JP5282516B2 - Power supply device, compression refrigerant cycle device, and hot water storage hot water supply system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power supply device which uses other different power sources concurrently, and to make it possible to store hot water generated by heating cold water using electricity supplied from the power supply device and supply the stored hot water to a hot water supply apparatus. <P>SOLUTION: A power supply device 200 is equipped with a plurality of inverters (a first inverter 208 and a second inverter 218) for performing switching control of electric powers supplied from a plurality of power sources (a commercial power supply 202 and a solar battery 212), and exclusively supplies electric power to a heat pump hot water supply apparatus 100 in a time-division manner from the plurality of inverters. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a power supply device that uses different power sources together, a hot water storage system that stores hot water generated by heating water using electricity supplied from the power supply device, and supplies the stored hot water to a hot water supply facility, and The present invention relates to a compression-type refrigerant cycle device.

  In general, an electric device (load) is operated by a commercial power source supplied from a system provided by an electric power company. For example, an emergency power generator in a facility that does not allow a power outage such as a hospital or an underground shopping mall, or a private power generator using renewable energy is used. In the case of an emergency power generation device, since it is not necessary to supply it normally, a storage battery or a fuel engine is often used, and the power source is switched after the power generation device is operated at the time of a power failure.

  As for private power generation using renewable energy, wind power generation has been popular in the past, but in recent years solar power generation has begun to spread. Since wind power generation differs significantly depending on wind power, electricity may be stored in a storage battery (lead storage battery) for use. When using a power generation device that uses renewable energy, there may be a difference in the amount of power generated depending on the weather. For example, the amount of power generated by solar power generation drastically decreases at night or in the rain, and wind power cannot be generated unless the wind blows. Moreover, even if it is a private power generation device using a motor, or micro hydropower generation, there is an upper limit in supply capability. In Patent Document 1, in order to suppress such unstable supply, a secondary battery (storage battery) is used together with a solar battery, so that the maximum output amount corresponding to the power generation amount is maintained and the load is increased more with respect to the load. A method is described which can be used to supply the power.

  Thus, renewable energy has low energy density and non-uniform power generation. For this reason, it must be in a state where power can always be generated and stored in a storage battery and used with equipment independent of the system, or the power generator can be connected to the system and always reverse flowed little by little, and then the necessary power can be reapplied. The form of receiving power from a commercial power source is expected to become popular in the future. When the power of private power generation is connected to the grid, the power from the storage battery or solar power generation is direct current power. Therefore, it is necessary to connect the direct current to alternating current, and there is a power converter called a power conditioner. Provided. There are several types of power conditioners depending on the presence or absence of insulation and the presence or absence of a transformer. In any case, the voltage level, phase, and frequency of the private power generator are synchronized with the grid before connection.

  When connecting to the grid, it is necessary to comply with the “Guidelines for grid interconnection technical requirements for ensuring power quality” and “Interpretation of technical standards for electrical equipment” issued by the Ministry of Economy, Trade and Industry. Therefore, the power conditioner has a voltage / current control function, a grid connection protection function (a function to detect overvoltage and undervoltage, overcurrent, frequency increase / decrease), an independent operation detection function (disconnected from the system) Or a function of detecting a reverse power flow state at the time of a system power failure).

  By the way, many electric appliances used in general households are once converted into direct current and operated. There is also a device that uses a direct current as an alternating current by converting it into a direct current and then chopping (switching) it using an inverter. For example, in the case of home air conditioners, the mainstream currently employs inverter control.

  An inverter means converting direct current into alternating current (reverse conversion). One type of inverter control is PWM (Pulse Width Modulation) control. The PWM control is a method for controlling the frequency and current amount of alternating current by converting direct current power into a high frequency pulse and changing the width of each pulse. In the PWM control, the switching element is ON / OFF controlled by the CPU. As a switching element, a MOS-FET is often used in a low-voltage electronic circuit, but an insulated gate bipolar transistor (IGBT) is often used in a large output device such as an air conditioner or a water heater.

On the other hand, in recent years, a hot water storage type hot water supply system using a compression heat pump has been popularized. The hot water storage hot water supply system uses hot night electricity to accumulate hot water and use it during the day. By introducing a hot water storage hot water supply system using a compression heat pump, it is possible to save approximately 30% energy and reduce carbon dioxide emissions by approximately 50% compared to conventional combustion water heaters. It is advantageous from the viewpoints of effective use and reduction of emissions of carbon dioxide, which is a greenhouse gas. Also in a compression heat pump of a hot water storage hot water supply system, inverter control is often used for a refrigerant compressor.
Japanese Patent Laid-Open No. 2007-300728

  As described above, when power is supplied from a plurality of different power sources, it is necessary to completely switch the power sources or connect them to form a single power source. In particular, when using an inverter-controlled load with a commercial power supply and a DC power supply (storage battery or solar battery), convert the DC power supply to AC, connect it, convert the combined AC power supply to DC, and then convert the inverter to an inverter. It is necessary to switch to AC and convert to AC. Since the current causes a loss each time the orthogonal transformation or the AC / DC transformation is performed, a wasteful loss is caused in the electric power of the renewable energy power generation apparatus having a low energy density.

  Further, in order to link the output of the power generation apparatus to the grid, a power conditioner having a large number of protection circuits and safety devices as described above is required, and various applications and permits are also required. Furthermore, the national policy for global environmental measures raises high goals for promoting the use of renewable energy. However, achieving the target value for promoting the use of renewable energy is difficult unless a technology based on a new idea other than the conventional technology is sought.

  Therefore, in view of such problems, the present invention has an object to provide a power supply device that can use two different power supplies together without being connected (coupled), and a hot water storage hot water supply system using the power supply device. It is said.

  As a result of intensive studies by the inventors to solve the above-mentioned problems, when switching the DC power supply in inverter control, the time-division pulse supply source does not have to be the same. Even if a pulse was supplied, it was thought that the electrical equipment (load) side was not in the know. In the first place, attention has been paid to the fact that a DC power source, such as a storage battery or a solar cell, can be used for inverter control without being converted to AC, and the present invention has been completed through further studies.

