Method and device for controlling and monitoring a capacitor bank of a reactive power compensation cabinet

Abstract

Method and device for controlling and monitoring a capacitor bank of a reactive power compensation cabinet One aspect of the invention relates to a method for controlling and monitoring at least one capacitor bank 20 in a reactive power compensation cabinet, comprising the steps of: determining a lifetime value upon initial powering up of the bank 20, during a period P1 subsequent to the initial powering up,: receiving E1 and storing E2 values ​​of voltage (U), temperature (T), determining an accelerated aging value (E3) based on predetermined nominal values ​​of the temperature and voltage, and the received values ​​(U, T), determining E4 and storing E5 a remaining lifetime of the bank (20) according to the accelerated aging value and the lifetime value, if the lifetime value is exceeded or negative, sending a command to quarantine the bank (E7).Figure to be published with the abstract: Figure 2.

Description

Title of the invention: method and device for controlling and monitoring a capacitor bank of a reactive power compensation cabinet TECHNICAL FIELD OF THE INVENTION

[0001] The technical field of the invention is that of the reactive power compensation cabinet.

[0002] The present invention generally relates to the monitoring of at least one capacitor bank. More particularly, the present invention relates to a method and a device for electronic control and monitoring of one or more banks of a capacitor bank of such a cabinet. TECHNOLOGICAL BACKGROUND OF THE INVENTION

[0003] Conventional electricity distribution networks provide single-phase or three-phase alternating current electricity to consumers in residential, commercial, and industrial buildings. The electricity distribution network is often a network of electrical distribution wires (more commonly referred to as "electrical transmission lines") that connect the electricity supplier to its consumers.

[0004] Electrical distribution networks experience a heavier load when large inductive loads are repeatedly connected and disconnected to the distribution network.

[0005] These variations in the flow of energy can result in high energy losses. For example, energy losses can occur when large inductive loads are connected to the distribution lines, which can produce an excessive amount of lagging reactive current in the line.

[0006] Apparent power, which is usually expressed in volt-amperes (VA) or kilovolt-amperes (kVA), is the product of the circuit current and voltage. It is often desirable to approximate a system's power factor of one, which is the ratio of the real (or "active") power used in a circuit to the apparent power used by the circuit.

[0007] Power factor correction (PFC) can be achieved, for example, by activating or deactivating capacitor banks of a reactive power compensation bank.

[0008] A capacitor bank is generally composed of a number of capacitors which can together be activated and deactivated. A control device used to control the activation and deactivation of the different banks of capacitors, on distribution lines, has power factor controllers to switch the connectivity of one or more bank steps as needed to correct the power factor for the load detected at a given time. Conventional power factor controllers thus switch the capacitor bank in and out of the power line based on a number of measurable parameters, such as reactive current, voltage.

[0009] Power capacitors are naturally subject to the effects of aging which can change their electrical characteristics (e.g., capacitance, equivalent series resistance, etc.), which in turn can reduce their efficiency.

[0010] Depending on the materials used, the type of design and the manufacturing details, some capacitors may be subject to different types of failure if their electrical characteristics change at a faster rate than expected due to normal aging. In some cases, these failures may be mitigated by a self-protection mechanism, which is activated, for example, by overpressure, overheating and / or overcurrent, removing the capacitor from the circuit. Other cases may lead to a failure where the self-protection mechanism does not operate which may result in a cabinet fire.

[0011] It is common today for capacitor bank installations to have very limited or no monitoring and diagnostics, partly due to the expense associated with monitoring capacitors through human intervention steps involving travel to the cabinet to perform voltage and current measurements within a capacitor bank. In addition, there is often a maintenance contract between the company that sold the reactive power compensation cabinet or bank, involving travel by an operational person not located on site to perform the measurements.

[0012] Due to this limited monitoring and diagnostics, it is very difficult to detect operational problems before they occur in order to mitigate operational problems and minimize service interruptions through regular maintenance efforts. Thus, capacitor banks can often be changed as a precautionary principle while they may still operate for a long period of time. Summary of the invention

[0013] The invention offers a solution to the problems mentioned above, by making it possible to monitor a step of capacitors of a battery in a reactive power compensation cabinet based on automatic measurements in the cabinet and send maintenance information according to an aging state determined according to these values.

[0014] One aspect of the invention relates to a method for controlling and monitoring at least one capacitor bank of a battery in a reactive power compensation cabinet, carried out by a control and monitoring module, comprising: • when an initial power-up of at least one step, from an initial power-up time tO, a step of determining a lifetime value, • during a determination period subsequent to the initial setting time t0, comprising during at least one determination time, the steps of: • receiving measurements comprising: • a sub-step of receiving voltage values ​​between at least two phases of the cabinet, at an instant of the period, • a sub-step of receiving temperature values ​​at an instant in the period, • storage of the measured temperature value and the measured voltage value received, • determination of an accelerated aging value of the step by means of a determination means based on predetermined nominal temperature and voltage values, and stored received temperature and / or voltage values, • determination of a remaining service life of the step from the determined accelerated aging value and the service life value, • storing the remaining life of the step as a life value for determining the life at the next determination time, • in case of exceeded or negative remaining lifetime value, sending of a quarantine command and maintenance information including information on the quarantined step.

[0015] Thanks to the invention, the capacitor bank is monitored by voltage, current, humidity and temperature measurements of the cabinet. Thus, it is simple to set up and it is possible to use temperature or voltage measurement sensors already installed in the cabinet. The capacitors age more or less quickly depending on the stability of the electrical network supplied by the electricity supplier. Indeed, the network voltage can have voltage peaks leading to premature aging of the charged capacitors. The same is true with the temperature, capacitors have a pre-estimated lifespan according to a given temperature range, but with climate changes, it is not uncommon for the temperature to go outside this temperature range. Thus the invention determines aging from measurements based at least on voltage and temperature which are two parameters of the environment in which the capacitors are located.

[0016] Initial power-up means that the step is powered up for the first time in the cabinet.

[0017] In this first aspect of the invention, the steps disconnected during voltage measurements outside the nominal range are not affected by this overvoltage and therefore do not have a determined aging value.

