the problem

In order to solve the above problems, an electric motor monitor of the present invention comprises: an operation unit connected to an electric motor control system comprising: a plurality of electric motors each including a rotating shaft; a plurality of rotating wheels connected to the plurality of rotating shafts; one or more inverters that supply an alternating current to the plurality of electric motors; a control unit that controls the inverter; and a current sensor that detects a current value flowing through each of the electric motors, the operating unit operating a rotational speed of the corresponding electric motor according to each of the current values; and a determination unit that detects an overheating condition of any one of the electric motors and / or an abnormality of a diameter difference between the plurality of rotating gears based on the current value and the rotational speed.

Advantageous Effects of the Invention

In the present invention, the state of the electric motor can be accurately detected.

Figure list

• [ 1 ] 1 Fig. 13 is a block diagram illustrating an electric motor control system according to a first embodiment of the present invention.
• [ 2 ] 2 Figure 13 is a block diagram illustrating a monitor.
• [ 3 ] 3 Fig. 16 is a block diagram illustrating a power operation unit.
• [ 4th ] 4th Fig. 13 is a diagram showing an example of an engine frequency and a direct current amount during acceleration.
• [ 5 ] 5 Fig. 13 is a view showing another example of the direct current amount during acceleration.
• [ 6th ] 6th Fig. 13 is a view showing still another example of the direct current amount and a proportional signal during acceleration.
• [ 7th ] 7th Fig. 13 is a view showing a determination result of an abnormality content based on a current difference between a low speed area and a high speed area.
• [ 8th ] 8th Fig. 13 is a flowchart showing an abnormality detection routine performed by the monitor.
• [ 9 ] 9 Fig. 13 is a block diagram illustrating an electric motor control system according to a second embodiment.
• [ 10 ] 10 Fig. 13 is a block diagram illustrating an electric motor control system according to a third embodiment.
• [ 11 ] 11 Fig. 13 is a block diagram illustrating an electric motor control system according to a fourth embodiment.
• [ 12th ] 12th Fig. 13 is a block diagram illustrating a steel rolling system according to a fifth embodiment.
• [ 13 ] 13 Fig. 13 is a side view showing a railroad vehicle according to a sixth embodiment.
• [ 14th ] 14th Fig. 13 is a bottom view showing a chassis according to a sixth embodiment.
• [ 15th ] 15th Fig. 13 is a side view showing a vehicle structure according to a seventh embodiment.

Description of embodiments

[First embodiment]

<Overall Configuration of First Embodiment>

1 Fig. 3 is a block diagram showing an electric motor control system 101 according to a first embodiment of the present invention.

In 1 includes the electric motor control system 101 two electric motors 10-1 , 10-2 , a drive device 20th , a monitoring device 40 (the electric motor monitor) and several current sensors 41 . The drive device 20th includes an inverter 22nd , a current sensor 24 and a control unit 30th . At this point are the electric motors 10-1 , 10-2 a three-phase induction electric motor and are connected in parallel with each other. Rotating shafts 14-1 , 14-2 the electric motors 10-1 , 10-2 are with rotating wheels 16-1 , 16-2 connected, while a mechanical component (not shown) such. B. a gear is interposed, or the rotating shafts 14-1 , 14-2 are directly with the rotary wheels 16-1 , 16-2 connected. The turning wheels 16-1 , 16-2 move a vehicle 12th in a tangential direction. Alternatively, a railroad track is in place of the object of transportation 12th provided and the rotating wheels 16-1 , 16-2 themselves can move in the tangential direction on the rail. Below are sometimes the electric motors 10-1 , 10-2 collectively referred to as "electric motor 10", the rotating shafts 14-1 , 14-2 are collectively referred to as "rotating shaft 14" and the rotating wheels 16-1 , 16-2 will be together referred to as "rotary wheel 16". The inverter 22nd applies a three-phase AC voltage to the electric motor 10 based on the control of the control unit 30th on.

The control unit 30th includes hardware as a general computer such as B. a CPU (central processing unit), a DSP (digital signal processor), a RAM (random access memory) and a ROM (read only memory). The ROM stores a control program executed by the CPU, a microprogram executed by the DSP, various data, and the like. Inside the control unit 30th in 1 functions implemented by the control program, the microprogram and the like are represented as blocks.

That is, the control unit 30th includes a command generator 32 , a deviation operation unit 33 , a vector control unit 34 , a dq / 3Φ converter 36 and a 3Φ / dq converter 38. With these configurations, the control unit 30th a vector control on the electric motor 10 through to the responsiveness of the electric motor 10 to improve.

The inverter 22nd outputs an alternating current of a U-phase, a V-phase and a W-phase to the electric motor 10 out. The current sensor 24 detects a two-phase current. That is, in the example of 1 the U-phase and W-phase currents are detected, and detection results are used as current detection values I _us , I _ws issued. Here, a rotation coordinate that rotates at a frequency f is assumed, axes that are orthogonal to the rotation coordinate are called the d-axis and q-axis, and a current sent to the electric motor 10 is supplied is expressed as a DC amount in the rotation coordinate. The current on the q-axis is a current component that is the torque of the electric motor 10 certainly. Hereinafter, the q-axis current is referred to as the torque current. The current on the d-axis is a component that leads to an excitation current of the electric motor 10 and is hereinafter referred to as the excitation current.

The 3Φ / dq converter 38 gives an excitation current detection value I _d and a torque current detection value I _q based on the current detection values I _us , I _ws out. The current detection values I _us , I _ws usually take in proportion to the number of electric motors 10 to. The control unit 30th however, assumes the number of electric motors 10 "One", as it is complicated, is parameters of the control unit 30th according to the number of electric motors 10 to change. For this reason, the 3Φ / dq converter 38 carries out a normalization by dividing the supplied current detection values lus, I _ws by the number of electric motors 10 and then calculates the detection values I _d , I _q .

The command generator 32 receives a torque command value τ * from a host device (not shown) and generates an excitation current command value I _d * and a torque current command value I _q * based on the torque command value τ * . The deviation operating unit 33 are deviations I _d * - I _d , I _q * - I _q based on the current command values I _d * , I _q * and the detection values I _d , I _q out. The vector control unit 34 gives an excitation voltage command value V _d * and a torque voltage _command value V _q * based on the deviations I _d * - I _d , I _q * - I _q and the like. The operation of the vector control unit 34 is described in more detail. The vector control unit 34 carries out a proportional integration control on the deviations I _d * - I _d , I _q * - I _q to obtain a frequency command ω1 (not shown) which is a command value of a synchronous speed. As used here, the synchronous speed is the rotational speed of the electric motor 10 if a slip is assumed to be "0".

The vector control unit 34 obtains a phase command θ1 (not shown) by integrating the frequency command ω1. The vector control unit 34 multiplies a vector by the current command values I _d * , I _q * is formed with the vector of an impedance of the electric motor 10 and as a result calculates the voltage command values V _d *, V _q *.

