JPH02273097A - Motor controller - Google Patents

Abstract

PURPOSE:To realize such control as the power factor of secondary current will be 1 by carrying out feedback control based on comparison between a secondary current command and an actual secondary current, and then carrying out output voltage control of an converter. CONSTITUTION:A secondary current peak value command Im* is operated based on the sum of an output from a feedback loop for bringing the difference between a voltage command Ed* and an actual voltage Ed to zero and the feedforward term of load current IL. Phase correction omegat proportional to the secondary current peak value command Im* is operated for the phase omegat of a sinusoidal signal si synchronized with zero point of the secondary voltage Es, then the phase correction omegat is added and a sinusoidal signal sin is pro duced for the corrected phase, thereafter the sinusoidal signal sin is multiplied by the secondary current peak value command Im* thus producing a secondary current command Is*. Then converter output voltage is operated based on the difference between the output from the feedback loop for bringing the difference between the secondary current command Is* and the actual secondary current Is to zero and the actual secondary voltage Es, and voltage control of converter is carried out based on the converter output voltage.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to a motor control device for an electric railway car.

(Prior Art) Generally, a motor control device for an electric railway car has a configuration as shown in FIG. In FIG. 2, electric power fed from the overhead wire 1 during the vehicle is supplied to the primary winding of the main transformer 3 through the vantograph 2. A secondary winding of the main transformer 3 is connected to a converter 5 via an AC reactor 4. The output of the converter 5 is connected to a capacitor 6, smoothed, and supplied to an inverter 7.

Inverter 7 drives induction motor 8 .

The converter 5 maintains a constant DC voltage Ed by a converter control device 9, and also maintains an input current I of the converter 5.
The power factor of s is controlled to be 1.

FIG. 3 is a block diagram of a conventional converter control device 9 in such a motor control device, and the DC voltage Ed detected by the voltage detector 10 in FIG. 2 is a constant DC voltage command value Ed. The peak value command 1 of the current command value Is* to be passed as the secondary current Is as an input to the converter 5 through the feedback compensation 11 is calculated by taking the difference between
m'' correction bone Δ1.m.

The peak value command 1m is Im obtained by feedforward compensation 12 of the DC load current ttct.

9 and the corrected bone Δ1m.

The phase 0 eclipse is generated by the secondary voltage Es of the main transformer 3 as shown in FIG. That is, in FIG. 2, the zero point of the secondary voltage detected by the secondary voltage detector 13 is detected by the zero cross comparator 14.

The output from this zero-cross comparator 14 is given to the clear input of the counter 15. In addition, a constant frequency oscillator 16 is connected to the clock input of this counter 15.
A pulse signal generated by the counter 15 is inputted, and the counter 15 becomes zero when the output of the zero cross comparator 14 is H. Thereafter, the counter 15 sequentially increments each time a clock pulse is input, and receives a signal corresponding to the phase of the secondary voltage Es of the main transformer 3. Output ωt.

By inputting this phase signal ωt to the sine wave generator 17 shown in FIG. 3, a sine wave signal s synchronized with the secondary voltage Es is generated.
This sine wave signal sin and the peak value command 1m* are multiplied by the multiplier 18 to obtain the secondary current command value Is. Then, this secondary current command value Is*
and the actual secondary current Is, and feedback compensation 1
9 and further corrected using the secondary voltage Es to obtain the converter output voltage EC.

(Problem to be Solved by the Invention) However, in such a conventional induction motor control device, in order to make the power factor of the secondary current Ig of the converter 5 1, the power factor must be within a range that does not cause the secondary current Is to oscillate or diverge. Either increase the gain of the feedback compensation 19 or increase the impedance of the AC reactor 4 (1/(L s +R))
There was only one way to compensate for the power factor, but the former method could not make the power factor completely 1, and the latter method could not reduce the actual secondary current! Since it takes the derivative of S, it is vulnerable to noise and has the problem of causing disturbance.

This invention was made in view of these conventional problems, and it is possible to reduce the power factor of the secondary current to 1 without using differentiation of the actual secondary current under the feedback gain within a range that maintains control stability. An object of the present invention is to provide an induction motor control device that can realize the following control.

[Configuration of the Invention (Means for Solving the Problem) The induction motor control device of the present invention includes an AC reactor and a converter connected in series on the secondary side of a main transformer, and a capacitor and an inverter on the output side of the converter. A capacitor voltage command is provided in order to control the secondary current so that the voltage across the capacitor is a constant voltage and the power factor of the secondary power of the main transformer is 1. a feedback loop that sets the difference between the voltage and the capacitor actual voltage to 0, a load current feedforward means, and an addition means that calculates a secondary current peak value command by the sum of the output of the feedback loop and the output of the feedforward means. , a phase detection means for detecting the phase of the secondary voltage of the main transformer, a means for calculating a phase correction proportional to the secondary current peak value command, and a phase correction signal from the phase correction means to be detected by the phase detection means. an addition means for adding to the phase signal from the addition means, a sine wave generation means for generating a sine wave signal synchronized with the eye signal from the addition means, and a sine wave signal from the sine wave generation means and the addition a secondary current command calculating means for calculating a secondary current command by multiplying the secondary current command by a secondary current peak value command from the means; and a secondary current command from the secondary current command calculating means and the actual secondary current of the main transformer. , and converter output voltage calculation means for calculating a converter output voltage based on the difference between the output of the feedback loop and the actual secondary voltage of the main transformer.

