NZ223591A - Electrical energy generator from solar energy - Google Patents

Description

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It- m : • .! Priority Date(s): Complete Specification Filed:^7r-. fl. Class: .Ob: Publication Date:". 27.1IO.V..t33Q P.O. Journal, No: .... E>5S=,- Patents Form No. 5 223591 Patents Act 1953 COMPLETE SPECIFICATICjN , GENERATOR FOR THE PRODUCTION OF ELECTRICAL ENERGY PARTICULARLY FROM SOLAR ENERGY I 1 ' Us CS v i ^ Xi I? I rki-&:■ i We, LE TERRITOIRE DE LA POLYNESIE FRANCAISE, represented by le Ministre de l'Equipement de 1'Amenagement, de l'Energie et des i Ok Tc.c\vf\xCftA uc\& £*\uSVr-»cJi rrieKn Mines, of B.P. 2551 Papeete, Tahiti, French Polynesia,/xLE COMMISSARIAT A L'ENERGIE ATOMIQUE ESTABLISSEMENT, a scientific, technical and industrial establishment, of 31/33 Rue de la Federation, 75015 Paris, France and AGENCE FRANCAISE POUR LA MAITRISE DE L'ENERGIE, a scientific, technical and 7S-73 ~j industrial establishment, of 27 Rue Louis Vicat, -7537" Paris, nlb(°11 France, hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: 1 (followed by la) 223591 la DESCRIPTION The present invention relates to a generator for producing electrical energy particularly from solar energy.

The invention applies to all electrical energy generators having means for producing energy, means for accumulating energy, means for regulating energy accumulation and an electrical output connected e.g. to use means. The invention more particularly applies to an electrical energy generator, which produces electrical energy from solar energy, the production means incorporating in this case photovoltaic cells.

In known manner, a photovoltaic cell converts the energy of photons into electrical energy. In order to obtain high voltages, advantageously several cells of this type are connected in series, which are regrouped into photovoltaic modules, a module having approximately 30 photovoltaic cells in series. Moreover, to obtain high currents, several modules are connected in parallel. The means for producing electrical energy from solar energy consequently have one or more modules in series and/or in parallel.

Throughout the remainder of the description the term production devices will relate to a group of one or more modules In series.

In order to be able to produce e.g. a power of approximately 400 watts, advantageously use is made of 5 production devices in parallel, each means having two modules in series of 35 photovoltaic cells in series.

Fig. 1 diagrammatically shows a known electrical energy generator, whose production means 1 comprise production devices 2 in series, each production device having several modules 2 in series. The electrical energy generator shown in Fig. 1 also comprises accumulation means 5 for accumulating energy, .regulation means 9 for regulating energy accumulation and an electrical output connected to use means 7.

UN fa? 2 2 SEP 1988 223591 Each production device 2 is connected via a non-return diode 11, e.g. of silicon to regulation means 9, which are also connected to the accumulation means 5 and the use means 7.

Means 1, 5, 7 and 9 are obvious 1y also connected to a reference potential, such as earth potential or the potential of the negative terminal of the accumulation means.

The accumulation means 5 e.g. incorporate in series one or more accumulation batteries, as a function of the maximum power produced by the production means 1 and the nominal voltage of the batteries used. Using once again the example referred to hereinbefore, in which the production means produce 400 watts power, use is made of e.g. two batteries with a nominal voltage of 12 volts.

The regulation means 9 have two functions, namely protecting the accumulation means 5 against overloads and against excessive discharges so that no damage occurs thereto. Thus, for accumulation means 5 incorporating e.g. a battery of nominal voltage 12 v, the maximum charging voltage V(<1 of said battery is preferably approximately 14 v and the minimum charging voltage approximately 11 v. Charging the battery to a value higher than the maximum charging voltage V causes problems such as the boiling of the liquid contained in the battery. Discharging the battery at a value below the minimum charging voltage leads to problems, such as the sulphating of the battery.

When the effective charging voltage Vg of accumulation means 5 is between the maximum charging voltage and the minimum charging voltage V , the regulation means 9 permit both accumulation in accumulation means 5 and use by use means 7 of the energy produced by production means 1. However, when the effective charging voltage of the accumulation means 5 exceeds the maximum charging voltage, the regulation means 9 only permit the use of the energy stored in the accumulation means 5. When the effective charging voltage of accumulation means 5 drops below the minimum charging voltage, the regulation means 9 only permit the accumulation of the energy produced by production means 9 1 in accumulation means 5, whereas the use means 7 can no li (^2 2SEP1988 use energy.

The non-return diodes 11 make it possible to avoid the discharge of accumulation means 5 into production devices 2 via regulation means 9, when the voltage supplied by the production means is below the effective charging voltage of the accumulation means 5. The effective charging voltage of the accumulation means 5 corresponds to the voltage between the positive terminal and the negative terminal of the accumulation means 5.

The use of non-return diodes 11 in a known electrical energy generator of the type described hereinbefore leads to numerous disadvantages. These are in particular an energy loss due to the voltage drops caused by the diodes. Thus, a module of 30 photovoltaic cells produces a power of approximately 25 watts and a non-return diode 11 consumes approximately 1.6 watt and, in the case of a silicon diode, leads to a voltage drop of approximately 0.8 V. Moreover, these diodes must be placed in a case so as to be protected from external effects and must be associated with coolers to prevent them heating excessively.

Thus, these different elements increase costs and also the complexity of the electrical energy generator.

The object of the present invention is to obviate these disadvantages and in particular to provide an electrical energy generator having regulation means making it possible to regulate the energy accumulation as a function of the voltage supplied by the production means, which makes it possible not to use a diode for each production device and which also makes it possible to use energy day and/or night, e.g. in the case of a photovoltaic generator.