[0018] When the aging value is later or positive, the steps during the PI period are repeated, each reiteration forming a new moment of determination. Quarantine avoids the risk of fire, sending information allows a platform or a maintenance operator to have the knowledge to carry out an order to change it.

[0019] In addition to the characteristics which have just been mentioned in the preceding paragraph, the method for controlling and monitoring at least one step according to one aspect of the invention may have one or more complementary characteristics among those mentioned in the following paragraphs, considered individually or according to all technically possible combinations:

[0020] According to one example, when the aging value is later or positive, and when the remaining lifetime value Dr is less than a predetermined maintenance value (number of days added to the current date in the case of a date), the method comprises a step of sending a time data item indicating a change in the step.

[0021] According to one example, the storage step stores all the received values.

[0022] According to one example, the storage step stores the received values ​​at least when the measured temperature value or the measured voltage value is outside a predetermined nominal temperature or voltage range or above a predetermined nominal temperature or voltage value respectively

[0023] According to one example, the measured current is respectively an effective or peak current and the measured voltage is an effective or peak voltage.

[0024] According to one embodiment, the means for determining the aging value of the step is according to the formula:

[0025] [Math.l] Vl(T,U)=tT,ve^

[0026] in which t is the aging time, Un the nominal voltage, Tn the nominal temperature, U the measured voltage, T the measured temperature, Ea / kB a predetermined constant.

[0027] Ea is a constant corresponding to the activation energy, which depends on the material used and its aging mechanisms, in Electron volts (eV) for the aging of dielectric material. Ea is therefore a measure of the minimum energy required to initiate degradation, this value is generally determined experimentally on the same step reference, the predetermined value can thus be memorized. For example, for polypropylene, the activation energy at room temperature (approximately 298 °K) is approximately 0.4 to 0.5 eV. The Ea value can also be a value referred to in specific documents from the manufacturer or in literature. For example, the activation energy Ea is of the order of 0.4 eV for aluminum electrolytic capacitors.

[0028] Kb is a Boltzmann constant in electron volts per Kelvin (ev / K) (8.617385 10-5 eV / °K). The value Ea / KB is therefore a predetermined constant and stored in the memory.

[0029] According to one embodiment, the method comprises a step of modifying the remaining lifetime value by deducing a security value from the determined remaining lifetime, the step of quarantining and sending information being sent according to this modified remaining lifetime value.

[0030] According to one embodiment, the method further comprises: • prior to the determination period, a step of measuring the initial current of a phase when the step is loaded under voltage, • a step of determining an initial value indicative of a capacitance value of all the capacitors in the step, based on at least the current initially measured, • during the determination period pl, pn, a capacity control step of a step comprising the sub-steps of: • reception of a measurement of the current of a phase when the capacitors of at least one step are charged under voltage • determination of a diagnostic value indicative of a capacitance value of all the capacitors of at least one step, in a similar manner to the initial value, based on at least the value of the measured current received, • determination of a capacity loss value by comparing the initial value indicative of a capacity value with the determined value to be diagnosed, • comparison of the determined loss value with a first capacity comparison threshold value, • when the determined loss value is greater than the first capacity comparison threshold value, sending a command to decommission at least one step and sending information to decommission the step.

[0031] This allows the stands to be monitored using another method to improve monitoring.

[0032] According to an example of this embodiment, the step of controlling the capacity of a step further comprises the sub-steps of: • comparison of the determined loss value with a second capacity comparison threshold value, the second capacity comparison threshold value being lower than the first threshold value, • when the determined loss value is greater than the second capacity comparison threshold value, sending maintenance information from at least one step, • when the determined loss value is lower than the second capacity comparison threshold value, the storage of the diagnostic time and the measured, determined and compared values ​​during this capacity control step of a step and the method repeats the steps of this determination period. This improves monitoring.

[0033] According to an example, the step of checking the capacity of a step further comprises, when the comparison of the loss value is greater than the second capacity comparison threshold value, the sub-steps: • if the time of diagnosis and the time of determination are different, determination of a time spent between the time of diagnosis and the time of determination, • comparison between the value of the time spent determined and the remaining life determined at the last moment of determination, then of the period comparison value to a threshold period, • if the value of the time spent is greater than a threshold period, sending the compared period and / or modifying the determination means, such that the modification allows the determination means to determine, at the time of diagnosis, an aging value of the step allowing the step of determining a remaining life to determine a remaining duration corresponding to the time spent value + or - the threshold period. This makes it possible to improve monitoring.

[0034] According to an example of this embodiment, the method comprises: • during initial power-up, a step of memorizing an identity for each step, and • During the capacity control step of a step, a sub-step of receiving and storing at least one identity of the powered step for each measurement received during the predetermination period, • in which the values ​​determined during the determination period are associated with at least one step identity, and when there are several steps the values ​​are associated with the set or each determined value, • in which the predetermined values ​​compared are each chosen from the number of powered steps and / or their identities, • the sending of information includes the identified step(s). This allows for improved monitoring.

[0035] According to one embodiment, the method further comprises: • a step of identifying the balance of the current of each phase of the cabinet supplying the different capacitor steps, comprising a sub-step: • reception of current measurements in the different phase lines, • comparison of the different values ​​received from current measurements in the different phase lines, and • when the current comparison value measured between two lines is greater than a balancing threshold comparison value, sending and storing the comparison value, current imbalance alert information. This makes it possible to inform an operator or a platform of a problem.

[0036] According to an example of this embodiment, when the current comparison value measured between two lines is greater than a balancing threshold comparison value, the method goes directly to the measurement reception step of the next determination time.

[0037] Another aspect of the invention relates to an electronic control device for a capacitor bank cabinet, comprising: • a modular industrial electrical cabinet box and • a control and monitoring module housed in the modular box, the control and monitoring module being configured to carry out the steps of the method according to the aspect of the invention described previously with or without one or more of the different characteristics of the preceding paragraphs, the control and monitoring module comprising: • inputs to receive information: • the status of a main circuit breaker to receive commissioning information, • temperature sensor to receive temperature measurement information from a sensor in the cabinet, and • a communication unit for communicating with a regulator of a capacitor bank, information, and sending information to an interface including maintenance information.

