Uninterruptible power supply circuit

Abstract

The invention relates to an uninterruptible power supply circuit in the form of an active double-bridge converter comprising first terminals configured to be connected to a first alternating current electrical network, second terminals configured to be connected to a second alternating current electrical network, third terminals configured to be connected to a direct current voltage source, the uninterruptible power supply circuit further comprising a transformer having a primary and a first secondary, a first electrical branch having said primary, the first electrical branch being connected to a first circuit of switches configured to allow energy exchange with the first terminals via said primary, and a second electrical branch having said first secondary.said second electrical branch being connected to a second circuit of switches configured to allow energy exchange with the second terminals via said first secondary. The first electrical branch comprises a first inductor connected in series with said primary, the second electrical branch comprises a second inductor connected in series with said first secondary, said transformer further comprises a second secondary, a third circuit of switches being connected to said second secondary and configured to allow energy exchange with the third terminals via said second secondary, so as to allow energy exchanges between the first AC electrical network and the DC voltage source and between the DC voltage source and the second AC electrical network.

Description

Title of the invention: Uninterruptible power supply circuit

[0001] The invention relates to an uninterruptible power supply circuit, in particular an uninterruptible power supply circuit configured to supply a second alternating electrical network from a first alternating electrical network, and in the event of failure of the first alternating electrical network, to supply the second alternating electrical network from a direct voltage source.

[0002] Uninterruptible power supplies or UPS, also called UPS (for Uninterruptible power supplies (UPSs) are electrical devices designed to provide continuity of service in the event of a power outage to an electrical system from a power grid. By interfacing between the power grid and the system, uninterruptible power supplies can also improve the quality of power provided by the power grid. Systems using UPSs include banks, hospitals, universities, and data centers.

[0003] Typically, a UPS is configured to perform two electrical conversions. In normal operation, the UPS implements an alternating-to-alternating (AC / AC) conversion in which energy taken from the alternating-current grid is delivered to the alternating-current system. In the event of a failure of the alternating-current grid, a direct-to-alternating (DC / AC) conversion is implemented between a direct-current voltage source, such as a battery, and the alternating-current system so as to continue powering the alternating-current system.

[0004] Typically, the DC voltage source is rechargeable. Its voltage level must be sufficient to enable the AC electrical system to be supplied, at least for a transient period. Generally, the DC voltage source is rechargeable via an independent electrical charger, which will charge the DC voltage source from the first AC electrical network. To ensure a supply of the AC electrical system in the event of a failure of the AC electrical network, a UPS circuit and an electrical charger circuit are therefore required. However, in a context of cost reduction and efficiency improvement, it would be advantageous to limit the number of electrical components required.

[0005] A solution is therefore sought to limit the electrical components in the use of an uninterruptible power supply allowing power supply by a backup DC voltage source, and an electrical charger intended to charge the backup DC voltage source.

[0006] To this end, the invention proposes an uninterruptible power supply circuit in the form of a dual active bridge converter comprising first terminals configured to be connected to a first alternating current electrical network, second terminals configured to be connected to a second alternating current electrical network, third terminals configured to be connected to a direct voltage source, the uninterruptible power supply circuit further comprising: i. a transformer comprising a primary and a first secondary; ii. a first electrical branch comprising said primary, the first electrical branch being connected to a first switch circuit configured to allow an exchange of energy with the first terminals via said primary; and iii. a second electrical branch comprising said first secondary, said second electrical branch being connected to a second switch circuit configured to allow an exchange of energy with the second terminals via said first secondary; uninterruptible power supply circuit, wherein: i. the first electrical branch comprises a first inductor connected in series with said primary; ii. the second electrical branch comprises a second inductor connected in series with said first secondary; iii. said transformer further comprises a second secondary, a third switch circuit being connected to said second secondary and being configured to allow an exchange of energy with the third terminals via said second secondary; so as to allow energy exchanges between the first alternating current network and the direct voltage source and between the direct voltage source and the second alternating current network.

[0007] Thanks to the first inductor, the second inductor, and the second secondary, a power supply of the second AC electrical network by the first AC electrical network can be carried out by transferring the energy from the first AC electrical network to the DC voltage source, then from the DC voltage source to the second AC electrical network. The DC voltage source is used to temporarily store the energy flowing from the first AC electrical network to the second AC electrical network. On this occasion, part of the energy can then be used to charge the DC voltage source. Thus, the electrical charger is integrated into the uninterruptible power supply. This eliminates the need for an independent electrical charger.In particular, thanks to the first inductance, the second inductance, and the second secondary, the uninterruptible power supply circuit is configured to allow an exchange of energy between the first electrical network and the direct voltage source, and between the second electrical network and the . direct voltage source. From a functional point of view, it can be considered that in the case of energy exchange between the first and second alternating current networks, it is carried out via the direct voltage source.

