Control apparatus

Abstract

To shorten the rise time of an output voltage while suppressing the occurrence of overshoot and ringing at the rising of the output voltage.SOLUTION: A control apparatus controls an output voltage output from a power supply device through digital processing by supplying a control signal dependent on an output control value to the power supply device, and includes: an adaptive control unit that generates a first control value that reduces a deviation between a reference output voltage value obtained by supplying a command value representing the output voltage to a predetermined reference model and an output voltage value obtained by detecting the output voltage; a disturbance removal unit that generates a second control value by subtracting an amount of control corresponding to an estimated disturbance component as an estimation of a disturbance contained in the output voltage from the first control value; and a stabilization unit that outputs, as an output control value, a value obtained by applying the second control value to a zero point stabilization controller that is a transfer function of a discrete time system.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a control device.

Background Art

[0002] A high-frequency power supply system used in a plasma processing apparatus or the like is known. Generally, the high-frequency power supply system includes a high-frequency power supply device that supplies high-frequency power to a plasma processing apparatus or the like serving as a load by outputting a high-frequency voltage (traveling wave voltage), and a matching device that performs impedance matching. However, it can also be configured not to include a matching device. Such a high-frequency power supply device performs feedback control in order to output a stable level of high-frequency voltage. When controlling the power value of the high-frequency power (for example, traveling wave power) supplied to the load as a control target, the high-frequency voltage output from the high-frequency power supply device is feedback-controlled so that the detected power value of the high-frequency power matches the target power value (target power value).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Non-Patent Documents

[0004]

Non-Patent Document 1

Non-Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, the plasma processing apparatus is a load as seen from the high-frequency power supply apparatus, and its load impedance changes moment by moment during the processing in the plasma processing apparatus. Further, it can be various loads such as a matching load (a load with a small reflection coefficient in the high-frequency power supply apparatus) or a total reflection load. In such a wide range of loads, even if feedback control is executed in the high-frequency power supply apparatus, for example, overshoot and ringing may occur at the start of power supply. For this reason, for example, the high-frequency power supply apparatuses described in Patent Document 1 and Patent Document 2 perform an asymptotic process of the voltage of the high-frequency signal instead of power feedback control at the start of power supply. That is, for example, the high-frequency power supply systems described in Patent Document 1 and Patent Document 2 increase the voltage level of the high-frequency signal over time and decrease the increase width as the voltage level of the high-frequency signal approaches the command value at the start of power supply.

[0006] However, such a conventional high-frequency power supply apparatus can suppress the occurrence of overshoot and ringing at the start of power supply, but since the feedback control is stopped at the start of power supply, the rise time until the voltage level of the high-frequency signal reaches the command value has become long.

[0007] The present invention has been made in view of the above, and provides, for example, a control device capable of shortening the rise time of the output voltage while suppressing the occurrence of overshoot and ringing at the rise of the output voltage output from a power supply device such as a high-frequency power supply device. Means for Solving the Problems

[0008] In order to solve the above-described problems and achieve the object, a control device according to the present invention is a control device that controls an output voltage output from a power supply device by digital processing by applying a control signal corresponding to an output control value to the power supply device, and includes an adaptive control unit that generates a first control value for reducing a deviation between a reference output voltage value obtained by applying a command value representing the output voltage to a predetermined reference model and an output voltage value obtained by detecting the output voltage; a disturbance removal unit that generates a second control value by reducing a control amount corresponding to an estimated disturbance component obtained by estimating a disturbance included in the output voltage from the first control value; and a stabilization unit that outputs, as the output control value, a value obtained by applying the second control value to a zero-point stabilization controller that is a transfer function of a discrete-time system. The zero-point stabilization controller is a transfer function that minimizes an absolute value of a discretized zero point in a discrete-time transfer function obtained by multiplying a discrete-time transfer function of the power supply device by the zero-point stabilization controller.

Advantages of the Invention

[0009] According to the present invention, it is possible to shorten a rising time of an output voltage while suppressing occurrence of overshoot and ringing during rising of the output voltage output from a power supply device.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Embodiments for Carrying Out the Invention

[0011] Figure 1 is a diagram showing the configuration of the voltage output circuit 10 according to the embodiment together with the load 100.

[0012] The voltage output circuit 10 acquires a command value representing the output voltage from the outside. The voltage output circuit 10 stabilizes the power of the output voltage according to the command value regardless of the impedance variation of the load 100 and supplies it to the load 100.