The dq / 3Φ converter 36 is a PWM signal that the inverter 22nd controls, on the basis of the voltage command values V _d *, V _q * of the rotary coordinate system. Specifically, the dq / 3Φ converter 36 first converts the voltage command values V _d *, V _q * of the rotation coordinate system into two-phase voltage values of a stationary coordinate system on the basis of the frequency command ω1 and phase command θ1. Furthermore, the dq / 3Φ converter 36 converts the two-phase voltage values obtained into three-phase voltage command values v _u *, v _v *, v _w * (not shown). Further, the dq / 3Φ converter 36 compares the three-phase voltage command values v _u *, v _v *, v _w * with a carrier wave (for example, a triangle wave) to obtain U-phase, V-phase and W-phase PWM Output signals. The inverter 22nd performs switching of the supplied DC voltage (not shown) on the basis of the supplied PWM signal, and outputs U-phase, V-phase and W-phase voltages to the electric motor 10 out.

<Configuration of the monitor 40>

2 Figure 3 is a block diagram showing the monitor 40 represents.

The monitoring device 40 includes hardware as a general computer such as B. a CPU, a DSP, a RAM and a ROM similar to the control unit 30th . The ROM stores a control program executed by the CPU, a microprogram executed by the DSP, various data, and the like. Inside the monitoring device 40 in 2 the functions implemented by the control program, the microprogram and the like are represented as blocks.

That is, the monitoring device 40 includes power units 42-1 , 42-2 (the operation unit), a feature quantity extractor 44 (Determining unit), a memory 46 and an abnormality determination unit 48 (the determining unit, the abnormality determining process).

The power units 42-1 , 42-2 (hereinafter sometimes referred to collectively as a power unit 42 respectively) detect U-phase current detection values I _u1 , I _u2 (same as the current detection value lu and the current value) and W-phase current detection values I _w1 , I _w2 (same as the current detection value I _w and the current value) from the corresponding current sensor 41 . On the basis of these detected values, the power unit outputs 42 DC amounts I _r1 , I _r2 (same as the DC amount I _r ), Proportional signals PLL_P1 , PLL_P2 (same as the proportional signal PLL_P ) and machine frequencies ω _rs1 , ω _rs2 (same as the machine frequency ω _rs and the rotation speed).

A meaning of the from the power units 42 signals output is made with reference to 3 described. 3 Figure 13 is a block diagram showing the power operating unit 42 represents.

The power unit 42 includes a 3Φ / αβ converter 52 , an arctangent converter 54 (the phase detector), a subtracter 45 (the PLL operating unit) and a phase operating unit 60 (the PLL operation unit, the rotation speed operation unit, the rotation speed operation process), a rotary coordinate converter 70 , an integrator 72 (the PLL operating unit) and a multiplier 74 . The phase operating unit 60 includes multipliers 62 , 64 , an integrator 66 and an adder 68 .

The 3Φ / αβ converter 52 converts the current detection values I _u , I _w into two-phase alternating currents I _α , I _β um, which are mutually orthogonal. The arctangent converter 54 calculates an AC phase angle detection value θ _i * on the basis of the alternating currents I _α , I _β . The subtracter 56 subtracts the AC phase angle detection value θ _i * from an AC phase angle θ _i (Details will be described later).

In the live operating unit 60 multiplies the multiplier 62 a difference value " θ _i * - θ _i “With a predetermined proportional gain KpPLL. The multiplication result of the multiplier 62 becomes a proportional signal PLL_P . The multiplier 64 multiplies the difference value " θ _i * - θ _i “With a predetermined integral gain KiPLL and the integrator 66 integrates the multiplication result. The integration result of the integrator 66 becomes integration signal PLL_I called. The adder 68 adds the proportional signal PLL_P and the integration signal PLL_I and outputs the addition result as a frequency signal ω _1s out.

The integrator 72 integrates the frequency signal ω _1s and gives the AC phase angle θ _i out. The AC phase angle θ _i becomes a subtracter 56 and also to the rotary coordinate converter 70 fed. The multiplier 74 multiplies the frequency signal ω _1s with "2 / P" (where P is the number of poles of the electric motor 10 is) and gives the multiplication result as machine frequency ω _rs out. At this point is the machine frequency ω _rs a signal representing an actual speed (the speed with the slip) of the electric motor 10 (please refer 1 ) corresponds. The rotary coordinate converter 70 converts the two-phase alternating currents I _α , I _β into the two-axis direct current amounts I _r , I _i in the rotation coordinate system, which is determined by the frequency signal ω _1s is rotated.

This is how the subtracters work 56 , the live operating unit 60 and the integrator 72 as PLL operating unit (phase locked loop operating unit) and give the frequency signal ω _1s and the AC phase angle θ _i so that the difference value " θ _i * - θ _i “Coming from the subtracter 56 is output, "0" is approaching.

With renewed reference to 2 extracts the feature quantity extraction means 44 several values called the feature quantity based on the DC amounts I _r1 , I _r2 that is the direct current amount I _r are that of each of the electric motors 10-1 , 10-2 corresponds to the proportional signals PLL_P1 , PLL_P2 and the machine frequencies ω _rs1 , ω _rs2 . Although details of each of the feature quantities will be described later, the “feature quantity” includes a low-speed range current difference I _L , a low speed range proportional signal difference H _L1 , H _L2 , a high speed range current difference I _H and a correction high speed range current difference I _Q (High speed range current difference).

The abnormality determination unit 48 detects the presence or absence of one Overheating of the electric motors 10-1 , 10-2 and a difference in diameter between the rotating wheels 16-1 , 16-2 (hereinafter referred to as the rotary wheel diameter difference) on the basis of these feature quantities. The abnormality determination unit 48 outputs various alarm signals to the outside based on these feature quantities. The memory 46 saves the contents of the feature quantities and the alarm signals. Any means such as Lighting of a lamp, sound emission of an alarm, and transmission of a radio wave through a wireless communication means capable of notifying the administrator can be used as an alarm signal. When the monitoring device 40 the first embodiment is installed in a severe environment, the monitoring device 40 preferably accommodated in a monitoring device housing, which takes a dustproof and waterproof measure. When the monitoring device 40 near a device such. B. the inverter 22nd is installed that generates noise, the monitoring device hits 40 preferably an intoxication measure.

There, as described above, the monitoring device 40 the electricity that goes through the electric motor 10 flows as a direct current amount, becomes a change in an internal state amount of the electric motor 10 easily detected with a transition phenomenon. Speed information in a variable speed drive can also be detected in a process of converting the alternating current amount to the direct current amount, so that a correlation with the rotating speed can be easily analyzed. The alternating current can be converted into the direct current by a simple algorithm, so that the edge processing of determining an abnormality can also be performed in the monitoring device. As a result, an amount of data can be significantly reduced, and analysis and diagnosis work becomes easier.

<Abnormal condition to be detected>

(Overheating of the electric motor)

In 1 depend on the electric motor resistance values and the like of the electric motors 10-1 , 10-2 on an operating temperature. At this point, a certain temperature (e.g. 20 ° C) is called the “reference temperature” and a parameter such as B. a resistance value at the reference temperature is called a "reference value". The electric motor resistance increases as the temperature of the electric motor increases 10 increases. A relationship between an electric motor temperature T and an electric motor resistance value RT is given by the following equation (1). $$\text{RT}=\text{R.}\mathrm{20th}\times \left(\mathrm{\delta }+\text{T}\right)/\left(\mathrm{\delta }+\mathrm{20th}\right)$$

In equation (1), δ is a reciprocal of a temperature coefficient of resistance of a wound copper wire, and R20 is an electric motor resistance reference value, namely the electric motor resistance value RT of the electric motor at the reference temperature (20 ° C.). According to the equation (1), for example, when the temperature increases by 40 ° C with respect to the reference temperature, the electric motor resistance value RT becomes approximately “1.16 times” the electric motor resistance reference value R20. When the temperature increases by 70 ° C with respect to the reference temperature, the electric motor resistance value RT becomes approximately “1.27 times” the electric motor resistance reference value R20. The same calculation formula can be applied to the case where the winding is made of aluminum wire or the like.

