Air switch test circuit

Abstract

The embodiment of the utility model relates to the technical field of air switch testing, in particular to an air switch testing circuit, which comprises a self-locking normally-open switch, a first connecting end of which is connected with a first power supply; a first connecting end of the first resistor is connected with a second connecting end of the self-locking normally open switch; the first connecting end of the first adjustable resistor is connected with the second connecting end of the first resistor, and the second connecting end of the first adjustable resistor is grounded; the first connecting end of the second resistor is connected with the second connecting end of the self-locking normally open switch; the first connecting end of the first thermistor is connected with the second connecting end of the second resistor, the second connecting end of the first thermistor is grounded, and the first thermistor is connected with the air switch; and the positive input end of the first operational amplifier is connected with the second connecting end of the first resistor. According to the air switch test circuit, whether the performance of the air switch to be tested is poor or not can be determined by judging whether the timer is triggered within the test duration or not.

Description

Technical Field

[0001] The embodiments in this specification relate to the field of air switch testing technology, specifically an air switch testing circuit. Background Technology

[0002] An air switch, also known as an air circuit breaker, is an important electrical protection device. When an abnormal situation such as a short circuit, overload, or leakage occurs in the circuit, the air switch can quickly cut off the circuit to prevent overheating of wires from causing a fire or other safety accidents.

[0003] In an energy storage system, if the performance of the circuit breaker itself is poor (relative to the energy storage system), the circuit breaker may trip due to excessive temperature rise, even if the energy storage system is working normally. (The circuit breaker contains a thermal trip unit (usually a bimetallic strip). As the temperature increases, the bimetallic strip deforms due to heat. When the temperature rises to a certain level, the bimetallic strip will bend and trigger the switch to trip.) This will affect the normal use of the entire energy storage system.

[0004] Therefore, it is necessary to test the circuit breakers in the energy storage system in advance to avoid using circuit breakers with poor performance. Utility Model Content

[0005] This specification addresses the shortcomings of existing technologies by proposing an air switch test circuit, comprising:

[0006] A self-locking normally open switch, the first connection terminal of which is connected to the first power supply;

[0007] The first resistor has its first connection terminal connected to the second connection terminal of the self-locking normally open switch.

[0008] The first connection terminal of the adjustable resistor is connected to the second connection terminal of the first resistor, and the second connection terminal of the adjustable resistor is grounded.

[0009] The second resistor has its first connection terminal connected to the second connection terminal of the self-locking normally open switch.

[0010] Thermistor 1 has its first connection terminal connected to the second connection terminal of the second resistor, the second connection terminal of thermistor 1 is grounded, and thermistor 1 is connected to the air switch.

[0011] The first operational amplifier has its positive input terminal connected to the second connection terminal of the first resistor, its inverting input terminal connected to the second connection terminal of the second resistor, its positive power supply terminal connected to the second connection terminal of the self-locking normally open switch, and its negative power supply terminal grounded.

[0012] The timer's positive power supply terminal is connected to the second connection terminal of the self-locking normally open switch, the timer's negative power supply terminal is grounded, and the timer's first timing terminal is connected to the output terminal of the first operational amplifier.

[0013] As a preferred option, it also includes:

[0014] The third resistor has its first connection terminal connected to the second connection terminal of the self-locking normally open switch.

[0015] The first connection terminal of the adjustable resistor 2 is connected to the second connection terminal of the third resistor, and the second connection terminal of the adjustable resistor 2 is grounded.

[0016] The fourth resistor has its first connection terminal connected to the second connection terminal of the self-locking normally open switch;

[0017] The second thermistor has its first connection terminal connected to the second connection terminal of the fourth resistor. The second connection terminal of the second thermistor is grounded, and the second thermistor is connected to the air switch.

[0018] The second operational amplifier has its positive input terminal connected to the second connection terminal of the third resistor, its inverting input terminal connected to the second connection terminal of the fourth resistor, its positive power supply terminal connected to the second connection terminal of the self-locking normally open switch, and its negative power supply terminal grounded.

[0019] The second timing terminal of the timer is connected to the output terminal of the second operational amplifier.

[0020] As a preferred option, it also includes:

[0021] A diode, the positive terminal of which is connected to the output of the second operational amplifier;

[0022] The gate of the N-type MOS transistor is connected to the output terminal of the first operational amplifier, and the source of the N-type MOS transistor is grounded.

[0023] The relay coil has its first connection terminal connected to the drain of an N-type MOSFET, and its second connection terminal connected to the negative terminal of a diode.

[0024] The relay contact has its first connection terminal connected to a second power supply, and its second connection terminal connected to an energy storage system.

[0025] As a preferred option, it also includes:

[0026] A diode, the positive terminal of which is connected to the output of the second operational amplifier;

[0027] The gate of the N-type MOS transistor is connected to the output terminal of the first operational amplifier, and the source of the N-type MOS transistor is grounded.

