WO2012088641A1

WO2012088641A1 - Inductor, method for reducing core size and core loss of inductor, and photovoltaic power generation system using same

Info

Publication number: WO2012088641A1
Application number: PCT/CN2010/002220
Authority: WO
Inventors: Yong Xu
Original assignee: General Electric Company
Priority date: 2010-12-30
Filing date: 2010-12-30
Publication date: 2012-07-05

Abstract

A photovoltaic (PV) power generation system includes at least one PV collection device (12) configured to generate a direct current (30), and a boost converter (32, 34) which is coupled to the PV collection device and configured to convert the direct current to an alternating current (36). The boost converter includes at least one direct current boost inductor (52). The boost inductor includes an inductor core (152) configured to form at least one closed magnetic circuit, at least one coil, and at least one permanent magnet configured to produce a first magnetic flux within the inductor core that flows in a first direction around the at least one closed magnetic circuit. A method for reducing core size and core loss of the inductor is also provided.

Description

INDUCTOR, METHOD FOR REDUCING CORE SIZE AND CORE LOSS OF INDUCTOR, AND PHOTOVOLTAIC POWER GENERATION SYSTEM USING SAME

BACKGROUND OF THE INVENTION

[0001] The field of the disclosure relates generally to a photovoltaic (PV) power generation system, and more specifically, to a boost power circuit for use in a PV power generation system.

[0002] Solar energy has increasingly become an attractive source of energy and has been recognized as a clean, renewable alternative form of energy. Solar energy in the form of sunlight may be converted to electrical energy by solar cells. A more general term for devices that convert light to electrical energy is "photovoltaic cells." Sunlight is a subset of light and solar cells are a subset of photovoltaic cells. A photovoltaic cell comprises a pair of electrodes and a light- absorbing photovoltaic material disposed therebetween. When the photovoltaic material is irradiated with light, electrons that have been confined to an atom in the photovoltaic material are released by light energy to move freely. Thus, free electrons and holes are generated. The free electrons and holes are efficiently separated so that electric energy is continuously extracted. Current commercial photovoltaic cells use a semiconductor photovoltaic material, typically silicon.

[0003] In order to obtain a higher current and voltage, solar cells are electrically connected to form a solar module. In addition to a plurality of solar cells, the solar module may also include sensors, for example, an irradiance sensor, a temperature sensor, a voltage meter, a current meter, and/or a power meter. Solar modules may also be connected to form a module string. Typically, the DC voltages output by the module strings are provided to a grid converter, for example, a DC to AC voltage inverter and/or a two-stage solar converter. The grid converter converts the DC voltage to three-phase alternating current (AC) voltage or current. Typically, the three-phase AC output from the grid converter is provided to a power transformer, which steps up the voltage to produce a three-phase high-voltage AC that is applied to an electrical grid.

[0004] A boost converter may be included within the grid converter to boost voltage and adjusting a power factor of power generated by the solar modules. The boost converter may be coupled between the solar modules and the electrical grid for conditioning the output of the solar modules before being applied to the electrical grid. A boost converter typically includes at least one inductor and at least one power switching component. For linear operation, the inductor must be configured such that current applied to the inductor will not cause the inductor core to saturate. The minimum size of the inductor core unfortunately is limited by the maximum magnetic fields the core can handle without driving the core into saturation. Furthermore, the efficiency of a solar power generation system is at least partially limited by the efficiency of the grid converter, of which core loss within the inductor is a component.

[0005] U.S. Patent No. 5,821,844 describes a D.C. reactor that includes a core structure and a pair of permanent magnets disposed on the core structure. The permanent magnets generate a bias flux within the core structure in an opposite direction to magnetic flux generated by current flowing through a reactor coil. The bias flux suppresses occurrence of core saturation and may reduce the size of a D.C. reactor.

BRIEF DESCRIPTION OF THE INVENTION

[0006] In one aspect, a photovoltaic (PV) power generation system is provided. The PV power generation system includes at least one photovoltaic (PV) module configured to generate a direct current. The PV power generation system also includes a boost converter coupled to the at least one PV module. The boost converter is configured to convert the direct current to an alternating current. The boost converter includes at least one direct current (DC) boost inductor. The at least one DC boost inductor includes an inductor core configured to form at least one closed magnetic circuit, at least one coil, and at least one permanent magnet. The at least one permanent magnet is configured to produce a first magnetic flux within the inductor core that flows in a first direction around the at least one closed magnetic circuit, which reduces a total magnetic flux within the inductor core.

