JP2013251963A - Dc stabilized power supply - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a DC stabilized power supply having a highly efficient backup function which insulates a battery from a commercial AC input and outputs a large power.SOLUTION: The DC stabilized power supply includes a full-wave rectifier 20 for rectifying an AC voltage from an AC power supply 201, a non-stabilized insulation DC/DC converter 10 which boosts a DC voltage from a battery 202 and outputs the voltage thus boosted as a non-stabilized voltage while insulating the battery 202 side and the full-wave rectifier 20 side, a boost power factor improvement circuit 30 which receives a rectified voltage from the full-wave rectifier 20 or a non-stabilized voltage from the non-stabilized insulation DC/DC converter 10 as an input voltage, improves the power factor of the input voltage and an input current, and further stabilizes the input voltage thus outputting a predetermined constant voltage, and an insulation DC/DC converter 40 which converts the magnitude of the predetermined constant voltage and outputs a desired stabilized DC voltage while insulating the boost power factor improvement circuit 30 and the output side. When the voltage of the AC power supply 201 drops below a predetermined level, the non-stabilized insulation DC/DC converter 10 is started.

Description

  The present invention relates to a stabilized DC power supply that outputs a stabilized DC voltage, and more particularly to a stabilized DC power supply having a backup function.

  An uninterruptible direct current stabilized power supply (for example, see Patent Document 1) in which a power failure countermeasure is provided by a backup function is used in various devices such as information devices. An example of the uninterruptible DC stabilized power supply is shown in FIG. The uninterruptible direct current stabilized power supply 100 outputs a stabilized direct current voltage as a direct current power source from the voltages of the alternating current power source 201 and the storage battery 202. The AC voltage of the AC power supply 201 is full-wave rectified by the full-wave rectifier 101 and converted into a DC voltage by the boost type power factor correction circuit 102. Thereafter, the voltage from the boost type power factor correction circuit 102 is input to the insulation type DC / DC converter 103. In addition, a DC voltage from the storage battery 202 is also input to the isolated DC / DC converter 103.

  In insulated DC / DC converter 103, inverter 103A converts the DC voltage from step-up power factor correction circuit 102 into an AC voltage and outputs the AC voltage to high-frequency transformer 103C. Similarly, the inverter 103B of the insulation type DC / DC converter 103 converts the DC voltage from the storage battery 202 into an AC voltage and outputs the AC voltage to the high-frequency transformer 103C. High-frequency transformer 103C converts the level of AC voltage from inverter 103A or inverter 103B, and outputs the converted AC voltage to converter 103D. The high-frequency transformer 103C is an insulating transformer, and insulates the input side and the output side of the uninterruptible DC stabilized power supply 100 and the AC power supply 201 and the storage battery 202. Converter 103D converts the AC voltage from high-frequency transformer 103C into a predetermined DC voltage, and outputs this DC voltage as a power source.

  In such an uninterruptible direct current stabilized power supply 100, a storage battery 202 is connected to a high-frequency transformer 103C of an insulated DC / DC converter 103 via an inverter 103B. For this purpose, the high-frequency transformer 103C is provided with a tertiary winding. And what can be output by the power supply from the storage battery 202 at the time of a power failure is provided for practical use.

  Incidentally, the output power required as a general power source for information equipment is typically 400 W or less. For this reason, even if a tertiary winding is provided in the high-frequency transformer 103C of the uninterruptible direct current stabilized power supply 100, the winding cross-sectional area of the high-frequency transformer 103C is not compressed and is sufficient in practical use.

JP 2005-295645 A

  However, the uninterruptible direct current stabilized power supply 100 described above has the following problems. The uninterruptible direct current stabilized power supply 100 may have an output power exceeding 400W. For example, if an output of 1 kW is required and an input voltage of only a typical rated voltage of 24 V of the storage battery 202 can be obtained, the DC input current at the time of a power failure becomes extremely large, typically exceeding 50A. Since the current flows, the winding sectional area of the tertiary winding of the high-frequency transformer 103C of the insulated DC / DC converter 103, to which the inverter 103B is connected, is increased. This increases the size of the high-frequency transformer 103C, which causes an adverse effect of reducing the magnetic coupling between the primary and secondary windings, which is important during normal operation. As a result, there has been a drawback that a high-performance DC stabilized power supply with a backup function cannot be realized.

  As an improvement measure, in a general high-power uninterruptible power supply, a dedicated high-voltage storage battery is connected to the output of a converter that converts commercial AC input into DC, via a charger. And at the time of a power failure, the structure which supplies energy from the storage battery is taken. According to such a system, since the charging voltage of the storage battery is high, the charging / discharging current of the storage battery is reduced even at a large output, which is effective.

  However, this method is limited to a case where a storage battery having a high charging voltage can be occupied by the uninterruptible power supply. When the output of the storage battery must be shared with other devices, for example, in the case of an uninterruptible power supply for ships, it is generally possible to obtain only a low voltage such as general-purpose 24V, and safety Therefore, the output of the storage battery needs to be insulated from the commercial AC input. For this reason, it is generally difficult to adopt this method.

  An object of the present invention is to solve the above-mentioned problems and provide a DC stabilized power supply with a high-efficiency backup function that insulates a storage battery from a commercial AC input and outputs a large amount of power.

  In order to solve the above-mentioned problem, the invention of claim 1 is a DC stabilized power supply that outputs a desired stabilized DC voltage from an AC power supply and a storage battery, and the AC power supply from the AC power supply A rectifier that rectifies the voltage, a DC voltage from the storage battery that is boosted and output as an unstabilized voltage, and an unstabilized insulation type DC / DC converter that insulates the storage battery side from the rectifier side, and the rectifier The input voltage is the rectified voltage from the above or the unstabilized voltage from the unstabilized isolated DC / DC converter, and the power factor between the input voltage and the input current is improved and the input voltage is stabilized to a predetermined value. A power factor improvement circuit that outputs a constant voltage of the power factor, a predetermined constant voltage from the power factor improvement circuit is converted into a desired stabilized DC voltage as an output voltage, and the power factor improvement circuit output And a DC stabilized DC / DC converter, wherein the non-stabilized insulated DC / DC converter is activated when the voltage of the AC power supply drops below a predetermined level. It is a power supply.

