JP3100238B2 - PWM converter 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 PWM converter control device for inductive current collection mounted on a magnetic levitation train or the like, and more particularly to a PWM converter control device having improved control accuracy and power conversion rate. .

[0002]

2. Description of the Related Art Conventionally, in a magnetic levitation type linear motor car, various DC loads are driven by a voltage induced in an induction current collecting coil on a vehicle side using an induction magnetic field from the ground side. . In this case, the AC power from the induction current collecting coil is converted to DC power via the PWM converter, but in order to use the induced power with high efficiency, it is necessary to optimally turn on and off the switching elements in the PWM converter. .

FIG. 4 shows a conventional PWM described in, for example, 22th Railway Cybernet Symposium No. 603, pp. 475-479, "Improvement of Active Power for Non-Contact Current Collection by PWM Converter".
It is a block diagram showing a converter control device. In the figure,
Reference numeral 1 denotes an induction current collecting coil facing a primary coil (not shown) on the ground side, and has an internal impedance R (resistor) and L
(Inductance), the induced voltages V _SU , V _SV and V
Three-phase voltage based on the _{SW V U,} V V and V _W and the three-phase currents I _U, and outputs the I _V and I _W.

[0004] Reference numeral 11 denotes a three-phase voltage V from the induction current collecting coil 1.
U, VV and VW and three-phase currents IU, a PWM converter IV and IW are input, self-extinguishing switch
It is composed of an inverter composed of a transistor bridge as a switching element, and converts AC power into DC power.
Note that a current transformer for detecting the three-phase currents IU, IV, and IW is provided in a line between the induction current collecting coil 1 and the PWM converter 11. Reference numeral 12 denotes a filter capacitor connected between the DC output terminals of the PWM converter 11, and reference numeral 13 denotes a load connected between both ends of the filter capacitor 12.

[0005] Reference numeral 2 denotes a three-phase voltage V which is arranged near the induction current collecting coil 1 and has substantially the same phase as the induced voltages V _SU , V _SV and V _SW.
The pickup coil 3 for detecting _SU ′, V _SV ′ and V _SW ′ detects the phase of the induced voltages V _SU , V _SV and V _SW from the three-phase voltages V _SU ′, V _SV ′ and V _SW ′ and performs PWM. A synchronous phase detection circuit for generating sine wave signals sinωt and cosωt necessary for controlling the converter 11, and 4 is a sine wave signal sinωt and cos
ωt and three-phase current I _U, a three-phase current I _U, 3-phase / 2-phase conversion circuit for detecting the active component I _P and reactive component I _Q of I _V and I _W on the basis of I _V and I _W.

A Q controller 5 for generating a reactive power command Q based on a deviation between the reactive component _IQ and the reactive power reference QR _;
6 V controller for generating a voltage command V based on a deviation between the output voltage V _F of the filter capacitor 12 and the output voltage reference F _R, 7 is active power command based on a deviation between the active component I _P and the voltage command V It is a P controller that generates P.

Reference numeral 8 denotes two-phase / three-phase which determines sine wave voltages e _U , e _V and e _W to be output by the PWM converter 11 based on the reactive power command Q and the active power command P and the sine wave signals sinωt and cosωt. The conversion circuit 9, based on the sinusoidal voltages e _U , e _V, and e _W , controls the control pulse C for the PWM converter 11.
PWM pulse generation circuit for determining _P , 10 is control pulse C _P
Is a gate circuit that amplifies the current and actually turns on and off the transistor in the PWM converter 11.

Next, a conventional PWM will be described with reference to FIG.
The operation of the converter control device will be described. First, the induction current collecting coil 1 converts the three-phase induced voltages V _SU , V _SV and V _SW collected by the induced magnetic field from the ground side into the three-phase voltages V _U and V _U via the internal impedances R and L, respectively. V _V and V _W and three-phase currents I _U , _IV and I _W are supplied to the PWM converter 11.

[0009] The PWM converter 11 converts the input three-phase AC power into DC power, and supplies the smoothed power to the load 13 via the filter capacitor 12. At this time,
By controlling the output voltage and the phase by turning on and off the transistor of the PWM converter 11, the active power and the reactive power are controlled, and the high efficiency operation in which the power factor becomes 1 is realized.

Usually, the inductance L which is the internal impedance of the induction current collecting coil 1 is very large, and the% impedance is 300% to 500%. Therefore, in order to obtain the maximum active power, the inductance L is generated. It is necessary to generate reactive power from the PWM converter 11 so as to cancel the reactive power generated. Further, in order to control the PWM converter 11 so that the power factor becomes 1, it is necessary to accurately know the zero point of the phases of the induced voltages V _SU , V _SV and V _SW .

