WO2013146773A1

WO2013146773A1 - Power supply system

Info

Publication number: WO2013146773A1
Application number: PCT/JP2013/058760
Authority: WO
Inventors: 沖田　真大; 三保谷　拓史
Original assignee: シャープ株式会社
Priority date: 2012-03-27
Filing date: 2013-03-26
Publication date: 2013-10-03

Abstract

Provided is a highly efficient power supply system that uses renewable energy. The parallel-operation type power supply system (100) is provided with: a DC generator (101) that uses renewable energy; a first DC-DC converter (104) that transforms the output of the DC generator (101); an AC generator (102); an AC-DC converter (105) that converts the output of the AC generator (102) into direct current; an inverter (106) that converts the output of the first DC-DC converter (104) and the output of the AC-DC converter (105) into alternating current; a switching unit (103) that switches the connection destination of the output of the AC generator (102) between the input of the AC-DC converter (105) and the output of the inverter (106); and a control unit (107) that controls the switching to be executed by the switch (103). Also provided is a hybrid-type power supply system (100A) that is equipped with a DC generator (101A) that uses renewable energy, a DC generator (101B), and an AC generator (102), and wherein power generation efficiency of the system as a whole is improved through the use of a switching unit (103) and a control unit (107).

Description

Power system

The present invention relates to a power supply system.

For example, a technique disclosed in Patent Document 1 is known as a power supply system that uses a plurality of power supplies in parallel and can supply power to the load from the plurality of power supplies in parallel. FIG. 14 is a block diagram showing the configuration of the power supply system of Patent Document 1. As shown in FIG.

The power supply system of Patent Document 1 includes a converter 2 that converts alternating current from a commercial power system 1 into direct current, a solar cell 9, and a maximum power point tracking control function for always taking out maximum power from the solar cell 9. A power supply device 5 including a DC-DC converter 8, an inverter 3 that converts direct current into alternating current having a predetermined frequency and voltage, a control circuit 4 that performs predetermined control, and a supply source of power supplied to the load 7 A connection switching device 6 for switching is provided.

In Patent Document 1, the output of the inverter 3 or the commercial power system is switched by switching the connection switching device 6 according to the control signal of the control circuit 4 according to the output power value of the power supply device 5, that is, the power generation state of the solar cell 9. Power is supplied from 1 to the load, and stable power can be supplied to the load without being affected by fluctuations in the power supply amount of the power supply device 5.

JP 2005-328656 A

However, when the technique of Patent Document 1 is applied to a parallel operation power supply system including a self-supporting generator independent of a commercial power system and a power supply using renewable energy such as a solar battery, the following problems arise. That is, in Patent Document 1, when the power supplied to the load 7 is insufficient with only the output of the power supply device 5, the converter 2 controlled by the control signal from the control circuit 4 operates, and the AC power of the commercial power system 1 is Is converted into DC power, and both the converted DC power and the output of the power supply device 5 are input to the inverter 3, and then necessary AC power is supplied from the inverter 3 to the load 7. That is, when parallel operation is performed in the power supply device 5 and the commercial power system 1, both are connected only at the direct current portion.

Therefore, when parallel operation is performed by the power supply device 5 and the commercial power system 1, the power supplied from the commercial power system 1 is once converted to direct current, then converted back to alternating current power and supplied to the load. In such conversion, power loss always occurs.

Further, when the output of the power supply device 5 falls below a preset output value, the connection switching device 6 is switched so that the output of the commercial power system 1 is directly supplied to the load 7. Depending on the case, power is always supplied to the load 7 only by the commercial power system 1, and in this case, the utilization factor of the solar cell 9 of the power supply device 5 is greatly impaired.

The present invention has been made in view of such problems, and an object thereof is to provide a highly efficient power supply system using renewable energy.

The present invention includes a DC input unit to which an output from a DC generator is input, an AC input unit to which an output from an AC generator is input, and an AC- that converts AC input to the AC input unit to DC. A DC converter, an inverter that converts the direct current input to the direct current input unit and the output of the AC-DC converter into alternating current, and a connection destination of the alternating current input unit is switched to the output of the AC-DC converter or the inverter The power supply system includes: a switching unit; and an output unit that selectively outputs an alternating current input to the alternating current input unit and an alternating current output from the inverter.

With this configuration, the DC generator and the AC generator can be operated in parallel according to the output of the DC generator, and switching control of the switching unit can be performed so that the output of the DC generator can be used to the maximum extent. . That is, according to the power supply system according to the present embodiment, the use ratio of the DC generator can be improved, and a highly efficient power supply system using renewable energy can be obtained.

The present invention also provides a DC input unit to which an output from the DC generator is input, an AC input unit to which an output from the AC generator is input, and an inverter that converts the DC input to the DC input unit into AC. A switching unit that switches between operation and stop of the AC generator and the DC generator, and an output unit that selectively outputs the AC input to the AC input unit and the AC output from the inverter. The power supply system is provided.

With this configuration, it is possible to switch between operation and stop of the AC generator and the DC generator so that the output of the DC generator can be used to the maximum according to the output of the DC generator. That is, according to the power supply system according to the present embodiment, the use ratio of the DC generator can be improved, and a highly efficient power supply system using renewable energy can be obtained.

According to the power supply system of the present invention, the usage ratio of the DC generator can be improved, and a highly efficient power supply system using renewable energy can be obtained.

It is a block diagram which shows Embodiment 1 of this invention. It is a block diagram which shows Embodiment 2 of this invention. It is a block diagram which shows Embodiment 3 of this invention. It is a graph which shows the relationship for every time of load power consumption at the time of fine weather, and a DC generator output. It is a graph which shows the relationship for every time of the load power consumption at the time of cloudy weather, and rainy weather, and a DC generator output. It is a graph which shows the relationship for every time of the load power consumption at the time of irregular weather, and a DC generator output. It is a graph explaining the balance of the maximum output of a DC generator and load power consumption. It is a block diagram which shows Embodiment 4 of this invention. It is a block diagram which shows Embodiment 5 of this invention. It is a block diagram which shows Embodiment 6 of this invention. It is a block diagram which shows Embodiment 7 of this invention. It is a block diagram which shows Embodiment 8 of this invention. FIG. 13 is a partial detail view of the block diagram shown in FIG. 12. It is a block diagram of the conventional power supply system.

The power supply system according to the present invention uses a parallel operation type power supply system (embodiments 1 to 3) when using a DC generator and an AC generator using renewable energy in parallel operation, and renewable energy. The present invention is preferably applied to a hybrid power supply system (Embodiments 4 to 8) when a plurality of DC generators including a DC generator and an AC generator are operated in a hybrid manner. First, the parallel operation type power supply system (Embodiments 1 to 3) will be sequentially described.

Embodiment 1
A first embodiment of the present invention will be described with reference to FIG. 1 and FIGS. FIG. 1 is a block diagram of a power supply system 100 according to the present invention, and FIGS. 4 to 6 are graphs showing the relationship between load power consumption and DC generator output depending on the weather.

