Electrical switching device for an electrical power circuit comprising a predictive maintenance system

Abstract

Electrical switching device for an electrical power circuit comprising a predictive maintenance system The invention relates to a device (100) for electrically switching an electrical power circuit (102) comprising a contactor and provided with a predictive maintenance system (115) comprising a storage unit (115a) configured to store an estimated aging profile (Nv) of the contactor (104) previously established, an acquisition unit (115b) configured to acquire values ​​of a set of input parameters relating to operating conditions of the contactor (104), a processing unit (115c) configured to calculate, each time the contactor (104) is opened, as a function of the estimated aging profile (Nv) and the operating conditions, a number (Nc) of remaining operability cycles. In addition, the contactor (104) comprises an internal memory (118) capable of storing said number (Nc) of remaining operability cycles.Figure for abstract: Fig. 2.

Description

Title of the invention: Electrical switching device for an electrical power circuit comprising a predictive maintenance system Domain

[0001] The present invention relates to an electrical switching device for an electrical power circuit comprising a predictive maintenance system.

[0002] According to an embodiment visible in [Fig.l], a switching device 1 of an electrical power circuit comprises: - at least one contactor 12 configured to occupy an open state in which it isolates an electrical source 14 and an electrical load 16 from the electrical power circuit as well as a closed state in which it connects the electrical source 14 and the electrical load 16, by means of contacts 12a, 12b, - a device 18 configured to cause the contactor 12 to close and remain in the closed state when the device 18 is powered, - a member 20 configured to cause the contactor 12 to open and remain in the open state when the device 18 is no longer powered, - a control power supply 22 configured to apply a control signal Sc to the device 18 upon receipt of a signal 24 and maintain this control signal Sc as long as the contactor 12 must remain in the closed state.

[0003] In the aeronautical field, current studies relate to electrically powered aircraft which must ensure the distribution and electrical protection of high-power circuits which are well above 1200V / 500A, thus combining the strong constraints of high voltage and current levels associated with severe environmental constraints (high temperature and pressure difference, reduced space, etc.). These constraints are associated with the need to keep the equipment as compact and light as possible. Consequently, certain equipment will no longer be able to guarantee nominal operation over the entire lifetime of the aircraft, as is currently the case on conventional programs.

[0004] In addition, these electrical switching devices for power electrical circuits used in the aeronautical field must make it possible to obtain very high breaking capacities in a reduced volume, all without being impacted by environmental conditions, mainly low pressure. However, over time, when the switching device must open a network under high current, an electric arc occurs at the contactor 12. This electric arc causes tearing of material at contacts 12a and 12b, causing the electrical switching device to gradually operate in a degraded manner.

[0005] Indeed, the contactor 12 loses its ability to clarify the arc and therefore potentially to clarify short circuits. This specificity cannot be taken into account by conventional monitoring devices which use mechanical auxiliaries reacting once the problem is proven.

[0006] There is therefore a strong interest in anticipating a degraded state of the electrical switching device in order to be able to replace it when necessary, and before the clarification problem becomes apparent.

[0007] The present invention aims to remedy all or part of the drawbacks of the prior art. SUMMARY

[0008] To this end, the invention relates to an electrical switching device for an electrical power circuit comprising a predictive maintenance system comprising: - at least one contactor connected to an upstream section and a downstream section of an electrical power circuit, the two sections being positioned on either side of the contactor, said contactor being configured to occupy one of the two open and closed states, - a control member configured to cause the contactor to close and remain in the closed state when said control member is powered, - an actuator member configured to cause the contactor to open and its maintenance in the open state when the control organ is no longer powered, - a control device configured to apply a control signal upon receipt of a signal to the control member and maintain this control signal as long as the contactor is to remain in the closed state.

[0009] According to the invention, the switching device comprises at least one predictive maintenance system comprising: - a storage unit configured to store a previously established estimated aging profile of the contactor, - an acquisition unit configured to acquire values ​​of a set of input parameters relating to operating conditions of the contactor, - a processing unit configured to calculate, each time the contactor is opened, based on the aging profile and operating conditions, a number of remaining operability cycles.

[0010] Furthermore, according to the invention, the contactor comprises an internal memory capable of storing said number of remaining operability cycles.

