Rocket-borne battery pack heating circuit

Abstract

The invention relates to a rocket-borne battery pack heating circuit, which comprises a heating belt, temperature relays, electromagnetic relays, diodes, connecting wires, a heating power supply input port and a heating state indication port, and is characterized in that a two-parallel two-serial temperature relay and two-parallel electromagnetic relay connection design is adopted in the heating circuit; safe and reliable anti-fusing of the circuit during large current-carrying is realized, redundant design is adopted, and temperature relays are arranged in a distributed manner, so that mistaken heating of the heating circuit caused by non-uniform temperature of the battery pack is prevented; and meanwhile, diodes are connected in parallel at two ends of the electromagnetic relay coil, and a two-series two-parallel design is adopted, so that single-point failure is avoided, inverse peak voltage at the moment of disconnection of the heating circuit is eliminated, and influence on a rocket system circuit is prevented. Before the heating circuit works, a heating power supply is connected, the heating belt is controlled to work through linkage of a temperature relay and an electromagnetic relay, and meanwhile, whether the heating state and the resistance value of the heating belt are abnormal or not is monitored by arranging a heating state indication port.

Description

Technical Field

[0001] The present invention belongs to the technical field of batteries, and particularly relates to a warming circuit for an on - arrow battery pack. Background Art

[0002] Due to advantages such as high energy density and good discharge performance, batteries are widely used in various fields such as aerospace, automotive, and electronic devices. However, currently commercially available batteries still cannot maintain high - performance operation in extremely low - temperature environments. In a low - temperature environment, the impedance of the battery significantly increases, which may cause irreversible damage to the battery, resulting in the inability to release the stored energy of the battery normally and making it difficult to meet the power supply requirements of power equipment; at the same time, due to limited heat dissipation conditions inside the battery pack, the temperature non - uniformity of the battery pack is significant under extreme working conditions, which easily causes local high - hot spots inside the battery pack and increases the risk of thermal runaway.

[0003] To enable the battery to be within the optimal operating temperature range during use, existing research has achieved temperature control by arranging a warming device inside the battery pack. The warming schemes used are mainly realized by connecting a temperature relay, an electromagnetic relay, a diode, and a heating tape, etc. Whether the warming circuit works is determined by controlling the on - off of the relay through the temperature relay. However, the aerospace field is committed to the high safety and high stability of the battery pack used, and requires a safety redundancy design when designing the battery system; controlling the circuit only through a single temperature relay and an electromagnetic relay cannot cope with the failure of the warming function caused by the damage of any electronic component in the circuit, and there is no anti - peak circuit for the electromagnetic relay, which will generate an anti - peak voltage when the relay coil is powered off and affect the rocket system circuit. Summary of the Invention

[0004] The technical problem solved by the present invention is: overcoming the deficiencies of the prior art, to meet the high - reliability requirements of the aerospace - used battery system, providing a warming circuit for an on - arrow battery pack, which has an anti - peak function and the ability to cope with partial damage of electronic components in the circuit without affecting the warming function.

[0005] The solution to the technical problem of the present invention is: a warming circuit for an on - arrow battery pack, which circuit includes an electromagnetic relay, a temperature relay group, a heating tape, and a diode group; wherein:

[0006] One end of the temperature relay group is connected to the positive terminal of the warming power supply, and the other end is connected to one end of the coil of the electromagnetic relay. The other end of the electromagnetic relay coil is grounded; one end of the contact switch of the electromagnetic relay is connected to the positive terminal of the heating power supply, and the other end is connected to one end of the heating tape. The other end of the heating tape is grounded; the diode group is connected in parallel across the two ends of the electromagnetic relay coil.

