JP3946154B2 - Charging device and program thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
In this invention, input AC power is full-wave rectified, and the full-wave rectified output is supplied and charged to a storage battery via a switching DC-DC converter (converter), and an on / off control pulse for a switching element of the DC-DC converter is supplied. The present invention relates to a charging device that performs pulse width modulation to control the charging current.
[0002]
[Prior art]
Conventionally, full-wave rectification of the input three-phase power is performed, and the full-wave rectified output is supplied and charged to the storage battery via the switching DC-DC converter, and the ON / OFF control pulse for the switching element of the DC-DC converter is pulse width. A charging device that modulates and controls the charging current has been proposed (see, for example, Patent Document 1).
FIG. 12 shows a conventional charging apparatus of this type. The three-phase AC power from the three-phase AC power supply 11 is full-wave rectified by a full-wave rectifier circuit 13 in the charging device 12, and the full-wave rectified output is supplied to the storage battery 15 via the switching DC-DC converter 14. Charged. In the DC-DC converter 14, for example, full-wave rectified power is converted into high-frequency AC power, such as 20 kHz, by an inverter 16 formed of a high-voltage semiconductor switching element such as IGBT, and this AC power is converted as necessary. Then, the voltage is boosted by the insulating transformer 17, and the output of the transformer 17 is rectified and smoothed by the rectifier circuit 18 to become DC power, and this DC power is supplied to the storage battery 15.
[0003]
The charging current supplied to the storage battery 15 is detected by the current detection unit 19, and the difference between the detected current value and the set value from the setting unit 22 in the control unit 21 is taken by the error calculation unit 23. In response, the correction unit 24 corrects the reference value from the register 25, and the corrected reference value is supplied to the PWM generation unit 26. The PWM generation unit 26 receives the input modulation signal (corrected reference value). ) Is output, and the switching element of the inverter 16 is controlled to be turned on / off by the pulse width modulation signal. The charging current is held at a set value by feedback control based on this charging current detection.
[0004]
[Patent Document 1]
Japanese Utility Model Publication No. 6-21343
[Problems to be solved by the invention]
The U-phase, V-phase, and W-phase of the input three-phase AC power are sequentially shifted by 120 degrees as shown by curves 27U, 27V, and 27W in FIG. 2, and the output waveform of the full-wave rectifier circuit 13 is a curve. As shown in FIG. As described above, the full-wave rectified output 28 includes a relatively large ripple. Further, although the pulse width W of the pulse width modulation signal is changed by the difference output in the correction unit, it is the same width W at each point as shown in FIG. 3B. For this reason, when the switching element is turned on at the maximum peak of the ripple, the value of the on-current is considerably different depending on when the switching element is turned on at the minimum peak. For example, when it is desired to set the target average current to 80 A, a current having a maximum value of 200 A and a minimum value of 50 A flows to the inverter 16, and the switching element of the inverter 16 needs to have an instantaneous withstand current capacity of 200 A or more.
[0006]
Not only the switching elements but also other elements constituting the inverter 16 have to be used with a large current capacity, and the whole becomes expensive.
Since the output of the rectifier circuit 18 includes a large ripple, when smoothing with a capacitor to absorb this ripple current, a capacitor having a large capacitance and a large withstand current and withstand voltage is used. In other words, it is usually omitted because it is large and expensive, and there is a problem of emitting unnecessary noise to the outside. Note that it is difficult to reduce the ripple using the instantaneous detection current by the current detection unit 19 because the instantaneous detection current is delayed.
[0007]
[Means for Solving the Problems]
According to the present invention, the negative phase corresponding value corresponding to the negative phase of the full-wave rectified output of the AC power is generated by the negative phase generating unit, and correction for obtaining the target charging current is performed on the negative phase corresponding value. A control value (modulation signal) is generated by the correction unit, and the control value is converted into a pulse width modulation signal by the pulse width modulation generation unit.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows an embodiment of the present invention in which parts corresponding to those in FIG. In this embodiment, the control unit 21 is provided with a reverse phase generation unit 31. The negative phase generation unit 31 generates a negative phase corresponding value corresponding to the negative phase of the full wave rectification output waveform of the full wave rectification circuit 13. That is, for example, as shown in FIG. 2, a curve corresponding to a curve 32 in which the ripple component of the full-wave rectified output waveform 28 is reversed (inverted) is obtained. Although the curve 32 is shown as being continuous, it is actually obtained as a digital value sampled at intervals of the switching period with respect to the switching element of the inverter 16.
