JP2016067166A - Power supply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power supply device that can obtain easily arbitrary two-dimensional output characteristics of output voltages and currents by function control and can be preferably applied to an electric dust collector.SOLUTION: Output voltages V and output currents I applied to loads I and II are detected; duty control for PWM control of a line commutation type converter is performed by a main controller 5; a two-dimensional relation between the output voltages V and the output currents I is represented; a native characteristic curve is used which crosses a target two-dimensional output characteristic and represents a two-dimensional relation between the output voltages V and the output currents I when the duty is retained constantly; the detected output voltages V and the detected output currents I are substituted into attractor function R uniquely determined from a shape of the two-dimensional characteristic; and on the basis of positive and negative codes obtained when determining a difference between the output voltages V and predetermined reference voltages Vin the attractor function R and a difference between the detected currents I and predetermined reference currents I, the duty for the PWM control is increased/decreased for every fixed time in a direction converging to the attractor function R.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a power supply device, and is particularly useful when applied to an electrostatic precipitator that requires a high voltage.

  A high-voltage power supply device for an electric dust collector requires a specific output characteristic. In other words, the electrostatic precipitator is composed of a charging unit (ionizer) that charges particles by corona discharge and a dust collecting unit (collector) that collects particles. As a result, a certain amount of particle charge when passing through the ionizer is secured. A corona discharge current is required. In addition, the collector requires a certain collector voltage to ensure dust collection efficiency.

  However, when the electrode of the electrostatic precipitator is viewed as a load of a high-voltage power supply, it is characterized by a large fluctuation width with time compared to a normal load, and the state of operation at one point of rated voltage and rated current is the electrode It is only the initial stage that hardly uses. In actual use, not only dust, mist and the like as dust collection objects accumulate on the dust collection part, but also dirt adheres to the discharge electrode and electrode support part of the ionizer. This makes it difficult for the ionizer to cause corona discharge and increases the voltage for maintaining the discharge current. On the other hand, the leakage current increases at the collector, and the terminal voltage becomes a drop.

  In order to maintain dust collection efficiency under such changes in dust collection conditions, the ionizer requires a constant current characteristic and the collector requires a constant voltage characteristic. In addition, since the electrode progresses continuously during the period of use of the electrode and it is necessary to maintain performance at any point in time, the output is not a single point but a function characteristic (two-dimensional characteristic) according to changes in voltage and current. Required for output characteristics of high-voltage power supply for dust collectors.

  Furthermore, if the voltage is increased without limitation in order to maintain a constant current, insulation cannot be maintained at the support portion or the like, so a certain degree of limitation is also required. In addition, if an unlimited current is applied to maintain a constant voltage, there is a risk that smoke will ignite due to the generation of Joule heat or the like, and it is also necessary to limit the collector current. In consideration of these characteristics, the output characteristics of the high-voltage power supply that the electrostatic precipitator is most likely to perform are constant voltage / constant current characteristics that show a box shape in a two-dimensional plane of voltage / current. Here, the box shape means that while the output current I in the X-axis direction increases from zero to the maximum value, the voltage maintains a predetermined constant voltage, and when the current reaches the maximum value, the Y-axis direction Even when the output voltage V increases or decreases, the current has a characteristic of maintaining a predetermined constant current and includes a point indicating the maximum value of both of the voltage and current. The box-shaped output characteristics will be described in detail later together with the embodiment (see FIG. 9).

  On the other hand, as a high-voltage power supply device according to this type of prior art, there is one disclosed in Patent Document 1, for example. This is a self-excited oscillation type high-voltage power supply with a ringing choke converter as a representative example. It is used in electrostatic precipitators and air purifiers, and an oscillation circuit is formed using the signal fed back from the tertiary winding. It is an analog circuit.

