Control device for a switch for an electromechanical actuator and method for controlling such a device.

The control device for semiconductor switches in electromechanical actuators addresses variability issues by detecting zero crossings and adjusting control instants, ensuring stable operation and reducing malfunctions.

FR3144724B1Active Publication Date: 2024-12-13SOMFY ACTIVITES SA
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Patent Information

Application Number
FR2022014668
Authority / Receiving Office
FR · FR
Patent Type
Patents
Current Assignee / Owner
Filing Date
2022-12-29
Publication Date
2024-12-13
Estimated Expiration
2042-12-29

AI Technical Summary

Technical Problem

Existing control devices for semiconductor switches in electromechanical actuators suffer from variability due to optocoupler dispersion, leading to potential malfunctions and load disruptions due to time shifts in zero crossing detection, which are influenced by component variability, temperature, and electrical or electromagnetic disturbances.

Method used

A control device for a bidirectional semiconductor switch that includes elements for detecting zero crossings, measuring alternating power signals, and determining control instants using a processing circuit to emit control pulses, compensating for optocoupler variability by measuring and adjusting delays based on detected edges and signal thresholds.

Benefits of technology

The solution stabilizes switch control by accurately determining control instants, reducing malfunctions and ensuring consistent operation despite optocoupler variability and disturbances, thereby maintaining reliable actuator performance.

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Abstract

The invention relates to a method and a control device (1) for a switch (2) controlled by an electromechanical actuator (ACT). The control device (1) comprises first determination elements (8) of a delay based on, on the one hand, a first primary instant at which the processing circuit (41) detects a rising or falling edge from an optocoupler (61, 62) when an alternating supply signal (U0) is substantially equal to zero, and on the other hand, a second primary instant at which a value measured by the measuring elements (7) reaches or exceeds a predetermined threshold value, and second determination elements (9) of a control instant for the switch, the control instant being determined from a first secondary instant of reception of the rising or falling edge from the optocoupler (61, 62) and the delay determined by the first determination elements (8). Figure 1
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Description

Title of the invention: Device for controlling a switch for an electromechanical actuator and method for controlling such a device. Technical field

[0001] The present invention relates to a device and a method for controlling a switch formed by a controlled bidirectional semiconductor element.

[0002] It also relates to an electromechanical actuator comprising such a control device and implementing such a method. State of the Art

[0003] A device for controlling a switch formed by a semiconductor element bidirectional controlled for an electromechanical actuator comprises a load arranged in series with the switch, the load being adapted to be electrically powered by an alternating supply signal periodically passing through zero. The control device further comprises coupling elements, the coupling elements comprising the switch and being configured to couple the alternating supply signal to the load, elements for detecting a zero crossing instant of the alternating supply voltage, the detection elements comprising an optocoupler configured to emit a rising edge or a falling edge on a logic input of a processing circuit when the alternating supply signal is substantially equal to zero,and control elements of the switch configured to emit control pulses on a control terminal of the switch following receipt of a control order from the electromechanical actuator, each pulse being adapted to place the switch in a closed state between two pulses and taking into account a control instant determined from a time of receipt of the rising edge or the falling edge of the optocoupler.

[0004] It is known to control the switch in full-wave mode with control pulses emitted in synchronism with the instant of reception of the rising edge or the falling edge of the optocoupler corresponding substantially to the zero crossing of the AC power supply signal. When using an optocoupler as a source of information to control the switch, it is crucial that the optocoupler does not disperse too much because a time shift of the rising edge or the falling edge of the optocoupler causes a time shift of the control of the switch relative to the actual zero crossing instant of the AC power supply signal. Consequently, depending on whether the pulse is emitted too early or too late by compared to the actual zero crossing time, the switch may not remain in a closed state between two control pulses and thus cause a malfunction of the load or even a sudden stop of the load.

[0005] A disadvantage of using such a control device is that the optocoupler is subject in operation to a large variability of detection, this variability being able to be linked for example to the variability between series of components, to the temperature, or to the electrical or electromagnetic disturbances to which the optocoupler is subjected.