[0038] According to one embodiment, the control and monitoring module is configured to carry out the steps of the method according to the embodiment comprising the step of controlling the capacity of a step or the step of identifying the balance of the current: the module further comprising a measurement input by a three-phase current sensor for receiving current measurement values ​​per phase by the current sensor.

[0039] According to one embodiment, the control and monitoring module comprises: • entries: • smoke sensor • emergency push button, • outputs to pilot: • the main circuit breaker according to information received from the emergency sensor or the smoke or temperature sensor, • at least one fan, • a heating resistor. Such a control module can thus, using information received from the smoke sensor or the controlled push button, cut off the main circuit breaker and send emergency information. The fans can be controlled on the one hand in the event of smoke detection but also in the event of excessive temperature.

[0040] Another aspect of the invention relates to a reactive power compensation cabinet comprising: • a main circuit breaker comprising one input and one output per phase, the number of phases being at least three, • a battery comprising a plurality of capacitor steps, • a power selection device, comprising: • one input connected to the main circuit breaker output and one output per step, • a power control unit for each step via its output, and • a regulator controlling each step, measuring the voltage between each phase, • a current sensor on each current line formed between the output of the main circuit breaker and an input of the selection device, • the control device according to the aspect described previously (with or without the different characteristics of the embodiments described previously) connected by its inputs to the current sensor, to the regulator and to the main circuit breaker.

[0041] Another aspect of the invention relates to a system comprising the cabinet according to the preceding aspect and a maintenance platform, the control and monitoring device sending the various measurements received, the various values ​​determined and the information sent to the maintenance platform.

[0042] The invention and its various applications will be better understood by reading the following description and examining the accompanying figures. BRIEF DESCRIPTION OF THE FIGURES

[0043] The figures are presented for information purposes only and in no way limit the invention.

[0044] [Fig. 1A] represents a diagram representing an example of a method for controlling and monitoring at least one step.

[0045] [Fig. IB] represents a diagram representing another example of a method for controlling and monitoring at least one step.

[0046] [Fig. IC] represents a diagram representing the example of the method represented in [Fig.lA] further comprising an optional current control block.

[0047] [Fig. 1D] represents a diagram representing another example of the optional block of [Fig.lC] following the example of the method of controlling and monitoring at least one step of [Fig.lA].

[0048] [Fig.2] represents a block diagram of an example of an electronic control device comprising a control and monitoring module configured to carry out the steps of the method represented in one of figures 1A to 1D.

[0049] [Fig.3] represents a block diagram of a monitoring and maintenance system comprising an electrical cabinet comprising the electronic control device shown in [Fig.2]. DETAILED DESCRIPTION

[0050] A first aspect of the invention is a method for controlling and monitoring at least one capacitor bank 20 of a battery 2 in a cabinet. reactive power compensation A as shown in [Fig.3] according to an example of an aspect of the invention.

[0051] According to one example, a step comprises at least one capacitor per phase, each capacitor comprising a common terminal and a terminal connected to one of the three phases. In this example, when a step is activated, the three phases are compensated.

[0052] According to another example, a step comprises several capacitors connected to a single phase. In this example, when a step is activated, only one phase is compensated.

[0053] [Fig.lA] shows a schematic representation of a diagram representing steps of an example according to an embodiment of the method for controlling and monitoring at least one of the capacitor steps 20 of the bank 2 in the reactive power compensation cabinet A. The cabinet A comprises in this example six capacitor steps 20a, 20b, 20c, 20d, 20e, 20f, each called in the following step 20, unless mentioned independently of each other.

[0054] The steps of the method described are carried out by a control and monitoring module 1 shown in [Fig.2], unless it is specified that the step is carried out by another device / platform / system / regulator / sensor.

[0055] The method firstly comprises, when an initial power-up of the at least one step 20, i.e. its first power-up in the cabinet A, from an initial instant t0 following the initial power-up, for example less than one hour after power-up, a step E0 of determining a lifetime value V0. The lifetime value V0 may be a value of the remaining lifetime time of the capacitors of the powered step 20 or an end-of-life date at which sending preventive maintenance request information will be necessary to change the step 20. This value may be predetermined or received.

[0056] According to another example of the method shown in [Fig. 1B], the method may comprise a step of receiving environmental parameter values ​​E01 prior to the determination step E0, making it possible to determine the lifetime value. For example, the reception of environmental parameter values ​​comprises initial voltage Ui and temperature T values ​​measured during an initial time MO starting before time t0 and comprising the time of the step of determining a lifetime value E0. The initial voltage value Ui received may be a predetermined voltage or a voltage measured between two phases of the cabinet A. The voltage value between two phases E10 may be an effective or peak voltage value. The voltage measured between two phases may be a single measurement between a first and a second phase or an average of measurements between each phase, i.e. three voltage measurements for a three-phase power supply. method may comprise, prior to receiving value E01, a step of measuring the temperature by a temperature sensor Th or by a regulator 30 of a power selection device 3 of the cabinet A, shown in [Fig. 3] and the voltage between two phases by a voltage sensor or by the regulator 30. The power selection device 3 further comprises a power control unit 31 controlled by the regulator 30, controlling the connection of the phases to the different steps 20. In the example shown, the power control unit 31 is a block but may also be different power contactors each controlling the power supply of a step 20, controlled by the regulator 30. Thus the reception of the initial voltage measurement values ​​Ui during the step of receiving environmental parameter values ​​E01 may be received by a sensor and / or by the regulator 30 as shown in the example of [Fig. 3].

[0057] By initial moment MO, is meant over a period of initial power-up, which may be before or when an initial power-up of the at least one step 20 is carried out. For example, a reception of an initial voltage value Ui may be received at a first moment and that of the temperature at a later moment during this moment MO. This measurement reception step may be carried out for all of the steps 20 or at different moments if each step 20 has an initial power-up at different moments.

