JP2012147563A - Power supply stabilizer and power supply stabilizer control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power supply stabilizer for eliminating the need for communicating between voltage converters of power source and capacitor for stabilizing a load side voltage.SOLUTION: A power supply stabilizer includes: a power source 20 for supplying power to a load; a capacitor 30 connected parallel to the power source 20 for supplying power to the load and charging a regenerative power generated with the load for storing the power; a first voltage converter 10 connected parallel to the power source 20 between the power source 20 and the capacitor 30 for detecting inter-terminal voltage of the capacitor 30, and converting the voltage of the power source 20 based on the capacitor 30 voltage; and a second voltage converter 11 connected parallel to the capacitor 30 and the first voltage converter 10 between terminals 40a and 40b connected to the capacitor 30 and the load for detecting the voltages of the terminals 40a and 40b and converting the inter-terminal voltage of the capacitor 30 based on the voltages of the terminals 40a and 40b.

Description

  The present invention relates to a power supply stabilization device, and more particularly, to a power supply stabilization device and a power supply stabilization device control method that can cope with load fluctuations.

  In recent years, in addition to conventional engines, hybrid vehicles using a DC power source, an inverter and a motor driven by an inverter as a power source, and electric vehicles using a DC power source, a motor driven by an inverter and an inverter as a power source are attracting attention. Has been. In a hybrid vehicle and an electric vehicle, in order to improve energy efficiency while driving the vehicle appropriately, power is supplied according to the load on the motor, and a secondary battery is used to efficiently recover energy during regeneration. There is provided a hybrid DC power supply device in which a (power supply) and a capacitor (capacitor) are connected in parallel.

  There are many systems that perform power compensation from both a secondary battery characterized by high energy density and a capacitor characterized by high power density (see, for example, Patent Document 1). In such a system, a control device such as a device for limiting charge / discharge current or a voltage converter (DCDC converter) is connected to either or both of the secondary battery and the capacitor to control the voltage or the like.

  In the conventional system, in order for the DCDC converter of each of the secondary battery and the capacitor to monitor both states, data exchange using communication, wiring processing across the DCDC converter, an external sensor, etc. are necessary. It was.

JP 2002-315109 A

  The present invention has been made in view of the above circumstances, and does not require communication between the voltage conversion devices of the power supply and the capacitor, and can provide a constant load-side voltage and a power supply stabilization device and a power supply stabilization device An object is to provide a control method.

  According to one aspect of the present invention, a power source that supplies power to a load, and a power source that is connected in parallel to the power source, supplies power to the load, and can store regenerative power generated at the load by charging. A capacitor, a first voltage converter connected in parallel with the power source between the power source and the capacitor, detecting a voltage between terminals of the capacitor, and converting and controlling the voltage of the power source based on the voltage between the terminals of the capacitor; and the capacitor And a terminal connected to the load are connected in parallel with the capacitor and the first voltage converter, a second voltage for detecting the voltage of the terminal and converting and controlling the voltage between the terminals of the capacitor based on the voltage of the terminal The gist of the invention is that it is a power supply stabilization device including a conversion device.

  According to another aspect of the present invention, during powering, the second voltage conversion device detects the voltage of the terminal connected to the load, and boosts the voltage across the terminals based on the voltage of the terminal; The first voltage converter detects the voltage of the capacitor and boosts the voltage of the power supply based on the voltage across the terminals of the capacitor. During regeneration, the second voltage converter detects the voltage of the terminal. A step of stepping down the voltage between the terminals of the capacitor based on the voltage of the terminal, and a step of stepping down the voltage of the power source based on the voltage between the terminals of the capacitor by the first voltage converter detecting the voltage between the terminals of the capacitor. The power supply stabilizing device control method includes the following.

  ADVANTAGE OF THE INVENTION According to this invention, the communication between the voltage converters of a power supply and a capacitor is unnecessary, and the power supply stabilization apparatus and power supply stabilization apparatus control method which can make load side voltage constant can be provided.

