Many people who are lucky enough to have a stream, stream, or even a small waterfall on their property, try to use it to generate electricity for their home, maybe a small workshop, and maybe even for sale to neighbors or Public network. Such a microhydrous system consists of a filtered water intake, a conduit, a small power plant (or even a box) containing a turbine and a generator, then a wiring from there to the house and some system that can regulate the speed of The turbine, Frequency and voltage. Normally, most people are able to figure out how to build everything except the speed / frequency governor. So shop for this item, and find that only a few small specialized companies in the world make them, and they are quite expensive, often becomes the most expensive item in the entire facility!
This article is intended to help such people by submitting a simple, low cost ELC that can be built from readily available components.
No ELC can cover every imaginable application. Some are more flexible than others. The ELC presented here has some flexibility, because it is controlled by software, but also has its limitations: It is designed for micro-hydro systems that use a single-phase synchronous alternator, working at 220-240V, 50Hz, in a power range of up to 25 Kilovatios, and using up to eight discharge loads, some or all of which may be "useful" loads, such as water boilers or ambient heaters. It can be built for 120V systems too, simply by using the proper power transformer, but will then be limited to half the power. It can also be set to 60Hz (or any other reasonable frequency) simply by setting a parameter in the software. In the form presented here, four of the outputs are used as a priority, with the other four having all the same (last) priority, with the energy that is distributed between them. This can be changed in the software as well, allowing any fully sequential priority combination to be totally "democratic" among all outputs.
This ELC uses a quartz crystal for reference, and in normal operation it blocks the speed of the generator / turbine to this quartz, resulting in a very precise frequency control. The software allows fine tuning of the frequency. However, if a heavy load change momentarily removes the lock system, the resulting lost or surplus cycles will not be recovered; Instead the system will try to recover the correct speed as quickly as possible. For this reason, in the presence of such transient loads it might not be stable enough to accurately run clocks that use the line frequency for reference, despite having quartz control. I do not have a clock dependent on the frequency of the line, so I have not tested how accurate this watch is with this ELC.
This ELC is designed for autonomous microhydrous systems. Can not be used with those connected to the network. And since it uses the frequency as input parameter, it is not very suitable for systems that force induction motors in the generator service. It may work, however, but if an induction motor is used instead of an actual generator, it is better to use an ELC that uses voltage as the input parameter. Real generators usually have their own built-in voltage regulators, so combine them with these ELC results in a system that has both regulated voltage and frequency, which is, in my humble opinion, by far the best way to go.
In addition, this ELC is not suitable for three-phase systems. The modification of three phases would require many more parts. And it does not have user load protection features against over or under voltage, or incorrect frequency, with only a basic ELC in place.