  According to the first aspect of the present invention, the direct current stabilized power source includes the rectifier, the non-stabilized insulated DC / DC converter, the power factor correction circuit, and the insulated DC / DC converter. When the voltage of the AC power supply falls below a predetermined level, the DC stabilized power supply activates the unstabilized insulated DC / DC converter and outputs a desired stabilized DC voltage stabilized from the storage battery. In such a DC stabilized power supply, the rectifier rectifies the AC voltage from the AC power supply, and the non-stabilized insulation type DC / DC converter boosts the DC voltage from the storage battery and outputs it as an unstabilized voltage. At the same time, the unstabilized insulated DC / DC converter insulates the storage battery side and the rectifier side. The power factor correction circuit uses the rectified voltage from the rectifier or the unregulated voltage from the unregulated isolated DC / DC converter as the input voltage, and improves the power factor between the input voltage and the input current. The input voltage is stabilized and a predetermined constant voltage is output. The isolated DC / DC converter converts the magnitude of a predetermined constant voltage from the power factor correction circuit, and uses a desired stabilized DC voltage as an output voltage. At the same time, the isolated DC / DC converter insulates the power factor correction circuit from the output side.

  According to a second aspect of the present invention, in the direct current stabilized power source according to the first aspect, the power factor correction circuit includes a boosting coil and a switching element that interrupts the current of the coil, and divides the input voltage. Power factor improvement and stabilization by controlling the switching of the switching element based on the input divided voltage, the output divided voltage obtained by dividing the output voltage, and the current of the coil or a current corresponding thereto. It is characterized by performing.

  According to a third aspect of the present invention, in the DC stabilized power supply according to the second aspect, the power factor correction circuit is configured to divide the input voltage when the non-stabilized insulated DC / DC converter is started. The input voltage is increased by switching the voltage dividing ratio.

  According to a fourth aspect of the present invention, in the DC stabilized power supply according to the second aspect, the power factor correction circuit includes an input divided voltage obtained by dividing the input voltage and an output divided voltage obtained by dividing the output voltage. And a multiplier which is controlled to be proportional to the square of the effective value of the input voltage and is multiplied by a coefficient for power factor improvement, and the multiplication result is a current output, and the current output from the multiplier is The power factor is improved and stabilized based on the converted voltage and the current of the coil or the current corresponding thereto, and when the unstabilized insulated DC / DC converter is started, The ratio of converting the current output into voltage is switched to increase the voltage.

  According to a fifth aspect of the present invention, in the stabilized DC power supply according to the second aspect, the power factor correction circuit performs an operation that is inversely proportional to the first divided input voltage obtained by dividing the input voltage. A multiplier that multiplies the calculation result of the calculation unit, the second input divided voltage obtained by dividing the input voltage, and the output divided voltage obtained by dividing the output voltage, and uses the multiplication result as a current output. And performing power factor improvement and stabilization based on a voltage obtained by converting the current output from the multiplier and a current of the coil or a current corresponding thereto, and the unstabilized insulation type DC When the DC / DC converter is activated, the voltage dividing ratio for dividing the first input voltage is switched to lower the first input divided voltage.

  According to the first aspect of the present invention, since the non-stabilized insulation type DC / DC converter is provided for the storage battery, the output of the storage battery having a low voltage and a high current is converted into a high voltage output, and the storage battery is converted from the AC power source. Can be insulated. According to the invention of claim 1, since the step-up type power factor correction circuit and the isolated DC / DC converter are provided, from the unstabilized voltage output from the unstabilized isolated DC / DC converter or the rectifier, An efficient stabilized DC voltage can be obtained with high output power.

  According to the invention of claim 2, since the power factor is improved and stabilized based on the input divided voltage, the output divided voltage, and the current, a desired stabilized DC voltage can be obtained.

  According to the invention of claim 3, when the non-stabilized insulated DC / DC converter is activated and the input voltage to the power factor correction circuit is reduced, the voltage dividing ratio for dividing the input voltage is switched to Increase the voltage. As a result, even if the output voltage of the non-stabilized insulation type DC / DC converter decreases, the input voltage division voltage rises in the power factor correction circuit that is the latter stage of the non-stabilization insulation type DC / DC converter. It is possible to obtain an efficient stabilized DC voltage with the same high output power as before the operation of the stabilized insulation type DC / DC converter.

  According to the fourth aspect of the present invention, when the unstabilized insulation type DC / DC converter is activated and the input voltage to the power factor correction circuit is lowered, the ratio of converting the current output from the multiplier into a voltage is switched. As a result, even if the output voltage of the non-stabilized insulated DC / DC converter decreases, the power output from the multiplier is converted in the power factor correction circuit that is the subsequent stage of the non-stabilized insulated DC / DC converter. Since the voltage increases, an efficient stabilized DC voltage can be obtained with the same high output power as that before the operation of the non-stabilized insulated DC / DC converter.

  According to the invention of claim 5, when the unstabilized insulation type DC / DC converter is activated and the input voltage to the power factor correction circuit is lowered, the voltage dividing ratio for dividing the first input voltage is switched. As a result, even if the output voltage of the non-stabilized insulation type DC / DC converter is lowered, the first input divided voltage is lowered in the power factor correction circuit that is the latter stage of the non-stabilization insulation type DC / DC converter, Since the voltage obtained by converting the current output from the multiplier is increased, it is possible to obtain an efficient stabilized DC voltage with the same high output power as before the operation of the unstabilized insulated DC / DC converter.

