JP2749559B2 - Control method of snow melting device using solar cell - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling a snow melting apparatus using a solar cell. More specifically, the present invention relates to a method for controlling a snow melting apparatus using a solar cell, which is useful as a method for easily and efficiently controlling a snow melting apparatus using a solar cell.

[0002]

2. Description of the Related Art A solar cell supplies electricity by converting the energy of sunlight into electric energy by a solar cell. A snow melting device using a solar cell considers this solar cell as a heating element, and gives sufficient heat to the solar cell itself to melt snow by applying an appropriate voltage to the solar cell from the outside. This is a device that melts snow by the heat generated by it.

[0003] Conventionally, as a general method of controlling the start and stop of the snow melting apparatus by electric heating, there is a method using a temperature or an overheat prevention sensor. In the control method using these sensors, the temperature of the heating element or the heating element is detected by the temperature sensor, and when the temperature exceeds a preset temperature, the heating device is controlled to prevent overheating of the heating element or the heating element. Stop operation.

However, in the control method using this temperature sensor, the temperature detection accuracy of the temperature sensor is easily affected by the temperature around the heating element or the heating element. Due to the rise, there is a problem that the snow melting device is stopped even if the snow cover remains. Accordingly, the present invention has been made in view of the above circumstances, and provides a control method that can easily and efficiently control a snow melting device using a solar cell without erroneous control. It is intended to be.

[0005]

According to the present invention, there is provided a method for controlling a snow melting device using a solar cell, the method comprising the steps of: A snowmelt using a solar cell characterized by detecting an increase in the current accompanying the rise and automatically stopping the snowmelting device when the current or the current variation at a certain interval reaches a threshold value arbitrarily set in advance. An apparatus control method (claim 1) is provided.

Further, according to the present invention, in the above-described method, after the snow melting device is stopped, control is performed so that the solar cell automatically starts power generation (claim 2). It can be controlled manually (Claim 3), or the timer is used to set an arbitrary time in advance, and the timer is automatically stopped by the timer with the elapse of the set time (Claim 3). Item 4) and the like are also in that mode.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION In the method for controlling a snow melting apparatus using a solar cell according to the present invention, as described above, after starting the snow melting apparatus using the solar cell, the current of the solar cell or the current variation at a certain interval. When each of the thresholds reaches an arbitrarily set current or current variation threshold, the snow melting apparatus is automatically stopped.

In practice, after the snow melting apparatus using the solar cell is manually started, the temperature of the solar cell rises as the snow on the surface of the solar cell melts, and the solar cell Since free carriers in a semiconductor such as silicon constituting silicon increase, the current from the solar cell increases. Then, for example, by using a current sensor or the like capable of detecting a current value associated with the temperature rise, whether the current of the solar cell or the current variation at certain intervals has reached a threshold value arbitrarily set in advance Is detected, and if not reached, snow melting is continued as it is, and if reached, the snow melting device is automatically stopped.

A snow melting apparatus using a solar cell is provided with a bidirectional inverter, which normally operates as an inverter and is set so that the solar cell can generate power. When the snow melting device is operated, the bidirectional inverter operates as a converter to perform snow melting. Then, after the end of snow melting, the mode is switched to the inverter again, and power generation is performed.

Therefore, according to the control method of the present invention, after snow melting is completed, that is, after the snow melting device is stopped, for example, the bidirectional inverter is controlled to automatically switch from the converter to the inverter, and the solar cell automatically generates power. You may make it start. Thus, unnecessary manual operation can be omitted, and power generation of the solar cell can be started efficiently.

In the control method of the present invention, for example,
If the snow is completely melted before the current of the solar cell reaches the set current value, it is not very efficient to continue operating the snow melting device as it is. May be stopped, or the snow melting apparatus may be stopped by using a timer in which an arbitrary time is set in advance. Thereby, the snow melting device can be operated efficiently.

The flow of each control step in the control method of the present invention can be, for example, a flowchart illustrated in FIG. First, the snow melting device is started. Thereby, the bidirectional inverter operates as a converter, and snow melting is performed. Then, automatic / manual control of stopping the snow melting operation is selected.

If automatic control is selected, the presence or absence of snowfall on the solar cell surface is detected by a snowfall sensor or the like, and the current value of the solar cell module by a current sensor or the like is normal, that is, whether or not the set current threshold has been reached or not. Detection,
Whether the temperature of the solar cell module is normal by an overheat prevention sensor or the like, that is, whether or not the set temperature threshold has been reached or not is detected. Snow melting is stopped.

