Charge Controllers - Revision history

Ranisha at 14:29, 18 February 2015

2015-02-18T14:29:39Z

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Ranisha at 14:08, 11 November 2014

2014-11-11T14:08:19Z

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Ranisha at 11:55, 15 August 2014

2014-08-15T11:55:07Z

Wiki Gardener at 10:38, 18 June 2014

2014-06-18T10:38:16Z

Wiki Gardener at 15:15, 13 July 2012

2012-07-13T15:15:29Z

Wiki Gardener at 09:51, 13 June 2012

2012-06-13T09:51:24Z

Wiki Gardener at 09:48, 13 June 2012

2012-06-13T09:48:44Z

Robert at 04:32, 6 September 2011

2011-09-06T04:32:45Z

Robert at 04:31, 6 September 2011

2011-09-06T04:31:40Z

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Katharina Meder at 14:28, 11 August 2011

2011-08-11T14:28:14Z

@@ Line 1: / Line 1: @@
 = Overview<br/> =
@@ Line 40: / Line 39: @@
 Since photovoltaic cells are current-limited by design (unlike batteries), PV modules and arrays can be short-circuited without any harm. The ability to short-circuit modules or an array is the basis of operation for shunt controllers.
-The shunt controller regulates the charging of a battery from the PV array by short-circuiting the array internal to the controller. All shunt controllers must have a blocking diode in series between the battery and the shunt element to prevent the battery from short-circuiting when the array is regulating. Because there is some voltage drop between the array and controller and due to wiring and resistance of the shunt element, the array is never entirely shortcircuited, resulting in some power dissipation within the controller. For this reason, most shunt controllers require a heat sink to dissipate power, and are generally limited to use in PV systems with array currents less than 20 amps.
+The shunt controller regulates the charging of a battery from the PV array by short-circuiting the array internal to the controller. All shunt controllers must have a blocking diode in series between the battery and the shunt element to prevent the battery from short-circuiting when the array is regulating. Because there is some voltage drop between the array and controller and due to wiring and resistance of the shunt element, the array is never entirely short circuited, resulting in some power dissipation within the controller. For this reason, most shunt controllers require a heat sink to dissipate power, and are generally limited to use in PV systems with array currents less than 20 amps.
 The regulation element in shunt controllers is typically a power transistor or MOSFET, depending on the specific design. There are a couple of variations of the shunt controller design. The first is a simple interrupting, or on-off type controller design. The second type limits the array current in a gradual manner, by increasing the resistance of the shunt element as the battery reaches full state of charge. These two variations of the shunt controller are discussed next.
@@ Line 66: / Line 65: @@
 As the name implies, this type of controller works in series between the array and battery, rather than in parallel as for the shunt controller. There are several variations to the series type controller, all of which use some type of control or regulation element in series between the array and the battery. While this type of controller is commonly used in small PV systems, it is also the practical choice for larger systems due to the current limitations of shunt controllers.
-In a series controller design, a relay or solid-state switch either opens the circuit between the array and the battery to discontinuing charging, or limits the current in a series-linear manner to hold the battery voltage at a high value. In the simpler seriesinterrupting design, the controller reconnects the array to the battery once the battery falls to the array reconnect voltage set point. As these on-off charge cycles continue, the ‘on’ time becoming shorter and shorter as the battery becomes fully charged.
+In a series controller design, a relay or solid-state switch either opens the circuit between the array and the battery to discontinuing charging, or limits the current in a series-linear manner to hold the battery voltage at a high value. In the simpler series interrupting design, the controller reconnects the array to the battery once the battery falls to the array reconnect voltage set point. As these on-off charge cycles continue, the ‘on’ time becoming shorter and shorter as the battery becomes fully charged.
