Title of Invention

ELECTRIC POWER SYSTEM

Abstract

A method of electric power transmission within an electric power system comprising a plurality of power units interconnected via a power consumption/supply line each of said power units comprising at least one electric power generation equipment and/or at least one electric power storage equipment; at least one power consumption appliance; and a power control equipment, said method comprising the steps of judging whether the electric power insufficiency occurs or whether the electric power excess occurs in the power unit comprising said power control equipment, said judging being done by the power control equipment; said power control equipment receiving the electric power from other power units comprising the electric power generation equipment and/or the electric power storage equipment in case the electric power insufficiency occurs in said power unit; and supplying power from the power control equipment to other power units in case the electric power excess occurs in said power unit.

Full Text

ELECTRIC POWER SYSTEM BACKGROUND OF THE INVENTION Field of the Invention The present invention is of an electric power system consisting of a plurality of units to supply and demand electric power (herein after referred to as "POWER UNIT(s)") interconnectedby control equipment to supply and demand electric power (herein after referred to as "POWER CONTROL EQUIPMENT") . Description of the Related Art As shown in FIG. 8, the conventional electric power system is basically a "radial system" with a large-scale power plant 91 located in the top and demanders 92 in the foot. In FIG. 8, in order to ensure a plurality of transmission systems, a "loop system" is partially introduced. This kind of the electric power system is provided as a single system in a wider area (for example, several tens of thousand km2) by a large scale (several tens of GW). On the other hand, recently, a system interconnection type dispersed power generation system by solar photovoltaic generation and fuel cell electric power generation (see for example Japanese Patent Application Laid Open (JP-A) no. 6-327146) attracts the attention. The system interconnection type dispersed power generation system is provided in general at the end area or a local area close to the end of the conventional radial electric power system with the premise of the interconnection with the electric power system. According to the conventional electric power system structure shown in FIG. 8, since the electricpower is transmitted by a large amount for a longdistance, the loss is large. Moreover, according to the electric power generation derived from such renewable energy as solar energy, wind power energy and so on, since the renewable energy is present unevenly, it is difficult to establish a large scale power plant utilizing the energy. Summary of the Invention An object of the present invention is to provide an electric power systemnot depend on the conventional electricpower system, provided with a plurality of POWER UNITS interconnected by POWER CONTROL EQUIPMENT. An electric power system according to the present invention comprises: at least one appliance selected from among one or a plurality of electric power generation equipment, one or a plurality of electric power storage equipment ; and one or a plurality of electric power consumption appliances, and a plurality of POWER UNITS comprising POWER CONTROL EQUIPMENT interconnected, wherein the POWER CONTROL EQUIPMENT judge whether or not the electricpower insufficiency occurs or whether or not the electric power excess occurs in the POWER UNITS comprising the POWER CONTROL EQUIPMENT so as to receive the electric power from the other POWER UNITS comprising the electric power generation equipment and/or the electric power storage equipment in case the electric power insufficiency-occurs in the POWER UNIT, or to provide the electric power to the other POWER UNITS in case the electric power excess occurs in the POWER UNIT. Moreover, an electric power system according to the present invention comprises: at least one equipment selected from among one or a plurality of electric power generation equipment, one or a plurality of electric power storage equipment, and one or a plurality of electric power consumption appliances; and a plurality of POWER UNITS comprising POWER CONTROL EQUIPMENT interconnected, wherein the plurality of the POWER UNITS are classified into a plurality of groups, the POWER CONTROL EQUIPMENT belonging to each group judge whether or not the electric power insufficiency occurs or whether or not the electric power excess occurs in the group so as to receive the electric power from the other groups to which the POWER UNITS belong comprising the electric power generation equipment and/or the electric power storage equipment in case the electric power insufficiency occurs in the group, or to provide the electric power to the other groups in case the electric power excess occurs in the group. According to the present invention, it is the electric power system basically with the POWER UNITS independent with each other without the conventional electric power system. That is, the POWER UNITS demand or supply the electric power among the other POWER UNITS in case the electric power insufficiency or the electric power excess occurs, and thereby the system as a whole can be provided independently. According to the present invention, the plurality of the POWER UNITS can be connected with a branched electric power transmission line, a linked electric power transmission line, a radial electric power transmission line, a mesh like electric power transmission line, or an electric power transmission line as a combination thereof. Moreover, according to the present invention, the POWER CONTROL EQUIPMENT can exchange the electric power demand and supply information via data communication network with respect to the POWER CONTROL EQUIPMENT of the other POWER UNITS. According to the present invention, a plurality of the POWER UNITS can be interconnected by DC in order to sufficiently utilize the advantage of the DC transmission and distribution. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram showing an embodiment of an electric power system of the present invention; FIG. 2 is an explanatory diagram of demand and supply of the AC electric power by POWER CONTROL EQUIPMENT of a POWER UNIT with the other POWER UNITS in the electric power system of the present invention; FIG. 3 is an explanatory diagram of demand and supply of the DC electric power by POWER CONTROL EQUIPMENT of a POWER UNIT with the other POWER UNITS in the electric power system of the present invention; FIG. 4 is an explanatory diagram showing the case of supplying the DC electric power to the load via an interior line of the POWER UNIT in the electric power system of the present invention; FIG. 5 is an explanatory diagram showing the state with the POWER UNITS classified in the electric power system of the present invention; FIG. 6A is an explanatory diagram of the case with the POWER UNITS connected in a branched form, FIG. 6B is an explanatory diagram of the case with the POWER UNITS connected in a star like form, FIG. 6C is an explanatory diagram of the case with the POWER UNITS connected in a mesh like form; FIG. 7 is a diagram showing an example of a POWER UNIT connected with a plurality of the other POWER UNITS via different electric power transmission lines; and FIG. 8 is an explanatory diagram showing the conventional electric power system. BEST MODE FOR CARRYING OUT THE INVENTION In the electric power system 1 of FIG. 1, only the Power Units 11 to 15 are shown out of a plurality of POWER UNITS. The POWER UNITS 11 to 15 are interconnected via an electric power transmission line W. The POWER UNIT 11 comprises electric power generation equipment 101, electric power storage equipment 102, a plurality of loads (electric appliances) 103, and POWER CONTROL EQUIPMENT 104. The plurality of the electric appliances 103 are shown by Al, A2, . . . , An. Moreover, in FIG. 1, the other POWER UNITS 12, 13, 14 and the other POWER UNITS not shown comprise electric power generation equipment, electric power storage equipment, a plurality of loads (electric appliances) and POWER CONTROL EQUIPMENT like the POWER UNIT 11, with the appliances connected with a branched interior line. According to the present invention, the POWER UNITS are linked separately. That is, the POWER UNITS are basically independent with each other and they receive the electric power from the other POWER UNITS in case of occurring the electric power insufficiency and supply the electric power to the other POWER UNITS in case of occurring the electric power excess. The POWER UNIT 11 is for example, a common house, an apartment house, a small, middle or large scale factory, a low, middle or high-rise building, or the like. Furthermore, a group of a plurality of the common houses, the apartment houses, or the like can be counted as the POWER UNIT 11 of the present invention. Typically, the electric power generation equipment 101 have a DC power source such as a solar photovoltaic generator, a fuel cell and so on. The wind electric power generation may beusedas the electric power generation equipment 101. Although the wind electric power generation equipment has an AC power source in general, it can be used as the DC power source with the output AC/DC conversion. Moreover, the electric power storage equipment 102 has a DC power source. The load 103 is for example a DC appliance or an AC appliance such as a light, an air conditioner, a refrigerator, an electromagnetic cooker, and a rice cooker. In case of occurring the electric power excess at the POWER UNIT 11, for example, the electric power use amount of the load 103 is reduced and the electric power storage equipment 102 gets to full charge or close to full charge, the POWER CONTROL EQUIPMENT 104 supplies the electric power generated by the electric power generation equipment 101 to the other POWER UNITS connected with the electric power transmission line W or the POWER UNIT 15. Moreover, in case of occurring the electric power insufficiency at the POWER UNIT 11, the Power Control Equipment 104 , for example, the electric power use amount of the load 103 is increased drastically, the POWER CONTROL EQUIPMENT 104 receives the electric power from the POWER CONTROL EQUIPMENT of the other POWER UNITS pl2, 13, 14, with the electric power excess occurred, connected with the electric power transmission line W, or via the POWER CONTROL EQUIPMENT 153 of the POWER UNIT 15 tobe described later so as to drive the load 103 or charge the electric power in the electric power storage equipment 102. ThePOWERUNIT 15 comprises the electric power generation equipment 151, the electric power storage equipment 152 and the POWER CONTROL EQUIPMENT 153 . The POWER UNIT may comprise either the electric power generation equipment or the electric power storage equipment. The electric power generation equipment 151 is typically the middle or small size equipment for thermal power, water power or wind power, or the like, and the electric power storage equipment 152 is typically a secondary battery. The