JP2733446B2 - Power control device control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control method of a power supply device equipped with a time-division multiplex digital closed loop automatic control circuit using a computer or the like.

[0002]

2. Description of the Related Art Performing time-division multiplex digital closed-loop control facilitates the production of a multifunctional, high-precision, high-performance power supply controller. In this case, even when a large change occurs in the gain or phase of the control loop due to a change in the load impedance of the power supply output, it is necessary for the power supply control device to maintain stability without being tuned.

A power supply control device controlled by a conventional time-division multiplex digital closed-loop control circuit of this type has a large control response compared to a power supply control device controlled by an analog closed-loop control circuit in order to prevent control upset. Must be selected late. The reason is that when the load impedance of the power supply output fluctuates over a wide range, the gain and phase of the open-loop transfer function greatly change, and the control response moves to a high frequency range, thereby eliminating the phase margin.

[0004] In other words, in a sample value control system for automatically controlling the power supply output in a time-division multiplex digital closed loop,
A control response for maintaining control stability must always be selected in a low frequency range equal to or less than half the sampling frequency. Further, when a delay element of the load accompanied by a gain fluctuation of the power supply output or an integral operation as a control operation is added, a phase delay is further added, so that the control response for maintaining the control stability operates in a lower frequency range. You have to choose. As a result, time-division multiplex digital closed-loop control with a slow control response results.

[0005] An example of a conventional DC power supply device equipped with such a time-division multiplex digital closed loop automatic control circuit will be described with reference to FIG.

In FIG. 9, reference numeral 1A denotes a time-division multiplex digital closed-loop automatic control circuit. In this time-division multiplex digital closed-loop automatic control circuit 1A, reference numeral 3 denotes a reference input signal converted into a digital signal, and reference numeral 4 denotes a digital signal. 5 is an overcurrent limit reference input signal converted to a digital signal, 6 is an overpower limit reference input signal converted to a digital signal, 7 is voltage V, current I or power in a normal mode. An operation selection function unit for P control, 8 is an operation selection function unit for voltage V, current I or power P control in an abnormal mode of overload, 9 is an abnormality determination function unit, 10A and 10B are switches for normal or abnormal mode, 11A and 11B are switchers for control signals of voltage V, current I or power P, 12 is a time-division digital control operation circuit for performing an integration operation, 13 is D / A converter for converting a digital signal into an analog signal, 14 denotes an A / D converter for converting an analog signal for detecting the output voltage into a digital signal, 15
Is an A / D converter that converts an analog signal for detecting an output current into a digital signal, 16 is a digital multiplier, 17 is a transistor drive circuit that operates on an analog signal, 20A,
20B, 21A and 21B are transistor switching elements for adjusting the output voltage V0, 22 is an input power supply, 23
Is a transformer, 24 is a rectifier, 25 is an inductance, 26
Is a capacitance, 27 is an output current detector, 28 is an output voltage detector, and 29 is a load impedance.

First, the normal mode of the automatic control circuit 1A thus configured will be described.

The switches 10A and 10B are switched to the normal mode side (both the switches 10A and 10B shown in FIG. 9 select the normal mode side). Further, the operation selection function unit 7 selects which mode of the control is the voltage V, the current I, or the power P control. The selection signal of the operation selection function unit 7 is set so that the switch 11B is switched via the switch 10A so that the feedback signal (voltage V, current I or power P) corresponding to the selection of the operation function selection unit 7 is selected. Switch.

A feedback signal (voltage V, current I or power P), which is an output signal of the switch 11B,
The signal is transmitted to the time division digital control operation circuit 12. Also,
The reference input signal 3 is transmitted to the time division digital control operation circuit 12 via the switch 10B. The output signal of the time-sharing digital control operation circuit 12 is converted to an analog signal by the D / A converter 13 and then transmitted to the transistor drive circuit 17. The output signal of the transistor drive circuit 17 is
It drives the transistor switch elements 20A, 20B, 21A and 21B. The DC power supplied from the input power supply 22 is supplied to the transistor switch elements 20A, 20B, 21
A and 21B are converted into AC by an inverter operation having a function of changing the output amount, and the transformer 23 and the rectifier 2
4 and is converted to direct current.

An output current detector 27 and an output voltage detector 28
Is a detector for detecting the state of the load, and a feedback signal which is an output signal of each of the detectors 27 and 28 is
The signal is sent to the switch 11B via the A / D converters 14, 15 and the multiplier 16.

When the power supply control device shown in the figure is operated in the normal mode under the automatic control of the closed loop, and the load 29 is overloaded due to a load abnormality of the power supply output, the output current detector 27 and the output voltage detector 28 Each output signal is transmitted to the operation selection function unit 8 via the A / D converters 14 and 15 and the multiplier 16, the operation selection function unit 8 selects an abnormal mode, and the abnormality determination function unit 9 determines abnormality. You.

