GB2436895A - A high voltage current generator using varying capactitance - Google Patents
A high voltage current generator using varying capactitance Download PDFInfo
- Publication number
- GB2436895A GB2436895A GB0606615A GB0606615A GB2436895A GB 2436895 A GB2436895 A GB 2436895A GB 0606615 A GB0606615 A GB 0606615A GB 0606615 A GB0606615 A GB 0606615A GB 2436895 A GB2436895 A GB 2436895A
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- Prior art keywords
- capacitance
- rotor
- high voltage
- direct current
- stator
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- 230000005284 excitation Effects 0.000 claims description 22
- 230000005540 biological transmission Effects 0.000 description 8
- 239000004020 conductor Substances 0.000 description 4
- 238000010586 diagram Methods 0.000 description 4
- 239000004411 aluminium Substances 0.000 description 3
- 229910052782 aluminium Inorganic materials 0.000 description 3
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 3
- 230000003247 decreasing effect Effects 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 239000011248 coating agent Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- 239000002131 composite material Substances 0.000 description 2
- 238000005094 computer simulation Methods 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 229920000642 polymer Polymers 0.000 description 2
- 238000000926 separation method Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 239000013585 weight reducing agent Substances 0.000 description 2
- 229910000838 Al alloy Inorganic materials 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 239000011888 foil Substances 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02N—ELECTRIC MACHINES NOT OTHERWISE PROVIDED FOR
- H02N1/00—Electrostatic generators or motors using a solid moving electrostatic charge carrier
- H02N1/06—Influence generators
- H02N1/08—Influence generators with conductive charge carrier, i.e. capacitor machines
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Control Of Eletrric Generators (AREA)
Abstract
A high voltage direct current generator (10) comprises a varying capacitance (12). The varying capacitance (12) includes a rotor (14) and a stator (16). The rotor (14) forms a first terminal (18) of the varying capacitance (12) and the stator (16) forms a second terminal (20) of the varying capacitance (12). The rotor (14) has a plurality of circumferentially spaced radially extending rotor blades (22) and the stator (16) has a plurality of circumferentially spaced radially extending stator vanes (24). The rotor blades (22) comprise an electrically conducting member and the stator vanes (24) comprise an electrically conducting member such that rotation of the rotor (14) varies the capacitance formed between the rotor blades (22) and the stator vanes (24) between a maximum capacitance when the rotor blades (22) and stator vanes (24) are angularly aligned and a minimum capacitance when the rotor blades (22) and stator vanes (24) are angularly misaligned. The rotor (14) is driven by a prime mover, for example a wind turbine (29).
Description
2436895
1
A HIGH VOLTAGE DIRECT CURRENT GENERATOR
The present invention relates to a high voltage direct current generator.
The current practice for long distance electrical 5 transmission is to use a transformer to step up the voltage from that at which it is generated to a higher voltage.
This reduces the current and thus losses in the electrical transmission line. The transmission may be either alternating current (AC) or direct current (DC) . With DC 10 transmission it is necessary to rectify the AC current from the transformer so as to create the required DC current.
• •
Thus, there is generally required an AC generator, a low ;
voltage to high voltage transformer, an AC to DC converter and then a DC transmission line to an electrical load. 15 Accordingly the present invention seeks to provide a
• • • •
novel high voltage direct current generator, which seeks to *..* ; minimise, preferably overcome, the above-mentioned problem.
• •
Accordingly the present invention provides a high ****
• • • •
voltage direct current generator comprising a varying •• * 20 capacitance, the varying capacitance including a rotor and a stator, the rotor forming a first terminal of the varying capacitance and the stator forming a second terminal of the varying capacitance, the rotor having a plurality of circumferentially spaced electrically conducting members 25 and the stator having a plurality of circumferentially spaced electrically conducting members such that rotation of the rotor varies the capacitance formed between the electrically conducting plates on the rotor and the electrically conducting plates on the stator between a 30 maximum capacitance when the plates on the rotor and the plates on the stator are angularly aligned and a minimum capacitance when the plates on the rotor and the plates on the stator are angularly misaligned.