[0008] According to one embodiment, the power supply circuit is configured so that the switch circuits are controlled by phase shifts, said energy exchanges being a function of the phase shifts between the first, second, and third circuits.

[0009] According to one embodiment, the uninterruptible power supply circuit is configured such that a voltage across the second terminals of the uninterruptible power supply circuit is determined by a phase shift between the third circuit and the second circuit.

[0010] According to one embodiment, the uninterruptible power supply circuit is configured such that a voltage across third terminals of the uninterruptible power supply circuit and / or a current across first terminals of the uninterruptible power supply circuit are determined by a phase shift between the first circuit and the third circuit.

[0011] According to one embodiment, the uninterruptible power supply circuit comprises a control unit configured to determine said phase shifts and control said switches as a function of said phase shifts.

[0012] According to one variant, said control unit comprises: i. a first control block configured to deliver a set power to the third terminals of the uninterruptible power supply circuit; ii. a second control block configured to determine a setpoint current at the first terminals of the uninterruptible power supply circuit as a function of said setpoint power and an instantaneous voltage at the first terminals of the uninterruptible power supply circuit; iii. a third control block configured to determine a phase shift between the first and third circuits based on a difference between the setpoint current and an instantaneous current at the first terminals of the uninterruptible power supply circuit.

[0013] According to a variant, the first control block is configured to deliver a first setpoint power to the third terminals of the uninterruptible power supply circuit as a function of a difference between a setpoint voltage and an instantaneous voltage at the third terminals of the uninterruptible power supply circuit.

[0014] According to a variant, the first control block is configured to deliver a second setpoint power as a function of a power to be injected into the first terminals of the uninterruptible power supply circuit.

[0015] According to a variant, the first control block is configured to deliver the first setpoint power in the event of an exchange of energy from the first terminals to the third terminals; and to deliver the second setpoint power in the event of an exchange of energy from the third terminals to the first terminals.

[0016] According to a variant: i. the first control block has a lower update frequency, in particular at least ten times lower, than a frequency of the first AC power grid; and ii. the second and third control blocks have update frequencies higher, in particular at least twenty times higher, than a frequency of the first AC network.

[0017] According to a variant, said control unit comprises a fourth control block configured to determine the phase shift between the third circuit and the second circuit as a function of a difference between a set voltage at the second terminals of the uninterruptible power supply circuit and an instantaneous voltage at the second terminals of the uninterruptible power supply circuit.

[0018] According to a variant, said control unit is configured so as to control two of the three switch circuits with phase shifts relative to the remaining switch circuit, called the “reference circuit”.

[0019] According to one embodiment, the switches of the first, second, and third circuits respectively form a complete bridge of switches or a half-bridge of switches.

[0020] Other characteristics and advantages of the present invention will appear better on reading the description which follows in relation to the following appended figures:

[0021] [Fig-1]: [Fig.l] represents an uninterruptible power supply circuit according to a example of the invention;

[0022] [Fig.2]: [Fig.2] represents a simplified electrical diagram of the power supply circuit without interruption illustrated in [Fig.l];

[0023] [Fig.3]: [Fig.3] represents an example of a circuit control unit uninterruptible power supply of [Fig.l];

[0024] [Fig.4]: [Fig.4] represents the evolutions over time of currents and voltages flowing through an example of a power supply circuit including the control unit of [Fig.3];

[0025] [Fig.5]: [Fig.5] represents another example of a circuit control unit uninterruptible power supply of [Fig.l];

[0026] [Fig.6]: [Fig.6] represents the evolutions over time of currents and voltages flowing through an example of a power supply circuit including the control unit of [Fig.5].

[0027] [Fig.l] shows an uninterruptible power supply circuit 100 according to an example of the invention. The power supply circuit 100 comprises first terminals B1 which are configured to be connected to a first AC electrical network 110 having a voltage Ve. The power supply circuit 100 also comprises second terminals B2 configured to be connected to a second AC electrical network 120 having a voltage Vs. Third terminals B3 are configured to be connected to a DC voltage source 130 having a voltage Vbat. Typically, the function of the power supply circuit 100 is to enable a power supply of the second AC electrical network 120 from the first AC electrical network 110. And in the event of a failure, to enable an emergency power supply of the second electrical network 120 from the DC voltage source 130. In particular, the DC voltage source 130 is rechargeable.In particular, it forms a temporary power supply, while a robust electrical source is being started, such as a generator for example. The direct voltage source 130 may be, among other things, a battery, such as a lithium / lead battery, or a supercapacitor. The battery may be embedded in a rack of the uninterruptible power supply circuit.