[0028] The first connection terminal of the time relay coil is connected to the drain of the N-type MOSFET, and the second connection terminal of the time relay coil is connected to the negative terminal of the diode.

[0029] The first connection terminal of the time relay contact is grounded.

[0030] The relay coil has its first connection terminal connected to the second connection terminal of the time relay contact, and the second connection terminal of the relay coil is connected to the negative terminal of the diode.

[0031] The relay contact has its first connection terminal connected to a second power supply, and its second connection terminal connected to an energy storage system.

[0032] As a preferred option, it also includes:

[0033] The gate of the N-type MOS transistor is connected to the output terminal of the first operational amplifier, and the source of the N-type MOS transistor is grounded.

[0034] The relay coil has its first connection terminal connected to the drain of an N-type MOSFET, and its second connection terminal connected to the second connection terminal of a self-locking normally open switch.

[0035] The relay contact has its first connection terminal connected to a second power supply, and its second connection terminal connected to an energy storage system.

[0036] As a preferred option, it also includes:

[0037] The gate of the N-type MOS transistor is connected to the output terminal of the first operational amplifier, and the source of the N-type MOS transistor is grounded.

[0038] The first connection terminal of the time relay coil is connected to the drain of the N-type MOSFET, and the second connection terminal of the time relay coil is connected to the second connection terminal of the self-locking normally open switch.

[0039] The first connection terminal of the time relay contact is grounded.

[0040] The relay coil has its first connection terminal connected to the second connection terminal of the time relay contact, and the second connection terminal of the relay coil is connected to the second connection terminal of the self-locking normally open switch.

[0041] The relay contact has its first connection terminal connected to a second power supply, and its second connection terminal connected to an energy storage system.

[0042] As a preferred embodiment, thermistor one is a negative temperature coefficient thermistor; thermistor two is a negative temperature coefficient thermistor.

[0043] Preferably, the thermistor is connected to a first metal sheet via thermally conductive adhesive, and the first metal sheet is detachably connected to the air switch via a first connector.

[0044] Preferably, the thermistor is connected to a second metal sheet via thermally conductive adhesive, and the second metal sheet is detachably connected to the air switch via a second connector.

[0045] Preferably, the resistance values ​​of the first resistor, the second resistor, the third resistor, and the fourth resistor are all the same.

[0046] Beneficial effects

[0047] The air switch test circuit of this specification embodiment can obtain the temperature of the air switch under test through a thermistor. As the temperature of the air switch under test increases, the resistance of the thermistor decreases. When the temperature of the air switch under test reaches the test temperature value, the resistance of the thermistor will begin to be less than the resistance of the adjustable resistor. This causes the voltage at the non-inverting input terminal of the operational amplifier to be greater than the voltage at the inverting input terminal, thereby making the output of the operational amplifier a positive voltage, which triggers the timer to start timing. Finally, by determining whether the timer is triggered within the test duration, it can be determined whether the air switch under test has poor performance.

[0048] Further or more detailed beneficial effects will be described in conjunction with specific embodiments in the detailed implementation. Attached Figure Description

[0049] Figure 1 This is a schematic diagram of the air switch test circuit in the embodiments of this specification. Detailed Implementation

[0050] The technical solution of this utility model will be further described below with reference to the accompanying drawings and specific embodiments.

[0051] Example 1:

[0052] like Figure 1 As shown, this embodiment provides an air switch test circuit, including: a self-locking normally open switch S, a first resistor R2, an adjustable resistor R6, a second resistor R4, a thermistor R8, a first operational amplifier Y1, and a timer J.

[0053] The first connection terminal of the self-locking normally open switch S is connected to the first power supply.

[0054] The first connection terminal of the first resistor R2 is connected to the second connection terminal of the self-locking normally open switch S.

[0055] The first connection terminal of the adjustable resistor R6 is connected to the second connection terminal of the first resistor R2, and the second connection terminal of the adjustable resistor R6 is grounded.

[0056] The first connection terminal of the second resistor R4 is connected to the second connection terminal of the self-locking normally open switch S.

[0057] The first connection terminal of thermistor R8 is connected to the second connection terminal of the second resistor R4. The second connection terminal of thermistor R8 is grounded, and thermistor R8 is connected to the air switch.

[0058] The positive input terminal of the first operational amplifier Y1 is connected to the second connection terminal of the first resistor R2, and the inverting input terminal of the first operational amplifier Y1 is connected to the second connection terminal of the second resistor R4. The positive power supply terminal of the first operational amplifier Y1 is connected to the second connection terminal of the self-locking normally open switch S, and the negative power supply terminal of the first operational amplifier Y1 is grounded. When the voltage at the non-inverting input terminal is greater than the voltage at the inverting input terminal, the output of the first operational amplifier Y1 is a positive voltage; when the voltage at the non-inverting input terminal is less than the voltage at the inverting input terminal, the output of the first operational amplifier Y1 is a negative voltage.