[0011] Thus, the electrical switching device has an indication representative of its aging. This indication being stored in the internal memory of the contactor, it remains associated with it, even if the contactor is dismantled to be used in another electrical power circuit. Thus, an operator will be able to systematically have access to the information relating to the level of aging of the contactor and will be able, consequently, to decide to change the contactor according to this information.

[0012] According to particular embodiments: - the input parameters relating to the operating conditions of the contactor are composed of the voltage and current values ​​applied to the contactor. - the aging profile is represented by aging curves established according to the values ​​of an operating voltage and current. - each time the voltage and current values ​​are acquired, the processing unit is configured to calculate a number of remaining operating cycles for opening the contactor, this number being stored in the internal memory of the contactor. - the number of remaining operating cycles of opening the contactor is calculated based on the previous number of remaining operating cycles. - the power circuit includes a current sensor configured to measure the current value when the contactor opens and to transmit this information to the predictive maintenance system.

[0013] The invention relates to a method for calculating the number of remaining operating cycles of a contactor of an electrical power circuit. According to the invention, the method comprises the following steps: - measurement of at least one input parameter relating to operating conditions of the contactor, - comparison of the value of this parameter with a threshold value representative of the nominal behavior of the contactor, - if the parameter value exceeds the threshold value, determination of the contactor aging value from the previously established contactor aging profile and calculation of the new number of remaining operability cycles of the contactor, or - if the parameter value does not exceed the threshold value, calculation of the new number of remaining operability cycles of the contactor, - storage of the new number of remaining operability cycles in the internal memory of the contactor.

[0014] According to particular embodiments: - the input parameter relating to operating conditions of the contactor is the fluent. - if the value of the parameter exceeds the value of the threshold parameter, the calculation of the new number of remaining operability cycles of the contactor is carried out by subtracting the calculated aging value from the previous number of remaining operability cycles, or, if the value of the parameter does not exceed the value of the threshold parameter, the calculation of the new number of remaining operability cycles of the contactor is carried out by subtracting the value 1 from the previous number (Nc-1) of remaining operability cycles.

[0015] Other features and advantages of the device according to the invention will become more apparent on reading the description given below, for informational but non-limiting purposes, with reference to the appended drawings in which:

[0016] [Fig-1] schematically illustrates an electrical switching device of a electrical power circuit according to the prior art;

[0017] [Fig.2] schematically illustrates an electrical switching device of a electrical power circuit according to the invention;

[0018] [Fig.3] represents a predictive maintenance system according to the invention;

[0019] [Fig.4] represents an example of an aging profile as a function of the conditions operation of a contactor;

[0020] [Fig.5] represents, in a simplified manner, a method for calculating the number of cycles remaining operability according to the invention.

[0021] In [Fig.2], a device 100 for electrically switching an electrical power circuit 102 comprises a contactor 104 connected to an upstream section 102a and a downstream section 102b of an electrical power circuit 102, the two sections 102a, 102b being positioned on either side of the contactor 104. The contactor 104 is configured to occupy an open state (visible in dotted lines), in which it isolates the upstream section 102a from the downstream section 102b and prohibits the passage of a current, as well as a closed state in which it connects the upstream and downstream sections 102a, 102b and authorizes the passage of a current. According to a non-limiting application, the contactor 104 is used to connect or isolate at least one electrical source 106 and at least one electrical load 108 in an electrical power circuit of an aircraft. The contactor 104 is configured to operate at high voltages, greater than 300 V, of the order of 1200 V.Of course, it could operate at lower voltages, for example around 115 V.

[0022] The electrical switching device 100 comprises a control member 110 configured to cause the contactor 104 to close and to maintain it in the closed state when said control member 110 is powered, as well as an actuator member 112 configured to cause the contactor 104 to open and to maintain it in the open state when the control member 110 is no longer powered. The device 100 comprises in furthermore a control device 114 configured to apply a control signal C to the control member 110 upon receipt of a signal 116 and maintain this control signal C as long as the contactor 104 must remain in the closed state.

[0023] The control signal C can be an energy, a voltage, an intensity or any other physical quantity.

[0024] According to one embodiment, the control member 110 is a coil comprising first and second end terminals to which the control signal C is applied.

