Objective[edit | edit source]
Due to the improving solar panel efficiency and the reduction in the cost of solar PV technology, rooftop Solar PV becomes a viable option for residential energy consumers to offset their electricity expenditure. Even though solar penetration has increased substantially in the past few years, the deregulated electricity market operators prevent the prosumers from feeding back excessively generated power back to the grid. This alone is detrimental to the expansion of rooftop solar PV into the residential sector. This background work aims to develop a system that would allow the users to implement a grid-tied Photovoltaic system for self-consumption that would not feedback power to the grid. Grid-tied and Standalone solar continue to dominate each other with each having its own advantages over the other. A small comparison has been drawn between these both by considering the cost and the problem statement.
Aziz, A. S., Tajuddin, M. F. N., Adzman, M. R., Mohammed, M. F., & Ramli, M. A. (2020). Feasibility analysis of grid-connected and islanded operation of a solar PV microgrid system: A case study of Iraq. Energy, 191, 116591.[edit | edit source]
- off-grid operation during grid failure
- Comparison of grid-connected and off-grid PV plants
- Simulated in HOMER, obtain optimal combination of energy system- High COE!
- Economical analysis Battery (Energy storage) recommended for the Analysis
Khezri, R., Mahmoudi, A., & Haque, M. H. (2020). Optimal capacity of solar PV and battery storage for Australian grid-connected households. IEEE Transactions on Industry Applications, 56(5), 5319-5329.[edit | edit source]
- Rooftop solar PV, ships excess power back to grid-Australia
- Calculation of technical parameters (VSC)
- Control of MPPT, decreases THD of system
Potential of Rooftop Solar PV[edit | edit source]
Distributed generation will become the major source of energy in the future, coupled with the decreasing cost of solar PV, rooftop PV would contribute a major share of distributed generation. This section would extrapolate the potential of rooftop solar in the near future and also some problems associated with it.
Gagnon, P., Margolis, R., Melius, J., Phillips, C., & Elmore, R. (2016). Rooftop solar photovoltaic technical potential in the united states. A detailed assessment (No. NREL/TP-6A20-65298). National Renewable Energy Lab. (NREL), Golden, CO (United States).[edit | edit source]
- DHS Light detection and ranging data sets are used to determine available rooftop area to compute the quantum of solar PV
- Analysis carried out for 128 cities (covers around 23% of buildings in the country) and are extrapolated for the entire country
- Around 40% of the annual consumption can be met alone by rooftop solar PV
International Renewable Energy agency Future of solar photovoltaic[edit | edit source]
- Solar generation would rise by 6times by 2050s
- LCOE will further fall from 0.085USD/kWh to 0.014-0.05USD/kWh by 2050
- Would provide employment to over 18.7 million people
Center for biological diversity 10 Sunny States Blocking Distributed Solar Development[edit | edit source]
Transfer Switch[edit | edit source]
A transfer switch works to switch one form of supply to another when a command signal is provided, transfer switches are looked upon to cut-off the solar PV from the grid when the excess solar generation feeds back to the grid.
Jean-Rostand, F. K., Mustapha, M. M., Adabara, I., & Hassan, A. S. (2019). Design of an Automatic Transfer Switch for Households Solar PV System Design of an Automatic Transfer Switch for Households Solar Pv System. European Journal of Advances in Engineering and Technology, 6(2), 54-65.[edit | edit source]
- cuts-off supply due to low voltage-low generation
- computed energy demand of household, sizing the rating of switch
- Microcontroller ATMEGA328-compares grid and inverter voltage, trips
Gupta, T. N., Singh, B., Chandra, A., & Al-Haddad, K. (2020, October). Control of single-phase solar PV-BES microgrid. In IECON 2020 The 46th Annual Conference of the IEEE Industrial Electronics Society (pp. 3660-3665). IEEE.[edit | edit source]
- Micro-grid with solar PV and BES, provide transition between on and off-grid
- Cascaded SOGI based current control
- synchronizing controller acts as a switch
Naqvi, S. B. Q., & Singh, B. (2020, December). A Solar PV System for Reliable Supply in Areas with Erratic Grid. In 2020 21st National Power Systems Conference (NPSC) (pp. 1-6). IEEE.[edit | edit source]
- Solar PV and BES
- MPP tracking with feed-forward algorithm
- PV system with BES modelled as transfer functions in Matlab
Matyac, M. (2020). Photovoltaic Transfer Switch with Non-Essential Load Cutoff U.S. Patent Application No. 16/599,826.[edit | edit source]
- Dividing the home appliances into essential and non-essential loads
- Microcontroller to sense the generation and regulating loads
- Cutting of non-essential loads leads to lower battery sizing, lower cost
Solar Inverter Control[edit | edit source]
Inverter functions as the brain of the solar PV plant, it is an integral part of a grid-tied solar PV. Various types of inverters ranging from grid-connected to microinverters are found in the market. Inverter switching pulse control is a versatile approach as it can act as power regulators and also as a switch with no additional equipment, various control philosophies of the solar inverters are discussed below.