When the temperature of the electric motor 10 due to an individual difference between the multiple electric motors 10 is distorted, takes in the electric motor 10 with a higher temperature, the specific resistance of the primary and secondary resistance increases and the electric motor resistance value RT increases. As a result, the torque of the electric motor is concentrated in the electric motor 10 with a low temperature and a problem that the object of transport 12th (please refer 1 ) cannot be accelerated smoothly is generated due to a lack of average torque. If such a condition continues, the electric motor sometimes falls 10 , in which the torque is concentrated, due to long-term overload.

(Difference in diameter of rotary wheel 16)

In 1 is when the turning wheel diameter difference between the turning wheels 16-1 , 16-2 that are connected to each electric motor, there is a difference in the rotational speed of each electric motor 10 generated by the rotary wheel diameter difference. A difference in the generation torque of each electric motor 10 is generated almost in proportion to the difference between the rotational speeds. At this point, the difference in the generation torque due to a rotation speed difference when the electric motor can be prevented 10 is configured so that a rated slip becomes large. Since the nominal slip on the other hand has a significant impact on the efficiency of the electric motor 10 affects, the nominal slip is preferably reduced in order to increase the efficiency of the electric motor 10 to improve. If the multiple electric motors 10 actually in the configuration of 1 are operated, the nominal slip is a certain amount actually ensured, since the difference in the turning wheel diameter is generated. When the diameter of each dial 16 is strictly managed, the electric motor can 10 can be constructed theoretically with the small nominal slip and the high efficiency. In this case, however, the maintenance of the rotating wheel becomes necessary 16 complicated.

A method of detecting the fact that the rotation wheel diameter difference becomes large will be discussed below. When a speed sensor on the rotating shaft 14th every electric motor 10 is appropriate, the increase in the rotation wheel diameter difference according to the difference in the rotational speed of each electric motor 10 can be detected. However, when the small rotation wheel diameter difference is detected, a sensor with high sensitivity is required, causing a problem that an increase in cost and an increase in labor for sensor maintenance are generated.

For this reason, the electric motor control system monitors 101 In the first embodiment, the states of an overheating state of each electric motor 10 and the turning wheel diameter difference (the diameter difference of each turning wheel 16 ) and accurately detects the abnormality when these abnormalities are generated.

<Principle of abnormality detection>

4th Fig. 13 is a diagram showing an example of an engine frequency ω _rs and of DC amounts I _r1 , I _r2 represents during acceleration.

In 4th gives the machine frequency ω _rs an example of the machine frequency during the acceleration of the electric motors 10-1 , 10-2 on. Generally there will be a difference between the machine frequencies ω _rs1 , ω _rs2 the electric motors 10-1 , 10-2 generated, but it is assumed that the machine frequency ω _rs in 4th one of the machine frequencies ω _rs1 , ω _rs2 is. The machine frequency ω _rs increases with the passage of time, as in 4th shown. Predetermined synchronous speeds f _L1 , f _L2 , f _H1 , f _H2 during the acceleration have a relationship of “f _L1 <f _L2 <f _H1 <f _H2 ”. The following is a range of the machine frequency ω _rs from “f _L1 <ω _rs <f _L2 ” referred to as “low speed range” and a range of the machine frequency ω _rs from "f _H1 <ω _rs <f _H2 " is referred to as the "high speed range". A period in which the machine frequency ω _rs belongs to the low-speed range is referred to as the low-speed range period T _L and a period in which the engine frequency ω _rs belongs to the high-speed range is referred to as the high-speed range period T _H.

DC amounts I _r101 , I _r201 are an example of the DC amounts I _r1 , I _r2 (please refer 2 ) during the acceleration of the machine frequency ω _rs . In this example it is assumed that the temperature of the electric motor 10-2 (please refer 1 ) is higher than the temperature of the electric motor 10-1 and that the rotary wheel diameter difference between the electric motors 10-1 , 10-2 Is "0". As the temperature of the electric motor 10-2 is higher than that of the electric motor 10-1 , is the DC amount I _r201 for the electric motor 10-2 smaller than the DC amount I _r101 for the electric motor 10-1 . " I _r1 - I _r2 "In the low-speed range period T _{L is} referred to as" low-speed range current difference I _L ". " I _r1 -I _r2 "In the high-speed range period T _H is referred to as" high-speed range current difference I _H ". The low-speed range current difference shows the small rotary wheel diameter difference I _L and the high speed range current difference I _H essentially the same value.

DC amounts I _r102 , I _r202 are another example of the DC amounts I _r1 , I _r2 During the acceleration of the machine frequency ω _rs - In the example it is assumed that the temperatures of the electric motors 10-1 , 10-2 (please refer 1 ) are equal to each other and that the rotary wheel diameter difference is generated. That is, the diameter of the rotating wheel 16-1 is a predetermined reference value and the diameter of the rotating wheel 16-2 is smaller than the reference value. There the dial 16-2 has the smaller diameter, is the direct current amount I _r202 even in the low speed range period T _{L, it is} slightly smaller than the DC amount I _r102 . The low speed range current difference I _L which is the difference between the direct current amount I _r202 and the amount of direct current I _r202 is, however, remains at a small value. In the high speed range period T _H , on the other hand, the influence of the rotary wheel diameter difference appears strong and the high speed range current difference appears I _H becomes a relatively large value.

How out 4th As can be seen, the influence of the electric motor resistance value RT, namely the temperature, is in the low speed range current difference I _L dominant and the influence of the rotary wheel diameter difference is in the high speed range current difference I _H dominant. Consequently, the electric motor can 10 generated heat based on the measurement result of the low speed range current difference I _L can be detected to give a warning. Based on the high speed range current difference measurement result I _H the rotary wheel diameter difference can be detected in order to give a warning. In the actual machine, however, it will be influenced by the heat generated by the electric motor 10 is generated, and the influence of the rotary wheel diameter difference is generated at the same time. Because of this, the influence of the electric motor 10 generated heat and the influence of the rotary wheel diameter difference is preferably separated from one another to the influence of the electric motor 10 accurately assess the heat generated and the influence of the difference in the turning wheel diameter.

5 Fig. 13 is a view showing another example of the DC amounts I _r1 , I _r2 represents during acceleration. As the machine frequency ω _rs over time in the same way as those in 4th changes, the description is omitted.

In 5 are amounts of direct current I _r103 , I _r203 another example of the DC amounts I _r1 , I _r2 during the acceleration of the machine frequency ω _rs (please refer 4th ). In the example it is assumed that the temperature of the electric motor 10-1 is the reference temperature and that is the temperature of the electric motor 10-2 the “reference temperature + 70 ° C” is. It is assumed that the diameter of the rotating wheel 16-1 (please refer 1 ) is a predetermined reference value and that the diameter of the rotary wheel 16-2 is smaller than the reference value.

