JP2008178176A - Induction machine controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve such problem of a conventional system that an operation error occurs in the speed of induction machines and the actual slippage of the induction machines increases and the induction machines get in step-out states, when the speed difference between the induction machines becomes large in the blanket control of a plurality of induction machines. <P>SOLUTION: A slip difference increase detection means which has estimated slippage and a slip command inputted and outputs a detection signal, and an operation logical unit which makes a control command from an operation command and a detection signal, are added anew, and the control command is inputted into a torque control means in place of the operation command. It can detect the idling of some axles and the increase of slip before the induction machine gets in a step-out state, and it can stop the torque control of the induction machine. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to torque control of induction machines, and in particular, avoids a step-out state during collective torque control of a plurality of induction machines.

FIG. 2 is a block diagram showing a conventional example. 101, 102, 103, 104 are induction machines, 2 is a current detector, 3 is a power converter, 4 is torque control means, 5 is a magnetic flux calculator, 6 is a frequency calculator, 7 is a slip calculator, and 8 is a speed. A calculator 9 is a slip frequency calculator.
In FIG. 2, only four induction machines are shown, but any number of induction machines may be used as long as there are a plurality of induction machines. Hereinafter, description will be made assuming that there are four induction machines.

ここで、Ｒ１は全誘導機の一次抵抗合成値、Ｌ２は二次自己インダクタンス合成値、Ｍは相互インダクタンス合成値、ＬｅＫは漏れインダクタンス合成値である。漏れインダクタンス合成値ＬｅＫは、

で与えられる。ここで、Ｌ１は全誘導機の一次自己インダクタンス合成値である。 The current detector 2 detects a total current i that is a sum of currents flowing through the individual induction machines connected to the power converter 3 for each phase.
The voltage system magnetic flux calculator 5 calculates the induction machine magnetic flux φ from the total current i and the voltage command v input to the power converter 3 by the equation (1).

Here, R1 is a primary resistance composite value of all induction machines, L2 is a secondary self-inductance composite value, M is a mutual inductance composite value, and LeK is a leakage inductance composite value. The leakage inductance composite value LeK is

Given in. Here, L1 is a primary self-inductance composite value of all induction machines.

ここで、ＦＡとＦＢは誘導機磁束φの成分である。
すべり演算器７は、総和電流ｉと誘導機磁束φから、式（４）を用いて推定すべりωｓｃを演算する。

ここで、Ｒ２は全誘導機の二次抵抗合成値である。
速度演算器８は、誘導機周波数ω１と推定すべりωｓｃから、式（５）を用いて誘導機速度ωｍを演算する。

The frequency calculator 6 calculates the induction machine frequency ω1 using the equation (3) from the induction machine magnetic flux φ.

Here, FA and FB are components of the induction machine magnetic flux φ.
The slip calculator 7 calculates the estimated slip ωsc from the total current i and the induction machine magnetic flux φ using the equation (4).

Here, R2 is a secondary resistance composite value of all induction machines.
The speed calculator 8 calculates the induction machine speed ωm using the equation (5) from the induction machine frequency ω1 and the estimated slip ωsc.

ここで、ωｍ１は誘導機１０１の速度、ωｍ２は誘導機１０２の速度、ωｍ３は誘導機１０３の速度、ωｍ４は誘導機１０４の速度である。 The induction machine speed ωm calculated by Expression (5) is an average value of the individual induction machine speeds, and is a value represented by Expression (6).

Here, ωm1 is the speed of the induction machine 101, ωm2 is the speed of the induction machine 102, ωm3 is the speed of the induction machine 103, and ωm4 is the speed of the induction machine 104.

The slip frequency calculator 9 calculates the slip command ωsr from the magnetic flux command φ * and the torque command τ * using the equation (7).

When the operation command N is ON, the torque control means 4 determines the slip command ωsr, the flux command φ *, and the torque command τ based on the induction machine speed ωm and the total current i. Output a voltage command v such that *. When the operation command N is OFF, the voltage command v is set to 0, and the induction machine is brought into an uncontrolled state.
The power converter 3 amplifies the voltage command v and supplies power to the induction machines 101 to 104 that are loads.

