KR102397829B1 - Driving control method and apparatus for electrochromic device - Google Patents

Abstract

The present invention relates to a driving control method and apparatus for an electrochromic device that can improve durability and reliability of a device by efficiently supplying a voltage driving an electrochromic device. The present invention can improve a discoloration speed without reducing durability and reliability of the electrochromic device by changing and supplying the driving voltage to be useful for a large area requiring quick and reliable discoloration particularly such as a window of a building.

Description

Driving control method and apparatus for electrochromic device

The present invention relates to a method and apparatus for controlling driving of an electrochromic device, and more particularly, to a driving of an electrochromic device capable of improving durability and reliability of the device by more efficiently supplying a voltage for driving the electrochromic device It relates to a control method and apparatus.

Electrochromism is a phenomenon in which the color changes reversibly depending on the direction of the electric field when power is applied. Devices with this characteristic are called electrochromic devices. Such an electrochromic device is formed in a structure in which a color-changing material and an electrolyte are interposed between transparent electrodes at predetermined intervals, as in Korean Patent Application Laid-Open Nos. 2006-0092362 and 2020-0128374.

The electrochromic element has no color when there is no electron movement from the outside. When power is applied to the transparent electrode, electrons are supplied to reduce the color-changing material or lose electrons to oxidize the color-changing material, and vice versa. In the absence of electron supply, the color-changing material has a color, but when electrons are supplied and reduced or oxidized by loss of electrons, the color disappears.

In particular, recently, electrochromic devices are receiving great attention when applied to large areas such as window glass of buildings. As a voltage difference between the edge and the center occurs, there is a problem in that the light transmittance is different depending on the location.

In order to induce faster and more uniform discoloration over a large area, a high power supply must be applied, but in this case, the device deteriorates, reducing the reliability and durability of the device, and in severe cases, the device may be damaged.

Republic of Korea Patent Publication No. 10-2006-0092362 (Title of the invention: electrochromic device and manufacturing method thereof) Republic of Korea Patent Publication No. 10-2020-0128374 (Title of the invention: electrochromic device)

The present invention has been devised to solve the above-described technical problem, and the present invention is to provide a method and apparatus for controlling the driving of an electrochromic element that does not reduce the reliability and durability of the electrochromic element while discoloring the electrochromic element more quickly and uniformly There is a purpose.

In order to achieve the above object, the present invention applies a driving voltage having a voltage application section to which a driving voltage is applied and a floating section to which a driving voltage is not applied to an electrochromic device, wherein the floating section is dependent on the magnitude of the driving voltage. Provided is an apparatus for controlling driving of an electrochromic element that is variable and applied to the electrochromic element.

In the present invention, the floating section is varied and applied to the electrochromic device according to the structure of the electrochromic device.

In the present invention, the structure of the electrochromic element is any one or more of the distance between the electrode terminals, the critical resistance, the material of the color change material, and the material of the electrolyte.

In the present invention, the driving control device of the electrochromic device sets the floating section according to the following.

(K: constant. 1<K<1,000, V _ON : driving voltage magnitude, ℓ: distance between a pair of electrode terminals provided in the electrochromic device, R _th : critical resistance)

In the present invention, the apparatus for controlling the driving of the electrochromic device sets the period from when the electric charge injected by the driving voltage is diffused inside to before the electrochromic device is discharged to the outside as the floating section.

In addition, the present invention provides a driving power supply for applying a driving voltage of a periodic waveform having a voltage application section to which a driving voltage is applied to the electrochromic device and a floating section to which a driving voltage is not applied, and the voltage of the electrochromic device to which the driving voltage is applied. Provided is an apparatus for controlling driving of another electrochromic device comprising: a device voltage measuring unit measuring

In the present invention, the driving power unit applies a driving voltage to the electrochromic device for a plurality of cycles.

In the present invention, the device voltage measuring unit measures the voltage of the electrochromic device in a plurality of floating sections (T _OFF ) between the voltage application sections.

