FR2746942A1 - PREPAYMENT ENERGY CONTROL SYSTEM - Google Patents

Abstract

An operational key comprising a tariff index is used by the energy management circuit to decrypt codes which are supplied to it. The tariff index defines the power limit value (Pli) applicable to the subscribed tariff. When the operational key is changed, the tariff index is extracted from the new key and used to update the power limit value (Pli, Pl). Several tariff indexes are associated with the same power limit value. The management circuit controls the opening of a switch when the power delivered, measured by the management circuit, is greater than the power limit value. The management circuit comprises means (M1, F17) for inhibiting and restoring the association between the tariff index and the power limit value.

Description

-4

  PREPAYMENT ENERGY CONTROL SYSTEM

  The invention relates to a prepaid energy control system comprising energy management means comprising: - means for measuring the electric power delivered to a user, - means for entering an encrypted code using an operational key comprising information representative of a tariff index, - means for entering an operational key change code comprising information representative of an operational key, - means for storing the key operational, - means for decrypting the encrypted code using the stored operational key,

  - And means for storing a power limit value.

  Prepaid energy control systems are known in which each user has a management circuit connected to a circuit for measuring the energy used and to a switch or a circuit breaker to interrupt the energy supply to the user when the amount of an energy credit, stored in the management circuit and reduced as the energy consumption progresses, is canceled. The amount of the credit can be modified by the introduction into the management circuit of a prepayment code. In known systems, this code is introduced either by means of a keyboard,

  either using a magnetic card or using an electronic chip holder.

  The current operation of these systems can therefore be done without the intervention of a technical agent on site to record energy consumption. The configuration of these systems can also be carried out using codes that no longer carry energy credit but technical data. It is therefore also possible to modify the technical operating conditions of these systems without moving an agent, in particular to adjust the

  maximum power level delivered by these systems.

  The invention aims to improve the financial security of such a system.

2 2746942

  This object is achieved by the fact that the energy management means comprise means for extracting and memorizing the tariff index of an operational key change code and means for determining and storing the power limit value from said tariff index, a plurality of tariff indexes being associated with the same power limit value. It is thus possible to ensure the financial security of such a device when the power limit delivered is configured by a technical code, without the intervention of an operator's agent but by the end user himself. There is thus indeed consistency between the power actually subscribed for the installation, ie the tariff regime used when purchasing an energy credit by the user, and the power limit actually

used in the system.

  According to an improvement of the invention, the energy management means comprise means for inputting a technical inhibition code comprising information representative of a technical power limit value, means for inhibiting the association between the power limit value and the tariff index when said technical inhibition code has been entered into the system, means for using the limit value

  of technical power as a power limit value.

  The energy management means then preferably comprise means for entering a technical restoration code, means for removing said inhibition and for determining the power limit value from the stored operational key, in

  response to the entry of the technical restoration code.

  According to a preferred embodiment, the energy management circuit comprises means for entering a credit code comprising information representative of an energy credit, means for storing said credit when entering credit code, means for measuring the amount of energy consumed, means for reducing the amount of memorized credit as a function of the amount of energy consumed, the system comprising interrupting means for interrupting the supply of energy, under the control of the energy management means, when the amount of the credit is canceled and when the power delivered is greater than the memorized power limit value, the energy management means comprising inhibition means for inhibit, under predetermined conditions, the interruption of the power supply when the power delivered is

  greater than the memorized power limit value.

  Other advantages and characteristics will emerge more clearly from the following description

  of an embodiment, given by way of nonlimiting example and represented by the appended drawings in which: FIG. 1 represents a prepaid energy control system according to the prior art, in which the invention can be implementation, Figures 2 to 5 illustrate particular embodiments of flowcharts of

  processing for the implementation of the invention in a system according to FIG. 1.

  The prepayment energy control system of FIG. 1 comprises a management circuit 1 and a switch 2. The switch 2 comprises contacts 3 interposed on supply lines L1 and L2 intended to supply energy to an user. The opening of the contacts 3 is controlled by a relay 4 of the switch 2, under the control of the circuit

management 1.

