Removable capacitor bank module and air conditioning system

Abstract

The present invention discloses a detachable capacitor group module and an air conditioning system. The detachable capacitor group module comprises: a carrier provided with a first pin group and a second pin group, a capacitor group encapsulated on the carrier, one end of the capacitor group is connected to the first pin group, and the other end is connected to the second pin group, at least one end of the capacitor group is connected to its corresponding pin group through a controllable switch, the on-off state of the controllable switch is switched by a control module, the control module detects the working parameters of the capacitor group, and disconnects the controllable switch when the working parameters exceed the set value. The present invention independently encapsulates the capacitor group into a detachable module, connects it to an external circuit through a pin, is easy to disassemble and replace, and reduces maintenance costs, and a controllable switch is provided between the capacitor group and the pin, and when the capacitor group fails, the bus capacitor is disconnected from the external circuit through the controllable switch to avoid damage to the bus capacitor.

Description

Technical Field

[0001] The present invention relates to the technical field of detachable capacitor group structures, and in particular to a detachable capacitor group module with a protective function and an air conditioning system. Background Art

[0002] like Figure 1 As shown, in the existing photovoltaic (storage) air conditioning system, the output voltage of the photovoltaic array is connected to the high-voltage DC bus through the first DC / DC converter, and the energy storage battery is connected to the high-voltage DC bus through the second DC / DC converter. On the one hand, the energy in the high-voltage DC bus can be connected to the grid or taken from the grid through the first DC / AC converter, and on the other hand, the energy in the bus is supplied to the compressor load through the second DC / AC converter. In this system, all converters are connected to the DC bus capacitor. The bus capacitor is a decoupling unit of AC and DC energy. Under normal circumstances, the bus capacitor is composed of multiple electrolytic capacitors connected in series and parallel. When any converter in the system has a short-circuit fault, the positive and negative poles of the bus capacitor can be short-circuited, resulting in damage to the bus capacitor. The first DC / DC converter, the first DC / AC converter and the bus capacitor are all installed in the converter controller. When the bus capacitor is damaged, the entire converter controller needs to be disassembled and replaced, which is difficult to disassemble and has high maintenance costs.

[0003] Therefore, how to design a detachable capacitor group module and an air-conditioning system is a technical problem that needs to be solved urgently in the industry. Summary of the invention

[0004] In order to solve the defects in the prior art, the present invention proposes a detachable capacitor group module with protection function and an air conditioning system. The capacitor group is independently packaged into a detachable module, connected to the external circuit through pins, easy to disassemble and replace, and reduce maintenance costs. A controllable switch is provided between the capacitor group and the pins. When the capacitor group fails, the controllable switch disconnects the bus capacitor from the external circuit to avoid damage to the bus capacitor.

[0005] The technical solution adopted by the present invention is to design a detachable capacitor group module, including: a carrier provided with a first pin group and a second pin group, and a capacitor group encapsulated on the carrier, one end of the capacitor group is connected to the first pin group, and the other end is connected to the second pin group, and at least one end of the capacitor group is connected to its corresponding pin group through a controllable switch.

[0006] Preferably, the carrier is further provided with a third pin group for feeding back the on-off state of the controllable switch.

[0007] Preferably, the controllable switch is a relay or a contactor, and the auxiliary contact of the controllable switch is connected to the third pin group.

[0008] Preferably, the on-off state of the controllable switch is switched by a control module, and the control module detects the operating parameters of the capacitor group and disconnects the controllable switch when the operating parameters exceed a set value.

[0009] Preferably, the control module includes:

[0010] A detection device for detecting working parameters of the capacitor bank;

[0011] A comparison circuit, which compares the operating parameter with a set value and outputs a comparison signal;

[0012] A conversion circuit receives the comparison signal and converts it into a control signal;

[0013] The execution circuit switches the on-off state of the controllable switch according to the control signal.

[0014] Preferably, the set value includes a first threshold value and a second threshold value lower than the first threshold value; the comparison circuit includes: a first comparator and a second comparator whose output ends are connected to the conversion circuit, the inverting end of the first comparator and the non-inverting end of the second comparator are both connected to the detection device, the non-inverting end of the first comparator is connected to a first input device providing a first threshold value, and the inverting end of the second comparator is connected to a second input device providing a second threshold value; the conversion circuit converts a low-level signal output by the first comparator or the second comparator into a high-level signal.