[0058] During this initial power-up, the remaining lifetime of the capacitors of the step 20 can also be a countdown, in days or hours, for example before sending preventive maintenance information for the step 20 concerned. In the case of a countdown, the remaining lifetime is therefore counted according to its time index (hours, days, months) as the step 20 has been in the cabinet A since this instant t0. For example, the lifetime value V0 of a step 20 is a predetermined value, for example 15 years, in a stable temperature / voltage environment, that is to say in a nominal voltage range and a nominal temperature range, 6 months later, the remaining lifetime is therefore counted by 6 months, or 14.5 years. Each step 20 has a stored lifetime value specific to it, whether it is a remaining lifetime value or an end-of-life date.

[0059] Preferably, when the at least one step 20 is initially powered up, only one step 20 is powered. In this example, the method receives an initial voltage value Ui measured between two phases per step 20. This makes it possible to set a time initialization to determine an aging time value, explained below, and to verify that the initial voltage Ui between two phases corresponds to a nominal voltage range. Otherwise, the method may comprise a step of sending unstable electrical network information, for example example to a maintenance platform Pm shown in [Fig.3], or to the regulator 30 or even to a device of a maintenance agent Dm or even an alarm of the cabinet to activate it.

[0060] The method comprises, during at least one determination time M1 of a determination period PI subsequent to the initial setting time t0, different successive steps described below. The method comprises, during the determination period PI, a reiteration of the steps described below at different determination times Mn. The determination time Mn can begin, for example, at each activation of a step 20, or deactivation of one of the steps 20 when several are activated and can follow one after the other after a predetermined time delay.

[0061] The method comprises for each determination time Mn, a step of receiving measurements EL This step of receiving measurements El comprises a sub-step of receiving El 1 temperature values ​​T measured at different times of the period PI and a sub-step of receiving E10 voltage values ​​U measured between at least two phases of the cabinet A. The first and second sub-steps can be at the same time or at different times in a time of the determination period PL

[0062] The method further comprises for each determination time Mn, a storage step E2, after the measurement reception step El, of the measured temperature value T received and the measured voltage value U received, at least either when the measured temperature T received is greater than a nominal value Ts or outside a predetermined nominal temperature range, or when the measured voltage U is outside a predetermined nominal voltage range Ul, U2. The values ​​can be stored according to the age of the data. All the received values ​​are stored in this example.

[0063] Of course, all temperature and / or voltage values ​​can be measured.

[0064] The method further comprises, for each determination moment Mn, a step E3 of determining an aging value VI of the step 20 or of all the activated steps 20. The control and monitoring module 1 comprises a determination means making it possible to determine the aging value V1 based on nominal values ​​of temperature Ts, voltage Ul, U2 previously stored and measured values ​​of temperature T and / or voltage U stored outside the range respectively of temperature Ts and nominal voltage Ul, U2. The nominal values ​​of voltage Ul, U2 previously stored may be, as in the example of [Fig.lB], a range based on the value of the initial voltage Ui received at the initial moment MO, for example Ul = 95% of Ui and U2 105% of Ui. Thus, the measurement reception step El may comprise several receptions of voltage U or temperature T measurement values ​​(in a loop or according to a predetermined period) until a received value is different from a range or a nominal value. For example, the measurement reception step El comprises a reception of a voltage U measurement value every 5 minutes or seconds, and that of the temperature only when it goes outside a range detected by the temperature sensor Th, for example every 5 minutes or seconds.

[0065] According to one example, the determining means is the means for determining the aging value of the step according to the formula:

[0066] [Math.2] Vl(TC)

[0067] according to which the aging value V1 is an aging duration, Un the nominal voltage, here in this case equivalent to the initial voltage Ui, Tn the nominal temperature, U the measured voltage, T the measured temperature, Ea / kB a constant. Ea is a predetermined activation energy value and Kb a Boltzmann constant in electron volts per Kelvin (ev / K) (8.617385 10-5 eV / °K).

[0068] This formula makes it possible to take into account two of the environmental parameters influencing the aging of the capacities (temperature and voltage) in the same formula in the event of exceeding the threshold range value by these two environmental parameters.

[0069] According to another example, the means for determining the aging value V1 of the step 20 is a table or a matrix or even a graph.

[0070] For example, 6 months after commissioning, a measured temperature has a value T beyond a temperature range, this temperature will deteriorate the capacitors of the step(s) 20 and therefore reduce the service life compared to that previously predetermined. This temperature T is thus used to determine an accelerated aging value for example according to the formula previously described. The determined aging value V1 can for example indicate an aging acceleration time in a unit of time, for example in hours or days or even a remaining service life.

[0071] The method further comprises, for each determination time Mn, a step E4 of determining a remaining lifetime Dr from the determined aging value VI and the lifetime value V0. In the case where the lifetime value V0 is a count or a date calculated from a predetermined value, the remaining lifetime Dr is equal to the value of the count or the date minus the accelerated aging value. For example, if the aging value V1 is an aging time of 3 months and the lifetime value VO life is a date for example 07 / 15 / 2035 or a countdown of 12 years, the remaining life Dr is respectively 04 / 15 / 2035 or 11 years and 9 months.

[0072] The method comprises for each determination time Mn, a step of storing the remaining lifetime E5 as lifetime value V0 for the remaining lifetime determinations Dr at the next determination time Mn + 1.

[0073] The method further comprises, for each determination time Mn, in this example, optionally, a step of modifying the remaining lifetime value E6 which can be carried out before or after the storage step E5. The step of modifying the remaining lifetime value E6 reduces the remaining lifetime value Dr by a safety value Drs. The safety value Drs is a time, for example in days if the remaining lifetime value Dr is a date, and is a time in the same unit of time as the remaining lifetime value Dr if it is a countdown. For example, the safety value Drs is equal to 1440 hours or 60 days. This safety value allows an operator to program a maintenance date on the site before sending a command to decommission this step 20.