  The management circuit 1 comprises a measurement circuit 5 connected to a microprocessor processing circuit 6. The measurement circuit 5 can comprise current, and possibly voltage sensors, arranged on the lines L1 and L2, the processing circuit 6

  can then calculate the power delivered to the user and the energy consumed.

  Alternatively, the measurement circuit 5 may include an energy meter of known type arranged so as to measure the energy supplied to the user by the lines

supply L1 and L2.

  In the management circuit 1, the processing circuit 6 is connected to a memory 7, to a display circuit 8 and to a keyboard 9. An energy credit C is stored in the memory 7. The processing circuit 6 decreases the amount of this credit according to the quantity

4 2746942

  of energy used W, the information necessary for measuring and / or calculating the amount of energy used being supplied to it by the measuring circuit 5. The amount of the memorized credit can be modified by means of a code entered by the keyboard 9 accessible to the user. The display circuit 8 allows the user to know the amount of the memorized credit, that is to say the remaining energy credit. When the amount of credit stored in the management circuit is canceled, the processing circuit 6 controls the relay 4 so that it opens the contacts 3, causing

  the interruption of the supply of energy by lines LI1 and L2 to the user.

  In known devices, the entry of a credit is effected by means of a credit code.

  This is encrypted to avoid fraud. The credit code includes in particular information allowing the identification of the management circuit 1 of the user, information concerning the amount of the credit paid and additional information intended to ensure the security of the transaction with a company distributing energy. This additional information notably indicates the date of purchase of the energy credit, the

  link between the management circuit and the energy distribution company.

  Furthermore, it is also known to configure the management circuit by entering codes, known as technical codes. One of the technical codes makes it possible in particular to determine the power limit value of the system. In practice, the technical code, encrypted, includes information representative of a power limit value Plt. This power limit value Plt is stored in the memory 7 of the management circuit 1 during the setting

  during installation, by entering the appropriate technical code using the keyboard 9.

  2s This limit can be modified later by introducing a new technical code, for example when changing the conditions of use of the installation associated with the

management circuit.

  In known systems, the management circuit 1 compares the measured power P with the

  limit value Plt and causes the opening of contacts 3, when P is greater than Plt.

2746942

  An operational key, comprising information representative of a tariff index, is stored in the management circuit when the system is started up. This operational key, known to the energy distributor, is used for encryption of the credit codes and technical codes supplied to the user. When a code is entered into the management circuit 1, it is decrypted using the operational key stored in the circuit. If the stored key does not match the key used for code encryption, the

  decryption cannot take place and the code is rejected. It is thus possible to limit fraud.

  As shown in FIG. 2, in normal operation, the processing circuit 6 verifies, in a step F1, the existence of an energy credit C of a non-zero amount in the memory 7. If the amount of the credit is canceled (C = 0), then the processing circuit proceeds to open the contacts 3 of the switch 2 during a step F2. For this, the processing circuit 6 controls the energization of the relay 4 which opens the contacts 3. To supply

  once again, the user must manually reset switch 2.

  However, any closing of the contacts before entry into the management circuit 1 of a non-zero energy credit by means of a credit code automatically leads to

  again when the contacts open 3.

  If there is a non-zero energy credit C, the processing circuit proceeds to a step F3 for measuring the value P of the power delivered from the values supplied by the measurement circuit. Then, in a step F4, it compares P with the value Pi previously stored in the memory 7. If P is greater than Pi, that is to say if the measured power P exceeds the power limit value Pl, the processing circuit 6 proceeds to step F2 of opening the contacts 3. Alternatively, the opening of the contacts can in this case be replaced by

  a load shedding function under the control of the management circuit 1.

  When the measured power P is less than or equal to Pi, the processing circuit goes to a step F5 of measuring the quantity of energy consumed W. This energy can be calculated by the processing circuit from current values, and possibly of voltage, supplied by the measurement circuit 5. Alternatively, the value W or a value representative of the power consumed, can be supplied to circuit 6 directly by the

measuring circuit 5.

6 2746942

  In a step F6, the amount of stored energy credit C is then reduced by the amount of energy consumed. The remaining credit C can then be displayed on the display circuit

8 (step F7).

  In known devices, the power limit value Pi used by the system is the

  Plt limit value supplied to the management circuit by a technical code.