  However, Patent Document 1 has a problem that the oscillation frequency varies depending on the temperature, and abnormal oscillations that enter the audible range occur depending on conditions, or that the oscillation does not oscillate and does not output high voltage if the ambient temperature is too low. The output current / voltage exhibits a so-called “U” characteristic, but in order to obtain constant voltage / constant current characteristics, control components are required, the number of circuit components increases, and this increases the cost. Also, even for slight changes in the output voltage and output current, each component constant must be determined in a trial-and-error manner. Not only does development take time, but the specification change cannot be handled immediately. There is also a problem.

  On the other hand, in a high voltage power supply using a separately-excited high voltage power supply using a dedicated IC and a microcomputer, for example, disclosed in Patent Document 2, constant voltage control or constant current control is performed by PWM control (pulse width control). Function control to obtain dimensional characteristics has not been achieved. Therefore, as in Patent Document 1, each of the control parts is required, the number of circuit parts is increased, which increases the cost, and it takes time to determine the constants of each part even if the output voltage / current changes slightly. Not only are there problems such as being unable to deal with specification changes immediately.

  Other related documents include Patent Document 3 (Japanese Patent Laid-Open No. 2003-143845), Patent Document 4 (Japanese Patent Laid-Open No. 2003-199338), Patent Document 5 (Japanese Patent Laid-Open No. 2008-109820), and the like. To do. These documents all control the output target value, but do not disclose or suggest the concept of function control (two-dimensional output characteristics). In addition, the shape of the output characteristics is important in the electrostatic precipitator, but there is nothing that has a problem with the shape of the output characteristics, and there is no one that continuously changes the output characteristics at high speed during operation. .

JP 2002-273267 A JP 2000-156373 A JP 2003-143845 A JP 2003-199338 A JP 2008-109820 A

  An object of the present invention is to provide a power supply device that can easily realize any two-dimensional output characteristics of output voltage and current by function control and can be applied well to an electric dust collector. To do.

The first aspect of the present invention for achieving the above object is as follows:
Simultaneously detecting the output voltage V and the output current I with respect to the load, and supplying the detected output voltage V and output current I to the control means, the control means performs PWM control by the separately-excited converter to which the load is connected. A power supply device configured to perform duty control for:
The control means represents a two-dimensional relationship as a pair of the output voltage V and the output current I, intersects a target two-dimensional output characteristic, fixes the duty constant, and sets the load resistance. A native characteristic curve representing a two-dimensional relationship between the output voltage V and the output current I obtained when changing from zero to infinity is used to obtain an attractor function R uniquely determined from the shape of the two-dimensional output characteristic. The detected output voltage V and output current I are simultaneously substituted, and the difference between the output voltage V and the predetermined reference voltage V ₀ in the attractor function at this time, and the output current I and the predetermined reference current I ₀ From the positive and negative signs when the difference is taken, the duty for the PWM control is increased / decreased at regular intervals in the direction to gather in the attractor function, and a predetermined voltage / current curve is obtained. In power supply apparatus characterized by performing the dynamic control as tags.

  According to this aspect, an arbitrary two-dimensional output characteristic can be easily created by combining attractor functions alone or in combination as appropriate.

The attractor function in the present invention is defined as follows. That is, as a common attribute of the attractor function R, the value of the output voltage V _{0 and} the value of the output current I ₀ as target values are included, and the value of the output voltage V and the value of the output current I as measured values are included. This is an evaluation function on the program that instructs the CPU to perform either up or down processing simultaneously as a set via the AD converter, and may be expressed by a primary expression or a secondary expression. , And may be expressed by a logical expression such as NOR / NAND. The process proceeds so that the control result gathers in the output curve as the target value regardless of the load resistance. However, since it is directed to dynamic equilibrium at the same time, the minute fluctuation is always repeated while straddling the target output, and it does not settle down to a constant value in a strict sense even if it gathers at the target value. These have the effect of facilitating quick response to load fluctuations, and are indispensable characteristics for two-dimensional control.