If manual control is selected at the time of automatic / manual selection, the snow melting operation is manually stopped. Also, at the same time that the bidirectional inverter operates as a converter,
The timer operates, and the snow melting operation is automatically stopped when a preset time elapses. When the snow melting operation is stopped automatically, manually or by a timer in this way, the bidirectional inverter is automatically switched from the converter to the inverter, and returns to the normal power generation state.

In the control method of the present invention, for example, the control of the snow melting apparatus using the solar cell can be efficiently performed by the flow of each control step. The selection of the automatic / manual control in the above description is arbitrarily performed. For example, the selection of the automatic control is used to control the snow melting device at night or when the operator of the snow melting device is absent.

Hereinafter, embodiments will be described, and embodiments of the present invention will be described in more detail. Of course, the present invention is not limited by the following examples.

[0017]

【Example】

(Embodiment 1) FIG. 1 illustrates a control circuit based on a method for controlling a snow melting apparatus using a solar cell according to an embodiment of the present invention, which is incorporated in a circuit of a snow melting apparatus using a solar cell. Have been.

In the control circuit illustrated in FIG. 1, the bidirectional inverter (2) is a part of the circuit of the snow melting apparatus.
The bidirectional inverter (2) switches to an inverter or a converter when the solar cell is switched to a power generation state or a snow melting state. Normally, the bidirectional inverter (2) operates as an inverter, so that the solar cell can always generate power. When a solar cell is used as a snow melting device, it operates by switching to a converter.

Therefore, first, the snow melting operation ON / OFF switch (4) is turned on in order to start the snow melting device. As a result, the relay R1 (6) is excited, and further, the electromagnetic contactor MCa (8) is excited. Then, the bidirectional inverter (2) is switched to a converter by this excitation, and operates as a converter. Simultaneously with the operation of this converter, the electromagnetic contactor M for diode bypass
C1 (9) to MC2 (10) are excited, and the backflow prevention diode (3) for preventing the backflow of the solar cell generated current to the solar cell is bypassed, that is, bypassed, and the solar cell module is energized. . In this way, snow melting using the solar cell operates.

This power supply stop control can be manually or automatically stopped by a manual / automatic changeover switch (5). When the manual / automatic changeover switch (5) is selected to be manual, energization is continued until the snowmelting operation ON / OFF switch (4) is manually turned off. When the selection is made automatically, the stop is automatically controlled by a current sensor (11) capable of detecting a current value accompanying a rise in the temperature of the solar cell module. The current sensor (11) detects the temperature and the current value of the solar cell module, performs stop control of the snow melting device based on whether the current or the current variation at a predetermined interval has reached a preset threshold value, If the current variation at a certain interval has not reached the set value, the snow melting is continued, and if it has reached, the snow melting device is stopped.

FIG. 3 is a conceptual diagram exemplifying a main part configuration of the current sensor (11). As illustrated in FIG. 3, the current sensor includes a DC CT (15) and a converter (1).
6), an integrator (17) and a setter (18), which are connected between the solar cell and the bidirectional inverter acting as a converter. In this current sensor,
The current value or a fixed time interval dt as illustrated in FIG.
The variation di / dt of the current value di at
7) is detected. If the detected value has reached a preset threshold value, the setter (18) sends a snowmelt stop signal to the bidirectional inverter to switch to the inverter.

When the snow melting device is stopped, the bidirectional inverter (2) automatically switches from the converter to the inverter, and the solar cell returns to a normal power generation state and starts power generation. As a result, useless manual switching operation can be omitted, and power generation of the solar cell can be started efficiently. Further, after turning on the snow melting operation ON / OFF switch (4), the timer (7) is started almost simultaneously with the excitation of the relay R1 (6). An arbitrary time is set in advance in the timer (7), and when the set time has elapsed, the snow melting device is automatically stopped. As described above, by performing the stop control of the snow melting apparatus for a certain period of time using the timer (7), the current switch may make a mistake in the stop control for some reason even if the snowfall is completely melted, or the manual control may be performed. It is possible to prevent unnecessary snowmelt time, for example, in the case of forgetting to stop even in the stop control by
It is also possible to prevent an overcurrent from flowing through the solar cell and prevent the solar cell from being overheated. As a result, efficient operation of the snow melting device can be ensured. (Embodiment 2) FIG. 2 illustrates a control circuit based on a method for controlling a snow melting apparatus using a solar cell according to an embodiment of the present invention, which is incorporated in a circuit of a snow melting apparatus using a solar cell. Have been. The circuit illustrated in FIG. 2 is a circuit in which the backflow prevention diode (3) in the circuit illustrated in FIG. 1 is not used.