Preferably the high voltage direct current generator 35 comprising a varying capacitance, the varying capacitance including a rotor and a stator, the rotor forming a first
2
terminal of the varying capacitance and the stator forming a second terminal of the varying capacitance, the rotor having a plurality of circumferentially spaced radially extending rotor blades and the stator having a plurality of 5 circumferentially spaced radially extending stator vanes, the rotor blades comprising an electrically conducting member, the stator vanes comprising an electrically conducting member such that rotation of the rotor varies the capacitance formed between the rotor blades and the 10 stator vanes between a maximum capacitance when the rotor blades and stator vanes are angularly aligned and a minimum capacitance when the rotor blades and stator vanes are angularly misaligned.
Preferably the rotor blades are equi-circumferentially 15 spaced, the stator vanes are equi-circumferentially spaced.
Preferably the number of rotor blades is equal to the number of stator vanes.
Preferably a negative terminal of an electrical excitation source is electrically connected to one of the 20 rotor and the stator, a positive terminal of the electrical excitation source is electrically connected to one of the stator and the rotor via a first diode, at least one electrical load is electrically connected in parallel with the first diode and a second diode is arranged in 25 electrical series with the at least one electrical load.
Preferably the electrical excitation source is a battery.
Alternatively the electrical excitation source is a pre-charged capacitance.
30 Preferably the pre-charged capacitance has a value of at least 10 times the peak value of the capacitance of the varying capacitance.
Preferably the pre-charged capacitance has a value of at least 50 times the peak value of the capacitance of the 35 varying capacitance.
> • • • • • •
3
Preferably the pre-charged capacitance has a value of at least 100 times the peak value of the capacitance of the varying capacitance.
Preferably the pre-charged capacitance has a value of 5 2\iF to 5^F.
Preferably the pre-charged capacitance has a value of 2 . 5(xF or 3|iF.
Preferably an auxiliary power supply is electrically connectable to the pre-charged capacitance to pre-charge 10 the pre-charged capacitance to lOkV to 1MV, preferably lOOkV.
Preferably the variable capacitance 12 has a value of 2.5nF to 25nF.
Preferably a prime mover is arranged to drive the 15 rotor. Preferably the prime mover comprises a wind turbine or a gas turbine engine.
The present invention will be more fully described by way of example with reference to the accompanying drawings in which:-
20 Figure 1 shows a front view of a high voltage direct current generator comprising a varying capacitance generator according to the present invention.
Figure 2 shows a side view of the high voltage direct current generator comprising a varying capacitance 25 generator shown in figure 1.
Figure 3 shows a circuit diagram of a high voltage direct current generator comprising a varying capacitance generator according to the present invention.
Figure 4A to 4D show the circuit diagram of the high 30 voltage direct current generator comprising a varying capacitance generator to illustrate its operation according to the present invention.
Figure 5 is a graph of capacitance and voltage against time to illustrate the operation of the high voltage direct 35 current generator comprising a varying capacitance generator according to the present invention.
• • • •
Figure 6 is a graph illustrating output power against load resistance for a high voltage direct current generator comprising a varying capacitance generator according to the present invention.
5 Figures 7, 8 and 9 are graphs illustrating the waveforms of current and voltage at three different loads.
Figure 10 is a graph illustrating power against speed for high voltage direct current generator comprising a varying capacitance generator according to the present 10 invention.
Figure 11 shows a circuit diagram of an alternative high voltage direct current generator comprising a varying I...;
capacitance generator according to the present invention. •• •
• •
Figure 12 shows a circuit diagram for a three-phase 15 high voltage direct current generator comprising varying •••
capacitance generators according to the present invention. .*
• • •
A high voltage direct current generator 10 according
• • • •
to the present invention is shown in figures 1 to 3, and comprises a varying capacitance 12. The varying
20 capacitance 12 includes a rotor 14 and a stator 16, as shown more clearly in figures 1 and 2. The rotor 14 forms a first terminal 18 of the varying capacitance 12 and the stator 16 forms a second terminal 20 of the varying capacitance 12. The rotor 14 has a plurality of
25 circumferentially spaced rotor blades 22 secured to the rotor 14. The rotor blades 22 extend radially outwardly from the rotor 14 and the rotor blades 22 are equi-angularly spaced around the rotor 14. The stator 16 has a plurality of circumferentially spaced stator vanes 24 30 secured to the stator 16. The stator vanes 24 extend radially inwardly and the stator vanes 24 are equi-angularly spaced around the stator 16. In addition the number of rotor blades 22 is equal to the number of stator vanes 24. Each rotor blade 22 comprises an electrically 35 conducting member and similarly each stator vane 24 comprises an electrically conducting member. The
electrically conducting members of the rotor blades 22 and the stator vanes 24 form the electrically conducting plates of the varying capacitance 12. All of the rotor blades 22 on the rotor 14 are electrically connected in parallel to 5 form a first plate of the varying capacitance 12 and all the stator vanes 24 on the stator 16 are electrically connected in parallel to form a second plate of the varying capacitance 12. The rotor 14 and stator 16 of the varying capacitance 12 are arranged in a vacuum chamber and the 10 vacuum chamber is evacuated to a suitably low pressure to prevent corona discharges.