[0007] When the battery pack is in a low-temperature environment, the temperature inside the battery pack is relatively low. When the temperature of the battery pack captured by the temperature-sensing surface of the temperature relay is lower than the return temperature of the temperature relay, the temperature relay closes. When a heating power supply is externally connected to the heating circuit, the coil of the electromagnetic relay is energized, and the contacts of the electromagnetic relay close. The heating circuit of the battery pack is completely conducted, and the heating tape starts to generate heat due to overcurrent to heat the battery pack. The temperature of the battery pack gradually rises under the action of the heating tape. When the temperature at the position where the temperature relay is arranged reaches the operating temperature of the temperature relay, the temperature relay disconnects, the heating circuit is disconnected, and the heating of the battery pack stops. At the same time, the reverse peak voltage generated by the power-off of the electromagnetic relay is gradually consumed through the diode circuit. Thus, one heating cycle of the heating circuit for the battery ends.

[0008] Preferably, the temperature relay group includes four temperature relays, and the four electromagnetic relay groups are connected in a series-parallel form.

[0009] Preferably, there are two electromagnetic relays, and the contact switches of the two electromagnetic relays are connected in parallel; the coils of the two electromagnetic relays are connected in parallel.

[0010] Preferably, the diode group is composed of four diodes, denoted as the first diode, the second diode, the third diode, and the fourth diode;

[0011] The first diode and the second diode are connected in series. The anode of the first diode is grounded, and the cathode of the second diode is connected to the temperature relay group;

[0012] The third diode and the fourth diode are connected in series. The anode of the third diode is grounded, and the cathode of the fourth diode is connected to the temperature relay group.

[0013] Preferably, the resistance value of the heating tape is determined by the following formula:

[0014] R = U 2 t·η / (C·m·ΔT)

[0015] Wherein, U is the heating voltage, unit V; t is the required heating time, unit s; m is the total weight of the battery pack cells, unit g; C is the specific heat capacity of the battery, unit J / (g·K); ΔT is the difference between the heating end temperature and the heating initial temperature, unit °C; η is the heating efficiency.

[0016] Preferably, the rated current of the electromagnetic relay meets the derating requirements of the on-board single unit of the launch vehicle, and the rated operating voltage is the same as the rated value of the heating voltage.

[0017] Preferably, the rated current of the temperature relay is more than 2 times the value of the heating voltage U divided by the resistance R of the electromagnetic relay coil. The rated operating voltage is the same as the rated value of the heating voltage. The recovery temperature T1 is taken not lower than the lowest temperature at which the battery pack meets the functional requirements, and the operating temperature T2 is taken as the optimal temperature at which the battery pack meets the functional requirements.

[0018] Preferably, the rated voltage of the diode generally takes a value not lower than 1000V. The rated current of the diode is more than 2 times the value of the rated voltage U divided by the resistance R of the electromagnetic relay coil. The reverse operating voltage takes a value more than 2 times the maximum value of the external heating voltage.

[0019] Preferably, the heating current of the connecting wire specification should not be higher than 75% of the rated current of the wire.

[0020] Preferably, the above-mentioned heating circuit of the on-board battery pack further includes a heating status indication port;

[0021] The heating status indication port is connected between the contact switch of the electromagnetic relay and the heating tape. By measuring the resistance between the heating status indication port and the positive terminal of the heating power supply, it can be confirmed whether the heating tape is working, and by measuring the resistance between the heating status indication port and the positive terminal of the heating power supply, it can be confirmed whether the resistance value of the heating tape is normal.

[0022] The beneficial effects of the present invention compared with the prior art are as follows:

[0023] (1) By connecting a diode group in parallel at both ends of the electromagnetic relay coil, the present invention realizes the safe elimination of the reverse peak high voltage of the electromagnetic relay at the moment when the heating circuit is disconnected, protecting the on-board system from the impact of the reverse peak voltage;

[0024] (2) By reasonably designing the number of relays and the series-parallel grouping method, the present invention ensures that the circuit can work normally when a single temperature relay and electromagnetic relay in the heating circuit are damaged, meeting the high-reliability design requirements of the battery system in the field of launch vehicles;

[0025] (3) The four temperature relays adopted by the present invention are distributed at different positions of the battery stack. By controlling the on-off of the relay group through multi-point temperature in the battery pack, it can effectively prevent misheating caused by uneven temperature inside the battery, which is beneficial to improving the accuracy of the on-off switching of the heating circuit;

[0026] (4) By combining the actual working requirements of the battery pack and determining the heating tape specification through calculation, the present invention ensures that the designed heating circuit can keep the temperature of the battery pack within the optimal working temperature range within a specified time;

[0027] (5) The present invention presets a heating status indication port, which can monitor the on-off status of the heating circuit and the resistance parameters of the heating tape to judge whether the heating tape is faulty. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a heating circuit diagram of an arrow-borne battery pack according to an embodiment of the present invention. DETAILED DESCRIPTION

[0029] The present invention will be further described below in conjunction with the embodiments.