Then, the switch 10A is operated by the abnormality determining function unit 9.
And the switch 10B are switched to the abnormal mode side. The operation selection function unit 8 selects one of the overvoltage, overcurrent, and overpower abnormality modes.
Switches the switch 11B via the switch 10A so as to select a feedback signal (voltage, current or power) corresponding to the selection of the operation selection function unit 8.

The feedback signal, which is the output signal of the switch 11B, is supplied to the time-division digital control operation circuit 12
Is transmitted to At the same time, the selection signal of the operation selection function unit 8 is switched to select the overvoltage limit reference input signal 4, the overcurrent limit reference input signal 5, or the overpower limit reference input signal 6 corresponding to the selection of the operation selection function unit 8. The container 11A is switched. Then, the overvoltage limit reference input signal 4, the overcurrent limit reference input signal 5, or the overpower limit reference input signal 6 is
The signal is transmitted to the time-division digital control operation circuit 12 via the switch 11A and the switch 10B. The operation after the time division digital control operation circuit 12 is the same as the operation in the normal mode.

In this manner, the power supply control device of FIG. 9 is automatically controlled in a closed loop, and is switched to the operation in the abnormal mode.

Next, the stability judgment of the closed loop automatic control system in the normal mode or the abnormal mode will be described.
FIGS. 10 to 12 are block diagrams showing an example of a control system of the time-division multiplex digital closed loop automatic control circuit 1A shown in FIG. 9, and the examples of FIGS. 10 to 12 show a constant current control system. 10 to 12 will be described with reference to FIG.

In FIGS. 10 to 12, Iref is a current reference input signal corresponding to the reference input signal 3 or the overcurrent limit reference input signal 5, Ifb is a current feedback signal corresponding to the output signal of the switch 11B, and Gi is a time signal. The transfer function Gs of the divided digital control operation circuit 12 is the sampling period T
The transfer function of the dead time element of s, Gc is the gain (excluding the delay element) of the ratio of the change amount of the input signal Vc of the transistor drive circuit 17 to the change amount of the output voltage Vo applied to the load 29, Gm is the transfer function of the second order lag element due to the inductance 25, the capacitance 26 and the load 29,
Gr is the reciprocal of the load impedance Ro, that is, the gain of the conductance. Gibb is the output current Io flowing through the load 29.
Of the current feedback signal Ifb which is the output signal of the current detector 27.

Gi, Gs, G shown in FIG. 10 and FIG.
c, Gm, Gr, Gibb are expressed by the following equations (1) to
It is defined by (4), (7), and (8).

[0018]

(Equation 1)

[0019]

(Equation 2)

[0020]

(Equation 3)

[0021]

(Equation 4)

Here, Vc (100%) is the rated voltage value of Vc Vo (100%) is the rated voltage value of Vo Io (100%) is the rated current value of Io Ro (100%) is the rated resistance value of Ro Ti is an integration constant S is a complex number, and ωn and ζωn in the equation (4) are expressed by the following equations (5),
It is defined by (6).

[0023]

(Equation 5)

[0024]

(Equation 6)

[0025]

(Equation 7)

[0026]

(Equation 8)

Here, Ifb (100%) is the rated current value of Ifb. In FIG. 11, Gidc and Git are represented by:
It is defined by the following equations (9) and (10).

[0028]

(Equation 9)

[0029]

(Equation 10)

With this definition, equation (10) represents a loop transfer function. In addition, when the above equations (3) and (7) are substituted for the GcGr part in the equation (9), the following equation (11) is obtained.

[0031]

[Equation 11]

Further, in equation (9), when the above equation (8) is substituted for the Gibb portion, the following equation (12) is obtained.

[0033]

(Equation 12)

Generally, Ifb (100%) is equal to Ifb (100%).
%) = Vc (100%). Therefore, equation (12) becomes the following equation (13), and the block diagram of FIG. 11 can be converted to the block diagram shown in FIG.

[0035]

(Equation 13)

The stability determination of the control is examined by using the block diagram of FIG. FIG. 13 is a Bode diagram of the loop transfer function Git in the block diagram of FIG. FIG.
In the Bode diagram of FIG. 3, the stability of the control is checked for the constant current control loop.

The transfer function Gm is given by L0 = 0.76 mH, C
0 = 3.3 μF. Rated load resistance Ro = Ro (10
0%) = 40Ω, Vo = Vo (100%) = 1000
When operating in the normal mode of V, Io = Io (100%) = 25 A, the gain | Git1 | d of the Bode diagram of FIG.
First, the stability determination when the diagram of B and the phase ∠Git1 is selected is examined. From the same diagram, when | Git1 | dB crosses 0 dB, the phase ∠Git1 is −130 deg, the phase margin is +50 deg, the control system is stable, and the control response at this time is 3.2 Krad / s.