It is a block diagram which shows the direct current | flow stabilized power supply by Embodiment 1 of this invention. It is a block diagram which shows the specific example of a non-stabilization insulation type DC / DC converter. It is a block diagram which shows the basic composition of a pressure | voltage rise type power factor improvement circuit. It is a block diagram which shows the specific example of a pressure | voltage rise type power factor improvement circuit. 6 is a configuration diagram illustrating a specific example of a boost type power factor correction circuit used in Embodiment 2. FIG. FIG. 10 is a configuration diagram illustrating a specific example of a boost type power factor correction circuit used in a third embodiment. It is a block diagram which shows the conventional uninterruptible direct-current stabilized power supply.

Next, embodiments of the present invention will be described in detail with reference to the drawings.
(Embodiment 1)
FIG. 1 shows a DC stabilized power supply according to this embodiment. In this embodiment, components that are the same as or the same as those in FIG. 7 described above are denoted by the same reference numerals, and description thereof is omitted. The stabilized DC power source 1 according to this embodiment outputs a desired stabilized stabilized DC voltage from the AC power source 201 and the storage battery 202 as a DC power source. For this purpose, the DC stabilized power supply 1 includes an unstabilized insulated DC / DC converter 10, a full-wave rectifier 20, a boost power factor correction circuit 30, and an insulated DC / DC converter 40. . The stabilized direct current power supply 1 activates the unstabilized insulated DC / DC converter 10 when the input voltage of the alternating current power supply 201 falls below a predetermined level.

  The unstabilized insulation type DC / DC converter 10 is activated when the AC power supply 201 falls below a predetermined voltage. That is, the non-stabilized insulated DC / DC converter 10 operates when the AC power supply 201 becomes abnormal. The non-stabilized insulation type DC / DC converter 10 boosts the DC voltage of the storage battery 202 and outputs the boosted DC voltage. For this purpose, the unstabilized insulated DC / DC converter 10 includes an inverter 11, a high-frequency transformer 12, and a converter 13. The inverter 11 is a DC / AC inverter and converts the direct current voltage of the storage battery 202 into an alternating voltage. The high-frequency transformer 12 is a step-up type insulating transformer, and the secondary side of the high-frequency transformer 12 is insulated from the primary side. The high-frequency transformer 12 boosts the primary side AC voltage from the inverter 11 and outputs the boosted voltage from the secondary side. The converter 13 is an AC / DC converter and converts an AC voltage from the secondary side of the high-frequency transformer 12 into a DC voltage.

  A specific example of such an unstabilized insulated DC / DC converter 10 is shown in FIG. The DC voltage of the storage battery 202 is applied to the input terminals 10 a and 10 b of the unstabilized insulated DC / DC converter 10. Further, the unstabilized insulation type DC / DC converter 10 outputs a DC voltage obtained by converting the voltage level from the output terminals 10c and 10d.

  The inverter 11 of the non-stabilized insulated DC / DC converter 10 includes switching elements 11a to 11d, amplifiers 11e to 11h, a pulse generator 11i, and a capacitor 11j.

  The pulse generator 11i outputs a pulse signal having a constant time ratio, typically, pulse signals 11ia and 11ib having a time ratio of 50% to the switching elements 11a to 11d. The phases of the pulse signals 11ia and 11ib output from the pulse generator 11i are shifted by 180 °.

  The amplifiers 11e and 11h amplify the pulse signal 11ib from the pulse generator 11i and output the amplified signal to the switching elements 11a and 11d. Similarly, the amplifiers 11f and 11g amplify the pulse signal 11ia from the pulse generator 11i and output the amplified signal to the switching elements 11b and 11c.

  The switching elements 11a and 11d are turned on / off by a pulse signal 11ib from the pulse generator 11i that has passed through the amplifiers 11e and 11h. Similarly, the switching elements 11b and 11c are turned on / off by the pulse signal 11ia from the pulse generator 11i that has passed through the amplifiers 11f and 11g. A series circuit in which the switching elements 11a and 11c are connected in series is connected between the input terminals 10a and 10b. Similarly, a series circuit in which the switching elements 11b and 11d are connected in series is connected between the input terminals 10a and 10b. Furthermore, the connection point of the switching elements 11a and 11c is connected to one end of the primary side winding 12a of the high frequency transformer 12, and the connection point of the switching elements 11b and 11d is connected to the other end of the primary side winding 12a of the high frequency transformer 12. It is connected. A capacitor 11j is connected between the input terminals 10a and 10b for noise removal and the like.

  In such an unstabilized insulation type DC / DC converter 10, the pulse generator 11 i outputs a pulse signal having a constant time ratio, typically 50% pulse signals 11 ia and 11 ib, and its phase is 180 ° Deviation. The pulse generator 11i switches the switching elements 11a and 11d and the switching elements 11b and 11c alternately by pulse signals 11ia and 11ib. The DC voltage from the storage battery 202 is converted into a square wave with a time ratio of 50% by the switching elements 11 a to 11 d and applied to the primary winding 12 a of the high-frequency transformer 12.

  As described above, the high-frequency transformer 12 is a step-up type insulating transformer. When an AC voltage is applied to the primary side winding 12a of the high-frequency transformer 12, the high-frequency transformer 12 has a winding ratio between the primary-side winding 12a and the secondary-side winding 12b, that is, the winding of the high-frequency transformer 5. A square wave corresponding to the line ratio is generated in the secondary winding 12b.

  As described above, the converter 13 is an AC / DC converter, and converts the AC voltage from the secondary winding 12b of the high-frequency transformer 12 into a DC voltage. For this purpose, the converter 13 includes rectifier diodes 13a and 13b, a coil 13c, and a capacitor 13d. The rectifier diodes 13a and 13b form a rectifier that full-wave rectifies the AC voltage from the secondary winding 12b of the high-frequency transformer 12. The coil 13c and the capacitor 13d form a smoothing filter circuit. Then, the voltage of the full-wave rectified waveform applied to the coil 13c is converted into a DC voltage, and the converted DC voltage is sent to the output terminals 10c and 10d.

