JPWO2017169084A1 - AC power regulator and AC power control method - Google Patents

Abstract

  In the AC power regulator that controls the power supply to the load by phase control, the output power is estimated based on the preset voltage information of the power source connected to the load and the measured value of the current flowing through the load. A value is calculated, and pseudo constant power control is performed based on the difference between this value and the target power value (product of a given target load factor and a preset maximum target power value). As a result, an AC power regulator that can perform control following a load having a resistance value fluctuation due to aging deterioration or the like, and that can achieve cost reduction and downsizing of the apparatus is obtained. be able to.

Description

  The present invention relates to an AC power regulator and an AC power control method for controlling power supply from an AC power supply to a load by phase control.

While the voltage (effective value) of a commercial AC power supply is a predetermined value (for example, 200V), since various electric devices (loads) have a power that varies depending on the operating state, An AC power regulator that adjusts the voltage of an AC power supply and supplies the load to a load is used.
Such a power regulator includes a phase control method, a time division control method, an amplitude control method, and the like as its control method. In addition to these types of control methods, there is also control (constant power control) for outputting power proportional to the input in power supply voltage fluctuations and resistance value fluctuations (such as those due to aging and temperature changes).
With regard to such a control method, Patent Document 1 discloses a technique related to constant power control in a phase control method.

Shokai 62-195814

By using constant power control, even if power supply voltage fluctuations or resistance value fluctuations occur, control that automatically follows them is performed. For example, silicon carbide heaters (loads with large resistance fluctuations due to aging) It is suitable for power control and the like.
However, in the conventional constant power control, since it is essential to measure the voltage and current in the load, a circuit for that purpose is necessary. In particular, parts (mainly transformers) necessary for voltage measurement are burdens in terms of cost and required space.

  In view of the above points, the present invention controls an AC power regulator and an AC power control method using a phase control method to follow a load having a resistance value variation due to aging degradation or the like. An object of the present invention is to provide an AC power regulator and an AC power control method capable of reducing the cost and downsizing the apparatus.

(Configuration 1)
An AC power regulator for controlling power supply to a load by phase control, the voltage information of a power source connected to the load set in advance, and a measured value of a current flowing through the load in a past phase control cycle, Based on the phase control information, an output power estimation unit that calculates an output power estimation value, a given target load factor, and a target power supplied to the load when the preset target load factor is 100% Based on the maximum target power value and the estimated output power value, the output power load factor / ignition angle is calculated by calculating the output power load factor obtained by correcting the target load factor and calculating the corresponding firing angle. An AC power regulator characterized by performing pseudo constant power control by comprising a calculation unit.

(Configuration 2)
The AC power regulator according to Configuration 1, wherein the phase control information in the past phase control cycle is an ignition angle in the past phase control cycle or an output power load factor in the past phase control cycle.

(Configuration 3)
An output current measuring unit for measuring the current flowing through the load; or an input unit for receiving an input of a current value flowing through the load; and a power supply voltage storage unit in which voltage information of the power supply is set. The estimated output voltage is calculated based on the output power load factor in the past phase control cycle or the effective load factor corresponding to the firing angle in the past phase control cycle, and the voltage information of the power source. An AC power adjustment according to Configuration 2, wherein the output power estimation value is calculated based on the output voltage estimation value and a current value flowing through the load. vessel.

(Configuration 4)
Configurations 1 to 3 further comprising a feedback control unit that performs feedback control based on a deviation between the target power calculated from the target load factor and the maximum target power value and the estimated output power value. AC power regulator as described in any one.

(Configuration 5)
An output current measuring unit for measuring the current flowing through the load; or an input unit for receiving an input of a current value flowing through the load; and a power supply voltage storage unit in which voltage information of the power supply is set. , Based on the output power load factor in the past phase control cycle or the effective load factor corresponding to the firing angle in the past phase control cycle, the current value flowing through the load, and the voltage information of the power source. And a maximum firing angle output power estimation unit that calculates a maximum firing angle output power estimation value that is an estimated value of output power when the firing angle is maximum. The AC power regulator described.

(Configuration 6)
The configuration according to claim 5, wherein the output power load factor is calculated by dividing a value obtained by multiplying the target load factor by the maximum target power value by the output power estimated value at the maximum firing angle. AC power regulator.

(Configuration 7)
The AC power regulator according to any one of configurations 1 to 6, further comprising: a thyristor; and a thyristor ignition processing unit that controls the thyristor based on the ignition angle.

(Configuration 8)
A voltage drop value in the power supply line is calculated based on a preset impedance of the power supply line and a measured value of the current flowing through the load in the past phase control cycle, and the voltage drop value is calculated as the voltage of the power supply. 8. The AC power regulator according to any one of Configurations 1 to 7, wherein the AC power regulator is subtracted from information.

(Configuration 9)
The AC power regulator according to any one of Configurations 1 to 7, wherein a load voltage generated in the load at a firing angle of 100% is preset as voltage information of the power source.

(Configuration 10)
An AC power control method for controlling power supply to a load by phase control, the voltage information of a power source connected to the load set in advance, and a measured value of a current flowing through the load in a past phase control cycle, Processing for calculating an output power estimation value based on the phase control information, a given target load factor, and a maximum target power that is a target power to be supplied to the load when the preset target load factor is 100% A process of calculating an output power load factor obtained by correcting the target load factor, and a process of calculating a firing angle corresponding to the output power load factor. An AC power control method characterized in that pseudo constant power control is performed.

(Configuration 11)
11. The AC power control method according to Configuration 10, wherein the phase control information in the past phase control cycle is an ignition angle in the past phase control cycle or an output power load factor in the past phase control cycle.