From this state, the load resistance becomes Ro in the normal mode.
= 40Ω to Ro = 0.4Ω in the abnormal mode, the gain shown in the above equation (13) changes from Gidc = 1 to Gid
c = 10 is increased. Due to this effect, the gain of the loop transfer function Git of the above equation (10) increases by 10 times, and | G shown in FIG.
it1 | dB The angular frequency crossing 0 dB in the diagram is 26 Kra.
d / s, the gain margin becomes -15 dB, and the control system becomes unstable.

In order to maintain stability even in the abnormal mode where the load is Ro = 4Ω, the control response is selected to be slower.
3 using the | Git2 | dB and ∠Git2 diagrams. In this case, the phase ΔGit2 when | Git2 | dB crosses 0 dB
Is -130 deg, the phase margin is +50 deg, the gain margin is +6 dB, the control system is stable, and the control response at this time is 3.2 Krad / s.

Thus, | Git2 | dB and ΔG in FIG.
Using the diagram of it2, stability can be maintained against a load change from Ro = 40Ω in the normal mode to Ro = 4Ω in the abnormal mode. However, the control response is 3.2 Krad
/ S to 320 rad / s. That is, when the graph of | Git2 | dB and ∠Git2 in FIG. 13 is selected, the stability can be maintained in the load fluctuation range, but when the load is Ro = 40Ω, the control response becomes 320 rad / s.
Becomes This is the control response when a diagram of | Git1 | dB and phase ΔGit1 is selected (Ro = 40Ω).
320 rad which is 1 decard lower than 2 Krad / s
/ S control response. Further, when the load varies from Ro = 40Ω in the normal mode to Ro = 0.4Ω in the abnormal mode, as shown in the graph of | Git3 | dB, Ro
The control response under a load condition of = 40Ω needs to be 32 rad / s. This is 3.2 Grad / s, which is the control response in the diagram of | Git1 | dB and phase ∠Git1,
The control response is lower by two decades.

Therefore, in order to obtain a stable maintenance of the control system with respect to the load fluctuation from Ro = 40Ω in the normal mode to Ro = 0.4Ω in the abnormal mode, the control response under the load condition of Ro = 40Ω must be 32 rad. / S.
As a result, time-division multiplex digital closed-loop control with a slow control response results.

Next, the stability determination when the constant power control is selected is examined. FIGS. 14 to 16 are block diagrams of the constant power control system, and FIGS. 14 to 16 will be described with reference to FIG.

14 to 16, Pref is a power reference input signal corresponding to the reference input signal 3 or the overpower limit reference input signal 6, Pfb is a power feedback signal corresponding to the output signal of the switch 11B, Gi , Gs, Gc and Gm are the same as the names and symbols shown in FIGS. 10 to 12, and Gp is the gain of the ratio of the variation between the output voltage Vo and the output power Po applied to the load 29, Gpfb Is the load 2
9 and the current detector 27.
And the gain of the ratio of the change amount of the power feedback signal Pfb from the output signal of the digital multiplier 16 that has received the output signal of the voltage detector 28.

Gp and Gpfb shown in FIGS. 14 and 15 are defined by the following equations (14) to (16).

[0045]

[Equation 14]

For stability of the control system, Vo is Vo (100
%). Therefore, Gp is given by the following equation (15).

[0047]

(Equation 15)

[0048]

(Equation 16)

Here, Po (100%) is the rated power value of Po. In FIG. 15, Gpdc and Gpt are
When defined by the following equations (17) and (18),

[0050]

[Equation 17]

[0051]

(Equation 18)

Equation (18) represents a loop transfer function. In addition, when the above equations (3) and (15) are substituted for GcGp in equation (17), the following equation (19) is obtained.

[0053]

[Equation 19]

Therefore, the above equation (17) is obtained by the following equation (2)
0).

[0055]

(Equation 20)

In general, Pfb (100%) = Vc (100
%) / 2. Therefore, the equation (20) becomes the following equation (21), and the block diagram of FIG. 15 can be converted into the block diagram of FIG.

[0057]

(Equation 21)

In this way, the stability determination of the control is examined using the block diagram of FIG. FIG. 16 is a graph showing the difference between Gpt of equation (18) of the loop transfer function and the above equation (10) as compared with FIG.
Git has the same gain. Therefore, the process is the same as the stability determination of the constant current control system shown in FIG. Therefore, in order to obtain stable maintenance of the constant power control system with respect to the load fluctuation from Ro = 40Ω in the normal mode to Ro = 0.4Ω in the abnormal mode, the control response is controlled in the same manner as in the constant current control system described above. It is necessary to select a slow time division multiplex digital closed loop control system.