In order to solve the above-described problems, a typical configuration of a power supply device according to the present invention includes a plurality of inverters that respectively switch and control power supplied from a plurality of power supplies, and one of the plurality of power supplies is a commercial power supply. An AC power source comprising an AC / DC converter between the AC power source and the inverter, and a plurality of power sources other than the AC power source is composed of a DC power generator or a combination of an AC power generator and a power storage unit It is a direct current power supply, and is characterized in that it supplies power exclusively in a time-sharing manner from a plurality of inverters to a load.

  According to the above configuration, the power supplied from the plurality of power supplies is time-division (switched) by the inverter corresponding to each power supply. The load (electrical device) that receives this operation is operated without being conscious of being supplied from a plurality of power sources because it operates with power supplied comprehensively by a large number of pulse currents. If the inverter pulses are supplied exclusively from a plurality of power supplies in this way, the load can be operated as if power is supplied from a single power supply without coupling the plurality of power supplies. .

As described above, one of the plurality of power sources is an AC power source composed of a commercial power source, and has an AC / DC converter between the AC power source and the inverter. power generator, or Ru DC power supply der which consist of a combination of power storage unit and the AC generator.

  In other words, there is no need to share the DC voltages of a plurality of power supplies, and the DC / DC that converts the DC voltage of the solar cell into a predetermined DC voltage, which was necessary when constructing the circuit configuration proposed in the prior art. Since the converter can be omitted, the power loss of the power generator can be reduced. In addition, when an AC / DC converter that does not perform reverse power flow, such as a half-wave rectifier, is used, it is not necessary to connect the output of the power generator to the system, eliminating the need for a power conditioner with a protection circuit or safety device. In addition, various applications and permits are not required. For this reason, it becomes easy to introduce the power generation apparatus, and it is possible to promote the use of renewable energy by self-consumption as a method other than grid connection.

  The distribution control unit further controls the output time ratio of the plurality of inverters, and the distribution control unit is configured to supply the shortage of power supplied from the DC power supply from the AC power supply according to the power consumption of the load. The output time ratio of the inverter may be controlled.

  Thereby, the electric power of a power generator can be mainly used, and a shortage can be supplied from a system power supply. Although the pulse width can be varied as the output time ratio, the overall output time ratio can be controlled by selecting which pulse is output from which power source. Note that the power shortage of the DC power supply can be determined by measuring the voltage or current of the DC power supply. By combining the power generated by the power generation device and the power from the grid, the shortage of the main power source can be procured from different power sources without waste according to the power consumption of the load.

  One of the DC power supplies is a solar battery, and the distribution control unit may set the power supplied from the DC power supply so that the amount of power generated by the solar battery is maximized.

  That is, the power distribution control unit performs control to extract the generated power of the solar cell to the maximum. That is, the power distribution control unit appropriately sets the voltage and current to be extracted from the solar cell, and compensates for the shortage from the commercial power supply, thereby allowing the solar cell to generate power with maximum efficiency and operating the load. In addition, when the power generation amount of the solar cell exceeds the required amount of load, the power generation amount may be adjusted by removing the voltage of the solar cell from the optimum point.

  You may provide the protective diode which suppresses that the electric current output from AC power supply supplied from a system | strain is applied to DC power supply in the downstream of DC power supply.

  When a pulse is output from one inverter, the other inverter stops outputting, but a reverse voltage is applied to the inverter. When the load is a permanent magnet motor, an electromotive force is generated when the power supply is stopped and then free-running (rotating with inertia). In this case, a reverse voltage is applied to the inverter, but it is considered that no reverse power flow will occur in the system when a AC / DC converter that does not perform reverse power flow such as a half-wave rectifier circuit is used. .

  On the other hand, since DC power supplies such as storage batteries and DC power generators are directly connected to the inverter circuit, the current from the commercial power supply and the voltage due to free run flow into the DC power supply side exceeding the breakdown voltage between the emitter and collector of the inverter. there is a possibility. Therefore, a protective diode is provided on the DC power supply side. Thereby, even if it is the structure which supplies electric power exclusively, DC power supply (a storage battery or a DC power generation device) can be protected.

  Further, the protection diode prevents the current from flowing from the commercial power source to the solar cell during the combined operation, and allows the solar cell to always operate at the maximum output point.

At least two of the DC power supplies are solar cells, and an inverter may be provided for each of the solar cells having the same installation direction. ｜
The solar cells have different maximum output points and maximum voltages when the solar radiation intensity is different. Therefore, out of the solar cells installed in various installation directions, all the solar cells installed in the same installation direction are collectively provided with an inverter so that any solar cell can be operated at the maximum output point. Good.

  When the DC power source is composed of a DC power generator, the power storage unit that stores the power output from the DC power source, the power output from the DC power source is guided to the power storage unit, the power is output from the power storage unit, or the DC power source A power storage control unit that outputs power to the inverter from both power storage units.

  When the DC power source is a DC power generator, the output of the DC power source is basically controlled by the inverter for the load. However, there is a case where the amount of power generation exceeds the load as in the case where the load (device) is not operating, and the output of the power generation device may be insufficient for the power consumption of the load. Therefore, when the output of the generator is surplus, the output power is led to the power storage unit for charging, and when the generator is not outputting, it is output from the storage battery, and further, the generator is output. However, if it does not reach the power consumption, the output from both the power generation device and the storage battery enables efficient use of the generated power, and the power supply from the system is minimized. Can be suppressed. Moreover, the effect which suppresses the fluctuation | variation of the power supply amount from a system | strain can also be expected.

