JPH0732522B2 - Linear motor power supply device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a power supply device for a linear motor used in a levitation railway or the like.

(Prior Art) In recent years, linear motor propulsion has attracted attention as one of propulsion systems for ultra high-speed railways. This linear motor is a general rotary electric motor developed on a straight line. Armature coils are arranged on the ground side to give a linear driving force to a traveling body corresponding to the rotor.

Conventionally, a non-circulation type cycloconverter has been used as a device that supplies a variable frequency polyphase alternating current to the armature coil of this linear motor, but it takes a lot of reactive power from the power supply side and the frequency on the load side. There was a drawback that its value fluctuated greatly in synchronization with. Therefore, not only the equipment on the power supply side is increased, but also various electric devices connected to the same system are adversely affected.

As a method of compensating the reactive power of this cycloconverter and keeping the fundamental wave power factor at the power receiving end at 1, for example,
There is a system shown in the figure.

In FIG. 8, VH is a traveling body having field poles, SE
C _n-1 , SEC _n , SEC _{n + 1} , ... are three-phase armature coil units (hereinafter referred to as sections) installed on the ground side, SW _n-1 , SW _n , SW
_{n + 1} , ... are three-phase switches, CC-A, CC-B are circulating current type cycloconverters that output three-phase sinusoidal current of variable frequency,
C is a phase advancing capacitor, BUS is a power line for a three-phase AC power supply, and SC
Is the section switching control circuit, and CONT-A and CONT-B are CC-
Control circuit for A and CC-B, QC for reactive power control circuit, PS for field position detector of vehicle VH, PTG for three-phase sine wave pattern generator, F-V for frequency-voltage converter, SPC for The speed control circuits, M _A and M _B are multipliers. Further, S _A and S _B are gate breakers of the cycloconverters CC-A and CC-B.

If traveling body VH is at the position of the section SEC _n-1, 3-phase sine wave current in section SEC _n-1 of the armature coil from the cycloconverter CC-A through the switch SW _n-1 is supplied. PS is for detecting the position of the field pole of the traveling body VH.
Generates a rectangular wave signal with a phase shift of 0 °.

The three-phase sine wave pattern generator PTG generates a three-phase sine wave of unit voltage in synchronization with the PS rectangular wave signal, and the multipliers M _A and M _B
Give a signal to the input of. In addition, PS by the FV converter
The digital signal from is converted into an analog value and input to the speed control circuit SPC. The SPC generates a signal I _Lm proportional to the speed deviation and inputs it to the multipliers M _A and M _B. The following three-phase positive wave current command ▲ I ^* _LA ▼ is generated from the multiplier M _A.

The same applies to the output signal ▲ I ^* _LB ▼ of the multiplier M _B.

In accordance with the three-phase current command (I ^* _LA) , the cycloconverter CC-A supplies a three-phase sine wave current to the armature coil and gives a linear driving force to the traveling body VH.

Similarly, the cycloconverter CC-B has the above command ▲ I ^* _LB ▼
Controlled according to.

Supplying armature current to sections where there are no moving bodies is wasteful, so cycloconverters CC-A and CC-B
Are alternately operated to sequentially switch the three-phase switches SW _n-1 , SW _n , ...

FIG. 9 is a time chart showing the operation modes of the apparatus shown in FIG. G ₁ and in G ₂ is a signal for respectively controlling the gate breaker S _B of the gate breaker cycloconverter CC-A S _A and CC-B, the detected control mode shown whether traveling body VH is in which section is doing.

When the length of the section is l ₁ and the length of the traveling body VH is l ₂ , G ₁ is ON only for the period of l ₁ + l ₂ and OFF for the period of l ₁ −l ₂ . G ₂ is operated to shift from G ₁ by the section length l _1, it has a lap time T _l2 between G _1. The section SEC _n-1 is supplied with power from CC-A via a three-phase switch SW _n-1 . The switch SW _n-1 is closed or opened when G ₁ is OFF, that is, when the cycloconverter CC-A is not operating.
That is, soon turned by the time t ₀ from the ON signal of the G _1, in G ₁
It opens for a time t ₀ later than the OFF signal. In this way, generation of an arc due to opening / closing of the switch SW _n-1 is prevented.

When the switch SW _n-1 is turned on and the three-phase sine wave current is supplied from the CC-A to the section SEC _n-1 , the driving force is obtained in the traveling body VH and the vehicle VH accelerates. When the leading end of the traveling body according to the section SEC _n, the switch SW _n from the cycloconverter CC-B in SEC _n
Powered through. As mentioned earlier, the turning on of SW _n is faster than the ON signal of G ₂ by t ₀ .

