JP4925595B2 - AC impedance measuring apparatus and method - Google Patents

Description

  The present invention relates to an alternating current impedance measuring apparatus and method for measuring alternating current impedance of a measurement object, and relates to an alternating current impedance measuring apparatus and method that enable highly accurate measurement with a simple configuration.

  For example, when power is supplied to a load from a power generator such as a battery, the deterioration state of the battery can be determined to some extent based on the internal impedance of the battery and the voltage between the battery terminals. This is because battery deterioration is detected by utilizing the tendency that the internal impedance increases and the terminal voltage decreases as the battery deterioration proceeds. For this purpose, it is important to measure the internal impedance of a power generator such as a battery.

  Such internal impedance measurement is important not only for DC resistance but also for AC impedance for AC components. This is because by measuring the frequency characteristics of the AC impedance of the battery, it is possible to indirectly observe the chemical change inside the battery that is the cause of deterioration. As is well known, the principle of AC impedance measurement is that an AC signal of a predetermined frequency is applied from a measurement signal generator to a measured object such as a battery, and the voltage generated at both ends of the measured object at that time, The absolute value of impedance can be obtained by measuring the current flowing through the body and dividing the voltage value by the current value. In addition, the phase difference between the voltage and the current can be known by measurement, and a desired type of AC impedance can be obtained based on the obtained absolute value of the impedance and the phase difference between the voltage and the current. If the AC impedance is measured sequentially while changing the frequency of the applied voltage, the frequency characteristics of the AC impedance can be obtained.

  Patent Documents 1 and 2 propose specific examples of a battery internal impedance measuring device.

  The basic configuration of the measuring device of Patent Document 1 is to connect a measurement signal generator in parallel to a closed circuit consisting of a battery to be measured and a load, detect the voltage applied to the battery and the flowing current, The internal impedance is obtained from the detection result.

  Moreover, in the measuring apparatus of patent document 2, the sine wave signal (preferably 20 Hz or less) prepared previously is applied to the battery via FET.

JP-A-2004-251625 (paragraph numbers [0012] to [0016], FIG. 1) JP-A-2004-119227 (paragraph numbers [0017] to [0021], FIG. 1)

  In the measuring apparatus described in Patent Document 1, it is necessary for the measurement signal generator to generate a DC voltage equal to or higher than that of the battery in addition to the AC measurement signal, and the configuration is complicated and expensive. . In particular, when the battery has a high voltage, a bias power source that generates a high voltage inside is necessary, and this problem becomes significant. The detection means for measuring only the alternating current flowing through the battery also employs a complicated configuration.

  In the measuring apparatus described in Patent Document 2, the alternating current supply means has a unipolar configuration, and the current flowing through the alternating current supply means can only flow in the direction in which the battery is discharged. For this reason, the actual measurement signal is obtained by superimposing an alternating current waveform on the direct current, and the direct current discharge current is larger than that of other batteries connected in series. However, a battery or the like has a property that the impedance changes depending on the DC discharge current, and if the DC discharge current changes for impedance measurement, an accurate impedance measurement is not performed.

  In order to solve this problem, it is necessary to use an alternating current supply means that can flow current not only in the direction of discharging the battery but also in the charging direction. Specifically, for example, it is necessary to add another transistor having a complementary polarity and a power source for flowing a current in the charging direction to form a so-called bipolar output. However, by doing so, the AC current supply means becomes large, and there is a disadvantage that it becomes an expensive and complicated means especially when the voltage of the battery is high.

  Moreover, the measuring apparatus described in Patent Document 2 enables measurement of AC impedance for a battery, and does not disclose measuring AC impedance of a load connected to the battery.

  The measuring device described in Patent Document 1 is intended to measure the impedance of a battery, and is not intended to measure the impedance of a load. However, the AC signal given from the AC source for measurement flows not only to the battery to be measured but also to the load. In particular, since the impedance of a battery greatly changes depending on the frequency, it has a drawback that it is difficult to manage the amount of alternating current applied to the battery alone.

  Therefore, an object of the present invention is to provide an AC impedance measuring apparatus and method capable of accurately measuring the AC impedance of a power generator or a load with a simple configuration.