The second aspect of the present invention is:
In the power supply device described in the first aspect,
The duty is increased by 1 digit only when both of the difference of the output voltage V with respect to the reference voltage V ₀ and the difference of the output current I with respect to the reference current I ₀ are negative, and all other cases are decreased by 1 digit. The power supply device is characterized in that the control is performed at the predetermined time intervals so that the two-dimensional output characteristic becomes a box-type two-dimensional constant voltage / constant current output characteristic.

  According to this aspect, it is possible to easily create a box-type two-dimensional constant voltage / constant current output characteristic.

The third aspect of the present invention is:
In the power supply device described in the first aspect,
When the attractor function R = V ₀ I + I ₀ V−V ₀ I ₀ represented by the linear expression is R> 0, the digit control is performed by 1 digit down in the duty control, and when R <0, the duty control is performed in the duty control. The two-dimensional output characteristic obtained by performing the control of increasing the digit by 1 and maintaining the previous state when R = 0 is the linear ramp voltage characteristic. It is in the power supply device characterized by this.

  According to this aspect, the linear gradient voltage characteristic of the two-dimensional output characteristic can be easily created.

The fourth aspect of the present invention is:
In the power supply device described in the first aspect,
The two-dimensional output characteristic generated by the control by the control means exhibits a constant voltage characteristic below a predetermined current, and a constant voltage / gradient voltage characteristic in which the voltage decreases as the current increases in a range exceeding the current. The power supply device is characterized by the following.

  According to this aspect, it is possible to easily create a two-dimensional output characteristic of a constant voltage / gradient voltage characteristic.

  According to the present invention, the duty control of the separately excited converter is performed by the control means, and the arbitrary two-dimensional output characteristics of the voltage and current of the high-voltage power source necessary for the load such as the electrostatic precipitator are the values of the instantaneous output voltage and output current. It is realized by the attractor function that contains the information. At this time, a significant cost reduction can be achieved by using the minimum necessary parts, and the characteristics of the output characteristics can be freely changed, and the characteristics are particularly utilized when mounted on an electrostatic precipitator as a load. That is, suppression of spark discharge itself, extinction of ignitable discharge, ensuring continuity of dust collection operation, and long-term operation can be realized.

It is a block diagram which shows the power supply device which concerns on embodiment of this invention. Is an explanatory view showing an area divided by a predetermined reference voltage V ₀ and the reference current I ₀ which generates a two-dimensional output characteristics. It is a characteristic view which shows an example of a native characteristic curve. It is a figure which shows various attractors, (a) is explanatory drawing which shows a constant voltage line attractor, (b) is explanatory drawing which shows a constant current line attractor, (c) is explanatory drawing which shows a box type attractor, (d) is L It is explanatory drawing which shows a type | mold attractor. It is explanatory drawing which shows the attractor function which forms an inclination type two-dimensional output characteristic. It is a characteristic view which shows the attractor function which forms a parabolic two-dimensional output characteristic. It is a characteristic view which shows the attractor function which forms a hyperbolic two-dimensional output characteristic. It is a characteristic view which shows an inclined type two-dimensional output characteristic. It is a characteristic view which shows a box-shaped two-dimensional output characteristic. It is a characteristic view which shows the two-dimensional output characteristic of constant power.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a block diagram showing a power supply apparatus according to an embodiment of the present invention. The power supply apparatus according to the present embodiment has an ionizer ionizer and collector as loads I and II. However, the load need not be limited to the ionizer and collector. The same operation and effect can be exhibited if the output of the chopper is boosted with a transformer to obtain a high voltage.