As the temperature of the electric motor 10-2 higher than the temperature of the electric motor 10-1 , has the low speed range current difference I _L a sufficiently large value. Because the diameter of the rotating wheel 16-2 is smaller than the diameter of the rotating wheel 16-1 , takes the difference between the DC amounts I _r103 , I _r203 with the lapse of time and becomes in the high speed range current difference I _H to a great value. The high speed range current difference I _H is a value that is determined by both the temperature difference and the rotary wheel diameter difference between the electric motors 10-1 , 10-2 being affected. In this case, the correction high speed range current difference I _Q (not shown) from “I _Q = | I _H | - | I _L | “can be obtained. The correction high speed range current difference I _Q has a value in which the influence of the rotary wheel diameter difference appears while the influence of the temperature difference is prevented.

In 5 are amounts of direct current I _r104 , I _r204 another example of DC amounts I _r1 , I _r2 during the acceleration of the machine frequency ω _rs (please refer 4th ). In the example it is assumed that the temperature of the electric motor 10-1 is the reference temperature and that is the temperature of the electric motor 10-2 the “reference temperature + 70 ° C” is. It is assumed that the diameter of the rotating wheel 16-1 (please refer 1 ) is smaller than a predetermined reference value and that the diameter of the rotary wheel 16-2 is the reference value. As the temperature of the electric motor 10-2 higher than the temperature of the electric motor 10-1 , has an absolute value | ILI of the low-speed range current difference has a sufficiently large value. Because the diameter of the rotating wheel 16-2 is smaller than the diameter of the rotating wheel 16-1 , becomes the difference between the DC amounts I _r104 , I _r204 decreased with the passage of time and vice versa. In this case, the correction high speed range current difference I _Q (not shown) from “IQ = | I _H | + | I _L | “can be obtained. The correction high speed range current difference I _Q also has a value in which the influence of the rotation wheel diameter difference appears while the influence of the temperature difference is prevented.

In the example of 5 is believed to be one of the temperatures of the electric motors 10-1 , 10-2 one is reference temperature while the other is higher than the reference temperature. However, if the electric motors have cooling functions 10-1 , 10-2 are simultaneously deteriorated, the difference between the DC amounts sometimes appears I _r1 , I _r2 not significant. In such cases it is difficult to track the overheating conditions of the electric motors 10-1 , 10-2 based only on the difference between the DC amounts I _r1 , I _r2 to detect.

An example is given with reference to 6th described. 6th Fig. 13 is a view showing still another example of the DC amounts I _r1 , I _r2 and the proportional signal PLL_P1 represents during acceleration.

In 6th are amounts of direct current I _r105 , I _r205 an example of the DC amounts I _r1 , I _r2 if both electric motors 10-1 , 10-2 lie at the reference temperature, while the rotary wheel diameter difference 0 is. DC amounts I _r106 , I _r206 in 6th are an example of the DC amounts I _r1 , I _r2 if both electric motors 10-1 , 10-2 are at the "reference temperature + 70 ° C", while the rotary wheel diameter difference 0 is. Since in the example there is a significant difference between the difference value " I _r105 - I _r205 ”And the difference value“ Irio6 - I _r206 ”does not appear, it is difficult to determine the overheating of the electric motors 10-1 , 10-2 on the basis of the difference between the difference value " I _r105 - I _r205 "And the difference value" I _r106 - I _r206 “To detect.

With renewed reference to 3 is in the multipliers 62 , 64 the phase operating unit 60 the difference value " θ _i * - θ _i “Is multiplied by a proportional gain KpPLL or an integral gain KiPLL. The gains KpPLL, KiPLL are set in such a way that the difference value " θ _i * - θ _i “Converges as soon as possible when the appropriate electric motor 10 is at the reference temperature. However, if the actual temperature of the electric motor 10 deviates from the reference temperature, the proportional gain KpPLL and the integral gain KiPLL move from away from the optimal values at this temperature, so that a range of fluctuation of the proportional signal PLL_P becomes larger as compared with the case where the proportional signal PLL_P is at the reference temperature. For this reason, by monitoring the fluctuation amplitude of the proportional signal PLL_P can be detected whether the corresponding electric motor 10 is in overheating condition.

The proportional signal PLL_P105 in 6th gives an example of a waveform of the proportional signal PLL_P1 (that is, the proportional signal PLL_P for the electric motor 10-1 ) in the low speed range period T _L (see 4th ) on. The temperature of the electric motor is at this point 10-1 on the reference temperature. The maximum value of the proportional signal PLL_P1 in the low speed range period T _L is referred to as PLL_P1max, the minimum value is referred to as PLL_P1min, and the difference between the maximum value and the minimum value is referred to as the low speed range proportional signal amplitude H _L designated. The low speed range proportional signal amplitude H _L for the proportional signal PLL_P105 is used in particular as the low-speed range proportional signal amplitude H _L105 designated.

The proportional signal PLL_P106 in 6th is another example of the waveform of the proportional signal PLL_P1 in the low speed range period T _L (see 4th ). The temperature of the electric motor is at this point 10-1 on the "reference temperature + 70 ° C". The low speed range proportional signal amplitude H _L for the proportional signal PLL_P106 is used in particular as the low-speed range proportional signal amplitude H _L106 designated. When the proportional signals PLL_P105 , PLL_P106 are compared with each other, there will be a significant difference between the low speed range proportional signal amplitudes H _L105 , H _L106 recognized. As a result, the electric motor may overheat 10 can be detected by monitoring the low speed range _proportional signal amplitude H _L. Sometimes the low speed range proportional signal amplitudes H _{L of} the electric motors 10-1 , 10-2 referred to as "H _L1 ", "H _L2 ".

7th Fig. 13 is a view showing an example of state determination based on the low-speed and high-speed range current differences I _L , I _H represents. This means, 7th is a comprehensive table of those relating to 4th to 6th described content.

In 7th it is determined that the rotary wheel diameter difference between the rotary wheels 16-1 , 16-2 "Normal" is when both the low speed range and correction high speed range current differences I _L , I _Q are small. On the other hand, the temperature rise of the electric motors 10-1 , 10-2 determined according to the low speed range proportional signal amplitude H _L. That is, it is determined that the signal for the small low-speed region proportional signal amplitude H _{L is} normal (see, for example H _L105 in 6th ). On the other hand, it is determined that the signal for the large low-speed region proportional signal amplitude H _{L is} abnormal (in the overheating state) (see, for example H _L106 in 6th ).

It can be determined that one of the electric motors 10 is in overheating condition (abnormal) while the turning wheel diameter difference between the two electric motors 10 is normal when the low speed range current difference I _L is large while the correction high speed range current difference I _Q is small. It can be determined that the abnormality is generated in the rotation wheel diameter difference between the two electric motors when the low-speed range current difference I _L is small while the correction high speed range current difference I _Q is great. On the other hand, the temperature rise of the electric motors 10-1 , 10-2 determined according to the low speed range proportional signal amplitude H _L. It can be determined that the abnormality is both in the temperature rise of one of the electric motors 10 as well as the difference in the turning wheel diameter between the two electric motors 10 is generated when both the low speed range and correction high speed range current differences I _L , I _Q are great.

<Operation of the first embodiment>

8th Fig. 13 is a flowchart showing an abnormality detection routine executed by the monitor 40 is carried out. The abnormality detection routine is performed every predetermined sampling period when the electric motors 10-1 , 10-2 are currently being accelerated.

In 8th will when processing to step S2 continues, current measurement processing is performed.

That is, in the monitoring facility 40 (please refer 2 ) record the current operating units 42-1 , 42-2 the current detection values I _u1 , I _w1 , I _u2 , and I _w2 from the current sensor 41 (please refer 1 ).

