Max Power Tracker Power Conditioning System

Single channel Three channels

DC components exclusively DC and AC components

Accommodate high-voltage and current Accommodate lower voltage which is less costly

Dedicated to PV Not technology-specific

Battery subsystem: Most PV storage subsystems today consist of flooded lead-acid batteries. Improved valve -regulated lead-acid (VRLA) batteries are now emerging in utility systems. Advanced batteries (such as lithium ion and zinc/bromine) are being developed and are at different levels of size and readiness for utility operation. Other electric storage subsystems are addressed briefly in the Overview of Energy Storage Technologies, including flywheels , superconducting magnetic energy storage (SMES) and supercapacitors.

Batteries store chemical energy during electrical charging from a DC source, such as a PV array, or AC power fro m the electric grid can be converted to DC to charge the battery subsystem. For this technology characterization, it i s assumed the battery is recharged from the grid during off-peak hours. The battery storage subsystem complements the PV array, whose output is delivered to a commercial building load.

Batteries are complex devices whose performance is a function of many variables, including rate and depth of charg e and discharge, temperature, and previous operating history [3]. The basic building block of the battery module is th e electrochemical cell. Cells are packaged together into modules which are connected in a matrix of parallel-serie s combinations to form a string. Lead-acid batteries consist of two-volt (at open circuit) cells which are connected i n series and parallel arrays as needed to match the desired electrical characteristics of the application. Extremely hig h discharges (thousands of amperes) are possible, and batteries can be switched very rapidly between open circuit, charge, or discharge.

Power Conditioning Subsystem: The PCS rectifies AC line power to DC to charge the battery, and inverts the DC power back to AC during discharge. It controls the rate of discharge and the switching time of the system. The power switches in a PCS are typically either GTO (gate turn off) or the newer, more flexible IGBT (insulated gate bipola r transistor) semiconductors. IGBT semiconductors have fewer requirements for driver circuitry, making inverters more compact and modular. IGBTs are used to overcome problems of poor power factor and high current harmonics [4].

The PCS functionally acts as a combination rectifier and inverter and may include a transformer. When the battery i s being charged, the converter behaves like a rectifier, changing the AC into DC. When the battery is being discharge d (supplying power to the system), the converter operates as an inverter. In the rectifier mode, the converter controls the voltage across the battery or the charging current. The PCS converts AC voltage to DC by firing power semiconductors so that the voltage in each of the transformer windings sums to that needed to cause the desired charge current to flow into the battery [5].

Additional PCS components include switchgear, both AC and DC; transformers as needed for voltage matching an d isolation; and a controller for operating the system and interfacing with the host supervisory system. The control system has three main functions: (a) the storage subsystem control monitors charge level, charge/discharge requirements, an d related operations, (b) the PCS control monitors the utility power supply and switches the system on- and off-line, and (c) the facility control monitors temperature, ventilation, and lighting in the structure housing the battery.

Balance of plant: Structural and mechanical equipment such as the protective enclosure, heating/ventilation/ai r conditioning (HVAC), and maintenance/auxiliary devices are non-trivial parts of the balance of plant. Other balance-of-plant features and costs include the foundation, structure (if needed), siting and permits, electrical protection an d safety equipment, metering equipment, data monitoring equipment, communications and control equipment, and project management and training.

DIY Battery Repair

DIY Battery Repair

You can now recondition your old batteries at home and bring them back to 100 percent of their working condition. This guide will enable you to revive All NiCd batteries regardless of brand and battery volt. It will give you the required information on how to re-energize and revive your NiCd batteries through the RVD process, charging method and charging guidelines.

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