System for operating and monitoring power cables

Abstract

The present invention refers to a system for remotely operating and monitoring the integrity of HV/MV/LV (High Voltage/Medium Voltage/Low Voltage), mono phasic or three-phase, power cables, regardless of the cable being under tension, wherein the protection against theft of power cables is one of several advantageous uses. The present invention is based on the principle of two-way communication between two modules, installed one on each end of the cable being operated and/or monitored, using the cable itself to communicate and is characterized by a communication Master module installed upstream to the infrastructure, Slave modules, installed at each end located downstream, and bypass modules to pass through circuit breakers. The system is based on determining the cable cutout (alarm condition sent via GSM/GPRS) when the communication between Master and Slave modules is interrupted. The present invention is applicable in the power cable industry and every other industry depending on power cable's integrity.

Claims

1. A system for operating and monitoring power cables of at least one of a high, medium, or low voltage comprising: a tower comprising a power transformer; a tower circuit breaker; an electric distribution enclosure; a master module, comprising a global system for mobile communications/a general packet radio service (GSM/GPRS) module; at least one cable configured to supply power to the master module and high frequency (HF) communication; at least one power transfer cable; a circuit breaker; a bypass module; a plurality of bypass cables configured to connect the circuit breaker to the bypass module; a motor/pump comprising connection terminals; a slave module; a slave cable configured to supply power to the slave module and HF communication; and support operative software, wherein the master module is located upstream to the at least one power transfer cable and communicates bi-directionally with the slave module, which is located downstream to the at least one power transfer cable, and wherein the circuit breaker is located downstream to the at least one power transfer cable and is connected to the bypass module through the plurality of bypass cables.

2. The system according to claim 1, wherein the master module periodically sends a request signal to the slave module and in response to the request signal, the slave module transmits at least one: (i) ACK or ACKNOWLEDGE signal, when communication between the two modules is effective; (ii) NACK or NOT ACKNOWLEDGE signal, when communication between the two modules is occurring with errors, and in response the master module triggers an alert condition; or (iii) no response, when communication between the two modules is interrupted, and in response the master modules triggers an alarm condition.

3. The system according to claim 1, wherein communication between the master module and the slave module is configured to be carried out by injection on the at least one power transfer cable of a high frequency carrier wave, and modulated to represent a state 0 and/or 1 for each bit, wherein each of a group of bits is sent when the high frequency carrier wave is centered at a zero voltage.

4. The system according to claim 1, wherein the circuit breaker is configured to cause interruption of the at least one power transfer cable by opening power contacts, and wherein the bypass module is configured to allow the passage of a high frequency carrier wave in response to the interruption thereby continuing communication.

5. The system according to claim 1, wherein operation and monitoring of the at least one power transfer cable is performed remotely.

6. The system according to claim 1 wherein the master module further comprises: a microcontroller; a transceiver; a power supply; a transceiver receiving section (RX) cable; a transceiver transmission section (TX) cable; and a feeder cable.

7. The system according to claim 3, wherein the bypass module comprises at least one inductor-capacitor (LC) series filter, having a resonant frequency approximately equal to a value of the high frequency carrier wave.

8. The system according to claim 1, wherein slave module comprises: a) a microcontroller; b) a transceiver; c) a power supply; d) a transceiver receiving section (RX) cable; e) a transceiver transmission section (TX) cable; and f) a feeder cable.

9. The system according to claim 1, wherein the support operative software is in a web server, and periodically sends a request signal to the master module and in response to the request signal, the master module transmits at least one of: (i) ACK or ACKNOWLEDGE signal, when communication is effective between the web server and the master module; (ii) NACK or NOT ACKNOWLEDGE signal, when communication between the web server and the master modules is occurring with errors, and in response the support operative software triggers an alert condition; or (iii) no response, when communication between the web server and the master module is interrupted, and in response the support operative software triggers an alarm condition.

10. The system according to claim 1, wherein communication between the master module and the slave module is not interrupted when the GSM/GPRS module is damaged or missing, and an alarm is triggered by the support operative software.

11. The system according to claim 1, wherein communication is interrupted when the at least one power transfer cable is ruptured outside the circuit breaker, and an alarm is triggered by the master module.

12. The system according to claim 1, wherein the at least one cable, the least one power transfer cable, the plurality of bypass cables, or the salve cable comprise at least copper.