[0059] The positive power supply terminal of timer J is connected to the second connection terminal of the self-locking normally open switch S, the negative power supply terminal of timer J is grounded, and the first timing terminal of timer J is connected to the output terminal of the first operational amplifier Y1.

[0060] Thermistor R8 is a negative temperature coefficient thermistor, meaning its resistance decreases as temperature increases. Thermistor R8 is connected to an air switch to obtain the air switch's temperature. Specifically, a first metal plate is connected to the thermistor R8 via thermally conductive adhesive. The first metal plate is detachably connected to the air switch via a first connector, which can be a screw. This structure allows for very convenient connection and disconnection of the thermistor R8 from the air switch being tested.

[0061] The value of the adjustable resistor R6 can be manually adjusted. Assuming the desired test temperature is 80 degrees Celsius, the resistance of the thermistor R8 at 80 degrees Celsius can be determined by looking up a table. Assuming the resistance of thermistor R8 at 80 degrees Celsius is 'a' ohms, then when setting up the circuit, the value of the adjustable resistor R6 should be adjusted to 'a' ohms. The adjustable resistor R6 serves to set the test temperature.

[0062] The first resistor R2 and the second resistor R4 have the same resistance value, and they function as a voltage divider. This embodiment does not limit the specific values ​​of the first resistor R2 and the second resistor R4; any reasonable value is acceptable. For example, when the value of the adjustable resistor R6 is a few ohms, the values ​​of the first resistor R2 and the second resistor R4 are also a few ohms; when the value of the adjustable resistor R6 is several hundred ohms, the values ​​of the first resistor R2 and the second resistor R4 are also several hundred ohms.

[0063] Test steps:

[0064] First, connect the thermistor R8 to the circuit breaker to be tested.

[0065] Then, determine the test temperature and test duration, and based on the test temperature, determine the resistance value of the thermistor R8 at that test temperature. Adjust the resistance value of the adjustable resistor R6 to match the test temperature resistance value. This embodiment assumes a test temperature of 80 degrees Celsius and a test duration of 4 hours.

[0066] Next, press the self-locking normally open switch S (and manually record the pressing time) to enable the energy storage system to operate normally. When the energy storage system is operating normally, it will generate heat, which will cause the temperature of the circuit breaker under test to rise. At this point, two scenarios are possible:

[0067] Scenario 1: The temperature of the circuit breaker under test continuously rises, causing the resistance of the thermistor R8 to continuously decrease. When the resistance of thermistor R8 becomes less than the resistance of the adjustable resistor R6, the voltage at the non-inverting input of the first operational amplifier Y1 is greater than the voltage at the inverting input, resulting in a positive output voltage from the first operational amplifier Y1. This ultimately triggers the first timing terminal of the timer J to start timing. Assume the self-locking normally open switch S was pressed at 10:23 AM, and the timer J recorded the time at 11:33 AM. This means the circuit breaker under test reached the test temperature value within the test time. This situation indicates that the circuit breaker under test has poor performance and failed the test.

[0068] Scenario 2: If timer J does not trigger during the test duration, it indicates that the circuit breaker under test performs well and passes the test. Generally, when the energy storage system is operating normally, a high-performance circuit breaker will stabilize at a certain temperature or experience a very slow temperature rise, so it will not trigger timer J during the test duration. However, a low-performance circuit breaker will experience a high temperature rise after operating for a period of time (which could be tens of minutes or one or two hours), thus triggering timer J.

[0069] The circuit breaker test circuit in this embodiment can determine whether the circuit breaker under test has poor performance by judging whether the timer J is triggered within the test duration. If the circuit breaker under test has poor performance, then a different circuit breaker is used for testing; if the performance of the circuit breaker under test meets the test requirements, then it can be used directly.

[0070] Furthermore, such as Figure 1 As shown, the air switch test circuit of this embodiment also includes: an N-type MOSFET M, a relay coil KM-1, and a relay contact KM-2.

[0071] The gate of the N-type MOS transistor M is connected to the output terminal of the first operational amplifier Y1, and the source of the N-type MOS transistor M is grounded.

[0072] The first connection terminal of the relay coil KM-1 is connected to the drain of the N-type MOSFET M, and the second connection terminal of the relay coil KM-1 is connected to the second connection terminal of the self-locking normally open switch S.

[0073] The first connection terminal of relay contact KM-2 is connected to the second power supply, and the second connection terminal of relay contact KM-2 is connected to the energy storage system.

[0074] Working principle:

[0075] As the temperature of the circuit breaker under test continuously rises, the resistance values ​​of thermistors R8 and R7 continuously decrease. When the resistance of thermistor R8 becomes less than the resistance of the adjustable resistor R6, the voltage at the non-inverting input of the first operational amplifier Y1 is greater than the voltage at the inverting input, resulting in a positive output voltage from the first operational amplifier Y1. At this point, the N-type MOSFET M turns on. When the N-type MOSFET M turns on, the relay coil KM-1 conducts, causing the relay contact KM-2 to open, thus actively disconnecting the power supply to the energy storage system.