When the traveling body VH is in the middle of the sections SEC _n-1 and SEC _n , the cycloconverters CC-A and CC-B operate simultaneously to give a driving force to the traveling body VH. When the rear end of the traveling body VH passes SEC _n-1 , the gate signal G ₁ is turned off and the operation of the cycloconverter CC-A is stopped. In the same way, the traveling body VH
Cycloconverters CC-A and CC-B operate alternately while lap power supply depending on the position of switch SW _n , SW _{n + 1} , S
Power is supplied to the sections SEC _n , SEC _{n + 1} , SEC _{n + 2} , ... Via W _{n + 2} ,.

The cycloconverters CC-A and CC-B are circulating current type three-phase output cycloconverters. The delay on the power supply side and the reactive power are the absolute value of the load current, the magnitude of the circulating current, and the sine of the firing control angle of the converter. Related to value.

For example, the delayed reactive current component l _REACT-A on the power supply side of the cycloconverter CC-A can be expressed as follows. However, I _U , I _V ,
I _W is a three-phase load current, I _OU , I _OV , I _OW are circulating currents, α _U , α
_V and α _W are firing control angles, and k ₁ is a conversion constant.

I _REACT-A = k ₁ {(| I _U | +2 ・ I _OU ) ・ sinα _U + (| I _V │ + 2 ・ I _OV ) ・ sinα _V + (| I _W │ + 2 ・ I _OW ) ・ sinα _W } …
(3) The delayed reactive current component I _{REACT-B of the} cycloconverter CC-B can be expressed in the same way.

On the other hand, since the reactive current I _cap advances to the phase advance capacitor C, the reactive current I _Q at the power receiving end is given as follows.

_{I Q = I REACT-A +} it REACT-B -I cap ... (4) QC of the Figure detects the reactive power Q (may be considered invalid current I _Q) of the receiving end, its value is zero The circulating currents of the cycloconverters CC-A and CC-B are controlled so that ▲ I
^* _OA ▼ is the command value of the circulating currents I _OU , I _OV , and I _OW described above. ▲
I ^* _OB ▼ has the same command value.

(Problems to be Solved by the Invention) The above-described conventional linear motor power supply device has a feature that the reactive power Q at the power receiving end can be controlled to zero and the input power factor can be always maintained at one.

However, the input current contains many harmonic components, which distorts the voltage of the power supply system and adversely affects other electric devices. Particularly, it is difficult to remove the sidebands (low-order harmonics) around the fundamental wave with an ordinary filter, so that it is necessary to install an active filter or the like. The active filter is usually composed of a self-extinguishing element such as a high power transistor or a gate turn-off thyristor, and it is inevitably an expensive device.

In addition, the upper limit of the output frequency of the cycloconverter of the conventional device is at most the input frequency (power supply frequency 50Hz or 60Hz), and the coil pitch of the armature coil must be increased to increase the speed of the linear motor. Had to do. For this reason, the length of the coil end becomes long, the leakage inductance increases correspondingly, and the load has a poor power factor. The capacity of the converter (cycloconverter) had to be increased due to the low load power factor, which had to be an uneconomical system.

The present invention has been made in view of the above problems, and supplies a sine wave current of 0 to several hundred Hz to an armature coil of a linear motor with respect to a commercial power supply frequency (50 Hz or 60 Hz), and An object of the present invention is to provide a power supply device for a linear motor that can control an input current supplied from a power supply to be a sine wave (having a small harmonic) in phase with the power supply voltage (power factor = 1).

[Structure of Invention]

(Means for Solving Problems) In order to achieve the above-mentioned object, the present invention alternately supplies power to armature coil units arranged in a large number along a track according to the position of a traveling body. A plurality of first cycloconverter groups, a high-frequency phase-advancing capacitor connected to an input side terminal of the first cycloconverter group, and a second cycloconverter having an input side terminal connected to the phase advancing capacitor. And an AC power source connected to the output side terminal of the second cycloconverter to form a power supply device for the linear motor, thereby supplying a sine wave current of 0 to several hundred Hz to the armature coil of the linear motor. In addition, the current supplied from the AC power supply is controlled to be a sine wave (having a small harmonic) in phase with the power supply voltage (power factor = 1).

(Operation) The second cycloconverter controls the magnitude of the current supplied from the AC power supply so that the peak value of the voltage applied to the high-frequency advance capacitor becomes substantially constant. At this time,
By controlling the current supplied from the power source to be a sine wave having the same phase as the power source voltage, it is possible to operate with a low harmonic component with an input power factor = 1.

The first cycloconverter group is composed of two or more cycloconverters, and alternately supplies a sinusoidal current of a variable voltage and a variable frequency to each armature coil unit of the linear motor.