More specifically, the present invention relates to an electrical energy generator having electrical energy production means, energy accumulation means, regulation means for regulating energy accumulation and an electrical output, said regulation ^ means being connected to the production means, to the accumulation means and to the electrical output of the generator, characterized in that the regulation means comprise fir and second switches positioned in series between the production means and the generator output, the centre point of said switches being connected in series to the accumulation means and control means for controlling the first and second switches as a function of the voltage Vp supplied by the production means, the effective charging voltage Vg of the accumulation means and the maximum and minimum charging voltages of the accumulation means.

The production means have a single production device and the regulation means comprise a diode disposed between the production means and the first switch, the control means being directly connected to said production device.

According to a variant, the energy production means have several production devices in parallel and the regulation means comprise a diode located between a production device and the first switch, the other production devices being connected to the first switch and the control means are directly connected to said production device.

The diode of the regulation means is preferably a Schottky diode, which has the characteristic of only bringing about a voltage drop of approximately 0.4 V. This diode makes it possible to avoid the discharge of the accumulation means into the production device to which same is connected, when the effective charging voltage Vg of the accumulation means exceeds the voltage Vp supplied by the production device. In this way, the voltage sampled by the control means directly at the output of the production device corresponds to the voltage supplied by said production device. In the case of a photovoltaic generator, this voltage is characteristic of the sunlight.

The diode used in the generator according to the invention forms part of the regulation means and is advantageously located in the same case as the other elements of the regulation means.

The control means comprise: first comparison means connected to the accumulation meaq^ and to the production means for comparing the voltage Vp supplied by the production means, the effective charging voltage V O of the accumulation means and at least one reference voltage characteristic of the maximum charging voltage VM of the accumulation means; first amplification means connected to the first comparison means and to the first switch for amplifying the electric signal supplied by the first comparison means, said amplified signal leading to the opening or closing of the first switch; second comparison means connected to the accumulation means for comparing the effective charging voltage of the accumulation means and at least one reference voltage characteristic of the minimum charging voltage Vm of the accumulation means; and second amplification means connected to the second comparison means and to the second switch for amplifying the electric signal supplied by the second comparison means, said amplified signal leading to the opening or closing of the second switch.

For the comparison performed by the first comparison means, it is possible to use both a reference voltage such as the maximum charging voltage VM and several reference voltages surrounding the voltage V^.

In the same way, for the comparison performed by the second comparison means, it is possible to use both a reference voltage such as the minimum charging voltage and several reference voltages surrounding voltage V .

The first comparison means compare the voltage Vp, the voltage Vg and first and second reference voltages VMJ and VM2, such that vMj<vM<vM2 Produced from said first comparison means, the electric signal supplied by said first comparison means and amplified by the first amplification means opening the first switch when the voltages V^, Vp and Vf<12 are such that Vg>VM2 and/or Vp<Vg and closing said first switch when the voltages VD, VD, V... and VM_ are such that b r Ml i*l c VD<VM. and/or Vd>Vd+ K, in which K is chosen so as to prevent)-*^..

O FM1 r D surging of the switch in the case of limited variations of the voltages V and V and in that the second comparison means B P 2235 compare the voltage VQ and first and second reference voltages V . and V „ such that V ,<V <V „ produced from said second ml m2 ml m mZ comparison means, the electric signal supplied by said second comparison means and amplified by said second amplification means opening the second switch when the voltages Vg and V^are such that Vg<Vmj and closing said second switch when the voltages V- and V „ are such that VD>V 0.

B m2 B m2 The condition Vg>VM2 leading to the opening of the first switch makes it possible to avoid overloading of the accumulation means. Condition Vp<Vg also bringing about the opening of the first switch makes it possible to prevent any discharge of the accumulation means into the production devices connected downstream of the diode. This condition is proved e.g. in the particular case of a photovoltaic generator, when the solar energy is low and such that the voltage Vp supplied proves this condition.

Condition VgCV^ leading to the closing of the first switch permits the charging of the accumulation means without any risk of overload. Condition Vp>Vg+ K leading to the closing of the first switch permits the charging of the accumulation means without any risk of the latter discharging into the production means.

Condition Vg<Vmj leading to the opening of the second switch makes it possible to avoid any discharging of the accumulation means with the risk of damage thereto, by making impossible any use of energy. Condition leadin9 to the closing of the second switch particularly authorizes the discharging of the accumulation means by use of energy e.g. by the use means connected to the generator output, without any risk of damaging the accumulation means.

In the case of a photovoltaic generator, this embodiment permits a use of energy both day and night, provided that the condition vB>vm2 is proved; For charging voltages VD, whose values are between the d reference voltages V^j and (VM]^VB^VM2^' or reference 9 9 voltages Vml and Vm2 (Vmi$VB<Vm2^' the first anc* second switches remain in the state which they had before these conditions were proved, in other words if they were open they remain open and if they were closed they remain closed. The fact of using reference voltages surrounding the maximum charging voltage and reference voltages surrounding the minimum charging voltage makes it possible to avoid the opening or closing of switches as a result of small variations to the voltages Vg and Bp. Thus, these reference voltages make it possible to stabilize the control of the first and second switches.

According to another preferred embodiment, the control means comprise first comparison means connected to the accumulation means for comparing the effective charging voltage VD, accumulation means and at least one reference voltage D characteristic of the maximum charging voltage VM of the accumulation means; first amplification means connected to the first comparison means and to the first switch for amplifying the electric signal supplied by the first comparison means, said amplified signal leading to the opening or closing of said first switch; second comparison means connected to the accumulation means and to the production means for comparing the voltage Vp supplied by the production means, the effective charging voltage Vg of the accumulation means and at least one reference voltage characteristic of the minimum charging voltage of the accumulation means; and second amplification means connected to the second comparison means and to the second switch for amplifying the electric signal supplied by the second comparison means, said amplified signal leading to the opening or closing of said second switch.

The production means of said generator preferably only have a single production device, in view of the fact that the first switch is not controlled as a function of the voltage Vp supplied by the production means.

