1. Field of the Invention
The present invention pertains to the art of power generation and power generation control systems and, more particularly, to power generation and power generation control systems that can be easily installed in a consumer household, a business or other end-user establishment.
2. Discussion of the Prior Art
In general, large centralized grids or networks are utilized to provide power to multitudes of consumer households, businesses and other end-users. Distribution of electric power from power plants to households and businesses is conducted over a network of utility lines connected to each residence and business. A standard consumer household, business or end user establishment has a consumer circuit that includes an end user circuit breaker that controls power to numerous individual circuits, each with its own circuit breaker. Generally, three-phase power is split into two sets of circuit breakers, one per phase, or two separate power phase groupings of circuit breakers. Should something happen to a specific circuit, that individual breaker opens and halts the flow of power to the device that failed. Should that individual circuit breaker fail, an upstream breaker opens and cuts the flow of power to all the circuits in the home business or end-user establishment.
Each of the large centralized grids is interconnected with various generating stations and substations that supply power to various loads and monitor utility lines for problems. Each of the large grids has a number of disadvantages, including reliance upon certain vital connections to power plants, as well as distribution difficulties during peak power demand periods. One solution to power supply problems is to install one or more power generating devices at a consumer's residence or business. In some instances, it is desirable to feed extra power generated by such devices back into the centralized grid, where the power may be shared. Such devices preferably include photovoltaics, wind power, hydroelectric generators and fuel cells, along with conventional and variable speed diesel engines, Stirling engines, gas turbines, micro-turbines and hybrid vehicles. Additionally, storage systems, such as batteries, super-conducting, flywheel, pumped water and capacitor types, may also provide power during outages. However, there are a number of problems associated with utilizing such power generation and storage devices. For example, the engineering, permitting and installation costs for a solar panel power generation and control system can be as much as the cost of the equipment being installed. Much of the installation cost results from the necessity of developing engineering documents, obtaining permits and hiring a qualified installer or electrician to connect the system to the centralized power grid based on particular engineering and building code specifications. Each end-user electrical system typically has the same components: a power generation system, a connection to the utility grid, safety systems and, preferably, an energy storage device. Although most end-user electrical systems are conceptually the same, each one requires a custom installation. Household appliances such as lamps, radios, stoves, etc. are also connected to the power grid but, unlike power generation systems, any consumer can buy and install such appliances without the need for developing engineering documents and hiring qualified installers such as an electrician.
Although there are many reasons why end-user power generation systems require a custom installation, one major reason they are not “plug and play” in the same way as appliances is that, if during a power grid outage, the end-user power generation system was to feed power back to the grid, it would become a danger to utility workers handling power lines. Household appliances such as lamps, radios, stoves, etc. present no such risk because they do not generate or provide power and, therefore, consumers may install them without developing engineering documents, obtaining permits or hiring an electrician. More specifically, when a utility line needs maintenance or repair, the lines are disconnected from the power grid and the utility workers assume that no power is being supplied to the line. If there is end-user power supplied to the line downstream of a disconnect point, that assumption could be fatal.
One such scenario is depicted in FIG. 1, showing a consumer household, business or other end-user establishment 20 including an end-user electric power generation system 25 in communication with a power grid 26 via a power line 28. A standard main circuit breaker 30 is provided between end-user electric power generation system 25 and power line 28, which connects to the main power grid 26 through switch 48. As depicted, households 40 are supplied with power 44 produced by a power plant 46. When an outage occurs, power 44 is blocked at switch 48 in order for a utility worker 50 to work on power line 28. However, end-user supplied power indicated by arrow 55 from electric power generation system 25 may continue to flow through power line 28, endangering the utility worker 50, and may even flow into an end-user establishment 60. This situation shows the importance of hiring a qualified electrician 61 when installing prior art electric power generation system 25.
One solution to such a problem is set forth in U.S. Patent Application Publication No. 2002/0036430 directed to a local area grid for distributed power. The '430 document notes that a utility can impress a “kill” signal on main power grid lines for power conditioning unit disconnect from a grid for servicing. This connection allows power utilities to monitor and track power flow. However, such a system requires expensive installation by trained professionals and relies on an external signal to be sent by the utility in order to provide a measure of safety for utility line workers.
Based on the above, there is a need for an end-user power generation and control system allowing for the transfer of power between an end-user installable power generator and a power line that eliminates the possible danger to utility workers and can be quickly and inexpensively installed.