[0007] In another aspect, a direct current (DC) boost inductor for use in a boost converter coupled to at least one photovoltaic (PV) module is provided. The DC boost inductor includes an inductor core configured to form at least one closed magnetic circuit and at least one coil positioned around the inductor core and configured to receive direct current from the at least one PV module. The DC boost inductor also includes at least one permanent magnet configured to produce a first magnetic flux in the inductor core that flows in a first direction around the at least one closed magnetic circuit and reduces a total magnetic flux within the inductor core.

[0008] In yet another aspect, a method for reducing a size of a direct current (DC) boost inductor included within a boost converter coupled to at least one photovoltaic (PV) module is provided. The boost converter further includes at least one power switching component coupled to the DC boost inductor, wherein the DC boost inductor includes at least one coil and an inductor core configured to form at least one closed magnetic circuit. The method includes providing the at least one coil with direct current from the at least one PV module. The method also includes applying a first magnetic flux generated by a permanent magnet to the inductor core. The permanent magnet is oriented with respect to the inductor core such that the first magnetic flux within the inductor core flows in a first direction around the at least one closed magnetic circuit, which reduces a total magnetic flux within the inductor core.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 is a block diagram of a photovoltaic (PV) power generation system.

[0010] Figure 2 is a first exemplary embodiment of a boost converter circuit that may be included within the grid converter shown in Figure 1.

[001 1] Figure 3 is a second exemplary embodiment of a boost converter circuit that may be included within the grid converter shown in Figure 1. [0012] Figure 4 is a third exemplary embodiment of a boost converter circuit that may be included within the grid converter shown in Figure 1.

[0013] Figure 5 is a cross-sectional view of an exemplary embodiment of a boost converter inductor that may be included within the boost converter circuits shown in Figures 2-4.

[0014] Figure 6 is an exemplary plot of current flowing through a boost converter inductor, for example, the boost converter inductor shown in Figure 5.

[0015] Figure 7 is an exemplary plot of a magnetization curve for a boost converter inductor, for example, the boost converter inductor shown in Figure 5.

[0016] Figure 8 is an exemplary embodiment of an equivalent magnetic circuit to the boost converter inductor shown in Figure 5.

[0017] Figure 9 is a flow chart of an exemplary method for reducing a size of a direct current (DC) boost inductor, for example, the boost converter inductor shown in Figure 5.

DETAILED DESCRIPTION OF THE INVENTION

[0018] The methods and systems described herein facilitate reducing a size and increasing an efficiency of a boost converter included within a photovoltaic (PV) power generation system. More specifically, the methods and systems described herein facilitate reducing a size of a magnetic core included within a direct current (DC) boost converter inductor. The methods and systems described herein minimize a DC bias magnetic field within the magnetic core by applying a magnetic flux generated by a permanent magnet to the magnetic core. A magnetic flux provided by the permanent magnet is applied to the magnetic core in an opposite direction to the magnetic flux generated by current flowing through the DC boost converter inductor, thereby reducing a total magnetic flux within the inductor core. Reducing the total magnetic flux within the inductor core allows use of a smaller inductor core, without increasing the risk of reaching magnetic saturation. [0019] Figure 1 is a block diagram of a photovoltaic (PV) power generation system 10. In the exemplary embodiment, system 10 includes a PV collection device 12, a grid converter 14, a transformer 16, and an electrical grid 18. As referred to herein, electrical grid 18 is a network of conductors and devices configured for distribution and/or transmission of electricity. Typically, PV collection device 12 includes a plurality of PV module strings coupled, for example, by a DC switch gear (not shown in Figure 1), that collects DC voltages from the PV module strings and outputs a direct current 30. Direct current 30 is provided to grid converter 14 which conditions direct current 30. For example, grid converter 14 may be a two- stage grid converter that includes a DC to DC boost converter 32 and a DC to AC voltage converter 34 configured to convert direct current 30 to an alternating current 36. Although described herein with respect to PV power generation system 10, the methods and systems described herein may also be included within an energy storage system, for example, but not limited to, an energy storage system that includes batteries.

