JP2000287390A - Energy storing and discharging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an energy storing and discharging device which stores electric power at the night time when an electric rate is low and discharges the stored electric power at the day time when the rate is high in an electric light contract based on time-slot rates, and which can be used with a photovoltaic power generation. SOLUTION: During the time when a time-slot discriminating unit 13 discriminates to be the night slot, energy is stored by an energy storing and discharging means made up of a double-way frequency converter 2, a power- generating electric motor 3 and a flywheel 4. During the time when the discriminating unit 13 discriminates to be the day slot, the stored energy is discharged. When the means is used with a photovoltaic power generation and if the rate of change of the electric power generated by a photovoltaic power generating means exceeds a given value, the storage and discharge of energy is controlled by the energy storing and discharging means in such a way as to suppress the rate of change.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an energy storage and discharge device for storing and releasing system power.

[0002]

2. Description of the Related Art FIG.
1 shows a configuration of a conventional energy storage / discharge device disclosed in Japanese Patent Application Laid-Open Publication No. H10-209,878. In the figure, 51 is a power system, 5
2 is a bidirectional frequency converter connected to the electric power system 51, 53 is a generator motor connected to the bidirectional frequency converter 52, 54 is a flywheel connected to the generator motor 53, and 55 is electric power. A power detector connected to the system 51, a load 57 connected to the power detector 55, and a controller 56 for receiving a signal from the power detector 55 and controlling the bidirectional frequency converter 52.

Next, the operation will be described. Power detector 5
Numeral 5 is for detecting and outputting the difference between the predetermined power and the power currently consumed by the load 57. Now, it is assumed that the load 57 is consuming only less than a predetermined amount of power.
At this time, the controller 56 receives the output signal of the power detector 55, controls the bidirectional frequency converter 52 to supply power equal to or lower than the power corresponding to the output signal to the generator motor 53, and Increase the rotation speed of the flywheel 54. With this operation, energy is stored in the flywheel 54. On the other hand, when the load 11 is consuming more power than the predetermined power, the controller 56 receives the output signal of the power detector 55 and outputs the power corresponding to the output signal to the bidirectional frequency converter 52. Under control, it is taken out from the generator motor 53 and supplied to the load 57. At this time, the rotation speeds of the generator motor 53 and the flywheel 54 are controlled to decrease. With this operation, energy is released from the flywheel 54.

[0004]

Since the conventional flywheel energy storage / discharge device is configured as described above, when the load 57 consumes less than a predetermined amount of electric energy, energy is supplied to the flywheel 54. Storing and storing energy by the flywheel 54 in connection with the hourly light rate electricity bill only by operating to release energy from the flywheel 54 when consuming more than predetermined electrical energy. , Is not configured to emit. Therefore, there is a problem that inexpensive nighttime electric power is not effectively used in the time-of-day light contract, and it is not economical.

In the conventional flywheel energy storage / discharge device, no consideration is given to storing and discharging energy by the flywheel 54 in relation to the power generated by the photovoltaic power generation system. Therefore, it does not have the function of suppressing fluctuations in the system power supply voltage due to sudden changes in the power generated by the solar power generation system. Therefore, there is a problem that the function of storing and discharging energy by the flywheel 54 is not sufficiently utilized.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and accumulates energy in the nighttime period when the electricity charge of the hourly light contract is low, thereby improving the power consumption during the daytime. It aims to obtain an economical energy storage and discharge device by releasing it during the time period. It is another object of the present invention to provide an energy storage / discharge device that enables a combined use of a photovoltaic power generation system and can suppress voltage fluctuations in a power system in that case.

[0007]

SUMMARY OF THE INVENTION The present invention provides an energy storage and discharge means for receiving power from a power system to store energy, and releasing the stored energy as power, a first time zone and a second time zone. Time zone discriminating means for discriminating between the time zone and the time zone discriminating means, based on a signal from the time zone discriminating means, the energy storage / discharge means stores energy in a first time zone and energy in a second time zone. And a control means for controlling to release the energy.

