JP6521174B2 - AC power regulator and AC power control method - Google Patents

Description

  The present invention relates to an AC power regulator and an AC power control method for performing control of 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, 200 V), various electric devices (loads) may change the necessary power depending on the operating state, so that commercial AC An AC power regulator that regulates the voltage of an AC power supply and supplies it to a load is used.
In such a power regulator, there are a phase control method, a time division control method, an amplitude control method and the like as a control method thereof. In addition to these types of control methods, there is control (constant power control) for outputting power proportional to the input also in power supply voltage fluctuation and resistance value fluctuation (due to aging deterioration or temperature change).
Patent Document 1 discloses a technique related to constant power control in a phase control method for such a control method.

Japanese Utility Model Sho 62-195814

By using the constant power control, even if the power supply voltage fluctuation and the resistance value fluctuation occur, the control that automatically follows them is performed. For example, a silicon carbide heater (a load with a large resistance value fluctuation due to aging) 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 at the load, a circuit therefor is necessary. In particular, components required for voltage measurement (mainly transformers) are burdensome in terms of cost and required space.

  The present invention, in view of the above point, in an AC power regulator using a phase control method and an AC power control method, controls a load having a resistance value fluctuation due to aging deterioration etc. by following this. It is an object of the present invention to provide an AC power regulator and an AC power control method capable of reducing costs and downsizing the apparatus.

(Configuration 1)
An AC power regulator that performs control of power supply to a load by phase control, wherein voltage information of a power supply connected to the preset load, and a measured value of current flowing to the load in a past phase control cycle An output power estimation unit that calculates an output power estimation value based on phase control information, a given target load factor, and a target power to be supplied to a load when the preset target load factor is 100% An output power load factor / ignition angle which calculates the output power load factor corrected the target load factor based on the maximum target power value and the output power estimated value, and calculates the ignition angle corresponding thereto An AC power regulator characterized by performing pseudo constant power control by including a calculation unit.

(Configuration 2)
The AC power conditioner 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 measurement unit that measures the current flowing to the load, or an input unit that receives an input of a current value flowing to the load, and a power supply voltage storage unit to which voltage information of the power supply is set An output voltage estimation value is calculated based on the output power load factor in the past phase control cycle or the load factor of the effective value corresponding to the firing angle in the past phase control cycle, and the voltage information of the power supply. The AC power adjustment according to Configuration 2, further comprising: calculating the output power estimated value based on the output voltage estimated value and the current value flowing to the load. vessel.

(Configuration 4)
A feedback control unit for performing 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; AC power regulator as described in any one.

(Configuration 5)
An output current measurement unit that measures the current flowing to the load, or an input unit that receives an input of a current value flowing to the load, and a power supply voltage storage unit to which voltage information of the power supply is set A load factor of an effective value corresponding to an output power load factor in the past phase control cycle or a firing angle in the past phase control cycle, a current value flowing to the load, and voltage information of the power supply And a maximum firing angle output power estimation unit that calculates a maximum firing angle output power estimation value that is an estimation value of the output power when the firing angle is maximum. AC power regulator as described.

(Configuration 6)
The output power load factor is calculated by dividing the value obtained by multiplying the target load factor by the maximum target power value by the maximum ignition angle output power estimate value. AC power regulator.

(Configuration 7)
7. An AC power conditioner as described in any one of configurations 1 to 6, comprising: a thyristor; and a thyristor-firing processing unit that controls the thyristor based on the firing angle.

(Configuration 8)
The voltage drop value in the power supply line is calculated based on the preset power supply line impedance and the measured value of the current flowing to the load in the past phase control cycle, and the voltage drop value is used as the voltage of the power supply. Configuration according to any of the configurations 1 to 7, characterized in that it is subtracted from the information.

(Configuration 9)
7. The AC power conditioner as set forth in any one of the constitution 1 to the constitution 7, wherein a load voltage generated in the load at a firing angle of 100% is preset as voltage information of the power supply.

(Configuration 10)
An AC power control method for performing control of power supply to a load by phase control, comprising: voltage information of a power supply connected to a preset load, and a measured value of current flowing to the load in a past phase control cycle A process of calculating an output power estimated value based on phase control information, a given target load factor, and a maximum target power which is a target power to be supplied to a load when the preset target load factor is 100%. Executing a process of calculating an output power load factor with the target load factor corrected based on a value and the output power estimated value, and a process of calculating a firing angle corresponding to the output power load factor The alternating current power control method characterized by performing pseudo | simulated constant power control by carrying out.