As hereinbefore, it is possible to use for the comparison by the first comparison means, the maximum charging voltage or preferably the reference voltages V^j and and for the 9 O Q r o * & o o X r\ O o comparison by the second comparison means, the minimum charging voltage Vm or preferably the reference voltages V , and V m 3 ml m2 Thus, advantageously,the first comparison means compare the voltage Vg and a first and a second reference voltages VMj and VM2 such that V^cV^cV^ produced from said second comparison means, the electric signal supplied by said first comparison means amplified by the first amplification means opening the first switch when the voltages V_ and V,,0 are such D He that Vg>vM2 and dosing said first switch when the voltages Vg and are such that Vg<V^j and in that the second comparison means compare the voltage Vp, the voltage Vg and a first and a second reference voltages V . and V „ such that V ,<V <V „ M ml m2 ml m m2 produced from said second comparison means, the electric signal supplied by said second comparison means amplified by the second amplification means opening the second switch when the voltages Vg, Vp and Vfflj are such that Vg<Vmj and/or Vp>Vg and closing said second switch when the voltages Vg, Vp, Vmj and V^ are such that vg>vm2 and VpCVg-k, in which k is chosen so as to prevent surging of the switch in the case of minor variations to the voltages VQ and Vp.

In the particular case of a photovoltaic generator, condition Vp<Vg+k leading to the closing of the second switch and therefore the possibility of using energy is proved when the solar energy is low and such that the voltage Yp proves said condition. However, the condition V_>VD leading to the opening r D of the second switch and consequently the impossibility of using energy is proved when the solar energy is high and such that the voltage Vp proves said condition.

Thus, in the case of a photovoltaic generator, this embodiment makes it possible to use energy only at night. For example, this generator can be used for lighting up pedestal lamps at nightfall and for extinguishing them at daylight.

According to another embodiment,the control means comprise first comparison means connected to the accumulation means and to the production means for comparing the voltage Vp supplied by the production means, the effective charging voltage V_ of the O P9 o r* Q 1 **•> <>j (J o J accumulation means and at least one reference voltage characteristic of the maximum charging voltage of the accumulation means; first amplification means connected to the first comparison means and to the first switch for amplifying the electric signal supplied by the first comparison means, said amplified signal leading to the opening or closing of said first switch; second comparison means connected to the accumulation means and to the production means for comparing the voltage Vp supplied by the production means, the effective charging voltage VD of 0 the accumulation means and at least one reference voltage characteristic of the minimum charging voltage of the accumulation means; and second amplification means connected to the second comparison means and to the second switch for amplifying the electric signal supplied by the second comparison means, said amplified signal leading to the opening or closing of said second switch.

The production means of said generator can have several production devices, in view of the fact that the first switch is controlled in particular as a function of the voltage supplied by the production means, thus making it possible to prevent any discharge of the accumulation means into the production means.

As hereinbefore, for the comparison by the first comparison means, it is possible to use the maximum charging voltage VH or preferably the reference voltages V^j and V^,, and for the comparison by the second comparison means the minimum charging voltage or preferably the reference voltages V^j and Vm2.

Thus, advantageously, the first comparison means compare the voltage Vp, the voltage Vg and a first and a second reference voltages V^j and VM2 such that VMl<vm<vm2 Proc'lJcec' from said first comparison means, the electric signal supplied by said first comparison means amplified by the first amplification means opening the first switch when the voltages Vg, VD and VMO are such that V_>VMO and/or V <V_ and closing said r o nc p D first switch when the voltages Vg, Vp V^j and V^ are such that Vp<Vjvjj and/or vp>vg+ K and in that t,ie second comparison means compare the voltage Vp, the voltage Vg and a first and a second reference voltages V , and V „ such that V ,<V <V _ produced ml m2 ml m mZ from said second comparison means, the electric signal supplied by said second comparison means amplified by the second amplification means opening the second switch when the voltages VD and V . are such that VD<V , and/or Vn>V_ and closing said B ml B ml P B 3 second switch when the voltages Vg, Vp, V^j and Vm2 are such that V_>V 0 and/or V_<VD+ k.

B m2 P B In the case of a photovoltaic generator, this embodiment makes it possible to use the energy only at night e.g. for supplying pedestal lamps.

Advantageously, an energy production device has several photovoltaic cells in series. These photovoltaic cells in series are regrouped into modules, each module having e.g. 30 photovoltaic cells in series. Thus, a device comprises one or more modules in series.

Advantageously, the first switch and/or the second switch is an electromagnetic relay or a transistor, such as a MOS transistor.

Moreover, the accumulation means preferably have at least one accumulation battery.

The invention is described in greater detail hereinafter relative to non-limitative embodiments and the attached drawings, wherein show: Fig.l Already described, diagrammatically a known electrical energy generator.

Fig. 2 DiagrammaticalIy an electrical energy generator according to the invention.

Fig. 3 Diagrammatically a first embodiment of the regulation means of an electrical energy generator according to the invention.

Fig. 4 A more detailed embodiment of the regulation means shown in Fig. 3. /" i 2 2 SEP 1988 K U W*b & & o I I - 11 - 31* a O """[.95.

Fig. 5 Diagrammatically a second embodiment of the regulation means of an electrical energy generator according to the invention.

Fig. 6 A more detailed embodiment of the regulation means shown in Fig. 5.

Fig. 7 Diagrammatically a variant of the embodiment shown in Fig. 5.

For reasons of clarity, the description is given for electrical energy generators of the photovoltaic type, in other 10 words the electrical energy production means incorporate photo-, voltaic cells, but obviously these examples are not limitative.

Fig. 2 diagrammatically shows an electrical energy generator according to the invention. This generator comprises electrical energy production means 1 having several production 15 devices 2 in parallel. Each of these devices has photovoltaic cells in series grouped into modules 3. A production device can have one or more modules in series. Obviously the production means 1 may only have a single production device.