[0008] The energy storage and discharge means includes a flywheel.

[0009] The energy storage and discharge means includes a storage battery.

[0010] A solar power generation means for receiving and generating solar light and, when the time change rate of the power generated by the solar power generation means exceeds a predetermined value, the time change rate is suppressed to a predetermined value or less. Filter means for filtering the current flowing out of the photovoltaic power generation means, and the power obtained by multiplying the voltage obtained by multiplying the difference between the current flowing out of the photovoltaic power generation means and the current filtered by the filter means by voltage. When the energy storage and release means performs either storage or release, the control means controls the current filtered by the filter means to flow backward to the power system.

The energy release control means includes means for detecting a load current to prevent reverse power flow, and control for controlling the bidirectional frequency converter to release a current equal to the load current. .

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a block diagram showing a configuration of an energy storage and discharge device according to one embodiment of the present invention. The energy storage and discharge device of the present invention is installed at a power consumer who has a time-based light contract with a power supplier. FIG. 2 is an electrical connection diagram. In these figures, 1 is a power system,
10 is a bidirectional frequency converter connected to the hourly light contract watt hour meter 10 connected to the power system 1, 2 is a bidirectional frequency converter connected to the hourly light contract watthour meter 10, and 3 is this bidirectional frequency converter. The generator motor 4 connected to the device 2 is a flywheel which is an energy storage and discharge means attached to the generator motor 3. 11 is a load connected to the hourly lamp contract watt hour meter 10 in parallel with the bidirectional frequency converter 2, 12 is a current detector for detecting the current flowing through the load 11, and 13 is A time zone discriminator for discriminating whether the time zone of the time-based light contract is a night time zone (first time zone) or a daytime time zone (second time zone);
Reference numeral 4 denotes a voltage detector that detects the voltage of the power system 1, and 15 denotes a rotation speed detector that detects the rotation speed of the generator motor 3. 1
Reference numeral 6 denotes a controller that controls the bidirectional frequency converter 2 by obtaining information from the current detector 12, the time zone discriminator 13, the voltage detector 14, and the rotation speed detector 15.

Next, the operation will be described. In the time-of-day light contract, the night time zone (for example, from 11 pm to 7
) And daytime hours (for example, from 7:00 am to 11:00 pm), for example, the nighttime energy charge is one third or less of the daytime energy charge.
The hourly electric lamp contract watt hour meter 10 has a watt hour meter 10a which operates at night time and a watt hour meter 10b which operates at day time.
And only one operates according to the time zone. If it is a night time zone, the electric power supplied from the power system 1 to the hourly light contract watt hour meter 10 is:
The power meter 10a is operated, passes through the current detector 12, and reaches the load 11 and the bidirectional frequency converter 2. The power that has reached the load 11 is consumed by the load 11. On the other hand, the power reaching the bidirectional frequency converter 2 is supplied to the generator motor 3 after the frequency and the magnitude of the voltage are converted by the bidirectional frequency converter 2, and the generator motor 3 operates as a motor. Then, the number of rotations of the generator motor 3 and the flywheel 4 attached thereto is increased. This series of operations is performed by transferring the electric energy of the power system 1 to the flywheel 4.
Is stored as mechanical energy. The controller 16 controls the bidirectional frequency converter 2 based on the rotation speed information output from the rotation speed detector 15 to increase the rotation speed of the generator motor 3 over an appropriate time during the night time, and When it reaches, it operates to keep the rotation speed.

On the other hand, during the daytime, the mechanical energy stored in the flywheel 4 is converted into a bidirectional frequency converter so that the generator motor 3 rotated by the flywheel 4 operates as a generator. 2 to controller 1
6, the electric power is converted into electric energy by the generator motor 3, and converted into electric power having the same frequency and the same voltage as the electric power of the electric power system 1 by the bidirectional frequency converter 2. There are two places where this power can flow.

