APEMS Design Philosophy
A primary driver for this product family is to transfer the technology from the existing high cost “bespoke” type to a set of mass producible “commoditized” products. Another primary driver has been to incorporate all the features that our analysis has deemed essential to the power supply of the 21st century.
Several criteria have to be met to achieve this objective:
1. The specific mass energy density has to be increased by a factor of at least 10.This is a major challenge; but the weight of a converter has a major impact onmanufacturing/material cost and transport and installation costs2. The volumetric efficiency should to be improved. Metalwork and transport volumes,warehouse space and consumer space all cost money3. Surface Mount technology is the technology of choice for the manufacture of consumerelectronics. In essence the process is completely automated, parts are loaded into machinesin reels, Printed Circuit Boards are machine-fed into one end and finished and tested boardscome out the other. Inspection is automated and quality control is basically built into theprocess4. The number of components not mounted on the Printed Circuit Board (PCB) should bereduced to a minimum. Ideally there should be no “off board” components at all5. Low frequency transformers are the most expensive component of power converters andinverters. Not because they are expensive in themselves but because they must have aminimum amount of copper and iron to function and are, because of this, very heavy. Thisincreased mass means that the case must be large and heavy to support the transformers.The APEMS unit avoids transformer weight by substituting a high-voltage energy storagesystem and thus avoids the transformer altogether. Competing products must usetransformer/s that weigh about 30kg for 5 kW6. The present practice of the use of large external heat-sinks has to be abandoned. All present power inverters use heat-sinks that are designed to have the power chips secured to them off the PCB. In our design the power chips are surface mounted and the heat-sinks are also surface mounted - the details of this process will be subject to a patent application.
Functionality:
The entire objective of the project has been to reduce the costs of inverters to a level that will allow them to be sold as a consumer product. It should be understood that functionality is not really a manufactured cost issue, it is a software issue. All the functionality of the inverter resides in software. Providing the hardware “hooks” are in place the functionality can be expanded to meet changes in the market and new market demands.
The inverters are fully compatible with existing products and have functionality that exceeds anything on the market at present.