The varying capacitance 12 is arranged in an electrical circuit 27 to form the high voltage direct
• •
current generator 10. The first terminal 18, and hence the 15 rotor 14, of the varying capacitance 12 is electrically ••• connected to a first negative terminal 28 of an electrical .* I*! excitation source 26 and the second terminal 20, and hence
• •••
the stator 16, of the varying capacitance 12 is
• • * •
electrically connected to a second positive terminal 30 of ;
20 the electrical excitation source 26 via a first diode 32. An electrical load 34 is electrically connected in parallel with the first diode 32 and a second diode 36 is arranged in electrical series with the electrical load 34. The electrical excitation source 26 is a battery or other 25 direct current supply. Alternatively, the second terminal 20, and hence the stator 16, of the varying capacitance 12 is electrically connected to a first negative terminal 28 of an electrical excitation source 26 and the first terminal 18, and hence the rotor 14, of the varying 30 capacitance 12 is electrically connected to a second positive terminal 30 of the electrical excitation source 26 via the first diode 32 as indicated in figure 3 by the numerals (18) and (20).
In operation of the varying capacitance 12 rotation of 35 the rotor 14 periodically varies the capacitance formed between the electrically conducting members of the rotor
blades 22 and the electrically conducting stator vanes 24 between a maximum capacitance when the rotor blades 22 and stator vanes 24 are fully angularly aligned and a minimum capacitance when the rotor blades 22 and stator vanes 24 5 are fully angularly misaligned. Fully angularly aligned means that the varying capacitance 12 is such that each rotor blade 22 is at the same angular position as a corresponding one of the stator vanes 24. Fully angularly misaligned means that the varying capacitance 12 is such 10 that each rotor blade 22 is at an angular position midway between two adjacent stator vanes 24. Angularly misaligned means the varying capacitance 12 is such that each rotor blade 22 is at an angular position between the fully •
• •
aligned position and fully misaligned position. 15 The operation of the high voltage direct current •••
generator 10 is explained in more detail with respect to .* 1*1
• • •
figures 4A to 4D and figure 5. Figure 5 illustrates the
• • • •
capacitance and voltage of the high voltage direct current generator 10 with time as the rotor 14 rotates and figures 20 4A to 4D show the current flowing in the electrical circuit 27.
At time A in figure 5 the varying capacitance 12 formed between the rotor blades 22 and the stator vanes 24 of the varying capacitance 12 is at a maximum value and the 25 voltage across the varying capacitance 12 is at a minimum value and the varying capacitance 12 is fully charged. At time A the rotor blades 22 and stator vanes 24 are fully angularly aligned as mentioned previously and this corresponds to Figure 4A.
30 At a time B in figure 5 the varying capacitance 12
formed between the rotor blades 22 and the stator vanes 24 is decreasing from the maximum value towards a minimum value and the voltage across the varying capacitance 12 is increasing correspondingly (Q=CV, where Q is charge, C is 35 capacitance and V is voltage) from the minimum value towards a maximum value. At time B the rotor blades 22 and
7
stator vanes 24 are angularly misaligned as mentioned previously and this corresponds to Figure 4B. The second diode 36 starts to conduct and current, power, flows through the electrical load 34 and back to the electrical 5 excitation source 26. At time B the charge Q in the varying capacitance 12 and the capacitance C of the varying capacitance 12 are decreasing, as current/power continues to flow to the electrical load 34 until the varying capacitance 12 reaches a minimum value of capacitance. 10 At a time C in figure 5 the capacitance of the varying capacitance 12 has reached a minimum value and the voltage across the varying capacitance 12 has reached a maximum value, and time C corresponds to a time when the rotor blades 22 and stator vanes 24 are fully angularly 15 misaligned as mentioned previously.