[0020] Alternating current 36 is provided to power transformer 16. In the exemplary embodiment, transformer 16 steps up a voltage of alternating current 36 and outputs a high-voltage alternating current 38, which is applied to a load, for example, electrical grid 18. System 10 also includes a system controller 40. System controller 40 is coupled to grid converter 14 and configured to control operation of grid converter 14. For example, system controller 40 may provide boost converter 32 with a switching frequency signal (e.g., a pulse width modulated signal), which controls the switching frequency of at least one power switching component included within boost converter 32. In the exemplary embodiment, system controller 40 includes a processing device. The term processing device, as used herein, refers to central processing units, microprocessors, microcontrollers, reduced instruction set circuits (RISC), application specific integrated circuits (ASIC), logic circuits, and any other circuit or processor capable of executing the functions described herein.

[0021] Figure 2 is a first exemplary embodiment of a boost converter circuit 50 that may be included within grid converter 14 (shown in Figure 1). In the exemplary embodiment, boost converter circuit 50 is a single-phase boost circuit that includes a DC boost converter inductor 52 and at least one power switching component 54. In the first exemplary embodiment, power switching component 54 comprises a transistor 56 and a diode 58. Transistor 56 may include a metal oxide semiconductor field-effect transistor (MOSFET), an insulated-gate bipolar transistor (IGBT), a bipolar junction transistor (BJT), and or any suitable switching device that allows boost circuit 50 to function as described herein. Boost converter inductor 52 receives direct current from PV collection device 12 (shown in Figure 1). In the exemplary embodiment, power switching component 54 is provided with a pulse width modulated (PWM) signal, for example, PWM signal 60 (shown in Figure 6), to control operation of boost circuit 50. Furthermore, boost converter circuit 50 includes a load 62.

[0022] Figure 3 is a second exemplary embodiment of a boost converter circuit 80 that may be included within grid converter 14 (shown in Figure 1). Boost converter circuit 80 is a two-phase boost circuit that includes a first boost converter inductor 82, a second boost converter inductor 84, and at least one power switching component 54. In the second exemplary embodiment, power switching component 54 includes a first transistor 86, a second transistor 88, a first diode 90, and a second diode 92. Furthermore, boost converter circuit 80 includes load 62.

[0023] Figure 4 is a third exemplary embodiment of a boost converter circuit 100 that may be included within grid converter 14 (shown in Figure 1). Boost converter circuit 100 is a three-phase boost circuit that includes a first boost converter inductor 102, a second boost converter inductor 104, a third boost converter inductor 106, and at least one power switching component 54. In the third exemplary embodiment, power switching component 54 includes a first transistor 108, a second transistor 1 10, a third transistor 1 12, a first diode 1 14, a second diode 1 16, and a third diode 1 18. In the exemplary embodiment, boost circuit 100 is a three channel interleaved boost converter topology. Furthermore, boost converter circuit 100 includes load 62. [0024] Figure 5 is a cross-sectional view of an exemplary embodiment of a boost converter inductor 150 that may be included within boost circuits 50, 80, and/or 100 (shown in Figures 2-4). In the exemplary embodiment, boost converter inductor 150 includes an inductor core 152 and at least one coil, for example, coil 154. In the exemplary embodiment, inductor core 152 includes a first leg 156, a second leg 158, and a third leg 160. Inductor core 152 forms at least one closed magnetic circuit, for example, a first magnetic circuit 162, which includes first leg 156 and second leg 158 and a second magnetic circuit 164, which includes second leg 158 and third leg 160. Inductor core 152 may include multiple sections. For example, inductor core 152 may include an I-shaped section and an E-shaped section relatively positioned to form inductor core 152. In another example, inductor core 152 may include a T-shaped section and a C-shaped section relatively positioned to form inductor core 152. Furthermore, inductor core 152 may include sections shaped in any other way that facilitates forming inductor core 152. Moreover, in the exemplary embodiment, inductor core 152 comprises a plurality of oriented silicon steel laminations and/or amorphous alloys, which have lower eddy current losses than non-oriented silicon steel laminations, coupled together to form inductor core 152.