13. The system according to claim 1, wherein the system is configured for use in at least one of remotely operating, monitoring and preventing theft and damage of at least one of the at least one cable, the least one power transfer cable, the plurality of bypass cables, the salve cable and the GSM/GPRS module, and wherein when communication is determined to be interrupted by the system, an alarm is triggered by the support operative software informing an operator that a deleterious event or attempt, such as a theft, an accident or an attack, has occurred.

14. The system according to claim 1, wherein the system is configured for use in at least one of remotely operating, monitoring and preventing theft and damage of an irrigation system, wherein the irrigation system comprises at least one a power transformer, at least one irrigation pump, at least one irrigation pivot and at least one electric distribution enclosure.

15. The system according to claim 14, wherein the irrigation system further comprises at least one of four irrigation pivots and six electric distribution enclosures.

16. The system according to claim 13, wherein the master module is installed in the electric distribution enclosure, and the one slave module and the bypass module each installed in additional electric distribution enclosures.

17. The system according to claim 15, wherein the master module is installed in the electric distribution enclosure, and further comprising ten slave modules and six bypass modules, wherein the ten slave modules include: (i) a slave module installed in the power transformer; (ii) a slave module installed in the pump; and (iii) two slave modules installed in each of the four irrigation pivots, and wherein each of the six electric distribution enclosures comprise a respective bypass module.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1Embodiment for the system of the invention, comprising:

(2) (1) Tower comprising a power transformer;

(3) (2) Cable(s) and circuit breaker(s);

(4) (3) Electric distribution enclosure(s);

(5) (4) Master module(s), comprising at least one GSM/GPRS module (17);

(6) (5) Cables) for supplying power to the master module and HF communication;

(7) (6) Power cable(s);

(8) (7) Circuit breaker;

(9) (8) Cable(s) connecting the circuit breaker (7) to the bypass module (9);

(10) (9) Bypass module(s);

(11) (10) Motor's connector terminals;

(12) (11) Cable(s) for supplying power to the slave module(s) and HF communication;

(13) (12) Slave module(s);

(14) (13) Motor/pump.

(15) FIG. 2Master module (4) comprising:

(16) (14) Microcontroller;

(17) (15) Transceiver;

(18) (16) Power supply;

(19) (17) at least one communication module, preferably GSM/GPRS module(s);

(20) (18) Transceiver receiving section (RX) cable;

(21) (19) Transceiver transmission section (TX) cable;

(22) (20) Feeder cable;

(23) (6) Power cable.

(24) FIG. 3Slave module (12) comprising:

(25) (14) Microcontroller;

(26) (15) Transceiver;

(27) (16) Power supply;

(28) (18) Transceiver receiving section (RX) cable;

(29) (19) Transceiver transmission section (TX) cable;

(30) (20) Feeder cable;

(31) (6) Power cable.

(32) FIG. 4Operative flowchart of the high level logic layer, alarm and alert condition, comprising:

(33) (21) Slave ID overflow node;

(34) (22) Slave ID Data Ready node;

(35) (23) acknowledge node;

(36) (24) not acknowledge node;

(37) (25) Number of tries counter node;

(38) (26) No Data node;

(39) (27) Number of tries counter node.

(40) FIG. 5Operative flowchart of communication between Slave and Master modules:

(41) (28) My own ID node;

(42) (29) No errors node.

(43) FIG. 6Implementation of the invention on a typical irrigation system, comprising:

(44) (30) Irrigation pivot;

(45) (31) Power transformer;

(46) (3) Electric distribution enclosure;

(47) (4) Master module;

(48) (6) Power cable(s);

(49) (9) Bypass module(s);

(50) (12) Slave module(s);

(51) (13) Motor/pump.

DETAILED DESCRIPTION OF THE INVENTION

(52) The system of the present invention for preventing the theft of electrical cables of any given voltage HV/MV/LV (High Voltage/Medium Voltage/Low Voltage) comprises the following modules, a preferred embodiment of which is provided in FIG. 1: at least one master module(s) (4), at least one slave module(s) (12) and at least one bypass module(s) (9).

(53) The alarm condition is triggered by at least one interrupted cable or by damaging the communication module, p.ex. an GSM/GPRS module, and is based on the following principle: A standard installation, according to FIG. 1, intends to protect the power cable(s) (6), with installed Master module(s) (4) upstream to the mentioned cable(s) and the Slave module(s) (12) located downstream, communicating bi-directionally, with each other, periodically, wherein a circuit breaker (7) located downstream to the, at least one, power cable (6) is connected to the, at least one, bypass module (9) through cable(s) (8) and the mentioned alarm condition is activated when communication between modules ceases.