Next, the stability determination when the constant voltage control system is selected is examined. When an output current such that a direct current continuously flows through the inductance 25 shown in FIG. 9 flows through the load 29, the output voltage Vo is controlled by the average value of the output voltage of the rectifier 24. However, the load 29
, No DC current flows through the inductance 25, and the output voltage Vo is reduced by the rectifier 24.
, The output voltage Vo becomes the peak value of the output voltage of the rectifier 24, and the constant voltage control of the output voltage is controlled by the peak value of the output voltage of the rectifier 24. Thus, when the load varies from full load to no load, the gain of the constant voltage control system varies significantly. Therefore, in order to obtain stable maintenance of the constant voltage control system, it is necessary to select a time division multiplex digital closed loop control system having a slow control response as in the case of the constant current control system described above.

[0060]

In the power supply control device controlled by the conventional time division multiplex digital closed loop control circuit, any one of a constant current control system, a constant power control system and a constant voltage control system is selected. Even when the load of the power output fluctuates from full load to no load, the gain and phase of each control system fluctuate greatly. There is a problem that a slow time division multiplex digital closed loop control system must be selected. Therefore, it is desired to develop a means optimal for a time-division multiplex digital closed loop control method capable of high-speed control response.

[Purpose] The present invention has been made in view of the above-mentioned problems, and has been made in consideration of a time division method capable of achieving a high-speed response even when a load of a power supply output fluctuates widely and a gain or a phase largely changes. It is an object to provide a multiplex digital closed loop control method.

[0062]

According to the first aspect of the present invention,
In a power supply control device having a time division multiplex digital closed loop control circuit, an analog closed loop circuit is connected to the next stage of the output of the time division multiplex digital closed loop control circuit, and the analog closed loop circuit is connected to the time division multiplex digital closed loop control circuit. A control method of a power supply control device that outputs a control signal that changes an output of a power supply according to an input analog input command signal, wherein the time division multiplex digital closed loop control circuit performs constant current control based on an output state of the power supply. If selected, the analog closed loop circuit also automatically selects constant current control, and if the time division multiplex digital closed loop control circuit selects constant voltage control based on the output state of the power supply, the analog closed loop circuit also sets constant current control. The voltage control is automatically selected, and the time division multiplex digital closed loop control circuit controls the power supply. If you select the constant power control is based on force state is characterized by performing the analog closed loop circuit also time-division multiplex digital closed-loop automatic control by automatically selecting the constant power control.

In this case, when the constant current control, the constant voltage control, or the constant power control is automatically selected, the analog closed loop circuit may include a constant current control system and a constant voltage control system. And the respective automatic stable loops of the constant power control system are formed to perform the time-division multiplex digital closed loop automatic control.

[0064]

According to the first and second aspects of the present invention, in a power supply control device having a time-division multiplex digital closed-loop control circuit, an analog closed-loop circuit is provided next to an output of the time-division multiplex digital closed-loop control circuit. A method of controlling a power supply control device, wherein said analog closed loop circuit outputs a control signal for changing an output of a power supply in accordance with an analog input command signal input from said time division multiplex digital closed loop control circuit, When the digital closed loop control circuit selects constant current control, constant voltage control or constant power control based on the output state of the power supply,
The analog closed loop circuit also performs automatic time division multiplex digital closed loop control by automatically selecting constant current control, constant voltage control or constant power control.

When the constant current control, the constant voltage control, or the constant power control is automatically selected, the analog closed loop circuit forms an automatic stable loop of the constant current control system, the constant voltage control system, and the constant power control system. And a function of performing the time-division multiplex digital closed loop automatic control. Therefore, even if the load of the power output fluctuates over a wide range, it is possible to suppress the gain fluctuation of the loop transfer function as a whole of the time-division multiplex digital closed loop and to achieve a high-speed control response.

[0066]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment will be described below in detail with reference to FIGS. 1 to 8 are diagrams showing an embodiment of a power supply control device to which a time division multiplex digital closed loop control circuit according to the present invention is applied.

First, the configuration will be described. FIG. 1 is a circuit diagram showing an embodiment of a DC power supply control device to which a time division multiplex digital closed loop control circuit according to the present invention is applied. FIG. 2 is an AC diagram to which the time division multiplex digital closed loop control circuit according to the present invention is applied. FIG. 3 is a circuit diagram illustrating an embodiment of a power supply control device. 1 and 2, the same components as those of the circuit diagram shown in FIG. 9 are denoted by the same reference numerals.