One is a power system 1 (the flow of power through the power system is called a reverse power flow), and the power flowing in the reverse power direction means that the power consumer sells the power to the power supplier. It is assumed that the hourly light contract watt hour meter 10 can measure the reverse power flow, and the power flowing in the reverse flow is controlled as follows. The controller 16 controls the bidirectional frequency converter 2 based on the rotation speed information output from the rotation speed detector 15, reduces the rotation speed of the generator motor 3 over a suitable time of daytime, and sets the rotation speed to a predetermined value. When the number of revolutions has been reached, the generator motor 3 is operated so as not to flow an electric current and to be in a free state.

Another load capable of flowing the power converted by the bidirectional frequency converter 2 so as to have the same frequency and the same voltage as the power of the power system 1 is the load 11.
In this case, the bidirectional frequency converter 2 is connected to the current detector 12
Controller 1 so that a current equal to the current flowing through
6, the bidirectional frequency converter 2 is controlled. However, when the mechanical energy of the flywheel 4 runs out, the control of the bidirectional frequency converter 2 is stopped.

Here, discharging power to the power grid of the power supplier is not permitted under the current regulations of the Electricity Business Law. However, in the energy storage and discharge device of the present invention, the power is stored during the night time. If the energy released during the daytime is controlled to be within the power consumed by the power consumer, the energy storage and emission device of the present invention that stores inexpensive nighttime power under the current regulations is used. be able to. When this regulation is abolished, it may be released to the electric power system of the electric power supplier.

As described above, in the energy storage and discharge device of the present invention shown in FIG. 1, a power consumer who has a time-based light contract can store nighttime power at a low power rate, and Since the fee is consumed during the expensive daytime, it is possible to save the amount of power charge shown by the following formula per day.

[0019]

(Equation 1)

Further, since the nighttime power is surplus, it is stored by the power consumer and used in the daytime when the power is not surplus, so that the load can be leveled, the peak value of the power generation can be suppressed, and the power generation by the power supplier can be suppressed. The effect is obtained that the equipment can be used effectively and the capacity of the power generation equipment can be reduced.

Embodiment 2 FIG. FIG. 3 shows a configuration of an energy storage / discharge device according to another embodiment of the present invention. 3, a power system 1, a bidirectional frequency converter 2, a generator motor 3, a flywheel 4, and a load 1
1, current detector 12, time zone discriminator 13, voltage detector 1
4 and the rotation speed detector 15 are the same as those in the above-described first embodiment, and a description thereof will be omitted. Reference numeral 17 denotes a solar power generation system, which includes a bidirectional frequency converter 2 and a load 1.
1 and connected in parallel. Solar power generation system 17
Is a DC / AC converter 17a connected to the electric power system 1, a solar cell 17c for receiving and generating sunlight, and a DC voltage connected to the solar cell 17c, as shown in FIG. And a DC / DC converter 17b for converting the level. When installing the photovoltaic power generation system 17, it is necessary to install two watthour meters, one for power purchase and one for power sale. Reference numeral 18 denotes a power purchase hourly electricity contract watt hour meter connected to the power system 1. Reference numeral 19 denotes a time-of-day light contract watt hour meter connected to the power-purchasing time-of-day light contract watt hour meter 18. The photovoltaic power generation system 17, the bidirectional frequency converter 2, and the load 11 are connected to the electric power contract watt hour meter 19 for each power selling time zone. Reference numeral 20 denotes a current detector for detecting a current flowing through the photovoltaic power generation system 17, and 21 denotes information obtained from the current detectors 12 and 20, the time zone discriminator 13, the voltage detector 14, and the rotation speed detector 15. And a controller for controlling the bidirectional frequency converter 2. In the present embodiment, the controller 21 includes:
A low-pass filter 21a is provided, and operates so as to release or store energy in the flywheel 4 so as to suppress the time change rate of the power generated by the photovoltaic power generation system 17 when it exceeds a predetermined value. Details will be described later.