  The operation command N is input to the power converter 3 instead of being input to the torque control means 4, and when the operation command N is ON, power corresponding to the voltage command v is supplied to the induction machines 101 to 104, and the operation command N is OFF. Even when the power supply is stopped, the same function can be obtained.

  With the above configuration, when the operation command N is ON, the total torque of a plurality of induction machines can be controlled to the torque command τ *. If the operation command N is turned OFF, a plurality of induction machines can be brought into an uncontrolled state.

  In vehicles, since bogie control and vehicle control are common, collective torque control of multiple induction machines is frequently used.

JP-A-11-069895

The prior art has the following problems.
When some wheel shafts that are collectively controlled in the vehicle are idling and, for example, the speed ωm3 of the induction machine 103 is higher than ωm1, ωm2, and ωm4, according to equation (6), ωm1, ωm2, ωm3, A calculation error of the induction machine speed ωm with respect to ωm4 occurs. If the idling of the induction machine 103 is large and the calculation error of the induction machine speed ωm is large, the induction machine 103 is in a step-out state. Furthermore, if the idling of the induction machine 103 becomes large, not only the induction machine 103 but also the induction machine 101, the induction machine 102, and the induction machine 104 will be out of step.

  In addition, when the sliding of some wheel shafts becomes large, the induction machine may be out of step as in the case of idling.

When the induction machine goes out of step, torque control becomes impossible, and in the worst case, overcurrent and overvoltage lead to destruction of the induction machine and power converter element.
The present invention has been made to solve the above problems.

According to the first aspect of the present invention, in order to solve the above-described problem, a magnetic flux calculator having a plurality of induction machines and calculating the induction machine magnetic flux from the total current and voltage of all induction machines, and the induction machine magnetic flux A slip calculator that calculates an estimated slip from the total current, a speed calculator that calculates an induction machine speed from the induction machine magnetic flux and the estimated slip, and a slip command calculator that calculates a slip command from a magnetic flux command and a torque command And an induction machine control device having torque control means for collectively controlling the torque of the induction machines based on the total current, the induction machine speed, the slip command, the magnetic flux command, the torque command, and the operation command. A slip difference expansion detecting means for inputting the estimated slip and the slip command and outputting a detection signal; and a driving logic unit for creating a control command from the driving command and the detection signal. Wherein the input to the torque control means control command in place of.

  Before the induction machine is out of step, it can be detected that some of the wheel shafts are idling and sliding, and torque control of the induction machine can be stopped.

  By newly adding the slip difference expansion detecting means 10, it is possible to detect that idling or sliding has occurred on some wheel shafts in all the induction machines. The detected logic is processed by the operation logic unit 11 to create a control command and input it to the torque control means 4 to stop the torque control of the induction machine.

  FIG. 1 is a block diagram showing an embodiment of the present invention, in which 10 is a slip difference enlargement detecting means and 11 is an operation logic unit.

The slip difference enlargement detecting means 10 receives the estimated slip ωsc and the slip command ωsr and outputs a detection signal K.
FIG. 3 is a diagram showing an embodiment of the slip difference enlargement detecting means, wherein K is turned on when | ωsc−ωsr |> α, and K is turned off when | ωsc−ωsr | <α. However, α is a detection threshold value and is a value of 0 or more.

  The detection signal K indicates that some of the wheel shafts in the plurality of induction machines are idling or sliding. α and the degree of idling or sliding are linked to each other, and when α is close to 0, the detection signal K is turned ON with a slight idling or gliding. On the other hand, if α is increased, the detection signal K is difficult to be turned ON with a little idling or sliding.

  It is assumed that only the induction machine 103 idles among the induction machines 101 to 104, and ωm3 becomes larger than ωm1, ωm2, and ωm4. According to equation (6), the speed calculation errors are ωm> ωm1, ωm> ωm2, ωm> ωm4, and ωm <ωm3. As a result, with respect to the slip command ωsr calculated from the torque command τ * and the magnetic flux command φ *, the actual slips of the induction machines 101, 102, and 104 increase, and the actual slip of the induction machine 103 decreases.