  Another object of the present invention is to provide an AC impedance measuring apparatus and method capable of accurately measuring the AC impedance of a power generator and a load simultaneously or separately with a simple configuration.

  In order to solve the above-described problems, the AC impedance measuring apparatus and method according to the present invention employ the following characteristic configuration.

(1) power generator is connected to the load, the AC impedance for determining the impedance of the power generating body及beauty impedance of the power generating body及beauty load based on the voltage applied to the current flowing to the load, or the power generating body In the measuring device,
Voltage detecting means for detecting a voltage applied to the power generator when the voltage applied to the power generating body及beauty load when obtaining the impedance of the power generator and the load detecting determines the impedance of the power generating body When,
A transformer in which an AC signal output from the measurement signal generating circuit is supplied to the primary side, a secondary side is inserted in series in the connection circuit between the power generator and the load, and an AC signal corresponding to the AC signal is supplied to the connection circuit. When,
Current detection means for detecting a current flowing in the primary side of the transformer;
Calculating means for determining the impedance of the impedance of the power generating body及beauty load based on the output of the voltage detecting means and said current detecting means, or the power generating body,
An AC impedance measuring apparatus comprising:
(2) In the AC impedance measuring device for determining the impedance of the power generator or the load based on the current that flows through the power generator or the load and the applied voltage when the power generator is connected to the load,
First and second voltage detection means for detecting a voltage applied to the power generator and the load;
A transformer in which an AC signal output from the measurement signal generating circuit is supplied to the primary side, a secondary side is inserted in series in the connection circuit between the power generator and the load, and an AC signal corresponding to the AC signal is supplied to the connection circuit. When,
Current detection means for detecting a current flowing in the primary side of the transformer;
Switch means for switching and outputting the voltage applied to the power generator and the load, which are the outputs of the first and second voltage detection means,
A calculation means for obtaining an impedance of the power generator or a load based on a voltage which is an output of the switch means and an output of the current detection means;
AC impedance measuring device comprising:
(3) In an alternating current impedance measuring apparatus for obtaining an impedance of the direct current source based on a current flowing in the direct current source and an applied voltage,
Voltage detecting means for detecting a voltage applied to the DC current source;
An AC signal output from the measurement signal generating circuit is flowed to the primary side, the DC current source is short-circuited on the secondary side in a DC manner, and an AC signal corresponding to the AC signal is supplied to the DC current source; ,
Current detection means for detecting a current flowing in the primary side of the transformer;
Calculation means for obtaining an impedance of the direct current source based on outputs of the voltage detection means and the current detection means;
An AC impedance measuring apparatus comprising:
(4) In the AC impedance measurement device for determining the impedance of the AC power generator on the basis of the voltage applied to the current flowing in the ac generators,
Voltage detection means for detecting a voltage applied to the AC generator;
An AC signal output from the measurement signal generating circuit is applied to the primary side with a constant current, a secondary side is connected to the AC power generator, and a transformer for passing an AC signal corresponding to the AC signal to the AC power generator;
Current detection means for detecting a current flowing in the primary side of the transformer;
Calculation means for obtaining the impedance of the AC power generator based on the outputs of the voltage detection means and the current detection means;
In an AC impedance measuring device comprising:
2. The AC impedance measuring apparatus according to claim 1, wherein the AC power generator is a voltage output, the number of windings on the secondary side of the transformer is increased, and the primary side of the transformer is driven with the constant current.
(5) In the AC impedance measurement device for determining the impedance of the AC power generator on the basis of the voltage applied to the current flowing in the ac generators,
Voltage detection means for detecting a voltage applied to the AC generator;
An AC signal output from the measurement signal generating circuit is applied to the primary side at a constant voltage, a secondary side is connected to the AC power generator, and a transformer for passing an AC signal corresponding to the AC signal to the AC power generator;
Current detection means for detecting a current flowing in the primary side of the transformer;
Calculation means for obtaining the impedance of the AC power generator based on the outputs of the voltage detection means and the current detection means;
In an AC impedance measuring device comprising:
An AC impedance measuring apparatus, wherein the AC power generator is a current output, the number of secondary windings of the transformer is reduced, and the primary side of the transformer is driven by the constant voltage.
(6) The AC impedance measuring apparatus according to any one of (1) to (3), wherein the primary side of the transformer is driven by constant voltage drive or constant current drive.
(7) The transformer is a clamp-type transformer configured such that the secondary side can be opened, and the wire part of the connection circuit of the power generator or the load is inserted from the open part and enclosed, and then closed. The AC impedance measuring apparatus according to any one of (1) to (6) above, wherein
(8) the power generator is connected to the load, the AC impedance for determining the impedance of the power generating body及beauty impedance of the power generating body及beauty load based on the voltage applied to the current flowing to the load, or the power generating body In the measurement method,
The power generator and detects a voltage applied to the power generating body及beauty load when obtaining the impedance of the load, by detecting the voltage applied to the power generator in the case of obtaining the impedance of the power generating body, measured An AC signal output from the signal generation circuit is flowed to the primary side, a secondary side is inserted in series in the connection circuit between the power generation body and the load, and a transformer for flowing an AC signal corresponding to the AC signal to the connection circuit detecting a current flowing through the primary side, the detected voltage and the impedance of the power generating body及beauty load based on the current, or AC impedance measuring method characterized by determining the impedance of the power generating body.
(9) In the AC impedance measuring method in which the power generator is connected to a load, and the impedance of the power generator or the load is obtained based on the current flowing through the power generator or the load and the applied voltage.
The voltage applied to the power generation body or the load is detected, the AC signal output from the measurement signal generation circuit is flowed to the primary side, the secondary side is inserted in series in the connection circuit between the power generation body and the load, Detecting a current flowing on the primary side of a transformer that sends an AC signal corresponding to the AC signal to the connection circuit, switching to detect a voltage applied to the power generator or load, and switching the detected voltage; An AC impedance measuring method, wherein an impedance of the power generator or a load is obtained based on the detected current.