  As described above, the non-stabilized insulated DC / DC converter 10 includes the inverter 11 that generates a high-frequency pulse voltage having a constant pulse width in the primary-side winding 12 a of the high-frequency transformer 12 and the secondary-side winding of the high-frequency transformer 12. And a converter 13 that converts the high-frequency pulse voltage of the line 12b into a direct current. Since the unstabilized insulation type DC / DC converter 10 having such a configuration does not perform feedback, a DC voltage obtained by boosting a DC voltage applied to the input terminals 10a and 10b, that is, an unstabilized unstabilized voltage, Output from the output terminals 10 c and 10 d to the boost type power factor correction circuit 30.

  The full wave rectifier 20 performs full wave rectification on the AC voltage from the AC power supply 201. The full wave rectifier 20 outputs the full wave rectified voltage to the boost type power factor correction circuit 30.

  The step-up type power factor correction circuit 30 performs control to make the input current proportional to the input voltage, that is, improves the power factor of the input power, and stabilizes the output voltage. That is, the step-up type power factor correction circuit 30 generates a stabilized DC voltage, that is, a predetermined constant voltage from the rectified voltage from the full-wave rectifier 20 or the unstabilized voltage from the unstabilized insulated DC / DC converter 10. Always output with high power. A basic configuration of such a boost type power factor correction circuit 30 is shown in FIG. 3 includes voltage dividers 31 and 38, capacitors 32 and 37, a coil 33, a current detector 34, a switch element 35, a diode 36, and a control unit 39. ing.

  The capacitor 32 of the boost type power factor correction circuit 30 smoothes the high-frequency current generated by turning on / off the switch element 35. The coil 33 is a boosting coil that boosts the input voltage together with the switch element 35. The positive side of the input voltage is added to one end of the coil 33. The switch element 35 is a field effect transistor that performs a switching operation to switch (intermittently) a current flowing in the coil 33 (hereinafter referred to as “coil current”), and is turned off by a low-level gate voltage, that is, a control voltage. Turns on at high level control voltage. When the switch element 35 is turned on, the other end of the coil 33 is connected to the negative side of the input voltage. As a result, the switch element 35 causes the coil 33 to accumulate electrical energy based on the input voltage. That is, the switch element 35 accumulates a large amount of electrical energy in the coil 33 when the time during which the switch element 35 is on becomes long. Thereafter, when the switch element 35 is turned off with a low-level control voltage, the electrical energy stored in the coil 33 is stored in the capacitor 37 via the diode 36. At this time, the voltage based on the electrical energy stored in the capacitor 37 is a value obtained by adding the voltage based on the electrical energy stored in the coil 33 to the input voltage. The diode 36 prevents the electrical energy stored in the capacitor 37 from flowing backward to the negative side when the switch element 35 is turned on. The capacitor 37 outputs a voltage based on the stored electrical energy as an output voltage.

  The voltage divider 31 divides the input voltage from the full-wave rectifier 20 or the non-stabilized insulated DC / DC converter 10 and sends the divided voltage to the control unit 39 as an input divided voltage. At this time, when the unstabilized insulation type DC / DC converter 10 is activated and the voltage from the storage battery 202 is applied, the voltage divider 31 receives the input voltage when the voltage from the AC power supply 201 is applied. An input divided voltage having a value higher than the divided voltage is generated, and this input divided voltage is sent to the control unit 39. The current detector 34 detects a negative current of the coil 33, that is, a current corresponding to the coil current, and sends it to the control unit 39 as a current corresponding voltage. The voltage divider 38 divides the output voltage from the capacitor 37 and sends it to the control unit 39 as an output divided voltage.

  The control unit 39 controls the on / off timing of the switch element 35. That is, the control unit 39 maintains the output voltage at a predetermined value by the input divided voltage from the voltage divider 31, the current corresponding voltage from the current detector 34, and the output divided voltage from the voltage divider 38, and A control voltage is generated so that the input current is proportional to the input voltage. Specifically, the control unit 39 generates a control voltage with a pulse signal, changes the time ratio of the pulse signal so that the output voltage is constant and the input current is proportional to the input voltage, and the switch element 35 The on-time is controlled.

  A specific example of the boost type power factor correction circuit 30 having such a configuration is shown in FIG. In the boost type power factor correction circuit 30 of FIG. 4, the resistors 31a, 31b and 31d and the switch 31c form the voltage divider 31, the resistor 34a forms the current detector 34, and the resistors 38a and 38b form the voltage divider 38. Forming. The reference voltage generator 39a, error amplifiers 39b and 39f, multiplier 39c, resistor 39d, amplifiers 39e and 39i, oscillator 39g, and comparator 39h form a control unit 39.

  The resistors 31a and 31b of the voltage divider 31 divide the input voltage and send the divided input voltage to the control unit 39 as the input divided voltage. The switch 31c of the voltage divider 31 switches whether the resistor 31d is connected in parallel to the resistor 31b. That is, when the non-stabilized insulation type DC / DC converter 10 is not activated, the switch 31c is turned on to increase the voltage dividing ratio by the resistors 31a and 31b. As a result, an input divided voltage when the AC power supply 201 is used is generated. When the non-stabilized insulated DC / DC converter 10 is activated, the switch 31c is turned off, and the voltage dividing ratio by the resistors 31a and 31b is reduced. Thereby, an input divided voltage having a larger value than that when the AC power supply 201 is used is generated. That is, the voltage divider 31 switches the voltage dividing ratio according to the AC power supply 201 or the storage battery 202 input to the DC stabilized power supply 1 and generates an input divided voltage.

  The resistor 34a of the current detector 34 generates a current corresponding to the coil current, that is, a voltage proportional to the coil current, and sends the generated voltage to the control unit 39 as a current corresponding voltage. That is, the current detector 34 feeds the coil current. In this embodiment, the coil current is detected by the resistor 34a. However, in addition to this, a method of measuring by inserting a current detection resistor in the route where the coil current returns, and the current of the switch element 35 are measured. There are various detection methods such as a method of obtaining the coil current by synthesizing the signals.