[0025] Whatever the embodiment, the control member 110 is configured to cause a change from the open state to the closed state of the contactor 104 against a force generated by the actuator member 112 when the control member 110 is powered by a control signal C. The actuator member 112 then causes a change from the closed state to the open state of the contactor 104 when the control member 110 is not powered.

[0026] According to one embodiment, the actuator member 112 is a spring configured to cause the contactor 104 to open and remain in the open state when the control member 110 is no longer powered.

[0027] When the electrical switching device 100 must open the electrical circuit 102 under high current, an electric arc occurs at the contactor 104, which causes material to be torn off at the contacts of the contactor 104. The operation of the electrical switching device 100 gradually degrades, which impacts the quality of the electrical circuit 102.

[0028] Consequently, according to the invention, the control device 114 comprises at least one predictive maintenance system 115 comprising ([Fig.3]): - a storage unit 115a configured to store a previously established aging profile Nv of the contactor 104, - an acquisition unit 115b configured to acquire values ​​of a set of input parameters relating to operating conditions of the contactor 104, - a processing unit 115c configured to calculate, based on the aging profile Nv and the operating conditions, a number of remaining operability cycles.

[0029] The aging profile Nv stored in the storage unit 115a represents the aging behavior Nv of the contactor 104 as a function of the conditions under which the contactor 104 is operated. An example of such a profile is shown in [Fig.3]. These aging profiles Nv are generally established by the manufacturer of the contactor.

[0030] [Fig.4] represents an estimated lifetime profile of a high voltage contactor depending on the voltage Vc and the current le applied at the time of opening of the contactor. Thus, for a voltage of 1500 VDC and a current of 5A, it is estimated that a new contactor will be able to carry out an initial number Nci of closing and opening cycles of 100,000. If the current applied at opening is greater than 5A, there will be a deterioration in the condition of the contactor, which causes its aging Nv and reduces the number of closing and opening cycles that the contactor will be able to ensure. Thus, referring to [Fig.4], for a voltage of 1500 VDC and a current of 100A, we can read that the number Ne 100 of estimated operability cycles decreases to 7000. It is therefore possible to calculate in real time the number Ne of remaining operability cycles during which the contactor can ensure a closing and an opening suitable for clarifying an electric arc and the resulting short circuit.

[0031] The acquisition unit 115b is configured to acquire values ​​of a set of input parameters relating to operating conditions of the contactor 104. This unit 115b must therefore have access to the values ​​of the set of input parameters relating to operating conditions of the contactor 104. In the example described in [Fig. 3], these values ​​are the current Vc and the voltage le. Consequently, it is important to measure the values ​​(Vc and le) of the voltage / current pair in order to provide this information to the acquisition unit 115b. It is for this reason that a current sensor 120 is installed between the load 108 and the contactor 104, on the section 102a. The sensor 120 measures the value of the current Ic when the contactor 104 opens and transmits this information to the predictive maintenance system 115 and more particularly to the acquisition unit 115b.

[0032] Finally, the processing unit 115c is configured to calculate, as a function of the aging profile Nv stored in the storage unit 115a and the operating conditions (voltage Vc / current le applied to the electrical power circuit and acquired by the acquisition unit 115b), a number Ne of remaining operability cycles. Thus, each time the contactor 104 opens, the predictive maintenance system 115 uses the voltage Vc and current le values ​​measured by the current sensor 120 and transmitted to the acquisition unit 115b to calculate the number Ne of remaining operability cycles that the contactor 104 can ensure.

[0033] The contactor 104 comprises an internal memory 118 in which the number Ne of remaining operating cycles is stored. Thus, if the contactor 104 must be dismantled to be installed on another electrical power circuit, the information relating to the number Ne of remaining operating cycles of the contactor will remain known and accessible at the new location of the contactor 104.

[0034] When the contactor 104 is produced, the internal memory 118 is initialized with an initial number Nci of remaining operability cycles corresponding to the maximum number of remaining operability cycles estimated by the contactor manufacturer for a new contactor. Using the example of aging profile Nv shown in [Fig.4], the value of the initial number Nci of estimated remaining operability cycles is 100000. In this exemplary embodiment, a voltage value Vc of 1500V is applied to the power electrical circuit 102.

