JPS5999904A - Controlling method for controller of electric rolling stock - Google Patents

Abstract

PURPOSE:To improve the stability of a system under a notch OFF condition by controlling the width of the modulation pulse of an inverter under the notch OFF condition and reducing the output voltage. CONSTITUTION:A reference slip frequency FSO and a correction slip frequency FS1 in response to a current pattern IP based on a current limiting value command IC are added to produce a slip frequency FS, and an inverter output frequency F is determined by a slip frequency FS and a rotating frequency FR. A modulation pulse mode calculator 32 sets a modulation pulse mode N to approximate to a sinusoidal wave in response to a notch command P. A modulation factor calculator 33 outputs a modulation factor AL so that the ratio V/F of the inverter output voltage V to the output frequency F becomes constant. The modulation factor output AL is limited to K1 or lower at the positive side and to K2 or lower at the negative side under notch ON condition, and attenuated at the change rate K2 under the notch OFF condition.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention provides a method for obtaining a predetermined modulation/malus by combining a synchronized wave modulation wave and a triangular wave carrier wave, and
The modulation rate determined by the ratio of the amplitude of the variable amplitude wave and the carrier wave is controlled to control the above-mentioned pulse rate.
A variable voltage variable frequency inverter (rw
This invention relates to an electric vehicle control device that drives an induction motor using a VR inverter (referred to as a "VR inverter"), and in particular to a control method that improves the stability of main circuit operation during notch-off and enables ATO operation (automatic operation). It is.

[Technical background of the invention]

FIG. 1 shows an example of a typical VWF' inverter control system for conventional lightning and air turbines. Figure 1 (,) shows the drive circuit system, where 1 is ノ'? 2 is a breaker, 3 is a filter reactor, 4 is a filter capacitor, 5 is a voltage detector that detects the terminal voltage of the filter capacitor, 6 is an inverter section, 7.8 is an induction motor, 9
．． 10 detects the rotating deposit of the electric motor and generates a corresponding frequency! This is a Zulu generator that outputs Luz.

1, 11 to 13 are current detectors that detect the motor current. Next, Figure 1(a) shows the control system of the inverter, in which the outputs PGM, PG
,? Then, the rotational frequency calculating section 2 counts the rotational frequency FR for a certain period of time. The current limit value command IC causes the current point and turn generating section 22 to control the current point and turn IP.
is calculated. Reference slip frequency generator 23 current f
Depending on the turn Ip input, the characteristics as shown in Figure 2, -
The reference slip frequency Fso is output at the e-turn. The amplifier 24 amplifies the deviation between the current pattern Ip and the detected motor current L+, and outputs a corrected frequency p B 1. The reference slip frequency FB and the corrected slip frequency Fs are added to obtain a slip frequency F8, and this is added to the rotational frequency FR via the slip frequency limiter 28 to determine the output frequency F. A normal VVVF inverter makes the motor current as close to a sine wave as possible.
The output voltage is controlled by approximate sine wave modulation.

25 is a variable nocellus mode performance section for the output frequency F and filter capacitor 〒1:? :FC(
Detected by viFE detector 5-Xn;E,)KITfU7:
Optimal moisture/4' Lusmode N is applied to the film. Weird! η
Noya Luss mode N has an output of 1i! ;It corresponds to the Lune number included in one cycle of the 149 number F, and basically, the larger the Noyals number, the closer the I→Raisha becomes to a sine wave, but on the other hand, This results in an increase in the switching loss of the elements constituting the inverter.

Therefore, at low speeds, the number of lupus increases, and as the speed increases, the number of lupus decreases, and eventually 1.
Control to reach mother Lus mode.

The modulation rate part 1'4 of each 26-digit pulse mode determines the magnitude of the inverter output FFEV, so that the ratio V/'F of the inverter output 11L pressure V and output frequency F is constant. , the modulation rate ALL is calculated using the output frequency F and the filter capacitor pressure Ec as shown in the following formula.
Output.

AN-F+BH ALI = 7, old (1) (here, AN+RN) is a constant determined by the P pulse mode. ) Figure 3 shows speed and no? The relationship between the loose mode and the modulation rate is shown. The 1-pulse mode has a variable frequency of 1 and is a constant voltage region where voltage control is not possible.