[0013] Note that the voltage output circuit 10 is, for example, a part that becomes a voltage source inside the high-frequency power supply device. The high-frequency power supply device generates a high-frequency voltage (traveling wave voltage) that is output toward the load using the voltage output from the voltage output circuit 10. In this case, the load 100 in FIG. 1 is the configuration after the voltage output circuit 10 of the high-frequency power supply device. For example, it includes a power conversion unit including a transformer inside the high-frequency power supply device and a plasma processing device.

[0014] Of course, the voltage output circuit 10 can also be used for applications other than the high-frequency power supply system that supplies power to the plasma processing device. Also, the frequency of the output voltage of the voltage output circuit 10 is not limited to the high-frequency region (for example, several hundred kHz or more). For example, the frequency of the output voltage of the voltage output circuit 10 may be a frequency in a relatively low-frequency region of about 1 kHz. Also, the frequency of the output voltage of the voltage output circuit 10 may be a frequency of about 100 Hz.

[0015] Furthermore, the voltage output circuit 10 may obtain a command value for changing the output voltage over time. In this case, the voltage output circuit 10 can supply the load 100 with an output voltage that changes according to the command value. In the present embodiment, the voltage output circuit 10 obtains a command value for changing the output voltage in a pulse shape, and supplies the load 100 with an output voltage that changes in a pulse shape.

[0016] The voltage output circuit 10 includes a control device 20, a DA conversion device 22, a power supply device 24, a voltage detection device 26, and an AD conversion device 28.

[0017] The control device 20 is a processing circuit that executes digital processing at predetermined sampling intervals. The control device 20 may be, for example, a CPU (Central Processing Unit) that executes a program, a DSP (Digital Signal Processor), or an FPGA (field-programmable gate array).

[0018] The control device 20 controls the output voltage output from the power supply device 24 by digital processing by giving a control signal corresponding to the output control value to the power supply device 24. That is, the control device 20 is a controller that controls the output physical quantity output from the control target device by digital processing at each sampling interval, with the power supply device 24 as the control target device.

[0019] More specifically, the control device 20 obtains, at each sampling interval, a command value representing the target voltage level of the output voltage from an external device. Further, the control device 20 obtains, at each sampling interval, an output voltage value obtained by detecting the output voltage output from the power supply device 24. The control device 20 executes digital processing for generating an output control value for instructing the output voltage to be generated from the power supply device 24 based on the command value and the output voltage value at each sampling interval. Then, the control device 20 gives the generated output control value to the DA conversion device 22 at each sampling interval.

[0020] The DA conversion device 22 digitally / analog-converts the output control value acquired from the control device 20, and generates a control signal of an analog voltage corresponding to the output control value. The DA conversion device 22 supplies the control signal to the power supply device 24. The power supply device 24 acquires the control signal of the analog voltage from the DA conversion device 22, and generates an output voltage at a voltage level corresponding to the control signal in a stabilized manner regardless of the variation of the load 100. The voltage detection device 26 detects the output voltage supplied to the load 100, and outputs a detection signal corresponding to the level of the detected output voltage. The AD conversion device 28 analog / digitally-converts the detection signal detected by the voltage detection device 26, and generates an output voltage value representing the level of the output voltage output from the power supply device 24. Then, the AD conversion device 28 supplies the generated output voltage value to the control device 20.

[0021] FIG. 2 is a diagram showing the functional configuration of the control device 20.

[0022] The control device 20 includes an adaptive control unit 32, a disturbance removal unit 34, and a stabilization unit 36. Each of the adaptive control unit 32, the disturbance removal unit 34, and the stabilization unit 36 executes digital processing at each sampling interval.

[0023] The adaptive control unit 32 acquires a command value, a second control value, and an output voltage value. The second control value is a value output from the disturbance removal unit 34. The adaptive control unit 32 executes model-based adaptive control based on the command value, the second control value, and the output voltage value, and generates a first control value. That is, the adaptive control unit 32 generates a first control value that reduces the deviation between the reference output voltage value obtained by applying the command value to a predetermined reference model and the output voltage value.

[0024] For example, the adaptive control unit 32 applies the command value to the reference model to generate a reference output voltage value. Then, the adaptive control unit 32 executes model following control based on the reference output voltage value, the output voltage value, and the second control value, and generates a first control value that causes the output voltage value to follow the reference output voltage value.