  The resistors 38a and 38b of the voltage divider 38 divide the output voltage and send the divided output voltage to the control unit 39 as an output divided voltage. That is, the voltage divider 38 performs feedback of the divided output voltage.

  The reference voltage generator 39a of the control unit 39 generates a reference voltage Vref serving as a reference for determining the output voltage.

  The error amplifier 39b compares the output divided voltage of the voltage divider 38 with the reference voltage Vref of the reference voltage generator 39a, and outputs an error voltage according to the comparison result. When there is no difference between the output divided voltage and the reference voltage Vref, that is, when the output voltage is a desired stabilized DC voltage, the error amplifier 39b outputs an error voltage of zero voltage, for example, a desired stabilization. When the output voltage is lower than the DC voltage, a positive error voltage is output.

  The multiplier 39c has an X terminal and a Y terminal. The input divided voltage from the voltage divider 31 is input to the X terminal, and the error voltage from the error amplifier 39b is input to the Y terminal. The multiplier 39c sets the input divided voltage at the X terminal as a value X and sets the output divided voltage at the Y terminal as a value Y. The multiplier 39c uses a coefficient kvff related to power factor improvement. The coefficient kvff is generally controlled to be proportional to the square of the effective value of the input voltage, but the value is optimized in order to improve the power factor. Then, the multiplier 39c performs the following multiplication.

XY (1 / kvff)
Thereafter, the multiplier 39c passes a current having a magnitude corresponding to the multiplication result. When the output voltage is a desired stabilized DC voltage, the multiplier 39c passes a predetermined amount of current (predetermined current). For example, when the output voltage is lower than the desired stabilized DC voltage. Causes a larger current to flow than a predetermined current. When the non-stabilized insulated DC / DC converter 10 is activated, the value X due to the input divided voltage increases, and the multiplier 39c passes a larger current than the predetermined current.

  The resistor 39d generates a voltage corresponding to the current from the multiplier 39c. When the output voltage is a desired stabilized DC voltage, the resistor 39d generates a predetermined voltage with a predetermined current. For example, when the output voltage is lower than the desired stabilized DC voltage, the resistor 39d has the predetermined voltage. A larger voltage is generated. In addition, when the non-stabilized insulation type DC / DC converter 10 is activated, the resistor 39d generates a voltage larger than the predetermined voltage.

  The amplifier 39e amplifies the voltage corresponding to the current generated by the resistor 34a and sends it to the amplifier 39e.

  The error amplifier 39f generates a level voltage corresponding to the output of the amplifier 39e, that is, the current-corresponding voltage with reference to the voltage generated in the resistor 39d. When the output voltage is a desired stabilized DC voltage, the error amplifier 39f generates a voltage of a predetermined level. For example, when the output voltage is lower than the desired stabilized DC voltage, the error amplifier 39f is caused by the resistor 39d. Since the reference voltage rises, a voltage larger than a predetermined level voltage is generated. Further, when the non-stabilized insulated DC / DC converter 10 is started, the voltage by the resistor 39d increases, so that the error amplifier 39f generates a voltage that is larger than a predetermined level voltage. Further, when the coil current increases, the voltage corresponding to the current from the amplifier 39e increases, so that a voltage smaller than a predetermined level voltage is generated.

  The oscillator 39g oscillates a sawtooth voltage and sends the oscillated sawtooth voltage to the comparator 39h.

  The comparator 39h has an X terminal and a Y terminal. The voltage from the error amplifier 39f is input to the X terminal, and the sawtooth voltage from the oscillator 39g is input to the Y terminal. The comparator 39h sets the input divided voltage at the X terminal to the value X and sets the magnitude of the sawtooth voltage at the Y terminal to the value Y. And the comparator 39h is

X> Y
If so, a high-level control voltage is generated. When the output voltage is a desired stabilized DC voltage, the comparator 39h generates a control voltage that is at a high level for a predetermined time. For example, when the output voltage decreases compared to the desired stabilized DC voltage. Since the error amplifier 39f generates a voltage larger than the voltage at a predetermined level, a control voltage that continues at a high level for a longer time than the predetermined time is generated. Further, when the non-stabilized insulation type DC / DC converter 10 is activated, the error amplifier 39f generates a voltage larger than the voltage at a predetermined level, so that the control voltage that continues to be at a high level for a longer time than the predetermined time. Is generated. Further, when the coil current increases, the error amplifier 39f generates a voltage smaller than a predetermined level voltage, and thus generates a control voltage that continues at a high level for a period shorter than a predetermined time.

  The amplifier 39 i amplifies the control voltage output from the comparator 39 h and outputs the amplified control voltage to the gate of the switch element 35.

  As described above, the boost type power factor correction circuit 30 multiplies the signal obtained by dividing the input voltage, the output of the error amplifier 39b of the output voltage, and the coefficient, and outputs the multiplication result as a current, and the current output. It is the structure provided with the function which switches the ratio which converts into voltage. The step-up type power factor correction circuit 30 having such a configuration controls on / off of the switch element 35 by pulse width control from the direct current voltage from the full-wave rectifier 20 or the unstabilized insulation type DC / DC converter 10. A predetermined constant voltage is output.

  The insulation type DC / DC converter 40 converts a predetermined constant voltage level output from the step-up type power factor correction circuit 30 and outputs a desired stabilized DC voltage. For this purpose, the insulated DC / DC converter 40 includes an inverter 41, a high-frequency transformer 42, and a converter 43. The inverter 41 is a DC / AC inverter, and converts a predetermined constant voltage from the boost type power factor correction circuit 30 into an AC voltage. The high frequency transformer 42 is an insulating transformer, and the secondary side of the high frequency transformer 42 is insulated from the primary side. The high-frequency transformer 42 transforms the primary side AC voltage from the inverter 41 and outputs it from the secondary side. The converter 43 is an AC / DC converter, and converts an AC voltage from the secondary side of the high-frequency transformer 42 into a DC voltage. Converter 43 then outputs the converted DC voltage as a desired stabilized DC voltage.

