JPS5842612B2 - Metamorphosis device - Google Patents

Description

[Detailed description of the invention] The present invention relates to a transformer using a saturable magnetic core.

Conventionally, there are DC-CT and DC-PT as means for detecting current and voltage recoil values in an insulated manner, but these use two magnetic cores (/') and pass the current to be detected through each excitation winding. It is not easy to know the polarity of the current to be detected since all the primary windings are connected in reverse series and excited by an AC□ power source.

To detect the polarity, methods such as winding a third winding around each magnetic core and detecting the phase of the induced voltage, and CT using semiconductor magnetic sensing elements are known, but these methods are not necessarily practical. do not have.

SUMMARY OF THE INVENTION An object of the present invention is to simplify the device by easily detecting the polarity of the current to be detected and by configuring the magnetic core around which the primary winding for passing this current is made of only one magnetic core.

That is, the present invention is intended to realize a transformer that can be used for both AC and DC, and also to realize a device that does not require an AC power source for excitation.

FIG. 1 shows an embodiment of the present invention, in which Vsl,
Vs2 is a DC power supply, and Ql and Q2 are transistors.

The symbols R and D are resistors and diodes, respectively, and OPA is an amplifier with sufficiently high gain, Cor.
l, Cor2 indicates the saturable magnetic core and the reactor magnetic core,
N10, N21, N31 and N22, N32 are the windings wound around Corl and Cor2, respectively, and start on the side marked with a black circle.

A current to be detected is passed through the N10 winding, and the current source is SI.

1 is an amplifier 2, 7 with a gain of 1 and high input impedance.
, 8° 11 is an inverter, 3 and 4 are AND gates, 9.
.

10. 12 is an OR gate, and 5 and 6 are one-shots, both of which are input terminals with a signal rLJ to r
When the state changes to HJ, a positive output signal is output to the 0 output terminal for a certain period of time.

The circuit shown in FIG. 1 is a transformer configured so that when the input current is passed through the N10 winding, the voltage drop Vo across the resistor Ro is obtained as an output.

In the circuit shown in FIG. 1 configured as above, i weight flow source S
Consider the case where there is no output current iL from I.

And now, if the output of amplifier OPA is positive (it is saturated), transistor Q1 is switched on, Q2
is kept in the OFF state.

Then, the common emitter potential ve of Ql and Q2 maintains a positive value (s1), but during that time a voltage of approximately Vsl is applied to the series circuit of N21N22 and Ro.

The N22 winding is a Cor2G-wound winding, which is also an acdle (for example, a Cor2G air cap is provided), and if the time change of the current is small (as Cor 1, it has a full-angle hysteresis characteristic). (Consider a magnetic core with a magnetic core having a magnetic core with a voltage of 1000 Ω), almost no voltage is induced in the N22 winding, and almost a Vs1 voltage is applied to the N21 winding.

During this time, the current flowing through N21N22 and Ro is Cor 1
Although this current increases with time, the magnetomotive force is small, so its absolute value is small, and its time change (-Li) is also small, so the voltage drop due to t RoG is small and the N22 winding voltage is also small.

During this period, the magnetic flux of Cor1 is assumed to shift from the negative saturation value -φm to the positive saturation value +φm, and as it approaches +φm, the excitation ampere-turn increases rapidly.

This increase increases the force/voltage burden on the actuator winding N22 ("," IJ i the voltage of the actuator winding N22" N22.11 where n22
is the number of turns of the N22 winding, and i is the excitation current component of Corl)
, the sum of the inverse series induced voltages of the N31 and N32 windings, which are wound on the same magnetic core as the N21 and N22 windings, varies from positive to positive before and after the N21 excitation current starts to increase rapidly. Switch to negative.

That is, the output voltage vi of the amplifier 1 switches from positive to negative.

Then, the a input terminal voltage of the AND gate 4 changes from negative to positive G, and the output of the AND gate 4 is inverted from negative to positive.

