JP3227009B2 - AC electric vehicle control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an AC electric vehicle using a pulse width modulation converter as a main circuit, and more particularly to a control device for an AC electric vehicle compatible with a different frequency AC power supply.

[0002]

2. Description of the Related Art In an AC electric vehicle using a thyristor / diode mixed bridge instead of a pulse width modulation converter, an example in which switching of a synchronous power supply for control is performed in response to frequency switching of an AC power supply is described in the 27th Railway Proceedings of the National Symposium on the Use of Cybernetics in Japan, No. 189-1
The main circuit and control system of a 309 inverter locomotive on page 93 (November 1990).

[0003]

The control of an AC electric vehicle is as follows.
Although it is necessary to synchronize with the AC power supply, the AC power supply voltage to be detected contains noise and harmonics, and the synchronous circuit malfunctions. Therefore, the synchronous power supply usually has a band-pass characteristic called an Otto filter. A filter is provided to reduce noise and harmonics and adjust the phase of the fundamental wave.
When the frequency of the AC power source changes, the phase of the synchronous power source, which is the output of the Otto filter, changes. And the control device becomes complicated.

An object of the present invention is to provide a control device having a simple configuration having only one synchronous power supply filter, and to cope with a different frequency AC power supply.

[0005]

SUMMARY OF THE INVENTION In a pulse width modulation converter, in order to perform power factor 1 control, a pulse width modulation converter 2
A secondary current command is generated, and feedback control is performed so that the actual secondary current follows the secondary current command. If one synchronous power supply filter is used, the power factor is reduced from 1 due to a change in the phase of the synchronous power supply. Therefore, the phase of the secondary current pattern with respect to the synchronous power supply is allowed to be changed, and the phase is adjusted by the frequency of the AC power supply.

[0006]

In order to generate the secondary current pattern, sine wave data is written in the ROM, and an address signal of the ROM is generated according to the electrical angle of the output of the synchronous power supply filter.
, And multiplying the read data by a peak value command of the secondary current. RO
When reading the data of M, if the address signal of the ROM is offset so as to compensate for the phase characteristic of the synchronous power supply filter that changes according to the frequency of the AC power supply, the phase of the input / output signal of the synchronous power supply filter changes. Also, a secondary current pattern in the same phase as the AC power supply can be generated.

[0007] As another method, if the phase of the ROM data itself is shifted in accordance with the frequency, the same function can be realized more easily without offsetting the address signal.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS.
You.

The AC power supplied from the AC power supply 1 of the substation to the overhead line 3 via the circuit breaker 2 is received by the electric vehicle by the pantograph 4. This AC power is supplied to the pulse width modulation converter main body 7 composed of a self-extinguishing element and the like via the transformer 6 via the circuit breaker 5 and the reactor 61 utilizing the leakage inductance of the transformer, and the pulse width The power is converted into DC power by the modulation inverter 7 and smoothed by the smoothing capacitor 8 and supplied to the pulse width modulation inverter 9. Pulse width modulation inverter 9
Thus, the AC motor 10 is driven.

In Japan, two types of frequencies, 50 Hz and 60 Hz, are used. Therefore, depending on the line section on which the electric vehicle runs, the frequency is switched when the substation supplying power to the overhead line 3 changes. There is.

The pulse width modulation converter main body 7 performs a conversion operation from AC to DC (forward conversion) during power running operation, and performs a conversion from DC to AC (reverse conversion) during regenerative operation.
Perform the operation. During both operations, the pulse width modulation converter body 7
Is to maintain the DC voltage Vd, which is the voltage across the smoothing capacitor 8, at a constant value, and to set the AC power supply voltage Es and the
The converter input voltage Vc generated by the pulse width modulation control is controlled so that the power factor cosφ determined by the phase difference φ with the next current Is becomes 1.

The primary voltage Ep of the transformer 6 is equal to the voltage detector 1
1, after removing noise and harmonics contained in the power supply by the synchronous power supply filter 14, and by the zero-cross detector 15, the zero-cross pulse ZXP of the primary voltage Ep
Get. However, the output SYC of the synchronous power supply filter 14 is
The phase differs from that of the AC power supply 1 depending on the frequency of the AC power supply 1. For example, if the frequency of the AC power supply 1 is 50 Hz
The output SY of the AC power supply 1 and the synchronous power supply filter 14
FIG. 4 shows a typical frequency characteristic of the synchronous power supply filter 14 when the characteristic of the synchronous power supply filter 14 is set so that the phase of C coincides. The frequency of AC power supply 1 is 60Hz
, The phase of the output SYC of the synchronous power supply filter 14 is delayed by about 12 degrees with respect to the AC power supply 1.

The output frequency of the zero-cross detector 15 is detected by a frequency detector 17. 5 detected frequencies
Depending on whether the frequency is 0 Hz or 60 Hz, the frequency switch 18 controls the phase offset signal PHS
20 to output a frequency switching signal FSS.

The 16 output ADCs that count the clock pulses CP and are reset by the output of the zero cross detector 15 indicate the electrical angle of SYC. An address ADR of the sine wave ROM 20 is generated by a signal obtained by adding the SYC and the phase offset signal PHS from the frequency switch 18 by the adder 19. Since the address ADR corresponds to the electrical angle of the primary voltage Ep, if the unit sine wave data corresponding to the electrical angle is written in the sine wave ROM 20, the primary voltage EDR is obtained.
A unit sine wave synchronized with p can be obtained as output data. When two types of AC power supplies, 50 Hz and 60 Hz, are used, the sine wave ROM 20 also stores 5 Hz.
Write two types of data, 0 Hz and 60 Hz,
It is necessary to switch data by the frequency switching signal FSS. This can be realized, for example, by connecting the frequency switching signal FSS to one of the address signals and switching the storage area. The output data SIN of the sine wave ROM 20 is input to the D / A converter 21 and converted into an analog signal. However, if the control device is digitally controlled, digital data can be handled as it is, so that D / A
The converter 21 is unnecessary.