Moreover, the power supply device according to the present embodiment includes a separately excited conversion device. More specifically, a switching element that switches a DC voltage applied from a rectifying / smoothing circuit or a DC power source (not shown in FIG. 1) once from AC of commercial power 50/60 Hz to DC at a frequency of 20 kHz to 100 kHz. Are chopped by the field effect transistor Tr and applied to the step-up transformer 1. Step-up transformer 1 has a primary and secondary winding for obtaining a predetermined high voltage, in its primary winding 1A, the resonant capacitor C ₀ is connected in parallel. The secondary winding 1B is connected to a rectifying voltage doubler circuit 2 that converts the secondary voltage into a direct current. Thus, a predetermined DC high voltage generated by being boosted by the step-up transformer 1 and rectified by the rectifier voltage doubler circuit 2 is applied to the load I (ionizer) and the load II (collector). Here, a voltage lower than the applied voltage of the load I is applied to the load II via the resistors R1 and R2 for voltage division. This is to match the rated voltage of both.

  The voltage detection circuit 3 detects a voltage applied to the load I, and sends a voltage signal S1 representing the voltage value at this time to the main controller 5 via the operational amplifier 4. On the other hand, the current detection circuit 6 detects the current supplied to the load I and the load II, and sends a current signal S2 representing the current value at this time to the main controller 5 via the operational amplifier 7.

  The main controller 5 includes an A / D converter 8, a CPU 9, and a PWM signal generation unit 10. Here, the A / D converter 8 converts the voltage signal S1 and the current signal S2, which are analog signals, into digital signals and supplies them to the CPU 9. The CPU 9 processes a digital signal based on the voltage signal S1 and the current signal S2 in a predetermined manner to determine a PWM duty, and generates a PWM signal S3 having a predetermined duty via the PWM signal generation unit 10 (in the CPU 9). The signal processing will be described in detail later). The switching circuit 11 performs ON / OFF control of the field effect transistor Tr at a predetermined interval based on the PWM signal S3.

  Thus, the CPU 9 of the main control device 5 starts up at the same time when the power supply of the power supply device is turned on to enter the initial startup routine. At this time, the field effect transistor Tr is cut off, and no current flows through the step-up transformer 1.

  On the other hand, the CPU 9 reaches the target voltage while detecting the voltage value and the current value based on the monitoring voltage signal (VDD signal) S1 and the current signal (IDD signal) S2 obtained through the monitoring circuit at every predetermined time T1. If not, the duty is increased by one digit. In this embodiment, T1 = 10 msec, but it can be further shortened as necessary. Further, the duty increases by 1/400 (= 0.25%) every time one digit increases.

  In this embodiment, when the initial start-up routine is entered, the primary current of the step-up transformer 1 always starts from the cutoff, particularly in the case of a high-voltage power supply device for an electric dust collector. This is because when there is some load abnormality, an overcurrent, a load short circuit, etc. are assumed, and it is possible to enter the initial startup routine after the abnormality is detected, and to easily proceed to the next processing.

The output voltage V and the output current I of the power supply apparatus that change every moment are taken into the CPU 9 via the voltage detection circuit 3 and the current detection circuit 6. Here, a two-dimensional plane in which the horizontal axis is current I and the vertical axis is voltage V is considered. As shown in FIG. 2, when the two-dimensional plane is divided into four regions based on a predetermined reference voltage V ₀ and a reference current I ₀ determined in advance based on the rating of the electric dust collector, the upper right region (1) The output voltage V is always higher than the reference voltage V ₀ and the output current I is always larger than the reference current I ₀ . Therefore, when the difference between the output voltage V and the reference voltage V _{0 and} the difference between the output current I and the reference current I ₀ are taken, both (V−V ₀ ) and (I−I ₀ ) are positive in the region (1). Table 1 shows the results of examining the positive and negative of (V−V ₀ ) and (I−I ₀ ) in the regions (2), (3), and (4) by the same method.

For each of the areas (1) to (4), there are two types of processing by the CPU 9 for increasing the duty by one digit (when the difference is negative) or down (when the difference is positive). In the case of the example, there are 16 modes (2 ⁴ ) in total.

