JP2004282159A - Variable power supply servo amplifier and method for controlling power supply voltage - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a variable power supply servo amplifier in a two power supply switching system which is compact and highly efficient. <P>SOLUTION: The variable power supply servo amplifier has two power supplies which supply the power to a power amplifier, and which are a variable voltage power supply 1 capable of adjusting the voltage within 50 % of a rated voltage and a peak power supply 2 with the short time rating for outputting a voltage of ≥ 150% of the rated voltage; a power supply voltage controller 9 which creates a signal for controlling an output voltage of the variable voltage power supply from a control command of a control system or the input from the power amplifier 8, and a signal for turning on/off the output of the peak voltage power supply; and a PID controller 10 for executing feedback control by detecting a current or a voltage of a load. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a servo amplifier for controlling a voltage or a current at high speed and precision, for example, a servo amplifier used for an actuator drive controller that requires high precision and high speed response such as force, speed, and position.
[0002]
[Prior art]
A PWM (Pulse Width Modulation) amplifier or a linear amplifier is used as a power amplifier for controlling the load current and voltage. However, when a high output current is required and a high-speed response is required, these power amplifiers are high. Power supply voltage is required. This power supply voltage governs the response characteristics, especially when the load is inductive. Therefore, the efficiency of the high-speed response power amplifier deteriorates because it is driven under an unnecessarily high power supply voltage in a steady state. In order to improve this, a plurality of power supply voltages are prepared and the power supply is switched and used. Alternatively, a technique of changing a power supply voltage in conjunction with a command or an output has been applied.
The “power amplifying device” disclosed in Patent Document 1 is one example of such a device, and it is possible to greatly increase the total output power of a plurality of power amplifiers while maintaining high efficiency. FIG. 3 is a block diagram of the circuit, in which the inputs to the signal input terminals 1A to 1E are input to a plurality of amplifiers 19A to 19E and the signal attenuation control unit 23 adjusts the attenuation in inverse proportion to the gain. The maximum value is selected from the signals at the plurality of input terminals, applied to the maximum value detection control unit 40 that outputs the selected signal, and amplified by the output of the dual power supply switching signal amplifying units 41A and 41B that amplify the signal at the output terminal. A plurality of amplifiers are controlled by controlling the dual power supply switching control unit 44 to activate or cut off the positive and negative high voltage power supply control transistors 80 and 82, respectively, depending on whether or not a predetermined threshold value is exceeded. The power supply voltage applied to 19A to 19E is switched between high and low.
Further, the “optical receiving apparatus” disclosed in Patent Document 2 is intended to enable normal reception without causing waveform distortion even when the level of an input optical signal is high. As shown in (1), the input signal is input to a plurality of preamplifiers 40 and 50 having different amplification factors and is converted into a plurality of voltage outputs. By switching and outputting an output that does not exceed the output, a saturation region operation is avoided, and a voltage signal that does not cause waveform distortion and has a high amplification factor is output.
[0003]
[Patent Document 1]
JP-A-8-31639 (paragraphs [0016 to 0032], FIG. 1)
[Patent Document 2]
JP-A-11-298259 (paragraphs [0022 to 0046], FIG. 1)
[0004]
[Problems to be solved by the invention]
However, in the above-described conventional technology, there are problems such as the cost of the power supply being too high and the increase in volume because several kinds of power supplies are used.
In addition, the method of continuously changing the voltage with a single power supply has a problem in that the voltage variable range and the response of the voltage become problems.
Therefore, the present invention sets the power supply voltage supplied to the power amplifier to a high voltage in order to improve the response when the command of the control system changes suddenly, and when the control system is in a steady state, or when the control system is approaching the steady state. An object of the present invention is to provide a variable power supply servo amplifier having a high power, high precision, and high speed response power amplifier by using a low voltage power supply that can be adjusted within a limited fixed range to reduce the power amplifier loss. And
[0005]
[Means for Solving the Problems]
In order to achieve the above object, an invention according to claim 1 is a variable voltage power supply that supplies power to a power amplifier and that can adjust the voltage within 50% of a rated voltage in a power amplifier based on pulse width modulation or linear amplification. And a short-time rated peak power supply that outputs a voltage of 150% or more of the rated voltage, a signal for controlling the output voltage of the variable voltage power supply from a control command of a control system or an input of the power amplifier, and the peak power supply. It has a power supply voltage controller for generating a signal for turning on and off the output of the voltage power supply, and a PID controller for detecting a load current or voltage and performing feedback control.