At a time D in figure 5 the varying capacitance 12 has gone past the minimum capacitance position and the capacitance is increasing from the minimum value towards the maximum value and the voltage across the varying 20 capacitance 12 has decreased from the maximum value to the minimum value. The second diode 36 ceases to conduct and current, power, ceases to flow through the electrical load 34 and back to the electrical excitation source 26, as shown in figure 4C.
25 At a time E in figure 5 the capacitance of the varying capacitance 12 is increasing towards the maximum value, the voltage across the varying capacitance 12 decreases to a value less than the voltage of the electrical excitation source 26 and the first diode 32 starts to conduct and 30 allows the varying capacitance 12 to be recharged.
Thus, it can be seen that the varying capacitance 12 in conjunction with the electrical circuit 27 is a high voltage direct current generator 10 and the high voltage direct current generator 10 produces a pulsed direct 35 current.
• ••• • • • • •
8
The rotor 14 is driven by any suitable mechanical drive 25 for example a prime mover, a wind turbine 29, a water turbine, a gas turbine engine etc. The mechanical drive may include a gearbox 31 between the rotor 14 and the 5 prime mover, wind turbine 29, water turbine, gas turbine engine etc to match the required speed of rotation of the rotor 12. The high voltage electrical generator 10 is particularly applicable to offshore wind turbines.
The capacitance of the varying capacitance 12 varies 10 due to the rotation of the rotor blades 22 with respect to the stator vanes 24. The capacitance of the varying capacitance 12 changes proportionally with the area of the rotor blades 22 seen by the stator vanes 24, which changes #«# .
• •
approximately linearly as a function of time. Therefore 15 the capacitance of the varying capacitance 12 follows a saw •••
tooth waveform. .*
• • •
A computer model of 1.75MW high voltage direct current
• • • •
generator driven by a wind turbine was analysed by varying
• • * •
the load, represented by a resistance to determine the *..• j 20 effect on output power. The effect of varying the resistance load electrically connected to the high voltage direct current generator 10 is shown in figure 6 for the 1.75MW high voltage direct current generator operating at a frequency of 16kHz. The output power may be increased at 25 the expense of increased peak voltage and a degraded, more spiky waveform, as shown in figures 7 to 9. Figures 7 to 9 show the current waveform and voltage waveform at 600ohms load, 3700ohms load and lOOOOohms load respectively.
The effect of the speed of rotation of the rotor 14 of 30 the varying capacitance 12 of the high voltage direct current generator 10 on the output power was investigated by running the computer model of the 1.75MW 100 pole high voltage direct current generator driven by a wind turbine with a resistance load of 600ohms at a variety of speeds 35 and the results are shown in figure 10.
A further high voltage direct current generator 110, according to the present invention, is shown in figure 11. The high voltage direct current generator 110 is substantially the same as that shown in figures 1 to 3 and 5 like parts are denoted by like numerals. The embodiment in figure 11 differs in that the electrical excitation source 126 is a pre-charged capacitance, rather than a battery, and the pre-charged capacitance 126 is electrically connected to an auxiliary electrical power supply 128. The 10 pre-charged capacitance 126 has a value of at least 10 times the peak value of the capacitance of the varying capacitance 12, preferably the pre-charged capacitance 126 J...;,
has a value of at least 50 times the peak value of the .* .
• • «
capacitance of the varying capacitance 12, more preferably 15 the pre-charged capacitance 126 has a value of at least 100 •!.
times the peak value of the capacitance of the varying .*
• • •
capacitance 12. The pre-charged capacitance 126 has a
• • • •
value of 2|4.F to 5fiF, more preferably the pre-charged "••••*
• •••
capacitance has a value of 2.5(J.F or 3|a.F. The variable • 20 capacitance 12 has a value of 2.5nF to 25nF. The auxiliary power supply is a high voltage direct current power supply of lOkV to 1MV, for example lOOkV, to charge the pre-charged capacitance to lOkV to 1MV, for example lOOkV. For a pre-charged capacitance 126 with a value less than 10 25 times the peak value of the capacitance of the varying capacitance 12, the voltage across the pre-charged capacitance 126 drops substantially during charging of the varying capacitance 12 and thus degrades operation. The pre-charged capacitance 126 preferably comprises a 30 plurality of pre-charged capacitances 126 of smaller capacitance arranged to improve reliability.