  Here, a native characteristic curve representing a two-dimensional relationship between the output voltage V and the output current I when the duty is fixed is considered. This native characteristic curve is a graph showing the correspondence between output voltage and output current obtained when the duty is fixed and the load resistance is continuously changed from 0 to ∞, and has a hyperbolic shape as shown in FIG. , And changes every time the duty increases by 1 digit (0.25%). Therefore, in this embodiment, there are 400 in total. FIG. 3 shows two examples.

Thus, the CPU 9 increases or decreases the pulse width every fixed time T1 by PWM control, and changes the native characteristic curve one after another. If processing of 1 digit up is performed in the region (1), the process shifts to the native characteristic curve on one line and both the output voltage V and the output current I increase, but (V−V ₀ ) and (I−I _0). ) are both positive for, the difference in time to up to without any increase divergence endlessly. Therefore, the up process in the area (1) cannot be used.

Next, when the down process is performed in the region (4), both (V−V ₀ ) and (I−I ₀ ) can hardly be made negative, and both the output voltage V and the output current I go to 0. When this area (4) is entered, output stops. In general, since the initial start-up starts from 0, it is impossible to start from this area (4). Therefore, the practicality of the down process in the region (4) is low.

  As described above, the area (1) is limited to the down process and the area (4) is limited to the up process, so the practical combinations are narrowed down to the following four. This is summarized in Table 2.

In NOT · A column in Table 2, in exceeds the reference voltage V ₀ region lowers the output, a process to increase in the region less than the reference voltage V _0. As a result, the output voltage V = the reference voltage V ₀ gathers in any region. That is, V = V ₀ represented by a straight line is an attractor of a constant voltage line as shown in FIG. Similarly, the output current I = reference current I _0, as shown in FIG. 4 (b), becomes attractor of the constant current line.

  Next, when the up process is performed only when entering the region (4) and the down process is performed otherwise, a box-type constant voltage / constant current characteristic is obtained. This is a box type as shown in FIG. Become an attractor.

  When positive is 1, negative is 0, up is 1 and down is 0, the box-type constant voltage and constant current characteristics correspond to A, NOR, and B. On the other hand, A · NAND · B has an L-type output characteristic as shown in FIG.

The above-mentioned four ways can start from 0 and give output characteristics without divergence / disappearance, but the box type constant voltage constant current characteristics are the most practical. However, the native characteristic curve needs to intersect the two-dimensional output characteristic curve. In this case, the attractor function R is R = _{I-I 0} in I <R = _V-V 0 in _{I 0, V} <V _0.

  An example of this type of attractor function can be summarized as follows.

<Inclined output attractor (see Fig. 5)>
The necessary output characteristic equation is modified and arranged as left side-right side = 0, and the attractor function R = I ₀ V + V ₀ I−V ₀ I ₀ is created. When R> 0, the PWM control duty is reduced by 1 digit (0.25%), when R <0, it is increased by 1 digit (0.25%), and when R = 0 If the CPU 9 performs the process of doing nothing for every fixed time T1, the output operating point goes to the line attractor regardless of the load resistance regardless of the load resistance, and then the load fluctuates. With an error of ± 1 digit, the output voltage V = −V ₀ / I ₀ (I−I ₀ ) is crossed up and down repeatedly. The output voltage V is decreased linearly with increasing load current, the output current I is used when characteristics to be limit is required on the reference current I ₀ during a short circuit. In this case, the conventional load series resistance is not required.

<Parabolic output attractor (see Fig. 6)>
The attractor function R and _{R = V / V 0 + (} I / I 0) 2 -2I / I 0, the case of R> 0, nothing is down, if R <up, in the case of R = 0, As a result, the operating points are gathered in a parabolic curved door tractor, and a parabolic output characteristic can be obtained.

<Hyperbolic output attractor (see FIG. 7)>
The attractor function R is R = VI−P ₀ (where P ₀ is the reference power). When R> 0, the hyperbolic output characteristic is obtained by down processing and when R <0, up processing. This is used when it is desired to keep the output power constant.