This generator also comprises energy accumulation means 5, 20 such as one or more accumulating batteries, regulation means 15 (2) for regulating energy accumulation and an electrical output connected e.g. to use means 7 for using the electrical energy. The regulation means 15 are connected to production means 1, to accumulation means 5 and to use means 7. Means 1, 5, 7 and 15 25 are connected to a reference potential, such as earth potential, CJ as shown in the drawing, or the potential of the negative terminal of the accumulation means.

The regulation means 15 according to the invention incorporate control means 17, a first and a second switch Ij and 30 Ig in series and a diode 19, such as a Schottky diode. Diode 19 is connected between a single production device 2 and switch Ij, the other production devices, in the case where the production means have several such devices, being connected directly to the first switch downstream of diode 19.

;P1988 , J .sJ £ Sv 2n o j: <jO Control means 17 are connected to the accumulation means 5, to the production means 1 upstream of diode 19 and to switches Ij and I2- Moreover, the centre point of switches Ij and I2 is connected to the accumulation means 5 and switch 1^ to use means 7.

By stopping a possible discharge of the accumulation means, diode 19 makes it possible to take a voltage equal to the voltage supplied by the production device to which it is connected, said voltage corresponding to the voltage supplied by the production means.

Means 17 make it possible to analyze, as will be shown hereinafter, the voltage Vp taken upstream of diode 19, the effective charging voltage V0 of accumulation means 5 and reference voltages characteristic of the maximum and minimum charging voltages Vf<1 and of the accumulation means 5 and are able to control as a function of these voltage values the opening or closing of switches Ij and 12, so as to cause no damage to accumulation means 5 and in accordance with the desired use of the electrical energy produced by the generator.

As has been shown hereinbefore, these reference voltages are the maximum and minimum charging voltages and Vm or the voltages VMj, and Vmj. Vm2 surrounding said values (Vui<Vu<V,.0 and V ,<V <V -). To stabilize the control of the Ml M M2 ml m m2 switches, the preferred reference voltage used is and V^, Vm2« Throughout the remainder of the description, reference voltages VMJ, VM2, , Vm2 will be used as examples.

Thus, when switches Ij and I2 are closed, the energy produced by the production means 1 is stored in the accumulation means 5 and can be used by the use means 7.

When switch Ij is closed and switch I2 open, the energy produced by production means 1 is only accumulated in the accumulation means 5. Conversely, when switch 1^ iS open and switch I2 closed, no energy is accumulated in the accumulation means 5, but conversely the energy used by the use means 7 comes from the accumulation means 5.

Fig. 3 gives an embodiment of the regulation means electrical energy generator according to the invention. 'vIt is 'C22S S^£JL' 1 '§ f Mi 4 I - 13 - I 4 $ possible to see the control means 17, diode 19 and switches I, 1 and L, together forming the regulation means.

$ C In this case, the control means 17 have first comparison means 21 connected to the production means upstream of diode 5 19. to the accumulation means 5 and to the first amplification means 23, the latter also being connected to switch Ij. The control means 17 also have second comparison means 25 connected to the accumulation means 5 and to the second amplification means 27, the latter also being connected to switch I2- / ' V, J' 223591 Comparison 21 compare the voltage Vp supplied by the production means 1, the effective charging voltage V_ of the D accumulation means 5 and the reference voltages Vf1j and produced by comparison means 21. Comparison means 25 compare the charging voltage Vg of accumulation means 5 and the reference 15 voltages and V^ produced by comparison means 25.

For information purposes, for accumulation means 5 of nominal voltage 12 v, the maximum charging voltage being approximately 14 v, e.g. the two reference voltages VMj and V^ are respectively chosen as 13.5 and 14.4 v. Moreover, as the 20 minimum charging voltage is approximately 11.5 v, e.g. the two reference voltages V^j and Vm2 are respectively chosen as 10.5 and 12.2 v. ^2) Thus, when voltage Vg is such that the electric signal from comparison means 21, amplified by amplification means 25 23, leads to the opening of switch Ij and the same occurs if voltage Vp is such that Vp<Vg. Conversely, when voltage Vg is such that VB<VfU and/or voltage Vp is such that Vp>V0+ K, switch Q Ij is closed by the electrical signal from the comparison means 21 and the amplification means 23.

Moreover, when the voltage Vg is such that vB<Vmj. the electrical signal from the comparison means 25 amplified by the amplification means 27 leads to the opening of switch 1^. Conversely, when voltage Vg is such that Vg>Vm2» the signal from comparison means 25, amplified by amplification means 27, leads 35 to the closing of said switch I^.

Fig. 4 shows in greater detail an embodiment of the O o. regulation means 15 of Fig. 3. In the latter, the reference potential of the different elements of the generator and the use means is the potential at a reference point B connected by a diode D0 to the negative terminal of the accumulation means 5. Diode D_ is e.g. of type 1N4004. d Moreover, in this case, switches Ij and I2 are electromagnetic relays respectively having inductive coils Bj and To avoid overvoltages, diodes Dj and D^ are respectively connected to the terminals of coils Bj and Bg.

Comparison means 21 incorporate a resistor Rj connected on the one hand upstream of diode 19 and on the other to a diode Dg, a resistor R^ connected on the one hand to the positive terminal of accumulation means 5 (or point A) and on the other to diode and to the base of a transistor Tj, " whose emitter is connected to point A.

Comparison means 21 also have between point A and point B, five resistors in series R^, R,., p^, Rg.R^, the collector of transistor Tj being connected to the centre of resistors R^ and by a resistor R^. Resistor Pj is a variable potentiometer. Moreover, between the centre of resistors and R^ and point B is connected a capacitor Cj, such as an electrochemical capacitor. Moreover, a transistor T2 is connected by its emitter to potentiometer Pj, by its collector to point A via a resistor Rg and by its base between a resistor Rg and a diode Zj of the Zener diode type. The other end of resistor Rg is connected to point A and the other end of diode Zj to point B.