When processing to step S4 continues, calculate the current operating units 42-1 , 42-2 the states of the electric motors 10-1 , 10-2 . That is, the power units 42-1 , 42-2 give the DC amounts I _r1 , I _r2 who have favourited proportional signals PLL_P1 , PLL_P2 and the machine frequencies ω _rs1 , ω _rs2 out. When processing to step S5 continues, determines the monitoring device 40 the speed range of the machine frequencies ω _rs1 , ω _rs2 and the subsequent processing is branched according to the determination result.

If both machine frequencies ω _rs1 , ω _{rs2 are} in the low _speed range, namely if both “f _L1 <ω _rs1 <f _L2 ” and “f _L1 <ω _rs2 <f _L2 ” are met, the processing parts of step S6 carried out. If both machine frequencies ω _rs1 , ω _{rs2 are} in the high-speed range, namely if both "f _H1 <ω _rs1 <f _H2 " and "f _H1 <ω _rs2 <f _H2 " are met, the processing parts of step S20 carried out. If none of them apply, the processing of the abnormality detection routine ends.

(Processing in the low speed range)

In step S6 performs the feature size extraction device 44 (please refer 2 ) perform low-speed area feature size extraction processing. That is, the low _{speed range} current _difference I _L = I _r1 -I _r2 and the low _{speed range proportional} signal _differences H _L1 , H _L2 (H _L in 6th ) of the electric motors 10-1 , 10-2 are being calculated. When processing to step S8 goes on, the abnormality determination unit determines 48 whether the absolute value | I _L | the low speed range current difference I _L a predetermined threshold I _LT exceeds.

If it is determined "Yes", processing goes to step S10 to determine whether "I _r1 > I _r2 " is _true . If it is in step S10 is determined as "yes", processing goes to step S12 further, and the abnormality determination unit 48 outputs an electric motor overheat alarm signal to the outside indicating that the electric motor is running 10-2 is in overheating condition. If the other hand in step S10 is determined as "No", processing goes to step S14 further and the abnormality determination unit 48 outputs the electric motor overheat alarm signal to the outside indicating that the electric motor is running 10-1 is in overheating condition.

When the absolute value | I _L | less than or equal to the threshold I _LT is it will step as a "no" S8 is determined and processing goes to step S16 further. In step S16 determines the abnormality determination unit 48 whether "H _L1 > G _L and H _L2 > G _L " are fulfilled. As used herein, G _{L is} a predetermined threshold constant that determines whether the amplitude of the proportional signal PLL_P is too big. If it is in step S16 is determined as "yes", processing goes to step S18 further, and the abnormality determination unit 48 outputs the electric motor overheat alarm signal to the outside indicating that both electric motors 10-1 , 10-2 are in overheating condition. If it is in step S16 is determined to be “No”, the processing of the abnormality detection routine ends.

In the step described above S16 it is determined that both electric motors 10-1 , 10-2 are in an overheating state if both "H _L1 > G _L " and "H _L2 > G _L " are met. At this point, if only one of “H _L1 > G _L ” and “H _L2 > G _L ” is satisfied, it is considered that the determination that the corresponding electric motor is in the overheating state is made. However, since the overheating condition of one of the electric motors is also made using the low speed range current difference I _L is determined (step S8 ), when the determination is made based on the low speed range proportional signal amplitude H _L , two determinations are made for the same event (the overheating state of one of the electric motors). For this reason, in the first embodiment, the overheating state of one of the electric motors is determined using the low-speed range current difference I _L detected (step S8 ) and the overheating conditions of both electric motors 10-1 , 10-2 are detected on the basis of the low speed range _proportional signal amplitude H _L (step S16 ).

(Processing in the high speed range)

When both machine frequencies ω _rs1 , ω _rs2 are in the high speed region, processing goes through the above-described step S5 to step S20 further, and the high-speed area feature quantity extraction process is performed by the feature quantity extraction means 44 (please refer 2 ) carried out. That is, the high-speed range current difference I _H = I _r1 - I _r2 is being computed. When processing to step S22 continues, the feature size extractor performs 44 perform current value correction processing to correct the high-speed range current difference I _Q to calculate.

At this point, the correction high speed range current difference becomes I _Q " I _H - I _L "For" I _H > 0 "and the correction high speed range current difference I _Q becomes " I _L - I _H "For" I _H <0 ". As described above, the abnormality detection routine is a routine that occurs during the acceleration of the electric motors 10-1 , 10-2 is carried out. For this reason, when the processing is in the high speed range of step S20 is performed, the low-speed processing in step S6 before processing in the high speed range of step S20 performed and the low speed range current difference I _L is being computed. The low speed range current difference II, which is shown in step S22 is used is the Low-speed range current difference II, which is measured in the low-speed range that appears immediately before the high-speed current range.

When processing to step S24 goes on, the abnormality determination unit determines 48 whether "I _Q > I _QH " is fulfilled. As used here, is I _QH a predetermined threshold constant that determines whether the correction high speed range current difference I _Q is excessive. When it is determined “No”, the processing of the abnormality processing routine ends. On the other hand, when it is determined "Yes", the processing goes to step S26 further and the abnormality determination unit 48 outputs the rotary wheel diameter difference alarm to the outside indicating that the rotary wheel diameter difference between the rotary wheels 16-1 , 16-2 is abnormal, and the processing of the abnormality detection routine ends. The detailed contents of the spin wheel diameter difference alarm signal are set according to the values of the low-speed range and high-speed range current differences I _L , I _H set.

For "I _L > 0 and I _H >0" the content of the rotary wheel diameter differential alarm signal indicates that "the diameter of the rotary wheel 16-2 is excessively small ”. For "I _L > 0 and I _H <0", the content of the rotary wheel diameter differential alarm signal indicates that "the diameter of the rotary wheel 16-2 is excessively large ”. For "I _L <0 and I _H <0", the content of the rotary wheel diameter differential alarm signal indicates that "the diameter of the rotary wheel 16-1 is excessively small ”. For "I _L <0 and I _H >0", the content of the rotary wheel diameter differential alarm signal indicates that "the diameter of the rotary wheel 16-1 is excessively large ”.

<Effects of the first embodiment>

As described above, in the first embodiment, the electric motor monitoring device ( 40 ) the operating unit ( 42 ), which is the rotational speed ( ω _rs ) of the corresponding electric motor ( 10 ) according to each current value ( I _u , I _w ) operates, and the determination unit ( 44 , 48 ) that indicate the overheating condition of any of the electric motors ( 10 ) and / or the abnormality of the difference in diameter between the multiple rotary wheels ( 16 ) based on the current values ( I _u , I _w ) and the speed ( ω _rs ) detected.

Consequently, in the first embodiment, the overheated state of the electric motor ( 10 ) or the abnormality of the difference in diameter between the multiple rotary wheels ( 16 ) based on the current values ( I _u , I _w ) can be detected. That is, the temperature sensor, the speed sensor, and the like can be omitted, so that a problem can be prevented in advance while a labor saving of maintenance is achieved.

The determination units ( 44 , 48 ) also have the function of calculating the low-speed range current difference ( I _L ), which is the difference between the maximum value and the minimum value in the several direct current amounts ( I _r ) is when the rotational speeds ( ω _rs ) the multiple electric motors ( 10 ) lie in the low speed range, which is a predetermined speed range, and the function of detecting the overheating state of the electric motor ( 10 ), which corresponds to the minimum direct current amount ( I _r ) based on the low speed range current difference (II).