The first cycloconverter group and the second cycloconverter spontaneously commutate using the high frequency voltage applied to the high frequency advance capacitor.

The voltage applied to the phase advancing capacitor is the first and the second.
It matches the frequency and phase of the reference voltage (given by an external oscillator) given to the phase control circuit of the cycloconverter. The frequency of the reference voltage is set to about 1kHz,
A high frequency voltage is applied to the phase advancing capacitor.

As a result, the upper limit value of the output frequency of the first cycloconverter group becomes high, and a sine wave current of 0 to several hundred Hz can be supplied to the linear motor.

Therefore, it is possible to increase the speed of the linear motor, increase the load power factor, and reduce the converter capacity without increasing the coil pitch of the armature coil.

(Embodiment) FIG. 1 is a configuration diagram showing an embodiment of a linear motor power feeding device of the present invention.

In the figure, VH is a running body having field poles, SEC _n-1 , SEC _n , SEC _{n + 1} , ... Are three-phase armature coil units (hereinafter referred to as sections) installed on the ground side, SW _n-1 , SW _n , SW
_{n + 1} , ... are 3-phase switches, LA, LB are 3-phase AC feeders, CC-
A, CC-B are circulating current type cycloconverters (first cycloconverter group) that output variable frequency 3-phase sine wave current, CAP is high frequency phase advance capacitor, TrA, TrB, TrZ are high frequency isolation transformer, CC- Z is the second cycloconverter, AC
L is an AC reactor and SUP is a three-phase AC power supply.

As a control circuit, a section switching control circuit SC,
Field position detector PS of traveling body VH, three-phase sine wave pattern generator PTG, frequency-voltage converter F-V, speed control circuit SPC,
Multipliers M _A , M _B , analog switches AS _A , AS _B , reactive power control circuits QC _A , QC _B , voltage control circuit AVR and control circuits of each cycloconverter CONT-A, CONT-B, CONT-Z and external Oscillator O _SC
Is prepared.

The input side terminals of the first cycloconverter group CC-A and CC-B are respectively connected to the high frequency phase advance capacitor CAP via insulating transformers TrA and TrB, and the output side terminals of each are connected to a three-phase AC. Connected to wires LA and LB. The AC feeder LA is connected to the sections SEC _n-1 , SEC _{n + 1} , SEC _{n + 3} , ... Via three-phase switches SW _n-1 , SW _{n + 1} , SW _{n + 3} ,. . The AC feeder LB is a three-phase switch SW _n , SW _{n + 2} ,
Are connected to the sections SEC _n , SEC _{n + 2} , ... via.

That is, when the traveling body VH is in the position of the section SEC _n-1 , from the cycloconverter CC-A, the three-phase switch SW
_{When the} three-phase sine wave current is supplied to the section SEC _n-1 via _n-1 and the traveling body VH comes to the position of the section SEC _n , the cycloconverter CC-B goes through the three-phase switch SW _n . Section SEC _n is supplied with 3-phase sinusoidal current. When in the middle position, lap power is supplied from CC-A and CC-B.

On the other hand, the input side terminal of the second cycloconverter CC-Z is
It is connected to the high frequency phase advance capacitor CAP via the isolation transformer TrZ, and the output side terminal of CC-Z is an AC reactor AC.
It is connected to the three-phase AC power supply via L.

The second cycloconverter CC-Z controls the current supplied from the AC power supply SUP so that the _peak value V _{cap of the} voltage applied to the phase advance capacitor CAP becomes substantially constant.

The phase advancing capacitor CAP serves as a high-frequency reactive power source for the first and second cycloconverters as a whole, and each cycloconverter performs natural commutation operation using the voltage applied to the phase advancing capacitor CAP. .

Here, the frequency of the voltage applied to the phase advancing capacitor CAP is the reactive reactive power taken by the phase advancing capacitor CAP,
The delay reactive powers of the cycloconverters CC-A, CC-B and CC-Z as a whole are determined to be just equal. In other words, when the phase reference voltage e _a , e _b , e _c of the cycloconverter is given by the oscillator O _sc from the outside, the phase advancing capacitor is added to the frequency and phase of the reference voltage e _a , e _a , e _c. The circulating current of the cycloconverter flows so that the frequencies and phases of the CAP voltages V _a , V _b , and V _c match.

In the embodiment shown in FIG. 1, the first cycloconverter group CC-
The circulating current of each cycloconverter CC-A, CC-B is controlled so that the reactive power on the input side (advancing capacitor side) of A, CC-B is always constant, and the second cycloconverter CC-Z The circulating current is uncontrolled. As a result, the external oscillator O _sc
The phase control reference voltage of the cycloconverters CC-A, CC-B, and CC-Z is applied to the second converter so that the frequency and phase of the reference voltage match the frequency and phase of the phase advancing capacitor CAP. The circulating current of the cycloconverter CC-Z is adjusted.

