JP2005051955A - Hybrid power generation system of solar energy generation and wind power generation - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that: in a conventional hybrid power generation system, (1) the rate of the utilization of the system cannot be sufficiently improved while surplus power is apparently utilized effectively by the use of a capacitor, but there has been some case that charged power has not been fully utilized because chargeable conditions are not easily satisfied, and (2) wind power generation has not been brought into successful utilization because there has not been provided a charging means adapted to the frequent rise and fall of power that is one of characteristics of the power generation efficiency of the wind power generation. <P>SOLUTION: Parallel generation is made possible by arranging a boosting and step-down machine improved in controllability at the output side of the wind power generation. The surplus power and power not satisfying a DC-AC converter input specification are accumulated by employing the capacitor, the generation output of the system is discharged when the output is less than a sales contract power value, and the efficiency of the system is improved as a whole. The system is made to be the one for constant monitor and control by arranging a control device for controlling a large number of apparatuses. Furthermore, an electric double-layer capacitor is employed in addition to a normal battery as a member of the capacitor, thus improving a storage property. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention relates to a method of supplying generated power of a hybrid power generation system including a solar power generation device, a wind power generation device, and a control device to internal consumption via an orthogonal converter and further connecting to an external power system.

Solar power generation and wind power generation are both power generation that uses clean natural energy, but are therefore affected by weather conditions, and are used in conjunction with an external commercial power system via an orthogonal converter. Is efficient. Various methods have been proposed to increase this efficiency, but few devices have been proposed to date for fine control in response to severe changes in weather conditions.
Japanese Patent Publication No. 2000-116007

FIG. 2 is a block diagram showing a circuit configuration of a hybrid power supply system including solar power generation and wind power generation according to the prior art, taking Japanese Patent Publication No. 2000-116007 as an example. In FIG. 2, the solar power generation device 21 and the wind power generation device 26 are AC-connected and connected to the external power system. However, when the wind power generation 26 is less than the predetermined output, the capacitor 30 is charged and the voltage V of the capacitor 30 is charged. _{When B} rises to a predetermined voltage and there is no output from the wind power generation 26, the on / off boxes 28 and 29 are closed and discharged to help lower the output. When the voltage V _{B of the} battery 30 drops to a predetermined voltage due to the discharge, the on / off box 28 is opened to stop the discharge, and the battery 30 is charged again by the wind power generator 26.

  According to the operation method described above, the utilization rate of the hybrid power generation system cannot be sufficiently improved. At first glance, it seems that surplus power can be used effectively by using a capacitor, but there are cases where the charged power is not utilized because the conditions under which discharge can be performed are difficult. Furthermore, since there is no charging means corresponding to the frequent rise and fall of electric power, which is a characteristic of the power generation efficiency of wind power generation, effective use of wind power generation is insufficient.

  The present invention eliminates the above-mentioned drawbacks of the prior art and improves the power generation efficiency of the hybrid power generation system.

  As a means for solving the above-described problems, in a hybrid power generation system that is connected to an external power system through an orthogonal converter, both the direct current output of the solar power generation apparatus and the direct current output of the wind power generation apparatus are turned on and off. A configuration in which a DC connection is made via a switch and a method for controlling the operation will be described below. (1) Parallel power generation: When there is an output of solar power generation during the day, a DC parallel connection is made to match the output voltage of the wind power generation with the output voltage of the solar power generation device and used as an orthogonal transformer input. (2) Solar power generation: When the output of wind power generation does not reach solar power generation, the DC parallel connection of wind power is cut off. (3) Single wind power generation: When there is no output of the solar power generation device such as at night, the solar power generation output terminal is shut off and only the output of the wind power generation is input to the orthogonal converter. (4) Not connected: A state in which neither solar power generation nor wind power generation reaches a predetermined voltage and normal output is not possible. (5) Charging: When (1) and (3) above, the output of wind power generation is high, and if there is enough power even if internal consumption is deducted, it is sent to the external power system and sold, but the sales power at this time is sold Since it is determined to be equal to or less than the contracted power value, the surplus power is charged in a battery in the system. (6) Weak charge: When the wind power generated during the non-connected state is not less than a value that can be charged while being weak, the state shifts to the charge state and charges the battery. (7) Discharge: When the amount of power stored in (6) reaches a predetermined level or more and the output from the system is lower than a predetermined output value, the state is changed to a discharge state. A hybrid power generation system of solar power generation and wind power generation, characterized by the direct current parallel connection of solar power generation and wind power generation as described above, and individual connection, disconnection, charging, discharging, and operation control thereof. It is to be.