(Configuration 11)
The AC power control method according to Configuration 10, wherein the phase control information in the past phase control cycle is a firing 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 load factor of the effective value corresponding to the firing angle in the past phase control cycle, and the voltage information of the power supply. The process according to Configuration 11, wherein the process of calculating the estimated output power value is performed based on the process, the estimated output voltage value, and a current value obtained by measuring the current flowing to the load. 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. AC power control method as described.

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

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

  According to the AC power regulator and the AC power control method of the present invention, the output power estimated value is calculated based on the voltage information of the power supply connected to the preset load and the measured value of the current flowing to the load. It is possible to perform pseudo constant power control based on the difference between this and the target power value (the product of the target load factor given and the preset maximum target power value). It is possible to control following a load having resistance value fluctuation. In addition, since a circuit for voltage measurement can be unnecessary, cost reduction and downsizing of the device can be achieved.

1 is a schematic block diagram showing the configuration of the AC power regulator of Embodiment 1 according to the present invention The flowchart which shows the outline of the processing operation regarding the present invention of the exchange power regulator of Embodiment 1 (A) A graph showing the conversion of the average value of power from the load factor to the firing angle, (b) A graph showing the conversion from the firing angle to the load factor of the effective value Schematic block diagram showing another configuration example of the AC power regulator according to the present 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 exchange power regulator of Embodiment 2 Schematic block diagram showing another configuration example of the AC power regulator according to the present invention The schematic block diagram which shows the structure of the alternating current power regulator of Embodiment 3 which concerns on this invention Schematic block diagram showing another configuration example of the AC power regulator according to the present 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 embodying this invention, Comprising: This invention is not limited within the range.

First Embodiment
FIG. 1 is a block diagram schematically showing the configuration of an AC power regulator according to a first embodiment of the present invention. The AC power regulator 100 according to the present embodiment is an AC power regulator that performs control of power supply to a load by phase control, and a target load factor (0) input from a temperature regulator (not shown) that is an external device. Control of the power supply from the AC power supply 3 to the heater which is the load 2 is performed on the basis of (100% to 100%).
The AC power regulator 100 of this embodiment is
The voltage information of the AC power supply 3 set in advance, the measured value of the current flowing to the load 2 in the past phase control cycle, and the phase control information in the past phase control cycle (in the present embodiment, phase control of the past phase control cycle An output power estimation unit 120 which 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 to be supplied to the load when the target load factor is 100%), and an output power estimated value An output power load factor / firing angle calculation unit 110 which calculates an output power load factor θ obtained by correcting the target load factor, and calculates a firing angle φ corresponding to the output power load factor θ,
A thyristor firing processing unit 130 that controls the thyristor 140 based on the firing angle φ;
And a thyristor 140 for switching power supply from the AC power supply 3 to the load 2 according to the ignition signal output from the thyristor ignition processing unit 130.
Note that the firing angle is the half cycle of the AC voltage in the section from the firing point, which is the timing to turn on the 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. The ratio to

The output power estimation unit 120
An output voltage estimation unit 121 of a previous cycle that calculates an estimated output voltage 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 measurement unit 122 of a previous cycle that measures an output current flowing to the load 2 in response to a signal from the current transformer 4 (external device);
The output power estimated value calculation unit 123 of the previous cycle calculates an output power estimated value from the output voltage estimated value and the output current measured value.
The output voltage estimation unit 121 of the previous cycle is
The firing angle of the previous cycle → effective value load factor conversion unit 1211 that calculates the load factor of the effective value corresponding to the firing angle φ,
A power supply voltage storage unit 1212 in which voltage information (effective value) of the AC power supply 3 is set;
The output voltage estimated value calculation unit 1213 of the previous cycle calculates the 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 / firing angle calculation unit 110
A maximum target power value storage unit 112 in which the maximum target power value given to the load 2 is stored;
A target power calculation unit 111 that calculates a target power value based on the target load factor and the maximum target power value given from the temperature controller that is an external device;
PID control (feedback control) is performed based on the deviation between the target power value and the output power estimated value obtained from the output power estimation unit 120 (deviation between the output value and the target value), and the output power load factor a PID control calculation unit 113 that calculates θ (a corrected target load factor);
A power load factor → ignition angle converter 114 is provided to convert the output power load factor θ into the ignition angle φ.