For DC voltage control, which is one of the main control functions, the DC voltage pattern Vdp and the detected DC voltage Vd are compared by an adder 22 and the deviation is input to an AVR (voltage regulator) 23. The multiplier 24 multiplies the secondary current peak value command Ism output from the AVR 23 by the output signal of the D / A converter 21 to generate a secondary current pattern Isp which is a sine wave. If the DC voltage pattern Vdp
If the DC voltage Vd is smaller, the AVR 23 becomes 2
By acting to increase the next current pattern Isp and increasing the converter output, Vd is increased and controlled to match Vdp. Conversely, if Vd is larger than Vdp, the AVR 23 decreases Isp to lower Vd.

Next, the control of the secondary current will be described. The secondary current pattern Isp output from the multiplier 24 and the current transformer 1
The secondary current Is detected in step 3 is compared by an adder 25, and the deviation is input to an ACR (current controller) 26. ACR26
Controls a command to the PWM (pulse width modulation) control unit 27 so that Is is equal to Isp. That is, Is
If Is is smaller than p, the converter input voltage Vc
Is set to zero voltage, or a voltage having a polarity opposite to that of the secondary voltage Es is generated, thereby acting to increase the current Is flowing from the secondary voltage Es. Conversely, Isp
If s is larger, a voltage higher than Es is generated as Vc, which acts to reduce Is. In this way, control is performed so that the secondary current Is matches the secondary current pattern Isp.

The PWM control section 27 gives a gate pulse to the self-extinguishing element of the converter main body 7 so that a predetermined voltage is generated as Vc at the converter input side by a signal from the ACR 26, and the self-extinguishing element is turned on. Turn on / off.

Here, if the characteristic of the synchronous power supply filter is such that the phase difference between input and output is 0 degree when the frequency is 50 Hz, if the frequency of the AC power supply 1 is 50 Hz, 1
The output is output from the zero cross detector 15 at the same time as the zero cross of the next voltage, and the counter 16 is reset.
Then, the phase of the secondary current pattern Isp is synchronized with the primary voltage Ep, and the operation is performed at the power factor of 1. Of course, the frequency switching signal FSS is 50H
A unit sine wave of z is generated.

When the frequency of the AC power supply 1 becomes 60 Hz, the output SYC of the synchronous power supply filter 14 becomes 1
The lag phase is about 12 degrees with respect to the next voltage Ep. When the frequency detector 17 detects that the frequency is 60 Hz, the frequency switch 18 outputs the phase offset signal PHS,
The output of the adder 19 is instructed to the output ADC of the counter 16 so as to output PHS data such that the phase is advanced by 12 degrees.

Thus, even if the output SYC of the synchronous power supply filter 14 has a phase different from that of the primary voltage Ep, the phase of the output SIN of the sine wave ROM 20 can be made to coincide with the phase of the primary voltage Ep. Energy saving operation at a rate of 1 can be performed.

[0021]

According to the present invention, there is no need to provide a plurality of synchronous power supply filters and switch between them, and it is possible to provide a control device for an AC electric vehicle which has a simple configuration and can handle different frequencies.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention.

FIG. 2 is an operation explanatory diagram of FIG. 1;

FIG. 3 is an operation explanatory diagram of FIG. 1;

FIG. 4 is a frequency characteristic diagram of a typical synchronous power supply filter.

[Explanation of symbols]

11: Transformer, 14: Synchronous power supply filter, 15: Zero cross detector, 16: Counter, 17: Frequency detector, 1
8 frequency switcher, 20 sine wave ROM.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-155402 (JP, A) JP-A-63-56101 (JP, A) JP-A-1-259702 (JP, A) JP-A-6-56702 169501 (JP, A) JP-A-6-197402 (JP, A) JP-A-4-117103 (JP, A) JP-A-3-63097 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B60L 9/30 B60L 9/24 H02M 7/155 H02M 7/48

Claims (1)

(57) [Claims] 1. An AC electric vehicle in which an AC power supply travels in two types of sections of 50 Hz and 60 Hz, wherein an AC side is connected to a secondary winding of a transformer having a primary winding connected to the AC power supply.
A pulse width modulation converter controlled based on a deviation between a detection value (Is) of a secondary current flowing through the AC side secondary winding and a command (secondary current command (Isp)); The DC side is connected, and the AC side is connected to an AC motor that drives the AC electric vehicle, and the control device for the AC electric vehicle is configured to pass the 50 Hz and 60 Hz components of the AC power supply voltage.
Of 50Hz or 60Hz
Outputting an AC voltage signal that matches the AC power supply voltage phase.
One synchronous power supply filter set to be constant
And the sine wave data is written and the address signal is added.
Then, a ROM for generating a sine wave signal and the synchronous power supply
Of the AC voltage signal of the frequency at which the
A counter for giving an address signal to the ROM at an angle (phase)
And the AC voltage signal output by the synchronous power supply filter.
The AC power in the running section is determined by the zero-cross cycle time.
Frequency detecting means for detecting the frequency of the source;
The frequency of the generated sine wave signal is detected by the frequency detecting means.
Switching to a known frequency and the synchronous power supply filter
The AC power supply of the other frequency for which the constant is not set
Address the phase offset signal to the ROM
Frequency switching means for performing phase compensation by giving as a signal.
For example, the AC power supply voltage AC electric vehicle control device being characterized in that so as to vary the phase and frequency of the secondary current command (Isp) depending on whether the frequency is 50Hz or 60Hz in.