First, the configuration of the power supply system 100 (parallel operation power supply system) will be described with reference to FIG. The power supply system 100 includes a DC generator 101 that uses renewable energy, a first DC-DC converter 104 that transforms the output of the DC generator 101, an AC generator 102 that uses fossil fuel, and an AC generator 102. AC-DC converter 105 that converts the output into direct current, inverter 106 that converts the output of first DC-DC converter 104 and AC-DC converter 105 into alternating current, and the output supply destination of AC generator 102 is an AC-DC converter. A switching unit 103 (switch) that switches to 105 or a load 109, a control unit 107 that performs system control, and a relay 108 that is interposed between the output of the inverter 106 and the load 109 are provided.

Next, each block described above will be specifically described. For the DC generator 101, for example, a solar power generation device of about 100 kW can be used. Moreover, not only solar power generation but also a power generation device using other renewable energy can be used.

The first DC-DC converter 104 is a step-up chopper method, and adjusts the step-up ratio by changing the duty ratio with a built-in microcomputer to perform maximum power point tracking control of the DC generator 101.

As the AC generator 102, for example, a gas turbine of about 100 kW is used. Further, it is preferable that the speed control can be performed so that the rotor always has a constant speed. For this speed control, a mechanical system using a centrifugal pendulum may be employed, or an electronic system (electronic governor) may be employed. Moreover, you may employ | adopt other rotary generators, such as not only a gas turbine but a diesel generator.

The AC-DC converter 105 is, for example, a combination of a rectifier circuit using a diode bridge and a DC-DC converter for voltage matching. Further, an internal microcomputer is provided, and the output is adjusted in accordance with the voltage fluctuation of the DC system caused by the first DC-DC converter 104 performing the maximum power point tracking control.

The inverter 106 is a transformerless system, and converts the direct current output of the first DC-DC converter 104 or the AC-DC converter 105 into alternating current by PWM (Pulse Width Modulation) control by a built-in microcomputer. Furthermore, an operational amplifier, a current transformer, and an output transformer are built in, and the current value and the voltage value are detected by amplifying the output value with the operational amplifier and performing AD conversion with the microcomputer. Furthermore, a signal is obtained by a sensor that detects a rotor, such as an encoder or resolver (not shown) incorporated in the AC generator 102, and is synchronized with the AC generator 102.

The switching unit 103 is a switch, and switches the output of the AC generator 102 to connection to the DC bus 114 or connection to the load 109 via the AC-DC converter 105.

The control unit 107 controls the operations of the first DC-DC converter 104, the AC-DC converter 105, the inverter 106, and the switch 103 using, for example, RS485 serial communication.

The relay 108 is connected to the operating state of the DC generator 101 and the AC generator 102 to connect between the output of the inverter 106 and the load 109.

Next, the basic operation of the parallel operation power supply system 100 will be described with reference to FIG. 1 and FIG. In the power supply system 100 of FIG. 1, the DC generator 101 and the AC generator 102 are operated in parallel according to the following procedure. FIG. 4 is a graph showing the relationship between the load power consumption and the output of the DC generator 101 during parallel operation on a sunny day all the time. Hereinafter, the case where the DC generator 101 is a solar power generation device will be described as an example.

Referring to FIG. 4, the relationship between the load power consumption during parallel operation and the output of the DC generator 101 will be described prior to the description of the basic operation. As shown in FIG. 4, the output curve POL of the DC generator 101 becomes irregular throughout the day because of the use of sunlight, and of course there is no output at night. Therefore, only the output (not shown) of the AC generator 102 is supplied to the load in the portion where the output curve POL of the DC generator 101 does not satisfy the value of the load power consumption curve PCL at each time.

Next, the actual basic operation of the power supply system 100 will be described with reference to FIG. As described above, when only the output of the AC generator 102 is supplied to the load at night, the output of the first DC-DC converter 104 and the inverter 106 is stopped because there is no output of the DC generator 101. The first DC-DC converter 104 sequentially monitors the input voltage from the DC generator 101 and transmits it to the control unit 107 every preset time. When the input voltage from the DC generator 101 reaches a preset voltage, the control unit 107 issues an operation instruction to the first DC-DC converter 104 and the inverter 106, and an output operation is started. Each of the first DC-DC converter 104, the inverter 106, and the AC-DC converter 105 measures at least the input current in addition to the input voltage and transmits them to the control unit 107. The output procedure from the inverter 106 is as follows.
(1) A reference sine wave having the same frequency as that of the AC generator 102 is created by a microcomputer built in the inverter 106.
(2) The relay 108 is turned off, and the inverter 106 acquires the voltage phase of the AC generator 102 from the detector 117 incorporated in the AC generator 102.
(3) The voltage phase of the reference sine wave is adjusted to match the voltage phase of the AC generator 102.
(4) When the phases in step (3) match, the relay 108 is turned on, and the inverter 106 and the output of the AC generator 102 are connected.
(5) The current value flowing out to the AC generator 102 is detected by the detector 118.
(6) Current feedback control of the inverter 106 is performed so that the value of the current flowing out to the AC generator 102 is maximized and the phase matches the reference sine wave (high power factor).

Next, details of the control operation of the power supply system 100 by the control unit 107 will be described. The control unit 107 controls the inverter 106, and the detector 116 of the inverter 106 detects the output current of the AC generator 102 and the detector 115 detects the voltage of the AC bus 113.

Also, the output current of the inverter 106 is controlled so as to maximize the current from the DC generator 101 within a range where the voltage of the AC bus 113 is acceptable. In this operation, even if the output voltage of the inverter 106 is increased, current feedback control is performed with a desired gain until the output current does not increase. That is, control is performed so that the output of the DC generator 101 is maximized in the system.

On the other hand, when the output current decreases while the output of the inverter 106 is maintained at a constant voltage, it is determined that the output of the DC generator 101 is decreasing due to weather conditions or the like, and the output current decreases. Control is performed to reduce the output voltage of the inverter 106 to a level at which it does not occur.

Further, switching control of the switching unit 103 is performed according to the output of the DC generator 101. Specifically, when the output ratio of the DC generator 101 is small, for example, less than ½ of the load power consumption, the switching unit 103 is switched to the AC bus 113 side according to an instruction from the control unit 107 and the AC -The operation of the basic operation described above is performed with the operation of the DC converter 105 stopped.

Further, when the output ratio of the DC generator 101 is large, for example, when the load power consumption is ½ or more, the switching unit 103 is switched to the AC-DC converter 105 side according to an instruction from the control unit 107 and the AC-DC Converter 105 starts operating. Here, the switching unit 103 may be a mechanical switch, but a switch using a semiconductor such as a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) or a triac is more preferable.