(Configuration 12)
An output voltage estimated value is calculated based on the output power load factor in the past phase control cycle or the effective load factor corresponding to the firing angle in the past phase control cycle and the voltage information of the power source. The process according to claim 11, wherein: a process, a process of calculating the output power estimated value based on an estimated value of the output voltage and a current value obtained by measuring a current flowing through the load are executed. AC power control method.

(Configuration 13)
In any one of Configurations 10 to 12, feedback control is performed based on a deviation between a target power calculated from the target load factor and the maximum target power value and the output power estimated value. The AC power control method described.

(Configuration 14)
The output power load factor in the past phase control cycle or the effective load factor corresponding to the firing angle in the past phase control cycle, the current value obtained by measuring the current flowing through the load, and the voltage information of the power source Based on the above, an AC power control method according to Configuration 11, wherein a process of calculating a maximum firing angle output power estimated value that is an estimated value of output power when the firing angle is maximum is executed. .

(Configuration 15)
The processing for calculating the output power load factor is executed by dividing a value obtained by multiplying the target load factor by the maximum target power value by the maximum firing angle output power estimated value. 14. The AC power control method according to 14.

  According to the AC power regulator and AC power control method of the present invention, the output power estimated value is calculated based on the voltage information of the power source connected to the preset load and the measured value of the current flowing through the load. However, since it is possible to perform pseudo constant power control based on the difference between this and the target power value (product of given target load factor and preset maximum target power value), It is possible to carry out control following a load having a variation in resistance value. In addition, since a circuit for voltage measurement can be omitted, the cost can be reduced and the apparatus can be downsized.

1 is a schematic block diagram showing the configuration of an AC power regulator according to a first embodiment of the present invention. The flowchart which shows the outline of the processing operation regarding the present invention of the alternating current power regulator of Embodiment 1. (A) A graph showing the correspondence of conversion from the average power load factor to the firing angle, (b) A graph showing the correspondence of conversion from the firing angle to the effective load factor The schematic block diagram which shows another structural example of the alternating current power regulator which concerns on this invention The schematic block diagram which shows the structure of the alternating current power regulator of Embodiment 2 which concerns on this invention. The flowchart which shows the outline of the processing operation regarding the present invention of the alternating current power regulator of Embodiment 2. The schematic block diagram which shows another structural example of the alternating current power regulator which concerns on this invention The schematic block diagram which shows the structure of the alternating current power regulator of Embodiment 3 which concerns on this invention. The schematic block diagram which shows another structural example of the alternating current power regulator which concerns on this invention

  Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings. In addition, the following embodiment is one form at the time of actualizing this invention, Comprising: This invention is not limited within the range.

<Embodiment 1>
FIG. 1 is a block diagram showing an outline of the configuration of the AC power regulator according to the first embodiment of the present invention. The AC power regulator 100 according to this embodiment is an AC power regulator that performs phase control to control power supply to a load. A target load factor (0) input from a temperature regulator (not shown) that is an external device. ˜100%), the power supply from the AC power supply 3 to the heater as the load 2 is controlled.
The AC power regulator 100 of the present embodiment is
The preset voltage information of the AC power supply 3, the measured value of the current flowing through the load 2 in the past phase control cycle, and the phase control information in the past phase control cycle (in this embodiment, the phase control of the past phase control cycle) Output power estimation unit 120 that calculates an output power estimation value based on the firing angle of the previous phase control cycle as information),
A target load factor given from a temperature controller (not shown), a preset maximum target power value (target power supplied to the load when the target load factor is 100%), and an output power estimation value An output power load factor / ignition angle calculation unit 110 that calculates an output power load factor θ corrected for the target load factor and calculates an ignition angle φ corresponding to the output power load factor θ;
A thyristor ignition processing unit 130 for controlling the thyristor 140 based on the ignition angle φ,
A thyristor 140 that switches power supply from the AC power supply 3 to the load 2 by an ignition signal output from the thyristor ignition processing unit 130.
The ignition angle is a half cycle of AC voltage in the section from the ignition point, which is the timing of turning on a semiconductor element that controls AC power, such as a thyristor, to the 0 V point of the AC voltage at which the element is turned off. Is the ratio of

The output power estimation unit 120
An output voltage estimator 121 of the previous cycle that calculates an output voltage estimated value based on the load factor of the effective value corresponding to the firing angle φ and the voltage of the AC power supply 3;
An output current measuring unit 122 of the previous cycle that receives a signal from the current transformer 4 (external device) and measures an output current flowing through the load 2;
The output power estimated value calculation part 123 of the previous cycle which calculates an output power estimated value from an output voltage estimated value and an output current measured value is provided.
The output voltage estimation unit 121 of the previous cycle is
Calculating the load factor of the effective value corresponding to the ignition angle φ, the ignition angle of the previous cycle → the effective value load factor conversion unit 1211;
A power supply voltage storage unit 1212 in which voltage information (effective value) of the AC power supply 3 is set;
An output voltage estimated value calculation unit 1213 for the previous cycle that calculates an output voltage estimated value based on the load factor of the effective value and the voltage of the AC power supply 3.

The output power load factor / ignition angle calculation unit 110 is
A maximum target power value storage unit 112 in which a maximum target power value to be given to the load 2 is stored;
A target power calculation unit 111 that calculates a target power value based on a target load factor and a maximum target power value given from a temperature controller that is an external device;
Based on the deviation between the target power value and the output power estimation value obtained from the output power estimation unit 120 (deviation between the output value and the target value), PID control (feedback control) is performed, and the output power load factor a PID control calculation unit 113 for calculating θ (corrected target load factor);
A power load factor for converting the output power load factor θ into the firing angle φ → the firing angle conversion unit 114.