  Next, the operation of the DC stabilized power supply according to this embodiment will be described. During normal operation of the DC stabilized power supply 1, the sine wave input voltage of the AC power supply 201 is full-wave rectified by the full-wave rectifier 20, and the boost power factor improvement circuit 30 improves the power factor of the input power. Typically, step-up stabilization is performed to DC 380V. When the input voltage of the AC power supply is AC 220 V and the output of the isolated DC / DC converter 40 is 1 kW, the input current of the boost type power factor correction circuit 30 is typically 5 Arms. Using the output of the boost type power factor correction circuit 30 as an input, a desired stabilized DC voltage is obtained by the isolated DC / DC converter 40.

  When the AC power supply 201 falls below a predetermined voltage, the DC stabilized power supply 1 activates the non-stabilized insulated DC / DC converter 10. The unstabilized insulation type DC / DC converter 10 insulates and boosts the DC voltage of the storage battery 202, typically DC 24V, to DC 192V. When the output of the non-stabilized insulation type DC / DC converter 10 is 1 kW, typically, an input current of 52 A flows into the non-stabilization insulation type DC / DC converter 10.

  The pulse generator 11i of the non-stabilized insulated DC / DC converter 10 outputs a pulse signal having a constant time ratio, typically, pulse signals 11ia and 11ib having a time ratio of 50%, and its phase is 180 degrees. It's off. The DC voltage from the storage battery 202 is converted into a square wave with a time ratio of 50% by the switching elements 11a to 11d that are alternately switched by the pulse signals 11ia and 11ib, and is applied to the primary winding 12a of the high-frequency transformer 12. Is done. A square wave corresponding to the winding ratio of the high-frequency transformer 12 is output to the secondary winding 12b of the high-frequency transformer 12, and is rectified to direct current by the rectifier diodes 13a and 13b. Since the time ratio of the pulse signals 11ia and 11ib is constant regardless of the input voltage of the storage battery 202, the output of the unstabilized insulation type DC / DC converter 10 is almost proportional to the voltage when the DC voltage of the storage battery 202 changes. Change. Since the input voltage is low and the input current is large, copper loss is more dominant than iron loss in the high-frequency transformer 12, but since the battery 202 is exclusively used, a sufficient conductor cross-sectional area can be secured. In addition, since the inter-winding coupling can be kept good, the loss generated in the high-frequency transformer 12 and the unstabilized insulated DC / DC converter 10 can be minimized. In addition, as a specific example of the unstabilized insulation type DC / DC converter 10, the full bridge method is shown, but other methods may be used as long as the voltage can be boosted by insulation, for example, a half bridge method, A forward method or a flyback method can be used.

  Because of such a system, even when the voltage of the storage battery 202 is as low as 24 V and a large current input of 52 A, the unstabilized insulation type DC / DC converter 10 isolates the output of the storage battery 202 from the AC power supply system, In addition, large power can be supplied.

  Thus, the non-stabilized insulation type DC / DC converter 10 performs insulation boosting, and the output DC 192 V and the current 5.8 A are input to the boosting power factor correction circuit 30. Since the step-up power factor correction circuit 30 is a step-up chopper whose circuit configuration stabilizes and outputs DC 380 V, the output of the unstabilized insulated DC / DC converter 10 can be stabilized to DC 380 V and 2.8 A.

  In other words, the boost type power factor correction circuit 30 includes a multiplier 39c in order to make the input current proportional to the input voltage and to stabilize the output voltage. The multiplier 39c multiplies the output of the error amplifier 39b of the output voltage, the output of the voltage divider 31 representing the amplitude signal of the input voltage, and the coefficient 1 / kvff. The coefficient kvff is generally controlled to be proportional to the square of the effective value of the input voltage, and the value is optimized to improve the power factor. However, when boosting the output of the unstabilized insulated DC / DC converter 10, the coefficient kvff is not always optimal.

  Specifically, when the output voltage of the non-stabilized insulation type DC / DC converter 10 is low, the output of the voltage divider 31 that becomes the input voltage of the X terminal of the multiplier 39c becomes small, so the output of the multiplier 39c is Get smaller. As a result, since the reference of the error amplifier 39f is small, a desired output (a desired stabilized DC voltage) may not be obtained. In order to cope with this, when boosting the output voltage of the unstabilized insulation type DC / DC converter 10, it is preferable to open the switch 31c and switch the voltage dividing ratio of the voltage divider 31 to increase the output of the voltage divider 31. It is. Essentially, since the voltage dividing ratio is switched so as to increase the output of the voltage divider 31 when the DC voltage is boosted, it is needless to say that the switching method can be other than the method shown in this embodiment.

  With the output of the boost type power factor correction circuit 30 as an input, the insulation type DC / DC converter 40 obtains a desired stabilized DC voltage. At this time, the high-frequency transformer 42 of the insulation type DC / DC converter 40 does not need to be provided with a tertiary winding for allowing the input current from the storage battery 202 to flow. Can be reduced in size.

  Thus, according to this embodiment, there is no need to provide a tertiary winding for flowing a large current to the high-frequency transformer 12 of the non-stabilized insulation type DC / DC converter 10, and a smaller size suitable for obtaining the output. High frequency transformer can be used. Further, in order to insulate and boost the power input of the storage battery 202, the unstabilized insulation type DC / DC converter 10 having a fixed duty ratio and the boost type power factor correction circuit 30 are combined, so that the output voltage of the storage battery 202 is low and other devices However, even when the output of the storage battery 202 is used, a safe and highly efficient DC stabilized power supply with a backup function can be realized.