When the DC power source is composed of a DC power generator, the power storage unit that stores the power output from the DC power source, the power output from the DC power source is guided to the power storage unit, the power is output from the power storage unit, or the DC power source A storage control unit that outputs power from both of the storage units to the inverter and a distribution control unit that controls the output time ratio of the plurality of inverters are further provided. The distribution control unit is supplied from a DC power source according to the power consumption of the load. Power to be supplied from the AC power source by controlling the output time ratio of the plurality of inverters so as to supply the shortage of the generated power from the AC power source, and further controlling the power output from the power storage unit by the power storage control unit It is better to prevent sudden fluctuations.

  The voltage of the AC power supplied from the grid is constantly changing depending on the state of the load that uses the grid power. An abrupt increase in load leads to an instantaneous voltage drop or flicker in the system. By utilizing the power storage unit, a load on the system can be suppressed, and adverse effects on other electric products that receive power from the system can be prevented.

  A typical configuration of a compression-type refrigerant cycle device according to the present invention may include the above-described power supply device and an electric compressor as a load.

  The heat pump unit also operates as a refrigerant cycle device by circulating the refrigerant through a path opposite to the path used in the hot water storage hot water supply system. With this configuration, the hot water storage hot water supply system can be used as a refrigerant cycle device.

  The refrigerant cycle device is a compression-type refrigerant cycle device, and includes a power recovery mechanism that rotates by power when the refrigerant expands. The DC power source includes a combination of an AC power generator and a power storage unit. You may generate electric power with the rotational force of a collection | recovery mechanism.

  By generating electricity using a power recovery mechanism provided in place of the expansion valve, the COP of the compression refrigerant cycle device can be improved and the power for operating the compressor can be obtained. As a result, the efficiency can be dramatically improved.

  Further, as a power recovery mechanism, other mechanisms such as a scroll and a reciprocating may be used instead of the turbine.

  Moreover, the use application of the compression-type refrigerant | coolant cycle apparatus provided with the said power recovery mechanism is not restricted to a hot water storage type hot-water supply apparatus.

  Moreover, the typical structure of the hot water storage type hot water supply system according to the present invention includes a compression type refrigerant cycle device.

  As a basic operation, the hot water storage type hot water supply apparatus accumulates hot hot water using inexpensive nighttime electric power and uses hot water during the day. And when hot water runs short during the day (when the temperature drops), additional operation (cooking) is performed, but by using the power supplied from the solar cell at that time, power can be generated efficiently in the daytime. Taking advantage of the characteristics of solar cells, the amount of heat needed can be procured inexpensively in the daytime. It is also beneficial from the viewpoint of peak shift that can reduce the power consumption during the daytime when power demand is concentrated.

  A typical configuration of a hot water storage type hot water supply system according to the present invention uses the above-described power supply device, an electric compressor as a load, a cooling pipe installed in a solar cell, and heat recovered by the cooling pipe. And a water heat exchanger for heating hot water in the hot water storage tank unit.

  In the hot water storage type hot water supply system, a cooling pipe may be installed in the solar battery, and the water inside the hot water storage tank may be heated using the heat recovered by the cooling pipe.

  Naturally, solar cells generate power by applying sunlight, but the solar cells become hot due to the radiant heat of the sun. The power generation efficiency of the solar cell is deteriorated when the surface temperature of the solar cell body is increased. Therefore, in order to generate electricity efficiently, the surface temperature of the solar cell body must be lowered. On the other hand, in a hot water supply system that heats water, it is considered that the amount of heat of the solar cell can be used effectively.

  Therefore, the solar cell can be cooled and the water can be preheated by installing a cooling pipe in the solar cell as described above and exchanging heat between the recovered heat and the water before being heated by the water heat exchanger. Can do. Thereby, the power generation efficiency is improved and the efficiency of the heat pump can be improved.

  ADVANTAGE OF THE INVENTION According to this invention, the power supply device which can use together two different power supplies, without connecting (combining), and the compression-type refrigerant | coolant cycle apparatus and hot water storage type hot-water supply system using this power supply device can be provided. .

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in the embodiments are merely examples for facilitating understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are denoted by the same reference numerals, and redundant description is omitted, and elements not directly related to the present invention are not illustrated. To do.

(First embodiment)
FIG. 1 is a diagram illustrating a configuration of a power supply device according to the present embodiment. A power supply apparatus 200 shown in FIG. 1 includes a plurality of (two in the present embodiment) power supplies, one of which is an AC power supply composed of a commercial power supply 202, and the other is a solar cell 212 as a DC power supply. . The power supply apparatus 200 includes a plurality of inverters that control switching of power supplied from the commercial power supply 202 and the solar battery 212, that is, a first inverter 208 and a second inverter 218. The power supply device 200 includes an AC / DC converter 204 between the commercial power source 202 and the first inverter 208. In addition, the power supply device 200 includes a distribution control unit 206, a capacitor 210, a voltmeter 216, a protection diode 220, and a heat pump hot water supply device 100A, which will be described later.

The power supply apparatus 200 is a power supply apparatus for exclusively using different power supplies, that is, power supplied from the commercial power supply 202 and the solar battery 212. The commercial power source 202 receives AC power from the system, and an AC / DC converter 204 is provided to rectify AC to DC.
The AC / DC converter 204 supplies a direct current to the first inverter 208, and the direct current is subjected to switching control by the first inverter 208.

  The solar cell 212 photoelectrically converts natural light energy to generate DC power, and supplies the generated DC power to the second inverter 218. The second inverter 218 performs switching control of the direct current generated by the solar battery 212.

  Switching control performed by the first inverter 208 and the second inverter 218 is a power supply circuit control method in which power is controlled by pulse modulation. The first inverter 208 and the second inverter 218 change the frequency at which switching is performed according to the target load. For example, by reducing the frequency when the load is light, switching loss can be reduced and standby power can be reduced. In addition, the higher the frequency, the smaller the passive element and the faster the response.

  The distribution control unit 206 determines how to distribute and use the power of the commercial power source 202 and the solar battery 212 according to the power consumption of the heat pump hot water supply apparatus 100A. In the present embodiment, power is supplied from a plurality of power sources by allocating the time that each power source outputs according to the amount of power that can be used. That is, the distribution control unit 206 controls the output time ratio of the first inverter 208 and the second inverter 218.