  Each of the above-described configurations may be configured by hardware using a dedicated circuit or the like, or may be realized by software on a general-purpose circuit such as a microcomputer.

The output current measuring unit 122 in the previous cycle measures the value of the output current in the load 2, but it is fundamental to acquire the output current value output in each control cycle in real time during the control cycle. Therefore, the output current value obtained from the output current measuring unit 122 in the previous cycle is the output current value in the previous control cycle.
“It is basically impossible to obtain the output current value in real time during the control cycle” means that the current measurement value (AD conversion instantaneous value) that is an instantaneous value obtained based on the sampling period is Because the output current value is obtained during the control cycle and the output current value is calculated based on this, the output current value of the current control cycle (real-time control cycle) can be obtained only at the timing when the current control cycle ends. is there.
This process (phase control) is for calculating the firing angle φ in the current control cycle, and in principle it is difficult to use the output current value of the current control cycle (real-time control cycle). The value of is used.

As described above, the output power estimation unit 120 is based on the preset voltage of the AC power supply 3, the load factor in the previous control cycle, and the measured value of the output current (output current value in the previous control cycle). Thus, an output power estimated value is calculated.
Further, the output power load factor / ignition angle calculation unit 110 calculates the ignition angle φ corresponding to the output power load factor θ based on the given target load factor, the maximum target power value, and the output power estimation value. Specifically, the target power value is calculated by the product of the given target load factor and the maximum target power value, and the deviation between the target power value and the estimated output power in the previous control cycle is calculated. Based on the PID control, the output power load factor θ is calculated, and the call angle φ corresponding to this is obtained.
In addition, PID control itself uses the technique used conventionally, The description regarding this is omitted.

Specifically, taking the deterioration of the SiC heater as an example, the case where the resistance value is used until it becomes twice the initial value (when the resistance value becomes twice, the life of the heater is described) will be described below.
The initial resistance value of the load (heater) is 20Ω, it is used until it becomes 40Ω due to aging, and the case where the power supply voltage is 200V will be described as a specific numerical value.
When the load power consumption 1000W (200V ÷ 40Ω × 200V) at the maximum firing angle at the resistance value 40Ω judged to be the life of the load is set as the maximum target power value and the target load factor is 100% This will be explained with specific numerical values. In this case, the target power is 1000 W (1.0 × (100%) 1000 W), but since there is no information on the previous cycle at the first control cycle, the target load factor (100%) is used as the output power load factor. Since the arc angle is calculated to be 100%, the output power is 2000 W (200 V ÷ 20Ω × 200 V). In the second cycle, since the firing angle of the previous cycle is 100%, the calculated value of the effective value load factor is 100%, and the output voltage estimated value of the previous cycle is calculated to be 200V. Further, since the ignition angle of the previous cycle is 100%, the measured current is 10 A (200 V ÷ 20Ω), so the estimated output power of the previous cycle is calculated as 2000 W (200 V × 10 A). On the other hand, since the target power is 1000 W, the deviation from the estimated output power is +1000 W. When this deviation is PID-calculated, the output power load factor of the next cycle becomes a value smaller than 100%. The same operation is repeated after the third time, and finally, the output power is stabilized at an output power load factor of 50% (ignition angle = 50%) at which the output power and the target power match.
Next, the case where the resistance value of the load deteriorates to 40Ω in the above example will be described. As in the case of 20Ω, since there is no information on the previous control cycle in the first control cycle, assuming that the output power load factor is 100%, which is the same as the target load factor, the firing angle is 100%. As a result, the output current is 5 A ( 200V ÷ 40Ω), and the output power is 1000 W (200 V × 5 A). For this reason, in the second and subsequent cycles, the power load factor is 100%, the measured current is 5 A, and the output power estimation value is 1000 W (200 V × 5 A), which is the same as the target power. Even so, since the output power load factor does not change from 100%, the firing angle is maintained at 100%. As a result, the output power continues to be 1000 W.
As described above, the case where the target load factor is 100% has been described. However, regardless of the value of the target load factor between 0% and 100%, the output power is the target load factor × the maximum firing angle output power value. Controlled by value. Further, the problem that the power value at the start of control becomes large when the load resistance value is 20Ω can be easily prevented by the soft start (function of gradually increasing the output), which is a conventional technique.

In addition, because of the processing for converting the output power load factor θ to the call angle φ described above, the power load factor → ignition angle conversion unit 114 supports each output power load factor θ for simplification and speedup of calculation. The table has a predetermined firing angle φ.
FIG. 3A shows a graph of the correspondence relationship between the output power load factor θ (the load factor of power (average value)) and the firing angle φ. A table corresponding to the correspondence relationship of the graph is provided in the power load factor → ignition angle conversion unit 114.
Similarly, in order to obtain the effective value load factor in the previous control cycle, the ignition angle → effective value load factor conversion unit 1211 in the previous cycle determines the effective value load factor corresponding to each ignition angle φ. Table.
FIG. 3B shows a graph of the correspondence relationship between the firing angle φ and the effective value load factor. A table corresponding to the correspondence relationship of the graph is provided in the firing angle → effective value load factor conversion unit 1211 of the previous cycle.
Rather than having a table, the firing angle φ is calculated from the output power load factor θ as needed based on the mathematical formula corresponding to the graph of FIG. 3 (or the effective load factor is calculated from the firing angle φ as needed. ).
Unless otherwise specified, each value such as voltage and current in the embodiment is an effective value, and the above-described load factor obtained by converting the firing angle φ is also an effective value load factor. The effective value load factor is the maximum value of the effective voltage value and effective current value (the effective value of the voltage applied to the load when the ignition angle is 100% or the effective value of the current flowing through the load). It is a value obtained by normalizing the effective value of the output voltage at the angle φ or the effective value of the output current.
On the other hand, the target load factor is a signal sent from the temperature controller, and is a load factor as an average power value in the phase control of the constant power control method. That is, the product of the target load factor and the maximum target power value is the target power value (average power value) supplied to the load. The output power load factor obtained by correcting the target load factor is also a load factor as an average power value.

