Thyristorised Real Time Power Factor Correction (TRTPFC) 1 Sanjay N. Patel, 2 Mulav P. Rathod, 3 Keyur C. Patel, 4 Parth H. Panchal, 5 Jaimin N. Prajapati 1, 2 Asst.Prof, Electrical dept., SVIT – Vasad, 3, 4, 5 Students, Electrical dept., SVIT - Vasad Abstract One of the concerns to put on the energy efficiency is in relation to the system power factor. From the view of industrial practices, low power factor might cause equipment failure and higher operation costs. This paper proposes a conceptual design of microcontroller based automatic power correction (APFC Relay) for 1 – ø and 3 - ø circuit with intension to be used in power factor (either linear or non-linear) loads applications. The design of this auto adjustable power factor correction is to ensure the entire power system always preserving almost unity power factor and thus optimizing the current consumption and compared with predetermines reference value. The conceptual design of power factor correction techniques has gone through a set of simulation tests using Power System Computer Aided Design (PSCAD).The results are obtained and verified that the proposed PSCAD circuit is capable to produce a reliable output and can be further be implemented in practical application. Keywords: Energy Saving, Reduction of Harmonics, Power Factor Correction 1. Introduction All Power factor is the relationship between working (active) power and total power consumed (apparent power). Essentially, power factor is a measurement of how effectively electrical power is being used. The higher the power factor, the more effectively electrical power is being used. Low power factor means poor electrical efficiency. The lower the power factor, the higher the apparent power drawn from the distribution Network. When low power factor is not corrected, the utility must provide the nonworking reactive power IN ADDITION to the working active power. This results in the use of larger generators, transformers, bus bars, wires, and other distribution system devices that otherwise would not be necessary. As the utility’s capital expenditures and operating costs are going to be higher, they are going to pass these higher expenses to Industrial users in the form of power factor penalties [1-4]. One of the new approaches is to use a variable inductor in parallel with a fixed capacitor as a reactive power compensating circuit [5]. The inductor current is controlled by adjusting the firing angle of two anti- parallel connected thyristors or using TRIAC. The adjustment of the thyristors' firing angle is made in Accordance to the result of a comparison between the measured values of a certain system parameter with its reference value [6]. This paper proposes a real time power factor correction scheme for 1-Ø and 3-Ø system. The selection of the capacitor according to load value and simulation for both systems with harmonics are including in this paper. 2. Block diagram of 1 – Ø system: The figure shows the block diagram of the 1 - Ø power factor correction system. There are two references namely Voltage and Current measured from the PT and CT. These two references are compared and their resultant angle is given as firing angle of Thyristor. Before them these references are gone through the band pass filter and zero crossing detector. ZCD converts the sinusoidal waveform into square waveforms for triggering thyristor at every zero crossing. Figure 1. Block Diagram of 1 - Ø System International Journal of Engineering Research & Technology (IJERT) Vol. 2 Issue 3, March - 2013 ISSN: 2278-0181 1 www.ijert.org