JP4162546B2 - Power control method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a power supply control technique, and more particularly to a control method for digitally controlling a power supply.
[0002]
[Prior art]
Reference numeral 801 in FIG. 6 is a conventional power supply, and FIG. 7 is a flowchart for controlling the power supply apparatus 801.
[0003]
The configuration of the power supply device 801 will be described. The power supply device 801 includes a transformer 805, an input capacitor 815 and a switching element 812 are disposed on the primary side, and a rectifier circuit 822 and a smoothing circuit are disposed on the secondary side. 824 is arranged.
[0004]
In the transformer 805, a primary winding 811 and a secondary winding 821 that are magnetically coupled to each other are disposed.
[0005]
A DC voltage is supplied from the DC voltage source 810 between the input terminals 851 and 852 on the primary side. The supplied DC voltage is smoothed by the input capacitor 815, and the primary winding 811 and the switching element 812 are connected in series. Applied to the circuit.
[0006]
A control circuit 840 is connected to the switching element 812, performs a switching operation according to a signal input from the control circuit 840, and causes a current to flow intermittently through the primary winding 811. An alternating voltage is induced in the secondary winding 821 by the current.
[0007]
The AC voltage induced in the secondary winding 821 is rectified and smoothed by the rectifier circuit 822 and the smoothing circuit 824, and applied to the output terminals 853 and 854 via the backflow prevention diode 825 and the current detection resistor 828, respectively. A load 850 is supplied.
[0008]
The output voltage appearing between the output terminals 853 and 854 and the magnitude of the output current flowing through the current detection resistor 828 are input to the control circuit 840, and a series of processing according to the flowchart of FIG. 7 is repeated every predetermined time. The power is supplied to the load 850 by a constant voltage operation or a constant current operation.
[0009]
Referring to the flowchart of FIG. ₁₁ , T ₃₁ Indicates the start of processing, and the detected output voltage and output current are converted into digital values, respectively. ₁₂ , T ₃₂ Is converted into a voltage measurement value VM and a current measurement value IM which are digital values.
[0010]
The voltage measurement value VM and the current measurement value IM are proportionally processed T ₁₇ , T ₃₇ And differential processing T ₁₈ , T ₃₈ And integration processing T ₁₅ , T ₃₅ And voltage addition processing T ₁₆ By each processing T of voltage ₁₇ , T ₁₈ , T ₁₅ Are weighted and added to obtain the voltage control value A, and the current addition process T ₃₆ By each processing T of current ₃₇ , T ₃₈ , T ₃₅ Are weighted and added to obtain a voltage control value C.
[0011]
The power supply device 801 is configured to operate in a constant voltage operation or a constant current operation in a steady state. Therefore, the voltage target value V of a constant voltage output during the constant voltage operation. _A Current target value I of constant current output during constant current operation _A And are set.
[0012]
Here, since the output current is determined by the size of the load 850 during the constant voltage operation, the output current is the current target value I. _A In contrast, during constant current operation, the output voltage is determined by the size of the load 850, so that the output voltage is equal to the voltage target value V. _A It fluctuates in a smaller range.
[0013]
Voltage control value A is the output voltage and voltage target value V _A The current control value C is the output current and the current target value I. _A Therefore, during constant voltage operation, the output current and the current target value I _A Therefore, the current control value C is large, but the output voltage is almost equal to the voltage target value V. _A Therefore, the voltage control value A is a value close to zero.
[0014]
On the other hand, during constant current operation, the output voltage and the voltage target value V _A Therefore, the voltage control value A is large. Conversely, the output current is approximately equal to the current target value I _A Therefore, the current control value C is a value close to zero.
[0015]
Comparison process T ₅₁ Compares the voltage control value A and the current control value C as described above, and selects a value closer to zero as a selection value E. As a result, the voltage control value A is adopted as the selection value E during the constant voltage operation, and the current control value C is adopted during the constant current operation.
[0016]
The selected value E is a D / P output process T ₅₂ When the signal is converted to a drive signal and output to the gate terminal of the switching element 812, the conduction period and the switching frequency of the switching element 812 change so that the value of the selection value E approaches zero.
[0017]
As a result, during constant voltage operation, the output voltage is almost equal to the voltage target value V. _A The output current is almost equal to the current target value V during constant current operation. _A Matches.
[0018]
However, when the operating state is switched between the constant voltage operation and the constant current operation in the power supply device 801 as described above, the output voltage and the output current greatly fluctuate, and it takes a relatively long time to stabilize. There is an inconvenience.
[0019]
[Prior Art Document 1]
JP-A-8-98515
[Problems to be solved by the invention]
The cause of the inconvenience is the voltage integration process S ₁₉ And current integration processing S ₃₉ Due to the nature of
[0020]
Voltage integration process S ₁₉ And current integration processing S ₃₉ The previous processing result of _n-1 , Ii _n-1 In this case, the current processing result Iv _n , Ii _n Is the previous processing result Iv as in the following equations (a) and (b): _n-1 , Ii _n-1 Voltage or current target value V _A , I _A And the voltage or current measured value VM measured this time _n , IM _n And the difference are obtained respectively.
Iv _n = Iv _n-1 + V _A -VM _n ...... (a)
Ii _n = Ii _n-1 + I _A -IM _n ...... (b)
[0021]
Processing result Iv _n , Ii _n Since only a finite number of bits are assigned to the variable that stores the value of, the processing result Iv _n , Ii _n Variables used in are prone to full scale.
[0022]
For example, when the operation is not constant voltage (V _A -VM _n ) Is large, but the voltage integration process S ₁₉ Since the above equation (a) is executed every time, the voltage processing result Iv _n Becomes full scale, and the voltage control value A becomes a large value.
[0023]
On the contrary, the current integration process S is performed even when the constant current operation is not performed. ₃₉ The above equation (b) is executed each time, and the current processing result Iiv _n Becomes full scale, and the control current value C becomes a large value.
[0024]
As a result, when there is a switch between constant voltage operation and constant current operation, voltage or current integration processing S ₁₉ , S ₃₉ Processing result Iv _n , Ii _n It takes a relatively long time to return to a normal value, and the response becomes slow.
[0025]
The present invention has been created to solve the above-described disadvantages of the prior art, and an object of the present invention is to provide a control method in which switching of the output state is fast.