Consequently, the overheating condition can be determined based on the low speed range current difference ( I _L ) can be determined.

The operating unit ( 42 ) includes the phase detector ( 54 ), which is the AC phase angle detection value ( θ _i ^* ) based on the current value ( I _u , I _w ) for any of the electric motors ( 10 ) and the PLL operating unit ( 56 , 60 , 72 ), which the proportional integration at the difference value ( θ _i * - θ _i ) between the input AC phase angle ( θ _i ) and the AC phase angle detection value ( θ _i ^* ) operates, and returns the AC phase angle ( θ _i ) such that the difference value ( θ _i * - θ _i ) becomes smaller. The operating unit ( 42 ) gives the proportional signal ( PLL_P ) corresponding to the difference value ( θ _i * - θ _i ) is proportional, off. The determination units ( 44 , 48 ) have the function of detecting the overheating condition in one of the electric motors ( 10 ) based on the proportional signal ( PLL_P ) on.

As a result, the overheating condition that occurs in the multiple electric motors ( 10 ) is generated, can be detected.

The determination units ( 44 , 48 ) also have the function of calculating the high-speed range current difference ( I _H ), which is the difference between the maximum value and the minimum value in the several direct current amounts ( I _r ) is when the rotational speeds ( ω _rs ) the multiple electric motors ( 10 ) lie in the high speed range, which is a predetermined speed range, and the function of detecting the rotary wheel diameter difference of the several electric motors ( 10 ) based on the high speed range current difference ( I _H ) on.

Consequently, the rotary wheel diameter difference between the multiple electric motors ( 10 ) can be detected.

The determination unit ( 44 , 48 ) gives the alarm signal when the overheating condition of any of the electric motors ( 10 ) and / or the Abnormality of the difference in diameter between the multiple turning wheels ( 16 ) can be detected.

As a result, a manager can be notified of various abnormalities.

[Second embodiment]

9 Fig. 3 is a block diagram showing an electric motor control system 102 according to a second embodiment of the present invention. In the following description, components that correspond to the components of the first embodiment are denoted by the same reference numerals, and the description is sometimes omitted.

In 9 includes the electric motor control system 102 N (N is a natural number of 3 or more) Electric motors 10-1 to 10-N and N Turning wheels 16-1 to 16-N that came with the N electric motors 10-1 to 10-N are connected, with rotating shafts 14-1 to 14-N are inserted in between. Two current sensors each 41 (2N in total) are on the U-phase and the W-phase of each of the electric motors 10-1 to 10-N attached and current detection values I _u1 to I _uN , I _w1 to I _wN become a monitoring device 150 (Electric motor monitoring device) supplied.

Although a configuration of the monitoring device 150 Not shown, N are power operating units in place of the two power operating units 42-1 , 42-2 in the monitoring device 40 the first embodiment (see 2 ) intended. The low speed range and high speed range current difference I _L , I _H (please refer 4th ) obtained by the feature size extraction means 44 is calculated is equal to a result in which the minimum value from the maximum value of the N-system direct current amounts I _r1 to I _rN is subtracted in the low speed range or high speed range. The other configurations and operations of the second embodiment are substantially the same as those of the first embodiment.

[Third embodiment]

10 Fig. 3 is a block diagram showing an electric motor control system 103 according to a third embodiment of the present invention. In the following description, components that correspond to the components of the first and second embodiments are denoted by the same reference numerals, and the descriptions are sometimes omitted.

in the 10 includes the electric motor control system 103 a monitoring device 160 (Electric motor monitoring device) instead of the monitoring device 40 (please refer 2 ) of the first embodiment. The monitoring device 160 is essentially the same as the monitor 40 . The abnormality determination unit 48 however, gives the electric motor overheating alarm signal and the rotary wheel diameter differential alarm signal (see 2 ) and issues a control instruction to the command generator 32 the drive device 20th out as required. As used herein, for example, the control instruction is an instruction to stop or slow down the electric motors 10-1 , 10-2 , making the electric motors 10-1 , 10-2 can be operated more safely and efficiently.

As described above, in the third embodiment, the determining unit ( 44 , 48 ) the control instruction to change the control state to the control unit ( 30th ) if the overheating condition of any of the electric motors ( 10 ) and / or the abnormality of the difference in diameter between the multiple rotary wheels ( 16 ) can be detected.

Consequently, the control status in the control unit ( 30th ) can be changed to the appropriate state.

(Fourth embodiment)

11 Fig. 3 is a block diagram showing an electric motor control system 104 according to a fourth embodiment of the present invention. In the following description, components that correspond to the components of the first to third embodiments are denoted by the same reference numerals, and the description is sometimes omitted. In 11 includes the electric motor control system 104 a drive and a monitoring device 170 who have favourited Electric Motors 10-1 , 10-2 and turning wheels 16-1 , 16-2 that with the electric motors 10-1 , 10-2 are connected, the rotating shafts 14-1 , 14-2 are inserted in between.

The drive and the monitoring device 170 includes the control unit 30th , the inverter 22nd , an abnormality detector 180 (Electric motor monitoring device) and an average value operating unit 182 . The mean value operating unit 182 calculates an average of the current detection values I _u1 , I _u2 and an average of the current detection values I _w1 , I _w2 , and gives the mean values as current detection values I _us , I _ws out.

The configurations of the control unit 30th and the inverter 22nd are the same as those of the first embodiment (see 1 ) and the configuration of the abnormality detector 180 is the same as that of the monitoring device 160 (please refer 10 ) of the third embodiment. Consequently instructs the drive and the monitoring device 170 of the fourth embodiment has a function in which the functions of the drive device 20th and the monitoring device 160 of the third embodiment are combined. The fourth embodiment can also be achieved by adding the abnormality detector 180 and the mean value operation unit 182 to the existing drive device 20th configured (see 10 ).

[Fifth embodiment]

12th Fig. 3 is a block diagram showing a steel rolling system 105 according to a fifth embodiment of the present invention. In the following description, components that correspond to the components of the first to fourth embodiments are denoted by the same reference numerals, and descriptions are sometimes omitted.

In 12th includes the steel rolling system 105 the N (N is a natural number of 3 or more) electric motors 10-1 to 10-N who have favourited N rotating shafts 14-1 to 14-N and the N spinning wheels 16-1 to 16-N , the drive device 20th and a monitoring device 150 .

The steel rolling system 105 also includes a table, the hot runner table 200 which is arranged horizontally. Each of the rotating wheels 16-1 to 16-N includes a warehouse 210 and a roller 220 . The steel rolling system 105 The fifth embodiment is provided in a stage following a finishing mill (not shown) and a high temperature steel sheet (not shown) is conveyed from the finishing mill.

The conveyed steel sheet is placed between the roller 220 and the hot runner table 200 inserted and the roller 220 is made by the electric motors 10-1 to 10-N rotated, whereby the steel sheet is rolled. The reels 220 the rotating wheels 16 are all driven under the same condition. Consequently, the electric motors are made with the same specifications on the electric motors 10-1 to 10-N applied which are the driving sources of the rollers 220 are. The other configurations of the fifth embodiment are the same as those of the second embodiment (see FIG 9 ).