[0076] To improve testing accuracy, this embodiment can set a higher test temperature, such as 90 degrees Celsius. However, at 90 degrees Celsius, the circuit breaker under test may trip due to excessive temperature rise, which would negatively impact the entire energy storage system. Therefore, this embodiment incorporates an N-type MOSFET M, a relay coil KM-1, and relay contacts KM-2. When the circuit breaker under test reaches the test temperature, the power supply to the energy storage system is actively disconnected via the N-type MOSFET M, relay coil KM-1, and relay contacts KM-2, thus preventing any adverse effects on the entire energy storage system.

[0077] Or, such as Figure 1 As shown, the air switch test circuit of this embodiment also includes: an N-type MOSFET M, a time relay coil KT-1, a time relay contact KT-2, a relay coil KM-1, and a relay contact KM-2.

[0078] The gate of the N-type MOS transistor M is connected to the output terminal of the first operational amplifier Y1, and the source of the N-type MOS transistor M is grounded.

[0079] The first connection terminal of the time relay coil KT-1 is connected to the drain of the N-type MOSFET M, and the second connection terminal of the time relay coil KT-1 is connected to the second connection terminal of the self-locking normally open switch S.

[0080] The first connection terminal of the time relay contact KT-2 is grounded.

[0081] The first connection terminal of relay coil KM-1 is connected to the second connection terminal of time relay contact KT-2, and the second connection terminal of relay coil KM-1 is connected to the second connection terminal of self-locking normally open switch S.

[0082] The first connection terminal of relay contact KM-2 is connected to the second power supply, and the second connection terminal of relay contact KM-2 is connected to the energy storage system.

[0083] Working principle:

[0084] As the temperature of the circuit breaker under test continuously rises, the resistance values ​​of thermistors R8 and R7 continuously decrease. When the resistance of thermistor R8 becomes less than that of the adjustable resistor R6, the voltage at the non-inverting input of the first operational amplifier Y1 becomes greater than the voltage at the inverting input, resulting in a positive output voltage from the first operational amplifier Y1. At this point, the N-type MOSFET M turns on. When the N-type MOSFET M turns on, the time relay coil KT-1 turns on. After the time relay coil KT-1 has been on for a period of time, the relay contact KM-2 closes. After the relay contact KM-2 closes, the relay coil KM-1 turns on, causing the relay contact KM-2 to open, thus actively disconnecting the power supply to the energy storage system.

[0085] The temperature value detected on the circuit breaker under test may fluctuate. That is, the temperature on the circuit breaker may reach the test temperature at a certain point in time, but then immediately drop back. In this case, it is not necessary to disconnect the power supply to the energy storage system. Therefore, in this embodiment, in addition to the N-type MOSFET M, relay coil KM-1, and relay contact KM-2, a time relay coil KT-1 and a time relay contact KT-2 are also provided. If the temperature of the circuit breaker under test only fluctuates to reach the test temperature and then immediately drops back, the time relay coil KT-1 will immediately open after conducting, and thus the relay contact KM-2 will not close. Therefore, the relay coil KM-1 will not conduct, the relay contact KM-2 will not open, and the power supply to the energy storage system will not be actively disconnected. Only when the temperature value on the circuit breaker under test stably reaches the test temperature will the relay contact KM-2 close, which in turn will the relay coil KM-1 conduct, and the relay contact KM-2 will open, thus actively disconnecting the power supply to the energy storage system.

[0086] Example 2:

[0087] like Figure 1 As shown, this embodiment provides an air switch test circuit, including: a self-locking normally open switch S, a first resistor R2, an adjustable resistor R6, a second resistor R4, a thermistor R8, a first operational amplifier Y1, a timer J, a third resistor R1, an adjustable resistor R5, a fourth resistor R3, a thermistor R7, and a second operational amplifier Y2.

[0088] The first connection terminal of the self-locking normally open switch S is connected to the first power supply.

[0089] The first connection terminal of the first resistor R2 is connected to the second connection terminal of the self-locking normally open switch S.

[0090] The first connection terminal of the adjustable resistor R6 is connected to the second connection terminal of the first resistor R2, and the second connection terminal of the adjustable resistor R6 is grounded.

[0091] The first connection terminal of the second resistor R4 is connected to the second connection terminal of the self-locking normally open switch S.

[0092] The first connection terminal of thermistor R8 is connected to the second connection terminal of the second resistor R4. The second connection terminal of thermistor R8 is grounded, and thermistor R8 is connected to the air switch.