According to the AC impedance measuring apparatus and method of the present invention, since the connection circuit between the power generator and the load constitutes a closed circuit, the current flowing through the power generator and the load is the same, and the AC impedance of the power generator or the load As described above, measurement can be performed without using a means for separating and correcting the measurement signal other than the measurement object. In addition, the measurement signal generator only needs to generate an arbitrary measurement signal suitable for measurement, and it is not necessary to generate a voltage equal to or higher than that of the power generator, which simplifies the circuit configuration and is advantageous in terms of cost. is there.
Furthermore, since the current value of the measurement signal applied to the power generator and the load through the secondary side of the transformer can be known on the primary side of the transformer, the circuit configuration of the measurement signal generation unit and the current detection unit is simplified and the cost is reduced. This is also advantageous.

  Hereinafter, preferred embodiments of an AC impedance measuring apparatus and method according to the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a circuit diagram showing an AC impedance measuring apparatus according to an embodiment of the present invention.
In the present embodiment, a power generation body 1 (for example, a battery) that is a measurement object and a load 2 are connected in series, power is supplied from the power generation body 1 to the load 2, and the AC impedance of each of the power generation body 1 and the load 2 is determined. taking measurement.

  The voltage applied to the power generator 1 and the load 2 necessary for measuring the AC impedance is detected by the voltage detection means 3 and 4, respectively. The voltages detected by the voltage detection means 3 and 4 are supplied to the input terminals 91 and 92 of the switch 9. The switch 9 switches and outputs one of the voltages input to the input terminals 91 and 92 to the output terminal 93. The voltage at the output terminal 93 of the switch 9 is sent to the AC impedance calculation means 10.

  An AC signal having a predetermined frequency generated from the measurement signal generator 6 is supplied to the primary side winding of the measurement signal injection transformer 5, and the secondary side winding is inserted into the series circuit of the power generator 1 and the load 2. The With this configuration, a current necessary for AC impedance measurement flows through the power generator 1 and the load 2. In this embodiment, the transformer 5 is inserted (connected) in series in a closed circuit including a power generator and a load, and the measurement signal current is superimposed on the load current. In addition, since the power generator 1 and the load 2 are connected in series and form a closed circuit, the currents flowing through them are the same value.

  The current from the measurement signal generator 6 flows through the resistor 7 connected in series to the primary side of the transformer 5 and is detected by the current detection means 8 based on the voltage generated at the resistor 7. The voltage detected by the current detection means 8 is sent to the AC impedance calculation means 10. When the primary side of the transformer 5 is driven at a constant current or when the driving impedance is not a problem, a simple and accurate current detection can be performed by using a resistor as shown in this figure.