That on the hot runner table 200 conveyed steel sheet has a considerably high temperature and the bearings 210 , Couplings (not shown) and the electric motors 10 are placed under a strict operating condition. For this reason, in order to generate a situation such as B. to prevent a line stop, generally sensors such. B. a temperature sensor and a speed sensor at each individual diagnostic target such. B. the camp 210 and the electric motor 10 is attached and the detection signal is analyzed to diagnose the abnormality. On the other hand, in the fifth embodiment, there is a need for the temperature sensor, the speed sensor and the like on each electric motor 10 to attach, eliminated, so that the generation of the situation such. B. the stop of the steel rolling line can be prevented in advance and at a low cost.

[Sixth embodiment]

13 Fig. 3 is a schematic view showing a railroad vehicle 310 according to a sixth embodiment of the present invention. In the following description, components that correspond to the components of the first to fifth embodiments are denoted by the same reference numerals, and the descriptions are sometimes omitted.

In 13 includes a railway vehicle 310 a vehicle body 312 , Chassis 314 , 315 , Bikes 316 , 317 , 318 , 319 and a drive and a monitoring device 320 . The chassis 314 , 315 support the vehicle body 312 from. The wheels 316 , 317 are on the chassis 314 mounted and the wheels 318 , 319 are on the chassis 315 assembled.

14th Figure 3 is a bottom plan view of the chassis 315 .

Two electric motors 10-1 , 10-2 are on the chassis 315 assembled. The electric motors 10-1 , 10-2 are with axes 334 , 344 connected, each being reduction gear 332 , 342 are inserted in between. A pair of left and right wheels 318 is on the axis 334 mounted and a pair of left and right wheels 319 is on the axis 344 assembled. Although the details of the chassis 314 not shown is the chassis 314 similar to the chassis 315 configured. That is, two electric motors 10-3 , 10-4 (not shown) are on the chassis 314 assembled and the railway vehicle 310 includes a total of four electric motors 10-1 to 10-4 .

With return to 13 is the drive and the monitoring device 320 similar to the drive and the monitoring device 170 the fourth embodiment (see 11 ) configured and the drive and the monitoring device 320 drives the four electric motors 10 at that in the railroad vehicle 310 and monitors the condition of the electric motor 10 and the same. That is, if one or more electric motors 10 are overheated, the drive and the monitoring device detect 320 the overheating of the electric motor 10 and gives that Electric motor overheating alarm signal off. In the example of 13 point the wheels 318 , 319 the rotary wheel diameters of d1, d2 and have a relationship of “d1 <d2”. When the turning wheel diameter difference between the wheels 318 , 319 becomes large, the drive and the monitoring device are detected as in the first to fifth embodiments 320 that the rotation wheel diameter difference is large, and outputs the rotation wheel diameter difference alarm signal.

When the temperature rise of the electric motor 10 is generated, the resistivity of the primary and secondary resistances of the electric motor increases 10 and the electric motor resistance value RT increases. As a result, the torque of the multiple electric motors is concentrated 10 that are driven in parallel in the electric motor with the small electric motor resistance value RT, so that a phenomenon is generated in which the railway vehicle 310 cannot be accelerated smoothly due to the lack of average torque. If the phenomenon persists, there is a possibility that the normal electric motor 10 also fails due to the long-term overload. In the sixth embodiment, the phenomenon can be detected to specify the electric motor, so that a major problem can be prevented in advance, and power saving of the electric motor 10 can be achieved more efficiently.

A method of managing the wheel diameter of the railway vehicle depends on a railway company, but in general, maintenance is performed such that the rotary wheel diameter difference falls within a fixed value in the vehicle. If the rotation wheel diameter difference of each wheel is strictly managed, the output imbalance of the multiple electric motors can 10 can be prevented, but maintenance becomes troublesome and is not realistic. In the sixth embodiment, the need to use sensors such as B. the temperature sensor and the speed sensor for each electric motor 10 to be attached is eliminated, and the overheating state of the electric motor and the abnormality of the rotation wheel diameter difference can only be detected from the alternating current flowing through the electric motor. Since a drive pattern is essentially constant for the railway vehicle, the electric motor may overheat 10 can be accurately detected by changing the evaluation information over time in the same running state or by statistical processing of the vehicle occupancy data.

[Seventh embodiment]

15th Fig. 13 is a side view showing a configuration of a vehicle body according to a seventh embodiment of the present invention. In the following description, components that correspond to the components of the first to sixth embodiments are denoted by the same reference numerals, and the descriptions are sometimes omitted.

In 15th includes a vehicle structure 300 Railway vehicles 310 , 360 and a connection unit 350 between wagons that carry the railway vehicles 310 , 360 connects. The railway vehicle 310 is the same as that of the sixth embodiment (see 13 ). The railway vehicle 360 is similar to the railway vehicle 310 configured.

That is, the railroad vehicle 360 includes chassis 364 , 365 , a vehicle body 362 , Bikes 366 , 367 , 368 , 369 and a drive and a monitoring device 370 . The chassis 364 , 365 support the vehicle body 362 from. The wheels 366 , 367 are on the chassis 364 mounted and the wheels 368 , 369 are on the chassis 365 assembled.

In the seventh embodiment, the drives and monitoring devices swap 320 , 370 Information from each other and detect the abnormalities of the overheating state of the electric motor and the turning wheel diameter difference of the wheels 316 to 319 , 366 to 369 based on information about the own vehicle and information about the other vehicle. Assuming that each of the railway vehicles 310 , 360 is a "group" is the vehicle structure 300 According to the seventh embodiment, a "multi-group drive system" and determines the abnormality of the electric motor or the rotary wheel diameter difference based on the comparison with the other group.

[Modifications]

1. (1) Da die Hardware der Steuereinheit 30, der Überwachungseinrichtungen 40, 150, 160 und des Anomalitätsdetektors 180 in den obigen Ausführungsformen durch einen allgemeinen Computer konstruiert sein kann, können der Algorithmus in 2 und 3 und das Programm in 8 in einem Speichermedium gespeichert werden oder durch einen Übertragungspfad verteilt werden.
2. (2) Der Algorithmus in 2 und 3 oder das Programm in 8 ist als Software-Verarbeitung unter Verwendung des Programms in jeder der obigen Ausführungsformen beschrieben. Alternativ kann ein Teil oder das Ganze davon durch Hardware-Verarbeitung unter Verwendung einer ASIC (anwendungsspezifischen integrierten Schaltung), eines FPGA (anwenderprogrammierbaren Verknüpfungsfeldes) oder dergleichen ersetzt werden.
3. (3) In der Konfiguration von 1 und dergleichen ist nur ein Wechselrichter 22 vorgesehen. Alternativ können mehrere Wechselrichter vorgesehen sein. Wenn der Wechselrichter für jeden Elektromotor 10 vorgesehen ist, kann der Elektromotor 10 ein Synchronelektromotor sein.
4. (4) In Schritt S16 (siehe 8) von jeder der obigen Ausführungsformen werden, wenn sowohl „H_L1 > G_L“ als auch „H_L2 > G_L“ erfüllt sind, beide Elektromotoren 10-1, 10-2 als im Überhitzungszustand bestimmt. Wenn nur eines von „H_L1 > G_L“ und „H_L2 > G_L“ erfüllt ist, kann alternativ der entsprechende Elektromotor als im Überhitzungszustand bestimmt werden.