[0006] It is therefore desirable to be able to have a device for controlling a switch formed by a controlled bidirectional semiconductor element capable of compensating for the variability of the optocoupler. Summary of the invention

[0007] Embodiments relate to a device for controlling a switch formed by a controlled bidirectional semiconductor element for an electromechanical actuator, the electromagnetic actuator comprising a load arranged in series with the switch and adapted to be electrically powered by an alternating power supply signal periodically passing through zero, the control device further comprising: - coupling elements, the coupling elements comprising the switch and being configured to couple the alternating supply signal to the load, - elements for detecting a zero crossing instant of the alternating supply signal, the detection elements comprising at least one optocoupler, the optocoupler being configured to emit a rising edge or a falling edge on a logic input of a processing circuit when the alternating supply signal is substantially equal to zero, - control elements of the switch, the control elements of the switch comprising the processing circuit and being configured to emit control pulses on a control terminal of the switch following receipt of a control order from the electromechanical actuator, each pulse being adapted to place the switch in a closed state between two pulses and taking into account a control instant determined from a first secondary instant of receipt of the rising edge or the falling edge of the optocoupler, and - measuring elements of the alternating power signal, the measuring elements being configured to measure a value of the alternating power signal.

[0008] The control device further comprises: - first elements for determining a delay as a function of a first primary instant at which the processing circuit detects a rising edge or a falling edge on the logic input of the processing circuit, and of a second primary instant at which a value measured by the measuring elements reaches or exceeds a predetermined threshold value, and - second elements for determining the control time, the control time being determined from the first secondary time and the delay determined by the first determining elements.

[0009] According to embodiments, the instants may also be determined as a time interval from a reference, for example by a counter. In particular, the second primary instant may be determined as an interval between the first primary instant and the second primary instant, a counter being able for example to be started at the time of the first primary instant and stopped at the second primary instant.

[0010] According to one embodiment, the coupling elements further comprise a phase conductor and a neutral conductor, the phase and neutral conductors being electrically powered by the alternating power signal, and in that the load is an electric motor, the electric motor comprising a stator, the stator comprising two windings, the two windings each comprising a common end so as to electrically connect them together, the common end being electrically connected to the neutral conductor via the switch, each of the two windings comprising another end constituting respectively a first phase terminal and a second phase terminal, the first phase terminal being electrically connected to the second phase terminal via a phase shift capacitor,the phase conductor being selectively either electrically connected to the first phase terminal to control the rotational drive of the electric motor in a first direction, or electrically connected to the second phase terminal to control the rotational drive of the electric motor in a second direction, the second direction being opposite to the first direction.

[0011] According to embodiments, the detection elements comprise third elements for determining a conduction state of a diode through which a current derived from the alternating supply signal flows, and in that the optocoupler is configured to detect the current flowing through the diode and emit a rising edge or a falling edge on a logic input of the processing circuit when the value of the current crosses a conduction threshold value of the diode at an instant when the alternating supply signal is substantially equal to zero.

[0012] According to embodiments, the control elements are configured to emitting at least one series of pulses, each pulse in the series of pulses being emitted in synchronism with the command instant.

[0013] According to embodiments, the measuring elements comprise a resistive voltage divider bridge, the resistive voltage divider bridge being electrically connected on the one hand to the alternating supply signal and on the other hand to a measurement input of the processing circuit, the divider bridge being configured to adapt the alternating supply signal to the measurement input of the processing circuit.

[0014] According to embodiments, the first determining elements comprise a time counter integrated into the processing circuit, the time counter being initiated at the first primary instant, then stopped at the second primary instant.

[0015] According to embodiments, the second determining elements comprise at least one piece of data recorded in a memory of the processing circuit, the recorded data comprising a value of a period of time characteristic of the alternating power supply signal to pass from a zero value to the predetermined threshold value.

[0016] Embodiments may also relate to a method of controlling a switch for an electromechanical actuator, the electromechanical actuator comprising a control device according to that described previously, the method comprising at least: - a first primary step of detecting a rising edge or a falling edge on the logic input of the processing circuit determining a first primary instant; - a second primary step of detecting the reaching or exceeding of a threshold value by a value measured by the measuring elements determining a second primary instant; - a third primary step of determining a delay value from the first primary instant and the second primary instant; - a first secondary step of detecting a rising edge or a falling edge on the logic input of the processing circuit determining a first secondary instant; - a second secondary step of determining a switch control time from the first secondary time and the delay value determined by the third primary step; and - a third secondary step of controlling the switch from the control time determined by the second secondary step.