[0093] The positive input terminal of the first operational amplifier Y1 is connected to the second connection terminal of the first resistor R2, and the inverting input terminal of the first operational amplifier Y1 is connected to the second connection terminal of the second resistor R4. The positive power supply terminal of the first operational amplifier Y1 is connected to the second connection terminal of the self-locking normally open switch S, and the negative power supply terminal of the first operational amplifier Y1 is grounded. When the voltage at the non-inverting input terminal is greater than the voltage at the inverting input terminal, the output of the first operational amplifier Y1 is a positive voltage; when the voltage at the non-inverting input terminal is less than the voltage at the inverting input terminal, the output of the first operational amplifier Y1 is a negative voltage.

[0094] The positive power supply terminal of timer J is connected to the second connection terminal of the self-locking normally open switch S, the negative power supply terminal of timer J is grounded, and the first timing terminal of timer J is connected to the output terminal of the first operational amplifier Y1.

[0095] The first connection terminal of the third resistor R1 is connected to the second connection terminal of the self-locking normally open switch S.

[0096] The first connection terminal of the adjustable resistor R5 is connected to the second connection terminal of the third resistor R1, and the second connection terminal of the adjustable resistor R5 is grounded.

[0097] The first connection terminal of the fourth resistor R3 is connected to the second connection terminal of the self-locking normally open switch S.

[0098] The first connection terminal of the second thermistor R7 is connected to the second connection terminal of the fourth resistor R3. The second connection terminal of the second thermistor R7 is grounded, and the second thermistor R7 is connected to the air switch.

[0099] The positive input terminal of the second operational amplifier Y2 is connected to the second connection terminal of the third resistor R1, the inverting input terminal of the second operational amplifier Y2 is connected to the second connection terminal of the fourth resistor R3, the positive power supply terminal of the second operational amplifier Y2 is connected to the second connection terminal of the self-locking normally open switch S, and the negative power supply terminal of the second operational amplifier Y2 is grounded.

[0100] The second timing terminal of timer J is connected to the output terminal of the second operational amplifier Y2.

[0101] Thermistor R8 is a negative temperature coefficient thermistor, meaning its resistance decreases as temperature increases. Thermistor R8 is connected to an air switch to obtain the air switch's temperature. Specifically, a first metal plate is connected to the thermistor R8 via thermally conductive adhesive. The first metal plate is detachably connected to the air switch via a first connector, which can be a screw. This structure allows for very convenient connection and disconnection of the thermistor R8 from the air switch being tested.

[0102] The value of the adjustable resistor R6 can be manually adjusted. Assuming the desired test temperature is 50 degrees Celsius, the resistance of the thermistor R8 at 50 degrees Celsius can be determined by looking up a table. Assuming the resistance of thermistor R8 at 50 degrees Celsius is b1 ohms, then when setting up the circuit, the value of the adjustable resistor R6 should be adjusted to b1 ohms. The adjustable resistor R6 serves to set the first test temperature value.

[0103] The first resistor R2 and the second resistor R4 have the same resistance value, and they function as a voltage divider. This embodiment does not limit the specific values ​​of the first resistor R2 and the second resistor R4; any reasonable value is acceptable. For example, when the value of the adjustable resistor R6 is a few ohms, the values ​​of the first resistor R2 and the second resistor R4 are also a few ohms; when the value of the adjustable resistor R6 is several hundred ohms, the values ​​of the first resistor R2 and the second resistor R4 are also several hundred ohms.

[0104] Thermistor R7 is a negative temperature coefficient thermistor, meaning its resistance decreases as temperature increases. Thermistor R7 is connected to an air switch to obtain the switch's temperature. Specifically, a second metal plate is connected to the thermistor R7 via thermally conductive adhesive. This second metal plate is detachably connected to the air switch via a second connector, which can be a screw. This structure allows for very convenient connection and disconnection of the thermistor R7 to the air switch being tested.

[0105] The value of the adjustable resistor R5 can be manually adjusted. Assuming the desired test temperature is 80 degrees Celsius, the resistance of the thermistor R7 at 80 degrees Celsius can be determined by looking up a table. Assuming the resistance of thermistor R7 at 80 degrees Celsius is b2 ohms, then the value of the adjustable resistor R5 should be adjusted to b2 ohms when setting up the circuit. The adjustable resistor R5 serves to set the second test temperature value.

[0106] The third resistor R1 and the fourth resistor R3 have the same resistance value, and they function as a voltage divider. This embodiment does not limit the specific values ​​of the third resistor R1 and the fourth resistor R3; any reasonable value is acceptable. For example, when the value of the adjustable resistor R5 is a few ohms, the values ​​of the third resistor R1 and the fourth resistor R3 are also a few ohms; when the value of the adjustable resistor R5 is several hundred ohms, the values ​​of the third resistor R1 and the fourth resistor R3 are also several hundred ohms.

[0107] Test steps:

[0108] First, connect thermistor R8 to the circuit breaker under test, and then connect thermistor R7 to the circuit breaker under test.