These comparison means are connected to the amplification means 23 by the centre of resistors Rg and R^ and by the centre of resistor Rg and the collector of transistor T^.

Amplification means 23 have a transistor T^, whose base is connected between resistor R and the collector of transistor O T2. The emitter of transistor T^ is connected to point A and its collector is connected via two resistors in series Rjj and RJ2 to point B. Means 23 also include a transistor T^, whose base is connected to the centre of resistors R^ and Rj2, whose emitter is connected to point B and whose collector is connected both^t^lfAi the centre of resistors Rg, R^ by a resistor and to one end of the inductive coil Bj of switch Ij. The other end of coil Comparison means 25 have between points A and B five resistors in series RJ3, R^, p2, RJ5, Rjg, resistor p2 being a potentiometer. Between the centre of resistors R^, R^ and point B is connected a capacitor C2, such as an electrochemical capacitor. Moreover, a transistor Tc is connected by its emitter t> to potentiometer p2 by its collector to point A via a resistor Rj^ and by its base between a resistor Rjg and a diode Z2 of the Zener diode type. Resistor RjQ is also connected to point A and diode Z2 to point B.

Amplification means 27 incorporate a transistor T&, whose base is connected to the centre of resistor R^ and the collector of transistor T,. The emitter of said transistor is connected to D point A and the collector is connected via two resistors in series R^ and R2j to point B. Means 27 also have a transistor Jy, whose base is connected to the centre of resistors R2Q and R2j, whose emitter is connected to point B and whose collector is connected both to the centre of resistors R^«Rjg a resistor Rjg and to one end of inductive coil B2, the other end of the latter being connected to point A.

For information purposes, the following table 1 gives the values of the resistors and capacitors usable in said embodiment, as well as the types of transistors and diodes.

B. is connected to point A. 22SEPI98& 1 r", (V t" ,\^-".' V.1'''V<1V ^x?it j ft sft't -|s M rif. i 1 "~§ ■k - 16 TABLE 1 2235 o eeesssscesrssss: I * I R I R I R I R I R I.

I. .1. .1. .1.

I. 1.2kSI | 820 SL j 3,3k & | 6.8kO | 2,2fcSTL | IkXI | 270XL BB3BC«58esatB!!SB5rS!!SS:tS!!SSEce5!55SE;eSeSSSfi5B555!SESreSsaS R J R |R I R I R I R I R 8 j 9 J 10 j 11 I 12 j 13 j 14 2i7Xl I 3.3ka I 12k XI | 2.7k n | 820 el | 6.8kn. | 2.2kfl R I R I R I R I R I R I R j 16 j 17 j 18 | 19 ! 20 : 21 i—:: i. 2,7kX* I 560X1. I 2,7kP. | 3*3kfl | 10kXi | 2,7k£l | 820X1 f, I f2 'S ... I I I..1 I c K I * I * .1. .1. .1.

V7k.fi. | 4,7kfl. | 220j+T | 220 | 1N4H8 | 1N4148 | 1N4004 BeeesefleeseteeaBoseeseeBBeeBeessBsseBefteBBBeBBeseBesBBBessMa I * I T« I.

I. 1 T2 1 T3 1 T* 1 T5 .1J IJ iJ I J. 6«8V | 6,8V | 2N2905 | 2N1711 | 2N2905 | 2N1711 | 2N1711 BSSSSBB=rBSBBEEeBSaOBBSBBSBaee»»*B«B«B»B»*B»M««**BB*II»«»«*" It | .! L-I I 2N2905 | 2N1711 | CBSssssss&Beeeesesa oootr The reference voltages Vf()j and Vf12, VmJ and Vm2 are not really reproduced by comparison means 21 and 25. In fact, a voltage divider bridge takes a fraction of the voltage of battery 5 and compares it with reference voltages produced by diodes 7 and Zener diodes Zj and Z^. The reference voltages V.., and V,.0, V . and V 0 are represented by a fraction of Ml MZ ml mi their value, namely WMj and W^, and Wm2. In the same way, voltage V0 of battery 5 is represented by Kg.

In order to carry out the comparison of Vg and Vf)2, transistor T0 compares voltage WQ with voltage WMO produced by i O 11 c. the Zener diode Zj. When the comparator changes state, the amplification means 23 follow and give a return signal called the feedback signal passing through resistor RjQ. On clearing the threshold V^. it is momentarily erased. Thus, the feedback signal adds a supplementary value H to the divider bridge. Thus, transistor T2 compares voltage Wg+ H with VM2, which amounts to comparing Wg and VM2- H. The negative feedback is calculated in such a way that WM2 - H = wMp Consequently this amounts to comparing W0 with WMj or Vg with Vfjj. If the threshold VMj is cleared, the feedback disappears and the comparison with threshold VM2 can take place again. The reasoning is the same for the second comparison means 25.

In order to carry out the comparison between V0 and Vm2, transistor Tg compares voltage Wg with Wm2, which is produced by Zener diode Z2- When the comparator changes state, the amplification means 27 follow and give a return signal or feedback signal passing through resistor Rjg. On clearing threshold V „ it is momentarily erased and the feedback signal adds a m2 value h to the divider bridge. Thus, transistor T^ compares voltage Wg + H with Wm2, which amounts to comparing Wg with ^m2 " ne9ak*ve feedback is calculated in such a way that Wm2 - h = W^j, which amounts to comparing Wg with W^j or Vg with Vmj. If threshold V^j is cleared, the feedback disappears and the comparison with threshold Vm2 can take place again.

For the comparison between V and Vn, there is a direct D i _ comparison (without voltage divider bridge) by resistor R_, A* // rv 'S2SEP1988 -< 223591 modifies the divider bridge constituted by resistors R^, Rg and Rg, R?.