  Here, an example of a two-dimensional output characteristic generated by the CPU 9 by appropriately combining the above attractor functions will be described.

<Inclined two-dimensional output characteristics>
Although this is a two-dimensional output characteristic as shown in FIG. 8, it can be generated by using the inclined output attractor shown in FIG.

In order to obtain such an inclined characteristic, a high voltage resistor is conventionally inserted in series with the output terminal so that the current value determined by the output voltage V and the high resistance value is not exceeded even when the load is short-circuited. Not only has the size increased due to the insulation of the resistor, but also problems such as having to be separated from surrounding components due to heat generation have occurred. On the other hand, similar characteristics can be easily obtained with the tilted two-dimensional output characteristics of this embodiment. That is, by calculating a predetermined linear expression as described above, which is determined from the values of the real-time output voltage V and output current I, the reference voltage V ₀ which is a no-load voltage, and the reference current I ₀ which is a load short-circuit current. By performing a predetermined operation at regular time intervals T1, the output repeats vertical movement across the inclined straight line. As a result, although it does not become a constant value indefinitely, substantial dynamic control can be sufficiently performed as an average by suppressing the time variation of the load and keeping the change width of 1 digit small. .

<Box type constant voltage and constant current output characteristics>
This is a two-dimensional output characteristic as shown in FIG. 9, but can be generated by using the box-type output attractor shown in FIG. 4 (c) alone. That is, the treatment according to “A · NOR · B” in Table 2 is realized by increasing / decreasing the duty by 1 digit by the CPU 9 at every predetermined time T1.

  The box type constant voltage constant current output characteristic can be used as it is not only in the steady state but also from the rising time when the power is turned on. Even in this case, the output voltage V and the output current I are not statically constant, and control as an average value is realized while constantly changing across the target value. The reason why the value is not fixed is because it is related to the charging characteristics of the electrostatic precipitator, and the charging performance is better when it is changed. Such dynamic control is useful as a power supply control method suitable for an electric dust collector.

  In the case of the collector (load II), there is no characteristic that it is more advantageous to fluctuate, but instead, the collector generally has a large dust collection area and an extremely large capacitance, so it is naturally smooth and constant. Therefore, it is not necessary to eliminate any ripples as a power supply. In this method, which is aimed at dynamic balance control that responds quickly to load fluctuations, it always includes a small ripple in the output voltage. It does not eliminate, but rather uses its properties effectively. In that sense, it is suitable not only for an ionizer but also as a power source for a collector as an electric dust collector.

<Constant power output characteristics>
This is a two-dimensional output characteristic as shown in FIG. 10, but can be generated by combining the box type output attractor shown in FIG. 4C and the hyperbolic output attractor of FIG. That is, the upper right corner (region where the constant voltage characteristic and the constant current characteristic curve intersect) in FIG. 4C of the box type output attractor is replaced by using the hyperbolic output attractor of FIG. .

  The intersection (operating point) between the discharge characteristic and the power supply output normally starts from a constant current region, and the discharge characteristic changes with time and moves to the constant voltage region. In the case of box-type output characteristics, the voltage and current both pass through corner points at which the output power showing the maximum value is maximized. Since the overall thermal design is determined on the basis of this corner point, a design with a margin can be achieved by slightly cutting this point, which is a short time.

  According to the constant power output characteristic of this example, this output characteristic can be realized simply by adding the condition of duty = X% or less. Even if it is desired to change the value of X on the way, it can be dealt with immediately. This is because the output characteristic with a constant duty is a characteristic close to a hyperbola that rises to the left and is also close to a curve with a constant output power.