[0028] The power supply circuit 100 is in the form of a dual active bridge converter (or “Dual active Bridge” in English). The inventors have discovered that such a topology known per se is particularly advantageous for the implementation of a resonant power supply circuit, in particular in that it makes it possible to integrate a charging function of the DC voltage source 130 into the uninterruptible power supply circuit 100. In particular, the dual active bridge converter topology allows direct AC / AC conversion without the need for intermediate rectification at the input or output of the uninterruptible power supply circuit; and resonant switching operation, which greatly reduces switching losses. Thus, the uninterruptible circuit according to the invention has an improved efficiency compared to the prior art, in particular greater than 97%.Furthermore, the resonant switching operation allows very high frequency switching of the switches, for example greater than 100kHz. Whereas a prior art uninterruptible power supply circuit typically switches at a frequency between 20 and 50kHz. Thanks to this very high frequency operation, the size of the uninterruptible power supply circuit can be reduced compared to the prior art.

[0029] The power supply circuit 100 comprises a transformer 140 which comprises a primary 141 and a first secondary 142. The primary 141 of the transformer 140 is part of a first electrical branch 145 connected, in particular at its terminals, to a first circuit of switches SL. The first secondary 142 is part of a second electrical branch 146 connected, in particular at its terminals, to a second circuit of switches S2. A second secondary 144 is connected to a third switch circuit S3. By determining the current flowing in the first electrical branch 145, the first switch circuit SI makes it possible to control the energy exchanged between the first terminals B1 and the rest of the uninterruptible power supply circuit 100, in particular between the first AC network 110 and the rest of the uninterruptible power supply circuit 100. Similarly, the second switch circuit S2 makes it possible to control the energy exchanged between the second terminals B2 and the rest of the uninterruptible power supply circuit 100, in particular between the second AC electrical network 120 and the rest of the uninterruptible circuit 100. The third switch circuit S3 makes it possible to control the energy exchanged between the third terminals B3 and the rest of the uninterruptible power supply circuit 100, in particular between the DC voltage source 130 and the rest of the power supply circuit 100.

[0030] In the first electrical branch 145, a first inductance L1 is in series with the primary 141; and in the second electrical branch 146, a second inductance L2 is in series with the first secondary 142. The first L1 and second L2 inductances make it possible to interpose the direct voltage source 130 in the energy path between the first alternating electrical network 110 and the second alternating electrical network 120. The direct voltage source 130 thus makes it possible to transiently store energy between the first alternating electrical network 110 and the second alternating electrical network 120.

[0031] This circuit architecture makes it possible to independently control an exchange of energy between the primary 141 and the second secondary 144 on the one hand and on the other hand between the second secondary 144 and the first secondary 142. Thus, a portion of the energy received by the DC voltage source 130 can be used to charge the DC voltage source 130.

[0032] The example of an uninterruptible power supply 100 comprises ammeters A and voltmeters V which are optional and make it possible to obtain current and voltage measurements in the circuit 100. The uninterruptible power supply circuit 100 may comprise filtering capacitors or inductances between, on the one hand, the first electrical network 110, the second electrical network 120, and the DC voltage source 130 and, on the other hand, the respective terminals B1, B2, B3 of the uninterruptible power supply circuit 100 to which they are connected. These filtering elements notably form EMC filters (for "electromagnetic compatibility") to comply with the standards for the emission of electromagnetic disturbances with respect to surrounding devices. The resonant operation of the uninterruptible power supply circuit according to the invention makes it possible to reduce the EMC disturbances emitted, and therefore the size of the EMC filters.

[0033] The switches of the first S1, second S2, and third S3 switch circuits are arranged in a full bridge. Thus, each switch circuit S1, S2, S3 comprises two switch arms connected between its respective terminals B1, B2, B3. In the first S1 and second S2 switch circuits, the electrical branch 145, 146 is connected to the midpoints of the two arms. In the third switch circuit S3, the second secondary 144 is connected to the midpoints of the arms. However, another switch arrangement is conceivable. For example, the switches could be arranged in a half-bridge, in particular one switch arm being replaced by a capacitor arm. The switches of the first S1 and second S2 circuits are preferably bidirectional so as to allow direct switching of the alternating current, thus making it possible to dispense with a rectifier stage. The switches of the third circuit S3 can be unidirectional, which would be sufficient for operation with the direct voltage source 130.Switches are mainly semiconductor switches, such as GaN or SiC technology. GaN or SiC technology components are fast and well suited to high-frequency operation. Silicon technology components are also possible, although possibly with a reduction in efficiency.