Thus, the transistor Tj has the following action: if VpCVg, a current passes through transistor R^ which acts on the divider bridge in a manner comparable to a large increase in V0, which leads to the action of Tg with all its consequences; if Vp>Vg + k, no current can pass through transistor R3, which allows the divider bridge to fulfil its initial function.

Fig. 5 shows a second embodiment of the regulation means of an electrical energy generator according to the invention.

This embodiment more particularly applies to an energy generator only having one energy production device 2.

Regulation means 15, in the manner described hereinbefore, have a diode 19, a first and a second switches Ij and and control means 17. Only the control means 17 differ from those described hereinbefore. These control means 17 incorporate first comparison means 29 connected to accumulation means 5 and to first amplification means 31, the latter also being connected to switch Ij.

Moreover, the control means 17 incorporates second comparison means 33 connected to the accumulation means 5, to the production means 1 and to the second amplification means 35, the latter also being connected to the second switch I^.

Comparison means 29 compare the effective charging voltage VD of D accumulation means 5 and the reference voltages VMj and produced by comparison means 29.

Comparison means 33 compare the voltage Vp taken upstream of diode 19 corresponding to the-voltage supplied by the production means 1, the effective charging voltage Vg of the accumulation means 5 and the reference voltages and produced by comparison means 33.

Thus, the control of switch I^ Is particularly dependent on voltage Vp. In the case of a photovoltaic generator, said voltage Vp makes it possible to analyze the lighting intensity received by the photovoltaic cells. Comparison means 33 and^pt e 22SEP1988 VC*' amplification means 35 can consequently control the opening of switch I2 at night and its closing by day, or vice versa.

In the reverse case, the generator makes it possible to supply the use means at night, such as one or more pedestal lamps 8. For this purpose, the electrical energy generator accumulates energy by day and uses its stored energy for supplying means 7 at night.

A generator according to the invention of the type shown in Fig. 5 and used e.g. for supplying means 7 at night, functions in the following way. When the voltages VD, Vm and V,,_ are such Is ii 1 I'lu that Vg>vM2' switch is open and when VB<VMI switch Ij is closed. Moreover, when these voltages Vn, Vn, V , and V „ are B P ml mz such that Vg>Vml and/or Vp>Vg + k, switch I2 is open and when VD>V 0 and Vn<VD, switch I0 is closed.

B mZ P B 2 Fig. 6 shows in greater detail an embodiment of the regulation means 15 described relative to Fig. 5 and making it possible tofscfaply a pedestal lamp 8 at night.

In the drawing, the reference potential of the different components of the electrical energy generator and of the pedestal lamp 8 is as in Fig. 4 the potential of the negative terminal of accumulation means 5. In this embodiment, switch Ij is an electromagnetic relay of the same type as that described relative to Fig. 4 and switch I2 is a field effect transistor T^.

Thus, it is advantageous to use as a switch a field effect transistor rather than an electromagnetic relay, in view of the fact that the latter consumes much more power than a transistor.

However, the use of a transistor as the switch is only advisable if the current passing through said transistor is relatively constant, i.e. having little or no overload. This condition is proved by switch I2, when the use means 7 are constituted by a pedestal lamp.

For reasons of clarity, the positve and negative terminals of the accumulation means 5 will be respectively designated A and C.

Between point A and point C of the accumulation means 5, comparison means 29 have five resistors in series R24, R25> 223591 R26' R27' A capacitor C3, such as an electrochemical capacitor, is connected between the centre of resistors R24, R25 and point C. Resistor is a potentiometer. The comparison means 29 also ("*) have a transistor T0, whose emitter is connected to point C via a diode of the Zener diode type, whose collector is connected across two resistors in series Rpg, ^8 *"° P°'n^ ^ anc* w^ose base is connected to potentiometer p3> A resistor R3q is also connected between the emitter of transistor Tg and point A.

The amplification means 31 incorporate a transistor Tjq, 10 whose base is connected to the centre of resistors R0Q and R0Q, c7 co whose emitter is connected to point A and whose collector is connected to the base of a transistor Tjj.A resistor is also connected between the collector of transistor TjQ and the emitter of transistor Tjj. The collector of transistor Tjj is 15 connected to point A and the emitter of said transistor is also connected to one end of the inductive coil Bj of switch Ij, the other end of the coil being connected to point C. As described hereinbefore, advantageously a diode Dj is connected to the terminals of coil Bj.

The comparison means 33 have a diode Dg connected to the production means 1 upstream of diode 19 and to a resistor R which is itself connected to the base of a transistor Tg. The £) ' emitter of transistor Tg is connected to point A and its collector is connected to point C via a resistor R£3. 25 Means 33 also include a transistor T.„, whose base is IC ' connected to the collector of transistor Tg, whose collector is connected to point A and whose emitter is connected to point C across five resistors in series R33> R34, p4> Rg5> R36» resistor p4 being a potentiometer. A capacitor C^, such as an 30 electrochemical capacitor is connected between the centre of resistors R33> R^ and point C. Means 33 also include a transistor Tjg, whose base is connected to a potentiometer p^, whose collector is connected by two resistors in series R^g. R3g to point A and whose emitter is connected by a diode Z^ of the 35 Zener diode type to point C. A resistor is connected between point A and the emitter of transistor Tj3. u 2 2SEPI988.

Amplification means 35 incorporate a transistor T^, whose base is connected to the centre of resistors R^g and R.^, whose emitter is connected to point A and whose collector is connected to point C by two resistors in series R^ and R^.

Moreover, the collector of this transistor is connected across a resistor R^j to the centre point of resistors R^ and R^g, said centre also being connected to point C by a resistor R^ The centre of resistors and R^3 is connected to the gate of transistor TM constituting switch I2 and to a Zener-type diode Zg also connected to point C. The source of transistor Tm is connected to point C and its drain is connected by a resistor R^ to point A. The use means 7 incorporating a pedestal lamp 8 are connected between the ends of resistor R^.