Adaramola, M. F., & Adelabu, M. A. (2017). Performance analysis of grid-tied sine-wave inverters in a hybrid power system. J. Energy Technol. Policy, 7(6), 47-58.[edit | edit source]
- Literature on advantages of CSI over VSI
- Literature on operational blocks of solar PV
- Inverter efficiency evaluation
Shawky, A., Ahmed, M., Orabi, M., & Aroudi, A. E. (2020).Classification of three-phase grid-tied microinverters in photovoltaic applications. Energies, 13(11), 2929.[edit | edit source]
- Z sourced inverters topology
- Reducing Capacitance at the DC size
Chouder, A., Silvestre, S., Sadaoui, N., & Rahmani, L. (2012). Modeling and simulation of a grid connected PV system based on the evaluation of main PV module parameters. Simulation Modelling Practice and Theory, 20(1), 46-58.[edit | edit source]
- Mathematical representation of Solar PV
- Single diode model of solar PV for simulation
- Validation of the mathematical model in real-time conditions
Ponnusamy, P., Sivaraman, P., Almakhles, D. J., Padmanaban, S., Leonowicz, Z., Alagu, M., & Ali, J. S. M. (2020). A New Multilevel Inverter Topology With Reduced Power Components for Domestic Solar PV Applications. IEEE Access, 8, 187483-187497.[edit | edit source]
- Dual-source multilevel inverter, with fewer switches
- Synchronous and Asynchronous operation
- Closed loop algorithm, steady-state analysis
Hota, A., Bhuyan, S. K., & Hota, P. K. (2020, February). Modeling & simulation of photovoltaic system connected to grid using Matlab. In 2020 International Conference on Renewable Energy Integration into Smart Grids: A Multidisciplinary Approach to Technology Modelling and Simulation (ICREISG) (pp. 16-21). IEEE.[edit | edit source]
- Voltage and Current control loop methods to control apparent power from inverter
- Suitable triggering pulses are provided for One-stage AC-DC Inverter
- Advantages of One-stage over Two-stage converters
Vakacharla, V. R., Gnana, K., Xuewei, P., Narasimaharaju, B. L., Bhukya, M., Banerjee, A., ... & Rathore, A. K. (2020). State-of-the-art power electronics systems for solar-to-grid integration. Solar Energy, 210, 128-148.[edit | edit source]
- Levelized solar generation, entire day
- Comprehensive MPPT techniques
- Voltage-fed HF transformer(isolated dc/dc converters) to boost solar voltage
Roselyn, J. P., Chandran, C. P., Nithya, C., Devaraj, D., Venkatesan, R., Gopal, V., & Madhura, S. (2020). Design and implementation of fuzzy logic based modified real-reactive power control of inverter for low voltage ride through enhancement in grid connected solar PV system. Control Engineering Practice, 101, 104494.[edit | edit source]
- Fuzzy logic to control real and reactive power
- Two-stage PV inverter simulated in Matlab Simulink
- Additional fault ride through conditions
Mishra, P., Pradhan, A. K., & Bajpai, P. (2020). Adaptive Distance Relaying for Distribution Lines Connecting Inverter-Interfaced Solar PV Plant. IEEE Transactions on Industrial Electronics, 68(3), 2300-2309.[edit | edit source]
- Distance relay to calculate impedance and to break the circuit
- Impedance calculated by measuring voltage and the directional current
- Solar PV will be connected to the grid during FRT
Madaria, P. K., Bajaj, M., Aggarwal, S., & Singh, A. K. (2020, February). A grid-connected solar PV module with autonomous power management. In 2020 IEEE 9th Power India International Conference (PIICON) (pp. 1-6). IEEE.[edit | edit source]
- Two level converter, VSE and DC-DC converter
- Designed L&C values for RC filters
- Insight on reducing THD of solar
Salem, Q., & Xie, J. (2018). A Novel Line Current Control Strategy to Control the Real Power Flow at PCC Using H-bridge Inverter. International Journal of Power Electronics and Drive Systems, 9(2), 602.[edit | edit source]