With the system as described above, instead of selecting only one of the conventional outputs as an output, the capacitor is charged according to the conditions, and at the time of output from any of the three of the photovoltaic power generation, wind power generation, and the storage device Can be connected and extracted simultaneously in parallel, and maximum efficiency can be obtained as hybrid power generation.

  By providing a step-up / down booster with good controllability on the output side of wind power generation, effective parallel power generation has become possible. Moreover, by adopting a capacitor, it is possible to increase the efficiency of the entire system by storing less than standard power and surplus power that are rapidly rising and falling in a short time and discharging when there is no wind power output. In order to control a large number of devices, a control device is provided to provide a continuous monitoring and constant control system. In addition, electric double layer capacitors are used as members of the electric storage device to improve the electric storage characteristics. As a result, it has become possible to realize a highly efficient hybrid power generation system.

  A configuration and a control method of a hybrid power generation system using solar power generation and wind power generation according to the present invention will be described below using examples, but the present invention is not limited to these examples.

FIG. 1 is a block diagram showing a circuit configuration of power and signals of the power generation system of the present invention. In FIG. 1, 1 is a solar power generation device, 2 is an on / off box for switching whether or not the power output of the solar power generation device is sent to the orthogonal transformer, and 3 is a power output connected to the orthogonal transformer. It is a connection box. Reference numeral 4 in FIG. 1 denotes a quadrature converter, which is an apparatus that converts DC power to AC power and sets the voltage to a predetermined level. Reference numeral 5 denotes a control device, which takes in the voltage on the output side 5s2 of the buck-boost 7 connected to the output unit 5s1 of the photovoltaic power generator and the wind power generator 6, and controls the output voltage of the buck-boost 7 and the four on / off boxes 2 , 8, 10, and 14 are controlled. Control signal lines 5c2, 5c6 are wired to the boosters 7 and 13, and control signal lines 5c1, 5c3, 5c4, 5c7 are wired to the on / off boxes 2, 8, 10, 14. Further, in order to control the output side of the power generation system, the current value of the internal power consumption 17 is detected by 5s4, the output current of the orthogonal transformer 4 is detected by 5s6, and the distribution panel 16 is connected to the external power system. Is detected by 5s5. The power generation output of the wind power generator 6 is connected in parallel with the output of the photovoltaic power generation 1 to the orthogonal transformer 4 via the connection box 9 via the on / off box 8. The output of the step-up / step-down device 7 is also connected to the on / off box 10, and when the power is turned on via 5 c 4 according to the control command of the control device 5 depending on the state of the system, the capacitor 12 is charged with electric power. The charged electric power senses the charged state of the battery 12 by 5s3, and is connected to the orthogonal transformer 4 via the step-up / step-down voltage regulator 13, the on / off box 14, and the connection box 15 according to the level, and outputs electric power. The orthogonal transformer 4 has different values for the start voltage and the stop voltage for stable operation of the system, and has hysteresis characteristics at the on / off. That is, for the orthogonal transformer 4 to enter the operating state from the stopped state, the input voltage to the device needs to have a certain height S _IN , and when returning from the operating state to the stopped state, S _OUT is required. S _iN is Yes set to a number greater than S _OUT, thereby has a stable operation of the system to avoid hunting.

Next, a specific system control operation will be described with reference to FIG. FIG. 3 is a state transition diagram of control in this system, in which circles indicate states and arrows indicate transitions from state to state. Each circle from a to h indicates the operation state, that is, the connection state of the hybrid power generation system. a is a state in which solar power generation and wind power generation are both connected and operated in parallel connection. In the case of the single solar connection of b, only the solar power generation device operates and outputs power alone and connected to the orthogonal converter, and in the case of the single wind connection of c, only the wind power generation device operates and outputs the quadrature converter. The state where both the solar power generator and the wind power generator are not connected to the output side is a state where both the solar power generator and the wind power generator are not connected. Furthermore, e is a state in which the power storage device is charged when wind power is output in parallel connection and is output more than the sales contract power, and f is a state in which the power storage device is charged when the generated power is output in excess of the sales contract power in the single wind connection. is there. The system output is constantly monitored in relation to the sales contract power, and data for that is obtained from 5s4, 5s5, and 5s6. g is a so-called weak charge state where the power is charged at a weak level that cannot be connected to the main power side even when wind power generation output is present in a single solar connection state, and h is also in a non-connection state Wind power generation is at a weak level, and it is a so-called weak charge state in which the power is charged. When the entire system is operating normally, the present system performs control to always select any one of the eight states at any given moment.