Therefore, the three-phase voltages V _SU ', V _SU having substantially the same phase as the induced voltage are detected by detecting magnetic flux changes due to the induced voltages V _SU , V _SV, and V _SW of the pickup coil 2 and the induction current collecting coil 1.
_SV ′ and V _SW ′ are obtained, and the synchronous phase detection circuit 3 outputs a sine wave signal sin having the peak value = 1 and the same phase as the detection voltage V _SU ′.
ωt and a sine wave signal cosωt having a phase difference of 90 ° are generated. or,
The three-phase / two-phase conversion circuit 4 converts the sine wave signals sinωt and cosωt
And three-phase current I _U, the calculation based on the I _V and I _W, detects the active component I _P and reactive component I _Q of the current.

[0012] Q controller 5 generates a reactive power command Q reactive power control by amplifying a deviation between the reactive component I _Q and the reactive power reference Q _R, also, V controller 6
Calculates a voltage command V for voltage control based on the deviation between the output voltage V _F which is fed back from the filter capacitor 12 and the output voltage reference F _R, P controller 7, and the active component I _P and the voltage command V , An active power command P for active power control is generated.

The two-phase / three-phase conversion circuit 8 outputs a reactive power command Q
And the active power command P and the sine wave signals sinωt and cosωt
, The instantaneous sine wave waveform of the voltage and phase to be output by the PWM converter 11 is determined and output as sine wave voltages e _U , e _V and e _W. PWM pulse generating circuit 9 compares the sine-wave voltage e _U, e _V and e _W for example a triangular wave carrier, to generate a pulse waveform to be output PWM converter 11 as a control pulse C _P.

[0014] Finally, the gate circuit 10, for turning on and off the transistors in the PWM converter 11 amplifies the control pulse C _P. Thus, a required DC voltage from a DC output terminal of the PWM converter 11 is output, the filter capacitor 12, load the output voltage V _F which has absorbed the DC ripple 1
Apply to 3. Thus, based on the three-phase voltages V _SU ′, V _SV ′ and V _SW ′ from the pickup coil 2, PW
It determines the reference phase of the control pulse C _P to M converter 11.

However, when affected by the peripheral magnetic field or the like, the phases of the three-phase voltages V _SU ′, V _SV ′ and V _SW ′ detected by the pickup coil 2 are changed by the induction current collecting coil 1.
And the phases of the induced voltages V _SU , V _SV, and V _SW may be significantly different. For this reason, a control error with respect to the PWM converter 11 increases, and for example, a phenomenon may occur in which the voltage at the DC output terminal fluctuates or the power supplied to the load 13 decreases. Therefore, if such a control error occurs, high-efficiency operation cannot be realized.

[0016]

As described above, the conventional PWM converter control device uses the pickup coil 2 as means for detecting the induced voltages V _SU , V _SV and V _SW in the induction current collecting coil 1. Therefore, there is a problem that the phase difference between the induction current collecting coil 1 and the pickup coil 2 increases due to the influence of the peripheral magnetic field and the like, and a control error increases, so that a required DC power cannot be obtained.

The present invention has been made to solve the above problems, and has a large inductance and a large induced current.
Using an induction current collecting coil, which is difficult to detect the voltage (power supply voltage)
Even in the case, instantaneous calculation of induced voltage of induction current collecting coil
, And using the induced voltage as a reference signal in PWM.
An object of the present invention is to provide a PWM converter control device in which a control error is reduced by operating a converter at a high power factor , and control accuracy and power conversion rate are improved.

[0018]

Means for Solving the Problems] PWM converter control apparatus according to the present invention, the three-phase currents and three-phase voltage and current collecting carp from the induction current collector coil is supplied to the PWM converter
An internal induced voltage detection circuit for obtaining an induced voltage in the induction current collecting coil by an instantaneous calculation based on the inductance of the coil.

[0019]

According to the present invention, the three-phase current and three-phase voltage input to the PWM converter and the inductor of the current collecting coil are provided.
Instantaneous calculation based on inductance to detect the induced voltage of the collector coil inductance is large induced voltage (power supply electric
Pressure) is difficult to detect using an inductive current collecting coil.
Even, the induced voltage of the induction current collecting coil is detected by instantaneous calculation
As possible, the PWM converter uses the induced voltage as a reference signal.
Operation at high power factor .