  As a specific method, the distribution control unit 206 calculates the difference between the power supplied from the second inverter 218 and the power consumption of the heat pump hot water supply apparatus 100A, and the second inverter 218 with respect to the power consumption of the heat pump hot water supply apparatus 100A. When the output power is insufficient, the output time is distributed so as to be output from the first inverter 208.

  FIG. 2 is a graph showing, in time series, the state of power supply controlled by the distribution control unit 206 of FIG. FIG. 2A shows a required output voltage value 209 and a pulse train 211 equivalent to the output voltage value 209 according to the power consumption required by the load. The distribution control unit 206 exclusively supplies the outputs from the first inverter 208 and the second inverter 218 in a time-sharing manner.

  As shown in FIG. 2B, the time division is a rule for switching so that as many pulse trains as possible are output from the second inverter 218 from the end of the pulse train of one cycle shown in FIG. You can go on. Alternatively, as shown in FIG. 2C, when one pulse is alternately supplied as much as possible and the output from the second inverter 218 cannot cover the pulse, the first inverter 208 continuously outputs pulses. You may go on. According to the situation at the time of supply, it can supply by a convenient method.

  As described above, the distribution control unit 206 controls the power switched by the first inverter 208 and the second inverter 218 so that the power is supplied based on the power required by the heat pump hot water supply apparatus 100A. When supplying, the distribution control unit 206 may preferentially supply the power output from the second inverter 218 as described above. By combining the electric powers supplied from the different power sources output using the switching control and using them simultaneously by the above-described method, the required electric power can be supplied to the heat pump hot water supply apparatus 100A. It becomes possible.

  According to the above-described switching control, even a power generation device having a small power generation capacity such as the solar battery 212 can use the generated power without waste by combining the generated power and the power from the system. Further, the shortage of the main power source (solar cell 212) can be easily procured from a different power source (commercial power source 202) such as power from the system according to the power consumption of the load.

  When each power source is used, the power source is exclusively switched under the control of the distribution control unit 206. The advantage of using them exclusively is that no interference occurs with the power supply device. Since the power sources used are not combined and any one power source always supplies power alternately, the power sources can be used without interference.

  By the way, in this embodiment, the commercial power source 202 to which power is supplied from the system and the solar battery 212 that supplies power generated by natural light are used in combination. When the two power sources are used in combination, the distribution control unit 206 may perform switching control by adjusting so that the efficiency of the solar cell 212 is maximized.

  The solar cell 212 has a point at which the product (power) of the output current and the output voltage is maximized, that is, the maximum output point that can be utilized most efficiently. Since the maximum output point of the solar cell 212 varies depending on the weather or the like, fine control is required to extract the efficiency of the solar cell 212. Of course, the maximum output point of the solar cell 212 and the power required by the load do not always match.

  The distribution control unit 206 slightly varies the DC voltage of the solar cell 212 at regular time intervals, measures the variation in the amount of power generation associated with the voltage variation, and determines the maximum output point, that is, the corresponding power value. The solar cell is operated at the determined maximum output point, and the power supply from the first inverter 208 is controlled so that the shortage can be compensated by the commercial power source 202.

  The protective diode 220 prevents the direct current voltage of the commercial power source 202 from affecting the direct current voltage of the solar cell 212 even when the maximum output voltage of the solar cell 212 is lower than the direct current voltage of the commercial power source. The battery 212 can be operated at the maximum output point.

  Moreover, when there are a plurality of installation directions of solar cells, an inverter may be provided for each installation direction. Any solar cell can be operated at the maximum output point.

  In addition, when the solar cell 212 generates power efficiently and there is excessive power, the load applied to the second inverter 218 may be increased. With this configuration, the solar cell 212 can be used more effectively and the power of the first inverter 208 can be reduced.

  By the way, in recent years, heat pump hot water supply apparatuses have been popularized from the viewpoint of effective use of energy and reduction of emission amount of carbon dioxide, which is a greenhouse gas. By introducing a heat pump hot water supply device, it is possible to save about 30% energy and reduce carbon dioxide emissions by about 50% compared to a conventional combustion water heater.

  FIG. 3 is a diagram illustrating the configuration of the heat pump type hot water supply device of the power supply device according to the present embodiment. The heat pump hot water supply apparatus 100A includes a heat pump unit 110A that generates hot water and a hot water storage tank unit 132 that stores hot water. Carbon dioxide is circulated in the heat pump unit 110A as a natural refrigerant (hereinafter referred to as “refrigerant”), and the refrigerant absorbs heat in the atmosphere. Then, in the compressor 114 in the heat pump unit 110A, the refrigerant that has absorbed heat is compressed by the electric motor. Thereby, a refrigerant | coolant will be in a high voltage | pressure state and generate | occur | produces high heat.

  Then, in the water heat exchanger 116 of the heat pump unit 110A, the water supplied from the hot water storage tank unit 132 is heated by the high heat of the refrigerant to make hot water. The generated hot water is stored in the hot water storage tank unit 132 and mixed with the water supplied through the water supply valve 142. Therefore, in the hot water storage tank unit 132, the upper half is a high temperature region and the lower half is a low sound region. Hot water in a high temperature region is supplied from the hot water storage tank unit 132 when the user needs it, and the temperature is adjusted by mixing with the supplied water by the mixing valve 140, and the hot water is supplied to the hot water supply equipment.

  Carbon dioxide used as a refrigerant in the heat pump unit 110A exchanges heat with water in the supercritical region. However, because of the high pressure, the pump power increases and the coefficient of performance (COP) decreases. Therefore, heat exchange with water is performed at a temperature around 100 degrees. That is, when a carbon dioxide refrigerant is used, the temperature difference between the refrigerant and water is reduced, so it is necessary to improve the heat conduction efficiency between the refrigerant and water. Therefore, in order to improve the heat conduction efficiency from the refrigerant (carbon dioxide) to water, the pipe in the heat exchanger has a double pipe structure in which a pipe through which the refrigerant flows is arranged outside the pipe through which water flows, The structure is extremely complicated, such as a structure in which a pipe through which a refrigerant flows is wound outside a pipe through which water flows, or a structure in which a pipe through which water flows and a pipe through which refrigerant flows.

