JP3164343U - Lossless DC-DC converter - Google Patents

Abstract

Disclosed is a lossless DC-DC converter that eliminates voltage conversion loss, has a power storage function, and has improved stability. A plurality of capacitors are connected through prevention of backflow prevention. Install a ripple prevention capacitor on the output side. [Selection] Figure 5

Description

  The present invention relates to the effective use of DC energy. By using the present invention, the conventional DC conversion between DCs has been done through AC through inverters, etc., and several times the conventional loss. This is related to a DC-DC converter with higher stability, which is compatible with a wide range of voltage and has a storage function in the converter itself. In addition to supplying a DC power supply that could not be used if an expensive power stabilizer or battery was not installed, it was also possible to quickly charge in the event of a power shortage due to a disaster, etc. It is also. Furthermore, the minute energy generated by the unstable power source of the photovoltaic power generation panel and the minute natural energy generated by wind power generation, temperature difference power generation, etc. are effectively stored and converted, so the minute energy can be converted. Stable power can be supplied.

  These days, the actual operating voltage of these semiconductor devices has become a low-voltage direct current of about 5V. Electronic devices such as mobile phones that are sold in large quantities are showing signs of energy saving due to the development of LED lighting. However, since the conventional power distribution system is centered on alternating current such as 100V alternating current, in order to supply power to recent high-efficiency devices, it is necessary to bother to convert alternating current into low-voltage direct current. The In addition, many of the power generation systems that use natural energy, such as solar power generation, generate direct current, but these natural energies are derived from nature as the name suggests, so there is a small amount of time when the sun is not rising or when there is no wind. In order to generate and change a wide range of energy and wind energy that exceeds the design value that wind power generation receives during typhoons, a limiter, etc. is attached in accordance with conventional power technology to prevent destruction of the power equipment. , The power generated from the natural energy is not used effectively. Taking solar power as an example, the amount of power generated by solar power generation increases when the sun comes out, and the amount of power generation decreases when clouds are applied. In addition, even if it rains at night or even if it rains, it is below the limit of the limiter even though it is generating a little, and it will be equivalent to not generating electricity. In addition, with solar power generation, if long rain continues, natural energy can no longer be expected, and even in such a case, if users cannot easily back up from the power source, they can gain confidence in the natural energy. I can't. Therefore, in the past, using batteries and using parts called conditioners so that they can communicate with the commercial power system are complicated, expensive to purchase, restricted by laws and regulations, and maintenance is difficult. It was. Energy conservation is one of the major themes for the prevention of global warming, and the amount of power used is reduced. To cover this, it is necessary to install a battery, sell electricity, etc. However, it is in a situation where it is necessary to use a large amount of expensive electrical equipment, and subsidies have been devised due to poor profitability. Prior to energy use, energy conservation in homes and offices has not progressed.

    Conventionally, when converting from a DC voltage to a desired DC voltage, it was first converted to AC and then converted again to DC. For this reason, conversion loss occurs, and in order to protect the conversion device, the minute energy or large energy exceeding the design value was cut off with a limiter to prevent the conversion device from being destroyed. As a result, it was very inefficient for wide-range inputs such as solar energy. As its name suggests, the DC-DC converter is intended only for conversion, and it could not be used as a power supply source unless a battery, conditioner, or other device was installed outside. In the present invention, voltage conversion to a wide range is possible without loss, and by providing a power storage function, stable power supply is measured, enabling quick charging in the event of a shortage of electricity, just lossless DC-DC It is intended to be a practical power supply instead of a converter.