Further, the control of the inverter 106 is changed to voltage feedback control in order to perform a constant voltage output operation similar to that when a general power conditioner autonomously operates. Below, the procedure of the voltage feedback control of the inverter 106 is demonstrated.
(1) A reference sine wave having the same frequency as that of the AC generator 102 is created by a microcomputer built in the inverter 106.
(2) The voltage phase of the reference sine wave is kept the same as before the switching unit 103 is switched. (At any time, the voltage phase of the AC generator 102 is detected by the detector 117 and corrected so that synchronization is maintained.)
(3) The voltage value of the AC bus 113 is detected by the detector 115.
(4) Monitor that the voltage of the AC bus 113 is within an allowable range, and perform voltage feedback control so that a constant voltage is maintained.

The change of the switching operation and the output control of the switching unit 103 is performed by the control unit 107 comparing the load power consumption and the output voltage of the DC generator 101 and instructing the AC generator 102 and the switch 103. At this time, there is no particular problem in the case of clear weather when the output of the DC generator 101 is small and stable compared to the load power consumption as shown in FIG. 4, or when it is cloudy or rainy as shown in FIG. However, when the weather changes irregularly in units of time, the output curve POL of the DC generator 101 may increase or decrease frequently as shown by the portion surrounded by the round broken line in FIG.

In such a case, if the switching of the switching unit 103 is switched too fast, the control and the synchronization with the inverter 106 become difficult. It is good to set beforehand so that it may switch, when continuing above.

According to the first embodiment, an output in which the output of the DC generator 101 and the output of the AC generator 102 are always supplied to the load 109 so that the output of the DC generator 101 is maximized in the system. Be controlled. Therefore, the use ratio of the renewable energy used for the DC generator 101 in the power supply system 100 can be maximized.

As described above, the parallel operation power supply system 100 according to this embodiment includes a DC input unit to which an output from the DC generator 101 is input, an AC input unit to which an output from the AC generator 102 is input, AC-DC converter 105 that converts AC input to the AC input unit to DC, an inverter 106 that converts DC input to the DC input unit and the output of the AC-DC converter 105 to AC, and connection of the AC input unit A switching unit 103 that switches the output to the output of the AC-DC converter 105 or the inverter 106 and an output unit that selectively outputs the AC input to the AC input unit and the AC output from the inverter 106 are provided.

With this configuration, by performing switching control of the switching unit 103 according to the output of the DC generator 101, the output of the DC generator 101 can be used to the maximum extent. That is, according to the power supply system 100 according to the present embodiment, the usage ratio of the DC generator 101 can be improved, and a highly efficient power supply system using renewable energy is obtained.

[Embodiment 2]
Another embodiment of the present invention will be described with reference to FIG. In FIG. 2, the same parts as those of the first embodiment are indicated by the same reference numerals. The present embodiment is different from the first embodiment in that a power factor adjustment unit 110 is added to the AC bus 113.

The power factor adjusting unit 110 includes a plurality of series circuits of capacitors, reactors, and switches. Moreover, it is more preferable to provide a circuit breaker that prevents excessive phase advance at light load. Then, the power factor adjusting unit 110 performs switching control of the switch by the control unit 107 and adjusts the power factor of the AC bus 113 to a specified power factor by adjusting the capacitor capacity in multiple stages. .

According to the second embodiment, it is possible to prevent the AC bus 113 from being overcurrent depending on the consumption current of the load by reducing the power factor when the inverter 106 is under voltage feedback control.

[Embodiment 3]
Still another embodiment of the present invention will be described with reference to FIGS. In FIG. 3, the same parts as those in the first embodiment or the second embodiment are denoted by the same reference numerals. FIG. 7 is a graph for explaining the balance between the maximum output of the DC generator and the load power consumption.

This embodiment is different from the first or second embodiment in that the power storage unit 111 is connected to the DC bus 114 via the second DC-DC converter 112.

First, the balance between the maximum output of the DC generator and the load power consumption will be described with reference to FIG. In the power supply system 100, the maximum output from the DC generator 101 is used as described in the above embodiment. In consideration of this, the maximum output of the DC generator 101 is assumed to be the assumed load power consumption. It is preferable to set so as not to exceed. However, for example, the maximum output of the DC generator 101 may exceed the load power consumption as shown in FIG. 7 due to the installation conditions of the system including the load. In such a case, the electric power in the portion surrounded by the broken broken line exceeding the load power consumption curve PCL is not actually output, and is converted as heat generated by the DC generator 101, so the utilization efficiency as electric power is reduced. Resulting in. In the present embodiment, as described above, the power storage unit 111 is connected to the DC bus 114 via the second DC-DC converter 112 in order to cope with such a situation.

Next, the specific configuration and operation of this embodiment will be described with reference to FIG. As the power storage unit 111, a lead battery, a nickel metal hydride battery, a lithium ion battery, an electric double layer capacitor, a lithium ion capacitor, or the like can be used. The second DC-DC converter 112 is a bidirectional converter that can control the direction of power bidirectionally.

The second DC-DC converter 112 includes a microcomputer inside, and the first DC-DC converter 104 performs control according to the voltage fluctuation of the DC bus 114 caused by the maximum power point tracking control of the DC generator 101. The step-up / step-down ratio is adjusted by the control of the unit 107, and the output of the DC bus 114 is adjusted. Although illustration is omitted, power storage unit 111 can also be connected to AC bus 113 via a bidirectional inverter.

According to the third embodiment, the output of the DC bus 114 is backed up by the power storage unit 111 when the output ratio of the DC generator 101 is high or when an output fluctuation occurs due to a sudden change in weather conditions. Thereby, even if the output fluctuation occurs in the DC generator 101, the power quality for the load 109 can be stabilized. Further, even when there is a fluctuation in the output of the DC generator 101, it is possible to suppress frequent switching of the current feedback control and voltage feedback control and the switch switching operation in the inverter 106.

Next, a description will be given of a hybrid power supply system (Embodiments 4 to 8) when a plurality of DC generators including a DC generator using renewable energy and an AC generator are used in a hybrid manner.

[Embodiment 4]
Another embodiment (Embodiment 4) of the present invention will be described with reference to FIG. FIG. 8 is a block diagram of a hybrid power supply system 100A according to the present invention.

First, the configuration of the hybrid power supply system 100A will be described with reference to FIG. The hybrid power supply system 100A includes a direct current generator 101A (a direct current power supply device, which corresponds to the second direct current generator of the present invention), a first DC-DC converter 104 that transforms the output of the direct current generator 101A, , A power storage unit 111 that stores the power of the DC generator 101A, a second DC-DC converter 112 that transforms the output of the power storage unit 111, an AC generator 102, and a DC generator 101B (the first DC generator of the present invention). And an inverter 106 that converts the output of the first DC-DC converter 104, the second DC-DC converter 112, and the DC generator 101B to AC, and a power unit that supplies power to the AC generator 102 and the DC generator 101B 119 and a switching unit 103 (switch to switch the power supply destination of the power unit 119 to the AC generator 102 or the DC generator 101B. And h), a control unit 107 for performing system control. Further, the relay 108 interposed between the output of the inverter 106 and the load 109, the relay 120 interposed between the output of the DC generator 101B and the DC bus 114, the output of the AC generator 102 and the AC bus A relay 121 interposed therebetween is provided.