 Because the series controller open-circuits rather than short-circuits the array as in shunt-controllers, no blocking diode is needed to prevent the battery from short-circuiting when the controller regulates.
@@ Line 104: / Line 103: @@
 === Series-Interrupting, Pulse Width Modulated (PWM) Design ===
-This algorithm uses a semiconductor switching element between the array and battery which is switched on/off at a variable frequency with a variable duty cycle to maintain the battery at or very close to the voltage regulation set point. Although a series type PWM design is discussed here, shunt-type PWM designs are also popular and perform battery charging in similar ways. Similar to the series-linear, constant-voltage algorithm in performance, power dissipation within the controller is considerably lower in the seriesinterrupting PWM design.
+This algorithm uses a semiconductor switching element between the array and battery which is switched on/off at a variable frequency with a variable duty cycle to maintain the battery at or very close to the voltage regulation set point. Although a series type PWM design is discussed here, shunt-type PWM designs are also popular and perform battery charging in similar ways. Similar to the series-linear, constant-voltage algorithm in performance, power dissipation within the controller is considerably lower in the series interrupting PWM design.
 By electronically controlling the high speed switching or regulation element, the PWM controller breaks the array current into pulses at some constant frequency, and varies the width and time of the pulses to regulate the amount of charge flowing into the battery as shown in Figure 12-8. When the battery is discharged, the current pulse width is practically fully on all the time. As the battery voltage rises, the pulse width is decreased, effectively reducing the magnitude of the charge current.
-The PWM design allows greater control over exactly how a battery approaches full charge and generates less heat. PWM type controllers can be used with '''all battery types''', however the controlled manner in which power is applied to the battery makes them preferential for use with '''sealed VRLA type batteries''' over on-off type controls. To limit overcharge and gassing, the voltage regulation set points for PWM and constantvoltage controllers are generally specified lower than those for on-off type controllers. For example, a PWM controller operating with a nominal 12 volt flooded lead-antimony battery might use a VR set point of 14.4 to 14.6 volts at 25°C, while an on-off controller used with the same battery might require a VR set point of between 14.7 and 15.0 volts to fully recharge the battery on a typical day.<ref>James P. Dunlop, Florida Solar Energy Center for Sandia National Laboratories: Batteries and Charge Control in Stand-Alone Photovoltaic Systems. Fundamentals and Application, 1997</ref>
+The PWM design allows greater control over exactly how a battery approaches full charge and generates less heat. PWM type controllers can be used with '''all battery types''', however the controlled manner in which power is applied to the battery makes them preferential for use with '''sealed VRLA type batteries''' over on-off type controls. To limit overcharge and gassing, the voltage regulation set points for PWM and constant voltage controllers are generally specified lower than those for on-off type controllers. For example, a PWM controller operating with a nominal 12 volt flooded lead-antimony battery might use a VR set point of 14.4 to 14.6 volts at 25°C, while an on-off controller used with the same battery might require a VR set point of between 14.7 and 15.0 volts to fully recharge the battery on a typical day.<ref>James P. Dunlop, Florida Solar Energy Center for Sandia National Laboratories: Batteries and Charge Control in Stand-Alone Photovoltaic Systems. Fundamentals and Application, 1997</ref>
 <br/>
@@ Line 114: / Line 113: @@
 = Further Information<br/> =
-For further information on charge controllers in [[Solar Home Systems|solar home systems]] see [[Standards for the Charge Regulator|standards for the charge regulator]].
+For further information on charge controllers in [[Solar Home Systems (SHS)|solar home systems]] see [[Standards for the Charge Regulator|standards for the charge regulator]].
 *[[Portal:Solar|Solar Portal on energypedia]]
@@ Line 121: / Line 120: @@
 <references />
 [[Category:Solar]]