Reference numeral 27 denotes a gate logic section that generates a dirt signal for the inverter according to the frequency F, modulation rate ALt, and variable pulse mode N described above, and outputs gate signals G1 to G6 to each element of the inverter 6. Then, the notch command P is input to the current pattern generating section 22, and when the notch is off, the current 9 turns rp is throttled down, and when the motor current IM becomes below a predetermined value, the current cutoff is performed to open the I @ device 2. In this case, when the current pattern rp is tightened, the reference smooth υ frequency dispersion generator 2
Since the reference slip frequency F'so, which is the output of No. 3, decreases, and therefore the slip frequency FB decreases, the effective current I2 in the equivalent circuit of the induction motor shown in FIG. 4 decreases. (In FIG. 4, R1 is the motor-order resistance, ll+ is the electric motor primary leakage inductance, lx is the motor secondary leakage inductance, and 1m is the motor excitation inductance.

) Since the effective power as seen from the DC power supply side is reduced, the fifth
As shown in the figure, the filter capacitor voltage Pc increases.

By the way, in the system shown in Fig. 4, the slip frequency F8 of the induction motor is low, that is, the slip S is small (
(light load), system stability deteriorates and voltage and current pulsate. This is equivalent secondary resistance R2 against disturbance.
This is because /S is a stabilizing (damping) element (the smaller R2/S is, the more stable it is). Furthermore, since voltage control is not possible in the l-2 Luss mode in the high speed range, when the filter capacitor voltage Ec increases as shown in FIG. 5, the excitation electric currents H and Iy increase, which further deteriorates the stability.

[Purpose of the invention]

An object of the present invention is to improve the stability of the system during notch-off in an electric vehicle control device that uses VV'VF inverter control to drive an induction motor, and to control the electric vehicle control device to enable ATO operation. The purpose is to provide a method.

[Summary of the invention]

In the present invention, at the time of notch-off, the output voltage is reduced by controlling the modulation pulse width of the inverter, and the voltage/frequency ratio of the power supplied to the four motors is reduced to reduce the motor current. It is characterized by doing.

[Embodiments of the invention]

FIG. 6 shows the configuration of an inverter control system in an embodiment of the present invention. The main difference in FIG. 6 from the case in FIG. 1(b) is that the notch command P is
Instead, it is inputted to the variable frequency pulse mode calculation section 32 and the modulation rate calculation section 33.

Modulation rate calculation unit 33 and modulation/Grus mode calculation unit 32
The details are shown in FIG. 7 and FIG. 8, respectively.

In FIG. 7, when the notch is turned on, a numerically calculated value ALI according to equation (1) is obtained by the reference modulation rate calculating section 41, and this numerically calculated value ALI is provided to the conversion limiter 42 via the selection switch 42 as AL.

Let the output of this change limiter 43 be #adjustment output AI,
The output AL2 of the selection switch 42 is the value ALO sampled from this output AL by the sample hold circuit 44.
and are input to the conversion limiter 43 to suppress the rate of change on the positive side to 1 or less and the rate of change on the negative side to 2 or less. When the notch is off, the output AL of the selection switch 42
The goose becomes O, and the modulation rate output AL attenuates at a rate of change of 2.

In FIG. 8, 51, 52, and 5.9 are reference modulation rate calculation units, and each g change rate ALe of the 9 i4 pulse, 5 pulse, and 3 nogle modes is determined by the above equation (1).

Calculate AL5 + AI, s. 54, 55, 56 is a maximum modulation rate calculation unit, which calculates the maximum modulation rate AL* (rnax), AL5 (max), AL
3 (max) is calculated. 57, 58, and 59 are comparators, which compare the above values ALN (N is 9, 5, 3 in this case) and ALN (max) in each pulse mode, and output "H" (...Irepel) and "L". It outputs # (low level) logic signals 9cT, 5cT, and 3cT. 60 is a pulse mode selection section, into which notch command P and signals 9CT + 5CT + 3CT are input, and modulation pulse mode N is selected according to these inputs. The logic table for the operation of this pulse mode selection section 60 is shown below.

1 pulse mode is not selected when the notch is off. Even when the mode is 17 or pulse mode just before notch-off, the mode can be switched to 3-pulse mode.