In the present invention, the capacitor on the input side accumulates from minute power to large power by utilizing the property that the capacitor absorbs unstable waves such as ripples of DC power supply and quick charge function. Although the amount of power generated by photovoltaic panels, etc. is unstable, the power of natural energy that can be generated reliably is stored in a capacitor as if it were a tank, and the variation was regarded as a large ripple. Naturally, even stable DC power is stored in the capacitor in the same way.
Although the maximum voltage is specified for the capacitor, there is no limit on the minimum voltage, so set the allowable voltage with a sufficient margin for the input voltage. At this time, a plurality of capacitors are connected in series or in parallel according to the input voltage and the target storage capacity, and the input voltage is stored in each capacitor. Capacitor series / parallel switching has been used for power factor improvement in the past, so connection switching itself has a long history. Capacitors have the characteristic of having a characteristic line with a known amount of electrical storage and voltage. By measuring the voltage between each capacitor terminal, the amount of electrical storage inside each capacitor can be reliably determined.
In addition, by measuring the past usage history and total voltage of each capacitor, it is possible to estimate the amount of electricity stored in each capacitor and voltage by calculation without measuring the voltage individually.
Not only small electric power such as sunlight, but also electric storage by instantaneous pressurization in an emergency etc. and inexpensive power supply by late-night power can be done with the same mechanism.
Next, the output side selects a capacitor to be connected selectively from among the capacitors that have been electrically stored according to the required voltage. In the same way as the input side, combination connection in series and parallel is made according to the operating voltage and capacity. The selected capacitor will decrease the voltage of the electricity storage capacity as the power is used, so a voltage drop will be prevented by connecting another capacitor in combination. In addition, in order to prevent ripple when switching the connection, put a ripple prevention capacitor on the output side. On the other hand, equipment that adjusts inflow power by intermittent voltage, such as LED lighting, can be directly fed without special converter by switching connection intermittently.
A stable voltage is supplied by automatically switching these connections to match the desired output voltage using a connection switching circuit such as a voltmeter or a relay, or an arithmetic computer. In addition, as described above, capacitors do not measure voltage individually, but store electricity and generate a voltage proportional to it, so for those whose output voltage fluctuation is not severe, past usage history, input side applied voltage and output voltage If you know, you can switch sequentially only by calculation.
Arrange the backflow prevention elements appropriately so that these capacitors do not come into electrical contact.

  With this device, it is possible to accumulate and use a combination of capacitors from micro power generated by natural energy such as photovoltaic power generation to maximum power without waste. In addition, we can create an immediate response system for power demand such as late-night power, emergency charging, and capacitor grid. The stored power can be taken out at the target voltage without using an inverter or transformer by using a series-parallel connection of capacitors, so there is no conversion loss. By using the quick charge function of the capacitor, it becomes a commercial power supply in seconds, and by using the lossless DC-DC converter according to the present invention, it is possible to achieve nighttime power use, reactive power use and significant energy saving, Costs can be reduced by reducing the number of parts and maintenance-free by not using batteries. In addition, natural energy can be used as reliable power.