[0030] like Figure 1 As shown, the present invention provides a heating circuit for an arrow-borne battery pack. The heating circuit is mainly composed of a temperature relay group, an electromagnetic relay group, a heating belt 6, a diode group, a connecting wire 2, etc.

[0031] A temperature relay group 4, one end of the temperature relay group is connected to the positive terminal 1 of the heating power supply, and the other end is connected to one end of the coil 3-1 of the electromagnetic relay, and the other end of the electromagnetic relay coil 3-1 is grounded; one end of the contact switch 3-2 of the electromagnetic relay is connected to the positive terminal of the heating power supply, and the other end is connected to one end of the heating belt 6, and the other end of the heating belt is grounded; the diode group 4 is connected in parallel at both ends of the electromagnetic relay coil; a heating status indication port 7 is set between the heating belt 6 and the contact switch 3-2 of the electromagnetic relay, and by measuring the resistance between the heating status indication port and the positive terminal of the heating power supply, it can be confirmed whether the heating belt is working, and by measuring the resistance between the heating status indication port and the positive terminal of the heating power supply, it can be confirmed whether the resistance value of the heating belt is normal.

[0032] When the battery pack is in a low temperature environment, the temperature inside the battery pack is low. When the battery pack temperature captured by the temperature relay sensing surface is lower than the recovery temperature of the temperature relay, the temperature relay closes. When the heating circuit is connected to an external heating power supply, the electromagnetic relay coil is energized, the electromagnetic relay contacts are closed, the battery pack heating circuit is fully turned on, and the heating belt begins to overcurrent and generate heat to heat the battery pack. The battery pack temperature gradually rises under the action of the heating belt. When the temperature at the temperature relay arrangement position reaches the temperature of the temperature relay, the temperature relay is disconnected, the heating circuit is disconnected, the battery pack heating stops, and at the same time, the reverse peak voltage generated by the electromagnetic relay power failure is gradually consumed through the diode circuit. At this point, the heating circuit ends one heating of the battery.

[0033] The temperature relay closes its switch within its operating temperature range, and then the electromagnetic relay closes its switch under the stimulation of the voltage stabilizer, and the heating circuit is turned on to realize the heating function of the battery pack. By monitoring the heating status indication port and the positive port of the external voltage stabilizer, real-time monitoring of the on-off of the heating circuit can be achieved. By monitoring the heating status indication port and the negative port of the external voltage stabilizer, the resistance of the heating circuit can be measured to determine whether the heating belt is faulty.

[0034] The temperature relay group consists of four temperature relays, and the four electromagnetic relay groups are connected in a series-parallel form. Even if a certain temperature relay in the circuit is damaged, it can still ensure the normal operation of the heating circuit. When two temperature relays in the circuit are damaged, the circuit still has the possibility of normal operation without affecting the heating function; at the same time, the four temperature relays are fixed at different positions of the battery stack, and the on-off of the relay group is controlled by the multi-point temperature in the battery pack, effectively improving the accuracy of the on-off switching of the heating circuit;

[0035] The electromagnetic relay group consists of two electromagnetic relays connected in parallel. Specifically, the contact switches of the two electromagnetic relays are connected in parallel; the coils of the two electromagnetic relays are connected in parallel. The on-off of the electromagnetic relay group is controlled by the external power supply on the arrow and the temperature relay. After the electromagnetic relay coil is energized, the switch contact closes. At the same time, the parallel design of the two electromagnetic relays ensures that the heating circuit can still operate normally when a certain electromagnetic relay in the circuit is damaged;

[0036] The diode group consists of four diodes and is designed in a two-series and two-parallel configuration to avoid single-point failure. The four diodes are respectively denoted as the first diode, the second diode, the third diode, and the fourth diode;

[0037] The first diode and the second diode are connected in series. The anode of the first diode is grounded, and the cathode of the second diode is connected to the temperature relay group;

[0038] The third diode and the fourth diode are connected in series. The anode of the third diode is grounded, and the cathode of the fourth diode is connected to the temperature relay group.