(","Assuming that both one-shots 5 and 6 have finished their one-shot operation, their outputs O are in the rLJ state,
In other words, each input terminal of AND gates 3 and 4 is kept positive.

) Then, the one-shot circuit 6 is activated and a positive voltage is applied to its output O terminal for a certain period of time.

This output is fed back to the b-power of the ant gate 3 via the inverter 8 to suppress the output of the ant gate 3 and the output of the or gate 3 (therefore, the output of the or gate 9 is kept at rLJ).
The output of the inverter 11 is given 1-Hj, and the output of the inverter 11 is
Therefore, the output voltage VO3 of the OR gate 12 becomes rLJ, so the positive phase input terminal voltage of the amplifier OPA becomes negative through R3 and R2. Transistor is on.

Ql is turned OFF.

In other words, the series circuit of Ro, N22, and N21 (to which a voltage of opposite polarity is applied).

In other words, the ve voltage is reversed from positive to negative.

This state is maintained unconditionally while the one-shot 6 is activated.

When the output of one shot 6 returns to JLJG from rHJ after a certain period of time has elapsed, since the induced voltage in the N31 winding is negative and the induced voltage in the N32 winding is small, the Vi output is negative and therefore the AND The output of gate 4 is kept positive, so (the output of OR gate 10 is also positive, and the output of inverter 11 is also negative, so the output of gate 12 is vo3R-rLj and the output of one shot 6 changes from "H" to "L"'', the output of the amplifier OPA remains negative.

During this time, Corl's magnetic flux φ1 moves from +φm toward the 1φm force direction, and eventually reaches around −φm (reaching its N21
When the excitation current in the winding tries to increase rapidly, the vi lightning voltage changes from negative to positive.

This change in turn makes the output of AND gate 3 less rLJ than r
The one-shot 5 operates and its output 1'-HJG is maintained for a certain period of time.

This one-shot operation suppresses the input voltage of the ant gate 4 and suppresses the operation of the one-shot 6, and also keeps the output of the OR gate 9.12 positive, that is, the positive phase input terminal voltage of the amplifier OPA is This changes the output to a positive value, keeping Ql ON and Q2 OFF.

Even after the output of one shot 5 returns from rHJ to rLJ, if vi is positive, the output of ant gate 3 is positive, and VO3 is made positive through OR gate 9.12, and the output of amplifier OPA is It remains true.

As described above, in the circuit of FIG. 1, as the magnetic flux of Corl approaches saturation, the applied voltage is switched, and self-controlled oscillation is continued.

During this time, the output voltage of the N32 and N31 windings connected in anti-series, that is, the vi lightning voltage ve output voltage, is positively fed back, but the relative relationship between the reactor winding N22 and the saturable magnetic core winding N21 (here, if When the N32 winding induced voltage overcomes the N31 winding induced voltage and reverses the ve voltage, immediately after that, the N31 winding induced voltage reverses its induced voltage polarity and overcomes the N32 induced voltage G. If the value of 1 is held immediately, the one-shot circuits 5 and 6 in the circuit of FIG. 1 are not required.

However, since a saturable magnetic core requires a certain amount of time to reverse its excitation polarity (one shot is used for the purpose of securing this time).

If this device is not present, linking may occur depending on the ve lightning voltage and the acdle winding voltage.

FIG. 5 shows the change in magnetic flux with respect to the exciting current G of the Corl and Cor 2 magnetic cores.

The gradient of this magnetic flux change represents the magnetic permeability μ, which is a value proportional to the inductance of each winding, but when Corl reaches saturation (point 11 (or point P'1)) ve Lightning voltage reverses and eventually reaches 22 points or higher, C.
or2 winding inductance > Corl winding inductance and N31 induced voltage > N32 induced voltage. After that, the positive feedback state is maintained stably and the switching is completed or the transition from 11 points to 22 points is completed. Until this happens, the one-shot described above maintains the feedback polarity at the same polarity.