In the present invention, the driving voltage control unit calculates the voltage change rate of the electrochromic element in the adjacent floating section and determines whether it is less than or equal to a reference value to vary the driving voltage.

In the present invention, when the voltage change rate of the electrochromic element is less than or equal to a reference value, the driving voltage control unit varies the magnitude or period of the driving voltage,

In the present invention, the driving voltage controller changes the driving voltage to a driving voltage having a smaller absolute value than the driving voltage applied immediately before the floating section in which the voltage of the electrochromic device is measured.

In the present invention, when the voltage change rate of the electrochromic element is equal to or less than a reference value, the driving voltage controller changes the voltage of the electrochromic element to a driving voltage having a duty ratio lower than that of the driving voltage duty ratio of the floating section in which the voltage is measured.

In addition, the present invention provides a method for controlling driving of an electrochromic device comprising the steps of: measuring a voltage of the electrochromic device to which the driving voltage is applied; and varying the driving voltage according to the voltage change of the color changing device.

In the present invention, a periodic waveform having a voltage application period to which a driving voltage is applied and a floating period to which a driving voltage is not applied is applied to the electrochromic device for a plurality of periods.

In the present invention, the voltage of the color-changing device is measured in a plurality of floating sections between voltage application sections.

In the present invention, it is determined whether the voltage change rate of the electrochromic element in the neighboring floating section is equal to or less than a reference value, and the reference value may be 0.1 to 5%.

In the present invention, when the voltage change rate of the electrochromic element is equal to or less than the reference value, the magnitude or period of the driving voltage is varied and applied to the electrochromic element.

In the present invention, when the voltage change rate of the electrochromic element is equal to or less than the reference value, a driving voltage having a smaller absolute value than the driving voltage applied immediately before the floating section in which the voltage of the electrochromic element is measured is applied to the electrochromic element.

In the present invention, when the voltage change rate of the electrochromic element is equal to or less than the reference value, a driving voltage having a lower duty ratio than the driving voltage duty ratio in the floating section in which the voltage of the electrochromic element is measured is applied to the electrochromic element.

According to the present invention, by supplying a variable driving voltage, it is possible to improve the discoloration speed without reducing the durability and reliability of the electrochromic device, and it is particularly useful for large areas requiring rapid and reliable discoloration, such as window glass of a building. .

1 is a diagram illustrating a driving voltage waveform applied to an electrochromic device according to the present invention.
2 is a cross-sectional view illustrating an electrochromic device whose driving is controlled according to the present invention.
3 is a block diagram illustrating a configuration of an apparatus for controlling driving of an electrochromic device according to another exemplary embodiment of the present invention.
4 is a graph illustrating a change in transmittance and resistance according to time when an electrochromic element is colored.
5 is a diagram illustrating a voltage of an electrochromic element measured when a driving voltage is continuously applied to the electrochromic element according to the present invention.
6 is a flowchart of a method for controlling driving of an electrochromic device according to the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

This embodiment is provided to more completely explain the present invention to those with average knowledge in the art, and the shape of elements in the drawings, the size of elements, the spacing between elements, etc. may be exaggerated or reduced for

In addition, when it is determined that the technical features of the present invention may be unnecessarily obscured as it is already obvious to a person skilled in the art, such as a known function or a known configuration related in principle in explaining the embodiment, the detailed description thereof A description will be omitted.

An apparatus for controlling driving of an electrochromic element according to an embodiment of the present invention is a device for applying a driving voltage to change color or discoloration of the electrochromic element, and the voltage application period T _{V_ON} shown in FIG. A square wave driving voltage Vm having an unapplied floating section T _{V_OFF} is applied.