@@ Line 1: / Line 1: @@
 = Overview<br/> =
@@ Line 7: / Line 8: @@
 Proper operation of a charge controller should prevent overcharge or over discharge of a battery regardless of the system sizing/design and seasonal changes in the load profile and operating temperatures. The algorithm or control strategy of a battery charge controller determines the effectiveness of battery charging and PV array utilization, and ultimately the ability of the system to meet the load demands. Additional features such as temperature compensation, alarms, and special algorithms can enhance the ability of a charge controller to maintain the health, maximize capacity, and extend the lifetime of a battery.<ref name="Polar Power Inc.">www.polarpowerinc.com/info/operation20/operation25.htm#2.5.2</ref>
+<br/>
 = Basics of Charge Controller Theory =
 While the specific control method and algorithm vary among charge controllers, all have basic parameters and characteristics. Manufacturer's data generally provides the limits of controller application such as PV and load currents, operating temperatures, losses, set points, and set point hysteresis values. In some cases the set points may be intentionally dependent upon the temperature of the battery and/or controller, and the magnitude of the battery current.
 <u>A discussion of the four basic charge controller set points follows:</u>
@@ Line 23: / Line 24: @@
 '''Low voltage disconnect hysteresis (LVDH):''' This set point is the voltage span or difference between the LVD set point and the voltage at which the load is reconnected to the battery. If the LVDH is too small, the load may cycle on and off rapidly at low battery state-of-charge, possibly damaging the load and/or controller. If the LVDH is too large, the load may remain off for extended periods until the array fully recharges the battery. With a large LVDH, battery health may be improved due to reduced battery cycling, but this will reduce load availability. The proper LVDH selection will depend on the battery chemistry, battery capacity, and PV and load currents.<ref name="Polar Powe Inc.">www.polarpowerinc.com/info/operation20/operation25.htm#2.5.2</ref>
+<br/>
 = Charge Controller Designs =
@@ Line 33: / Line 34: @@
 Some of the more common design approaches for charge controllers are described in this section.
+<br/>
 == Shunt Controller Designs ==
@@ Line 43: / Line 44: @@
 The regulation element in shunt controllers is typically a power transistor or MOSFET, depending on the specific design. There are a couple of variations of the shunt controller design. The first is a simple interrupting, or on-off type controller design. The second type limits the array current in a gradual manner, by increasing the resistance of the shunt element as the battery reaches full state of charge. These two variations of the shunt controller are discussed next.
+<br/>
 === Shunt-Interrupting Design ===
@@ Line 51: / Line 52: @@
 Shunt-interrupting charge controllers can be used on '''all battery types''', however the way in which they apply power to the battery may not be optimal for all battery designs. In general, constant-voltage, PWM or linear controller designs are recommended by manufacturers of gelled and AGM lead-acid batteries. However, shunt-interrupting controllers are simple, low cost and perform well in most small stand-alone PV systems.
+<br/>
 === Shunt-Linear Design ===
@@ Line 59: / Line 60: @@
 Shunt-linear controllers are popular for use with '''sealed VRLA batteries'''. This algorithm applies power to the battery in a preferential method for these types of batteries, by limiting the current while holding the battery at the regulation voltage.
+<br/>
 == Series Controller Designs ==
@@ Line 69: / Line 70: @@
 Because the series controller open-circuits rather than short-circuits the array as in shunt-controllers, no blocking diode is needed to prevent the battery from short-circuiting when the controller regulates.
+<br/>
 === Series-Interrupting Design ===
@@ Line 77: / Line 78: @@
 Similar to the shunt-interrupting type controller, the series-interrupting type designs are best suited for use with '''flooded batteries''' rather than the sealed VRLA types due to the way power is applied to the battery.
+<br/>
 === Series-Interrupting, 2-step, Constant-Current Design ===
@@ Line 83: / Line 84: @@
 This type of controller is similar to the series-interrupting type, however when the voltage regulation set point is reached, instead of totally interrupting the array current, a limited constant current remains applied to the battery. This ‘trickle charging’ continues either for a pre-set period of time, or until the voltage drops to the array reconnect voltage due to load demand. Then full array current is once again allowed to flow, and the cycle repeats. Full charge is approached in a continuous fashion, instead of smaller steps as described above for the on-off type controllers. Some two-stage controls increase array current immediately as battery voltage is pulled down by a load. Others keep the current at the small trickle charge level until the battery voltage has been pulled down below some intermediate value (usually 12.5-12.8 volts) before they allow full array current to resume.
+<br/>
 === Series-Interrupting, 2-Step, Dual Set Point Design ===
@@ Line 91: / Line 92: @@
 This type of regulation strategy can be effective at maintaining high battery state of charge while minimizing battery gassing and water loss for '''flooded lead-acid types'''. The designer must make sure that the dual regulation set points are properly adjusted for the battery type used. For example, typical set point values (at 25°C) for this type of controller used with a flooded lead-antimony battery might be 15.0 to 15.3 volts for the higher regulation voltage, and between 14.2 and 14.4 volts for the lower regulation voltage.
+<br/>
 === Series-Linear, Constant-Voltage Design ===
@@ Line 99: / Line 100: @@
 Series-linear, constant-voltage controllers can be used on '''all types of batteries'''. Because they apply power to the battery in a controlled manner, they are generally more effective at fully charging batteries than on-off type controllers. These designs, along with PWM types are recommended over on-off type controllers for sealed VRLA type batteries.
+<br/>
 === Series-Interrupting, Pulse Width Modulated (PWM) Design ===
@@ Line 109: / Line 110: @@
 The PWM design allows greater control over exactly how a battery approaches full charge and generates less heat. PWM type controllers can be used with '''all battery types''', however the controlled manner in which power is applied to the battery makes them preferential for use with '''sealed VRLA type batteries''' over on-off type controls. To limit overcharge and gassing, the voltage regulation set points for PWM and constantvoltage controllers are generally specified lower than those for on-off type controllers. For example, a PWM controller operating with a nominal 12 volt flooded lead-antimony battery might use a VR set point of 14.4 to 14.6 volts at 25°C, while an on-off controller used with the same battery might require a VR set point of between 14.7 and 15.0 volts to fully recharge the battery on a typical day.<ref>James P. Dunlop, Florida Solar Energy Center for Sandia National Laboratories: Batteries and Charge Control in Stand-Alone Photovoltaic Systems. Fundamentals and Application, 1997</ref>
+<br/>
 = Further Information<br/> =
 For further information on charge controllers in [[Solar Home Systems|solar home systems]] see [[Standards for the Charge Regulator|standards for the charge regulator]].
 = <br/>References<br/> =
@@ Line 119: / Line 121: @@
 <references />
 [[Category:Battery_Charging_Systems]]