First, in order to start the snow melting apparatus, the snow melting operation ON / OFF switch (4) is manually turned on.
As a result, the relay R1 (6) is excited, and further, the electromagnetic contactor MCa (8) is excited. Then, the excitation switches the bidirectional inverter (2) to a converter, operates as a converter, and energizes the solar cell module. Thus, the snow melting device using the solar cell operates.

The stop of the energization, that is, the stop control of the snow melting, can be selected by a manual or automatic changeover switch (5). When manual operation is selected, snow melting is stopped by manually turning off the snow melting operation ON / OFF switch (4). When automatic is selected, snow melting is automatically stopped by the current sensor (11).

When the snow melting device is stopped, the bidirectional inverter (2) automatically switches from the converter to the inverter, and the solar cell returns to a normal power generation state and starts generating power. As a result, useless manual switching operation can be omitted, and power generation of the solar cell can be started efficiently. Further, after turning on the snow melting operation ON / OFF switch (4), the timer (7) is started almost simultaneously with the excitation of the relay R1 (6). An arbitrary time is set in advance in the timer (7), and when the set time has elapsed, the snow melting device is automatically stopped. As a result, efficient operation of the snow melting device can be ensured.

Since the control circuit shown in FIG. 2 does not use the backflow prevention diode (3), there is no need to use a diode bypass electromagnetic contactor for bypassing the backflow prevention diode (3). Therefore, there is an advantage that the circuit is simplified and miniaturized, and further, the cost is reduced. The control circuit illustrated in FIG. 1 in the first embodiment and FIG. 2 in the second embodiment includes a solar cell module 2 including a plurality of solar cell units (14) for power generation / snow melting.
In this case, the number of connected solar battery units is different depending on the capacity of the photovoltaic power generation equipment. Therefore, as illustrated in FIGS. 1 and 2, in the control circuit, a diode bypass electromagnetic contactor and a current sensor (11) are incorporated in each of the solar cell unit circuits connected in parallel.
By this. Since snow melting can be controlled for each solar cell unit, it is possible to accurately control the snow melting device.

[0027]

As described in detail above, the present invention provides a new use for a solar cell by using a solar cell generally used for power generation in a snow melting device,
The solar cell can be used more efficiently, and the spread of the solar cell can be promoted. Further, the control for snow melting can be performed easily and very efficiently.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating a control circuit based on a method for controlling a snow melting apparatus using a solar cell according to an embodiment of the present invention.

FIG. 2 is a configuration diagram illustrating a control circuit based on a method for controlling a snow melting apparatus using a solar cell according to an embodiment of the present invention.

FIG. 3 is a conceptual diagram illustrating a configuration of a main part of a current sensor used in FIG. 2;

FIG. 4 is a diagram illustrating a relationship between time and current, illustrating a current variation at a fixed time interval detected by the integrator in FIG. 3;

FIG. 5 is a flowchart illustrating a method for controlling a snow melting apparatus using a solar cell according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Commercial power supply AC 2 Bidirectional inverter 3 Backflow prevention diode 4 Snow melting operation ON / OFF switch 5 Manual / automatic switch 6 Relay 7 Timer 8 Electromagnetic contactor 9 Electromagnetic contactor for diode bypass 10 Electromagnetic contactor for diode bypass 11 Current Sensor 12 Snowfall sensor 13 Overheat prevention sensor 14 Solar cell unit 15 DC CT 16 Converter 17 Integrator 18 Setting device

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hideo Minami 3-12-15 Wakao-ji Temple, Amagasaki City, Hyogo Prefecture Inside Sonoda Keiki Kogyo Co., Ltd. (56) References JP-A-8-260409 (JP, A) Sho-63-78472 (JP, A) Shokai 4-46106 (JP, U)

Claims (4)

(57) [Claims] 1. A method for controlling a snow melting device using a solar cell, comprising: starting the snow melting device, detecting an increase in current accompanying a rise in the temperature of the solar cell, and detecting a current or a current change at regular intervals. A method for controlling a snow melting device using a solar cell, wherein the snow melting device is automatically stopped when each of the minutes reaches a predetermined threshold value. 2. The control method according to claim 1, wherein after the snow melting device is stopped, control is performed so that the solar cell automatically starts generating electric power. 3. The control method according to claim 1, wherein the stop of the snow melting device can be controlled not only automatically but also manually. 4. The control method according to claim 1, wherein a timer in which an arbitrary time is set in advance is used, and as the arbitrary set time elapses, the timer is automatically stopped by the timer. Of controlling a snow melting device using a solar cell.