  When performing constant voltage driving, it is preferable to use a current detecting means such as a Hall element or a fluxgate sensor, in which direct current resistance does not become a problem. Alternatively, another AC current transformer is used for current detection, the primary side is connected between the measurement signal source 6 and the transformer 5, and the shunt resistor is connected to the secondary side to thereby obtain the current-voltage. There is also a way to convert. By this method, the influence of the direct current resistance for current detection can be reduced.

  The AC impedance calculation means 10 receives the detection current from the current detection means 8 and the detection voltage from the output terminal 93 of the switch 9 and calculates the AC impedance of the power generator 1 and the load 2 by calculation. That is, the AC impedance calculation means 10 is based on the applied voltage of the power generation body 1 and the load 2 obtained by the voltage detection means 3 and 4 and the detection current obtained by the current detection means 8. Impedance is calculated.

  In FIG. 1, the voltages detected by the voltage detection means 3 of the power generator 1 and the voltage detection means 4 of the load 2 are switched by a switch 9 and applied to the AC impedance calculation means 10 to measure each impedance. Without providing the switch 9, the voltage detected by the voltage detecting means 3 of the power generator 1 is supplied to the AC impedance calculating means 10 to measure the impedance of the power generator 1, or detected by the voltage detecting means 4 of the load 2. The impedance of the load 2 can be measured by applying the obtained voltage to the AC impedance calculation means 10. Further, both of the voltages detected by the voltage detection means 3 of the power generator 1 and the voltage detection means 4 of the load 2 are both supplied to the AC impedance calculation means 10 to calculate each impedance, thereby simultaneously measuring each impedance. A configuration can also be adopted.

  In the present invention, since the current of the same value flows through both the power generator 1 and the load 2, the current detected by the current detection means 8 can be used in common in both calculations.

  In this embodiment, the power generator 1 and the load 2 are connected in series, and the flowing currents are the same, so that one current detection means can be shared. Therefore, it is possible to measure the impedance of the power generator 1 and the load 2 by changing the voltage detection points of the power generator 1 and the load 2.

  The transformer 5 is a current transformer that uses a split core or a toroidal core that is not saturated by the direct current component of the load current. The output of the measurement signal generator 6 is given to the resistor 7 and the signal injection transformer 5. The primary side current of the transformer 5 is measured by the current detection means 8 constituted by a preamplifier. The resistor 7 also serves as a current limiting resistor when the impedance of the measured object (power generation body or load) is low.

  In any of the above circuit configurations, the transformer 5 for injecting the measurement signal and the power generation body 1 and / or the load 2 as the measurement target are always connected in series, and the current path flows in a branched manner. Therefore, all measurement signal currents always flow through the device under test (power generator 1 and / or load 2). Further, since the measurement signal generator 6 and the measured object (the power generator 1 and / or the load 2) are electrically insulated, the measurement signal generator 6 needs to output a voltage equal to or higher than that of the power generator 1. The measurement signal generator can be manufactured with the minimum necessary circuit scale. For example, even when measuring the internal impedance of a 100 V battery, if it is sufficient to generate 100 mV of alternating current as a measurement signal, the measurement signal generator may generate a voltage calculated by (100 mV × voltage transformation ratio).

  FIG. 2 shows a circuit diagram according to another embodiment of the present invention. In the present embodiment, a load 2 alone is assumed as a measured body, and the AC impedance of the load 2 is measured. Both ends of the secondary winding of the transformer 5 are connected to the load 2 as the measured body.

  FIG. 3 is a circuit diagram according to still another embodiment of the present invention. In this embodiment, a DC power generator (for example, a DC voltage source such as a battery) alone is assumed as a measured object, and the AC impedance when the power generator 1 is unloaded is measured. Is connected to the power generator 1 which is a device to be measured, and the capacitor 11 is connected in series to the secondary side of the transformer 5 to prevent a direct current from flowing to the secondary side of the transformer 5.

  When the power generator is a DC current source, the no-load state for the current source is a load short-circuit state, so the capacitor 11 is unnecessary and can be short-circuited in a DC manner by the secondary side connection of the transformer 5. In such a case, a more complete short circuit state can be obtained by using a thick conducting wire with a low DC resistance for the secondary side winding of the transformer 5 or by reducing the number of secondary side windings.