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

Although the output current measurement unit 122 of the previous cycle measures the value of the output current at the load 2, it is basic to acquire the output current value output in each control cycle in real time during the control cycle. The output current value obtained from the output current measurement unit 122 of 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 its control cycle” means that the current measurement value (the AD conversion instantaneous value), which is an instantaneous value obtained based on the sampling cycle, Since the output current value is obtained based on this during the control cycle, the output current value of the current control cycle (the real-time control cycle) can be obtained only at the timing when the current control cycle ends. is there.
The present process (phase control) is for calculating the firing angle φ in the current control cycle, and it is basically difficult to use the output current value of the current control cycle (the control cycle in real time), and thus the previous cycle Use the value of

As described above, the output power estimation unit 120 is based on the voltage of the AC power supply 3 set in advance, the load factor in the previous control cycle, and the measured value of the output current (the output current value in the previous control cycle). To calculate an estimated output power value.
Further, output power load factor / firing angle calculation section 110 sets firing angle φ corresponding to output power load factor θ based on the given target load factor, maximum target power value, and output power estimated value. Specifically, the target power value is calculated from the product of the given target load factor and the maximum target power value, and the difference between the target power value and the estimated output power value in the previous control cycle is calculated. Based on the PID control, the output power load factor θ is calculated, and the call-calling angle φ corresponding to this is obtained.
In addition, PID control itself uses the technique conventionally used, and the description regarding this is omitted.

Specifically, taking the deterioration of the SiC heater as an example, the case where it is used until the resistance value is twice the initial value (when the resistance value is twice the life of the heater) will be described below.
The initial resistance value of the load (heater) is 20Ω, and it is used until it becomes 40Ω by aging, and the case where the power supply voltage is 200V is described as a specific numerical value as an example.
Power consumption 1000 W (200 V ÷ 40 Ω × 200 V) of the load at the maximum firing angle at a resistance value of 40 Ω determined to be the life of the load is set as the maximum target power value, and the target load factor is 100%. It explains with a concrete numerical value. In this case, the target power is 1000 W (1.0 × (100%) 1000 W), but since there is no information of the previous cycle at the first control cycle, the target load factor (100%) is taken as the output power load factor. Since the arc angle is calculated to be 100%, the output power is 2000 W (200 V ÷ 20 Ω × 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 firing angle of the previous cycle is 100% and the measured current is 10 A (200 V ÷ 20 Ω), the output power estimated value 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 output power estimated value is +1000 W. When this deviation is subjected to PID calculation, the output power load factor of the next cycle becomes a value smaller than 100%. The same operation is repeated from the third time onwards, and finally, the output power and the target power are stabilized at an output power load ratio of 50% (ignition angle = 50%) at which the target power matches.
Next, the case where the resistance value of the load is degraded to 40 Ω in the above example will be described. As in the case of 20Ω, since the information on the previous control cycle is not available 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% and the output current is 5A The output power is 1000 W (200 V × 5 A). Therefore, in the second and subsequent cycles, the power load factor is 100%, the measured current is 5A, and the output power estimated value is the same as the target power of 1000W (200V x 5A), so the deviation between them is 0W. However, 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 at 1000 W.
As mentioned above, although the case where the target load factor was 100% was explained, the output power is the target load factor × the output power value at the maximum firing angle regardless of the target load factor being any value between 0 and 100%. 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 to gradually increase the output) or the like which is the prior art.

Since the process of converting the output power load factor θ into the call-off angle φ, the power load factor → firing angle converter 114 corresponds to each output power load factor θ for simplification and speeding up of the calculation. Has a table with a defined firing angle φ.
FIG. 3A shows a graph of the correspondence between the output power load factor θ (load factor of power (average value)) and the firing angle φ. A table corresponding to the correspondence relationship of the graphs is provided in the power load factor → firing angle conversion unit 114.
Similarly, in order to obtain the load factor of the effective value in the previous control cycle, the firing angle of the previous cycle → effective value load factor conversion unit 1211 determines the load factor of the effective value corresponding to each firing angle φ. Have a table.
FIG. 3B shows a graph of the correspondence between the firing angle φ and the load factor of the effective value. 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.
Instead of holding the table, the firing angle φ is calculated from the output power load factor θ as needed based on the equation corresponding to the graph of FIG. 3 (or the load factor of the effective value is calculated as needed from the firing angle φ). ) May be.
In addition, unless there is particular notice, each value such as voltage and current in the embodiment is an effective value, and the load factor obtained by converting the firing angle φ described above is also a load factor of the effective value. The load factor of the effective value is the effective voltage value, the maximum value of the effective current value (the effective value of the voltage applied to the load when the firing angle is 100%, or the effective value of the current flowing to the load). The effective value of the output voltage at the angle φ or the normalized value of 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 corrected for the target load factor is also the load factor as the average power value.