[0026]
[Means for Solving the Problems]
In order to solve the above problems, the invention according to claim 1 is a voltage integration process for obtaining a voltage integration process result using a voltage measurement value indicating the magnitude of the output voltage, and a current measurement indicating the magnitude of the output current. A current integration process for determining a current integration process result using the value, a voltage control value calculation process for determining a voltage control value using the voltage integration process result, and a current control value using the current integration process result. A current control value calculation process to be obtained and a selection process that compares at least the control values including the voltage control value and the current control value, selects any one control value based on the magnitude relationship, and outputs the selected control value And a drive signal output process that converts the selected value into a drive signal, outputs the selected signal to a switching element, and causes the switching element to perform a switching operation according to the drive signal, and repeats each of the processes. In addition, a current corresponding to the switching operation is passed through the primary winding connected to the switching element, a voltage is induced in the secondary winding magnetically coupled to the primary winding, and the induced voltage is rectified. A method for controlling a power supply apparatus that rectifies and smoothes in a smoothing circuit and supplies a load to a load, wherein the voltage integration processing is performed by calculating a difference between the voltage measurement value and a preset voltage target value by performing a previous processing of the voltage integration processing The current integration process includes the voltage integration calculation that adds the result to the current process result, and the current integration process adds the difference between the current measurement value and the preset current target value to the previous process result of the current integration process. Current integration calculation as a result of the current processing, and the voltage integration processing is configured such that the voltage integration calculation is not performed this time when the previous selection value in the selection processing is not the voltage control value. And Serial current integration process, when the selected value of the last in the selection process the current control value is not in the current integral calculation is configured control method so as not to perform this.
The invention according to claim 2 is the control method according to claim 1, wherein the voltage bias value and the current bias value of a predetermined value are preset, and the absolute value of the difference between the voltage control value and the current control value is When the voltage bias value is equal to or less than the voltage bias value, the voltage integration calculation is performed even if the previous selected value is not the voltage control value. When the absolute value of the difference is equal to or less than the current bias value, the previous selection value is determined. In this control method, the current integration calculation is performed even if the value is not the current control value.
The invention according to claim 3 is a voltage proportional process in which a difference between the voltage measurement value and the voltage target value is a current process result, and a current in which a difference between the current measurement value and the current target value is a current process result. Proportional processing, voltage differentiation processing in which the difference between the current voltage measurement value and the previous voltage measurement value is the current processing result, and the difference between the current measurement value and the previous current measurement value is the current processing. Current control processing as a result, and the voltage control value calculation processing multiplies the processing result of the voltage integration processing, the processing result of the voltage proportional processing, and the processing result of the voltage differentiation processing by a predetermined coefficient, respectively. The current control value calculation processing is performed by adding the processing result of the current integration processing, the processing result of the current proportional processing, and the processing result of the current differentiation processing to a predetermined coefficient, respectively. Multiply and add A control method of any one of claims 1 or claim 2, the flow control value.
According to a fourth aspect of the present invention, there is provided a power integration process for obtaining a power integration process result using a power measurement value indicating the magnitude of output power, and a power control value calculation for obtaining a power control value using the power integration process result. The control value to be compared by the selection process includes the power control value, and the power integration process calculates a difference between the power measurement value and a preset power target value. The control method according to any one of claims 1 to 3, further comprising a power integration calculation that is added to the previous processing result of the current processing result to obtain the current processing result.
According to a fifth aspect of the present invention, a power integration process for obtaining a power integration process result using a power measurement value indicating the magnitude of output power, and a difference between the power measurement value and the power target value as a current process result A power proportional process, a power differentiation process in which a difference between the current power measurement value and the previous power measurement value is a current process result, a process result of the power integration process, a process result of the power proportional process, A power control value calculation process that multiplies a result of the power differentiation process by a predetermined coefficient and adds the result to the power control value, and the control value to be compared by the selection process includes the power control value The power integration process includes a power integration calculation in which a difference between the power measurement value and a preset power target value is added to a previous process result of the power integration process to obtain a current process result. The control method according to Item 3.
According to a sixth aspect of the present invention, in the power integration process, when the value previously selected in the selection process is not the power control value, the power integration calculation is not performed in the current power integration process. 6. The control method according to claim 4, wherein the control method is configured.
The invention according to claim 7 is the control method according to claim 6, wherein the first and second power bias values of a predetermined value are preset, and the absolute difference between the voltage control value and the power control value is determined. When the value is less than or equal to the first power bias value and the absolute value of the difference between the current control value and the power control value is less than or equal to the second power bias value, the previous selected value is This is a control method for performing the power integration calculation even if it is not a power control value. The invention according to claim 8 is a voltage integration process for obtaining a voltage integration process result using a voltage measurement value indicating the magnitude of the output voltage, and a current integration process using a current measurement value indicating the magnitude of the output current. A current integration process for obtaining a result, a power integration process for obtaining a power integration process result using a power measurement value indicating the magnitude of output power, and a voltage control value calculation for obtaining a voltage control value using the voltage integration process result Processing, current control value calculation processing for determining a current control value using the current integration processing result, power control value calculation processing for determining a power control value using the power integration processing result, and at least the voltage control value The control value including the current control value and the power control value, select one of the control values based on the magnitude relationship, and output the selected value as a selected value, and drive the selected value Change to signal And a driving signal output process for outputting to the switching element and causing the switching element to perform a switching operation according to the driving signal, repeatedly performing each of the processes, and a primary winding connected to the switching element, A current of a power supply device that supplies a current corresponding to the switching operation, induces a voltage in a secondary winding magnetically coupled to the primary winding, rectifies and smoothes the induced voltage by a rectifying and smoothing circuit, and supplies the rectified smoothing circuit to a load In the control method, the voltage integration processing includes adding a difference between the voltage measurement value and a preset voltage target value to a previous processing result of the voltage integration processing to obtain a current processing result. The current integration process includes adding a difference between the measured current value and a preset current target value to a previous process result of the current integration process to obtain a current process result. The power integration process includes a power integration calculation that adds a difference between the power measurement value and a preset power target value to a previous process result of the power integration process to obtain a current process result, In the voltage integration process, if the previous selection value is not a voltage control value in the selection process, the voltage integration calculation is not performed this time, and the power integration process is performed in the selection process. The power integration calculation is not performed this time when the control value is not a control value, and the current integration process is a control method in which the current integration calculation is not performed this time when the previous selection value is not a current control value. The first and second voltage bias values, the first and second power bias values, and the first and second current bias values are set, and the difference between the voltage control value and the power control value is set. The absolute value of the first voltage When the absolute value of the difference between the voltage control value and the current control value is less than or equal to the second voltage bias value, the previous selected value is not the voltage control value. The voltage integration calculation is performed, the absolute value of the difference between the power control value and the voltage control value is less than or equal to the first power bias value, and the absolute value of the difference between the power control value and the current control value is When the second power bias value is less than or equal to the second power bias value, the power integration calculation is performed even if the previous selected value is not the power control value, and the absolute value of the difference between the current control value and the voltage control value is When the absolute value of the difference between the current control value and the power control value is less than or equal to the second current bias value, the previous selected value is the current control value. It is a control method for performing the current integration calculation even if .