In FIGS. 1 and 2, reference numeral 1B denotes a time-division multiplex digital closed loop automatic control circuit equipped with an analog closed loop circuit as an automatic stabilizing circuit, and reference numeral 2 denotes an analog closed loop circuit as an automatic stabilizing circuit. 11C is the voltage V,
A switch for a current I or power P control signal, 18 is an analog control operation circuit for performing proportional and integral operations, 19 is an analog multiplier, and the other parts are denoted by the same reference numerals as those shown in FIG. And the description is omitted.

Next, the operation will be described. In the automatic control circuit 1B shown in FIGS. 1 and 2, the operation in the normal mode will be described first.

The switch 10A and the switch 10B are connected to the normal mode side (the switch 10A and the switch 10B shown in FIGS. 1 and 2).
Are both switched to the normal mode side). The operation selection function unit 7 in the normal mode controls the voltage V,
The current mode or the power P control mode is selected. The selection signal of the operation selection function unit 7 is used as a feedback signal (voltage V, current I, or current V) corresponding to the selection mode of the operation selection function unit 7 by setting each switching position of the switch 11B and the switch 11C via the switch 10A. Switching is performed so that power P) is selected.

The digital feedback signal, which is the output signal of the switch 11B, is transmitted to the time division digital control operation circuit 12, and the analog feedback signal, which is the output signal of the switch 11C, is output to the analog control operation circuit 1.
8 is transmitted. The reference input signal 3 is supplied to the switch 10
The signal is transmitted to the time division digital control operation circuit 12 via B. The output signal of the time division digital control operation circuit 12 is
After being converted into an analog signal by the D / A converter 13,
The signal is transmitted to the analog control operation circuit 18 as an analog input command signal to the analog closed loop circuit 2. Then, the output signal of the analog control operation circuit 18 is transmitted to the transistor drive circuit 17.

In FIG. 1, transistor drive circuit 17
Are output from the transistor switching elements 20A and 20A.
B, 21A and 21B. The DC power supplied from the input power supply 22 is
A, 20B, 21A, and 21B convert the output into AC by an inverter operation having a function of changing the output amount, and then convert into DC through a transformer 23 and a rectifier 24. The DC converted power is sent to the load 29 via the inductance 25 and the capacitance 26.

In FIG. 2, the output signal of the transistor drive circuit 17 is
A, 20B, 21A and 21B are driven. Input power 2
2 is converted into AC by an inverter operation having a function of changing the output amount by the transistor switching elements 20A, 20B, 21A and 21B, and the power converted into AC is supplied to the transformer 23. After passing through, it is sent to the load 29 via the inductance 25 and the capacitance 26.

In FIG. 1 and FIG.
The output voltage detector 28 is a detector for monitoring the state of the load, and the feedback signal, which is the output signal of each of the detectors 27 and 28, is directed directly to the analog closed loop circuit 2 and via the analog multiplier 19. Switcher 11c
A /
Switch 1 via D converters 14 and 15 and multiplier 16
1B.

When the power supply control device of FIGS. 1 and 2 is operated in the normal mode under the automatic control of the closed loop,
When the load 29 is overloaded due to a load abnormality of the power output, each output signal of the output current detector 27 and the output voltage detector 28 is
The signal is transmitted to the operation selection function unit 8 via the A / D converters 14 and 15 and the multiplier 16, the operation selection function unit 8 selects an abnormal mode, and the abnormality determination function unit 9 determines abnormality.

Then, the abnormality determining function unit 9 switches the switch 10A.
And the switch 10B are switched to the abnormal mode side. The operation selection function unit 8 selects one of the overvoltage, overcurrent, and overpower abnormality modes.
The selection signal of (1) switches the switches 11B and 11C via the switch 10A so as to select a feedback signal (voltage, current or power) corresponding to the selection of the operation selection function unit 8.

The digital feedback signal output from the switch 11B is transmitted to the time-division digital control operation circuit 12, and the analog feedback signal output from the switch 11c is transmitted to the analog control operation circuit 18. At the same time, the selection signal of the operation selection function unit 8 is switched by the switch 11A so as to select the overvoltage limit reference input signal 4, the overcurrent limit reference input signal 5, or the overpower limit reference input signal 6 corresponding to the selected mode. Switch. Then, the overvoltage limit reference input signal 4, the overcurrent limit reference input signal 5, or the overpower limit reference input signal 6 is transmitted to the time division digital control operation circuit 12 via the switch 11A and the switch 10B.

The output signal of the time division digital control operation circuit 12 is converted into an analog signal by the D / A converter 13 and then transmitted to the analog control operation circuit 18 as an analog input command signal to the analog closed loop circuit 2. . The operation after the analog control operation circuit 18 is the same as the operation in the normal mode.