The position of resistor and consequently the pedestal lamp 8 between switches Ij and 1^. instead of being on the other side of transistor T.., means that the latter is a N channel M transistor. In the case of a P channel transistor T^, resistor 44 would be located on the other side of switch I^, i.e. as in Fig, 5.

For information purposes, the following table gives the values of the resistors and capacitors usable in this embodiment, as well as the types of transistors and diodes.

I Ss jS&r •5//- y\<! i-: f 1 1 223591 T A B L E ' 2 o 1 R 22 R 23 I R 24 f R 1 R 1 24 R 27 R I 28 J 10k JX 22k ci | 3,3ktf- | 1k si | 1k n. 360 n 2.7kn | I R 29 R I R 3' 1 R 1 32 I * i 33 R 34 R I | 3 .3k n. .6kXl | 12k.o. | 820 s3. | 4.7k a 1.8ka 4.7ka | i R 36 R 37 I R 38 i R " *40 R 41 R I 42 J 390X1 CO | 3,3k*i. | 10k S. .6kn- 2.7k sx. 2,2kft | 1 R 43 R 44 !3 ! • c 3 C 4 o I | 6,8kfi. 10k n. | 2.,2k& I 2,2ka 470jJ 470^F 1N4004 | jS z 4 iS !'■ T 9 T T I 11 1 *'7v 4.7V | 15V | BC177 2N1711 2N2905 2N1711 | 1 T12 | T13 I T1« 1 | TP1 1 | 2N1711 2N1711 | 2N2905 | BUZ10 iS4ifJV£antf»«o— 2235 The reference voltages VMj and VM2> Vmj and are not really reproduced by the comparison means 29 and 33. Thus, a voltage divider bridge takes a fraction of the voltage from battery 5 and compares it with reference voltages produced by Zener diodes Z3 and Z^. The reference voltages V^j, V^. V^j and Vm2 are represented by a fraction of their value, i.e. W,^, and Wm2- In the same way voltage Vg of battery is represented by WD. d In order to carry out the comparison of Vg and V^. transistor Tn compares voltage W-, with voltage WM0, which is y D vM produced by the Zener diode Z^ When the comparator changes state, the amplification means 31 follow and give a return signal, called the feedback signal passing through R3J. When threshold V^j is cleared, it is momentarily erased. Thus, the feedback signal adds a supplementary value H to the divider bridge. Thus, transistor Tg compares voltage Wg + H with W^, which amounts to comparing Wg with W(^- H. The feedback is calculated in such a way that - H WMj, which amounts to comparing Wg with W^j or Vg with On clearing threshold Vj(jj, the feedback disappears and the comparison with threshold V(12 can again take place. The reasoning is the same for the second comparison means 33.

To carry out the comparison of Vg with Vm2, transistor Tj3 compares voltage Wg wili^fr^produced by the Zener diode Z^ when the comparator changes state, amplification means 35 following and giving a return or feedback signal passing through R4r On clearing threshold Vm2, it is momentarily erased, so that the feedback signal adds a value h to the divider bridge.

Thus, transistor TJ3 compares the voltage Wg + h with Wm2, which amounts to comparing Wg with W^ - h. The feedback is calculated in such a way that W „ - h = W ,, which therefore amounts to v m2 ml comparing Wg with W^j or Vg with V^j. On clearing threshold V^j the feedback disappears and it is again possible to carry out a comparison with threshold Vm2.

For the comparison between V and V , there is a direct D r 22SEP1988 comparison (without voltage divider bridge) by transistor TQ.

O The latter supplies a signal which blocks or saturates transistor T^, the latter supplying the voltage divider bridge constituted by resistors R_n, R0., p., Roc and R,r. in 4 6b ob The action of transistors Ta and T 'is as follows: O 1 C with Vp<Vg, the voltage divider bridge is normally supplied, so that it can fulfil its initial function, whereas if Vp>Vg + k, the supply of the voltage divider bridge is interrupted and is comparable to a considerable decrease of Vg, which leads to the action of transistor Tj3 with all its consequences.

Fig. 7 gives a constructional variant of the electrical energy generator of Fig. 5. In this variant, the energy production means 1 comprise several production devices 2 in parallel. Moreover, in order that the accumulation means 5 do not discharge into the production devices, apart from that connected to diode 19 when voltages Vp and Vg are such that Vp<Vg, use is made of comparison means 21 and amplification means 23 of the same type as described relative to Fig. 3, thus making it possible to compare these two voltages and amplify the signal from means 21 for controlling the switch Ij as a consequence thereof. The other means are identical to those shown in Fig. 5.

Thus, e.g. for a photovoltaic generator used for supplying pedestal lamps at night, when voltages Vg, Vp, V^ and are such that VD>V.,_ and/or Vn<Vn, switch I, is open and when D nc r O 1 V0>V_ + K and V„ < V,., switch I, is closed. Moreover, when P B o Ml l voltages Vg, Vp, Vm2> V j are such that VB<Vml or Vp>Vg + k, switch I0 is open and when V_>v „ and VD<VD switch I0 is closed. 2 K B m2 P B 2 The embodiments of the electrical energy generator according to the invention are in no way limitative and constructional variants can be made thereto without passing beyond the scope of the invention.