- Line current control
- Control of power flow from a set of distributed generations in a microgrid
- Capacitive and inductive operation modes
Ansari, M. A., Rahman, K., Roomi, M. M., Pervez, I., Lodi, K. A., Tariq, M., & Mishra, N. (2020, October). Solar PV fed Three Phase Cascaded H Bridge Multi-level Inverter. In IECON 2020 The 46th Annual Conference of the IEEE Industrial Electronics Society (pp. 3325-3330). IEEE.[edit | edit source]
- H-Bridge Multi-level inverter
- Comparison of Unipolar and Bipolar switching schemes
- Perturb & Observe used to maximize converter output power
Bijukumar, B., Ilango, G. S., & Nagamani, C. (2020). Design and implementation of a current controlled grid connected inverter for thermoelectric generator sources. Sādhanā, 45, 1-13.[edit | edit source]
- Current controlled voltage sourced inverter control
- Constant voltage behind impedance- Source
- Developed transfer function
Mandal, N., Dey, B. K., Paul, A., & Bhattacharjee, A. (2020). A Novel Three-Phase Five-Level Inverter Control and Its Performance Analysis for a Grid-Connected Solar PV Power System. In Advances in Energy Research, Vol. 2 (pp. 839-850). Springer, Singapore.[edit | edit source]
- AC side Power control, five-level diode clamped inverter
- Realtime grid, Synchronous reference frame PLL
- RC filter to reduce harmonics, MATLAB Simulink
Saad, E., Elkoteshy, Y., & AbouZayed, U. (2020). Modelling and analysis of grid-connected solar-PV system through current-mode controlled VSC. In E3S Web of Conferences (Vol. 167, p. 05005). EDP Sciences.[edit | edit source]
- Reference current signal to monitor power
- LC filter (calculated) to absorb harmonics/ generated during current control mode
- Simulated in PSCAD/EMTDC with current control mode
Srivastava, S. K. (2020, February). Analysis of Constant Real Power Flow Injection From PV System to Power Grid. In 2020 International Conference on Electrical and Electronics Engineering (ICE3) (pp. 396-401). IEEE.[edit | edit source]
- Hybrid PV system
- Regulate Real power, supplies constant value to the grid, charges battery
- Fixed grid frequency & voltage throughout the experiment
- different loading conditions considered
Lusis, P., Andrew, L. L., Liebman, A., & Tack, G. (2020). The Added Value of Coordinating Inverter Control. IEEE Transactions on Smart Grid.[edit | edit source]
- Coordinated and autonomous inverter control
- Coordinated inverter control, gathers output power dates, feeds data to inverter
- Autonomous inverter control, works on droop characteristics (voltage)
- Coordinated inverter, better power flow control, lower losses
Afxentis, S., Florides, M., Machamint, V., Yianni, C., Norgaard, P., Bindner, H., ... & Georghiou, G. E. (2019). Energy class dependent residential battery storage sizing for PV systems in Cyprus. The Journal of Engineering, 2019(18), 4770-4774.[edit | edit source]
- BESS to absorb excess energy, prevent grid feedback
- Design kWh to the average consumption-household
Patents[edit | edit source]
These patents concentrate on the principle of preventing bi-directional current and cutting of Solar PV during grid feedback.
Drew Bowen , Grid backfeed prevention system, Publication No. US 20120235487 A1[edit | edit source]
- Prevent grid feedback of residential auxiliary power sources like rooftop solar and geothermal energy
- Reads the current value difference, disconnects and connects accordingly
- CT is used to measure current
- PLU is used to communicate with the circuit opener
Rogers, G. N. (2020). Energy generation load compensation U.S. Patent Application No. 16/441,571.[edit | edit source]
- Control power to the grid
- Microcontroller to monitoring forward, reverse power flow
- Cuts off from grid during an outage.