The thyristor ignition processing unit 130 drives the thyristor 140, and turns on the thyristor 140 at the timing of the ignition angle φ input from the output power load factor / ignition angle calculation unit 110. The thyristor 140 is turned off at the timing of zero crossing, whereby the power supplied from the AC power source 3 to the load 2 is controlled (constant power phase control is performed).
As a switching element for phase control, a thyristor or a triac is generally used, but other various switching elements may be used to perform phase control.

As understood from the above, the output voltage estimated value is obtained by calculating (estimating) the output voltage based on the load factor and the power supply voltage (set value), and the estimated output voltage and the actually measured value are The output power estimated value is obtained by estimating the output power from a certain output current value.
The power supply voltage is different, for example, when a power supply having a very poor quality is used, but usually the fluctuation is not large, and it is in the range of several percent if any. On the other hand, for example, in a silicon carbide heater, the resistance value reaches 3 to 4 times the initial value due to aging (the life is reached when it reaches 3 to 4 times). In other words, when considering “constant power control for outputting power proportional to the input even with respect to power supply voltage fluctuations and load fluctuations”, the load gravity is actually overwhelmingly more specific. It can be said that the necessity for dealing with fluctuations in power supply voltage is not high. The present invention pays attention to this point, which has not been particularly conscious until now, and uses the estimated value calculated from the power supply voltage stored as a preset value and the output firing angle instead of the measured value for the output voltage. In this way, cost reduction and device miniaturization are achieved.

  Next, the processing operation related to the present invention of the AC power regulator 100 of the first embodiment having the above-described configuration will be described with reference to FIG.

Step 201 is an initialization process, and 1 is substituted for n. n is an integer value indicating a control cycle. If n = 1, the first control cycle is indicated, and if n = 100, the 100th control cycle is indicated. Note that the control cycle of phase control is usually the same as the half cycle of the AC power supply voltage, and in this embodiment, the half cycle of the AC power supply voltage is used as the control cycle.
n is a variable used for convenience of explanation, and is not necessarily required in the actual control processing of the apparatus.

In step 202, it is determined whether or not the control cycle n is 1. If it is 1, the process proceeds to step 203. If it is not 1, the process proceeds to step 204.
In the case of the first control cycle, the given target load factor is set as the output power load factor θ (step 202: Yes → step 203).
In the first control cycle, since there is no “previous control cycle”, processing that requires a result in the previous control cycle (feedback control) is skipped.

  On the other hand, if it is the second and subsequent control cycles, the process proceeds to step 204 where the target power calculation unit 111 sets the target load factor n (target load factor in the nth control cycle. The subscript n is the nth control cycle. This indicates that there is, and the following subscripts are also synonymous) and is multiplied by the maximum target power value, and this is set as the target power value n.

In the output voltage estimation unit 121 of the previous cycle, the ignition angle φn−1 (process of step 211 (process of the previous cycle) described later) is stored in the ignition angle → effective value load factor conversion unit 1211 of the previous cycle. ) Is converted into an execution value load factor n-1, and the output voltage estimated value calculation unit 1213 of the previous cycle multiplies the effective value load factor n-1 by the power supply voltage obtained from the power supply voltage storage unit 1212. The output voltage estimated value n-1 is calculated (steps 205 to 206).
Further, the output current flowing through the load 2 is measured by the output current measuring unit 122 in the previous cycle, and the output current measured value n-1 is acquired (step 207).

The output power estimated value calculation unit 123 of the previous cycle multiplies the output voltage estimated value n−1 obtained by Steps 205 to 207 by the output current measured value n−1 to obtain the output power estimated value n. -1 is calculated (step 208).
Note that the processing in steps 204 to 208 is to calculate values (target power value n and output power estimated value n−1) necessary for the next processing in step 209, and these steps are performed before step 209. As long as the value can be calculated, the order of each processing in steps 204 to 208 does not matter.

In step 209, the PID control calculation unit 113 performs PID control based on the deviation between the target power value n obtained in step 204 and the output power estimated value n−1 obtained in step 208. The output power load factor θn is calculated.
The process of converting the output power load factor θn to the firing angle φn is performed in the power load factor → ignition angle conversion unit 114 (step 210), and the thyristor firing processing unit 130 is operated based on the firing angle φn. 140 is driven (step 212). The firing angle φn acquired in step 210 is temporarily stored for use in the processing of the next cycle (step 211).

  The series of processes from step 202 to step 212 is repeated for each control cycle. That is, n is incremented in synchronization with the control cycle (step 213), the process returns to step 202, and the above process is repeated (if the end instruction is given, the process ends (step 214: Yes). → End)).

According to the AC power regulator 100 of the present embodiment having the above-described configuration and processing operation, the voltage information of the preset AC power source, the firing angle of the previous cycle, the measured value of the current flowing through the load 2, Based on the output power estimated value, and based on the difference between this and the target power value (the product of a given target load factor and a preset maximum target power value), a pseudo-tracking load variation Constant power control can be performed. As a result, an AC power regulator that can perform control following a load having a resistance value fluctuation due to aging deterioration or the like, and that can achieve cost reduction and downsizing of the apparatus is obtained. (Transformer for voltage measurement, which has been a burden in terms of cost and required space, can be eliminated).
As a specific application, it is suitable for a load whose resistance value fluctuates due to aging, such as a silicon carbide heater, but there is a load fluctuation due to other factors (for example, there is a resistance value fluctuation accompanying a temperature change). It is also effective for loads).