[0074] The method further comprises a step of sending a command to quarantine the step and maintenance information E7 in the event of a remaining lifetime value Dr being exceeded (in the case of a date) or negative (in the case of a period, for example hours remaining). The information comprising the quarantine and the identity of the step. The information can be sent to the maintenance platform Pm. The information sent can further potentially include one or more or even all of the stored values.Conversely, when the aging value is later or positive, the steps of this determination period PI are repeated, when the remaining lifetime value Dr is less than a predetermined maintenance value (number of days added to the current date in the case of a date), the method comprises a step of sending a time data item indicating a change in the step. The succession of these steps of this determination period PI are therefore carried out in a first determination moment M1 and at each reiteration, each step is carried out in determination moments Mn subsequent to the first moment M1, until at least the step of sending maintenance information E7 for this step 20 is carried out.After the step of sending maintenance information E7, the method of course continues to repeat each of these steps in determination times Mn for the other powered steps 20, and optionally also for this step 20 whose information was flooded during this determination period PL.

[0075] The method may optionally comprise, during this period PI, an optional balanced current control step IE represented in dotted lines and optionally a capacity control step of a step C represented in dotted lines.

[0076] Each of the two steps IE and C comprise different sub-steps described below, which can be carried out during the determination time, i.e. in parallel with steps E1 to E7, or during a diagnostic time Gn of the determination period, different from the determination times Mn. In this example, the diagnostic time is located between two determination times Mn, i.e. following the step of sending maintenance information E7 or of storing the remaining service life E5, or even, optionally, the step of modifying the remaining service life value E6. According to another example, the diagnostic time is offset from that of the determination time, for example the determination time is dependent on the measurement value received beyond a range of values, and the diagnostic time is every minute.

[0077] [Fig.lC] schematically represents the method comprising the steps according to the example of [Fig.lA], and in addition the step of identifying the balance of the current IE following the step E6 or E7. The step of identifying the balance of the current IE comprises a sub-step of receiving current measurements IE1 in the different lines of comparison phases IE1. Of course, the method can further comprise the steps of current measurements carried out by one or more current sensors 4, only one of which is shown in [Fig.3] mounted on each of the lines (phases) of the cabinet.

[0078] The current balance identification step IE further comprises a sub-step IE2 of comparing the different current measurement values ​​received in the different phase lines with each other. The current balance identification step IE comprises, when one of the current comparison values ​​measured between two lines is greater than a balancing threshold comparison value, a sub-step of sending current imbalance alert information IE3. According to one example, after the current balance identification step IE, the method repeats a new determination time Mn+1 and therefore moves on to the measurement reception step E1 of the following determination time Mn+1 or optionally to the capacity control step C of a step directly after the comparison sub-step IE2 if each current comparison value measured between two lines is less than the threshold comparison value.

[0079] [Fig.lD] schematically represents the method comprising the steps according to the example of [Fig.lA] and in addition the step of checking the capacity of a step C, following step E6 or E7 and optionally the comparison sub-step IE2. The method comprises carrying out the step of checking the capacity of a step C, at a time of the initial power-up, i.e. prior to the period of PI determination, a step of receiving an initial current measurement IC of a phase when at least one step is charged under voltage and a step of DC determination of an initial value indicative of a capacitance value of all the capacitors of the step, based on at least the current initially measured.

[0080] The current measurement reception step IC can be before or after or during the step of determining a lifetime value E0. The step of determining DC an initial value CD indicative of a capacitance value of all the capacitors of the step 20 can be carried out at any time before the first step of checking the capacitance of a step C. In this example, the step of determining DC the initial value CD is carried out at the same time as the step of determining a lifetime value E0.

[0081] The initial value CD indicative of a capacitance value of all the capacitors of the step 20 can be the capacitance but also another value linearly dependent on the capacitance, for example the reactive power.

[0082] In this example, the determination step calculates the capacitance according to this formula CD=I / coUi in which CD is the capacitance of the step (set of capacitors), I the initial current, Ui the initial voltage (measured or predetermined) and co the pulsation expressed in rad / s. Preferably, this step is carried out for each new step when it is powered up, i.e. step by step when the cabinet A is put into service. According to one example, the method comprises a step of measuring the initial voltage Ui as described previously at the initial power-up to enable the capacitance C to be calculated. According to another example, the initial voltage Ui is a predetermined value. The pulsation co can be predetermined or determined from the initial current measured and / or the initial voltage measured.

[0083] The capacity control step of a step C comprises the sub-steps of: • reception of a measurement of the current Cl of a phase supplying step 20 when the capacitors of the step are charged under voltage, • determination C2 of a value to be diagnosed Cd indicative of a capacitance value of all the capacitors of at least one step 20, in a similar manner to the initial value, based on at least the value of the measured current Id received, for example Cd=Id / coUd, • determination C3 of a capacity loss value Cp by comparing the initial value indicative of a capacity value CD with the value to be diagnosed Cd, • comparison C4 of the capacity loss value Cp determined with a first capacity comparison threshold value C1S, • when the determined capacity loss value Cp is greater than the first capacity comparison threshold value C1S, step C includes a sub-step of sending a command C40 to decommission the at least one step 20 and sending information C41 to decommission the step.

[0084] The first threshold value C1S can be predetermined or be calculated according to a percentage of the initial value CD indicative of a capacitance value of all the capacitors of the step 20, for example, 5% of the initial value CD indicative of a capacitance value of all the capacitors of the step 20. Thus this amounts to verifying that the value to be diagnosed Cd has lost less or more than 5% of the initial value CD.

[0085] The value to be diagnosed Cd and the first threshold value C1S can also be dependent on the number of steps supplied by the phase on which the current is measured.

[0086] The decommissioning command can be sent to the regulator 30 which controls the power control unit 31 of the power selection device 3. The decommissioning information can be sent to the maintenance platform Pm or to the device of a maintenance agent Dm. According to an example not shown, if the comparison of the loss value is less than the first capacity comparison threshold value, the method can continue to repeat the steps of this determination period PL

[0087] The capacity control step of a step C further comprises, in this example shown, the sub-steps of: • comparison C5 of the determined loss value Cp with a second capacity comparison threshold value C2s, the second capacity comparison threshold value C2s being: • less than the first threshold value Cl s, and • corresponds to a capacity loss value of all the capacitors in a step at risk, for example 10% of the initial value CD, which is greater than or equal to a capacity loss of step 20 when the remaining life value DR is zero, • sending maintenance information for at least one C50 step, when the determined loss value Cp is greater than the second capacity comparison threshold value C2s.