[0039] The diode group is connected in parallel across the electromagnetic relay group to eliminate the reverse peak voltage at the moment when the heating circuit is disconnected and prevent it from affecting the circuit of the system on the arrow.

[0040] As shown in the appendix Figure 1 , a highly reliable design method for the heating circuit of an on-arrow battery pack, includes:

[0041] Step 101: According to the voltage of the heating power supply on the arrow and the heating time requirement, calculate the specific resistance value of the heating tape, and complete the design of the heating tape size specification in combination with the available space in the battery pack; specifically:

[0042] According to the energy conservation equation: C·m·ΔT = U 2 / R·t·η, that is, R = U 2t·η / (C·m·ΔT), where U is the heating voltage in V, t is the required heating time in s, m is the total weight of the battery pack cells in g, C is the specific heat capacity of the battery in J / (g·K), ΔT is the difference between the end temperature and the initial temperature of heating in °C, and η is the heating efficiency, generally taking values from 60% to 70%. Based on this, the resistance of the heating tape can be determined, and then the shape of the heating tape can be designed according to the available space inside the battery and the heating position to meet the functional requirements of the heating tape.

[0043] Step 102: Combine the available space inside the battery pack and the overcurrent magnitude of the heating circuit to complete the selection of electromagnetic relays, with the quantity being 2;

[0044] The electromagnetic relay is selected according to the heating current I, heating voltage U, and the parameters of the mechanical test conditions on the rocket. The rated current of the electromagnetic relay should meet the derating requirements of the single unit on the launch vehicle, generally not less than the value of I / 0.75, and the rated working voltage is selected to be the same as the rated value of the heating voltage. The environmental adaptability of the selected electromagnetic relay should also meet the requirements of mechanical test conditions such as shock, acceleration, and high-frequency vibration of the battery single unit.

[0045] Step 103: Combine the optimal temperature range for the battery pack to operate, the actual environmental conditions of the battery pack application scenario, and the overcurrent magnitude of the circuit to determine the optimal reset temperature and operating temperature of the temperature relay, and complete the selection of the temperature relay, with the quantity being 4;

[0046] The temperature relay is selected according to parameters such as the heating current I, heating voltage U, reset temperature T1, and operating temperature T2 requirements. The rated current is taken as more than 2 times the value of the heating voltage U divided by the resistance R of the electromagnetic relay coil, and the rated working voltage is selected to be the same as the rated value of the heating voltage. The value of the reset temperature T1 is based on taking not less than the lowest temperature at which the battery pack meets the functional requirements. To reduce the heating time before rocket launch, it is generally taken around 15°C. The value of the operating temperature T2 is based on taking the optimal temperature at which the battery pack meets the functional requirements, generally 25°C - 30°C.

[0047] Step 104: Combine the resistance of the electromagnetic relay coil and the magnitude of the heating voltage to complete the selection of diodes, with the quantity being 4;

[0048] The selection of diodes mainly depends on the rated voltage, rated current, and reverse working voltage. The rated voltage generally takes a value not less than 1000V. The rated current is taken as more than 2 times the value of the rated voltage U divided by the resistance R of the electromagnetic relay coil, and the reverse working voltage is taken as more than 2 times the maximum value of the external heating voltage.

[0049] Step 105: Select a suitable connection wire specification in combination with the overcurrent magnitude of the heating circuit;

[0050] Select a wire that can withstand the overcurrent during heating according to the magnitude of the heating current. The heating current should not be higher than 75% of the rated current of the wire.