Further, according to this embodiment, when using the boost type power factor correction circuit 30 and the insulated DC / DC converter 40 and using the storage battery 202, the switch 31c of the boost type power factor improvement circuit 30 is opened. By switching the voltage dividing ratio of the voltage divider 31, the signal level input to the multiplier 39c can be increased, and sufficient power can be output. That is, by using the storage battery 202, even if the output of the non-stabilized insulation type DC / DC converter 10 is low, the voltage generated in the resistor 39d is increased by the output current of the multiplier 39c, and a large amount of electric power is output. The mold power factor correction circuit 30 operates normally. As a result, even if the storage battery 202 is used, the output from the non-stabilized insulated DC / DC converter 10 can be stabilized and a desired stabilized DC voltage can be obtained.
(Embodiment 2)
In the DC stabilized power supply according to this embodiment, the voltage divider 31 and the control unit 39 of the boost type power factor correction circuit 30 are as follows. In this embodiment, components that are the same as or the same as those of the DC stabilized power supply 1 of the first embodiment described above are denoted by the same reference numerals, and the description thereof is omitted. As shown in FIG. 5, in the voltage divider 31 of the boost type power factor correction circuit 30 according to this embodiment, the switch 31c and the resistor 31d provided in the first embodiment are omitted.

  In the control unit 39 according to this embodiment, a switch 39j and a resistor 39k are provided. The switch 39j and the resistor 39k are connected in series, and a series circuit of the switch 39j and the resistor 39k is connected in parallel to the resistor 39d. The switch 39j switches whether the resistor 39k is connected in parallel to the resistor 31d. That is, when the AC power supply 201 is normal, the switch 31c is turned on, and the reference voltage used by the error amplifier 39f is generated by the combined resistance of the resistor 31d and the resistor 39k. When the non-stabilized insulated DC / DC converter 10 is activated, the switch 31c is turned off, and a reference voltage having a large value is generated by the resistor 39d having a higher value than the combined resistance of the resistor 31d and the resistor 39k. To do. That is, the reference voltage used for the error amplifier 39f is generated according to the AC power supply 201 and the storage battery 202 used in the DC stabilized power supply 1.

  Next, the operation of the DC stabilized power supply according to this embodiment will be described. As described in the previous embodiment, the step-up type power factor correction circuit 30 includes a multiplier 39c in order to make the input current proportional to the input voltage and stabilize the output voltage. The multiplier 39c multiplies the output of the error amplifier 39b of the output voltage, the output of the voltage divider 31 representing the amplitude signal of the input voltage, and the coefficient 1 / kvff. The multiplier 39c generally has a current output, and the resistor 39d can change the output amplitude of the multiplier 39c. The coefficient kvff is generally controlled to be proportional to the square of the effective value of the input voltage, and the value is optimized to improve the power factor. However, when boosting the output of the unstabilized insulated DC / DC converter 10, the coefficient 1 / kvff is not always optimal.

  Specifically, when the input voltage to the boost type power factor correction circuit 30 is low, the output of the voltage divider 31 that becomes the input voltage of the X terminal of the multiplier 39c becomes small, so that the multiplication that becomes the reference of the error amplifier 39f In some cases, the output of the device 39c becomes small and a desired stabilized DC voltage cannot be obtained. To cope with this, when boosting the output voltage of the unstabilized insulated DC / DC converter 10, the switch 39j is opened to increase the resistance value of the resistor 39d. Thus, it is preferable to increase the output of the multiplier 39c and increase the amplitude of the reference signal of the error amplifier 39f. In essence, since the reference value of the error amplifier 39f is increased at the time of DC voltage boosting, it is needless to say that the method is possible other than the method shown in this embodiment.

According to this embodiment, the signal obtained by dividing the input voltage, the error amplifier output of the output voltage is multiplied by a coefficient, the multiplier 39c that outputs the multiplication result as a current, and the ratio for converting the current output into a voltage By providing the function of switching between, the same effect as in the first embodiment can be obtained.
(Embodiment 3)
In the DC stabilized power supply according to this embodiment, the voltage divider 31 and the control unit 39 of the boost type power factor correction circuit 30 are as follows, and the voltage divider 31A is newly provided in the boost type power factor improvement circuit 30. . In this embodiment, components that are the same as or the same as those of the DC stabilized power supply 1 of the first embodiment described above are denoted by the same reference numerals, and the description thereof is omitted. As shown in FIG. 6, in the voltage divider 31 of the boost type power factor correction circuit 30 according to this embodiment, the switch 31c and the resistor 31d provided in the first embodiment are omitted. In the control unit 39 according to this embodiment, a filter 39m and a calculator 39n are newly provided, and a multiplier 39p is used instead of the multiplier 39c.

  In the voltage divider 31A, the resistor 31Aa and the resistor 31Ab are connected in series to form a series circuit, and this series circuit is connected to the input side to divide the voltage. A series circuit in which a resistor 31Ac and a switch 31Ad are connected in series is connected in parallel to the resistor 31Ab. The switch 31Ad switches whether the resistor 31Ac is connected in parallel to the resistor 31Ab. That is, when the AC power supply 201 is normal, the switch 31c is turned off, and the voltage divider 31A generates a voltage obtained by dividing the input voltage by the resistor 31Aa and the resistor 31Ab. When the non-stabilized insulated DC / DC converter 10 is activated, the switch 31c is turned on, and a combined resistance of the resistor 31Ab and the resistor 31Ac is formed. As a result, a voltage having a lower value than the voltage divided by the resistor 31Aa and the resistor 31Ab is generated. That is, the voltage divider 31 </ b> A generates an input divided voltage (first input divided voltage) obtained by dividing the input voltage according to the AC power supply 201 or the storage battery 202 used in the DC stabilized power supply 1.

  The filter 39m passes the low frequency component of the input divided voltage generated by the voltage divider 31A.

  The arithmetic unit 39n has an X terminal, uses the input divided voltage from the filter 39m as an input to the X terminal, and performs the following calculation that is inversely proportional to the input.

1 / X ²
Thereafter, the calculator 39n outputs a voltage representing the calculation result. When the unstabilized insulation type DC / DC converter 10 is activated, the value X due to the input divided voltage becomes small, and the arithmetic unit 39n has a large value (1 / X compared to when the AC power supply 201 is normal). ² ) Output the voltage corresponding to.