1 is a schematic circuit diagram of a power supply stabilization device according to an embodiment of the present invention. It is a flowchart which shows operation | movement of the 1st voltage converter provided in the power supply side in the electric power supply stabilization apparatus which concerns on embodiment of this invention. It is a schematic circuit diagram which shows the operation | movement at the time of the power running of the 1st voltage converter provided in the power supply side in the electric power supply stabilization apparatus which concerns on embodiment of this invention. It is a schematic circuit diagram which shows the operation | movement at the time of regeneration of the 1st voltage converter provided in the power supply side in the electric power supply stabilization apparatus which concerns on embodiment of this invention. It is a flowchart which shows operation | movement of the 2nd voltage converter provided in the capacitor side in the electric power supply stabilization apparatus which concerns on embodiment of this invention. It is a schematic circuit diagram which shows the operation | movement at the time of the power running of the 2nd voltage converter provided in the capacitor side in the electric power supply stabilization apparatus which concerns on embodiment of this invention. It is a schematic circuit diagram which shows the operation | movement at the time of regeneration of the 2nd voltage converter provided in the capacitor side in the electric power supply stabilization apparatus which concerns on embodiment of this invention. It is a schematic circuit diagram for demonstrating the power supply stabilization apparatus control method which concerns on embodiment of this invention. It is a flowchart which shows the operation | movement at the time of power running in the electric power supply stabilization apparatus control method which concerns on embodiment of this invention. It is a flowchart which shows the operation | movement at the time of regeneration in the electric power supply stabilization apparatus control method which concerns on embodiment of this invention. It is a schematic circuit diagram of the electric power supply stabilization apparatus which concerns on other embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, the drawings are schematic, and the relationship between the thickness and the planar dimensions, the ratio of the thickness of each layer, and the like are different from the actual ones. Therefore, specific thicknesses and dimensions should be determined in light of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

(Embodiment)
As shown in FIG. 1, the power supply stabilization apparatus according to the first embodiment of the present invention is connected to a power source 20 that supplies power to a load, and is connected in parallel to the power source 20. Is connected in parallel with the power source 20 between the power source 20 and the capacitor 30, and the voltage between the terminals of the capacitor 30 is detected. The capacitor 30 and the first voltage converter 10 are connected between the first voltage converter 10 that converts and controls the voltage of the power supply 20 based on the voltage between the terminals of the capacitor 30 and the terminals 40a and 40b connected to the capacitor 30 and the load. And a second voltage conversion device 11 that detects the voltages of the terminals 40a and 40b and converts and controls the voltage across the terminals of the capacitor 30 based on the voltages of the terminals 40a and 40b. .

  The power source 20 is a secondary battery that can be used as a battery by storing electricity by charging a lithium ion battery, a nickel metal hydride battery, or the like. Since the power supply 20 can be repeatedly charged and discharged, it can be used repeatedly.

  The capacitor 30 is, for example, an electric double layer capacitor connected in parallel with the power supply 20. The capacitor 30 stores electricity by charging and functions as an auxiliary to the power source 20.

  A load (not shown) is connected to the terminals 40a and 40b. The load is, for example, a DC motor. When the DC motor as a load requires a large amount of power during acceleration or the like, the power stored in the power source 20 and the capacitor 30 is supplied from both. When the DC motor as the load is in a steady state, power is supplied only from the power source 20. Further, the load generates a regenerative current (electric power) when operating as a generator. The regenerative current is accumulated in the power supply 20 and the capacitor 30.

  The first voltage converter (DCDC converter) 10 is provided in parallel between the power supply 20 and the capacitor 30. The first voltage conversion device 10 detects the voltage between the terminals of the capacitor 30 and performs a boost operation when the voltage between the terminals of the capacitor 30 is lower than a predetermined value. The voltage between the terminals of the capacitor 30 is higher than the predetermined value. When this happens, step-down operation is performed. The predetermined value in the voltage between the terminals of the capacitor 30 refers to a value determined in advance by the rated voltage (normal use voltage), the withstand voltage, or the like of the capacitor 30.

The operation during powering of the first voltage converter 10 will be described with reference to FIGS. 2 and 3. When power is supplied from the capacitor 30 to the load during power running, the inter-terminal voltage V _cap of the capacitor 30 decreases. In step S11 of FIG. 2, the first voltage converter 10 detects the inter-terminal voltage V _cap of the capacitor 30 and determines whether or not the inter-terminal voltage V _cap of the capacitor 30 has become lower than a predetermined value V ′ _cap. To do. When determining that the voltage V _cap between the terminals of the capacitor 30 has become lower than the predetermined value V ′ _cap , the first voltage converter 10 performs a boosting operation in step S12. As shown in FIG. 3, the first voltage converter 10 performs a step-up operation to supply power from the power supply 20 to the capacitor 30.