Next, each block described above will be specifically described. The DC generator 101A is a second DC generator using renewable energy, and for example, a solar power generator is used. Moreover, not only solar power generation but also a power generation device using other renewable energy can be used.

The first DC-DC converter 104 is a step-up chopper method, and adjusts the step-up ratio by changing the duty ratio with a built-in microcomputer to perform maximum power point tracking control of the DC generator 101A.

The power storage unit 111 can be a lead battery, a nickel metal hydride battery, a lithium ion battery, an electric double layer capacitor, a lithium ion capacitor, or the like. The power storage unit 111 can use only the above-described battery, or the battery and the capacitor are connected in parallel to the output of the first DC-DC converter 104 via separate DC-DC converters (not shown). You can also.

The second DC-DC converter 112 includes a microcomputer therein, and the first DC-DC converter 104 performs control according to the voltage fluctuation of the DC bus 114 caused by the maximum power point tracking control of the DC generator 101A. The step-up / step-down ratio is adjusted by the control of the unit 107, and the output of the DC bus 114 is adjusted. In addition, although illustration is abbreviate | omitted, the electrical storage part 111 can also be connected to AC bus-bar 113 via a bidirectional | two-way inverter.

The AC generator 102 and the DC generator 101B are both rotary generators, for example, and are powered by the power unit 119 to generate power. In particular, a dynamo or an alternator can be used for the DC generator 101B. Preferably, an alternator with less fluctuation in the amount of power generation due to a change in the rotational speed is used.

As the power unit 119, for example, an internal combustion engine such as an engine using fossil fuel, or an external combustion engine such as a steam turbine using nuclear power or biomass can be used.

The inverter 106 is a transformer-less system, and converts the DC output of the first DC-DC converter 104, the second DC-DC converter 112, and the DC generator 101B into AC by PWM (Pulse Width Modulation) control by a built-in microcomputer. . In addition, an operational amplifier, a current transformer, and an output transformer are built in. The output value is amplified by the operational amplifier, and AD conversion is performed by the built-in microcomputer, so that the voltage value and current value are respectively obtained from the voltage detector 115 and the current detector 116. Detection is performed. Further, the phase of the rotor is detected by a detector 117 composed of an encoder, a resolver, or the like, and is synchronized with the AC generator 102.

The switching unit 103 transmits the power of the power unit 119 to the AC generator 102 or the DC generator 101B. The switching of the power transmission destination by the switching unit 103 is performed by, for example, providing the switching unit 103, the AC generator 102, and the DC generator 101B each with a gear for switching power transmission, and changing the power transmission destination of the power unit 119 to AC. Switch to the generator 102 or the DC generator 101B for transmission. Further, the switching unit 103 is provided with a neutral position that does not transmit power to any gear of the AC generator 102 and the DC generator 101B, and the power supplied to the load 109 is supplied to the DC generator 101A and the power storage unit. When the output of 111 is covered, the DC generator 101B and the AC generator 102 can be stopped.

Since this state is a power supply system using the output of the DC generator 101A using the renewable energy and the power storage unit 111, the usage ratio of the DC generator using the renewable energy can be improved, and high efficiency is achieved. Power system. That is, it can be said that the switching unit 103 has a function of switching operation or stop of the AC generator 102 and the DC generator (101A, 101B).

The control unit 107 controls the operations of the first DC-DC converter 104, the second DC-DC converter 112, the inverter 106, and the switching unit 103, for example, using RS485 serial communication.

The relay 108 is connected to the operating state of the DC generator 101A and the AC generator 102 to open and close between the output of the inverter 106 and the load 109.

The relay 120 is opened and closed so that the output fluctuation due to the rotation speed change when the DC generator 101B is stopped or operated does not affect the interconnection operation with the inverter 106. Similarly, the relay 121 is opened and closed so that the output fluctuation due to the change in the rotation speed when the AC generator 102 is stopped or operated does not affect the interconnection operation with the inverter 106. More specifically, when stopping the generator connected to each relay, first, the generator is stopped after opening the relay, and when the generator is operated, the output of each generator is stable. Open the relay until it is closed and close it after stabilization. By doing in this way, the output fluctuation | variation by the change of the rotation speed of each generator is prevented from affecting the interconnection | linkage operation | movement with the inverter 106. FIG.

Next, the basic operation of the hybrid power supply system 100A will be described with reference to FIG. When there is no output of the DC generator 101A at night or the like and only the output of the AC generator 102 is supplied to the load, the outputs of the first DC-DC converter 104 and the inverter 106 are stopped, but the first DC-DC converter 104 sequentially monitors the input voltage from the DC generator 101A and transmits it to the control unit 107 every preset time. When the input voltage from DC generator 101A reaches a preset voltage, control unit 107 issues an operation instruction to first DC-DC converter 104, second DC-DC converter 112, and inverter 106, and an output operation is started. The first DC-DC converter 104, the second DC-DC converter 112, and the inverter 106 measure at least the input current in addition to the input voltage, and transmit these to the control unit 107. The output procedure from the inverter 106 is as follows.
(1) A reference sine wave having the same frequency as that of the AC generator 102 is created by a microcomputer built in the inverter 106.
(2) The relay 108 is turned off, and the inverter 106 acquires the voltage phase of the AC generator 102 from the detector 117 connected to the AC generator 102.
(3) The voltage phase of the reference sine wave is adjusted to match the voltage phase of the AC generator 102.
(4) When the phases in step (3) match, the relay 108 is turned on, and the inverter 106 and the output of the AC generator 102 are connected.
(5) The current value flowing out to the AC generator 102 is detected by the detector 118.
(6) Current feedback control of the inverter 106 is performed so that the value of the current flowing out to the AC generator 102 is maximized and the phase matches the reference sine wave.

Next, the details of the control operation of the hybrid power supply system 100A by the control unit 107 will be described. The control unit 107 controls the inverter 106, the detector 116 of the inverter 106 detects the output current of the AC generator 102, and the detector 115 detects the voltage of the AC bus 113.

Also, the output current of the inverter 106 is controlled so as to maximize the current from the DC generator 101A within the allowable range of the voltage of the AC bus 113. In this operation, even if the output voltage of the inverter 106 is increased, current feedback control is performed with a desired gain until the output current does not increase. That is, control is performed so that the output of the DC generator 101A is maximized in the system.

On the other hand, when the output current decreases while the output of the inverter 106 is maintained at a constant voltage, it is determined that the output of the first DC generator 101A has decreased due to weather conditions or the like, and the output current Control is performed to reduce the output voltage of the inverter 106 to a level at which does not decrease.

Also, switching control of the switching unit 103 is performed according to the output of the DC generator 101A using renewable energy. Here, when the power consumption L of the load 109, the output power α of the AC generator 102, and the output power β of the inverter 106, if the power supply-demand balance is maintained in a relationship of L = α + β, the output power of the inverter 106 β varies relatively depending on the output of the DC generator 101A.

