TWI829323B - Rapid shutdown system of energy storage device and method thereof - Google Patents

Abstract

A rapid shutdown system of an energy storage device includes a battery module, a boost circuit, a second switch element and an output circuit. The battery module has a first end and a second end, the boost circuit includes a first switch element and an active or passive switch element, one end of the first switch element is connected to the active or passive switch element, the other end is connected to the second end, and the first switch element is controlled by a first control signal to conduct or not conduct between the first end and the second end. The second switching element has a third end and a fourth end, and the third end is connected to the active or passive switching element. The output circuit has a fifth end and a sixth end, an output voltage exists between the fifth terminal and the sixth terminal, the fifth end is connected to the fourth end, and the sixth end is connected to the second end. The second switch element is controlled by a second control signal to conduct or not conduct between the boost circuit and the output circuit.

Description

Quick shutdown system of energy storage device and method thereof

The present invention relates to a shutdown system, and in particular to a quick shutdown system of an energy storage device.

Energy storage devices are, for example, lithium batteries, solar cells, fuel cells and other modules. In order to improve the safety of the energy storage device, when a safety fault occurs, the energy storage device can quickly shut down. When the safety fault disappears, the energy storage device can be shut down quickly. Energy devices can resume power generation. Generally speaking, each photovoltaic module in a solar photovoltaic system needs to be installed with a circuit breaker. When the safety fault disappears, the circuit breaker is reopened so that the photovoltaic module connected to the circuit breaker can output electrical energy. In other words, the current solar photovoltaic system needs to be equipped with a system controller to implement a quick shutdown function under regulatory requirements. This additional equipment is a DC circuit breaker (DC Breaker), control logic relay (Relay), etc. Thus increasing the construction cost.

The invention relates to a quick shutdown system of an energy storage device, which can integrate a quick shutdown component into a boost circuit to reduce construction costs.

According to one aspect of the present invention, a quick shutdown system for an energy storage device is proposed, which includes a battery module, a boost circuit, a second switching element and an output circuit. The battery module has a first terminal and a second terminal. There is a DC voltage between the first terminal and the second terminal. The boost circuit includes a first switching element and an active or passive switching element. One end of the first switching element is connected to the active or passive switching element, and the other end is connected to the second end. The first switching element is controlled by a first control signal to conduct or not conduct between the first end and the second end. between. The second switching element has a third terminal and a fourth terminal, and the third terminal is connected to the active or passive switching element. The output circuit has a fifth terminal and a sixth terminal. There is an output voltage between the fifth terminal and the sixth terminal. The fifth terminal is connected to the fourth terminal, and the sixth terminal is connected to the second terminal. The second switching element is controlled by a second control signal to conduct or not conduct between the boost circuit and the output circuit.

In order to have a better understanding of the above and other aspects of the present invention, examples are given below and are described in detail with reference to the accompanying drawings:

100,100’,101,101’: Quick shutdown system of energy storage device

110:Battery module

120: Boost circuit

122: First switching element

123: Diode

124:Active switching element

130: Second switching element

140:Output circuit

A1: first end

A2:Second end

A3:Third end

A4: fourth end

A5: The fifth terminal

A6:Sixth end

A7: Anode

A8:Cathode

C1: Boost capacitor

C2: Output capacitor

L1: Boost inductor

R1: output resistance

G1, G2, G3: gate

Vi: DC voltage

Vo: output voltage

I _AV : inductor current

Io: output current

Figure 1A is a schematic diagram of a quick shutdown system of an energy storage device according to an embodiment of the present invention; Figures 1B and 1C are schematic diagrams of the first switching element when it is conducting and not conducting respectively; and Figure 2 is a schematic diagram of the energy storage device according to an embodiment of the present invention. A schematic diagram of a quick shutdown system of an energy storage device according to another embodiment of the present invention; Figure 3 shows the waveform diagram of the first switching element, the diode/active switching element, the second switching element and the inductor current; Figures 4A and 5 respectively illustrate the rapid operation of the energy storage device according to another two embodiments of the present invention. A schematic diagram of the shutdown system; and Figures 4B and 4C respectively illustrate schematic diagrams of the first switching element when it is conducting and when it is not conducting.

The technical solutions in the embodiments of the present disclosure will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, rather than all of the embodiments. Based on the embodiments in this disclosure, all other embodiments that can be easily understood by a person with ordinary skill in the art fall within the scope of protection of this application. The following description uses the same/similar symbols to indicate the same/similar components.