[0017] According to embodiments, the third primary step comprises: - a first primary sub-step of determining a third primary instant from the second primary instant, the third primary instant being calculated from a characteristic time period of the alternating supply signal to pass from a zero value to the threshold value; - a second primary sub-step of determining the delay as a difference between the third primary instant and the first primary instant.

[0018] According to embodiments, the primary steps of the method are implemented when the switch is placed in an open state and / or when the electrical load is not electrically powered by the alternating power signal.

[0019] According to embodiments, the primary steps of the method are repeated an integer number n of times and in that the value of the control instant corresponds to an average value of the values ​​of the control instants determined at each repetition of the primary steps. Brief description of the figures

[0020] The present invention will be better understood with the aid of the following description with reference to the appended figures, in which identical reference signs correspond to structurally and / or functionally identical or similar elements.

[0021] [Fig-1] Figure No. 1 represents a general diagram of an actuator comprising a control device according to one embodiment of the invention.

[0022] [Fig.2] Figure No. 2 represents a detailed diagram of an actuator comprising a control device according to an embodiment of the invention.

[0023] [Fig.3] Figure No. 3 represents a flowchart of a method according to an embodiment of the invention.

[0024] [Fig.4] Figure No. 4 represents a timing diagram of the output signal of an optocoupler of the control device, of the measurement of the alternating power supply signal of the control device carried out by measuring elements and of the control signal of a switch. Detailed description

[0025] The present invention finds its application in any type of electromechanical actuator such as a closing, concealment and / or solar protection device, for example a motorized blind, or a heating and / or ventilation and / or air conditioning device.

[0026] The electromechanical actuator ACT is configured to be electrically powered by an electrical network distributing an alternating power supply signal U0 periodically passing through zero, commonly called "mains", the alternating power supply signal U0 being able to be for example of the 230 V - 50 Hz type. The electromechanical actuator ACT typically comprises a load adapted to be electrically powered by the alternating power supply signal U0, the load being arranged in series with a switch formed by a controlled bidirectional semiconductor element.

[0027] Figure No. 1 represents a control device 1 of a switch 2 formed by a controlled bidirectional semiconductor element, the control device 1 being able to be used in an electromechanical actuator ACT according to a first embodiment.

[0028] The control device 1 comprises a load 3 arranged in series with a switch 2. The load 3 is adapted to be electrically powered by the alternating power supply signal U0.

[0029] Switch 2 is formed by a controlled bidirectional semiconductor element such as a triac or two thyristors mounted head to tail.

[0030] The control device 1 further comprises coupling elements 5. The coupling elements 5 comprise the switch 2 and are configured to couple the alternating supply signal U0 to the load 3.

[0031] The control device 1 further comprises elements 6 for detecting a zero crossing instant of the alternating supply signal U0. The detection elements 6 comprise an optocoupler 61 (also called a photocoupler), the optocoupler 61 being configured to emit a rising edge or a falling edge on a logic input INI of a processing circuit 41 when the alternating supply signal U0 is substantially equal to zero.

[0032] The control device 1 further comprises control elements 4 of the switch 2, the control elements 4 comprising the processing circuit 41 and being configured to emit control pulses on a control terminal of the switch 2 following reception of a control order from the electromechanical actuator ACT, each pulse being adapted to place the switch 2 in a closed state between two pulses and taking into account a control instant te determined from a first secondary instant tsl of reception of the rising edge or the falling edge of the optocoupler.

[0033] Advantageously, the control elements 4 are configured to emit at least one series of control pulses for the switch 2, each pulse in the series of pulses being emitted in synchronism with the control instant te.

[0034] Advantageously, the processing circuit 41 comprises a processor or a microcontroller, and at least one memory, the memory being able to be internal or external to the processor or microcontroller.

[0035] Advantageously, the control device 1 can also be controlled by a remote command reception circuit not shown, such as for example a radio command receiver.

[0036] The control device 1 further comprises measuring elements 7 of the alternating supply signal U0. The measuring elements 7 are configured to measure a value of the alternating power supply signal UO.

[0037] Advantageously, the measuring elements 7 comprise a resistive voltage divider bridge, the resistive voltage divider bridge being electrically connected on the one hand to the alternating supply signal UO and on the other hand to a measurement input INO of the processing circuit 41, the divider bridge being configured to adapt the alternating supply signal UO to the measurement input INO of the processing circuit 41.