[0088] The second threshold value C2S can be predetermined or can be calculated according to a percentage of the initial value CD indicative of a capacitance value of all the capacitors of the step 20, for example, 10% of the initial value CD indicative of a capacitance value of all the capacitors of the step 20. Thus this amounts to verifying that the value to be diagnosed Cd has lost less or more than 10% of the initial value CD.

[0089] The method can continue during this determination period PI to repeat the steps of this determination time Ml, Mn then that of the diagnosis time Gl, Gn, if the comparison of the loss value is lower than the second capacity comparison threshold value.

[0090] According to an example, after sending maintenance information for the at least one step C50, the step of checking the capacity of a step C is completed and the method can continue during this determination period PI to reiterate the steps of this determination time Mn or the step of checking the capacity of a step C can, as shown in this example in [Fig. 1D], further comprise the sub-steps of: • determination of a time spent C51 between the time of diagnosis Gl, Gn, and the time of determination Ml, Mn, • comparison C52 between the value of the time spent determined and the remaining lifetime Dr determined at the last determination moment Ml, Mn, • if the period comparison value is greater than a threshold period, sending of the compared period or / and modification of the determination means C53, such that the modification allows the determination means to determine at the diagnosis moment Gl, Gn, an aging value of the step VI allowing step E4 to obtain a remaining lifetime Dr corresponding to the value of the time spent + or - the threshold period.

[0091] It will now be described how the method works when there are several stages supplied during the measurements received during the predetermination period PI.

[0092] The method comprises, preferably before the determination period PI, for example during the step of determining a lifetime value E0 or during the step of receiving environmental parameter values ​​E01 or between its two steps, a sub-step of receiving by the regulator 30 an identity for each step supplied one by one during commissioning.

[0093] The method further comprises a sub-step of storing an identity for each step E01, and a step of receiving at least one powered step identity E12 for each measurement received during the determination period EL. The sub-step of receiving and storing at least one powered step identity 112 can be received at the same time as the measurement step El or / and current measurement reception step IE1, or / and the current reception step Cl or even before or even after one of these steps.

[0094] The values ​​determined during the PI determination period during the different steps are associated with at least one step identity, and when there are several steps the values ​​are associated with the set or with each determined value. For example, if steps 1 and 2 are powered during the measurements of steps El, the step of determining an accelerated aging value of step E3 will associate the accelerated aging value VI with the two steps 1 and 2. Thus, de facto, the remaining lifetime determined in step E4 for: • step 1, will be from this accelerated aging value VI and the remaining life value Dr of step 1, • step 2, will be from the lifetime value Dr of step 2 and this accelerated aging value VI.

[0095] The same applies to the measured current received in step C1, for example when powering steps 2 and 3, the initial value indicative of a capacitance value is therefore according to that of two steps (chosen from the number of steps powered when determining a capacitance loss value) and the determination of the capacitance value and for steps 2 and 3. Thus the capacitance loss value achieved in step C3 is achieved for all steps 2 and 3.

[0096] The selection of the step ordered to be put out of service can be based on the history of the last capacity loss values ​​of each step, for example if step 2 (can be compared to a threshold or a percentage) has a capacity value Cd significantly lower than that of step 3 in another previous measurement, the method can send the information for controlling the putting into service of step 2 making it possible to avoid a fire starting.

[0097] According to an example, during step C and several steps supplied by the same phase, the method can send a request for power supply step by step (also called self-diagnostic routine) when there is a capacity loss value Cp greater than the first or second threshold and carry out steps, for example all the steps of the method of the determination period, or only the sub-steps of the capacity control step of a step C for each step.

[0098] [Fig.2] represents an electronic control device D for a capacitor bank cabinet, comprising a modular housing DI of an industrial electrical cabinet and a control and monitoring module 1 housed in the modular housing DI. Thus the control and monitoring module 1 is a single block making it possible to carry out the different steps described previously and those described below.

[0099] The control and monitoring module 1 comprises a memory, a control and determination unit (for example comprising a processor) of the digital inputs E, in this case five inputs E. For example, each input is intended to be connected to a device of the compensation cabinet A, for example: • a first input el intended to be connected to an emergency push button 5 mounted on cabinet A, allowing the control module and monitoring 1 to send urgent shutdown information for cabinet A, for example to platform Pm, • a second input e2 intended to be connected to an auxiliary contact of the main circuit breaker 6 of the electrical cabinet A, allowing the control and monitoring module 1 to send information to power up the cabinet or to disconnect the cabinet, • a third input e3 intended to be connected to a fault contact of the main circuit breaker 6, allowing the control and monitoring module 1 to send fault disconnection information from the cabinet, • a fourth input e4 intended to be connected to an input of an air conditioning device to cool the interior of the cabinet, • a fifth input e5 intended to be connected to a smoke detector 8 allowing the control and monitoring module 1 to send smoke detection information and a disconnection command for cabinet A and therefore for the steps 20.

[0100] The control and monitoring module 1 comprises a power supply input Ualim, to power it and intended to be connected between two phases of the cabinet under a voltage U, for example 230 volts, as visible in [Fig.3]. According to one example, the input also makes it possible to measure the voltage U between these two phases.

[0101] The control and monitoring module 1 may comprise a Salim power supply output, for supplying a device, for example a control contact of a cabinet contactor, having a power supply output voltage of, for example, 24 volts.

[0102] The control and monitoring module 1 may comprise one or more analog inputs to each be connected, for example, to a measuring device, for example a three-phase current sensor 4.

[0103] The control and monitoring module 1 comprises a communication unit Com comprising a wired output / input, for example of the Ethernet or / and USB type, or wireless communication means adapted to communicate with a wireless protocol, for example Wifi or / and Bluetooth, to communicate with a maintenance platform Pm or / and an interface, for example, of a user device Dm which can be on site or remotely.