The stator 16 and stator vanes 24 may comprise any suitable electrically conducting material, preferably aluminium or aluminium alloy for weight reduction. The 35 rotor 14 and rotor blades 22 may comprise any suitable electrically conducting material. Aluminium, aluminium
10
alloy or a polymer composite rotor and rotor blades with a metal coating on the rotor blades, e.g. glass reinforced polymer composite rotor and rotor blades with a metal foil conductor coating on the rotor blades, may be used for low-5 speed operation for weight reduction. The rotor 14 and rotor blades 22 may comprise steel or other suitable high strength electrically conducting material for high-speed operation.
A shunt resistance may be provided to bleed charge out 10 of the pre-charged capacitance 126 if a reduction in output voltage is required.
A three-phase high voltage direct current generator 210 according to the present invention is shown in figure 12 to provide improved overall performance, particularly 15 reduced torque ripple. The three-phase high voltage direct current generator 310 comprises three varying capacitances 12A, 12B and 12C provided on a single rotor. The rotor is divided into three electrically isolated portions and the stator is divided into three electrically isolated portions 20 with each stator portion being associated with a respective one of the rotor portions to form the three varying capacitances 12A, 12B and 12C. Each rotor portion and each stator portion has a respective terminal.
The rotor blades in the three portions of the rotor 25 are arranged at the same angular positions and the stator vanes in the three portions of the stator are arranged at different angular positions such that there is sixty electrical degree angular separation between the electrical signals from the three varying capacitances 12A, 12B and 30 12C.
Alternatively, the stator vanes in the three portions of the stator are arranged at the same angular positions and the rotor blades in the three portions of the rotor are arranged at different angular positions such that there is 35 sixty electrical degree angular separation between the
11
electrical signals from the three varying capacitances 12A, 12B and 12C.
Each varying capacitance 12A, 12B and 12C has an electrical excitation source 26A, 26B and 26C respectively, 5 a first diode 32A, 32B and 32C respectively and a second diode 36A, 36B and 36C respectively.
Each of the second diodes 36A, 36B and 36C is electrically connected to the electrical load 34 via respective inductances 42A, 42B and 42C respectively and a 10 high voltage direct current transmission line 44. The inductances regulate the voltage so that one phase does not interfere with any of the others.
To complete the electrical circuit 27 from the electrical load 34 back to the electrical excitation 15 sources 26A, 26B and 26C the electrical load 34 is electrically connected to earth 46L and the positive terminals of each of the electrical excitation sources 26A, 26B and 26C are electrically connected to earth 46A, 46B and 46C respectively to form an earth return. 20 Alternatively, to complete the electrical circuit 27 from the electrical load 34 back to the electrical excitation sources 26A, 26B and 26C the electrical load 34 is electrically connected to the positive terminals of each of the electrical excitation sources 26A, 26B and 26C via a 25 high voltage direct current transmission line 48 and branch lines 50A, 50B and 50C.
Although the present invention has been described with reference to a rotor 14 with a single stage of rotor blades 22 and a stator 16 with a single stage of stator vanes 24 30 it may be possible and beneficial to provide a plurality of axially spaced stages of rotor blades 24 on the rotor 14 and a corresponding number of stages of stator vanes 24 on the stator 16.
Although the present invention has been described with 35 reference to all the rotor blades 22 in a single stage being electrically connected in parallel and all the stator
<* • i
^ ,
« •
* «• « A 4 •
• ••* » «
« * • 4
• * i •
12
vanes 24 in a single stage being electrically connected in parallel, it may be possible for the rotor blades 22 in different axially spaced stages to be connected in electrical parallel and/or in electrical series and the 5 stator vanes 24 in different axially spaced stages to be connected in electrical parallel and/or in electrical series.
Although the present invention has been described with reference to a single-phase high voltage direct current 10 generator and a three-phase high voltage direct current generator it is equally possible to apply the present invention to other multi-phase high voltage direct current r .
• • * • i generator for improved overall performance particularly r • i reduced torque ripple. * *
15 Thus the high voltage direct current generator of the present invention is of lighter weight and potentially of .
• • #
higher efficiency than a prior art generator, which generates a low voltage alternating current (LVAC) , •***".