[0025] In the exemplary embodiment, first coil 154 comprises a conductive foil, for example, but not limited to, a copper foil and/or an aluminum foil wound on inductor core 152. Using a thin conductive foil facilitates decreasing core loss caused by eddy current and/or skin effect. Coil 154 receives direct current from PV collection device 12. As described above, boost converter inductor 150 may be included within a DC boost circuit, for example, DC boost circuit 50 (shown in Figure 2). DC boost circuit 50 includes at least one power switching component 54, which is coupled to a boost converter inductor such as boost converter inductor 150. The at least one power switching component 54 causes the direct current flowing through coil 154 to vary, which induces a first magnetic field 174, also referred to herein as a first coil magnetic flux, and a second magnetic field 176, also referred to herein as a second coil magnetic flux, within inductor core 152. [0026] In the exemplary embodiment, a first permanent magnet 200 and a second permanent magnet 202 are coupled to inductor core 152. For example, first permanent magnet 200 is coupled to a first exterior surface 210 of inductor core 152 and second permanent magnet 202 is coupled to a second exterior surface 212 of inductor core 152. First permanent magnet 200 produces a first permanent magnet bias flux 220 within inductor core 152 and second permanent magnet 202 produces a second permanent magnet bias flux 222 within inductor core 152. The magnetic fields produced by first permanent magnet 200 and second permanent magnet 202 interact and bias flux 220 and 222 are shown as a general representation of the resultant flux within inductor core 152. A polarity of first permanent magnet 200 with respect to inductor core 152 is determined such that first permanent magnet bias flux 220 flows in a direction opposite to first coil magnetic flux 174. Additionally, a polarity of second permanent magnet 202 with respect to inductor core 152 is determined such that the second permanent magnet bias flux 222 flows in a direction opposite second coil magnetic flux 176.

[0027] Figure 6 is an exemplary plot 250 of an amount of current 252 flowing through an inductor, for example, inductor 52 (shown in Figure 2) included within a boost converter circuit, for example, boost converter circuit 50 (shown in Figure 2). The at least one power switching component 54 (shown in Figure 2) causes · the direct current 252 flowing through a coil of inductor 52 to vary with respect to time. More specifically, current 252 varies from a first current level (II) to a second current level (12) based on a PWM signal provided to power switching component 54. In a typical boost converter application, the PWM signal, and therefore current 252, have a frequency in, for example, the kilohertz range (e.g., from one kilohertz to one megahertz). Furthermore, current 252 received from PV collection device 12 is always positive and includes a DC bias current 254.

[0028] Figure 7 is an exemplary plot 280 of a magnetization curve for a boost converter inductor, for example, inductor 52 (shown in Figure 2). A first magnetic working region 282 is illustrated as an example of a magnetic working region of a boost converter inductor that does not include permanent magnets 200 and/or 202 (shown in Figure 5). Since current 252 varies between II and 12 but is always positive, as shown in Figure 6, the magnetic field in inductor core 152 is also always positive. Therefore, the negative region of the magnetization curve is not utilized. This may cause inductor 52 to more easily reach magnetic saturation.

[0029] A second magnetic working region 290 is also illustrated. Second magnetic working region 290 is an example of a magnetic working region of a boost converter inductor that includes at least one permanent magnet, for example, boost converter inductor 150 (shown in Figure 5), which includes permanent magnets 200 and 202. A substantially constant combined bias flux 292 represents the effect of first permanent magnet bias flux 220 and second permanent magnet bias flux 222 within inductor core 152, which is to reduce a total magnetic flux within inductor core 152. In the exemplary embodiment, permanent magnets 200 and 202 reduce the total magnetic flux within inductor core 152 such that second magnetic working region 290 is at least partially in the negative region of the magnetization curve. By reducing the total magnetic flux within inductor core 152, boost converter inductor operates at a region within the magnetization curve farther from magnetic saturation than without permanent magnets 200 and 202.

[0030] Figure 8 is an exemplary embodiment of an equivalent magnetic circuit 300 to boost converter inductor 150 (shown in Figure 5). Equivalent magnetic circuit 300 includes an equivalent magnetic resistance (RMI) 310 of permanent magnet 200 (shown in Figure 5) and an equivalent magnetic resistance (RM₂) 312 of permanent magnet 202 (shown in Figure 5). Permanent magnet 200 creates a first permanent magnet magnetomotive force (F I) 314 and permanent magnet 202 creates a second permanent magnet magnetomotive force (FM2) 316. Inductor core 152 is represented as an equivalent magnetic resistance (R) 318. Current 252 flowing through coil 154 generates a coil magnetomotive force (Fi) 320. Furthermore, equivalent magnetic circuit 300 includes a first equivalent magnetic resistance (R§i) 322 and a second equivalent magnetic resistance (Rg₂) 324 of air gaps included within boost converter inductor 150. [0031] In the exemplary embodiment, when coil 154 is magnetized by current 252 of a boost circuit, for example, boost circuit 50 (shown in Figure 2), coil 154 produces first coil magnetic flux 174 and second coil magnetic flux 176. Permanent magnets 200 and 202 generate first permanent magnet bias flux 220 and second permanent magnet bias flux 222, respectively. First permanent magnet bias flux 220 substantially eliminates a DC component of first coil magnetic flux 174, leaving only an alternating component of first coil magnetic flux 174. Similarly, second permanent magnet bias flux 222 substantially eliminates a DC component of second coil magnetic flux 176, leaving only an alternating component of second magnetic flux 176. Reducing the DC components of first coil magnetic flux 174 and second coil magnetic flux 176 facilitates reducing a size and/or weight of inductor core 152.