  Note that the output power estimation unit 120 outputs based on the preset voltage information of the AC power source, the firing angle (the load factor of the effective value corresponding thereto), and the measured value of the current flowing through the load 2. Any device capable of calculating the power estimation value may be used. In the AC power regulator 100 of FIG. 1, the output power estimated value n−1 is calculated by multiplying the output voltage estimated value n−1 and the output current measured value n−1 by way of example. For example, as shown in FIG. 4, the load resistance estimation value n-1 is calculated from the output voltage estimation value n-1 and the output current measurement value n-1 (the load resistance estimation unit 124 of the previous cycle is provided). ), An output power estimated value n-1 is calculated from the load resistance estimated value n-1 and the output voltage estimated value n-1 (the output voltage estimated value n-1 squared is the load resistance estimated value n- (Divide by 1). (Or, the output current measurement value n-1 squared may be multiplied by the load resistance estimation value n-1, both of which are conceptually similar.)

  In the present embodiment, as an example of feedback control, an example of performing PID control is used, but other feedback control (for example, PI control) may be used.

<Embodiment 2>
FIG. 5 is a block diagram showing an outline of the configuration of the AC power regulator according to the second embodiment of the present invention. About the structure similar to Embodiment 1, the code | symbol similar to FIG. 1 is used, and description here is abbreviate | omitted or simplified.

In the AC power regulator 100 of the first embodiment, the output power load factor θ is calculated by calculating the output power estimated value and performing feedback control based on the deviation between the output power estimated value and the target power value. On the other hand, the AC power regulator 300 according to the present embodiment calculates an output power estimated value at the maximum firing angle, which is an estimated value of the output power when the firing angle is maximum (100%), and this maximum firing angle. The output power load factor θ obtained by correcting the target load factor is calculated based on the estimated output power value and the target power value.
In order to calculate the maximum firing angle output power estimated value, the AC power adjuster 300 uses the output power estimation unit 120 in the previous cycle maximum firing angle output current estimation unit 125 and the previous cycle maximum firing. And an angular output power estimation unit 126.
Further, in order to perform correction processing using the estimated output power at the maximum firing angle, the output power load factor / ignition angle calculation unit 110 uses an output power load factor calculation unit 115 instead of the PID control calculation unit 113. I have.

The output power estimation unit 120 in the AC power regulator 300 includes an effective load ratio corresponding to the firing angle in the previous control cycle, a current value flowing through the load 2 in the previous control cycle, voltage information of the power source, Based on the above, an output power estimated value at the maximum firing angle is calculated.
Therefore, the maximum firing angle output current estimation unit 125 of the previous cycle has an effective value load corresponding to the ignition angle in the previous control cycle obtained from the ignition angle of the previous cycle → the effective value load factor conversion unit 1211. Based on the rate and the output current measurement value in the previous control cycle obtained from the output current measurement unit 122, the output current in the case of the maximum firing angle (100%) in the previous control cycle is calculated (estimated). The
The maximum firing angle output power estimation unit 126 of the previous cycle is an estimated output current value in terms of the maximum firing angle (100%) in the previous control cycle obtained from the maximum firing angle output current estimation unit 125 of the previous cycle. Based on (maximum firing angle output current estimated value) and the power supply voltage value obtained from the power supply voltage storage unit 1212, the maximum firing angle output power estimated value is calculated.
Specifically, the maximum firing angle (100% in the previous control cycle) is obtained by dividing the output current measurement value in the previous control cycle by the effective load factor corresponding to the firing angle in the previous control cycle. ) Calculate the converted output current estimated value (maximum firing angle output current estimated value) and multiply this by the power supply voltage value to calculate the maximum firing angle output power estimated value in the previous control cycle .
In addition, the output power load factor calculation unit 115 in the output power load factor / ignition angle calculation unit 110 includes a target power value obtained from the target power calculation unit 111 and an output at the maximum ignition angle obtained from the output power estimation unit 120. Based on the estimated power value, an output power load factor θ obtained by correcting the target load factor is calculated.
Specifically, the output power load factor θ is calculated by dividing the target power value by the estimated output power at the maximum firing angle in the previous control cycle.