[0015] Preferably, the controllable switch adopts a normally closed relay or contactor, and the execution circuit includes: a power supply branch for supplying power to the coil of the controllable switch, a switch tube connected in series in the power supply branch, and the control end of the switch tube is connected to the conversion circuit. When the conversion circuit outputs a high-level signal, the coil of the controllable switch is energized to disconnect the main contacts of the controllable switch.

[0016] Preferably, the carrier is provided with a fourth pin group connected to the input end of the power supply branch and a fifth pin group connected to the output end of the power supply branch.

[0017] Preferably, the detection device uses a current transformer for detecting the current of the capacitor bank.

[0018] The present invention also provides an air conditioning system, in which the above-mentioned detachable capacitor group module is plugged and installed.

[0019] Preferably, the air conditioning system comprises: a controller provided with a first DC / AC converter, an AC load connected to the controller via a second DC / AC converter, the AC side of the first DC / AC converter being connected to an AC power source, and the DC side being connected to the second DC / AC converter. The detachable capacitor group module is plugged into the controller, the first pin group comprises a first pin C, the second pin group comprises a second pin D, the first pin C and the second pin D are connected to the DC side of the first DC / AC converter.

[0020] Preferably, the controller is further provided with a first DC / DC converter, the input side of the first DC / DC converter is connected to the photovoltaic array, and the output side is connected to the energy storage battery through the second DC / DC converter, the first pin group includes a first pin A, the second pin group includes a second pin B, and the first pin A and the second pin B are connected to the output side of the first DC / DC converter.

[0021] In a feasible embodiment, one end of the capacitor group is connected to the first pin A through the controllable switch K1 and the first pin C through the controllable switch K2, and / or the other end of the capacitor group is connected to the second pin B through the controllable switch K3 and the second pin D through the controllable switch K4.

[0022] Compared with the prior art, the present invention has the following technical effects:

[0023] 1. The capacitor group is independently packaged into a detachable module, which is connected to the external circuit through pins, making it easy to plug and replace, reducing maintenance costs;

[0024] 2. The capacitor bank is connected to the external circuit through a controllable switch. When a fault occurs in the capacitor bank, the controllable switch is disconnected to avoid damage to the busbar capacitor;

[0025] 3. The on / off state of the controllable switch is switched by the control module. The control module detects the working parameters of the capacitor bank and determines whether the capacitor bank is abnormal according to the working parameters. When the capacitor bank is abnormal, the controllable switch is automatically disconnected to improve safety and reliability.

[0026] 4. The detachable module is provided with a third pin group for feedback of the on / off status of the controllable switch. The third pin group can be connected to an external controller. When the controllable switch is disconnected, the external controller sends out an alarm to notify relevant personnel to check. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The present invention is described in detail below with reference to the embodiments and accompanying drawings, wherein:

[0028] Figure 1 It is a circuit connection diagram of the existing photovoltaic air conditioning system;

[0029] Figure 2 is a pin diagram of a detachable capacitor bank module in the present invention;

[0030] Figure 3 It is a circuit connection schematic diagram of the detachable capacitor bank module in the present invention;

[0031] Figure 4 It is a circuit connection diagram of the photovoltaic air conditioning system in the present invention. DETAILED DESCRIPTION

[0032] The detachable capacitor bank module proposed by the present invention is to independently encapsulate the busbar capacitor bank into a detachable module, which is suitable for use in air conditioning systems to solve the major safety problem that the busbar capacitor positive and negative electrodes are short-circuited due to converter short-circuit failure in existing air conditioners, causing explosion and further paralysis of the system. Of course, the detachable capacitor bank module can also be used in other electrical appliances and plugged into the converter of the electrical appliance.

[0033] Specifically, if Figure 2 , 3 As shown, the detachable capacitor group module includes a carrier 1 and a main circuit 2 packaged on the carrier 1, the carrier 1 is provided with a first pin group and a second pin group, the first pin group is provided with more than one first pin, and the second pin group is provided with more than one second pin, the main circuit 2 includes a capacitor group and a controllable switch connected to the capacitor group, the capacitor group is composed of at least one bus capacitor, and in an embodiment given in the present invention, the bus capacitors C1 to the bus capacitors Cn are connected in parallel to form a capacitor group, and multiple bus capacitors can also be connected in series and parallel, and the number and connection method of the bus capacitors can be flexibly adjusted according to actual use needs.