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

As understood from the above, the output voltage estimated value is the output voltage calculated (estimated) based on the load factor and the power supply voltage (set value), and the estimated output voltage and the measured value are used. An output power estimated value is an output power estimated by a certain output current value.
Although the power supply voltage is different if a very poor quality power supply is used, etc., the fluctuation is usually not large, and is in the range of several percent if any. On the other hand, for example, in the case of a silicon carbide-based heater, the resistance value reaches 3 to 4 times the initial value due to aging (the life is taken as 3 to 4 times the initial value). That is, when considering "constant power control to output power proportional to the input even for power supply voltage fluctuation and load fluctuation", the load fluctuation response is substantially greater in specific gravity substantially, It can be said that the need for coping with supply voltage fluctuations is not high. The present invention pays attention to this point which has not been particularly conscious until now, and uses not the measured value for the output voltage but the power supply voltage stored as a preset value and the estimated value calculated from the output firing angle Thus, the cost can be reduced and the device can be miniaturized.

  Next, the processing operation regarding the present invention of the alternating current power regulator 100 of the embodiment 1 having the configuration described above will be described with reference to FIG.

Step 201 is an initialization process in which 1 is substituted for n. n is an integer value indicating a control cycle. When n = 1, the first control cycle is shown, and when n = 100, the 100th control cycle is shown. The control cycle of the phase control is usually the same as the half cycle of the AC power supply voltage, and the half cycle of the AC power supply voltage is the control cycle in this embodiment as well.
n is a variable used for the convenience of description and is not necessarily required in the control process of an actual device.

In step 202, it is determined whether or not the control cycle n is one. If it is one, the process goes to step 203, and if it is other than one, the process goes to step 204.
In the case of the first control cycle, the given target load factor is taken 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 (feedback control) that requires the result in the previous control cycle 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 calculates the target load factor n (the target load factor in the nth control cycle. It indicates that there is a certain value, and each subsequent subscript is also synonymous), the maximum target power value is multiplied, and this is taken as the target power value n.

In the output voltage estimation unit 121 of the previous cycle, the firing angle? Effective value load factor conversion unit 1211 of the previous cycle is stored by the firing angle? N-1 (processing of step 211 described later (processing of the previous cycle) By converting the load factor n-1 of the effective value by the power supply voltage obtained from the power supply voltage storage unit 1212 in the output voltage estimated value calculation unit 1213 of the previous cycle. The output voltage estimated value n-1 is calculated (steps 205 to 206).
Further, the output current measurement unit 122 of the previous cycle measures the output current flowing to the load 2 and acquires the output current measurement value n-1 (step 207).

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

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 estimated output power value n-1 obtained in step 208. , Output power load factor θn.
A process of converting the output power load factor θn into the firing angle φn is performed in the power load factor → firing angle conversion unit 114 (step 210), and the thyristor-firing processing unit 130 generates a thyristor based on the firing angle φn. Drive 140 (step 212). The firing angle φ n acquired in step 210 is temporarily stored for use in the processing of the next cycle (step 211).

  The series of processes of step 202 to step 212 described above are repeated for each control cycle. That is, n is incremented in synchronization with the control cycle (step 213), and the process returns to step 202 to repeat the above process (if the end instruction is issued, the process is terminated (step 214: Yes) → Finish)).

According to the AC power regulator 100 of the present embodiment having the above configuration and processing operation, the voltage information of the AC power source set in advance, the firing angle of the previous cycle, and the measured value of the current flowing through the load 2 Based on the above, the output power estimate value is calculated, and based on the difference between this and the target power value (the product of the given target load factor and the preset maximum target power value), the load fluctuation is followed in a pseudo manner Constant power control can be performed. Thereby, it is possible to perform control following to a load having a resistance value fluctuation due to aging deterioration etc., and obtain an AC power regulator in which cost reduction and downsizing of the device are achieved. (The transformer for voltage measurement can be eliminated, which has been a burden in terms of cost and space).
As a specific application, it is suitable for a load with large resistance fluctuation due to aging with silicon carbide heater etc., but there is load fluctuation due to other factors (eg resistance fluctuation with temperature change) It is also effective for load etc.).