(54) Communication between modules is carried out by the injection, on the power cable(s) (6) to protect, of a HF (high frequency) carrier wave, modulated to represent states 0/1 for each bit. The information is sent centered at zero voltage. When a module transmits, the other is receiving, being always the Master module the one to trigger the communication.

(55) In a situation where the existence of a protective device or a circuit breaker (7) causes the interruption of the cable by opening power contacts, the existent bypass module (9) allows the passage of a communication HF signal, since it's transparent to the communication frequency and opaque to the power mains frequency.

(56) FIG. 1 discloses a typical embodiment of the present invention, which aims to protect the power cable (6). Electric current originated in a power transformer (not shown) installed in the tower (1), descends through the cable and circuit breaker (2) and ends in an electric distribution enclosure (3).

(57) At one end, upstream to cable (6) and connected to the electric distribution enclosure (3) through cable (5), is the Master module (4). This connection allows, in addition to the power supply for the Master module (4), the injection of a HF communication carrier in cable (6), monitoring it.

(58) Downstream to cable (6) there is a circuit breaker (7) to which the bypass module (9) is connected through cables (8), allowing the HF communication carrier wave to transpose the circuit breaker (7) even when it is opened. The other end of cable (6) is connected to pump connector terminals (10) of motor/pump (13), on which the Slave module (12) is installed, connected through cable (11), being the function of this connection the module power supply and the HF communication, as explained previously regarding Master module (4).

(59) The Master module (4) on FIG. 2 comprises the following functional blocks: The microcontroller (14) that implements all the logic control, communications, alarm and alert conditions. The transceiver (15), which is the specific hardware to transmit and receive data according to the principle of a modulated HF carrier, on the power cable. The power supply (16) is responsible for assuring energy supply to the electronic section of the module. The GSM/GPRS module (17) is for remote communication. The receiving section (RX) of the transceiver block (15) is connected to the power cable (6), through cable (18) which receives data from the power cable (6). The transmitting section (TX) output of the same module, is connected to the mentioned power cable (6) through cable (19), which sends data to the power cable (6). The power supply (16) is also connected to power cable (6) through cable (20).

(60) In FIG. 2, all cables (6, 19 and 20) are marked as having 2 internal conductor wires because even if it is a three phase cable (6), the communication is always done through 2 of them.

(61) Regarding FIG. 3, representing the Slave module (12), it should be noted that from the point of view of functional electronic blocks, except for the GSM/GPRS module, everything else is identical to the master module (4). Thus we have: The microcontroller (14), responsible for the logical operation of the module. The transceiver (15), responsible for receiving and transmitting data, according to the requests of Master (4), the input and output lines RX and TX, connect to the power cable (6), respectively through cables (18) and (19). The power supply (16) connects to the mentioned power line (6), through cable (20).

(62) The, at least one bypass module (9) comprises at least one LC-series filter, with resonant frequency near to the value of the HF communication carrier. The resonant circuit of the LC-filter theoretically offers zero impedance for the HF communication carrier frequency and a very high resistance to the mains frequency.

(63) The interaction between modules works as follows, considering also FIG. 1: The Master module (4) periodically sends requests to Slave module (12) and this one must return to the Master module (4), the message ACK or NACK (acknowledge or not acknowledge), provided that the information reaches its target, respectively, without or with error. If Master (4) receives the ACK reply, it waits a few seconds before repeating the process. If the answer is NACK, the Master module (4) performs 3 attempts before triggering the alert condition.

(64) As previously mentioned, the total lack of response by Slave module (12) implies that Master module (4) triggers the alarm condition, given that communication ceases only if the power cable (6) is interrupted, considering therefore a possible cut of the cable.

(65) In resume, communication between modules can create three different situations: Master receives ACK and that means communication is ok, Master receives NACK and that means communication is occurring with errors (Master triggers Alert condition, not Alarm) and Master don't receive any answer that means communication is interrupted (Master triggers Alarm condition).

(66) The procedure of communication previously described also occurs between the Master module (4) and the support software resident in a web server, and in this case, the supporting software periodically sends requests for response to the Master module (4), and if it does not get a response (situation caused by destruction of the GSM/GPRS module antenna, for example) the support software triggers an alarm (FIGS. 4 and 5).