The invention according to claim 9 is a voltage proportional process in which a difference between the voltage measurement value and the voltage target value is a current process result, and a current in which a difference between the current measurement value and the current target value is a current process result. Proportional processing, current proportional processing in which the difference between the power measurement value and the power target value is the current processing result, and voltage in which the difference between the current voltage measurement value and the previous voltage measurement value is the current processing result Differentiation processing, current differentiation processing in which the difference between the current measurement value of this time and the previous current measurement value is the current processing result, and the difference between the current power measurement value and the previous power measurement value are processed this time. Power differential processing as a result, and the voltage control value calculation processing includes a predetermined coefficient for the processing result of the voltage integration processing, the processing result of the voltage proportional processing, and the processing result of the voltage differentiation processing, respectively. Multiply and add to obtain the voltage control value The current control value calculation processing is performed by multiplying the processing result of the current integration processing, the processing result of the current proportional processing, and the processing result of the current differentiation processing by multiplying each by a predetermined coefficient, and adding the current control value. And the power control value calculation processing adds the processing result of the power integration processing, the processing result of the power proportional processing, and the processing result of the power differentiation processing by multiplying each by a predetermined coefficient, and adds the power. The control method according to claim 8, wherein the control value is used.
[0027]
The present invention is configured as described above. When the difference among the voltage control value, the power control value, and the current control value is large, the integral calculation is not performed on the control value that is not selected in the selection process. Therefore, the control value does not saturate to the maximum value, and the transition between operating states is smooth.
[0028]
In addition, voltage, power, and current bias values are set, and in the vicinity of the point at which the operating state switches, the magnitude of the control value at the switching destination is also close to zero, so even if it is not selected in the selection process, it switches. The integration calculation is performed on the previous control value, and the transition of the operation state is performed smoothly.
[0029]
DETAILED DESCRIPTION OF THE INVENTION
Reference numeral 101 in FIG. 1 shows an example of a power supply apparatus to which the control method of the present invention can be applied.
The power supply device 101 includes a transformer 105, a switching element 112, a rectifier circuit 122, and a smoothing circuit 124.
[0030]
Inside the transformer 105, a primary winding 111 and a secondary winding 121 magnetically coupled to the primary winding 111 are provided.
[0031]
The primary winding 111 and the switching element 112 are connected in series. The terminal on the primary winding 111 side of the series connection circuit is connected to the first input terminal 151, and the terminal on the switching element 112 side is the second. Are connected to the input terminal 152. Therefore, the first and second input terminals 151 and 152 are connected by a series connection circuit of the primary winding 111 and the switching element 112.
[0032]
An input capacitor 115 is connected between the first and second input terminals 151 and 152, and a series connection circuit of the primary winding 111 and the switching element 112 is connected in parallel with the input capacitor 115.
[0033]
A DC voltage source 110 is connected between the first and second input terminals 151 and 152. Here, the high voltage side terminal of the DC voltage source 110 is connected to the first input terminal 151, and the ground voltage side terminal is connected to the second input terminal 152, which is output from the DC voltage source 110. The voltage is smoothed by the input capacitor 115 and applied to the series connection circuit of the primary winding 111 and the switching element 112.
[0034]
The rectifier circuit 122 includes two rectifier elements 123. ₁ , 123 ₂ The smoothing circuit 124 has a choke coil 125 and an output capacitor 126.
[0035]
Both ends of the secondary winding 121 are connected to different rectifier elements 123. ₁ , 123 ₂ Are connected to the anode terminals of the two rectifier elements 123, respectively. ₁ , 123 ₂ The cathode terminal is connected to one end of the choke coil 125.
[0036]
An output capacitor 126 is connected between the other end of the choke coil 125 and one end of the secondary winding 121. The terminal on the high voltage side of the output capacitor 126, here the terminal connected to the choke coil 125, is connected to the first output terminal 153 via the backflow prevention diode 129, and the terminal on the low voltage side is The current detection resistor 128 is connected to the second output terminal 154.
[0037]
When the DC voltage is output from the DC voltage source 110 and is applied to the series connection circuit of the primary winding 111 and the switching element 112, when the switching element 112 performs a switching operation, a current flows intermittently through the primary winding. An AC voltage is induced in the next winding 121.
[0038]
The AC voltage induced in the secondary winding 121 is a rectifying element 123. ₁ , 123 ₂ The current flows in one direction in the choke coil 124, and the output capacitor 126 is charged and discharged. As a result, the rectified voltage is smoothed and a DC voltage is obtained.
[0039]
The DC voltage is applied between the first and second output terminals 153 and 154 via the diode 129 and the current detection resistor 128, and is connected between the first and second output terminals 153 and 154. 150.
[0040]
The power supply device 101 can be operated by switching between a constant voltage operation for supplying a constant voltage to the load 150 from the first and second output terminals 153 and 154 and a constant current operation for supplying a constant current depending on the state of the load 150. The constant voltage output by the constant voltage operation and the value of the constant voltage output by the constant current operation are the target voltage V in the power supply device 101. _A And target current I _A Is preset.
[0041]
FIG. 5 (a) is a graph for explaining the operating state of the power supply device 101, and the output current is zero or more. _A (Ampere) The following code L ₁ Is approximately the target voltage V _A Is output and the output voltage is zero or more V _D The following symbol L _Three In the range of approximately target current I _A Operates so that is output. Reference symbol F in FIG. 5A indicates a point at which the constant voltage operation and the constant current operation are switched.