  As described above, in the present invention, since all the measurement signal current always flows through the measurement object, the AC impedance is accurately obtained without being affected by the measurement signal current flowing outside the measurement object as in the prior art. Can be measured.

  Since the signal current for measurement can be calculated by the primary side current of the transformer 5 and the current transformation ratio of the transformer 5, the measurement target current (the power generation body 1 or the load 2) can be obtained simply by measuring the primary side current of the transformer 5. The flowing measurement signal current can be known.

  In the above-described embodiment, when the transformer 5 is a clamp-type current transformer, it is only necessary to clamp an electric wire of an already installed circuit (in the above-described embodiment of FIG. 1, a series circuit of the power generator 1 and the load 2). Since the transformer 5 is connected in series, impedance measurement can be performed with a very simple operation. A measurement signal can be easily applied without disconnecting the series circuit of the power generator 1 and the load 2. If such a clamp type transformer is used, in order to measure the measurement signal current flowing through the object to be measured, it is not necessary to disconnect and add the object to be measured like, for example, a shunt resistor or a normal current detection transformer. The clamp-type transformer has a publicly known configuration, the secondary side can be opened, and the wire portion of the power generator or load connection circuit is inserted from the open portion and enclosed, and then closed. Has been.

  In addition, for example, if a clamp-type current sensor is separately used to measure the measurement signal current flowing through the device under test, it is not necessary to disconnect the device under test for current detection, but the current sensor itself is expensive. There is a problem that there is. Especially when a large battery and a load are connected, the impedance is measured by superimposing a measurement signal on a large DC current, so the current sensor becomes large and it is difficult to accurately detect a small measurement signal. It has the disadvantage of being.

  In the present embodiment, a configuration in which the current flowing through the object to be measured is known from the primary current of the transformer 5 can be used, and a current detecting means using the shunt resistor 7 can be used. Since only an alternating current corresponding to the measurement signal from the signal generator 6 flows, an inexpensive shunt resistor with low power consumption resistance can be used. On the other hand, when a shunt resistor is used on the secondary side of the transformer 5 as in the prior art, it is not only necessary to disconnect the power generator 1 and the load 2 and add a shunt resistor, but also from the power generator 1 The power consumption is large enough to allow the direct current flowing through the load 2 to flow.

  By the way, the AC impedance of the power generator changes depending on the presence or absence of a load or the weight of the load. Also, in the case of a load such as an electronic circuit that exhibits nonlinear impedance characteristics with respect to voltage or current, the AC impedance of the load may change depending on the voltage or current supplied from the power generator. For this reason, in order to perform an accurate measurement, it is required to measure the AC impedance in a state close to the actual operating state to the extent that it can be regarded as equivalent to the case where an actual power generator and an actual load are connected.

  In the embodiment of FIG. 1, when the measurement signal is applied by connecting the secondary side of the transformer 5 between the power generator 1 and the load 2, for example, when the primary side of the transformer 5 is opened, mutual induction This is the same state as if an inductor was inserted between the power generator 1 and the load 2. When a measurement signal is applied to the primary side of the transformer 5 using a constant current source such as a constant current output amplifier, the output side of the constant current source is high, so the secondary side of the transformer opens the primary side of the transformer. In the same manner, the state is as if an inductor was inserted between the power generator 1 and the load 2.

  When considering a state where a load with a large current change such as an inverter is connected to a DC power generator such as a battery, the load seen from the power generator appears when an inductor is inserted between the power generator and the load. Since the impedance appears to increase as the frequency increases and is different from the actual operating state, accurate AC impedance measurement cannot be performed in a state close to the actual operating state.

  Here, when the measurement signal is applied by connecting the secondary side of the transformer 5 between the power generator 1 and the load 2, for example, when the primary side of the transformer 5 is short-circuited, it is as if contrary to the open state. The state is the same as when no inductor is inserted between the power generator 1 and the load 2. When a measurement signal is applied to the primary side of the transformer 5 using a constant voltage source such as a constant voltage output amplifier, the secondary side of the transformer 5 is connected to the primary side of the transformer 5 because the output impedance of the constant voltage source is low. As with the short circuit, the state is the same as when no inductor is inserted between the power generator 1 and the load 2, and changes due to the insertion of the transformer hardly appear.