[0035] The aging profile Nv of the contactor 104 may be a function of a set of input parameters relating to operating conditions of the contactor 104: the parameters may, for example, be chosen from the following list, without this list being limiting: current, voltage, power. This aging profile Nv is stored in the storage unit 115a of the predictive maintenance system 115.

[0036] In operation, upon receipt of a signal 116 to close the contactor 104, the control device 114 generates a control signal C and applies it to the control member 110. The control signal C is maintained as long as the contactor 104 must remain in the closed state. The control member 110 then causes a change from the open state to the closed state of the contactor 104 against a force generated by the actuator member 112. When the control member 110 no longer receives the control signal C, the actuator member 112 causes a change from the closed state to the open state of the contactor 104. Each time the contactor 104 opens, the current 1e is measured by the current sensor 120 and its value is transmitted to the acquisition unit 115b of the predictive maintenance system 115.

[0037] The calculation unit 115c uses the aging profile Nv stored in the storage unit 115a, the current le and voltage Vc values ​​as well as the value of the number Nc-1 of previous remaining operability cycles stored in the internal memory 118 to calculate the new value of the number Ne of remaining cycles. This new calculated number Ne is sent by the calculation unit 115c to the internal memory 118 of the contactor 104 so that it is stored there, in doing so, this new number Ne of remaining operability cycles overwrites the number Nc-1 previously calculated.

[0038] The invention also relates to a method for calculating the number Ne of remaining operability cycles shown in [Fig. 5]. According to the invention, the method comprises a first step of measuring at least one input parameter relating to operating conditions of the contactor. In operation, in this exemplary embodiment, this input parameter is the current Ie carried by the contactor 104. The current Ie is measured using the current sensor 120 installed between the contactor 104 and the load 108.

[0039] The measurement of the current Ic is transferred to the acquisition unit 115b and used by the calculation unit 115c which compares it with a threshold current value Is representative of a nominal behavior of the contactor.

[0040] In the example of the aging profile Nv as a function of the operating conditions of a contactor shown in [Fig.4], we see that, for a current lower than 5A, this contactor 104 does not undergo aging Nv. Thus, for this example of realization, the threshold current value Is representative of the nominal behavior of the contactor is 5A. Obviously, this threshold current value Is is representative of the contactor considered and can therefore change depending on the contactor manufacturer.

[0041] Thus, if the value of the measured current Ic is less than or equal to Is, the contactor 104 undergoes standard aging Nv. In this case, the calculation unit 115c calculates the number Ne of remaining operability cycles, for example by subtracting 1 from the number of remaining cycles Nc-1 of the previous cycle (step 130).

[0042] On the other hand, if the value of the current is greater than Is, the contactor 104 undergoes aging Nv. The calculation unit 115c then calculates, using the aging profile Nv stored in the storage unit 115a, the aging Nv induced by this operating current Ic (step 140). Then, the calculation unit 115a calculates the number Ne of remaining operability cycles. For example, the aging Nv can be subtracted from the number Nc-1 of remaining operability cycles of the previous cycle in order to calculate the new number Ne of remaining operability cycles (step 150).

[0043] Regardless of the value of the current le, the new value of the number Ne of remaining operability cycles calculated by the calculation unit 115a is transferred to the internal memory 118 (step 160) to be stored there until the next cycle. In doing so, the new value Ne overwrites the previous value of the number Nc-1.

[0044] When the number Ne of remaining operability cycles reaches or approaches zero, the predictive maintenance system 115 emits a maintenance signal Sm so that an operator replaces the contactor 104, before the latter becomes inoperative or exhibits significantly degraded behavior.

[0045] The number Ne of operability cycles stored in the internal memory 118 of the predictive maintenance system 115 may be accessible using any reading means known to those skilled in the art, for example using a cable connection to the internal memory 118 and reading / displaying on a computer screen.

[0046] The advantages of such a predictive maintenance system 115 are numerous: - Improvement of the robustness of the checks carried out during different maintenance interventions thanks to real-time knowledge of the aging of the contactor 104, - Taking into account and traceability of the aging Nv of the contactor 104 thanks to the internal memory 118, - Optimization of the maintenance of contactor 104 allowing interventions on contactors to be limited to only those necessary.