[0042]
A control circuit 140 is connected to the gate terminal of the switching element 112.
The constant voltage output during the constant voltage operation, the constant current output during the constant current operation, and the switching between the constant voltage operation and the constant current operation are performed by the control circuit 140 according to the on / off ratio and the frequency of the switching element 112. It is done by controlling.
[0043]
The inside of the control circuit 140 will be described. The control circuit 140 includes first and second level converters 131 and 132, first and second A / D converters 133 and 134, and a CPU 141. Yes.
[0044]
The voltage between the first and second output terminals 153 and 154 and the voltage across the current detection resistor 128 are level-shifted to an appropriate level by the first and second level converters 131 and 132, respectively. The second A / D converters 133 and 134 are input.
[0045]
The first and second A / D converters 133 and 134 A / D convert the input voltage at regular intervals, and convert the voltage value between the first and second output terminals 153 and 154 into a digital value. The voltage measurement value VM is output, and the voltage value at both ends of the current detection resistor 128, that is, the current magnitude is output as a digital current measurement value IM.
[0046]
The voltage measurement value VM and the current measurement value IM are zero or a positive number, and are digitally converted so as to increase as the output voltage or output current value increases. These voltage measurement value VM and current measurement value IM are input to the CPU 141.
[0047]
Symbol S in the flowchart of FIG. ₁₁ , S ₃₁ Shows the start of processing by voltage detection between the first and second output terminals 153 and 154 and the start of processing by voltage detection at both ends of the current detection resistor 128.
[0048]
A storage circuit 142 is connected to the CPU 141, and a voltage target value V output during constant voltage operation is stored in the storage device 142. _A Current target value I output during constant current operation _A Is remembered.
[0049]
Since A / D conversion of voltage and current and each processing described later are repeatedly performed at regular intervals, the current measurement result and processing result are represented by the subscript n, and the previous measurement result and processing result are represented by the subscript n-1. In this case, the current voltage measurement value and the current measurement value are denoted by the symbol VM, respectively. _n , IM _n The previous voltage measurement value and current measurement value are represented by the symbols VM, respectively. _n-1 , IM _n-1 It is represented by
[0050]
The storage circuit 142 has a voltage target value V _A And current target value I _A Not only the previous voltage measurement value VM _n-1 And the previous measured current value IM _n-1 Etc. are also memorized.
[0051]
Current voltage measurement value VM input to CPU 141 _n Is proportional to the voltage proportional processing S as follows: ₁₇ And voltage differentiation S ₁₈ And voltage integration processing S ₁₉ And measured current value IM _n Is the current proportional processing S ₃₇ And current differentiation S ₃₈ And current integration processing S ₃₉ And processed.
[0052]
First, voltage proportional processing S ₁₇ And current proportional processing S ₃₇ , Voltage proportional processing S ₁₇ And current proportional processing S ₃₇ This processing result Pv _n , Pi _n Is the current measured voltage VM _n And voltage target value V _A Voltage difference and current measurement value IM _n And current target value I _A Is obtained as shown in the following formula.
Pv _n = V _A -VM _n ...... (1)
Pi _n = I _A -IM _n ...... (2)
[0053]
In addition, voltage differentiation processing S ₁₈ And current differentiation S ₃₈ Then, this processing result Dv _n , Di _n Is the current measured voltage VM _n And the previous voltage measurement value VM _n-1 Voltage difference and current measurement value IM _n And previous voltage measurement value IM _n-1 Are obtained as shown in the following calculation formulas.
Dv _n = VM _n-1 -VM _n ...... (3)
Di _n = IM _n-1 -IM _n ...... (4)
[0054]
Voltage integration process S ₁₉ And current integration processing S ₃₉ First, voltage determination processing S ₁₃ And current judgment processing S ₃₃ Are executed, and the processing is branched into two types according to the criteria described later. The branch destination is the voltage determination process S ₁₃ Then, the processing destination is the voltage integration operation S ₁₅ And voltage control value calculation processing S ₁₆ And current judgment processing S ₃₃ Then, the current integration calculation S ₃₅ And current control value calculation processing S ₃₆ It is.
[0055]
The storage circuit 142 includes a voltage integration process S. ₁₉ And current integration processing S ₃₉ Last processing result Iv _n-1 , Ii _n-1 Is stored, and the voltage integration operation S ₁₅ Is executed, the voltage integration process S ₁₉ Last processing result Iv _n-1 In addition, this voltage measurement value VM _n And voltage target value V _A The value obtained by adding the difference voltage to the voltage integration process S ₁₉ This processing result Iv _n Current integration operation S ₃₅ Is executed, the previous processing result Iv _n-1 In addition, current measurement value IM _n And current target value I _A The value obtained by adding the difference current to the current processing result Ii _n As required.
[0056]
After all, the processing is voltage integration operation S ₁₅ And current integration operation S ₃₅ If each is executed, the current processing result Iv _n , Ii _n Is represented by the following formula.
Iv _n = Iv _n-1 + V _A -VM _n ...... (5 ₁ )
Ii _n = Ii _n-1 + I _A -IM _n ...... (6 ₁ )
[0057]
On the other hand, voltage determination processing S ₁₃ From the voltage control value calculation process S ₁₆ When the process moves to, voltage integration calculation S ₁₅ Is not executed, and the current determination process S ₃₃ Current control value calculation processing S ₃₆ When the process moves to, current integration calculation S ₃₅ Is not executed, and the current processing result Iv is _n , Ii _n Is the previous processing result Iv _n-1 , Ii _n-1 To the same value.
Iv _n = Iv _n-1 ...... (5 ₂ )
Ii _n = Ii _n-1 ...... (6 ₂ )
[0058]
Voltage measurement VM _n Each processing S ₁₇ , S ₁₈ , S ₁₉ Processing result Pv _n , Dv _n , Iv _n Is a predetermined coefficient a for weighting. ₁ ~ A _Three Are multiplied and added, and a comparison process S described later is performed. ₅₁ The voltage control value for is determined. The current voltage control value is indicated by symbol A _n It is calculated by the following formula.
A _n = A ₁ × Pv _n + A ₂ × Dv _n + A _Three × Iv _n ...... (7)
Here, the coefficient a ₁ ~ A _Three , And coefficient b below ₁ ~ B _Three , C ₁ ~ C _Three Is a positive value.
