Energy saving and loss reduction in each electrical system constitute a significant part of a saving-oriented society under construction, especially that a power distribution system has a large coverage that means saving energy and reducing losses not only matter to the quality of power supply consumed by each and every household, but also directly impact the economic benefits of electric power suppliers. In many cases, evident peak and valley periods do exist in terms of a transformer's operating load; in the valley period, the transformer load approximate to zero or a no load state, i.e., in such duration, the transformer's no-load loss covers about 40% of the total power supply loss. As a result, reducing the no-load loss during a transformer's light loading is very significant to the reduction of the total power supply loss.
A S11-M.ZT intelligent on-load capacity regulating transformer is a new type of energy saving transformer jointly developed by our company and China Electric Power Research Institute [CEPRI] for meeting above-narrated requirements. This product line, including intelligent on-load capacity regulating distribution transformers and intelligent on-load capacity regulating electrical transformers, adopts intelligent on-load capacity regulating technology to lower a transformer's no-load loss, possessing distinct energy saving effects. Among them, intelligent on-load capacity regulating distribution transformers are applicable to 10kV power distribution desk area and packaged substations in rural areas, urban business districts, industrial development zones, residential estates where a large variation does exist in seasonal load or in daily load; while intelligent on-load capacity regulating electrical transformers are applicable to a 35kV power transmission and distribution system in the next higher level, i.e., the first choice in an intelligent power transformation and distribution desk area, which have been listed in the specially promoted new technology catalogue of No.1 priority in 2011 by State Grid Corporation of China [SGCC].
Structured Block Diagram, Overall Plan for Intelligent On-Load Capacity Regulating Transformers
- Gaining fine economic and social benefits through reducing loss and saving energy;
- Solving the current issues like “a big house pulls a large carriage” and severe overloads resulted from seasonal load variations in desk areas;
- Substituting “mother-daughter transformers”, saving investment costs and the holding land area;
- Overcoming the disadvantage of inevitable manual regulation post power cut-off in terms of no-load capacity regulating operation;
- Providing testing data to both power distribution integrated management system and economic power grid running system and such practice does satisfy intelligent power
- Helping to alter power supply management mode and thereby enhance power distribution management level.
Each of our-produced intelligent on-load capacity regulating transformers has taken the lead in the introduction of a segmental structure in the same industry, which may be used in any place associated either with a high voltage rating or with a low voltage rating while keeping an unchanged precision in either case. Taking 100/200KV/2mA segments for an example, when functioning as a one segment device, it may be used in the 100KV/4mA segmental range, which has found use in DC high voltage testing of an electrical device within a 35KV or less system, and in such circumstance, it helps to guarantee the measurement accuracy and avoid a big horse's pulling of a small carriage; when functioning as a two segment device like an intelligent DC high-voltage generator, it may be used not only in the 200KV/2mA segmental range, but also in 220KV, 110KV or less segmental ranges (for the latter, such as being used in DC testing of a zinc oxide lightning arrester or in DC voltage withstand testing of cross-linking cables), i.e., genuinely realizing one unit for double uses that bring about a lot of conveniences to our onsite users.
Environmental Conditions for Product Use
installation location : indoor, outdoor.
ambient temperature : -25℃ -+40 ℃.
relative humidity : less than or equal to 95%.
Altitude : 1000m.
Note: special environment should be stated in the order.
The operating principle of an intelligent on-load capacity regulating transformer is shown in Fig. 1. To be particular, a on-load capacity regulation controller makes a judgment as to the magnitude of a load current at this moment via testing the voltage and current on the transformer's low-voltage side; thereupon, if capacity regulating conditions are met, then the controller will give a capacity regulation order to an on-load capacity regulating switch that will switch over capacities according to such given order, so as to realize Y-△conversion and switching-over between serial and parallel connections. This way, the capacity switching-over is fulfilled on a transformer under loading conditions.
Fig. 1 Intelligent On-load Capacity-regulating Transformer Operating Principle Diagram
An intelligent on-load capacity regulating transformer consists of a power distribution transformer, an on-load capacity regulating switch, an on-load capacity regulation controller, and auxiliaries. The power distribution transformer may connect with a notebook computer via a serial interface /USB interface or with the aid of a ZIGBEE radio transceiver module of micro-power consumption, connect with a portable PDA terminal, in order to realize data download, data review, and parameter tuning just on the spot. In addition, via an external GPRS module or an Ethernet module, operating data are transmitted to a remote control center, thereby realizing a remote control function with regard to an on-load capacity regulating transformer.