Therefore, a threshold Th is set for the output P1 of the DC generator 101A using renewable energy, and switching control is performed based on the threshold Th, and the DC generator 101B or the AC generator 102 is operated. This threshold Th is, for example, the ratio of the output P1 of the DC generator 101A to the power consumption L of the load 109. The switching control based on the threshold value Th is performed as shown in Table 1 below, for example.

Table 1 shows the operating state of the DC generator 101B or the AC generator 102 when the switching unit 103 is switched by the value of the output P1 of the DC generator 101A with respect to the threshold Th. When the output P1 of the DC generator 101A falls below the threshold Th, the switching unit 103 is switched to the AC generator 102 side according to an instruction from the control unit 107, and the power of the power unit 119 is transmitted to the AC generator 102. The operation according to the basic operation described above is performed.

Further, when the output P1 of the DC generator 101A using renewable energy exceeds the threshold Th, the switching unit 103 is switched to the DC generator 101B side according to the instruction of the control unit 107, and the power of the power unit 119 is changed. It is transmitted to the DC generator 101B. As a result, the AC generator 102 stops, the output of the DC generator 101B is connected in parallel with the output of the second DC-DC converter 112 and the output of the first DC-DC converter 104, and the total output thereof is input to the inverter 106. Is done. At this time, the power supply to the load 109 is only the output power of the inverter 106.

When the output of the DC generator 101A using renewable energy maintains 90% or more of the rating, the switching unit 103 is in the neutral position, that is, the power of the power unit 119 is the DC generator 101B, AC power generation Both generators are stopped by controlling not to transmit to any of the machines 102 so that the input to the inverter 106 becomes the total output of the first DC-DC converter 104 and the second DC-DC converter 112. good.

The switching operation of the switching unit 103 and the change of the output control are performed by the control unit 107 instructing the AC generator 102 and the switching unit 103 by comparing the power consumption of the load 109 and the output power of the DC generator 101A. Is done. Note that if the weather condition changes irregularly in time units, the output of the DC generator 101A may increase or decrease frequently. In such a case, if the switching of the switching unit 103 is switched too fast, the power transmission control to the AC generator 102 or the DC generator 101B and the synchronization with the inverter 106 become difficult. Is preferably set in advance so that switching is performed when a state requiring switching continues for a certain period of time or longer, for example, 30 minutes or longer.

The hybrid type power supply system 100A including the independent AC generator 102 and the DC generator 101B independent of the commercial power system and the DC generator 101A using renewable energy such as a solar battery has been described. As an example, it is possible to connect the output of the inverter 106 to a commercial power system (not shown) without using the AC generator 102 in the configuration of FIG. In this case, the switching unit 103 is unnecessary, and the power unit 119 and the DC generator 101B are directly connected.

According to the fourth embodiment, when the output of the DC generator 101A using renewable energy is sufficiently high and the power supply to the load 109 is only the output of the inverter 106, the DC generator is parallel to the DC generator 101A. The output of 101B is input to the inverter 106. Therefore, since the input power to the inverter 106 does not include power loss due to conversion from AC to DC, the power generation efficiency of the system is improved.

As described above, the power supply system 100A according to the present embodiment includes a DC input unit to which an output from the DC generator (101A, 101B) is input, an AC input unit to which an output from the AC generator 102 is input, An inverter 106 that converts direct current input to a direct current input unit into alternating current, a switching unit 103 that switches between operation and stop of the alternating current generator 102 and the direct current generator (101A, 101B), and alternating current input to the alternating current input unit And an output unit that selectively outputs the alternating current output from the inverter 106.

With this configuration, by performing switching control of the switching unit 103 in accordance with the output of the DC generator (101A, 101B), the output of the DC generator can be used to the maximum extent. That is, according to the power supply system 100A according to the present embodiment, the use ratio of renewable energy can be improved.

[Embodiment 5]
Another embodiment of the present invention will be described with reference to FIG. FIG. 9 is a block diagram of a hybrid power supply system 200. In FIG. 9, the same parts as those of the fourth embodiment are indicated by the same reference numerals.

In the fourth embodiment, the output of the DC generator 101B may be smaller than that of the AC generator 102. That is, the power required for the DC generator 101B may be smaller than the power required for the AC generator 102.

Therefore, in this embodiment, a power unit 202 and a switching unit 201 that are smaller than the power unit 119 are used. The DC generator 101B is operated by the power unit 202, the AC generator 102 is operated by the power unit 119, and the switching unit 201 switches between the power unit 119 and the power unit 202. The switching unit 201 is a switch that operates the power unit 119 or the power unit 202 in response to an instruction from the control unit 107.

In addition, although illustration is abbreviate | omitted, the motive power part 119 and the motive power part 202 may be provided with one fuel system, and may be provided separately. In addition, the operation description related to power generation is the same as that of the fourth embodiment, and a detailed description thereof is omitted.

According to the fifth embodiment, since the DC generator 101B and the AC generator 102 are operated by separate power units, the scale of each power unit can be optimized. Thereby, since the fuel consumption with respect to the electric power generation amount of the power part 202 can be suppressed especially, the electric power generation efficiency of a system improves more.

[Embodiment 6]
Still another embodiment of the present invention will be described with reference to FIG. FIG. 10 is a block diagram of a hybrid power supply system 300. In FIG. 10, the same parts as those in the fourth or fifth embodiment are denoted by the same reference numerals.

The output control range of the rotary generator described in the fourth and fifth embodiments is generally operated within a range of 30 to 100% of the rating in order to suppress a decrease in power generation efficiency and a decrease in operation reliability. . However, in the above-described embodiment, depending on the value of the output P1 of the DC generator 101A using renewable energy, the operation of the AC generator 102 is set to a rated value of 30 in order to balance supply and demand with the power consumption of the load 109. It is necessary to deliberately suppress the output of the DC generator 101A, or it is not preferable in terms of power generation efficiency and operation reliability.

Therefore, in order to avoid such a situation, the present embodiment includes a switching unit 301,

power units

302 and 304, and

AC generators

303 and 305 that are different from those in the fourth or fifth embodiment. In addition, a relay 306 and

detectors

307 and 308 are provided between the AC generator 305 and the AC bus 113. The operations of the

detectors

307 and 308 are the same as those of the

detectors

117 and 118, and a description thereof will be omitted.

The

power units

302 and 304 and the

AC generators

303 and 305 are obtained by dividing the power unit 119 and the AC generator 102 in the fifth embodiment into two parts, and when the required rated output of the AC generator 102 is 1, 1 Two

AC generators

303 and 305 with a rated output are prepared, and the rating is satisfied with this total output. The same applies to the

power units

302 and 304. The required rated output of the AC generator is equal to the rated output of the DC generator 101A using renewable energy, and the rated output of the DC generator 101A is Pmax. The rated output is 1 / 2Pmax.