  The heat pump hot water supply apparatus 100A uses cheap late-night power to boil hot water and store it in the hot water storage tank unit 132. However, when a large amount of hot water is required, it is necessary to retreat using expensive daytime power. It was. If the stored hot water is used up, it will be necessary to make additional cooking using only the daytime system power supply, which is expensive.

  However, by using this embodiment, the lack of hot water can be procured in the daytime, taking advantage of the characteristics of the solar cell that can efficiently generate power in the daytime. Since it is not necessary to use equipment that should be used at night during the daytime when power demand is concentrated, it is also preferable from the viewpoint of peak shift. In the case of the heat pump system, it is originally more efficient to operate in the daytime when the temperature is high because of the characteristic that the refrigerant is heated by the heat of the air.

  Another feature of the present embodiment is that DC power obtained by the solar cell 212 is directly supplied to the second inverter 218. Conventionally, a method has been used in which AC power is converted to AC using a power conditioner, and the converted AC power is reversely coupled to the grid (reverse power flow), and AC power is supplied from the grid again.

  When converting AC power and DC power, it is known that power that should originally be available decreases. That is, a loss associated with the conversion occurs. Performing inverter control using a conventional method involves conversion of DC power generated to AC, rectification of AC power to DC, and switching using an inverter. . According to the present embodiment, it is not necessary to share the DC circuits of a plurality of inverters, loss caused at every conversion can be prevented, and the obtained power can be used more efficiently.

  In addition, in the conventional method in which the commercial power supplied from the system and the power supplied from the power generator are used in combination, there is a problem that the device for reverse power flow becomes large and the initial investment increases. .

  In the present embodiment, the power supply apparatus 200 is configured using a circuit that does not involve reverse power flow, such as a half-wave rectifier circuit, in the AC / DC converter 116. When using the power supply device 200, the power supplied from the power supply of the power generation device is exclusively used without being connected to the system, thereby simplifying the device and reducing the cost, and using renewable energy, etc. It is possible to boost the installation of the power generation device such as the solar cell 212 utilized in the above.

  Further, by using this embodiment, it is possible to supply a combination of power supplied from different power sources. Therefore, it can be used as a standby power supply in the event that one of the power supplies goes down. By providing a spare power supply, system redundancy can be achieved and the stability of power supply can be improved.

  The pump 120 of the heat pump hot water supply apparatus 100 </ b> A is stopped if the supply of electric power to the electric motor is stopped, but the electric motor connected to the compressor 114 is rotated by the pressure difference inside the compressor 114 even after the electric power supply is stopped. Such a state is called free run.

  In a motor using a permanent magnet, a back electromotive force is generated by the rotation of the motor during free run. The generated back electromotive force flows backward to the commercial power source 202 or the solar cell 212 if left untreated. In view of this, a protection diode 220 is provided on the downstream side of the solar cell 212 to prevent the current output from the power source from being applied to the solar cell 212.

  Back electromotive force generated from the motor during free run is collected by a capacitor 210 provided between the first inverter 208 and the AC / DC converter 204.

  The commercial power source 202 is in a state where the upstream side of the first inverter 208 is rectified to DC power. However, when the AC / DC converter 204 is a unit that does not perform reverse power flow, such as a half-wave rectifier circuit, the commercial power source 202 does not flow back into the system. When the load is a permanent magnet motor, a free-running electromotive force is generated when the motor is stopped. Therefore, no diode is installed on the commercial power source 202 side.

(Second Embodiment)
FIG. 4 is a diagram illustrating the configuration of the power supply device according to the second embodiment. To describe only the differences from FIG. 1, the power supply device 201 shown in FIG. 4 newly includes a DC / DC converter 214, a power storage control unit 222, a power storage unit 224, and a third inverter 226.

  In the present embodiment, the power storage unit 224 is provided in order to more effectively use the DC power generated by the solar battery 212. When power is generated by the solar battery 212, it is often impossible to consume all the generated power, such as in the daytime in fine weather. Therefore, the power storage control unit 222 controls whether or not the power storage unit 224 stores surplus power. When storing electricity, the DC / DC converter 214 is turned on, and surplus power generated by the solar cell 212 is guided.

  In the case of a power generation system using a conventional solar cell, a reverse power flow is made to the system. In the case of the present embodiment, since switching is performed by the inverter with the generated DC power, the surplus power is guided to the power storage unit 224 and stored without causing reverse power flow. The power storage control unit 222 performs such control.

  The power storage control unit 222 also performs control to discharge the electricity stored in the power storage unit 224 when the amount of power generation is small or at night. The discharged power is supplied through the third inverter 226. With this function, the stored electricity can be effectively used.

  As another function of the power storage control unit 222, control is performed so that the power storage unit 224 discharges when the heat pump hot water supply apparatus 100A operates. When the distribution control unit 206 is aware of the operation of the heat pump hot water supply device 100A, the storage control unit 222 is operated, and when the heat pump hot water supply device 100A operates, a sudden load is applied to the commercial power supply 202 by the consumed power. To prevent.

  The power storage unit 224 may be a lead storage battery, an electric double layer capacitor, or the like. In addition, any battery may be used as long as it is a means capable of storing electricity and can be used efficiently. For example, a nickel metal hydride battery, a lithium ion battery, a nickel cadmium battery, or the like may be used.

  The power storage unit 224 may be provided between the solar cell 212 and the third inverter 226 as in the present embodiment. Even if solar cell 212 is sufficiently generating power, distribution control unit 206 discharges from power storage unit 224 when the amount of power generated by solar cell 212 is less than the power consumption of heat pump hot water supply apparatus 100A. Thus, the power supplied from the first inverter 208 can be reduced.