Next, the operation will be described. As described above, the energy storage and discharge device in the present embodiment
A solar power generation system 1 is added to the configuration of the first embodiment.
7. A power contract meter for each time slot for power sale 19 and a current detector 20 are added. The energy storage and discharge device according to the present embodiment performs two functions, one of which is the same as the function described in the first embodiment of FIG. Electrical energy is converted into mechanical energy and stored, and conversely, mechanical energy is converted into electrical energy during the daytime and released to the power system 1 and the load 11.

Another function is due to the addition of the solar power generation system 17. The photovoltaic system 17 generates power by receiving solar radiation from the sun, and the generated power flows through the electric power grid 1 through the power contract hourly electricity meter 19 for power sale. In this way, a power consumer who has installed the solar power generation system 17 can sell power to a power supplier. Incidentally, the amount of solar radiation received by the solar cells in the photovoltaic power generation system 17 changes from moment to moment, and depending on the weather, the amount of power generation changes very quickly, causing fluctuations in the voltage of the power system 1. This is a serious problem for the power supplier, and is considered to hinder the mass diffusion of the photovoltaic power generation system 17. Therefore, the solar power generation system 17
Also, stable power generation or power generation according to the power supply and demand of the entire power system 1 is required. Therefore, when the power generation amount of the photovoltaic power generation system 17 changes suddenly, the controller 21 controls the bidirectional frequency conversion device 2 so as to suppress the sudden change.

When the power generation amount of the photovoltaic power generation system 17 changes suddenly, the amount of increase in the current to be passed by the bidirectional frequency converter 2 (the flow direction is assumed to be positive) is actually The current is flowing out of it
The difference between the (effective value) and the filtered current is bar formed by passing it through the low-pass filter 21a (this current changes slowly and the time rate of change is suppressed) (is-is bar). . The controller 21 controls the bidirectional frequency converter 2 to flow this current. From the current value (is-is bar), the energy stored in the night time zone according to the first operation similar to that shown in the first embodiment is converted into mechanical energy in the daytime period into electrical energy, and the power system 1 and When the value obtained by subtracting the current released to the load 11 is positive, the power obtained by multiplying the voltage by the voltage is stored in the flywheel 4 as mechanical energy, and when the value is negative, the power is released in reverse. As shown in FIG. 3, when the photovoltaic power generation system is added to the energy storage / discharge device, the current generated by the photovoltaic power generation system 17 and flowing into the electric power system 1 is the is bar. This has the effect of suppressing the effect of the fluctuation of the generated power on the voltage fluctuation of the power system 1.

The method of determining the response speed of the low-pass filter introducing the current is bar is, for example, about 3 seconds is sufficient for the power supplier to respond to a sudden load change in thermal power generation or the like. For example, a first-order lag filter having a time constant of several seconds to several tens of seconds may be used so as to respond to the sudden change of. Also, if the response speed is several tens of seconds or more, of course, the voltage of the power system 1 can further suppress the fluctuation of the power generation amount of the photovoltaic power generation system 17 due to sudden change.
If the response speed is too long, it is necessary to increase the energy storage capacity of the flywheel 4 accordingly.

As described above, in this embodiment, the same effects as those of the first embodiment can be obtained, and it is also possible to use a photovoltaic power generation system together with an electric power consumer. When the rate of change of generated power exceeds a predetermined value, energy is released or stored so as to suppress the change, thereby suppressing fluctuations in the voltage of the power receiving end of the power consumer and, consequently, the voltage of the power supply system of the power supplier. Therefore, the function of storing and discharging energy by the flywheel 4 can be fully utilized.

Embodiment 3 Embodiments 1 and 2 above
Has shown an example in which a flywheel is used as an energy storage / release means for storing energy. In this embodiment, an example in which a storage battery is used instead of a flywheel will be described. FIG. 4 is a block diagram showing the configuration of the present embodiment. In FIG. 4, reference numeral 22 denotes a bidirectional power converter, which is a power system 1
It is connected to the. Reference numeral 23 denotes a storage battery connected to the bidirectional power converter 22, and reference numeral 24 denotes a storage battery 2.
3 is a voltage detector for detecting the voltage of FIG. A controller 25 controls the power converter 22 based on time zone information output by the time zone discriminator 13 and voltage information of the voltage detector 24. The other configuration is the same as that of the first embodiment, and the description is omitted here. In addition, FIG.
It is an electrical connection diagram of this Embodiment.