The detailed operation will be described below.

FIG. 2 shows a second cycloconverter CC of the device shown in FIG.
It is a block diagram which shows the specific Example of -Z.

In the figure, V _R , V _S , V _T are three-phase AC voltage of AC power supply SUP, L _SR , L _SS , L
_ST is each phase of AC reactor ACL, CC-ZR, CC-ZS, CC-ZT is each phase of cycloconverter CC-Z, TR-ZR, TR-ZS, TR-ZT
Is for each phase of isolation transformer TR-Z, HFB is phase advancing capacitor CAP
Is an electric line of a high frequency voltage source connected to.

R-phase cycloconverter CC-ZR is a positive group converter SSP _R
And the negative group converter SSN _R and the DC reactors L ₀₁ and L _{02. The} positive group and negative group converters are insulated on the input side by the high frequency isolation transformer TR-ZR.

The output side is connected to the R-phase power supply V _R from the intermediate tap of the DC reactors L ₀₁ and L ₀₂ via the AC reactor L _SR .

The S-phase and T-phase cycloconverters CC-ZS and CC-ZT are similarly constructed.

As a control circuit, each phase cycloconverter control circuit CONT-ZR, CONT-ZS, CONT-ZT, comparator C _V , voltage control compensation circuit G _cap (s), power supply current detector CT _R , CT _S , CT _T is prepared.

R-phase cycloconverter control circuit CONT-ZR is multiplier M
L _R , comparator C _R , current control compensation circuit G _R (s), inverting amplifier
It consists of OA and phase control circuits PHP _R and PHN _R.

The S-phase and T-phase control circuits CONT-ZS and CONT-ZT are similarly constructed.

First, the current control operation of the R-phase cycloconverter CC-ZR will be described.

The power supply current I _SR of the R phase detected by the current detector CT _R, and inputs to the comparator C _R.

Further, the output signal I _sm (current _peak value command) from the voltage control circuit G _cap (s) and the R-phase voltage V _R = V _sm · si are output by the multiplier ML _R.
The unit sine wave φ _R = sinωt synchronized with nωt is multiplied to obtain the R-phase power supply current command value ▲ I ^* _SR ▼ = I _sm · sinωt.

Compared by a comparator C _R the current command value ▲ I ^* _SR ▼ and the R-phase current detection value I _SR, a deviation ^{_{ε R = ▲ I * SR ▼}} -I SR. The deviation ε _R is amplified by the next current control compensation circuit G _R (s) (G _R (s) = K _R ), and one is directly input to the phase control circuit PHP _R of the positive group converter SSP _R. ,
The other one is input to the phase control circuit PHN _R of the negative group converter SSN _R via the inverting amplifier OA. The input voltage υ _αP ,
υ _αN is expressed as follows, respectively.

υ _αP = K _R · ε _R (5) υ _αN = -K _R · ε _R (6) As a result, the output voltage V _PR of the positive group converter SSP _R has a positive value in the direction of the arrow in the figure. In this case, V _PR = k _v · V _cap · cos α _PR = k _v · υ _αP (7), and when the output voltage V _NR of the negative group converter SSN _R is a positive value in the direction of the arrow in the figure, V _NR = −k _v · V _cap · cos α _NR = −k ′ _v · υ _αN = k ′ _v · υ _αP (8) However, kv and k ′ _v are proportional constants, and V _cap is a voltage peak value of the phase advance capacitor CAP.

When I ^* _SR > _ISR , the deviation ε _R has a positive value, and the cycloconverter CC-ZR outputs the output voltage V _CR = (V
_PR + V _NR ) / 2 is generated to increase the power supply current I _SR . On the contrary, when I ^* _SR <I _SR , the deviation ε _R becomes a negative value, and the cycloconverter CC-ZR outputs the output voltage V _{CR in the} direction opposite to the arrow in the figure.
To reduce the power supply current I _SR . So finally I
It is controlled so that _SR ≈ I ^* _SR .

When the current command value I ^* _SR is changed in a sine wave shape, the actual current also changes in a sine wave shape following the change.

In the steady state, the output voltage V _PR of the positive group converter and the output voltage V _NR of the negative group converter are equal and balanced, so there is no increase or decrease in the circulating current I _OR of the cycloconverter CC-ZR. The value of the circulating current I _OR is the phase reference voltage in which the frequencies and phases of the voltages V _a , V _b , and V _c applied to the phase advance capacitor CAP are given to the phase control circuits PHP _R , PHN _R , ... Of the cycloconverter. It is determined so as to match the frequency and phase of e _a , e _b , and e _c . The explanation will be given later.