POWER UNIT 15 can supply the electric power via the POWER CONTROL EQUIPMENT 153 to the POWER UNIT 11 (or the other POWER UNITS 12 to 14, or the like) as mentioned above. Moreover, on the contrary, the POWER UNIT 15 can receive the electric power from the POWER UNIT 11 (or the other POWER UNITS 12 to 14, or the like). The electric power supplied from the POWER UNIT 15 to the POWER UNIT 11, or the like is the electric power generated by the electric power generation equipment 151 or the electric power charged in the electric power storage equipment 152. The electric power supplied from the POWER UNIT 11 or the like to the POWER UNIT 15 is charged in the electric power storage equipment 152. According to the electric power system shown in FIG. 1, in case of demand or supply of the electric power with the other POWER UNITS 12 to 15, the POWER CONTROL EQUIPMENT 104 exchanges the information with the POWER CONTROL EQUIPMENT of the other Power Units so as to determine the demand and supply conditions, or the like. According to the electric power system shown in FIG. 1, the electric power demand and supply among the POWER UNITS can be carried out by either current of AC or DC. In either case, it may be provided as a local electric power system, or as a large scale electric power system as a combination of the local electric power systems. According to the electric power system shown in FIG. 1, although it is not shown, the POWER UNIT comprising only the load can be connected with the electric power transmission line W. Moreover, according to the electric power system of FIG. 1, the electric power demand and supply can be evened according to the interconnection of a large number of various POWER UNITS. In case the cost is increased if the electric power storage equipment 102 of the POWER UNIT. 11 has a large capacity, it is possible to use an electric power storage equipment 102 having a small capacity (or without providing the having the electric power storage equipment 102) and use the electric power supplied from the other POWER UNITS for dealing with the load. In this case, it is preferable that the POWER UNITS having different time slot electric power consumption patterns (for example, houses and offices) are present in the electric power system 1. Moreover, it is preferable that the POWER UNIT 15 having different electricpower generation forms (for example, the solar photovoltaic generation equipment and the wind electric power generation equipment) are present. FIG. 2 is an explanatory diagram showing an electric power system with demand and supply of the AC electric power by POWER CONTROL EQUIPMENT of POWER UNIT with the other POWER UNITS. The POWER UNITS 11a, 12a, 13a, 14a and 15a in FIG. 2 correspond to the POWER UNITS 11, 12, 13, 14 and 15 in FIG. 1. The POWER CONTROL EQUIPMENT 51 of the POWER UNIT 11a in FIG. 2 comprises control equipment 511 and a two way AC/DC converter 512. The control equipment of the POWER UNITS can carry out the data communication with each other by a communication line CL so that the demand and supply information can be exchanged at the time of the electric power demand and supply. Moreover, the POWER CONTROL EQUIPMENT 61 of the POWER UNIT 15a comprises control equipment 611, and a two-way AC/AC or DC/AC converter 612. In the case of receiving and supplying of the AC electric power among the POWER UNITS, the voltage, the electric current, the frequency and the phase should be matched therebetween. The matching operation is executed by the POWER CONTROL EQUIPMENT 51, 61. Although it is not shown in FIG. 2, the POWER CONTROL EQUIPMENT 51, 61 may further have a current limiting device, an integrating wattmeter, or the like. FIG. 3 is an explanatory diagram showing an electric power system with demand and supply of the DC electric power by POWER CONTROL EQUIPMENT of POWER UNIT with the other POWER UNITS. The POWER UNITS lib, 12b, 13b, 14b and 15b in FIG. 3 correspond to the POWER UNITS 11, 12, 13, 14 and 15 in FIG. 1. The POWER CONTROL EQUIPMENT 71 of the POWER UNIT 15b in FIG. 3 comprises control equipment 711 and a two way DC/DC converter 712. The control equipment of the POWER UNITS can carry out the data communication with each other by a communication line CL so that the demand and supply information can be exchanged at the time of the electric power demand and supply. Moreover, the POWER CONTROL EQUIPMENT 81 of the POWER UNIT lib comprises a control equipment 811 and a two way DC/DC or DC/AC converter 812. In case of demand and supply of the DC electric power among the POWER UNITS, the voltage and the electric current are matched therebetween. Although it is not shown in FIG. 3, the POWER CONTROL EQUIPMENT 71, 81 may further comprise a current limiting device, an integrating wattmeter, or the like. FIG. 4 is an explanatory diagram of the case of supplying the DC electric power to the load via an interior line of the POWER UNIT. According to the POWER UNIT lie of FIG. 4, the electric power generation equipment, the electric power storage equipment and a plurality of loads in the POWER UNIT 11 shown in FIG. 1 are shown specifically. The POWER CONTROL EQUIPMENT 71 of FIG. 4 is same as the POWER CONTROL EQUIPMENT 71 of FIG. 3. According to the POWER UNIT lie, the electric power generation equipment is a solar photovoltaic generation equipment 701, the electric power storage equipment is a battery 702, and a plurality of the loads are a DC load 7031 and an AC load 7032. Here, the two way DC/DC converter 712 demands and supplies the electric power with the battery 702, the solar photovoltaic generation equipment 701, and