Please refer to FIG. 1A , which is a schematic diagram of a rapid shutdown system 100 of an energy storage device according to an embodiment of the present invention. The quick shutdown system 100 of the energy storage device includes a battery module 110, a boost circuit 120 including a first switching element 122 and a passive switching element (such as a diode 123), a second switching element 130 and a Output circuit 140. The battery module 110 has a first terminal A1 and a second terminal A2. There is a direct current voltage Vi between the first terminal A1 and the second terminal A2. One end of the first switching element 122 is connected to the passive switching element (for example, the anode A7 of the diode 123), and the other end is connected to the second end A2. The first switching element 122 is controlled by a first control signal to conduct or not conduct between the first terminal A1 and the second terminal. between A2. The second switching element 130 has a third terminal A3 and a fourth terminal A4. The third terminal A3 is connected to the passive switching element (for example, the cathode A8 of the diode 123). The output circuit 140 has a fifth terminal A5 and a sixth terminal A6. There is an output voltage Vo between the fifth terminal A5 and the sixth terminal A6. The fifth terminal A5 is connected to the fourth terminal A4, and the sixth terminal A6 is connected to the second terminal A5. Terminal A2. The second switching element 130 is controlled by a second control signal to conduct or not conduct between the boost circuit 120 and the output circuit 140 .

Specifically, the battery module 110 is, for example, a solar photovoltaic module or other type of energy storage module. The photovoltaic module can be composed of a plurality of series/parallel photovoltaic element arrays to output direct current. This direct current It can be converted into alternating current through a converter and then output to the power grid. Taking solar photovoltaic modules as an example, the solar photovoltaic modules need to convert low voltage into high voltage through the boost circuit 120, and then convert it into AC voltage output through a DC/AC converter (not shown). However, the voltage of the series/parallel photovoltaic element array is very high, so the battery module 110 needs to be additionally equipped with a quick shutdown system 100 to improve the safety of the energy storage device. When a safety fault occurs, the energy storage device can quickly shut down. When the safety fault disappears, the energy storage device can resume power generation.

In this embodiment, the quick shutdown system 100 is integrated into the boost circuit 120 and does not require additional equipment such as a DC breaker (DC Breaker) or a control logic relay (Relay), thus effectively reducing the construction cost. cost.

As shown in FIG. 1A , the boost circuit 120 includes a boost capacitor C1 and a boost inductor L1 in addition to the first switching element 122 and the diode 123 . In addition, the above-mentioned output circuit 140 also includes an output capacitor C2 and an output resistor R1. The output capacitor C2 and the output resistor R1 are connected in parallel between the fifth terminal A5 and the sixth terminal A6 of the output circuit 140 .

As shown in Figure 1A, the two ends of the boost capacitor C1 are respectively connected to the first terminal A1 and the second terminal A2 of the battery module 110, and the two ends of the boost inductor L1 are respectively connected between the first terminal A1 and the diode 123. Anode A7. The first switching element 122 is, for example, a metal oxide semiconductor field effect transistor (MOSFET) or an insulated gate bipolar transistor (IGBT). The insulated gate bipolar transistor (IGBT) is a bipolar junction transistor (BJT). ) and a MOSFET. The control end (gate G1) of the first switching element 122 is connected to a controller (not shown, such as a microcontroller MCU). The controller can generate the above-mentioned first control signal ( For example, a pulse width modulation signal) makes the first switching element 122 conductive or non-conductive. By turning on or off the first switching element 122, the DC voltage Vi generated by the battery module 110 is boosted to the output voltage Vo.

In addition, the diode 123 is a one-way conducting element, which only allows the current to flow from the anode A7 of the diode 123 to the cathode A8, but does not allow the current to flow from the cathode A8 of the diode 123 to the anode A7, so the output circuit 140 can be cut off. Reverse current flowing to the boost circuit 120 . The diode 123 can cooperate with the first switching element 122 to be conductive or non-conductive and correspondingly be non-conductive or conductive.

Please refer to Figure 1B. When the first switching element 122 is turned on, the voltage at the anode A7 terminal of the diode 123 is lower than the output voltage Vo of the output circuit 140. At this time, the diode 123 is reverse biased. When it is turned on, the current I _AV passes through the boost inductor L1 in a clockwise direction. The boost inductor L1 begins to generate a magnetic field to store energy. Therefore, the current I _AV of the boost inductor L1 increases and the boost capacitor C1 is charged. The output capacitor C2 of the output circuit 140 releases energy to the output resistor R1, the output voltage of the output resistor R1 is Vo, and the current of the output resistor R1 is Io.