[0034] In order to control the energy exchanges in the uninterruptible power supply circuit 100, the switches of the first S1, second S2, and third S3 switch circuits are preferably controlled by phase shift. Figure 2 shows a simplified electrical diagram of the power supply circuit 100. The first inductor L1 forms an input resonance inductor and the second inductor forms an output resonance inductor L2. The second secondary 144 and the third switch circuit S3 form an intermediate circuit between, on the one hand, the primary 141 and the first switch circuit S1 and, on the other hand, the first secondary 142 and the second switch circuit S2.The graphs in the lower part of Figure 2 respectively represent the current flowing in the primary 141 which is connected to the first switch circuit SI, the second secondary 144 which is connected to the third circuit S3, and the first secondary 142 which is connected to the second switch circuit S2. In particular, the switches of the switch circuits SI, S2, S3 are controlled with the same switching frequency and the same duty cycle. The switching frequency is for example between 100 and 500kHz, in particular equal to 100kHz. The duty cycle is for example 1.

[0035] In particular, the phase shift <1> b between the first switch circuit SI and the third switch circuit S3 determines the voltage at the third terminals B3, i.e. the DC voltage Vbat of the DC voltage source 130. Furthermore, this phase shift <1> b determines in particular the current flowing through the first terminals Bl of the uninterruptible power supply circuit SL In particular, during the func operation of the uninterruptible power supply circuit 100, the current flowing through the first terminals B1 is regulated so as to be in phase with the voltage Ve delivered by the first electrical network 110. In particular, the phase shift <bî2 entre le troisième circuit d’interrupteurs S3 et le deuxième circuit d’interrupteurs S2 détermine la tension aux deuxièmes bornes B2, c’est-à-dire la tension alternative Vs du deuxième réseau électrique alternatif 120.

[0036] In order to control the switches, the uninterruptible power supply 100 comprises in particular a control unit 170 shown schematically in [Fig. 3]. The control unit 170 notably implements pulse width modulation (or PWM for “Pulse Width Modulation”), by delivering opening / closing signals to the switches of the switch circuits S1, S2, S3.

[0037] The control unit 170 comprises a processing unit 6 which delivers signals PWM1, PWM2, PWM3 respectively to the first S1, second S2, and third S3 switch circuits. The processing unit 6 is in particular an electronic unit, such as a microcontroller for example. The processing unit 6 calculates the signals PWM1, PWM2, PWM3 from phase shifts determined by control blocks 1-5 described in the following.

[0038] A first control block 1 determines a setpoint power to be delivered to the third terminals B3. The first control block 1 forms in particular a regulation loop. For this purpose, a unit 12 calculates a difference between a setpoint voltage Vbat0 and an instantaneous voltage Vbat at the third terminals B3. Such a setpoint voltage Vbat0 corresponds to a nominal voltage of the DC voltage source 130, which is in particular necessary to ensure its emergency power supply function. The instantaneous voltage Vbat can be measured between the third terminals B3. From this difference, the setpoint power, i.e. the power to be delivered to the DC voltage source 130 to obtain a setpoint voltage Vbat0 at its terminals, is determined, in particular using a proportional-integral corrector PL. The instantaneous voltage Vbat can be filtered by a low-pass filter 14 to improve the quality of the control block 1.An activation circuit 16 may be used to activate block 1 when the DC voltage source 130 is to be used by the uninterruptible power supply circuit 100.

[0039] A second control block 2 determines a setpoint current to be obtained at the first terminals B1 from the setpoint power delivered by the first block 1 and the instantaneous voltage Ve between the first terminals B1, i.e. the voltage delivered by the first electrical network 110. The second block 2 obtains the setpoint current by dividing the setpoint power by the squared effective voltage and multiplying it by the instantaneous voltage Ve, the effective voltage being obtained from the instantaneous voltage Ve. The setpoint current is determined so as to be in phase with the voltage Ve between the first terminals Bl, and thus correct a power factor at the input of the uninterruptible power supply circuit 100.

[0040] A third control block 3 determines the phase shift <e>n between the first SI and the third S3 circuit. The third control block 3 forms in particular a control loop. For this purpose, a unit 32 calculates a difference between the setpoint current delivered by the second block 2 and an instantaneous current le at the first terminals Bl. The instantaneous current le can be measured at one of the first terminals BL The phase shift <f>n is determined from this difference, in particular using a proportional integral corrector PL The instantaneous current le can be filtered by a low-pass filter 34 to improve the quality of the control block 2. An activation circuit 36 ​​can be used to activate the second block 2 when the first AC electrical network 110 must be used by the uninterruptible power supply circuit 100.