[0051] Step 106: Connect the above-selected electronic components and wires in sequence as shown in the appendix. Among them, the heating tape in Step 101 is connected in series in the main circuit of the heating circuit; the four temperature relays in Step 102 are designed with two in parallel and two in series, and are connected in series in the heating circuit, and the four temperature relays are distributed at the positions where heat is likely to concentrate in the battery pack; the two electromagnetic relays in Step 103 are designed in parallel. After the coils of the electromagnetic relays are connected in parallel, they are jointly connected in series in the heating circuit with the temperature relay circuit. After the contacts of the electromagnetic relays are connected in parallel, they are jointly connected in series in the heating circuit with the heating tape circuit. The four diodes in Step 104 are designed with two in series and two in parallel, and are integrally connected in parallel across the two ends of the electromagnetic relay coil; a heating state indication port is preset between the heating resistor and the contacts of the electromagnetic relay. Figure 1 Step 107: Connect a heating power supply to the heating circuit. First, the temperature relay determines whether the battery temperature has reached the recovery temperature. If the temperature reaches, the temperature relay closes, the electromagnetic relay coil is overcurrent, and the contacts of the electromagnetic relay close to achieve heating. By measuring that the resistance between the heating state indication port and the positive port of the heating power supply is close to 0, it is determined that the heating circuit is completely conducting. When the temperature of the battery pack reaches the operating temperature of the temperature relay after heating, the temperature relay disconnects, the electromagnetic relay coil loses power, and the contacts of the electromagnetic relay disconnect, and the heating ends. By measuring that the resistance between the heating state indication port and the positive port of the heating power supply is infinite, it is determined that the heating circuit is completely disconnected. At the same time, the peak voltage of the electromagnetic relay coil is gradually consumed on the coil through the parallel diode circuit.

[0052] By adopting the above technical solutions, it is possible to ensure that the heating circuit maintains a highly reliable state during operation, and the heating circuit will not lose its heating ability due to the damage of a single type of relay. At the same time, the temperature relays are fixed at different positions of the battery stack, and the on-off of the relay group is controlled by the multi-point temperature in the battery pack, effectively improving the accuracy of the on-off switching of the heating circuit during operation; finally, it is possible to confirm whether the heating tape is working by measuring the resistance between the heating state indication port and the positive port of the heating power supply, and to confirm whether the resistance value of the heating tape is normal by measuring the resistance between the heating state indication port and the positive port of the heating power supply. Therefore, the heating circuit designed by the present invention can not only achieve a highly reliable design, but also realize the real-time monitoring of the heating state of the battery pack.

[0053] The main working principle of the present invention:

[0054] The main working principle of the present invention:

[0055] When the battery pack is in a low-temperature environment, the temperature inside the battery pack is relatively low. When the temperature of the battery pack captured by the temperature-sensing surface of the temperature relay is lower than its reset temperature, the temperature relay closes. On the premise that a heating power supply is externally connected to the heating circuit, the electromagnetic relay coil is energized, and the electromagnetic relay contacts close, making the battery pack heating circuit fully conductive. The heating tape starts to generate heat through overcurrent and warms the battery pack. The temperature of the battery pack gradually rises under the action of the heating tape. When the temperature at the location where the temperature relay is installed reaches its operating temperature, the temperature relay disconnects, the heating circuit is disconnected, and the heating of the battery pack stops. At the same time, the reverse peak voltage generated by the power-off of the electromagnetic relay is gradually consumed through the diode circuit. Thus, one heating cycle of the heating circuit for the battery ends. When the temperature of the battery pack is less than the reset temperature of the temperature relay again, if it is necessary to warm the battery pack, simply externally connect a heating power supply to the heating circuit to enable the heating function of the heating circuit for the battery pack again.