For convenience, the one-dot chain line of Cor2' is a straight line having the same slope as the magnetic flux characteristic of Cor2, and was drawn so as to be in contact with the magnetic flux characteristic of Cor1 in order to find 22 points.

``The resistor R4 connected in parallel to the N22 winding of Cor, 2 has a relatively high value, and is mainly provided to stabilize the circuit operation (dampening the stray capacitance of the winding). Now, in the circuit shown in Fig. 1 that performs eye oscillation as described above, the output current i from the current source SI
Consider the case where L flows in the direction shown in the figure.

Now, assuming that the state is Q10N1Q2OFF, N
Co
rl is in the unsaturated region, and the current 12 flowing through the N21 winding (number of turns n2) flows in the direction shown in the figure according to the equal ampere-turn law, and has a value of 12=UIL.

However, 2 Ignore the excitation current 0 12 is VslQl −N21N
22-Ro-V It flows in the course of 81, and the 12 value, ie, the iL value, is known as the voltage drop Vo of Ro.

When Corl approaches saturation in this state, Ql turns OFF,
Ql turns ON, but the 12 current still has the same polarity as above, Vs2 Q2N21 N22
The polarity of the Vo sub-output remains the same as when Q1 is turned on.

During this time, current 12 flows from the collector to the emitter of transistor Q2.
When the amplification rate of i2 is insufficient, it passes through diode D2.
flows.

During this time, Q1 does not turn on, so diode D3 exists, and Ql does not turn on due to the heavy pressure of the diode D3.

While repeating GQl, Ql or alternately turning ON and OFF in the manner described above, a value proportional to iL is obtained as a sub-output of Vo.

Conversely, when the output current iL from SI flows in a polarity opposite to that shown in the figure, the current 12 also flows in a polarity opposite to that shown in the figure, and the output Vo is also inverted.

Therefore, the Vo output polarity changes according to the polarity of iL, and the polarity of iL can be known from the output.

In addition, Figure 1 shows the circuit beam axle Cor2 and N22N32.
Although it can operate without winding, etc., in that case, Co
Since rl reaches a sufficiently deep saturation and the excitation current becomes large, a large spike-like ripple appears in the Vo sub-output every time the ve lightning voltage is reversed.

In order to suppress it, a reactor (Cor2 etc.) is inserted and C
Since the ve lightning voltage switching control is performed just before the orl reaches a deep saturation G, the o output (in this case, almost no spike ripple appears).

The second diagram shows the circuit operation in Figure 1 over time.
It is a diagram.

The left and right halves of Figure 2 are the output current iL from the current source SI.
This is a case in which the current flows in the polarity shown in FIG. 1 and the opposite polarity.

In the figure, a is the output current iL from the current source SI, b is the transistor Q1, and the common emitter voltage Vesc of Ql is C
The movement of the magnetic flux φ1 of orl, d is the reactor winding N22
The voltage appearing on ■N2□, e is the output voltage vi of amplifier 1
, fg are the respective outputs of the one-shot circuits 5 and 6,
h represents the positive-phase input signal voltage VO3 of the amplifier OPA, and i represents the voltage drop Vo of the resistor Ro, that is, the output of the circuit in FIG. 1, respectively.

In addition, the dotted lines in S, c, and i in the figure are 1L.
= 0, which is the case of O. As is clear from Figure 2, ve depends on the polarity of iL.
It can be seen that the lightning voltage in the positive direction (negative direction) increases and decreases (decreases and increases).

It is also clear that the output of this device can be obtained from the value of the lightning voltage ve instead of Ro.

In addition, it goes without saying that the portion mainly composed of Ql, Ql, OPA, etc. in FIG. 1 may be replaced with a power amplifier.

FIG. 3 shows another embodiment of the present invention, and is an example in which a single DC power supply is used.

Instead, four transistors are required, but they basically have a concentric function as the circuit in Figure 1.

