Predictive Voltage Control of Transformerless Dynamic Voltage Restorer
This project presents a predictive voltage control scheme for the effective control of a transformer less dynamic voltage restorer (TDVR). This control scheme utilizes the discrete model of a voltage source inverter and an interfacing filter for the generation of the switching strategy of inverter switches. Predictive voltage control algorithm- based TDVR tracks the reference voltage effectively and maintains load voltages sinusoidal during various voltage disturbances as well as load conditions. Moreover, this scheme does not require any linear controller or modulation technique.
Generally, pulse width-modulation technique, hysteresis controller, sliding-mode controller, etc., are used to control the switches of the voltage source inverter (VSI). Recently, a predictive control scheme has found applications in the control of power electronic converters such as single-phase and three phase VSIs, rectifiers, active power filters, uninterrupted power supplies, dc–dc converters, and motor drive. Increasing interest in predictive control schemes over other controllers is due to the fact that the scheme is easy to implement in modern digital signal processor (DSP), has fast dynamic response, and does not require any modulator. Moreover, system nonlinearities and necessary constraints can be easily accommodated in the control scheme.
This project presents a predictive voltage control scheme for TDVR to maintain load voltage at a constant value during voltage disturbance as well as under unbalanced and nonlinear loads. A detailed discrete-time state-space model of the TDVR compensated system is derived to predict the future values of the load voltage, which depends upon the sensed currents and voltages. A cost function is chosen for the selection of the appropriate switching state such that the square of error between the actual and reference voltages is minimized. Simulation and experimental results confirm the feasibility and usefulness of the proposed scheme.
TOOLS AND SOFTWARE USED:
- MP LAB
Chandan Kumar, Student Member, IEEE, and Mahesh K. Mishra, Senior Member, IEEE, “Predictive Voltage Control of Transformerless Dynamic Voltage Restorer”, IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, VOL. 62, NO. 5, MAY 2015