Please refer to Figure 1C. When the first switching element 122 is not conducting, the voltage at the anode A7 terminal of the diode 123 is higher than the output voltage Vo of the output terminal. At this time, the diode 123 is forward biased and conducts. The current I _AC of the boost inductor L1 flows to the output circuit 140, and the boost capacitor C1 discharges. The current I _AV continues to pass through the boost inductor L1 in a clockwise direction, but the current I _AV decreases and charges the output capacitor C2 through the diode 123. The power of the output capacitor C2 is due to the power of the battery module 110 and the power of the boost capacitor C1. The electric energy and the electric energy of the boost inductor L1 are collected and increased. Therefore, the output capacitor C2 can store more electric energy, thus boosting the output voltage Vo to increase, and the current Io of the output resistor R1 also increases relatively.

As can be seen from the above description, the boost circuit 120 can turn on or off the first switching element 122 to boost the DC voltage Vi generated by the battery module 110 to the output voltage Vo and output it through the output circuit 140 .

Please refer to Figure 2, which illustrates a schematic diagram of a quick shutdown system 100' of an energy storage device according to another embodiment of the present invention. The difference between this embodiment and the above embodiment is that the diode 123 is replaced by an active switching element 124 . The active switching element 124 is, for example, a metal oxide semiconductor field effect transistor (MOSFET) or an insulated gate bipolar transistor (IGBT). The control terminal (gate G3 ) of the active switching element 124 is connected to a controller (not shown, for example Microcontroller (MCU), the controller can generate a control signal (such as a pulse width modulation signal) to turn the active switching element 124 on or off.

When the first switching element 122 is conductive, the active switching element 124 is controlled not to conduct, just like the diode 123 is reverse biased and not to conduct. At this time, the output capacitor C2 of the output circuit 140 releases energy to the output resistor R1, the output voltage of the output resistor R1 is Vo, and the current of the output resistor R1 is Io. When the first switching element 122 is not conducting, the active switching element 124 is controlled to be conducting, just like the diode 123 is forward biased and conducting. At this time, the output capacitor C2 can store more electric energy, thereby boosting the output voltage Vo to increase, and the current Io of the output resistor R1 also increases relatively.

In addition, please refer to Figures 1A and 2, the third terminal A3 of the second switching element 130 is connected to the cathode A8 of the diode 123 (see Figure 1A) or connected to one end of the active switching element 124 (see Figure 2), and The fourth terminal A4 is connected to the fifth terminal A5 of the output circuit 140 . The second switching element 130 is, for example, a metal oxide semiconductor field effect transistor (MOSFET) or an insulated gate bipolar transistor (IGBT). The control terminal (gate G2 ) of the second switching element 130 is connected to a controller (not shown in the figure). , such as a microcontroller MCU), the controller can generate a second control signal (such as a pulse width modulation signal) to turn the second switching element 130 on or off. The quick shutdown system 100 is turned on or off by the second switching element 130 being turned on or off.

In addition, referring again to FIG. 1A , the second switching element 130 and the diode 123 can form a bidirectional blocking switching element group, or the second switching element 130 and the diode 123 can form an insulated gate bipolar circuit. crystal (IGBT), and as shown in Figure 2, the second switching element 130 can form a source with the active switching element 124. Groups of MOSFET switching elements that are connected to each other. That is to say, the second switching element 130 serves as a fast turn-off element and can be integrated with the boost circuit 120 to reduce the construction cost.

Please refer to FIG. 3, which illustrates the waveform diagram of the first switching element 122, the diode 123, the second switching element 130 and the inductor current I _AV . When the first switching element 122 is conductive, the diode 123 is reverse biased (not conductive); and when the first switching element 122 is not conductive, the diode 123 is forward biased (conductive). Therefore, the waveforms of the first switching element 122 and the diode 123 in the same cycle are opposite to each other. In addition, the waveform of the inductor current I _AV also relatively increases or decreases as the first switching element 122 is turned on or off. In addition, when the second switching element 130 is turned on, the quick turn-off system 100 is not turned on, so the waveform of the inductor current I _AV is not affected. When the second switching element 130 is not turned on, the fast turn-off system 100 is turned on to boost the voltage. The inductor current I _AV is blocked between the circuit 120 and the output circuit 140, so the inductor current I _AV cannot be output.