(67) FIG. 4 shows the operative flowchart of the high level logic layer, alarm and alert condition. As noted above, based on the logic of monitoring the power cable (6) by communication between 2 modules located at both ends of the cable, on one end the Master module (4) that interrogates the Slave module (12) and on the other end the Slave Module (12) that responds or not, as a result of the integrity of the power cable (6). The communication between modules, whereas there may be several Slaves (12), comprises the addressing of these by the Master module (4) and the response of Slave modules (12) could assume one of two possible conditions, according to the success of the communication, i.e. with error (NACK) or without error (ACK). A third condition exists when the power cable (6) is cut, that implies no response from Slave module (12).

(68) According to FIG. 4, Master module (4) inquires all Slaves (12) sequentially, one at a time, by selecting the appropriate Slave ID. Firstly it resets the number of tries and Slaves ID. Afterwards, value 1 is added to the previous ID, because Slaves are numbered from 1 to n. The node Slave ID (21) verifies if Slave ID is greater than the maximum number of ID of the installation and sets it to 1 in case of true, otherwise Master sends data to Slave (inquiring it) and stops in the node Slave ID Data Ready (22) awaiting for the Slave response.

(69) The waiting loop of node Slave ID Data Ready (22) will end after Master receives a response from the Slave and stops in the node ACK (23). After that, node (23) verifies if the returned data is an ACK. In case of ACK is validated, that means the data reached the slave without error, the Master finishes the procedure after turning off the alarm and alert conditions and sets the try counter to 0. (The term try in FIG. 4 means attempts before action).

(70) Back to node ACK (23), if Slave returns back a different response than ACK, it goes to node NACK (24) to verify if the response is NACK. In case of NACK, Alert condition is activated by Master but only after three attempts, verified by node Try=3 (25), if not, attempt counter will be incremented (Try=Try+1).

(71) Back to node NACK (24), in case of lack of Slave response evaluated by node No Data (26), Master will assume Alarm condition only after three attempts, like mentioned before. Back to node No Data (26), in case of Slave response different than ACK and NACK, the Master will assume wrong data, and in this case, Alert condition will be triggered after three tries.

(72) Note that the execution sequence of the flowchart works in loop way.

(73) According with FIG. 5 Operative flowchart of communication between Slave and Master module(s), the response of each inquired Slave can assume three different pre-defined conditions; send back a ACK, NACK or no response. Whenever a Master inquire arrives to node My own ID (28) it checks if the ID is correct. If the ID is not correct, Slave returns nothing. In case of correct ID, it goes to node No Errors (29) and send ACK if true condition, otherwise it sends NACK.

(74) As noted before, the communication is based on sending information by modulating a HF (high frequency) carrier to determine each state of data bit sent that is injected into the power cable (6), the same which is under monitoring.

(75) In one embodiment, for each half-cycle, information bits are sent in reversed order, compared to RS232 communication. Each group of bits are sent, centered with the zero of the AC voltage, because this is the range experiencing lower noise and interference.

(76) According to FIG. 6, implementation preferred embodiment of the present invention in an irrigation system comprising one power transformer (31), one irrigation pump (13), four irrigation pivots (30) and six electric distribution enclosures (3) (with circuit breakers), comprises the installation of one master module (4) (in the main electric distribution enclosure (3)), ten slave modules (12), (one installed in the power transformer (31), one in the pump (13) and two in each pivot (30)) and six bypass modules (9) (one in each electric distribution enclosure (3)).

(77) This solution allows the monitoring and protection of all irrigation system power cables (6) and at the same time allows the operation of the existing equipment (pivots (30) and pumps (13)) by sending appropriate commands, using the same communication system. Those commands, among other operations, allows the user to switch on/off pivots (30) and pumps (13) and change pivot speed, program several operation parameters and also to collect information regarding operating pressure, flow rates and energy consumption.

(78) The present invention, differs from usual remote control solutions that comprises at least one communication module(s) (preferably gsm/gprs or radio) for each equipment.

(79) The proposed present solution differs from the previous disclosures by the operation principle, i.e., comprising intrinsic communication through the mains line, as well as through the bypass module, being the objective technical problem to be solved: how to improve or modify the previous disclosures in order to accomplish the continuity of communication of the carrier wave through the circuit breaker (7) even when this is opened, due to the bypass module (9) and assure the operator is notified in real time when communication between master(s) and slaves(s) modules is experiencing errors and/or when it is interrupted. We therefore believe the present invention is new, inventive and has wide industrial applicability.

(80) Lisbon, 30 Jun. 2014.