  The output power estimation unit 120 outputs based on the voltage information of the AC power supply set in advance, the firing angle (the load factor of the effective value corresponding to that), and the measured value of the current flowing through the load 2 It is sufficient that the power estimated value can be calculated. 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 estimated value n-1 is calculated from the output voltage estimated value n-1 and the output current measured value n-1 (a load resistance estimating unit 124 of the previous cycle is provided). The 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 square of the output voltage estimated value n-1 is the load resistance estimated value n− It may be divided by 1. (Alternatively, the value obtained by squaring the output current measurement value n-1 may be multiplied by the load resistance estimated value n-1. Any one of them is similar in concept.)

  In the present embodiment, as an example of feedback control, one that performs PID control is taken as an example, but other feedback control (for example, PI control or the like) may be used.

Second Embodiment
FIG. 5 is a block diagram showing an outline of the configuration of an AC power regulator according to a second embodiment of the present invention. About the same composition as Embodiment 1, the same numerals as FIG. 1 are used, and explanation here is omitted or simplified.

In the AC power regulator 100 of the first embodiment, the output power estimated value is calculated, and feedback control is performed based on the deviation between this and the target power value to calculate the output power load factor θ. On the other hand, in the AC power regulator 300 of the present embodiment, the maximum firing angle output power estimated value, which is the estimated value of the output power when the firing angle is at the maximum (100%), is calculated. Based on the hourly output power estimated value and the target power value, the output power load ratio θ is calculated by correcting the target load ratio.
In order to calculate the maximum firing angle output power estimated value, AC power regulator 300 causes output power estimating unit 120 to calculate maximum firing angle output current estimation unit 125 for the previous cycle and maximum firing for the previous cycle. And an angular output power estimation unit 126.
Further, in order to perform correction processing using the estimated value of the maximum firing angle output power, the output power load factor / ignition angle calculator 110 replaces the PID control calculator 113 with the output power load factor calculator 115. Have.

Output power estimating section 120 in AC power regulator 300 has a load factor of an effective value corresponding to the firing angle in the previous control cycle, a current value flowing to load 2 in the previous control cycle, voltage information of the power supply, The maximum firing angle output power estimated value is calculated based on
Therefore, in the maximum firing angle output current estimation unit 125 of the previous cycle, the load of the effective value corresponding to the firing angle in the previous control cycle obtained from the firing angle → effective value load factor conversion unit 1211 of the previous cycle. The output current for the maximum firing angle (100%) in the previous control cycle is calculated (estimated) based on the ratio and the output current measurement value in the previous control cycle obtained from the output current measurement unit 122 Ru.
The maximum firing angle output power estimation unit 126 in the previous cycle estimates the maximum firing angle (100%) converted output current in the previous control cycle obtained from the maximum firing angle output current estimation unit 125 in the previous cycle. Based on (maximum ignition angle output current estimated value) and the power supply voltage value obtained from the power supply voltage storage unit 1212, the maximum ignition 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 load factor of the effective value corresponding to the firing angle in the previous control cycle. ) Estimate the maximum firing angle output power estimated value in the previous control cycle by calculating the converted output current estimated value (maximum firing angle output current estimated value) and multiplying it by the power supply voltage value .
Further, the output power load factor calculation unit 115 in the output power load factor / firing angle calculation unit 110 outputs the target power value obtained from the target power calculation unit 111 and the maximum firing angle output obtained from the output power estimation unit 120. Based on the estimated power value, the output power load factor θ is calculated by correcting the target load factor.
Specifically, output power load ratio θ is calculated by dividing the target power value by the estimated value at maximum firing angle output power in the previous control cycle.