Thus, the power supply control device of FIG. 1 and FIG.
The operation is switched to the abnormal mode by automatic control of the closed loop. A high-speed control response can be realized by the above series of operations. The basic principle and the stability determination for realizing the high-speed control response will be described based on the closed-loop automatic control system in the normal mode and the abnormal mode in the power supply control device shown in FIGS.

The output signal of the time-division digital control operation circuit 12 shown in FIGS.
A method of integrating the difference between the reference input signal, which is the output signal of the switch 11B, and the feedback signal, which is the output signal of the switch 11B, and further adds the reference input signal, which is the output signal of the switch 10B, to the integrated signal as a bias amount. And other methods are conceivable.

FIG. 3 is a block diagram showing an example of a control system of the time-division multiplex digital closed loop automatic control circuit 1B shown in FIGS. 1 and 2, and the example of FIG. 3 shows a constant current control system. FIG. 3 will be described with reference to FIG.

In FIG. 3A, Iref is a current reference input signal corresponding to the reference input signal 3 or the overcurrent limit reference input signal 5, Ie is a current input command signal to the analog control operation circuit 18, and Ifb is a switch. A current feedback signal corresponding to the output signal of 11B or 11c, Gi is a transfer function of the time division digital control operation circuit 12, Gs is a transfer function of a dead time element of the sampling period Ts, Gpi is a transfer function of the analog control operation circuit 18, Gc is a gain (not including a delay element) of a ratio of a change amount of the input signal Vc of the transistor drive circuit 17 to a change amount of the output voltage Vo applied to the load 29, and Gm is an inductance 25, a capacitance 26, and a load. The transfer function of the second-order lag element according to 29, Gr is the reciprocal of load impedance Ro, that is, the gain of conductance, and Gibb is negative It is the gain of the ratio of both the change in the output current Io flowing through 29 and the amount of change in current feedback signal Ifb is the output signal of the current detector 27. Note that Gi, Gs, Gc, Gm, Gr, and Gib have the same definitions as the names and symbols shown in the conventional block diagrams of FIGS. 10 and 11, respectively.

In FIG. 3A, Gpi is calculated by the following equation (2)
Defined by 2).

[0084]

(Equation 22)

Here, K is a proportional constant and Tpi is an integral constant. Also, in the block diagram of FIG.
Is defined by the following equation (23), the block diagram of FIG. 3A can be converted to the block diagram of FIG.

[0086]

(Equation 23)

The ratio Ife / Ifb of Ifb / Ifb shown in FIG.
Ie is an analog closed-loop transfer function, where M is represented by the following equation (24).

[0088]

(Equation 24)

The loop transfer function Gilt in FIG. 3 is given by the following equation (25).

[0090]

(Equation 25)

Time-division multiplex digital closed loop automatic control circuit 1 of the analog closed loop circuit 2 as an automatic stabilizing circuit
The effect in B is the effect of the analog closed loop transfer function shown in equation (24). FIG. 4 shows a Bode diagram of the analog closed-loop transfer function.
In the closed loop control system of the analog closed loop circuit 2 shown in FIG. 2, the load resistance changes 100 times from Ro = 40Ω in the normal mode to Ro = 0.4Ω in the abnormal mode. Transfer function gain of 100
The gain | M | dB of the Bode diagram of FIG.
And the closed loop control system M indicated by the phase ΔM is stable and shows little gain fluctuation.

Further, due to the effect of the analog closed loop circuit 2, the phase margin is large and a high frequency control response can be obtained. That is, as shown in FIG. 4, in a wide range of control response from 0 Krad / s to 15 Krad / s, the gain | M | dB of the closed loop is in the range of 0 dB to −10 dB, and the phase delay of the phase ΔM of the closed loop is , 40de
g or less. For this reason, the analog closed loop circuit 2 exhibiting the effect of the above equation (24) is an automatic stabilization circuit with a high-speed response.

Next, the Bode diagram of the above equation (25), which is a loop transfer function of the digital closed loop automatic control system to which the analog closed loop circuit 2 which is a good automatic stabilizing circuit is added, shown in the block diagram of FIG. This will be described with reference to FIG.

First, when the constant current control system is selected, in the Bode diagram of FIG.
The stability determination of the control in the case of varying from = 40Ω to Ro = 0.4Ω in the abnormal mode is examined.