@@ Line 1: / Line 1: @@
-= Introduction<br/> =
+= Overview<br/> =
-The primary function of a '''charge controller''' in a stand-alone [[Photovoltaic_(PV)|photovoltaic (PV)]] system is to protect the [[Batteries|battery]] from overcharge and over discharge. Any system that has unpredictable [[Lamps and Electric Appliances|loads]], user intervention, optimized or undersized battery storage (to minimize initial cost), or any characteristics that would allow excessive battery overcharging or over discharging requires a charge controller and/or low-voltage load disconnect. Lack of a controller may result in shortened battery lifetime and decreased load availability.
+The primary function of a '''charge controller''' in a stand-alone '''[[Photovoltaic (PV)|photovoltaic (PV)]]''' system is to protect the [[Batteries|battery]] from overcharge and over discharge. Any system that has unpredictable [[Lamps and Electric Appliances|loads]], user intervention, optimized or undersized battery storage (to minimize initial cost), or any characteristics that would allow excessive battery overcharging or over discharging requires a charge controller and/or low-voltage load disconnect. Lack of a controller may result in shortened battery lifetime and decreased load availability.
 Systems with small, predictable, and continuous loads may be designed to operate without a battery charge controller. If system designs incorporate oversized battery storage and battery charging currents are limited to safe finishing charge rates (C/SO flooded or C/100 sealed) at an appropriate voltage for the battery technology, a charge controller may not be required in the PV system.
@@ Line 11: / Line 11: @@
 = Basics of Charge Controller Theory =
-While the specific control method and algorithm vary among charge controllers, all have basic parameters and characteristics. Manufacturer's data generally provides the limits of controller application such as PV and load currents, operating temperatures, losses, set points, and set point hysteresis values. In some cases the set points may be intentionally dependent upon the temperature of the battery and/or controller, and the magnitude of the battery current. A discussion of the four basic charge controller set points follows:
+While the specific control method and algorithm vary among charge controllers, all have basic parameters and characteristics. Manufacturer's data generally provides the limits of controller application such as PV and load currents, operating temperatures, losses, set points, and set point hysteresis values. In some cases the set points may be intentionally dependent upon the temperature of the battery and/or controller, and the magnitude of the battery current.
 '''Regulation set point (VR):''' This set point is the maximum voltage a controller allows the battery to reach. At this point a controller will either discontinue battery charging or begin to regulate the amount of current delivered to the battery. Proper selection of this set point depends on the specific battery chemistry and operating temperature.
@@ Line 116: / Line 118: @@
 <references />