The present embodiment is configured as described above. As in the first embodiment, the bidirectional power converter 2 converts the electric energy of the electric power system 1 into the night time zone of the hourly light contract.
2, the electric energy of the storage battery 23 is discharged to the power system 1 and the load 11 during the daytime. Therefore, also in this embodiment, similarly to the first embodiment, the present apparatus is operated so as to store energy in the nighttime period when the power rate is low, and in the daytime time when the power rate is expensive. Since energy is released, it is possible to reduce the electricity rate of electricity consumers, and to use the excess nighttime electricity during the daytime, thereby performing load leveling. There is an effect that the power generation equipment can be used effectively.

Embodiment 4 FIG. 6 is a block diagram showing a configuration of the energy storage / discharge device according to Embodiment 4 of the present invention. As shown in FIG.
As in the third embodiment shown in FIG. 4, a storage battery 23 is used as an energy storage / discharge means, and a solar power generation system 17 is added as in the second embodiment shown in FIG. For other configurations, see the second embodiment.
And 3 are the same as those of FIG. Note that a low-pass filter 21a (not shown here, see FIG. 3) is provided in the controller 26, similarly to the controller 21 shown in the second embodiment of FIG. Controller 26
Is the operation of the controller 25 (FIG. 4) of the third embodiment,
Similarly to the controller 21 of the second embodiment, the current (is-is bar) is supplied by the low-pass filter 21a (see FIG. 3).
To the bidirectional power converter 22 so as to flow through the bidirectional power converter 22.

In this embodiment, as in the third embodiment, the energy is stored in the storage battery 23 during the night time when the energy charge is inexpensive, and the energy is stored during the daytime when the energy charge is expensive. 23, it is possible to reduce the electricity charge of the electricity demander, and to use the excess nighttime electricity during the daytime, thereby performing load leveling. This has the effect of making effective use of power generation equipment,
As in the second embodiment, when the rate of change in the power generated by the photovoltaic power generation system exceeds a predetermined value, the low-pass filter 21a is used to release or store energy so as to suppress the change. It is possible to suppress the fluctuation of the power supply voltage of the power system of the user and to make full use of the storage and discharge function of the storage battery 23.

Embodiment 5 In the second embodiment shown in FIG. 3, the bidirectional frequency converter 2 includes, as shown in FIG. 7, a bidirectional AC / DC converter 2a connected to the power supply side, and a generator motor 3 side. And a bidirectional DC / AC converter 2b connected to the DC / AC converter 2b.
As shown in FIG. 9, the photovoltaic power generation system 17 of FIG. 3 includes a DC / AC converter 17a connected to the power supply side.
And a DC / DC converter 17b connected to the solar cell 17c. In this case, since the bidirectional AC / DC converter 2a has the same function as the DC / AC converter 17a, it can be shared.

FIG. 7 shows a configuration of an energy storage / discharge device according to Embodiment 5 of the present invention having the configuration based on the above. In FIG. 7, a photovoltaic power generation system 27 is different from the photovoltaic power generation system 17 of FIG. 3 in that the photovoltaic power generation system 27 does not include the DC / AC converter 17a (accordingly, the photovoltaic power generation system 2).
7 is shown by a dashed line in FIG. 9). 28 is a current detector for detecting a direct current. Reference numeral 29 denotes a controller, which is different from the controller 21 of FIG. 3 in that a current detector 28 is used instead of the current detector 20 of FIG.
Is connected. Also in this embodiment, a low-pass filter 21a (see FIG. 3) is provided in the controller 29. FIG. 8 shows an electrical connection diagram of the energy storage and discharge device according to the fifth embodiment.