The current control of the S-phase and T-phase cycloconverters CC-ZS and CC-ZT is similarly performed.

Next, the control operation of the voltage applied to the phase advancing capacitor CAP will be described.

In Fig. 1, the voltage V applied to the phase advancing capacitor CAP
_A , V _b , V _c are detected by the converter PT _cap , and three-phase rectifier circuit D
The voltage peak value V _cap is obtained via. Voltage peak value V _cap
Is input to the comparator C _V in FIG. 2 and compared with the command value ▲ V ^* _cap ▼. The deviation ε _{v =} ▲ _V ^* _cap ▼ enter the -V _cap to the voltage control compensation circuit G _cap (s), it is amplified. However, G
_{Let cap} (s) be the proportional element K _cap .

The output _Ism of G _cap (s) becomes the peak value command of the power supply currents I _SR , I _SS , and I _ST .

The power supply currents I _SR , I _SS , and I _{ST for} each phase are the above command values ▲ I ^* _SR ▼, ▲ I
^As described above, control is performed so as to match ^* _SS ▼ and ▲ I ^* _ST ▼, respectively.

Therefore, each phase power supply current I _SR , I _SS , I _ST becomes a sine wave of the same phase as the power supply voltage V _R , V _S , V _T, and the input power factor = 1 and the current has few harmonics.

▲ V ^* _cap ▼> In the case of V _cap, deviation _{^{ε v = ▲ V * cap ▼}} -V cap
Becomes a positive value, and the current _peak value _Ism is increased to a positive value. Therefore active power from power supply SUP Is supplied to the high frequency phase advance capacitor CAP with energy P _s
・ Accumulate t = (1/2) ・ C _cap・ ▲ V ² _cap ▼. Therefore, the voltage V _cap increases and is controlled so that V _cap = V ^* _cap .

On the contrary, when ▲ V ^* _cap ▼ <V _cap , the deviation ε _v becomes a negative value, the peak value command _Ism also becomes negative, and the phase advance capacitor C
AP energy (1/2) C _cap · V ² _cap ▼ is regenerated to the power supply SUP. Therefore, the voltage V _cap decreases, and again V _cap = ▲
V ^* _cap ▼ and calm down.

As described above, the voltage peak value V of the phase advancing capacitor CAP
_{The cap} is controlled to be almost constant.

Control circuit of the second cycloconverter CC-Z CONT-ZR, CONT
-ZS, CONT-ZT does not include circulating current control circuit.
That is, the circulating current CC-Z is a uncontrolled, the truth voltage V _a applied to the capacitor CAP, V _b, the frequency of V _c and phase, the cycloconverter CC-A, CC-B, CC -The circulating current of CC-Z is adjusted to match the frequency and phase of the three-phase reference voltage (generated from the external oscillator _Osc ) e _a , e _b , e _c given to the phase control circuit of -Z. It

The operation will be described below.

First, the phase-advancing capacitor by the cycloconverter CC-Z
The starting operation for establishing the voltages V _a , V _b , and V _c of the CAP will be described.

The R, S, and T phase voltages of the three-phase AC power supply SUP can be expressed by the following equation. However, V _sm is the voltage peak value, and ω _s = 2πf _s is the power source angular frequency.

Cycloconverter CC-Z for the frequency f _{s of the} power supply
Assuming that the frequency f _cap on the input side (advancing capacitor side) of is sufficiently high, the power supply voltage V _R , V _S ,
V _T can be replaced with a DC voltage.

FIG. 3 shows how the phase advance capacitor CAP is charged through the positive group converter SSP _R of the R-phase cycloconverter CC-ZR, and the ignition pulse is given to the thyristors S ₂ and S ₄ . Indicate the case.

One charging s flow I _{SR ^{is, V R + → L SR →}} S 4 → C ab → S 2 → V R - path and one flow of ^{_{V R + → L SR → S}} 4 → C ca → C _bc → S ₂ → V _R
^-Follow the route.

This result is in phase advancing capacitor C _ab voltage V _ab = + V _R is applied, phase advance capacitor C _bc and C each in _ca voltage V _bc = - (1
/ 2) V _R and V _ca =-(1/2) V _R are applied.

Next, when a firing pulse is applied to thyristor S ₃ , the voltage of capacitor C _bc is applied to thyristor S ₂ and S ₂ is turned off. As a _{result, V ab = + (1/2)} V R, V bc = + (1 /
2) _{Charged to} V _R , V _ca = -V _R.

Then, an ignition pulse is applied to thyristor S ₅ and thyristor S ₄ is turned off, and V _ab = − (1/2) V _R , V _bc ＝ ＋ V _R , V _ca ＝ − (1/2) ・ V _R Will be charged.