The present invention is not limited to the above embodiments, but various modifications can be made. The above embodiments are illustrated, for example, for the purpose of easy understanding of the present invention, but not necessarily include all of the described configurations. A part of the configuration of one embodiment can be replaced with a configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of an embodiment. A different configuration can be deleted from or added to and replaced by other configurations for part of the configuration of each embodiment. The control lines and information lines shown in the drawings indicate those that are considered necessary for the description, but do not necessarily indicate all control lines and information lines required for the product. In fact, it can be considered that almost all components are interconnected. Possible modifications to the above embodiments are, for example, as follows.

1. (1) As the hardware of the control unit 30th , the monitoring equipment 40 , 150 , 160 and the abnormality detector 180 may be constructed by a general computer in the above embodiments, the algorithm in 2 and 3 and the program in 8th stored in a storage medium or distributed through a transmission path.
2. (2) The algorithm in 2 and 3 or the program in 8th is described as software processing using the program in each of the above embodiments. Alternatively, part or all of it can be replaced by hardware processing using an ASIC (Application Specific Integrated Circuit), FPGA (User Programmable Link Panel), or the like.
3. (3) In the configuration of 1 and the like is just an inverter 22nd intended. Alternatively, several inverters can be provided. If the inverter for each electric motor 10 is provided, the electric motor 10 be a synchronous electric motor.
4. (4) In step S16 (please refer 8th ) of each of the above embodiments, if both “H _L1 > G _L ” and “H _L2 > G _L ” are satisfied, both electric motors 10-1 , 10-2 as determined in the overheating state. If only one of “H _L1 > G _L ” and “H _L2 > G _L ” is met, the corresponding electric motor can alternatively be determined to be in the overheating state.

List of reference symbols

10, 10-1 to 10-N

Electric motor

14th

Rotating shaft

16

Rotary wheel

22nd

Inverter

30th

Control unit

40

Monitoring device (electric motor monitoring device)

41

Current sensor

42, 42-1 to 42-N

Current operating unit (operating unit)

44

Feature size extraction unit (determination unit)

48

Abnormality determination unit (determination unit, abnormality determination process)

54

Arc tangent converter (phase detector)

56

Subtractor (PLL operating unit)

60

Phase operation unit (PLL operation unit, rotation speed operation unit, rotation speed operation process)

72

Integrator (PLL operating unit)

101 to 104

Electric motor control system

105

Steel rolling system

150, 160

Monitoring device (electric motor monitoring device)

180

Anomaly detector (electric motor monitoring device)

220

roller

θ _i *

AC phase angle detection value

θ _i * -θ _i

Difference value

θ _i

AC phase angle

τ *

Torque command

ω _rs

Machine frequency (rotational speed)

I _H

High speed range current difference

I _L N

low speed range current difference

I _Q

Correction high speed range current difference (high speed range current difference)

I _q *

Torque current command value

I _q

Torque current detection value

I _u , I _w , I _u1 to I _uN , I _w1 to I _wN

Current detection value (current value)

PLL_P

Proportional signal

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• WO 2013/035185 A1 [0004]
• JP 61210801 A [0004]

Claims (9)

Electric motor monitoring device, which comprises: an operation unit connected to an electric motor control system comprising: a plurality of electric motors each of which includes a rotating shaft; a plurality of rotating wheels connected to the plurality of rotating shafts; one or more inverters that supply an alternating current to the plurality of electric motors; a control unit that controls the inverter; and a current sensor that detects a current value flowing through each of the electric motors, the operation unit operating a rotational speed of the corresponding electric motor according to each of the current values; and a determination unit that detects an overheat state of any of the electric motors and / or an abnormality of a diameter difference between the plurality of rotating gears based on the current value and the rotation speed. Electric motor monitoring device according to Claim 1 wherein the one inverter supplies the alternating current to the plurality of electric motors, the operating unit operates a plurality of direct current amounts corresponding to the electric motors based on the current value, and the determining unit comprises: a function of operating a low-speed range current difference that is a difference between a maximum value and is a minimum value in the plurality of DC amounts when the rotation speeds of the plurality of electric motors are in a low speed range that is a predetermined speed range; and a function of detecting the overheating state of the electric motor corresponding to the minimum direct current amount on the basis of the low speed range current difference. Electric motor monitoring device according to Claim 2 wherein the operation unit comprises: a phase detector that obtains an AC phase angle detection value based on the current value for any one of the electric motors; and a PLL operating unit (phase locked loop operating unit) that operates a proportional integration on a difference value between the input AC phase angle and the AC phase angle detection value and outputs the AC phase angle such that the difference value becomes smaller, the operating unit outputs a proportional signal that is proportional to the difference value, and the determination unit a Having a function of detecting the overheating state of the one electric motor on the basis of the proportional signal. Electric motor monitoring device according to Claim 1 wherein the one inverter supplies the alternating current to the plurality of electric motors, the operating unit operates a plurality of direct current amounts corresponding to the electric motors based on the current value, and the determining unit includes: a function of operating a high-speed range current difference that is a difference between a maximum value and is a minimum value in the plurality of DC amounts when the rotational speeds of the plurality of electric motors are in a high speed range that is a predetermined speed range; and a function of detecting a rotation wheel diameter difference between the plurality of electric motors on the basis of the high speed range current difference. Electric motor monitoring device according to Claim 1 wherein the determination unit outputs an alarm signal when the overheating state of any of the electric motors and / or the abnormality of the diameter difference between the plurality of rotating wheels are detected. Electric motor monitoring device according to Claim 1 wherein the determining unit outputs a control instruction to change the control state to the control unit when the overheating state of any of the electric motors and / or the abnormality of the diameter difference between the plurality of rotating wheels are detected. An electric motor control system comprising: a plurality of electric motors each including a rotating shaft; a plurality of rotating wheels connected to the plurality of rotating shafts; an inverter that supplies an alternating current to the plurality of electric motors; a current sensor that detects a current value flowing through each of the electric motors; a rotation speed operation unit that operates a rotation speed of the corresponding electric motor according to each of the current values; and an abnormality determination unit that detects an overheating state of any one of the electric motors and / or an abnormality of a diameter difference between the plurality of rotating gears based on the current value and the rotation speed. Steel rolling system that includes: a plurality of electric motors each including a rotating shaft; a plurality of rotating wheels connected to the plurality of rotating shafts, each of the rotating wheels including a roller that presses a steel sheet; an inverter that supplies an alternating current to the plurality of electric motors; a current sensor that detects a current value flowing through each of the electric motors; a rotation speed operation unit that operates a rotation speed of the corresponding electric motor according to each of the current values; and an abnormality determination unit that detects an overheating condition of any one of the electric motors and / or an abnormality of a diameter difference between the plurality of rotating gears based on the current value and the rotation speed. An electric motor monitoring method performed by an electric motor monitoring device in an electric motor control system comprising: a plurality of electric motors each of which includes a rotating shaft; a plurality of rotating wheels connected to the plurality of rotating shafts; an inverter that supplies an alternating current to the plurality of electric motors; a current sensor that detects a current value flowing through each of the electric motors, and the electric motor monitoring device, the electric motor monitoring method comprising: a rotation speed operating process of operating a rotation speed of the corresponding electric motor according to each of the current values; and an abnormality detection process for detecting an overheating state of any one of the electric motors and / or an abnormality of a diameter difference between the plurality of rotating wheels based on the current value and the rotation speed.

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