♦ • • «
transforms the low voltage alternating current (LVAC) to a
• • «
20 high voltage alternating current (HVAC) and finally rectifies the high voltage alternating current (HVAC) to produce a high voltage direct current (HVDC). The present invention generates high voltage direct current (HVDC) directly and dispenses with the need for a low voltage 25 alternating current (LVAC) generator, a low voltage alternating current (LVAC) to high voltage alternating current (HVAC) transformer and a rectifier.
The high voltage direct current generator of the present invention is of lighter weight and potentially of 30 higher efficiency than a prior art generator, which generates a low voltage alternating current (LVAC), transforms the low voltage alternating current (LVAC) to a high voltage alternating current (HVAC). The present invention generates high voltage direct current (HVDC) 35 directly and dispenses with the need for a low voltage alternating current (LVAC) generator and a low voltage
13
alternating current (LVAC) to high voltage alternating current (HVAC) transformer.
The high voltage direct current generator of the present invention potentially reduces system cost, making 5 high voltage direct current even more economical than high voltage alternating current for shorter transmission lines.
Although the present invention has been described with reference to a varying capacitance comprising a rotor with a plurality of angularly spaced radially extending blades 10 and a stator with a plurality of angularly spaced radially extending vanes, the blades and vanes comprising conducting members to form the plates of the capacitance, it may be possible to provide a varying capacitance comprising a rotor with a plurality of angularly spaced axially 15 extending plates and a stator with a plurality of axially extending plates. The axially extending plates on the rotor, for example may be placed on an outer cylindrical, or conical, surface of the rotor and the axially extending plates on the stator may be placed on an inner cylindrical, 20 or conical, surface of the stator or visa-versa.
M 4
* |
• •
• # »
* « • t ► • •
•• •
% » • • • •
• Ml • • •
•• •
14
Claims (1)
- Claims:-1. A high voltage direct current generator comprising a varying capacitance, the varying capacitance including a rotor and a stator, the rotor forming a first terminal of5 the varying capacitance and the stator forming a second terminal of the varying capacitance, the rotor having a plurality of circumferentially spaced electrically conducting members and the stator having a plurality of circumferentially spaced electrically conducting members 10 such that rotation of the rotor varies the capacitance formed between the electrically conducting plates on the rotor and the electrically conducting plates on the stator between a maximum capacitance when the plates on the rotor and the plates on the stator are angularly aligned and a 15 minimum capacitance when the plates on the rotor and the plates on the stator are angularly misaligned.2. A high voltage direct current generator as claimed in claim 1 comprising a varying capacitance generator, the varying capacitance including a rotor and a stator, the20 rotor forming a first terminal of the varying capacitance and the stator forming a second terminal of the varying capacitance, the rotor having a plurality of circumferentially spaced radially extending rotor blades and the stator having a plurality of circumferentially 25 spaced radially extending stator vanes, the rotor blades comprising an electrically conducting member, the stator vanes comprising an electrically conducting member such that rotation of the rotor varies the capacitance formed between the rotor blades and the stator vanes between a 30 maximum capacitance when the rotor blades and stator vanes are angularly aligned and a minimum capacitance when the rotor blades and stator vanes are angularly misaligned.3. A high voltage direct current generator as claimed in claim 2 wherein the rotor blades are equi-circumferentially35 spaced, the stator vanes are equi-circumferentially spaced.I • • • •154. A high voltage direct current generator as claimed in claim 2 or claim 3 wherein the number of rotor blades is equal to the number of stator vanes.5. A high voltage direct current generator as claimed in 5 any of claims 1 to 4 wherein a negative terminal of an electrical excitation source is electrically connected to one of the rotor and the stator, a positive terminal of the electrical excitation source is electrically connected to one of the stator and the rotor via a first diode, at least 10 one electrical load is electrically connected in parallel with the first diode and a second diode is arranged in electrical series with the at least one electrical load.6. A high voltage direct current generator as claimed in claim 5 wherein the electrical excitation source is a15 