Claims (9)

-A.. 223591 i WHAT WE CLAIM IS:

1. An electrical energy generator having electrical energy production means, energy accumulation means, regulation means for regulating energy accumulation and an electrical output, said regulation means being connected to the production means, to the accumulation means and to the electrical output of the generator, characterised in that: the regulation means comprise first and second switches positioned in series between the production means and the generator output, the centre point of said switches being W./ connected in series to the accumulation means and control means for controlling the first and second switches as a function of the voltage Vp supplied by the production means, the effective charging voltage VB of the accumulation means and the maximum and minimum charging voltages of the accumulation means; the energy production means have a single production device and the regulation means incorporate a diode located between the production device and the first switch, the control means being directly connected to said production device; the control means comprise first comparison means connected to the accumulation means for comparing the effective charging voltage VB of the accumulation means and a (^) first and a second reference voltages VM1 and VH2 for second comparison means; first amplification means connected to the first comparison means and to the first switch, said amplification means amplifying the electrical signal supplied by the first comparison means, said amplified signal opening the first switch when VB>VH2 and closing said first switch when VB<VH1; second comparison means connected to the accumulation means and to the production means, said second comparison means comparing the voltage Vp supplied by the productions means, the effective charging voltage VB of the accumulation means and at least one reference voltage characteristic of the minimum charging voltage Vm of the accuipul^tion means; and 25 O ?23 second amplification means connected to the second comparison means and to the second switch, said second amplification means amplifying the electrical signal supplied by the second comparison means, said amplified signal controlling the operation of said second switch, the second comparison means comparing the voltage Vp, the voltage VB and a first and a second reference voltages Vml and such that when for said second comparison means, the electrical signal supplied by said second comparison means amplified by the second amplification means opens the second switch when v8<vmi and/or vp>vb and closing said second switch when and Vp<VB - k, in which k is chosen so as to prevent surging of the second switch in the case of small variations in the voltages VB and Vp.

2. An electrical energy generator having electrical energy production means, energy accumulation means, regulation means for regulating energy accumulation and an electrical output, said regulation means being connected to the production means, to the accumulation means and to the electrical output of the generator, characterised in that: the regulation means comprise first and second switches positioned in series between the production means and the generator output, the centre point of said switches being connected in series to the accumulation means and control means for controlling the first and second switches as a function of the voltage Vp supplied by the production means, the effective charging voltage VB of the accumulation means and the maximum and minimum charging voltages of the accumulation means; the energy production means have several production devices in parallel and the regulation means incorporate a diode located between one production device and the first switch, the other production devices being connected to said switch downstream of said diode and to the control means are directly connected to said production device; «" ' „ the control means comprise first comparison means •sfc-.hr* -:u' ? 2 3 5 91 o o connected to the accumulation means and to the production means, said first comparison means comparing the voltage Vp supplied by the production means, the effective charging voltage VB of the accumulation means and first and second reference voltages VH1 and VM2 for said first comparison means; first amplification means connected to the first comparison means and to the first switch, said first amplification means amplifying the electrical signal supplied by the first comparison means, said amplified signal opening the first switch when V8>VH2 and/or Vp<Vg and closing said switch when VB<VH1 and/or Vp>V8 + K, in which K is chosen so as to prevent surging of the first switch in the case of small variations of the voltages VB and Vp; second comparison means, connected to the accumulation means, compare the voltage VB and first and second reference voltages Vm1 and such that when V^Vfor said second comparison means, the electric signal supplied by said second comparison means and amplified by second amplification means opens the second switch when VB<Vml and closes said second switch when V^V^.

3. An electrical energy generator according to claim 1 or claim 2 characterised in that the control means comprise: first comparison means, connected to the accumulation means and to the production means, for comparing the voltage Vp supplied by the production means, the effective charging voltage VB of the accumulation means and at least one reference voltage characteristic of the maximum charging voltage VH of the accumulation means; first amplification means, connected to the first comparison means and to the first switch, for amplifying the electric signal supplied by the first comparison means, said amplified signal controlling the operation of said first switch; second comparison means connected to the accumulation means and to the production means for comparing the voltage Vp supplied by the production means, the 27 n O o' voltage V0 of the accumulation means and at least one reference voltage characteristic of the minimum charging voltage Vm of the accumulation means; and second amplification means connected to the second comparison means and to the second switch for amplifying the electric signal supplied by the second comparisons means, said amplified signal controlling the operation of said second switch.

4. An electrical energy generator according to claim 3, characterised in that the first comparison means compare voltage Vp, voltage VB and a first and a second reference voltages VH1 and VH2 such that when VH1<VM<VH2 for said first comparison means, the electrical signal supplied by said first comparison means and amplified by said first amplification means opens the first switch when VB>VH2 and/or Vp<VB and closes said first switch when Vp<VH1 and/or Vp>VB + K, in which K is chosen so as to avoid surging of the switch in the case of small variations in the voltages VB and Vp; and in that the second comparison means compare the voltage Vp, the voltage VB and a first and a second reference voltages Vffl1 and V^ such that when V|n1<Vn)<Vm2 for said second comparison means, the electric signal supplied by said second comparison means and amplified by the second amplification means opens the second switch when VB<Vm1 and/or Vp>VB and closes said second switch when and Vp<VB - k, in which k is chosen in such a way as to prevent surging of the second switch in the case of small variations of the voltages VB and Vp.

5. An electrical energy generator accordinq to any one of the claims 1 to 4, characterised in that saici energy production means have several photovoltaic modules in series.

6. An electrical energy generator according to any one of the claims 1 to 5, characterised in that the first switch, and/or the second switch is an electromagnetic relay..^-...^. 28 2 2 3 5 9

7. An electrical energy generator according to any one of the claims 1 to 5, characterised in that the first switch and /or the second switch is a transistor.

8. An electrical energy generatpr according to any one of the claims 1 to 7, characterised in that the energy accumulation means incorporate at least one accumulation battery.

9. An electrical energy generator substantially as hereinbefore described and with reference to any one of Figs. 2 to 7 of the accompanying drawings. LA TERRITOIRE DE LA POLYNESIE FRANCAISE, LE COMMISSARIAT A L'ENERGIE ATOMIOUE ESTABLISSEMENT. and L'AGENCIE FRANCAISE POUR LA MAITRISE DE L'ENERGIE. by their authorised agents, P.L. BERRY & ASSOCIATES. per: 29