[0059]
Similarly, the current measurement value IM _n Each processing S ₃₇ , S ₃₈ , S ₃₉ Processing result Pi _n , Di _n , Ii _n Is a predetermined coefficient c for weighting. ₁ ~ C _Three Is multiplied and added to the current control value C _n Is required.
C _n = C ₁ × Pi _n + C ₂ × Di _n + C _Three × Ii _n ...... (8)
Voltage control value A _n And current control value C _n Is stored in the storage circuit 142.
[0060]
Here, reference sign L in FIG. 4A during constant voltage operation. ₁ In this range, the magnitude of the output voltage is the voltage target value V _A Is close to the voltage value indicated by _n And voltage target value V _A And the voltage measurement value VM of this time _n And the previous voltage measurement value VM _n-1 The difference between is small. Therefore, during the constant voltage operation, the voltage control value A _n Is close to zero.
[0061]
On the other hand, the output current during constant voltage operation is the current target value I. _A Current measurement value IM. _n And current target value I _A The current control value C _n Becomes a large positive number.
[0062]
Therefore, the target voltage value V _A Is output during the voltage control value A _n <Current control value C _n Is established. Conversely, the target current value I during constant current operation _A Is output while the current control value C _n <Voltage control value A _n Is established.
[0063]
Comparison process S ₅₁ Then, each control value A to be compared _n , C _n Of these, the value closer to zero is the selected value E _n Selected as. Therefore, during constant voltage operation, the selected value E _n Voltage control value A _n Is selected, and during the constant current operation, the current control value C _n Is selected.
[0064]
A digital-pulse conversion circuit 136 is disposed at the output destination of the CPU 141, and a drive signal output process (D / P output process) S ₅₂ To select value E _n The drive circuit 138 is operated according to the value of the selected value E _n The switching element 112 is controlled to be turned on / off so as to approach zero.
[0065]
As a result, the selected value E _n Voltage control value A as _n Is selected, the next measured voltage value VM _{n + 1} Is the current measured voltage VM _n Voltage target value V _A The selected value E _n Current control value C as _n Is selected, the next measured current value IM _{n + 1} Is the current measured value IM _n Current target value I than _A As a result, constant voltage or constant current operation is achieved.
[0066]
Drive signal output processing S ₅₂ Is completed, the current series of processes is terminated, and the next process is started (S ₁₁ , S ₃₁ ).
[0067]
Note that the output voltage fluctuates even during constant voltage operation, and the output current fluctuates even during constant current operation, but the current target value I _A Voltage target value V _A Voltage target value V _A And current target value I _A The difference voltage and current between them are small and can be ignored.
[0068]
Next, voltage determination processing S ₁₃ And current judgment processing S ₃₃ In the storage circuit 142, the voltage and current bias value Q is described. ₁ , Q ₂ Is stored, and voltage determination processing S ₁₃ Then, the voltage bias value Q ₁ And the previous voltage control value A _n-1 And the previous current control value C _n-1 Therefore, when the following inequality is satisfied, the voltage control value calculation process S ₁₆ If it does not hold directly, the voltage integration operation S ₁₅ It is supposed to move to.
A _n-1 > C _n-1 + Q ₁ ...... (9)
[0069]
In addition, the current determination process S ₃₃ Then, the current bias value Q ₂ And the previous voltage control value A _n-1 And current control value C _n-1 Therefore, when the following inequality is satisfied, the current control value calculation process S ₃₆ If it is not established, the current integration calculation S ₃₅ It is supposed to move to.
C _n-1 > A _n-1 + Q ₂ ...... (10)
[0070]
Voltage and current bias value Q ₁ , Q ₂ If is zero, the previous comparison process S ₅₁ Selection value E _n-1 Is the voltage control value A _n-1 If not (Voltage control value A _n-1 > Current control value C _n-1 (9), the above equation (9) is established, and the equation (10) is not established.
[0071]
Therefore, if the expression (9) is satisfied and the expression (10) is not satisfied, the voltage determination process S ₁₃ The determination result is “yes” and the current determination process S ₃₃ The determination result is “no”, and the voltage determination process S ₁₃ From the voltage control value calculation process S ₁₆ Is transferred to the voltage integration calculation S ₁₅ Is not executed and the voltage control value calculation process S ₁₆ Is done. In this case, the above (5 ₁ (5) ₂ ) Voltage integration process S ₁₉ Is done.
[0072]
On the other hand, current determination processing S ₃₃ From the current integration calculation S ₃₅ And the current integration calculation S ₃₅ Through the current control value calculation process S ₃₆ The addition process is performed. In this case, the above (6 ₁ ) Current integration process S ₃₉ Is done.
[0073]
Contrary to those cases, the previous comparison process S ₅₁ Selection value E _n-1 Is the current control value C _n-1 If not (Voltage control value A _n-1 <Current control value C _n-1 (9), the above equation (9) does not hold and the equation (10) holds.
[0074]
If the expression (9) is not established and the expression (10) is established, the voltage determination process S ₁₃ Starts from voltage integration S ₁₅ Is transferred to the voltage integration calculation S ₁₅ Through the voltage control value calculation process S ₁₆ The addition process is performed. Therefore, the voltage integration process S ₁₉ Is the above (5 ₁ ) Is performed according to the equation.
[0075]
On the other hand, current determination processing S ₃₃ From the current control value calculation process S ₃₆ And the current integration calculation S ₃₅ The addition process is performed without going through. Therefore, the current integration process S ₃₉ Is the above (6 ₂ ) Is performed according to the equation.
[0076]
Next, voltage and current bias value Q ₁ , Q ₂ Including the case where is a positive number, the current control value C _n-1 And voltage control value A _n-1 Absolute value of difference (| C _n-1 -A _n-1 )) Is small, voltage and current bias value Q ₁ , Q ₂ And the following equation (13):
｜ C _n-1 -A _n-1 | ≦ Q ₁ ...... (13)
(9) does not hold when the relationship is _n-1 Is the voltage control value A _n-1 Even current control value C _n-1 Even voltage integration operation S ₁₅ Is executed.
[0077]
In addition, the following formula (14):
｜ C _n-1 -A _n-1 | ≦ Q ₂ ...... (14)
If the above relationship is established, the above equation (10) is not established, and similarly, the current integration calculation S ₃₅ Is executed.