  Considering the case where a load with a large current change such as an inverter is connected to a DC power generator such as a battery, a state in which nothing is connected between the power generator and the load, that is, It can be almost the same as the actual operating state, and an accurate AC impedance measurement can be performed.

  As described above, the power generator that does not change with time and the load that changes with time have been described, but conversely, for example, an AC power generator such as a generator, that is, a power generator that changes voltage and current, and a resistive load Consider a combination with a load with little temporal change. Also in this case, since the current flowing between the power generator and the load changes with time, if an equivalent inductor is present, the current operating state is different, and accurate AC impedance measurement cannot be performed. In such a case as well, accurate alternating current impedance measurement can be performed by driving the transformer primary side at a constant voltage.

  As described above, if the transformer primary side is driven at a constant voltage in the present invention, the transformer does not become an inductor equivalently, and when at least one of the power generator and the load fluctuates with time, an accurate alternating current can be obtained. It becomes an important means for performing impedance measurement.

  However, if neither the power generator nor the load changes over time, such as a combination of a DC power generator and a resistive load, there is no effect even if an equivalent inductor exists between the power generator and the load. The influence of the primary side drive condition is negligible. In such a case, the DC resistance of the transformer secondary winding is more important.

  Further, in this case, when the impedance of the power generator or the load varies depending on the measurement frequency, the measurement signal current flowing through the power generator or the load can be kept constant by driving the transformer primary side with a constant current.

  In the embodiment shown in FIG. 3, in order to measure the AC impedance in the no-load state of the DC power generator (DC voltage source), a capacitor is inserted between the power generator and the load so that no DC current flows. It was.

  Another embodiment of the present invention performs AC impedance measurement in an unloaded state of the AC power generator. FIG. 4 shows a circuit diagram of this embodiment.

When the AC power generator 12 is voltage output, it is in a no-load state if almost no output current flows.
Here, the load connected to the AC power generator 12 is the secondary side of the measurement signal applying transformer 5 in the present invention. In order to prevent the output current of the AC power generator 12 from flowing through this load, In order to make the load look like a sufficiently large inductor, the number of windings on the secondary side of the transformer 5 connected to the AC power generator 12 is increased, and the primary side of the transformer 5 is driven with a constant current when a measurement signal is applied. To do. How much the number of windings on the secondary side of the transformer 5 is to be increased and how much the driving impedance on the primary side of the transformer 5 is to be increased (that is, how much the degree of constant current is brought close to perfection). The selection may be made on the basis that the error in the AC impedance measurement result of the AC generator 12 becomes small enough to be ignored.

  On the other hand, when the AC power generator 12 outputs a current, the no-load state for the current source is a load short-circuit state, so it is sufficient that the secondary side of the transformer 5 appears almost short-circuit in terms of AC. In such a case, the number of windings on the secondary side of the transformer 5 may be reduced and the primary side may be driven at a constant voltage. How much the number of windings on the secondary side of the transformer 5 is to be reduced and how much the drive impedance on the primary side of the transformer 5 is to be reduced (that is, how much the degree of constant voltage property is brought close to perfection). The selection may be made on the basis that the error in the AC impedance measurement result of the AC generator 12 becomes small enough to be ignored.

The embodiments described above have the following effects in relation to the prior art.
When a measurement signal is applied to measure the AC impedance of the power generator and / or the load with the power generator and the load connected, according to the present invention, the measurement signals of both the power generator and the load are made to have the same current value. can do. In the prior art, since the measurement signal is shunted to the power generator and the load, it is necessary to detect only the current flowing through the measurement target. In particular, when it is desired to know the AC impedance of both the power generation body and the load, it is necessary to provide current detection means for both the power generation body and the load, and two current detection means are required. Further, when the impedance change of the power generator or the load greatly changes depending on the frequency, the measurement signal current is biased depending on the level of the impedance, which may make accurate measurement difficult.