4 shows a relationship between the fundamental wave of the applied voltage V _ab and the phase voltage V _a of the arc pulse mode and the capacitor C _ab of the thyristors S ₁ to S ₆ of FIG. 3.

Since it is charged via the voltage V _ab reactor L _SR , it gradually rises as shown by the broken line. When the time is set to 2δ, the fundamental wave component of V _ab is delayed by δ. The phase voltage V _a lags the line voltage V _ab by (π / 6) radians.

As can be seen by comparing the firing mode and the phase voltage V _a , the phase control angle α _PR when the converter SSP _R is started is α _PR = π−δ (radian) (12). Since δ is not so large, it means that the operation is approximately at α _PR = 180 °.

The output voltage V _PR of the converter SSP _{R at} this time is V _PR = k _v · V _cap · cos α _PR <0 (13), which is in balance with the power supply voltage V _R.

However, in this state, the phase advancing capacitor CAP is not charged with a voltage higher than the power supply voltage V _R. Therefore, the firing phase angle α _PR is slightly shifted in the direction of 90 °. Then, the output voltage V _PR shown in the above equation decreases and V _R > −V _PR . As a result, the charging current I _SR increases, the capacitor voltage V _cap increases, and V _R = -V _PR is settled down. At this time, I _SR is zero. If it is desired to further increase V _cap , it can be achieved by further shifting the phase angle α _PR in the direction of 90 ° and decreasing the output voltage V _PR . At α _PR = 90 °, V _PR = O ^V
Therefore, theoretically, the capacitor voltage V _cap can be charged to a large value even if the power supply voltage V _R is a very small value.
However, in reality, there is a circuit loss, so that power supply becomes indispensable.

When the power supply voltage V _R fluctuates, the phase angle α _PR can be changed accordingly to keep the capacitor voltage V _cap at a substantially constant value.

The above description is based on the case where the power supply voltage V _R is positive, but
When V _R becomes a negative value, the capacitor CAP can be charged through the negative group converter SSN _R.

Further, when the R, S, and T phases are operated at the same time, although the operation becomes slightly complicated, the phase advancing capacitor CAP can be charged similarly.

Next, the voltages V _a , V _b , V _c of the phase-advancing capacitor CAP established in this way are the cycloconverters CC-A, CC-B,
Three-phase reference voltage e _a , e _b , e _c given to the CC-Z phase control circuit
It will be explained that the frequency and the phase match with.

The firing phase angle of the R-phase positive group converter of the second cycloconverter CC-Z is α _PR , and the firing phase angle of the R-phase negative group converter is α
_{When NR} is set, the relationship of α _NR ≈180 ° −α _PR (14) holds in a balanced state with V _PR = V _NR .

FIG. 5 shows the relationship between the reference voltage e _a , e _b , e _c for phase control and the ignition pulse of the R-phase cycloconverter CC-ZR.
_It represents the case where _PR = 45 ° and α _N = 135 °.

The reference voltages e _a , e _b , and e _c are given by the external oscillator O _sc , and can be expressed by the following equation.

Here, ω _c = 2πf _c is a high frequency angular frequency, for example,
It is selected to be f _c = 1 kHz.

The phase voltage V _a , V _b , V _c of the phase-advancing capacitor CAP is the reference voltage e _a ,
e _b, if they match the frequency of e _c and phase output voltage V _PR and V _NR of positive group and negative group converters, as mentioned above V _PR
= V _NR , the circulating current I _OR does not increase or decrease.

If from this state, the frequency of the capacitor voltage is low, the case became as dashed _{▲ V 'a, V' b} , and V _'c.

The firing phase angle of SSP _R changes from α _PR to α ′ _PR , and the firing phase angle of SSN _R changes from α _NR to α ′ _NR . As a result, V _PR > V
_It becomes _NR and increases the circulating current I _OR . At this time, the circulating currents I _OS and I _{OT of} the S-phase and T-phase cycloconverters also increase.

The circulating currents I _OR , I _OS , and I _OT become delayed reactive power on the input side (high-frequency side) of the cycloconverter CC-Z.

FIG. 6 shows an equivalent circuit for one phase on the input side (high frequency side) of the cycloconverter CC-Z. The cycloconverter CC-Z has a variable inductance L _cc that takes a delay current.
Is replaced by

The resonant frequency f _cap of this circuit is Becomes

The increase of the circulating current is equivalent to the decrease of the equivalent inductance L _cc , the frequency f _cap is increased, and V ′ is increased.
The wave number f _cap of _a , V ′ _b , V ′ _c is the frequency of the reference voltage e _a , e _b , e _c
Get closer to f _c .