[0109] Then, the first test temperature value, the second test temperature value, and the temperature rise time (temperature rise time refers to the time elapsed from reaching the first test temperature value) are determined. Based on the first test temperature value, the resistance value of the thermistor R8 at the first test temperature value is determined, and the resistance value of the adjustable resistor R6 is adjusted to be the same as the resistance value at the first test temperature. Based on the second test temperature value, the resistance value of the thermistor R7 at the second test temperature value is determined, and the resistance value of the adjustable resistor R5 is adjusted to be the same as the resistance value at the second test temperature. Assume that the first test temperature value in this embodiment is 50 degrees Celsius, and the second test temperature value is 80 degrees Celsius. Assume the temperature rise time is 2 hours.

[0110] Next, press the self-locking normally open switch S to enable the energy storage system to operate normally. When the energy storage system is operating normally, it will generate heat, which will cause the temperature of the circuit breaker under test to rise. At this point, two scenarios are possible:

[0111] Scenario 1: The temperature of the circuit breaker under test continuously rises, causing the resistances of thermistors R8 and R7 to continuously decrease. When the resistance of thermistor R8 becomes less than the resistance of the adjustable resistor R6, the voltage at the non-inverting input of operational amplifier Y1 becomes greater than the voltage at the inverting input, resulting in a positive output voltage from operational amplifier Y1, which ultimately triggers the first timing terminal of timer J. Subsequently, during the temperature rise period, the temperature of the circuit breaker under test continues to rise, causing the resistances of thermistors R8 and R7 to continue to decrease. When the resistance of thermistor R7 becomes less than the resistance of the adjustable resistor R5, the voltage at the non-inverting input of operational amplifier Y2 becomes greater than the voltage at the inverting input, resulting in a positive output voltage from operational amplifier Y2, which ultimately triggers the second timing terminal of timer J. This scenario indicates that the circuit breaker under test has poor performance and fails the test.

[0112] Scenario 2: The temperature of the circuit breaker under test continuously rises, causing the resistance values ​​of thermistors R8 and R7 to continuously decrease. When the resistance of thermistor R8 becomes less than the resistance of the adjustable resistor R6, the voltage at the non-inverting input of the first operational amplifier Y1 is greater than the voltage at the inverting input, resulting in a positive output voltage from the first operational amplifier Y1. This triggers the first timing terminal of timer J to start timing. Subsequently, during the temperature rise time, the temperature of the circuit breaker under test either stabilizes after reaching a certain value or rises very slowly, so the second timing terminal of timer J is not triggered. If timer J does not trigger timing when the temperature rise time is reached, this indicates that the circuit breaker under test performs well and passes the test.

[0113] Compared to Example 1, this example eliminates the need for manual recording of the pressing time, making operation simpler. Furthermore, the time from the start of the test to reaching the first test temperature value is typically significantly affected by environmental factors. Therefore, this example calculates the time starting from when the air switch reaches the first test temperature value, thereby improving test accuracy.

[0114] Furthermore, the circuit breaker test circuit of this embodiment can also be used to select the best-performing circuit breaker from multiple circuit breakers to be tested. For example, the first circuit breaker to be tested takes 90 minutes to rise from the first test temperature value to the second test temperature value; the second circuit breaker takes 30 minutes; the third circuit breaker takes 50 minutes; and the fourth circuit breaker does not rise from the first test temperature value to the second test temperature value within the temperature rise time. Clearly, the fourth circuit breaker to be tested has the best performance, so it is used.

[0115] Furthermore, such as Figure 1 As shown, the air switch test circuit of this embodiment also includes: diode D, N-type MOSFET M, relay coil KM-1 and relay contact KM-2.

[0116] The positive terminal of diode D is connected to the output terminal of the second operational amplifier Y2.

[0117] The gate of the N-type MOS transistor M is connected to the output terminal of the first operational amplifier Y1, and the source of the N-type MOS transistor M is grounded.

[0118] The first connection terminal of the relay coil KM-1 is connected to the drain of the N-type MOSFET M, and the second connection terminal of the relay coil KM-1 is connected to the negative terminal of the diode D.

[0119] The first connection terminal of relay contact KM-2 is connected to the second power supply, and the second connection terminal of relay contact KM-2 is connected to the energy storage system.

[0120] Working principle:

[0121] As the temperature of the circuit breaker under test continuously rises, the resistances of thermistors R8 and R7 continuously decrease. When the resistance of thermistor R8 becomes less than that of the adjustable resistor R6, the voltage at the non-inverting input of the first operational amplifier Y1 exceeds the voltage at its inverting input, resulting in a positive output voltage for the first operational amplifier Y1. At this point, the N-type MOSFET M meets the conduction condition. Subsequently, during the temperature rise period, the temperature of the circuit breaker under test continues to rise, causing the resistances of thermistors R8 and R7 to continue to decrease. When the resistance of thermistor R7 becomes less than that of the adjustable resistor R5, the voltage at the non-inverting input of the second operational amplifier Y2 exceeds the voltage at its inverting input, resulting in a positive output voltage for the second operational amplifier Y2. At this point, the N-type MOSFET M conducts. When the N-type MOSFET M conducts, the relay coil KM-1 conducts, causing the relay contact KM-2 to open, thus actively disconnecting the power supply to the energy storage system.