[0025] The reference model is a model that serves as a standard for the operation of the power supply device 24, which is the device to be controlled. For example, the reference model is a transfer function of a discrete-time system. In the present embodiment, the reference model is a first-order lag transfer function of a discrete-time system. For example, the reference model is the transfer function of an RC circuit and is represented by ωT / (z - 1). ω is the angular frequency. T is the period. z is a variable of the transfer function of the discrete-time system. By using such a reference model that is a first-order lag transfer function of a discrete-time system, the adaptive control unit 32 can facilitate the design and processing.

[0026] Such an adaptive control unit 32 can perform feedback control on the power supply device 24 so that the output voltage output from the power supply device 24 follows the reference output voltage value, which is the output when a command value is given to the reference model.

[0027] The disturbance removal unit 34 acquires a first control value from the adaptive control unit 32. Also, the disturbance removal unit 34 acquires an output voltage value obtained by detecting the output voltage output from the power supply device 24. Then, based on the first control value and the output voltage value, the disturbance removal unit 34 generates a second control value obtained by subtracting a control amount corresponding to the estimated disturbance component, which is the disturbance estimated from the first control value, from the first control value.

[0028] More specifically, the disturbance removal unit 34 generates an ideal output voltage value by applying the second control value to an ideal controlled object model that models the power supply device 24. The ideal controlled object model is a model that outputs the output voltage output from the power supply device 24 when the second control value is applied in a state where the load 100 has an ideal impedance and is stabilized and no disturbance is included. Subsequently, the disturbance removal unit 34 subtracts the output voltage value from the ideal output voltage value to generate an estimated disturbance component. Subsequently, the disturbance removal unit 34 applies the estimated disturbance component to a disturbance observer, which is a model based on the inverse system of the power supply device 24, to generate a control amount corresponding to the estimated disturbance component. Then, the disturbance removal unit 34 generates a second control value by subtracting the control amount corresponding to the estimated disturbance component from the first control value.

[0029] Such a disturbance removal unit 34 can correct the output control value so as to cancel out the disturbance component included in the output voltage, and remove the disturbance from the output voltage.

[0030] The stabilization unit 36 acquires the second control value generated by the disturbance removal unit 34. The stabilization unit 36 outputs, as the output control value, a value obtained by giving the second control value to the zero-point stabilization controller.

[0031] The zero-point stabilization controller is a transfer function of a discrete-time system. More specifically, the zero-point stabilization controller is a transfer function that minimizes the absolute value of the discretized zero in the transfer function of the discrete-time system obtained by multiplying the transfer function of the discrete-time system of the power supply device 24 by the zero-point stabilization controller.

[0032] When the power supply device 24 represented by a transfer function of a continuous-time system with a relative degree of two or more is represented by a transfer function of a discrete-time system, there may occur discretized zeros at unstable positions that do not correspond to the zeros of the original continuous-time system. When discretized zeros at unstable positions occur, the control device 20 cannot stabilize and control the output voltage output from the power supply device 24.

[0033] However, since the zero-point stabilization controller is provided in the previous stage of the power supply device 24, it is possible to minimize the discretized zeros in the transfer function of the discrete-time system obtained by multiplying the transfer function of the discrete-time system of the power supply device 24 by the zero-point stabilization controller. As a result, the zero-point stabilization controller can rearrange the poles in the transfer function of the discrete-time system representing the power supply device 24 so as to virtually approach 1 or -1. Such a stabilization unit 36 can output a stable output voltage from the power supply device 24 without oscillation or the like occurring when the power supply device 24 is feedback-controlled by digital processing.

[0034] Then, the control device 20 supplies the output control value generated by the stabilization unit 36 to the DA conversion device 22 for each sampling interval, and supplies a control signal corresponding to the output control value from the DA conversion device 22 to the power supply device 24. Thereby, the control device 20 can control the output voltage output from the power supply device 24 by digital processing.

[0035] (Zero-point stabilization controller) Next, the zero-point stabilization controller will be further described.

[0036] Non-Patent Document 1 and Non-Patent Document 2 describe a general controller that moves the discretized zero point in the controlled device in model following control. When the general controller shown in Non-Patent Document 1 and Non-Patent Document 2 is Taylor-expanded and the order of up to the second order is extracted, the controller of the second order or lower is represented by Equation (1). [Number]

[0037] Equation (1) is a transfer function represented by a continuous-time system. s is a variable of the transfer function of the continuous-time system. t s is the sampling period. In Equation (1), p1 and p2 are poles.