Please refer to Figures 4 and 5, which respectively illustrate schematic diagrams of quick shutdown systems 101 and 101' of energy storage devices according to another second embodiment of the present invention.

The quick shutdown system 101, 101' of the energy storage device includes a battery module 110, a boost circuit 120 including a first switching element 122 and an active or passive switching element (123, 124), and a second switching element. 130 and an output circuit 140. The battery module 110 has a first terminal A1 and a second terminal A2. There is a direct current voltage Vi between the first terminal A1 and the second terminal A2. One end of the first switching element 122 is connected to the active or passive switching element (123, 124), and the other end is connected to the second terminal A2. The first switching element 122 is controlled by a first control signal to conduct or not conduct at the first terminal. Between A1 and the second end A2. The second switch element 130 has a third terminal A3 and a fourth terminal A4, and the fourth terminal A4 is connected to the second terminal A2. The output circuit 140 has a fifth terminal A5 and a sixth terminal A6. There is an output voltage Vo between the fifth terminal A5 and the sixth terminal A6. The fifth terminal A5 is connected to the active or passive switching element (123, 124). The sixth terminal A6 is connected to the third terminal A3 of the second switching element 130 . The second switching element 130 is controlled by a second control signal to conduct or not conduct between the boost circuit 120 and the output circuit 140 .

In FIGS. 4A and 5 , except that the arrangement of the second switching element 130 is different from that of the second switching element 130 in FIGS. 1A and 2 , other elements are substantially the same and will not be described again. Referring to FIG. 4A, the second switching element 130 has a third terminal A3 and a fourth terminal A4. The third terminal A3 is connected to the sixth terminal A6 of the output circuit 140, the fourth terminal A4 is connected to the second terminal A2 of the battery module 110, and the second switching element 130 and the diode 123 are respectively connected to both ends of the output capacitor C2. The second switching element 130 and the diode 123 can form a bidirectional blocking switching element group, or the second switching element 130 and the diode 123 can form an insulated gate bipolar transistor (IGBT).

Please refer to Figure 4B. When the first switching element 122 is turned on, the diode 123 is reverse biased and does not turn on. Please refer to Figure 4C. When the first switching element 122 is not conducting, the diode 123 is forward biased and conducts. The control method is as shown in Figures 1B and 1C, which will not be described again here.

In addition, please refer to FIG. 5 , the second switching element 130 and the active switching element 124 are respectively connected to both ends of the output capacitor C2. Second switching element 130 It can form a bidirectional cutoff switching element group with the active switching element 124 .

According to the above description, the present invention proposes a quick shutdown method for the quick shutdown system 100, 100', 101, 101' of the above-mentioned energy storage device. In a normal state, a first control signal (such as a gate voltage signal) is input to control whether the first switching element 122 is conductive or not. When the first switching element 122 is conductive, the active or passive switching elements 123 and 124 are not conductive; When a switching element 122 is not conducting, the active or passive switching elements 123 and 124 are conducting. When the system determines that a safety failure occurs in the battery module 110, a second control signal (such as a gate voltage reduction signal) is input to control the second switching element 130 so that the second switching element 130 is not conductive to the boost circuit 120 and the output circuit 140. when the system determines that the safety fault of the battery module 110 disappears, a second control signal (such as an increase gate voltage signal) is input to control the second switching element 130, so that the second switching element 130 is turned on between the boost circuit 120 and between output circuits 140.

The quick shutdown system of the energy storage device in the above embodiment of the present invention is integrated into the boost circuit. There is no need to install additional equipment such as a DC breaker (DC Breaker) or a control logic relay (Relay). Therefore, it can effectively reduce the construction cost. purchase cost.

In summary, although the present invention has been disclosed above through embodiments, they are not intended to limit the present invention. Those with ordinary knowledge in the technical field to which the present invention belongs can make various modifications and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be determined by the appended patent application scope.