@@ Line 1: / Line 1: @@
 = Introduction<br/> =
-The primary function of a '''charge controller''' in a stand-alone [[Photovoltaic_(PV)|photovoltaic (]][[Photovoltaics|PV)]]system is to protect the [[Batteries|battery]] from overcharge and over discharge. Any system that has unpredictable [[Lamps and Electric Appliances|loads]], user intervention, optimized or undersized battery storage (to minimize initial cost), or any characteristics that would allow excessive battery overcharging or over discharging requires a charge controller and/or low-voltage load disconnect. Lack of a controller may result in shortened battery lifetime and decreased load availability.
+The primary function of a '''charge controller''' in a stand-alone [[Photovoltaic_(PV)|photovoltaic (PV)]] system is to protect the [[Batteries|battery]] from overcharge and over discharge. Any system that has unpredictable [[Lamps and Electric Appliances|loads]], user intervention, optimized or undersized battery storage (to minimize initial cost), or any characteristics that would allow excessive battery overcharging or over discharging requires a charge controller and/or low-voltage load disconnect. Lack of a controller may result in shortened battery lifetime and decreased load availability.
 Systems with small, predictable, and continuous loads may be designed to operate without a battery charge controller. If system designs incorporate oversized battery storage and battery charging currents are limited to safe finishing charge rates (C/SO flooded or C/100 sealed) at an appropriate voltage for the battery technology, a charge controller may not be required in the PV system.
-Proper operation of a charge controller should prevent overcharge or over discharge of a battery regardless of the system sizing/design and seasonal changes in the load profile and operating temperatures. The algorithm or control strategy of a battery charge controller determines the effectiveness of battery charging and PV array utilization, and ultimately the ability of the system to meet the load demands. Additional features such as temperature compensation, alarms, and special algorithms can enhance the ability of a charge controller to maintain the health, maximize capacity, and extend the lifetime of a battery.<ref name="www.polarpowerinc.com/info/operation20/operation25.htm#2.5.2">Polar Power Inc.</ref>
+Proper operation of a charge controller should prevent overcharge or over discharge of a battery regardless of the system sizing/design and seasonal changes in the load profile and operating temperatures. The algorithm or control strategy of a battery charge controller determines the effectiveness of battery charging and PV array utilization, and ultimately the ability of the system to meet the load demands. Additional features such as temperature compensation, alarms, and special algorithms can enhance the ability of a charge controller to maintain the health, maximize capacity, and extend the lifetime of a battery.<ref name="Polar Power Inc.">www.polarpowerinc.com/info/operation20/operation25.htm#2.5.2</ref>
@@ Line 23: / Line 19: @@
 '''Low voltage disconnect (LVD):''' The set point is voltage at which the load is disconnected from the battery to prevent over discharge. The LVD defines the actual allowable maximum depth-of-discharge and available capacity of the battery. The available capacity must be carefully estimated in the system design and sizing process. Typically, the LVD does not need to be temperature compensated unless the batteries operate below 0°C on a frequent basis. The proper LVD set point will maintain good battery health while providing the maximum available battery capacity to the system.
-'''Low voltage disconnect hysteresis (LVDH):''' This set point is the voltage span or difference between the LVD set point and the voltage at which the load is reconnected to the battery. If the LVDH is too small, the load may cycle on and off rapidly at low battery state-of-charge, possibly damaging the load and/or controller. If the LVDH is too large, the load may remain off for extended periods until the array fully recharges the battery. With a large LVDH, battery health may be improved due to reduced battery cycling, but this will reduce load availability. The proper LVDH selection will depend on the battery chemistry, battery capacity, and PV and load currents.
+'''Low voltage disconnect hysteresis (LVDH):''' This set point is the voltage span or difference between the LVD set point and the voltage at which the load is reconnected to the battery. If the LVDH is too small, the load may cycle on and off rapidly at low battery state-of-charge, possibly damaging the load and/or controller. If the LVDH is too large, the load may remain off for extended periods until the array fully recharges the battery. With a large LVDH, battery health may be improved due to reduced battery cycling, but this will reduce load availability. The proper LVDH selection will depend on the battery chemistry, battery capacity, and PV and load currents.<ref name="Polar Powe Inc.">www.polarpowerinc.com/info/operation20/operation25.htm#2.5.2</ref>
@@ Line 48: / Line 40: @@
 The regulation element in shunt controllers is typically a power transistor or MOSFET, depending on the specific design. There are a couple of variations of the shunt controller design. The first is a simple interrupting, or on-off type controller design. The second type limits the array current in a gradual manner, by increasing the resistance of the shunt element as the battery reaches full state of charge. These two variations of the shunt controller are discussed next.
 === Shunt-Interrupting Design ===
@@ Line 54: / Line 48: @@
 Shunt-interrupting charge controllers can be used on '''all battery types''', however the way in which they apply power to the battery may not be optimal for all battery designs. In general, constant-voltage, PWM or linear controller designs are recommended by manufacturers of gelled and AGM lead-acid batteries. However, shunt-interrupting controllers are simple, low cost and perform well in most small stand-alone PV systems.
 === Shunt-Linear Design ===
@@ Line 70: / Line 66: @@
 Because the series controller open-circuits rather than short-circuits the array as in shunt-controllers, no blocking diode is needed to prevent the battery from short-circuiting when the controller regulates.
 === Series-Interrupting Design ===
@@ Line 76: / Line 74: @@
 Similar to the shunt-interrupting type controller, the series-interrupting type designs are best suited for use with '''flooded batteries''' rather than the sealed VRLA types due to the way power is applied to the battery.
 === Series-Interrupting, 2-step, Constant-Current Design ===
 This type of controller is similar to the series-interrupting type, however when the voltage regulation set point is reached, instead of totally interrupting the array current, a limited constant current remains applied to the battery. This ‘trickle charging’ continues either for a pre-set period of time, or until the voltage drops to the array reconnect voltage due to load demand. Then full array current is once again allowed to flow, and the cycle repeats. Full charge is approached in a continuous fashion, instead of smaller steps as described above for the on-off type controllers. Some two-stage controls increase array current immediately as battery voltage is pulled down by a load. Others keep the current at the small trickle charge level until the battery voltage has been pulled down below some intermediate value (usually 12.5-12.8 volts) before they allow full array current to resume.
 === Series-Interrupting, 2-Step, Dual Set Point Design ===
@@ Line 86: / Line 88: @@
 This type of regulation strategy can be effective at maintaining high battery state of charge while minimizing battery gassing and water loss for '''flooded lead-acid types'''. The designer must make sure that the dual regulation set points are properly adjusted for the battery type used. For example, typical set point values (at 25°C) for this type of controller used with a flooded lead-antimony battery might be 15.0 to 15.3 volts for the higher regulation voltage, and between 14.2 and 14.4 volts for the lower regulation voltage.
 === Series-Linear, Constant-Voltage Design ===
@@ Line 92: / Line 96: @@
 Series-linear, constant-voltage controllers can be used on '''all types of batteries'''. Because they apply power to the battery in a controlled manner, they are generally more effective at fully charging batteries than on-off type controllers. These designs, along with PWM types are recommended over on-off type controllers for sealed VRLA type batteries.
 === Series-Interrupting, Pulse Width Modulated (PWM) Design ===