[0122] To improve testing accuracy, this embodiment can set the second test temperature value to a higher level, such as 90 degrees Celsius. However, when the second test temperature is 90 degrees Celsius, the circuit breaker under test may trip due to excessive temperature rise, which would negatively impact the entire energy storage system. Therefore, this embodiment incorporates a diode D, an N-type MOSFET M, a relay coil KM-1, and a relay contact KM-2. When the circuit breaker under test reaches the second test temperature value, the power supply to the energy storage system is actively disconnected via diode D, N-type MOSFET M, relay coil KM-1, and relay contact KM-2, thereby preventing any adverse effects on the entire energy storage system.

[0123] Or, such as Figure 1 As shown, the air switch test circuit of this embodiment also includes: diode D, N-type MOSFET M, time relay coil KT-1, time relay contact KT-2, relay coil KM-1, and relay contact KM-2.

[0124] The positive terminal of diode D is connected to the output terminal of the second operational amplifier Y2.

[0125] The gate of the N-type MOS transistor M is connected to the output terminal of the first operational amplifier Y1, and the source of the N-type MOS transistor M is grounded.

[0126] The first connection terminal of the time relay coil KT-1 is connected to the drain of the N-type MOSFET M, and the second connection terminal of the time relay coil KT-1 is connected to the negative terminal of the diode D.

[0127] The first connection terminal of the time relay contact KT-2 is grounded.

[0128] The first connection terminal of relay coil KM-1 is connected to the second connection terminal of time relay contact KT-2, and the second connection terminal of relay coil KM-1 is connected to the negative terminal of diode D.

[0129] The first connection terminal of relay contact KM-2 is connected to the second power supply, and the second connection terminal of relay contact KM-2 is connected to the energy storage system.

[0130] Working principle:

[0131] As the temperature of the circuit breaker under test continuously rises, the resistances of thermistors R8 and R7 continuously decrease. When the resistance of thermistor R8 becomes less than that of the adjustable resistor R6, the voltage at the non-inverting input of the first operational amplifier Y1 is greater than the voltage at the inverting input, resulting in a positive output voltage for the first operational amplifier Y1. At this point, the N-type MOSFET M meets the conduction condition. Subsequently, during the temperature rise period, the temperature of the circuit breaker under test continues to rise, causing the resistances of thermistors R8 and R7 to continue to decrease. When the resistance of thermistor R7 becomes less than that of the adjustable resistor R5, the voltage at the non-inverting input of the second operational amplifier Y2 is greater than the voltage at the inverting input, resulting in a positive output voltage for the second operational amplifier Y2. At this point, the N-type MOSFET M conducts. When the N-type MOSFET M is turned on, the time relay coil KT-1 is turned on; after the time relay coil KT-1 has been turned on for a period of time, the relay contact KM-2 is closed; after the relay contact KM-2 is closed, the relay coil KM-1 is turned on, and then the relay contact KM-2 is opened, so that the power supply to the energy storage system is actively disconnected.

[0132] The temperature value detected on the circuit breaker under test may fluctuate. That is, the temperature value on the circuit breaker may reach the second test temperature value at a certain point in time, but then immediately drop back. In this case, it is not necessary to disconnect the power supply to the energy storage system. Therefore, in addition to diode D, N-type MOSFET M, relay coil KM-1, and relay contact KM-2, this embodiment also includes a time relay coil KT-1 and a time relay contact KT-2. If the temperature of the circuit breaker under test only fluctuates to the second test temperature value and then immediately drops back, the time relay coil KT-1 will immediately open after conducting, and thus relay contact KM-2 will not close. Therefore, relay coil KM-1 will not conduct, relay contact KM-2 will not open, and the power supply to the energy storage system will not be actively disconnected. Only when the temperature value on the circuit breaker under test stably reaches the second test temperature value will relay contact KM-2 close, which in turn will relay coil KM-1 conduct, relay contact KM-2 will open, and the power supply to the energy storage system will be actively disconnected.

[0133] The above embodiments are merely descriptions of preferred embodiments of the present invention and are not intended to limit the concept and scope of the present invention. Various modifications and improvements made to the technical solutions of the present invention by those skilled in the art without departing from the design concept of the present invention should fall within the protection scope of the present invention. The technical content for which protection is sought in the present invention has been fully described in the claims.