[0056] The above specific description further elaborates on the purpose, technical solution, and beneficial effects of the invention. It should be understood that the above is only a specific embodiment of the present invention and is not used to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

[0057] Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solution of the present invention using the methods and technical content disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes, and decorations made to the above embodiments based on the technical essence of the present invention without departing from the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

Claims

1. An arrow-borne battery pack heating circuit, characterized in that It includes electromagnetic relay, temperature relay group, heating belt and diode group; among which: One end of the temperature relay group is connected to the positive end of the heating power supply, and the other end is connected to one end of the coil of the electromagnetic relay, and the other end of the electromagnetic relay coil is grounded; one end of the contact switch of the electromagnetic relay is connected to the positive end of the heating power supply, and the other end is connected to one end of the heating belt, and the other end of the heating belt is grounded; the diode group is connected in parallel at both ends of the electromagnetic relay coil; When the battery pack is in a low temperature environment, the temperature inside the battery pack is low. When the battery pack temperature captured by the temperature relay sensing surface is lower than the recovery temperature of the temperature relay, the temperature relay closes. When the heating circuit is connected to an external heating power supply, the electromagnetic relay coil is energized, the electromagnetic relay contacts are closed, the battery pack heating circuit is fully turned on, and the heating belt begins to overcurrent and generate heat to heat the battery pack. The battery pack temperature gradually rises under the action of the heating belt. When the temperature at the temperature relay arrangement position reaches the temperature of the temperature relay, the temperature relay is disconnected, the heating circuit is disconnected, the battery pack heating stops, and at the same time, the reverse peak voltage generated by the electromagnetic relay power failure is gradually consumed through the diode circuit. At this point, the heating circuit ends one heating of the battery.

2. The heating circuit of an arrow-borne battery pack according to claim 1, wherein, The temperature relay group includes four temperature relays, and the four electromagnetic relay groups are connected in series and parallel.

3. The heating circuit of an arrow-borne battery pack according to claim 1, wherein There are two electromagnetic relays, and the contact switches of the two electromagnetic relays are connected in parallel; the coils of the two electromagnetic relays are connected in parallel.

4. The heating circuit of an arrow-borne battery pack according to claim 1, characterized in that The diode group consists of four diodes, which are denoted as a first diode, a second diode, a third diode, and a fourth diode; The first diode and the second diode are connected in series, the anode of the first diode is grounded, and the cathode of the second diode is connected to the temperature relay group; The third diode and the fourth diode are connected in series, the anode of the third diode is grounded, and the cathode of the fourth diode is connected to the temperature relay group.

5. The heating circuit of an on-arrow battery pack according to claim 1, characterized in that The resistance value of the heating belt is determined by the following formula: R = U 2 t·η / (C·m·ΔT) Wherein, U is the heating voltage, unit V, t is the required heating time, unit s, m is the total weight of the battery pack cells, unit g, C is the battery specific heat capacity, unit J / (g·K), ΔT is the difference between the heating end temperature and the heating initial temperature, unit ℃, and η is the heating efficiency.

6. The heating circuit of an arrow-borne battery pack according to claim 1, wherein, The rated current of the electromagnetic relay meets the derating requirement for a single unit on a launch vehicle, and the rated working voltage is the same as the heating voltage rating.

7. The heating circuit of an arrow-borne battery pack according to claim 1, characterized in that, The rated current of the temperature relay is more than twice the value of the heating voltage U divided by the resistance R of the electromagnetic relay coil. The rated working voltage is the same as the rated value of the heating voltage. The recovery temperature T1 is based on taking a value that is not lower than the lowest temperature at which the battery pack meets the functional requirements. The action temperature T2 is based on taking the optimal temperature at which the battery pack meets the functional requirements.

8. The heating circuit of an arrow-borne battery pack according to claim 1, wherein The rated voltage of the diode is generally not less than 1000V, the rated current of the diode is more than twice the value of the rated voltage U divided by the resistance R of the electromagnetic relay coil, and the reverse working voltage is more than twice the maximum value of the external heating voltage.

9. The heating circuit of an arrow-mounted battery pack according to claim 1, characterized in that The heating current of the connecting wire specification should not be higher than 75% of the rated current of the wire.

10. The heating circuit of an arrow-borne battery pack according to claim 1, characterized in that, Also includes a heating status indication port; The heating status indication port is connected between the contact switch of the electromagnetic relay and the heating tape. By measuring the resistance between the heating status indication port and the positive terminal of the heating power supply, it can be confirmed whether the heating tape is working, and by measuring the resistance between the heating status indication port and the positive terminal of the heating power supply, it can be confirmed whether the resistance value of the heating tape is normal.

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