[0034] One end of the capacitor group is connected to the first pin group, and the other end is connected to the second pin group. At least one end of the capacitor group is connected to its corresponding pin group through a controllable switch. It should be noted that the carrier 1 is not limited to a shape, and can be in the form of a circuit board, a package, etc. The pin group on the carrier is used to plug and connect with the external circuit. When the capacitor group is damaged and needs to be repaired, the controllable switch is disconnected so that the circuit where the capacitor group is located is cut off, the capacitor group is isolated from the external circuit, and the capacitor group module can be disassembled and replaced separately.

[0035] The capacitor group may have only one end connected to the corresponding pin group through a controllable switch, or both ends may be connected to the corresponding pin group through a controllable switch. In one embodiment of the present invention, the first pin group includes two first pins, namely, a first pin A and a first pin C, and the second pin group includes two second pins, namely, a second pin B and a second pin D. Taking one end of the capacitor group connected to the first pin group through a controllable switch as an example, a controllable switch connecting all the first pins may be connected in series at one end of the capacitor group, and the controllable switch uniformly controls the on-off state of the branch where all the first pins are located, or a controllable switch may be connected in series at one end of each first pin, and the controllable switch individually controls the on-off state of the branch where the first pin is located.

[0036] Preferably, the on-off state of the controllable switch is switched by the control module 3 encapsulated on the carrier 1. The control module 3 detects the working parameters of the capacitor group and determines whether the capacitor group is abnormal according to whether the working parameters exceed the settings. When the working parameters exceed the settings, the capacitor group is determined to be abnormal, and the control module 3 automatically disconnects the controllable switch to avoid damage to the busbar capacitor and improve safety and reliability. Furthermore, the carrier 1 is also provided with a third pin group E for feedback of the on-off state of the controllable switch. The third pin group E can be connected to an external controller. The external controller sends an alarm when the controllable switch is disconnected to notify relevant personnel to check in time. In a preferred embodiment, the controllable switch adopts a relay or a contactor, and the auxiliary contact of the controllable switch is connected to the third pin group E.

[0037] The specific circuit structure of the control module 3 includes: a detection device, a comparison circuit, a conversion circuit and an execution circuit. The detection device is used to detect the working parameters of the capacitor group. The comparison circuit compares the working parameter with the set value and outputs a comparison signal. The conversion circuit receives the comparison signal and converts it into a control signal. The execution circuit switches the on-off state of the controllable switch according to the control signal.

[0038] Among them, the set value includes a first threshold value and a second threshold value, the first threshold value VREF1 is higher than the second threshold value VREF2, in a preferred embodiment, the detection device uses a current transformer J1 for detecting the current of the capacitor group, assuming that the charging current of the capacitor group is positive and the discharging current is negative, then the maximum value of the charging current of the capacitor group can be set as the first threshold value VREF1, and the minimum value of the discharging current of the capacitor group can be set as the second threshold value VREF2 according to the operating parameters of the system used by the capacitor group module. In practical applications, the current transformer J1 can convert the collected current into a voltage signal and output it to the comparator, the first threshold value and the second threshold value are converted into corresponding voltage values, and the first input device and the second input device respectively provide the voltage value to the corresponding comparator.

[0039] like Figure 3 As shown, the comparison circuit includes: a first comparator U1_1 and a second comparator U1_2, the inverting end of the first comparator U1_1 and the non-inverting end of the second comparator are both connected to the detection device, the non-inverting end of the first comparator U1_1 is connected to a first input device providing a first threshold, the inverting end of the second comparator U1_2 is connected to a second input device providing a second threshold, the output ends of the first comparator U1_1 and the second comparator U1_2 are both connected to a conversion circuit, and the conversion circuit is a reverse driver, which converts the low-level signal into a high-level signal when the first comparator U1_1 or the second comparator U1_2 outputs a low-level signal, and converts the high-level signal into a low-level signal when the first comparator U1_1 and the second comparator U1_2 both output high-level signals.

[0040] The controllable switch adopts a normally closed relay or contactor, and the execution circuit includes: a power supply branch for supplying power to the coil of the controllable switch, a switch tube connected in series in the power supply branch, and the switch tube can be a triode, etc. The control end of the switch tube is connected to the conversion circuit. When the conversion circuit outputs a high-level signal, the coil of the controllable switch is energized to disconnect the main contact of the controllable switch. The carrier 1 is provided with a fourth pin group F connected to the input end of the power supply branch and a fifth pin group G connected to the output end of the power supply branch. After the detachable capacitor group module is plugged into the external circuit, the power supply branch is powered through the fourth pin group F, and the emitter of the switch tube is provided with a reference voltage through the fifth pin group G.