The N31 and N32 windings wound around the saturable magnetic core Cor1 and the reactor magnetic core Cor2 are fed back with current through resistors R3 and R4, and the deviation is amplified by the amplifier 1, which is then input to the Nant gates 3 and 4. Next door Nantes Gate 5, 7.9
and Nant gate 6.8.10 each function as a one-shot circuit, and their respective outputs are connected to the respective negative phase and positive phase inputs of comparator amplifier 11.12 to drive the bridge transistors of transistors Q1 to Q4. Thus, the series circuit of N21, N22, and Ro is alternately excited.

ZD1 to ZD4 indicate Zener diodes.

The amplifiers 1, 11 and 12 in the figure may be operated with a single power supply (Vs).

FIG. 4 shows yet another embodiment of the present invention, in which N21 and N22 are used as the secondary winding (excitation winding) of the saturable magnetic core Corl.
A secondary winding is prepared.

By alternately turning on transistors Q1 and Q2, a current that satisfies the equal ampere turn law on the secondary side for canceling the iL constant current flows alternately through the N21 and N22 windings, which is detected by resistors Ro1 and Ro2, and the current is detected by resistors Ro1 and Ro2. The output sum of the device Vo
is obtained as the output of this device.

The reactor magnetic core Cor2 is Q in the embodiment shown in FIG.
1 and Q2 side windings N41, N51 and N42, N52 are configured as having a common core, but it goes without saying that magnetic cores may be provided individually.

In the above embodiment, the description was made on the assumption that the saturable magnetic core Cor1 has a rectangular hysteresis characteristic, but a magnetic core such as a soft ferrite core that is not rectangular but has a hysteresis characteristic with a large slope may also be used. .

In that case, the rapid increase in excitation current is sensed and fed back to the reactor (trowel), so the excitation polarity is reversed just before it approaches saturation, resulting in a device with small output ripple.

Furthermore, in the embodiments shown in FIGS. 1, 3, and 4, the switching operation is performed by matching and feeding back the outputs of the Corl winding and the Cor2 winding.
Corl (
Only the winding voltage of Cor2) may be fed back.

In this case, the saturation of Corl tends to become a little deeper, but the current increase is suppressed by the winding of Cor2, so the ripple does not necessarily become so thick, and the device can be made slightly simpler.

In all of the above explanations, only SI was used as the input current source, but if the voltage source is replaced with SI, the number of turns of the N10 winding can be relatively large, and if a high impedance is inserted in series, the output Vo can be increased. It goes without saying that an output proportional to the voltage of the voltage source can be obtained.

As is clear from the above description, according to the present invention, an output proportional to an input current or voltage can be used as an isolated output, and its polarity can also be detected.

In other words, it can function for both DC and AC inputs.

Furthermore, since the circuit performs self-controlled oscillation, no separate AC power source is required, which simplifies the device.

Further, since the magnetic core around which the input winding (the winding through which input current is passed) is wound is composed of only one magnetic core, the device is simple.

[Brief explanation of drawings]

1, 3, and 4 each show an embodiment of the present invention, FIG. 2 is a diagram for explaining the operation of the circuit in FIG. 1, and FIG. 5 is for explaining the relationship between the magnetic cores. This is a diagram for In the figure, Vs 1, Vs2, Vs are DC power supplies, Corl
, Cor2 indicates the magnetic core, OPA, 1 indicates the amplifier, and Q
, D, ZD, and R indicate transistors, diodes, Zener diodes, and resistors, respectively. Further, the symbol N indicates a winding wound around Corl or Cor2, and SI indicates a current source. C1 and C2 indicate capacitors. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] ” A saturable transformer having a saturable magnetic core that is vibrated from a DC power source via a semiconductor switch or a power amplifier, and an excitation winding that is excited via a reactor, □ responsive to the voltage of the above transformer or reactor. feedback means for causing self-controlled oscillation by operating the semiconductor switch or power amplifier; switching auxiliary means for ensuring the switching operation of this means; A transformer comprising a wire and means for extracting the excitation winding current or the current of the excitation winding current.