An operation during regeneration of the first voltage converter 10 will be described with reference to FIGS. 2 and 4. When regenerative current is supplied from the load to the capacitor 30 during regeneration, the inter-terminal voltage V _cap of the capacitor 30 increases. In step S11 of FIG. 2, the first voltage converter 10 detects the voltage between the terminals of the capacitor 30 and determines whether or not the voltage V _cap between the terminals of the capacitor 30 is higher than a predetermined value V ′ _cap . When determining that the voltage V _cap between the terminals of the capacitor 30 has become higher than the predetermined value V ′ _cap , the first voltage conversion device 10 performs a step-down operation in step S13. As shown in FIG. 4, the first voltage converter 10 performs a step-down operation and supplies power from the capacitor 30 to the power supply 20.

  The second voltage converter (DCDC converter) 11 is provided in parallel between the capacitor 30 and the terminals 40a and 40b connected to the load. The second voltage conversion device 11 is also provided in parallel with the first voltage conversion device 10. The second voltage converter 11 detects the voltages at the terminals 40a and 40b, performs a boost operation when the voltages at the terminals 40a and 40b are lower than a predetermined value, and the voltages at the terminals 40a and 40b are higher than the predetermined value. When this happens, step-down operation is performed. The predetermined value in the voltage of the terminals 40a and 40b is a value determined in advance by the rated voltage of the load connected to the terminals 40a and 40b.

The operation at the time of power running of the second voltage converter 11 will be described with reference to FIGS. 5 and 6. When power is supplied from the capacitor 30 to the load during power running, the voltage _Vout between the terminals 40a and 40b decreases. The second voltage converting device 11 in step S21 in FIG. 5, the terminal 40a, and detects the voltage V _out between 40b, whether the terminal 40a, the voltage V _out between 40b becomes lower than a predetermined value V _'out Judging. When determining that the voltage V _out between the terminals 40a and 40b has become lower than the predetermined value V ′ _out , the second voltage conversion device 11 performs a boosting operation in step S22. As shown in FIG. 6, the second voltage converter 11 performs a step-up operation and supplies power from the capacitor 30 to the load.

The operation at the time of regeneration of the second voltage converter 11 will be described with reference to FIGS. 5 and 7. When regenerative current is supplied from the load to the capacitor 30 during regeneration, the voltage _Vout between the terminals 40a and 40b increases. The second voltage converting device 11 in step S21 in FIG. 5, the terminal 40a, and detects the voltage V _out between 40b, whether the terminal 40a, the voltage V _out between 40b becomes higher than a predetermined value V _'out Judging. When determining that the voltage V _out between the terminals 40a and 40b has become higher than the predetermined value V ′ _out , the second voltage conversion device 11 performs a step-down operation in step S23. As shown in FIG. 7, the second voltage conversion device 11 performs a step-down operation and supplies power from the load to the capacitor 30.

  Hereinafter, a power supply stabilization device control method during powering using the power supply stabilization device according to the embodiment of the present invention will be described with reference to the flowcharts of FIGS. 8 and 9.

First, in step S31 of FIG. 9, a DC motor or the like is activated (powering state). The load increases when the DC motor or the like is started. When the load increases, the voltage _Vout between the terminals 40a and 40b shown in FIG. 8 decreases (step S32).

Next, in step S33, the second voltage converter 11 is a DCDC converter the capacitor 30 side terminals 40a, since the detection voltage V _out between 40b directly, the terminal 40a, the voltage V _out between 40b Due to the low voltage, the voltage supplied from the capacitor 30 is boosted. Since the capacitor 30 supplies power to the load, the inter-terminal voltage V _cap of the capacitor 30 decreases (step S34).

Next, in step S35, the first voltage conversion device 10 which is a DCDC converter on the power source 20 side directly detects the inter-terminal voltage V _cap of the capacitor 30, so the inter-terminal voltage V _cap of the capacitor 30 becomes low. As a result, the voltage supplied from the power supply 20 is boosted.

  Hereinafter, a method for controlling the power supply stabilization apparatus during regeneration using the power supply stabilization apparatus according to the embodiment of the present invention will be described with reference to the flowcharts of FIGS. 8 and 10.

First, in step S41 of FIG. 10, the DC motor or the like brakes, so that the load operates as a generator to generate a regenerative current (regenerative state). When the DC motor or the like generates a regenerative current, the voltage _Vout between the terminals 40a and 40b shown in FIG. 8 increases (step S42).