An example similar to that of Embodiment 1 will be specifically described.
Similarly to the first embodiment, the load power consumption 1000 W (200 V ÷ 40Ω × 200 V) when the resistance value determined to be the life of the load becomes 40Ω is set to the maximum target power value, thereby using the load. A specific numerical value will explain that the relationship between the target load factor and the power consumption of the load can be kept unchanged from the start to the lifetime. First, the case where the resistance value of the load is the initial value of 20Ω and the target load factor is 100% will be described. In this case, the target power is 1000 W (1.0 (100%) × 1000 W). However, since there is no information on the previous cycle in the first control cycle, the output power load factor is set to 100%, which is the same as the target load factor. When the thyristor is turned on with 100% of the value converted to the firing angle, the output current becomes 10 A (200 V ÷ 20Ω), and the output power becomes 2000 W (200 V × 10 A). In the second cycle, the maximum point of the previous control cycle is calculated from the effective load factor 100% of the previous cycle calculated from the firing angle 100% of the first control cycle and the output current measurement value 10A of the first control cycle. An arc angle output current estimated value 10A is calculated, and the maximum ignition angle output power estimated value of the previous control cycle is calculated as 2000 W from the value and the power supply voltage (200 V). If the target power is 1000 W, the same as the first control cycle, the output power load factor (target power / maximum firing angle output power estimated value) will be 0.5 (50%). The thyristor is turned on with 50% converted to a corner. As a result, the output power becomes 1000 W which is the same as the target power. In the third control cycle, the effective load factor 0.707 (0.5 (50%) square root) of the previous cycle calculated from the firing angle 50% of the second control cycle and the second control cycle From the output current measured value 7.07A (effective value), the maximum firing angle output current estimated value 10A (7.07A ÷ 0.707 (70.7%)) of the previous control cycle is calculated. The output power load factor 50% (1000 W ÷ 2000 W = 0) from the estimated power value 2000 W at the maximum firing angle of the previous cycle calculated from the product of this value and the power supply voltage and the target power 1000 W (the same as the first control cycle). .5) is calculated. When this value is converted to the firing angle and the thyristor is turned on at 50%, the output power becomes 1000 W, the same as in the second control cycle. Since the fourth time is the same numerical processing as the third control cycle, the output power is 1000 W, which is the same value as the target power. As described above, when the resistance value of the load is 20Ω, the output power of the second and subsequent control cycles becomes the same value as the target power.
Next, the case where the resistance value of the load deteriorates to 40Ω in the above specific example will be described. Similarly to when the load resistance is 20Ω, since there is no information on the previous cycle in the first control cycle, the output power load factor is set to 100% which is the same as the target load factor, and the value is converted to the firing angle, which is 100%. The output current is 5A (200V ÷ 40Ω), and the output power is 1000W (200V × 5A). In the second cycle, the effective load factor 100% calculated from the firing angle 100% of the previous cycle and the output current estimated value 5A (5A ÷ 1 (100%) at the maximum firing angle from the output current measurement value 5A of the previous cycle )) Is calculated, and the output power estimated value 1000 W (200 V × 5 A) of the previous cycle is calculated from the value and the power supply voltage. Since the target power is 1000 W, the output power load factor (target power / maximum firing angle output power estimated value) is 1.0 (100%), and when this value is converted into the firing angle, it becomes 100%. Therefore, the output power is 1000 W which is the same as the target power. The same result is obtained after the third time.
As described above, the case where the target load factor is 100% has been described. However, regardless of the value of the target load factor between 0 and 100%, the output power is the target load factor × the maximum firing angle output power. Controlled by value. Also, the problem that the power in the first control cycle becomes large when the load resistance value is 20Ω can be easily prevented by the soft start (function of gradually increasing the output), which is a conventional technique.

  Next, the processing operation for each control cycle related to the present invention of the AC power regulator 300 of Embodiment 2 will be described with reference to FIG. The same reference numerals are used for the same processing concept as in the first embodiment (FIG. 2), and the description here is omitted or simplified.

  The processing from step 201 to step 207 is basically the same as in the first embodiment, but in this embodiment, instead of the output voltage estimated value n-1 calculation processing (step 206) in the first embodiment, the maximum score is obtained. A calculation process (step 601) of the output current estimated value n-1 at the arc angle (100%) is executed. As described above, this processing is performed by dividing the output current measurement value n-1 by the load factor n-1 of the execution value in the maximum firing angle output current estimation unit 125 of the previous cycle.

In step 602 following step 601, the maximum firing angle output power estimation unit 126 of the previous cycle multiplies the maximum firing angle output current estimated value n-1 by the power supply voltage value obtained from the power supply voltage storage unit 1212. Thus, the output power estimated value n-1 at the maximum firing angle is calculated.
In the subsequent step 603, the output power load factor calculation unit 115 divides the target power value n obtained from the target power calculation unit 111 by the maximum firing angle output power estimated value n-1 calculated in step 602. Thus, the output power load factor θn is calculated.

  The processing after the output power load factor θn is calculated is the same as in the first embodiment.

According to the AC power regulator 300 of the present embodiment having the above-described configuration and processing operation, the circuit for voltage measurement (particularly the transformer) can be deleted as in the first embodiment. It is possible to obtain an AC power regulator in which the size of the device is reduced.
In addition, it is possible to obtain a faster response than feedback control such as PID control in the first embodiment.

  Note that the output power estimation unit 120 determines the maximum point based on the preset voltage information of the power source, the firing angle (the load factor of the effective value corresponding thereto), and the measured value of the current flowing through the load 2. What is necessary is just to be able to calculate the estimated output power at the arc angle. In the AC power regulator 300 of FIG. 5, the maximum firing angle output current estimated value n-1 is calculated and then multiplied by the power supply voltage to obtain the maximum firing angle output power estimated value n-1. For example, as shown in FIG. 7, the load resistance estimated value n−1 is calculated from the output voltage estimated value n−1 and the output current measured value n−1 (as shown in FIG. A cycle load resistance estimation unit 124 is provided), and the power output voltage squared may be divided by the load resistance estimated value n−1 to calculate the maximum firing angle output power estimated value n−1. . (Alternatively, the output current estimated value n-1 at the maximum firing angle may be calculated and squared to be multiplied by the load resistance estimated value n-1, both of which are similar in concept. )

<Embodiment 3>
FIG. 8: is a block diagram which shows the outline of a structure of the alternating current power regulator of Embodiment 3 which concerns on this invention. About the structure similar to Embodiment 1 and 2, the code | symbol similar to FIG. 1 and FIG. 5 is used, and description here is abbreviate | omitted or simplified.