[0038] The control device 1 further comprises first elements 8 for determining a delay T1 as a function of a first primary instant tpi at which the processing circuit 41 detects a rising edge or a falling edge on the logic input INI, IN2 of the processing circuit 41, and of a second primary instant tp2 at which a value measured by the measuring elements 7 reaches or exceeds a predetermined threshold value VS.

[0039] Advantageously, the first determination elements 8 comprise a time counter integrated into the processing circuit 41, the time counter being initiated at the first primary instant tpi, then stopped at the second primary instant tp2.

[0040] The control device 1 further comprises second elements 9 for determining the control instant te, the control instant te being determined from the first secondary instant tsl and the delay Tl determined by the first determining elements 8.

[0041] Advantageously, the second determining elements 9 comprise at least one piece of data recorded in a memory of the processing circuit 41, the recorded data comprising a value of a period of time characteristic of the alternating supply signal U0 to pass from a zero value to the threshold value VS.

[0042] In a second embodiment of the invention, shown in Figure 2, elements similar to those of the first embodiment bear the same references and operate as explained above. In the following, we mainly describe what distinguishes this second embodiment from the first embodiment. In the following, when a reference sign is used in the description without being reproduced in Figure 2 or reproduced in Figure 2 without being mentioned in the description, it corresponds to the object bearing the same reference in Figure 1.

[0043] A control device 1 according to the second embodiment of the invention will now be described with reference to figure 2, in which the load 3 is a single-phase asynchronous type MOT electric motor with permanent capacitor.

[0044] Here, the coupling elements 5 further comprise a phase conductor ACP and a neutral conductor ACN. The phase conductors ACP and neutral conductor ACN are electrically powered by the alternating power supply signal U0.

[0045] Here, the load 3 is an electric motor MOT, the electric motor MOT comprising a stator, the stator comprising two windings L1, L2. The two windings each comprise a common end NO so as to electrically connect them together, the common end NO being electrically connected to the neutral conductor ACN via the switch 2, each of the two windings L1, L2 comprising another end constituting respectively a first phase terminal PI and a second phase terminal P2, the first phase terminal PI being electrically connected to the second phase terminal P2 via a phase shift capacitor CM, the phase conductor ACP being selectively either electrically connected to the first phase terminal PI to control the rotational drive of the electric motor MOT in a first direction DIR1, or electrically connected to the second phase terminal P2 to control the rotational drive of the electric motor MOT in a second direction DIR2, the second direction DIR2 being opposite to the first direction DIR1.

[0046] Here, the control device 1 further comprises a switch K. The switch K has at least two closed positions in which the phase conductor ACP is electrically connected to one or the other of the two phase terminals PI, P2. The switch K may be manually controlled, or be controlled by a relay coil which can itself be controlled by a remote command reception circuit not shown, such as for example a radio command receiver. The switch K may, furthermore, have a third open position in addition to the two closed positions, in which the phase conductor ACP is electrically disconnected from the two phase terminals PI, P2. The switch K may optionally not be part of the electromechanical actuator ACT.

[0047] Here, depending on whether the switch K is presented either in the first closed position or in the second closed position, the phase conductor ACP is selectively electrically connected either to the first phase terminal PI to control the rotational drive of the electric motor MOT in a first direction DIR1, or to the second phase terminal P2 to control the rotational drive of the electric motor MOT in a second direction DIR2, the second direction DIR2 being opposite to the first direction DIRL.

[0048] Advantageously, the control device 1 further comprises a resistive circuit CR, a first diode DI and a second diode D2. The resistive circuit CR comprises a first resistor RI, a Zener diode Z1, and a capacitor CL. The first diode DI and the second diode D2 are electrically connected together by an electrode of the same nature to one end A of the first resistor RI, the other electrode of each diode D1, D2 being respectively connected to the first phase terminal PI and to the second phase terminal P2. The other end of the first resistor RI constitutes a floating electrical ground GND of the control device 1. The floating electrical ground GND is electrically connected to the neutral conductor ACN via the Zener diode ZI and the capacitor Cl electrically connected in parallel. The processing circuit 41 is electrically powered by an electrical voltage present at the terminals of the Zener diode ZI and the capacitor Cl, between the neutral conductor ACN electrically connected to a positive supply terminal VDD of the processing circuit 41, and the floating electrical ground GND of the control device 1 electrically connected to a negative supply terminal VSS of the processing circuit 41. The detail of the electrical power supply of the processing circuit 41, which includes electrical voltage step-down and regulating components, is not shown in the figures.