[0009]
The period T _{V of the} curve 32 is 1/6 of the period of one phase of the input three-phase AC power. Each reverse-phase corresponding value in the period T _V, i.e. pulse width modulation unit sample value as a modulation signal when generating the pulse width modulated signal with (PWM generator) 26, the average current (effective value) is, the conventional In the charging device, each negative phase corresponding value (sample value) within the period T _V is set in advance so that it is equal to the average current (effective value) in the same section (T _V ) when the reference value is a pulse width modulation signal. Decide it.
The correction unit 33 corrects the effective value of the output current of the inverter 16 to the target value (set value) with respect to the negative phase corresponding value from the negative phase generation unit 31, and the corrected reverse The phase-corresponding value is supplied as a control value (modulation signal) to the PWM generation unit (pulse width modulation unit) 26 to generate a pulse width modulation signal, and the switching element of the inverter 16 is on / off controlled by this pulse width modulation signal. .
[0010]
In this configuration, the value corresponding to the negative phase corresponds to the sample value of the curve 32 as shown in FIG. 3A, for example, and this value is the minimum value at the peak value of the ripple of the three-phase full-wave rectified output 28. The pulse width of the modulation signal is Wmin and the minimum width, the sample value is maximum at the minimum value portion of the ripple, and the pulse width of the pulse width modulation signal is also the maximum value Wmax. The area of each pulse width modulation signal is made substantially the same, that is, as described above, it differs from the conventional one (FIG. 3B) in which the pulse width W of the pulse width modulation signal is made the same according to each part of the ripple. . In the case of the same correction value, the pulse width modulation value within the same period (cycle) is set to the same effective value as the conventional one. If the width of each pulse of each pulse width modulation signal in one cycle T _V in the case of no correction Oke obtained in advance as described above, the correction value for the charging current control can be used with the same value, each reverse What is necessary is just to change a phase corresponding value according to a correction value in the state which hold | maintained the relative ratio. For example, the counter 37 counts so that the switching in the inverter 16 is the maximum ripple value of the rectified waveform 28 and the pulse width of the pulse width modulation signal is the minimum value Wmin, and the minimum pulse width is the maximum value Wmax. The clock is advanced from the PWM pulse.
[0011]
Thus, in this embodiment, the area of each pulse width modulation signal is the same, and the DC-DC converter 14 is an element having a small current capacity without particularly increasing power at the peak portion of the three-phase full-wave rectified output 28. Thus, an inexpensive charging device can be obtained. Further, since the effective value (average value) of the output of the PWM generation unit 26 is controlled to be a set value, the charging current is controlled without a delay as in the control by the detection of the conventional current detection unit 19. be able to.
FIG. 4 shows a specific example of the reverse phase generation unit 31 mainly in the control unit 21 with the same reference numerals assigned to the portions corresponding to FIG. 1 cycle T _V min of the waveform of the reverse-phase waveform 32 shown in FIG. 2 is stored in the waveform memory 35 in this embodiment. In the three-phase full-wave rectified output waveform 28 for an ideal three-phase AC power, if the amplitude of the three-phase AC power is determined and the switching period of the switching DC-DC converter 14 is determined, one period T _{V of the} ripple Each sample value in can be calculated, and the reciprocal of each sample value can be calculated. Each value of the inverse, i.e. one period T _V content is stored in the waveform memory 35.
[0012]
On the other hand, AC power input to the charging device 12 (in the case of three-phase AC power input, one phase voltage of the three-phase AC power) is input to the zero-cross detection unit 36, and a zero-cross point of the voltage in the input AC power is detected. Is done. Each time a zero cross point is detected, the n-ary counter 37 is reset. n-ary counter 37, a clock synchronized with the pulse width modulated signal from the PWM generating unit 26, i.e. by counting a clock synchronized with the switching to the switching elements of the inverter 16, when the period of the clock and T _C, n = T When counting the _V / T _C-number clock are those reset.