  To improve the financial security of the system, the power limit value PI is linked to the price index of the operational key used by the management circuit for decryption

different codes.

  This connection is made by the management circuit and is updated when entering a code

  change of operational key in the management circuit.

  The processing of an operational key change code is more particularly

illustrated in figure 3.

  After a step F8 of reading and validating the code, which uses the previous operational key for its decryption, the processing circuit 6 extracts the tariff index from the code during a step F9. Then, in F10, it determines from this tariff index and stores a power limit value Pli associated with the tariff index. Then, at F11, it stores in memory 7 the value Pli as the power limit value Pl. Thus the value Pli extracted from the new operational key and linked to the tariff index contained in this key determines the power limit value Pl taken taken into account by the management circuit during step F4 of FIG. 2 to interrupt the supply of energy if the power delivered is greater than PI. A step F12 of displaying the new value of PI can be

scheduled after step F1i1.

  In a preferred embodiment, the tariff index consists of a two-digit code. The power limit value Pli associated with the tariff index is preferably

7 2746942

  expressed in kVA. An example of correspondence between the tariff index and the Pli value is provided in the table below: Pli (kVA) Tariff index Number of associated tariffs

1 10 to 19 10

2 20 to 29 10

3 30 to 39 10

4 40 to 49 10

50 to 59 10

6 60 to 69 10

7 70 to 79 10

8 80 to 89 10

9 90 to 99 10

13.8 00 to 09 10

  It appears from this table that several price indexes are associated with the same Pli power limit value. In the example above, 10 tariff indexes, i.e. 10 different tariffs, are associated with the same limit value. For example, a first tariff may be the normal tariff, while a second tariff is reserved for farmers, a third tariff reserved for needy people, the other tariffs can be allocated according to other criteria. AT

  o0 each of these tariffs corresponds to a different tariff index and a different price.

  In the table, the limit value Pli corresponds to the tens digit of the tariff index when the limit value Pli is between 1 and 9 kVA. For example, for an index

  tariff between 50 and 59, the limit value Pli is equal to 5kVA.

  On the other hand, if the tariff index is between 00 and 09, the limit value Pli is equal to the maximum power acceptable by the system. In the example chosen this maximum value

  corresponds to 60A at 230V, or 13.8 kVA.

8 2746942

  The entry into the management circuit of a technical inhibition code comprising information representative of a Pit technical power limit value, can allow

  inhibit the link between the tariff index and the power limit value Pi.

  FIG. 4 illustrates the processing of a technical inhibition code, by the processing circuit 6. After a step F13 of reader and validation of the technical inhibition code, an MI code memorized by the circuit is set to a first predetermined value, 0 in FIG. 4, during a step F14. Then, in F15, the limit value Plt of the technical code is stored as the power limit value PI. This value Pi = io Plt will therefore subsequently be the value Pi taken into account by the management circuit in step F4. A step F16 of displaying the new value of PI can be provided after step F15. The taking into account of the code M1 is illustrated in FIG. 3. An additional step F17 is introduced i5 between steps F10 and F11 during the processing of an operational key change code. During step F17, the processing circuit checks the value of the memorized code M1. If the code M1 has a second predetermined value, different from 0 in FIG. 3, the processing circuit normally proceeds to step F11 On the other hand, if the code M1 has the first predetermined value, 0 in FIG. 3, the circuit processing circuit bypasses step F11 and goes directly to step F12. There is therefore, in this case, no modification of the value P1 previously memorized, which thus corresponds to the last

  Plt value entered during phase F 15.

  Thus, the entry of a technical inhibition code containing a power limit value Plt inhibits the association between the limit value PI and the tariff index. Step F17 can optionally be introduced between steps F9 and F10, or respectively between F8 and F9, steps F10 and F11 respectively F9 to F11 then being short-circuited if M1 = 0. There is therefore also this case inhibition of determination and memorization of Pli,

  respectively from the extraction of the tariff index.

  To restore the association between the limit value Pl and the tariff index, a code is provided

  restoration technique, the treatment of which is illustrated in Figure 5.