In this state, when torque control is performed by the torque control means 4 so that the total current i is constant, the total torque coincides with the torque command τ *, but the estimated slip ωsc according to the equation (4) is the induction machine 101, The average value of 102, 103, 104 is different from the slip command ωsr.
The magnitude of | ωsc−ωsr | depends on the degree of idling. However, if idling is large, | ωsc−ωsr | As a result, the detection signal of the slip difference enlargement detecting means 10 is turned on. Here, the idling is taken as an example, but the same applies to the case of sliding.

  The operation logic unit 11 performs a logical operation of the operation command N and the detection signal K, and outputs a control command NN. If the operation command N is ON and the detection signal K is OFF, the control command NN is ON.

  When the control command NN is ON, the torque control means 4 is based on the induction machine speed ωm and the total current i so that the magnetic flux and total torque of all induction machines become the flux command φ * and the torque command τ *. Command v is output. When the control command NN is OFF, the voltage command v is set to 0, and the induction machine is set to a non-control state.

  The control command NN is input to the power converter 3 instead of being input to the torque control means 4, and when the control command NN is ON, power corresponding to the voltage command v is supplied to the induction machines 101 to 104, and the control command NN is OFF. Even when the power supply is stopped, the same function can be obtained.

  By adopting the above configuration, it is possible to detect that the idling and sliding of some axles have increased before the induction machine is in a step-out state, and torque control of the induction machine can be stopped. Here, by adjusting the detection threshold value α in FIG. 3, it is possible to adjust the degree of idling and sliding of some axles that stop the torque control of the induction machine.

  This is not limited to the speed calculation error due to idling or sliding of some wheel shafts in vehicle control, but even if there is a difference in the shaft speeds of some induction machines that are subject to collective torque control. The invention is effective.

  In the control of a plurality of induction machines such as a vehicle, it is possible to detect idling and sliding of some wheel shafts. Furthermore, the induction machine control can be stopped by the detection signal K before reaching the induction machine step-out state caused by the idling and sliding of some wheel shafts.

  Not only the speed calculation error due to idling or sliding of some wheel shafts in vehicle control, but also when there is a difference in the shaft speed of some induction machines that are subject to collective torque control. The induction machine control can be stopped by the detection signal K before reaching the machine step-out state.

  By stopping the induction machine control, it is possible to prevent the destruction of the induction machine and the element destruction of the power converter 3 due to the overcurrent and overvoltage caused by the induction machine step-out state.

FIG. 1 is a block diagram showing an embodiment of the present invention. FIG. 2 is a block diagram showing a conventional example. FIG. 3 is a diagram showing an embodiment of the slip difference enlargement detecting means.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Induction machine 102 Induction machine 103 Induction machine 104 Induction machine 2 Current detector 3 Power converter 4 Torque control means 5 Magnetic flux calculator 6 Frequency calculator 7 Slip calculator 8 Speed calculator 9 Slip frequency calculator 10 Slip difference expansion detection Means 11 Operation logic unit

i ... Total current v ... Voltage command τ * ... Torque command φ * ... Magnetic flux command ω1 ... Induction machine frequency ωm ... Induction machine speed ωsc ... Estimated slip ωsr ... Slip command φ ... Induction machine magnetic flux N ... Operation command K ... Detection signal NN ... Control command

Claims (1)

A magnetic flux calculator having a plurality of induction machines and calculating the induction machine magnetic flux from the total current and voltage of all induction machines, the slip calculation unit calculating the estimated slip from the induction machine magnetic flux and the total current, and the induction machine magnetic flux And a speed calculator that calculates the induction machine speed from the estimated slip, and a slip command calculator that calculates a slip command from the magnetic flux command and the torque command, the total current, the induction machine speed, the slip command, and the magnetic flux In the induction machine control device having torque control means for collectively controlling the torque of the induction machines based on the command, the torque instruction and the operation instruction,
A slip difference expansion detecting means for inputting the estimated slip and the slip command and outputting a detection signal, and a driving logic unit for creating a control command from the driving command and the detection signal are newly added, instead of the driving command. An induction machine control device that inputs the control command to the torque control means.

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