the DC load 7031 as well as it demands and supplies the electric power with the AC load 7032 via the DC/AC converter 706. The electric power generated by the solar photovoltaic generation equipment 701 is supplied for example to the battery 702 and the DC load 7031 via the two way DC/DC converter 712, or it is supplied to the AC load 7032 via the DC/AC converter 706. The POWER CONTROL EQUIPMENT 71 has a function of controlling the battery 702 charging operation and a function of compensating the stable output to the interior line L side. The electric power from the POWER CONTROL EQUIPMENT 71 is supplied to the DC load 7031 via the interior line L and the DC plug socket 7051, and the electric power from the POWER CONTROL EQUIPMENT 71 is supplied to the AC load 7032 via the interior line L, the DC/AC converter 706 and the AC plug socket 7052. Although the DC plug socket and the AC plug socket are shown each by only one in FIG. 4, it is possible to provide them each by a plurality, connected with the DC loads and the AC loads, respectively. According to the electric power system of FIG. 1, a group of the POWER UNITS of an optional number may be dealt with as a POWER UNIT. As shown in FIG. 5, the POWER UNIT groups Gil, G12, . . . represent a group at the time (for example, about several tens to several tens of thousands of the POWER UNITS). In FIG. 5, the POWER UNIT groups Gil, G12, ... are interconnected with each other via the POWER CONTROL EQUIPMENT SI. Moreover, the upper class of the POWER UNIT groups Gil, G12, ... is shown by G21, G22, and the further upper class thereof is shown by G311, G32, G 33 .... Although it is not shown here, a further upper class of G31, G32, G33, ... is provided. For example, the POWER UNIT groups Gil, G12 are of a "town" unit, G21, G22, . . . are of a "city" unit, and G31, G32, G33, . . . are of a "prefecture" unit.- In FIG. 5, although the POWER UNIT groups Gil, G12, . . . are interconnected with the POWER UNIT by POWER CONTROL EQUIPMENT SI, with the upper class and the lower class interconnected via the POWER CONTROL EQUIPMENT S2, S3, S4, .... In the above-mentioned embodiment, the case of the branched connection of the POWER UNITS as shown in FIG. 6Ahas been explained. The POWER UNITS may be connected by a star like form as shown in FIG. 6B, or they may be connected by a mesh like form as shown in FIG. 6C. Furthermore, they may be connected by a composite form thereof. FIG. 7 is a diagram showing an example of a POWER UNIT connected with a plurality of the other POWER UNITS via different Power Unit lines. In FIG. 7, the two way DC/DC converter 712 transfer the electric power among the POWER UNIT lines Wl, W2, W3 by the connection form of the POWER UNITS as shown in FIG. 6C so as to intermediate the electric power demand and supply among the other POWER UNITS. According to the present invention, an electric power system with a plurality of POWER UNITS interconnected by POWER CONTROL EQUIPMENT, independent of the conventional electric power system can be provided. WHAT IS CLAIMES IS: 1. An electric power system comprising: at least one equipment selected from among one or a plurality of electric power generation equipment, one or a plurality of electric power storage equipment, and one or a plurality of power consumption appliances; and a plurality of POWER UNITS comprising POWER CONTROL EQUIPMENT interconnected, wherein the POWER CONTROL EQUIPMENT judge whether or not the electric power insufficiency occurs or whether or not the electric power excess occurs in the POWER UNITS comprising the POWER CONTROL EQUIPMENT so as to receive the electric power from the other POWER UNITS comprising the electric power generation equipment and/or the electric storage equipment in case the electric power insufficiency occurs in the POWER UNIT, or to provide the electric power to the other POWER UNITS in case the electric power excess occurs in the POWER UNIT. 2. An electric power system comprising: at least one equipment selected from the group consisting of one or a plurality of electric power generation equipment, one or a plurality of electric power storage equipment, and one or a plurality of power consumption appliances; and a plurality of POWER UNITS comprising POWER CONTROL EQUIPMENT, wherein the plurality of the POWER UNITS are classified into a plurality of groups, the POWER CONTROL EQUIPMENT belonging to each group judge whether or not the electric power insufficiency occurs or whether or not the electric power excess occurs in the group so as to receive the electric power from the other groups to which the POWER UNITS belong comprising the electric power generation equipment and/or the electric power storage equipment in case the electric power insufficiency occurs in the group, or to provide the electric power to the other groups in case the electric power excess occurs in the group. 3. The electric power system according to claim 1 or 2, wherein the plurality of the POWER UNITS are connected with a branched electric power transmission line, a linked electric power transmission line, a radial electric power transmission line, a mesh like electric power transmission line, or an electric power transmission line as a combination thereof. 4. The electric power system according to any of claims 1 to 3, wherein the POWER CONTROL EQUIPMENT exchange the electric power demand and supply information via data communication network with respect to the POWER CONTROL EQUIPMENT of the other POWER UNITS. 5. The electric power system according to any of claims 1 to 4, wherein a plurality of the POWER UNITS are interconnected by DC.