Also in this embodiment, the current id detected by the current detector 28 and flowing out of the photovoltaic power generation system 27 and the current id are applied to the low-pass filter 2.
1a (not shown here, see FIG. 3), the difference (id) from the filtered current id bar (the change in this current is slow and the rate of change over time is suppressed).
-Id bar) is passed by the bidirectional DC / AC converter 2b controlled by the controller 29 to suppress the influence of the fluctuation of the power generated by the photovoltaic power generation system 27 on the voltage fluctuation of the power system 1. Can be.

Since this embodiment is configured as described above, it has the same effect as that of the second embodiment shown in FIG. 3, and further has the bidirectional AC / DC of the bidirectional frequency converter 2. Since the converter 2a and the DC / AC converter 17a to be provided in the photovoltaic power generation system are shared, the configuration of the photovoltaic power generation system can be simplified and the number of parts can be reduced. Therefore, the effect that the manufacturing cost can be reduced can be obtained.

Embodiment 6 FIG. FIG. 10 shows a configuration of an energy storage / discharge device according to Embodiment 6 of the present invention. In Embodiment 4 of FIG. 6 described above,
The side of the bidirectional power converter 22 connected to the storage battery 23 is direct current. Therefore, as a photovoltaic power generation system, the DC / DC converter 1 shown in Embodiment 5 of FIG.
When using the photovoltaic power generation system 27 composed of 7b and the solar cell 17c, as shown in FIG.
It can be connected to the DC side of the bidirectional power converter 22. In FIG. 10, reference numeral 30 denotes a controller, which operates as follows.

The current detector 28 detects the current id flowing out of the photovoltaic power generation system 27 and passes it through a low-pass filter 21a (not shown here, see FIG. 3). The conversion of the current is slow and the rate of change in time is suppressed) and the output power of the photovoltaic power generation system multiplied by the output voltage of the photovoltaic power generation system.
The controller 30 controls the controller 30 so as to release the electric power obtained by adding the energy stored in the power system 1 and the load 11 during the daytime period. Thereby, the solar power generation system 27
This has the effect of suppressing the effect of the fluctuation of the generated power on the voltage fluctuation of the power system 1.

Also in this embodiment, the same effects as those of the fourth embodiment can be obtained, and the photovoltaic power generation system 27 without the DC / AC converter 17a is used as the photovoltaic power generation system. In addition, since the configuration of the photovoltaic power generation system can be simplified and the number of components can be reduced, the effect of reducing the manufacturing cost can be obtained.

[0038]

According to the present invention, there is provided an energy storage / release means for receiving power from a power system, storing energy, and releasing the stored energy as power.
Time zone determining means for determining the first time zone and the second time zone, and based on a signal from the time zone determining means, the energy storage and discharge means stores energy in the first time zone, In the second time zone, control means for controlling energy release is provided, so that, for example, energy is stored in the night time zone when the electricity rate is low, and the daytime hours when the energy rate is high. Energy can be released into the power supply zone, which can reduce the electricity bill of the electricity consumers.Also, the surplus electricity at night can be used during the day, so that it acts as a load leveler, There is an effect that the power generation equipment can be used effectively.

Also, since the energy storage and discharge means is provided with a flywheel, electric energy is stored as mechanical energy in the flywheel during the night time when the electricity charge is low, and stored during the daytime when the electricity charge is high. Since the converted mechanical energy is converted into electric energy and released, it is possible to always supply economical and stable power to power consumers.

Also, since the energy storage and discharge means includes a storage battery, the electric energy is stored in the storage battery during the night time when the electricity charge is inexpensive, and the energy stored during the daytime when the energy charge is high is released. Therefore, economical and stable power can always be supplied to the power consumer.

Further, a photovoltaic power generating means for receiving and generating solar light, and when the time rate of change of the power generated by the photovoltaic power generating means exceeds a predetermined value, the time rate of change is suppressed to a predetermined value or less. Filter means for filtering the current flowing out of the photovoltaic power generation means, and the power obtained by multiplying the voltage obtained by multiplying the difference between the current flowing out of the photovoltaic power generation means and the current filtered by the filter means by voltage. Since the energy storage and discharge means performs either storage or release, the control means controls the current filtered by the filter means to flow backward to the power system, so that the solar power generation means generates power. When the rate of change of power over time exceeds a predetermined value, the difference between the filtered current with reduced rate of change of time and the actually generated current Since the power multiplied by the voltage is stored or released in the energy storage and discharge means, and the filtered current flows backward to the power system, the fluctuation of the voltage at the receiving end of the power consumer and, consequently, the voltage of the power system of the power supplier. Can be suppressed.