[0038] The transfer function of a general single-input single-output continuous-time system is represented by Equation (2). [Number]

[0039] In Equation (2), q1, q2, …, q m are zeros. Note that m is a positive integer. In Equation (2), p1, p2, …, p n are poles. Note that n is a positive integer. K is a constant.

[0040] The transfer function of the discrete-time system obtained by discretizing Equation (2) using a sampler with a sampling period of τ and a zero-order hold with the same period is represented by Equation (3).

Equation

[0041] z is a variable of the transfer function of the discrete-time system. τ is the sampling period. e is the Napier's number. C τ is a constant. In Equation (3), p1, p2, …, p n are poles. In Equation (3), γ1(τ), γ2(τ), …, γ (n-1) (τ) is a function representing the discretized zeros with τ as a variable.

[0042] Here, assume that the transfer function representing the power supply device 24, which is the control target device according to the embodiment, is a second-order lag transfer function (G1(s)) represented by Equation (4).

Equation

[0043] In Equation (4), p1 and p2 are poles in the second-order lag transfer function representing the power supply device 24.

[0044] Also, when the controller obtained by extracting the order of second degree or less shown in Equation (1) is used as the zero-point stabilizing controller, the transfer function (G2(s)) of the continuous-time system synthesized by the power supply device 24 and the zero-point stabilizing controller is represented as in Equation (5).

Equation

[0045] Also, rewrite C(s) as in Equation (6).

Number

[0046] In this case, P3 in Equation (6) is a new pole added to the transfer function of Equation (5). q in Equation (6) is a new zero added to the transfer function of Equation (5).

[0047] Also, the discretization zeros of the transfer function of the discrete-time system obtained by discretizing the transfer function of the continuous-time system in Equation (5) are represented as γ1 and γ2. The transfer function of the discrete-time system obtained by discretizing the transfer function of the continuous-time system in Equation (5) is stabilized by minimizing |γ1| and |γ2|, which are the absolute values of γ1 and γ2.

[0048] Therefore, it is considered to minimize |γ1| and |γ2| by adjusting q and p3.

[0049] Non-Patent Document 1 and Non-Patent Document 2 show discretization zeros approaching -1. When the discretization zero approaching -1 is γ2(τ), the discretization zero approaching -1 is Taylor-expanded as in Equation (7).

Number

[0050] Also, Non-Patent Document 1 and Non-Patent Document 2 show discretization zeros approaching 1. When the discretization zero approaching 1 is γ1(τ), the discretization zero approaching 1 is Taylor-expanded as in Equation (8).

Number

[0051] Based on Equation (7) and Equation (8), when |γ1| and |γ2| are minimized, q in the equation (s) of Equation (6) becomes the value represented by Equation (9).

Number

[0052] Also, based on equations (7) and (8), when minimizing |γ1| and |γ2|, p3 in equation (6) becomes the value represented by equation (10).

Number

[0053] Then, when substituting q in equation (9) and p3 in equation (10) into C(s) and discretizing it using a sampler with a sampling period of τ and a zero-order hold with the same period, the transfer function of the discrete-time system obtained is represented by equation (11).

Number

[0054] From the above, when considering the transfer function of the continuous-time system representing the power supply device 24 as equation (5), the zero-point stabilization controller becomes the transfer function of the discrete-time system represented by C(z) in equation (11).

[0055] By using such a zero-point stabilization controller, the stabilization unit 36 can move the discretized zero point in the direction closer to -1 or 1 compared to the transfer function of the discrete-time system representing the power supply device 24 and perform feedback control by digital processing. As a result, the control device 20 can stabilize and control the power supply device 24. Furthermore, by considering the power supply device 24 as a continuous-time second-order lag transfer function, the stabilization unit 36 can move the discretized zero point with a simple transfer function. As a result, the stabilization unit 36 can stably control the output voltage output from the power supply device 24 by digital processing.

[0056] (Model Reference Adaptive Control) Next, the model reference adaptive control by the adaptive control unit 32 will be further explained.