[0049] Here, the first diode DI and the second diode D2 are electrically connected together by their respective anode to one end A of the first resistor RI, the cathode of the first diode DI is connected to the first phase terminal PI, and the cathode of the second diode D2 is electrically connected to the second phase terminal P2.

[0050] Advantageously, the detection elements 6 comprise a first optocoupler 61 and a second optocoupler 62, the first optocoupler 61 and the second optocoupler 62 being inserted in the control device 1 to detect a current flowing in the first diode DI and in the second diode D2. An output of the first optocoupler 61 is electrically connected to a first logic input INI of the processing circuit 41, and an output of the second optocoupler 62 is electrically connected to a second logic input IN2 of the processing circuit 4L. Each optocoupler 61, 62 switches the corresponding logic input INI, IN2 to the high state when the corresponding diode conducts. The processing circuit 41 is thus able to identify the conduction or blocking state of the first diode DI and the second diode D2.

[0051] The main advantage of this assembly is that, with the motor stopped, when the phase conductor ACP is electrically connected to the first phase terminal PI, the instant of start of conduction of the first diode D1, and therefore of appearance of a rising edge on the logic input INI, corresponds to the instant at which the alternating supply signal U0 is substantially equal to zero when passing from a positive half-wave to a negative half-wave, in other words when the alternating supply signal U0 passes through zero when passing from a positive half-wave to a negative half-wave.The instant of end of conduction of the first diode D1, and therefore of appearance of a falling edge on the logic input INI, corresponds to the instant at which the alternating supply signal U0 is substantially equal to zero when passing from a negative half-wave to a positive half-wave, in other words when the alternating supply signal U0 passes through zero when passing from a negative half-wave to a positive half-wave.

[0052] Similarly, when the phase conductor ACP is electrically connected to the second phase terminal P2, the instant of start of conduction of the second diode D2, and therefore of appearance of a rising edge on the logic input IN2, corresponds to the instant at which the alternating supply signal U0 is substantially equal to zero when passing from a positive half-wave to a negative half-wave, in other words at the zero crossing of the alternating supply signal U0 when passing from a positive half-wave to a negative half-wave. The instant of end of conduction of the second diode D2, and therefore of appearance of a falling edge on the logic input IN2, corresponds to the instant at which the alternating supply signal U0 is substantially equal to zero when passing from a negative half-wave to a positive half-wave, in other words at the zero crossing of the alternating supply signal U0 when passing from a negative half-wave to a positive half-wave.

[0053] Here, the measuring elements 7 comprise a third diode D3, a fourth diode D4, and a resistive voltage divider bridge consisting of at least a second resistor R2. The third diode D3 and the fourth diode D4 are electrically connected together by an electrode of the same nature to one end B of the second resistor R2, the other electrode of each diode D3, D4 being respectively connected to the first phase terminal PI and to the second phase terminal P2. The other end of the second resistor R2 is electrically connected to the floating electrical ground GND of the control device 1. The end B of the second resistor R2 is electrically connected to a measurement input INO of the processing circuit 4L. Thus, the processing circuit 41 is adapted to measure a value of the alternating power supply signal U0 by measuring an electrical voltage across the terminals of the second resistor R2.

[0054] Here, the third diode D3 and the fourth diode D4 are electrically connected together by their respective cathode to the end B of the second resistor R2, the anode of the third diode D3 is connected to the first phase terminal PI, and the anode of the fourth diode D4 is electrically connected to the second phase terminal P2. The diodes DI and D3 operate here in opposition, as do the diodes D2 and D4.

[0055] Figure No. 3 illustrates steps of a method for controlling a switch 2, according to one embodiment. The control method is implemented by the processing circuit 4L

[0056] The steps of the control method are described in the following, in correspondence with figure 4 which represents a time diagram of the detection signal of the optocoupler 61, 62 detected by the detection elements 6, of the alternating power supply signal U0, of the control signal of the switch 2 generated by the control elements 4, and of the signal present at the terminals of the second resistor R2 measured by the measuring elements 7. This case makes it possible to illustrate the control method implemented for a control device conforming to a mode of rea- lization.

[0057] Advantageously, the primary steps of the method are implemented when the switch 2 is placed in an open state and / or when the electrical load 3 is not electrically powered by the alternating power supply signal U0.