An example similar to that of Embodiment 1 will be specifically described.
As in the first embodiment, use of the load is achieved by setting the power consumption 1000 W (200 VΩ40 Ω × 200 V) of the load when the resistance value determined to be the life of the load is 40 Ω to the maximum target power value. A concrete numerical value demonstrates that it is possible to prevent the relationship between the target load factor and the power consumption of the load from changing from the start to the end of the life. First, the case where the resistance value of the load is 20 Ω which is the initial value and the target load factor is 100% will be described. The target power in this case is 1000 W (1.0 (100%) × 1000 W), but since there is no information of the previous cycle in the first control cycle, the output power load factor is 100% the same as the target load factor. When the thyristor is turned on at 100% where the value is converted to the firing angle, the output current is 10 A (200 V ÷ 20 Ω) and the output power is 2000 W (200 V × 10 A). In the second cycle, the maximum load point of the previous control cycle is calculated from the actual load ratio 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. The arc angle output current estimated value 10A is calculated, and the maximum firing 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). Assuming that the target power is 1000 W as in the first control cycle, the output power load factor (target power 電力 maximum firing angle output power estimated value) is 0.5 (50%), and this value is fired. At 50% converted to corners, turn on the thyristor. As a result, the output power is 1000 W, which is the same as the target power. In the third control cycle, the effective load factor of the previous cycle 0.707 (square root of 0.5 (50%)) calculated from the firing angle of 50% of the second control cycle, and the second control cycle From the measured value of the output current 7.07 A (effective value), the output current estimated value 10 A at the maximum firing angle of the previous control cycle (7.07 A ÷ 0.707 (70.7%)) is calculated. Based on the product of this value and the power supply voltage, the output power load factor is 50% (1000 W ÷ 2000 W = 0) from the maximum firing angle output power estimate 2000 W for the previous cycle and the target power 1000 W .5) Calculate. When the thyristor is turned on at 50% after converting this value to the firing angle, the output power becomes 1000 W 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 has the same value as the target power.
Next, the case where the resistance value of the load is degraded to 40 Ω in the above specific example will be described. As in the case where the load resistance is 20Ω, the output power load factor is 100%, which is the same as the target load factor, since there is no information on the previous cycle in the first control cycle. The output current is 5 A (200 V ÷ 40 Ω), and the output power is 1000 W (200 V × 5 A). In the second cycle, the maximum load angle output current estimated value 5A (5A ÷ 1 (100%) from the effective load ratio 100% calculated from the firing angle 100% in the previous cycle and the measured output current 5A in the previous cycle )), 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. Also, 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 this value is 100% when converted to the firing angle. Therefore, the output power is 1000 W, which is the same as the target power. The same results are obtained for the third and subsequent times.
As mentioned above, although the case where the target load factor was 100% was explained, the output power is the target load factor × the output power at the maximum firing angle when the target load factor is any value between 0 and 100%. Controlled by value. Further, 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) or the like which is the prior art.

  Next, the processing operation of the AC power regulator 300 of the second embodiment in each control cycle according to the present invention will be described with reference to FIG. The same processing concept as in the first embodiment (FIG. 2) is denoted by the same reference numeral, and the description thereof is omitted or simplified.

  The processes in steps 201 to 207 are basically the same as in the first embodiment, but in the present embodiment, the maximum point instead of the calculation process (step 206) of the output voltage estimated value n-1 in the first embodiment A calculation process (step 601) of the output current estimated value n-1 at the arc angle (100%) is executed. The process 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 as described above.

In step 602 following step 601, the maximum firing angle output power estimation unit 126 in 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 maximum firing angle output power estimated value n-1 is calculated.
In the following step 603, the output power load factor calculating unit 115 divides the target power value n obtained from the target power calculating unit 111 by the maximum firing angle output power estimated value n-1 calculated in step 602. Then, the output power load factor θn is calculated.

  The process after the output power load factor θn is calculated is the same as that of the first embodiment.

According to the AC power regulator 300 of the present embodiment having the above-described configuration and processing operation, as in the first embodiment, the circuit for voltage measurement (in particular, the transformer) can be eliminated, thereby reducing cost and It is possible to obtain an AC power regulator whose device has been miniaturized.
Further, compared to feedback control such as PID control in the first embodiment, it is possible to obtain a high-speed response.

  Note that the output power estimation unit 120 determines the maximum point based on the voltage information of the power supply set in advance, the firing angle (the load factor of the effective value corresponding to that), and the measured value of the current flowing through the load 2 It is sufficient that the arc angle output power estimated value can be calculated. In AC power regulator 300 of FIG. 5, after calculating the maximum firing angle output current estimated value n-1, by multiplying this by the power supply voltage, 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. The maximum firing angle output power estimate value n-1 may be calculated by dividing the power supply voltage squared by the load resistance estimate value n-1 by providing the load resistance estimation unit 124 of the cycle). . (Alternatively, the value obtained by squaring the maximum firing angle output current estimate value n-1 may be multiplied by the load resistance estimate value n-1. The concept is the same. )