  Thus, by storing the electric power generated by the solar cell 212, instability of the supply amount of the solar cell 212 itself can be covered. In addition, power supply from the system can be minimized.

  FIG. 5 is a graph showing the state of power supply in time series when the three power sources including the third inverter 226 are used in combination as shown in FIG. The power supply by time division can be distributed by the same method as in FIG. That is, in order to output the pulse train of FIG. 5 (a), as shown in FIG. 5 (b), the output from the second inverter 218 is utilized to the maximum at the center of one cycle, and the shortage is first. The inverter 208 and the third inverter 226 may be supplemented. Alternatively, as shown in FIG. 5C, one pulse may be alternately supplied as much as possible.

(Third embodiment)
FIG. 6 is a diagram illustrating the configuration of the power supply device according to the third embodiment. To describe only the differences from FIGS. 1 and 4, the power supply device 201b shown in FIG. 6 includes two solar cells 212a and 212b, and voltmeters 216a, 216b, Second inverters 218a and 218b and protection diodes 220a and 220b are newly included.

  In the present embodiment, two inverters, that is, the second inverters 218a and 218b are provided for each installation direction in order to more effectively use the DC power generated by the solar cells 212a and 212b having different installation directions.

  At least two of the DC power supplies are solar cells, and an inverter may be provided for each of the solar cells having the same installation direction.

  The solar cells have different maximum output points and maximum voltages when the solar radiation intensity is different. Therefore, among the solar cells 212a and 212b installed in various installation directions, the second inverters 220a and 220b are provided for each of the solar cells 212a and 212b installed in the same installation direction, and any of the solar cells 212a and 212b is provided. However, it can be operated at the maximum output point.

  Of the power generated by power generation, surplus power is stored in the power storage unit 224 via the DC / DC converter 214.

  FIG. 7 is a graph showing, in time series, the state of power supply when four power sources including the second inverters 218a and 218b are used in combination as shown in FIG. The power supply by time division can be distributed by the same method as in FIG. That is, in order to output the pulse train of FIG. 7 (a), as shown in FIG. 7 (b), the output from the second inverters 218a and 218b is utilized to the maximum at the center of one cycle, and the shortage is reduced. The first inverter 208 and the third inverter 226 may be supplemented. Alternatively, as shown in FIG. 7C, one pulse may be alternately supplied as much as possible, and a large number of burdens may be assigned to the second inverters 218a and 218b.

(Fourth embodiment)
FIG. 8 is a diagram illustrating the configuration of the power supply device 203 according to the fourth embodiment. FIG. 9 is a diagram illustrating the configuration of the heat pump type hot water supply apparatus 100B of FIG. 8 will be described only with respect to the difference from FIG. 4. The power supply device 203 shown in FIG. 8 newly includes a power storage unit 228, a fourth inverter 230, an AC / DC conversion unit 232, and a power recovery mechanism 234. 100B includes a new heat pump unit 110B.

  For example, in the heat pump hot water supply apparatus 100A of FIG. 3, the refrigerant is expanded while adjusting the pressure by using the expansion valve 118 in order to expand the refrigerant after the compressed refrigerant exchanges heat. On the other hand, in the heat pump type hot water supply apparatus 100B of the present embodiment, as shown in FIG. 9, a power recovery mechanism 234 is used instead of the expansion valve 118.

  FIG. 10 is a diagram depicting the pressure and specific enthalpy of carbon dioxide, which is the refrigerant of the heat pump used in this embodiment. The vertical axis represents pressure and the horizontal axis represents enthalpy.

  Not only the refrigerant used in the present embodiment, but the gas becomes high temperature by being compressed. In order to increase the temperature of the refrigerant efficiently, the cold refrigerant can be warmed using the outside air, so that energy for compression can be further saved. For this reason, heat can be efficiently extracted as compared with the case where all are compressed to a high temperature. Point D1 is a state in which the refrigerant is cold, and when it is warmed by the outside air, the point D1 transitions to point A.

  The pressure is applied from the point A to the point B with the force of the compressor 114. Therefore, point B is located above point A. That is, the amount of work by the compressor 114 is performed between the points A and B.

  Next, the high temperature refrigerant heats the water supplied by the water heat exchanger 116. The heat energy held by the refrigerant by heating is transferred to the hot water stored in the hot water storage tank unit 132. In the diagram, points B to C correspond to this state.

  Since the refrigerant maintains the pressure, the points B and C are parallel to the horizontal axis. The refrigerant is in a state of high pressure and low temperature by warming water (point C). If the expansion valve 118 is used, the pressure returns to the normal pressure (point D1) through this. When expanding, normally, no particular work is performed, so the head is directed to the point D1 parallel to the vertical axis, but the energy at the time of expansion is not particularly utilized.

  The present embodiment is characterized in that, instead of using the expansion valve 118, the power recovery mechanism 234 is used to extract the energy during expansion as electric energy. Since there is a pressure difference between the left and right of the power recovery mechanism 234, the power recovery mechanism 234 rotates with the energy of expansion during the expansion of the refrigerant. Electricity is generated by rotation, rectified by the AC / DC converter 232, and electric power is stored in the power storage unit 228.

  The power storage unit 228 may be a lead storage battery, an electric double layer capacitor, or the like. In addition, any battery may be used as long as it is a means for storing electricity and can be used efficiently. For example, a nickel metal hydride battery, a lithium ion battery, a nickel cadmium battery, or the like may be used.

  On the other hand, the temperature of the refrigerant decreases during expansion. The refrigerant whose temperature has decreased is warmed by the outside air and travels to the first compressor 114. When the compressor 114 is rotated, the efficiency recovered can be further improved by using the energy recovered in the present embodiment together.

The most important feature of this embodiment is that it collects energy that was once discarded. Thereby, a coefficient of performance (COP) improves.
Since the power recovery mechanism 234 can be operated at an arbitrary number of revolutions, the energy during expansion can be recovered without difficulty.