[0020]

[Embodiment 1] Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a first embodiment of the present invention, wherein 1 and 3 to 13 are the same as those described above. 20
Is an internal induced voltage detection circuit for detecting the induced voltages V _SU , V _SV and V _SW in the induction current collecting coil 1. The three-phase current I _U supplied from the induction current collecting coil 1 to the PWM converter 11 is Based on I _V and I _W and the three-phase voltages V _U , V _V and V _W , the three-phase voltages V corresponding to the induced voltages V _SU , V _SV and V _SW
SU ′, V _SV ′ and V _SW ′ are obtained by calculation. A voltage sensor (not shown) for detecting the three-phase voltages V _U , V _V and V _W is provided on a line between the induction current collecting coil 1 and the PWM converter 11.

FIG. 2 is a circuit diagram showing the configuration of one phase (U phase) of the internal induced voltage detection circuit 20 in FIG. 1. Reference numeral 21 denotes an input terminal of the U-phase input current I _U of the PWM converter 11 and an arithmetic operation. amplifier
A resistor inserted between the input terminal (described later) of the operational amplifier to determine the proportional gain, a resistor 22 connected between the input and output terminals of the operational amplifier to determine the differential coefficient, and a resistor 23 A capacitor 24 is connected in parallel between both ends of the resistor 21 to determine the differential coefficient.
This is an operational amplifier inserted between the output terminal of the phase detection voltage V _SU '. Note that the U-phase detection voltage V _SU ′ is
It is given by the sum of the U-phase input voltage V _U of the output voltage V _A and the induction PWM converter 11.

Next, the operation of the first embodiment of the present invention shown in FIG. 1 will be described with reference to FIG. The operation other than that of the internal induced voltage detection circuit 20 is the same as that described above, and will not be described here. Based on the three-phase input currents I _U , _IV and I _W of the PWM converter 11 and the three-phase input voltages V _U , V _V and V _W , the internal induced voltage detection circuit 20 generates an induced voltage in the induction current collecting coil 1. V _SU, V _SV and V _SW three-phase voltage V _SU corresponds to the to ', V _SV' calculates a and V _SW '.

Here, an equivalent circuit of the induction current collecting coil 1 is as follows.
It can be considered as a voltage source including internal impedances R and L as shown in FIG. Therefore, considering the U-phase, for example, the U-phase induced voltage V _SU , the U-phase of the PWM converter 11
The following relationship holds between the phase input voltage V _U and the U-phase input current I _U.

V _SU = V _U + R · I _U + L (dI _U / dt)

However, the formula holds for the instantaneous values of each input voltage and input current. Therefore, according to the equation, based on the instantaneous values of the U-phase input voltage V _U and the U-phase input current I _U and the values of the internal impedances R and L, the U-phase induced voltage V U
_It can be seen that the instantaneous waveform of _SU can be obtained.

Here, assuming that the resistance value R and the inductance L, which are the internal impedances of the induction current collecting coil 1, are fixed, the internal impedance value Z
Is represented as follows.

Z = R + jωL ...

However, in the equation, the angular frequency ω is represented by ω = 2πf using the frequency f. From the formula, the formula is transformed as follows.

V _SU = V _U + (R + jωL) I _U.

Accordingly, a circuit using the operational amplifier 24 as shown in FIG. From FIG. 2, the U-phase induced voltage V _SU 'output from the internal induced voltage detection circuit 20 is expressed as follows.

V _SU ′ = V _U + (R ₂ / R ₁ + jωCR ₂ ) I _U.

From the equation and the equation, the resistor 2
If the circuit constants of 1, 22, and the capacitor 23 are selected, the expression matches the expression, and the operation of the expression can be performed for each instantaneous value.

R = R ₂ / R ₁ ; L = CR ₂ .

Therefore, by installing the circuit having the same configuration as that of FIG. 2 for three phases, the three-phase voltage V _SU ′ corresponding to the instantaneous waveforms of the induced voltages V _SU , V _SV and V _SW in the induction current collecting coil 1 is obtained. , V _SV ′ and V _SW ′ can be obtained. Less than,
As before, it is possible, based on the three-phase voltage V _SU ', V _SV' and V _SW ', to obtain a control pulse C _P precision which is not affected by the ambient magnetic field or the like.

As described above, only by providing the internal induced voltage detection circuit 20, the three-phase induced voltage in the induction current collecting coil 1 can be obtained. Therefore, there is no need to install a pickup coil near the inductive current collecting coil 1 as shown in FIG. 4, and it is not necessary to install long wiring. Further, since the internal induced voltage detection circuit 20 can be built in the PWM converter 11, it can be made smaller and less expensive.