In the present embodiment, the DC generator 101B and the

AC generators

303 and 305 are individually operated according to the output status of the DC generator 101A. That is, a plurality of threshold values Th are set for the output P1 of the DC generator 101A using renewable energy, and the switching unit 301 is switched based on the plurality of threshold values Th to change the DC generator 101B and the

AC generators

303 and 305. Is operated. The threshold value Th is, for example, the ratio of the output P1 of the DC generator 101A to the power consumption L of the load 109. Switching control based on the plurality of threshold values Th is performed, for example, as shown in Table 2 below.

Table 2 shows the DC generator 101B or the AC generator 303 when the switching unit 301 is switched according to the value of the output P1 of the DC generator 101A with respect to Th1 as the first threshold and Th2 as the second threshold. 305 shows the operation state. The magnitude relationship between the thresholds Th1 and Th2 is Th1 <Th2.

In Table 2, when the output P1 of the DC generator 101A maintains a relationship of P1 <Th1 with respect to the threshold Th1, the switching unit 301 is switched to the

power units

302 and 304 according to an instruction from the control unit 107. The

AC generators

303 and 305 are operated by the power of the

power units

302 and 304. When the output P1 of the DC generator 101A changes from a value lower than the threshold Th1 to a value higher than the threshold Th1, the relay 306 is opened and the AC generator 305 is disconnected from the AC bus 113, and then the AC generator Until the output of 303 rises to the specified output, the insufficient power may be output from the power storage unit 111 and supplemented. Moreover, the AC generator 305 stops the operation promptly after disconnection.

When the output P1 of the DC generator 101A using renewable energy is in the relationship of Th1 <P1 <Th2 with respect to the threshold value Th1 and the threshold value Th2, the switching unit 301 is instructed by the instruction of the control unit 107. It is switched to 302 and only the AC generator 303 is operated.

Further, when the output P1 of the DC generator 101A changes from a value lower than the threshold Th2 to a value higher than the threshold Th2, the AC is maintained with the relay 121 closed until the DC generator 101B is activated and the output is stabilized. After the operation of the generator 303 is continued and the switching unit 301 is switched to the power unit 202 after the output of the DC generator 101B is stabilized, the AC generator 303 may be stopped and the relay 121 may be disconnected.

Further, when the output P1 of the DC generator 101A is Th2 <P1 with respect to the threshold Th2, the switching unit 301 is switched to the power unit 202 according to an instruction from the control unit 107, and the DC generator 101B is operated.

When the output of the DC generator 101A is maintained at 90% or more of the rated value, the switching unit 301 is controlled to stop all of the

power units

202, 302, and 304 by controlling the switching unit 301. The generator 101B and the

AC generators

303 and 305 may be stopped, and the input to the inverter 106 may be the total output of the first DC-DC converter 104 and the second DC-DC converter 112.

The operation of each generator will be described more specifically. For example, when the power consumption of the load 109 is 10 kW, the rated output of the DC generator 101A using renewable energy is 10 kW, and the ratings of the

AC generators

303 and 305 are Each output is 5 kW, and the rated output of the DC generator 101B is 2.5 kW. Then, assuming that the range in which the inverter 106 can be connected to the AC generator satisfies, for example, an inverter output of 7.5 kW + an AC generator output of 2.5 kW, Th1 is set to 50% and Th2 is set to 75%. In this case, when P1 <50%, the

AC generators

303 and 305 are each operated at a rated 5 kW.

When 50% <P1 <75%, the AC generator 303 operates in the range of 5 kW to 2.5 kW. That is, the AC generator 303 is operated in a range of rated to 50% of rated. Further, the DC generator 101B operates in the range of 2.5 kW to 1 kW while 75% <P1 <90%. That is, the DC generator 101B is operated within a range of 40% of the rating to the rating.

According to the sixth embodiment, since the number of AC generators that supply power to the load 109 is plural, when the power supply to the load 109 is performed by the output operation of the inverter 106 and the AC generator connected operation, According to the power generation state of the DC generator 101A, the output power of the AC generator with respect to the power consumption of the load 109, in other words, the number of operations of the AC generator can be controlled.

Therefore, since the fuel consumption in the power section can be finely controlled, the power generation efficiency of the system is further improved. Also, since the output control of each generator can be operated in the range of 40 to 100%, a power supply system with high operation reliability can be constructed without suppressing the output of the DC generator 101A using renewable energy. .

[Embodiment 7]
Embodiment 7 as a modification of Embodiment 6 will be described with reference to FIG. FIG. 11 is a block diagram of a hybrid power supply system 400. In FIG. 11, the same parts as those of the sixth embodiment are denoted by the same reference numerals. The main part of this embodiment is different from the sixth embodiment in that a power unit 404 and a third DC generator 405 are provided instead of the power unit 304 and the AC generator 305.

In the sixth embodiment, the operation explanation in the case where 75% output of the load power consumption is satisfied as the interconnectable operation range of the inverter 106 with the AC generator is illustrated. However, the interconnectable output of the inverter is not limited to this. It is also conceivable that the ratio is lower than the above ratio.

As described above, the number of AC generators and DC generators may be appropriately changed depending on the balance between the inverter output and the AC generator output. For example, in this embodiment, when the rated output of the DC generator 101A using renewable energy is Pmax, the rated output of the AC generator 303 is Pmax, the DC generator 101B, and the (third) DC generator 405. A description will be given assuming that each rated output is 1/4 Pmax. In addition, the switching control of the operation state of each generator in the present embodiment is performed, for example, as shown in Table 3 below. Note that the condition for the threshold Th is the same as in the sixth embodiment.

In Table 3, when the output P1 of the DC generator 101A using renewable energy maintains the relationship of P1 <Th1 with respect to the threshold Th1, the switching unit 301 is set to the power unit in accordance with an instruction from the control unit 107. Then, the AC generator 303 is operated by the power of the power unit 302.

Further, when the output P1 of the DC generator 101A has a relationship of Th1 <P1 <Th2 with respect to the threshold Th1 and the threshold Th2, the switching unit 301 is switched to the

power units

202 and 404 according to an instruction from the control unit 107. The DC generator 101B and the DC generator 405 are operated.

When the output P1 of the DC generator 101A is Th2 <P1 with respect to the threshold Th2, the switching unit 301 is switched to the power unit 202 according to an instruction from the control unit 107, and only the DC generator 101B is operated. .

power units

202, 302, 404, that is, the neutral position. And the input to the inverter 106 may be the total output of the first DC-DC converter 104 and the second DC-DC converter 112.

The operation of each generator will be described more specifically. For example, when the power consumption of the load 109 is 10 kW, the rated output of the DC generator 101A using renewable energy is 10 kW, and the rated output of the AC generator 303 is The rated output of 10 kW, DC generator 101B, and DC generator 405 is 2.5 kW each. Then, assuming that the range in which the inverter 106 can be connected to the AC generator satisfies, for example, the state of the inverter output 5 kW + the AC generator output 5 kW, when Th1 is set to 50% and Th2 is set to 75%, P1 < In the case of 50%, the AC generator 303 operates within the range from the rating to 50% of the rating.