  Next, transition between the states will be described. In this system, no condition other than a predetermined route is added to transition from an arbitrary state to another state. For example, when transitioning from the c state to the b state, 1) c⇒b, 2) c⇒a⇒b, 3) c⇒d⇒b, 4) c⇒a⇒d⇒b, 5) c⇒d There are five possible routes ⇒a⇒b, but this system can be controlled by any of these five routes depending on the situation.

The factors that cause the transition are mainly natural conditions of sunlight and wind power, and there are secondary control factors. The concept of the occurrence factor determination map is shown in FIG. FIG. 4 shows that a specific operating state is determined in a divided area on a plane of sunlight intensity × wind intensity, with the intensity of sunlight on the horizontal axis and the intensity of wind power on the vertical axis. S _IN on the horizontal axis in the graph of Figure 4 shows the intensity of the limits photovoltaic to function effectively, the region of possible solar power with the value of S _IN when the sunlight intensity is high state from a low state become. Conversely sunlight intensity is in the region of the impossible photovoltaic with S _OUT when going from a high state to a low state. W _L and W _U on the vertical axis indicate wind power generation effective wind speed and wind power generation dangerous wind speed, respectively. Wind power generation works effectively when the wind intensity is between W _L and W _U. These values of S _IN , S _OUT , W _L and W _U are specific to each system. In the areas 41 and 42 in FIG. 4, there is a risk that the windmill is damaged when the wind force is equal to or greater than W _U , so the windmill is stopped or a certain restriction is imposed on the rotation of the windmill. The state of the region 41 corresponds to the state d in FIG. In the region 42 in FIG. 4, solar power generation is performed, and the region 42 corresponds to the state b in FIG. If the rotation of the windmill is limited without stopping the windmill in the state of the areas 41 and 42, it is considered as the range of the areas 43 and 45. In the region 43 of FIG. 4, wind power generation is performed, and the region 43 corresponds to the state c of FIG.

In the region 44 of FIG. 4, when the power output of wind power generation is large and internal consumption is subtracted, the surplus power is sold to the external power system when there is surplus power, but the sold power exceeds the sales contract power value. In this case, the battery prepared in advance is charged, and this region corresponds to the state f in FIG. In region 45 in FIG. 4, parallel power generation is performed, and region 45 corresponds to state a in FIG. In the area 46 of FIG. 4, when the power generation output of the parallel power generation is large and the internal consumption is subtracted, the surplus power is sold to the external power system when there is surplus power, but the sold power exceeds the sales contract power value. The battery prepared in advance is charged, and this region corresponds to the state e in FIG.

In the region 47 in FIG. 4, neither sunlight nor wind power is generated, and this region corresponds to the state d in FIG. In the region 48 of FIG. 4, charging is performed when wind power generation at a level that can be charged is obtained although the voltage cannot be raised up to the level input to the orthogonal transformer, and this region corresponds to the weak charging h of FIG. In the region 49 of FIG. 4, solar power generation is performed, which corresponds to the state of FIG. In the region 50 of FIG. 4, charging is performed when wind power generation of a level that can be charged is obtained, but the voltage cannot be raised up to the level input to the orthogonal converter, and this region is solar single power generation + weak charging of FIG. corresponding to g.

FIG. 5 illustrates the discharge / non-discharge of the system. g is a non-discharge state and the system does not discharge. j is a state in which the stored electric power is discharged, and this state is controlled independently of each state in FIG. 3, but there is an exception. The exception is that the discharge state does not overlap with e and f in FIG. In other words, charging is performed so that the system output does not exceed the power sales contract power value. At that time, the system output has reached the limit value, and there is room for further discharge to increase the system output. There is no.

When the system is not in the above-described charged state of e and f, the capacity of the battery exceeds a certain value, and the system output does not satisfy the sales contract power value, the control device 5 gives an instruction to discharge. It is in a discharged state. The discharge is continued until the storage capacity of the storage battery becomes a predetermined value or less.

Next, the specific operation of the system according to the present invention will be described using an example. First, in this example, it is assumed that S _IN and S _OUT described above are 100 V and 60 V, respectively, and W _L and W _U are 100 V and 200 V, respectively, in terms of voltage. This is because the values of S _IN and S _{OUT depend on} the characteristics of the orthogonal transformer, and the start voltage is 100 V and the stop voltage is 60 V. The start is to switch from the open state to the switch, and the stop is to close the switch. It is to make the switch open from this state.