For the sake of simplicity, Fig. 1 shows a conceptual diagram of the case where the input voltage of 10V is stepped down to the output voltage of 2.5V and the input voltage of 2.5V is boosted to the output voltage of 10V. . First, the case where the input voltage of 10V is stepped down to the output of 2.5V is used in Fig. 1. Four capacitors (1-1) to (1-4) having a maximum allowable voltage of 2.5 V are connected in series via backflow prevention elements (2-1-1) to (2-4-1). The voltage is applied and the power is stored in the capacitor up to 10V. (FIG. 1 (a)) Next, capacitors (1-1) to (1-4) are connected in parallel via backflow prevention prevention (2-1-2) to (2-4-2). 5V output is obtained. (FIG. 1 (b)) Since the voltage decreases with the use of power due to the capacitor characteristics, capacitors (1-1) and (1-2) are connected in series, and (1-3) and (1-4) Are connected in parallel via reverse flow prevention block (2-1-2) through (2-4-2) to obtain 2.5V again. (Fig. 1 (c)) Since the voltage decreases further as the voltage is used, capacitors (1-1) to (1-4) are prevented from being blocked (2-1-2) to (2-4-2). Connect in series and get 2.5V again. (Fig. 1 (d)) In addition, when electricity storage is not required, it can be handled by repeating only Fig. 1 (a) and Fig. 1 (b).
Next, the case where the voltage of 2.5V power reception is boosted to 10V in Fig. 2 is explained. Sixteen capacitors (1-1) to (1-16) having a maximum allowable voltage of 2.5 V are connected in parallel via the backflow prevention elements (2-1-1) to (2-16-1). Accumulate voltage up to 5V. (FIG. 2 (a)) Next, capacitors (1-1) to (1-4) are connected in series via backflow prevention prevention (2-1-2) to (2-4-2) to output 10V. Get. At this time, capacitors (1-5) to (1-8), (1-9) to (1-12), and (1-13) to (1-16) are similarly connected in series and connected in parallel. The (FIG. 2 (b)) Since the voltage decreases due to the use of power, the capacitors (1-1) to (1-8) the backflow prevention elements (2-1-2) to (2-8-2), Connected in series through the capacitor (1-9) to (1-16) in series and connected in parallel to obtain 10V again. (FIG. 2 (c)) When the voltage further decreases, capacitors (1-1) to (1-16) are connected in series via backflow prevention elements (2-1-2) to (2-16-2). Connect and get 10V again. (Fig. 2 (d)) In addition, when electricity storage is not required, it can be handled by repeating only Fig. 2 (a) and Fig. 2 (b).
The power output curves of Figs. 1 and 2 are shown in Figs. 3 (a) and 3 (b). In order to reduce voltage fluctuations, prepare multiple units and use them continuously by alternately storing and discharging, and start the next unit in parallel when the voltage drops slightly. An example of leveling the drop is shown in Fig. 3 (c).
It is also possible to adjust the output by turning the output on and off intentionally with a changeover switch, and use it directly for input limiting circuits such as LEDs. FIG. 3 (d)
Fig. 4 shows an example of a circuit for realizing Fig. 1 to Fig. 3. The input voltage and output voltage are measured, the accumulated power in the capacitor is estimated, and input and output are switched by the input / output switch (3). At the same time, reverse the polarity of prevention of backflow prevention. The series / parallel switch (4) is used to switch the capacitor series.
Further, in the case where it is necessary to stabilize the power in FIG. 5, a large number of capacitors are made into blocks, and an input circuit, an output voltage, and individual capacitor voltages are measured by an arithmetic circuit, and a backflow prevention element is selectively selected from the capacitor block An example of selecting and connecting an appropriate capacitor via is shown below.

Example of converting 10V to 2.5V Example of converting 2.5V to 10V Output characteristics Example 1 of simple implementation circuit Example of an implementation circuit that randomly selects a capacitor by calculation

(1) is a capacitor (1-1 to 1-16)
(2) is a backflow prevention element (2-1-1 to 2-16-1) (2-1-2 to 2-16-2).
(3) Input / output changeover switch (4) Series-parallel changeover switch (5) Output ripple prevention capacitor (6) Voltmeter

Claims (5)

A lossless DC-DC converter in which a plurality of capacitors are connected via a backflow prevention element to receive an input voltage, and the series-parallel connection of the capacitors is changed in connection with a desired output voltage and output via the backflow prevention element. The input voltage is measured to estimate the capacitor storage capacity, the input is terminated at the desired voltage and switched to the output, and the output voltage is measured to switch the series / parallel of the capacitor to obtain the desired output voltage. Lossless DC-DC converter. The lossless DC-DC converter according to claim 2, wherein a plurality of lossless outputs according to claim 2 are combined at different operation timings. 4. The lossless DC-DC converter according to claim 3, wherein a ripple prevention capacitor is attached to the output side. Block many capacitors, measure the voltage of each capacitor with an arithmetic circuit, determine whether it is for input or output based on the design conditions, and connect it in series and parallel via a backflow prevention element to convert the input voltage into an output voltage The lossless DC-DC converter according to claim 4.

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