[0032] Figure 9 is a flow chart 350 of an exemplary method 352 for reducing a size of a direct current (DC) boost converter inductor, for example, boost converter inductor 150 (shown in Figure 5). As described above, in the exemplary embodiment, boost converter inductor 150 may be included within a boost converter 32 (shown in Figure 1) coupled to at least one PV collection device 12 (shown in Figure 1). In the exemplary embodiment, method 352 includes providing 354 at least one coil 154 with direct current from PV collection device 12.

[0033] In the exemplary embodiment, method 352 also includes applying 356 a first magnetic flux, for example, permanent magnet bias flux 220 (shown in Figure 5), generated by a permanent magnet, for example, permanent magnet 200, to inductor core 152. Permanent magnet 200 is oriented such that permanent magnet bias flux 220 opposes the coil magnetic flux 174 within inductor core 152 and reduces a total magnetic flux within inductor core 152. Applying 356 the first permanent magnet bias flux 220 includes applying a magnetic field having a negative DC bias flux that substantially eliminates a DC component of coil magnetic flux 174. Furthermore, the applied 356 permanent magnet bias flux 220 is operative to increase a current level threshold that causes boost inductor 150 to reach saturation. Reducing a total magnetic flux within inductor core 152 facilitates reducing a size of inductor core 152 compared to an inductor core that does not include permanent magnet 200.

[0034] DC boost inductors are a significant contributor to the size, power loss, and cost of a PV converter. The methods and apparatus described herein facilitate reducing a size, power loss, and cost of DC boost inductors used in a PV converter. The methods and apparatus described herein utilize permanent magnets to create a DC bias flux within a core of the DC boost inductor that opposes a DC bias flux induced within the core by current flowing through an inductor coil. Reducing the total magnetic flux within the inductor core allows use of a smaller inductor core, without increasing the risk of reaching magnetic saturation.

[0035] Described herein are exemplary methods and systems for reducing a size of a DC boost inductor included within a PV converter. More specifically, the methods, systems, and apparatus described herein facilitate reducing a total magnetic flux within a core of the DC boost inductor, therefore, facilitating use of a smaller inductor core without increasing the risk of reaching magnetic saturation.

[0036] The methods and systems described herein facilitate efficient and economical operation of a PV converter. Exemplary embodiments of methods and systems are described and/or illustrated herein in detail. The methods and systems are not limited to the specific embodiments described herein, but rather, components of each system, as well as steps of each method, may be utilized independently and separately from other components and steps described herein. Each component, and each method step, can also be used in combination with other components and/or method steps.

[0037] When introducing elements/components/etc. of the methods, systems, and apparatus described and/or illustrated herein, the articles "a", "an", "the", and "said" are intended to mean that there are one or more of the element(s)/component(s)/etc. The terms "comprising", "including", and "having" are intended to be inclusive and mean that there may be additional element(s)/component(s)/etc. other than the listed element(s)/component(s)/etc. [0038] This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.

Claims

WHAT IS CLAIMED IS:

1. A photovoltaic (PV) power generation system comprising: at least one photovoltaic (PV) collection device configured to generate a direct current; and a boost converter coupled to said at least one PV collection device, said boost converter configured to convert the direct current to an alternating current, said boost converter comprising at least one direct current (DC) boost inductor, wherein said at least one DC boost inductor comprises an inductor core configured to form at least one closed magnetic circuit, at least one coil, and at least one permanent magnet, said at least one permanent magnet configured to produce a first magnetic flux within said inductor core that flows in a first direction around the at least one closed magnetic circuit, which reduces a total magnetic flux within said inductor core.

2. A PV power generation system in accordance with Claim 1, wherein said at least one DC boost inductor comprises a first DC boost inductor, a second DC boost inductor, and a third DC boost inductor each coupled to a respective phase of a multiple phase PV power generation system.