Embodiment 3
FIG. 8 is a block diagram showing an outline of a configuration of an AC power regulator according to a third embodiment of the present invention. About the structure similar to Embodiment 1 or 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 output power estimated value is calculated by using the power supply voltage (effective value) of the AC power supply 3 preset in the power supply voltage storage unit 1212 as it is. On the other hand, the AC power regulator of the present 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 determines the voltage drop in the power supply line based on the preset power supply line impedance and the measured value of the current flowing to 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 supply.
The AC power regulator 500 of FIG. 8 includes an output voltage calculation unit 150 for calculating an output voltage obtained by subtracting a voltage drop in a power supply line from a power supply voltage.
The output voltage calculation unit 150
A power supply line resistance value storage unit 153 in which the impedance value of the power supply line is preset;
Multiplying the output current estimated value at the firing angle 100% of the previous cycle obtained from the maximum firing angle output current estimation unit 125 of the previous cycle (similar to the second embodiment) by the impedance value of the power supply line And the maximum firing angle output voltage drop calculation unit 152 in the previous cycle that calculates (estimates) the voltage drop value in the power supply line when the firing angle is 100% in the previous cycle;
Before performing processing of subtracting the voltage drop in the power supply 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 A maximum firing angle output voltage calculation unit 151 of the cycle,
Equipped with
Here, as the firing angle of the previous cycle → effective value load factor conversion unit 1211, the firing angle storage unit of the previous cycle for temporarily storing the firing angle of the previous cycle, and the point of FIG. Although it is illustrated as having a firing angle → load factor conversion unit for converting each firing angle φ into a load factor (effective value) from the correspondence relationship between the arc angle φ and the load factor (effective value) The concept is similar to that of the firing angle of the previous cycle → effective value load factor conversion unit 1211 in the first and second embodiments.
Further, as maximum target power value storage unit 112, a rated current storage unit in which a rated current flowing through load 2 is preset, and a power supply voltage preset in the set rated current and power supply voltage storage unit 1212 And a rated power calculation unit that calculates a rated power (maximum power) by multiplying the powers by the same as the maximum target power value storage unit 112 in the first and second embodiments as a concept. It is.

  The AC power regulator 500 according to the present embodiment calculates “the output voltage at the firing angle 100% 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 of FIG. 2). In addition, since it is the same as that of Embodiment 1 except this, explanation here is omitted.

  As described above, according to the AC power regulator 500 of the present embodiment, processing is performed in consideration of the voltage drop in the power supply line, so that the processing accuracy can be further enhanced. The equipment installed in the factory often requires the power supply line to be long due to the arrangement, and therefore, the resistance value of the power supply cable may become a non-negligible size. In addition, 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 size that can not be ignored. According to the AC power regulator 500 of the present embodiment, even in such a case, the voltage drop due to the impedance of the power supply line is corrected, so that processing can be performed with high accuracy, which is preferable.

The AC power regulator 500 of FIG. 8 is an example in which the concept of “compensate for the voltage drop in the power supply line” is applied to the first embodiment, but “compensate for the voltage drop in the power supply line” in this embodiment. The concept of can be naturally 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 configuration and the processing concept thereof are the same, the description regarding the AC power regulator 600 is omitted.
Similarly, the concept of “correcting the voltage drop in the power supply line” in the present embodiment can, of course, be applied to those illustrated in FIGS. 4 and 7.

  The “impedance of the power supply line” set in advance in the power supply line resistance storage unit 153 may be determined by measuring the impedance of the corresponding portion 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 being processed, etc.).

In the present 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 to the load in the past phase control cycle, Although 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, the load voltage generated in the load 2 at the firing angle 100% is obtained in advance And the like, and the load voltage generated in the load 2 when the firing angle is 100% may be set in advance in the power supply voltage storage unit 1212.
That is, the configuration of the AC power regulator is the same as that of the first embodiment (or the second embodiment), and the output of the firing angle is 100% in the state where the actual target device is installed. The generated load voltage may be measured and preset in the power supply voltage storage unit 1212 (the process itself may be the same as in the first embodiment (FIG. 2) or the second embodiment (FIG. 6)).
By using “the load voltage generated at load 2 when the firing angle is 100%”, “compensating for the voltage drop in the power supply line (portion other than load 2)” is equivalent to the state in which the correction has already been performed. While the processing itself is the same as Embodiment 1 or Embodiment 2, similar effects can be obtained.