[0041] It should be noted that when there are more than two controllable switches, an execution circuit is designed for each controllable switch, and all execution circuits are connected to the output end of the same conversion circuit. Alternatively, a conversion circuit may be designed for each execution circuit, and all conversion circuits are connected in parallel to the output ends of the first comparator U1_1 and the second comparator U1_2. In one embodiment of the present invention, the first pin group includes two first pins, namely the first pin A and the first pin C, one end of the capacitor group is connected to the first pin A and the first pin C through the controllable switch K1 and the controllable switch K2, respectively, the execution circuit of the controllable switch S1 includes the coil S1, the switch tube Q1 and the current limiting resistor R1 of the controllable switch K1, the conversion circuit of the controllable switch S1 is the reverse driver U2_1, the execution circuit of the controllable switch includes the coil S2, the switch tube Q2 and the current limiting resistor R2 of the controllable switch K2, and the conversion circuit of the controllable switch S1 is the reverse driver U2_2.

[0042] The working process of the control module is as follows.

[0043] When the output signal VOUT of the detection device is between the first threshold VREF1 and the second threshold VREF2, the first comparator U1_1 and the second comparator U1_2 both output high-level signals, the conversion circuit converts the high-level signal into a low-level signal, the switch tube is disconnected, the coil of the controllable switch is de-energized, and the main contacts of the controllable switch are closed.

[0044] When the output signal VOUT of the detection device is higher than the first threshold VREF1, the first comparator U1_1 outputs a low-level signal, and the second comparator U1_2 outputs a high-level signal. The first comparator U1_1 pulls down the input end of the conversion circuit to a low-level signal, and the conversion circuit converts the low-level signal into a high-level signal. The switch tube is turned on, and the coil of the controllable switch is energized to disconnect the main contacts of the controllable switch, cutting off the connection between the capacitor group and the external circuit. At the same time, the disconnection state of the controllable switch is uploaded to the external controller, and the fault is reported to notify relevant personnel to avoid short circuit between the positive and negative poles of the capacitor group, which may cause explosion and damage.

[0045] When the output signal VOUT of the detection device is lower than the second threshold VREF2, the first comparator U1_1 outputs a high-level signal, and the second comparator U1_2 outputs a low-level signal. The second comparator U1_2 pulls down the input end of the conversion circuit to a low-level signal, and the conversion circuit converts the low-level signal into a high-level signal. The switch tube is turned on, and the coil of the controllable switch is energized to disconnect the main contacts of the controllable switch, cutting off the connection between the capacitor group and the external circuit. At the same time, the disconnection state of the controllable switch is uploaded to the external controller, and a fault is reported to notify relevant personnel.

[0046] The present invention also provides an air conditioning system, in which the above-mentioned detachable capacitor group module is plugged and installed.

[0047] In one embodiment, the air conditioning system includes: a controller and an AC load, the controller is provided with a first DC / AC converter, the AC load 5 is connected to the controller through a second DC / AC converter, the AC side of the first DC / AC converter is connected to an AC power source, and the DC side is connected to the second DC / AC converter. The detachable capacitor group module is plugged into the controller, the first pin group includes a first pin C, the second pin group includes a second pin D, and the first pin C and the second pin D are connected to the DC side of the first DC / AC converter. One end of the capacitor group is connected to the first pin C through a controllable switch, or the other end of the capacitor group is connected to the second pin D through a controllable switch, or both ends of the capacitor group are connected to the corresponding pins through a controllable switch.

[0048] like Figure 4 As shown, in another embodiment, the air-conditioning system is a photovoltaic air-conditioning system. In addition to the controller and AC load in the previous embodiment, the photovoltaic air-conditioning system is also connected to the photovoltaic array 6 and the energy storage battery. In addition to the first DC / AC converter, the controller is also provided with a first DC / DC converter. The input side of the first DC / DC converter is connected to the photovoltaic array, and the output side is connected to the energy storage battery through the second DC / DC converter.

