Hi, i am charanraj studying B.E and i want to do seminar about the topic UPQC. I need brief explanation,advantage,disadvantage,limitation,aplication of the topic please provide it soon.
Unified Power Quality Conditioners (UPQCs) allow the mitigation of voltage and current disturbances that could affect sensitive electrical loads while compensating for the reactive power of the load. Various control techniques have been proposed to evaluate the instantaneous output voltage of the UPQC serial active power filter but in most cases these controllers can only compensate for one type of voltage disturbance.
Power quality can be defined as any power problem faced in the frequency, current or deviation of the voltage leading to the malfunction of the customer equipment. It has always been difficult to maintain the quality of electrical energy to keep it within acceptable limits. Mainly the use of electronic power devices that acts as non-linear load is responsible for the degradation of poor power quality. Poor power quality gives rise to various problems in distribution systems such as higher power losses, harmonics, subsidence and swelling in the voltage, poor distortion and displacement factor. Recent developments in communications, digital electronics and control systems have rapidly increased the number of sensitive loads requiring a sinusoidal supply voltage ideal for proper operation. Therefore, it was necessary to include some type of compensation to comply with the limits proposed by the standards. Here the Unified Power Quality (UPQC) conditioner has been used to overcome the problem of power quality. UPQC, which is a combination of back-to-back connected series and shunt APF through a common DC link voltage, the two APFs operate differently. The active by-pass filter is mainly advantageous in eliminating the problems related to current and the improvement of the power factor and the regulation of the DC link voltage. While the APF series helps in the correction of stress related problems by acting as a controlled voltage source. The voltage which is injected in series with the load by the active power filter of the series is made to follow a control law which results in a sinusoidal charge voltage which is the sum of the voltage injected by the inverter of the series And the input voltage. While the shunt APF acts as a current source that injects a harmonic harmonic current to have a sinusoidal inrush current in phase. Several control strategies have been reported in the literature that determine reference values for voltage and current. Two control strategies have been described, namely the UVTG (unit vector template generation) and the synchronous reference frame, the P-Q technique. UVTG is used for serial control and active power filter bypass, while in the other method synchronous reference method is used for SAF control and the P-Q method is used for control of APF bypass. UPQC has the ability to compensate for harmonic current, reactive power, voltage unbalance, and voltage sag and sink. It also helps to reduce energy losses occurring in the element of power systems and also increases the safety of operation.