[0104] The communication unit Com comprises a first communication bus BUS1, for example of the RJ45 type, for receiving information from the regulator 30 and sending it, including control information, for example for decommissioning an identified step. The regulator 30 can transmit the identity of the powered steps and measurements, such as voltage and / or current and / or reactive power measurements to be compensated and / or compensated, etc.

[0105] The communication unit Com comprises in this example a second communication bus BUS2 intended to be connected to a temperature sensor Th and in this case also humidity. According to another example, the module 1 comprises another analog or digital input instead of the communication bus to receive the temperature (and optionally humidity) measurement values.

[0106] The control and monitoring module 1 may further comprise outputs, for example: • an output of an audio alarm device Al such as a buzzer, the control module is configured to control or power it, for example in the event of excessively high temperature and / or smoke detection, for example by a dry contact in series with the power supply of the module or a control output to control it, • a thermal resistance output Rth, the control module 1 is configured to control or supply a thermal resistance 7, for example in the event of a temperature that is too low and / or humidity that is too high, for example by a dry contact in series with the power supply of the module 1 or a control output to control it, • an all-or-nothing information output, to send information or a command to a device, for example the air conditioning device, • at least one output of a fan, here in this case two outputs for controlling or powering two fans VI, V2 via a dry contact, the control module is configured to control or power each fan VI, V2 associated (connected) with an output, for example in the event of a temperature that is too low and / or humidity that is too high, for example via a dry contact in series with the module power supply or a control output, and • a main circuit breaker control output Dj, the control module is configured to control the main circuit breaker 6 to trip the cabinet in the event of a received temperature value exceeding a risk threshold value.

[0107] In the case of at least one fan, VI, V2, and a main circuit breaker 6 in the cabinet A, a control contact of which is connected to one of the power supply outputs of the monitoring and control module 1, the method may further comprise a step of monitoring the temperature and controlling the ventilation of the cabinet, carried out by the control and monitoring module 1 comprising a sub-step of: • a sub-step of receiving temperature measurement value, • checking whether a fan is powered, • comparison of the measured temperature value received with: • a first threshold value if no fan is powered, and • at the risk threshold value higher than the first threshold, if at least a fan is powered, • if the temperature is higher than the first threshold value compared, control of at least one fan, • if the temperature is lower than the risk threshold value, a comparison step with a second threshold value lower than the first threshold value in which if the temperature value received is lower than the first threshold value, a command to stop the fans, • if the temperature is higher than the risk threshold value, control the main circuit breaker to trip the cabinet.

[0108] The step of monitoring the temperature and controlling the ventilation of the cabinet may further comprise a sub-step of storing the received temperature values ​​and the ventilation time.

[0109] In the case of at least one heating resistor Rth and a humidity sensor in the cabinet, each connected respectively to an output and an input of the control and monitoring module 1, the method may further comprise a step of monitoring humidity and controlling the heating resistor of the cabinet, carried out by the control and monitoring module 1 comprising: • a sub-step of receiving humidity measurement value, • checking whether the resistance is powered, • comparison of the received humidity measurement value to: • a first humidity threshold value if the resistance is not powered, and • at second humidity threshold value higher than the first humidity threshold value, if the resistance is powered, • if the temperature is higher than the first humidity threshold value compared, the resistance power supply control, • if the temperature is lower than the second humidity threshold value, a control step to stop the power supply to the resistor.

[0110] The step of monitoring the temperature and controlling the ventilation of the cabinet may further comprise a sub-step of storing the received humidity values.

[0111] The step of monitoring the temperature and controlling the ventilation or heating resistance of the cabinet may comprise: • a sub-step of checking an air conditioning device before the sub-step of checking whether a fan and / or a resistor is on, and • if an air conditioning device is active, the step includes a comparison of the measured temperature value with the second threshold value and if the temperature is higher than the risk threshold value, controlling the main circuit breaker to trip the cabinet.

[0112] Another aspect of the invention relates to a system comprising the control and monitoring control module 1 configured to carry out the control and monitoring method and the maintenance platform Pm receiving the information sent as well as all the measurement values ​​received and the determined values. The maintenance platform Pm calculates the average of each value according to their age: after one day, average per minute, after one week, average per hour, after one month, average per day.

[0113] This makes it possible to optimize memory space and to have a substantial history of the evolution of the values ​​received and determined.

[0114] Unless otherwise specified, the same element appearing in different figures has a single reference.

Claims

1. Claims Method for controlling and monitoring at least one capacitor bank (20) of a battery in a reactive power compensation cabinet, carried out by a control and monitoring module (1), comprising: - when an initial power-up of the at least one step (20), from an initial power-up time t0, a step of determining a lifetime value (E0), - during a determination period (PI) subsequent to the initial setting time tO, comprising during at least one determination time (Ml, Mn), the steps of: • receiving measurements (El) comprising:

1. a sub-step of receiving (E10) values ​​of the voltage (U) between at least two phases of the cabinet, at an instant of the period, 2. a sub-step of receiving (El 1) temperature values ​​(T) at an instant of the period, • storage (E2) of the measured temperature value (T) and the measured voltage value (U) received, • determination of an accelerated aging value (VI) of the step (E3) by means of a determination means based on predetermined nominal temperature and voltage values, and stored temperature and / or voltage values ​​received (U, T), • determination of a remaining service life (E4) of the step (20) from the determined accelerated aging value and the service life value, • storing the remaining life (E5) of the step (20) as the life value for the determination of lifetime at the next determination time (Mn+1), - in the event of a remaining lifetime value exceeded or negative, sending a quarantine command for the step and maintenance information (E7) including information data for the step (20) placed in quarantine.

2. Control and monitoring method according to the preceding claim, in which the means for determining the aging value (VI) of the step (20) is according to the formula: Vi(T,U)=tnue^ - in which t is the aging time, Un the nominal voltage, Tn the nominal temperature, U the measured voltage, T the measured temperature, Ea / kB a predetermined constant.

3. Method for controlling and monitoring at least one step according to claim 1 or 2, comprising a step of modifying the remaining lifetime value (E6) by deducting a safety value from the determined remaining lifetime, the step of quarantining and sending information (E7) being sent according to this modified remaining lifetime value.