[0078]
Voltage integration calculation S ₁₅ The condition that is not executed is the previous comparison process S ₅₁ Voltage control value A _n-1 Is not selected and the above equation (13) does not hold, and the current integration calculation S ₃₅ The condition that is not executed is the previous comparison process S ₅₁ Current control value C _n-1 Is not selected, and the above equation (14) is not satisfied. These conditions depend on the voltage and current bias values Q ₁ , Q ₂ The same is true if both are zero or if one or both are not zero.
[0079]
As described above, the current control value C _n-1 And voltage control value A _n-1 Is small, the voltage integration process S ₁₉ And current integration processing S ₃₉ If the difference is large, the target value V _A , I _A If the difference between the ₁₅ , S ₃₅ Is not executed. That is, when the operation is not constant voltage, the voltage integration operation S ₁₅ Is not executed and the current integration calculation S is not performed when the constant current operation is not performed. ₃₅ Is not executed.
[0080]
Voltage integration process S ₁₉ And current integration processing S ₃₉ The number of bits assigned to the variable for storing the value of the processing result is limited, but if the difference is large, the integral operation S ₁₅ , S ₃₅ Is not executed, voltage integration processing S ₁₉ And current integration processing S ₃₉ The variables for storing the processing results Iv and Ii are not the maximum value, and the response speed when shifting to a different operation is fast.
[0081]
On the contrary, the previous voltage control value A increases as the above formulas (13) and (14) hold. _n-1 And the previous current control value C _n-1 If the difference between the two is small, the voltage integration operation S can be performed even if the constant voltage operation is not performed. ₁₅ In addition, the current integration operation S is performed even if the constant current operation is not performed. ₃₅ By executing the voltage control value A _n And current control value C _n Is the voltage bias value Q ₁ Or the current bias value Q ₂ Since the above is ensured, the operation state can be smoothly switched.
[0082]
The following formulas (15) and (16) (the following two formulas are mutually rewritten),
C _n-1 -Q ₂ ≦ A _n-1 ≦ C _n-1 + Q ₁ ...... (15)
A _n-1 -Q ₁ ≦ C _n-1 ≦ A _n-1 + Q ₂ ...... (16)
Is satisfied, both of the above formulas (9) and (10) are not satisfied. _n-1 Regardless of the voltage integration operation S ₁₅ And current integration operation S ₃₅ Both are executed.
[0083]
In the above control method, there are two types of operation states of constant voltage operation and constant current operation, and the control method switches between them, but the present invention is not limited to this, and has other operation states May be.
[0084]
The flowchart shown in FIG. 3 is a power supply control method for operating the power supply apparatus 101 of FIG. 1, and has a constant power operation in addition to a constant voltage operation and a constant current operation.
In FIG. 3, the same processes as those in FIG.
[0085]
The control method of FIG. 3 is a series of processes S related to constant power operation. _{twenty two} ~ S ₂₉ Voltage target value V _A And current target value I _A In addition, power target value P _A Is set, and the output power is the power target value P _A Until it reaches the constant value, the power target value P _A The output current reaches the current target value I _A Until reaching the current target value I _A After reaching the value, constant current operation is performed.
[0086]
This operation is shown in FIG. Symbol L ₁ ~ L _Three These show the range of constant voltage operation, the range of constant power operation, and the range of constant current operation, respectively.
[0087]
In this control method, the symbol S ₁₁ , S ₃₁ After the start of the process at the voltage and current A / D conversion process S ₁₂ , S ₃₂ Voltage measurement V _M And current measurement I _M Is obtained, the power calculation process S _{twenty two} To obtain the measured voltage value V _M And current measurement I _M From the measured power P _M Is calculated.
[0088]
The processing of the voltage measurement value VM and the processing of the current measurement value IM are the same as described above, but the power measurement value PM is the power proportional processing S. ₂₇ And power differentiation S ₂₈ And power integration processing S ₂₉ This processing result PP is obtained by the following equation. _n , DP _n , IP _n Is required.
Pp _n = P _A -PM _n ...... (21)
Dp _n = PM _n-1 -PM _n ...... (23)
Ip _n = Ip _n-1 + P _A -PM _n ...... (25 ₁ )
[0089]
Power control value calculation process S ₂₆ Then, as shown in the following formula, this processing result PP _n , DP _n , IP _n Positive coefficient b for weighting ₁ ~ B _Three Are multiplied and added, and the power control value B is _n Is required.
[0090]
B _n = B ₁ × Pp _n + B ₂ × Dp _n + B _Three × Ip _n ...... (28)
Power control value B _n Separately from the voltage control value A _n And current control value C _n And each is required. Even in this control method, the comparison process S ₅₁ Each control value A _n , B _n , C _n Value closest to zero is selected and selected value E _n To be.
[0091]
Power control value B during constant power operation _n Is close to zero and the voltage control value A _n And current control value C _n Because the value of is large, the power control value B _n Is selected. Voltage control value A during constant voltage operation _n Is selected, and during the constant current operation, the current control value C _n Is selected.
[0092]
Drive signal output processing S ₅₂ Then the selection value E _n Is output to the drive circuit 138, and the drive circuit 138 receives the selection value E. _n ON / OFF of the switching element 112 is controlled so as to approach zero.
[0093]
In this control method, the voltage bias value R ₁ And current bias value R ₂ And the first and second power bias values R _Three , R _Four Is set, and voltage determination processing S ₁₃ 'And current judgment processing S ₃₃ 'Is the voltage integration operation S when the following sign formula is satisfied. ₁₅ And current integration calculation S ₃₅ Are not performed.
A _n-1 > B _n-1 + R ₁ ...... (29)
C _n-1 > B _n-1 + R ₂ ...... (30)
[0094]
Voltage judgment process S ₁₃ If the above equation (29) holds in ' ₅₁ Last selected value E in ' _n-1 Is the voltage control value A _n-1 And the previous voltage control value A _n-1 And the previous power control value B _n-1 The absolute value of the difference is the voltage bias value R ₁ This is the case. In addition, the current determination process S ₃₃ In ', the above equation (30) is established because the previous selection value E _n-1 Is the current control value C _n-1 And the previous current control value C _n-1 And the previous power control value B _n-1 The absolute value of the difference between the current bias value R ₂ This is the case.