  After a step F18 of reading and validating the technical code, the code M1 is set to the second predetermined value, 1 in FIG. 5. Then the value Ply, which had been memorized during step F10 during the last change of key operational, is stored as the PI power limit value. In the variant according to which step F17 is between F9 and F10, an additional step, corresponding to step F10 of determining and storing Ply from the tariff index, must be added between steps F19. If F17 is arranged between F8 and F9, a step of extracting the tariff index corresponding to step F9 must also be added. A step F21 for displaying the new value of P1 can be provided after step F20. The introduction of the technical restoration code thus makes it possible to remove the inhibition introduced, permanently, by a technical inhibition code comprising a value Plt. The processing circuit then re-establishes the link between Pi and the last operational key or the last

  Tariff index taken into account by the system.

  The management circuit preferably also includes means for inhibiting the interruption of the power supply when the power delivered P exceeds the stored limit value Pl. For this, as shown in FIG. 2, a step F22 is introduced between steps F3 and F4. During this step F22, the processing circuit checks the value of a code M2. If the code M2 has a first predetermined value, different from 0 in FIG. 2, the processing circuit normally proceeds to step F4. On the other hand, if the code M2 has a second predetermined value, 0 in FIG. 2, the processing circuit short-circuits step F4 and goes directly to step F5. So there is, in this case,

  inhibition of the interruption of the energy supply when P is greater than PI.

  The M2 code is preferably supplied to the management circuit by means of a technical code

  particular. It is also possible to provide manual means, such as micro-

  switches to modify this value. Of course, in the latter case, these micro-

  switch must not be accessible to the user and the value of M2 must only be able to be modified by an approved installer. Sealing or padlocking devices

  can be used for this purpose.

2746942

Claims (7)

  1.- Prepaid energy control system comprising means (1) for energy management comprising: - means (5, 6) for measuring the electric power delivered to a user, - means (9) d entry of an encrypted code by means of an operational key comprising information representative of a tariff index, means (9) for entering an operational key change code comprising information representative of a key operational, o10 - means (7) for storing the operational key, - means (F8, F13, F18) for decrypting the encrypted code by means of the stored operational key, - and means (7) for setting in memory of a power limit value (Pi), system characterized in that the energy management means (1) comprise means (F9) for extracting and memorizing the tariff index of a change of operational key and means (F10, F11) for determining and storage of the power limit value (PI, Pli) from said tariff index, a plurality of indexes   tariffs being associated with the same power limit value (Pli).   2.- System according to claim 1, characterized in that said tariff index is   consisting of a two-digit code.   3.- System according to claim 2, characterized in that the power limit value (Pli, Pi), expressed in kVA, corresponds to a figure representative of tens of   the tariff index for a power limit value between 1 and 9 kVA.   4.- System according to claim 2, characterized in that the power limit value (Pli, Pi), is equal to the maximum value acceptable by the system when the index   tariff is between 00 and 09.   5.- System according to any one of claims 1 to 4, characterized in that the   energy management means (1) comprise means (9) for inputting a technical inhibition code comprising information representative of a technical power limit value (Pit), means (F14, F17) for inhibit the association between the power limit value (Pi) and the tariff index when said technical inhibition code has been entered into the system, means (F15) for using the technical power limit value (Plt) as a value power limit (Pl). - 6. System according to claim 5, characterized in that the means (1) for energy management comprise means (9) for entering a technical restoration code, means (F19, F17, F20) for removing said inhibition and to determine the power limit value (Pl) from the stored operational key, in response to   the entry of the technical restoration code.   7.- System according to any one of claims 1 to 6, characterized in that the   energy management circuit (1) comprises means (9) for entering a credit code comprising information representative of an energy credit, means (7) for storing said credit during the entry of the credit code, means (5, F5) for measuring the amount (W) of energy consumed, means (F6) for reducing the amount (C) of memorized credit as a function of the amount (W) of energy consumed, the system comprising means (2) for interrupting to interrupt the energy supply, under the control (F1, F2, F4) of the energy management means, when the amount (C) of the credit is canceled and when the power delivered (P) is greater than the memorized power limit value (P1), the energy management means comprising   inhibition means (M2, F22) for inhibiting, under predetermined conditions.   the interruption of the energy supply (F2) when the delivered power (PI) is   greater than the stored power limit value (Pl).