An example of the operating state of the hybrid power generation system will be described with an example from nighttime wind power generation to no power generation in the morning mist, daytime parallel operation, evening parallel operation to wind power single operation. Before dawn, there was a weak wind and it was operated by wind power alone operation c, and an output in the range of 70 to 90 V was output. During this time, the step-up / step-down device 7 was operated without being operated. Eventually, when the eastern sky gradually turned white, the windmill stopped and the output of the wind power generation became 0V, and both were disconnected d. About 30 minutes later, a wind in the opposite direction came out and the operation continued in the state of single wind c connection, and the output of 63-70V continued for a while, the surroundings became brighter, the sun angle gradually increased, and finally sunlight The power generation output 5s1 has reached 100V. At this time, the control device 5 first issues a voltage drop command to the lifting device 7 and drops the voltage until the sensor 5s2 detects 100V.

Next, the on / off box 2 is connected, and the system becomes parallel connection a to generate power in parallel. From this time point, the voltage booster 7 is activated by the control command of the control device 5, and the voltage value of the sensor 5s2 is controlled to match the voltage value of the sensor 5s1. The parallel power generation a continues for many hours during the day, but there are several interruptions and the solar single connection b is reached, but the procedure proceeds as follows. When the wind has weakened, the control device 5 issues a command to the step-up / step-down booster 7 through 5c2 to increase the pressure. However, if the level still does not reach the level of solar power generation, a control signal is output through 5c3 to cut the on / off box 8. Thereby, it will be in the state b of sunlight single connection. However, wind power generation is output even though it does not reach the level of solar power generation. In order to effectively use this power, the on / off box 10 is closed and a so-called weakly charged state g is reached in which the battery is charged. The power double layer capacitor of the present system performs effective charging corresponding to the fluctuation of wind power in the state of weak charging g. In the evening, wind power recovered again and parallel power generation continued. Eventually, the sun tilted to the west and the sunlight gradually weakened. When the output finally exceeded 60V, the control device 5 cut the on / off box 2 through 5c1 and switched to the wind power single connection c.

As described above using the example, the hybrid power generation system according to the present invention functions effectively and can generate power efficiently.

It is a circuit block diagram of a hybrid power generation system of solar power generation and wind power generation. It is a circuit block diagram of the conventional hybrid power generation system of solar power generation and wind power generation. It is a state transition diagram which shows the view which controls the connection of an electric circuit in a hybrid electric power generation system. It is a control area map which shows the division | segmentation method of the system control area with respect to the fluctuation | variation of natural environments in a hybrid electric power generation system. It is a state transition diagram which shows the view of discharge in a hybrid electric power generation system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photovoltaic generator 2 On / off switch 4 Orthogonal converter 5 Control apparatus 6 Wind power generator 7 Buck-boost 8 On / off switch 10 On / off switch 11 Current controller 12 Capacitor 13 Buck-boost 14 On / off switch 17 Internal power consumption

Claims (4)

In a hybrid power generation system in which the direct current output of a solar power generator that is connected to the system power supply via an orthogonal converter and the direct current output of the wind power generator are connected to each other via an on / off switch, a voltage is applied to the output side of the wind power generation. By installing a step-up / step-down regulator and adjusting it to the same level as the output voltage level of photovoltaic power generation, it is possible to add power capacity by connecting the photovoltaic power generator output and wind power generator output in parallel, making it orthogonal It is linked to internal consumption and external power system via a converter, and also controls corresponding to the operating state of only solar power generation or wind power generation in response to changes in the natural environment. Hybrid power generation system of solar power generation and wind power generation. Capacitor is provided at the output part of the wind power generation to charge the system so that the generated power does not exceed the sales contract power value and output to the external power system at the time of parallel power generation or wind power generation alone. The hybrid power generation system is improved in efficiency by charging the weak wind power generated when the voltage does not reach the photovoltaic power generation output voltage and discharging when the output of the entire hybrid power generation system is weak. The hybrid power generation system of solar power generation and wind power generation according to 1. Four operation states of parallel power generation, solar power generation, wind power generation, and non-connection are provided as operation control methods, and when the wind power generation is not connected, weak generated power of the wind power generation is stored in a battery in the system. Any of 8 operating states including 2 weakly charged states and 2 charged states where power is stored in the battery in the system so that the sales contract power value is not exceeded when selling to an external power system. The solar power generation and wind power generation according to claim 1 and 2, characterized by an operation control method for selecting the power supply, and an operation control method for performing discharge at any time within a range where the sales power is within contract power. And hybrid power generation system.   By using an electric double layer capacitor in combination with a normal battery as a configuration of the electric storage device described in claim 2, it is possible to provide charging with little loss even with a sawtooth-like electric power that rises and falls sharply. The hybrid power generation system of solar power generation and wind power generation according to claim 2.

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