According to the present invention, the measurement signal current can be known from the primary side current of the transformer 5 and the transformation ratio of the transformer. Since it is insulated by the transformer, the reference potential of the power generator or load may be different from the reference potential of the measurement signal generator.
Even if the power generator is at a high voltage, since it is insulated by the transformer 5, it is not necessary to generate a high voltage at the measurement signal generator.

  According to the method of the present invention in which the measurement signal current is known on the primary side of the transformer 5, the current detector can be simplified. In particular, when a large DC current is flowing between a DC power generator and a load, current detection by a normal technique needs to detect a small AC signal superimposed on a large DC current, which can make the device large. It was difficult to measure accurately. For example, as in Patent Document 1, a complicated configuration for direct current cancellation is required, or a large current sensor capable of handling a large current is required.

  In the present invention, since only the measurement signal needs to be given to the primary side of the transformer 5, the apparatus can be simplified. Even if the power generator has a high voltage, it is not necessary to generate a high voltage in the measurement signal.

Further, in the present invention, the impedance of the measurement signal applying unit (transformer secondary side) can be determined by the number of windings of the transformer and the driving method on the transformer primary side. In order to reduce the influence when a power generator or a load whose impedance changes with time is connected, it is desired to reduce the impedance of the measurement signal applying unit. For this purpose, the number of windings on the secondary side of the transformer may be reduced and increased, and the primary side of the transformer may be driven at a constant voltage.
If you want to increase the impedance of the measurement signal application section, such as when measuring the impedance of the AC power generator 6 with no load, increase the number of windings on the secondary side of the transformer and drive the primary side of the transformer at a constant current. It ’s fine.

  If a clamp-type transformer is used to apply a measurement signal, it is not necessary to disconnect the power generator and the load, and measurement can be performed easily. Particularly when the power generator is at a high voltage or a large current, it is dangerous to disconnect it. However, such a large-scale power generator often takes time, cost, and labor to stop and restart, and it is also difficult to stop power generation once in order to avoid danger when disconnecting. If the connection is disconnected or reconnected, the state of the wiring may change, and the actual power generation state or load state may not be achieved.

  The configuration of the preferred embodiment of the present invention has been described above. However, it should be noted that such examples are merely illustrative of the invention and do not limit the invention in any way. Those skilled in the art will readily understand that various modifications and changes can be made according to a specific application without departing from the gist of the present invention.

It is a circuit diagram of the alternating current impedance measuring apparatus by one Example of invention. It is a circuit diagram of the alternating current impedance measuring apparatus by the other Example of this invention. It is a circuit diagram of the alternating current impedance measuring apparatus by further another Example of invention. It is a circuit diagram of the alternating current impedance measuring apparatus by other Example of invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Power generation body 2 Load 3, 4 Voltage detection means 5 Transformer 6 Measurement signal generator 7 Resistance 8 Current detection means 9 Switch 91, 92 Input terminal 93 Output terminal 10 AC impedance calculation means 11 Capacitor 12 AC power generation body

Claims (9)