As shown in FIG. 2, the electrochromic device to which a square wave is applied is a secondary battery type in which electrode layers 12 and 16, color change material layers 13 and 15, and electrolyte 14 are formed between transparent substrates 11 and 17. It may be an electrochromic device 10 , and electrode terminals 18 and 19 are provided on the electrode layers 12 and 16 to apply a driving voltage. As long as the electrochromic element 10 can be discolored by a driving voltage, various types of elements can be applied regardless of the structure shown in FIG. A color-changing device, another type of secondary battery type device in which any one of the color-changing material layers is replaced with an ion storage layer, or a hybrid electrochromic device in which a color-changing material layer is formed only on one electrode layer and another color-changing material is mixed in an electrolyte can also be used.

In the electrochromic element 10 , the injected electric charge is diffused inside by the applied driving voltage, and the color is changed as the electric charge is diffused from the edge where the electrode terminals 18 and 19 are provided to the center. At this time, the driving control device of the electrochromic element sufficiently diffuses the electric charge injected into the electrochromic element over the entire area of the element, and converts the driving voltage obtained by varying the floating section T _{V_OFF} so that the diffused charge is not discharged to the electrochromic element. To apply, a floating section (T _{V_OFF} ) is set as shown in Equation 1 below.

Here, K is a proportional value according to the material characteristics of a discoloration material or electrolyte, and is a constant ranging from 1 to 1,000, and V _ON is the driving voltage level. ℓ is a distance between a pair of electrode terminals 18 and 19 provided in the electrochromic device 10 as shown in FIG. 2 . In addition, R _th is a threshold resistance in a critical transmittance section in which transmittance hardly changes even when a driving voltage is applied to the electrochromic device as described later. K, ℓ, R _th are set in advance from the electrochromic element to be discolored.

The floating section (T _{V_OFF} ) calculated in this way is from the point at which the charge injected into the electrochromic element is sufficiently diffused from the inside to the center as well as the edge, and then spreads to the entire surface of the device so that the charge is discharged to the outside. It is set as the previous section, that is, the electrochromic device charge diffusion time < the floating section (T _{V_OFF} ) < the electrochromic device discharge time.

Here, the charge diffusion time inside the electrochromic element 10 can be determined by comparing the voltages measured at the edges and the center of the element provided with the electrode terminals 18 and 19 with a set reference value, and the discharge time of the element is determined by the electrode It can be determined whether the current value measured by the terminals 18 and 19 is equal to or greater than a predetermined reference value.

In this way, by setting the floating section T _{V_OFF} according to the magnitude of the applied driving voltage and the structural characteristics of the electrochromic device, while supplying sufficient charge so that the electrochromic device is discolored, the safety and safety of the device due to excessive supply of driving voltage and It is possible to prevent deterioration of durability and unnecessary power consumption.

3 is a block diagram illustrating the configuration of an apparatus 100 for controlling driving of an electrochromic device according to another embodiment of the present invention. FIG. 1 is an example of applying one driving voltage, and FIG. 3 is a plurality of driving This is an example of applying voltage.

The driving control device 100 of the electrochromic device of FIG. 3 includes a driving power supply unit 110 that applies a driving voltage for coloring or decolorizing the electrochromic device to the electrochromic device, and measures the voltage of the electrochromic device to which the driving voltage is applied. The device voltage measurement unit 120 and the driving power control unit 130 for varying the driving voltage according to the voltage of the electrochromic device measured at different time points.

The driving power unit 110 applies a driving voltage to color or decolorize the electrochromic device 10, and the driving voltage is a voltage application period (T _{V_ON} ) to which a driving voltage is applied, as shown in FIG. 1 , a driving voltage is applied. It is a square wave having a period (T) of a floating section (T _{V_OFF} ) that does not occur. The driving power unit 110 applies the square wave driving voltage to the electrochromic device 10 for a plurality of cycles to decolorize or color the device.

The device voltage measuring unit 120 is configured to measure device voltage by connecting the measuring terminals to the electrode terminals 18 and 19 of the electrochromic device 10, and is controlled by the driving power control unit 130 to control the electrochromic device ( 10) Measure the voltage. At this time, the device voltage measuring unit 120 measures the device voltage in the floating section (T _{V_OFF} ) to which the driving voltage is not applied, and each floating section (T _{V_OFF} ) to which the driving voltage is applied as a plurality of driving voltages are applied. Each device voltage is measured. The device voltages measured in this way are compared and determined by the driving power control unit 130 .