[0057] Note that the control target of the adaptive control of the model canonical form in this embodiment is a transfer function obtained by multiplying the zero-point stabilization controller and the transfer function of the power supply device 24. Therefore, in the description of the adaptive control of the model canonical form in this embodiment, the transfer function of the discrete-time system of the control target is expressed as H(z) = C(z) × G(z). C(z) represents the transfer function of the zero-point stabilization controller in the discrete-time system. G(z) represents the transfer function of the power supply device 24 in the discrete-time system.

[0058] FIG. 3 is a diagram showing the configuration of the adaptive control unit 32. The adaptive control unit 32 includes a reference model unit 42 and a model following control unit 44.

[0059] The reference model unit 42 acquires a command value. The reference model unit 42 outputs a reference output voltage value obtained by applying the command value to the reference model. In this embodiment, the transfer function of the reference model is a first-order lag transfer function of the discrete-time system.

[0060] The model following control unit 44 acquires the reference output voltage value, the output voltage value, and the second control value. The model following control unit 44 generates a first control value that causes the output voltage value to follow the reference output voltage value by executing model following control based on the reference output voltage value, the output voltage value, and the second control value.

[0061] The model following control unit 44 includes a first MRACS coefficient unit 50, a second MRACS coefficient unit 52, a third MRACS coefficient unit 54, a first addition unit 56, a second addition unit 58, and a fourth MRACS coefficient unit 60.

[0062] The first MRACS coefficient unit 50 outputs a value obtained by applying the reference output voltage value to the first MRACS coefficient. The first MRACS coefficient is a transfer function of the discrete-time system and is represented as D(z) in this embodiment.

[0063] The second MRACS coefficient unit 52 outputs a value obtained by applying the output voltage value to the second MRACS coefficient. The second MRACS coefficient is a transfer function of a discrete-time system, and is represented as R(z) in the present embodiment.

[0064] The third MRACS coefficient unit 54 outputs a value obtained by applying the second control value to the third MRACS coefficient. The third MRACS coefficient is a transfer function of a discrete-time system, and is represented as B(z) in the present embodiment.

[0065] The first adder 56 outputs a value obtained by adding the output value of the second MRACS coefficient unit 52 and the output value of the third MRACS coefficient unit 54.

[0066] The second adder 58 outputs a value obtained by subtracting the output value of the first adder 56 from the output value of the first MRACS coefficient unit 50.

[0067] The fourth MRACS coefficient unit 60 outputs a value obtained by applying the output value of the second adder 58 to the fourth MRACS coefficient. The fourth MRACS coefficient is a transfer function of a discrete-time system, and is represented as 1 / b0 in the present embodiment.

[0068] Then, the model following control unit 44 having such a configuration supplies the output value of the fourth MRACS coefficient unit 60 to the disturbance removing unit 34 as the first control value.

[0069] Here, let H(z) = B(z) / A(z).

[0070] B(z) is represented by Equation (12).

Equation

[0071] A(z) is represented by Equation (13).

Equation

[0072] The output voltage of the power supply device 24 is expressed as y(k)=H(z)u(k), and the reference output voltage value output from the reference model is y M (k)=H M (z)u M (k). In this case, by performing model following control so that y(k) follows y M (k), the error equation shown in Equation (14) holds.

Equation

[0073] Here, D(z) is expressed as shown in Equation (15).

Equation

[0074] From the configuration of the model following control unit 44 shown in FIG. 3, u(k), which is the input of the power supply device 24, is expressed as shown in Equation (16).

Equation

[0075] Also, from the configuration of the model following control unit 44 shown in FIG. 3, y(k), which is the output of the power supply device 24, is expressed as shown in Equation (17).

Equation

[0076] B(z) is expressed as shown in Equation (18).

Equation

[0077] Also, R(z) is expressed as shown in Equation (19).

Equation

[0078] When the error equation of Equation (14) substitutes y(k) of Equation (17), it is converted as shown in Equation (20).

[0079]

Number

[0080] When the right side of Equation (20) substitutes Equation (16) into u(k), it becomes 0. Therefore, the model following control unit 44 with the configuration shown in FIG. 3 can control the output voltage from the power supply device 24 to follow the reference output voltage value output from the reference model.

[0081] Note that the second MRACS coefficient R(z), the third MRACS coefficient B(z), and the fourth MRACS coefficient 1 / b0 are determined by setting D(z), which is the first MRACS coefficient. In this embodiment, D(z) is (1 - 0.1z -1 ) 3 is set to.

[0082] (Disturbance removal unit 34) Next, the disturbance removal unit 34 will be further described.