Similarly, when f _cap > f _c , the circulating current decreases, L _cc increases, and f _cap = f _c also remains and settles down.

When the phase of the voltage of the phase-advancing capacitor CAP lags the phase of the reference voltage, as in the case of the above f _cap <f _c ,
The circulating current increases and advances the voltage phase of the phase advancing capacitor.

On the contrary, when the voltage phase of the phase advancing capacitor CAP leads the reference voltage, the circulating current decreases as in the case where the above f _cap > f _c, and the voltage phase of the phase advancing capacitor CAP is delayed.

In this way, the circulating current I _OR of the cycloconverter CC-Z is adjusted so that the voltages V _a , V _b , and V _c of the phase advancing capacitor CAP have the same frequency and phase as the reference voltages e _a , e _b , and e _c. The size of, I _OS , I _OT is automatically adjusted. Therefore, the capacitors V _a , V _b , and V _c are expressed by the following equation.

On the other hand, the circulating currents of the first cycloconverter group CC-A, CC-B are controlled so that the reactive powers Q _A and Q _B on the input side (high-frequency phase advance capacitor side) become constant. Therefore, it does not affect the frequency and phase of the voltage of the phase advancing capacitor CAP.

Next, the control operation of the first cycloconverter group CC-A, CC-B will be described.

The cycloconverters CC-A and CC-B use the voltage of the phase-advancing capacitor CAP established as described above to spontaneously commutate.

Both CC-A and CC-B are circulating current type cycloconverters and control each circulating current so that reactive powers Q _A and Q _B on the input side (advancing capacitor side) are almost constant. Therefore, when the leading reactive power of the phase-advancing capacitor CAP is Q _cap , the delayed reactive power Q _Z taken by the second cycloconverter CC- _Z is Q _Z = Q _cap − (Q _A + Q _B )… (18) If the voltage V _cap applied to the phase advancing capacitor CAP and the frequency f _cap are constant, then Q _Z = constant.

Of course, set the first cycloconverter group CC-A and CC-B to 1
We believe that the set, also control the Q _A + Q _B = constant, can be operated with the Q _Z constant.

The three-phase load current I _LA supplied from the cycloconverter CC-A to the armature coil of the linear motor is its command value ▲ I ^* _LA ▼
Controlled according to. The command value is the same as that calculated by the equation (1). The command value ▲ I ^* _LA ▼ is sent to the control circuit CONT-A via the analog switch AS _A. The analog switch AS _A is a section switching control circuit SC
Controlled by the signal G ₁ from.

Similarly, the three-phase load current I _LB of the cycloconverter CC-B is
It is controlled according to the command value ▲ I ^* _LB ▼ obtained by the equation (2). The command value ▲ I ^* _LB ▼ is transmitted to the control circuit CONT-B via the analog switches AS _B. The analog switch
AS _B is controlled by the signal G ₂ from the section switching control circuit SC.

FIG. 7 is a time chart diagram showing the operation mode of the device of FIG. 1 and the magnitude of active power of each cycloconverter.

When the signal G ₁ from the section switching control circuit SC is "1", the analog switch AS _A is closed to the "a" side, and the three-phase sine wave with the _peak value I _Lm as the load current command value ▲ I ^* _LA ▼. A current command is given. When G ₁ is “0”, AS _A is closed on the “b” side, and the load current command ▲ I ^* _LA ▼ is zero.

Similarly, the analog switch AS _B operates according to the signal of G ₂ and the load current command ▲ I ^* _LB ▼ is given. At this time, the cycloconverter CC-A and CC-B is in a constantly operating state regardless of the mode of the signal G ₁ and G _2, is performed reactive power control to each other. That is, both Q _A and Q _B are kept constant.

On the other hand, the active power P _A of the cycloconverter CC-A is
Output when VH is at the location of section SEC _n-1 , SEC _{n + 1} , SEC _{n + 3} , .... The active power P _B of the cycloconverter CC-B is measured by the traveling vehicle VH in the sections SEC _n , SEC _{n + 2} , SE.
Output when in the location of C _{n + 4} , .... When the traveling body moves from section SEC _n-1 to SEC _n , for example, the counter electromotive force generated in SEC _n-1 gradually decreases, and conversely, the counter electromotive force generated in SEC _n gradually increases. Therefore, the active power P _A supplied from CC-A also gradually decreases, and the power P _B supplied from CC-B gradually increases. Therefore, the first cycloconverter group CC-
The sum P _A + P _B of the active powers of A and CC-B is almost constant, and thus the active power P _Z = P _A + P _B supplied to the second cycloconverter CC-Z is also almost constant.

As a result, for example, when the output capacity of each of the cycloconverters CC-A and CC-B is 10 MW, the cycloconverter CC-Z
The capacity of 10 MW should be prepared.