In the Bode diagram shown in FIG. 5, Ro = 4
When the diagram of | Gilt1 | dB at 0Ω crosses 0 dB, the phase ΔGilt1 is −161 dB, and the phase margin is + 19d.
eg, the control system is stable, and the control response at this time is 2.4.
Krad / s is obtained. | G at Ro = 0.4Ω
When the diagram of ilt2 | dB crosses 0 dB, the phase ΔGilt2 is −157 dB, the phase margin is +23 deg, the control system is stable, and the control response at this time is 4.5 Krad / s. Since the control response of the conventional digital closed-loop automatic control system is limited to 32 rad / s, compared with the control response of the digital closed-loop automatic control system of the present embodiment, (2.4 Krad / s) / (32 rad / s) ) = 75 times improvement in control response. Further, since the operations of the constant power control system and the constant voltage control system, which are different control modes, are the same as the operations of the constant current control system, as shown in the Bode diagram of FIG. Even if it fluctuates over a wide range from Ro = 40Ω in mode to Ro = 0.4Ω in abnormal mode,
The gain variation of the loop transfer function as the whole digital closed loop automatic control system of the present embodiment can be suppressed, and a high-speed control response can be achieved.

Next, every time the control mode is switched in the time-division multiplex digital closed loop automatic control circuit 1B due to a load error or the like in the feedback signal, the analog closed loop circuit 2
The function of automatically selecting and switching to the feedback signal of the switched control mode will be described.

First, a description will be given with reference to an example of a block diagram of a constant power control system in the DC power supply control device of FIG. 1 shown in FIG. 6, Pe is an analog power input command signal input to the analog control operation circuit 18 of FIG. 1 from the time division digital control operation circuit 12 via the D / A converter 13. In addition, in FIGS. 6 to 8, the other names and symbols have the same definitions as the names and symbols shown in the above-described conventional block diagrams of FIGS. 10 to 12 and FIGS. 14 to 16. In the example of FIG. 6, both the main loop corresponding to the time-division multiplex digital closed-loop automatic control circuit 1B and the automatic stabilization loop corresponding to the analog closed-loop circuit 2 as the automatic stabilization circuit are in the power control state.

When the constant power control operation as shown in FIG. 6 is performed with the load Ro = 40Ω in the normal mode, the load fluctuates, and the load changes to Ro = 0.4Ω, resulting in an excessive load. A case will be described in which a current flows, and an overcurrent limiting control in the abnormal mode is performed to switch to an operation limited to the rated current Io (100%).

In the overcurrent state, the main loop selects the overcurrent limit reference input signal and the current feedback signal, and switches to the overcurrent limit control mode. Then, the power supply control device enters a constant current operation state limited to the rated current Io (100%). In this case, a control system when the feedback signal of the automatic stabilization loop maintains the normal mode as the power feedback signal will be described with reference to a block diagram shown in FIG.

A comparison between the output power values in both control modes before and after the switching of the control system shown in FIG. 6 in the normal mode and FIG. 7 in the abnormal mode shows that in FIG.
An analog power input command signal Pe having a value corresponding to the following equation (26) is input.

[0101]

(Equation 26)

On the other hand, in FIG. 7 in the abnormal mode, the analog power input command signal P having a value corresponding to the following equation (27) is set.
e is entered.

[0103]

[Equation 27]

By comparing the equations (26) and (27), that is, it can be seen that Pe of the two is different by 100 times. In other words, the gain of the loop transfer function of the main loop of FIG. 7 is 100 times larger than the gain of the loop transfer function of the main loop of FIG. Therefore, in FIG. 7, it is necessary to reduce the gain Gi by 100 times as compared with FIG. In order to solve this problem, when an overcurrent state occurs, the control system of the block diagram shown in FIG. 8 in which the current feedback signal is selected as the feedback signal of the automatic stabilization loop is used.

By doing so, the control system of FIG. 8 becomes the same as the control system of the block diagram shown in FIG. 3, and the load of the power supply output is changed from Ro = 40Ω in the normal mode to Ro = 0 in the abnormal mode. Even if it fluctuates over a wide range up to 0.4Ω, the gain fluctuation of the loop transfer function of the entire digital closed loop automatic control system of the present embodiment can be suppressed, and high-speed control response can be achieved.

That is, every time the control mode changes from the normal mode to the abnormal mode or from the abnormal mode to the normal mode, the present invention converts a reference input signal and a feedback signal corresponding to the control mode into a digital circuit (operation selection function). A high-speed automatic selection by the unit 8 and the abnormality determination function unit 9). For example, a closed loop control circuit different from FIG. 6 to FIG. 8 or FIG. 8 to FIG. is there. Also, when any one of the voltage, current and power control modes is selected in the normal mode, for the same reason as described above, the automatic stabilization loop by the analog closed loop circuit 2 generates a feedback signal in accordance with the selected control mode. Select

As is apparent from the above description, the control method of the present invention can be applied to the case where the load of the power output fluctuates widely due to the effect of adding the automatic stabilization circuit to the next stage of the time division digital control operation circuit. The gain fluctuation of the loop transfer function as the whole time-division multiplex digital closed loop can be suppressed, and a high-speed control response can be achieved. Also, by realizing the high-speed control response, a power supply control device for charging an electric vehicle battery equipped with a multi-function charging pattern such as constant voltage, constant current and constant power control, and a semiconductor manufacturing apparatus requiring a similar high-speed control response. The present invention can be applied to a power supply control device that requires multifunctional high-speed control, such as a power supply control device for plasma generation.