[0058] The method comprises a first series of primary steps EP and a second series of secondary steps ES, the first series of steps being carried out upstream of the second series of steps. The delay T1 existing between a rising or falling edge of the optocoupler and the real zero sector is determined by the first series of steps in order to be able to be used in the second series of steps to control the switch 2 following the reception of a control order from the electromechanical actuator ACT.

[0059] The method comprises a primary step EP0 of determining a time period T2 characteristic of the alternating power supply signal U0 to pass from a zero value to the threshold value VS.

[0060] Advantageously, the time period T2 can be measured by means of the measuring elements 7, or predetermined in a memory of the processing circuit 41 when the value of the alternating supply signal U0 is considered fixed and stabilized.

[0061] Advantageously, the primary step EP0 is implemented when the processing circuit 41 determines that the signal received from the optocoupler 61, 62 is stabilized, for example when the interval between each rising edge or falling edge received on the logic input INI, IN2 is determined to be constant for a predetermined duration corresponding to a predetermined number of rising or falling edges received on the logic input INI, IN2.

[0062] The method further comprises a first primary step EPI of detecting a rising edge or a falling edge on the logic input INI, IN2 of the processing circuit 41 determining a first primary instant tpi.

[0063] The method further comprises a second primary step EP2 of detecting the reaching or exceeding of a threshold value VS by a value measured by the measuring elements 7 determining a second primary instant tp2 and / or a time period T3 corresponding to a time interval between the first primary instant tpi and the second primary instant tp2, the second primary instant tp2 being located after the first primary instant tpi.

[0064] The method further comprises a third primary step EP3 of determining a value of a delay T1 from the first primary instant tpi and the second primary instant tp2, or from the time period T2 and the time period T3, the time period corresponding to the delay T1 preceding the time period T2, the time period T3 running in parallel with the time period T1 and / or the time period T2.

[0065] Advantageously, the third primary step EP3 comprises at least one first primary substep EP32 for determining a third primary instant tp3 from the second primary instant tp2, the third primary instant tp3 being calculated from the time period T2 characteristic of the alternating power supply signal UO to pass from a zero value to the threshold value VS, and a second primary substep EP33 for determining the delay Tl as a difference between the third primary instant tp3 and the first primary instant tpi, or a difference between the time period T3 and the time period T2. The third primary instant tp3 is located between the first primary instant tpi and the second primary instant tp2, the second primary instant tp2 being located after the first primary instant tpi. The threshold value VS can for example be set at 100 mV to limit the risk of false measurement on the measurement input INO of the processing circuit 4L

[0066] The method further comprises a first secondary step ESI of detecting a rising edge or a falling edge on the logic input of the processing circuit determining a first secondary instant tsl.

[0067] The method further comprises a second secondary step ES2 of determining a control time te of the switch from the first secondary time tsl and the delay value Tl determined by the third primary step EP3.

[0068] The method further comprises a third secondary step ES3 of controlling the switch 2 from the control time te determined by the second secondary step ES2.

[0069] According to an exemplary embodiment illustrated by figures n°3 and n°4, the electromechanical actuator ACT is a motorized blind powered by an alternating power supply signal U0 of type 230 V - 50 Hz.

[0070] It is assumed as initial conditions that the control device 1 is powered up during an initialization step of the electromechanical actuator ACT, for example when the electromechanical actuator ACT is powered up. The load 3 of the electromechanical actuator ACT is initially stopped and not electrically powered, in other words immobile, and no control command is received by the electromechanical actuator ACT. As illustrated in [Fig. 4], each rising edge received on the logic input INI of the processing circuit 41 corresponds here to the zero crossing of the alternating power supply signal U0 during the transition from a negative half-wave to a positive half-wave of the alternating power supply signal U0.

[0071] The processing circuit 41 analyzes the signal from the optocoupler 61 over a time interval comprising four occurrences of rising edges of the optocoupler 61, and determines that the signal from the optocoupler 61 is stabilized.