4. Method for controlling and monitoring at least one step according to any one of the preceding claims, comprising: - prior to the determination period (PI), a step of measuring the initial current (IC) of a phase when the step is charged under voltage, - a step of determining (ID) an initial value indicative of a capacitance value of all the capacitors of the step, based on at least the current measured initially, - during the determination period pl, pn, a step of controlling the capacitance of a step (C) comprising the sub-steps of: • receiving a measurement of the current (Cl) of a phase when the capacitors of at least one step (20) are charged under voltage • determination (C2) of a value to be diagnosed (Cd) indicative of a capacitance value of all the capacitors of at least one step, in a similar manner to the initial value, based on at least the value of the measured current received, • determination (C3) of a capacitance loss value (Cp) by comparing the initial value (CD) indicative of a capacitance value with the determined value to be diagnosed (Cd), • comparison (C4) of the determined loss value (Cp) with a first threshold value (ClS) for capacitance comparison, • when the determined loss value (Cp) is greater than the first threshold value (ClS) for capacitance comparison, sending a command (C40) for decommissioning the at least one step and sending information for decommissioning (C41) the step.

5. Method for controlling and monitoring at least one step according to the preceding claim, the step of controlling the capacity of a step (C) further comprises the sub-steps of: - comparing the determined loss value (Cp) with a second capacity comparison threshold value (C5), the second capacity comparison threshold value being lower than the first threshold value, - when the determined loss value (Cp) is higher than the second capacity comparison threshold value, sending maintenance information for the at least one step (C50), - when the determined loss value (Cp) is lower than the second capacity comparison threshold value (C2s), storing the diagnostic time and the measured, determined and compared values ​​during this step of controlling the capacity of a step (C) and the method repeats the steps of this determination period (PI).

6. Method for controlling and monitoring at least one step according to the preceding claim, the step of controlling the capacity of a

7. step (C) further includes when the comparison of the loss value is greater than the second capacity comparison threshold value, the sub-steps: • if the time of diagnosis (Gl, Gn), and the time of determination (Ml, Mn) are different, determination of a time spent (C51) between the time of diagnosis (Gl, Gn), and the time of determination (Ml, Mn), • comparison (C52) between the value of the time spent determined and the remaining life (Dr) determined at the last moment of determination (Ml, Mn), then of the period comparison value to a threshold period, • if the value of the time spent is greater than a threshold period, sending the compared period or / and modification of the determination means (C53), such that the modification allows the determination means to determine, at the time of diagnosis (Gl, Gn), an aging value (VI) of the step (20) allowing the step of determining a remaining life (E4) to determine a remaining duration (Dr) corresponding to the time spent value + or - the threshold period. Method for controlling and monitoring at least one step according to one of the preceding claims 4 to 6, comprising: - During initial power-up, a step of memorizing an identity for each step, and - During the step of checking the capacity of a step (C), a sub-step of receiving and storing (112) at least one identity of the powered step for each measurement received during the predetermination period (PI), - in which the values ​​determined during the determination period are associated with the at least one step identity, and when there are several steps the values ​​are associated with the set or each determined value, - in which the predetermined values ​​compared are each chosen from the number of powered steps and / or their identities, - the sending of information includes the identified step(s).

8. Method for controlling and monitoring at least one step according to one of the preceding claims, further comprising a step of identifying the balance of the current (IE) of each phase of the cabinet supplying the different capacitor steps, comprising a sub-step: - of receiving current measurements (IE1) in the different phase lines, - of comparing (IE2) the different received values ​​of current measurements in the different phase lines, and - when the comparison value of the current measured between two lines is greater than a balancing threshold comparison value, sending and storing the comparison value, current imbalance alert information (IE3).

9. Method for controlling and monitoring at least one step according to the preceding claim, in which when the current comparison value measured between two lines is greater than a balancing threshold comparison value, the method goes directly to the measurement reception step (El) of the following determination time (Mn+1).

10. Electronic control device (D) for a capacitor bank cabinet, comprising a modular housing (Dl) of an industrial electrical cabinet and a control and monitoring module (1) housed in the modular housing (Dl), the control and monitoring module (1) being configured to carry out the steps of the method according to any one of the preceding claims, the control and monitoring module (1) comprising: - inputs (e) for receiving information: • of the state of a main circuit breaker (6) to receive commissioning information, • of a temperature sensor to receive temperature measurement information by a sensor (TH) in the cabinet (A), and - a communication unit (Com) for communicating with a regulator (30) of a bank (2) of capacitor steps (20), information, and sending to an interface information including maintenance information.

11. Electronic control device for a capacitor bank cabinet according to the preceding claim, wherein the control and monitoring module 1 is configured to carry out the steps of the method according to one of claims 4 to 9, further comprising: a measurement input by a three-phase current sensor (4), for receiving current measurement values ​​per phase by the current sensor (4).

12. Electronic control device for capacitor bank cabinet according to claim 10 or 11, wherein the control and monitoring module 1 comprises: - inputs: • smoke sensor (8) • emergency push button (5) - outputs for controlling: • the main circuit breaker (6) according to information received from the emergency sensor or the smoke sensor, or temperature, • at least one fan (VI, V2), • a heating resistor (7).

13. Reactive power compensation cabinet (A) comprising: - a main circuit breaker (6) comprising one input and one output per phase, the number of phases being equal to at least three, - a bank (2) comprising a plurality of capacitor steps (20), - a power selection device (3), comprising: • an input connected to the output of the main circuit breaker (6) and one output per step (20), • a power control unit (31) of each step (20) by its output, and • a regulator (30) controlling each step, measuring the voltage between each phase, - a current sensor (4) on each current line formed between the output of the main circuit breaker (6) and an input of the selection device (3), - the control device according to one of the preceding claims 10 to 12 connected by its inputs to the current sensor

14. current (4), to the regulator (30) and to the main circuit breaker (6). System comprising the cabinet according to the preceding claim and a maintenance platform (Pm), the control and monitoring device sending the various measurements received, the various values ​​determined and the information sent to the maintenance platform (Pm).

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