The driving power control unit 130 compares the measured device voltage and varies the driving voltage generated by the driving power unit 110 according to the change. To this end, the driving power control unit 130 calculates a voltage change rate from the device voltages measured in a plurality of floating sections T _{V_OFF} and compares it with a reference value, which will be described in detail below.

First, in the electrochromic element 10 to which the driving voltage is applied, the measured element voltage varies as the electric charge injected into the electrode terminals 18 and 19 is diffused to the central portion and discoloration proceeds. 4 is a diagram for explaining this, and shows a relationship between transmittance of the electrochromic element and a change in resistance of the electrochromic element according to time during coloring. Referring to this, as the driving voltage is applied and coloring proceeds, the resistance value of the electrochromic device gradually increases. And after the critical transmittance (P _th ) where the coloring is almost completed by applying a plurality of square wave driving voltages, in the critical transmittance section (T _th ) where there is little change in transmittance, the electrochromic element has reached a high critical resistance (R _th ) There is almost no change in resistance.

Therefore, in the critical transmittance section (T _th ), even when the driving voltage is applied, no change in transmittance occurs, and almost no change in resistance occurs, so the measured device voltage hardly changes. The example of FIG. 4 describes an example of coloring the electrochromic element, and in the case of discoloration, the applied voltage is the same except that it is negative (-). As a result, the driving voltage applied to the electrochromic device that has reached the critical transmittance does not induce _{discoloration} , and if it is continuously applied, the safety and durability of the device is reduced and unnecessary power is consumed. It is necessary to supply the driving voltage up to

Accordingly, the driving power control unit 130 determines whether the electrochromic device to which the driving voltage is applied has reached the threshold transmittance P _th by comparing the device voltages measured in different floating sections T _{V_OFF} . 5 is a first square-wave voltage (V ₁ ), a second square-wave voltage (V ₂ ) ... n-th square-wave voltage (V _n ), n+1-th square-wave voltage (V _{n +1} ) continuously applied over time ), the n+2th square wave voltage (V _{n + 2} ) is shown, and the device voltage measured in the floating period (T _{V1_OFF,} T _{V2_OFF,} T _{V3_ OFF} ,..., T _{Vn _OFF} ) of each square wave voltage is shown. The magnitudes (V _m1 ,V _m2 ,V _m3 ,..,,V _mn ,V _mn+1 ,V _mn+2 ) are also shown.

Here, the measured device voltage increases while being colored as the square wave voltage is applied, and when the nth square wave voltage (V _n ) is applied, the threshold voltage (V _th . The device voltage at the above-described critical transmittance (P _th )) is reached and , the n+1th square wave voltage applied thereafter (V _{n +1} . V _n Voltage less than voltage, n+2 square wave voltage (V _{n +2} . V _n A voltage having a duty ratio smaller than the voltage) is applied to maintain the threshold voltage V _th .

Meanwhile, the driving power control unit 130 calculates the device voltage change rate in the adjacent floating section as shown in the following equation, and determines whether the device voltage change rate is less than or equal to a reference value.

Here, V _mn-1 is the n-1th measured device voltage, and V _mn is It is the nth measured device voltage level (n is an integer greater than or equal to 2).

In this case, the reference value corresponds to the voltage change rate of the electrochromic element after reaching the above-described critical transmittance, and may be set in advance, and may be generally set in the range of 0.1 to 5%. Therefore, when the change rate of the device voltage exceeds the reference value, it is determined that the color change is in progress without reaching the threshold transmittance.

According to the device voltage change rate determined as described above, the driving voltage controller 130 varies the driving voltage. When the device voltage change rate exceeds the reference value, the device voltage is supplied at the same magnitude and cycle as the driving voltage applied immediately before the measured floating section. to continuously discolor the device.