Claims

Claims

1. Device (100) for electrically switching an electrical power circuit (102) comprising: - at least one contactor (104) connected to an upstream section (102a) and a downstream section (102b) of an electrical power circuit (102), the two sections (102a, 102b) being positioned on either side of the contactor (104), said contactor (104) being configured to occupy one of the two open and closed states, - a control member (110) configured to cause the contactor (104) to close and remain in the closed state when said control member (110) is powered, - an actuator member (112) configured to cause opening the contactor (104) and keeping it in the open state when the control member (110) is no longer powered, - a control device (114) configured to apply a control signal (C) upon receipt of a signal (116) to the control member (110) and maintain this control signal (C) as long as the contactor (104) must remain in the closed state. characterized in that the switching device (100) comprises a predictive maintenance system (115) comprising: - a storage unit (115a) configured to store an estimated aging profile (Nv) of the contactor (104) previously established, - an acquisition unit (115b) configured to acquire values ​​of a set of input parameters relating to operating conditions of the contactor (104), - a processing unit (115c) configured to calculate, each time the contactor (104) is opened, as a function of the estimated aging profile (Nv) and the operating conditions, a number (Ne) of remaining operability cycles, and in that the contactor (104) comprises an internal memory (118) capable of storing said number (Ne) of remaining operability cycles).

2. Device (100) for electrically switching an electrical circuit of power (102) according to claim 1 characterized in that the input parameters relating to operating conditions of the contactor are composed of the voltage (Ie) and / or current (Vc) values ​​applied to the contactor (104).

3. Device (100) for electrically switching an electrical power circuit (102) according to claim 1 or 2, characterized in that the aging profile (Nv) is represented by aging curves established as a function of the values ​​of an operating voltage (Vc) and current (Ie).

4. Device (100) for electrically switching an electrical power circuit (102) according to claim 2 characterized in that at each acquisition of the voltage (Vc) and current (Ie) values, the processing unit (115c) is configured to calculate a number of remaining operability cycles (Ne) of opening of the contactor (104), this number (Ne) being stored in the internal memory (118) of the contactor (104).

5. Device (100) for electrically switching an electrical power circuit (102) according to the preceding claim, characterized in that the number (Ne) of remaining operability cycles of opening of the contactor is calculated as a function of the previous number (Nc-1) of remaining operability cycles.

6. Device according to any one of the preceding claims, characterized in that the power circuit (102) comprises a current sensor (120) configured to measure the value of the current (Vc) when the contactor (104) opens and to transmit this information to the predictive maintenance system (115).

7. Method for implementing an electrical switching device (100) according to any one of the preceding claims, characterized in that it comprises the following steps: - measurement of at least one input parameter relating to operating conditions of the contactor (104), - comparison of the value of this parameter with a threshold parameter value (Is) representative of a nominal behavior of the contactor (104), - if the value of the parameter exceeds the value of the threshold parameter (Is), determination of the aging value (Nv) of the contactor (104) from the estimated aging profile of the contactor (104) previously established (step 140) and calculation of the new number (Ne) of remaining operability cycles of the contactor (104) (step 150), or - if the value of the parameter does not exceed the value of the threshold parameter (Is), calculation of the new number (Ne) of remaining operability cycles of the contactor (104) (step 130), - storage of the new number (Ne) of remaining operability cycles in the internal memory (118) of the contactor (104) (step 160).

8. Method for implementing an electrical switching device (100) according to the preceding claim, characterized in that the input parameter relating to operating conditions of the contactor (104) is the current (Ic).

9. Method for implementing an electrical switching device (100) according to claim 6 or 7 characterized in that: - if the value of the parameter exceeds the value of the threshold parameter (Is), the calculation of the new number (Ne) of remaining operability cycles of the contactor (104) (step 150) is carried out by subtracting the calculated aging value (Nv) from the previous number (Nc-1) of remaining operability cycles, or - if the value of the parameter does not exceed the value of the threshold parameter (Is), the calculation of the new number (Ne) of remaining operability cycles of the contactor (104) is carried out by subtracting the value 1 from the previous number (Nc-1) of remaining operability cycles (step 130).

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