The upper limit of the output frequency of the first cycloconverter group CC-A and CC-B is the input frequency, that is, the phase advance capacitor CAP.
It is possible to increase the frequency of the voltage applied to the circuit (for example, 1 kHz), and it is possible to shorten the coil pitch of the armature coil even in an ultra-high-speed train or the like. As a result, the coil end length of the armature coil becomes shorter and the leakage inductance also becomes smaller. As a result, the load power factor is improved and the capacity of the cycloconverter can be reduced.

As described above, according to the device of the present invention, the current supplied from the power supply is controlled to be a sine wave in phase with the power supply voltage, and the input power factor = 1 and the converter has less harmonics. In addition, the current supplied to the linear motor is a sine wave and can be operated at a high frequency. In addition, all cycloconverters have the advantage that they can be naturally commutated by using the voltage applied to the high-frequency phase-advancing capacitor CAP, are highly reliable, and have a very large capacity.

In the apparatus shown in FIG. 1, the synchronous motor system in which the traveling body VH has field poles has been described, but it goes without saying that an induction motor system having a secondary conductor in the traveling body VH can also be used.

In addition, as a first cycloconverter group, a system in which two cycloconverters CC-A and CC-B are alternately operated has been described as an example. However, this can be performed by using three or more cycloconverters. It goes without saying that the same can be achieved by the method of sequentially switching.

〔The invention's effect〕

As described above, according to the linear motor power supply device of the present invention, the current supplied from the power supply is controlled to be a sine wave in phase with the power supply voltage, the input power factor is always 1, and operation with few harmonics is possible. Become. As a result, the installation of the required filter is no longer necessary and the adverse effect on the power supply system can be eliminated.

In addition, the upper limit of the frequency supplied to the linear motor can be increased, and the coil pitch of the armature coils can be shortened to reduce the leakage inductance and enable operation with a good load power factor.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a linear motor power supply device of the present invention, FIG. 2 is a block diagram showing a concrete embodiment for explaining the device of FIG. 1, and FIG. FIG. 4 is an equivalent circuit diagram for explaining the starting operation of the device of FIG. 4, FIG. 4 is the same time chart diagram, FIG. 5 is a time chart diagram for explaining the phase control operation of the device of FIG. 1, and FIG. FIG. 7 is an equivalent circuit diagram, FIG. 7 is a time chart diagram for explaining the operation of the device of FIG. 1, FIG. 8 is a configuration diagram of a conventional linear motor power feeding device, and FIG. 9 is an operation mode of the device of FIG. It is a time chart figure which shows. VH: Vehicle SEC _n-1 , SEC _n , SEC _{n + 1} , ...: Section SW _n-1 , SW _n , SW _{n + 2} , ...: 3-phase switch LA, LB: 3-phase AC feeder CC-A , CC-B: 1st cycloconverter group CAP: High frequency advance capacitor TrA, TrB, TrZ: High frequency isolation transformer CC-Z: 2nd cycloconverter ACL: AC reactor SUP: 3 phase AC power supply SC: Section switching control Circuit PS: Field-of-travel position detector PTG: Sine wave pattern generator F-V: Frequency-voltage converter SPC: Speed control circuit M _A , M _B : Multiplier AS _A , AS _B : Analog switch QC _A , QC _B : Reactive power control circuit CONT-A, CONT-B: Control circuit of first cycloconverter group AVR: Voltage control circuit CONT-Z: Control circuit of second cycloconverter O _sc : External oscillator PT _cap ： Transformer D: Rectifier circuit

Claims (1)

[Claims] 1. A plurality of first circulating current type cycloconverter groups for alternately supplying power to armature coil units arranged in a plurality of divisions along an orbit in accordance with the position of a traveling body, and the first group. Of the circulating current type cycloconverter, a high frequency advanced capacitor commonly connected between the input side terminals, a second circulating current type cycloconverter having the high frequency advanced capacitor connected between the input terminals, and the second An alternating current power supply connected to the output side terminal of the circulating current type cycloconverter, an external oscillator that provides a phase reference voltage that serves as a reference for controlling the phase of each circulating current type cycloconverter, and the phase of the voltage of the high-frequency advance capacitor and The AC power supply according to the deviation between the peak value reference value and the peak value detection value so that the frequency matches the phase and frequency of the phase reference voltage and the peak value becomes constant. And a means for controlling a current supplied to the high frequency advanced capacitor via the second circulating current type cycloconverter, and the first circulating current type cycloconverter group uses the high frequency advanced capacitor as a voltage source, A linear motor power feeding device comprising means for controlling the current supplied to the armature coil and the reactive power on the input side of each circulating current type cycloconverter to a constant value.