In the first and second embodiments, the power supply voltage (effective value) of the AC power supply 3 preset in the power supply voltage storage unit 1212 is used as it is to calculate the output power estimated value. On the other hand, the AC power regulator of this embodiment corrects (subtracts) the voltage drop in the power supply line with respect to the power supply voltage (effective value) of the AC power supply 3. More specifically, the AC power regulator according to the present embodiment is configured such that the voltage drop in the power supply line is based on the preset impedance of the power supply line and the measured value of the current flowing through the load in the past phase control cycle. A value is calculated, and the voltage drop value is subtracted from the voltage information of the power source.
The AC power regulator 500 shown in FIG. 8 includes an output voltage calculation unit 150 for calculating an output voltage obtained by subtracting a voltage drop in the power supply line from the power supply voltage.
The output voltage calculation unit 150
A power line resistance value storage unit 153 in which the impedance value of the power line is preset,
Multiplying the output current estimated value at the 100% firing angle of the previous cycle obtained from the previous cycle maximum firing angle output current estimating unit 125 (similar to the second embodiment) by the impedance value of the power line. Then, the output voltage drop calculation unit 152 at the maximum ignition angle at the previous cycle for calculating (estimating) the voltage drop value in the power supply line when the ignition angle at the previous cycle is 100%,
Before performing the process of subtracting the voltage drop in the power line calculated by the maximum firing angle output voltage drop calculation unit 152 of the previous cycle from the power supply voltage of the AC power supply 3 preset in the power supply voltage storage unit 1212 Output voltage calculation unit 151 at the maximum firing angle of the cycle;
Is provided.
Here, as the ignition angle of the previous cycle → the effective value load factor conversion unit 1211, the ignition angle storage unit of the previous cycle that temporarily stores the ignition angle of the previous cycle, and the point of FIG. From the correspondence between the arc angle φ and the load factor (effective value), it is illustrated as including an ignition angle → load factor conversion unit that converts each ignition angle φ into a load factor (effective value). The concept is the same as that of the ignition angle → rms load factor conversion unit 1211 of the previous cycle in the first and second embodiments.
Further, as the maximum target power value storage unit 112, a rated current storage unit in which a rated current flowing in the load 2 is set in advance, and a power supply voltage set in advance in the set rated current and power supply voltage storage unit 1212 , And a rated power calculation unit that calculates a rated power (maximum scale power) by multiplying by the same as the maximum target power value storage unit 112 in the first and second embodiments. It is.

  The AC power regulator 500 according to the present embodiment includes the “output voltage at the 100% firing angle of the previous cycle obtained by subtracting the voltage drop in the power supply line from the power supply voltage” calculated by the above configuration, and the load factor of the previous cycle. A process of calculating (estimating) the output voltage of the previous cycle is performed by multiplying (effective value) (this process is performed in step 206 in FIG. 2). Since the rest is the same as that of the first embodiment, the description thereof is omitted here.

  As described above, according to the AC power regulator 500 of the present embodiment, the processing is performed in consideration of the voltage drop in the power supply line, so that the processing accuracy can be further increased. Each device installed in a factory often has to have a long power line because of its layout, and therefore, the resistance value of the power cable may be so large that it cannot be ignored. Further, a transformer or the like is provided on the power supply line, and the impedance in the power supply line due to these may be a magnitude that cannot be ignored. According to the AC power regulator 500 of this embodiment, even in such a case, the voltage drop due to the impedance of the power supply line is corrected, so that it is possible to perform processing with high accuracy, which is preferable.

The AC power regulator 500 in FIG. 8 is an example in which the concept of “correcting the voltage drop in the power supply line” is applied to the first embodiment, but “correcting the voltage drop in the power supply line” in the present embodiment. This concept can naturally be applied to the second embodiment. FIG. 9 shows an AC power regulator 600 to which the concept of “correcting the voltage drop in the power supply line” is applied to the second embodiment. Since each structure and its processing concept are the same, the description regarding AC power regulator 600 is abbreviate | omitted.
Similarly, the concept of “correcting the voltage drop in the power supply line” in this embodiment can be applied to the examples illustrated in FIGS. 4 and 7 as well.

  Note that the “power line impedance” preset in the power line resistance value storage unit 153 may be determined by measuring the impedance of the corresponding part of the actual target device by various known methods (or used for the target device). The impedance may be calculated from the specifications of each member that is used).

In this embodiment, in order to “correct the voltage drop in the power supply line”, the impedance of the power supply line is set in advance, and based on this and the measured value of the current flowing through the load in the past phase control cycle, The voltage drop value in the past phase control cycle in the power supply line is calculated, and the voltage drop value is subtracted from the voltage information of the power supply. However, the load voltage generated in the load 2 when the firing angle is 100% is acquired (measured) in advance. Etc.), and the load voltage generated in the load 2 when the firing angle is 100% may be set in the power supply voltage storage unit 1212 in advance.
That is, the configuration of the AC power regulator is the same as that of the first embodiment (or the second embodiment), and the load 2 is set to an output with an ignition angle of 100% with the actual target device installed. The generated load voltage may be measured, and this may be preset in the power supply voltage storage unit 1212 (the processing itself is the same as in the first embodiment (FIG. 2) or the second embodiment (FIG. 6)).
By using the “load voltage generated at the load 2 when the firing angle is 100%”, it is synonymous with the state where “correction of the voltage drop in the power line (portion other than the load 2)” has already been performed. The processing itself remains the same as in the first and second embodiments, and the same effect can be obtained.

  In each of the above embodiments, the firing angle of the previous cycle is used as the “phase control information in the past phase control cycle” by the firing angle of the previous cycle → the effective value load factor conversion unit 1211 to load the effective value. Although an example of conversion into a rate is taken as an example, a square root (effective value load factor) of the output power load factor θ of the previous control cycle calculated by the PID control calculation unit 113 and the output power load factor calculation unit 115 is obtained. This may be used as “phase control information in the past phase control cycle”. However, when the firing angle is corrected by other functions such as soft start, a correct result can be obtained by simply using the square root of the output power load factor θ of the previous control cycle. Absent. Therefore, in this case, it is necessary to use the method described in the embodiment or to perform processing in consideration of the influence of other functions such as soft start. Note that the calculation process of the square root of the output power load factor θ (the load factor of the effective value) increases the calculation load. Therefore, a table (a table for converting the output power load factor θ into the load factor of the effective value) in advance is used. You may make it prepare.