[0013]
The waveform stored in the waveform memory 35 is sequentially read according to the count value of the n-ary counter 37, that is, the opposite-phase corresponding values are sequentially obtained, and this is supplied to the PWM generator 26 through the correction unit 33 to generate a pulse width modulation signal. Is done.
This pulse width modulation signal is also branched and supplied to the output value calculation unit 41, and the effective value or average value of the pulse width modulation signal in one cycle T _V is calculated, and this effective value or average value is set from the setting unit 42. The difference from the target value is obtained by the error calculation unit 43, and the difference output is supplied to the correction unit 33. In the correction unit 33, the output of the error calculation unit 43 becomes zero, that is, the calculated effective value. Or the correction | amendment with respect to the negative phase corresponding value output from the waveform memory 35 is performed so that an average value may approach the set target value. The zero cross detector 36 is preferably insulated from its input side and output side through a step-down transformer or the like.
[0014]
Another embodiment of the reverse phase generation unit 31 is shown in FIG. In this example, the three-phase AC power input to the charging device 12 is also supplied to the inter-phase voltage detection unit 45, and three inter-phase voltages, that is, U-phase, V-phase, and W-phase voltages V _U = Vsin (θ), V _V = Vsin (θ-2π / 3) and V _W = Vsin (θ + 2π / 3) are detected. Here, θ is assumed to be successively taken from 0 to each value expressed in radians at each point where the switching cycle T _{C of the} inverter 16 is cut by one cycle (1/50 Hz or 1/60 Hz) of the three-phase AC power.
The maximum value among the absolute values of the interphase voltages V _U , V _V , and V _W detected at each clock cycle T _C is selected by the maximum value selection unit 46, and the reciprocal of the selected maximum value is calculated as the reciprocal. Calculated in part 53. That is, 1 / (maximum value {| V _U |, | V _V |, | V _W |}) is calculated for each clock, and the reciprocal value is supplied to the PWM generation unit 26 through the correction unit 33. However, in the correction unit 33, even if the difference output from the error calculation unit 43 is zero, the constant α is multiplied so that the effective value or average value of the charging current in one cycle matches that of the conventional charging device. Is done.
[0015]
When the three-phase AC power is ideal as shown in FIG. 2, it is sufficient to calculate the effective value or average value of the PWM pulse between adjacent zero cross points detected by the zero cross detection unit 36 by the output value calculation unit 41. However, the waveforms of the interphase voltages V _U , V _V , and V _W may not necessarily be the same, and in some cases, the absolute value waveforms may be different between the positive side and the negative side of one interphase voltage.
FIG. 6 shows still another embodiment of the reverse phase generation unit 31 that is particularly preferable in such a case. In this example, the full-wave rectified output voltage waveform from the three-phase full-wave rectifier circuit 13 is detected by the voltage detector 51. In this case, it is preferable to insulate the input side and the output side of the voltage detector 51 using an isolation amplifier or the like. The voltage waveform detected by the voltage detector 51 is sampled by the A / D converter 52 by the clock from the PWM generator 26 and converted into a digital value, and the reciprocal of each digital value is detected by the reciprocal calculator 53. The calculated reciprocal is supplied to the PWM generation unit 26 through the correction unit 33 as an anti-phase corresponding value.
[0016]
The pulse width modulation signal from the PWM generation unit 26 is supplied to the DC-DC converter 14 and also to the output value calculation unit 41. Instead of obtaining the effective value or average value between the detection zero cross point of from zero-crossing detector 36 in an output value calculation section 41, one period of the three-phase AC power that is known in advance T _S (usually 1/50 Hz or 1 / 60 Hz) and the detected zero cross point, the effective value or output value for each period T _S / 6 is calculated based on the detected zero cross point, and the difference between this value and the set value is obtained, and charging is performed for each T _S / 6. Correct the current.
[0017]
Even if the waveform disturbance is different for each of the U-phase, V-phase, and W-phase, the input 3-phase AC power often repeats the same disturbance for each phase, so the charging current is corrected for each phase. Can be controlled. The correction control for each T _S / 6 may also be performed in the embodiment shown in FIGS. In the embodiment shown in FIGS. 5 and 6, the same sample value for each phase of each detected interphase voltage or full-wave rectified output is averaged by the storage / average unit 55, 56 and the average value is used. Thus, it may be prevented from being affected by instantaneous disturbance. In each of the embodiments shown in FIGS. 4, 5, and 6, as shown in FIG. 1, correction of the charging current by the current detection unit 19 shown in FIG. 7 may be used together.
