JP2012231645A - Power conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a power conditioner which suppresses power consumption and noise while efficiently cooling a heating part by changing the blast amount of a blower according to the temperature of the heating part and the temperature of the outer air.SOLUTION: A power conditioner 100 is attached to a wall surface and includes a DC-AC conversion circuit converting direct current power generated by solar cells into alternating current power. The power conditioner 100 includes: a body housing the DC-AC conversion circuit therein; a heating part provided in the body and generating heat; an outer air temperature detection part detecting the air temperature of the exterior of the body; a heating part temperature detection part detecting the temperature of the heating part; a blower fan flowing the air around the heating part in the body and cooling the heating part; and a control part controlling the blast amount of the blower fan on the basis of the outer air temperature detected by the outer air temperature detection part and the temperature of the heating part detected by the heating part temperature detection part.

Description

  The present invention relates to a power conditioner that is used in a solar power generation system and converts DC power generated by a solar cell into AC power.

  Conventionally, a power conditioner that is used in a solar power generation system and converts DC power generated by a solar battery into AC power is used. The power conditioner includes an orthogonal transformation circuit for converting DC power into AC power. The orthogonal transform circuit is provided with a power element such as an IGBT (Insulated Gate Bipolar Transistor) or a reactor. The power element generates heat during operation of the power conditioner.

  If the power element becomes too hot due to heat generation, it may be destroyed. Therefore, for example, Patent Document 1 discloses a technique for cooling the power element by flowing air around the power element using a blower fan.

JP 2004-357474 A

  However, according to the above prior art, there is a problem in that power is wasted or noise is generated by operating the blower fan regardless of the temperature of the power element and the temperature of the outside air.

  The present invention has been made in view of the above, and by changing the air flow rate of the blower in accordance with the temperature of the heat generating part and the temperature of the outside air, while efficiently cooling the heat generating part, It aims at obtaining the power conditioner which can suppress a noise.

  In order to solve the above-described problems and achieve the object, the present invention is a power conditioner including an orthogonal transformation circuit that is attached to a wall surface and converts DC power generated by a solar cell into AC power. A main body that houses the conversion circuit, a heat generating part that is provided inside the main body and generates heat, an outside air temperature detecting part that detects the temperature outside the main body, and a heat generating part temperature detection part that detects the temperature of the heat generating part A blower fan that cools the heat generating part by causing the air around the heat generating part to flow inside the main body, the external air temperature detected by the outside air temperature detecting part, and the temperature of the heat generating part detected by the heat generating part temperature detecting part And a control unit that controls the amount of air blown by the blower fan.

  According to the present invention, by changing the air flow rate of the blower according to the temperature of the heat generating part and the temperature of the outside air, the power condition capable of suppressing power consumption and noise while efficiently cooling the heat generating part. There is an effect that na can be obtained.

FIG. 1 is an external perspective view of a power conditioner according to a first embodiment of the present invention. FIG. 2 is a diagram illustrating an orthogonal transform circuit included in the power conditioner. FIG. 3 is a diagram schematically showing the internal configuration of the power conditioner. FIG. 4 is a diagram illustrating a connection example of the control circuit, the blower fan, and the thermistor. FIG. 5 is a diagram showing the temporal transition of the temperature of the power element and the external temperature. FIG. 6 is a diagram showing an operating state of the blower fan in the temperature transition shown in FIG. FIG. 7 is a diagram showing the time transition of the temperature of the power element and the external temperature as another example. FIG. 8 is a diagram showing an operating state of the blower fan in the temperature transition shown in FIG. FIG. 9 is a diagram showing a time transition of the temperature of the power element and the external temperature as yet another example. FIG. 10 is a diagram illustrating an operating state of the blower fan in the temperature transition illustrated in FIG. 9. FIG. 11 is a flowchart illustrating a procedure for controlling the air volume of the blower fan as shown in FIGS.