When 50% <P1 <75%, the DC generator 101B and the DC generator 405 operate in a total range of 5 kW to 2.5 kW. That is, both the

DC generators

101B and 405 operate within a range of rated to 50% of rated. Further, the DC generator 101B operates in the range of 2.5 kW to 1 kW while 75% <P1 <90%. That is, the DC generator 101B is operated within a range of 40% of the rating to the rating.

In the above description, the inverter 106 has been described in the case where the range in which the inverter 106 can be connected to the AC generator satisfies the state of the inverter output 5 kW + the AC generator output 5 kW. Except when the interconnectable operation range of the inverter 106 satisfies an output of about 75% of the load power consumption (for example, only 60% output of the load power consumption is satisfied as the interconnectable operation range of the inverter 106), That is, it can be suitably applied in the range of 50% or more and less than 75% of load power consumption.

Further, although detailed description is omitted, the interconnection operation possible range of the inverter 106 is less than 50% of the load power consumption, that is, the interconnection power is generated unless the power generation amount of the AC generator 303 always exceeds the output of the inverter 106. If this is not possible, the number of DC generators may be set to 3 or more in consideration of the general output control range of the rotary generator described above (rated to 30% of the rating is a guideline). Even in this case, the AC generator is one with a rated output of Pmax.

Further, an AC-DC converter (not shown) is interposed between the output of the AC generator 303 and the DC bus 114, so that the output P1 of the inverter 106 exceeds the interconnectable range, and Th1 (here, rated 50) %) Until the relay 121 is opened and the AC generator 303 is disconnected from the AC bus 113, the DC power output from the AC-DC converter (not shown) is supplied to the DC bus 114. Then, after P1> Th1, the AC generator 303 can be stopped and the DC generator 101B and the DC generator 405 can be operated. In this case, two DC generators are sufficient.

Also in this embodiment, since the output control of each generator can be operated in the range of 40 to 100%, the power supply with high operation reliability can be obtained without suppressing the output of the DC generator 101A using renewable energy. You can build a system.

[Embodiment 8]
Another embodiment of the present invention will be described with reference to FIGS. FIG. 12 is a block diagram of a hybrid power supply system 500. FIG. 13 is a partial detail view of FIG. In FIG. 12, the same parts as those in the fourth to seventh embodiments are denoted by the same reference numerals. This embodiment is different from the fourth to seventh embodiments in that a condensing heat collecting unit 501, a heat storage unit 503, and a power unit 502 are provided.

In FIG. 12, the concentrated heat collecting unit 501 and the heat storage unit 503 and the power unit 502 are added to the concentrated heat collecting unit 501 and the heat storage unit 503 in FIG. 8, and the power unit 119 is replaced with the power unit 502. Show. In addition to this, the

power units

119 and 202 of FIG. 9 may be replaced with the power unit 502, and the light collecting and collecting unit 501 and the heat storage unit 503 may be connected to the respective power units. Similarly, the

power units

202, 302, and 304 in FIG. 10 may be replaced with the power unit 502, and the light collecting and collecting unit 501 and the heat storage unit 503 may be connected to the respective power units.

First, the outline of the present embodiment will be described with reference to FIG. In the fourth to seventh embodiments, an internal combustion engine such as an engine is used as a power unit of a generator other than the DC generator 101A using renewable energy, but in this embodiment, heat energy is generated by the light collecting and collecting unit 501. Then, the power unit 502 is driven using this thermal energy as a power source.

Next, a more detailed configuration and operation will be described with reference to FIG. The condensing heat collecting unit 501 includes a concentrator 504 for concentrating sunlight in one place, and a heat converter 505 that receives the condensed sunlight and outputs it as thermal energy. Although the heat storage unit 503 is not particularly illustrated in detail, for example, a heat storage tank or the like can be used. For example, a steam turbine or the like can be used for the power unit 503.

Concentrator 504 is composed of a mirror, a reflector, a lens, etc., and concentrates sunlight in one place. In addition, it is more preferable that the light collector 504 can move the light collecting direction in accordance with the irradiation direction of sunlight. The solar energy collected by the condenser 504 is sent to the heat converter 505 and converted into heat, and the converted heat energy is sent to the power unit 502. In the power unit 502, the steam turbine is rotated by the thermal energy received from the heat converter 505, and the power of the DC generator 101B or the AC generator 102 is generated.

Further, the heat storage unit 503 stores the excess heat energy within the sunshine hours, and transmits the heat energy to the power unit 502 when the heat energy from the heat collection unit 501 cannot be obtained at night or the like. In the present embodiment, operations related to power generation other than those described above are the same as those in the fourth embodiment, and a detailed description thereof will be omitted.

According to the eighth embodiment, since the renewable energy is used in the operation of the DC generator 101B and the AC generator 102, the power generation efficiency by the renewable energy of the entire system is improved.

As described above, the means for solving the problem corresponding to claim 1 of the present invention includes a DC input unit to which an output from the DC generator 101 is input and an AC input to which an output from the AC generator 102 is input. , An AC-DC converter 105 that converts alternating current input to the alternating current input portion into direct current, an inverter 106 that converts direct current input to the direct current input portion and the output of the AC-DC converter 105 into alternating current, and an alternating current input A switching unit 103 that switches the connection destination of the unit to the output of the AC-DC converter 105 or the inverter 106, an output unit that selectively outputs the AC input to the AC input unit and the AC output from the inverter 106, The power supply system 100 is provided.

The effect corresponding to claim 1 is that the switching unit is configured so that the DC generator 101 and the AC generator 102 can be operated in parallel according to the output of the DC generator 101 and the output of the DC generator 101 can be used to the maximum. 103 switching control can be performed. That is, according to the power supply system 100 according to the present embodiment, the usage ratio of the DC generator 101 can be improved, and a highly efficient power supply system using renewable energy can be obtained.

Means for solving the problem corresponding to claim 2 includes a control unit 107 that controls switching of the switching unit 103, and the control unit 107 is configured such that the output ratio of the DC generator 101 is less than ½ of the load power consumption. When the output of the AC generator 102 is connected to the output of the inverter 106 and the output ratio of the DC generator 101 is 1/2 or more of the load power consumption, the output of the AC generator 102 is input to the input of the AC-DC converter 105. The switching unit 103 is switched to connect. The effect corresponding to claim 2 is that the load 109 is always supplied with an output that is the sum of the output of the DC generator 101 and the output of the AC generator 102, and the output of the DC generator 101 is the maximum in the system. Can be controlled to be Therefore, it is possible to obtain a power supply system that can maximize the use ratio of the renewable energy used for the DC generator 101.

Means for solving the problem corresponding to claim 3 includes a power factor adjustment unit 110 connected in parallel to the output of the AC generator 102. The effect corresponding to claim 3 can prevent the AC bus 113 from becoming overcurrent depending on the current consumption of the load.

