# Constant voltage method

Constant voltage method

Constant voltage method is a type of MPPT algorithm. This method makes use of the fact that the ratio of maximum power point voltage and the open circuit voltage is 0.76. It is the simplest MPPT control method.

## Algorithm

The operating point of the PV array is kept near the MPP by regulating the array voltage and matching it to a fixed reference voltage Vref. The Vref value is set equal to the maximum power point voltage of the characteristic PV module or to another calculated best fixed voltage. One of the approximations of this method is that, variations encountered by individual panels need not be considered as the constant reference voltage can be considered as the maximum power point voltage. The data for this method varies with geographical location and has to be processed differently for different geographical locations. The CV method does not require any input. It is important to observe that when the PV panel is in low insolation conditions, the CV technique is more effective than either the P&O method or the IC method (analyzed below) . Thanks to this characteristic, CV is sometime combined together with other MPPT techniques.

## Drawbacks

• The current from the photovoltaic array must be set to zero momentarily to measure the open circuit voltage and then afterwards set to 76% of the measured voltage.
• Energy is wasted during the time the current is set to zero.
• The approximation setting the voltage to 76% of the measured voltage is not accurate.

Wikimedia Foundation. 2010.

Поможем написать курсовую

### Look at other dictionaries:

• Constant voltage speaker system — Constant voltage speaker systems refer to networks of loudspeakers which are connected to an audio amplifier using step up and step down transformers to simplify impedance calculations and to minimize power loss over the speaker cables. They are… …   Wikipedia

• Voltage regulator — A popular three pin 12 V DC voltage regulator IC. A voltage regulator is an electrical regulator designed to automatically maintain a constant voltage level. A voltage regulator may be a simple feed forward design or may include negative feedback …   Wikipedia

• High-voltage direct current — HVDC or high voltage, direct current electric power transmission systems contrast with the more common alternating current systems as a means for the bulk transmission of electrical power. The modern form of HVDC transmission uses technology… …   Wikipedia

• Open-circuit time constant method — The open circuit time constant method is an approximate analysis technique used in electronic circuit design to determine the corner frequency of complex circuits. It also is known as the zero value time constant technique. The method provides a… …   Wikipedia

• Planck constant — Planck s relation redirects here. For the law governing black body radiation, see Planck s law. Values of h Units 6.62606957(29)×10−34 J·s 4.135 …   Wikipedia

• Time constant — In physics and engineering, the time constant usually denoted by the Greek letter au , (tau), characterizes the frequency response of a first order, linear time invariant (LTI) system. Examples include electrical RC circuits and RL circuits. It… …   Wikipedia

• Maximum power point tracking — Current voltage characteristics of a solar cell at a particular light level, and in darkness. The area of the yellow rectangle gives the output power. Pmax denotes the maximum power point Maximum power point tracking (MPPT) is a technique that… …   Wikipedia

• Multijunction photovoltaic cell — Multi junction solar cells or tandem cells are solar cells containing several p n junctions. Each junction is tuned to a different wavelength of light, reducing one of the largest inherent sources of losses, and thereby increasing efficiency.… …   Wikipedia

• Solar inverter — Internal view of a solar inverter. A solar inverter or PV inverter is a critical component in a Photovoltaic system. It performs the conversion of the variable DC output of the Photovoltaic (PV) modules into a utility frequency AC current that… …   Wikipedia

• Solar cell — A solar cell made from a monocrystalline silicon wafer …   Wikipedia