The invention according to claim 2 is characterized in that a control power semiconductor element is connected to the output of the variable voltage power supply, and the voltage ripple and voltage regulation characteristics of the variable voltage power supply are improved by performing a linear operation. And
According to a third aspect of the present invention, there is provided a power supply voltage controller for a variable power supply servo amplifier according to any one of the first to second aspects, wherein the control amount is controlled when the time variation of the control command or the operation amount is large. Power is supplied from the peak voltage power supply to the power amplifier until the deviation becomes smaller than a certain value in order to provide a high-speed response, and when the time variation of the control command or the operation amount is small or the deviation is small, the power amplifier A value commensurate with the control command or the manipulated variable so as to reduce loss and output ripple, that is, the absolute value of the input u of the power amplifier is
| U | <δ (where δ is a constant set according to design specifications),
The method is characterized in that the voltage of the variable voltage power supply is adjusted so as to perform coarse adjustment, and fine adjustment is also performed by controlling the control power semiconductor element.
As described above, there are two systems, a high-voltage / short-time rated peak voltage power supply and a low-voltage variable voltage power supply with a small control system deviation or a steady-state power supply, as a power supply with a large control system deviation and high-speed response. And a power supply for supplying power to the power amplifier. The two kinds of power supplies are roughly adjusted by a power supply voltage controller based on a control system command or an operation amount (input of the power amplifier). Then, the transistor connected in series with the output of this power supply is operated to fine-tune the voltage, and the transistor connected in series with the output of the peak voltage power supply is turned on and off to supply power to the power amplifier. In this case, the power supply voltage is controlled to switch between high and low by switching between the peak voltage and the variable voltage power supply. It was turned on, when the steady-state and high-speed response not needed, turn off the peak voltage, so that can improve power efficiency by controlling the coarse and fine adjustment of the variable voltage power supply.
[0006]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing a control system of the variable power servo amplifier according to the first embodiment of the present invention.
In Figure 1, 1 is a variable voltage source (VVPS), 2 and 3 at the peak voltage supply ± _{V p} (HVPS), is generated by a variable voltage power supply 1 of, for example, step-up DC / DC converter or the like. 4 and 5 are voltage adjusting transistors (T _PD ) and (T _ND ). Reference numerals 6 and 7 are reverse voltage blocking diodes (D _P ) and (D _N ). 8 is a power amplifier (P.AMP), 9 is a power supply voltage controller (V.CON), 10 is a servo controller (S.CON), 11 is a load L, and 12 and 13 are transistors for a peak voltage output switch. _TP and _TN .
In each signal system, x ^* is a command, _xf is a feedback signal, _Vcc is a variable voltage control signal, u is an operation amount, _Vch is a peak voltage output switch signal, and _Vcf is a control signal for a voltage fine adjustment switch. is there.
[0007]
Next, the operation will be described.
As described above, FIG. 1 shows two power supplies, a peak voltage power supply (HVPS) 2 having a voltage of 150% or more of the rated voltage and a variable voltage power supply (VVPS) 1 for adjusting the voltage within 50% of the rated voltage, and a power amplifier. (P.AMP) 8, the transistor _{(T P,} T N) for turning on and off the output of the peak voltage power source 2 12,13 peak voltage output switches constituting at variable voltage power source (VVPS) voltage adjustment the first voltage to the fine A voltage fine-tuning switch (voltage regulator) composed of transistors ( _TPD , _TND ) 4, 5; a power supply voltage for controlling the peak voltage output switch and the coarse adjustment of the voltage of the variable voltage power supply and the fine adjustment by the voltage fine adjustment switch It comprises a controller (V.CON) 9 and diodes 6 and 7 for blocking reverse voltage.