[0095]
Power integration process S ₂₉ Then, the first power determination process S _{twenty three} And second power determination processing S _{twenty four} Are processed in order and performed according to the following formula.
B _n-1 > A _n-1 + R _Three ...... (31)
B _n-1 > C _n-1 + R _Four ...... (32)
[0096]
If both of the above equations (31) and (32) are not satisfied, the integral operation S _{twenty five} When one of the conditions is satisfied, the integral operation S _{twenty five} Direct power control value calculation processing S without branching to ₂₆ Branch to In short, the power integration process S ₂₉ Then, the selection process S ₅₁ ', The previous selected value is not the power control value and the previous power control value B _n-1 And the previous voltage control value A _n-1 Is the first power bias value R _Three Or the previous power control value B _n-1 And the previous current control value C _n-1 Is the second power bias value R _Four If this is the case, the current power integration process S ₂₉ Then, power integration calculation S _{twenty five} Is not done.
[0097]
In the control method as described above, the voltage integration process S ₁₉ And current integration processing S ₃₉ Processing result Iv _n , Ii as well as a variable for storing power integration processing S ₂₉ The variable for storing the processing result Ip is not the maximum value, and the transition between the constant voltage operation, the constant power operation, and the constant current operation is smooth.
[0098]
In addition, the voltage bias value R ₁ And current bias value R ₂ In addition to the first and second power bias values R _Three , R _Four Is used, the operating state can smoothly transition.
[0099]
Further, another example of the present invention will be described. The voltage integration process S of the control method is as follows. ₁₉ Then, the previous voltage control value A _n-1 And power control value B _n-1 As shown in FIG. 4, the second voltage determination process S ₁₄ At the previous current control value C _n-1 And the second voltage bias value U ₁ And may be determined based on the following two formulas.
A _n-1 > B _n-1 + R ₁ ...... (29)
A _n-1 > C _n-1 + U ₁ ...... (33)
[0100]
If both of the above equations (29) and (33) are not satisfied, the voltage integration operation S ₁₅ When either one of the equations is satisfied, the voltage integration operation S ₁₅ Voltage control value calculation process S without going through ₁₆ Branch directly to.
[0101]
Also, the current integration process S ₃₉ Also, the previous current control value C _n-1 Also, when both of the following equations (30) and (34) are not satisfied, the current integration calculation is executed, and when either of the equations is satisfied, the current control value is calculated without performing the current integration calculation. Process S ₃₆ You may make it branch directly to.
C _n-1 > B _n-1 + R ₂ ...... (30)
C _n-1 > A _n-1 + U ₂ ...... (34)
[0102]
The voltage integration process S can be performed even when the constant power operation is included by judging by the two expressions (29) and (33) and the two expressions (30) and (34). ₁₉ Of processing result Iv and current integration processing S ₃₉ The variable of the processing result Ii is reliably prevented from becoming the maximum value.
[0103]
The first and second voltage bias values R ₁ , U ₁ And first and second current bias values R ₂ , U ₂ Is used, the transition of the operating state is smoother.
[0104]
【The invention's effect】
The operating state transitions quickly. In addition, the transition is smooth.
[Brief description of the drawings]
FIG. 1 is a circuit diagram of an example of a power supply to which the present invention can be applied.
FIG. 2 is a flowchart of a first example of the present invention.
FIG. 3 is a flowchart of a second example of the present invention.
FIG. 4 is a flowchart of a third example of the present invention.
5A is a graph for explaining an output state of a control method for switching between constant voltage operation and constant current operation. FIG. 5B is an output state of a control method for switching between constant voltage operation, constant power operation and constant current operation. Chart to explain
FIG. 6 is a circuit diagram for explaining a conventional control method;
FIG. 7 is a flowchart for explaining a conventional control method;
[Explanation of symbols]
S ₁₉ , S ₁₉ '…… Voltage integration processing
S ₂₉ …… Power integration processing
S ₃₉ , S ₃₉ '…… Current integration processing
S ₁₆ ...... Voltage control value calculation process
S ₂₆ …… Power control value calculation processing
S ₃₆ ...... Current control value calculation processing
S ₅₁ , S ₅₁ '…… Selection processing
S ₁₅ …… Voltage integration calculation
S _{twenty five} …… Power integration calculation
S ₃₅ …… Current integration calculation
S ₅₂ ...... Drive signal output processing
VM: Voltage measurement value
PM: Power measurement
IM: Current measurement value
E …… Selected value
111 …… Primary winding
112 …… Switching element
121 …… Secondary winding

Claims (9)

Voltage integration processing for obtaining a voltage integration processing result using a voltage measurement value indicating the magnitude of the output voltage; and
Current integration processing for obtaining a current integration processing result using a current measurement value indicating the magnitude of the output current; and
A voltage control value calculation process for obtaining a voltage control value using the voltage integration process result;
A current control value calculation process for obtaining a current control value using the current integration process result;
A selection process of comparing at least the voltage control value and the control value including the current control value, selecting any one control value based on the magnitude relationship, and outputting as a selection value;
A drive signal output process that converts the selected value into a drive signal, outputs it to a switching element, and causes the switching element to perform a switching operation according to the drive signal;
Each of the above processes is repeated, a current corresponding to the switching operation is caused to flow through the primary winding connected to the switching element, and a voltage is induced in the secondary winding magnetically coupled to the primary winding. A method of controlling a power supply apparatus that rectifies and smoothes the generated voltage with a rectifying and smoothing circuit and supplies the voltage to a load,
The voltage integration process includes a voltage integration calculation in which a difference between the voltage measurement value and a preset voltage target value is added to a previous process result of the voltage integration process to obtain a current process result,
The current integration process includes a current integration calculation in which a difference between the current measurement value and a preset current target value is added to a previous process result of the current integration process to obtain a current process result,
The voltage integration process is configured not to perform the voltage integration calculation this time when the previous selection value in the selection process is not the voltage control value,
The current integration processing is a control method configured such that the current integration calculation is not performed this time when the previous selection value in the selection processing is not the current control value. The control method according to claim 1, wherein a voltage bias value and a current bias value of a predetermined value are preset.