[0049] The detachable capacitor group module is plugged into the controller, the first pin group includes the first pin A and the first pin C, the second pin group includes the second pin B and the second pin D, the first pin A and the second pin B are connected to the output side of the first DC / DC converter. The connection method between the capacitor group and the controller includes the following three methods: one end of the capacitor group is connected to the first pin A and the first pin C through the controllable switch K1 and the controllable switch K2, respectively, or the other end of the capacitor group is connected to the second pin B and the second pin D through the controllable switch K3 and the controllable switch K4, respectively, or both ends of the capacitor group are connected to the corresponding pins through the controllable switch. When the capacitor group is damaged and needs to be repaired and replaced, it is only necessary to take out the capacitor group module separately and replace it, and there is no need to replace the controller or other converters, which reduces the replacement cost and facilitates the maintenance of the unit.

[0050] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. Removable capacitor bank module, including: A carrier having a first pin group and a second pin group, and a capacitor group packaged on the carrier is provided, wherein one end of the capacitor group is connected to the first pin group, and the other end is connected to the second pin group, and at least one end of the capacitor group is connected to its corresponding pin group through a controllable switch.

2. The detachable capacitor bank module according to claim 1, characterized in that: The carrier is also provided with a third pin group for feeding back the on-off state of the controllable switch.

3. The detachable capacitor bank module according to claim 2, characterized in that: The controllable switch is a relay or a contactor, and the auxiliary contact of the controllable switch is connected to the third pin group.

4. The detachable capacitor bank module according to any one of claims 1 to 3, characterized in that: The on-off state of the controllable switch is switched by a control module, and the control module detects the working parameters of the capacitor group and disconnects the controllable switch when the working parameters exceed a set value.

5. The detachable capacitor bank module according to claim 4, characterized in that: The control module comprises: A detection device for detecting working parameters of the capacitor bank; A comparison circuit, which compares the operating parameter with a set value and outputs a comparison signal; A conversion circuit receives the comparison signal and converts it into a control signal; An execution circuit switches the on-off state of the controllable switch according to the control signal.

6. The detachable capacitor bank module according to claim 5, characterized in that: The set value includes a first threshold value and a second threshold value lower than the first threshold value; The comparison circuit comprises: a first comparator and a second comparator whose output end is connected to the conversion circuit, an inverting end of the first comparator and a non-inverting end of the second comparator are both connected to the detection device, the non-inverting end of the first comparator is connected to a first input device providing the first threshold value, and the inverting end of the second comparator is connected to a second input device providing the second threshold value; The conversion circuit converts a low-level signal output by the first comparator or the second comparator into a high-level signal.

7. The detachable capacitor bank module according to claim 6, characterized in that: The controllable switch adopts a normally closed relay or contactor, and the execution circuit includes: a power supply branch for supplying power to the coil of the controllable switch, and a switch tube connected in series in the power supply branch; the control end of the switch tube is connected to the conversion circuit, and when the conversion circuit outputs a high-level signal, the coil of the controllable switch is energized to disconnect the main contacts of the controllable switch.

8. The detachable capacitor bank module according to claim 7, characterized in that: The carrier is provided with a fourth pin group connected to the input end of the power supply branch and a fifth pin group connected to the output end of the power supply branch.

9. The detachable capacitor bank module according to claim 5, characterized in that: The detection device uses a current transformer for detecting the current of the capacitor group.

10. An air conditioning system, characterized in that The air conditioning system is plugged and installed with the detachable capacitor group module according to any one of claims 1 to 9.

11. The air conditioning system according to claim 10, characterized in that: The air conditioning system comprises: a controller provided with a first DC / AC converter, an AC load connected to the controller via a second DC / AC converter, wherein the AC side of the first DC / AC converter is connected to an AC power source, and the DC side is connected to the second DC / AC converter; The detachable capacitor group module is plugged into the controller, the first pin group includes a first pin C, the second pin group includes a second pin D, and the first pin C and the second pin D are connected to the DC side of the first DC / AC converter.

12. The air conditioning system according to claim 11, characterized in that: The controller is also provided with a first DC / DC converter, the input side of the first DC / DC converter is connected to the photovoltaic array, and the output side is connected to the energy storage battery through a second DC / DC converter; The first pin group includes a first pin A, the second pin group includes a second pin B, and the first pin A and the second pin B are connected to the output side of the first DC / DC converter.

13. The air conditioning system according to claim 12, characterized in that: One end of the capacitor group is connected to the first pin A through the controllable switch K1 and the first pin C through the controllable switch K2, and / or the other end of the capacitor group is connected to the second pin B through the controllable switch K3 and the second pin D through the controllable switch K4.

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