@@ Line 1: / Line 1: @@
-The primary function of a '''charge controller''' in a stand-alone [[Photovoltaics|PV]] system is to protect the [[Batteries|battery]] from overcharge and over discharge. Any system that has unpredictable [[Lamps and Electric Appliances|loads]], user intervention, optimized or undersized battery storage (to minimize initial cost), or any characteristics that would allow excessive battery overcharging or over discharging requires a charge controller and/or low-voltage load disconnect. Lack of a controller may result in shortened battery lifetime and decreased load availability.
+= Introduction<br/> =
 Systems with small, predictable, and continuous loads may be designed to operate without a battery charge controller. If system designs incorporate oversized battery storage and battery charging currents are limited to safe finishing charge rates (C/SO flooded or C/100 sealed) at an appropriate voltage for the battery technology, a charge controller may not be required in the PV system.
-Proper operation of a charge controller should prevent overcharge or over discharge of a battery regardless of the system sizing/design and seasonal changes in the load profile and operating temperatures. The algorithm or control strategy of a battery charge controller determines the effectiveness of battery charging and PV array utilization, and ultimately the ability of the system to meet the load demands. Additional features such as temperature compensation, alarms, and special algorithms can enhance the ability of a charge controller to maintain the health, maximize capacity, and extend the lifetime of a battery.
+Proper operation of a charge controller should prevent overcharge or over discharge of a battery regardless of the system sizing/design and seasonal changes in the load profile and operating temperatures. The algorithm or control strategy of a battery charge controller determines the effectiveness of battery charging and PV array utilization, and ultimately the ability of the system to meet the load demands. Additional features such as temperature compensation, alarms, and special algorithms can enhance the ability of a charge controller to maintain the health, maximize capacity, and extend the lifetime of a battery.<ref name="www.polarpowerinc.com/info/operation20/operation25.htm#2.5.2">Polar Power Inc.</ref>
@@ Line 97: / Line 99: @@
 By electronically controlling the high speed switching or regulation element, the PWM controller breaks the array current into pulses at some constant frequency, and varies the width and time of the pulses to regulate the amount of charge flowing into the battery as shown in Figure 12-8. When the battery is discharged, the current pulse width is practically fully on all the time. As the battery voltage rises, the pulse width is decreased, effectively reducing the magnitude of the charge current.
-The PWM design allows greater control over exactly how a battery approaches full charge and generates less heat. PWM type controllers can be used with '''all battery types''', however the controlled manner in which power is applied to the battery makes them preferential for use with '''sealed VRLA type batteries''' over on-off type controls. To limit overcharge and gassing, the voltage regulation set points for PWM and constantvoltage controllers are generally specified lower than those for on-off type controllers. For example, a PWM controller operating with a nominal 12 volt flooded lead-antimony battery might use a VR set point of 14.4 to 14.6 volts at 25°C, while an on-off controller used with the same battery might require a VR set point of between 14.7 and 15.0 volts to fully recharge the battery on a typical day.
+The PWM design allows greater control over exactly how a battery approaches full charge and generates less heat. PWM type controllers can be used with '''all battery types''', however the controlled manner in which power is applied to the battery makes them preferential for use with '''sealed VRLA type batteries''' over on-off type controls. To limit overcharge and gassing, the voltage regulation set points for PWM and constantvoltage controllers are generally specified lower than those for on-off type controllers. For example, a PWM controller operating with a nominal 12 volt flooded lead-antimony battery might use a VR set point of 14.4 to 14.6 volts at 25°C, while an on-off controller used with the same battery might require a VR set point of between 14.7 and 15.0 volts to fully recharge the battery on a typical day.<ref>James P. Dunlop, Florida Solar Energy Center for Sandia National Laboratories: Batteries and Charge Control in Stand-Alone Photovoltaic Systems. Fundamentals and Application, 1997</ref>
-Source: James P. Dunlop, Florida Solar Energy Center for Sandia National Laboratories: Batteries and Charge Control in Stand-Alone Photovoltaic Systems. Fundamentals and Application, 1997.
+= Further Information<br/> =
-For further information on charge controllers in [[Solar Home Systems|solar home systems]] see [[Standards for the Charge Regulator|standards for the charge regulator]].
+= <br/>References<br/> =
-<br/>[[Category:PLAGIAT]] <br/> <br/>
+<references />