(Function) In the induction motor control device of the present invention, in order to control the secondary current Is so that the voltage Ed across the capacitor is constant and the power factor of the secondary power of the main transformer is 1, the voltage command Ed is The secondary current peak value command Im'' is calculated by the sum of the output of the feedback loop that makes the difference between `` and the actual voltage Ed zero, and the feedforward term of the load current 11d.

And a sine wave signal sl synchronized with the zero point of the secondary voltage Es
The secondary current command Is is obtained by multiplying n by the secondary current peak value command 1m. Phase correction Δωt proportional to current peak value command 1m*
is calculated and added, and the phase after this correction (ωt + Δωt)
A sine wave signal sin is generated, and this is multiplied by the secondary current peak value command 1m to obtain the secondary current command Is.
”

Then, the converter output voltage is calculated based on the difference between the output of the feedback loop that makes the difference between the secondary current command Is* and the actual secondary current IS zero, and the actual secondary voltage Es, and based on this converter output voltage, Performs voltage control of the converter.

(Example) Hereinafter, embodiments of the present invention will be explained in detail based on the drawings.

FIG. 1 shows a converter control device according to an embodiment of the present invention, and this converter control device is used as a control device 9 for a converter 5 of a general electric motor control device shown in FIG.

In the embodiment shown in FIG. 1, the third
The same parts as those in the converter control device shown in the figure are designated by the same reference numerals. The feature of this embodiment is that a phase correction 20 is provided which gives a correction Δωt proportional to the peak value command Im* to the secondary voltage phase ωt manually input to the sine wave generator 17.

Therefore, converter control device 9 in the motor control device of this embodiment operates as follows.

The voltage Ed across the capacitor 6 detected by the voltage detector 10 in FIG. A correction bone Δ1m of the peak value command 1m of the current command value Is to be passed as the secondary current Is is output.

The feedforward compensation 12 outputs a current peak value command Imo* proportional to the input of the load current 11d, and this peak value command 1mo is based on the feedback compensation 1
This is the peak value for the secondary current command Is.

The command is 1m.

The sine wave generator 17 receives a sum signal of the phase ωt of the secondary voltage from the counter 15 in FIG. The sine wave signal sfn is generated by the
(ωt+Δωt) is output, and this is given to the multiplier 18.

The multiplier 18 multiplies the secondary current peak value command 1m* and the sine wave signal sin from the sine wave generator 17,
Outputs secondary current command Is*.

This secondary current command Is* is then compared with the actual secondary current Is, and the difference is given to the feedback compensation 19,
The output of this feedback compensation 19 is the secondary voltage command ΔE
s, and the difference output from the actual secondary voltage ES is taken as the output voltage Ec of the converter 5.

In this way, it is possible to control the power factor to 1 without using differentiation of the actual secondary current Is while keeping the feedback gain within a stable range.

[Effects of the Invention] As described above, according to the present invention, a phase correction proportional to the secondary current peak value command of the main transformer is calculated, and in addition to the phase of the sine wave synchronized with the zero point of the main transformer secondary voltage. , This is combined with the secondary current peak value command to form the secondary current command,
Since the output voltage of the converter is controlled through feedback control based on comparison with the actual secondary current, the power factor of the secondary current of the main transformer can be set to 1 without affecting the stability of current feedback. control can be carried out.

[Brief explanation of drawings]

FIG. 1 is a feedback block diagram of an embodiment of the present invention, FIG. 2 is a block diagram of the main circuit of a general electric railway car, and FIG. 3 is a feedback block diagram of a conventional example. 1... AC overhead wire 2... Pantograph 3.
... Main transformer 4 ... Reactor 5 ... Converter 6 ... Capacitor 7 ... Inverter 8 ... Induction motor 9 ... Converter control device 10 ... Voltage detector 11 ... Feedback compensation 12... Feedforward term 13... Voltage detector 14... Zero cross comparator 15... Counter 16... Oscillator 17...
・Sine wave generator 18... Multiplier 19... Feedback compensation 20... Phase correction

Claims (1)

[Claims] An AC reactor and a converter are connected in series on the secondary side of the main transformer, and a main circuit is provided on the output side of the converter in which a capacitor and an inverter are connected in parallel. In order to control the secondary current so that the power factor of the secondary power of the transformer becomes 1, a feedback loop that sets the difference between the capacitor voltage command and the capacitor actual voltage to 0, and a load current feedforward means; addition means for calculating a secondary current peak value command based on the sum of the output of the feedback loop and the output of the feedforward means; a phase detection means for detecting the phase of the secondary voltage of the main transformer; means for calculating a phase correction proportional to the high value command; addition means for adding the phase correction signal from the phase correction means to the phase signal from the phase detection means; A sine wave generating means for generating a sine wave signal; and a secondary current command calculation for calculating a secondary current command by multiplying the sine wave signal from the sine wave generating means and a secondary current peak value command from the adding means. means, a feedback loop that sets the difference between the secondary current command from the secondary current command calculation means and the actual secondary current of the main transformer to 0, and an output of this feedback loop and an actual secondary voltage of the main transformer. converter output voltage calculation means for calculating a converter output voltage based on the difference between the converter output voltage and the converter output voltage.