And, when the measured device voltage change rate is less than or equal to the reference value, a driving voltage having a different magnitude or period from the driving voltage supplied immediately before the floating section in which the device voltage is measured by varying the driving voltage is applied. 5 shows the driving voltage varied by the driving power control unit 130, the driving voltage (V _n+ ) having a smaller magnitude than the previously supplied driving voltages (V ₁ , V ₂ , .... V _n ). ₁ ) and a driving voltage V _n+1 with a reduced duty ratio due to an increase in the floating section are shown.

When the critical transmittance is reached and it is determined that the discoloration is almost complete, a driving voltage having a smaller size or a lower duty ratio than the previously supplied driving voltage is applied to induce discoloration, thereby improving the safety and durability of the electrochromic device. maintain and save power. On the other hand, the meaning that the magnitude is smaller than the driving voltage means that the driving voltage is a positive (+) value when coloring and a negative (-) value when discoloring, so that the absolute value is small.

A flowchart of a driving control method using the electrochromic device driving control apparatus 100 shown in FIG. 3 is shown in FIG. 6 . First, a square wave driving voltage having a voltage application period T _{V_ON} and a floating period T _{V_OFF} to which no voltage is applied is applied to the electrochromic device 10 for a plurality of periods ( S110 ). At this time, the device voltage of the electrochromic device is measured for each floating section T _{V_OFF} between the voltage application section T _{V_ON} ( S120 ). Then, it is determined whether the voltage change rate of the color-changing element measured in the neighboring floating section T _{V_OFF} is equal to or less than a reference value ( S130 ). If the reference value is exceeded, the same driving voltage as the driving voltage applied just before the measured floating period (T _{V_OFF} ) is applied (S140), and if it is less than the reference value, the driving applied immediately before the measured floating period (T _{V_OFF} ) Driving voltages having different magnitudes or duty ratios are applied (S150).

According to the present invention, it is possible to improve the discoloration rate without degrading the durability and reliability of the electrochromic device, and it is particularly useful for large areas requiring rapid and reliable discoloration, such as window glass of a building.

The present invention described above is not limited to the described embodiments, and it is apparent to those skilled in the art that various modifications and variations can be made without departing from the spirit and scope of the present invention. Accordingly, it should be said that such variations or modifications fall within the scope of the claims of the present invention.

10: electrochromic element 11, 17: transparent substrate
12, 16: electrode layer 13, 15: color-changing material layer
14: electrolyte 18, 19: electrode terminal
100: drive control device 110: drive power unit
120: device voltage measuring unit 130: driving power control unit
T _{V_ON} : Voltage application section T _{V _OFF} : Floating section
P _th : critical transmittance T _th : critical transmittance interval
R _th : critical resistance
V ₁ , V ₂ , V ₃ , V _n : 1st, 2nd, 3rd, ...n square wave driving voltage
T _{V1_OFF,} T _{V2_OFF,} T _{V3_OFF} ,., T _{Vn _OFF} : 1st, 2nd, 3rd, ..n square wave driving voltage floating section
V _m1 , V _m2 , V _m3 ,...,V _mn : Device voltage measured in the 1st, 2nd, 3rd,...,n floating section

Claims (20)

In an apparatus for controlling driving of an electrochromic device comprising a pair of electrode layers, one electrode layer having an electrode terminal on one side and the other electrode layer having an electrode terminal on the other side,
A square wave driving voltage having a voltage application section to which a voltage is applied to the electrochromic device and a floating section to which no voltage is applied is applied through the pair of electrode terminals,
The floating section is an electrochromic device driving control device, characterized in that it is set according to the following equation.

(K: constant. 1<K<1,000, V _ON : driving voltage magnitude, ℓ: distance between a pair of electrode terminals provided in the electrochromic device, R _th : critical resistance) delete delete delete The method of claim 1,
The driving control device of the electrochromic device,
and a period from a point in time when the charge injected by the driving voltage is diffused inside to before the electrochromic element is discharged to the outside is set as the floating period. delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete

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