[0041] The phase shift <l>i3 between the first SI and the third S3 circuit is therefore determined from two dynamics. One is implemented by the first control block 1 and aims to regulate the voltage between the third terminals B3, i.e. the voltage Vbat at the terminals of the DC voltage source 130. Another dynamic is implemented by the second control block 2, which aims to ensure a correction of the power factor at the first terminals Bl of the uninterruptible power supply circuit 100. The third block 3 which aims to adjust the current at the first terminals Bl can be updated at the same frequency as the second control block 2. In particular, the first control block 1 has a slower update frequency than that of the second 2 and the third 3 block, which allows parallel operation of these two dynamics.

[0042] Furthermore, the first control block 1 preferably has an update frequency lower than the frequency of the first AC electrical network 110. The second 2 and the third 3 control block preferably have update frequencies higher than the frequency of the first AC electrical network 110. This is to ensure that the current delivered by the first AC electrical network 110 is in phase with the voltage.

[0043] In particular, the first control block 1 has an update frequency at least ten times lower, or even 100 to 1000 times lower, than the frequency of the first alternating current network 110. The second 2 and the third 3 control block have in particular update frequencies at least twenty times, or even at least one hundred times, higher than the frequency of the first alternating current network 110.

[0044] An additional control block 5 can be inserted between the second block 2 and the third block 3. This additional block 3 is known per se, and aims to avoid potential malfunctions when the voltage Ve delivered by the first alternating current network 110. For this purpose, when the voltage Ve becomes lower than a first voltage threshold, the output value is set to zero. When the voltage Ve becomes higher than a second voltage threshold, the block 5 is put into sleep mode. For example, for a first alternating current network 110 with an effective voltage of 230V, the first and second thresholds are between 10 and 20V. The first and second thresholds are in particular equal.

[0045] The control unit 170 notably comprises a fourth control block 4, which determines the phase shift <e>32 between the third S3 and the second S2 circuit. The fourth control block 4 forms in particular a regulation loop. For this purpose, a unit 42 calculates a difference between a set voltage VSo at the second terminals B2, i.e. a set voltage of the second AC electrical network 120, and an instantaneous voltage Vs at the second terminals B2. The instantaneous voltage Vs can be measured between the second terminals B2. The phase shift <bî2 est déterminé à partir de cette différence, notamment à l’aide d’un correcteur proportionnel intégral PL La tension instantanée Vs peut être filtrée par un filtre passe-bas 44 pour améliorer la qualité du bloc de contrôle 4. Un circuit d’activation 46 peut être utilisé pour activer le quatrième bloc 4 lorsque le deuxième réseau électrique alternatif 120 doit être utilisé par le circuit d’alimentation sans interruption 100.

[0046] The processing unit 6 determines the modulation signals PWM1, PWM2, PWM3 from the phase shifts <e> i3, <e>32 determined by the control blocks, with a switching frequency. The controls of the switch circuits S1-S3 can be realized by taking the third switch circuit S3 as the phase reference. However, the phase reference can be another of the switch circuits. For example, if the first switch circuit SI is the reference circuit, the signals PWM1, PWM2, PWM3 supplied to the first circuit SI, the second circuit S2, and the third circuit S3 can be as follows:

[0047] [Math.l] PWMÏ = xz))

[0048] [Math.2] PWM3 = sign(sm(Wd xt- O13))

[0049] [Math.3] PWM2 = 5zgn(sin(Wd xt - O ] 3))

[0050] Where t is the time in seconds, Wd is the switching pulse, sign is the function that returns the sign value of its argument, and <e>i2 is the phase shift between the first circuit of switches SI and the second circuit of switches S2 such that

[0051] [Math.4] 2 ~ 3 + *$*32

[0052] An activation circuit 66 may be used to activate the transmission of the modulation signal PWM2 to the second switch circuit S2 when the second AC power network 120 is to be used by the uninterruptible power supply circuit 100.

[0053] A signal 67 can be used to inhibit the transmission of the modulation signal PWM1 to the first switch circuit SI when the first AC electrical network 110 is not available. As illustrated for example in [Fig.l], this same signal 67 can be used to open a switch 102 so as to disconnect the first AC electrical network 110 from the first terminals B1 of the power supply circuit 100. This is particularly the case when the first electrical network 110 is faulty.

[0054] In the control unit 170, the activation circuits 16, 36, 46, 66 are particularly useful for enabling sequencing of the start-up of the uninterruptible power supply circuit 100. They therefore enable in particular the activation of the elements of the power supply circuit 100 in the correct order.

