Constant Power Generation Control Research Articles

A Modified Maximum Power Point Tracking with Constant Power Generation Using Adaptive Neuro-Fuzzy Inference System Algorithm


 
 
 
 Renewable energy is being used to lessen the consumption of fossil fuels. Solar energy is a common source of renewable energy. Solar energy is the most promising source of energy due to its long-term sustainability and availability. The output power of solar panels is strongly influenced by the intensity of sunlight and the temperature of the solar panels. Maximum Power Point Tracking (MPPT) control, which aims to optimize the output power of solar panels, is commonly used to increase the efficiency of solar panels. However, MPPT control often causes overvoltage disturbance in systems directly connected to the load. To limit the output power of solar panels, additional Constant Power Generation (CPG) control is required. In this research, a solar panel system will be created to supply submersible DC pumps without any energy storage devices. DC-DC SEPIC Converter is designed with MPPT control combined with CPG control to limit the output power of the converter using the Adaptive Neuro-Fuzzy Inference System method by 150 watts. When the output power of the solar panel is less than the power limit, then MPPT mode will work. While CPG mode works when the PV output power is greater than the limit power. The results of this research showed that the system can provide optimal power generated by solar panels in MPPT mode by increasing efficiency by up to 33.04% and CPG mode can limit power to 150 Watts to avoid overvoltage disturbance at load.
 
 
 

WITHDRAWN: Constant power generation in single and two stage PVPPS with CPG and MPPT modes of operation

Abstract Photovoltaic Power Plants (PVPPs) functions through the tracking of maximum power point with a view for maximizing the conversion efficiency of the power plants. Grid voltage disturbances, over voltages overloading etc., are some newer challenges faced by the power system operators while operating this photovoltaic power plants. Maximum Power Point Tracking (MPPT) algorithm and Constant Power Generation (CPG) algorithm are used for obtaining maximum output voltage from these power plants. Often the output voltage of the PVPPs varies according with the grid disturbances, overloading and overvoltage conditions. The MPPT and CPG algorithms are introduced in these power plants to stabilize the output voltage levels. This paper of study encapsulates a single algorithm for gaining a maximum stable output voltage with less oscillation and which gives a fast dynamic response. This algorithm is formed by the combination of both MPPT-Perturb and Observe and CPG algorithms (MPPTPO-CPG). This algorithm would be suitable enough to get a constant power output from the Photovoltaic Power Plants (PVPPs) and is suitable for both single-stage and two-stage Photovoltaic Power Plants. The MPPT algorithm is utilized for fetching the maximum power output from the PVPPs. Maximum output voltage; fast dynamic response and higher oscillation are gains of using the MPPT algorithm. Output voltage is destabilized during higher oscillation and hence constant power generation algorithm is introduced, which gives low oscillation and maximum power output, but the dynamic response is slow. Hence these two algorithms are combined to a new algorithm that provides maximum output voltage, efficiency and a fast dynamic response. The boost converter is the eminent component used in the proposed system for achieving CPG and MPPT control.

High-Performance Photovoltaic Constant Power Generation Control With Rapid Maximum Power Point Estimation

Photovoltaic (PV) constant power generation (CPG) control is regarded as an advanced active power control by limiting the maximum feed-in power in order to avoid the adverse impacts of high-penetration PV systems such as overloading and overvoltage. Conventional CPG strategies show obvious limitations in terms of the dynamics response, oscillations during the steady state, and the estimation speed of limited power points (LPPs). In this article, a novel CPG control with the rapid approach to LPPs is proposed with the estimation of maximum power point (MPP), which guarantees fast converging speed in response to rapid changes in environmental conditions and low power oscillations for the steady state. Specifically, the proposed control allocates the operating point at the left-hand side of the MPP, which can not only avoid the instability issue but also simplify the MPP and LPP estimation according to the single-diode PV equivalent model. Furthermore, based on the estimated available power $P_{\rm avi}$, the proposed CPG control contributes a direct solution in approaching the region around LPP or MPP, which improves the converging speed under environmental-changing conditions. Thus, regardless of the changes in irradiance or temperature, high-performance and reliable operation are ensured by switching the maximum power point tracking mode and CPG mode smoothly. The proposed control can be directly applied for the existing PV system and no additional hardware devices such as irradiance sensors are required, which is cost effective. A systematic comparison of the proposed control with other advanced CPG strategies was made under various scenarios and the advantages of the proposed control were validated experimentally.

Delta Power Control Strategy for Multistring Grid-Connected PV Inverters

With a still increasing penetration level of grid-connected photovoltaic (PV) systems, more advanced active power control functionalities have been introduced in certain grid regulations. A delta power constraint, where a portion of the active power from the PV panels is reserved during operation, is required for grid support (e.g., during frequency deviation). In this paper, a cost-effective solution to realize delta power control (DPC) for grid-connected PV systems is presented, where the multistring PV inverter configuration is adopted. This control strategy is a combination of maximum power point tracking (MPPT) and constant power generation (CPG) modes. In this control scheme, one PV string operating in the MPPT mode estimates the available power, whereas the other PV strings regulate the total PV power by the CPG control strategy in such a way that the delta power constraint for the entire PV system is achieved. Simulations and experiments have been performed on a 3-kW single-phase grid-connected PV system. The results have confirmed the effectiveness of the proposed DPC strategy, where the power reserve according to the delta power constraint is achieved under several operating conditions.

High-Performance Constant Power Generation in Grid-Connected PV Systems

An advanced power control strategy by limiting the maximum feed-in power of PV systems has been proposed, which can ensure a fast and smooth transition between maximum power point tracking and constant power generation (CPG). Regardless of the solar irradiance levels, high-performance and stable operation are always achieved by the proposed control strategy. It can regulate the PV output power according to any set point, and force the PV systems to operate at the left side of the maximum power point without stability problems. Experimental results have verified the effectiveness of the proposed CPG control in terms of high accuracy, fast dynamics, and stable transitions.

A Hybrid Power Control Concept for PV Inverters With Reduced Thermal Loading

This letter proposes a hybrid power control concept for grid-connected photovoltaic (PV) inverters. The control strategy is based on either a maximum power point tracking control or a constant power generation (CPG) control depending on the instantaneous available power from the PV panels. The essence of the proposed concept lies in the selection of an appropriate power limit for the CPG control to achieve an improved thermal performance and an increased utilization factor of PV inverters, and thus, to cater for a higher penetration level of PV systems with intermittent nature. A case study on a single-phase PV inverter under yearly operation is presented with analyses of the thermal loading, lifetime, and annual energy yield. It has revealed the trade-off factors to select the power limit and also verified the feasibility and the effectiveness of the proposed control concept.