  In the above embodiments, the firing angle of the previous cycle → effective value load factor conversion unit 1211 uses the firing angle of the previous control cycle as “phase control information in the past phase control cycle”, and loads the effective value. In this example, the rate conversion is used, but the square root (load rate of the effective value) of the output power load factor θ of the previous control cycle calculated by the PID control calculation unit 113 or 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 another function such as soft start, for example, the square root of the output power load factor θ of the previous control cycle is simply used to obtain the correct result. Absent. Therefore, in this case, it is necessary to use the method described in the embodiment or to consider the influence of other functions such as soft start. The calculation process of the square root of the output power load factor θ (load factor of effective value) increases the calculation load, so a table (table for converting the output power load factor θ into a load factor of effective value) is previously It may be provided.

  In each embodiment, the output current measurement unit 122 of 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 Alternatively, the AC power regulator may be provided with only an input unit for receiving an input of the output current value (without the output current measurement unit 122 of the previous cycle) or the like.

In each embodiment, the “previous control cycle (past phase control cycle)” is described as the closest (previous cycle) cycle, but the “previous control cycle (past phase)” in the present invention is described. The “control cycle)” is not limited to this, and, for example, several cycles before may be “previous control cycle (past phase control cycle)”.
What defines each operation of the “current control cycle” (each embodiment) is more preferable based on the measurement value of the last (one previous) cycle, etc., but, for example, a control cycle two cycles before As “preceding control cycle (past phase control cycle)”, the problem is as an operation even if each operation of “this control cycle” is determined based on the measured value etc. in the control cycle two cycles before. Absent.

  In each embodiment, an example is described in which the output power estimated value (or the maximum firing angle output power estimated value) or each value for calculating this is calculated for each control cycle, but the present invention Is not limited to this. For example, if the main purpose is to follow the aging of the resistance value, it is not always necessary to detect the influence of the change in the resistance value every control cycle. In such a case, for example, the maximum firing angle output power estimated value described in the second embodiment is calculated in cycles of daily units, monthly units, etc., and stored (stored in cycles of daily units, monthly units, etc.). Even if the target power calculation unit 111 calculates the target power value by multiplying the target load rate by the stored maximum firing angle output power estimated value, etc. Good.

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

Claims (9)

An AC power regulator that performs control of power supply to a load by phase control, comprising:
Output power estimation for calculating an output power estimated value based on voltage information of a power supply connected to the load set in advance, and a measured value of current flowing to the load in the past phase control cycle and phase control information Department,
The target load factor is determined based on the given target load factor, the maximum target power value which is the target power supplied to the load when the preset target load factor is 100%, and the output power estimated value. An output power load factor / firing angle calculation unit that calculates a corrected output power load factor and calculates a firing angle corresponding to the calculated output power load factor;
An AC power regulator characterized by performing pseudo constant power control by providing   The AC power regulator according to claim 1, wherein the phase control information in the past phase control cycle is a firing angle in the past phase control cycle or an output power load factor in the past phase control cycle. The output power estimation unit
An output current measurement unit that measures a current flowing to the load, or an input unit that receives an input of a current value flowing to 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 load factor of the effective value corresponding to the firing angle in the past phase control cycle, and the voltage information of the power supply. An output voltage estimation unit,
Equipped 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 to the load.   A feedback control unit for performing feedback control based on a deviation between a target power calculated from the target load factor and the maximum target power value and the estimated output power value is provided. The alternating current power regulator according to any one of 3. The output power estimation unit
An output current measurement unit that measures a current flowing to the load, or an input unit that receives an input of a current value flowing to 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 load factor of the effective value corresponding to the firing angle in the past phase control cycle, the current value flowing to the load, and the voltage information of the power supply A maximum firing angle output power estimation unit that calculates a maximum firing angle output power estimated value that is an estimated value of output power when the firing angle is maximum;
The AC power regulator according to claim 2, comprising:   The output power load factor is calculated by dividing the value obtained by multiplying the target load factor by the maximum target power value by the estimated output power at the maximum firing angle. AC power regulator. With a thyristor,
A thyristor firing unit that controls the thyristor based on the firing angle;
The AC power regulator according to any one of claims 1 to 6, comprising:   The voltage drop value in the power supply line is calculated based on the preset power supply line impedance and the measured value of the current flowing to the load in the past phase control cycle, and the voltage drop value is used as the voltage of the power supply. The AC power regulator according to any one of claims 1 to 7, which subtracts from information.   The AC power regulator according to any one of claims 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 supply. .

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