[0083] FIG. 4 is a diagram showing the configuration of the disturbance removal unit 34. The disturbance removal unit 34 includes a third adder 72, an ideal output voltage value generation unit 74, a fourth adder 76, and a disturbance observer unit 78.

[0084] The third adder 72 acquires the first control value. The third adder 72 also acquires a control amount corresponding to the estimated disturbance component obtained by estimating the disturbance included in the output voltage. Then, the third adder 72 generates a second control value obtained by subtracting the control amount corresponding to the estimated disturbance component from the first control value.

[0085] The ideal output voltage value generation unit 74 acquires the second control value from the third adder 72. The ideal output voltage value generation unit 74 generates an ideal output voltage value by applying the second control value to the ideal control object model.

[0086] The fourth adder 76 acquires the ideal output voltage value from the ideal output voltage value generation unit 74. Also, the fourth adder 76 acquires the output voltage value. Then, the fourth adder 76 generates an estimated disturbance component obtained by subtracting the output voltage value from the ideal output voltage value.

[0087] The disturbance observer unit 78 acquires the estimated disturbance component from the fourth adder 76. The disturbance observer unit 78 generates a control amount corresponding to the estimated disturbance component by applying the estimated disturbance component to the disturbance observer.

[0088] The disturbance observer is a transfer function of a discrete-time system and is a model based on the inverse system of the power supply device 24. That is, the disturbance observer is a model that generates a control amount input for the power supply device 24 to generate a voltage value by applying a voltage value.

[0089] For example, the disturbance observer is a discrete-time transfer function obtained by multiplying a model representing the inverse system of the power supply device 24 by a second-order low-pass filter. When the model representing the inverse system of the power supply device 24 is represented by a discrete-time transfer function, it includes a differential term. Therefore, since the disturbance observer is a transfer function obtained by multiplying a transfer function obtained by multiplying a model representing the inverse system of the power supply device 24 by a second-order low-pass filter, the disturbance observer is realized by a transfer function that does not include discrete-time differential operations. Note that the discrete-time transfer function of the second-order low-pass filter is 5ω 2 T 2 / (z - 1) 2 represented by.

[0090] Then, the disturbance observer unit 78 feeds back the control amount calculated in this way to the third adder 72. The third adder 72 uses the control amount generated by the disturbance observer unit 78 for calculating the second control value at the next sampling timing.

[0091] Such a disturbance removal unit 34 generates a second control value that cancels out the disturbance component included in the output voltage. Thereby, the disturbance removal unit 34 can remove the disturbance included in the output voltage.

[0092] (Simulation Results) FIG. 5 is a diagram showing the reference output voltage value (Vref) and the output voltage value (Vout) with respect to the elapsed time (time) when the first simulation is executed. FIG. 6 is an enlarged view of the period from 0.004 seconds to 0.006 seconds in FIG. 5.

[0093] In the first simulation, the control device 20 executes the function of the adaptive control unit 32 and stops the functions of the disturbance removal unit 34 and the stabilization unit 36. Further, in the first simulation, the load 100 changes in impedance at the time of 0.005 seconds.

[0094] In the first simulation, as shown in FIG. 5, the output voltage value (Vout) increases in the vicinity of 0.005 seconds. Also, in the first simulation, as shown in the region surrounded by A in FIG. 6, the output voltage value (Vout) has overshoot and ringing at the time of rising.

[0095] FIG. 7 is a diagram showing the reference output voltage value (Vref) and the output voltage value (Vout) with respect to the elapsed time (time) when the second simulation is executed. FIG. 8 is an enlarged view of the period from 0.004 seconds to 0.006 seconds in FIG. 7.

[0096] In the second simulation, the control device 20 executes the functions of the adaptive control unit 32 and the disturbance removal unit 34 and stops the function of the stabilization unit 36. Further, in the second simulation, the load 100 changes in impedance at the time of 0.005 seconds.

[0097] In the second simulation, as shown in FIG. 7, the output voltage value (Vout) increases in the vicinity of 0.005 seconds. Further, in the second simulation, as shown in the region surrounded by B in FIG. 8, an overshoot occurs in the output voltage value (Vout) at the rising edge.

[0098] FIG. 9 is a diagram showing the reference output voltage value (Vref) and the output voltage value (Vout) with respect to the elapsed time (time) when the third simulation is executed. FIG. 10 is an enlarged view of the period from 0.004 seconds to 0.006 seconds in FIG. 9.