The energy release control means includes means for detecting a load current to prevent reverse power flow, and control for controlling the bidirectional frequency converter to discharge a current equal to the load current. As a result, energy stored at nighttime and released during daytime can be controlled so that it is within the power consumed by power consumers, and can be used even under current regulations where reverse power flow is not recognized. It is possible to always supply economical and stable electric power to electric power consumers.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an energy storage / discharge device according to Embodiment 1 of the present invention.

FIG. 2 is an electrical connection diagram of the energy storage / discharge device of FIG. 1;

FIG. 3 is a block diagram showing a configuration of an energy storage / discharge device according to Embodiment 2 of the present invention.

FIG. 4 is a block diagram showing a configuration of an energy storage / discharge device according to Embodiment 3 of the present invention.

FIG. 5 is an electrical connection diagram of the energy storage / discharge device of FIG. 4;

FIG. 6 is a block diagram showing a configuration of an energy storage / discharge device according to Embodiment 4 of the present invention.

FIG. 7 is a block diagram showing a configuration of an energy storage / discharge device according to Embodiment 5 of the present invention.

FIG. 8 is an electrical connection diagram of the energy storage / discharge device of FIG. 7;

FIG. 9 is a block diagram showing a configuration of solar power generation systems 17 and 27.

FIG. 10 is a block diagram showing a configuration of an energy storage / discharge device according to Embodiment 6 of the present invention.

FIG. 11 is a block diagram showing a configuration of a conventional energy storage / discharge device.

[Explanation of symbols]

1 power system, 2 bidirectional frequency converter, 3 generator motor, 4 flywheel, 5 power detector, 6 controller, 10 hours electric light contract watt hour meter, 11 load,
2 Current detector, 13 time zone detector, 14 Voltage detector, 15 Rotational speed detector, 16 Controller, 17 Solar power system, 18 Electricity contract watt hour meter by power purchase time zone, 19 Power sales time Band-specific lighting contract watt-hour meter, 21 controller, 22 bidirectional power converter, 23 storage battery, 2
4 voltage detector, 25 controller, 27 photovoltaic power generation system, 28 current detector, 29 controller, 30 controller.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5F051 JA17 KA03 KA10 5G066 HA10 HB02 HB06 HB08 HB09 JA05 JA07 JB02 JB03

Claims (5)

[Claims] 1. An energy storage and discharge means for receiving energy from a power system to store energy and releasing the stored energy as power, and determining a first time zone and a second time zone. Time zone discriminating means for storing energy in the first time zone and releasing energy in the second time zone based on a signal from the time zone discriminating means. Energy storage and discharge device, comprising: control means for controlling the energy storage and discharge. 2. The energy storage and release device according to claim 1, wherein said energy storage and release means includes a flywheel. 3. The energy storage and release device according to claim 1, wherein said energy storage and release means includes a storage battery. 4. A photovoltaic power generation means for receiving and receiving sunlight and generating power when the time change rate of the power generated by the photovoltaic power generation means exceeds a predetermined value. Filter means for filtering the current flowing out of the photovoltaic power generation means so as to suppress the difference between the current flowing out of the photovoltaic power generation means and the current filtered by the filter means. The control means controls the electric power multiplied by the voltage so that the energy storage and discharge means stores or discharges the electric power, so that the current filtered by the filter means flows backward into the power system. The energy storage / discharge device according to any one of claims 1 to 3, characterized in that: 5. A means for detecting a load current in the energy release control means to prevent a reverse power flow, a control for controlling the bidirectional frequency converter to release a current equal to the load current, The energy storage / discharge device according to claim 1, further comprising: