AU2015100624A4 - Domestic Electrical Demand Limiting Controller - Google Patents

Abstract

Abstract: The Domestic Electrical Demand Limiting Controller [hereafter referred to as DEDLC], consists of monitoring modules, installed by an authorised person in a standard electrical switchboard, which are connected via a pre-wired umbilical cable to a control console mounted outside the switchboard but adjacent to it. The domestic electrical demand limiting controller (DEDLC) has 2 distinct applications. The first is 'off-the-grid' & 'battery supported' solar installations, commonly used in remote locations. In this scenario the 'life cycle', of the battery pack, being a significant maintenance cost, is maximised by the ability to charge and discharge under specific controlled conditions. Without the DEDLC the user has only manual control with little indication of the effectiveness of the actions taken. In practical applications manual control can reduce the 'life time' of a battery pack which is commonly rated for maximum efficiency at 1500 discharge cycles of 100% to 50% of charge. Common the result is less than half that. More significantly still, over discharge can cause irrecoverable loss of capacity. Nearly all Solar charge controllers have some inbuilt protection of the battery but this is merely over voltage and under voltage control. Very few offer over current in the battery load part of the circuit (Shunt required) and none can match the load to the efficiency specifications. The DEDLC is programmed with the specifications of the battery pack (configurable at the HIM), and using the feedback from the solar cells and the battery itself, it will control the load to within limits that most closely corresponds to the ideal for the battery being used. This is achieved by controlling the load while attempting to maintain a level of service designated by the owner. Obviously this balancing act will depend on the availability of input electrical energy, but that strategic balance is maximised by orders of magnitude with real time monitoring of the various components in the system. The second scenario and the one with the most numerous in potential candidate users, is 'on-the grid' or 'beside-the-grid' installations usually being associated with solar panels on the roof. The DEDLC includes some consumption reduction ability but is primarily used to move consumption to outside the high tariff, 'peak demand' periods. And where possible use surplus back-up power, if it exists, to bridge the shortfall. Because of regional differences the strategy (selectable at the HIM) will be either time dependant or the controller can use smart meter signals to achieve this effect. Applying systematic control to an unpredictable collection of inputs depends on the adjustable capacity of the system and the inbuilt intelligence of the model. This inbuilt intelligence is only partly installed, its critical set-points are learned (or more accurately described, is that they are adjusted automatically). The DEDLC uses its unique 'diversity model' to anticipate the high peak demand periods and consequently utilise solar capacity (an unpredictable variable), or other non grid sources, or as last option to use medium tariff grid supply to prime all auto starting devices and restricting access to 'elective use' outlets. Some major white goods manufactures are already including a smart component in their products, but the effect of such devices is problematic. Australian Standards have vaguely defined a device referred to as a DRED, but a uniform protocol is yet to emerge. The level of control possible by selecting the best response to a 'whole-of-house' usage situation under the DEDLC, is demonstrably superior to the option of relying on individual smart devices. They have a roll where a DEDLC is not being used. Planned by the manufacturers of products for the top of the market products are even more sophisticated smart control options which use the DRED, as specified by Australian standard AS4755. The DEDLC has hardware allowance for future advancements of the DRED standard although it can only be speculative. The software required to drive it will follow as the standard continues to develop and produce clearly defined protocol's. When they do, sooner or later get to this point, the DEDLC can use them and integrate their enhanced ability into the 'whole-of-house' concept; mutually improving the effectiveness of both. The DRED standard is too early in its development to allow meaningful programming but memory is set aside for it. When and if that standard is defined and consequently adopted by white goods manufacturers it will require a software only upgrade to use it in the DEDLC. In the standard domestic installation with no solar, the DEDLC still can play an important role. The demand limitation function is equally as relevant to any 'tariff connected' installation. It can be configured by the house owner to almost completely avoid the high tariff 'peak demand' period, but this can be too radical for many consumers and is prone to unacceptable inconvenience. The inconvenience of this is reduced by preconditioning the installation (as above) for the minimal tariff period and prioritising essential circuits. Every kilowatt saved is a win for the owner, the distributing utility and the environment. The only option to the DEDLC in an unmonitored full tariff connected installation is 'eternal vigilance'. Regardless of the devotion of the manual method that person can not be aware of the complete load at any one time. 'Militant vigilance' is a practice which is recommended if the owner intends to do nothing else, some will have no option. Use of the DEDLC potentially will achieve savings that even the most vigilant manual manipulation can not achieve because it is instantly aware of changes in demand due to automatically starting devices (such as a refrigerator). In many jurisdictions the billing regime in itself induces a small but constant influence to inflate the cost of consumed power. The ability of the DEDLC to prevent this distortion of the real consumption, resulting from 30 minute block charging, is a less obvious but accumulative saving worth achieving. domestic Electrical demand Limiting Cortro. Monitoring Module To ELCB & Main Switch System Circuit Breaker Module Contacts C.T. Signal Condition Circuit To Load hren 1nf Ach+'c Ck+ 1 nF A

Description

Description: Application # 2105100624 The Domestic Electrical Demand Limiting Controller [hereafter referred to as DEDLC], is a device to be installed in a domestic electrical switchboard, for the purpose of automatically logging the power in each circuit; and by controlled switching, limit the demand content of the installations electrical consumption. The DEDLC consists of 2 discrete types of device. The first is a module (one for each selected circuit in a domestic electrical installation) which is capable of measuring the current being consumed by all the devices on that circuit plus the ability to switch this circuit. This device is the same size and is mounted as is a standard circuit breaker, on the standard din-rail in all commercially available switchboards. It is wired (by an authorised person) in series (following) with a standard load protection circuit breaker, in the active leg of that circuit. The second component is a master control console. Each individual measuring module is wired over a short umbilical link (approx 0.6M) to the master control console. This link supplies the primary data to the master control in the form of a current level signal and feeds back a control signal for the switching function as required. Also input into the master control is the secondary data which is the relevant combination of external measurements optioned from the following list: Solar cell voltage Battery voltage Ambient temperature Grid supply present DRED status notifications Generator (stand-by) status. The master control console is mounted outside the enclosure. It uses a display for HIM (Human Interface Module) capability. Electrical Specifications: The components that are included in the 240Vac electrical circuit are part type tested to a rating of 4KVA. The umbilical link is electrically isolated from the medium voltage of the 240Vac and the cable is rated appropriately for use in a low voltage environment (240Vac). The link carries logic level signals (5Vdc) from the measuring module and an extra low voltage signal (12/24Vdc) to switch the circuit. The master operates at the extra low voltage of 12/24Vdc. The 240Vac to 12/24Vdc power supply to the master controller is not included in this application but will be a standard double insulated, commercially available unit for grid supplied installations. Where Batteries are a component of the installation the master will be preferably supplied from the battery pack at 24Vdc/12Vdc. Page 1 of 1