Claims

1. An air switch test circuit, characterized by, Comprising: A self-locking normally open switch (S) whose first connection end is connected with a first power supply; A first resistor (R2) whose first connection end is connected with the second connection end of the self-locking normally open switch (S); An adjustable resistor one (R6) whose first connection end is connected with the second connection end of the first resistor (R2), and whose second connection end is grounded; A second resistor (R4) whose first connection end is connected with the second connection end of the self-locking normally open switch (S); A thermistor one (R8) whose first connection end is connected with the second connection end of the second resistor (R4), and whose second connection end is grounded, and which is connected with an air switch; A first operational amplifier (Y1) whose positive input end is connected with the second connection end of the first resistor (R2), whose reverse input end is connected with the second connection end of the second resistor (R4), whose positive power supply end is connected with the second connection end of the self-locking normally open switch (S), and whose negative power supply end is grounded; A timer (J) whose positive power supply end is connected with the second connection end of the self-locking normally open switch (S), whose negative power supply end is grounded, and whose first timing end is connected with the output end of the first operational amplifier (Y1).

2. The air switch test circuit of claim 1, wherein, Further comprising: A third resistor (R1) whose first connection end is connected with the second connection end of the self-locking normally open switch (S); An adjustable resistor two (R5) whose first connection end is connected with the second connection end of the third resistor (R1), and whose second connection end is grounded; A fourth resistor (R3) whose first connection end is connected with the second connection end of the self-locking normally open switch (S); A thermistor two (R7) whose first connection end is connected with the second connection end of the fourth resistor (R3), and whose second connection end is grounded, and which is connected with an air switch; A second operational amplifier (Y2) whose positive input end is connected with the second connection end of the third resistor (R1), whose reverse input end is connected with the second connection end of the fourth resistor (R3), whose positive power supply end is connected with the second connection end of the self-locking normally open switch (S), and whose negative power supply end is grounded; The second timing end of the timer (J) is connected with the output end of the second operational amplifier (Y2).

3. The air switch test circuit of claim 2, wherein, Further comprising: A diode (D) whose anode end is connected with the output end of the second operational amplifier (Y2); An N-type MOS tube (M) whose gate is connected with the output end of the first operational amplifier (Y1), and whose source is grounded; A relay coil (KM-1) whose first connection end is connected with the drain of the N-type MOS tube (M), and whose second connection end is connected with the cathode end of the diode (D); A relay contact (KM-2) has a first connection end connected to a second power supply, and a second connection end connected to an energy storage system.

4. The air switch test circuit of claim 2, wherein, Further comprising: A diode (D) has a positive terminal connected to an output terminal of the second operational amplifier (Y2); An N-type MOS transistor (M) has a gate connected to an output terminal of the first operational amplifier (Y1), and a source connected to ground; A time relay coil (KT-1) has a first connection end connected to a drain of the N-type MOS transistor (M), and a second connection end connected to a negative terminal of the diode (D); A time relay contact (KT-2) has a first connection end connected to ground; A relay coil (KM-1) has a first connection end connected to a second connection end of the time relay contact (KT-2), and a second connection end connected to a negative terminal of the diode (D); A relay contact (KM-2) has a first connection end connected to a second power supply, and a second connection end connected to an energy storage system.

5. The air switch test circuit of claim 1, wherein, Further comprising: An N-type MOS transistor (M) has a gate connected to an output terminal of the first operational amplifier (Y1), and a source connected to ground; A relay coil (KM-1) has a first connection end connected to a drain of the N-type MOS transistor (M), and a second connection end connected to a second connection end of the self-holding normally open switch (S); A relay contact (KM-2) has a first connection end connected to a second power supply, and a second connection end connected to an energy storage system.

6. The air switch test circuit of claim 1, wherein, Further comprising: An N-type MOS transistor (M) has a gate connected to an output terminal of the first operational amplifier (Y1), and a source connected to ground; A time relay coil (KT-1) has a first connection end connected to a drain of the N-type MOS transistor (M), and a second connection end connected to a second connection end of the self-holding normally open switch (S); A time relay contact (KT-2) has a first connection end connected to ground; A relay coil (KM-1) has a first connection end connected to a second connection end of the time relay contact (KT-2), and a second connection end connected to a second connection end of the self-holding normally open switch (S); A relay contact (KM-2) has a first connection end connected to a second power supply, and a second connection end connected to an energy storage system.

7. The air switch test circuit of claim 2, wherein, The first thermistor (R8) is a negative temperature coefficient thermistor; the second thermistor (R7) is a negative temperature coefficient thermistor.

8. The air switch test circuit of claim 7, wherein, The first thermistor (R8) is connected with a first metal sheet through thermal conductive glue, and the first metal sheet is detachably connected with the air switch through a first connecting piece.

9. The air switch test circuit of claim 7, wherein, The second thermistor (R7) is connected with a second metal sheet through thermal conductive glue, and the second metal sheet is detachably connected with the air switch through a second connecting piece.

10. The air switch test circuit of claim 2, wherein, The resistance values of the first resistor (R2), the second resistor (R4), the third resistor (R1), and the fourth resistor (R3) are all the same.

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