battery.7. A high voltage direct current generator as claimed in claim 5 wherein the electrical excitation source is a pre-charged capacitance.8. A high voltage direct current generator as claimed in 20 claim 7 wherein the pre-charged capacitance has a value of at least 10 times the peak value of the capacitance of the varying capacitance.9. A high voltage direct current generator as claimed in claim 7 wherein the pre-charged capacitance has a value of25 at least 50 times the peak value of the capacitance of the varying capacitance.10. A high voltage direct current generator as claimed in claim 7 wherein the pre-charged capacitance has a value of at least 100 times the peak value of the capacitance of the30 varying capacitance.11. A high voltage direct current generator as claimed in any of claims 7 to 10 wherein the pre-charged capacitance has a value of 2(J,F to 5(0.F.12. A high voltage direct current generator as claimed in 35 claim 11 wherein the pre-charged capacitance has a value of2 . 5(iF or 3|iF.13. A high voltage direct current generator as claimed in any of claims 7 to 12 wherein an auxiliary power supply is electrically connectable to the pre-charged capacitance to pre-charge the pre-charged capacitance to lOkV to IMV. 5 14. A high voltage direct current generator as claimed in claim 13 wherein the auxiliary power supply is electrically connectable to the pre-charged capacitance to pre-charge the pre-charged capacitance to lOOkV.15. A high voltage direct current generator as claimed in 10 any of claims 1 to 14 wherein the variable capacitance has a value of 2.5nF to 25nF.16. A high voltage direct current generator as claimed in any of claims 1 to 15 wherein a prime mover is arranged to• •drive the rotor.15 17. A high voltage direct current generator as claimed in 'I' claim 16 wherein the prime mover comprises a wind turbine or a gas turbine engine.• • • •18. A high voltage direct current generator substantially ••••• • • •as hereinbefore described with reference to and as shown in *..* I 20 figures 1, 2 and 3 of the accompanying drawings.19. A high voltage direct current generator substantially as hereinbefore described with reference to and as shown in figures 1, 2 and 11 of the accompanying drawings.20. A high voltage direct current generator substantially 25 as hereinbefore described with reference to and as shown in figures 1, 2 and 12 of the accompanying drawings.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB0606615A GB2436895A (en) | 2006-04-03 | 2006-04-03 | A high voltage current generator using varying capactitance |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB0606615A GB2436895A (en) | 2006-04-03 | 2006-04-03 | A high voltage current generator using varying capactitance |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB0606615D0 GB0606615D0 (en) | 2006-05-10 |
| GB2436895A true GB2436895A (en) | 2007-10-10 |
Family
ID=36425096
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB0606615A Withdrawn GB2436895A (en) | 2006-04-03 | 2006-04-03 | A high voltage current generator using varying capactitance |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2436895A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2010097022A1 (en) * | 2009-02-27 | 2010-09-02 | Feng Lianjie | Cylinder belt-type ceramic generator |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NL7702944A (en) * | 1977-03-18 | 1978-09-20 | Stamm Robert | Generator for wind driven electricity generator - drives shaft at constant speed in first stage and then fitting electrostatic dynamo |
| US4127804A (en) * | 1976-05-24 | 1978-11-28 | The United States Of America As Represented By The Secretary Of The Air Force | Electrostatic energy conversion system |
| JPS5829379A (en) * | 1981-08-13 | 1983-02-21 | Toko Seiki Seisakusho:Kk | Electrostatic generator |
| US4622510A (en) * | 1981-10-29 | 1986-11-11 | Ferdinand Cap | Parametric electric machine |
-
2006
- 2006-04-03 GB GB0606615A patent/GB2436895A/en not_active Withdrawn
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4127804A (en) * | 1976-05-24 | 1978-11-28 | The United States Of America As Represented By The Secretary Of The Air Force | Electrostatic energy conversion system |
| NL7702944A (en) * | 1977-03-18 | 1978-09-20 | Stamm Robert | Generator for wind driven electricity generator - drives shaft at constant speed in first stage and then fitting electrostatic dynamo |
| JPS5829379A (en) * | 1981-08-13 | 1983-02-21 | Toko Seiki Seisakusho:Kk | Electrostatic generator |
| US4622510A (en) * | 1981-10-29 | 1986-11-11 | Ferdinand Cap | Parametric electric machine |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2010097022A1 (en) * | 2009-02-27 | 2010-09-02 | Feng Lianjie | Cylinder belt-type ceramic generator |
Also Published As
| Publication number | Publication date |
|---|---|
| GB0606615D0 (en) | 2006-05-10 |
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