[0072] The processing circuit 41 implements the primary step EP0 in which it detects for the first time the appearance of a rising edge on the logic input INI then measures the value of the alternating supply signal UO on the measurement input INO until the measured value is zero, in other words equal to zero. The processing circuit 41 then triggers a time counter at the instant when the measured value is zero and continues to measure the value of the alternating supply signal UO on the measurement input INO until the measured value reaches the threshold value VS, here 100 mV. Once the threshold value is reached, the processing circuit 41 stops the time counter and then records the value of the measured time period T2 in a memory of the processing circuit 41. Here, the value of the recorded time period T2 corresponds to a time period between a first instant when the value of the alternating supply signal UO is zero and a second instant when the value of the alternating supply signal UO has reached the predetermined threshold value VS.

[0073] The processing circuit 41 then implements the first primary step EPI in which it waits for the appearance of a new rising edge on the logic input INI until the detection of a rising edge on the logic input INI, thus determining a first primary instant tpi.

[0074] Following detection of the rising edge, the processing circuit 41 implements the second primary step EP2 in which it triggers a time counter at the primary instant tpi and measures the value of the alternating supply signal U0 on the measurement input INO until the threshold value VS is reached. Once the threshold value VS is reached at a second primary instant tp2, the processing circuit 41 stops the time counter and then reads the value of the time counter corresponding to a time period T3.

[0075] The processing circuit 41 then implements the third primary step EP3 in which it determines the value of the delay T1 by the relation T1 = T3 - T2, the value of the delay T1 corresponding to a time interval between the first primary instant tpi corresponding to the appearance of a rising edge of the optocoupler, and a third primary instant tp3 corresponding to the instant following the first primary instant tpi where the value of the alternating supply signal U0 is zero, in other words at the zero crossing of the alternating supply signal U0.

[0076] The processing circuit 41 then waits for receipt of a control order from the electromechanical actuator ACT, following which it implements a series of secondary steps in which it controls the switch 2 each time a rising edge appears on the logic input INI, each control pulse from the switch 2 being emitted at a control instant te with the delay Tl determined by the processing circuit 4L.

[0077] It will be clear to those skilled in the art that the present invention is susceptible to various embodiment variants and application variants. In particular, the direction of mounting of the diodes DI to D4 is susceptible to a multitude of variants having to modify the nature of the edge detected by the optocoupler. Similarly, the components forming the resistive circuit of the control device are susceptible to numerous variations, notably described in patent FR2886786.

Claims

Claims

1. Control device (1) of a switch (2) formed by a bidirectional semiconductor element controlled for an electromechanical actuator (ACT), the electromechanical actuator (ACT) comprising a load (3) arranged in series with the switch (2) and adapted to be electrically powered by an alternating power supply signal (UO) periodically passing through zero, the control device (1) further comprising: - coupling elements (5), the coupling elements (5) comprising the switch (2) and being configured to couple the alternating supply signal (UO) to the load (3), - detection elements (6) for detecting a zero crossing instant of the alternating supply signal (UO), the detection elements (6) comprising at least one optocoupler (61, 62), the optocoupler (61, 62) being configured to emit a rising edge or a falling edge on a logic input (INI, IN2) of a processing circuit (41) when the alternating supply signal (UO) is substantially equal to zero, - control elements (4) of the switch (2), the control elements of the switch (2) comprising the processing circuit (41) and being configured to emit control pulses on a control terminal of the switch (2) following receipt of a control command from the electromechanical actuator (ACT),each pulse being adapted to place the switch (2) in a closed state between two pulses and taking into account a control instant (te) determined from a first secondary instant (tsl) of reception of the rising edge or the falling edge of the optocoupler (61, 62), and, - measuring elements (7) of the alternating supply signal (UO), the measuring elements (7) being configured to measure a value of the alternating supply signal (UO), characterized in that the control device (1) further comprises: - first elements for determining (8) a delay (Tl) as a function of a first primary instant (tpi) at which the circuit processing circuit (41) detects a rising edge or a falling edge on the logic input (INI, IN2) of the processing circuit (41), and a second primary instant (tp2) at which a value measured by the measuring elements (7) reaches or exceeds a predetermined threshold value (VS), and - second determining elements (9) of the control instant (te), the control instant (te) being determined from the first secondary instant (tsl) and the delay (Tl) determined by the first determining elements (8).