[0055] [Fig.4] represents an example of currents and voltages flowing through the power supply circuit 100 during its operation. Graph a) represents the voltage Ve of the first AC electrical network 110. Graph b) represents the current Ia flowing in the first terminals B1 of the uninterruptible power supply circuit 100. Graph c) represents the voltage Vs delivered to the second AC electrical network 120. Graph d) represents the current Is flowing in the second terminals B2 of the uninterruptible power supply circuit 100. Graph e) represents the voltage Vbat of the DC voltage source 130.

[0056] Between the times T0 and T1, the first AC electrical network 110 is connected to the uninterruptible power supply circuit 100 and delivers an AC voltage Ve to it. The voltage Ve delivered by the first AC electrical network 110 is characterized for example by a peak voltage of 325 V or an effective voltage of 230 V for a frequency of 50 Hz. The input current 1e is regulated so as to be in phase with the voltage Ve delivered by the first AC electrical network 110 and to allow a substantially constant voltage Vbat, for example approximately 198 V, at the terminals of the DC voltage source 130. A voltage Vs delivered to the second AC electrical network 120 is for example regulated to a peak voltage of 325 V or an effective voltage of 230 V for a frequency of 60 Hz.A sinusoidal current Is in phase with the voltage Vs flows in the second terminals B2 of the uninterruptible power supply circuit 100, because in this example the load connected to the second terminals B2 is a resistor. But the current Is could be out of phase with the voltage Vs, especially if the load were inductive or capacitive.

[0057] At time T1, the first alternating electrical network 100 is disconnected from the circuit uninterruptible power supply 100. The voltage VS across the terminals of the direct voltage source 130 decreases because it then supplies the second alternating current network 120. It can be seen that the voltage Vs and the current Is are not impacted by this disconnection and are maintained thanks to the emergency power supply provided by the direct voltage source 130.

[0058] At time T2, the first AC electrical network 110 is reconnected to the uninterruptible power supply circuit 100. It is again noted that the voltage Vs and the current Is maintain their shape. The voltage Vbat at the terminals of the DC voltage source 130 increases progressively, thanks to the energy supplied by the first AC electrical network 110. The speed of charging of the DC voltage source 130 can be more or less rapid depending on the power devoted to charging by the uninterruptible power supply circuit.

[0059] The uninterruptible power supply circuit 100 therefore correctly performs its backup power supply function for the second AC electrical network 120, while allowing charging of the DC voltage source 130 when the first AC electrical network 110 is operational.

[0060] More generally, the uninterruptible power supply circuit 100 allows energy exchanges in all directions. For example, the DC voltage source 130 or the second AC electrical network 120 can send energy to the first AC electrical network 110. This is particularly advantageous when the first AC electrical network 110 also has high electrical consumption. In particular, the second AC electrical network 120 can supply energy when it contains energy production means, for example decentralized renewable energy production means. The energy exchanges mentioned above between the first AC electrical network 110 and the DC voltage source 130 and / or between the DC voltage source 130 and the second AC electrical network 130 can thus be negative.

[0061] The uninterruptible power supply circuit according to the invention can thus be used for network storage, i.e. the storage and restitution of energy between the first alternating network 110 and the direct voltage source 130, while providing a high-quality and uninterrupted alternating voltage to the second alternating electrical network 120.

[0062] In this application, during the storage phase, the uninterruptible power supply circuit 100 operates so as to ensure an uninterrupted power supply to the second AC electrical network 120. Energy is taken from the first AC electrical network 110 to ensure the charging of the DC voltage source 130, for example by regulation based on a setpoint voltage, and to ensure the needs of the second AC electrical network 120. The first network 110 provides then the accumulation of the power required to charge the direct voltage source 130 and the power required by the second network 120 (through the direct voltage source).

[0063] The energy destocking phase corresponds to an injection, into the first AC electrical network 110, of a portion of the energy stored in the DC voltage source 130. The uninterruptible power supply circuit 100 then behaves as a producer of electrical energy with respect to the first AC electrical network 110. This may be desired, for example, to carry out storage / destocking arbitrations depending on variations in the price of electricity, or as a service to support the balance between supply and demand of electricity on the first AC electrical network 110. This service may, for example, be a service to assist in regulating the frequency on the first AC electrical network 110.Such a regulation assistance service notably comprises the injection into it of an electrical power which is a function of the deviation of the frequency of the first alternating electrical network 110 with respect to its reference frequency, notably below it. For example, the reference frequency is 50Hz.

[0064] In the energy destocking phase, the power to be injected into the first AC electrical network 110 can be known. This power is in particular destocked from the DC voltage source 130 which thus provides both the power injected into the first AC electrical network 110 and the power required by the second AC electrical network 120.

[0065] In order to best manage the destocking phase, the uninterruptible power supply circuit 100 may comprise a control unit 180 shown schematically in [Fig.5].