[0018]
Moreover, like the charging device 60 illustrated in FIG. 7, the step-down chopper circuit DC-DC converter 62 may be configured using the step-down chopper circuit 61, and the charging device 60 of the present invention may be configured.
In this case, the three-phase AC power supply 11 is electrically connected to the three-phase transformer 63 and the three-phase transformer 63 to the full-wave rectifier circuit 13, respectively. The full-wave rectifier circuit 13 is electrically connected to a step-down chopper circuit 61 that constitutes a DC-DC converter 62. The step-down chopper circuit 61 includes a control unit 21, a current detection unit 19, and a current detection unit 19. The control unit 21 and the live battery 15 are electrically connected to each other. The configuration of the control unit 21 is the same as the configuration shown in FIG. 1, and specific examples thereof are the same as those illustrated in FIGS. 4 to 6.
[0019]
FIG. 8 is an example of a circuit diagram of the step-down chopper circuit 61 of FIG.
As illustrated in FIG. 8, the step-down chopper circuit 61 includes a switching element 71, a choke coil 72, a diode 73, and a capacitor 74 that are high breakdown voltage semiconductors such as IGBTs. The collector of the switching element 71 is an input terminal 76 electrically connected to the full-wave rectifier circuit 13, the emitter is one end of the choke coil 72 and the forward output end of the diode 73, and the base which is the control terminal 79 is controlled. Each part 21 is electrically connected. The other end of the choke coil 72 is electrically connected to one end of the capacitor 74 and an output terminal 77 electrically connected to the power source detection unit 19, and the other end of the capacitor 74 is electrically connected to the power source detection unit 19. Are connected to the output terminal 78, the forward input terminal of the diode 73, and the input terminal 75 electrically connected to the full-wave rectifier circuit 13, respectively. Further, in the configuration of FIG. 7, instead of the step-down chopper circuit 61, a step-up chopper circuit may be used to form a step-up chopper type DC-DC converter 62, thereby constituting the charging device 60 of the present invention.
[0020]
FIG. 9 is an example of a circuit diagram of the boost chopper circuit 80.
As illustrated in FIG. 9, the step-up chopper circuit 80 includes a switching element 81, a choke coil 82, a diode 83, and a capacitor 84 that are high voltage semiconductors such as IGBTs. The emitter of the switching element 81 is electrically connected to one end of a capacitor 84, an input terminal 85 electrically connected to the full-wave rectifier circuit 13, and an output terminal 88 electrically connected to the power supply detection unit 19. The collector is electrically connected to one end of the choke coil 82 and the forward input end of the diode 83, and the base as the control terminal 89 is electrically connected to the control unit 21. The other end of the capacitor 84 is electrically connected to the output terminal 87 electrically connected to the power source detection unit 19 and the forward output end of the diode 83, and the other end of the choke coil 82 is full-wave rectified. The input terminal 86 electrically connected to the circuit 13 is electrically connected.
In the case of the charging device 60 using the step-down chopper circuit 61 or the step-up chopper circuit 80, the three-phase supply current supplied from the three-phase AC power supply 11 is boosted by the three-phase transformer 63, and the full-wave rectifier circuit 13 After the wave rectification, the voltage is supplied to a step-down chopper type or step-up chopper type DC-DC converter 62. The DC-DC converter 62 supplied with the full-wave rectified current turns on and off the switching elements 71 and 81 in accordance with the pulse width modulation signal supplied from the PWM generation unit 26 of the control unit 21. Adjust the output current value supplied to.
[0021]
Note that the current value of the charging current supplied in this way is detected by the current detection unit 19 and fed back to the control unit 21, and a pulse width modulation signal is generated using the detected value. These processes are the same as the processes performed by the charging device 12 shown in FIGS. 1 and 4 to 6 described above.