[0099] Note that in the third simulation, the control device 20 executes all the functions of the adaptive control unit 32, the disturbance removal unit 34, and the stabilization unit 36. Further, in the third simulation, the impedance of the load 100 changes at the time of 0.005 seconds.

[0100] In the third simulation, as shown in FIG. 9, the output voltage value (Vout) accurately follows the variation of the reference output voltage value (Vref) regardless of the variation in the impedance of the load 100. Further, in the third simulation, as shown in the region surrounded by C in FIG. 10, neither overshoot nor ringing occurs in the output voltage value (Vout) at the rising edge.

[0101] As described above, the control device 20 according to the present embodiment can start up the output voltage so as to accurately follow the reference output voltage value, and suppress the occurrence of overshoot and ringing at the rising edge of the output voltage output from the power supply device 24. Further, the control device 20 according to the present embodiment can cancel out the disturbance component included in the output voltage and eliminate the destabilization of the transfer function of the power supply device 24 generated by digital processing. In addition, the control device 20 according to the present embodiment can shorten the rising time of the output voltage by continuously executing feedback control even at the rising edge of the output voltage.

[0102] When the voltage output circuit 10 using the control device 20 according to the present embodiment is applied to a high-frequency power supply device, the high-frequency power supply device generates a high-frequency voltage (progressive wave voltage) that is output toward the load using the voltage output from the voltage output circuit 10. Even in this case, the same effects as described above can be obtained.

[0103] As described above, the embodiments of the present invention have been described. However, these embodiments are presented as examples and are not intended to limit the scope of the invention. The embodiments can be modified in various ways.

Explanation of Reference Numerals

[0104] 10 Voltage output circuit, 20 Control device, 22 DA conversion device, 24 Power supply device, 26 Voltage detection device, 28 AD conversion device, 32 Adaptive control unit, 34 Disturbance removal unit, 36 Stabilization unit, 42 Norm model unit, 44 Model following control unit, 50 First MRACS coefficient unit, 52 Second MRACS coefficient unit, 54 Third MRACS coefficient unit, 56 First addition unit, 58 Second addition unit, 60 Fourth MRACS coefficient unit, 72 Third addition unit, 74 Ideal output voltage value generation unit, 76 Fourth addition unit, 78 Disturbance observer unit

Claims

1. A control device that controls the output voltage output from a power supply device by digital processing by applying a control signal according to an output control value, an adaptive control unit that generates a first control value for reducing the deviation between a reference output voltage value obtained by applying a command value representing the output voltage to a predetermined reference model and an output voltage value obtained by detecting the output voltage, a disturbance removal unit that generates a second control value obtained by subtracting a control amount corresponding to an estimated disturbance component obtained by estimating a disturbance included in the output voltage from the first control value, a stabilization unit that outputs, as the output control value, a value obtained by applying the second control value to a zero-point stabilization controller that is a transfer function of a discrete-time system, comprising, the zero-point stabilization controller is a transfer function that minimizes the absolute value of a discretized zero point in a discrete-time transfer function obtained by multiplying the discrete-time transfer function of the power supply device by the zero-point stabilization controller control device.

2. the zero-point stabilization controller is a discrete-time transfer function represented by C(z) of Equation (11), 【Number 1】 z is a variable of the discrete-time transfer function, q is - / τ, p ３ = -(4 / τ) - (p １ + p ２ ) and p １ and p ２ are poles when the power supply device is represented by a second-order lag transfer function in the continuous-time domain, τ is the sampling period, e is the Napier number The control device according to claim 1.

3. The reference model is a discrete-time first-order lag transfer function The control device according to claim 1.

4. The adaptive control unit includes a reference model unit that acquires the command value and outputs the reference output voltage value, a model following control unit that acquires the reference output voltage value, the output voltage value, and the second control value, and generates the first control value that causes the output voltage value to follow the reference output voltage value by executing model following control The control device according to claim 3, including.

5. The disturbance removal unit generates an ideal output voltage value by applying the second control value to an ideal control object model that models the power supply device, generates the estimated disturbance component by subtracting the output voltage value from the ideal output voltage value, generates the control amount corresponding to the estimated disturbance component by applying the estimated disturbance component to a disturbance observer, the disturbance observer is a discrete-time transfer function obtained by multiplying a model representing the inverse system of the power supply device by a second-order low-pass filter The control device according to claim 1.

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