  Below, the power conditioner concerning embodiment of this invention is demonstrated in detail based on drawing. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
FIG. 1 is an external perspective view of a power conditioner according to a first embodiment of the present invention. FIG. 2 is a diagram illustrating an orthogonal transform circuit included in the power conditioner. FIG. 3 is a diagram schematically showing the internal configuration of the power conditioner. FIG. 4 is a diagram illustrating a connection example of the control circuit, the blower fan, and the thermistor.

  The power conditioner 100 includes a main body 1, an orthogonal transformation circuit 3, an outside air temperature detection thermistor (outside air temperature detection unit) 7, a heat generation unit temperature detection thermistor (heat generation unit temperature detection unit) 8, a blower fan 9, and a control circuit 10. Configured.

  The main body 1 constitutes the outline of the power conditioner 100. The main body 1 is formed with an intake port 1a for taking outside air into the inside and a discharge port 1b for discharging internal air to the outside. In the present embodiment, two intake ports 1 a are formed on the side surface and bottom surface of the main body 1, and one discharge port 1 b is formed on the side surface of the main body 1.

  The orthogonal transform circuit 3 is accommodated in the main body 1. The orthogonal transform circuit 3 includes a booster unit 4, an inverter unit 5, and a filter unit 6. As shown in FIG. 2, the power conditioner 100 for photovoltaic power generation boosts the power generation voltage of the solar cell 50 by the boosting unit 4, converts it to alternating current by the inverter unit 5, and adjusts the waveform by the filter unit 6 for commercial use. Output to the grid.

  As shown in FIG. 3, a power element (heat generating portion) 2 such as an IGBT (Insulated Gate Bipolar Transistor) or a reactor is used in a part of the orthogonal transformation circuit 3. The power element 2 generates heat during operation of the power conditioner 100 and may be destroyed if the temperature becomes too high.

  The outside temperature detection thermistor 7 detects the temperature outside the main body 1. As shown in FIG. 3, the outside temperature detection thermistor 7 is provided in the vicinity of the intake 1 a of the main body 1. By providing the outside temperature detection thermistor 7 in the vicinity of the intake port 1a, the temperature of the air taken into the main body 1 can be detected. Information on the detected temperature of the outside air is sent to the control circuit 10.

  The heat generating part temperature detection thermistor 8 detects the temperature of the power element 2 as a heat generating part. For example, it is provided so as to be in direct contact with the power element 2 and detects the temperature of the power element 2. Information on the detected temperature of the power element 2 is sent to the control circuit 10.

  The blower fan 9 is provided inside the main body 1 and causes the air around the orthogonal transformation circuit 3 (power element 2) to flow. Specifically, outside air is taken in from the intake port 1a of the main body 1 and discharged from the discharge port 1b.

  By causing the air around the orthogonal transformation circuit 3 to flow, the heat dissipation efficiency from the power element 2 can be improved, and the power element 2 as the heat source unit can be cooled. In addition, the heat radiation efficiency increases as the outside air temperature is lower than the temperature of the power element 2, and the effect of cooling the power element 2 also increases.

  The blower fan 9 is controlled by the control circuit 10 to be switched between a weak operation in which the blown air volume is small, a strong operation in which the blown air volume is large, and a stopped state. The effect of cooling the power element 2 is higher in the strong operation in which more air around the orthogonal transformation circuit 3 flows than in the weak operation.

  The control circuit 10 is provided inside the main body 1. The control circuit 10 controls the operation of the blower fan 9 based on the external air temperature detected by the outside temperature detection thermistor 7 and the temperature of the power element 2 detected by the heat generating portion temperature detection thermistor 8. Hereinafter, the control of the blower fan 9 by the control circuit 10 will be described more specifically.