  Since this method is used for an inverter power source that drives a compressor without converting the generated DC power into a commercial frequency, loss due to AC / DC conversion can be avoided.

  FIG. 11 is a graph showing the state of power supply in time series when the four power sources including the fourth inverter 230 are used in combination as shown in FIG. The power supply by time division can be distributed by the same method as in FIG. That is, in order to output the pulse train of FIG. 11 (a), as shown in FIG. 11 (b), the outputs from the second inverter 218 and the third inverter 226 are utilized to the maximum at the center of one cycle, The shortage may be compensated by the first inverter 208 and the fourth inverter 230. Alternatively, as shown in FIG. 11C, one pulse may be alternately supplied as much as possible, and the second inverter 218 may be assigned a large number of burdens.

  FIG. 12 is a flowchart representative of the operation of the fourth embodiment shown in FIGS. 8 and 9. When a load is generated (S300), it is first determined whether the power generated by the solar cell 212 can be used (S302). When the use of the solar battery 212 is impossible (“NO” in S302), the process proceeds to step S308 described later. When the solar cell 212 can be used (“YES” in S302), supply is performed from the solar cell 212 (S304).

  Next, it is determined whether or not power is satisfied with respect to the load by supply from the solar battery 212 (S306). If power is not sufficient for the load (“NO” in S306), it is determined whether or not the power storage unit 224 of the solar cell 212 can be used (S308). When the power storage unit 224 is usable (“YES” in S308), supply is performed from the power storage unit 224 (S310).

  Next, it is determined whether or not the power for the load is sufficient, including the power from the power storage unit 224 of the solar battery 212 (S312). When the power is not sufficient for the load (“NO” in S312), it is determined whether the power recovered by the power recovery mechanism 234 of the heat pump hot water supply apparatus 100 can be used (S314). When the power recovered by the power recovery mechanism 234 is usable (“YES” in S314), the power recovered by the power recovery mechanism 234 is supplied (S316).

  Next, it is determined whether the power for the load is sufficient, including the power recovered by the power recovery mechanism 234 (S318). When the power for the load is not satisfied (“NO” in S318), power is supplied from the commercial power source 202 (S320), and the process returns to step S300.

  If only the battery supplied by the solar battery 212 is sufficient for power (“YES” in S306), it is determined whether there is surplus power (S320). If there is surplus power (“YES” in S320), the power is stored in the power storage unit 228 (S322), and the process returns to step S300. On the other hand, when there is no surplus power (“NO” in S320), the process returns to step S300. When power is supplied to the load by supplying power from the solar battery 212, the power storage unit 224, etc. (“YES” in S312), the process returns to step S300. Also, when the power recovery mechanism 234 or the like has sufficient power for the load (“YES” in S318), the process returns to step S300.

(Fifth embodiment)
FIG. 13 is a diagram illustrating the configuration of the heat pump type hot water supply device of the power supply device according to the present embodiment. In the present embodiment, since the heat pump type hot water supply apparatus 100A of the power supply apparatus according to the first embodiment is replaced with the heat pump type hot water supply apparatus 100C of FIG. 13, the entire power supply apparatus is not shown. The heat pump hot water supply apparatus 100C includes a heat pump unit 110C, a compressor 114, a water heat exchanger 116, an expansion valve 118, a pump 120, a hot water storage tank unit 132, a mixing valve 140, a water supply valve 142, a cooling pipe 240, a solenoid valve 242, and the reverse. A stop valve 244, an electromagnetic valve 246, a check valve 248, and a water heat exchanger 254 are configured.

  The feature of this embodiment is that a solar cell 212 is used instead of the air heat exchanger of the heat pump hot water supply apparatus 100C. That is, the solar battery 212 which is one of the power supply devices is used in the heat pump unit 110C in cooperation with the heat pump hot water supply device 100C. Specifically, the cooling pipe 240 is passed through the back side of the solar cell 212 to perform the function instead of the air heat exchanger.

  The heat pump unit 110C is forcibly operated by the compressor 114 instead of a normal air heat exchanger at night, but when cooling in the daytime, the refrigerant is naturally circulated while being adjusted by the electromagnetic valve 242 and the electromagnetic valve 246. Then, the hot water stored in the hot water storage tank 132 is heated by the water heat exchanger 254. With this configuration, heating can be performed and the solar cell 212 can be cooled.

  Note that the check valve 244 and the check valve 248 can prevent back flow of the naturally circulated refrigerant. The refrigerant used is not limited as long as it is generally used as a refrigerant such as carbon dioxide.

(Sixth embodiment)
14 is a diagram illustrating the configuration of the heat pump hot water supply device of the power supply device according to the sixth embodiment. In this embodiment, the heat pump type hot water supply apparatus 100A of the power supply apparatus according to the first embodiment is replaced with the heat pump type hot water supply apparatus 100D of FIG. The heat pump hot water supply apparatus 100 </ b> D includes an air heat exchanger 112, a pump 250, and a cooling pipe 252.

  Similarly to the fifth embodiment, this embodiment also cools the solar battery 212 that is one of the power supply devices. This embodiment is different from the fifth embodiment in that a cooling pipe 252 is installed and the refrigerant is forcibly circulated using the pump 250 when the solar cell 212 is cooled.

  Compared to the natural circulation of the fifth embodiment, since this embodiment performs forced circulation, power consumption used in the pump 250 is generated, but efficient cooling can be performed from the viewpoint of cooling the solar cell 212, Improvement in power generation efficiency can be expected. In addition, since the refrigerant is forcibly circulated by the pump 250, the installation location of the power source is not selected.

(Refrigerant cycle device)
Although the heat pump type hot water supply apparatus shown in the embodiments so far is an apparatus for supplying hot water using a heat pump, it can be used as a refrigerant cycle apparatus by reversing the flow path of the refrigerant. At this time, a four-way valve may be installed. The refrigerant flow can be reversed quickly by the action of the four-way valve.