  The multiplier 39p has an X terminal, a Y terminal, and a Z terminal. Similarly to the previous embodiment, the X terminal and the Y terminal of the multiplier 39p obtain the input divided voltage (second input divided voltage) from the voltage divider 31 and the error voltage from the error amplifier 39b. As input. The voltage from the arithmetic unit 39n is input to the Z terminal of the multiplier 39p. Then, the multiplier 39p performs the next multiplication using these input voltages.

XYZ
Thereafter, the multiplier 39p passes a current corresponding to the multiplication result. At this time, when the non-stabilized insulation type DC / DC converter 10 is activated, the calculator 39n outputs a large voltage, so that the value Z increases and the multiplier 39p generates a large current compared to the predetermined current. Shed.

  Next, the operation of the DC stabilized power supply according to this embodiment will be described. As described in the previous embodiment, the multiplier 39p is provided internally in order to make the input current proportional to the input voltage and stabilize the output voltage. The multiplier 39p multiplies the output of the error amplifier 39b of the output voltage, the amplitude signal of the input voltage, and the output of the calculator 39n. The value of the arithmetic unit 39n is optimized to improve the power factor, but is not necessarily optimal when boosting the output of the unstabilized insulated DC / DC converter 10.

  Specifically, when the input voltage to the boost type power factor correction circuit 30 is low, the output of the voltage divider 31 that becomes the input voltage of the X terminal of the multiplier 39p becomes small, so that the multiplication that becomes the reference of the error amplifier 39f In some cases, the output of the device 39p becomes small and the desired stabilized DC voltage cannot be obtained. To cope with this, when boosting the output voltage of the unstabilized insulation type DC / DC converter 10, the switch 31Ad of the voltage divider 31A is closed to increase the output of the calculator 39n. Thus, it is preferable to increase the output of the multiplier 39p and increase the amplitude of the reference signal of the error amplifier 39f. Since the essence is a method of increasing the output signal of the arithmetic unit 39n at the time of DC voltage boosting, it is needless to say that the method is possible other than the method shown in this embodiment.

  According to this embodiment, the multiplier 39p that multiplies the signal obtained by dividing the input voltage by the output of the error amplifier 39b of the output voltage and the coefficient has a function of switching the coefficient, thereby providing the first embodiment and the first embodiment. Similar effects can be obtained.

DESCRIPTION OF SYMBOLS 1 DC stabilized power supply 10 Unstabilized insulation type DC / DC converter 11 Inverter 12 High frequency transformer 13 Converter 20 Full wave rectifier 30 Boost type power factor improvement circuit 31, 38 Voltage divider 31a, 31b, 31d Resistance 31c Switch 32, 37 Capacitor 33 Coil 34 Current detector 35 Switch element 36 Diode 39 Control unit 39a Reference voltage generator 39b, 39f Error amplifier 39c Multiplier 39d, 39k Resistor 39e, 39i Amplifier 39g Oscillator 39h Comparator 39j Switch voltage divider 31A
31Aa to 31Ac Resistor 31Ad Switch 39m Filter (Calculation unit)
39n arithmetic unit (arithmetic unit)
39p Multiplier 40 Isolated DC / DC Converter

Claims (5)

A DC stabilized power supply that outputs a desired stabilized DC voltage from an AC power supply and a storage battery,
A rectifier for rectifying an AC voltage from the AC power source;
An unstabilized insulation type DC / DC converter that boosts a DC voltage from the storage battery and outputs it as an unstabilized voltage, and insulates the storage battery side from the rectifier side;
The rectified voltage from the rectifier or the unstabilized voltage from the unstabilized isolated DC / DC converter is used as an input voltage, and the power factor of the input voltage and the input current is improved and the input voltage is stabilized. A power factor correction circuit that outputs a predetermined constant voltage,
An isolated DC / DC converter that converts a predetermined constant voltage from the power factor correction circuit to obtain a desired stabilized DC voltage as an output voltage and insulates the power factor improvement circuit from the output side. When,
With
When the voltage of the AC power supply falls below a predetermined level, the unstabilized insulated DC / DC converter is activated.
DC stabilized power supply characterized by that. The power factor correction circuit includes a boosting coil and a switching element that interrupts the current of the coil, an input divided voltage obtained by dividing the input voltage, and an output divided voltage obtained by dividing the output voltage. The power factor is improved and stabilized by controlling the switching of the switching element based on the current of the coil or the current corresponding thereto.
The DC stabilized power supply according to claim 1. The power factor correction circuit increases the input divided voltage by switching a voltage dividing ratio for dividing the input voltage when the non-stabilized insulated DC / DC converter is activated.
The stabilized DC power supply according to claim 2. The power factor correction circuit is:
An input divided voltage obtained by dividing the input voltage, an output divided voltage obtained by dividing the output voltage, and a coefficient that is controlled to be proportional to the square of the effective value of the input voltage and that is related to power factor improvement. Multiplier and a multiplier that outputs the multiplication result as a current output
Based on the voltage converted from the current output from the multiplier and the current of the coil or the current corresponding thereto, the power factor is improved and stabilized, and the unstabilized insulated DC / DC converter is activated. When switching the ratio of converting the current output from the multiplier to a voltage, this voltage is increased.
The stabilized DC power supply according to claim 2. The power factor correction circuit is:
A calculation unit that performs a calculation inversely proportional to the first input divided voltage obtained by dividing the input voltage;
A multiplier that multiplies a calculation result of the calculation unit, a second input divided voltage obtained by dividing the input voltage, and an output divided voltage obtained by dividing the output voltage, and uses the multiplication result as a current output; ,
With
Based on the voltage converted from the current output from the multiplier and the current of the coil or the current corresponding thereto, the power factor is improved and stabilized, and the unstabilized insulated DC / DC converter is activated. And switching the voltage dividing ratio for dividing the first input voltage to lower the first input divided voltage.
The stabilized DC power supply according to claim 2.