[0108]

According to the first and second aspects of the present invention, even if the load of the power supply output varies over a wide range, the gain variation of the loop transfer function of the entire time-division multiplex digital closed loop can be suppressed. Fast control response is possible.

[Brief description of the drawings]

FIG. 1 is a circuit block diagram of a DC power supply control device including a time division multiplex digital closed loop automatic control circuit according to the present invention.

FIG. 2 is a circuit block diagram of an AC power supply control device including a time-division multiplex digital closed-loop automatic control circuit according to the present invention.

FIG. 3 is a block diagram of a constant current control system in the DC power supply control device of FIG. 1 according to the present invention.

FIG. 4 is a Bode diagram of a constant current control closed loop transfer function of the automatic ballast circuit 2 of FIG. 1 according to the present invention.

FIG. 5 is a Bode diagram of a loop transfer function of a constant current control loop in the DC power supply control device of FIG. 1 according to the present invention.

FIG. 6 is a block diagram of a normal mode of a constant power control system in the DC power supply control device of FIG. 1 according to the present invention.

FIG. 7 is a block diagram of an overcurrent state of a constant current control system in the DC power supply control device of FIG. 1 according to the present invention.

FIG. 8 is a block diagram of an abnormal mode of a constant current control system in the DC power supply control device of FIG. 1 according to the present invention.

FIG. 9 is a circuit block diagram of a DC power supply control device provided with a conventional time-division multiplex digital closed loop automatic control circuit.

FIG. 10 is a block diagram of a constant current control system in the DC power supply control device of FIG. 9;

FIG. 11 is a block diagram of a constant current control system in the DC power supply control device of FIG. 9;

FIG. 12 is a block diagram of a constant current control system in the DC power supply control device of FIG. 9;

FIG. 13 is a Bode diagram of a loop transfer function of the constant current control loop in the DC power supply control device of FIG. 9;

FIG. 14 is a block diagram of a constant power control system in the DC power supply control device of FIG. 9;

FIG. 15 is a block diagram of a constant power control system in the DC power supply control device of FIG. 9;

FIG. 16 is a block diagram of a constant power control system in the DC power supply control device of FIG. 9;

[Explanation of symbols]

 1A Time division multiplex digital closed loop automatic control circuit 1B Time division multiplex digital closed loop automatic control circuit 2 Analog closed loop circuit 3 Reference input signal 4 Overvoltage limit reference input signal 5 Overcurrent limit reference input signal 6 Overpower limit reference input signal 7 Operation selection function Unit 8 Operation selection function unit 9 Abnormality determination function unit 10A, 10B switch 11A, 11B, 11C switch 12 Time division digital control operation circuit 13 D / A converter 14 A / D converter 15 A / D converter 16 Digital Multiplier 17 Transistor drive circuit 18 Analog control operation circuit 19 Analog multiplier 20A, 20B Transistor switch element 21A, 21B Transistor switch element 22 Input power supply 23 Transformer 24 Rectifier 25 Inductance 26 Capacitance 27 Output current detector 28 Output voltage detection 29 load impedance

Claims (2)

(57) [Claims] 1. A power supply control device provided with a time division multiplex digital closed loop control circuit, wherein an analog closed loop circuit is connected to the next stage of the output of the time division multiplex digital closed loop control circuit, and the analog closed loop circuit is connected to the time division multiplex digital loop control circuit. A control method of a power supply control device that outputs a control signal that changes an output of a power supply according to an analog input command signal input from a digital closed loop control circuit, wherein the time division multiplex digital closed loop control circuit is based on an output state of the power supply. When the constant current control is selected, the analog closed loop circuit also automatically selects the constant current control, and when the time division multiplex digital closed loop control circuit selects the constant voltage control based on the output state of the power supply, The analog closed loop circuit also automatically selects the constant voltage control, and the time division multiplex digital closed loop control circuit When the constant power control is selected based on the output state of the power supply, the analog closed loop circuit also automatically selects the constant power control and performs time division multiplex digital closed loop automatic control. Method. 2. The analog closed loop circuit forms an automatic stable loop of a constant current control system, a constant voltage control system, and a constant power control system when constant current control, constant voltage control or constant power control is automatically selected. 2. The control method for a power supply control device according to claim 1, wherein said time-division multiplex digital closed loop automatic control is performed.