  As described above, according to the present embodiment, as the dust collection operation of the electric dust collector proceeds, the discharge characteristics themselves change due to the change in the load, so that the operating point changes so that only the two-dimensional output characteristic curve changes. Instantaneous values of the voltage V and the output current I are quickly taken in from the voltage detection circuit 3 and the current detection circuit 6 and immediately reflected in the duty of the PWM control so that the load change is not deviated from the two-dimensional output characteristic curve. The duty update timing must be determined by the speed. Since the change in the final output voltage and current varies depending on the operating point even with a change of 1 digit, the operating point is quasi-steady and dynamically balanced at any load. Apparently, it is operating as if it had taken only the values on the constant voltage / constant current characteristic curve. In other words, the vehicle is always operated across the two-dimensional output characteristic curve. By doing so, not only can the load change be handled instantaneously, but also the target value change can be handled quickly, and the two-dimensional output characteristic curve itself can be changed instantaneously. When the current value of the constant current characteristic is changed, it is performed only by changing the target numerical value. When the voltage gradient characteristic is changed, only the expression is changed. This is preferable when applied to a high-voltage power supply for electrostatic dust collection, because the load state changes during use, and the load characteristics can be changed and controlled according to this change. That is, it is possible to operate with dynamic two-dimensional output characteristics.

  Incidentally, in the case of the conventional analog type, switching is not easy, such as replacing the power supply itself or preparing another part and switching with a relay.

  In the power supply device described in the above embodiment, in preparation for a runaway control system, another control system for controlling the entire apparatus may be mounted separately from the main control system. Thus, even when the other side becomes uncontrollable, recovery is ensured by resetting from the other side, which can contribute to improvement of reliability.

  INDUSTRIAL APPLICABILITY The present invention can be effectively used in an industrial field where manufacture and sale of equipment using a high voltage power source such as an electric dust collector is performed.

V output voltage I output current V ₀ reference voltage I ₀ reference current I, II load Tr field effect transistor 1 step-up transformer 2 rectifier voltage doubler circuit 3 voltage detection circuit 5 main controller 6 current detection circuit 9 CPU
10 PWM signal generator

Claims (4)

Simultaneously detecting the output voltage V and the output current I with respect to the load, and supplying the detected output voltage V and output current I to the control means, the control means performs PWM control by the separately-excited converter to which the load is connected. A power supply device configured to perform duty control for:
The control means represents a two-dimensional relationship as a pair of the output voltage V and the output current I, intersects a target two-dimensional output characteristic, fixes the duty constant, and sets the load resistance. A native characteristic curve representing a two-dimensional relationship between the output voltage V and the output current I obtained when changing from zero to infinity is used to obtain an attractor function R uniquely determined from the shape of the two-dimensional output characteristic. The detected output voltage V and output current I are simultaneously substituted, and the difference between the output voltage V and the predetermined reference voltage V ₀ in the attractor function at this time, and the output current I and the predetermined reference current I ₀ From the positive and negative signs when the difference is taken, the duty for the PWM control is increased / decreased at regular intervals in the direction to gather in the attractor function, and a predetermined voltage / current curve is obtained. Power supply, characterized in that performing the dynamic control as tags. The power supply device according to claim 1,
The duty is increased by 1 digit only when both of the difference of the output voltage V with respect to the reference voltage V ₀ and the difference of the output current I with respect to the reference current I ₀ are negative, and all other cases are decreased by 1 digit. A power supply apparatus, wherein the two-dimensional output characteristics become box-shaped two-dimensional constant voltage / constant current output characteristics by performing the control at the predetermined time intervals. The power supply device according to claim 1,
When the attractor function R = V ₀ I + I ₀ V−V ₀ I ₀ represented by the linear expression is R> 0, the digit control is performed by 1 digit down in the duty control, and when R <0, the duty control is performed in the duty control. The two-dimensional output characteristic obtained by performing the control of increasing the digit by 1 and continuing the previous state when R = 0 is the linear ramp voltage characteristic. A power supply device characterized by that. The power supply device according to claim 1,
The two-dimensional output characteristic generated by the control by the control means exhibits a constant voltage characteristic below a predetermined current, and a constant voltage / gradient voltage characteristic in which the voltage decreases as the current increases in a range exceeding the current. A power supply characterized by.

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