Power supply switching control as described above is performed by switching between two power supplies, a peak voltage power supply (HVPS) and a variable voltage power supply (VVPS), and further, by switching between coarse adjustment and fine adjustment of the variable voltage power supply (VVPS). Including control.
The switching control, first, the command ^{x *,} load L (motor) servo controller the obtained deviation e with PID control law by the various feedback _{x f} of the current or voltage from 11 (S.CON) 10 The operation amount u is thus calculated.
Command x ^*, when the operation amount u has a sudden change, performs power supply voltage controller (V.CON) 9 is a threshold determined based on the operation amount u, and outputs a peak voltage output switch signal v _ch peak The voltage output switch transistors 12 and 13 are turned on to supply power from the peak voltage power supply HVPS to the power amplifier (P.AMP) 8.
In other cases, such as during normal operation or when high-speed response is not necessary, the peak voltage output switch transistors 12 and 13 are turned off to switch to the power supply of the variable voltage power supply (VVPS) 1 and to be varied by the variable voltage control signal _Vcc. coarsely adjusting the voltage ± _{V D} of the voltage source (VVPS) 1, if necessary for voltage regulation transistor by the voltage control signal vcf fine tuning switch _{(T PD,} T ND) by controlling the gate voltage and the like of 4,5, Performs fine voltage control. Reverse voltage blocking diodes (D _P , D _N ) 6 for blocking the application of high voltage from peak voltage power supplies (HVPS: ± V _P ) 2, 3 are provided to the outputs of transistors T _PD , T _ND of this voltage fine adjustment switch. 7 is inserted.
It should be noted that if the effect on the power amplifier (P.AMP) 8 is negligible even with the roughly adjusted output voltage of the variable voltage power supply (VVPS) 1, the voltage fine adjustment switch is unnecessary.
The peak voltage power supplies (HVPS) 2 and 3 are generated by boosting the output of the variable voltage power supply (VVPS) 1 using a DC / DC converter. However, an AC power supply may be used as an input. Further, the voltages of the peak voltage power supplies 2 and 3 may be constant, or may be changed according to a command value or a required settling time.
[0008]
Next, a second embodiment of the present invention will be described with reference to the drawings.
FIG. 2 is a block diagram of a current control system of the variable power servo amplifier according to the second embodiment of the present invention.
2, FIG. 1 and different configurations, a peak voltage power supply (HVPS) ± _{V P} is, the step-up transformer, switch, rectifier diode, the peak voltage power supply with a booster constituted by charging capacitor, etc. (HVPS) 14, 15 , The servo controller (S.CON) is changed to a current controller (I.CON) 17, a current detector (I.DET) 16 is added, and the feedback signal x _f is changed to the feedback current _if and the command x ^* has changed to the current command i ^* .
The same components as those in FIG. 1 are denoted by the same reference numerals, and redundant description will be omitted.
[0009]
The block in FIG. 2 described above is a current control system for controlling the current of the inductive load (L) 11 at high speed and with high precision. This control system includes the following elements (1) to (5) for control. It is divided and configured.
(1) Power amplifier (P.AMP) 8 for linear amplification.
(2) Two power supplies, a variable voltage power supply (VVPS) 1 for supplying power of voltage ± _VDD to the power amplifier (P.AMP) 8, a peak voltage power supply (HVPS) 2, and outputs of these power supplies Transistors 4, 5, 12 ', 13' for switching voltages and reverse blocking diodes 6, 7;
(3) A power supply voltage controller (V.CON) 9 that outputs control signals V _cc , V _cf , and V _ch for these transistors.
(4) A current detector (I.DET) 16 that obtains a load current feedback signal _if for performing current control.
(5) A current controller (I.CON) 17 that outputs a manipulated variable u (input of the power amplifier P.AMP) from the current command i ^* and the current feedback signal if.
[0010]
Next, the operation will be described.
First, the power supply voltage controller 9 outputs a command i ^* , u which is an output of a current controller (I. CON) 17 for performing a proportional, integral, or differential operation, that is, a PID operation, or a combination of these signals, The voltage ± _VDD supplied to the amplifier (P, AMP) 8 is switched as follows.