  In each embodiment, the output current measurement unit 122 in the previous cycle that receives the signal from the current transformer 4 (external device) and obtains the output current value is taken as an example, but the current transformer 4 is included in the AC power regulator. It may be. Or as an alternating current power regulator, what is provided only with an input part which receives input of an output current value (thing which does not have output current measurement part 122 of the previous cycle), etc. may be sufficient.

In each of the embodiments, the “previous control cycle (past phase control cycle)” is described as the most recent (previous) cycle. "Control cycle)" is not limited to this, and for example, a few cycles before may be referred to as "previous control cycle (past phase control cycle)".
Although it is more preferable that each operation of the “current control cycle” is determined based on the measurement value of the most recent (one previous) cycle or the like (each embodiment), for example, the control cycle two cycles before As the “previous control cycle (past phase control cycle)”, even if each operation of the “current control cycle” is determined based on the measured value in the control cycle two cycles before, Absent.

  In each embodiment, the output power estimated value (or the maximum firing angle output power estimated value) or each value for calculating the value is calculated as an example for each control cycle. It is not limited to this. For example, if the main purpose is to follow the resistance value over time, it is not always necessary to detect the effect of a change in resistance value for each control cycle. In such a case, for example, the maximum firing angle output power estimated value described in the second embodiment is calculated in a cycle such as a daily unit or a monthly unit, and is stored (in a cycle such as a daily unit or a monthly unit). Update), and the target power value is calculated by the target power calculation unit 111 by multiplying the stored maximum firing angle output power estimated value by the target load factor. Good.

100, 200, 300, 400, 500, 600. . . AC power regulator 110. . . Output power load factor / ignition angle calculation unit 111. . . Target power calculation unit 112. . . Maximum target power value storage unit 113. . . PID control calculation unit (feedback control unit)
114. . . Electric power load factor → ignition angle conversion unit 115. . . Output power load factor calculation unit 120. . . Output power estimation unit 121. . . Output voltage estimation unit for previous cycle 1211. . . The firing angle of the previous cycle → the effective value load factor conversion unit 1212. . . Power supply voltage storage unit 1213. . . Output voltage estimated value calculation unit 122. . . 123. Output current measurement unit of previous cycle . . 124. Output power estimated value calculation unit of previous cycle . . Load resistance estimation unit for previous cycle 125. . . 126. Output current estimator at maximum firing angle of previous cycle . . Output power estimation unit at maximum firing angle of previous cycle 130. . . Thyristor firing processing unit 140. . . Thyristor 150. . . Output voltage calculation unit 151. . . 152. Maximum firing angle output voltage calculation unit . . Output voltage drop calculation unit at maximum firing angle of previous cycle 153. . . Power line resistance value storage

Claims (9)

An AC power regulator for controlling power supply to a load by phase control,
Output power estimation that calculates an output power estimation value based on voltage information of a power source connected to the preset load, a measured value of current flowing in the load in the past phase control cycle, and phase control information And
Based on the given target load factor, the maximum target power value that is the target power supplied to the load when the preset target load factor is 100%, and the output power estimated value, the target load factor is An output power load factor / ignition angle calculation unit for calculating a corrected output power load factor and calculating a corresponding ignition angle;
An AC power regulator characterized in that pseudo constant power control is performed.   2. The AC power regulator according to claim 1, wherein the phase control information in the past phase control cycle is an ignition angle in the past phase control cycle or an output power load factor in the past phase control cycle. The output power estimation unit is
An output current measuring unit that measures a current flowing through the load, or an input unit that receives an input of a current value flowing through the load;
A power supply voltage storage unit in which voltage information of the power supply is set;
An output voltage estimated value is calculated based on the output power load factor in the past phase control cycle or the effective load factor corresponding to the firing angle in the past phase control cycle and the voltage information of the power source. An output voltage estimator;
With
The AC power regulator according to claim 2, wherein the output power estimated value is calculated based on the output voltage estimated value and a current value flowing through the load.   The feedback control unit that performs feedback control based on a deviation between a target power calculated from the target load factor and the maximum target power value and the output power estimated value. 4. The AC power regulator according to any one of 3. The output power estimation unit is
An output current measuring unit that measures a current flowing through the load, or an input unit that receives an input of a current value flowing through the load;
A power supply voltage storage unit in which voltage information of the power supply is set;
Based on the output power load factor in the past phase control cycle or the effective load factor corresponding to the firing angle in the past phase control cycle, the current value flowing through the load, and the voltage information of the power source A maximum firing angle output power estimator that calculates a maximum firing angle output power estimate that is an estimated output power when the firing angle is maximum;
The AC power regulator according to claim 2, further comprising:   6. The output power load factor is calculated by dividing a value obtained by multiplying the target load factor by the maximum target power value by the output power estimated value at the maximum firing angle. AC power regulator. With thyristor,
A thyristor firing processing unit for controlling the thyristor based on the firing angle;
The AC power regulator according to any one of claims 1 to 6, further comprising:   A voltage drop value in the power supply line is calculated based on a preset impedance of the power supply line and a measured value of the current flowing through the load in the past phase control cycle, and the voltage drop value is calculated as the voltage of the power supply. The AC power regulator according to claim 1, wherein the AC power regulator is subtracted from the information.   8. The AC power regulator according to claim 1, wherein a load voltage generated in the load at a firing angle of 100% is set in advance as the voltage information of the power source. 9. .

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