In the above-described embodiment, the case of three-phase AC power input has been described as an example. However, the present invention may be applied to a case of single-phase AC power input. However, in the embodiment illustrated in FIG. 5, the charging current is corrected and controlled for each phase of the U phase, V phase, and W phase, and the same sample value for each phase of each detected interphase voltage or full wave rectified output is obtained. The averaging in the storage averaging units 55 and 56 and the correction control using the average value are based on the assumption of a three-phase AC power input, and are not limited to this.
[0022]
FIG. 10 is a circuit diagram of the full-wave rectifier circuit 90 when the single-phase AC power supply 100 is used as an input, and FIG. 11 is a diagram illustrating the full-wave rectified waveform output from the full-wave rectifier circuit 90. is there.
As illustrated in FIG. 10, the full-wave rectifier circuit 90 includes diodes 91 to 94, a thyristor 95 b, a resistor 95 a, and an electrolytic capacitor 96, and the DC-DC converter 14 or 62 is electrically connected. The resistor 95a and the thyristor 95b constitute an inrush current preventing circuit 95.
One end of the single-phase AC power supply 100 is electrically connected to the input terminal of the diode 91 and the output terminal of the diode 92, and the other end is electrically connected to the input terminal of the diode 94 and the output terminal of the diode 93. The output terminals of the diodes 91 and 94 are the input terminal of the thyristor 95b and one end of the resistor 95a, and the other end of the resistor 95a is the output terminal of the thyristor 95b, one end of the electrolytic capacitor 96 and the output terminal 97, and the electrolytic capacitor 96. The other end is electrically connected to the output terminal 98 and the input terminals of the diodes 92 and 93, respectively.
[0023]
In the case of the full-wave rectified waveform 110 of the single-phase AC power (FIG. 11), the waveform drops greatly in the vicinity of the zero cross points 111 to 113, and the ripple is also the full-wave rectified waveform of the three-phase AC power illustrated in FIG. Larger than Therefore, in this full-wave rectifier circuit 90, an electrolytic capacitor 96 having a large capacity is used in order to dull the output waveform (output full-wave rectified waveform 120) and reduce the ripple. Since such a large-capacitance electrolytic capacitor 96 is used, the inrush current also increases, and there is a risk that excessive current flows through the rectifying diodes 91 to 94. Therefore, inrush current prevention as shown in FIG. A circuit 95 is provided. Note that the thyristor 95b of the inrush current prevention circuit 95 is turned off at the initial stage of applying the AC power of the single-phase AC power supply 100 to the charging device, but is turned on after a certain amount of charge is accumulated in the electrolytic capacitor 96. To be.
[0024]
The above-described charging device of the present invention can be realized by a computer. In this case, the processing contents of the functions that the charging device of the present invention should have are described by a program, and the processing functions can be realized on the computer by executing the program on the computer.
The program describing the processing contents can be recorded on a computer-readable recording medium. The computer-readable recording medium may be any medium such as a magnetic recording device, an optical disk, a magneto-optical recording medium, or a semiconductor memory. Specifically, for example, the magnetic recording device may be a hard disk device or a flexible Discs, magnetic tapes, etc. as optical disks, DVD (Digital Versatile Disc), DVD-RAM (Random Access Memory), CD-ROM (Compact Disc Read Only Memory), CD-R (Recordable) / RW (ReWritable), etc. As the magneto-optical recording medium, MO (Magneto-Optical disc) or the like can be used, and as the semiconductor memory, EEP-ROM (Electronically Erasable and Programmable-Read Only Memory) or the like can be used.
[0025]
The program is distributed by selling, transferring, or lending a portable recording medium such as a DVD or CD-ROM in which the program is recorded. Furthermore, the program may be distributed by storing the program in a storage device of the server computer and transferring the program from the server computer to another computer via a network.
A computer that executes such a program first stores, for example, a program recorded on a portable recording medium or a program transferred from a server computer in its storage device. When executing the process, the computer reads the program stored in its own recording medium and executes the process according to the read program. As another execution form of the program, the computer may read the program directly from the portable recording medium and execute processing according to the program, and the program is transferred from the server computer to the computer. Each time, the processing according to the received program may be executed sequentially. Also, the program is not transferred from the server computer to the computer, and the above-described processing is executed by a so-called ASP (Application Service Provider) type service that realizes the processing function only by the execution instruction and result acquisition. It is good.