Generators are connected to a load, the impedance of the power generating body及beauty load based on the voltage applied to the current flowing in the power generating body及beauty load, or the AC impedance measuring device for determining the impedance of the power generating body ,
Voltage detecting means for detecting a voltage applied to the power generator when the voltage applied to the power generating body及beauty load when obtaining the impedance of the power generator and the load detecting determines the impedance of the power generating body When,
A transformer in which an AC signal output from the measurement signal generating circuit is supplied to the primary side, a secondary side is inserted in series in the connection circuit between the power generator and the load, and an AC signal corresponding to the AC signal is supplied to the connection circuit. When,
Current detection means for detecting a current flowing in the primary side of the transformer;
Calculating means for determining the impedance of the impedance of the power generating body及beauty load based on the output of the voltage detecting means and said current detecting means, or the power generating body,
An AC impedance measuring apparatus comprising: In the AC impedance measuring device, wherein the power generator is connected to a load, and the impedance of the power generator or the load is obtained based on the current flowing through the power generator or the load and the applied voltage.
First and second voltage detection means for detecting a voltage applied to the power generator and the load;
A transformer in which an AC signal output from the measurement signal generating circuit is supplied to the primary side, a secondary side is inserted in series in the connection circuit between the power generator and the load, and an AC signal corresponding to the AC signal is supplied to the connection circuit. When,
Current detection means for detecting a current flowing in the primary side of the transformer;
Switch means for switching and outputting the voltage applied to the power generator and the load, which are the outputs of the first and second voltage detection means,
A calculation means for obtaining an impedance of the power generator or a load based on a voltage which is an output of the switch means and an output of the current detection means;
An AC impedance measuring apparatus comprising: In the AC impedance measuring device for obtaining the impedance of the DC current source based on the current flowing through the DC current source and the applied voltage,
Voltage detecting means for detecting a voltage applied to the DC current source;
An AC signal output from the measurement signal generating circuit is flowed to the primary side, the DC current source is short-circuited on the secondary side in a DC manner, and an AC signal corresponding to the AC signal is supplied to the DC current source; ,
Current detection means for detecting a current flowing in the primary side of the transformer;
Calculation means for obtaining an impedance of the direct current source based on outputs of the voltage detection means and the current detection means;
An AC impedance measuring apparatus comprising: In the AC impedance measuring device for obtaining the impedance of the AC power generator based on the current flowing through the AC power generator and the applied voltage,
Voltage detection means for detecting a voltage applied to the AC generator;
An AC signal output from the measurement signal generating circuit is applied to the primary side with a constant current, a secondary side is connected to the AC power generator, and a transformer for passing an AC signal corresponding to the AC signal to the AC power generator;
Current detection means for detecting a current flowing in the primary side of the transformer;
Calculation means for obtaining the impedance of the AC power generator based on the outputs of the voltage detection means and the current detection means;
In an AC impedance measuring device comprising:
2. The AC impedance measuring apparatus according to claim 1, wherein the AC power generator is a voltage output, the number of windings on the secondary side of the transformer is increased, and the primary side of the transformer is driven with the constant current. In the AC impedance measuring device for obtaining the impedance of the AC power generator based on the current flowing through the AC power generator and the applied voltage,
Voltage detection means for detecting a voltage applied to the AC generator;
An AC signal output from the measurement signal generating circuit is applied to the primary side at a constant voltage, a secondary side is connected to the AC power generator, and a transformer for passing an AC signal corresponding to the AC signal to the AC power generator;
Current detection means for detecting a current flowing in the primary side of the transformer;
Calculation means for obtaining the impedance of the AC power generator based on the outputs of the voltage detection means and the current detection means;
In an AC impedance measuring device comprising:
An AC impedance measuring apparatus, wherein the AC power generator is a current output, the number of secondary windings of the transformer is reduced, and the primary side of the transformer is driven by the constant voltage.   The AC impedance measuring apparatus according to claim 1, wherein the primary side of the transformer is driven by constant voltage driving or constant current driving.   The transformer is a clamp-type transformer configured such that the secondary side can be opened, and the wire portion of the connection circuit of the power generator or load is inserted from the open portion and enclosed, and then closed. The AC impedance measuring apparatus according to any one of claims 1 to 6. Generators are connected to a load, the AC impedance measuring method for determining the impedance of the power generating body及beauty impedance of the power generating body及beauty load based on the voltage applied to the current flowing to the load, or the power generating body ,
The power generator and detects a voltage applied to the power generating body及beauty load when obtaining the impedance of the load, by detecting the voltage applied to the power generator in the case of obtaining the impedance of the power generating body, measured An AC signal output from the signal generation circuit is flowed to the primary side, a secondary side is inserted in series in the connection circuit between the power generation body and the load, and a transformer for flowing an AC signal corresponding to the AC signal to the connection circuit detecting a current flowing through the primary side, the detected voltage and the impedance of the power generating body及beauty load based on the current, or AC impedance measuring method characterized by determining the impedance of the power generating body. In the AC impedance measurement method in which the power generator is connected to a load, and the impedance of the power generator or the load is obtained based on the current flowing in the power generator or the load and the applied voltage.
The voltage applied to the power generation body or the load is detected, the AC signal output from the measurement signal generation circuit is flowed to the primary side, the secondary side is inserted in series in the connection circuit between the power generation body and the load, Detecting a current flowing on the primary side of a transformer that sends an AC signal corresponding to the AC signal to the connection circuit, switching to detect a voltage applied to the power generator or load, and switching the detected voltage; An AC impedance measuring method, wherein an impedance of the power generator or a load is obtained based on the detected current.

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