  FIG. 5 is a diagram showing a temporal transition of the temperature t1 of the power element 2 and the external temperature t0. FIG. 6 is a diagram showing an operating state of the blower fan in the temperature transition shown in FIG. In the example shown in FIG. 5, the temperature t1 of the power element 2 rises with time. However, since the external temperature t0 is relatively high, the temperature t1 of the power element 2 is initially lower than the external temperature t0, and the temperature t1 of the power element 2 is external as time passes. It becomes higher than the temperature t0. Such a change in temperature is often seen in the summer when the temperature is relatively high.

  When the temperature t1 of the power element 2 is lower than the outside air temperature t0 (A region shown in FIG. 6), the control circuit 10 causes the blower fan 9 to operate with a small air volume or blower fan. The operation of 9 is stopped.

  In the region A, since the temperature t1 of the power element 2 is low, the necessity for cooling the power element 2 is low. Further, since the temperature t1 of the power element 2 is lower than the outside air temperature t0, the cooling efficiency by the outside air is low. For this reason, priority is given to suppression of power consumption and noise over cooling of the power element 2 by causing the blower fan 9 to operate with a small air volume or to stop the blower fan 9.

  When the temperature t1 of the power element 2 is higher than the external air temperature t0 (B region shown in FIG. 6), the control circuit 10 causes the blower fan 9 to operate with a large air volume. In the region B, since the temperature t1 of the power element 2 is high, the necessity for cooling the power element 2 is high. Moreover, since the temperature t1 of the power element 2 is higher than the outside air temperature t0, the cooling efficiency by the outside air is also increased. Therefore, the air fan 9 is operated with a large air volume to efficiently cool the power element 2.

  FIG. 7 is a diagram showing the temporal transition of the temperature t1 of the power element 2 and the external temperature t0 as another example. FIG. 8 is a diagram showing an operating state of the blower fan in the temperature transition shown in FIG. In the example shown in FIG. 7, the temperature t1 of the power element 2 rises with time. However, since the external temperature t0 is changing at a relatively low temperature, the temperature t1 of the power element 2 is always higher than the external temperature t0. Such a change in temperature is often seen in the winter when the temperature is relatively low.

  When the difference between the external temperature t0 and the temperature t1 of the power element 2 is equal to or less than a predetermined threshold value x (C region shown in FIG. 8), the control circuit 10 The operation of the blower fan 9 is stopped.

  In the C region, since the temperature t1 of the power element 2 is low, the necessity for cooling the power element 2 is low. Further, although the external temperature t0 is lower than the temperature t1 of the power element 2, the efficiency of cooling by the outside air is low because the difference between the external temperature t0 and the temperature t1 of the power element 2 is small. For this reason, priority is given to suppression of power consumption and noise over cooling of the power element 2 by causing the blower fan 9 to operate with a small air volume or to stop the blower fan 9.

  When the difference between the external temperature t0 and the temperature t1 of the power element 2 is larger than a predetermined threshold value x (area D shown in FIG. 8), the control circuit 10 Let's drive. In the D region, since the temperature t1 of the power element 2 is high, it is highly necessary to cool the power element 2. In addition, since the outside air temperature t0 is lower than the temperature t1 of the power element 2 and the difference between the outside air temperature t0 and the temperature t1 of the power element 2 is large, the efficiency of cooling by the outside air is also increased. Therefore, the air fan 9 is operated with a large air volume to efficiently cool the power element 2.

  FIG. 9 is a diagram showing a time transition of the temperature t1 of the power element and the external temperature t0 as still another example. FIG. 10 is a diagram illustrating an operating state of the blower fan in the temperature transition illustrated in FIG. 9. 9 and 10, the blower fan 9 is controlled by combining the controls shown in FIGS. 6 and 8.

  More specifically, even when the temperature t1 of the power element 2 is higher than the external temperature t0, the difference between the temperature t1 of the power element 2 and the external temperature t0 is equal to or less than the threshold value x (FIG. 10). In the region E), the control circuit 10 causes the blower fan 9 to operate with a small air volume or stops the blower fan 9 from operating. That is, when the difference between the external temperature t0 and the temperature t1 of the power element 2 is small and the cooling efficiency by the outside air is low, control is performed with priority given to suppression of power consumption and noise.