Embodiment 2 FIG. In the first embodiment, the internal induced voltage detecting circuit 20 is constituted by an analog circuit as shown in FIG. 2, but may be constituted by a microcomputer as shown in FIG.

In FIG. 3, reference numeral 25 denotes an AD converter for converting the U-phase input current I _U of the PWM converter 11 into a digital signal, and reference numeral 26 denotes an A for converting the U-phase input voltage V _U to a digital signal.
The D converter 27 takes in the U-phase input current I _U and the U-phase input voltage V _U converted into digital signals, and the U-phase induced voltage V U
A microcomputer for calculating _SU 'is a DA converter for converting the calculated U-phase induced voltage _VSU ' into an analog signal.

The microcomputer 27 has a differentiating function 27a for differentiating the U-phase input current I _U via the AD converter 25.
A multiplication function 27b for multiplying the differentiated U-phase input current I _U by an internal inductance value L; a multiplication function 27c for multiplying the U-phase input current I _U via the AD converter 25 by an internal resistance value R; including the operation result of the multiplication function 27b and 27c as well as a summing function 27d for adding the U-phase input voltage V _U from the AD converter 26.

It is apparent that the operation of the microcomputer 17 in FIG. 3 can obtain the U-phase induced voltage VSU 'corresponding to the equation, and the second embodiment has the same effect as the first embodiment. I understand. In each of the above embodiments, a transistor is used as the self-extinguishing type switching element in the PWM converter 11, but a GTO thyristor, an IGBT, or the like may be used.

[0040]

As described above, according to the present invention, the induction in the induction current collecting coil is based on the three-phase current and three-phase voltage supplied from the induction current collecting coil to the PWM converter and the inductance of the current collecting coil. It provided the internal induced voltage detector circuit for determining the instantaneous operational voltage, inductance magnitude
Inductive current collecting coil that is difficult to detect induced voltage (power supply voltage)
Even when using
It can be detected by instantaneous calculation, and the induced voltage is used as a reference signal.
Since the PWM converter is configured to operate at a high power factor , a PWM converter control device that is not affected by peripheral magnetic fields and the like, reduces control errors, and improves control accuracy and power conversion rate can be obtained. effective.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a first embodiment of the present invention.

FIG. 2 is a circuit diagram showing an internal induced voltage detection circuit in FIG.

FIG. 3 is a circuit diagram showing another example of the configuration of the internal induced voltage detection circuit in FIG. 1;

FIG. 4 is a configuration diagram showing a conventional PWM converter control device.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 induction current collecting coil 3 synchronous phase detection circuit 4 2 phase / 3 phase conversion circuit 5 Q controller 7 P controller 8 3 phase / 2 phase conversion circuit 9 PWM pulse generation circuit 11 PWM converter 13 load 20 internal induced voltage detection circuit I _U , I _V , I _W Three-phase currents V _U , V _V , V _W Three-phase voltages V _SU , V _SV , V _SW induced voltages V _SU ', V _SV ', V _SW 'Computed induced voltages sinωt, cosωt Sine wave signal I _P active component I _Q reactive component V _F PWM converter output voltage F _R output voltage reference P active power command Q _R reactive power reference Q reactive power command _{e U, e V, e W} PWM converter voltage to be output C _P control pulse

Continuation of the front page (72) Inventor Toshiaki Matsuura 1-2-1, Wadazakicho, Hyogo-ku, Kobe Mitsubishi Electric Corporation Kobe Works (56) References JP-A-2-299472 (JP, A) JP-A Sho 59-188304 (JP, A) JP 1-50161 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) B60L 5/00 B60L 1/00 B60L 11/18 H02M 7 / 219

Claims (1)

(57) [Claims] A self-extinguishing switch for converting AC power from an induction current collecting coil into DC power and supplying the DC power to a load.
A control apparatus for PWM converter including a ring element, the current and voltage input to the PWM converter and
An internal induced voltage detection circuit that obtains an induced voltage in the induction current collection coil based on the inductance of the current collection coil by instantaneous calculation; a synchronous phase detection circuit that generates a sine wave signal based on the induced voltage; A first conversion circuit for detecting an effective component and an ineffective component of the current based on the current input to the converter and the sine wave signal; and an effective component based on an output voltage of the PWM converter, an output voltage reference, and the effective component. A P controller for generating a power command; a Q controller for generating a reactive power command based on the reactive power reference and the reactive component; and a PWM controller based on the sine wave signal, the active power command and the reactive power command. a second converting circuit for generating a voltage to be output, on the basis of the voltage to be output the PWM converter
A PWM pulse generation circuit that generates a control pulse for opening and closing the self-extinguishing type switching element.