Next, the operation in such a configuration will be explained.

FIG. 9 shows the operating waveforms of this embodiment. In the 1-pulse mode, when notched off, the modulation pulse width l
' In the performance section 32, the armband mode is switched from 1 noguru to 3 noguru, and at the same time, in the modulation rate calculation section 33, AL2 = x Q, and the modulation rate AL
Since the rate of change decreases due to snow, the output voltage of the inverter 6 decreases, and the output voltage (V)/output frequency (F) becomes smaller, so the motor current decreases. At this time, the slip frequency F increases temporarily, but is suppressed by the slip frequency limiter 28.

In this manner, the motor current is attenuated by reducing the output voltage of the inverter 6 at the time of notch-off, and the slip frequency is not reduced, so that the stability of the system is not lost even under light loads. Furthermore, even if the inverter is in the 1-pulse mode without voltage control capability, the output voltage of the inverter 6 can be constrained by returning to the multiple-pulse mode when the notch is turned off. These things make it possible to continue stable impeller operation without opening the main circuit even during coasting operation after notch-off. .

It should be noted that the present invention is not limited to the embodiments shown on page 171, as described above, and can be implemented with various modifications without changing the gist thereof. do not have.

[Efficacy of invention]

According to the present invention, in an electric vehicle control device using VVVF inverter control for stable induction motor operation, the stability of the system at the time of notch-off is improved, and the AT
A control method for an electric vehicle control device that enables O-wheel rotation can be provided.

[Brief explanation of the drawing]

Figures 1 (a) and (b) show typical conventional V
Kuri i1+ shows an example of the configuration of a VVF inverter system.
11 A circuit diagram of the circuit system and a block diagram of its inverter control system. Figure 2 is a diagram showing the characteristics and mother turn of the reference slip frequency F'so with respect to the current pattern in the same example. Figure 3 is a diagram showing the modulation with respect to speed in the same example.・♀Russ mode,
FIG. 4 is a circuit diagram showing a VVVF inverter equivalent circuit including an induction motor in the same example.
FIG. 5 is a main circuit operation waveform diagram during notch-off in the same example, FIG. 6 is a block diagram showing the configuration of an inverter control system according to an embodiment of the present invention, and FIGS. 7 and 8 are respectively in the same embodiment. FIG. 9 is a block diagram showing the details of the modulation rate calculation section and the modulation/Grus mode calculation section, and is a main circuit operation waveform diagram for explaining the operation of the same embodiment. 1... Noguntagraph, 2... Breaker, 3...
Filter reactor, 4... Filter capacitor, 5
... Voltage detector, 6... Inverter, 7, 8...
Induction motor, 9.10...Pulse generator, 11
゜12.13...Current detector, 21...Rotation frequency calculation unit, 22.31...Current nog turn generation unit, 23
...Reference slip frequency/mother turn generation section, 24...
Deviation amplifier, 25.32... Modulation nogle mode calculation unit, 26.33... Modulation rate calculation unit, 27... Key
28... Slip frequency limiter, 41... Reference modulation rate calculation unit, 42... Changeover switch, 43... Change rate limiter, 44... Sample *-#)' circuit , 51.52.53...Reference modulation rate calculation unit for each Noculus mode, 54.55.56...Each...
57.58°59.
... Comparator, 60... Pulse mode selection logic section. Applicant's agent Patent attorney Takehiko Suzue 13- Figure 8-22- Figure 9 Not ↑ Off ↓ ■ 11111to11111111■

Claims (1)

[Claims] Obtaining a predetermined modulation pulse by comparing a synchronized sinusoidal variable VK wave and a triangular carrier wave, and controlling the modulation pulse width by changing a modulation rate determined by the ratio of the magnitude of the modulation wave and the carrier wave, In an electric vehicle control device that drives and controls an induction motor with a variable voltage variable frequency pulse width modulation control inverter that operates an inverter using this modulated pulse and converts DC power into AC IN power, when the inverter is turned off, By controlling the modulation pulse width, the output voltage is increased and the wave number ratio of the power supplied to the motor is reduced, and the electric p! 1. A control method for a Raigin 1g control device, which is characterized by performing current reduction and cutoff to reduce lightning current.