Documents:

2245-chenp-2005 abstract-duplicate.pdf

2245-CHENP-2005 ABSTRACT.pdf

2245-CHENP-2005 CLAIMS GRANTED.pdf

2245-chenp-2005 claims-duplicate.pdf

2245-CHENP-2005 CORRESPONDENCE OTHERS.pdf

2245-CHENP-2005 CORRESPONDENCE PO.pdf

2245-chenp-2005 description (complete)-duplicate.pdf

2245-chenp-2005 drawings-duplicate.pdf

2245-CHENP-2005 FORM 1.pdf

2245-CHENP-2005 FORM 3.pdf

2245-CHENP-2005 PCT.pdf

2245-CHENP-2005 PETITIONS.pdf

2245-CHENP-2005 POWER OF ATTORNEY.pdf

2245-chenp-2005-abstract.pdf

2245-chenp-2005-claims.pdf

2245-chenp-2005-correspondnece-others.pdf

2245-chenp-2005-correspondnece-po.pdf

2245-chenp-2005-description(complete).pdf

2245-chenp-2005-drawings.pdf

2245-chenp-2005-form 1.pdf

2245-chenp-2005-form 3.pdf

2245-chenp-2005-form 5.pdf

2245-chenp-2005-other-documents.pdf

2245-chenp-2005-pct.pdf