In addition, the program in the above is an instruction to the electronic computer, which is combined so that one result can be obtained, and other information provided for processing by the electronic computer, which conforms to the program Is also included.
The present invention is not limited to the embodiment described above.
[0026]
【The invention's effect】
As described above, according to the present invention, the width of the PWM pulse is substantially minimum at the maximum point of the ripple of the full-wave rectified output, is substantially maximum at the minimum point of the ripple, and the DC-DC converter has a small current capacity. An inexpensive element can be used. Further, the ripple of the output of the DC-DC converter becomes small, and it can be smoothed by using a capacitor having a small capacity, and noise emission can be prevented.
[Brief description of the drawings]
FIG. 1 is a functional configuration diagram showing an embodiment of the present invention.
FIG. 2 is a diagram showing a three-phase full-wave rectified waveform and a reversed-phase waveform of the ripple.
FIG. 3 is a diagram showing an example of a pulse width modulation signal.
FIG. 4 is a functional configuration diagram showing a part of an embodiment of the present invention.
FIG. 5 is a functional configuration diagram showing a part of another embodiment of the present invention.
FIG. 6 is a functional configuration diagram showing a part of still another embodiment of the present invention.
FIG. 7 is a functional configuration diagram showing an embodiment of the present invention.
FIG. 8 is a circuit diagram of a step-down chopper circuit according to an embodiment of the present invention.
FIG. 9 is a circuit diagram of a step-down chopper circuit according to an embodiment of the present invention.
FIG. 10 is a circuit diagram of a full-wave rectifier circuit when a single-phase AC power supply is used.
11 is a full-wave rectified waveform diagram output from the full-wave rectifier circuit of FIG.
FIG. 12 is a diagram showing a functional configuration of a conventional three-phase input charging device.

Claims (4)

The input AC power is full-wave rectified by a full-wave rectifier circuit, supplied to the storage battery via a switching DC-DC converter, charged, and the charging current is detected by the detection unit, and the detected charging current becomes a predetermined value. In the charging device for controlling the pulse width of the pulse width modulation signal for controlling on / off of the switching element of the DC-DC converter by the control unit,
A negative phase generation unit for generating a negative phase corresponding value corresponding to the negative phase of the full-wave rectified output,
A correction unit that generates a control value by performing correction to obtain the target charging current for the negative phase corresponding value;
A pulse width modulation generation unit for converting the control value into the pulse width modulation signal;
Equipped with,
The reverse phase generator is
A voltage detector for detecting the voltage of the full-wave rectified output;
An A / D converter that periodically converts the detected voltage into a digital value;
Charger you anda reciprocal calculation unit for outputting as the inverse phase corresponding value by calculating the reciprocal of the digital values. The input AC power is full-wave rectified by a full-wave rectifier circuit, supplied to the storage battery via a switching DC-DC converter, charged, and the charging current is detected by the detection unit, and the detected charging current becomes a predetermined value. In the charging device for controlling the pulse width of the pulse width modulation signal for controlling on / off of the switching element of the DC-DC converter by the control unit,
A negative phase generation unit for generating a negative phase corresponding value corresponding to the negative phase of the full-wave rectified output,
A correction unit that generates a control value by performing correction to obtain the target charging current for the negative phase corresponding value;
A pulse width modulation generation unit for converting the control value into the pulse width modulation signal;
Equipped with,
The input AC power is
3-phase AC power,
The reverse phase generation unit includes an interphase voltage detection unit that periodically detects an interphase voltage of the input three-phase AC power;
A maximum value selection unit for selecting a value having the maximum absolute value in the detected three phase voltages;
Charger you anda reciprocal calculation unit to calculate the inverse of the selected absolute value maximum value is output as the inverse-phase corresponding value. An output value calculation unit for calculating an effective value or an average value of the pulse width modulation signal;
An error calculation unit for obtaining a difference between the calculated effective value or average value and the set value,
The correction unit is the difference between the output of from the error calculation unit is input, the charging device according to claim 1 or 2, characterized in that to perform the correction so that the difference becomes smaller.   A charging program for causing a computer to function as the charging device according to claim 1.

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