  The refrigerant cycle apparatus will be described with reference to FIG. When used for hot water supply, the refrigerant is compressed by the compressor 114 and then moves through the heat pump unit 110A in the order of the water heat exchanger 116, the expansion valve 118, and the air heat exchanger 112.

  On the other hand, when used as a refrigerant cycle device, the refrigerant is compressed by the compressor 114, and then moves through the air heat exchanger 112 and the heat pump unit 110A in the order of the expansion valve 118 and the water heat exchanger 116. With such a configuration, the heat pump type hot water supply apparatus 100A can be used not only for hot water supply but also for cooling.

  The use of the power supply device of the present embodiment is not limited to the hot water storage type hot water supply system and the refrigerant cycle device. Specifically, IH heaters, AC arc furnaces, inverter welding machines, pumps, blowers, air compressors, packaged air conditioners, refrigerators, self-excited SVCs, fluorescent lamps, etc. May be. Moreover, you may use for not only single phase load but three phase load.

  As mentioned above, although the suitable Example of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to this embodiment. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

  The present invention relates to a power supply device that uses different power sources together, a hot water storage system that stores hot water generated by heating water using electricity supplied from the power supply device, and supplies the stored hot water to a hot water supply facility, and It can be used as a heat pump type refrigerant cycle device.

It is a figure explaining the structure of the power supply device concerning 1st Embodiment. It is the graph which showed the mode of the electric power supply controlled by the distribution control part of FIG. 1 in time series. It is a figure explaining the structure of the heat pump type hot-water supply apparatus of FIG. It is a figure explaining the structure of the power supply device concerning 2nd Embodiment. It is the graph which showed the mode of the electric power supply controlled by the distribution control part of FIG. 4 in time series. It is a figure explaining the structure of the power supply device concerning 3rd Embodiment. It is the graph which showed the mode of the electric power supply controlled by the distribution control part of FIG. 6 in time series. It is a figure explaining the structure of the power supply device concerning 4th Embodiment. It is a figure explaining the structure of the heat pump type hot-water supply apparatus of FIG. It is a pressure and specific enthalpy diagram of the heat pump unit of FIG. It is the graph which showed the mode of the electric power supply controlled by the distribution control part of FIG. 8 in time series. It is a flowchart which shows operation | movement of the power supply device of FIG. It is a figure explaining the structure of the heat pump type hot-water supply apparatus of the power supply device concerning 5th Embodiment. It is a figure explaining the structure of the heat pump type hot-water supply apparatus of the power supply device concerning 6th Embodiment.

Explanation of symbols

100A, 100B, 100C, 100D ... Heat pump type hot water supply device, 110A, 110B, 110C ... Heat pump unit, 112 ... Air heat exchanger, 114 ... Compressor, 116 ... Water heat exchanger, 118 ... Expansion valve, 120 ... Pump, DESCRIPTION OF SYMBOLS 132 ... Hot water storage tank unit, 142 ... Water supply valve, 200, 201, 201b, 203 ... Power supply device, 202 ... Power supply, 204 ... AC / DC conversion part, 206 ... Distribution control part, 208 ... 1st inverter, 210 ... Capacitor, 212 ... Solar cell, 214 ... DC / DC converter, 216 ... Voltmeter, 218, 218a, 218b ... Second inverter, 220, 220a, 220b ... Protection diode, 222 ... Power storage control unit, 224 ... Power storage unit, 226 ... Third inverter 228 ... power storage unit, 230 ... fourth 232 ... AC / DC converter, 234 ... Power recovery mechanism, 240 ... Cooling pipe, 242 ... Solenoid valve, 244 ... Check valve, 246 ... Solenoid valve, 248 ... Check valve, 250 ... Pump, 254 ... Water heat exchange vessel

Claims (9)

Provided with a plurality of inverters for switching control of power supplied from a plurality of power sources,
One of the plurality of power sources is an AC power source composed of a commercial power source,
An AC / DC converter between the AC power source and the inverter;
Other than the AC power supply among the plurality of power supplies, it is a DC power supply consisting of a combination of a DC power generation device or an AC power generation device and a power storage unit,
A power supply device that supplies power exclusively in a time-sharing manner from the plurality of inverters to a load. A distribution control unit for controlling an output time ratio of the plurality of inverters;
The distribution control unit controls an output time ratio of the plurality of inverters so that a shortage of power supplied from the DC power supply is supplied from the AC power supply according to power consumption of the load. The power supply device according to claim 1 . One of the DC power supplies is a solar cell,
The power supply apparatus according to claim 1 , wherein the distribution control unit sets the power supplied from the DC power supply so that the power generation amount of the solar cell is maximized. The power supply according to claim 1 , further comprising a protective diode that prevents a current output from the AC power supplied from a system from being applied to the DC power supply downstream of the DC power supply. apparatus. At least two of the DC power sources are solar cells,
The power supply device according to claim 1 , wherein an inverter is provided for each solar cell having the same installation direction. In the case where the DC power source is a DC power generator,
A power storage unit that stores power output from the DC power supply; and
A power storage control unit that guides power output from the DC power source to the power storage unit, outputs power from the power storage unit, or outputs power from both the DC power source and the power storage unit to the inverter;
The power supply device according to claim 1 , further comprising: In the case where the DC power source is a DC power generator,
A power storage unit that stores power output from the DC power supply; and
A power storage control unit that guides power output from the DC power source to the power storage unit, outputs power from the power storage unit, or outputs power from both the DC power source and the power storage unit to the inverter;
A distribution control unit for controlling an output time ratio of the plurality of inverters;
The distribution control unit controls an output time ratio of the plurality of inverters so as to supply a shortage of power supplied from the DC power supply from the AC power supply according to power consumption of the load, The power supply device according to claim 1, wherein an output of electric power from the power storage unit by the power storage control unit is controlled to prevent a sudden change in power supplied from the AC power source. The power supply device according to any one of claims 1 to 3 ,
An electric compressor as a load;
A compression-type refrigerant cycle device comprising: A hot water storage type hot water supply system comprising the compression type refrigerant cycle device according to claim 8 .

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