← Older revision		Revision as of 04:32, 6 September 2011
Line 105:		Line 105:


−	For further information on charge controllers in [[Solar Home Systems\|solar home systems]] see ~~the EnDev wiki page on~~ [[Standards for the Charge Regulator\|standards for the charge regulator]].	+	For further information on charge controllers in [[Solar Home Systems\|solar home systems]] see [[Standards for the Charge Regulator\|standards for the charge regulator]].

−	[[Category:PLAGIAT]]	+	<br/>[[Category:PLAGIAT]] <br/> <br/>

@@ Line 101: / Line 101: @@
 <br>
-Source: [http://www.energypedia.info/index.php/file:Dunlop_batteries_and_charge_control_in_stand-alone_pv_systems.fundamentals_and_application.pdf James P. Dunlop, Florida Solar Energy Center for Sandia National Laboratories: Batteries and Charge Control in Stand-Alone Photovoltaic Systems. Fundamentals and Application, 1997.]
+Source: [[:file:Dunlop_batteries_and_charge_control_in_stand-alone_pv_systems.fundamentals_and_application.pdf|James P. Dunlop, Florida Solar Energy Center for Sandia National Laboratories: Batteries and Charge Control in Stand-Alone Photovoltaic Systems. Fundamentals and Application, 1997.]]
 <br>
@@ Line 111: / Line 111: @@
 <br>
-[[Category:Solar]][[Category:PLAGIAT]]
+[[Category:Solar]] [[Category:PLAGIAT]]