Next, in step S43, the second voltage converter 11 is a DCDC converter the capacitor 30 side terminals 40a, since the detection voltage V _out between 40b directly, the terminal 40a, the voltage V _out between 40b Due to the increase, the voltage supplied to the capacitor 30 is stepped down. Since the capacitor 30 is supplied with power from the load, the inter-terminal voltage V _cap of the capacitor 30 increases (step S44).

Next, in step S45, the first voltage conversion device 10 which is a DCDC converter on the power supply 20 side directly detects the voltage V _cap of the capacitor 30, so that the terminal voltage V _cap of the capacitor 30 has increased. Thus, the voltage supplied to the power supply 20 is stepped down.

  According to the power supply stabilization device and the power supply stabilization device control method according to the embodiment, the first voltage conversion device 10 and the second voltage conversion device 11 are connected in parallel, and the two-stage step-up type or the two-step step-down type. By doing, the 1st voltage converter 10 and the 2nd voltage converter 11 can detect each voltage value directly. Accordingly, the first voltage conversion device 10 and the second voltage conversion device 11 that can directly capture necessary data do not need to exchange data using communication, and can perform processing without data delay or the like. it can. In addition, the first voltage conversion device 10 and the second voltage conversion device 11 do not require wiring processing, an external sensor, or the like, so that wiring can be simplified and the number of components can be reduced.

  Furthermore, according to the power supply stabilization device and the power supply stabilization device control method according to the embodiment, the first voltage conversion device 10 and the second voltage conversion device 11 are respectively connected to the power source (secondary battery) 20 and the capacitor 30. By using this, it is possible to perform a step-up operation and a step-down operation, respectively, so that the load side voltage can be made constant in response to any load fluctuation.

(Other embodiments)
As described above, the present invention has been described according to the embodiment. However, it should not be understood that the description and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques should be apparent to those skilled in the art.

  For example, although the power supply 20 is described as a secondary battery in the embodiment, as shown in FIG. 11, a power supply including an AC system power supply 21 and a rectifier 22 that converts AC generated from the system power supply 21 into DC. It does not matter. In this case, the regenerative current is supplied to the system power supply 21. As the rectifier 22, a switch circuit having a diode and a protection diode can be used.

  Thus, it should be understood that the present invention includes various embodiments and the like not described herein. Therefore, the present invention is limited only by the invention specifying matters in the scope of claims reasonable from this disclosure.

DESCRIPTION OF SYMBOLS 10 ... 1st voltage converter 11 ... 2nd voltage converter 20 ... Power supply 21 ... System power supply 22 ... Rectifier 30 ... Capacitor 40a, 40b ... Terminal

Claims (6)

A power source for supplying power to the load;
A capacitor connected in parallel with the power source, supplying power to the load, and capable of storing regenerative power generated by the load by charging;
A first voltage converter connected in parallel with the power source between the power source and the capacitor, detecting a voltage between terminals of the capacitor, and converting and controlling the voltage of the power source based on the voltage between terminals of the capacitor. When,
Connected in parallel with the capacitor and the first voltage converter between the capacitor and a terminal connected to the load, detects the voltage of the terminal, and based on the voltage of the terminal, between the terminals of the capacitor A power supply stabilization device comprising: a second voltage conversion device that converts and controls voltage.   The first voltage converter performs a step-up operation when a voltage between terminals of the capacitor becomes lower than a predetermined value, and performs a step-down operation when the voltage between terminals of the capacitor becomes higher than a predetermined value. The power supply stabilization device according to claim 1.   The second voltage conversion device performs a step-up operation when a voltage at the terminal becomes lower than a predetermined value, and performs a step-down operation when the voltage at the terminal becomes higher than a predetermined value. The power supply stabilization device according to 1 or 2.   The power supply stabilization device according to any one of claims 1 to 3, wherein the power source is a secondary battery capable of storing regenerative power generated by the load by charging.   The power supply stabilization device according to any one of claims 1 to 3, wherein the power source includes an AC system power source and a rectifier that converts AC generated from the system power source into DC. A power supply stabilization device control method for a power supply stabilization device according to any one of claims 1 to 5,
During power running, the second voltage converter detects a voltage of a terminal connected to a load and boosts the voltage across the terminals of the capacitor based on the voltage of the terminal; Detecting the voltage and boosting the voltage of the power source based on the voltage between the terminals of the capacitor,
In regeneration, the second voltage converter detects the voltage of the terminal and reduces the voltage across the terminals of the capacitor based on the voltage of the terminal; and the first voltage converter between the terminals of the capacitor And a step of detecting a voltage and stepping down the voltage of the power source based on the voltage across the terminals of the capacitor.

Images