Rogers, G. N. (2016). Zero export relay U.S. Patent Application No. 15/111,351.[edit | edit source]
- Controllable switch to break circuit during direction change
- PLC or Microcontroller to control switching operation
- Controllable switch comprises of V&I sensing
- Sensor to reclose the circuit after a break
Varma, R. K. (2020). Multivariable modulator controller for power generation facility U.S. Patent Application No. 16/541,349.[edit | edit source]
- Small scale wind and solar, grid-connected
- Regulator of Power flow, captive system
- Usage of a controller, Optimal power control, voltage regulation
Johnson, L., Peter, W. B., & Johnson, R. (2017). Master-slave architecture for controlling operation of photovoltaic power plants U.S. Patent No. 9,680,301. Washington, DC: U.S. Patent and Trademark Office.[edit | edit source]
- Single master controller, slave microinverters
- master inverter controls power, direction and voltage
Safaei, F. R. P. (2018). Systems and methods for controlling PV production within energy export constraints. U.S. Patent No. 10,139,847. Washington, DC: U.S. Patent and Trademark Office.[edit | edit source]
- Grid feedback for PV system with a battery
- Flowchart of operation
- Computes gross power(household) sets PV gen accordingly
- Turns-off PV gen when gross power<PV generation
Knox, Cameron, and Tian Ting. Behind-the-meter system and method for controlled distribution of solar energy in multi-unit buildings. U.S. Patent Application No. 16/500,957.[edit | edit source]
- Power control by central inverter
- Microcontroller to compare the required power and PV Generation
- Used where installed capacity>inverter capacity
Zero export- Grid tie limiter[edit | edit source]
Grid-tie limiter can be an additional function of solar inverters, this section focuses on its operation principle and its execution.
Kakkattukunnumal, J., Das, N., & Palmer, E. (2019, November). Techno-Economic Performance Analysis of Grid-tie and Standalone PV System in Victoria. In 2019 29th Australasian Universities Power Engineering Conference (AUPEC) (pp. 1-6). IEEE.[edit | edit source]
- Grid or off-grid, eco and tech analysis by HOMER software
- Various combination-solar, wind, DG and BES
- LCOE off-grid > grid-connected
Prajogo, S., & Santoso, B. H. (2019). Performance Analysis Of Grid Tie Inverter With Power Limiter To Increase Utility Power Reduction In One Way kWh Meter Circuit. Journal of Physics: Conference Series, 1364, 012070. DOI[edit | edit source]
- Model of Grid-tied inverter with limiter
- Comparison of grid-tied inverters with and without a limiter
- Consideration of battery for energy storage
Nabavi, S. M., Meek, L., & Abshar, M. (2014). Dynamic performance response evaluation of solar gate: Zero export injection equipment for photovoltaic power generation systems. In 2014 Australasian Universities Power Engineering Conference (AUPEC) (pp. 1-5). IEEE.[edit | edit source]
- Grid limiter operation principle
- Measuring demand and matching solar generation
- Equivalent PWM wave for inverter
Lim, Y. S., Wong, J., Liew, M. S. S., & Khaw, L. Y. A. (2020). Proportional integrator (PI) and fuzzy-controlled energy storage for zero-power flow between grid and local network with photovoltaic system. Sustainable Energy Technologies and Assessments, 37, 100629.[edit | edit source]
- Measures the power from the Grid with a CT
- PI and fuzzy logic to control power flow from PV
- Successful balance- PI, Faster Response- Fuzzy
Vukovic, M., & Supic, L. (2016, September). Realization of project of grid tied self-consumption PV system. In 2016 4th International Symposium on Environmental Friendly Energies and Applications (EFEA) (pp. 1-4). IEEE.[edit | edit source]
- Hub1 system
- MODBUS communication btw MPPT and inverter
- MPPT also functions to regulate power
Burlaka, V., Gulakov, S., & Podnebennaya, S. (2019, April). Low-Cost Transformerless Grid-Tie Inverter For Photovoltaic System. In 2019 IEEE 6th International Conference on Energy Smart Systems (ESS) (pp. 334-338). IEEE.[edit | edit source]
- Flowchart of inverter (CSI) with PI controller, MPPT
- Control on inverter- Zero export grid
Commercially available grid-tie limiter[edit | edit source]
These specialized inverters are available in the market which mainly operates to prevent the grid feedback from the captive power source, the operation principle of the grid-tie inverters are studied and analysed.
Microcare Grid Tie Limiter[edit | edit source]
- Equivalent circuit of Solar PV with grid-tie inverter
Sun Electronics-Zero Export Grid Tie-Experience[edit | edit source]
- Introduction to the problem statement
- Grid-tie solar PV with a central inverter
- Advantages of grid connected system over off-grid system
Grid Tie Inverter External Limiter Install[edit | edit source]
- Installation of rooftop solar PV, central inverter
- Requirement of Energy storage
Sun Grid Tie Inverter + Safety Devices[edit | edit source]
- Circuit schematic/Protection of the setup
- Utilisation of Sun Electronics inverters, zero grid export
Power Control: Zero Export System[edit | edit source]
- MODBUS communication with the PV inverter
Zero Export Device[edit | edit source]
- Measures current and matches generation
- 4 in 1 Zero Export Device with built in Remote Monitoring
