A Novel Wireless Multifunctional Electronic Current Transformer based on ZigBee-based Communication
ABSTARCT :
This paper proposes a new ZigBee-based communication for multifunctional electronic current transformers (ECTs), which are used in overhead and underground line monitoring. To tackle ZigBee’s low transmission rate, the proposed method involving a transmission strategy can make the ZigBee-based communication satisfy both measurable and protective purposes of multifunctional ECTs. Finally, the new ZigBee-based wireless communication is implemented and integrated with an ECT, which is based on the coreless Hall-effect current transformer (HCT), and the proposed ZigBee-based wireless multifunctional HCT is called ZiHCT. The measurement results show that the ZiHCT can achieve accuracy not only to Class 0.5 for measuring CTs, but also to Class 5P20 for protective CTs according to IEC standard 60044-8.
EXISTING SYSTEM :
? We are monitoring current and voltage through ADC and displayed on the LCD.
? The monitoring of power grid has become an important part of maintaining the security and stability of power grid.
? Smart grid collects the working information of power grid using sensors and judges the working state of power grid in the server of the monitoring center.
? The emergence of wireless communication technology makes sensor constitute wireless sensor network, and the transmission of data does not need to rely on data lines such as optical fiber, saving more costs.
DISADVANTAGE :
? The problem of core saturation still exists, and the sizes of the sensors are also almost the same as those of traditional CTs.
? Moreover, the problem of different DC voltage levels existing in three amplified Hall voltages is also solved, and then the Hall voltages are sent to a low-pass filter to filter noise.
? ZigBee characterizes the low transmission rate, the traditional ZigBee-based wireless communication used in real-time current waveform measurement will result in problems of signal packet error and serious delay.
? The reconstructed waveform is similar to the actual current waveform, resolving the problem that ZigBee cannot be used for waveform transmission.
PROPOSED SYSTEM :
• It is the wireless device for transmitting and receiving purpose or simply it called as Transceiver.
• In the transmitter section three sensors are interfaced to the LPC2148 controller and this controller is responsible for entire manipulations and the updated condition is displayed on the LCD and the same status is transmitted to the receiver section by using zigbee communication and is displayed on the pc which is on the receiver section.
• A GSM modem is also interfaced to the controller to send the status to the pre-stored mobile number.
• This project uses two power supplies, one is regulated 5V for modules and other one is 3.3V for microcontroller. 7805 three terminal voltage regulator is used for voltage regulation.
ADVANTAGE :
? The ZiHCT has price and size advantages to potentially replace traditional CTs and other ECTs.
? Traditional current transformers (CTs), mainly used to measure currents in power systems, are wound on closed cores of silicon steel sheets; thus, they are easily influenced by magnetic saturation and hysteresis.
? The magnification design of the small and medium current ranges, the minified Hall voltages are transmitted to the positive inputs of an amplification circuit with two built-in instrumentation amplifiers, and then a DC offset adjustment circuit is used to produce two different voltage offsets to the negative inputs of amplification circuit.
? An autotransformer T1 is used to control the special transformer T2, which has only one turn in its secondary winding.
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