2. Control device according to claim 1, characterized in that the coupling elements (5) further comprise a phase conductor (ACP) and a neutral conductor (ACN), the phase conductors (ACP) and neutral conductors (ACN) being electrically powered by the alternating supply signal (UO), and in that the load (3) is an electric motor (MOT), the electric motor (MOT) comprising a stator, the stator comprising two windings (L1, L2), the two windings (L1, L2) each comprising a common end (NO) so as to electrically connect them together, the common end (NO) being electrically connected to the neutral conductor (ACN) via the switch (2), each of the two windings (L1, L2) comprising another end constituting respectively a first phase terminal (PI) and a second phase terminal (P2),the first phase terminal (PI) being electrically connected to the second phase terminal (P2) via a phase shift capacitor (CM), the phase conductor (ACP) being selectively either electrically connected to the first phase terminal (PI) to control the rotational drive of the electric motor (MOT) in a first direction (DIR1), or electrically connected to the second phase terminal (P2) to control the rotational drive of the electric motor (MOT) in a second direction (DIR2), the second direction (DIR2) being opposite to the first direction (DIR1).,

3. Control device (1) according to claim 1 or according to claim 2, characterized in that the detection elements (6) comprise third elements for determining a conduction state of a diode (D1, D2) through which a current derived from the alternating supply signal (UO) flows, and in that the optocoupler (61, 62) is configured to detect the current flowing through the diode (D1, D2) and emit a rising edge or a falling edge on a logic input (INI, IN2) of the processing circuit (41) when the value of the current crosses a conduction threshold value of the diode at an instant when the alternating power supply signal (UO) is substantially equal to zero.

4. Control device (1) according to any one of the preceding claims, characterized in that the control elements (4) are configured to emit at least one series of pulses, each pulse of the series of pulses being emitted in synchronism with the control instant (te).

5. Control device (1) according to any one of the preceding claims, characterized in that the measuring elements (7) comprise a resistive voltage divider bridge, the resistive voltage divider bridge being electrically connected on the one hand to the alternating supply signal (UO) and on the other hand to a measurement input (INO) of the processing circuit (41), the divider bridge being configured to adapt the alternating supply signal (UO) to the measurement input (INO) of the processing circuit (41).

6. Control device (1) according to any one of the preceding claims, characterized in that the first determining elements (8) comprise a time counter integrated into the processing circuit (41), the time counter being initiated at the first primary instant (tpi), then stopped at the second primary instant (tp2).

7. Control device (1) according to any one of the preceding claims, characterized in that the second determining elements (9) comprise at least one data item recorded in a memory of the processing circuit (41), the recorded data item comprising a value of a time period (T2) characteristic of the alternating supply signal (UO) to pass from a zero value to the predetermined threshold value (VS).

8. Method for controlling a switch (2) for an electromechanical actuator (ACT), the electromechanical actuator (ACT) comprising a control device (1) according to any one of claims 1 to 7, characterized in that the method comprises at least: - a first primary step (EPI) of detecting a rising edge or a falling edge on the logic input (INI,

9. IN2) of the processing circuit (41) determining a first primary instant (tpi); - a second primary step (EP2) of detecting the reaching or exceeding of a threshold value (VS) by a value measured by the measuring elements (7) determining a second primary instant (tp2); - a third primary step (EP3) of determining a delay value (Tl) from the first primary instant (tpi) and the second primary instant (tp2); - a first secondary step (ESI) of detecting a rising edge or a falling edge on the logic input (INI, IN2) of the processing circuit (41) determining a first secondary instant (tp2); - a second secondary step (ES2) for determining a control time (te) of the switch (2) from the first secondary time (tsl) and the delay value (Tl) determined by the third primary step (EP3); and - a third secondary step (ES3) of controlling the switch (2) from the control time (te) determined by the second secondary step (ES2). Control method according to claim 8, in which the third primary step (EP3) comprises: - a first primary sub-step (EP31) for determining a third primary instant (tp3) from the second primary instant (tp2), the third primary instant (tp3) being calculated from a time period (T2) characteristic of the alternating power supply signal (UO) to pass from a zero value to the threshold value (VS); - a second primary sub-step (EP32) for determining the delay (Tl) as a difference between the third primary instant (tp3) and the first primary instant (tpi).

10. Control method according to claim 8, characterized in that the primary steps of the method are implemented when the switch (2) is placed in an open state and / or when the electrical load (3) is not electrically powered by the AC power signal (UO).

11. Control method according to any one of claims 7 to 10, characterized in that the primary steps of the method are repeated an integer number n of times and in that the value of the control instant (te) corresponds to an average value of the values ​​of the control instants determined at each repetition of the primary steps.