Case 1: when the command ^{i *} or u has a sudden change, to on-peak voltage output switch transistor _{(T PHV, T NHV) 12'} , the 13 '. That is, power is supplied from a peak voltage power supply (HVPS).
Case 2: Other than Case 1. The output voltage ± _{V D} of the variable power supply voltage (VVPS) 1,
| U | <δ (where δ> 0 is a constant),
Or, corresponding to i ^* ,
When | i ^* | <i _L (where i _L is a constant current value determined by design specifications), V _D = V _DL (V _DL is the lower limit value of the output voltage of V _VPS ).
| When> _{ⁱ L,} | _i *
The output of the variable voltage power supply is roughly adjusted to V _D = V _DL + K | i ^* | (where K is a proportionality constant), and the transistors (T _PHV , T _NHV ) 12 ′ and 13 ′ are turned off. Further, if necessary, the transistors (T _PCV , T _NCV ) 4 and 5 are finely adjusted.
As described above, the current of the load L can be efficiently and quickly and precisely controlled.
[0011]
【The invention's effect】
As described above, according to the present invention, the power supply voltage supplied to the power amplifier is set to a high voltage in order to improve the response when the control system command is suddenly changed. When the control system enters a steady state or approaches a steady state, a low-voltage power supply that can be adjusted within a limited fixed range is used. As described above, there is an effect that the loss of the power amplifier can be reduced and a compact, space-saving power amplifier with high output, precision, and high-speed response can be realized.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a control system of a variable power servo amplifier according to a first embodiment of the present invention.
FIG. 2 is a block diagram of a current control system of a variable power servo amplifier according to a second embodiment of the present invention.
FIG. 3 is a block diagram of a conventional power amplifier.
FIG. 4 is a block diagram of a conventional optical receiver.
[Explanation of symbols]
1 Variable voltage power supply VVPS
2, 3, 14, 15 Peak voltage power supply HVPS
4, 5 Voltage Adjusting Transistors T _PD , T _ND
6, 7 Reverse voltage blocking diodes D _P , D _N
8 Power amplifier AMP
9 Power supply voltage controller CON
10 Servo controller S. CON
11 Load L
12, 13, 12 ', 13' Peak voltage output switches T _PHV , T _NHV
16 Current detector I. DET
17 Current controller I. CON
_if feedback current i ^* current command L load u manipulated variable V _CC variable voltage control signal V _ch peak voltage output switch signal V _cf voltage fine adjustment switch control signal x ^* command x _f feedback signal

Claims (3)

In power amplifiers using pulse width modulation or linear amplification,
Two power supplies, a variable voltage power supply that supplies power to the power amplifier and can adjust the voltage within 50% of the rated voltage and a short-time rated peak power supply that outputs a voltage of 150% or more of the rated voltage;
A power supply voltage controller that creates a signal for controlling an output voltage of the variable voltage power supply and a signal for turning on and off the output of the peak voltage power supply from a control command of a control system or an input of the power amplifier,
A variable power servo amplifier comprising: a PID controller for detecting a load current or voltage and performing feedback control. 2. The variable power supply servo amplifier according to claim 1, wherein a control power semiconductor element is connected to an output of the variable voltage power supply, and a voltage ripple and a voltage regulation characteristic of the variable voltage power supply are improved by performing a linear operation. . The power supply voltage controller of the variable power supply servo amplifier according to any one of claims 1 and 2, wherein when the time variation of the control command or the operation amount is large, the deviation is smaller than a fixed value to make the control amount a high-speed response. The power is supplied from the peak voltage power supply to the power amplifier until it becomes smaller, and the time variation of the control command or the manipulated variable is small, or when the deviation is small, the loss and the output ripple of the power amplifier are reduced. The value corresponding to the control command or the operation amount, that is, the absolute value of the input u of the power amplifier is
| U | <δ (where δ is a constant set according to design specifications),
A method of controlling a power supply voltage of a variable power supply servo amplifier, wherein the voltage of the variable voltage power supply is adjusted so as to make coarse adjustment, and fine adjustment is further performed by controlling a control power semiconductor element.

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