When the absolute value of the difference between the voltage control value and the current control value is equal to or less than the voltage bias value, the voltage integration calculation is performed even if the previous selection value is not the voltage control value,
A control method for performing the current integration calculation even when the previous selected value is not the current control value when the absolute value of the difference is equal to or less than the current bias value. A voltage proportional process in which the difference between the voltage measurement value and the voltage target value is the current processing result;
A current proportional processing in which the difference between the current measurement value and the current target value is the current processing result;
A voltage differentiation process in which the difference between the current voltage measurement value and the previous voltage measurement value is the current processing result;
A current differentiation process in which the difference between the current measurement value this time and the previous current measurement value is the current processing result,
The voltage control value calculating process multiplies the processing result of the voltage integration process, the processing result of the voltage proportional process, and the processing result of the voltage differentiation process by multiplying each by a predetermined coefficient to obtain the voltage control value. ,
The current control value calculation processing is performed by multiplying the processing result of the current integration processing, the processing result of the current proportional processing, and the processing result of the current differentiation processing by multiplying each by a predetermined coefficient, and adding the current control value. The control method according to any one of claims 1 and 2. Power integration processing for obtaining a power integration processing result using a power measurement value indicating the magnitude of output power; and
A power control value calculation process for obtaining a power control value using the power integration process result,
The control value to be compared by the selection process includes the power control value,
The power integration process includes a power integration calculation in which a difference between the power measurement value and a preset power target value is added to a previous process result of the power integration process to obtain a current process result. The control method according to claim 3. Power integration processing for obtaining a power integration processing result using a power measurement value indicating the magnitude of output power; and
A power proportional process in which the difference between the power measurement value and the power target value is the current processing result;
A power differentiation process in which the difference between the current power measurement value and the previous power measurement value is the current processing result;
A power control value calculation process for multiplying and adding a predetermined coefficient to the processing result of the power integration process, the processing result of the power proportional process, and the processing result of the power differentiation process to obtain the power control value. Including
The control value to be compared by the selection process includes the power control value,
4. The power integration process includes a power integration calculation in which a difference between the power measurement value and a preset power target value is added to a previous process result of the power integration process to obtain a current process result. Control method. The power integration process is configured such that the power integration calculation is not performed in the current power integration process when the value previously selected in the selection process is not the power control value. 6. The control method according to any one of items 5. The control method according to claim 6, wherein the first and second power bias values of a predetermined value are preset.
The absolute value of the difference between the voltage control value and the power control value is less than or equal to the first power bias value, and the absolute value of the difference between the current control value and the power control value is the second power bias value. A control method for performing the power integration calculation even when the previous selection value is not the power control value when the following is true. Voltage integration processing for obtaining a voltage integration processing result using a voltage measurement value indicating the magnitude of the output voltage; and
Current integration processing for obtaining a current integration processing result using a current measurement value indicating the magnitude of the output current; and
Power integration processing for obtaining a power integration processing result using a power measurement value indicating the magnitude of output power; and
A voltage control value calculation process for obtaining a voltage control value using the voltage integration process result;
A current control value calculation process for obtaining a current control value using the current integration process result;
A power control value calculation process for obtaining a power control value using the power integration process result;
A selection process of comparing at least the voltage control value, the current control value and the control value including the power control value, selecting any one control value based on the magnitude relationship, and outputting as a selection value;
A drive signal output process that converts the selected value into a drive signal, outputs it to a switching element, and causes the switching element to perform a switching operation according to the drive signal;
Each of the above processes is repeated, a current corresponding to the switching operation is caused to flow through the primary winding connected to the switching element, and a voltage is induced in the secondary winding magnetically coupled to the primary winding. A method of controlling a power supply apparatus that rectifies and smoothes the generated voltage with a rectifying and smoothing circuit and supplies the voltage to a load,
The voltage integration process includes a voltage integration calculation in which a difference between the voltage measurement value and a preset voltage target value is added to a previous process result of the voltage integration process to obtain a current process result,
The current integration process includes a current integration calculation in which a difference between the current measurement value and a preset current target value is added to a previous process result of the current integration process to obtain a current process result,
The power integration process includes a power integration calculation in which a difference between the power measurement value and a preset power target value is added to a previous process result of the power integration process to obtain a current process result,
In the selection process, the voltage integration calculation is not performed this time when the previous selection value is not a voltage control value in the selection process.
In the selection process, the power integration calculation is not performed this time when the previous selection value is not a power control value in the selection process.
The current integration process is a control method in which the current integration calculation is not performed this time when the previous selection value is not a current control value,
First and second voltage bias values, first and second power bias values, and first and second current bias values that are predetermined values are set.
The absolute value of the difference between the voltage control value and the power control value is less than or equal to the first voltage bias value, and the absolute value of the difference between the voltage control value and the current control value is the second voltage bias value. If the following, the voltage integration calculation is performed even if the previous selection value is not the voltage control value,
The absolute value of the difference between the power control value and the voltage control value is less than or equal to the first power bias value, and the absolute value of the difference between the power control value and the current control value is the second power bias value. If the following, the power integration calculation is performed even if the previous selection value is not the power control value,
The absolute value of the difference between the current control value and the voltage control value is less than or equal to the first current bias value, and the absolute value of the difference between the current control value and the power control value is the second current bias value. A control method for performing the current integration calculation even when the previous selection value is not the current control value when the following is true. A voltage proportional process in which the difference between the voltage measurement value and the voltage target value is the current processing result;
A current proportional processing in which the difference between the current measurement value and the current target value is the current processing result;
A current proportional process in which the difference between the power measurement value and the power target value is the current processing result;
A voltage differentiation process in which the difference between the current voltage measurement value and the previous voltage measurement value is the current processing result;
A current differentiation process in which the difference between the current measurement value this time and the previous current measurement value is the current processing result;
A power differentiation process in which the difference between the current power measurement value and the previous power measurement value is the current processing result;
Including
The voltage control value calculating process multiplies the processing result of the voltage integration process, the processing result of the voltage proportional process, and the processing result of the voltage differentiation process by multiplying each by a predetermined coefficient to obtain the voltage control value. ,
The current control value calculation processing is performed by multiplying the processing result of the current integration processing, the processing result of the current proportional processing, and the processing result of the current differentiation processing by multiplying each by a predetermined coefficient, and adding the current control value. age,
The power control value calculation processing includes adding the processing result of the power integration processing, the processing result of the power proportional processing, and the processing result of the power differentiation processing by multiplying each by a predetermined coefficient, and adding the power control value. The control method according to claim 8.

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