100: Quick shutdown system of energy storage device

110:Battery module

120: Boost circuit

122: First switching element

123: Diode

130: Second switching element

140:Output circuit

A1: first end

A2:Second end

A3:Third end

A4: fourth end

A5: The fifth terminal

A6:Sixth end

A7: Anode

A8:Cathode

C1: Boost capacitor

C2: Output capacitor

L1: Boost inductor

R1: output resistance

G1, G2: gate

Vi: DC voltage

Vo: output voltage

Claims (20)

A quick shutdown system of an energy storage device includes: a battery module having a first terminal and a second terminal; a boost circuit including a first switching element and an active or passive switching element, the first One end of the switching element is connected to the active or passive switching element, and the other end is connected to the second end. The first switching element is controlled by a first control signal to conduct or not conduct between the first end and the second end; A second switching element has a third terminal and a fourth terminal, the third terminal is connected to the active or passive switching element; and an output circuit has a fifth terminal and a sixth terminal, the fifth terminal and There is an output voltage between the sixth terminal, the fifth terminal is connected to the fourth terminal, and the sixth terminal is connected to the second terminal, wherein the second switching element is controlled by a second control signal to conduct or not conduct. between the boost circuit and the output circuit. The quick shutdown system of claim 1, wherein the boost circuit further includes a boost capacitor and a boost inductor, and two ends of the boost capacitor are respectively connected to the first terminal and the second terminal. Two ends of the piezoinductor are respectively connected to the first end and the active or passive switching element. The quick shutdown system of claim 1, wherein the passive switching element is a diode. The quick shutdown system of claim 3, wherein when the first switching element is turned on, the diode is reverse biased and does not conduct; when the first switching element does not conduct, the diode is forward biased. And conduction. The quick shutdown system of claim 3, wherein the second switching element and the diode form a bidirectional cutoff switching element group or an insulated gate bipolar transistor. The fast shutdown system of claim 1, wherein the active switching element is a metal oxide semiconductor field effect transistor (MOSFET). The fast turn-off system of claim 7, wherein the second switching element and the active switching element form a MOSFET switching element group whose sources are connected to each other. The quick shutdown system of claim 1, wherein the output circuit includes an output capacitor and an output resistor, and the output capacitor is connected in parallel with the output battery group between the fifth terminal and the sixth terminal of the output circuit. between. A quick shutdown system of an energy storage device includes: a battery module having a first terminal and a second terminal; a boost circuit including a first switching element and an active or passive switching element, the first One end of the switching element is connected to the active or passive switching element, and the other end is connected to the second end. The first switching element is controlled by a first control signal to conduct or not conduct between the first end and the second end; A second switching element has a third terminal and a fourth terminal, the fourth terminal is connected to the second terminal; and an output circuit has a fifth terminal and a sixth terminal, the fifth terminal and the third terminal There is an output voltage between the six terminals, the fifth terminal is connected to the active or passive switching element, and the sixth terminal is connected to the third terminal of the second switching element, wherein the second switch The element is controlled by a second control signal to conduct or not conduct between the boost circuit and the output circuit. The quick shutdown system of claim 9, wherein the boost circuit further includes a boost capacitor and a boost inductor, and two ends of the boost capacitor are respectively connected to the first terminal and the second terminal. Two ends of the piezoinductor are respectively connected to the first end and the active or passive switching element. The quick shutdown system of claim 9, wherein the passive switching element is a diode. The fast shutdown system of claim 11, wherein when the first switching element is turned on, the diode is reverse biased and does not conduct; when the first switching element does not conduct, the diode is forward biased. And conduction. The fast shutdown system of claim 11, wherein the second switching element and the diode form a bidirectional cutoff switching element group or an insulated gate bipolar transistor. The fast shutdown system of claim 10, wherein the active switching element is a metal oxide semiconductor field effect transistor (MOSFET). The fast shutdown system of claim 9, wherein the first switching element and the second switching element are metal oxide semiconductor field effect transistors (MOSFETs). The quick shutdown system of claim 9, wherein the output circuit includes an output capacitor and an output resistor, and the output capacitor is connected in parallel with the output battery group between the fifth terminal and the sixth terminal of the output circuit. between. A quick shutdown method for a quick shutdown system of an energy storage device as described in claim 1 or 9, including: inputting a first control signal to control the first switching element to be conductive or non-conductive, wherein the first switch When the element is turned on, the active or passive switching element is not turned on; when the first switching element is not turned on, the active or passive switching element is turned on; and a second control signal is input to control the second switching element so that the second switch The component is conductive or non-conductive between the boost circuit and the output circuit. The quick turn-off method of claim 17, wherein the passive switching element is a diode, and the second switching element and the diode form a bidirectional cutoff switching element group or an insulated gate bipolar transistor. The fast turn-off method as claimed in claim 17, wherein the second switching element and the active switching element form a MOSFET switching element group whose sources are connected to each other. The quick turn-off method of claim 17, wherein the second switching element and the active switching element form a bidirectional cut-off switching element group.

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