Means for solving the problem corresponding to claim 4 includes: a DC input unit to which an output from the DC generator (101A, 101B) is input; an AC input unit to which an output from the AC generator 102 is input; An inverter 106 that converts direct current input to the input unit into alternating current, a switching unit 103 that switches between operation and stop of the alternating current generator 102 and the direct current generator (101A, 101B), and alternating current and inverter input to the alternating current input unit The power supply system 100 </ b> A includes an output unit that selectively outputs the alternating current output from 106. The effect corresponding to claim 4 is that the AC generator 102 and the DC generator (in order to maximize the use of the output of the DC generator (101A, 101B) according to the output of the DC generator (101A, 101B). 101A and 101B) can be switched between operation and stop. That is, according to the power supply system according to the present embodiment, the usage ratio of the DC generators (101A, 101B) can be improved, and a highly efficient power supply system using renewable energy can be obtained.

A means for solving the problem corresponding to claim 5 is that the DC generator includes a first and a second plurality of DC generators (101A, 101B). The effect corresponding to the fifth aspect is that a highly efficient hybrid power supply system in which a plurality of DC generators (101A, 101B) and an AC generator 102 are used.

The means for solving the problem corresponding to claim 6 is that the second DC generator 101A is composed of a solar power generation device. The effect corresponding to the sixth aspect can provide a highly efficient power supply system using renewable energy.

Means for solving the problem corresponding to claim 7 includes a control unit 107 that controls switching of the switching unit 103, and the control unit 107 sets a predetermined output of the second DC generator 101A for the power consumption of the load as a threshold value. The control unit 107 operates the AC generator 102 when the output of the second DC generator 101A falls below the threshold, and the first DC generator when the output exceeds the threshold. The control unit 103 is controlled to operate the machine 101B. The effect corresponding to the seventh aspect can improve the use ratio of the second DC generator 101A using renewable energy, and the AC generator 102 according to the output of the second DC generator 101A. Since the operation of the first DC generator 101B can be controlled, the power generation efficiency of the power supply system can be improved.

The means for solving the problem corresponding to claim 8 is that the two threshold values are set, and the control unit 107 operates the AC generator 102 when the output of the second DC generator 101A is lower than the first threshold value. The first DC generator 101B is operated when the second threshold value is larger than the first threshold value, exceeds the first threshold value, and falls below the second threshold value. This is to control the switching unit 103 to stop 101B and operate the AC generator 102. The effect corresponding to claim 8 is that the use ratio of the DC generator 101A using renewable energy can be improved, and the operation of the AC generator 102 and the first DC generator 101B can be controlled. The power generation efficiency of the system can be improved.

Means for solving the problem corresponding to claim 9 is that the two threshold values are set, and the control unit 107 operates the AC generator 102 when the output of the second DC generator 101A falls below the first threshold value. The first DC generator 101B is operated when the second threshold value is larger than the first threshold value, exceeds the first threshold value, and falls below the second threshold value. This is to control the switching unit 103 to operate 101B and stop the AC generator 102. The effect corresponding to claim 9 is that the use ratio of the DC generator 101A using renewable energy can be improved and the operation of the AC generator 102 can be finely controlled, so that the power generation efficiency of the power supply system is further improved. To do.

A means for solving the problem corresponding to claim 10 is to include a power storage unit 111 connected to the DC input unit. The effect corresponding to claim 10 is that power can be supplied to load 109 using DC power stored in power storage unit 111. Therefore, the usage ratio of the DC generators (101, 101A) can be improved, and a highly efficient power supply system using renewable energy can be obtained.

The embodiment disclosed this time is illustrative in all respects and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

The power supply system according to the present invention can be widely applied to all power supply systems including a system interconnected with a commercial power system.

100 power supply system 100A, 200-500 power supply system (hybrid type)
101, 101A DC generator (using renewable energy)
101B, 405 DC generator 102 AC generator 103 Switching unit (switch)
104 First DC-DC converter 105 AC-DC converter 106 Inverter 107 Control unit 108 Relay 109 Load 110 Power factor adjustment unit 111 Power storage unit 112 Second DC-DC converter 113 AC bus 114

DC bus

115, 116, 117, 118

Detector

119 , 202, 302, 304, 404, 502

Power unit

303, 305 AC generator 501 Condensing heat collecting unit 503 Heat accumulating unit 504 Concentrator 505 Heat converter PCL Load power consumption curve POL Output curve

Claims

A DC input unit to which the output from the DC generator is input;
An AC input unit to which the output from the AC generator is input;
An AC-DC converter that converts alternating current input to the alternating current input section into direct current;
An inverter that converts the direct current input to the direct current input unit and the output of the AC-DC converter into alternating current;
A switching unit for switching the connection destination of the AC input unit to the output of the AC-DC converter or the inverter;
An output unit that selectively outputs an alternating current input to the alternating current input unit and an alternating current output from the inverter.
A control unit that controls switching of the switching unit, and the control unit connects the output of the AC generator to the output of the inverter when the output ratio of the DC generator is less than ½ of load power consumption; And when the output ratio of the DC generator is 1/2 or more of load power consumption, the switching unit is switched so as to connect the output of the AC generator to the input of the AC-DC converter. The power supply system according to claim 1.
The power supply system according to claim 1, further comprising a power factor adjustment unit connected in parallel to the output of the AC generator.
A DC input unit to which the output from the DC generator is input;
An AC input unit to which the output from the AC generator is input;
An inverter that converts direct current input to the direct current input section into alternating current;
A switching unit for switching between operation and stop of the AC generator and the DC generator;
An output unit that selectively outputs an alternating current input to the alternating current input unit and an alternating current output from the inverter.
The power system according to claim 4, wherein the DC generator includes a first and a second plurality of DC generators.
The power supply system according to claim 5, wherein the second DC generator includes a solar power generation device.
A control unit that controls switching of the switching unit;
The control unit controls switching of the switching unit with a predetermined output of the second DC generator for power consumption of a load as a threshold,
The control unit operates the switching unit to operate the AC generator when an output of the second DC generator is lower than the threshold, and to operate the first DC generator when the output is higher than the threshold. It controls, The power supply system of Claim 6 characterized by the above-mentioned.
Two thresholds are set, and the control unit
Operating the alternator when the output of the second dc generator is below a first threshold;
Operating the first DC generator when a second threshold value greater than the first threshold value is exceeded;
8. The switching unit is controlled to stop the first DC generator and operate the AC generator when it exceeds the first threshold and falls below the second threshold. Power supply system as described in.
Two thresholds are set, and the control unit
Operating the alternator when the output of the second dc generator is below a first threshold;
Operating the first DC generator when a second threshold value greater than the first threshold value is exceeded;
8. The switching unit is controlled to operate the first DC generator and stop the AC generator when it exceeds the first threshold and falls below the second threshold. Power supply system as described in.
The power supply system according to claim 1, further comprising a power storage unit connected to the DC input unit.