[0066] This control unit 180 is similar to the control unit 170 illustrated in [Fig. 3], except that the first control block 1 comprises a control sub-block 1'. The control sub-block 1' makes it possible to select either a first power determined as a function of the difference between a setpoint voltage and an instantaneous voltage at the third terminals B3 of the circuit 100, or a second power Pinj to be injected into the first AC electrical network 110. For this purpose, the sub-block 1' may comprise a selection unit MUX which selectively connects the circuit delivering the first power or the circuit delivering the second power. An activation circuit 16' may be used to activate the sub-block 1' when the DC voltage source 130 must be used for energy de-storage by the uninterruptible power supply circuit 100.Control sub-block 1' then delivers the selected power to the following control blocks, as the setpoint power. The other control blocks operate as described previously.

[0067] [Fig.6] shows an example of currents and voltages flowing through the circuit power supply 100 during such storage and retrieval operation with respect to the first electrical network 110, while ensuring the uninterrupted power supply of the second electrical network 120. Graph a) represents the voltage Ve of the first AC electrical network 110. Graph b) represents the current Is flowing in the first terminals B1 of the uninterrupted power supply circuit 100. Graph c) represents the voltage Vs delivered to the second AC electrical network 120. Graph d) represents the current Is flowing in the second terminals B2 of the uninterrupted power supply circuit 100. Graph e) represents the input power Pe, i.e. the power exchanged with the first AC electrical network 110.

[0068] Between the initial time T0 and the time T3, the unpowered circuit 100 operates in a similar manner to the operation illustrated in [Fig.4].Between time T0 and time T1, the power supply circuit 100 operates so that the first electrical network 110 supplies both the DC voltage source 130 - charging it if necessary - and the second electrical network 120. The input power Pe is positive. Then at time T1, the unpowered circuit 100 switches to autonomous operation in which the second electrical network 120 is supplied only by the DC voltage source. The input power Pe is then zero, since the first electrical network 110 is disconnected. At time T2, the first electrical network 110 becomes available again, and begins to supply the second electrical network 120 again, as well as recharging the DC voltage source 130 which was partially discharged during the autonomous operation phase. As can be seen in [Fig.6], after time T2, the input power Pe is higher than that over the period T0-T1, due to the fact that the direct voltage source 130 has been partly discharged and therefore requires recharging.

[0069] Following a triggering event at time T3, the unpowered circuit 100 switches to a mode in which it injects electrical power into the first electrical network 110. The input power becomes negative and is for example regulated to -100W. For this purpose, the setpoint power delivered by the first control block is -100W. Following the regulation, an electrical power of 100W is injected into the first network, from the DC voltage source 130; while the second electrical network 120 continues to be supplied without interruption also from the DC voltage source 130. This injection of power into the first electrical network 110 is typically carried out by injecting a current Ie into the first electrical network 110 in phase opposition with the voltage Ve of the first electrical network 110. The injected power value of 100W is purely illustrative.Other values ​​are possible depending on the needs of the first electrical network 110 and the storage capacities of the direct voltage source 130 and / or the second electrical network 120.

[0070] The second electrical network 120 is correctly supplied without interruption during all of the successive phases of operation. This shows the correct operation of the uninterruptible power supply circuit 100, in particular in a context of network storage / retrieval or other services to the first network 110 requiring the injection of electricity available from the DC voltage source 130 or the second electrical network 120.

[0071] Thus, in the uninterruptible power supply circuit according to an embodiment of the invention, the first control block 1 can be configured to determine a setpoint power to be delivered to the third terminals B3 of the uninterruptible power supply circuit 100 as a function of a difference between a setpoint voltage Vbat0 and an instantaneous voltage Vbat at the third terminals B3 of the uninterruptible power supply circuit 100, as for example illustrated in FIGS. 3 and 5. The first control block can further be configured to determine the setpoint power as a function of a power Pinj to be delivered to the first terminals B1 of the uninterruptible power supply circuit 100, as for example illustrated in [Fig.5].< / e> < / e> < / e> < / e> < / l> < / f> < / e>