3. A PV power generation system in accordance with Claim 1, further comprising an electrical grid coupled to said boost converter and configured to receive a power output of said boost converter.

4. A PV power generation system in accordance with Claim 3, wherein said boost converter further comprises at least one power switching component coupled between said at least one DC boost inductor and said electrical grid.

5. A PV power generation system in accordance with Claim 4, wherein said at least one power switching component operates at a switching frequency within a range of one kilohertz to one megahertz.

6. A PV power generation system in accordance with Claim 4, wherein said at least one power switching component causes the direct current flowing through said at least one coil to vary with respect to time, which induces a second magnetic flux in said inductor core that flows in a second direction around the at least one closed magnetic circuit, wherein the second direction is opposite to the first direction and the total magnetic flux within said inductor core comprises the first magnetic flux minus the second magnetic flux.

7. A PV power generation system in accordance with Claim 6, wherein said at least one permanent magnet is configured to substantially eliminate a DC component of the second magnetic flux, leaving only an alternating component of the second magnetic flux.

8. A PV power generation system in accordance with Claim 1, wherein said at least one permanent magnet is configured to adjust a magnetic working region of said at least one DC boost inductor from a positive magnetic flux region to an at least partially negative magnetic flux region.

9. A PV power generation system in accordance with Claim 1, wherein said at least one coil comprises a conductive foil wound around said inductor core.

10. A PV power generation system in accordance with Claim 1, wherein said inductor core comprises a plurality of oriented silicon steel laminations.

11. A direct current (DC) boost inductor for use in a boost converter coupled to at least one photovoltaic (PV) collection device, said DC boost inductor comprising: an inductor core configured to form at least one closed magnetic circuit; at least one coil positioned around said inductor core and configured to receive direct current from the at least one PV collection device; and at least one permanent magnet configured to produce a first magnetic flux in said inductor core that flows in a first direction around the at least one closed magnetic circuit and reduces a total magnetic flux within said inductor core.

12. A DC boost inductor in accordance with Claim 11, wherein said DC boost inductor is coupled between the at least one PV collection device and at least one power switching component, said at least one power switching component causes the direct current flowing through said at least one coil to vary with respect to time, which induces a second magnetic flux in said inductor core that flows in a second direction around the at least one closed magnetic circuit, wherein the second direction is opposite to the first direction.

13. A DC boost inductor in accordance with Claim 12, wherein the at least one permanent magnet is configured to substantially eliminate a DC component of the second magnetic flux, leaving only an alternating component of the second magnetic flux.

14. A DC boost inductor in accordance with Claim 11, wherein said at least one permanent magnet is configured to produce a first magnetic flux that adjusts a magnetic working region of said DC boost inductor from a positive magnetic flux region to an at least partially negative magnetic flux region.

15. A DC boost inductor in accordance with Claim 11, wherein said at least one coil comprises a conductive foil wound around said inductor core.

16. A DC boost inductor in accordance with Claim 11, wherein said inductor core comprises a plurality of oriented silicon steel laminations.

17. A method for reducing a size of a direct current (DC) boost converter inductor included within a boost converter coupled to at least one PV collection device, the boost converter further including at least one power switching component coupled to the DC boost converter inductor, wherein the DC boost converter inductor includes at least one coil and an inductor core configured to form at least one closed magnetic circuit, said method comprising: providing the at least one coil with direct current from the at least one PV collection device; and applying a first magnetic flux generated by a permanent magnet to the inductor core, the permanent magnet oriented with respect to the inductor core such that the first magnetic flux within the inductor core flows in a first direction around the at least one closed magnetic circuit, which reduces a total magnetic flux within the inductor core.

18. A method in accordance with Claim 17, further comprising configuring the at least one switching component to operate at a switching frequency that causes the direct current flowing through the at least one coil to vary with respect to time, which induces a second magnetic flux in the inductor core that flows in a second direction around the at least one closed magnetic circuit, wherein the second direction is opposite to the first direction and the total magnetic flux within the inductor core comprises the first magnetic flux minus the second magnetic flux.

19. A method in accordance with Claim 18, wherein applying a first magnetic flux generated by a permanent magnet comprises applying a magnetic flux that substantially eliminates a DC component of the second magnetic flux and increases a current level threshold that causes the boost inductor to reach magnetic saturation.

20. A method in accordance with Claim 17, further comprising configuring the at least one switching component to output a substantially constant DC link voltage.