  For example, when the temperature t1 of the power element 2 approaches the power element breakdown temperature upper limit value by a predetermined value or more, the blower fan 9 is set to a large air volume regardless of the difference between the temperature t1 of the power element 2 and the external temperature t0. You may comprise so that it may drive | operate. When the temperature t1 of the power element 2 approaches the upper limit value of the power element breakdown temperature, the power fan 2 is controlled with the highest priority given to cooling the power element 2 rather than the cooling efficiency. Can be prevented.

  FIG. 11 is a flowchart illustrating a procedure for controlling the air volume of the blower fan as shown in FIGS. First, the temperature t1 of the power element 2 is compared with the external temperature t0 (step S1). If the temperature t1 of the power element 2 is lower than the external temperature t0 (step S2, No), the blower fan 9 is turned on. The operation is performed with a small amount of air or the operation is stopped (step S3).

  When the temperature t1 of the power element 2 is higher than the external temperature t0 (step S2, Yes), the difference between the temperature t1 of the power element 2 and the external temperature t0 is compared with the threshold value x (step S4).

  If the difference between the temperature t1 of the power element 2 and the external temperature t0 is equal to or less than the threshold value x (step S5, No), the blower fan 9 is operated with a small air volume or is stopped (step S6). If the difference between the temperature t1 of the power element 2 and the outside air temperature t0 is larger than the threshold value x (step S5, Yes), the blower fan 9 is operated with a large air volume (step S7).

  As described above, in the power conditioner 100, the air blowing amount of the blower fan 9 is controlled based on the temperature t <b> 1 of the power element 2 and the external air temperature t <b> 0, thereby efficiently cooling the heat generating portion. In addition, power consumption and noise can be suppressed.

  The power conditioner 100 may be provided with a switch (not shown) for setting summer and winter. In this case, the control circuit 10 may be configured to determine whether to perform the control shown in FIG. 6 or the control shown in FIG. 8 based on the summer and winter settings set by the user.

  As described above, the power conditioner according to the present invention is useful for a power conditioner that converts direct-current power generated by a solar cell into alternating-current power, and is particularly suitable for a power conditioner that includes a heating part such as a power element. Yes.

DESCRIPTION OF SYMBOLS 1 Main body 1a Intake port 1b Outlet port 2 Power element (heat generating part)
3 Orthogonal transformation circuit 4 Booster unit 5 Inverter unit 6 Filter unit 7 Thermistor for detecting outside air temperature (outside air temperature detecting unit)
8 Heating part temperature detection thermistor (heating part temperature detection part)
9 Blower fan 10 Control circuit 50 Solar cell 100 Power conditioner

Claims (3)

A power conditioner that is attached to a wall surface and includes an orthogonal transformation circuit that converts DC power generated by a solar cell into AC power,
A main body for accommodating the orthogonal transformation circuit therein;
A heat generating part that is provided inside the main body and generates heat;
An outside air temperature detector for detecting the temperature outside the main body;
A heating part temperature detection part for detecting the temperature of the heating part;
A blower fan that cools the heat generating part by flowing air around the heat generating part inside the main body;
A controller that controls the amount of air blown by the blower fan based on the outside air temperature detected by the outside air temperature detector and the temperature of the heat generator detected by the heat generator temperature detector. Power conditioner characterized by   The control unit operates the blower fan with a small amount of air when the external temperature is higher than the temperature of the heat generating unit, and the air with a large amount of air when the external temperature is lower than the temperature of the heat generating unit. The power conditioner according to claim 1, wherein the fan is operated.   The control unit has a large air volume when the external air temperature is lower than the temperature of the heat generating unit and the difference between the external air temperature and the temperature of the heat generating unit is larger than a predetermined threshold. The power conditioner according to claim 1 or 2, wherein the blower fan is operated.

Images