Claims

1. Claims Uninterruptible power supply circuit (100) in the form of a dual active bridge converter comprising first terminals (B1) configured to be connected to a first alternating electrical network (110), second terminals (B2) configured to be connected to a second alternating electrical network (120), third terminals (B3) configured to be connected to a direct voltage source (130), the uninterruptible power supply circuit (100) further comprising: i. a transformer (140) comprising a primary (141) and a first secondary (142), ii. a first electrical branch (145) comprising said primary (141), the first electrical branch (145) being connected to a first switch circuit (SI) configured to allow an exchange of energy with the first terminals (Bl) via said primary (141), and iii. a second electrical branch (146) comprising said first secondary (142), said second electrical branch (146) being connected to a second switch circuit (S2) configured to allow an exchange of energy with the second terminals (B2) via said first secondary (142); uninterruptible power supply circuit (100), wherein: i. the first electrical branch (145) comprises a first inductance (Ll) connected in series with said primary (141), ii. the second electrical branch (146) comprises a second inductor (L2) connected in series with said first secondary (142), iii. said transformer (140) further comprises a second secondary (144), a third switch circuit (S3) being connected to said second secondary (144) and being configured to allow an exchange of energy with the third terminals (B3) via said second secondary (144), so as to allow energy exchanges between the first network alternating current source (110) and the direct current voltage source (130) and between the direct current voltage source (130) and the second alternating current network (120).

2. Uninterruptible power supply circuit (100) according to claim 1, configured so that the switch circuits (SI, S2, S3) are controlled by phase shifts, said energy exchanges being a function of the phase shifts (On, Oî2) between the first, second, and third circuits (SI, S2, S3).

3. An uninterruptible power supply circuit (100) according to claim 2, configured such that a voltage across the second terminals (B2) of the uninterruptible power supply circuit (100) is determined by a phase shift ( <f>32) between the third circuit (S3) and the second circuit (S2).

4. An uninterruptible power supply circuit (100) according to claim 2 or 3, configured such that a voltage at the third terminals (B3) of the uninterruptible power supply circuit (100) and / or a current at the first terminals (B1) of the uninterruptible power supply circuit (100) are determined by a phase shift (¢13) between the first circuit (SI) and the third circuit (S3).

5. Uninterruptible power supply circuit (100) according to one of claims 2 to 4, comprising a control unit (170, 180) configured to determine said phase shifts ( <e>i3, ¢32) and control said switches according to said phase shifts (¢13, ¢32)-

6. Uninterruptible power supply circuit (100) according to the preceding claim, wherein said control unit (170, 180) comprises: i. a first control block (1) configured to deliver a setpoint power to the third terminals (B3) of the uninterruptible power supply circuit (100); ii. a second control block (2) configured to determine a setpoint current (Ie) at the first terminals (B1) of the uninterruptible power supply circuit (100) as a function of said setpoint power and an instantaneous voltage (Ve) at the first terminals (B1) of the uninterruptible power supply circuit (100); iii. a third control block (3) configured to determine a phase shift (¢13) between the first (S1) and the third circuit (S3) as a function of a difference between the current of setpoint and an instantaneous current (Ie) at the first terminals (Bl) of the uninterruptible power supply circuit (100).

7. An uninterruptible power supply circuit (100) according to claim 6, wherein the first control block (1) is configured to deliver a first setpoint power to the third terminals (B3) of the uninterruptible power supply circuit (100) as a function of a difference between a setpoint voltage (Vbato) and an instantaneous voltage (Vbat) at the third terminals (B3) of the uninterruptible power supply circuit (100).

8. Uninterruptible power supply circuit (100) according to claim 6, wherein the first control block (1) is configured to deliver a second setpoint power as a function of a power to be injected (Pinj) at the first terminals (Bl) of the uninterruptible power supply circuit (100).

9. Uninterruptible power supply circuit (100) according to claims 7 and 8, wherein the first control block (1) is configured to deliver the first setpoint power in the event of an exchange of energy from the first terminals (B1) to the third terminals (B3); and to deliver the second setpoint power in the event of an exchange of energy from the third terminals (B3) to the first terminals (B1).

10. Uninterruptible power supply circuit (100) according to one of claims 6 to 9, wherein: i. the first control block (1) has a lower update frequency, in particular at least ten times lower, than a frequency of the first alternating current network (110); and ii. the second (2) and the third (3) control block have higher update frequencies, in particular at least twenty times higher, than a frequency of the first alternating current network (110).

11. Uninterruptible power supply circuit (100) according to one of claims 5 to 10, wherein said control unit (170; 180) comprises a fourth control block (4) configured to determine the phase shift (¢32) between the third circuit (S3) and the second circuit (S2) as a function of a difference between a set voltage

12.

13. (Vso) at the second terminals (B2) of the uninterruptible power supply circuit (100) and an instantaneous voltage (Vs) at the second terminals (B2) of the uninterruptible power supply circuit (100). Uninterruptible power supply circuit (100) according to one of claims 5 to 11, wherein said control unit (170, 180) is configured to control two of the three switch circuits with phase shifts relative to the remaining switch circuit, called the "reference circuit". Uninterruptible power supply circuit (100) according to one of the preceding claims, wherein the switches of the first, second, and third circuits (S1, S2, S3) respectively form a full bridge of switches or a half-bridge of switches.< / e> < / f>

Images